xref: /linux/arch/x86/Kconfig (revision 17a2a129b309d502d638164b2c515ff205c148df)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
46840999bSSam Ravnborg	bool "64-bit kernel" if ARCH = "x86"
5ffee0de4SDavid Woodhouse	default ARCH != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17341c787eSIngo Molnar	select HAVE_AOUT
18341c787eSIngo Molnar	select HAVE_GENERIC_DMA_COHERENT
19341c787eSIngo Molnar	select MODULES_USE_ELF_REL
20341c787eSIngo Molnar	select OLD_SIGACTION
21daa93fabSSam Ravnborg
22daa93fabSSam Ravnborgconfig X86_64
233120e25eSJan Beulich	def_bool y
243120e25eSJan Beulich	depends on 64BIT
25d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
26e1073d1eSAneesh Kumar K.V	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
28d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
29d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
30d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
31d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
321032c0baSSam Ravnborg
33d94e0685SIngo Molnar#
34d94e0685SIngo Molnar# Arch settings
35d94e0685SIngo Molnar#
36d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
37d94e0685SIngo Molnar#   ported to 32-bit as well. )
38d94e0685SIngo Molnar#
398d5fffb9SSam Ravnborgconfig X86
403c2362e6SHarvey Harrison	def_bool y
41c763ea26SIngo Molnar	#
42c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
43c763ea26SIngo Molnar	#
446471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
456e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
466471b825SIngo Molnar	select ANON_INODES
476471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
486471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
4991dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
50fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5121266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
526471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5372d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
546974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
55957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
565c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
57ea8c64acSChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
5810bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
59c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
6039208aa7SKees Cook	select ARCH_HAS_REFCOUNT
610aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
62d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
636471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
64ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
65ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
66ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
67c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
6865f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
696471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
706471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
725e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
736471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
746471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
756471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
766471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
776471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
78ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
79c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8038d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
816471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
826471b825SIngo Molnar	select CLKEVT_I8253
836471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
846471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
856471b825SIngo Molnar	select DCACHE_WORD_ACCESS
8645471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
8745471cd9SLinus Torvalds	select EDAC_SUPPORT
886471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
896471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
906471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
916471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
926471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9361dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
946471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
956471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
966471b825SIngo Molnar	select GENERIC_IOMAP
97c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
980fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
99ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1006471b825SIngo Molnar	select GENERIC_IRQ_PROBE
101c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1026471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1036471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1046471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1056471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1066471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1076471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1087edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1096471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1106471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1116471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1126471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1136471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1146471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
115d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1166471b825SIngo Molnar	select HAVE_ARCH_KGDB
1179e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1189e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1191b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
1206471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
121f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
1226471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1236471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
124a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
125e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
126c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1276471b825SIngo Molnar	select HAVE_CC_STACKPROTECTOR
1286471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1296471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1306471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
131c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1326471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1336471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1346471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1356471b825SIngo Molnar	select HAVE_DMA_API_DEBUG
1369c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
137677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
13806aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
139c763ea26SIngo Molnar	select HAVE_EBPF_JIT			if X86_64
14058340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1415f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
142644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1436471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1446471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1456471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1466b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1470067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1486471b825SIngo Molnar	select HAVE_IDE
1496471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1506471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1516471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1526471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1536471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1546471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1556471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1566471b825SIngo Molnar	select HAVE_KERNEL_LZO
1576471b825SIngo Molnar	select HAVE_KERNEL_XZ
1586471b825SIngo Molnar	select HAVE_KPROBES
1596471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
160540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1616471b825SIngo Molnar	select HAVE_KRETPROBES
1626471b825SIngo Molnar	select HAVE_KVM
1636471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1646471b825SIngo Molnar	select HAVE_MEMBLOCK
1656471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1660102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
167ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
16842a0bb3fSPetr Mladek	select HAVE_NMI
1696471b825SIngo Molnar	select HAVE_OPROFILE
1706471b825SIngo Molnar	select HAVE_OPTPROBES
1716471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1726471b825SIngo Molnar	select HAVE_PERF_EVENTS
173c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
17492e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
175c5e63197SJiri Olsa	select HAVE_PERF_REGS
176c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1779e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1786471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
17911af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
180c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
1816471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1826471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1837c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
184c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
185df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1866471b825SIngo Molnar	select PERF_EVENTS
1873195ef59SPrarit Bhargava	select RTC_LIB
188d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1896471b825SIngo Molnar	select SPARSE_IRQ
19083fe27eaSPranith Kumar	select SRCU
1916471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
19215f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
1936471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
1946471b825SIngo Molnar	select VIRT_TO_BUS
1956471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
1967d8330a5SBalbir Singh
197ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
1983120e25eSJan Beulich	def_bool y
1993120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
200ba7e4d13SIngo Molnar
20151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
20251b26adaSLinus Torvalds	string
20351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
20451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
20551b26adaSLinus Torvalds
20673531905SSam Ravnborgconfig ARCH_DEFCONFIG
207b9b39bfbSSam Ravnborg	string
20873531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
20973531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
210b9b39bfbSSam Ravnborg
2118d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2123c2362e6SHarvey Harrison	def_bool y
2138d5fffb9SSam Ravnborg
2148d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2153c2362e6SHarvey Harrison	def_bool y
2168d5fffb9SSam Ravnborg
2178d5fffb9SSam Ravnborgconfig MMU
2183c2362e6SHarvey Harrison	def_bool y
2198d5fffb9SSam Ravnborg
2209e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2219e08f57dSDaniel Cashman	default 28 if 64BIT
2229e08f57dSDaniel Cashman	default 8
2239e08f57dSDaniel Cashman
2249e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2259e08f57dSDaniel Cashman	default 32 if 64BIT
2269e08f57dSDaniel Cashman	default 16
2279e08f57dSDaniel Cashman
2289e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2299e08f57dSDaniel Cashman	default 8
2309e08f57dSDaniel Cashman
2319e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2329e08f57dSDaniel Cashman	default 16
2339e08f57dSDaniel Cashman
2348d5fffb9SSam Ravnborgconfig SBUS
2358d5fffb9SSam Ravnborg	bool
2368d5fffb9SSam Ravnborg
2373bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE
2383120e25eSJan Beulich	def_bool y
239a6dfa128SKonrad Rzeszutek Wilk	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
2403bc4e459SFUJITA Tomonori
24118e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH
2424a14d84eSAndrew Morton	def_bool y
24318e98307SFUJITA Tomonori
2448d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2453120e25eSJan Beulich	def_bool y
2463120e25eSJan Beulich	depends on ISA_DMA_API
2478d5fffb9SSam Ravnborg
2488d5fffb9SSam Ravnborgconfig GENERIC_BUG
2493c2362e6SHarvey Harrison	def_bool y
2508d5fffb9SSam Ravnborg	depends on BUG
251b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
252b93a531eSJan Beulich
253b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
254b93a531eSJan Beulich	bool
2558d5fffb9SSam Ravnborg
2568d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2573c2362e6SHarvey Harrison	def_bool y
2588d5fffb9SSam Ravnborg
2598d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2603120e25eSJan Beulich	def_bool y
2613120e25eSJan Beulich	depends on ISA_DMA_API
2628d5fffb9SSam Ravnborg
2631032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2643120e25eSJan Beulich	def_bool y
2651032c0baSSam Ravnborg
2661032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2671032c0baSSam Ravnborg	def_bool y
2681032c0baSSam Ravnborg
2699a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2709a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2718d5fffb9SSam Ravnborg
2721b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2731b27d05bSPekka Enberg	def_bool y
2741b27d05bSPekka Enberg
275dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
27689c9c4c5SBrian Gerst	def_bool y
277b32ef636Stravis@sgi.com
27808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
27908fc4580STejun Heo	def_bool y
28008fc4580STejun Heo
28108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28211124411STejun Heo	def_bool y
28311124411STejun Heo
284801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
285801e4062SJohannes Berg	def_bool y
286801e4062SJohannes Berg
287f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
288f4cb5700SJohannes Berg	def_bool y
289f4cb5700SJohannes Berg
290cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
291cfe28c5dSSteve Capper	def_bool y
292cfe28c5dSSteve Capper
29353313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
29453313b2cSSteve Capper	def_bool y
29553313b2cSSteve Capper
2968d5fffb9SSam Ravnborgconfig ZONE_DMA32
297e0fd24a3SJan Beulich	def_bool y if X86_64
2988d5fffb9SSam Ravnborg
2998d5fffb9SSam Ravnborgconfig AUDIT_ARCH
300e0fd24a3SJan Beulich	def_bool y if X86_64
3018d5fffb9SSam Ravnborg
302765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
303765c68bdSIngo Molnar	def_bool y
304765c68bdSIngo Molnar
3056a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3066a11f75bSAkinobu Mita	def_bool y
3076a11f75bSAkinobu Mita
308d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
309d6f2d75aSAndrey Ryabinin	hex
310d6f2d75aSAndrey Ryabinin	depends on KASAN
311d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
312d6f2d75aSAndrey Ryabinin
31369575d38SShane Wangconfig HAVE_INTEL_TXT
31469575d38SShane Wang	def_bool y
3156ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
31669575d38SShane Wang
3176b0c3d44SSam Ravnborgconfig X86_32_SMP
3186b0c3d44SSam Ravnborg	def_bool y
3196b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3206b0c3d44SSam Ravnborg
3216b0c3d44SSam Ravnborgconfig X86_64_SMP
3226b0c3d44SSam Ravnborg	def_bool y
3236b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3246b0c3d44SSam Ravnborg
325ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
326ccbeed3aSTejun Heo	def_bool y
3272bc2f688SKees Cook	depends on X86_32 && CC_STACKPROTECTOR_NONE
328ccbeed3aSTejun Heo
3292b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3302b144498SSrikar Dronamraju	def_bool y
3312b144498SSrikar Dronamraju
332d20642f0SRob Herringconfig FIX_EARLYCON_MEM
333d20642f0SRob Herring	def_bool y
334d20642f0SRob Herring
33598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
33698233368SKirill A. Shutemov	int
33777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
33898233368SKirill A. Shutemov	default 4 if X86_64
33998233368SKirill A. Shutemov	default 3 if X86_PAE
34098233368SKirill A. Shutemov	default 2
34198233368SKirill A. Shutemov
342506f1d07SSam Ravnborgsource "init/Kconfig"
343dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3448d5fffb9SSam Ravnborg
345506f1d07SSam Ravnborgmenu "Processor type and features"
346506f1d07SSam Ravnborg
3475ee71535SRandy Dunlapconfig ZONE_DMA
3485ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3495ee71535SRandy Dunlap	default y
3505ee71535SRandy Dunlap	help
3515ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3525ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3535ee71535SRandy Dunlap	  Disable if no such devices will be used.
3545ee71535SRandy Dunlap
3555ee71535SRandy Dunlap	  If unsure, say Y.
3565ee71535SRandy Dunlap
357506f1d07SSam Ravnborgconfig SMP
358506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
359506f1d07SSam Ravnborg	---help---
360506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3614a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3624a474157SRobert Graffham	  than one CPU, say Y.
363506f1d07SSam Ravnborg
3644a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
365506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
366506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3674a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
368506f1d07SSam Ravnborg	  will run faster if you say N here.
369506f1d07SSam Ravnborg
370506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
371506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
372506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
373506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
374506f1d07SSam Ravnborg
375506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
376506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
377506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
378506f1d07SSam Ravnborg
379395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
380c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
381506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
382506f1d07SSam Ravnborg
383506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
384506f1d07SSam Ravnborg
3859def39beSJosh Triplettconfig X86_FEATURE_NAMES
3869def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
3879def39beSJosh Triplett	default y
3889def39beSJosh Triplett	---help---
3899def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
3909def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
3919def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
3929def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
3939def39beSJosh Triplett
3949def39beSJosh Triplett	  If in doubt, say Y.
3959def39beSJosh Triplett
3966e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS
3976e1315feSBorislav Petkov	bool "Fast CPU feature tests" if EMBEDDED
3986e1315feSBorislav Petkov	default y
3996e1315feSBorislav Petkov	---help---
4006e1315feSBorislav Petkov	  Some fast-paths in the kernel depend on the capabilities of the CPU.
4016e1315feSBorislav Petkov	  Say Y here for the kernel to patch in the appropriate code at runtime
4026e1315feSBorislav Petkov	  based on the capabilities of the CPU. The infrastructure for patching
4036e1315feSBorislav Petkov	  code at runtime takes up some additional space; space-constrained
4046e1315feSBorislav Petkov	  embedded systems may wish to say N here to produce smaller, slightly
4056e1315feSBorislav Petkov	  slower code.
4066e1315feSBorislav Petkov
40706cd9a7dSYinghai Luconfig X86_X2APIC
40806cd9a7dSYinghai Lu	bool "Support x2apic"
40919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41006cd9a7dSYinghai Lu	---help---
41106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41206cd9a7dSYinghai Lu
41306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
41506cd9a7dSYinghai Lu
41606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
41706cd9a7dSYinghai Lu
4186695c85bSYinghai Luconfig X86_MPPARSE
4196e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4207a527688SJan Beulich	default y
4215ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4228f9ca475SIngo Molnar	---help---
4236695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4246695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4256695c85bSYinghai Lu
42626f7ef14SYinghai Luconfig X86_BIGSMP
42726f7ef14SYinghai Lu	bool "Support for big SMP systems with more than 8 CPUs"
42826f7ef14SYinghai Lu	depends on X86_32 && SMP
4298f9ca475SIngo Molnar	---help---
43026f7ef14SYinghai Lu	  This option is needed for the systems that have more than 8 CPUs
431506f1d07SSam Ravnborg
432ddd70cf9SJun Nakajimaconfig GOLDFISH
433ddd70cf9SJun Nakajima       def_bool y
434ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
435ddd70cf9SJun Nakajima
43676b04384SDavid Woodhouseconfig RETPOLINE
43776b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43876b04384SDavid Woodhouse	default y
43976b04384SDavid Woodhouse	help
44076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44476b04384SDavid Woodhouse
44576b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
44676b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
44776b04384SDavid Woodhouse	  it is not entirely pointless.
44876b04384SDavid Woodhouse
449f01d7d51SVikas Shivappaconfig INTEL_RDT
450f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
45178e99b4aSFenghua Yu	default n
45278e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
45359fe5a77SThomas Gleixner	select KERNFS
45478e99b4aSFenghua Yu	help
455f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
456f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
457f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
458f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
45978e99b4aSFenghua Yu
46078e99b4aSFenghua Yu	  Say N if unsure.
46178e99b4aSFenghua Yu
4628425091fSRavikiran G Thirumalaiif X86_32
463c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
464c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
465c5c606d9SRavikiran G Thirumalai	default y
4668f9ca475SIngo Molnar	---help---
46706ac8346SIngo Molnar	  If you disable this option then the kernel will only support
46806ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
46906ac8346SIngo Molnar	  systems out there.)
47006ac8346SIngo Molnar
4718425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4728425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
473cb7b8023SBen Hutchings		Goldfish (Android emulator)
4748425091fSRavikiran G Thirumalai		AMD Elan
4758425091fSRavikiran G Thirumalai		RDC R-321x SoC
4768425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
47783125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4783f4110a4SThomas Gleixner		Moorestown MID devices
47906ac8346SIngo Molnar
48006ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48106ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4828425091fSRavikiran G Thirumalaiendif
48306ac8346SIngo Molnar
4848425091fSRavikiran G Thirumalaiif X86_64
4858425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4868425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4878425091fSRavikiran G Thirumalai	default y
4888425091fSRavikiran G Thirumalai	---help---
4898425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4908425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4918425091fSRavikiran G Thirumalai	  systems out there.)
4928425091fSRavikiran G Thirumalai
4938425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4948425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
49544b111b5SSteffen Persvold		Numascale NumaChip
4968425091fSRavikiran G Thirumalai		ScaleMP vSMP
4978425091fSRavikiran G Thirumalai		SGI Ultraviolet
4988425091fSRavikiran G Thirumalai
4998425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5008425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5018425091fSRavikiran G Thirumalaiendif
502c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
503c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
50444b111b5SSteffen Persvoldconfig X86_NUMACHIP
50544b111b5SSteffen Persvold	bool "Numascale NumaChip"
50644b111b5SSteffen Persvold	depends on X86_64
50744b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
50844b111b5SSteffen Persvold	depends on NUMA
50944b111b5SSteffen Persvold	depends on SMP
51044b111b5SSteffen Persvold	depends on X86_X2APIC
511f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
51244b111b5SSteffen Persvold	---help---
51344b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
51444b111b5SSteffen Persvold	  enable more than ~168 cores.
51544b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
51603b48632SNick Piggin
5176a48565eSIngo Molnarconfig X86_VSMP
518c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5196276a074SBorislav Petkov	select HYPERVISOR_GUEST
5206a48565eSIngo Molnar	select PARAVIRT
5216a48565eSIngo Molnar	depends on X86_64 && PCI
522c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
523ead91d4bSShai Fultheim	depends on SMP
5248f9ca475SIngo Molnar	---help---
5256a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5266a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5276a48565eSIngo Molnar	  if you have one of these machines.
5286a48565eSIngo Molnar
529c5c606d9SRavikiran G Thirumalaiconfig X86_UV
530c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
531c5c606d9SRavikiran G Thirumalai	depends on X86_64
532c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
53354c28d29SJack Steiner	depends on NUMA
5341ecb4ae5SAndrew Morton	depends on EFI
5359d6c26e7SSuresh Siddha	depends on X86_X2APIC
5361222e564SIngo Molnar	depends on PCI
537c5c606d9SRavikiran G Thirumalai	---help---
538c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
539c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
540c5c606d9SRavikiran G Thirumalai
541c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
542c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
543506f1d07SSam Ravnborg
544ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
545ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
546cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
547ddd70cf9SJun Nakajima       ---help---
548ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
549ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
550ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
551ddd70cf9SJun Nakajima
552c751e17bSThomas Gleixnerconfig X86_INTEL_CE
553c751e17bSThomas Gleixner	bool "CE4100 TV platform"
554c751e17bSThomas Gleixner	depends on PCI
555c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5566084a6e2SJiang Liu	depends on X86_IO_APIC
557c751e17bSThomas Gleixner	depends on X86_32
558c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
55937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
560da6b737bSSebastian Andrzej Siewior	select OF
561da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
562c751e17bSThomas Gleixner	---help---
563c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
564c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
565c751e17bSThomas Gleixner	  boxes and media devices.
566c751e17bSThomas Gleixner
5674cb9b00fSDavid Cohenconfig X86_INTEL_MID
56843605ef1SAlan Cox	bool "Intel MID platform support"
56943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
570edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5711ea7c673SAlan Cox	depends on PCI
5723fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5731ea7c673SAlan Cox	depends on X86_IO_APIC
5747c9c3a1eSAlan Cox	select SFI
5754cb9b00fSDavid Cohen	select I2C
5767c9c3a1eSAlan Cox	select DW_APB_TIMER
5771ea7c673SAlan Cox	select APB_TIMER
5781ea7c673SAlan Cox	select INTEL_SCU_IPC
57915a713dfSMika Westerberg	select MFD_INTEL_MSIC
5801ea7c673SAlan Cox	---help---
5814cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5824cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5834cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5841ea7c673SAlan Cox
5854cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5864cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
58743605ef1SAlan Cox
5888bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5898bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5908bbc2a13SBryan O'Donoghue	depends on X86_32
5918bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5928bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5938bbc2a13SBryan O'Donoghue	depends on X86_TSC
5948bbc2a13SBryan O'Donoghue	depends on PCI
5958bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
5968bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
5978bbc2a13SBryan O'Donoghue	select IOSF_MBI
5988bbc2a13SBryan O'Donoghue	select INTEL_IMR
5999ab6eb51SAndy Shevchenko	select COMMON_CLK
6008bbc2a13SBryan O'Donoghue	---help---
6018bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6028bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6038bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6048bbc2a13SBryan O'Donoghue
6053d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6063d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
607eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6083d48aab1SMika Westerberg	select COMMON_CLK
6090f531431SMathias Nyman	select PINCTRL
610eebb3e8dSAndy Shevchenko	select IOSF_MBI
6113d48aab1SMika Westerberg	---help---
6123d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6133d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6140f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6150f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6163d48aab1SMika Westerberg
61792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
61892082a88SKen Xue	bool "AMD ACPI2Platform devices support"
61992082a88SKen Xue	depends on ACPI
62092082a88SKen Xue	select COMMON_CLK
62192082a88SKen Xue	select PINCTRL
62292082a88SKen Xue	---help---
62392082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
62492082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
62592082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
62692082a88SKen Xue	  implemented under PINCTRL subsystem.
62792082a88SKen Xue
628ced3ce76SDavid E. Boxconfig IOSF_MBI
629ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
630ced3ce76SDavid E. Box	depends on PCI
631ced3ce76SDavid E. Box	---help---
632ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
633ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
634ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
635ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
636ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
637ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
638ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
639ced3ce76SDavid E. Box	   - BayTrail
640ced3ce76SDavid E. Box	   - Braswell
641ced3ce76SDavid E. Box	   - Quark
642ced3ce76SDavid E. Box
643ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
644ced3ce76SDavid E. Box
645ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
646ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
647ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
648ed2226bdSDavid E. Box	---help---
649ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
650ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
651ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
652ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
653ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
654ed2226bdSDavid E. Box	  device they want to access.
655ed2226bdSDavid E. Box
656ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
657ed2226bdSDavid E. Box
658c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
659c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
660506f1d07SSam Ravnborg	depends on X86_32
661c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
662c5c606d9SRavikiran G Thirumalai	select M486
663c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
664c5c606d9SRavikiran G Thirumalai	---help---
665c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
666c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
667c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
668c5c606d9SRavikiran G Thirumalai
669e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6709c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6719c398017SIngo Molnar	depends on X86_32 && SMP
672c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6738f9ca475SIngo Molnar	---help---
674b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
675b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
676b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
677b5660ba7SH. Peter Anvin	  one and will fallback to default.
678d49c4288SYinghai Lu
679c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
680d49c4288SYinghai Lu
681d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6826fc108a0SJan Beulich	def_bool y
683d949f36fSLinus Torvalds	# MCE code calls memory_failure():
684d949f36fSLinus Torvalds	depends on X86_MCE
685d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
686d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
687d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
688d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
689d949f36fSLinus Torvalds
69083125a3aSAlessandro Rubiniconfig STA2X11
69183125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
69283125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
69383125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
69483125a3aSAlessandro Rubini	select X86_DMA_REMAP
69583125a3aSAlessandro Rubini	select SWIOTLB
69683125a3aSAlessandro Rubini	select MFD_STA2X11
6970145071bSLinus Walleij	select GPIOLIB
69883125a3aSAlessandro Rubini	default n
69983125a3aSAlessandro Rubini	---help---
70083125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70183125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70283125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
70383125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
70483125a3aSAlessandro Rubini	  standard PC machines.
70583125a3aSAlessandro Rubini
70682148d1dSShérabconfig X86_32_IRIS
70782148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
70882148d1dSShérab	depends on X86_32
70982148d1dSShérab	---help---
71082148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71182148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71282148d1dSShérab	  needed to do so, which is what this module does at
71382148d1dSShérab	  kernel shutdown.
71482148d1dSShérab
71582148d1dSShérab	  This is only for Iris machines from EuroBraille.
71682148d1dSShérab
71782148d1dSShérab	  If unused, say N.
71882148d1dSShérab
719ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7203c2362e6SHarvey Harrison	def_bool y
7213c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
722a87d0914SKen Chen	depends on X86
7238f9ca475SIngo Molnar	---help---
724506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
725506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
726506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
727506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
728506f1d07SSam Ravnborg
729506f1d07SSam Ravnborg	  If in doubt, say "Y".
730506f1d07SSam Ravnborg
7316276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7326276a074SBorislav Petkov	bool "Linux guest support"
7338f9ca475SIngo Molnar	---help---
7346276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7356276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7366276a074SBorislav Petkov	  setup.
737506f1d07SSam Ravnborg
7386276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7396276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
740506f1d07SSam Ravnborg
7416276a074SBorislav Petkovif HYPERVISOR_GUEST
742506f1d07SSam Ravnborg
743e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
744e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7458f9ca475SIngo Molnar	---help---
746e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
747e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
748e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
749e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
750e61bd94aSEduardo Pereira Habkost
7516276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7526276a074SBorislav Petkov	bool "paravirt-ops debugging"
7536276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7546276a074SBorislav Petkov	---help---
7556276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7566276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7576276a074SBorislav Petkov
758b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
759b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7606ea30386SKees Cook	depends on PARAVIRT && SMP
761b4ecc126SJeremy Fitzhardinge	---help---
762b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
763b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
764b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
765b4ecc126SJeremy Fitzhardinge
7664c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7674c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
768b4ecc126SJeremy Fitzhardinge
7694c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
770b4ecc126SJeremy Fitzhardinge
77145e898b7SWaiman Longconfig QUEUED_LOCK_STAT
77245e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
773cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
77445e898b7SWaiman Long	---help---
77545e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
77645e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
77745e898b7SWaiman Long	  them on debugfs.
77845e898b7SWaiman Long
7796276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7806276a074SBorislav Petkov
7816276a074SBorislav Petkovconfig KVM_GUEST
7826276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7836276a074SBorislav Petkov	depends on PARAVIRT
7846276a074SBorislav Petkov	select PARAVIRT_CLOCK
7856276a074SBorislav Petkov	default y
7866276a074SBorislav Petkov	---help---
7876276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7886276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7896276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7906276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7916276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7926276a074SBorislav Petkov
7931e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
7941e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
7951e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
7961e20eb85SSrivatsa Vaddagiri	default n
7971e20eb85SSrivatsa Vaddagiri	---help---
7981e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
7991e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8001e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8011e20eb85SSrivatsa Vaddagiri
8026276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8036276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8046276a074SBorislav Petkov	depends on PARAVIRT
8056276a074SBorislav Petkov	default n
8066276a074SBorislav Petkov	---help---
8076276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8086276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8096276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8106276a074SBorislav Petkov	  that, there can be a small performance impact.
8116276a074SBorislav Petkov
8126276a074SBorislav Petkov	  If in doubt, say N here.
8136276a074SBorislav Petkov
8147af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8157af192c9SGerd Hoffmann	bool
8167af192c9SGerd Hoffmann
8174a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8184a362601SJan Kiszka	bool "Jailhouse non-root cell support"
819abde587bSArnd Bergmann	depends on X86_64 && PCI
82087e65d05SJan Kiszka	select X86_PM_TIMER
8214a362601SJan Kiszka	---help---
8224a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8234a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8244a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8254a362601SJan Kiszka
8266276a074SBorislav Petkovendif #HYPERVISOR_GUEST
82797349135SJeremy Fitzhardinge
82808677214SYinghai Luconfig NO_BOOTMEM
829774ea0bcSYinghai Lu	def_bool y
83008677214SYinghai Lu
831506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
832506f1d07SSam Ravnborg
833506f1d07SSam Ravnborgconfig HPET_TIMER
8343c2362e6SHarvey Harrison	def_bool X86_64
835506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8368f9ca475SIngo Molnar	---help---
837506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
838506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
839506f1d07SSam Ravnborg	  present.
840506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
841506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
842506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8434e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8444e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
845506f1d07SSam Ravnborg
846506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
847506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
848506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
849506f1d07SSam Ravnborg
850506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
851506f1d07SSam Ravnborg
852506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8533c2362e6SHarvey Harrison	def_bool y
8549d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
855506f1d07SSam Ravnborg
856bb24c471SJacob Panconfig APB_TIMER
857933b9463SAlan Cox       def_bool y if X86_INTEL_MID
858933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
85906c3df49SJamie Iles       select DW_APB_TIMER
860a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
861bb24c471SJacob Pan       help
862bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
863bb24c471SJacob Pan         The APBT provides a stable time base on SMP
864bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
865bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
866bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
867bb24c471SJacob Pan
8686a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
869506f1d07SSam Ravnborg# The code disables itself when not needed.
8707ae9392cSThomas Petazzoniconfig DMI
8717ae9392cSThomas Petazzoni	default y
872cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8736a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8748f9ca475SIngo Molnar	---help---
8757ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8767ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8777ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8787ae9392cSThomas Petazzoni	  BIOS code.
8797ae9392cSThomas Petazzoni
880506f1d07SSam Ravnborgconfig GART_IOMMU
88138901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
882506f1d07SSam Ravnborg	select SWIOTLB
88323ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8848f9ca475SIngo Molnar	---help---
885ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
886ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
887ced3c42cSIngo Molnar
888ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
889ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
890ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
891ced3c42cSIngo Molnar
892ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
893ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
894ced3c42cSIngo Molnar
895ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
896ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
897ced3c42cSIngo Molnar	  32-bit limited device.
898ced3c42cSIngo Molnar
899ced3c42cSIngo Molnar	  If unsure, say Y.
900506f1d07SSam Ravnborg
901506f1d07SSam Ravnborgconfig CALGARY_IOMMU
902506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
903506f1d07SSam Ravnborg	select SWIOTLB
9046ea30386SKees Cook	depends on X86_64 && PCI
9058f9ca475SIngo Molnar	---help---
906506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
907506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
908506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
909506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
910506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
911506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
912506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
913506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
914506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
915506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
916506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
917506f1d07SSam Ravnborg	  If unsure, say Y.
918506f1d07SSam Ravnborg
919506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9203c2362e6SHarvey Harrison	def_bool y
9213c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
922506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9238f9ca475SIngo Molnar	---help---
924506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
925506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
926506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
927506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
928506f1d07SSam Ravnborg	  If unsure, say Y.
929506f1d07SSam Ravnborg
930506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround
931506f1d07SSam Ravnborgconfig SWIOTLB
932a1afd01cSJoerg Roedel	def_bool y if X86_64
9338f9ca475SIngo Molnar	---help---
934506f1d07SSam Ravnborg	  Support for software bounce buffers used on x86-64 systems
9354454d327SJoe Millenbach	  which don't have a hardware IOMMU. Using this PCI devices
9364454d327SJoe Millenbach	  which can only access 32-bits of memory can be used on systems
9374454d327SJoe Millenbach	  with more than 3 GB of memory.
9384454d327SJoe Millenbach	  If unsure, say Y.
939506f1d07SSam Ravnborg
940a8522509SFUJITA Tomonoriconfig IOMMU_HELPER
9413120e25eSJan Beulich	def_bool y
9423120e25eSJan Beulich	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
943d25e26b6SLinus Torvalds
9441184dc2fSMike Travisconfig MAXSMP
945ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9466ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94736f5101aSMike Travis	select CPUMASK_OFFSTACK
9488f9ca475SIngo Molnar	---help---
949ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9501184dc2fSMike Travis	  If unsure, say N.
951506f1d07SSam Ravnborg
952506f1d07SSam Ravnborgconfig NR_CPUS
95336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
9542a3313f4SMichael K. Johnson	range 2 8 if SMP && X86_32 && !X86_BIGSMP
9557bbcbd3dSThomas Gleixner	range 2 64 if SMP && X86_32 && X86_BIGSMP
9567bbcbd3dSThomas Gleixner	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
957b53b5edaSJosh Boyer	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
95878637a97SMike Travis	default "1" if !SMP
959b53b5edaSJosh Boyer	default "8192" if MAXSMP
960b5660ba7SH. Peter Anvin	default "32" if SMP && X86_BIGSMP
961c5c19941SKirill A. Shutemov	default "8" if SMP && X86_32
962c5c19941SKirill A. Shutemov	default "64" if SMP
9638f9ca475SIngo Molnar	---help---
964506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
965bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
966cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
967506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
968506f1d07SSam Ravnborg
969506f1d07SSam Ravnborg	  This is purely to save memory - each supported CPU adds
970506f1d07SSam Ravnborg	  approximately eight kilobytes to the kernel image.
971506f1d07SSam Ravnborg
972506f1d07SSam Ravnborgconfig SCHED_SMT
973506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
974c8e56d20SBorislav Petkov	depends on SMP
9758f9ca475SIngo Molnar	---help---
976506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
977506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
978506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
979506f1d07SSam Ravnborg	  N here.
980506f1d07SSam Ravnborg
981506f1d07SSam Ravnborgconfig SCHED_MC
9823c2362e6SHarvey Harrison	def_bool y
9833c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
984c8e56d20SBorislav Petkov	depends on SMP
9858f9ca475SIngo Molnar	---help---
986506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
987506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
988506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
989506f1d07SSam Ravnborg
990de966cf4STim Chenconfig SCHED_MC_PRIO
991de966cf4STim Chen	bool "CPU core priorities scheduler support"
9920a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
9930a21fc12SIngo Molnar	select X86_INTEL_PSTATE
9940a21fc12SIngo Molnar	select CPU_FREQ
995de966cf4STim Chen	default y
9965e76b2abSTim Chen	---help---
997de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
998de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
999de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1000de966cf4STim Chen	  single threaded workloads) than others.
1001de966cf4STim Chen
1002de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1003de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1004de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1005de966cf4STim Chen	  overall system performance can be achieved.
1006de966cf4STim Chen
1007de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1008de966cf4STim Chen
1009de966cf4STim Chen	  If unsure say Y here.
10105e76b2abSTim Chen
1011506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
1012506f1d07SSam Ravnborg
101330b8b006SThomas Gleixnerconfig UP_LATE_INIT
101430b8b006SThomas Gleixner       def_bool y
1015ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
101630b8b006SThomas Gleixner
1017506f1d07SSam Ravnborgconfig X86_UP_APIC
101850849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
101950849eefSJan Beulich	default PCI_MSI
102038a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10218f9ca475SIngo Molnar	---help---
1022506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1023506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1024506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1025506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1026506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1027506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1028506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1029506f1d07SSam Ravnborg	  lockups.
1030506f1d07SSam Ravnborg
1031506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1032506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1033506f1d07SSam Ravnborg	depends on X86_UP_APIC
10348f9ca475SIngo Molnar	---help---
1035506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1036506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1037506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1038506f1d07SSam Ravnborg
1039506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1040506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1041506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1042506f1d07SSam Ravnborg
1043506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10443c2362e6SHarvey Harrison	def_bool y
10450dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1046b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
104752f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1048506f1d07SSam Ravnborg
1049506f1d07SSam Ravnborgconfig X86_IO_APIC
1050b1da1e71SJan Beulich	def_bool y
1051b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1052506f1d07SSam Ravnborg
105341b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
105441b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
105541b9eb26SStefan Assmann	depends on X86_IO_APIC
10568f9ca475SIngo Molnar	---help---
105741b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
105841b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
105941b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
106041b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
106141b9eb26SStefan Assmann
106241b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
106341b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
106441b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
106541b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
106641b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
106741b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
106841b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
106941b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
107041b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
107141b9eb26SStefan Assmann	  down (vital) interrupt lines.
107241b9eb26SStefan Assmann
107341b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
107441b9eb26SStefan Assmann	  increased on these systems.
107541b9eb26SStefan Assmann
1076506f1d07SSam Ravnborgconfig X86_MCE
1077bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1078648ed940SChen, Gong	select GENERIC_ALLOCATOR
1079e57dbaf7SBorislav Petkov	default y
1080506f1d07SSam Ravnborg	---help---
1081bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1082bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1083506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1084bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
10854efc0670SAndi Kleen
10865de97c9fSTony Luckconfig X86_MCELOG_LEGACY
10875de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
10885de97c9fSTony Luck	depends on X86_MCE
10895de97c9fSTony Luck	---help---
10905de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
10915de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
10925de97c9fSTony Luck	  rasdaemon solution.
10935de97c9fSTony Luck
1094506f1d07SSam Ravnborgconfig X86_MCE_INTEL
10953c2362e6SHarvey Harrison	def_bool y
10963c2362e6SHarvey Harrison	prompt "Intel MCE features"
1097c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
10988f9ca475SIngo Molnar	---help---
1099506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1100506f1d07SSam Ravnborg	   the thermal monitor.
1101506f1d07SSam Ravnborg
1102506f1d07SSam Ravnborgconfig X86_MCE_AMD
11033c2362e6SHarvey Harrison	def_bool y
11043c2362e6SHarvey Harrison	prompt "AMD MCE features"
1105f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11068f9ca475SIngo Molnar	---help---
1107506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1108506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1109506f1d07SSam Ravnborg
11104efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11116fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1112c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11134efc0670SAndi Kleen	---help---
11144efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11155065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11164efc0670SAndi Kleen	  line.
11174efc0670SAndi Kleen
1118b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1119b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11206fc108a0SJan Beulich	def_bool y
1121b2762686SAndi Kleen
1122ea149b36SAndi Kleenconfig X86_MCE_INJECT
1123bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1124ea149b36SAndi Kleen	tristate "Machine check injector support"
1125ea149b36SAndi Kleen	---help---
1126ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1127ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1128ea149b36SAndi Kleen	  QA it is safe to say n.
1129ea149b36SAndi Kleen
11304efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11314efc0670SAndi Kleen	def_bool y
11325bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11334efc0670SAndi Kleen
113407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1135e633c65aSKan Liang
11365aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11371e642812SIngo Molnar	bool "Legacy VM86 support"
11385aef51c3SAndy Lutomirski	default n
1139506f1d07SSam Ravnborg	depends on X86_32
11408f9ca475SIngo Molnar	---help---
11415aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11425aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11435aef51c3SAndy Lutomirski
11445aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11455aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11465aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11475aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11485aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11491e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11501e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11511e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11521e642812SIngo Molnar	  enable this option.
11535aef51c3SAndy Lutomirski
11541e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11551e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11561e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11571e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11585aef51c3SAndy Lutomirski
11591e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11601e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11615aef51c3SAndy Lutomirski
11621e642812SIngo Molnar	  If unsure, say N here.
11635aef51c3SAndy Lutomirski
11645aef51c3SAndy Lutomirskiconfig VM86
11655aef51c3SAndy Lutomirski       bool
11665aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
116734273f41SH. Peter Anvin
116834273f41SH. Peter Anvinconfig X86_16BIT
116934273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
117034273f41SH. Peter Anvin	default y
1171a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
117234273f41SH. Peter Anvin	---help---
117334273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
117434273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
117534273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
117634273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
117734273f41SH. Peter Anvin
117834273f41SH. Peter Anvinconfig X86_ESPFIX32
117934273f41SH. Peter Anvin	def_bool y
118034273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1181506f1d07SSam Ravnborg
1182197725deSH. Peter Anvinconfig X86_ESPFIX64
1183197725deSH. Peter Anvin	def_bool y
118434273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1185506f1d07SSam Ravnborg
11861ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
11871ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
11881ad83c85SAndy Lutomirski       default y
11891ad83c85SAndy Lutomirski       depends on X86_64
11901ad83c85SAndy Lutomirski       ---help---
11911ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
11921ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
11931ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
11941ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
11951ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
11961ad83c85SAndy Lutomirski	 0xffffffffff600?00.
11971ad83c85SAndy Lutomirski
11981ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
11991ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12001ad83c85SAndy Lutomirski
12011ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12021ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12031ad83c85SAndy Lutomirski
1204506f1d07SSam Ravnborgconfig TOSHIBA
1205506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1206506f1d07SSam Ravnborg	depends on X86_32
1207506f1d07SSam Ravnborg	---help---
1208506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1209506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1210506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1211506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1212506f1d07SSam Ravnborg
1213506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1214506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1215506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1216506f1d07SSam Ravnborg
1217506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1218506f1d07SSam Ravnborg	  Say N otherwise.
1219506f1d07SSam Ravnborg
1220506f1d07SSam Ravnborgconfig I8K
1221039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1222949a9d70SJean Delvare	select HWMON
1223039ae585SPali Rohár	select SENSORS_DELL_SMM
1224506f1d07SSam Ravnborg	---help---
1225039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1226039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1227039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1228039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1229039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1230039ae585SPali Rohár	  needed userspace package i8kutils.
1231506f1d07SSam Ravnborg
1232039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1233039ae585SPali Rohár	  use userspace package i8kutils.
1234506f1d07SSam Ravnborg	  Say N otherwise.
1235506f1d07SSam Ravnborg
1236506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12379ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12389ba16087SJan Beulich	depends on X86_32
1239506f1d07SSam Ravnborg	---help---
1240506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1241506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1242506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1243506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1244506f1d07SSam Ravnborg	  system.
1245506f1d07SSam Ravnborg
1246506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12475e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1248506f1d07SSam Ravnborg
1249506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1250506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1251506f1d07SSam Ravnborg	  Say N otherwise.
1252506f1d07SSam Ravnborg
1253506f1d07SSam Ravnborgconfig MICROCODE
12549a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12559a2bc335SBorislav Petkov	default y
125680030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1257506f1d07SSam Ravnborg	select FW_LOADER
1258506f1d07SSam Ravnborg	---help---
1259506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12605f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12615f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12625f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12635f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12645f9c01aaSBorislav Petkov	  the Linux kernel.
1265506f1d07SSam Ravnborg
12665f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
12675f9c01aaSBorislav Petkov	  in Documentation/x86/early-microcode.txt. For that you need to enable
12685f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
12695f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1270506f1d07SSam Ravnborg
1271c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1272c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1273c508c46eSBenjamin Gilbert	  config option.
1274506f1d07SSam Ravnborg
12758d86f390SPeter Orubaconfig MICROCODE_INTEL
1276e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
12778d86f390SPeter Oruba	depends on MICROCODE
12788d86f390SPeter Oruba	default MICROCODE
12798d86f390SPeter Oruba	select FW_LOADER
12808f9ca475SIngo Molnar	---help---
12818d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
12828d86f390SPeter Oruba	  processors.
12838d86f390SPeter Oruba
1284b8989db9SAlan	  For the current Intel microcode data package go to
1285b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1286b8989db9SAlan	  'Linux Processor Microcode Data File'.
12878d86f390SPeter Oruba
128880cc9f10SPeter Orubaconfig MICROCODE_AMD
1289e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
129080cc9f10SPeter Oruba	depends on MICROCODE
129180cc9f10SPeter Oruba	select FW_LOADER
12928f9ca475SIngo Molnar	---help---
129380cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
129480cc9f10SPeter Oruba	  processors will be enabled.
129580cc9f10SPeter Oruba
1296506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
12973c2362e6SHarvey Harrison	def_bool y
1298506f1d07SSam Ravnborg	depends on MICROCODE
1299506f1d07SSam Ravnborg
1300506f1d07SSam Ravnborgconfig X86_MSR
1301506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13028f9ca475SIngo Molnar	---help---
1303506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1304506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1305506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1306506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1307506f1d07SSam Ravnborg	  systems.
1308506f1d07SSam Ravnborg
1309506f1d07SSam Ravnborgconfig X86_CPUID
1310506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13118f9ca475SIngo Molnar	---help---
1312506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1313506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1314506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1315506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1316506f1d07SSam Ravnborg
1317506f1d07SSam Ravnborgchoice
1318506f1d07SSam Ravnborg	prompt "High Memory Support"
13196fc108a0SJan Beulich	default HIGHMEM4G
1320506f1d07SSam Ravnborg	depends on X86_32
1321506f1d07SSam Ravnborg
1322506f1d07SSam Ravnborgconfig NOHIGHMEM
1323506f1d07SSam Ravnborg	bool "off"
1324506f1d07SSam Ravnborg	---help---
1325506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1326506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1327506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1328506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1329506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1330506f1d07SSam Ravnborg	  "high memory".
1331506f1d07SSam Ravnborg
1332506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1333506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1334506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1335506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1336506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1337506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1338506f1d07SSam Ravnborg	  possible.
1339506f1d07SSam Ravnborg
1340506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1341506f1d07SSam Ravnborg	  answer "4GB" here.
1342506f1d07SSam Ravnborg
1343506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1344506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1345506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1346506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1347506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1348506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1349506f1d07SSam Ravnborg
1350506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1351506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1352506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1353506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1354506f1d07SSam Ravnborg	  kernel at boot time.)
1355506f1d07SSam Ravnborg
1356506f1d07SSam Ravnborg	  If unsure, say "off".
1357506f1d07SSam Ravnborg
1358506f1d07SSam Ravnborgconfig HIGHMEM4G
1359506f1d07SSam Ravnborg	bool "4GB"
13608f9ca475SIngo Molnar	---help---
1361506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1362506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1363506f1d07SSam Ravnborg
1364506f1d07SSam Ravnborgconfig HIGHMEM64G
1365506f1d07SSam Ravnborg	bool "64GB"
1366eb068e78SH. Peter Anvin	depends on !M486
1367506f1d07SSam Ravnborg	select X86_PAE
13688f9ca475SIngo Molnar	---help---
1369506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1370506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgendchoice
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgchoice
13756a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1376506f1d07SSam Ravnborg	default VMSPLIT_3G
1377506f1d07SSam Ravnborg	depends on X86_32
13788f9ca475SIngo Molnar	---help---
1379506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1380506f1d07SSam Ravnborg
1381506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1382506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1383506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1384506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1385506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1386506f1d07SSam Ravnborg	  available to user programs, making the address space there
1387506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1388506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1389506f1d07SSam Ravnborg	  kernel modules.
1390506f1d07SSam Ravnborg
1391506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1392506f1d07SSam Ravnborg	  option alone!
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborg	config VMSPLIT_3G
1395506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1396506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1397506f1d07SSam Ravnborg		depends on !X86_PAE
1398506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1399506f1d07SSam Ravnborg	config VMSPLIT_2G
1400506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1401506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1402506f1d07SSam Ravnborg		depends on !X86_PAE
1403506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1404506f1d07SSam Ravnborg	config VMSPLIT_1G
1405506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1406506f1d07SSam Ravnborgendchoice
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgconfig PAGE_OFFSET
1409506f1d07SSam Ravnborg	hex
1410506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1411506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1412506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1413506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1414506f1d07SSam Ravnborg	default 0xC0000000
1415506f1d07SSam Ravnborg	depends on X86_32
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborgconfig HIGHMEM
14183c2362e6SHarvey Harrison	def_bool y
1419506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborgconfig X86_PAE
14229ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1423506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
14249d99c712SChristian Melki	select SWIOTLB
14258f9ca475SIngo Molnar	---help---
1426506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1427506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1428506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1429506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1430506f1d07SSam Ravnborg
143177ef56e4SKirill A. Shutemovconfig X86_5LEVEL
143277ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
143377ef56e4SKirill A. Shutemov	depends on X86_64
143477ef56e4SKirill A. Shutemov	---help---
143577ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
143677ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
143777ef56e4SKirill A. Shutemov	  physical address space.
143877ef56e4SKirill A. Shutemov
143977ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
144077ef56e4SKirill A. Shutemov
144177ef56e4SKirill A. Shutemov	  Note: a kernel with this option enabled can only be booted
144277ef56e4SKirill A. Shutemov	  on machines that support the feature.
144377ef56e4SKirill A. Shutemov
144477ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
144577ef56e4SKirill A. Shutemov	  information.
144677ef56e4SKirill A. Shutemov
144777ef56e4SKirill A. Shutemov	  Say N if unsure.
144877ef56e4SKirill A. Shutemov
1449600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT
14503120e25eSJan Beulich	def_bool y
14513120e25eSJan Beulich	depends on X86_64 || X86_PAE
1452600715dcSJeremy Fitzhardinge
145366f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT
14543120e25eSJan Beulich	def_bool y
14553120e25eSJan Beulich	depends on X86_64 || HIGHMEM64G
145666f2b061SFUJITA Tomonori
145710971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1458e5008abeSLuis R. Rodriguez	def_bool y
14594675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14608f9ca475SIngo Molnar	---help---
146110971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
146210971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
146310971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
146410971ab2SIngo Molnar	  that we have them enabled.
14659e899816SNick Piggin
14667744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
14677744ccdbSTom Lendacky	def_bool y
14687744ccdbSTom Lendacky
14697744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
14707744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
14717744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
14727744ccdbSTom Lendacky	---help---
14737744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
14747744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
14757744ccdbSTom Lendacky	  Encryption (SME).
14767744ccdbSTom Lendacky
14777744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
14787744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
14797744ccdbSTom Lendacky	default y
14807744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
14817744ccdbSTom Lendacky	---help---
14827744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
14837744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
14847744ccdbSTom Lendacky
14857744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
14867744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
14877744ccdbSTom Lendacky
14887744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
14897744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
14907744ccdbSTom Lendacky
1491f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1492f88a68faSTom Lendacky	def_bool y
1493f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1494f88a68faSTom Lendacky
1495506f1d07SSam Ravnborg# Common NUMA Features
1496506f1d07SSam Ravnborgconfig NUMA
1497fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1498506f1d07SSam Ravnborg	depends on SMP
1499b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1500b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15018f9ca475SIngo Molnar	---help---
1502506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1503fd51b2d7SKOSAKI Motohiro
1504506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1505506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1506506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1507506f1d07SSam Ravnborg
1508c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1509fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1510fd51b2d7SKOSAKI Motohiro
1511b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15127cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1513fd51b2d7SKOSAKI Motohiro
1514fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1515506f1d07SSam Ravnborg
1516eec1d4faSHans Rosenfeldconfig AMD_NUMA
15173c2362e6SHarvey Harrison	def_bool y
15183c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15195da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15208f9ca475SIngo Molnar	---help---
1521eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1522eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1523eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1524eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1525eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1526506f1d07SSam Ravnborg
1527506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15283c2362e6SHarvey Harrison	def_bool y
15293c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1530506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1531506f1d07SSam Ravnborg	select ACPI_NUMA
15328f9ca475SIngo Molnar	---help---
1533506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1534506f1d07SSam Ravnborg
15356ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15366ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15376ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15386ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15396ec6e0d9SSuresh Siddha# for details.
15406ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15416ec6e0d9SSuresh Siddha	def_bool y
15426ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15436ec6e0d9SSuresh Siddha
1544506f1d07SSam Ravnborgconfig NUMA_EMU
1545506f1d07SSam Ravnborg	bool "NUMA emulation"
15461b7e03efSTejun Heo	depends on NUMA
15478f9ca475SIngo Molnar	---help---
1548506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1549506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1550506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1551506f1d07SSam Ravnborg
1552506f1d07SSam Ravnborgconfig NODES_SHIFT
1553d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
155451591e31SDavid Rientjes	range 1 10
155551591e31SDavid Rientjes	default "10" if MAXSMP
1556506f1d07SSam Ravnborg	default "6" if X86_64
1557506f1d07SSam Ravnborg	default "3"
1558506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15598f9ca475SIngo Molnar	---help---
15601184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1561692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1562506f1d07SSam Ravnborg
1563506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15643c2362e6SHarvey Harrison	def_bool y
1565506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1566506f1d07SSam Ravnborg
1567506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE
15683c2362e6SHarvey Harrison	def_bool y
1569506f1d07SSam Ravnborg	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1570506f1d07SSam Ravnborg
1571506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1572506f1d07SSam Ravnborg	def_bool y
15733b16651fSTejun Heo	depends on X86_32 && !NUMA
1574506f1d07SSam Ravnborg
1575506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1576506f1d07SSam Ravnborg	def_bool y
1577b263295dSChristoph Lameter	depends on NUMA && X86_32
1578506f1d07SSam Ravnborg
1579506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1580506f1d07SSam Ravnborg	def_bool y
1581b263295dSChristoph Lameter	depends on NUMA && X86_32
1582b263295dSChristoph Lameter
1583506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1584506f1d07SSam Ravnborg	def_bool y
15856ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1586506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1587506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1588506f1d07SSam Ravnborg
15893b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
15903b16651fSTejun Heo	def_bool y
15913b16651fSTejun Heo	depends on X86_64
15923b16651fSTejun Heo
1593506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1594506f1d07SSam Ravnborg	def_bool y
1595b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1598a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
15993120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1600a0842b70SToshi Kani	help
1601a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1602a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1603a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1604506f1d07SSam Ravnborg
16053b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16063b16651fSTejun Heo	def_bool y
16073b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16083b16651fSTejun Heo
1609a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1610a29815a3SAvi Kivity       hex
1611a29815a3SAvi Kivity       default 0 if X86_32
1612a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1613a29815a3SAvi Kivity
1614506f1d07SSam Ravnborgsource "mm/Kconfig"
1615506f1d07SSam Ravnborg
16167a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16177a67832cSDan Williams	bool
16187a67832cSDan Williams
1619ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16207a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16219f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16229f53f9faSDan Williams	depends on BLK_DEV
16237a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16249f53f9faSDan Williams	select LIBNVDIMM
1625ec776ef6SChristoph Hellwig	help
1626ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1627ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1628ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1629ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1630ec776ef6SChristoph Hellwig
1631ec776ef6SChristoph Hellwig	  Say Y if unsure.
1632ec776ef6SChristoph Hellwig
1633506f1d07SSam Ravnborgconfig HIGHPTE
1634506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16356fc108a0SJan Beulich	depends on HIGHMEM
16368f9ca475SIngo Molnar	---help---
1637506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1638506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1639506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1640506f1d07SSam Ravnborg	  entries in high memory.
1641506f1d07SSam Ravnborg
16429f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16439f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16448f9ca475SIngo Molnar	---help---
16459f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16469f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16479f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16489f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16499f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16509f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16519f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16528c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16539f077871SJeremy Fitzhardinge
16549f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16559f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16569f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16579f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16589f077871SJeremy Fitzhardinge
16599f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16609f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16619f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16629f077871SJeremy Fitzhardinge	  memory.
16639f077871SJeremy Fitzhardinge
1664c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1665c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1666c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1667c885df50SJeremy Fitzhardinge	default y
16688f9ca475SIngo Molnar	---help---
1669c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1670c885df50SJeremy Fitzhardinge	  on or off.
1671c885df50SJeremy Fitzhardinge
16729ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1673d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1674d0cd7425SH. Peter Anvin	default 64
1675d0cd7425SH. Peter Anvin	range 4 640
16768f9ca475SIngo Molnar	---help---
1677d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1678fc381519SIngo Molnar
1679d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1680d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1681fc381519SIngo Molnar
1682d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1683d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1684d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1685d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1686fc381519SIngo Molnar
1687d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1688d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1689d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1690d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1691d0cd7425SH. Peter Anvin	  entire low memory range.
1692d0cd7425SH. Peter Anvin
1693d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1694d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1695d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1696d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1697d0cd7425SH. Peter Anvin	  typical corruption patterns.
1698d0cd7425SH. Peter Anvin
1699d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1700fc381519SIngo Molnar
1701506f1d07SSam Ravnborgconfig MATH_EMULATION
1702506f1d07SSam Ravnborg	bool
1703a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1704506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1705506f1d07SSam Ravnborg	---help---
1706506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1707506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1708506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1709506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1710506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1711506f1d07SSam Ravnborg	  coprocessor or this emulation.
1712506f1d07SSam Ravnborg
1713506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1714506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1715506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1716506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1717506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1718506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1719506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1720506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1721506f1d07SSam Ravnborg
1722506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1723506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1724506f1d07SSam Ravnborg
1725506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1726506f1d07SSam Ravnborg	  kernel, it won't hurt.
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborgconfig MTRR
17296fc108a0SJan Beulich	def_bool y
17306a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1731506f1d07SSam Ravnborg	---help---
1732506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1733506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1734506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1735506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1736506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1737506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1738506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1739506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1740506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1741506f1d07SSam Ravnborg
1742506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1743506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1744506f1d07SSam Ravnborg	  as well:
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1747506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1748506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1749506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1750506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1751506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1752506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1755506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1756506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1759506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1760506f1d07SSam Ravnborg
17617225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1762506f1d07SSam Ravnborg
176395ffa243SYinghai Luconfig MTRR_SANITIZER
17642ffb3501SYinghai Lu	def_bool y
176595ffa243SYinghai Lu	prompt "MTRR cleanup support"
176695ffa243SYinghai Lu	depends on MTRR
17678f9ca475SIngo Molnar	---help---
1768aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1769aba3728cSThomas Gleixner	  add writeback entries.
177095ffa243SYinghai Lu
1771aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1772692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1773aba3728cSThomas Gleixner	  mtrr_chunk_size.
177495ffa243SYinghai Lu
17752ffb3501SYinghai Lu	  If unsure, say Y.
177695ffa243SYinghai Lu
177795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1778f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1779f5098d62SYinghai Lu	range 0 1
1780f5098d62SYinghai Lu	default "0"
178195ffa243SYinghai Lu	depends on MTRR_SANITIZER
17828f9ca475SIngo Molnar	---help---
1783f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178495ffa243SYinghai Lu
178512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178712031a62SYinghai Lu	range 0 7
178812031a62SYinghai Lu	default "1"
178912031a62SYinghai Lu	depends on MTRR_SANITIZER
17908f9ca475SIngo Molnar	---help---
179112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1792aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179312031a62SYinghai Lu
17942e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17956fc108a0SJan Beulich	def_bool y
17966a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17972a8a2719SIngo Molnar	depends on MTRR
17988f9ca475SIngo Molnar	---help---
17992e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1800042b78e4SVenki Pallipadi
18012e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18022e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18032e5d9c85Svenkatesh.pallipadi@intel.com
18042e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1805042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18062e5d9c85Svenkatesh.pallipadi@intel.com
18072e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18082e5d9c85Svenkatesh.pallipadi@intel.com
180946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181046cf98cdSVenkatesh Pallipadi	def_bool y
181146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181246cf98cdSVenkatesh Pallipadi
1813628c6246SH. Peter Anvinconfig ARCH_RANDOM
1814628c6246SH. Peter Anvin	def_bool y
1815628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1816628c6246SH. Peter Anvin	---help---
1817628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1818628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1819628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1820628c6246SH. Peter Anvin	  secure hardware random number generator.
1821628c6246SH. Peter Anvin
182251ae4a2dSH. Peter Anvinconfig X86_SMAP
182351ae4a2dSH. Peter Anvin	def_bool y
182451ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
182551ae4a2dSH. Peter Anvin	---help---
182651ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
182751ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
182851ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
182951ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
183051ae4a2dSH. Peter Anvin
183151ae4a2dSH. Peter Anvin	  If unsure, say Y.
183251ae4a2dSH. Peter Anvin
1833aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1834796ebc81SRicardo Neri	def_bool y
1835aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1836aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1837aa35f896SRicardo Neri	---help---
1838aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1839aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1840796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1841796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1842796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1843796ebc81SRicardo Neri
1844796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1845796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1846796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1847796ebc81SRicardo Neri	  results are dummy.
1848aa35f896SRicardo Neri
184972e9b5feSDave Hansenconfig X86_INTEL_MPX
185072e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
185172e9b5feSDave Hansen	def_bool n
1852df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1853df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1854df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
185572e9b5feSDave Hansen	---help---
185672e9b5feSDave Hansen	  MPX provides hardware features that can be used in
185772e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
185872e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
185972e9b5feSDave Hansen	  overflow or underflow bugs.
186072e9b5feSDave Hansen
186172e9b5feSDave Hansen	  This option enables running applications which are
186272e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
186372e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
186472e9b5feSDave Hansen	  against bad memory references.
186572e9b5feSDave Hansen
186672e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
186772e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
186872e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
186972e9b5feSDave Hansen	  will increase the kernel memory overhead of each
187072e9b5feSDave Hansen	  process and adds some branches to paths used during
187172e9b5feSDave Hansen	  exec() and munmap().
187272e9b5feSDave Hansen
187372e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
187472e9b5feSDave Hansen
187572e9b5feSDave Hansen	  If unsure, say N.
187672e9b5feSDave Hansen
187735e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1878284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
187935e97790SDave Hansen	def_bool y
1880284244a9SDave Hansen	# Note: only available in 64-bit mode
188135e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
188252c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188352c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1884284244a9SDave Hansen	---help---
1885284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1886284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1887284244a9SDave Hansen	  page tables when an application changes protection domains.
1888284244a9SDave Hansen
1889284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1890284244a9SDave Hansen
1891284244a9SDave Hansen	  If unsure, say y.
189235e97790SDave Hansen
1893506f1d07SSam Ravnborgconfig EFI
18949ba16087SJan Beulich	bool "EFI runtime service support"
18955b83683fSHuang, Ying	depends on ACPI
1896f6ce5002SSergey Vlasov	select UCS2_STRING
1897022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1898506f1d07SSam Ravnborg	---help---
18998b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1900506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1901506f1d07SSam Ravnborg
19028b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19038b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19048b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19058b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19068b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19078b2cb7a8SHuang, Ying	  platforms.
1908506f1d07SSam Ravnborg
1909291f3632SMatt Flemingconfig EFI_STUB
1910291f3632SMatt Fleming       bool "EFI stub support"
1911b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19127b2a583aSMatt Fleming       select RELOCATABLE
1913291f3632SMatt Fleming       ---help---
1914291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1915291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1916291f3632SMatt Fleming
19174172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19180c759662SMatt Fleming
19197d453eeeSMatt Flemingconfig EFI_MIXED
19207d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19217d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19227d453eeeSMatt Fleming	---help---
19237d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19247d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19257d453eeeSMatt Fleming	   mode.
19267d453eeeSMatt Fleming
19277d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19287d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19297d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19307d453eeeSMatt Fleming
19317d453eeeSMatt Fleming	   If unsure, say N.
19327d453eeeSMatt Fleming
1933506f1d07SSam Ravnborgconfig SECCOMP
19343c2362e6SHarvey Harrison	def_bool y
19353c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19368f9ca475SIngo Molnar	---help---
1937506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1938506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1939506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1940506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1941506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1942506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19439c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1944506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1945506f1d07SSam Ravnborg	  defined by each seccomp mode.
1946506f1d07SSam Ravnborg
1947506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1948506f1d07SSam Ravnborg
1949506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1950506f1d07SSam Ravnborg
1951506f1d07SSam Ravnborgconfig KEXEC
1952506f1d07SSam Ravnborg	bool "kexec system call"
19532965faa5SDave Young	select KEXEC_CORE
19548f9ca475SIngo Molnar	---help---
1955506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1956506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1957506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1958506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1959506f1d07SSam Ravnborg
1960506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1961506f1d07SSam Ravnborg
1962506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1963506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1964bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1965bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1966bf220695SGeert Uytterhoeven	  made.
1967506f1d07SSam Ravnborg
196874ca317cSVivek Goyalconfig KEXEC_FILE
196974ca317cSVivek Goyal	bool "kexec file based system call"
19702965faa5SDave Young	select KEXEC_CORE
197174ca317cSVivek Goyal	select BUILD_BIN2C
197274ca317cSVivek Goyal	depends on X86_64
197374ca317cSVivek Goyal	depends on CRYPTO=y
197474ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
197574ca317cSVivek Goyal	---help---
197674ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
197774ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
197874ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
197974ca317cSVivek Goyal	  accepted by previous system call.
198074ca317cSVivek Goyal
19818e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
19828e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
198374ca317cSVivek Goyal	depends on KEXEC_FILE
19848e7d8381SVivek Goyal	---help---
19858e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
1986d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
19878e7d8381SVivek Goyal
1988d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
1989d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
1990d8eb8940SBorislav Petkov	  loaded in order for this to work.
19918e7d8381SVivek Goyal
19928e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
19938e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
19948e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
19958e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
19968e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
19978e7d8381SVivek Goyal	---help---
19988e7d8381SVivek Goyal	  Enable bzImage signature verification support.
19998e7d8381SVivek Goyal
2000506f1d07SSam Ravnborgconfig CRASH_DUMP
200104b69447SPavel Machek	bool "kernel crash dumps"
2002506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20038f9ca475SIngo Molnar	---help---
2004506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2005506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2006506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2007506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2008506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2009506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2010506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2011506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2012506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2013506f1d07SSam Ravnborg
20143ab83521SHuang Yingconfig KEXEC_JUMP
20156ea30386SKees Cook	bool "kexec jump"
2016fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20178f9ca475SIngo Molnar	---help---
201889081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
201989081d17SHuang Ying	  code in physical address mode via KEXEC
20203ab83521SHuang Ying
2021506f1d07SSam Ravnborgconfig PHYSICAL_START
20226a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2023ceefccc9SH. Peter Anvin	default "0x1000000"
20248f9ca475SIngo Molnar	---help---
2025506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2026506f1d07SSam Ravnborg
2027506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2028506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2029506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2030506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2031506f1d07SSam Ravnborg	  address.
2032506f1d07SSam Ravnborg
2033506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2034506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2035506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2036506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2037506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2038506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2039506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2040506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2041506f1d07SSam Ravnborg
2042ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2043ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2044ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2045ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2046ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2047ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2048ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2049ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2050ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2051506f1d07SSam Ravnborg
2052506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2053506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2054506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2055506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2056506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2057506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2058506f1d07SSam Ravnborg	  line.
2059506f1d07SSam Ravnborg
2060506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2061506f1d07SSam Ravnborg
2062506f1d07SSam Ravnborgconfig RELOCATABLE
206326717808SH. Peter Anvin	bool "Build a relocatable kernel"
206426717808SH. Peter Anvin	default y
20658f9ca475SIngo Molnar	---help---
2066506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2067506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2068506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2069506f1d07SSam Ravnborg	  but are discarded at runtime.
2070506f1d07SSam Ravnborg
2071506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2072506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2073506f1d07SSam Ravnborg	  kernel.
2074506f1d07SSam Ravnborg
2075506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2076506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
20778ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2078506f1d07SSam Ravnborg
20798ab3820fSKees Cookconfig RANDOMIZE_BASE
2080e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
20818ab3820fSKees Cook	depends on RELOCATABLE
20826807c846SIngo Molnar	default y
20838ab3820fSKees Cook	---help---
2084e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2085e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2086e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2087e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2088e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2089e8581e3dSBaoquan He	  code internals.
2090e8581e3dSBaoquan He
2091ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2092ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2093ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2094ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2095ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2096ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2097ed9f007eSKees Cook
2098ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2099ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2100ed9f007eSKees Cook	  512MB (8 bits of entropy).
21018ab3820fSKees Cook
2102a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2103e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2104e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2105ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2106ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2107ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2108ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2109ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2110ed9f007eSKees Cook	  limited due to memory layouts.
2111e8581e3dSBaoquan He
21126807c846SIngo Molnar	  If unsure, say Y.
2113da2b6fb9SKees Cook
21148ab3820fSKees Cook# Relocation on x86 needs some additional build support
2115845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2116845adf72SH. Peter Anvin	def_bool y
21178ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2118845adf72SH. Peter Anvin
2119506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2120a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21218ab3820fSKees Cook	default "0x200000"
2122a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2123a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21248f9ca475SIngo Molnar	---help---
2125506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2126506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2127506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2128506f1d07SSam Ravnborg
2129506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2130506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2131506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2132506f1d07SSam Ravnborg
2133506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2134506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2135506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2136506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2137506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2138506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2139506f1d07SSam Ravnborg	  above alignment restrictions.
2140506f1d07SSam Ravnborg
2141a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2142a0215061SKees Cook	  this value must be a multiple of 0x200000.
2143a0215061SKees Cook
2144506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2145506f1d07SSam Ravnborg
21460483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21470483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21480483e1faSThomas Garnier	depends on X86_64
21490483e1faSThomas Garnier	depends on RANDOMIZE_BASE
21500483e1faSThomas Garnier	default RANDOMIZE_BASE
21510483e1faSThomas Garnier	---help---
21520483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21530483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21540483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21550483e1faSThomas Garnier
21560483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21570483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21580483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21590483e1faSThomas Garnier	   addresses for each memory section.
21600483e1faSThomas Garnier
21616807c846SIngo Molnar	   If unsure, say Y.
21620483e1faSThomas Garnier
216390397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
216490397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
216590397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
216690397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
216790397a41SThomas Garnier	default "0x0"
216890397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
216990397a41SThomas Garnier	range 0x0 0x40
217090397a41SThomas Garnier	---help---
217190397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
217290397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
217390397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
217490397a41SThomas Garnier	   address randomization.
217590397a41SThomas Garnier
217690397a41SThomas Garnier	   If unsure, leave at the default value.
217790397a41SThomas Garnier
2178506f1d07SSam Ravnborgconfig HOTPLUG_CPU
21797c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
218040b31360SStephen Rothwell	depends on SMP
2181506f1d07SSam Ravnborg	---help---
21827c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
21837c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
21847c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
21857c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
21867c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2187506f1d07SSam Ravnborg
218880aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
218980aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
219080aa1dffSFenghua Yu	default n
21912c922cd0SKees Cook	depends on HOTPLUG_CPU
219280aa1dffSFenghua Yu	---help---
219380aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
219480aa1dffSFenghua Yu
219580aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
219680aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
219780aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
219880aa1dffSFenghua Yu
219980aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
220080aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
220180aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
220280aa1dffSFenghua Yu
220380aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
220480aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
220580aa1dffSFenghua Yu
220680aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
220780aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
220880aa1dffSFenghua Yu	  be other CPU0 dependencies.
220980aa1dffSFenghua Yu
221080aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
221180aa1dffSFenghua Yu	  you enable this feature.
221280aa1dffSFenghua Yu
221380aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
221480aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
221580aa1dffSFenghua Yu	  parameter cpu0_hotplug.
221680aa1dffSFenghua Yu
2217a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2218a71c8bc5SFenghua Yu	def_bool n
2219a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22202c922cd0SKees Cook	depends on HOTPLUG_CPU
2221a71c8bc5SFenghua Yu	---help---
2222a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2223a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2224a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2225a71c8bc5SFenghua Yu
2226a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2227a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2228a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2229a71c8bc5SFenghua Yu
2230a71c8bc5SFenghua Yu	  If unsure, say N.
2231a71c8bc5SFenghua Yu
2232506f1d07SSam Ravnborgconfig COMPAT_VDSO
2233b0b49f26SAndy Lutomirski	def_bool n
2234b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2235953fee1dSIngo Molnar	depends on COMPAT_32
22368f9ca475SIngo Molnar	---help---
2237b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2238b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2239b0b49f26SAndy Lutomirski	  indicated in its segment table.
2240e84446deSRandy Dunlap
2241b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2242b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2243b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2244b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2245b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2246506f1d07SSam Ravnborg
2247b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2248b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2249b0b49f26SAndy Lutomirski
2250b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2251b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2252b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2253b0b49f26SAndy Lutomirski
2254b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2255b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2256506f1d07SSam Ravnborg
22573dc33bd3SKees Cookchoice
22583dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22593dc33bd3SKees Cook	depends on X86_64
22603dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22613dc33bd3SKees Cook	help
22623dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22633dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22643dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22653dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22663dc33bd3SKees Cook
22673dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
22683dc33bd3SKees Cook	  line parameter vsyscall=[native|emulate|none].
22693dc33bd3SKees Cook
22703dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22713dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22723dc33bd3SKees Cook	  to improve security.
22733dc33bd3SKees Cook
22743dc33bd3SKees Cook	  If unsure, select "Emulate".
22753dc33bd3SKees Cook
22763dc33bd3SKees Cook	config LEGACY_VSYSCALL_NATIVE
22773dc33bd3SKees Cook		bool "Native"
22783dc33bd3SKees Cook		help
22793dc33bd3SKees Cook		  Actual executable code is located in the fixed vsyscall
22803dc33bd3SKees Cook		  address mapping, implementing time() efficiently. Since
22813dc33bd3SKees Cook		  this makes the mapping executable, it can be used during
22823dc33bd3SKees Cook		  security vulnerability exploitation (traditionally as
22833dc33bd3SKees Cook		  ROP gadgets). This configuration is not recommended.
22843dc33bd3SKees Cook
22853dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
22863dc33bd3SKees Cook		bool "Emulate"
22873dc33bd3SKees Cook		help
22883dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
22893dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
22903dc33bd3SKees Cook		  non-executable, but it still contains known contents,
22913dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
22923dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
22933dc33bd3SKees Cook		  still uses the vsyscall area.
22943dc33bd3SKees Cook
22953dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
22963dc33bd3SKees Cook		bool "None"
22973dc33bd3SKees Cook		help
22983dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
22993dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23003dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23013dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23023dc33bd3SKees Cook		  malicious userspace programs can be identified.
23033dc33bd3SKees Cook
23043dc33bd3SKees Cookendchoice
23053dc33bd3SKees Cook
2306516cbf37STim Birdconfig CMDLINE_BOOL
2307516cbf37STim Bird	bool "Built-in kernel command line"
23088f9ca475SIngo Molnar	---help---
2309516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2310516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2311516cbf37STim Bird	  necessary or convenient to provide some or all of the
2312516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2313516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2314516cbf37STim Bird
2315516cbf37STim Bird	  To compile command line arguments into the kernel,
2316516cbf37STim Bird	  set this option to 'Y', then fill in the
231769711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2318516cbf37STim Bird
2319516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2320516cbf37STim Bird	  should leave this option set to 'N'.
2321516cbf37STim Bird
2322516cbf37STim Birdconfig CMDLINE
2323516cbf37STim Bird	string "Built-in kernel command string"
2324516cbf37STim Bird	depends on CMDLINE_BOOL
2325516cbf37STim Bird	default ""
23268f9ca475SIngo Molnar	---help---
2327516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2328516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2329516cbf37STim Bird	  command line at boot time, it is appended to this string to
2330516cbf37STim Bird	  form the full kernel command line, when the system boots.
2331516cbf37STim Bird
2332516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2333516cbf37STim Bird	  change this behavior.
2334516cbf37STim Bird
2335516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2336516cbf37STim Bird	  by the boot loader) should specify the device for the root
2337516cbf37STim Bird	  file system.
2338516cbf37STim Bird
2339516cbf37STim Birdconfig CMDLINE_OVERRIDE
2340516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2341516cbf37STim Bird	depends on CMDLINE_BOOL
23428f9ca475SIngo Molnar	---help---
2343516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2344516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2345516cbf37STim Bird
2346516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2347516cbf37STim Bird	  be set to 'N' under normal conditions.
2348516cbf37STim Bird
2349a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2350a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2351a5b9e5a2SAndy Lutomirski	default y
2352a5b9e5a2SAndy Lutomirski	---help---
2353a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2354a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2355a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2356a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2357a5b9e5a2SAndy Lutomirski	  threading libraries.
2358a5b9e5a2SAndy Lutomirski
2359a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2360a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2361a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2362a5b9e5a2SAndy Lutomirski
2363a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2364a5b9e5a2SAndy Lutomirski
2365b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2366b700e7f0SSeth Jennings
2367506f1d07SSam Ravnborgendmenu
2368506f1d07SSam Ravnborg
23693072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23703072e413SMichal Hocko	def_bool y
23713072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23723072e413SMichal Hocko
2373506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2374506f1d07SSam Ravnborg	def_bool y
2375506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2376506f1d07SSam Ravnborg
237735551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
237835551053SGary Hade	def_bool y
237935551053SGary Hade	depends on MEMORY_HOTPLUG
238035551053SGary Hade
2381e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2382645a7919STejun Heo	def_bool y
2383e534c7c5SLee Schermerhorn	depends on NUMA
2384e534c7c5SLee Schermerhorn
23859491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
23869491846fSKirill A. Shutemov	def_bool y
23879491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
23889491846fSKirill A. Shutemov
2389c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2390c177c81eSNaoya Horiguchi	def_bool y
2391c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2392c177c81eSNaoya Horiguchi
23939c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
23949c670ea3SNaoya Horiguchi	def_bool y
23959c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
23969c670ea3SNaoya Horiguchi
2397da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2398e279b6c1SSam Ravnborg
2399e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24003c2362e6SHarvey Harrison	def_bool y
2401e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2402e279b6c1SSam Ravnborg
2403e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2404e279b6c1SSam Ravnborg
2405e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2406e279b6c1SSam Ravnborg
2407efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2408efafc8b2SFeng Tang
2409a6b68076SAndi Kleenconfig X86_APM_BOOT
24106fc108a0SJan Beulich	def_bool y
2411282e5aabSPaul Bolle	depends on APM
2412a6b68076SAndi Kleen
2413e279b6c1SSam Ravnborgmenuconfig APM
2414e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2415efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2416e279b6c1SSam Ravnborg	---help---
2417e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2418e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2419e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2420e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2421e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2422e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2423e279b6c1SSam Ravnborg
2424e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2425e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2426e279b6c1SSam Ravnborg
2427e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2428e279b6c1SSam Ravnborg	  machines with more than one CPU.
2429e279b6c1SSam Ravnborg
2430e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24312dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24322dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2433e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2434e279b6c1SSam Ravnborg
2435e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2436e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2437e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2438e279b6c1SSam Ravnborg
2439e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2440e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2441e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2442e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2443e279b6c1SSam Ravnborg
2444e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2445e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2446e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2447e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2448e279b6c1SSam Ravnborg	  APM in your BIOS).
2449e279b6c1SSam Ravnborg
2450e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2451e279b6c1SSam Ravnborg	  "weird" problems:
2452e279b6c1SSam Ravnborg
2453e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2454e279b6c1SSam Ravnborg	  enabled.
2455e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2456e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2457e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2458e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2459e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2460e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2461e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2462e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2463e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2464e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2465e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2466e279b6c1SSam Ravnborg	  11) exchange RAM chips
2467e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2468e279b6c1SSam Ravnborg
2469e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2470e279b6c1SSam Ravnborg	  module will be called apm.
2471e279b6c1SSam Ravnborg
2472e279b6c1SSam Ravnborgif APM
2473e279b6c1SSam Ravnborg
2474e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2475e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
24768f9ca475SIngo Molnar	---help---
2477e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2478e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2479e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2482e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2483e279b6c1SSam Ravnborg	---help---
2484e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2485e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2486e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2487e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2488e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2489e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2490e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2491e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2492e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2493e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2494e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2495e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2496e279b6c1SSam Ravnborg	  this feature.
2497e279b6c1SSam Ravnborg
2498e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2499dd8af076SLen Brown	depends on CPU_IDLE
2500e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25018f9ca475SIngo Molnar	---help---
2502e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2503e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2504e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2505e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2506e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2507e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2508e279b6c1SSam Ravnborg	  this option does nothing.)
2509e279b6c1SSam Ravnborg
2510e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2511e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25128f9ca475SIngo Molnar	---help---
2513e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2514e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2515e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2516e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2517e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2518e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2519e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2520e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2521e279b6c1SSam Ravnborg	  especially if you are using gpm.
2522e279b6c1SSam Ravnborg
2523e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2524e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25258f9ca475SIngo Molnar	---help---
2526e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2527e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2528e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2529e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2530e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2531e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2532e279b6c1SSam Ravnborg
2533e279b6c1SSam Ravnborgendif # APM
2534e279b6c1SSam Ravnborg
2535bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2536e279b6c1SSam Ravnborg
2537e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2538e279b6c1SSam Ravnborg
253927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
254027471fdbSAndy Henroid
2541e279b6c1SSam Ravnborgendmenu
2542e279b6c1SSam Ravnborg
2543e279b6c1SSam Ravnborg
2544e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborgconfig PCI
25471ac97018SIngo Molnar	bool "PCI support"
25481c858087SAdrian Bunk	default y
25498f9ca475SIngo Molnar	---help---
2550e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2551e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2552e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2553e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2554e279b6c1SSam Ravnborg
2555e279b6c1SSam Ravnborgchoice
2556e279b6c1SSam Ravnborg	prompt "PCI access mode"
2557efefa6f6SIngo Molnar	depends on X86_32 && PCI
2558e279b6c1SSam Ravnborg	default PCI_GOANY
2559e279b6c1SSam Ravnborg	---help---
2560e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2561e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2562e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2563e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2564e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2567e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2568e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2569e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2570e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2571e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2572e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2575e279b6c1SSam Ravnborg	bool "BIOS"
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2578e279b6c1SSam Ravnborg	bool "MMConfig"
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2581e279b6c1SSam Ravnborg	bool "Direct"
2582e279b6c1SSam Ravnborg
25833ef0e1f8SAndres Salomonconfig PCI_GOOLPC
258476fb6570SDaniel Drake	bool "OLPC XO-1"
25853ef0e1f8SAndres Salomon	depends on OLPC
25863ef0e1f8SAndres Salomon
25872bdd1b03SAndres Salomonconfig PCI_GOANY
25882bdd1b03SAndres Salomon	bool "Any"
25892bdd1b03SAndres Salomon
2590e279b6c1SSam Ravnborgendchoice
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborgconfig PCI_BIOS
25933c2362e6SHarvey Harrison	def_bool y
2594efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2595e279b6c1SSam Ravnborg
2596e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2597e279b6c1SSam Ravnborgconfig PCI_DIRECT
25983c2362e6SHarvey Harrison	def_bool y
25990aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
26023c2362e6SHarvey Harrison	def_bool y
26035f0db7a2SFeng Tang	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2604e279b6c1SSam Ravnborg
26053ef0e1f8SAndres Salomonconfig PCI_OLPC
26062bdd1b03SAndres Salomon	def_bool y
26072bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26083ef0e1f8SAndres Salomon
2609b5401a96SAlex Nixonconfig PCI_XEN
2610b5401a96SAlex Nixon	def_bool y
2611b5401a96SAlex Nixon	depends on PCI && XEN
2612b5401a96SAlex Nixon	select SWIOTLB_XEN
2613b5401a96SAlex Nixon
2614e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26153c2362e6SHarvey Harrison	def_bool y
2616e279b6c1SSam Ravnborg	depends on PCI
2617e279b6c1SSam Ravnborg
2618e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2619e279b6c1SSam Ravnborg	bool "Support mmconfig PCI config space access"
2620e279b6c1SSam Ravnborg	depends on X86_64 && PCI && ACPI
2621e279b6c1SSam Ravnborg
26223f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26236a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26246ea30386SKees Cook	depends on PCI
26253f6ea84aSIra W. Snyder	help
26263f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26273f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26283f6ea84aSIra W. Snyder	  not have ACPI.
26293f6ea84aSIra W. Snyder
263064a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
263164a5fed6SBjorn Helgaas	  is known to be incomplete.
263264a5fed6SBjorn Helgaas
263364a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
263464a5fed6SBjorn Helgaas
2635e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2636e279b6c1SSam Ravnborg
26373a495511SWilliam Breathitt Grayconfig ISA_BUS
2638*17a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26393a495511SWilliam Breathitt Gray	help
2640*17a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
2641*17a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
2642*17a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
2643*17a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
2644*17a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26453a495511SWilliam Breathitt Gray
26463a495511SWilliam Breathitt Gray	  If unsure, say N.
26473a495511SWilliam Breathitt Gray
26481c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2649e279b6c1SSam Ravnborgconfig ISA_DMA_API
26501c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26511c00f016SDavid Rientjes	default y
26521c00f016SDavid Rientjes	help
26531c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26541c00f016SDavid Rientjes	  If unsure, say Y.
2655e279b6c1SSam Ravnborg
265651e68d05SLinus Torvaldsif X86_32
265751e68d05SLinus Torvalds
2658e279b6c1SSam Ravnborgconfig ISA
2659e279b6c1SSam Ravnborg	bool "ISA support"
26608f9ca475SIngo Molnar	---help---
2661e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2662e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2663e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2664e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2665e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2666e279b6c1SSam Ravnborg
2667e279b6c1SSam Ravnborgconfig EISA
2668e279b6c1SSam Ravnborg	bool "EISA support"
2669e279b6c1SSam Ravnborg	depends on ISA
2670e279b6c1SSam Ravnborg	---help---
2671e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2672e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2673e279b6c1SSam Ravnborg
2674e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2675e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2676e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2677e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2678e279b6c1SSam Ravnborg
2679e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2680e279b6c1SSam Ravnborg
2681e279b6c1SSam Ravnborg	  Otherwise, say N.
2682e279b6c1SSam Ravnborg
2683e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2684e279b6c1SSam Ravnborg
2685e279b6c1SSam Ravnborgconfig SCx200
2686e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26878f9ca475SIngo Molnar	---help---
2688e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2689e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2690e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2691e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2692e279b6c1SSam Ravnborg
2693e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2694e279b6c1SSam Ravnborg
2695e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2696e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2697592913ecSJohn Stultz	depends on SCx200
2698e279b6c1SSam Ravnborg	default y
26998f9ca475SIngo Molnar	---help---
2700e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2701e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2702e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2703e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2704e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2705e279b6c1SSam Ravnborg
27063ef0e1f8SAndres Salomonconfig OLPC
27073ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
270854008979SThomas Gleixner	depends on !X86_PAE
27093c554946SAndres Salomon	select GPIOLIB
2710dc3119e7SThomas Gleixner	select OF
271145bb1674SDaniel Drake	select OF_PROMTREE
2712b4e51854SGrant Likely	select IRQ_DOMAIN
27138f9ca475SIngo Molnar	---help---
27143ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27153ef0e1f8SAndres Salomon	  XO hardware.
27163ef0e1f8SAndres Salomon
2717a3128588SDaniel Drakeconfig OLPC_XO1_PM
2718a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
271997c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2720a3128588SDaniel Drake	select MFD_CORE
2721bf1ebf00SDaniel Drake	---help---
272297c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2723bf1ebf00SDaniel Drake
2724cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2725cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2726cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2727cfee9597SDaniel Drake	---help---
2728cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2729cfee9597SDaniel Drake	  programmable wakeup source.
2730cfee9597SDaniel Drake
27317feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27327feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
2733d8d01a63SDaniel Drake	depends on OLPC && OLPC_XO1_PM
2734ed8e47feSRandy Dunlap	depends on INPUT=y
2735d8d01a63SDaniel Drake	select POWER_SUPPLY
27367feda8e9SDaniel Drake	select GPIO_CS5535
27377feda8e9SDaniel Drake	select MFD_CORE
27387feda8e9SDaniel Drake	---help---
27397feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27407bc74b3dSDaniel Drake	   - EC-driven system wakeups
27417feda8e9SDaniel Drake	   - Power button
27427bc74b3dSDaniel Drake	   - Ebook switch
27432cf2baeaSDaniel Drake	   - Lid switch
2744e1040ac6SDaniel Drake	   - AC adapter status updates
2745e1040ac6SDaniel Drake	   - Battery status updates
27467feda8e9SDaniel Drake
2747a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2748a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2749d8d01a63SDaniel Drake	depends on OLPC && ACPI
2750d8d01a63SDaniel Drake	select POWER_SUPPLY
2751a0f30f59SDaniel Drake	---help---
2752a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2753a0f30f59SDaniel Drake	   - EC-driven system wakeups
2754a0f30f59SDaniel Drake	   - AC adapter status updates
2755a0f30f59SDaniel Drake	   - Battery status updates
2756e279b6c1SSam Ravnborg
2757d4f3e350SEd Wildgooseconfig ALIX
2758d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2759d4f3e350SEd Wildgoose	select GPIOLIB
2760d4f3e350SEd Wildgoose	---help---
2761d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2762d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2763d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2764d4f3e350SEd Wildgoose	  get added here.
2765d4f3e350SEd Wildgoose
2766d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2767d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2768d4f3e350SEd Wildgoose
2769d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2770d4f3e350SEd Wildgoose
2771da4e3302SPhilip Prindevilleconfig NET5501
2772da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2773da4e3302SPhilip Prindeville	select GPIOLIB
2774da4e3302SPhilip Prindeville	---help---
2775da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2776da4e3302SPhilip Prindeville
27773197059aSPhilip A. Prindevilleconfig GEOS
27783197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27793197059aSPhilip A. Prindeville	select GPIOLIB
27803197059aSPhilip A. Prindeville	depends on DMI
27813197059aSPhilip A. Prindeville	---help---
27823197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27833197059aSPhilip A. Prindeville
27847d029125SVivien Didelotconfig TS5500
27857d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27867d029125SVivien Didelot	depends on MELAN
27877d029125SVivien Didelot	select CHECK_SIGNATURE
27887d029125SVivien Didelot	select NEW_LEDS
27897d029125SVivien Didelot	select LEDS_CLASS
27907d029125SVivien Didelot	---help---
27917d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27927d029125SVivien Didelot
2793e279b6c1SSam Ravnborgendif # X86_32
2794e279b6c1SSam Ravnborg
279523ac4ae8SAndreas Herrmannconfig AMD_NB
2796e279b6c1SSam Ravnborg	def_bool y
27970e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2798e279b6c1SSam Ravnborg
2799e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2800e279b6c1SSam Ravnborg
2801388b78adSAlexandre Bounineconfig RAPIDIO
2802fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2803388b78adSAlexandre Bounine	depends on PCI
2804388b78adSAlexandre Bounine	default n
2805388b78adSAlexandre Bounine	help
2806fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2807388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2808388b78adSAlexandre Bounine
2809388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2810388b78adSAlexandre Bounine
2811e3263ab3SDavid Herrmannconfig X86_SYSFB
2812e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2813e3263ab3SDavid Herrmann	help
2814e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2815e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2816e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2817e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2818e3263ab3SDavid Herrmann	  to x86.
2819e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2820e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2821e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2822e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2823e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2824e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2825e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2826e3263ab3SDavid Herrmann
2827e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2828e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2829e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2830e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2831e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2832e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2833e3263ab3SDavid Herrmann	  incompatible with simplefb.
2834e3263ab3SDavid Herrmann
2835e3263ab3SDavid Herrmann	  If unsure, say Y.
2836e3263ab3SDavid Herrmann
2837e279b6c1SSam Ravnborgendmenu
2838e279b6c1SSam Ravnborg
2839e279b6c1SSam Ravnborg
2840e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2841e279b6c1SSam Ravnborg
2842e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2843e279b6c1SSam Ravnborg
2844e279b6c1SSam Ravnborgconfig IA32_EMULATION
2845e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2846e279b6c1SSam Ravnborg	depends on X86_64
284739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2848d1603990SRandy Dunlap	select BINFMT_ELF
2849a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
285039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28518f9ca475SIngo Molnar	---help---
28525fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28535fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28545fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2855e279b6c1SSam Ravnborg
2856e279b6c1SSam Ravnborgconfig IA32_AOUT
2857e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28586b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28598f9ca475SIngo Molnar	---help---
2860e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2861e279b6c1SSam Ravnborg
28620bf62763SH. Peter Anvinconfig X86_X32
28636ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28649b54050bSBrian Gerst	depends on X86_64
28655fd92e65SH. J. Lu	---help---
28665fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28675fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28685fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28695fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28705fd92e65SH. J. Lu
28715fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28725fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28735fd92e65SH. J. Lu	  option set.
28745fd92e65SH. J. Lu
2875953fee1dSIngo Molnarconfig COMPAT_32
2876953fee1dSIngo Molnar	def_bool y
2877953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2878953fee1dSIngo Molnar	select HAVE_UID16
2879953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2880953fee1dSIngo Molnar
2881e279b6c1SSam Ravnborgconfig COMPAT
28823c2362e6SHarvey Harrison	def_bool y
28830bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2884e279b6c1SSam Ravnborg
28853120e25eSJan Beulichif COMPAT
2886e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28873120e25eSJan Beulich	def_bool y
2888e279b6c1SSam Ravnborg
2889e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28903c2362e6SHarvey Harrison	def_bool y
28913120e25eSJan Beulich	depends on SYSVIPC
28923120e25eSJan Beulichendif
2893ee009e4aSDavid Howells
2894e279b6c1SSam Ravnborgendmenu
2895e279b6c1SSam Ravnborg
2896e279b6c1SSam Ravnborg
2897e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2898e5beae16SKeith Packard	def_bool y
2899e5beae16SKeith Packard	depends on X86_32
2900e5beae16SKeith Packard
29014692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29024692d77fSAlessandro Rubini	bool
290383125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29044692d77fSAlessandro Rubini
2905f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2906f7219a53SAlessandro Rubini	bool
290783125a3aSAlessandro Rubini	depends on STA2X11
2908f7219a53SAlessandro Rubini
2909e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2910e585513bSKirill A. Shutemov	def_bool y
2911e585513bSKirill A. Shutemov
2912e279b6c1SSam Ravnborgsource "net/Kconfig"
2913e279b6c1SSam Ravnborg
2914e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2915e279b6c1SSam Ravnborg
2916e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2917e279b6c1SSam Ravnborg
2918e279b6c1SSam Ravnborgsource "fs/Kconfig"
2919e279b6c1SSam Ravnborg
2920e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2921e279b6c1SSam Ravnborg
2922e279b6c1SSam Ravnborgsource "security/Kconfig"
2923e279b6c1SSam Ravnborg
2924e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2925e279b6c1SSam Ravnborg
2926edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2927edf88417SAvi Kivity
2928e279b6c1SSam Ravnborgsource "lib/Kconfig"
2929