1daa93fabSSam Ravnborg# Select 32 or 64 bit 2daa93fabSSam Ravnborgconfig 64BIT 36840999bSSam Ravnborg bool "64-bit kernel" if ARCH = "x86" 4ffee0de4SDavid Woodhouse default ARCH != "i386" 58f9ca475SIngo Molnar ---help--- 6daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 7daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 8daa93fabSSam Ravnborg 9daa93fabSSam Ravnborgconfig X86_32 103120e25eSJan Beulich def_bool y 113120e25eSJan Beulich depends on !64BIT 12daa93fabSSam Ravnborg 13daa93fabSSam Ravnborgconfig X86_64 143120e25eSJan Beulich def_bool y 153120e25eSJan Beulich depends on 64BIT 161032c0baSSam Ravnborg 171032c0baSSam Ravnborg### Arch settings 188d5fffb9SSam Ravnborgconfig X86 193c2362e6SHarvey Harrison def_bool y 206471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 216e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 226471b825SIngo Molnar select ANON_INODES 236471b825SIngo Molnar select ARCH_CLOCKSOURCE_DATA 246471b825SIngo Molnar select ARCH_DISCARD_MEMBLOCK 256471b825SIngo Molnar select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 26446f24d1SStephen Boyd select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 2721266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 286471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 2972d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 30957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 315c9a8750SDmitry Vyukov select ARCH_HAS_KCOV if X86_64 3296601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 3367a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 346471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 35c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 366471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 376471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3877fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 395e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 406471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 413b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 42be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 436471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 446471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 456471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 466471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 476471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 4872b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 495aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 50da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 516471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 526471b825SIngo Molnar select ARCH_WANT_OPTIONAL_GPIOLIB 536471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 546471b825SIngo Molnar select CLKEVT_I8253 556471b825SIngo Molnar select CLKSRC_I8253 if X86_32 566471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 576471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 586471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 596471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 606471b825SIngo Molnar select DCACHE_WORD_ACCESS 6145471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 6245471cd9SLinus Torvalds select EDAC_SUPPORT 636471b825SIngo Molnar select GENERIC_CLOCKEVENTS 646471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 656471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 666471b825SIngo Molnar select GENERIC_CMOS_UPDATE 676471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 686471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 696471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 706471b825SIngo Molnar select GENERIC_IOMAP 716471b825SIngo Molnar select GENERIC_IRQ_PROBE 726471b825SIngo Molnar select GENERIC_IRQ_SHOW 736471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 746471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 756471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 766471b825SIngo Molnar select GENERIC_STRNLEN_USER 776471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 786471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 796471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 806471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 816471b825SIngo Molnar select HAVE_AOUT if X86_32 826471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 836471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 846471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 856471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 866471b825SIngo Molnar select HAVE_ARCH_KGDB 876471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 889e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 899e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 906471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 916471b825SIngo Molnar select HAVE_ARCH_SOFT_DIRTY if X86_64 926471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 936471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 946077776bSDaniel Borkmann select HAVE_EBPF_JIT if X86_64 956471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 966471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 976471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 986471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 99c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 1006471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1016471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1026471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 1036471b825SIngo Molnar select HAVE_DMA_API_DEBUG 1049c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 105677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10606aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10758340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1085f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 1096471b825SIngo Molnar select HAVE_FENTRY if X86_64 1106471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1116471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_FP_TEST 1126471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1136471b825SIngo Molnar select HAVE_FUNCTION_TRACER 114*6b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 1156471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1160067f129SK.Prasad select HAVE_HW_BREAKPOINT 1176471b825SIngo Molnar select HAVE_IDE 1186471b825SIngo Molnar select HAVE_IOREMAP_PROT 1196471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1206471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1216471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1226471b825SIngo Molnar select HAVE_KERNEL_GZIP 1236471b825SIngo Molnar select HAVE_KERNEL_LZ4 1246471b825SIngo Molnar select HAVE_KERNEL_LZMA 1256471b825SIngo Molnar select HAVE_KERNEL_LZO 1266471b825SIngo Molnar select HAVE_KERNEL_XZ 1276471b825SIngo Molnar select HAVE_KPROBES 1286471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1296471b825SIngo Molnar select HAVE_KRETPROBES 1306471b825SIngo Molnar select HAVE_KVM 1316471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1326471b825SIngo Molnar select HAVE_MEMBLOCK 1336471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1340102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 13542a0bb3fSPetr Mladek select HAVE_NMI 1366471b825SIngo Molnar select HAVE_OPROFILE 1376471b825SIngo Molnar select HAVE_OPTPROBES 1386471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1396471b825SIngo Molnar select HAVE_PERF_EVENTS 140c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 141c5e63197SJiri Olsa select HAVE_PERF_REGS 142c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1436471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1446471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1450c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1466471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1477c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 148c0185808SThomas Gleixner select IRQ_FORCED_THREADING 149786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1506471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1515b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1526471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1536471b825SIngo Molnar select PERF_EVENTS 1543195ef59SPrarit Bhargava select RTC_LIB 1556471b825SIngo Molnar select SPARSE_IRQ 15683fe27eaSPranith Kumar select SRCU 1576471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 1586471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1596471b825SIngo Molnar select VIRT_TO_BUS 1606471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1616471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 162d4883d5dSJosh Poimboeuf select HAVE_STACK_VALIDATION if X86_64 16363c17fb8SDave Hansen select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS 16466d37570SDave Hansen select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS 1657d8330a5SBalbir Singh 166ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1673120e25eSJan Beulich def_bool y 1683120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 169ba7e4d13SIngo Molnar 17051b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 17151b26adaSLinus Torvalds string 17251b26adaSLinus Torvalds default "elf32-i386" if X86_32 17351b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 17451b26adaSLinus Torvalds 17573531905SSam Ravnborgconfig ARCH_DEFCONFIG 176b9b39bfbSSam Ravnborg string 17773531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 17873531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 179b9b39bfbSSam Ravnborg 1808d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1813c2362e6SHarvey Harrison def_bool y 1828d5fffb9SSam Ravnborg 1838d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1843c2362e6SHarvey Harrison def_bool y 1858d5fffb9SSam Ravnborg 1868d5fffb9SSam Ravnborgconfig MMU 1873c2362e6SHarvey Harrison def_bool y 1888d5fffb9SSam Ravnborg 1899e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 1909e08f57dSDaniel Cashman default 28 if 64BIT 1919e08f57dSDaniel Cashman default 8 1929e08f57dSDaniel Cashman 1939e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 1949e08f57dSDaniel Cashman default 32 if 64BIT 1959e08f57dSDaniel Cashman default 16 1969e08f57dSDaniel Cashman 1979e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 1989e08f57dSDaniel Cashman default 8 1999e08f57dSDaniel Cashman 2009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 2019e08f57dSDaniel Cashman default 16 2029e08f57dSDaniel Cashman 2038d5fffb9SSam Ravnborgconfig SBUS 2048d5fffb9SSam Ravnborg bool 2058d5fffb9SSam Ravnborg 2063bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 2073120e25eSJan Beulich def_bool y 208a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 2093bc4e459SFUJITA Tomonori 21018e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 2114a14d84eSAndrew Morton def_bool y 21218e98307SFUJITA Tomonori 2138d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 2143120e25eSJan Beulich def_bool y 2153120e25eSJan Beulich depends on ISA_DMA_API 2168d5fffb9SSam Ravnborg 2178d5fffb9SSam Ravnborgconfig GENERIC_BUG 2183c2362e6SHarvey Harrison def_bool y 2198d5fffb9SSam Ravnborg depends on BUG 220b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 221b93a531eSJan Beulich 222b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 223b93a531eSJan Beulich bool 2248d5fffb9SSam Ravnborg 2258d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2263c2362e6SHarvey Harrison def_bool y 2278d5fffb9SSam Ravnborg 2288d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2293120e25eSJan Beulich def_bool y 2303120e25eSJan Beulich depends on ISA_DMA_API 2318d5fffb9SSam Ravnborg 2321032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2333120e25eSJan Beulich def_bool y 2341032c0baSSam Ravnborg 2351032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2361032c0baSSam Ravnborg def_bool y 2371032c0baSSam Ravnborg 2389a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2399a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2408d5fffb9SSam Ravnborg 2411b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2421b27d05bSPekka Enberg def_bool y 2431b27d05bSPekka Enberg 244dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 24589c9c4c5SBrian Gerst def_bool y 246b32ef636Stravis@sgi.com 24708fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 24808fc4580STejun Heo def_bool y 24908fc4580STejun Heo 25008fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 25111124411STejun Heo def_bool y 25211124411STejun Heo 253801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 254801e4062SJohannes Berg def_bool y 255801e4062SJohannes Berg 256f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 257f4cb5700SJohannes Berg def_bool y 258f4cb5700SJohannes Berg 259cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 260cfe28c5dSSteve Capper def_bool y 261cfe28c5dSSteve Capper 26253313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 26353313b2cSSteve Capper def_bool y 26453313b2cSSteve Capper 2658d5fffb9SSam Ravnborgconfig ZONE_DMA32 266e0fd24a3SJan Beulich def_bool y if X86_64 2678d5fffb9SSam Ravnborg 2688d5fffb9SSam Ravnborgconfig AUDIT_ARCH 269e0fd24a3SJan Beulich def_bool y if X86_64 2708d5fffb9SSam Ravnborg 271765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 272765c68bdSIngo Molnar def_bool y 273765c68bdSIngo Molnar 2746a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2756a11f75bSAkinobu Mita def_bool y 2766a11f75bSAkinobu Mita 277d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 278d6f2d75aSAndrey Ryabinin hex 279d6f2d75aSAndrey Ryabinin depends on KASAN 280d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 281d6f2d75aSAndrey Ryabinin 28269575d38SShane Wangconfig HAVE_INTEL_TXT 28369575d38SShane Wang def_bool y 2846ea30386SKees Cook depends on INTEL_IOMMU && ACPI 28569575d38SShane Wang 2866b0c3d44SSam Ravnborgconfig X86_32_SMP 2876b0c3d44SSam Ravnborg def_bool y 2886b0c3d44SSam Ravnborg depends on X86_32 && SMP 2896b0c3d44SSam Ravnborg 2906b0c3d44SSam Ravnborgconfig X86_64_SMP 2916b0c3d44SSam Ravnborg def_bool y 2926b0c3d44SSam Ravnborg depends on X86_64 && SMP 2936b0c3d44SSam Ravnborg 294ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 295ccbeed3aSTejun Heo def_bool y 29660a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 297ccbeed3aSTejun Heo 298d61931d8SBorislav Petkovconfig ARCH_HWEIGHT_CFLAGS 299d61931d8SBorislav Petkov string 300d61931d8SBorislav Petkov default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 301d61931d8SBorislav Petkov default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 302d61931d8SBorislav Petkov 3032b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3042b144498SSrikar Dronamraju def_bool y 3052b144498SSrikar Dronamraju 306d20642f0SRob Herringconfig FIX_EARLYCON_MEM 307d20642f0SRob Herring def_bool y 308d20642f0SRob Herring 3099ccaf77cSKees Cookconfig DEBUG_RODATA 3109ccaf77cSKees Cook def_bool y 3119ccaf77cSKees Cook 31298233368SKirill A. Shutemovconfig PGTABLE_LEVELS 31398233368SKirill A. Shutemov int 31498233368SKirill A. Shutemov default 4 if X86_64 31598233368SKirill A. Shutemov default 3 if X86_PAE 31698233368SKirill A. Shutemov default 2 31798233368SKirill A. Shutemov 318506f1d07SSam Ravnborgsource "init/Kconfig" 319dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3208d5fffb9SSam Ravnborg 321506f1d07SSam Ravnborgmenu "Processor type and features" 322506f1d07SSam Ravnborg 3235ee71535SRandy Dunlapconfig ZONE_DMA 3245ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3255ee71535SRandy Dunlap default y 3265ee71535SRandy Dunlap help 3275ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3285ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3295ee71535SRandy Dunlap Disable if no such devices will be used. 3305ee71535SRandy Dunlap 3315ee71535SRandy Dunlap If unsure, say Y. 3325ee71535SRandy Dunlap 333506f1d07SSam Ravnborgconfig SMP 334506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 335506f1d07SSam Ravnborg ---help--- 336506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3374a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3384a474157SRobert Graffham than one CPU, say Y. 339506f1d07SSam Ravnborg 3404a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 341506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 342506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3434a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 344506f1d07SSam Ravnborg will run faster if you say N here. 345506f1d07SSam Ravnborg 346506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 347506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 348506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 349506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 350506f1d07SSam Ravnborg 351506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 352506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 353506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 354506f1d07SSam Ravnborg 355395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 356506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 357506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 358506f1d07SSam Ravnborg 359506f1d07SSam Ravnborg If you don't know what to do here, say N. 360506f1d07SSam Ravnborg 3619def39beSJosh Triplettconfig X86_FEATURE_NAMES 3629def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3639def39beSJosh Triplett default y 3649def39beSJosh Triplett ---help--- 3659def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3669def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3679def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3689def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3699def39beSJosh Triplett 3709def39beSJosh Triplett If in doubt, say Y. 3719def39beSJosh Triplett 3726e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS 3736e1315feSBorislav Petkov bool "Fast CPU feature tests" if EMBEDDED 3746e1315feSBorislav Petkov default y 3756e1315feSBorislav Petkov ---help--- 3766e1315feSBorislav Petkov Some fast-paths in the kernel depend on the capabilities of the CPU. 3776e1315feSBorislav Petkov Say Y here for the kernel to patch in the appropriate code at runtime 3786e1315feSBorislav Petkov based on the capabilities of the CPU. The infrastructure for patching 3796e1315feSBorislav Petkov code at runtime takes up some additional space; space-constrained 3806e1315feSBorislav Petkov embedded systems may wish to say N here to produce smaller, slightly 3816e1315feSBorislav Petkov slower code. 3826e1315feSBorislav Petkov 38306cd9a7dSYinghai Luconfig X86_X2APIC 38406cd9a7dSYinghai Lu bool "Support x2apic" 38519e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 38606cd9a7dSYinghai Lu ---help--- 38706cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 38806cd9a7dSYinghai Lu 38906cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 39006cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 39106cd9a7dSYinghai Lu 39206cd9a7dSYinghai Lu If you don't know what to do here, say N. 39306cd9a7dSYinghai Lu 3946695c85bSYinghai Luconfig X86_MPPARSE 3956e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3967a527688SJan Beulich default y 3975ab74722SIngo Molnar depends on X86_LOCAL_APIC 3988f9ca475SIngo Molnar ---help--- 3996695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4006695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4016695c85bSYinghai Lu 40226f7ef14SYinghai Luconfig X86_BIGSMP 40326f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 40426f7ef14SYinghai Lu depends on X86_32 && SMP 4058f9ca475SIngo Molnar ---help--- 40626f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 407506f1d07SSam Ravnborg 408ddd70cf9SJun Nakajimaconfig GOLDFISH 409ddd70cf9SJun Nakajima def_bool y 410ddd70cf9SJun Nakajima depends on X86_GOLDFISH 411ddd70cf9SJun Nakajima 4128425091fSRavikiran G Thirumalaiif X86_32 413c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 414c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 415c5c606d9SRavikiran G Thirumalai default y 4168f9ca475SIngo Molnar ---help--- 41706ac8346SIngo Molnar If you disable this option then the kernel will only support 41806ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 41906ac8346SIngo Molnar systems out there.) 42006ac8346SIngo Molnar 4218425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4228425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 423cb7b8023SBen Hutchings Goldfish (Android emulator) 4248425091fSRavikiran G Thirumalai AMD Elan 4258425091fSRavikiran G Thirumalai RDC R-321x SoC 4268425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 42783125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 4283f4110a4SThomas Gleixner Moorestown MID devices 42906ac8346SIngo Molnar 43006ac8346SIngo Molnar If you have one of these systems, or if you want to build a 43106ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4328425091fSRavikiran G Thirumalaiendif 43306ac8346SIngo Molnar 4348425091fSRavikiran G Thirumalaiif X86_64 4358425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4368425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4378425091fSRavikiran G Thirumalai default y 4388425091fSRavikiran G Thirumalai ---help--- 4398425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4408425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4418425091fSRavikiran G Thirumalai systems out there.) 4428425091fSRavikiran G Thirumalai 4438425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4448425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 44544b111b5SSteffen Persvold Numascale NumaChip 4468425091fSRavikiran G Thirumalai ScaleMP vSMP 4478425091fSRavikiran G Thirumalai SGI Ultraviolet 4488425091fSRavikiran G Thirumalai 4498425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4508425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4518425091fSRavikiran G Thirumalaiendif 452c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 453c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 45444b111b5SSteffen Persvoldconfig X86_NUMACHIP 45544b111b5SSteffen Persvold bool "Numascale NumaChip" 45644b111b5SSteffen Persvold depends on X86_64 45744b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 45844b111b5SSteffen Persvold depends on NUMA 45944b111b5SSteffen Persvold depends on SMP 46044b111b5SSteffen Persvold depends on X86_X2APIC 461f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 46244b111b5SSteffen Persvold ---help--- 46344b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 46444b111b5SSteffen Persvold enable more than ~168 cores. 46544b111b5SSteffen Persvold If you don't have one of these, you should say N here. 46603b48632SNick Piggin 4676a48565eSIngo Molnarconfig X86_VSMP 468c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4696276a074SBorislav Petkov select HYPERVISOR_GUEST 4706a48565eSIngo Molnar select PARAVIRT 4716a48565eSIngo Molnar depends on X86_64 && PCI 472c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 473ead91d4bSShai Fultheim depends on SMP 4748f9ca475SIngo Molnar ---help--- 4756a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4766a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4776a48565eSIngo Molnar if you have one of these machines. 4786a48565eSIngo Molnar 479c5c606d9SRavikiran G Thirumalaiconfig X86_UV 480c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 481c5c606d9SRavikiran G Thirumalai depends on X86_64 482c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 48354c28d29SJack Steiner depends on NUMA 4841ecb4ae5SAndrew Morton depends on EFI 4859d6c26e7SSuresh Siddha depends on X86_X2APIC 4861222e564SIngo Molnar depends on PCI 487c5c606d9SRavikiran G Thirumalai ---help--- 488c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 489c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 490c5c606d9SRavikiran G Thirumalai 491c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 492c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 493506f1d07SSam Ravnborg 494ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 495ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 496cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 497ddd70cf9SJun Nakajima ---help--- 498ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 499ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 500ddd70cf9SJun Nakajima Goldfish emulator say N here. 501ddd70cf9SJun Nakajima 502c751e17bSThomas Gleixnerconfig X86_INTEL_CE 503c751e17bSThomas Gleixner bool "CE4100 TV platform" 504c751e17bSThomas Gleixner depends on PCI 505c751e17bSThomas Gleixner depends on PCI_GODIRECT 5066084a6e2SJiang Liu depends on X86_IO_APIC 507c751e17bSThomas Gleixner depends on X86_32 508c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 50937bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 510da6b737bSSebastian Andrzej Siewior select OF 511da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 512c751e17bSThomas Gleixner ---help--- 513c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 514c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 515c751e17bSThomas Gleixner boxes and media devices. 516c751e17bSThomas Gleixner 5174cb9b00fSDavid Cohenconfig X86_INTEL_MID 51843605ef1SAlan Cox bool "Intel MID platform support" 51943605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 520edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 5211ea7c673SAlan Cox depends on PCI 5223fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 5231ea7c673SAlan Cox depends on X86_IO_APIC 5247c9c3a1eSAlan Cox select SFI 5254cb9b00fSDavid Cohen select I2C 5267c9c3a1eSAlan Cox select DW_APB_TIMER 5271ea7c673SAlan Cox select APB_TIMER 5281ea7c673SAlan Cox select INTEL_SCU_IPC 52915a713dfSMika Westerberg select MFD_INTEL_MSIC 5301ea7c673SAlan Cox ---help--- 5314cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5324cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5334cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5341ea7c673SAlan Cox 5354cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5364cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 53743605ef1SAlan Cox 5388bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5398bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5408bbc2a13SBryan O'Donoghue depends on X86_32 5418bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5428bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5438bbc2a13SBryan O'Donoghue depends on X86_TSC 5448bbc2a13SBryan O'Donoghue depends on PCI 5458bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5468bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5478bbc2a13SBryan O'Donoghue select IOSF_MBI 5488bbc2a13SBryan O'Donoghue select INTEL_IMR 5499ab6eb51SAndy Shevchenko select COMMON_CLK 5508bbc2a13SBryan O'Donoghue ---help--- 5518bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5528bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5538bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5548bbc2a13SBryan O'Donoghue 5553d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5563d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 557eebb3e8dSAndy Shevchenko depends on X86 && ACPI 5583d48aab1SMika Westerberg select COMMON_CLK 5590f531431SMathias Nyman select PINCTRL 560eebb3e8dSAndy Shevchenko select IOSF_MBI 5613d48aab1SMika Westerberg ---help--- 5623d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5633d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5640f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5650f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5663d48aab1SMika Westerberg 56792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 56892082a88SKen Xue bool "AMD ACPI2Platform devices support" 56992082a88SKen Xue depends on ACPI 57092082a88SKen Xue select COMMON_CLK 57192082a88SKen Xue select PINCTRL 57292082a88SKen Xue ---help--- 57392082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 57492082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 57592082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 57692082a88SKen Xue implemented under PINCTRL subsystem. 57792082a88SKen Xue 578ced3ce76SDavid E. Boxconfig IOSF_MBI 579ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 580ced3ce76SDavid E. Box depends on PCI 581ced3ce76SDavid E. Box ---help--- 582ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 583ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 584ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 585ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 586ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 587ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 588ced3ce76SDavid E. Box This list is not meant to be exclusive. 589ced3ce76SDavid E. Box - BayTrail 590ced3ce76SDavid E. Box - Braswell 591ced3ce76SDavid E. Box - Quark 592ced3ce76SDavid E. Box 593ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 594ced3ce76SDavid E. Box 595ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 596ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 597ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 598ed2226bdSDavid E. Box ---help--- 599ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 600ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 601ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 602ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 603ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 604ed2226bdSDavid E. Box device they want to access. 605ed2226bdSDavid E. Box 606ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 607ed2226bdSDavid E. Box 608c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 609c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 610506f1d07SSam Ravnborg depends on X86_32 611c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 612c5c606d9SRavikiran G Thirumalai select M486 613c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 614c5c606d9SRavikiran G Thirumalai ---help--- 615c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 616c5c606d9SRavikiran G Thirumalai as R-8610-(G). 617c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 618c5c606d9SRavikiran G Thirumalai 619e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 6209c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 6219c398017SIngo Molnar depends on X86_32 && SMP 622c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 6238f9ca475SIngo Molnar ---help--- 624b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 625b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 626b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 627b5660ba7SH. Peter Anvin one and will fallback to default. 628d49c4288SYinghai Lu 629c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 630d49c4288SYinghai Lu 631d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6326fc108a0SJan Beulich def_bool y 633d949f36fSLinus Torvalds # MCE code calls memory_failure(): 634d949f36fSLinus Torvalds depends on X86_MCE 635d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 636d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 637d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 638d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 639d949f36fSLinus Torvalds 64083125a3aSAlessandro Rubiniconfig STA2X11 64183125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 64283125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 64383125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 64483125a3aSAlessandro Rubini select X86_DMA_REMAP 64583125a3aSAlessandro Rubini select SWIOTLB 64683125a3aSAlessandro Rubini select MFD_STA2X11 64783125a3aSAlessandro Rubini select ARCH_REQUIRE_GPIOLIB 64883125a3aSAlessandro Rubini default n 64983125a3aSAlessandro Rubini ---help--- 65083125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 65183125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 65283125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 65383125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 65483125a3aSAlessandro Rubini standard PC machines. 65583125a3aSAlessandro Rubini 65682148d1dSShérabconfig X86_32_IRIS 65782148d1dSShérab tristate "Eurobraille/Iris poweroff module" 65882148d1dSShérab depends on X86_32 65982148d1dSShérab ---help--- 66082148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 66182148d1dSShérab to shut themselves down properly. A special I/O sequence is 66282148d1dSShérab needed to do so, which is what this module does at 66382148d1dSShérab kernel shutdown. 66482148d1dSShérab 66582148d1dSShérab This is only for Iris machines from EuroBraille. 66682148d1dSShérab 66782148d1dSShérab If unused, say N. 66882148d1dSShérab 669ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6703c2362e6SHarvey Harrison def_bool y 6713c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 672a87d0914SKen Chen depends on X86 6738f9ca475SIngo Molnar ---help--- 674506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 675506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 676506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 677506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 678506f1d07SSam Ravnborg 679506f1d07SSam Ravnborg If in doubt, say "Y". 680506f1d07SSam Ravnborg 6816276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6826276a074SBorislav Petkov bool "Linux guest support" 6838f9ca475SIngo Molnar ---help--- 6846276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6856276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6866276a074SBorislav Petkov setup. 687506f1d07SSam Ravnborg 6886276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6896276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 690506f1d07SSam Ravnborg 6916276a074SBorislav Petkovif HYPERVISOR_GUEST 692506f1d07SSam Ravnborg 693e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 694e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 6958f9ca475SIngo Molnar ---help--- 696e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 697e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 698e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 699e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 700e61bd94aSEduardo Pereira Habkost 7016276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7026276a074SBorislav Petkov bool "paravirt-ops debugging" 7036276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 7046276a074SBorislav Petkov ---help--- 7056276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7066276a074SBorislav Petkov a paravirt_op is missing when it is called. 7076276a074SBorislav Petkov 708b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 709b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7106ea30386SKees Cook depends on PARAVIRT && SMP 71162c7a1e9SIngo Molnar select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 712b4ecc126SJeremy Fitzhardinge ---help--- 713b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 714b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 715b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 716b4ecc126SJeremy Fitzhardinge 7174c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 7184c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 719b4ecc126SJeremy Fitzhardinge 7204c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 721b4ecc126SJeremy Fitzhardinge 72245e898b7SWaiman Longconfig QUEUED_LOCK_STAT 72345e898b7SWaiman Long bool "Paravirt queued spinlock statistics" 72445e898b7SWaiman Long depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS 72545e898b7SWaiman Long ---help--- 72645e898b7SWaiman Long Enable the collection of statistical data on the slowpath 72745e898b7SWaiman Long behavior of paravirtualized queued spinlocks and report 72845e898b7SWaiman Long them on debugfs. 72945e898b7SWaiman Long 7306276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 7316276a074SBorislav Petkov 7326276a074SBorislav Petkovconfig KVM_GUEST 7336276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7346276a074SBorislav Petkov depends on PARAVIRT 7356276a074SBorislav Petkov select PARAVIRT_CLOCK 7366276a074SBorislav Petkov default y 7376276a074SBorislav Petkov ---help--- 7386276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7396276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7406276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7416276a074SBorislav Petkov underlying device model, the host provides the guest with 7426276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7436276a074SBorislav Petkov 7441e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7451e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7461e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7471e20eb85SSrivatsa Vaddagiri default n 7481e20eb85SSrivatsa Vaddagiri ---help--- 7491e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7501e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7511e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7521e20eb85SSrivatsa Vaddagiri 7536276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7546276a074SBorislav Petkov 7556276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7566276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7576276a074SBorislav Petkov depends on PARAVIRT 7586276a074SBorislav Petkov default n 7596276a074SBorislav Petkov ---help--- 7606276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7616276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7626276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7636276a074SBorislav Petkov that, there can be a small performance impact. 7646276a074SBorislav Petkov 7656276a074SBorislav Petkov If in doubt, say N here. 7666276a074SBorislav Petkov 7677af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7687af192c9SGerd Hoffmann bool 7697af192c9SGerd Hoffmann 7706276a074SBorislav Petkovendif #HYPERVISOR_GUEST 77197349135SJeremy Fitzhardinge 77208677214SYinghai Luconfig NO_BOOTMEM 773774ea0bcSYinghai Lu def_bool y 77408677214SYinghai Lu 775506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 776506f1d07SSam Ravnborg 777506f1d07SSam Ravnborgconfig HPET_TIMER 7783c2362e6SHarvey Harrison def_bool X86_64 779506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7808f9ca475SIngo Molnar ---help--- 781506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 782506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 783506f1d07SSam Ravnborg present. 784506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 785506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 786506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 7874e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 7884e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 789506f1d07SSam Ravnborg 790506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 791506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 792506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 793506f1d07SSam Ravnborg 794506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 795506f1d07SSam Ravnborg 796506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 7973c2362e6SHarvey Harrison def_bool y 7989d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 799506f1d07SSam Ravnborg 800bb24c471SJacob Panconfig APB_TIMER 801933b9463SAlan Cox def_bool y if X86_INTEL_MID 802933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 80306c3df49SJamie Iles select DW_APB_TIMER 804a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 805bb24c471SJacob Pan help 806bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 807bb24c471SJacob Pan The APBT provides a stable time base on SMP 808bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 809bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 810bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 811bb24c471SJacob Pan 8126a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 813506f1d07SSam Ravnborg# The code disables itself when not needed. 8147ae9392cSThomas Petazzoniconfig DMI 8157ae9392cSThomas Petazzoni default y 816cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 8176a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 8188f9ca475SIngo Molnar ---help--- 8197ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 8207ae9392cSThomas Petazzoni here unless you have verified that your setup is not 8217ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 8227ae9392cSThomas Petazzoni BIOS code. 8237ae9392cSThomas Petazzoni 824506f1d07SSam Ravnborgconfig GART_IOMMU 82538901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 826506f1d07SSam Ravnborg select SWIOTLB 82723ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 8288f9ca475SIngo Molnar ---help--- 829ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 830ced3c42cSIngo Molnar GART based hardware IOMMUs. 831ced3c42cSIngo Molnar 832ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 833ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 834ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 835ced3c42cSIngo Molnar 836ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 837ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 838ced3c42cSIngo Molnar 839ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 840ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 841ced3c42cSIngo Molnar 32-bit limited device. 842ced3c42cSIngo Molnar 843ced3c42cSIngo Molnar If unsure, say Y. 844506f1d07SSam Ravnborg 845506f1d07SSam Ravnborgconfig CALGARY_IOMMU 846506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 847506f1d07SSam Ravnborg select SWIOTLB 8486ea30386SKees Cook depends on X86_64 && PCI 8498f9ca475SIngo Molnar ---help--- 850506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 851506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 852506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 853506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 854506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 855506f1d07SSam Ravnborg prevents them from going anywhere except their intended 856506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 857506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 858506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 859506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 860506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 861506f1d07SSam Ravnborg If unsure, say Y. 862506f1d07SSam Ravnborg 863506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8643c2362e6SHarvey Harrison def_bool y 8653c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 866506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8678f9ca475SIngo Molnar ---help--- 868506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 869506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 870506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 871506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 872506f1d07SSam Ravnborg If unsure, say Y. 873506f1d07SSam Ravnborg 874506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 875506f1d07SSam Ravnborgconfig SWIOTLB 876a1afd01cSJoerg Roedel def_bool y if X86_64 8778f9ca475SIngo Molnar ---help--- 878506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8794454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8804454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8814454d327SJoe Millenbach with more than 3 GB of memory. 8824454d327SJoe Millenbach If unsure, say Y. 883506f1d07SSam Ravnborg 884a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8853120e25eSJan Beulich def_bool y 8863120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 887d25e26b6SLinus Torvalds 8881184dc2fSMike Travisconfig MAXSMP 889ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8906ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 89136f5101aSMike Travis select CPUMASK_OFFSTACK 8928f9ca475SIngo Molnar ---help--- 893ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 8941184dc2fSMike Travis If unsure, say N. 895506f1d07SSam Ravnborg 896506f1d07SSam Ravnborgconfig NR_CPUS 89736f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 8982a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 899bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 900b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 90178637a97SMike Travis default "1" if !SMP 902b53b5edaSJosh Boyer default "8192" if MAXSMP 903b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 904c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 905c5c19941SKirill A. Shutemov default "64" if SMP 9068f9ca475SIngo Molnar ---help--- 907506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 908bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 909cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 910506f1d07SSam Ravnborg minimum value which makes sense is 2. 911506f1d07SSam Ravnborg 912506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 913506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 914506f1d07SSam Ravnborg 915506f1d07SSam Ravnborgconfig SCHED_SMT 916506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 917c8e56d20SBorislav Petkov depends on SMP 9188f9ca475SIngo Molnar ---help--- 919506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 920506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 921506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 922506f1d07SSam Ravnborg N here. 923506f1d07SSam Ravnborg 924506f1d07SSam Ravnborgconfig SCHED_MC 9253c2362e6SHarvey Harrison def_bool y 9263c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 927c8e56d20SBorislav Petkov depends on SMP 9288f9ca475SIngo Molnar ---help--- 929506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 930506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 931506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 932506f1d07SSam Ravnborg 933506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 934506f1d07SSam Ravnborg 93530b8b006SThomas Gleixnerconfig UP_LATE_INIT 93630b8b006SThomas Gleixner def_bool y 937ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 93830b8b006SThomas Gleixner 939506f1d07SSam Ravnborgconfig X86_UP_APIC 94050849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 94150849eefSJan Beulich default PCI_MSI 94238a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9438f9ca475SIngo Molnar ---help--- 944506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 945506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 946506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 947506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 948506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 949506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 950506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 951506f1d07SSam Ravnborg lockups. 952506f1d07SSam Ravnborg 953506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 954506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 955506f1d07SSam Ravnborg depends on X86_UP_APIC 9568f9ca475SIngo Molnar ---help--- 957506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 958506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 959506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 960506f1d07SSam Ravnborg 961506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 962506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 963506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 964506f1d07SSam Ravnborg 965506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9663c2362e6SHarvey Harrison def_bool y 9670dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 968b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 96952f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 970506f1d07SSam Ravnborg 971506f1d07SSam Ravnborgconfig X86_IO_APIC 972b1da1e71SJan Beulich def_bool y 973b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 974506f1d07SSam Ravnborg 97541b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 97641b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 97741b9eb26SStefan Assmann depends on X86_IO_APIC 9788f9ca475SIngo Molnar ---help--- 97941b9eb26SStefan Assmann This option enables a workaround that fixes a source of 98041b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 98141b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 98241b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 98341b9eb26SStefan Assmann 98441b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 98541b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 98641b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 98741b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 98841b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 98941b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 99041b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 99141b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 99241b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 99341b9eb26SStefan Assmann down (vital) interrupt lines. 99441b9eb26SStefan Assmann 99541b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 99641b9eb26SStefan Assmann increased on these systems. 99741b9eb26SStefan Assmann 998506f1d07SSam Ravnborgconfig X86_MCE 999bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1000648ed940SChen, Gong select GENERIC_ALLOCATOR 1001e57dbaf7SBorislav Petkov default y 1002506f1d07SSam Ravnborg ---help--- 1003bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1004bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1005506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1006bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 10074efc0670SAndi Kleen 1008506f1d07SSam Ravnborgconfig X86_MCE_INTEL 10093c2362e6SHarvey Harrison def_bool y 10103c2362e6SHarvey Harrison prompt "Intel MCE features" 1011c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10128f9ca475SIngo Molnar ---help--- 1013506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1014506f1d07SSam Ravnborg the thermal monitor. 1015506f1d07SSam Ravnborg 1016506f1d07SSam Ravnborgconfig X86_MCE_AMD 10173c2362e6SHarvey Harrison def_bool y 10183c2362e6SHarvey Harrison prompt "AMD MCE features" 1019c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10208f9ca475SIngo Molnar ---help--- 1021506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1022506f1d07SSam Ravnborg the DRAM Error Threshold. 1023506f1d07SSam Ravnborg 10244efc0670SAndi Kleenconfig X86_ANCIENT_MCE 10256fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1026c31d9633SAndi Kleen depends on X86_32 && X86_MCE 10274efc0670SAndi Kleen ---help--- 10284efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 10295065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 10304efc0670SAndi Kleen line. 10314efc0670SAndi Kleen 1032b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1033b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10346fc108a0SJan Beulich def_bool y 1035b2762686SAndi Kleen 1036ea149b36SAndi Kleenconfig X86_MCE_INJECT 1037c1ebf835SAndi Kleen depends on X86_MCE 1038ea149b36SAndi Kleen tristate "Machine check injector support" 1039ea149b36SAndi Kleen ---help--- 1040ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1041ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1042ea149b36SAndi Kleen QA it is safe to say n. 1043ea149b36SAndi Kleen 10444efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10454efc0670SAndi Kleen def_bool y 10465bb38adcSAndi Kleen depends on X86_MCE_INTEL 10474efc0670SAndi Kleen 104807dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1049e633c65aSKan Liang 10505aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10511e642812SIngo Molnar bool "Legacy VM86 support" 10525aef51c3SAndy Lutomirski default n 1053506f1d07SSam Ravnborg depends on X86_32 10548f9ca475SIngo Molnar ---help--- 10555aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10565aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10575aef51c3SAndy Lutomirski 10585aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10595aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10605aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10615aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10625aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10631e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10641e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10651e642812SIngo Molnar mode might be faster than emulation and you might want to 10661e642812SIngo Molnar enable this option. 10675aef51c3SAndy Lutomirski 10681e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10691e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10701e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10711e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10725aef51c3SAndy Lutomirski 10731e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10741e642812SIngo Molnar and slows down exception handling a tiny bit. 10755aef51c3SAndy Lutomirski 10761e642812SIngo Molnar If unsure, say N here. 10775aef51c3SAndy Lutomirski 10785aef51c3SAndy Lutomirskiconfig VM86 10795aef51c3SAndy Lutomirski bool 10805aef51c3SAndy Lutomirski default X86_LEGACY_VM86 108134273f41SH. Peter Anvin 108234273f41SH. Peter Anvinconfig X86_16BIT 108334273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 108434273f41SH. Peter Anvin default y 1085a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 108634273f41SH. Peter Anvin ---help--- 108734273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 108834273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 108934273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 109034273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 109134273f41SH. Peter Anvin 109234273f41SH. Peter Anvinconfig X86_ESPFIX32 109334273f41SH. Peter Anvin def_bool y 109434273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1095506f1d07SSam Ravnborg 1096197725deSH. Peter Anvinconfig X86_ESPFIX64 1097197725deSH. Peter Anvin def_bool y 109834273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1099506f1d07SSam Ravnborg 11001ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 11011ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 11021ad83c85SAndy Lutomirski default y 11031ad83c85SAndy Lutomirski depends on X86_64 11041ad83c85SAndy Lutomirski ---help--- 11051ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 11061ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 11071ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 11081ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 11091ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 11101ad83c85SAndy Lutomirski 0xffffffffff600?00. 11111ad83c85SAndy Lutomirski 11121ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 11131ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 11141ad83c85SAndy Lutomirski 11151ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 11161ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 11171ad83c85SAndy Lutomirski 1118506f1d07SSam Ravnborgconfig TOSHIBA 1119506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1120506f1d07SSam Ravnborg depends on X86_32 1121506f1d07SSam Ravnborg ---help--- 1122506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1123506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1124506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1125506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1126506f1d07SSam Ravnborg 1127506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1128506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1129506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1130506f1d07SSam Ravnborg 1131506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1132506f1d07SSam Ravnborg Say N otherwise. 1133506f1d07SSam Ravnborg 1134506f1d07SSam Ravnborgconfig I8K 1135039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1136949a9d70SJean Delvare select HWMON 1137039ae585SPali Rohár select SENSORS_DELL_SMM 1138506f1d07SSam Ravnborg ---help--- 1139039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1140039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1141039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1142039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1143039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1144039ae585SPali Rohár needed userspace package i8kutils. 1145506f1d07SSam Ravnborg 1146039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1147039ae585SPali Rohár use userspace package i8kutils. 1148506f1d07SSam Ravnborg Say N otherwise. 1149506f1d07SSam Ravnborg 1150506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11519ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11529ba16087SJan Beulich depends on X86_32 1153506f1d07SSam Ravnborg ---help--- 1154506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1155506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1156506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1157506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1158506f1d07SSam Ravnborg system. 1159506f1d07SSam Ravnborg 1160506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11615e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1162506f1d07SSam Ravnborg 1163506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1164506f1d07SSam Ravnborg enable this option even if you don't need it. 1165506f1d07SSam Ravnborg Say N otherwise. 1166506f1d07SSam Ravnborg 1167506f1d07SSam Ravnborgconfig MICROCODE 11689a2bc335SBorislav Petkov bool "CPU microcode loading support" 11699a2bc335SBorislav Petkov default y 117080030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1171506f1d07SSam Ravnborg select FW_LOADER 1172506f1d07SSam Ravnborg ---help--- 1173506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 11745f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 11755f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 11765f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 11775f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 11785f9c01aaSBorislav Petkov the Linux kernel. 1179506f1d07SSam Ravnborg 11805f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 11815f9c01aaSBorislav Petkov in Documentation/x86/early-microcode.txt. For that you need to enable 11825f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 11835f9c01aaSBorislav Petkov initrd for microcode blobs. 1184506f1d07SSam Ravnborg 11855f9c01aaSBorislav Petkov In addition, you can build-in the microcode into the kernel. For that you 11865f9c01aaSBorislav Petkov need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 11875f9c01aaSBorislav Petkov to the CONFIG_EXTRA_FIRMWARE config option. 1188506f1d07SSam Ravnborg 11898d86f390SPeter Orubaconfig MICROCODE_INTEL 1190e43f6e67SBorislav Petkov bool "Intel microcode loading support" 11918d86f390SPeter Oruba depends on MICROCODE 11928d86f390SPeter Oruba default MICROCODE 11938d86f390SPeter Oruba select FW_LOADER 11948f9ca475SIngo Molnar ---help--- 11958d86f390SPeter Oruba This options enables microcode patch loading support for Intel 11968d86f390SPeter Oruba processors. 11978d86f390SPeter Oruba 1198b8989db9SAlan For the current Intel microcode data package go to 1199b8989db9SAlan <https://downloadcenter.intel.com> and search for 1200b8989db9SAlan 'Linux Processor Microcode Data File'. 12018d86f390SPeter Oruba 120280cc9f10SPeter Orubaconfig MICROCODE_AMD 1203e43f6e67SBorislav Petkov bool "AMD microcode loading support" 120480cc9f10SPeter Oruba depends on MICROCODE 120580cc9f10SPeter Oruba select FW_LOADER 12068f9ca475SIngo Molnar ---help--- 120780cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 120880cc9f10SPeter Oruba processors will be enabled. 120980cc9f10SPeter Oruba 1210506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 12113c2362e6SHarvey Harrison def_bool y 1212506f1d07SSam Ravnborg depends on MICROCODE 1213506f1d07SSam Ravnborg 1214506f1d07SSam Ravnborgconfig X86_MSR 1215506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 12168f9ca475SIngo Molnar ---help--- 1217506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1218506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1219506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1220506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1221506f1d07SSam Ravnborg systems. 1222506f1d07SSam Ravnborg 1223506f1d07SSam Ravnborgconfig X86_CPUID 1224506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 12258f9ca475SIngo Molnar ---help--- 1226506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1227506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1228506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1229506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1230506f1d07SSam Ravnborg 1231506f1d07SSam Ravnborgchoice 1232506f1d07SSam Ravnborg prompt "High Memory Support" 12336fc108a0SJan Beulich default HIGHMEM4G 1234506f1d07SSam Ravnborg depends on X86_32 1235506f1d07SSam Ravnborg 1236506f1d07SSam Ravnborgconfig NOHIGHMEM 1237506f1d07SSam Ravnborg bool "off" 1238506f1d07SSam Ravnborg ---help--- 1239506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1240506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1241506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1242506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1243506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1244506f1d07SSam Ravnborg "high memory". 1245506f1d07SSam Ravnborg 1246506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1247506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1248506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1249506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1250506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1251506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1252506f1d07SSam Ravnborg possible. 1253506f1d07SSam Ravnborg 1254506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1255506f1d07SSam Ravnborg answer "4GB" here. 1256506f1d07SSam Ravnborg 1257506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1258506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1259506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1260506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1261506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1262506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1263506f1d07SSam Ravnborg 1264506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1265506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1266506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1267506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1268506f1d07SSam Ravnborg kernel at boot time.) 1269506f1d07SSam Ravnborg 1270506f1d07SSam Ravnborg If unsure, say "off". 1271506f1d07SSam Ravnborg 1272506f1d07SSam Ravnborgconfig HIGHMEM4G 1273506f1d07SSam Ravnborg bool "4GB" 12748f9ca475SIngo Molnar ---help--- 1275506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1276506f1d07SSam Ravnborg gigabytes of physical RAM. 1277506f1d07SSam Ravnborg 1278506f1d07SSam Ravnborgconfig HIGHMEM64G 1279506f1d07SSam Ravnborg bool "64GB" 1280eb068e78SH. Peter Anvin depends on !M486 1281506f1d07SSam Ravnborg select X86_PAE 12828f9ca475SIngo Molnar ---help--- 1283506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1284506f1d07SSam Ravnborg gigabytes of physical RAM. 1285506f1d07SSam Ravnborg 1286506f1d07SSam Ravnborgendchoice 1287506f1d07SSam Ravnborg 1288506f1d07SSam Ravnborgchoice 12896a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1290506f1d07SSam Ravnborg default VMSPLIT_3G 1291506f1d07SSam Ravnborg depends on X86_32 12928f9ca475SIngo Molnar ---help--- 1293506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1294506f1d07SSam Ravnborg 1295506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1296506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1297506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1298506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1299506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1300506f1d07SSam Ravnborg available to user programs, making the address space there 1301506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1302506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1303506f1d07SSam Ravnborg kernel modules. 1304506f1d07SSam Ravnborg 1305506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1306506f1d07SSam Ravnborg option alone! 1307506f1d07SSam Ravnborg 1308506f1d07SSam Ravnborg config VMSPLIT_3G 1309506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1310506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1311506f1d07SSam Ravnborg depends on !X86_PAE 1312506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1313506f1d07SSam Ravnborg config VMSPLIT_2G 1314506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1315506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1316506f1d07SSam Ravnborg depends on !X86_PAE 1317506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1318506f1d07SSam Ravnborg config VMSPLIT_1G 1319506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1320506f1d07SSam Ravnborgendchoice 1321506f1d07SSam Ravnborg 1322506f1d07SSam Ravnborgconfig PAGE_OFFSET 1323506f1d07SSam Ravnborg hex 1324506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1325506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1326506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1327506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1328506f1d07SSam Ravnborg default 0xC0000000 1329506f1d07SSam Ravnborg depends on X86_32 1330506f1d07SSam Ravnborg 1331506f1d07SSam Ravnborgconfig HIGHMEM 13323c2362e6SHarvey Harrison def_bool y 1333506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1334506f1d07SSam Ravnborg 1335506f1d07SSam Ravnborgconfig X86_PAE 13369ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1337506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13389d99c712SChristian Melki select SWIOTLB 13398f9ca475SIngo Molnar ---help--- 1340506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1341506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1342506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1343506f1d07SSam Ravnborg consumes more pagetable space per process. 1344506f1d07SSam Ravnborg 1345600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13463120e25eSJan Beulich def_bool y 13473120e25eSJan Beulich depends on X86_64 || X86_PAE 1348600715dcSJeremy Fitzhardinge 134966f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13503120e25eSJan Beulich def_bool y 13513120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 135266f2b061SFUJITA Tomonori 135310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1354e5008abeSLuis R. Rodriguez def_bool y 1355e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13568f9ca475SIngo Molnar ---help--- 135710971ab2SIngo Molnar Certain kernel features effectively disable kernel 135810971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 135910971ab2SIngo Molnar supports them), so don't confuse the user by printing 136010971ab2SIngo Molnar that we have them enabled. 13619e899816SNick Piggin 1362506f1d07SSam Ravnborg# Common NUMA Features 1363506f1d07SSam Ravnborgconfig NUMA 1364fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1365506f1d07SSam Ravnborg depends on SMP 1366b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1367b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13688f9ca475SIngo Molnar ---help--- 1369506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1370fd51b2d7SKOSAKI Motohiro 1371506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1372506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1373506f1d07SSam Ravnborg NUMA awareness to the kernel. 1374506f1d07SSam Ravnborg 1375c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1376fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1377fd51b2d7SKOSAKI Motohiro 1378b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13797cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1380fd51b2d7SKOSAKI Motohiro 1381fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1382506f1d07SSam Ravnborg 1383eec1d4faSHans Rosenfeldconfig AMD_NUMA 13843c2362e6SHarvey Harrison def_bool y 13853c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13865da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13878f9ca475SIngo Molnar ---help--- 1388eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1389eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1390eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1391eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1392eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1393506f1d07SSam Ravnborg 1394506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 13953c2362e6SHarvey Harrison def_bool y 13963c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1397506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1398506f1d07SSam Ravnborg select ACPI_NUMA 13998f9ca475SIngo Molnar ---help--- 1400506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1401506f1d07SSam Ravnborg 14026ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 14036ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 14046ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 14056ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 14066ec6e0d9SSuresh Siddha# for details. 14076ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 14086ec6e0d9SSuresh Siddha def_bool y 14096ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 14106ec6e0d9SSuresh Siddha 1411506f1d07SSam Ravnborgconfig NUMA_EMU 1412506f1d07SSam Ravnborg bool "NUMA emulation" 14131b7e03efSTejun Heo depends on NUMA 14148f9ca475SIngo Molnar ---help--- 1415506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1416506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1417506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1418506f1d07SSam Ravnborg 1419506f1d07SSam Ravnborgconfig NODES_SHIFT 1420d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 142151591e31SDavid Rientjes range 1 10 142251591e31SDavid Rientjes default "10" if MAXSMP 1423506f1d07SSam Ravnborg default "6" if X86_64 1424506f1d07SSam Ravnborg default "3" 1425506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 14268f9ca475SIngo Molnar ---help--- 14271184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1428692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1429506f1d07SSam Ravnborg 1430506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 14313c2362e6SHarvey Harrison def_bool y 1432506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1433506f1d07SSam Ravnborg 1434506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14353c2362e6SHarvey Harrison def_bool y 1436506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1437506f1d07SSam Ravnborg 1438506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1439506f1d07SSam Ravnborg def_bool y 14403b16651fSTejun Heo depends on X86_32 && !NUMA 1441506f1d07SSam Ravnborg 1442506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1443506f1d07SSam Ravnborg def_bool y 1444b263295dSChristoph Lameter depends on NUMA && X86_32 1445506f1d07SSam Ravnborg 1446506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1447506f1d07SSam Ravnborg def_bool y 1448b263295dSChristoph Lameter depends on NUMA && X86_32 1449b263295dSChristoph Lameter 1450506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1451506f1d07SSam Ravnborg def_bool y 14526ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1453506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1454506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1455506f1d07SSam Ravnborg 14563b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14573b16651fSTejun Heo def_bool y 14583b16651fSTejun Heo depends on X86_64 14593b16651fSTejun Heo 1460506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1461506f1d07SSam Ravnborg def_bool y 1462b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1463506f1d07SSam Ravnborg 1464506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1465a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14663120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1467a0842b70SToshi Kani help 1468a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1469a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1470a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1471506f1d07SSam Ravnborg 14723b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14733b16651fSTejun Heo def_bool y 14743b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14753b16651fSTejun Heo 1476a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1477a29815a3SAvi Kivity hex 1478a29815a3SAvi Kivity default 0 if X86_32 1479a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1480a29815a3SAvi Kivity 1481506f1d07SSam Ravnborgsource "mm/Kconfig" 1482506f1d07SSam Ravnborg 14837a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14847a67832cSDan Williams bool 14857a67832cSDan Williams 1486ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 14877a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 14889f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14899f53f9faSDan Williams depends on BLK_DEV 14907a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 14919f53f9faSDan Williams select LIBNVDIMM 1492ec776ef6SChristoph Hellwig help 1493ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1494ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1495ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1496ec776ef6SChristoph Hellwig they can be used for persistent storage. 1497ec776ef6SChristoph Hellwig 1498ec776ef6SChristoph Hellwig Say Y if unsure. 1499ec776ef6SChristoph Hellwig 1500506f1d07SSam Ravnborgconfig HIGHPTE 1501506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 15026fc108a0SJan Beulich depends on HIGHMEM 15038f9ca475SIngo Molnar ---help--- 1504506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1505506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1506506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1507506f1d07SSam Ravnborg entries in high memory. 1508506f1d07SSam Ravnborg 15099f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 15109f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 15118f9ca475SIngo Molnar ---help--- 15129f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 15139f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 15149f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 15159f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 15169f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 15179f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 15189f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 15199f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 15209f077871SJeremy Fitzhardinge 15219f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 15229f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 15239f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 15249f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 15259f077871SJeremy Fitzhardinge 15269f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 15279f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 15289f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 15299f077871SJeremy Fitzhardinge memory. 15309f077871SJeremy Fitzhardinge 1531c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1532c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1533c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1534c885df50SJeremy Fitzhardinge default y 15358f9ca475SIngo Molnar ---help--- 1536c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1537c885df50SJeremy Fitzhardinge on or off. 1538c885df50SJeremy Fitzhardinge 15399ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1540d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1541d0cd7425SH. Peter Anvin default 64 1542d0cd7425SH. Peter Anvin range 4 640 15438f9ca475SIngo Molnar ---help--- 1544d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1545fc381519SIngo Molnar 1546d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1547d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1548fc381519SIngo Molnar 1549d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1550d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1551d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1552d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1553fc381519SIngo Molnar 1554d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1555d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1556d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1557d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1558d0cd7425SH. Peter Anvin entire low memory range. 1559d0cd7425SH. Peter Anvin 1560d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1561d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1562d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1563d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1564d0cd7425SH. Peter Anvin typical corruption patterns. 1565d0cd7425SH. Peter Anvin 1566d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1567fc381519SIngo Molnar 1568506f1d07SSam Ravnborgconfig MATH_EMULATION 1569506f1d07SSam Ravnborg bool 1570a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1571506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1572506f1d07SSam Ravnborg ---help--- 1573506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1574506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1575506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1576506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1577506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1578506f1d07SSam Ravnborg coprocessor or this emulation. 1579506f1d07SSam Ravnborg 1580506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1581506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1582506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1583506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1584506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1585506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1586506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1587506f1d07SSam Ravnborg intend to use this kernel on different machines. 1588506f1d07SSam Ravnborg 1589506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1590506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1591506f1d07SSam Ravnborg 1592506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1593506f1d07SSam Ravnborg kernel, it won't hurt. 1594506f1d07SSam Ravnborg 1595506f1d07SSam Ravnborgconfig MTRR 15966fc108a0SJan Beulich def_bool y 15976a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1598506f1d07SSam Ravnborg ---help--- 1599506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1600506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1601506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1602506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1603506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1604506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1605506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1606506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1607506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1608506f1d07SSam Ravnborg 1609506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1610506f1d07SSam Ravnborg control registers on other processors can be easily supported 1611506f1d07SSam Ravnborg as well: 1612506f1d07SSam Ravnborg 1613506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1614506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1615506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1616506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1617506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1618506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1619506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1620506f1d07SSam Ravnborg 1621506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1622506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1623506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1624506f1d07SSam Ravnborg 1625506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1626506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1627506f1d07SSam Ravnborg 16287225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1629506f1d07SSam Ravnborg 163095ffa243SYinghai Luconfig MTRR_SANITIZER 16312ffb3501SYinghai Lu def_bool y 163295ffa243SYinghai Lu prompt "MTRR cleanup support" 163395ffa243SYinghai Lu depends on MTRR 16348f9ca475SIngo Molnar ---help--- 1635aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1636aba3728cSThomas Gleixner add writeback entries. 163795ffa243SYinghai Lu 1638aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1639692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1640aba3728cSThomas Gleixner mtrr_chunk_size. 164195ffa243SYinghai Lu 16422ffb3501SYinghai Lu If unsure, say Y. 164395ffa243SYinghai Lu 164495ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1645f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1646f5098d62SYinghai Lu range 0 1 1647f5098d62SYinghai Lu default "0" 164895ffa243SYinghai Lu depends on MTRR_SANITIZER 16498f9ca475SIngo Molnar ---help--- 1650f5098d62SYinghai Lu Enable mtrr cleanup default value 165195ffa243SYinghai Lu 165212031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 165312031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 165412031a62SYinghai Lu range 0 7 165512031a62SYinghai Lu default "1" 165612031a62SYinghai Lu depends on MTRR_SANITIZER 16578f9ca475SIngo Molnar ---help--- 165812031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1659aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 166012031a62SYinghai Lu 16612e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16626fc108a0SJan Beulich def_bool y 16636a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16642a8a2719SIngo Molnar depends on MTRR 16658f9ca475SIngo Molnar ---help--- 16662e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1667042b78e4SVenki Pallipadi 16682e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16692e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16702e5d9c85Svenkatesh.pallipadi@intel.com 16712e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1672042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16732e5d9c85Svenkatesh.pallipadi@intel.com 16742e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16752e5d9c85Svenkatesh.pallipadi@intel.com 167646cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 167746cf98cdSVenkatesh Pallipadi def_bool y 167846cf98cdSVenkatesh Pallipadi depends on X86_PAT 167946cf98cdSVenkatesh Pallipadi 1680628c6246SH. Peter Anvinconfig ARCH_RANDOM 1681628c6246SH. Peter Anvin def_bool y 1682628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1683628c6246SH. Peter Anvin ---help--- 1684628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1685628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1686628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1687628c6246SH. Peter Anvin secure hardware random number generator. 1688628c6246SH. Peter Anvin 168951ae4a2dSH. Peter Anvinconfig X86_SMAP 169051ae4a2dSH. Peter Anvin def_bool y 169151ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 169251ae4a2dSH. Peter Anvin ---help--- 169351ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 169451ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 169551ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 169651ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 169751ae4a2dSH. Peter Anvin 169851ae4a2dSH. Peter Anvin If unsure, say Y. 169951ae4a2dSH. Peter Anvin 170072e9b5feSDave Hansenconfig X86_INTEL_MPX 170172e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 170272e9b5feSDave Hansen def_bool n 170372e9b5feSDave Hansen depends on CPU_SUP_INTEL 170472e9b5feSDave Hansen ---help--- 170572e9b5feSDave Hansen MPX provides hardware features that can be used in 170672e9b5feSDave Hansen conjunction with compiler-instrumented code to check 170772e9b5feSDave Hansen memory references. It is designed to detect buffer 170872e9b5feSDave Hansen overflow or underflow bugs. 170972e9b5feSDave Hansen 171072e9b5feSDave Hansen This option enables running applications which are 171172e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 171272e9b5feSDave Hansen itself inside the kernel or to protect the kernel 171372e9b5feSDave Hansen against bad memory references. 171472e9b5feSDave Hansen 171572e9b5feSDave Hansen Enabling this option will make the kernel larger: 171672e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 171772e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 171872e9b5feSDave Hansen will increase the kernel memory overhead of each 171972e9b5feSDave Hansen process and adds some branches to paths used during 172072e9b5feSDave Hansen exec() and munmap(). 172172e9b5feSDave Hansen 172272e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 172372e9b5feSDave Hansen 172472e9b5feSDave Hansen If unsure, say N. 172572e9b5feSDave Hansen 172635e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 1727284244a9SDave Hansen prompt "Intel Memory Protection Keys" 172835e97790SDave Hansen def_bool y 1729284244a9SDave Hansen # Note: only available in 64-bit mode 173035e97790SDave Hansen depends on CPU_SUP_INTEL && X86_64 1731284244a9SDave Hansen ---help--- 1732284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1733284244a9SDave Hansen page-based protections, but without requiring modification of the 1734284244a9SDave Hansen page tables when an application changes protection domains. 1735284244a9SDave Hansen 1736284244a9SDave Hansen For details, see Documentation/x86/protection-keys.txt 1737284244a9SDave Hansen 1738284244a9SDave Hansen If unsure, say y. 173935e97790SDave Hansen 1740506f1d07SSam Ravnborgconfig EFI 17419ba16087SJan Beulich bool "EFI runtime service support" 17425b83683fSHuang, Ying depends on ACPI 1743f6ce5002SSergey Vlasov select UCS2_STRING 1744022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1745506f1d07SSam Ravnborg ---help--- 17468b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1747506f1d07SSam Ravnborg available (such as the EFI variable services). 1748506f1d07SSam Ravnborg 17498b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17508b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17518b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17528b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17538b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17548b2cb7a8SHuang, Ying platforms. 1755506f1d07SSam Ravnborg 1756291f3632SMatt Flemingconfig EFI_STUB 1757291f3632SMatt Fleming bool "EFI stub support" 1758b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17597b2a583aSMatt Fleming select RELOCATABLE 1760291f3632SMatt Fleming ---help--- 1761291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1762291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1763291f3632SMatt Fleming 17644172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17650c759662SMatt Fleming 17667d453eeeSMatt Flemingconfig EFI_MIXED 17677d453eeeSMatt Fleming bool "EFI mixed-mode support" 17687d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17697d453eeeSMatt Fleming ---help--- 17707d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17717d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17727d453eeeSMatt Fleming mode. 17737d453eeeSMatt Fleming 17747d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17757d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17767d453eeeSMatt Fleming the EFI handover protocol must be used. 17777d453eeeSMatt Fleming 17787d453eeeSMatt Fleming If unsure, say N. 17797d453eeeSMatt Fleming 1780506f1d07SSam Ravnborgconfig SECCOMP 17813c2362e6SHarvey Harrison def_bool y 17823c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17838f9ca475SIngo Molnar ---help--- 1784506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1785506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1786506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1787506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1788506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1789506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17909c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1791506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1792506f1d07SSam Ravnborg defined by each seccomp mode. 1793506f1d07SSam Ravnborg 1794506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1795506f1d07SSam Ravnborg 1796506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1797506f1d07SSam Ravnborg 1798506f1d07SSam Ravnborgconfig KEXEC 1799506f1d07SSam Ravnborg bool "kexec system call" 18002965faa5SDave Young select KEXEC_CORE 18018f9ca475SIngo Molnar ---help--- 1802506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1803506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1804506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1805506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1806506f1d07SSam Ravnborg 1807506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1808506f1d07SSam Ravnborg 1809506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1810506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1811bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1812bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1813bf220695SGeert Uytterhoeven made. 1814506f1d07SSam Ravnborg 181574ca317cSVivek Goyalconfig KEXEC_FILE 181674ca317cSVivek Goyal bool "kexec file based system call" 18172965faa5SDave Young select KEXEC_CORE 181874ca317cSVivek Goyal select BUILD_BIN2C 181974ca317cSVivek Goyal depends on X86_64 182074ca317cSVivek Goyal depends on CRYPTO=y 182174ca317cSVivek Goyal depends on CRYPTO_SHA256=y 182274ca317cSVivek Goyal ---help--- 182374ca317cSVivek Goyal This is new version of kexec system call. This system call is 182474ca317cSVivek Goyal file based and takes file descriptors as system call argument 182574ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 182674ca317cSVivek Goyal accepted by previous system call. 182774ca317cSVivek Goyal 18288e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 18298e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 183074ca317cSVivek Goyal depends on KEXEC_FILE 18318e7d8381SVivek Goyal ---help--- 18328e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1833d8eb8940SBorislav Petkov the kexec_file_load() syscall. 18348e7d8381SVivek Goyal 1835d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1836d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1837d8eb8940SBorislav Petkov loaded in order for this to work. 18388e7d8381SVivek Goyal 18398e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 18408e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 18418e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 18428e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 18438e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 18448e7d8381SVivek Goyal ---help--- 18458e7d8381SVivek Goyal Enable bzImage signature verification support. 18468e7d8381SVivek Goyal 1847506f1d07SSam Ravnborgconfig CRASH_DUMP 184804b69447SPavel Machek bool "kernel crash dumps" 1849506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18508f9ca475SIngo Molnar ---help--- 1851506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1852506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1853506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1854506f1d07SSam Ravnborg a specially reserved region and then later executed after 1855506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1856506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1857506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1858506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1859506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1860506f1d07SSam Ravnborg 18613ab83521SHuang Yingconfig KEXEC_JUMP 18626ea30386SKees Cook bool "kexec jump" 1863fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18648f9ca475SIngo Molnar ---help--- 186589081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 186689081d17SHuang Ying code in physical address mode via KEXEC 18673ab83521SHuang Ying 1868506f1d07SSam Ravnborgconfig PHYSICAL_START 18696a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1870ceefccc9SH. Peter Anvin default "0x1000000" 18718f9ca475SIngo Molnar ---help--- 1872506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1873506f1d07SSam Ravnborg 1874506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1875506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1876506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1877506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1878506f1d07SSam Ravnborg address. 1879506f1d07SSam Ravnborg 1880506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1881506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1882506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1883506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1884506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1885506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1886506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1887506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1888506f1d07SSam Ravnborg 1889ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1890ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1891ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1892ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1893ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1894ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1895ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1896ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1897ceefccc9SH. Peter Anvin for more details about crash dumps. 1898506f1d07SSam Ravnborg 1899506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1900506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1901506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1902506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1903506f1d07SSam Ravnborg is present because there are users out there who continue to use 1904506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1905506f1d07SSam Ravnborg line. 1906506f1d07SSam Ravnborg 1907506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1908506f1d07SSam Ravnborg 1909506f1d07SSam Ravnborgconfig RELOCATABLE 191026717808SH. Peter Anvin bool "Build a relocatable kernel" 191126717808SH. Peter Anvin default y 19128f9ca475SIngo Molnar ---help--- 1913506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1914506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1915506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1916506f1d07SSam Ravnborg but are discarded at runtime. 1917506f1d07SSam Ravnborg 1918506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1919506f1d07SSam Ravnborg must live at a different physical address than the primary 1920506f1d07SSam Ravnborg kernel. 1921506f1d07SSam Ravnborg 1922506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1923506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 19248ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1925506f1d07SSam Ravnborg 19268ab3820fSKees Cookconfig RANDOMIZE_BASE 1927e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 19288ab3820fSKees Cook depends on RELOCATABLE 19298ab3820fSKees Cook default n 19308ab3820fSKees Cook ---help--- 1931e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 1932e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 1933e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 1934e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 1935e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 1936e8581e3dSBaoquan He code internals. 1937e8581e3dSBaoquan He 1938e8581e3dSBaoquan He The kernel physical and virtual address can be randomized 1939e8581e3dSBaoquan He from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that 1940e8581e3dSBaoquan He using RANDOMIZE_BASE reduces the memory space available to 1941e8581e3dSBaoquan He kernel modules from 1.5GB to 1GB.) 19428ab3820fSKees Cook 1943a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1944e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 1945e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 1946e8581e3dSBaoquan He supported, then entropy is read from the i8254 timer. 19478ab3820fSKees Cook 1948e8581e3dSBaoquan He Since the kernel is built using 2GB addressing, and 1949e8581e3dSBaoquan He PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of 1950e8581e3dSBaoquan He entropy is theoretically possible. Currently, with the 1951e8581e3dSBaoquan He default value for PHYSICAL_ALIGN and due to page table 1952e8581e3dSBaoquan He layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits. 1953e8581e3dSBaoquan He 1954e8581e3dSBaoquan He If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot 1955e8581e3dSBaoquan He time. To enable it, boot with "kaslr" on the kernel command 1956e8581e3dSBaoquan He line (which will also disable hibernation). 19578ab3820fSKees Cook 1958da2b6fb9SKees Cook If unsure, say N. 1959da2b6fb9SKees Cook 19608ab3820fSKees Cook# Relocation on x86 needs some additional build support 1961845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1962845adf72SH. Peter Anvin def_bool y 19638ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1964845adf72SH. Peter Anvin 1965506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1966a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19678ab3820fSKees Cook default "0x200000" 1968a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1969a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19708f9ca475SIngo Molnar ---help--- 1971506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1972506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1973506f1d07SSam Ravnborg address which meets above alignment restriction. 1974506f1d07SSam Ravnborg 1975506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1976506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1977506f1d07SSam Ravnborg address aligned to above value and run from there. 1978506f1d07SSam Ravnborg 1979506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1980506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1981506f1d07SSam Ravnborg load address and decompress itself to the address it has been 1982506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 1983506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 1984506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 1985506f1d07SSam Ravnborg above alignment restrictions. 1986506f1d07SSam Ravnborg 1987a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 1988a0215061SKees Cook this value must be a multiple of 0x200000. 1989a0215061SKees Cook 1990506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1991506f1d07SSam Ravnborg 1992506f1d07SSam Ravnborgconfig HOTPLUG_CPU 19937c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 199440b31360SStephen Rothwell depends on SMP 1995506f1d07SSam Ravnborg ---help--- 19967c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 19977c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 19987c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 19997c13e6a3SDimitri Sivanich automatically on SMP systems. ) 20007c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 2001506f1d07SSam Ravnborg 200280aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 200380aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 200480aa1dffSFenghua Yu default n 20052c922cd0SKees Cook depends on HOTPLUG_CPU 200680aa1dffSFenghua Yu ---help--- 200780aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 200880aa1dffSFenghua Yu 200980aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 201080aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 201180aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 201280aa1dffSFenghua Yu 201380aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 201480aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 201580aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 201680aa1dffSFenghua Yu 201780aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 201880aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 201980aa1dffSFenghua Yu 202080aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 202180aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 202280aa1dffSFenghua Yu be other CPU0 dependencies. 202380aa1dffSFenghua Yu 202480aa1dffSFenghua Yu Please make sure the dependencies are under your control before 202580aa1dffSFenghua Yu you enable this feature. 202680aa1dffSFenghua Yu 202780aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 202880aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 202980aa1dffSFenghua Yu parameter cpu0_hotplug. 203080aa1dffSFenghua Yu 2031a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2032a71c8bc5SFenghua Yu def_bool n 2033a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20342c922cd0SKees Cook depends on HOTPLUG_CPU 2035a71c8bc5SFenghua Yu ---help--- 2036a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2037a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2038a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2039a71c8bc5SFenghua Yu 2040a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2041a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2042a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2043a71c8bc5SFenghua Yu 2044a71c8bc5SFenghua Yu If unsure, say N. 2045a71c8bc5SFenghua Yu 2046506f1d07SSam Ravnborgconfig COMPAT_VDSO 2047b0b49f26SAndy Lutomirski def_bool n 2048b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2049af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 20508f9ca475SIngo Molnar ---help--- 2051b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2052b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2053b0b49f26SAndy Lutomirski indicated in its segment table. 2054e84446deSRandy Dunlap 2055b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2056b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2057b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2058b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2059b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2060506f1d07SSam Ravnborg 2061b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2062b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2063b0b49f26SAndy Lutomirski 2064b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2065b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2066b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2067b0b49f26SAndy Lutomirski 2068b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2069b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2070506f1d07SSam Ravnborg 20713dc33bd3SKees Cookchoice 20723dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 20733dc33bd3SKees Cook depends on X86_64 20743dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 20753dc33bd3SKees Cook help 20763dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 20773dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 20783dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 20793dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 20803dc33bd3SKees Cook 20813dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 20823dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 20833dc33bd3SKees Cook 20843dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 20853dc33bd3SKees Cook static binaries, you can say None without a performance penalty 20863dc33bd3SKees Cook to improve security. 20873dc33bd3SKees Cook 20883dc33bd3SKees Cook If unsure, select "Emulate". 20893dc33bd3SKees Cook 20903dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 20913dc33bd3SKees Cook bool "Native" 20923dc33bd3SKees Cook help 20933dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 20943dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 20953dc33bd3SKees Cook this makes the mapping executable, it can be used during 20963dc33bd3SKees Cook security vulnerability exploitation (traditionally as 20973dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 20983dc33bd3SKees Cook 20993dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 21003dc33bd3SKees Cook bool "Emulate" 21013dc33bd3SKees Cook help 21023dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 21033dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 21043dc33bd3SKees Cook non-executable, but it still contains known contents, 21053dc33bd3SKees Cook which could be used in certain rare security vulnerability 21063dc33bd3SKees Cook exploits. This configuration is recommended when userspace 21073dc33bd3SKees Cook still uses the vsyscall area. 21083dc33bd3SKees Cook 21093dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 21103dc33bd3SKees Cook bool "None" 21113dc33bd3SKees Cook help 21123dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 21133dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 21143dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 21153dc33bd3SKees Cook will be reported to dmesg, so that either old or 21163dc33bd3SKees Cook malicious userspace programs can be identified. 21173dc33bd3SKees Cook 21183dc33bd3SKees Cookendchoice 21193dc33bd3SKees Cook 2120516cbf37STim Birdconfig CMDLINE_BOOL 2121516cbf37STim Bird bool "Built-in kernel command line" 21228f9ca475SIngo Molnar ---help--- 2123516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2124516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2125516cbf37STim Bird necessary or convenient to provide some or all of the 2126516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2127516cbf37STim Bird to not rely on the boot loader to provide them.) 2128516cbf37STim Bird 2129516cbf37STim Bird To compile command line arguments into the kernel, 2130516cbf37STim Bird set this option to 'Y', then fill in the 213169711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2132516cbf37STim Bird 2133516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2134516cbf37STim Bird should leave this option set to 'N'. 2135516cbf37STim Bird 2136516cbf37STim Birdconfig CMDLINE 2137516cbf37STim Bird string "Built-in kernel command string" 2138516cbf37STim Bird depends on CMDLINE_BOOL 2139516cbf37STim Bird default "" 21408f9ca475SIngo Molnar ---help--- 2141516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2142516cbf37STim Bird image and used at boot time. If the boot loader provides a 2143516cbf37STim Bird command line at boot time, it is appended to this string to 2144516cbf37STim Bird form the full kernel command line, when the system boots. 2145516cbf37STim Bird 2146516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2147516cbf37STim Bird change this behavior. 2148516cbf37STim Bird 2149516cbf37STim Bird In most cases, the command line (whether built-in or provided 2150516cbf37STim Bird by the boot loader) should specify the device for the root 2151516cbf37STim Bird file system. 2152516cbf37STim Bird 2153516cbf37STim Birdconfig CMDLINE_OVERRIDE 2154516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2155516cbf37STim Bird depends on CMDLINE_BOOL 21568f9ca475SIngo Molnar ---help--- 2157516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2158516cbf37STim Bird command line, and use ONLY the built-in command line. 2159516cbf37STim Bird 2160516cbf37STim Bird This is used to work around broken boot loaders. This should 2161516cbf37STim Bird be set to 'N' under normal conditions. 2162516cbf37STim Bird 2163a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2164a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2165a5b9e5a2SAndy Lutomirski default y 2166a5b9e5a2SAndy Lutomirski ---help--- 2167a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2168a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2169a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2170a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2171a5b9e5a2SAndy Lutomirski threading libraries. 2172a5b9e5a2SAndy Lutomirski 2173a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2174a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2175a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2176a5b9e5a2SAndy Lutomirski 2177a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2178a5b9e5a2SAndy Lutomirski 2179b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2180b700e7f0SSeth Jennings 2181506f1d07SSam Ravnborgendmenu 2182506f1d07SSam Ravnborg 2183506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2184506f1d07SSam Ravnborg def_bool y 2185506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2186506f1d07SSam Ravnborg 218735551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 218835551053SGary Hade def_bool y 218935551053SGary Hade depends on MEMORY_HOTPLUG 219035551053SGary Hade 2191e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2192645a7919STejun Heo def_bool y 2193e534c7c5SLee Schermerhorn depends on NUMA 2194e534c7c5SLee Schermerhorn 21959491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 21969491846fSKirill A. Shutemov def_bool y 21979491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 21989491846fSKirill A. Shutemov 2199c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2200c177c81eSNaoya Horiguchi def_bool y 2201c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2202c177c81eSNaoya Horiguchi 2203da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2204e279b6c1SSam Ravnborg 2205e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 22063c2362e6SHarvey Harrison def_bool y 2207e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2208e279b6c1SSam Ravnborg 2209e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2210e279b6c1SSam Ravnborg 2211e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2212e279b6c1SSam Ravnborg 2213efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2214efafc8b2SFeng Tang 2215a6b68076SAndi Kleenconfig X86_APM_BOOT 22166fc108a0SJan Beulich def_bool y 2217282e5aabSPaul Bolle depends on APM 2218a6b68076SAndi Kleen 2219e279b6c1SSam Ravnborgmenuconfig APM 2220e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2221efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2222e279b6c1SSam Ravnborg ---help--- 2223e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2224e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2225e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2226e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2227e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2228e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2229e279b6c1SSam Ravnborg 2230e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2231e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2232e279b6c1SSam Ravnborg 2233e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2234e279b6c1SSam Ravnborg machines with more than one CPU. 2235e279b6c1SSam Ravnborg 2236e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22372dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22382dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2239e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2240e279b6c1SSam Ravnborg 2241e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2242e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2243e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2244e279b6c1SSam Ravnborg 2245e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2246e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2247e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2248e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2249e279b6c1SSam Ravnborg 2250e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2251e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2252e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2253e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2254e279b6c1SSam Ravnborg APM in your BIOS). 2255e279b6c1SSam Ravnborg 2256e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2257e279b6c1SSam Ravnborg "weird" problems: 2258e279b6c1SSam Ravnborg 2259e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2260e279b6c1SSam Ravnborg enabled. 2261e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2262e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2263e279b6c1SSam Ravnborg the "no387" option to the kernel 2264e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2265e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2266e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2267e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2268e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2269e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2270e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2271e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2272e279b6c1SSam Ravnborg 11) exchange RAM chips 2273e279b6c1SSam Ravnborg 12) exchange the motherboard. 2274e279b6c1SSam Ravnborg 2275e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2276e279b6c1SSam Ravnborg module will be called apm. 2277e279b6c1SSam Ravnborg 2278e279b6c1SSam Ravnborgif APM 2279e279b6c1SSam Ravnborg 2280e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2281e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 22828f9ca475SIngo Molnar ---help--- 2283e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2284e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2285e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2286e279b6c1SSam Ravnborg 2287e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2288e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2289e279b6c1SSam Ravnborg ---help--- 2290e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2291e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2292e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2293e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2294e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2295e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2296e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2297e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2298e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2299e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2300e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2301e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2302e279b6c1SSam Ravnborg this feature. 2303e279b6c1SSam Ravnborg 2304e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2305dd8af076SLen Brown depends on CPU_IDLE 2306e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 23078f9ca475SIngo Molnar ---help--- 2308e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2309e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2310e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2311e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2312e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2313e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2314e279b6c1SSam Ravnborg this option does nothing.) 2315e279b6c1SSam Ravnborg 2316e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2317e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 23188f9ca475SIngo Molnar ---help--- 2319e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2320e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2321e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2322e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2323e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2324e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2325e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2326e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2327e279b6c1SSam Ravnborg especially if you are using gpm. 2328e279b6c1SSam Ravnborg 2329e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2330e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 23318f9ca475SIngo Molnar ---help--- 2332e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2333e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2334e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2335e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2336e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2337e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2338e279b6c1SSam Ravnborg 2339e279b6c1SSam Ravnborgendif # APM 2340e279b6c1SSam Ravnborg 2341bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2342e279b6c1SSam Ravnborg 2343e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2344e279b6c1SSam Ravnborg 234527471fdbSAndy Henroidsource "drivers/idle/Kconfig" 234627471fdbSAndy Henroid 2347e279b6c1SSam Ravnborgendmenu 2348e279b6c1SSam Ravnborg 2349e279b6c1SSam Ravnborg 2350e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2351e279b6c1SSam Ravnborg 2352e279b6c1SSam Ravnborgconfig PCI 23531ac97018SIngo Molnar bool "PCI support" 23541c858087SAdrian Bunk default y 23558f9ca475SIngo Molnar ---help--- 2356e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2357e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2358e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2359e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2360e279b6c1SSam Ravnborg 2361e279b6c1SSam Ravnborgchoice 2362e279b6c1SSam Ravnborg prompt "PCI access mode" 2363efefa6f6SIngo Molnar depends on X86_32 && PCI 2364e279b6c1SSam Ravnborg default PCI_GOANY 2365e279b6c1SSam Ravnborg ---help--- 2366e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2367e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2368e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2369e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2370e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2371e279b6c1SSam Ravnborg 2372e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2373e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2374e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2375e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2376e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2377e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2378e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2379e279b6c1SSam Ravnborg 2380e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2381e279b6c1SSam Ravnborg bool "BIOS" 2382e279b6c1SSam Ravnborg 2383e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2384e279b6c1SSam Ravnborg bool "MMConfig" 2385e279b6c1SSam Ravnborg 2386e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2387e279b6c1SSam Ravnborg bool "Direct" 2388e279b6c1SSam Ravnborg 23893ef0e1f8SAndres Salomonconfig PCI_GOOLPC 239076fb6570SDaniel Drake bool "OLPC XO-1" 23913ef0e1f8SAndres Salomon depends on OLPC 23923ef0e1f8SAndres Salomon 23932bdd1b03SAndres Salomonconfig PCI_GOANY 23942bdd1b03SAndres Salomon bool "Any" 23952bdd1b03SAndres Salomon 2396e279b6c1SSam Ravnborgendchoice 2397e279b6c1SSam Ravnborg 2398e279b6c1SSam Ravnborgconfig PCI_BIOS 23993c2362e6SHarvey Harrison def_bool y 2400efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2401e279b6c1SSam Ravnborg 2402e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2403e279b6c1SSam Ravnborgconfig PCI_DIRECT 24043c2362e6SHarvey Harrison def_bool y 24050aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2406e279b6c1SSam Ravnborg 2407e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 24083c2362e6SHarvey Harrison def_bool y 24095f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2410e279b6c1SSam Ravnborg 24113ef0e1f8SAndres Salomonconfig PCI_OLPC 24122bdd1b03SAndres Salomon def_bool y 24132bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 24143ef0e1f8SAndres Salomon 2415b5401a96SAlex Nixonconfig PCI_XEN 2416b5401a96SAlex Nixon def_bool y 2417b5401a96SAlex Nixon depends on PCI && XEN 2418b5401a96SAlex Nixon select SWIOTLB_XEN 2419b5401a96SAlex Nixon 2420e279b6c1SSam Ravnborgconfig PCI_DOMAINS 24213c2362e6SHarvey Harrison def_bool y 2422e279b6c1SSam Ravnborg depends on PCI 2423e279b6c1SSam Ravnborg 2424e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2425e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2426e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2427e279b6c1SSam Ravnborg 24283f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 24296a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 24306ea30386SKees Cook depends on PCI 24313f6ea84aSIra W. Snyder help 24323f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24333f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24343f6ea84aSIra W. Snyder not have ACPI. 24353f6ea84aSIra W. Snyder 243664a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 243764a5fed6SBjorn Helgaas is known to be incomplete. 243864a5fed6SBjorn Helgaas 243964a5fed6SBjorn Helgaas You should say N unless you know you need this. 244064a5fed6SBjorn Helgaas 2441e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2442e279b6c1SSam Ravnborg 24431c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2444e279b6c1SSam Ravnborgconfig ISA_DMA_API 24451c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 24461c00f016SDavid Rientjes default y 24471c00f016SDavid Rientjes help 24481c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 24491c00f016SDavid Rientjes If unsure, say Y. 2450e279b6c1SSam Ravnborg 245151e68d05SLinus Torvaldsif X86_32 245251e68d05SLinus Torvalds 2453e279b6c1SSam Ravnborgconfig ISA 2454e279b6c1SSam Ravnborg bool "ISA support" 24558f9ca475SIngo Molnar ---help--- 2456e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2457e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2458e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2459e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2460e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2461e279b6c1SSam Ravnborg 2462e279b6c1SSam Ravnborgconfig EISA 2463e279b6c1SSam Ravnborg bool "EISA support" 2464e279b6c1SSam Ravnborg depends on ISA 2465e279b6c1SSam Ravnborg ---help--- 2466e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2467e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2468e279b6c1SSam Ravnborg 2469e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2470e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2471e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2472e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2473e279b6c1SSam Ravnborg 2474e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2475e279b6c1SSam Ravnborg 2476e279b6c1SSam Ravnborg Otherwise, say N. 2477e279b6c1SSam Ravnborg 2478e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2479e279b6c1SSam Ravnborg 2480e279b6c1SSam Ravnborgconfig SCx200 2481e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 24828f9ca475SIngo Molnar ---help--- 2483e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2484e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2485e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2486e279b6c1SSam Ravnborg for other scx200_* drivers. 2487e279b6c1SSam Ravnborg 2488e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2489e279b6c1SSam Ravnborg 2490e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2491e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2492592913ecSJohn Stultz depends on SCx200 2493e279b6c1SSam Ravnborg default y 24948f9ca475SIngo Molnar ---help--- 2495e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2496e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2497e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2498e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2499e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2500e279b6c1SSam Ravnborg 25013ef0e1f8SAndres Salomonconfig OLPC 25023ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 250354008979SThomas Gleixner depends on !X86_PAE 25043c554946SAndres Salomon select GPIOLIB 2505dc3119e7SThomas Gleixner select OF 250645bb1674SDaniel Drake select OF_PROMTREE 2507b4e51854SGrant Likely select IRQ_DOMAIN 25088f9ca475SIngo Molnar ---help--- 25093ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 25103ef0e1f8SAndres Salomon XO hardware. 25113ef0e1f8SAndres Salomon 2512a3128588SDaniel Drakeconfig OLPC_XO1_PM 2513a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 251497c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2515a3128588SDaniel Drake select MFD_CORE 2516bf1ebf00SDaniel Drake ---help--- 251797c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2518bf1ebf00SDaniel Drake 2519cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2520cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2521cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2522cfee9597SDaniel Drake ---help--- 2523cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2524cfee9597SDaniel Drake programmable wakeup source. 2525cfee9597SDaniel Drake 25267feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 25277feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2528d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2529ed8e47feSRandy Dunlap depends on INPUT=y 2530d8d01a63SDaniel Drake select POWER_SUPPLY 25317feda8e9SDaniel Drake select GPIO_CS5535 25327feda8e9SDaniel Drake select MFD_CORE 25337feda8e9SDaniel Drake ---help--- 25347feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25357bc74b3dSDaniel Drake - EC-driven system wakeups 25367feda8e9SDaniel Drake - Power button 25377bc74b3dSDaniel Drake - Ebook switch 25382cf2baeaSDaniel Drake - Lid switch 2539e1040ac6SDaniel Drake - AC adapter status updates 2540e1040ac6SDaniel Drake - Battery status updates 25417feda8e9SDaniel Drake 2542a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2543a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2544d8d01a63SDaniel Drake depends on OLPC && ACPI 2545d8d01a63SDaniel Drake select POWER_SUPPLY 2546a0f30f59SDaniel Drake ---help--- 2547a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2548a0f30f59SDaniel Drake - EC-driven system wakeups 2549a0f30f59SDaniel Drake - AC adapter status updates 2550a0f30f59SDaniel Drake - Battery status updates 2551e279b6c1SSam Ravnborg 2552d4f3e350SEd Wildgooseconfig ALIX 2553d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2554d4f3e350SEd Wildgoose select GPIOLIB 2555d4f3e350SEd Wildgoose ---help--- 2556d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2557d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2558d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2559d4f3e350SEd Wildgoose get added here. 2560d4f3e350SEd Wildgoose 2561d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2562d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2563d4f3e350SEd Wildgoose 2564d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2565d4f3e350SEd Wildgoose 2566da4e3302SPhilip Prindevilleconfig NET5501 2567da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2568da4e3302SPhilip Prindeville select GPIOLIB 2569da4e3302SPhilip Prindeville ---help--- 2570da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2571da4e3302SPhilip Prindeville 25723197059aSPhilip A. Prindevilleconfig GEOS 25733197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 25743197059aSPhilip A. Prindeville select GPIOLIB 25753197059aSPhilip A. Prindeville depends on DMI 25763197059aSPhilip A. Prindeville ---help--- 25773197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 25783197059aSPhilip A. Prindeville 25797d029125SVivien Didelotconfig TS5500 25807d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 25817d029125SVivien Didelot depends on MELAN 25827d029125SVivien Didelot select CHECK_SIGNATURE 25837d029125SVivien Didelot select NEW_LEDS 25847d029125SVivien Didelot select LEDS_CLASS 25857d029125SVivien Didelot ---help--- 25867d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 25877d029125SVivien Didelot 2588e279b6c1SSam Ravnborgendif # X86_32 2589e279b6c1SSam Ravnborg 259023ac4ae8SAndreas Herrmannconfig AMD_NB 2591e279b6c1SSam Ravnborg def_bool y 25920e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2593e279b6c1SSam Ravnborg 2594e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2595e279b6c1SSam Ravnborg 2596388b78adSAlexandre Bounineconfig RAPIDIO 2597fdf90abcSAlexandre Bounine tristate "RapidIO support" 2598388b78adSAlexandre Bounine depends on PCI 2599388b78adSAlexandre Bounine default n 2600388b78adSAlexandre Bounine help 2601fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2602388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2603388b78adSAlexandre Bounine 2604388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2605388b78adSAlexandre Bounine 2606e3263ab3SDavid Herrmannconfig X86_SYSFB 2607e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2608e3263ab3SDavid Herrmann help 2609e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2610e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2611e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2612e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2613e3263ab3SDavid Herrmann to x86. 2614e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2615e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2616e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2617e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2618e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2619e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2620e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2621e3263ab3SDavid Herrmann 2622e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2623e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2624e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2625e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2626e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2627e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2628e3263ab3SDavid Herrmann incompatible with simplefb. 2629e3263ab3SDavid Herrmann 2630e3263ab3SDavid Herrmann If unsure, say Y. 2631e3263ab3SDavid Herrmann 2632e279b6c1SSam Ravnborgendmenu 2633e279b6c1SSam Ravnborg 2634e279b6c1SSam Ravnborg 2635e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2636e279b6c1SSam Ravnborg 2637e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2638e279b6c1SSam Ravnborg 2639e279b6c1SSam Ravnborgconfig IA32_EMULATION 2640e279b6c1SSam Ravnborg bool "IA32 Emulation" 2641e279b6c1SSam Ravnborg depends on X86_64 2642d1603990SRandy Dunlap select BINFMT_ELF 2643a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 26443bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 26458f9ca475SIngo Molnar ---help--- 26465fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 26475fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 26485fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2649e279b6c1SSam Ravnborg 2650e279b6c1SSam Ravnborgconfig IA32_AOUT 2651e279b6c1SSam Ravnborg tristate "IA32 a.out support" 26526b213e1bSDavid Woodhouse depends on IA32_EMULATION 26538f9ca475SIngo Molnar ---help--- 2654e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2655e279b6c1SSam Ravnborg 26560bf62763SH. Peter Anvinconfig X86_X32 26576ea30386SKees Cook bool "x32 ABI for 64-bit mode" 26589b54050bSBrian Gerst depends on X86_64 26595fd92e65SH. J. Lu ---help--- 26605fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 26615fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 26625fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 26635fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 26645fd92e65SH. J. Lu 26655fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 26665fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 26675fd92e65SH. J. Lu option set. 26685fd92e65SH. J. Lu 2669e279b6c1SSam Ravnborgconfig COMPAT 26703c2362e6SHarvey Harrison def_bool y 26710bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2672e279b6c1SSam Ravnborg 26733120e25eSJan Beulichif COMPAT 2674e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 26753120e25eSJan Beulich def_bool y 2676e279b6c1SSam Ravnborg 2677e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 26783c2362e6SHarvey Harrison def_bool y 26793120e25eSJan Beulich depends on SYSVIPC 2680e279b6c1SSam Ravnborg 2681ee009e4aSDavid Howellsconfig KEYS_COMPAT 26823120e25eSJan Beulich def_bool y 26833120e25eSJan Beulich depends on KEYS 26843120e25eSJan Beulichendif 2685ee009e4aSDavid Howells 2686e279b6c1SSam Ravnborgendmenu 2687e279b6c1SSam Ravnborg 2688e279b6c1SSam Ravnborg 2689e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2690e5beae16SKeith Packard def_bool y 2691e5beae16SKeith Packard depends on X86_32 2692e5beae16SKeith Packard 26934692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 26944692d77fSAlessandro Rubini bool 269583125a3aSAlessandro Rubini depends on X86_64 || STA2X11 26964692d77fSAlessandro Rubini 2697f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2698f7219a53SAlessandro Rubini bool 269983125a3aSAlessandro Rubini depends on STA2X11 2700f7219a53SAlessandro Rubini 270193e5eaddSLi, Aubreyconfig PMC_ATOM 270293e5eaddSLi, Aubrey def_bool y 270393e5eaddSLi, Aubrey depends on PCI 270493e5eaddSLi, Aubrey 2705185a383aSKeith Buschconfig VMD 2706185a383aSKeith Busch depends on PCI_MSI 2707185a383aSKeith Busch tristate "Volume Management Device Driver" 2708185a383aSKeith Busch default N 2709185a383aSKeith Busch ---help--- 2710185a383aSKeith Busch Adds support for the Intel Volume Management Device (VMD). VMD is a 2711185a383aSKeith Busch secondary PCI host bridge that allows PCI Express root ports, 2712185a383aSKeith Busch and devices attached to them, to be removed from the default 2713185a383aSKeith Busch PCI domain and placed within the VMD domain. This provides 2714185a383aSKeith Busch more bus resources than are otherwise possible with a 2715185a383aSKeith Busch single domain. If you know your system provides one of these and 2716185a383aSKeith Busch has devices attached to it, say Y; if you are not sure, say N. 2717185a383aSKeith Busch 2718e279b6c1SSam Ravnborgsource "net/Kconfig" 2719e279b6c1SSam Ravnborg 2720e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2721e279b6c1SSam Ravnborg 2722e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2723e279b6c1SSam Ravnborg 2724e279b6c1SSam Ravnborgsource "fs/Kconfig" 2725e279b6c1SSam Ravnborg 2726e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2727e279b6c1SSam Ravnborg 2728e279b6c1SSam Ravnborgsource "security/Kconfig" 2729e279b6c1SSam Ravnborg 2730e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2731e279b6c1SSam Ravnborg 2732edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2733edf88417SAvi Kivity 2734e279b6c1SSam Ravnborgsource "lib/Kconfig" 2735