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 12341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 13341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 14341c787eSIngo Molnar select CLKSRC_I8253 15341c787eSIngo Molnar select CLONE_BACKWARDS 16341c787eSIngo Molnar select HAVE_AOUT 17341c787eSIngo Molnar select HAVE_GENERIC_DMA_COHERENT 18341c787eSIngo Molnar select MODULES_USE_ELF_REL 19341c787eSIngo Molnar select OLD_SIGACTION 20daa93fabSSam Ravnborg 21daa93fabSSam Ravnborgconfig X86_64 223120e25eSJan Beulich def_bool y 233120e25eSJan Beulich depends on 64BIT 24d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 25d94e0685SIngo Molnar select ARCH_HAS_GIGANTIC_PAGE 26d94e0685SIngo Molnar select ARCH_SUPPORTS_INT128 27d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 28d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 29d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 30d94e0685SIngo Molnar select X86_DEV_DMA_OPS 311032c0baSSam Ravnborg 32d94e0685SIngo Molnar# 33d94e0685SIngo Molnar# Arch settings 34d94e0685SIngo Molnar# 35d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 36d94e0685SIngo Molnar# ported to 32-bit as well. ) 37d94e0685SIngo Molnar# 388d5fffb9SSam Ravnborgconfig X86 393c2362e6SHarvey Harrison def_bool y 406471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 416e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 426471b825SIngo Molnar select ANON_INODES 436471b825SIngo Molnar select ARCH_CLOCKSOURCE_DATA 446471b825SIngo Molnar select ARCH_DISCARD_MEMBLOCK 4591dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 4621266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 476471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 4872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 49957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 505c9a8750SDmitry Vyukov select ARCH_HAS_KCOV if X86_64 5196601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 5267a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 536471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 54c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 556471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 566471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 5777fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 585e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 596471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 603b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 616471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 626471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 636471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 646471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 6572b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 665aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 67da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 686471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 696471b825SIngo Molnar select CLKEVT_I8253 706471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 716471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 726471b825SIngo Molnar select DCACHE_WORD_ACCESS 7345471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 7445471cd9SLinus Torvalds select EDAC_SUPPORT 756471b825SIngo Molnar select GENERIC_CLOCKEVENTS 766471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 776471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 786471b825SIngo Molnar select GENERIC_CMOS_UPDATE 796471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 806471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 816471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 826471b825SIngo Molnar select GENERIC_IOMAP 836471b825SIngo Molnar select GENERIC_IRQ_PROBE 846471b825SIngo Molnar select GENERIC_IRQ_SHOW 856471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 866471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 876471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 886471b825SIngo Molnar select GENERIC_STRNLEN_USER 896471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 906471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 916471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 926471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 936471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 945b710f34SKees Cook select HAVE_ARCH_HARDENED_USERCOPY 956471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 966471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 976471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 986471b825SIngo Molnar select HAVE_ARCH_KGDB 996471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 1009e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1019e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1026471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 1036471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1046471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 1050f60a8efSKees Cook select HAVE_ARCH_WITHIN_STACK_FRAMES 1066077776bSDaniel Borkmann select HAVE_EBPF_JIT if X86_64 107e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 1086471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 1096471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1106471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1116471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 112c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 1136471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1146471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1156471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 1166471b825SIngo Molnar select HAVE_DMA_API_DEBUG 1179c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 118677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 11906aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 12058340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1215f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 1226471b825SIngo Molnar select HAVE_FENTRY if X86_64 1236471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1246471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1256471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1266b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 1270067f129SK.Prasad select HAVE_HW_BREAKPOINT 1286471b825SIngo Molnar select HAVE_IDE 1296471b825SIngo Molnar select HAVE_IOREMAP_PROT 1306471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1316471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1326471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1336471b825SIngo Molnar select HAVE_KERNEL_GZIP 1346471b825SIngo Molnar select HAVE_KERNEL_LZ4 1356471b825SIngo Molnar select HAVE_KERNEL_LZMA 1366471b825SIngo Molnar select HAVE_KERNEL_LZO 1376471b825SIngo Molnar select HAVE_KERNEL_XZ 1386471b825SIngo Molnar select HAVE_KPROBES 1396471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1406471b825SIngo Molnar select HAVE_KRETPROBES 1416471b825SIngo Molnar select HAVE_KVM 1426471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1436471b825SIngo Molnar select HAVE_MEMBLOCK 1446471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1450102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 14642a0bb3fSPetr Mladek select HAVE_NMI 1476471b825SIngo Molnar select HAVE_OPROFILE 1486471b825SIngo Molnar select HAVE_OPTPROBES 1496471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1506471b825SIngo Molnar select HAVE_PERF_EVENTS 151c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 152c5e63197SJiri Olsa select HAVE_PERF_REGS 153c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1546471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1556471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1560c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1576471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1587c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 159c0185808SThomas Gleixner select IRQ_FORCED_THREADING 1606471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1616471b825SIngo Molnar select PERF_EVENTS 1623195ef59SPrarit Bhargava select RTC_LIB 163d6faca40SArnd Bergmann select RTC_MC146818_LIB 1646471b825SIngo Molnar select SPARSE_IRQ 16583fe27eaSPranith Kumar select SRCU 1666471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 16715f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 1686471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1696471b825SIngo Molnar select VIRT_TO_BUS 1706471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 171d4883d5dSJosh Poimboeuf select HAVE_STACK_VALIDATION if X86_64 1727d8330a5SBalbir Singh 173ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1743120e25eSJan Beulich def_bool y 1753120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 176ba7e4d13SIngo Molnar 17751b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 17851b26adaSLinus Torvalds string 17951b26adaSLinus Torvalds default "elf32-i386" if X86_32 18051b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 18151b26adaSLinus Torvalds 18273531905SSam Ravnborgconfig ARCH_DEFCONFIG 183b9b39bfbSSam Ravnborg string 18473531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 18573531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 186b9b39bfbSSam Ravnborg 1878d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1883c2362e6SHarvey Harrison def_bool y 1898d5fffb9SSam Ravnborg 1908d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1913c2362e6SHarvey Harrison def_bool y 1928d5fffb9SSam Ravnborg 1938d5fffb9SSam Ravnborgconfig MMU 1943c2362e6SHarvey Harrison def_bool y 1958d5fffb9SSam Ravnborg 1969e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 1979e08f57dSDaniel Cashman default 28 if 64BIT 1989e08f57dSDaniel Cashman default 8 1999e08f57dSDaniel Cashman 2009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 2019e08f57dSDaniel Cashman default 32 if 64BIT 2029e08f57dSDaniel Cashman default 16 2039e08f57dSDaniel Cashman 2049e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 2059e08f57dSDaniel Cashman default 8 2069e08f57dSDaniel Cashman 2079e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 2089e08f57dSDaniel Cashman default 16 2099e08f57dSDaniel Cashman 2108d5fffb9SSam Ravnborgconfig SBUS 2118d5fffb9SSam Ravnborg bool 2128d5fffb9SSam Ravnborg 2133bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 2143120e25eSJan Beulich def_bool y 215a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 2163bc4e459SFUJITA Tomonori 21718e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 2184a14d84eSAndrew Morton def_bool y 21918e98307SFUJITA Tomonori 2208d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 2213120e25eSJan Beulich def_bool y 2223120e25eSJan Beulich depends on ISA_DMA_API 2238d5fffb9SSam Ravnborg 2248d5fffb9SSam Ravnborgconfig GENERIC_BUG 2253c2362e6SHarvey Harrison def_bool y 2268d5fffb9SSam Ravnborg depends on BUG 227b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 228b93a531eSJan Beulich 229b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 230b93a531eSJan Beulich bool 2318d5fffb9SSam Ravnborg 2328d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2333c2362e6SHarvey Harrison def_bool y 2348d5fffb9SSam Ravnborg 2358d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2363120e25eSJan Beulich def_bool y 2373120e25eSJan Beulich depends on ISA_DMA_API 2388d5fffb9SSam Ravnborg 2391032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2403120e25eSJan Beulich def_bool y 2411032c0baSSam Ravnborg 2421032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2431032c0baSSam Ravnborg def_bool y 2441032c0baSSam Ravnborg 2459a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2469a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2478d5fffb9SSam Ravnborg 2481b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2491b27d05bSPekka Enberg def_bool y 2501b27d05bSPekka Enberg 251dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 25289c9c4c5SBrian Gerst def_bool y 253b32ef636Stravis@sgi.com 25408fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 25508fc4580STejun Heo def_bool y 25608fc4580STejun Heo 25708fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 25811124411STejun Heo def_bool y 25911124411STejun Heo 260801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 261801e4062SJohannes Berg def_bool y 262801e4062SJohannes Berg 263f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 264f4cb5700SJohannes Berg def_bool y 265f4cb5700SJohannes Berg 266cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 267cfe28c5dSSteve Capper def_bool y 268cfe28c5dSSteve Capper 26953313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 27053313b2cSSteve Capper def_bool y 27153313b2cSSteve Capper 2728d5fffb9SSam Ravnborgconfig ZONE_DMA32 273e0fd24a3SJan Beulich def_bool y if X86_64 2748d5fffb9SSam Ravnborg 2758d5fffb9SSam Ravnborgconfig AUDIT_ARCH 276e0fd24a3SJan Beulich def_bool y if X86_64 2778d5fffb9SSam Ravnborg 278765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 279765c68bdSIngo Molnar def_bool y 280765c68bdSIngo Molnar 2816a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2826a11f75bSAkinobu Mita def_bool y 2836a11f75bSAkinobu Mita 284d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 285d6f2d75aSAndrey Ryabinin hex 286d6f2d75aSAndrey Ryabinin depends on KASAN 287d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 288d6f2d75aSAndrey Ryabinin 28969575d38SShane Wangconfig HAVE_INTEL_TXT 29069575d38SShane Wang def_bool y 2916ea30386SKees Cook depends on INTEL_IOMMU && ACPI 29269575d38SShane Wang 2936b0c3d44SSam Ravnborgconfig X86_32_SMP 2946b0c3d44SSam Ravnborg def_bool y 2956b0c3d44SSam Ravnborg depends on X86_32 && SMP 2966b0c3d44SSam Ravnborg 2976b0c3d44SSam Ravnborgconfig X86_64_SMP 2986b0c3d44SSam Ravnborg def_bool y 2996b0c3d44SSam Ravnborg depends on X86_64 && SMP 3006b0c3d44SSam Ravnborg 301ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 302ccbeed3aSTejun Heo def_bool y 30360a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 304ccbeed3aSTejun Heo 3052b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3062b144498SSrikar Dronamraju def_bool y 3072b144498SSrikar Dronamraju 308d20642f0SRob Herringconfig FIX_EARLYCON_MEM 309d20642f0SRob Herring def_bool y 310d20642f0SRob Herring 3119ccaf77cSKees Cookconfig DEBUG_RODATA 3129ccaf77cSKees Cook def_bool y 3139ccaf77cSKees Cook 31498233368SKirill A. Shutemovconfig PGTABLE_LEVELS 31598233368SKirill A. Shutemov int 31698233368SKirill A. Shutemov default 4 if X86_64 31798233368SKirill A. Shutemov default 3 if X86_PAE 31898233368SKirill A. Shutemov default 2 31998233368SKirill A. Shutemov 320506f1d07SSam Ravnborgsource "init/Kconfig" 321dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3228d5fffb9SSam Ravnborg 323506f1d07SSam Ravnborgmenu "Processor type and features" 324506f1d07SSam Ravnborg 3255ee71535SRandy Dunlapconfig ZONE_DMA 3265ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3275ee71535SRandy Dunlap default y 3285ee71535SRandy Dunlap help 3295ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3305ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3315ee71535SRandy Dunlap Disable if no such devices will be used. 3325ee71535SRandy Dunlap 3335ee71535SRandy Dunlap If unsure, say Y. 3345ee71535SRandy Dunlap 335506f1d07SSam Ravnborgconfig SMP 336506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 337506f1d07SSam Ravnborg ---help--- 338506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3394a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3404a474157SRobert Graffham than one CPU, say Y. 341506f1d07SSam Ravnborg 3424a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 343506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 344506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3454a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 346506f1d07SSam Ravnborg will run faster if you say N here. 347506f1d07SSam Ravnborg 348506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 349506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 350506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 351506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 352506f1d07SSam Ravnborg 353506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 354506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 355506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 356506f1d07SSam Ravnborg 357395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 358506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 359506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 360506f1d07SSam Ravnborg 361506f1d07SSam Ravnborg If you don't know what to do here, say N. 362506f1d07SSam Ravnborg 3639def39beSJosh Triplettconfig X86_FEATURE_NAMES 3649def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3659def39beSJosh Triplett default y 3669def39beSJosh Triplett ---help--- 3679def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3689def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3699def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3709def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3719def39beSJosh Triplett 3729def39beSJosh Triplett If in doubt, say Y. 3739def39beSJosh Triplett 3746e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS 3756e1315feSBorislav Petkov bool "Fast CPU feature tests" if EMBEDDED 3766e1315feSBorislav Petkov default y 3776e1315feSBorislav Petkov ---help--- 3786e1315feSBorislav Petkov Some fast-paths in the kernel depend on the capabilities of the CPU. 3796e1315feSBorislav Petkov Say Y here for the kernel to patch in the appropriate code at runtime 3806e1315feSBorislav Petkov based on the capabilities of the CPU. The infrastructure for patching 3816e1315feSBorislav Petkov code at runtime takes up some additional space; space-constrained 3826e1315feSBorislav Petkov embedded systems may wish to say N here to produce smaller, slightly 3836e1315feSBorislav Petkov slower code. 3846e1315feSBorislav Petkov 38506cd9a7dSYinghai Luconfig X86_X2APIC 38606cd9a7dSYinghai Lu bool "Support x2apic" 38719e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 38806cd9a7dSYinghai Lu ---help--- 38906cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 39006cd9a7dSYinghai Lu 39106cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 39206cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 39306cd9a7dSYinghai Lu 39406cd9a7dSYinghai Lu If you don't know what to do here, say N. 39506cd9a7dSYinghai Lu 3966695c85bSYinghai Luconfig X86_MPPARSE 3976e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3987a527688SJan Beulich default y 3995ab74722SIngo Molnar depends on X86_LOCAL_APIC 4008f9ca475SIngo Molnar ---help--- 4016695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4026695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4036695c85bSYinghai Lu 40426f7ef14SYinghai Luconfig X86_BIGSMP 40526f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 40626f7ef14SYinghai Lu depends on X86_32 && SMP 4078f9ca475SIngo Molnar ---help--- 40826f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 409506f1d07SSam Ravnborg 410ddd70cf9SJun Nakajimaconfig GOLDFISH 411ddd70cf9SJun Nakajima def_bool y 412ddd70cf9SJun Nakajima depends on X86_GOLDFISH 413ddd70cf9SJun Nakajima 4148425091fSRavikiran G Thirumalaiif X86_32 415c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 416c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 417c5c606d9SRavikiran G Thirumalai default y 4188f9ca475SIngo Molnar ---help--- 41906ac8346SIngo Molnar If you disable this option then the kernel will only support 42006ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 42106ac8346SIngo Molnar systems out there.) 42206ac8346SIngo Molnar 4238425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4248425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 425cb7b8023SBen Hutchings Goldfish (Android emulator) 4268425091fSRavikiran G Thirumalai AMD Elan 4278425091fSRavikiran G Thirumalai RDC R-321x SoC 4288425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 42983125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 4303f4110a4SThomas Gleixner Moorestown MID devices 43106ac8346SIngo Molnar 43206ac8346SIngo Molnar If you have one of these systems, or if you want to build a 43306ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4348425091fSRavikiran G Thirumalaiendif 43506ac8346SIngo Molnar 4368425091fSRavikiran G Thirumalaiif X86_64 4378425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4388425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4398425091fSRavikiran G Thirumalai default y 4408425091fSRavikiran G Thirumalai ---help--- 4418425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4428425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4438425091fSRavikiran G Thirumalai systems out there.) 4448425091fSRavikiran G Thirumalai 4458425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4468425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 44744b111b5SSteffen Persvold Numascale NumaChip 4488425091fSRavikiran G Thirumalai ScaleMP vSMP 4498425091fSRavikiran G Thirumalai SGI Ultraviolet 4508425091fSRavikiran G Thirumalai 4518425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4528425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4538425091fSRavikiran G Thirumalaiendif 454c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 455c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 45644b111b5SSteffen Persvoldconfig X86_NUMACHIP 45744b111b5SSteffen Persvold bool "Numascale NumaChip" 45844b111b5SSteffen Persvold depends on X86_64 45944b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 46044b111b5SSteffen Persvold depends on NUMA 46144b111b5SSteffen Persvold depends on SMP 46244b111b5SSteffen Persvold depends on X86_X2APIC 463f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 46444b111b5SSteffen Persvold ---help--- 46544b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 46644b111b5SSteffen Persvold enable more than ~168 cores. 46744b111b5SSteffen Persvold If you don't have one of these, you should say N here. 46803b48632SNick Piggin 4696a48565eSIngo Molnarconfig X86_VSMP 470c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4716276a074SBorislav Petkov select HYPERVISOR_GUEST 4726a48565eSIngo Molnar select PARAVIRT 4736a48565eSIngo Molnar depends on X86_64 && PCI 474c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 475ead91d4bSShai Fultheim depends on SMP 4768f9ca475SIngo Molnar ---help--- 4776a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4786a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4796a48565eSIngo Molnar if you have one of these machines. 4806a48565eSIngo Molnar 481c5c606d9SRavikiran G Thirumalaiconfig X86_UV 482c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 483c5c606d9SRavikiran G Thirumalai depends on X86_64 484c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 48554c28d29SJack Steiner depends on NUMA 4861ecb4ae5SAndrew Morton depends on EFI 4879d6c26e7SSuresh Siddha depends on X86_X2APIC 4881222e564SIngo Molnar depends on PCI 489c5c606d9SRavikiran G Thirumalai ---help--- 490c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 491c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 492c5c606d9SRavikiran G Thirumalai 493c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 494c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 495506f1d07SSam Ravnborg 496ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 497ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 498cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 499ddd70cf9SJun Nakajima ---help--- 500ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 501ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 502ddd70cf9SJun Nakajima Goldfish emulator say N here. 503ddd70cf9SJun Nakajima 504c751e17bSThomas Gleixnerconfig X86_INTEL_CE 505c751e17bSThomas Gleixner bool "CE4100 TV platform" 506c751e17bSThomas Gleixner depends on PCI 507c751e17bSThomas Gleixner depends on PCI_GODIRECT 5086084a6e2SJiang Liu depends on X86_IO_APIC 509c751e17bSThomas Gleixner depends on X86_32 510c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 51137bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 512da6b737bSSebastian Andrzej Siewior select OF 513da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 514c751e17bSThomas Gleixner ---help--- 515c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 516c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 517c751e17bSThomas Gleixner boxes and media devices. 518c751e17bSThomas Gleixner 5194cb9b00fSDavid Cohenconfig X86_INTEL_MID 52043605ef1SAlan Cox bool "Intel MID platform support" 52143605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 522edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 5231ea7c673SAlan Cox depends on PCI 5243fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 5251ea7c673SAlan Cox depends on X86_IO_APIC 5267c9c3a1eSAlan Cox select SFI 5274cb9b00fSDavid Cohen select I2C 5287c9c3a1eSAlan Cox select DW_APB_TIMER 5291ea7c673SAlan Cox select APB_TIMER 5301ea7c673SAlan Cox select INTEL_SCU_IPC 53115a713dfSMika Westerberg select MFD_INTEL_MSIC 5321ea7c673SAlan Cox ---help--- 5334cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5344cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5354cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5361ea7c673SAlan Cox 5374cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5384cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 53943605ef1SAlan Cox 5408bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5418bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5428bbc2a13SBryan O'Donoghue depends on X86_32 5438bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5448bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5458bbc2a13SBryan O'Donoghue depends on X86_TSC 5468bbc2a13SBryan O'Donoghue depends on PCI 5478bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5488bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5498bbc2a13SBryan O'Donoghue select IOSF_MBI 5508bbc2a13SBryan O'Donoghue select INTEL_IMR 5519ab6eb51SAndy Shevchenko select COMMON_CLK 5528bbc2a13SBryan O'Donoghue ---help--- 5538bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5548bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5558bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5568bbc2a13SBryan O'Donoghue 55758cbbee2SVadim Pasternakconfig MLX_PLATFORM 55858cbbee2SVadim Pasternak tristate "Mellanox Technologies platform support" 55958cbbee2SVadim Pasternak depends on X86_64 56058cbbee2SVadim Pasternak depends on X86_EXTENDED_PLATFORM 56158cbbee2SVadim Pasternak ---help--- 56258cbbee2SVadim Pasternak This option enables system support for the Mellanox Technologies 56358cbbee2SVadim Pasternak platform. 56458cbbee2SVadim Pasternak 56558cbbee2SVadim Pasternak Say Y here if you are building a kernel for Mellanox system. 56658cbbee2SVadim Pasternak 56758cbbee2SVadim Pasternak Otherwise, say N. 56858cbbee2SVadim Pasternak 5693d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5703d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 571eebb3e8dSAndy Shevchenko depends on X86 && ACPI 5723d48aab1SMika Westerberg select COMMON_CLK 5730f531431SMathias Nyman select PINCTRL 574eebb3e8dSAndy Shevchenko select IOSF_MBI 5753d48aab1SMika Westerberg ---help--- 5763d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5773d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5780f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5790f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5803d48aab1SMika Westerberg 58192082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 58292082a88SKen Xue bool "AMD ACPI2Platform devices support" 58392082a88SKen Xue depends on ACPI 58492082a88SKen Xue select COMMON_CLK 58592082a88SKen Xue select PINCTRL 58692082a88SKen Xue ---help--- 58792082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 58892082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 58992082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 59092082a88SKen Xue implemented under PINCTRL subsystem. 59192082a88SKen Xue 592ced3ce76SDavid E. Boxconfig IOSF_MBI 593ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 594ced3ce76SDavid E. Box depends on PCI 595ced3ce76SDavid E. Box ---help--- 596ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 597ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 598ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 599ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 600ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 601ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 602ced3ce76SDavid E. Box This list is not meant to be exclusive. 603ced3ce76SDavid E. Box - BayTrail 604ced3ce76SDavid E. Box - Braswell 605ced3ce76SDavid E. Box - Quark 606ced3ce76SDavid E. Box 607ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 608ced3ce76SDavid E. Box 609ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 610ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 611ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 612ed2226bdSDavid E. Box ---help--- 613ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 614ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 615ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 616ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 617ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 618ed2226bdSDavid E. Box device they want to access. 619ed2226bdSDavid E. Box 620ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 621ed2226bdSDavid E. Box 622c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 623c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 624506f1d07SSam Ravnborg depends on X86_32 625c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 626c5c606d9SRavikiran G Thirumalai select M486 627c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 628c5c606d9SRavikiran G Thirumalai ---help--- 629c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 630c5c606d9SRavikiran G Thirumalai as R-8610-(G). 631c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 632c5c606d9SRavikiran G Thirumalai 633e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 6349c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 6359c398017SIngo Molnar depends on X86_32 && SMP 636c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 6378f9ca475SIngo Molnar ---help--- 638b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 639b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 640b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 641b5660ba7SH. Peter Anvin one and will fallback to default. 642d49c4288SYinghai Lu 643c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 644d49c4288SYinghai Lu 645d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6466fc108a0SJan Beulich def_bool y 647d949f36fSLinus Torvalds # MCE code calls memory_failure(): 648d949f36fSLinus Torvalds depends on X86_MCE 649d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 650d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 651d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 652d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 653d949f36fSLinus Torvalds 65483125a3aSAlessandro Rubiniconfig STA2X11 65583125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 65683125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 65783125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 65883125a3aSAlessandro Rubini select X86_DMA_REMAP 65983125a3aSAlessandro Rubini select SWIOTLB 66083125a3aSAlessandro Rubini select MFD_STA2X11 6610145071bSLinus Walleij select GPIOLIB 66283125a3aSAlessandro Rubini default n 66383125a3aSAlessandro Rubini ---help--- 66483125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 66583125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 66683125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 66783125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 66883125a3aSAlessandro Rubini standard PC machines. 66983125a3aSAlessandro Rubini 67082148d1dSShérabconfig X86_32_IRIS 67182148d1dSShérab tristate "Eurobraille/Iris poweroff module" 67282148d1dSShérab depends on X86_32 67382148d1dSShérab ---help--- 67482148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 67582148d1dSShérab to shut themselves down properly. A special I/O sequence is 67682148d1dSShérab needed to do so, which is what this module does at 67782148d1dSShérab kernel shutdown. 67882148d1dSShérab 67982148d1dSShérab This is only for Iris machines from EuroBraille. 68082148d1dSShérab 68182148d1dSShérab If unused, say N. 68282148d1dSShérab 683ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6843c2362e6SHarvey Harrison def_bool y 6853c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 686a87d0914SKen Chen depends on X86 6878f9ca475SIngo Molnar ---help--- 688506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 689506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 690506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 691506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 692506f1d07SSam Ravnborg 693506f1d07SSam Ravnborg If in doubt, say "Y". 694506f1d07SSam Ravnborg 6956276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6966276a074SBorislav Petkov bool "Linux guest support" 6978f9ca475SIngo Molnar ---help--- 6986276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6996276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7006276a074SBorislav Petkov setup. 701506f1d07SSam Ravnborg 7026276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7036276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 704506f1d07SSam Ravnborg 7056276a074SBorislav Petkovif HYPERVISOR_GUEST 706506f1d07SSam Ravnborg 707e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 708e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 7098f9ca475SIngo Molnar ---help--- 710e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 711e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 712e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 713e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 714e61bd94aSEduardo Pereira Habkost 7156276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7166276a074SBorislav Petkov bool "paravirt-ops debugging" 7176276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 7186276a074SBorislav Petkov ---help--- 7196276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7206276a074SBorislav Petkov a paravirt_op is missing when it is called. 7216276a074SBorislav Petkov 722b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 723b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7246ea30386SKees Cook depends on PARAVIRT && SMP 725b4ecc126SJeremy Fitzhardinge ---help--- 726b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 727b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 728b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 729b4ecc126SJeremy Fitzhardinge 7304c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 7314c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 732b4ecc126SJeremy Fitzhardinge 7334c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 734b4ecc126SJeremy Fitzhardinge 73545e898b7SWaiman Longconfig QUEUED_LOCK_STAT 73645e898b7SWaiman Long bool "Paravirt queued spinlock statistics" 737cfd8983fSPeter Zijlstra depends on PARAVIRT_SPINLOCKS && DEBUG_FS 73845e898b7SWaiman Long ---help--- 73945e898b7SWaiman Long Enable the collection of statistical data on the slowpath 74045e898b7SWaiman Long behavior of paravirtualized queued spinlocks and report 74145e898b7SWaiman Long them on debugfs. 74245e898b7SWaiman Long 7436276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 7446276a074SBorislav Petkov 7456276a074SBorislav Petkovconfig KVM_GUEST 7466276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7476276a074SBorislav Petkov depends on PARAVIRT 7486276a074SBorislav Petkov select PARAVIRT_CLOCK 7496276a074SBorislav Petkov default y 7506276a074SBorislav Petkov ---help--- 7516276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7526276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7536276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7546276a074SBorislav Petkov underlying device model, the host provides the guest with 7556276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7566276a074SBorislav Petkov 7571e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7581e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7591e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7601e20eb85SSrivatsa Vaddagiri default n 7611e20eb85SSrivatsa Vaddagiri ---help--- 7621e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7631e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7641e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7651e20eb85SSrivatsa Vaddagiri 7666276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7676276a074SBorislav Petkov 7686276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7696276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7706276a074SBorislav Petkov depends on PARAVIRT 7716276a074SBorislav Petkov default n 7726276a074SBorislav Petkov ---help--- 7736276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7746276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7756276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7766276a074SBorislav Petkov that, there can be a small performance impact. 7776276a074SBorislav Petkov 7786276a074SBorislav Petkov If in doubt, say N here. 7796276a074SBorislav Petkov 7807af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7817af192c9SGerd Hoffmann bool 7827af192c9SGerd Hoffmann 7836276a074SBorislav Petkovendif #HYPERVISOR_GUEST 78497349135SJeremy Fitzhardinge 78508677214SYinghai Luconfig NO_BOOTMEM 786774ea0bcSYinghai Lu def_bool y 78708677214SYinghai Lu 788506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 789506f1d07SSam Ravnborg 790506f1d07SSam Ravnborgconfig HPET_TIMER 7913c2362e6SHarvey Harrison def_bool X86_64 792506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7938f9ca475SIngo Molnar ---help--- 794506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 795506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 796506f1d07SSam Ravnborg present. 797506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 798506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 799506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8004e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8014e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 802506f1d07SSam Ravnborg 803506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 804506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 805506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 806506f1d07SSam Ravnborg 807506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 808506f1d07SSam Ravnborg 809506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8103c2362e6SHarvey Harrison def_bool y 8119d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 812506f1d07SSam Ravnborg 813bb24c471SJacob Panconfig APB_TIMER 814933b9463SAlan Cox def_bool y if X86_INTEL_MID 815933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 81606c3df49SJamie Iles select DW_APB_TIMER 817a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 818bb24c471SJacob Pan help 819bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 820bb24c471SJacob Pan The APBT provides a stable time base on SMP 821bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 822bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 823bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 824bb24c471SJacob Pan 8256a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 826506f1d07SSam Ravnborg# The code disables itself when not needed. 8277ae9392cSThomas Petazzoniconfig DMI 8287ae9392cSThomas Petazzoni default y 829cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 8306a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 8318f9ca475SIngo Molnar ---help--- 8327ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 8337ae9392cSThomas Petazzoni here unless you have verified that your setup is not 8347ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 8357ae9392cSThomas Petazzoni BIOS code. 8367ae9392cSThomas Petazzoni 837506f1d07SSam Ravnborgconfig GART_IOMMU 83838901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 839506f1d07SSam Ravnborg select SWIOTLB 84023ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 8418f9ca475SIngo Molnar ---help--- 842ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 843ced3c42cSIngo Molnar GART based hardware IOMMUs. 844ced3c42cSIngo Molnar 845ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 846ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 847ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 848ced3c42cSIngo Molnar 849ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 850ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 851ced3c42cSIngo Molnar 852ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 853ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 854ced3c42cSIngo Molnar 32-bit limited device. 855ced3c42cSIngo Molnar 856ced3c42cSIngo Molnar If unsure, say Y. 857506f1d07SSam Ravnborg 858506f1d07SSam Ravnborgconfig CALGARY_IOMMU 859506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 860506f1d07SSam Ravnborg select SWIOTLB 8616ea30386SKees Cook depends on X86_64 && PCI 8628f9ca475SIngo Molnar ---help--- 863506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 864506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 865506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 866506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 867506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 868506f1d07SSam Ravnborg prevents them from going anywhere except their intended 869506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 870506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 871506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 872506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 873506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 874506f1d07SSam Ravnborg If unsure, say Y. 875506f1d07SSam Ravnborg 876506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8773c2362e6SHarvey Harrison def_bool y 8783c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 879506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8808f9ca475SIngo Molnar ---help--- 881506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 882506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 883506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 884506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 885506f1d07SSam Ravnborg If unsure, say Y. 886506f1d07SSam Ravnborg 887506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 888506f1d07SSam Ravnborgconfig SWIOTLB 889a1afd01cSJoerg Roedel def_bool y if X86_64 8908f9ca475SIngo Molnar ---help--- 891506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8924454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8934454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8944454d327SJoe Millenbach with more than 3 GB of memory. 8954454d327SJoe Millenbach If unsure, say Y. 896506f1d07SSam Ravnborg 897a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8983120e25eSJan Beulich def_bool y 8993120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 900d25e26b6SLinus Torvalds 9011184dc2fSMike Travisconfig MAXSMP 902ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9036ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 90436f5101aSMike Travis select CPUMASK_OFFSTACK 9058f9ca475SIngo Molnar ---help--- 906ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9071184dc2fSMike Travis If unsure, say N. 908506f1d07SSam Ravnborg 909506f1d07SSam Ravnborgconfig NR_CPUS 91036f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 9112a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 912bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 913b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 91478637a97SMike Travis default "1" if !SMP 915b53b5edaSJosh Boyer default "8192" if MAXSMP 916b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 917c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 918c5c19941SKirill A. Shutemov default "64" if SMP 9198f9ca475SIngo Molnar ---help--- 920506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 921bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 922cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 923506f1d07SSam Ravnborg minimum value which makes sense is 2. 924506f1d07SSam Ravnborg 925506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 926506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 927506f1d07SSam Ravnborg 928506f1d07SSam Ravnborgconfig SCHED_SMT 929506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 930c8e56d20SBorislav Petkov depends on SMP 9318f9ca475SIngo Molnar ---help--- 932506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 933506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 934506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 935506f1d07SSam Ravnborg N here. 936506f1d07SSam Ravnborg 937506f1d07SSam Ravnborgconfig SCHED_MC 9383c2362e6SHarvey Harrison def_bool y 9393c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 940c8e56d20SBorislav Petkov depends on SMP 9418f9ca475SIngo Molnar ---help--- 942506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 943506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 944506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 945506f1d07SSam Ravnborg 946506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 947506f1d07SSam Ravnborg 94830b8b006SThomas Gleixnerconfig UP_LATE_INIT 94930b8b006SThomas Gleixner def_bool y 950ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 95130b8b006SThomas Gleixner 952506f1d07SSam Ravnborgconfig X86_UP_APIC 95350849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 95450849eefSJan Beulich default PCI_MSI 95538a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9568f9ca475SIngo Molnar ---help--- 957506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 958506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 959506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 960506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 961506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 962506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 963506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 964506f1d07SSam Ravnborg lockups. 965506f1d07SSam Ravnborg 966506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 967506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 968506f1d07SSam Ravnborg depends on X86_UP_APIC 9698f9ca475SIngo Molnar ---help--- 970506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 971506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 972506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 973506f1d07SSam Ravnborg 974506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 975506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 976506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 977506f1d07SSam Ravnborg 978506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9793c2362e6SHarvey Harrison def_bool y 9800dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 981b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 98252f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 983506f1d07SSam Ravnborg 984506f1d07SSam Ravnborgconfig X86_IO_APIC 985b1da1e71SJan Beulich def_bool y 986b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 987506f1d07SSam Ravnborg 98841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 98941b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 99041b9eb26SStefan Assmann depends on X86_IO_APIC 9918f9ca475SIngo Molnar ---help--- 99241b9eb26SStefan Assmann This option enables a workaround that fixes a source of 99341b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 99441b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 99541b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 99641b9eb26SStefan Assmann 99741b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 99841b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 99941b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 100041b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 100141b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 100241b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 100341b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 100441b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 100541b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 100641b9eb26SStefan Assmann down (vital) interrupt lines. 100741b9eb26SStefan Assmann 100841b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 100941b9eb26SStefan Assmann increased on these systems. 101041b9eb26SStefan Assmann 1011506f1d07SSam Ravnborgconfig X86_MCE 1012bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1013648ed940SChen, Gong select GENERIC_ALLOCATOR 1014e57dbaf7SBorislav Petkov default y 1015506f1d07SSam Ravnborg ---help--- 1016bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1017bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1018506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1019bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 10204efc0670SAndi Kleen 1021506f1d07SSam Ravnborgconfig X86_MCE_INTEL 10223c2362e6SHarvey Harrison def_bool y 10233c2362e6SHarvey Harrison prompt "Intel MCE features" 1024c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10258f9ca475SIngo Molnar ---help--- 1026506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1027506f1d07SSam Ravnborg the thermal monitor. 1028506f1d07SSam Ravnborg 1029506f1d07SSam Ravnborgconfig X86_MCE_AMD 10303c2362e6SHarvey Harrison def_bool y 10313c2362e6SHarvey Harrison prompt "AMD MCE features" 1032c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10338f9ca475SIngo Molnar ---help--- 1034506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1035506f1d07SSam Ravnborg the DRAM Error Threshold. 1036506f1d07SSam Ravnborg 10374efc0670SAndi Kleenconfig X86_ANCIENT_MCE 10386fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1039c31d9633SAndi Kleen depends on X86_32 && X86_MCE 10404efc0670SAndi Kleen ---help--- 10414efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 10425065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 10434efc0670SAndi Kleen line. 10444efc0670SAndi Kleen 1045b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1046b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10476fc108a0SJan Beulich def_bool y 1048b2762686SAndi Kleen 1049ea149b36SAndi Kleenconfig X86_MCE_INJECT 1050c1ebf835SAndi Kleen depends on X86_MCE 1051ea149b36SAndi Kleen tristate "Machine check injector support" 1052ea149b36SAndi Kleen ---help--- 1053ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1054ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1055ea149b36SAndi Kleen QA it is safe to say n. 1056ea149b36SAndi Kleen 10574efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10584efc0670SAndi Kleen def_bool y 10595bb38adcSAndi Kleen depends on X86_MCE_INTEL 10604efc0670SAndi Kleen 106107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1062e633c65aSKan Liang 10635aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10641e642812SIngo Molnar bool "Legacy VM86 support" 10655aef51c3SAndy Lutomirski default n 1066506f1d07SSam Ravnborg depends on X86_32 10678f9ca475SIngo Molnar ---help--- 10685aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10695aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10705aef51c3SAndy Lutomirski 10715aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10725aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10735aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10745aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10755aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10761e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10771e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10781e642812SIngo Molnar mode might be faster than emulation and you might want to 10791e642812SIngo Molnar enable this option. 10805aef51c3SAndy Lutomirski 10811e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10821e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10831e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10841e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10855aef51c3SAndy Lutomirski 10861e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10871e642812SIngo Molnar and slows down exception handling a tiny bit. 10885aef51c3SAndy Lutomirski 10891e642812SIngo Molnar If unsure, say N here. 10905aef51c3SAndy Lutomirski 10915aef51c3SAndy Lutomirskiconfig VM86 10925aef51c3SAndy Lutomirski bool 10935aef51c3SAndy Lutomirski default X86_LEGACY_VM86 109434273f41SH. Peter Anvin 109534273f41SH. Peter Anvinconfig X86_16BIT 109634273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 109734273f41SH. Peter Anvin default y 1098a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 109934273f41SH. Peter Anvin ---help--- 110034273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 110134273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 110234273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 110334273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 110434273f41SH. Peter Anvin 110534273f41SH. Peter Anvinconfig X86_ESPFIX32 110634273f41SH. Peter Anvin def_bool y 110734273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1108506f1d07SSam Ravnborg 1109197725deSH. Peter Anvinconfig X86_ESPFIX64 1110197725deSH. Peter Anvin def_bool y 111134273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1112506f1d07SSam Ravnborg 11131ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 11141ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 11151ad83c85SAndy Lutomirski default y 11161ad83c85SAndy Lutomirski depends on X86_64 11171ad83c85SAndy Lutomirski ---help--- 11181ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 11191ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 11201ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 11211ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 11221ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 11231ad83c85SAndy Lutomirski 0xffffffffff600?00. 11241ad83c85SAndy Lutomirski 11251ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 11261ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 11271ad83c85SAndy Lutomirski 11281ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 11291ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 11301ad83c85SAndy Lutomirski 1131506f1d07SSam Ravnborgconfig TOSHIBA 1132506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1133506f1d07SSam Ravnborg depends on X86_32 1134506f1d07SSam Ravnborg ---help--- 1135506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1136506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1137506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1138506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1139506f1d07SSam Ravnborg 1140506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1141506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1142506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1143506f1d07SSam Ravnborg 1144506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1145506f1d07SSam Ravnborg Say N otherwise. 1146506f1d07SSam Ravnborg 1147506f1d07SSam Ravnborgconfig I8K 1148039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1149949a9d70SJean Delvare select HWMON 1150039ae585SPali Rohár select SENSORS_DELL_SMM 1151506f1d07SSam Ravnborg ---help--- 1152039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1153039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1154039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1155039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1156039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1157039ae585SPali Rohár needed userspace package i8kutils. 1158506f1d07SSam Ravnborg 1159039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1160039ae585SPali Rohár use userspace package i8kutils. 1161506f1d07SSam Ravnborg Say N otherwise. 1162506f1d07SSam Ravnborg 1163506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11649ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11659ba16087SJan Beulich depends on X86_32 1166506f1d07SSam Ravnborg ---help--- 1167506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1168506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1169506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1170506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1171506f1d07SSam Ravnborg system. 1172506f1d07SSam Ravnborg 1173506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11745e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1175506f1d07SSam Ravnborg 1176506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1177506f1d07SSam Ravnborg enable this option even if you don't need it. 1178506f1d07SSam Ravnborg Say N otherwise. 1179506f1d07SSam Ravnborg 1180506f1d07SSam Ravnborgconfig MICROCODE 11819a2bc335SBorislav Petkov bool "CPU microcode loading support" 11829a2bc335SBorislav Petkov default y 118380030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1184506f1d07SSam Ravnborg select FW_LOADER 1185506f1d07SSam Ravnborg ---help--- 1186506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 11875f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 11885f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 11895f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 11905f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 11915f9c01aaSBorislav Petkov the Linux kernel. 1192506f1d07SSam Ravnborg 11935f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 11945f9c01aaSBorislav Petkov in Documentation/x86/early-microcode.txt. For that you need to enable 11955f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 11965f9c01aaSBorislav Petkov initrd for microcode blobs. 1197506f1d07SSam Ravnborg 11985f9c01aaSBorislav Petkov In addition, you can build-in the microcode into the kernel. For that you 11995f9c01aaSBorislav Petkov need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 12005f9c01aaSBorislav Petkov to the CONFIG_EXTRA_FIRMWARE config option. 1201506f1d07SSam Ravnborg 12028d86f390SPeter Orubaconfig MICROCODE_INTEL 1203e43f6e67SBorislav Petkov bool "Intel microcode loading support" 12048d86f390SPeter Oruba depends on MICROCODE 12058d86f390SPeter Oruba default MICROCODE 12068d86f390SPeter Oruba select FW_LOADER 12078f9ca475SIngo Molnar ---help--- 12088d86f390SPeter Oruba This options enables microcode patch loading support for Intel 12098d86f390SPeter Oruba processors. 12108d86f390SPeter Oruba 1211b8989db9SAlan For the current Intel microcode data package go to 1212b8989db9SAlan <https://downloadcenter.intel.com> and search for 1213b8989db9SAlan 'Linux Processor Microcode Data File'. 12148d86f390SPeter Oruba 121580cc9f10SPeter Orubaconfig MICROCODE_AMD 1216e43f6e67SBorislav Petkov bool "AMD microcode loading support" 121780cc9f10SPeter Oruba depends on MICROCODE 121880cc9f10SPeter Oruba select FW_LOADER 12198f9ca475SIngo Molnar ---help--- 122080cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 122180cc9f10SPeter Oruba processors will be enabled. 122280cc9f10SPeter Oruba 1223506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 12243c2362e6SHarvey Harrison def_bool y 1225506f1d07SSam Ravnborg depends on MICROCODE 1226506f1d07SSam Ravnborg 1227506f1d07SSam Ravnborgconfig X86_MSR 1228506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 12298f9ca475SIngo Molnar ---help--- 1230506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1231506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1232506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1233506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1234506f1d07SSam Ravnborg systems. 1235506f1d07SSam Ravnborg 1236506f1d07SSam Ravnborgconfig X86_CPUID 1237506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 12388f9ca475SIngo Molnar ---help--- 1239506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1240506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1241506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1242506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1243506f1d07SSam Ravnborg 1244506f1d07SSam Ravnborgchoice 1245506f1d07SSam Ravnborg prompt "High Memory Support" 12466fc108a0SJan Beulich default HIGHMEM4G 1247506f1d07SSam Ravnborg depends on X86_32 1248506f1d07SSam Ravnborg 1249506f1d07SSam Ravnborgconfig NOHIGHMEM 1250506f1d07SSam Ravnborg bool "off" 1251506f1d07SSam Ravnborg ---help--- 1252506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1253506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1254506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1255506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1256506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1257506f1d07SSam Ravnborg "high memory". 1258506f1d07SSam Ravnborg 1259506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1260506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1261506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1262506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1263506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1264506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1265506f1d07SSam Ravnborg possible. 1266506f1d07SSam Ravnborg 1267506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1268506f1d07SSam Ravnborg answer "4GB" here. 1269506f1d07SSam Ravnborg 1270506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1271506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1272506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1273506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1274506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1275506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1276506f1d07SSam Ravnborg 1277506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1278506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1279506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1280506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1281506f1d07SSam Ravnborg kernel at boot time.) 1282506f1d07SSam Ravnborg 1283506f1d07SSam Ravnborg If unsure, say "off". 1284506f1d07SSam Ravnborg 1285506f1d07SSam Ravnborgconfig HIGHMEM4G 1286506f1d07SSam Ravnborg bool "4GB" 12878f9ca475SIngo Molnar ---help--- 1288506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1289506f1d07SSam Ravnborg gigabytes of physical RAM. 1290506f1d07SSam Ravnborg 1291506f1d07SSam Ravnborgconfig HIGHMEM64G 1292506f1d07SSam Ravnborg bool "64GB" 1293eb068e78SH. Peter Anvin depends on !M486 1294506f1d07SSam Ravnborg select X86_PAE 12958f9ca475SIngo Molnar ---help--- 1296506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1297506f1d07SSam Ravnborg gigabytes of physical RAM. 1298506f1d07SSam Ravnborg 1299506f1d07SSam Ravnborgendchoice 1300506f1d07SSam Ravnborg 1301506f1d07SSam Ravnborgchoice 13026a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1303506f1d07SSam Ravnborg default VMSPLIT_3G 1304506f1d07SSam Ravnborg depends on X86_32 13058f9ca475SIngo Molnar ---help--- 1306506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1307506f1d07SSam Ravnborg 1308506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1309506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1310506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1311506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1312506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1313506f1d07SSam Ravnborg available to user programs, making the address space there 1314506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1315506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1316506f1d07SSam Ravnborg kernel modules. 1317506f1d07SSam Ravnborg 1318506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1319506f1d07SSam Ravnborg option alone! 1320506f1d07SSam Ravnborg 1321506f1d07SSam Ravnborg config VMSPLIT_3G 1322506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1323506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1324506f1d07SSam Ravnborg depends on !X86_PAE 1325506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1326506f1d07SSam Ravnborg config VMSPLIT_2G 1327506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1328506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1329506f1d07SSam Ravnborg depends on !X86_PAE 1330506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1331506f1d07SSam Ravnborg config VMSPLIT_1G 1332506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1333506f1d07SSam Ravnborgendchoice 1334506f1d07SSam Ravnborg 1335506f1d07SSam Ravnborgconfig PAGE_OFFSET 1336506f1d07SSam Ravnborg hex 1337506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1338506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1339506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1340506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1341506f1d07SSam Ravnborg default 0xC0000000 1342506f1d07SSam Ravnborg depends on X86_32 1343506f1d07SSam Ravnborg 1344506f1d07SSam Ravnborgconfig HIGHMEM 13453c2362e6SHarvey Harrison def_bool y 1346506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1347506f1d07SSam Ravnborg 1348506f1d07SSam Ravnborgconfig X86_PAE 13499ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1350506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13519d99c712SChristian Melki select SWIOTLB 13528f9ca475SIngo Molnar ---help--- 1353506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1354506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1355506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1356506f1d07SSam Ravnborg consumes more pagetable space per process. 1357506f1d07SSam Ravnborg 1358600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13593120e25eSJan Beulich def_bool y 13603120e25eSJan Beulich depends on X86_64 || X86_PAE 1361600715dcSJeremy Fitzhardinge 136266f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13633120e25eSJan Beulich def_bool y 13643120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 136566f2b061SFUJITA Tomonori 136610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1367e5008abeSLuis R. Rodriguez def_bool y 1368e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13698f9ca475SIngo Molnar ---help--- 137010971ab2SIngo Molnar Certain kernel features effectively disable kernel 137110971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 137210971ab2SIngo Molnar supports them), so don't confuse the user by printing 137310971ab2SIngo Molnar that we have them enabled. 13749e899816SNick Piggin 1375506f1d07SSam Ravnborg# Common NUMA Features 1376506f1d07SSam Ravnborgconfig NUMA 1377fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1378506f1d07SSam Ravnborg depends on SMP 1379b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1380b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13818f9ca475SIngo Molnar ---help--- 1382506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1383fd51b2d7SKOSAKI Motohiro 1384506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1385506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1386506f1d07SSam Ravnborg NUMA awareness to the kernel. 1387506f1d07SSam Ravnborg 1388c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1389fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1390fd51b2d7SKOSAKI Motohiro 1391b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13927cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1393fd51b2d7SKOSAKI Motohiro 1394fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1395506f1d07SSam Ravnborg 1396eec1d4faSHans Rosenfeldconfig AMD_NUMA 13973c2362e6SHarvey Harrison def_bool y 13983c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13995da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 14008f9ca475SIngo Molnar ---help--- 1401eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1402eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1403eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1404eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1405eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1406506f1d07SSam Ravnborg 1407506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 14083c2362e6SHarvey Harrison def_bool y 14093c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1410506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1411506f1d07SSam Ravnborg select ACPI_NUMA 14128f9ca475SIngo Molnar ---help--- 1413506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1414506f1d07SSam Ravnborg 14156ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 14166ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 14176ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 14186ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 14196ec6e0d9SSuresh Siddha# for details. 14206ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 14216ec6e0d9SSuresh Siddha def_bool y 14226ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 14236ec6e0d9SSuresh Siddha 1424506f1d07SSam Ravnborgconfig NUMA_EMU 1425506f1d07SSam Ravnborg bool "NUMA emulation" 14261b7e03efSTejun Heo depends on NUMA 14278f9ca475SIngo Molnar ---help--- 1428506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1429506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1430506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1431506f1d07SSam Ravnborg 1432506f1d07SSam Ravnborgconfig NODES_SHIFT 1433d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 143451591e31SDavid Rientjes range 1 10 143551591e31SDavid Rientjes default "10" if MAXSMP 1436506f1d07SSam Ravnborg default "6" if X86_64 1437506f1d07SSam Ravnborg default "3" 1438506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 14398f9ca475SIngo Molnar ---help--- 14401184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1441692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1442506f1d07SSam Ravnborg 1443506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 14443c2362e6SHarvey Harrison def_bool y 1445506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1446506f1d07SSam Ravnborg 1447506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14483c2362e6SHarvey Harrison def_bool y 1449506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1450506f1d07SSam Ravnborg 1451506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1452506f1d07SSam Ravnborg def_bool y 14533b16651fSTejun Heo depends on X86_32 && !NUMA 1454506f1d07SSam Ravnborg 1455506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1456506f1d07SSam Ravnborg def_bool y 1457b263295dSChristoph Lameter depends on NUMA && X86_32 1458506f1d07SSam Ravnborg 1459506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1460506f1d07SSam Ravnborg def_bool y 1461b263295dSChristoph Lameter depends on NUMA && X86_32 1462b263295dSChristoph Lameter 1463506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1464506f1d07SSam Ravnborg def_bool y 14656ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1466506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1467506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1468506f1d07SSam Ravnborg 14693b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14703b16651fSTejun Heo def_bool y 14713b16651fSTejun Heo depends on X86_64 14723b16651fSTejun Heo 1473506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1474506f1d07SSam Ravnborg def_bool y 1475b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1476506f1d07SSam Ravnborg 1477506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1478a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14793120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1480a0842b70SToshi Kani help 1481a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1482a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1483a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1484506f1d07SSam Ravnborg 14853b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14863b16651fSTejun Heo def_bool y 14873b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14883b16651fSTejun Heo 1489a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1490a29815a3SAvi Kivity hex 1491a29815a3SAvi Kivity default 0 if X86_32 1492a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1493a29815a3SAvi Kivity 1494506f1d07SSam Ravnborgsource "mm/Kconfig" 1495506f1d07SSam Ravnborg 14967a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14977a67832cSDan Williams bool 14987a67832cSDan Williams 1499ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 15007a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 15019f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 15029f53f9faSDan Williams depends on BLK_DEV 15037a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 15049f53f9faSDan Williams select LIBNVDIMM 1505ec776ef6SChristoph Hellwig help 1506ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1507ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1508ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1509ec776ef6SChristoph Hellwig they can be used for persistent storage. 1510ec776ef6SChristoph Hellwig 1511ec776ef6SChristoph Hellwig Say Y if unsure. 1512ec776ef6SChristoph Hellwig 1513506f1d07SSam Ravnborgconfig HIGHPTE 1514506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 15156fc108a0SJan Beulich depends on HIGHMEM 15168f9ca475SIngo Molnar ---help--- 1517506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1518506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1519506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1520506f1d07SSam Ravnborg entries in high memory. 1521506f1d07SSam Ravnborg 15229f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 15239f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 15248f9ca475SIngo Molnar ---help--- 15259f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 15269f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 15279f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 15289f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 15299f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 15309f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 15319f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 15329f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 15339f077871SJeremy Fitzhardinge 15349f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 15359f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 15369f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 15379f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 15389f077871SJeremy Fitzhardinge 15399f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 15409f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 15419f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 15429f077871SJeremy Fitzhardinge memory. 15439f077871SJeremy Fitzhardinge 1544c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1545c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1546c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1547c885df50SJeremy Fitzhardinge default y 15488f9ca475SIngo Molnar ---help--- 1549c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1550c885df50SJeremy Fitzhardinge on or off. 1551c885df50SJeremy Fitzhardinge 15529ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1553d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1554d0cd7425SH. Peter Anvin default 64 1555d0cd7425SH. Peter Anvin range 4 640 15568f9ca475SIngo Molnar ---help--- 1557d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1558fc381519SIngo Molnar 1559d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1560d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1561fc381519SIngo Molnar 1562d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1563d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1564d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1565d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1566fc381519SIngo Molnar 1567d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1568d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1569d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1570d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1571d0cd7425SH. Peter Anvin entire low memory range. 1572d0cd7425SH. Peter Anvin 1573d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1574d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1575d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1576d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1577d0cd7425SH. Peter Anvin typical corruption patterns. 1578d0cd7425SH. Peter Anvin 1579d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1580fc381519SIngo Molnar 1581506f1d07SSam Ravnborgconfig MATH_EMULATION 1582506f1d07SSam Ravnborg bool 1583a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1584506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1585506f1d07SSam Ravnborg ---help--- 1586506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1587506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1588506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1589506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1590506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1591506f1d07SSam Ravnborg coprocessor or this emulation. 1592506f1d07SSam Ravnborg 1593506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1594506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1595506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1596506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1597506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1598506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1599506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1600506f1d07SSam Ravnborg intend to use this kernel on different machines. 1601506f1d07SSam Ravnborg 1602506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1603506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1604506f1d07SSam Ravnborg 1605506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1606506f1d07SSam Ravnborg kernel, it won't hurt. 1607506f1d07SSam Ravnborg 1608506f1d07SSam Ravnborgconfig MTRR 16096fc108a0SJan Beulich def_bool y 16106a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1611506f1d07SSam Ravnborg ---help--- 1612506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1613506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1614506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1615506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1616506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1617506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1618506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1619506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1620506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1621506f1d07SSam Ravnborg 1622506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1623506f1d07SSam Ravnborg control registers on other processors can be easily supported 1624506f1d07SSam Ravnborg as well: 1625506f1d07SSam Ravnborg 1626506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1627506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1628506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1629506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1630506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1631506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1632506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1633506f1d07SSam Ravnborg 1634506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1635506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1636506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1637506f1d07SSam Ravnborg 1638506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1639506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1640506f1d07SSam Ravnborg 16417225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1642506f1d07SSam Ravnborg 164395ffa243SYinghai Luconfig MTRR_SANITIZER 16442ffb3501SYinghai Lu def_bool y 164595ffa243SYinghai Lu prompt "MTRR cleanup support" 164695ffa243SYinghai Lu depends on MTRR 16478f9ca475SIngo Molnar ---help--- 1648aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1649aba3728cSThomas Gleixner add writeback entries. 165095ffa243SYinghai Lu 1651aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1652692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1653aba3728cSThomas Gleixner mtrr_chunk_size. 165495ffa243SYinghai Lu 16552ffb3501SYinghai Lu If unsure, say Y. 165695ffa243SYinghai Lu 165795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1658f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1659f5098d62SYinghai Lu range 0 1 1660f5098d62SYinghai Lu default "0" 166195ffa243SYinghai Lu depends on MTRR_SANITIZER 16628f9ca475SIngo Molnar ---help--- 1663f5098d62SYinghai Lu Enable mtrr cleanup default value 166495ffa243SYinghai Lu 166512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 166612031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 166712031a62SYinghai Lu range 0 7 166812031a62SYinghai Lu default "1" 166912031a62SYinghai Lu depends on MTRR_SANITIZER 16708f9ca475SIngo Molnar ---help--- 167112031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1672aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 167312031a62SYinghai Lu 16742e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16756fc108a0SJan Beulich def_bool y 16766a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16772a8a2719SIngo Molnar depends on MTRR 16788f9ca475SIngo Molnar ---help--- 16792e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1680042b78e4SVenki Pallipadi 16812e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16822e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16832e5d9c85Svenkatesh.pallipadi@intel.com 16842e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1685042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16862e5d9c85Svenkatesh.pallipadi@intel.com 16872e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16882e5d9c85Svenkatesh.pallipadi@intel.com 168946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 169046cf98cdSVenkatesh Pallipadi def_bool y 169146cf98cdSVenkatesh Pallipadi depends on X86_PAT 169246cf98cdSVenkatesh Pallipadi 1693628c6246SH. Peter Anvinconfig ARCH_RANDOM 1694628c6246SH. Peter Anvin def_bool y 1695628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1696628c6246SH. Peter Anvin ---help--- 1697628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1698628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1699628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1700628c6246SH. Peter Anvin secure hardware random number generator. 1701628c6246SH. Peter Anvin 170251ae4a2dSH. Peter Anvinconfig X86_SMAP 170351ae4a2dSH. Peter Anvin def_bool y 170451ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 170551ae4a2dSH. Peter Anvin ---help--- 170651ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 170751ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 170851ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 170951ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 171051ae4a2dSH. Peter Anvin 171151ae4a2dSH. Peter Anvin If unsure, say Y. 171251ae4a2dSH. Peter Anvin 171372e9b5feSDave Hansenconfig X86_INTEL_MPX 171472e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 171572e9b5feSDave Hansen def_bool n 171672e9b5feSDave Hansen depends on CPU_SUP_INTEL 171772e9b5feSDave Hansen ---help--- 171872e9b5feSDave Hansen MPX provides hardware features that can be used in 171972e9b5feSDave Hansen conjunction with compiler-instrumented code to check 172072e9b5feSDave Hansen memory references. It is designed to detect buffer 172172e9b5feSDave Hansen overflow or underflow bugs. 172272e9b5feSDave Hansen 172372e9b5feSDave Hansen This option enables running applications which are 172472e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 172572e9b5feSDave Hansen itself inside the kernel or to protect the kernel 172672e9b5feSDave Hansen against bad memory references. 172772e9b5feSDave Hansen 172872e9b5feSDave Hansen Enabling this option will make the kernel larger: 172972e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 173072e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 173172e9b5feSDave Hansen will increase the kernel memory overhead of each 173272e9b5feSDave Hansen process and adds some branches to paths used during 173372e9b5feSDave Hansen exec() and munmap(). 173472e9b5feSDave Hansen 173572e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 173672e9b5feSDave Hansen 173772e9b5feSDave Hansen If unsure, say N. 173872e9b5feSDave Hansen 173935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 1740284244a9SDave Hansen prompt "Intel Memory Protection Keys" 174135e97790SDave Hansen def_bool y 1742284244a9SDave Hansen # Note: only available in 64-bit mode 174335e97790SDave Hansen depends on CPU_SUP_INTEL && X86_64 174452c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 174552c8e601SIngo Molnar select ARCH_HAS_PKEYS 1746284244a9SDave Hansen ---help--- 1747284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1748284244a9SDave Hansen page-based protections, but without requiring modification of the 1749284244a9SDave Hansen page tables when an application changes protection domains. 1750284244a9SDave Hansen 1751284244a9SDave Hansen For details, see Documentation/x86/protection-keys.txt 1752284244a9SDave Hansen 1753284244a9SDave Hansen If unsure, say y. 175435e97790SDave Hansen 1755506f1d07SSam Ravnborgconfig EFI 17569ba16087SJan Beulich bool "EFI runtime service support" 17575b83683fSHuang, Ying depends on ACPI 1758f6ce5002SSergey Vlasov select UCS2_STRING 1759022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1760506f1d07SSam Ravnborg ---help--- 17618b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1762506f1d07SSam Ravnborg available (such as the EFI variable services). 1763506f1d07SSam Ravnborg 17648b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17658b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17668b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17678b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17688b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17698b2cb7a8SHuang, Ying platforms. 1770506f1d07SSam Ravnborg 1771291f3632SMatt Flemingconfig EFI_STUB 1772291f3632SMatt Fleming bool "EFI stub support" 1773b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17747b2a583aSMatt Fleming select RELOCATABLE 1775291f3632SMatt Fleming ---help--- 1776291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1777291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1778291f3632SMatt Fleming 17794172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17800c759662SMatt Fleming 17817d453eeeSMatt Flemingconfig EFI_MIXED 17827d453eeeSMatt Fleming bool "EFI mixed-mode support" 17837d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17847d453eeeSMatt Fleming ---help--- 17857d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17867d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17877d453eeeSMatt Fleming mode. 17887d453eeeSMatt Fleming 17897d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17907d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17917d453eeeSMatt Fleming the EFI handover protocol must be used. 17927d453eeeSMatt Fleming 17937d453eeeSMatt Fleming If unsure, say N. 17947d453eeeSMatt Fleming 1795506f1d07SSam Ravnborgconfig SECCOMP 17963c2362e6SHarvey Harrison def_bool y 17973c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17988f9ca475SIngo Molnar ---help--- 1799506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1800506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1801506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1802506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1803506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1804506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 18059c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1806506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1807506f1d07SSam Ravnborg defined by each seccomp mode. 1808506f1d07SSam Ravnborg 1809506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1810506f1d07SSam Ravnborg 1811506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1812506f1d07SSam Ravnborg 1813506f1d07SSam Ravnborgconfig KEXEC 1814506f1d07SSam Ravnborg bool "kexec system call" 18152965faa5SDave Young select KEXEC_CORE 18168f9ca475SIngo Molnar ---help--- 1817506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1818506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1819506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1820506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1821506f1d07SSam Ravnborg 1822506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1823506f1d07SSam Ravnborg 1824506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1825506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1826bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1827bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1828bf220695SGeert Uytterhoeven made. 1829506f1d07SSam Ravnborg 183074ca317cSVivek Goyalconfig KEXEC_FILE 183174ca317cSVivek Goyal bool "kexec file based system call" 18322965faa5SDave Young select KEXEC_CORE 183374ca317cSVivek Goyal select BUILD_BIN2C 183474ca317cSVivek Goyal depends on X86_64 183574ca317cSVivek Goyal depends on CRYPTO=y 183674ca317cSVivek Goyal depends on CRYPTO_SHA256=y 183774ca317cSVivek Goyal ---help--- 183874ca317cSVivek Goyal This is new version of kexec system call. This system call is 183974ca317cSVivek Goyal file based and takes file descriptors as system call argument 184074ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 184174ca317cSVivek Goyal accepted by previous system call. 184274ca317cSVivek Goyal 18438e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 18448e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 184574ca317cSVivek Goyal depends on KEXEC_FILE 18468e7d8381SVivek Goyal ---help--- 18478e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1848d8eb8940SBorislav Petkov the kexec_file_load() syscall. 18498e7d8381SVivek Goyal 1850d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1851d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1852d8eb8940SBorislav Petkov loaded in order for this to work. 18538e7d8381SVivek Goyal 18548e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 18558e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 18568e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 18578e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 18588e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 18598e7d8381SVivek Goyal ---help--- 18608e7d8381SVivek Goyal Enable bzImage signature verification support. 18618e7d8381SVivek Goyal 1862506f1d07SSam Ravnborgconfig CRASH_DUMP 186304b69447SPavel Machek bool "kernel crash dumps" 1864506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18658f9ca475SIngo Molnar ---help--- 1866506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1867506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1868506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1869506f1d07SSam Ravnborg a specially reserved region and then later executed after 1870506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1871506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1872506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1873506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1874506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1875506f1d07SSam Ravnborg 18763ab83521SHuang Yingconfig KEXEC_JUMP 18776ea30386SKees Cook bool "kexec jump" 1878fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18798f9ca475SIngo Molnar ---help--- 188089081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 188189081d17SHuang Ying code in physical address mode via KEXEC 18823ab83521SHuang Ying 1883506f1d07SSam Ravnborgconfig PHYSICAL_START 18846a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1885ceefccc9SH. Peter Anvin default "0x1000000" 18868f9ca475SIngo Molnar ---help--- 1887506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1888506f1d07SSam Ravnborg 1889506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1890506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1891506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1892506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1893506f1d07SSam Ravnborg address. 1894506f1d07SSam Ravnborg 1895506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1896506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1897506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1898506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1899506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1900506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1901506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1902506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1903506f1d07SSam Ravnborg 1904ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1905ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1906ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1907ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1908ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1909ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1910ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1911ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1912ceefccc9SH. Peter Anvin for more details about crash dumps. 1913506f1d07SSam Ravnborg 1914506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1915506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1916506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1917506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1918506f1d07SSam Ravnborg is present because there are users out there who continue to use 1919506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1920506f1d07SSam Ravnborg line. 1921506f1d07SSam Ravnborg 1922506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1923506f1d07SSam Ravnborg 1924506f1d07SSam Ravnborgconfig RELOCATABLE 192526717808SH. Peter Anvin bool "Build a relocatable kernel" 192626717808SH. Peter Anvin default y 19278f9ca475SIngo Molnar ---help--- 1928506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1929506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1930506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1931506f1d07SSam Ravnborg but are discarded at runtime. 1932506f1d07SSam Ravnborg 1933506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1934506f1d07SSam Ravnborg must live at a different physical address than the primary 1935506f1d07SSam Ravnborg kernel. 1936506f1d07SSam Ravnborg 1937506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1938506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 19398ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1940506f1d07SSam Ravnborg 19418ab3820fSKees Cookconfig RANDOMIZE_BASE 1942e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 19438ab3820fSKees Cook depends on RELOCATABLE 19448ab3820fSKees Cook default n 19458ab3820fSKees Cook ---help--- 1946e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 1947e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 1948e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 1949e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 1950e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 1951e8581e3dSBaoquan He code internals. 1952e8581e3dSBaoquan He 1953ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 1954ed9f007eSKees Cook randomized separately. The physical address will be anywhere 1955ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 1956ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 1957ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 1958ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 1959ed9f007eSKees Cook 1960ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 1961ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 1962ed9f007eSKees Cook 512MB (8 bits of entropy). 19638ab3820fSKees Cook 1964a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1965e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 1966e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 1967ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 1968ed9f007eSKees Cook usable entropy is limited by the kernel being built using 1969ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 1970ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 1971ed9f007eSKees Cook theoretically possible, but the implementations are further 1972ed9f007eSKees Cook limited due to memory layouts. 1973e8581e3dSBaoquan He 1974e8581e3dSBaoquan He If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot 1975e8581e3dSBaoquan He time. To enable it, boot with "kaslr" on the kernel command 1976e8581e3dSBaoquan He line (which will also disable hibernation). 19778ab3820fSKees Cook 1978da2b6fb9SKees Cook If unsure, say N. 1979da2b6fb9SKees Cook 19808ab3820fSKees Cook# Relocation on x86 needs some additional build support 1981845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1982845adf72SH. Peter Anvin def_bool y 19838ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1984845adf72SH. Peter Anvin 1985506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1986a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19878ab3820fSKees Cook default "0x200000" 1988a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1989a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19908f9ca475SIngo Molnar ---help--- 1991506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1992506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1993506f1d07SSam Ravnborg address which meets above alignment restriction. 1994506f1d07SSam Ravnborg 1995506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1996506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1997506f1d07SSam Ravnborg address aligned to above value and run from there. 1998506f1d07SSam Ravnborg 1999506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2000506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2001506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2002506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2003506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2004506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2005506f1d07SSam Ravnborg above alignment restrictions. 2006506f1d07SSam Ravnborg 2007a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2008a0215061SKees Cook this value must be a multiple of 0x200000. 2009a0215061SKees Cook 2010506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2011506f1d07SSam Ravnborg 20120483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 20130483e1faSThomas Garnier bool "Randomize the kernel memory sections" 20140483e1faSThomas Garnier depends on X86_64 20150483e1faSThomas Garnier depends on RANDOMIZE_BASE 20160483e1faSThomas Garnier default RANDOMIZE_BASE 20170483e1faSThomas Garnier ---help--- 20180483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 20190483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 20200483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 20210483e1faSThomas Garnier 20220483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 20230483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 20240483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 20250483e1faSThomas Garnier addresses for each memory section. 20260483e1faSThomas Garnier 20270483e1faSThomas Garnier If unsure, say N. 20280483e1faSThomas Garnier 202990397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 203090397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 203190397a41SThomas Garnier depends on RANDOMIZE_MEMORY 203290397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 203390397a41SThomas Garnier default "0x0" 203490397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 203590397a41SThomas Garnier range 0x0 0x40 203690397a41SThomas Garnier ---help--- 203790397a41SThomas Garnier Define the padding in terabytes added to the existing physical 203890397a41SThomas Garnier memory size during kernel memory randomization. It is useful 203990397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 204090397a41SThomas Garnier address randomization. 204190397a41SThomas Garnier 204290397a41SThomas Garnier If unsure, leave at the default value. 204390397a41SThomas Garnier 2044506f1d07SSam Ravnborgconfig HOTPLUG_CPU 20457c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 204640b31360SStephen Rothwell depends on SMP 2047506f1d07SSam Ravnborg ---help--- 20487c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 20497c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 20507c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 20517c13e6a3SDimitri Sivanich automatically on SMP systems. ) 20527c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 2053506f1d07SSam Ravnborg 205480aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 205580aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 205680aa1dffSFenghua Yu default n 20572c922cd0SKees Cook depends on HOTPLUG_CPU 205880aa1dffSFenghua Yu ---help--- 205980aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 206080aa1dffSFenghua Yu 206180aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 206280aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 206380aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 206480aa1dffSFenghua Yu 206580aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 206680aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 206780aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 206880aa1dffSFenghua Yu 206980aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 207080aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 207180aa1dffSFenghua Yu 207280aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 207380aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 207480aa1dffSFenghua Yu be other CPU0 dependencies. 207580aa1dffSFenghua Yu 207680aa1dffSFenghua Yu Please make sure the dependencies are under your control before 207780aa1dffSFenghua Yu you enable this feature. 207880aa1dffSFenghua Yu 207980aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 208080aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 208180aa1dffSFenghua Yu parameter cpu0_hotplug. 208280aa1dffSFenghua Yu 2083a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2084a71c8bc5SFenghua Yu def_bool n 2085a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20862c922cd0SKees Cook depends on HOTPLUG_CPU 2087a71c8bc5SFenghua Yu ---help--- 2088a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2089a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2090a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2091a71c8bc5SFenghua Yu 2092a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2093a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2094a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2095a71c8bc5SFenghua Yu 2096a71c8bc5SFenghua Yu If unsure, say N. 2097a71c8bc5SFenghua Yu 2098506f1d07SSam Ravnborgconfig COMPAT_VDSO 2099b0b49f26SAndy Lutomirski def_bool n 2100b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2101af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 21028f9ca475SIngo Molnar ---help--- 2103b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2104b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2105b0b49f26SAndy Lutomirski indicated in its segment table. 2106e84446deSRandy Dunlap 2107b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2108b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2109b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2110b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2111b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2112506f1d07SSam Ravnborg 2113b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2114b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2115b0b49f26SAndy Lutomirski 2116b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2117b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2118b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2119b0b49f26SAndy Lutomirski 2120b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2121b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2122506f1d07SSam Ravnborg 21233dc33bd3SKees Cookchoice 21243dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 21253dc33bd3SKees Cook depends on X86_64 21263dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 21273dc33bd3SKees Cook help 21283dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 21293dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 21303dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 21313dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 21323dc33bd3SKees Cook 21333dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 21343dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 21353dc33bd3SKees Cook 21363dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 21373dc33bd3SKees Cook static binaries, you can say None without a performance penalty 21383dc33bd3SKees Cook to improve security. 21393dc33bd3SKees Cook 21403dc33bd3SKees Cook If unsure, select "Emulate". 21413dc33bd3SKees Cook 21423dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 21433dc33bd3SKees Cook bool "Native" 21443dc33bd3SKees Cook help 21453dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 21463dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 21473dc33bd3SKees Cook this makes the mapping executable, it can be used during 21483dc33bd3SKees Cook security vulnerability exploitation (traditionally as 21493dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 21503dc33bd3SKees Cook 21513dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 21523dc33bd3SKees Cook bool "Emulate" 21533dc33bd3SKees Cook help 21543dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 21553dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 21563dc33bd3SKees Cook non-executable, but it still contains known contents, 21573dc33bd3SKees Cook which could be used in certain rare security vulnerability 21583dc33bd3SKees Cook exploits. This configuration is recommended when userspace 21593dc33bd3SKees Cook still uses the vsyscall area. 21603dc33bd3SKees Cook 21613dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 21623dc33bd3SKees Cook bool "None" 21633dc33bd3SKees Cook help 21643dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 21653dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 21663dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 21673dc33bd3SKees Cook will be reported to dmesg, so that either old or 21683dc33bd3SKees Cook malicious userspace programs can be identified. 21693dc33bd3SKees Cook 21703dc33bd3SKees Cookendchoice 21713dc33bd3SKees Cook 2172516cbf37STim Birdconfig CMDLINE_BOOL 2173516cbf37STim Bird bool "Built-in kernel command line" 21748f9ca475SIngo Molnar ---help--- 2175516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2176516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2177516cbf37STim Bird necessary or convenient to provide some or all of the 2178516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2179516cbf37STim Bird to not rely on the boot loader to provide them.) 2180516cbf37STim Bird 2181516cbf37STim Bird To compile command line arguments into the kernel, 2182516cbf37STim Bird set this option to 'Y', then fill in the 218369711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2184516cbf37STim Bird 2185516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2186516cbf37STim Bird should leave this option set to 'N'. 2187516cbf37STim Bird 2188516cbf37STim Birdconfig CMDLINE 2189516cbf37STim Bird string "Built-in kernel command string" 2190516cbf37STim Bird depends on CMDLINE_BOOL 2191516cbf37STim Bird default "" 21928f9ca475SIngo Molnar ---help--- 2193516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2194516cbf37STim Bird image and used at boot time. If the boot loader provides a 2195516cbf37STim Bird command line at boot time, it is appended to this string to 2196516cbf37STim Bird form the full kernel command line, when the system boots. 2197516cbf37STim Bird 2198516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2199516cbf37STim Bird change this behavior. 2200516cbf37STim Bird 2201516cbf37STim Bird In most cases, the command line (whether built-in or provided 2202516cbf37STim Bird by the boot loader) should specify the device for the root 2203516cbf37STim Bird file system. 2204516cbf37STim Bird 2205516cbf37STim Birdconfig CMDLINE_OVERRIDE 2206516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2207516cbf37STim Bird depends on CMDLINE_BOOL 22088f9ca475SIngo Molnar ---help--- 2209516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2210516cbf37STim Bird command line, and use ONLY the built-in command line. 2211516cbf37STim Bird 2212516cbf37STim Bird This is used to work around broken boot loaders. This should 2213516cbf37STim Bird be set to 'N' under normal conditions. 2214516cbf37STim Bird 2215a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2216a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2217a5b9e5a2SAndy Lutomirski default y 2218a5b9e5a2SAndy Lutomirski ---help--- 2219a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2220a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2221a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2222a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2223a5b9e5a2SAndy Lutomirski threading libraries. 2224a5b9e5a2SAndy Lutomirski 2225a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2226a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2227a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2228a5b9e5a2SAndy Lutomirski 2229a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2230a5b9e5a2SAndy Lutomirski 2231b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2232b700e7f0SSeth Jennings 2233506f1d07SSam Ravnborgendmenu 2234506f1d07SSam Ravnborg 2235506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2236506f1d07SSam Ravnborg def_bool y 2237506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2238506f1d07SSam Ravnborg 223935551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 224035551053SGary Hade def_bool y 224135551053SGary Hade depends on MEMORY_HOTPLUG 224235551053SGary Hade 2243e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2244645a7919STejun Heo def_bool y 2245e534c7c5SLee Schermerhorn depends on NUMA 2246e534c7c5SLee Schermerhorn 22479491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 22489491846fSKirill A. Shutemov def_bool y 22499491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 22509491846fSKirill A. Shutemov 2251c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2252c177c81eSNaoya Horiguchi def_bool y 2253c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2254c177c81eSNaoya Horiguchi 2255da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2256e279b6c1SSam Ravnborg 2257e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 22583c2362e6SHarvey Harrison def_bool y 2259e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2260e279b6c1SSam Ravnborg 2261e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2262e279b6c1SSam Ravnborg 2263e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2264e279b6c1SSam Ravnborg 2265efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2266efafc8b2SFeng Tang 2267a6b68076SAndi Kleenconfig X86_APM_BOOT 22686fc108a0SJan Beulich def_bool y 2269282e5aabSPaul Bolle depends on APM 2270a6b68076SAndi Kleen 2271e279b6c1SSam Ravnborgmenuconfig APM 2272e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2273efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2274e279b6c1SSam Ravnborg ---help--- 2275e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2276e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2277e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2278e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2279e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2280e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2281e279b6c1SSam Ravnborg 2282e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2283e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2284e279b6c1SSam Ravnborg 2285e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2286e279b6c1SSam Ravnborg machines with more than one CPU. 2287e279b6c1SSam Ravnborg 2288e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22892dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22902dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2291e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2292e279b6c1SSam Ravnborg 2293e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2294e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2295e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2296e279b6c1SSam Ravnborg 2297e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2298e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2299e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2300e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2301e279b6c1SSam Ravnborg 2302e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2303e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2304e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2305e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2306e279b6c1SSam Ravnborg APM in your BIOS). 2307e279b6c1SSam Ravnborg 2308e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2309e279b6c1SSam Ravnborg "weird" problems: 2310e279b6c1SSam Ravnborg 2311e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2312e279b6c1SSam Ravnborg enabled. 2313e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2314e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2315e279b6c1SSam Ravnborg the "no387" option to the kernel 2316e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2317e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2318e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2319e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2320e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2321e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2322e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2323e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2324e279b6c1SSam Ravnborg 11) exchange RAM chips 2325e279b6c1SSam Ravnborg 12) exchange the motherboard. 2326e279b6c1SSam Ravnborg 2327e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2328e279b6c1SSam Ravnborg module will be called apm. 2329e279b6c1SSam Ravnborg 2330e279b6c1SSam Ravnborgif APM 2331e279b6c1SSam Ravnborg 2332e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2333e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 23348f9ca475SIngo Molnar ---help--- 2335e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2336e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2337e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2338e279b6c1SSam Ravnborg 2339e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2340e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2341e279b6c1SSam Ravnborg ---help--- 2342e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2343e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2344e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2345e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2346e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2347e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2348e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2349e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2350e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2351e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2352e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2353e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2354e279b6c1SSam Ravnborg this feature. 2355e279b6c1SSam Ravnborg 2356e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2357dd8af076SLen Brown depends on CPU_IDLE 2358e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 23598f9ca475SIngo Molnar ---help--- 2360e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2361e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2362e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2363e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2364e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2365e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2366e279b6c1SSam Ravnborg this option does nothing.) 2367e279b6c1SSam Ravnborg 2368e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2369e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 23708f9ca475SIngo Molnar ---help--- 2371e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2372e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2373e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2374e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2375e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2376e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2377e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2378e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2379e279b6c1SSam Ravnborg especially if you are using gpm. 2380e279b6c1SSam Ravnborg 2381e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2382e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 23838f9ca475SIngo Molnar ---help--- 2384e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2385e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2386e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2387e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2388e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2389e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2390e279b6c1SSam Ravnborg 2391e279b6c1SSam Ravnborgendif # APM 2392e279b6c1SSam Ravnborg 2393bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2394e279b6c1SSam Ravnborg 2395e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2396e279b6c1SSam Ravnborg 239727471fdbSAndy Henroidsource "drivers/idle/Kconfig" 239827471fdbSAndy Henroid 2399e279b6c1SSam Ravnborgendmenu 2400e279b6c1SSam Ravnborg 2401e279b6c1SSam Ravnborg 2402e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2403e279b6c1SSam Ravnborg 2404e279b6c1SSam Ravnborgconfig PCI 24051ac97018SIngo Molnar bool "PCI support" 24061c858087SAdrian Bunk default y 24078f9ca475SIngo Molnar ---help--- 2408e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2409e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2410e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2411e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2412e279b6c1SSam Ravnborg 2413e279b6c1SSam Ravnborgchoice 2414e279b6c1SSam Ravnborg prompt "PCI access mode" 2415efefa6f6SIngo Molnar depends on X86_32 && PCI 2416e279b6c1SSam Ravnborg default PCI_GOANY 2417e279b6c1SSam Ravnborg ---help--- 2418e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2419e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2420e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2421e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2422e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2423e279b6c1SSam Ravnborg 2424e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2425e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2426e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2427e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2428e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2429e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2430e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2431e279b6c1SSam Ravnborg 2432e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2433e279b6c1SSam Ravnborg bool "BIOS" 2434e279b6c1SSam Ravnborg 2435e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2436e279b6c1SSam Ravnborg bool "MMConfig" 2437e279b6c1SSam Ravnborg 2438e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2439e279b6c1SSam Ravnborg bool "Direct" 2440e279b6c1SSam Ravnborg 24413ef0e1f8SAndres Salomonconfig PCI_GOOLPC 244276fb6570SDaniel Drake bool "OLPC XO-1" 24433ef0e1f8SAndres Salomon depends on OLPC 24443ef0e1f8SAndres Salomon 24452bdd1b03SAndres Salomonconfig PCI_GOANY 24462bdd1b03SAndres Salomon bool "Any" 24472bdd1b03SAndres Salomon 2448e279b6c1SSam Ravnborgendchoice 2449e279b6c1SSam Ravnborg 2450e279b6c1SSam Ravnborgconfig PCI_BIOS 24513c2362e6SHarvey Harrison def_bool y 2452efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2453e279b6c1SSam Ravnborg 2454e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2455e279b6c1SSam Ravnborgconfig PCI_DIRECT 24563c2362e6SHarvey Harrison def_bool y 24570aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2458e279b6c1SSam Ravnborg 2459e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 24603c2362e6SHarvey Harrison def_bool y 24615f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2462e279b6c1SSam Ravnborg 24633ef0e1f8SAndres Salomonconfig PCI_OLPC 24642bdd1b03SAndres Salomon def_bool y 24652bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 24663ef0e1f8SAndres Salomon 2467b5401a96SAlex Nixonconfig PCI_XEN 2468b5401a96SAlex Nixon def_bool y 2469b5401a96SAlex Nixon depends on PCI && XEN 2470b5401a96SAlex Nixon select SWIOTLB_XEN 2471b5401a96SAlex Nixon 2472e279b6c1SSam Ravnborgconfig PCI_DOMAINS 24733c2362e6SHarvey Harrison def_bool y 2474e279b6c1SSam Ravnborg depends on PCI 2475e279b6c1SSam Ravnborg 2476e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2477e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2478e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2479e279b6c1SSam Ravnborg 24803f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 24816a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 24826ea30386SKees Cook depends on PCI 24833f6ea84aSIra W. Snyder help 24843f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24853f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24863f6ea84aSIra W. Snyder not have ACPI. 24873f6ea84aSIra W. Snyder 248864a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 248964a5fed6SBjorn Helgaas is known to be incomplete. 249064a5fed6SBjorn Helgaas 249164a5fed6SBjorn Helgaas You should say N unless you know you need this. 249264a5fed6SBjorn Helgaas 2493e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2494e279b6c1SSam Ravnborg 24953a495511SWilliam Breathitt Grayconfig ISA_BUS 24963a495511SWilliam Breathitt Gray bool "ISA-style bus support on modern systems" if EXPERT 24973a495511SWilliam Breathitt Gray select ISA_BUS_API 24983a495511SWilliam Breathitt Gray help 24993a495511SWilliam Breathitt Gray Enables ISA-style drivers on modern systems. This is necessary to 25003a495511SWilliam Breathitt Gray support PC/104 devices on X86_64 platforms. 25013a495511SWilliam Breathitt Gray 25023a495511SWilliam Breathitt Gray If unsure, say N. 25033a495511SWilliam Breathitt Gray 25041c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2505e279b6c1SSam Ravnborgconfig ISA_DMA_API 25061c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 25071c00f016SDavid Rientjes default y 25081c00f016SDavid Rientjes help 25091c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 25101c00f016SDavid Rientjes If unsure, say Y. 2511e279b6c1SSam Ravnborg 251251e68d05SLinus Torvaldsif X86_32 251351e68d05SLinus Torvalds 2514e279b6c1SSam Ravnborgconfig ISA 2515e279b6c1SSam Ravnborg bool "ISA support" 25168f9ca475SIngo Molnar ---help--- 2517e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2518e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2519e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2520e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2521e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2522e279b6c1SSam Ravnborg 2523e279b6c1SSam Ravnborgconfig EISA 2524e279b6c1SSam Ravnborg bool "EISA support" 2525e279b6c1SSam Ravnborg depends on ISA 2526e279b6c1SSam Ravnborg ---help--- 2527e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2528e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2529e279b6c1SSam Ravnborg 2530e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2531e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2532e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2533e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2534e279b6c1SSam Ravnborg 2535e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2536e279b6c1SSam Ravnborg 2537e279b6c1SSam Ravnborg Otherwise, say N. 2538e279b6c1SSam Ravnborg 2539e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2540e279b6c1SSam Ravnborg 2541e279b6c1SSam Ravnborgconfig SCx200 2542e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 25438f9ca475SIngo Molnar ---help--- 2544e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2545e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2546e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2547e279b6c1SSam Ravnborg for other scx200_* drivers. 2548e279b6c1SSam Ravnborg 2549e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2550e279b6c1SSam Ravnborg 2551e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2552e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2553592913ecSJohn Stultz depends on SCx200 2554e279b6c1SSam Ravnborg default y 25558f9ca475SIngo Molnar ---help--- 2556e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2557e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2558e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2559e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2560e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2561e279b6c1SSam Ravnborg 25623ef0e1f8SAndres Salomonconfig OLPC 25633ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 256454008979SThomas Gleixner depends on !X86_PAE 25653c554946SAndres Salomon select GPIOLIB 2566dc3119e7SThomas Gleixner select OF 256745bb1674SDaniel Drake select OF_PROMTREE 2568b4e51854SGrant Likely select IRQ_DOMAIN 25698f9ca475SIngo Molnar ---help--- 25703ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 25713ef0e1f8SAndres Salomon XO hardware. 25723ef0e1f8SAndres Salomon 2573a3128588SDaniel Drakeconfig OLPC_XO1_PM 2574a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 257597c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2576a3128588SDaniel Drake select MFD_CORE 2577bf1ebf00SDaniel Drake ---help--- 257897c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2579bf1ebf00SDaniel Drake 2580cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2581cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2582cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2583cfee9597SDaniel Drake ---help--- 2584cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2585cfee9597SDaniel Drake programmable wakeup source. 2586cfee9597SDaniel Drake 25877feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 25887feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2589d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2590ed8e47feSRandy Dunlap depends on INPUT=y 2591d8d01a63SDaniel Drake select POWER_SUPPLY 25927feda8e9SDaniel Drake select GPIO_CS5535 25937feda8e9SDaniel Drake select MFD_CORE 25947feda8e9SDaniel Drake ---help--- 25957feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25967bc74b3dSDaniel Drake - EC-driven system wakeups 25977feda8e9SDaniel Drake - Power button 25987bc74b3dSDaniel Drake - Ebook switch 25992cf2baeaSDaniel Drake - Lid switch 2600e1040ac6SDaniel Drake - AC adapter status updates 2601e1040ac6SDaniel Drake - Battery status updates 26027feda8e9SDaniel Drake 2603a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2604a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2605d8d01a63SDaniel Drake depends on OLPC && ACPI 2606d8d01a63SDaniel Drake select POWER_SUPPLY 2607a0f30f59SDaniel Drake ---help--- 2608a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2609a0f30f59SDaniel Drake - EC-driven system wakeups 2610a0f30f59SDaniel Drake - AC adapter status updates 2611a0f30f59SDaniel Drake - Battery status updates 2612e279b6c1SSam Ravnborg 2613d4f3e350SEd Wildgooseconfig ALIX 2614d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2615d4f3e350SEd Wildgoose select GPIOLIB 2616d4f3e350SEd Wildgoose ---help--- 2617d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2618d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2619d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2620d4f3e350SEd Wildgoose get added here. 2621d4f3e350SEd Wildgoose 2622d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2623d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2624d4f3e350SEd Wildgoose 2625d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2626d4f3e350SEd Wildgoose 2627da4e3302SPhilip Prindevilleconfig NET5501 2628da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2629da4e3302SPhilip Prindeville select GPIOLIB 2630da4e3302SPhilip Prindeville ---help--- 2631da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2632da4e3302SPhilip Prindeville 26333197059aSPhilip A. Prindevilleconfig GEOS 26343197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 26353197059aSPhilip A. Prindeville select GPIOLIB 26363197059aSPhilip A. Prindeville depends on DMI 26373197059aSPhilip A. Prindeville ---help--- 26383197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 26393197059aSPhilip A. Prindeville 26407d029125SVivien Didelotconfig TS5500 26417d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 26427d029125SVivien Didelot depends on MELAN 26437d029125SVivien Didelot select CHECK_SIGNATURE 26447d029125SVivien Didelot select NEW_LEDS 26457d029125SVivien Didelot select LEDS_CLASS 26467d029125SVivien Didelot ---help--- 26477d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 26487d029125SVivien Didelot 2649e279b6c1SSam Ravnborgendif # X86_32 2650e279b6c1SSam Ravnborg 265123ac4ae8SAndreas Herrmannconfig AMD_NB 2652e279b6c1SSam Ravnborg def_bool y 26530e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2654e279b6c1SSam Ravnborg 2655e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2656e279b6c1SSam Ravnborg 2657388b78adSAlexandre Bounineconfig RAPIDIO 2658fdf90abcSAlexandre Bounine tristate "RapidIO support" 2659388b78adSAlexandre Bounine depends on PCI 2660388b78adSAlexandre Bounine default n 2661388b78adSAlexandre Bounine help 2662fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2663388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2664388b78adSAlexandre Bounine 2665388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2666388b78adSAlexandre Bounine 2667e3263ab3SDavid Herrmannconfig X86_SYSFB 2668e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2669e3263ab3SDavid Herrmann help 2670e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2671e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2672e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2673e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2674e3263ab3SDavid Herrmann to x86. 2675e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2676e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2677e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2678e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2679e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2680e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2681e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2682e3263ab3SDavid Herrmann 2683e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2684e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2685e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2686e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2687e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2688e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2689e3263ab3SDavid Herrmann incompatible with simplefb. 2690e3263ab3SDavid Herrmann 2691e3263ab3SDavid Herrmann If unsure, say Y. 2692e3263ab3SDavid Herrmann 2693e279b6c1SSam Ravnborgendmenu 2694e279b6c1SSam Ravnborg 2695e279b6c1SSam Ravnborg 2696e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2697e279b6c1SSam Ravnborg 2698e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2699e279b6c1SSam Ravnborg 2700e279b6c1SSam Ravnborgconfig IA32_EMULATION 2701e279b6c1SSam Ravnborg bool "IA32 Emulation" 2702e279b6c1SSam Ravnborg depends on X86_64 2703*39f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2704d1603990SRandy Dunlap select BINFMT_ELF 2705a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 2706*39f88911SIngo Molnar select COMPAT_OLD_SIGACTION 27078f9ca475SIngo Molnar ---help--- 27085fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 27095fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 27105fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2711e279b6c1SSam Ravnborg 2712e279b6c1SSam Ravnborgconfig IA32_AOUT 2713e279b6c1SSam Ravnborg tristate "IA32 a.out support" 27146b213e1bSDavid Woodhouse depends on IA32_EMULATION 27158f9ca475SIngo Molnar ---help--- 2716e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2717e279b6c1SSam Ravnborg 27180bf62763SH. Peter Anvinconfig X86_X32 27196ea30386SKees Cook bool "x32 ABI for 64-bit mode" 27209b54050bSBrian Gerst depends on X86_64 27215fd92e65SH. J. Lu ---help--- 27225fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 27235fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 27245fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 27255fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 27265fd92e65SH. J. Lu 27275fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 27285fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 27295fd92e65SH. J. Lu option set. 27305fd92e65SH. J. Lu 2731e279b6c1SSam Ravnborgconfig COMPAT 27323c2362e6SHarvey Harrison def_bool y 27330bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2734e279b6c1SSam Ravnborg 27353120e25eSJan Beulichif COMPAT 2736e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 27373120e25eSJan Beulich def_bool y 2738e279b6c1SSam Ravnborg 2739e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 27403c2362e6SHarvey Harrison def_bool y 27413120e25eSJan Beulich depends on SYSVIPC 2742e279b6c1SSam Ravnborg 2743ee009e4aSDavid Howellsconfig KEYS_COMPAT 27443120e25eSJan Beulich def_bool y 27453120e25eSJan Beulich depends on KEYS 27463120e25eSJan Beulichendif 2747ee009e4aSDavid Howells 2748e279b6c1SSam Ravnborgendmenu 2749e279b6c1SSam Ravnborg 2750e279b6c1SSam Ravnborg 2751e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2752e5beae16SKeith Packard def_bool y 2753e5beae16SKeith Packard depends on X86_32 2754e5beae16SKeith Packard 27554692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 27564692d77fSAlessandro Rubini bool 275783125a3aSAlessandro Rubini depends on X86_64 || STA2X11 27584692d77fSAlessandro Rubini 2759f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2760f7219a53SAlessandro Rubini bool 276183125a3aSAlessandro Rubini depends on STA2X11 2762f7219a53SAlessandro Rubini 276393e5eaddSLi, Aubreyconfig PMC_ATOM 276493e5eaddSLi, Aubrey def_bool y 276593e5eaddSLi, Aubrey depends on PCI 276693e5eaddSLi, Aubrey 2767e279b6c1SSam Ravnborgsource "net/Kconfig" 2768e279b6c1SSam Ravnborg 2769e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2770e279b6c1SSam Ravnborg 2771e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2772e279b6c1SSam Ravnborg 2773e279b6c1SSam Ravnborgsource "fs/Kconfig" 2774e279b6c1SSam Ravnborg 2775e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2776e279b6c1SSam Ravnborg 2777e279b6c1SSam Ravnborgsource "security/Kconfig" 2778e279b6c1SSam Ravnborg 2779e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2780e279b6c1SSam Ravnborg 2781edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2782edf88417SAvi Kivity 2783e279b6c1SSam Ravnborgsource "lib/Kconfig" 2784