1daa93fabSSam Ravnborg# Select 32 or 64 bit 2daa93fabSSam Ravnborgconfig 64BIT 36840999bSSam Ravnborg bool "64-bit kernel" if ARCH = "x86" 4ffee0de4SDavid Woodhouse default ARCH != "i386" 58f9ca475SIngo Molnar ---help--- 6daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 7daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 8daa93fabSSam Ravnborg 9daa93fabSSam Ravnborgconfig X86_32 103120e25eSJan Beulich def_bool y 113120e25eSJan Beulich depends on !64BIT 12daa93fabSSam Ravnborg 13daa93fabSSam Ravnborgconfig X86_64 143120e25eSJan Beulich def_bool y 153120e25eSJan Beulich depends on 64BIT 161032c0baSSam Ravnborg 171032c0baSSam Ravnborg### Arch settings 188d5fffb9SSam Ravnborgconfig X86 193c2362e6SHarvey Harrison def_bool y 206471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 216e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 226471b825SIngo Molnar select ANON_INODES 236471b825SIngo Molnar select ARCH_CLOCKSOURCE_DATA 246471b825SIngo Molnar select ARCH_DISCARD_MEMBLOCK 256471b825SIngo Molnar select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 26446f24d1SStephen Boyd select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 2721266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 286471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 2972d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 30957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 31*5c9a8750SDmitry Vyukov select ARCH_HAS_KCOV if X86_64 3296601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 3367a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 346471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 35c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 366471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 376471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3877fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 395e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 406471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 413b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 42be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 436471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 446471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 456471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 466471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 476471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 4872b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 495aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 50da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 516471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 526471b825SIngo Molnar select ARCH_WANT_OPTIONAL_GPIOLIB 536471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 546471b825SIngo Molnar select CLKEVT_I8253 556471b825SIngo Molnar select CLKSRC_I8253 if X86_32 566471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 576471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 586471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 596471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 606471b825SIngo Molnar select DCACHE_WORD_ACCESS 6145471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 6245471cd9SLinus Torvalds select EDAC_SUPPORT 636471b825SIngo Molnar select GENERIC_CLOCKEVENTS 646471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 656471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 666471b825SIngo Molnar select GENERIC_CMOS_UPDATE 676471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 686471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 696471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 706471b825SIngo Molnar select GENERIC_IOMAP 716471b825SIngo Molnar select GENERIC_IRQ_PROBE 726471b825SIngo Molnar select GENERIC_IRQ_SHOW 736471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 746471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 756471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 766471b825SIngo Molnar select GENERIC_STRNLEN_USER 776471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 786471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 796471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 806471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 816471b825SIngo Molnar select HAVE_AOUT if X86_32 826471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 836471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 846471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 856471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 866471b825SIngo Molnar select HAVE_ARCH_KGDB 876471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 889e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 899e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 906471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 916471b825SIngo Molnar select HAVE_ARCH_SOFT_DIRTY if X86_64 926471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 936471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 946471b825SIngo Molnar select HAVE_BPF_JIT if X86_64 956471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 966471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 976471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 986471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 99c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 1006471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1016471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1026471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 1036471b825SIngo Molnar select HAVE_DMA_API_DEBUG 1049c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 105677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10606aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10758340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1086471b825SIngo Molnar select HAVE_FENTRY if X86_64 1096471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1106471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_FP_TEST 1116471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1126471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1136471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1140067f129SK.Prasad select HAVE_HW_BREAKPOINT 1156471b825SIngo Molnar select HAVE_IDE 1166471b825SIngo Molnar select HAVE_IOREMAP_PROT 1176471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1186471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1196471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1206471b825SIngo Molnar select HAVE_KERNEL_GZIP 1216471b825SIngo Molnar select HAVE_KERNEL_LZ4 1226471b825SIngo Molnar select HAVE_KERNEL_LZMA 1236471b825SIngo Molnar select HAVE_KERNEL_LZO 1246471b825SIngo Molnar select HAVE_KERNEL_XZ 1256471b825SIngo Molnar select HAVE_KPROBES 1266471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1276471b825SIngo Molnar select HAVE_KRETPROBES 1286471b825SIngo Molnar select HAVE_KVM 1296471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1306471b825SIngo Molnar select HAVE_MEMBLOCK 1316471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1320102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 1336471b825SIngo Molnar select HAVE_OPROFILE 1346471b825SIngo Molnar select HAVE_OPTPROBES 1356471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1366471b825SIngo Molnar select HAVE_PERF_EVENTS 137c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 138c5e63197SJiri Olsa select HAVE_PERF_REGS 139c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1406471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1416471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1420c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1436471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1447c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 145c0185808SThomas Gleixner select IRQ_FORCED_THREADING 146786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1476471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1485b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1496471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1506471b825SIngo Molnar select PERF_EVENTS 1513195ef59SPrarit Bhargava select RTC_LIB 1526471b825SIngo Molnar select SPARSE_IRQ 15383fe27eaSPranith Kumar select SRCU 1546471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 1556471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1566471b825SIngo Molnar select VIRT_TO_BUS 1576471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1586471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 159d4883d5dSJosh Poimboeuf select HAVE_STACK_VALIDATION if X86_64 16063c17fb8SDave Hansen select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS 16166d37570SDave Hansen select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS 1627d8330a5SBalbir Singh 163ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1643120e25eSJan Beulich def_bool y 1653120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 166ba7e4d13SIngo Molnar 1677fb0f1deSPeter Zijlstraconfig PERF_EVENTS_INTEL_UNCORE 1687fb0f1deSPeter Zijlstra def_bool y 169ce5686d4SPeter Zijlstra (Intel) depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 1707fb0f1deSPeter Zijlstra 17151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 17251b26adaSLinus Torvalds string 17351b26adaSLinus Torvalds default "elf32-i386" if X86_32 17451b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 17551b26adaSLinus Torvalds 17673531905SSam Ravnborgconfig ARCH_DEFCONFIG 177b9b39bfbSSam Ravnborg string 17873531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 17973531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 180b9b39bfbSSam Ravnborg 1818d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1823c2362e6SHarvey Harrison def_bool y 1838d5fffb9SSam Ravnborg 1848d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1853c2362e6SHarvey Harrison def_bool y 1868d5fffb9SSam Ravnborg 1878d5fffb9SSam Ravnborgconfig MMU 1883c2362e6SHarvey Harrison def_bool y 1898d5fffb9SSam Ravnborg 1909e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 1919e08f57dSDaniel Cashman default 28 if 64BIT 1929e08f57dSDaniel Cashman default 8 1939e08f57dSDaniel Cashman 1949e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 1959e08f57dSDaniel Cashman default 32 if 64BIT 1969e08f57dSDaniel Cashman default 16 1979e08f57dSDaniel Cashman 1989e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 1999e08f57dSDaniel Cashman default 8 2009e08f57dSDaniel Cashman 2019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 2029e08f57dSDaniel Cashman default 16 2039e08f57dSDaniel Cashman 2048d5fffb9SSam Ravnborgconfig SBUS 2058d5fffb9SSam Ravnborg bool 2068d5fffb9SSam Ravnborg 2073bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 2083120e25eSJan Beulich def_bool y 209a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 2103bc4e459SFUJITA Tomonori 21118e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 2124a14d84eSAndrew Morton def_bool y 21318e98307SFUJITA Tomonori 2148d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 2153120e25eSJan Beulich def_bool y 2163120e25eSJan Beulich depends on ISA_DMA_API 2178d5fffb9SSam Ravnborg 2188d5fffb9SSam Ravnborgconfig GENERIC_BUG 2193c2362e6SHarvey Harrison def_bool y 2208d5fffb9SSam Ravnborg depends on BUG 221b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 222b93a531eSJan Beulich 223b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 224b93a531eSJan Beulich bool 2258d5fffb9SSam Ravnborg 2268d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2273c2362e6SHarvey Harrison def_bool y 2288d5fffb9SSam Ravnborg 2298d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2303120e25eSJan Beulich def_bool y 2313120e25eSJan Beulich depends on ISA_DMA_API 2328d5fffb9SSam Ravnborg 2331032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2343120e25eSJan Beulich def_bool y 2351032c0baSSam Ravnborg 2361032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2371032c0baSSam Ravnborg def_bool y 2381032c0baSSam Ravnborg 2399a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2409a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2418d5fffb9SSam Ravnborg 2421b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2431b27d05bSPekka Enberg def_bool y 2441b27d05bSPekka Enberg 245dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 24689c9c4c5SBrian Gerst def_bool y 247b32ef636Stravis@sgi.com 24808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 24908fc4580STejun Heo def_bool y 25008fc4580STejun Heo 25108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 25211124411STejun Heo def_bool y 25311124411STejun Heo 254801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 255801e4062SJohannes Berg def_bool y 256801e4062SJohannes Berg 257f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 258f4cb5700SJohannes Berg def_bool y 259f4cb5700SJohannes Berg 260cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 261cfe28c5dSSteve Capper def_bool y 262cfe28c5dSSteve Capper 26353313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 26453313b2cSSteve Capper def_bool y 26553313b2cSSteve Capper 2668d5fffb9SSam Ravnborgconfig ZONE_DMA32 267e0fd24a3SJan Beulich def_bool y if X86_64 2688d5fffb9SSam Ravnborg 2698d5fffb9SSam Ravnborgconfig AUDIT_ARCH 270e0fd24a3SJan Beulich def_bool y if X86_64 2718d5fffb9SSam Ravnborg 272765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 273765c68bdSIngo Molnar def_bool y 274765c68bdSIngo Molnar 2756a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2766a11f75bSAkinobu Mita def_bool y 2776a11f75bSAkinobu Mita 278d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 279d6f2d75aSAndrey Ryabinin hex 280d6f2d75aSAndrey Ryabinin depends on KASAN 281d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 282d6f2d75aSAndrey Ryabinin 28369575d38SShane Wangconfig HAVE_INTEL_TXT 28469575d38SShane Wang def_bool y 2856ea30386SKees Cook depends on INTEL_IOMMU && ACPI 28669575d38SShane Wang 2876b0c3d44SSam Ravnborgconfig X86_32_SMP 2886b0c3d44SSam Ravnborg def_bool y 2896b0c3d44SSam Ravnborg depends on X86_32 && SMP 2906b0c3d44SSam Ravnborg 2916b0c3d44SSam Ravnborgconfig X86_64_SMP 2926b0c3d44SSam Ravnborg def_bool y 2936b0c3d44SSam Ravnborg depends on X86_64 && SMP 2946b0c3d44SSam Ravnborg 295ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 296ccbeed3aSTejun Heo def_bool y 29760a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 298ccbeed3aSTejun Heo 299d61931d8SBorislav Petkovconfig ARCH_HWEIGHT_CFLAGS 300d61931d8SBorislav Petkov string 301d61931d8SBorislav Petkov default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 302d61931d8SBorislav Petkov default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 303d61931d8SBorislav Petkov 3042b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3052b144498SSrikar Dronamraju def_bool y 3062b144498SSrikar Dronamraju 307d20642f0SRob Herringconfig FIX_EARLYCON_MEM 308d20642f0SRob Herring def_bool y 309d20642f0SRob Herring 3109ccaf77cSKees Cookconfig DEBUG_RODATA 3119ccaf77cSKees Cook def_bool y 3129ccaf77cSKees Cook 31398233368SKirill A. Shutemovconfig PGTABLE_LEVELS 31498233368SKirill A. Shutemov int 31598233368SKirill A. Shutemov default 4 if X86_64 31698233368SKirill A. Shutemov default 3 if X86_PAE 31798233368SKirill A. Shutemov default 2 31898233368SKirill A. Shutemov 319506f1d07SSam Ravnborgsource "init/Kconfig" 320dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3218d5fffb9SSam Ravnborg 322506f1d07SSam Ravnborgmenu "Processor type and features" 323506f1d07SSam Ravnborg 3245ee71535SRandy Dunlapconfig ZONE_DMA 3255ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3265ee71535SRandy Dunlap default y 3275ee71535SRandy Dunlap help 3285ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3295ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3305ee71535SRandy Dunlap Disable if no such devices will be used. 3315ee71535SRandy Dunlap 3325ee71535SRandy Dunlap If unsure, say Y. 3335ee71535SRandy Dunlap 334506f1d07SSam Ravnborgconfig SMP 335506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 336506f1d07SSam Ravnborg ---help--- 337506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3384a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3394a474157SRobert Graffham than one CPU, say Y. 340506f1d07SSam Ravnborg 3414a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 342506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 343506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3444a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 345506f1d07SSam Ravnborg will run faster if you say N here. 346506f1d07SSam Ravnborg 347506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 348506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 349506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 350506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 351506f1d07SSam Ravnborg 352506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 353506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 354506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 355506f1d07SSam Ravnborg 356395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 357506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 358506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 359506f1d07SSam Ravnborg 360506f1d07SSam Ravnborg If you don't know what to do here, say N. 361506f1d07SSam Ravnborg 3629def39beSJosh Triplettconfig X86_FEATURE_NAMES 3639def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3649def39beSJosh Triplett default y 3659def39beSJosh Triplett ---help--- 3669def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3679def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3689def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3699def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3709def39beSJosh Triplett 3719def39beSJosh Triplett If in doubt, say Y. 3729def39beSJosh Triplett 3736e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS 3746e1315feSBorislav Petkov bool "Fast CPU feature tests" if EMBEDDED 3756e1315feSBorislav Petkov default y 3766e1315feSBorislav Petkov ---help--- 3776e1315feSBorislav Petkov Some fast-paths in the kernel depend on the capabilities of the CPU. 3786e1315feSBorislav Petkov Say Y here for the kernel to patch in the appropriate code at runtime 3796e1315feSBorislav Petkov based on the capabilities of the CPU. The infrastructure for patching 3806e1315feSBorislav Petkov code at runtime takes up some additional space; space-constrained 3816e1315feSBorislav Petkov embedded systems may wish to say N here to produce smaller, slightly 3826e1315feSBorislav Petkov slower code. 3836e1315feSBorislav Petkov 38406cd9a7dSYinghai Luconfig X86_X2APIC 38506cd9a7dSYinghai Lu bool "Support x2apic" 38619e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 38706cd9a7dSYinghai Lu ---help--- 38806cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 38906cd9a7dSYinghai Lu 39006cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 39106cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 39206cd9a7dSYinghai Lu 39306cd9a7dSYinghai Lu If you don't know what to do here, say N. 39406cd9a7dSYinghai Lu 3956695c85bSYinghai Luconfig X86_MPPARSE 3966e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3977a527688SJan Beulich default y 3985ab74722SIngo Molnar depends on X86_LOCAL_APIC 3998f9ca475SIngo Molnar ---help--- 4006695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4016695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4026695c85bSYinghai Lu 40326f7ef14SYinghai Luconfig X86_BIGSMP 40426f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 40526f7ef14SYinghai Lu depends on X86_32 && SMP 4068f9ca475SIngo Molnar ---help--- 40726f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 408506f1d07SSam Ravnborg 409ddd70cf9SJun Nakajimaconfig GOLDFISH 410ddd70cf9SJun Nakajima def_bool y 411ddd70cf9SJun Nakajima depends on X86_GOLDFISH 412ddd70cf9SJun Nakajima 4138425091fSRavikiran G Thirumalaiif X86_32 414c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 415c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 416c5c606d9SRavikiran G Thirumalai default y 4178f9ca475SIngo Molnar ---help--- 41806ac8346SIngo Molnar If you disable this option then the kernel will only support 41906ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 42006ac8346SIngo Molnar systems out there.) 42106ac8346SIngo Molnar 4228425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4238425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 424cb7b8023SBen Hutchings Goldfish (Android emulator) 4258425091fSRavikiran G Thirumalai AMD Elan 4268425091fSRavikiran G Thirumalai RDC R-321x SoC 4278425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 42883125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 4293f4110a4SThomas Gleixner Moorestown MID devices 43006ac8346SIngo Molnar 43106ac8346SIngo Molnar If you have one of these systems, or if you want to build a 43206ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4338425091fSRavikiran G Thirumalaiendif 43406ac8346SIngo Molnar 4358425091fSRavikiran G Thirumalaiif X86_64 4368425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4378425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4388425091fSRavikiran G Thirumalai default y 4398425091fSRavikiran G Thirumalai ---help--- 4408425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4418425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4428425091fSRavikiran G Thirumalai systems out there.) 4438425091fSRavikiran G Thirumalai 4448425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4458425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 44644b111b5SSteffen Persvold Numascale NumaChip 4478425091fSRavikiran G Thirumalai ScaleMP vSMP 4488425091fSRavikiran G Thirumalai SGI Ultraviolet 4498425091fSRavikiran G Thirumalai 4508425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4518425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4528425091fSRavikiran G Thirumalaiendif 453c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 454c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 45544b111b5SSteffen Persvoldconfig X86_NUMACHIP 45644b111b5SSteffen Persvold bool "Numascale NumaChip" 45744b111b5SSteffen Persvold depends on X86_64 45844b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 45944b111b5SSteffen Persvold depends on NUMA 46044b111b5SSteffen Persvold depends on SMP 46144b111b5SSteffen Persvold depends on X86_X2APIC 462f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 46344b111b5SSteffen Persvold ---help--- 46444b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 46544b111b5SSteffen Persvold enable more than ~168 cores. 46644b111b5SSteffen Persvold If you don't have one of these, you should say N here. 46703b48632SNick Piggin 4686a48565eSIngo Molnarconfig X86_VSMP 469c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4706276a074SBorislav Petkov select HYPERVISOR_GUEST 4716a48565eSIngo Molnar select PARAVIRT 4726a48565eSIngo Molnar depends on X86_64 && PCI 473c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 474ead91d4bSShai Fultheim depends on SMP 4758f9ca475SIngo Molnar ---help--- 4766a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4776a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4786a48565eSIngo Molnar if you have one of these machines. 4796a48565eSIngo Molnar 480c5c606d9SRavikiran G Thirumalaiconfig X86_UV 481c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 482c5c606d9SRavikiran G Thirumalai depends on X86_64 483c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 48454c28d29SJack Steiner depends on NUMA 4851ecb4ae5SAndrew Morton depends on EFI 4869d6c26e7SSuresh Siddha depends on X86_X2APIC 4871222e564SIngo Molnar depends on PCI 488c5c606d9SRavikiran G Thirumalai ---help--- 489c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 490c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 491c5c606d9SRavikiran G Thirumalai 492c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 493c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 494506f1d07SSam Ravnborg 495ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 496ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 497cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 498ddd70cf9SJun Nakajima ---help--- 499ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 500ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 501ddd70cf9SJun Nakajima Goldfish emulator say N here. 502ddd70cf9SJun Nakajima 503c751e17bSThomas Gleixnerconfig X86_INTEL_CE 504c751e17bSThomas Gleixner bool "CE4100 TV platform" 505c751e17bSThomas Gleixner depends on PCI 506c751e17bSThomas Gleixner depends on PCI_GODIRECT 5076084a6e2SJiang Liu depends on X86_IO_APIC 508c751e17bSThomas Gleixner depends on X86_32 509c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 51037bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 511da6b737bSSebastian Andrzej Siewior select OF 512da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 513c751e17bSThomas Gleixner ---help--- 514c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 515c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 516c751e17bSThomas Gleixner boxes and media devices. 517c751e17bSThomas Gleixner 5184cb9b00fSDavid Cohenconfig X86_INTEL_MID 51943605ef1SAlan Cox bool "Intel MID platform support" 52043605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 521edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 5221ea7c673SAlan Cox depends on PCI 5233fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 5241ea7c673SAlan Cox depends on X86_IO_APIC 5257c9c3a1eSAlan Cox select SFI 5264cb9b00fSDavid Cohen select I2C 5277c9c3a1eSAlan Cox select DW_APB_TIMER 5281ea7c673SAlan Cox select APB_TIMER 5291ea7c673SAlan Cox select INTEL_SCU_IPC 53015a713dfSMika Westerberg select MFD_INTEL_MSIC 5311ea7c673SAlan Cox ---help--- 5324cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5334cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5344cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5351ea7c673SAlan Cox 5364cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5374cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 53843605ef1SAlan Cox 5398bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5408bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5418bbc2a13SBryan O'Donoghue depends on X86_32 5428bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5438bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5448bbc2a13SBryan O'Donoghue depends on X86_TSC 5458bbc2a13SBryan O'Donoghue depends on PCI 5468bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5478bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5488bbc2a13SBryan O'Donoghue select IOSF_MBI 5498bbc2a13SBryan O'Donoghue select INTEL_IMR 5509ab6eb51SAndy Shevchenko select COMMON_CLK 5518bbc2a13SBryan O'Donoghue ---help--- 5528bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5538bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5548bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5558bbc2a13SBryan O'Donoghue 5563d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5573d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 558eebb3e8dSAndy Shevchenko depends on X86 && ACPI 5593d48aab1SMika Westerberg select COMMON_CLK 5600f531431SMathias Nyman select PINCTRL 561eebb3e8dSAndy Shevchenko select IOSF_MBI 5623d48aab1SMika Westerberg ---help--- 5633d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5643d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5650f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5660f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5673d48aab1SMika Westerberg 56892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 56992082a88SKen Xue bool "AMD ACPI2Platform devices support" 57092082a88SKen Xue depends on ACPI 57192082a88SKen Xue select COMMON_CLK 57292082a88SKen Xue select PINCTRL 57392082a88SKen Xue ---help--- 57492082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 57592082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 57692082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 57792082a88SKen Xue implemented under PINCTRL subsystem. 57892082a88SKen Xue 579ced3ce76SDavid E. Boxconfig IOSF_MBI 580ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 581ced3ce76SDavid E. Box depends on PCI 582ced3ce76SDavid E. Box ---help--- 583ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 584ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 585ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 586ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 587ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 588ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 589ced3ce76SDavid E. Box This list is not meant to be exclusive. 590ced3ce76SDavid E. Box - BayTrail 591ced3ce76SDavid E. Box - Braswell 592ced3ce76SDavid E. Box - Quark 593ced3ce76SDavid E. Box 594ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 595ced3ce76SDavid E. Box 596ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 597ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 598ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 599ed2226bdSDavid E. Box ---help--- 600ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 601ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 602ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 603ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 604ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 605ed2226bdSDavid E. Box device they want to access. 606ed2226bdSDavid E. Box 607ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 608ed2226bdSDavid E. Box 609c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 610c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 611506f1d07SSam Ravnborg depends on X86_32 612c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 613c5c606d9SRavikiran G Thirumalai select M486 614c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 615c5c606d9SRavikiran G Thirumalai ---help--- 616c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 617c5c606d9SRavikiran G Thirumalai as R-8610-(G). 618c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 619c5c606d9SRavikiran G Thirumalai 620e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 6219c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 6229c398017SIngo Molnar depends on X86_32 && SMP 623c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 6248f9ca475SIngo Molnar ---help--- 625b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 626b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 627b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 628b5660ba7SH. Peter Anvin one and will fallback to default. 629d49c4288SYinghai Lu 630c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 631d49c4288SYinghai Lu 632d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6336fc108a0SJan Beulich def_bool y 634d949f36fSLinus Torvalds # MCE code calls memory_failure(): 635d949f36fSLinus Torvalds depends on X86_MCE 636d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 637d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 638d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 639d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 640d949f36fSLinus Torvalds 64183125a3aSAlessandro Rubiniconfig STA2X11 64283125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 64383125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 64483125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 64583125a3aSAlessandro Rubini select X86_DMA_REMAP 64683125a3aSAlessandro Rubini select SWIOTLB 64783125a3aSAlessandro Rubini select MFD_STA2X11 64883125a3aSAlessandro Rubini select ARCH_REQUIRE_GPIOLIB 64983125a3aSAlessandro Rubini default n 65083125a3aSAlessandro Rubini ---help--- 65183125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 65283125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 65383125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 65483125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 65583125a3aSAlessandro Rubini standard PC machines. 65683125a3aSAlessandro Rubini 65782148d1dSShérabconfig X86_32_IRIS 65882148d1dSShérab tristate "Eurobraille/Iris poweroff module" 65982148d1dSShérab depends on X86_32 66082148d1dSShérab ---help--- 66182148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 66282148d1dSShérab to shut themselves down properly. A special I/O sequence is 66382148d1dSShérab needed to do so, which is what this module does at 66482148d1dSShérab kernel shutdown. 66582148d1dSShérab 66682148d1dSShérab This is only for Iris machines from EuroBraille. 66782148d1dSShérab 66882148d1dSShérab If unused, say N. 66982148d1dSShérab 670ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6713c2362e6SHarvey Harrison def_bool y 6723c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 673a87d0914SKen Chen depends on X86 6748f9ca475SIngo Molnar ---help--- 675506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 676506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 677506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 678506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 679506f1d07SSam Ravnborg 680506f1d07SSam Ravnborg If in doubt, say "Y". 681506f1d07SSam Ravnborg 6826276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6836276a074SBorislav Petkov bool "Linux guest support" 6848f9ca475SIngo Molnar ---help--- 6856276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6866276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6876276a074SBorislav Petkov setup. 688506f1d07SSam Ravnborg 6896276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6906276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 691506f1d07SSam Ravnborg 6926276a074SBorislav Petkovif HYPERVISOR_GUEST 693506f1d07SSam Ravnborg 694e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 695e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 6968f9ca475SIngo Molnar ---help--- 697e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 698e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 699e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 700e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 701e61bd94aSEduardo Pereira Habkost 7026276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7036276a074SBorislav Petkov bool "paravirt-ops debugging" 7046276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 7056276a074SBorislav Petkov ---help--- 7066276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7076276a074SBorislav Petkov a paravirt_op is missing when it is called. 7086276a074SBorislav Petkov 709b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 710b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7116ea30386SKees Cook depends on PARAVIRT && SMP 71262c7a1e9SIngo Molnar select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 713b4ecc126SJeremy Fitzhardinge ---help--- 714b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 715b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 716b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 717b4ecc126SJeremy Fitzhardinge 7184c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 7194c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 720b4ecc126SJeremy Fitzhardinge 7214c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 722b4ecc126SJeremy Fitzhardinge 72345e898b7SWaiman Longconfig QUEUED_LOCK_STAT 72445e898b7SWaiman Long bool "Paravirt queued spinlock statistics" 72545e898b7SWaiman Long depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS 72645e898b7SWaiman Long ---help--- 72745e898b7SWaiman Long Enable the collection of statistical data on the slowpath 72845e898b7SWaiman Long behavior of paravirtualized queued spinlocks and report 72945e898b7SWaiman Long them on debugfs. 73045e898b7SWaiman Long 7316276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 7326276a074SBorislav Petkov 7336276a074SBorislav Petkovconfig KVM_GUEST 7346276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7356276a074SBorislav Petkov depends on PARAVIRT 7366276a074SBorislav Petkov select PARAVIRT_CLOCK 7376276a074SBorislav Petkov default y 7386276a074SBorislav Petkov ---help--- 7396276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7406276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7416276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7426276a074SBorislav Petkov underlying device model, the host provides the guest with 7436276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7446276a074SBorislav Petkov 7451e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7461e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7471e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7481e20eb85SSrivatsa Vaddagiri default n 7491e20eb85SSrivatsa Vaddagiri ---help--- 7501e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7511e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7521e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7531e20eb85SSrivatsa Vaddagiri 7546276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7556276a074SBorislav Petkov 7566276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7576276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7586276a074SBorislav Petkov depends on PARAVIRT 7596276a074SBorislav Petkov default n 7606276a074SBorislav Petkov ---help--- 7616276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7626276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7636276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7646276a074SBorislav Petkov that, there can be a small performance impact. 7656276a074SBorislav Petkov 7666276a074SBorislav Petkov If in doubt, say N here. 7676276a074SBorislav Petkov 7687af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7697af192c9SGerd Hoffmann bool 7707af192c9SGerd Hoffmann 7716276a074SBorislav Petkovendif #HYPERVISOR_GUEST 77297349135SJeremy Fitzhardinge 77308677214SYinghai Luconfig NO_BOOTMEM 774774ea0bcSYinghai Lu def_bool y 77508677214SYinghai Lu 776506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 777506f1d07SSam Ravnborg 778506f1d07SSam Ravnborgconfig HPET_TIMER 7793c2362e6SHarvey Harrison def_bool X86_64 780506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7818f9ca475SIngo Molnar ---help--- 782506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 783506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 784506f1d07SSam Ravnborg present. 785506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 786506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 787506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 7884e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 7894e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 790506f1d07SSam Ravnborg 791506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 792506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 793506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 794506f1d07SSam Ravnborg 795506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 796506f1d07SSam Ravnborg 797506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 7983c2362e6SHarvey Harrison def_bool y 7999d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 800506f1d07SSam Ravnborg 801bb24c471SJacob Panconfig APB_TIMER 802933b9463SAlan Cox def_bool y if X86_INTEL_MID 803933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 80406c3df49SJamie Iles select DW_APB_TIMER 805a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 806bb24c471SJacob Pan help 807bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 808bb24c471SJacob Pan The APBT provides a stable time base on SMP 809bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 810bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 811bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 812bb24c471SJacob Pan 8136a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 814506f1d07SSam Ravnborg# The code disables itself when not needed. 8157ae9392cSThomas Petazzoniconfig DMI 8167ae9392cSThomas Petazzoni default y 817cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 8186a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 8198f9ca475SIngo Molnar ---help--- 8207ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 8217ae9392cSThomas Petazzoni here unless you have verified that your setup is not 8227ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 8237ae9392cSThomas Petazzoni BIOS code. 8247ae9392cSThomas Petazzoni 825506f1d07SSam Ravnborgconfig GART_IOMMU 82638901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 827506f1d07SSam Ravnborg select SWIOTLB 82823ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 8298f9ca475SIngo Molnar ---help--- 830ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 831ced3c42cSIngo Molnar GART based hardware IOMMUs. 832ced3c42cSIngo Molnar 833ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 834ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 835ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 836ced3c42cSIngo Molnar 837ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 838ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 839ced3c42cSIngo Molnar 840ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 841ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 842ced3c42cSIngo Molnar 32-bit limited device. 843ced3c42cSIngo Molnar 844ced3c42cSIngo Molnar If unsure, say Y. 845506f1d07SSam Ravnborg 846506f1d07SSam Ravnborgconfig CALGARY_IOMMU 847506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 848506f1d07SSam Ravnborg select SWIOTLB 8496ea30386SKees Cook depends on X86_64 && PCI 8508f9ca475SIngo Molnar ---help--- 851506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 852506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 853506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 854506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 855506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 856506f1d07SSam Ravnborg prevents them from going anywhere except their intended 857506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 858506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 859506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 860506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 861506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 862506f1d07SSam Ravnborg If unsure, say Y. 863506f1d07SSam Ravnborg 864506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8653c2362e6SHarvey Harrison def_bool y 8663c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 867506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8688f9ca475SIngo Molnar ---help--- 869506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 870506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 871506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 872506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 873506f1d07SSam Ravnborg If unsure, say Y. 874506f1d07SSam Ravnborg 875506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 876506f1d07SSam Ravnborgconfig SWIOTLB 877a1afd01cSJoerg Roedel def_bool y if X86_64 8788f9ca475SIngo Molnar ---help--- 879506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8804454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8814454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8824454d327SJoe Millenbach with more than 3 GB of memory. 8834454d327SJoe Millenbach If unsure, say Y. 884506f1d07SSam Ravnborg 885a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8863120e25eSJan Beulich def_bool y 8873120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 888d25e26b6SLinus Torvalds 8891184dc2fSMike Travisconfig MAXSMP 890ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8916ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 89236f5101aSMike Travis select CPUMASK_OFFSTACK 8938f9ca475SIngo Molnar ---help--- 894ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 8951184dc2fSMike Travis If unsure, say N. 896506f1d07SSam Ravnborg 897506f1d07SSam Ravnborgconfig NR_CPUS 89836f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 8992a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 900bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 901b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 90278637a97SMike Travis default "1" if !SMP 903b53b5edaSJosh Boyer default "8192" if MAXSMP 904b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 905c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 906c5c19941SKirill A. Shutemov default "64" if SMP 9078f9ca475SIngo Molnar ---help--- 908506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 909bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 910cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 911506f1d07SSam Ravnborg minimum value which makes sense is 2. 912506f1d07SSam Ravnborg 913506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 914506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 915506f1d07SSam Ravnborg 916506f1d07SSam Ravnborgconfig SCHED_SMT 917506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 918c8e56d20SBorislav Petkov depends on SMP 9198f9ca475SIngo Molnar ---help--- 920506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 921506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 922506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 923506f1d07SSam Ravnborg N here. 924506f1d07SSam Ravnborg 925506f1d07SSam Ravnborgconfig SCHED_MC 9263c2362e6SHarvey Harrison def_bool y 9273c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 928c8e56d20SBorislav Petkov depends on SMP 9298f9ca475SIngo Molnar ---help--- 930506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 931506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 932506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 933506f1d07SSam Ravnborg 934506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 935506f1d07SSam Ravnborg 93630b8b006SThomas Gleixnerconfig UP_LATE_INIT 93730b8b006SThomas Gleixner def_bool y 938ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 93930b8b006SThomas Gleixner 940506f1d07SSam Ravnborgconfig X86_UP_APIC 94150849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 94250849eefSJan Beulich default PCI_MSI 94338a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9448f9ca475SIngo Molnar ---help--- 945506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 946506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 947506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 948506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 949506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 950506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 951506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 952506f1d07SSam Ravnborg lockups. 953506f1d07SSam Ravnborg 954506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 955506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 956506f1d07SSam Ravnborg depends on X86_UP_APIC 9578f9ca475SIngo Molnar ---help--- 958506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 959506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 960506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 961506f1d07SSam Ravnborg 962506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 963506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 964506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 965506f1d07SSam Ravnborg 966506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9673c2362e6SHarvey Harrison def_bool y 9680dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 969b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 97052f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 971506f1d07SSam Ravnborg 972506f1d07SSam Ravnborgconfig X86_IO_APIC 973b1da1e71SJan Beulich def_bool y 974b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 975506f1d07SSam Ravnborg 97641b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 97741b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 97841b9eb26SStefan Assmann depends on X86_IO_APIC 9798f9ca475SIngo Molnar ---help--- 98041b9eb26SStefan Assmann This option enables a workaround that fixes a source of 98141b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 98241b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 98341b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 98441b9eb26SStefan Assmann 98541b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 98641b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 98741b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 98841b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 98941b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 99041b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 99141b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 99241b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 99341b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 99441b9eb26SStefan Assmann down (vital) interrupt lines. 99541b9eb26SStefan Assmann 99641b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 99741b9eb26SStefan Assmann increased on these systems. 99841b9eb26SStefan Assmann 999506f1d07SSam Ravnborgconfig X86_MCE 1000bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1001648ed940SChen, Gong select GENERIC_ALLOCATOR 1002e57dbaf7SBorislav Petkov default y 1003506f1d07SSam Ravnborg ---help--- 1004bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1005bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1006506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1007bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 10084efc0670SAndi Kleen 1009506f1d07SSam Ravnborgconfig X86_MCE_INTEL 10103c2362e6SHarvey Harrison def_bool y 10113c2362e6SHarvey Harrison prompt "Intel MCE features" 1012c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10138f9ca475SIngo Molnar ---help--- 1014506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1015506f1d07SSam Ravnborg the thermal monitor. 1016506f1d07SSam Ravnborg 1017506f1d07SSam Ravnborgconfig X86_MCE_AMD 10183c2362e6SHarvey Harrison def_bool y 10193c2362e6SHarvey Harrison prompt "AMD MCE features" 1020c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10218f9ca475SIngo Molnar ---help--- 1022506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1023506f1d07SSam Ravnborg the DRAM Error Threshold. 1024506f1d07SSam Ravnborg 10254efc0670SAndi Kleenconfig X86_ANCIENT_MCE 10266fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1027c31d9633SAndi Kleen depends on X86_32 && X86_MCE 10284efc0670SAndi Kleen ---help--- 10294efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 10305065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 10314efc0670SAndi Kleen line. 10324efc0670SAndi Kleen 1033b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1034b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10356fc108a0SJan Beulich def_bool y 1036b2762686SAndi Kleen 1037ea149b36SAndi Kleenconfig X86_MCE_INJECT 1038c1ebf835SAndi Kleen depends on X86_MCE 1039ea149b36SAndi Kleen tristate "Machine check injector support" 1040ea149b36SAndi Kleen ---help--- 1041ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1042ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1043ea149b36SAndi Kleen QA it is safe to say n. 1044ea149b36SAndi Kleen 10454efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10464efc0670SAndi Kleen def_bool y 10475bb38adcSAndi Kleen depends on X86_MCE_INTEL 10484efc0670SAndi Kleen 10495aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10501e642812SIngo Molnar bool "Legacy VM86 support" 10515aef51c3SAndy Lutomirski default n 1052506f1d07SSam Ravnborg depends on X86_32 10538f9ca475SIngo Molnar ---help--- 10545aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10555aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10565aef51c3SAndy Lutomirski 10575aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10585aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10595aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10605aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10615aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10621e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10631e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10641e642812SIngo Molnar mode might be faster than emulation and you might want to 10651e642812SIngo Molnar enable this option. 10665aef51c3SAndy Lutomirski 10671e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10681e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10691e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10701e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10715aef51c3SAndy Lutomirski 10721e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10731e642812SIngo Molnar and slows down exception handling a tiny bit. 10745aef51c3SAndy Lutomirski 10751e642812SIngo Molnar If unsure, say N here. 10765aef51c3SAndy Lutomirski 10775aef51c3SAndy Lutomirskiconfig VM86 10785aef51c3SAndy Lutomirski bool 10795aef51c3SAndy Lutomirski default X86_LEGACY_VM86 108034273f41SH. Peter Anvin 108134273f41SH. Peter Anvinconfig X86_16BIT 108234273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 108334273f41SH. Peter Anvin default y 1084a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 108534273f41SH. Peter Anvin ---help--- 108634273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 108734273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 108834273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 108934273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 109034273f41SH. Peter Anvin 109134273f41SH. Peter Anvinconfig X86_ESPFIX32 109234273f41SH. Peter Anvin def_bool y 109334273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1094506f1d07SSam Ravnborg 1095197725deSH. Peter Anvinconfig X86_ESPFIX64 1096197725deSH. Peter Anvin def_bool y 109734273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1098506f1d07SSam Ravnborg 10991ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 11001ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 11011ad83c85SAndy Lutomirski default y 11021ad83c85SAndy Lutomirski depends on X86_64 11031ad83c85SAndy Lutomirski ---help--- 11041ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 11051ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 11061ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 11071ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 11081ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 11091ad83c85SAndy Lutomirski 0xffffffffff600?00. 11101ad83c85SAndy Lutomirski 11111ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 11121ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 11131ad83c85SAndy Lutomirski 11141ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 11151ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 11161ad83c85SAndy Lutomirski 1117506f1d07SSam Ravnborgconfig TOSHIBA 1118506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1119506f1d07SSam Ravnborg depends on X86_32 1120506f1d07SSam Ravnborg ---help--- 1121506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1122506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1123506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1124506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1125506f1d07SSam Ravnborg 1126506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1127506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1128506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1129506f1d07SSam Ravnborg 1130506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1131506f1d07SSam Ravnborg Say N otherwise. 1132506f1d07SSam Ravnborg 1133506f1d07SSam Ravnborgconfig I8K 1134039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1135949a9d70SJean Delvare select HWMON 1136039ae585SPali Rohár select SENSORS_DELL_SMM 1137506f1d07SSam Ravnborg ---help--- 1138039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1139039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1140039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1141039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1142039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1143039ae585SPali Rohár needed userspace package i8kutils. 1144506f1d07SSam Ravnborg 1145039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1146039ae585SPali Rohár use userspace package i8kutils. 1147506f1d07SSam Ravnborg Say N otherwise. 1148506f1d07SSam Ravnborg 1149506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11509ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11519ba16087SJan Beulich depends on X86_32 1152506f1d07SSam Ravnborg ---help--- 1153506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1154506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1155506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1156506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1157506f1d07SSam Ravnborg system. 1158506f1d07SSam Ravnborg 1159506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11605e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1161506f1d07SSam Ravnborg 1162506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1163506f1d07SSam Ravnborg enable this option even if you don't need it. 1164506f1d07SSam Ravnborg Say N otherwise. 1165506f1d07SSam Ravnborg 1166506f1d07SSam Ravnborgconfig MICROCODE 11679a2bc335SBorislav Petkov bool "CPU microcode loading support" 11689a2bc335SBorislav Petkov default y 116980030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1170506f1d07SSam Ravnborg select FW_LOADER 1171506f1d07SSam Ravnborg ---help--- 1172506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 11735f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 11745f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 11755f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 11765f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 11775f9c01aaSBorislav Petkov the Linux kernel. 1178506f1d07SSam Ravnborg 11795f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 11805f9c01aaSBorislav Petkov in Documentation/x86/early-microcode.txt. For that you need to enable 11815f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 11825f9c01aaSBorislav Petkov initrd for microcode blobs. 1183506f1d07SSam Ravnborg 11845f9c01aaSBorislav Petkov In addition, you can build-in the microcode into the kernel. For that you 11855f9c01aaSBorislav Petkov need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 11865f9c01aaSBorislav Petkov to the CONFIG_EXTRA_FIRMWARE config option. 1187506f1d07SSam Ravnborg 11888d86f390SPeter Orubaconfig MICROCODE_INTEL 1189e43f6e67SBorislav Petkov bool "Intel microcode loading support" 11908d86f390SPeter Oruba depends on MICROCODE 11918d86f390SPeter Oruba default MICROCODE 11928d86f390SPeter Oruba select FW_LOADER 11938f9ca475SIngo Molnar ---help--- 11948d86f390SPeter Oruba This options enables microcode patch loading support for Intel 11958d86f390SPeter Oruba processors. 11968d86f390SPeter Oruba 1197b8989db9SAlan For the current Intel microcode data package go to 1198b8989db9SAlan <https://downloadcenter.intel.com> and search for 1199b8989db9SAlan 'Linux Processor Microcode Data File'. 12008d86f390SPeter Oruba 120180cc9f10SPeter Orubaconfig MICROCODE_AMD 1202e43f6e67SBorislav Petkov bool "AMD microcode loading support" 120380cc9f10SPeter Oruba depends on MICROCODE 120480cc9f10SPeter Oruba select FW_LOADER 12058f9ca475SIngo Molnar ---help--- 120680cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 120780cc9f10SPeter Oruba processors will be enabled. 120880cc9f10SPeter Oruba 1209506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 12103c2362e6SHarvey Harrison def_bool y 1211506f1d07SSam Ravnborg depends on MICROCODE 1212506f1d07SSam Ravnborg 1213506f1d07SSam Ravnborgconfig X86_MSR 1214506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 12158f9ca475SIngo Molnar ---help--- 1216506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1217506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1218506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1219506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1220506f1d07SSam Ravnborg systems. 1221506f1d07SSam Ravnborg 1222506f1d07SSam Ravnborgconfig X86_CPUID 1223506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 12248f9ca475SIngo Molnar ---help--- 1225506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1226506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1227506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1228506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1229506f1d07SSam Ravnborg 1230506f1d07SSam Ravnborgchoice 1231506f1d07SSam Ravnborg prompt "High Memory Support" 12326fc108a0SJan Beulich default HIGHMEM4G 1233506f1d07SSam Ravnborg depends on X86_32 1234506f1d07SSam Ravnborg 1235506f1d07SSam Ravnborgconfig NOHIGHMEM 1236506f1d07SSam Ravnborg bool "off" 1237506f1d07SSam Ravnborg ---help--- 1238506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1239506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1240506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1241506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1242506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1243506f1d07SSam Ravnborg "high memory". 1244506f1d07SSam Ravnborg 1245506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1246506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1247506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1248506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1249506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1250506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1251506f1d07SSam Ravnborg possible. 1252506f1d07SSam Ravnborg 1253506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1254506f1d07SSam Ravnborg answer "4GB" here. 1255506f1d07SSam Ravnborg 1256506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1257506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1258506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1259506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1260506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1261506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1262506f1d07SSam Ravnborg 1263506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1264506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1265506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1266506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1267506f1d07SSam Ravnborg kernel at boot time.) 1268506f1d07SSam Ravnborg 1269506f1d07SSam Ravnborg If unsure, say "off". 1270506f1d07SSam Ravnborg 1271506f1d07SSam Ravnborgconfig HIGHMEM4G 1272506f1d07SSam Ravnborg bool "4GB" 12738f9ca475SIngo Molnar ---help--- 1274506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1275506f1d07SSam Ravnborg gigabytes of physical RAM. 1276506f1d07SSam Ravnborg 1277506f1d07SSam Ravnborgconfig HIGHMEM64G 1278506f1d07SSam Ravnborg bool "64GB" 1279eb068e78SH. Peter Anvin depends on !M486 1280506f1d07SSam Ravnborg select X86_PAE 12818f9ca475SIngo Molnar ---help--- 1282506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1283506f1d07SSam Ravnborg gigabytes of physical RAM. 1284506f1d07SSam Ravnborg 1285506f1d07SSam Ravnborgendchoice 1286506f1d07SSam Ravnborg 1287506f1d07SSam Ravnborgchoice 12886a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1289506f1d07SSam Ravnborg default VMSPLIT_3G 1290506f1d07SSam Ravnborg depends on X86_32 12918f9ca475SIngo Molnar ---help--- 1292506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1293506f1d07SSam Ravnborg 1294506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1295506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1296506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1297506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1298506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1299506f1d07SSam Ravnborg available to user programs, making the address space there 1300506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1301506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1302506f1d07SSam Ravnborg kernel modules. 1303506f1d07SSam Ravnborg 1304506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1305506f1d07SSam Ravnborg option alone! 1306506f1d07SSam Ravnborg 1307506f1d07SSam Ravnborg config VMSPLIT_3G 1308506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1309506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1310506f1d07SSam Ravnborg depends on !X86_PAE 1311506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1312506f1d07SSam Ravnborg config VMSPLIT_2G 1313506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1314506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1315506f1d07SSam Ravnborg depends on !X86_PAE 1316506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1317506f1d07SSam Ravnborg config VMSPLIT_1G 1318506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1319506f1d07SSam Ravnborgendchoice 1320506f1d07SSam Ravnborg 1321506f1d07SSam Ravnborgconfig PAGE_OFFSET 1322506f1d07SSam Ravnborg hex 1323506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1324506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1325506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1326506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1327506f1d07SSam Ravnborg default 0xC0000000 1328506f1d07SSam Ravnborg depends on X86_32 1329506f1d07SSam Ravnborg 1330506f1d07SSam Ravnborgconfig HIGHMEM 13313c2362e6SHarvey Harrison def_bool y 1332506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1333506f1d07SSam Ravnborg 1334506f1d07SSam Ravnborgconfig X86_PAE 13359ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1336506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13379d99c712SChristian Melki select SWIOTLB 13388f9ca475SIngo Molnar ---help--- 1339506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1340506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1341506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1342506f1d07SSam Ravnborg consumes more pagetable space per process. 1343506f1d07SSam Ravnborg 1344600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13453120e25eSJan Beulich def_bool y 13463120e25eSJan Beulich depends on X86_64 || X86_PAE 1347600715dcSJeremy Fitzhardinge 134866f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13493120e25eSJan Beulich def_bool y 13503120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 135166f2b061SFUJITA Tomonori 135210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1353e5008abeSLuis R. Rodriguez def_bool y 1354e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13558f9ca475SIngo Molnar ---help--- 135610971ab2SIngo Molnar Certain kernel features effectively disable kernel 135710971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 135810971ab2SIngo Molnar supports them), so don't confuse the user by printing 135910971ab2SIngo Molnar that we have them enabled. 13609e899816SNick Piggin 1361506f1d07SSam Ravnborg# Common NUMA Features 1362506f1d07SSam Ravnborgconfig NUMA 1363fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1364506f1d07SSam Ravnborg depends on SMP 1365b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1366b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13678f9ca475SIngo Molnar ---help--- 1368506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1369fd51b2d7SKOSAKI Motohiro 1370506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1371506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1372506f1d07SSam Ravnborg NUMA awareness to the kernel. 1373506f1d07SSam Ravnborg 1374c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1375fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1376fd51b2d7SKOSAKI Motohiro 1377b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13787cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1379fd51b2d7SKOSAKI Motohiro 1380fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1381506f1d07SSam Ravnborg 1382eec1d4faSHans Rosenfeldconfig AMD_NUMA 13833c2362e6SHarvey Harrison def_bool y 13843c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13855da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13868f9ca475SIngo Molnar ---help--- 1387eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1388eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1389eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1390eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1391eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1392506f1d07SSam Ravnborg 1393506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 13943c2362e6SHarvey Harrison def_bool y 13953c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1396506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1397506f1d07SSam Ravnborg select ACPI_NUMA 13988f9ca475SIngo Molnar ---help--- 1399506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1400506f1d07SSam Ravnborg 14016ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 14026ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 14036ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 14046ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 14056ec6e0d9SSuresh Siddha# for details. 14066ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 14076ec6e0d9SSuresh Siddha def_bool y 14086ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 14096ec6e0d9SSuresh Siddha 1410506f1d07SSam Ravnborgconfig NUMA_EMU 1411506f1d07SSam Ravnborg bool "NUMA emulation" 14121b7e03efSTejun Heo depends on NUMA 14138f9ca475SIngo Molnar ---help--- 1414506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1415506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1416506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1417506f1d07SSam Ravnborg 1418506f1d07SSam Ravnborgconfig NODES_SHIFT 1419d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 142051591e31SDavid Rientjes range 1 10 142151591e31SDavid Rientjes default "10" if MAXSMP 1422506f1d07SSam Ravnborg default "6" if X86_64 1423506f1d07SSam Ravnborg default "3" 1424506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 14258f9ca475SIngo Molnar ---help--- 14261184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1427692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1428506f1d07SSam Ravnborg 1429506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 14303c2362e6SHarvey Harrison def_bool y 1431506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1432506f1d07SSam Ravnborg 1433506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14343c2362e6SHarvey Harrison def_bool y 1435506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1436506f1d07SSam Ravnborg 1437506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1438506f1d07SSam Ravnborg def_bool y 14393b16651fSTejun Heo depends on X86_32 && !NUMA 1440506f1d07SSam Ravnborg 1441506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1442506f1d07SSam Ravnborg def_bool y 1443b263295dSChristoph Lameter depends on NUMA && X86_32 1444506f1d07SSam Ravnborg 1445506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1446506f1d07SSam Ravnborg def_bool y 1447b263295dSChristoph Lameter depends on NUMA && X86_32 1448b263295dSChristoph Lameter 1449506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1450506f1d07SSam Ravnborg def_bool y 14516ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1452506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1453506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1454506f1d07SSam Ravnborg 14553b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14563b16651fSTejun Heo def_bool y 14573b16651fSTejun Heo depends on X86_64 14583b16651fSTejun Heo 1459506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1460506f1d07SSam Ravnborg def_bool y 1461b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1462506f1d07SSam Ravnborg 1463506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1464a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14653120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1466a0842b70SToshi Kani help 1467a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1468a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1469a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1470506f1d07SSam Ravnborg 14713b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14723b16651fSTejun Heo def_bool y 14733b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14743b16651fSTejun Heo 1475a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1476a29815a3SAvi Kivity hex 1477a29815a3SAvi Kivity default 0 if X86_32 1478a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1479a29815a3SAvi Kivity 1480506f1d07SSam Ravnborgsource "mm/Kconfig" 1481506f1d07SSam Ravnborg 14827a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14837a67832cSDan Williams bool 14847a67832cSDan Williams 1485ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 14867a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 14879f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14889f53f9faSDan Williams depends on BLK_DEV 14897a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 14909f53f9faSDan Williams select LIBNVDIMM 1491ec776ef6SChristoph Hellwig help 1492ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1493ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1494ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1495ec776ef6SChristoph Hellwig they can be used for persistent storage. 1496ec776ef6SChristoph Hellwig 1497ec776ef6SChristoph Hellwig Say Y if unsure. 1498ec776ef6SChristoph Hellwig 1499506f1d07SSam Ravnborgconfig HIGHPTE 1500506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 15016fc108a0SJan Beulich depends on HIGHMEM 15028f9ca475SIngo Molnar ---help--- 1503506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1504506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1505506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1506506f1d07SSam Ravnborg entries in high memory. 1507506f1d07SSam Ravnborg 15089f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 15099f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 15108f9ca475SIngo Molnar ---help--- 15119f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 15129f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 15139f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 15149f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 15159f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 15169f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 15179f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 15189f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 15199f077871SJeremy Fitzhardinge 15209f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 15219f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 15229f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 15239f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 15249f077871SJeremy Fitzhardinge 15259f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 15269f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 15279f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 15289f077871SJeremy Fitzhardinge memory. 15299f077871SJeremy Fitzhardinge 1530c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1531c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1532c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1533c885df50SJeremy Fitzhardinge default y 15348f9ca475SIngo Molnar ---help--- 1535c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1536c885df50SJeremy Fitzhardinge on or off. 1537c885df50SJeremy Fitzhardinge 15389ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1539d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1540d0cd7425SH. Peter Anvin default 64 1541d0cd7425SH. Peter Anvin range 4 640 15428f9ca475SIngo Molnar ---help--- 1543d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1544fc381519SIngo Molnar 1545d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1546d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1547fc381519SIngo Molnar 1548d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1549d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1550d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1551d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1552fc381519SIngo Molnar 1553d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1554d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1555d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1556d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1557d0cd7425SH. Peter Anvin entire low memory range. 1558d0cd7425SH. Peter Anvin 1559d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1560d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1561d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1562d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1563d0cd7425SH. Peter Anvin typical corruption patterns. 1564d0cd7425SH. Peter Anvin 1565d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1566fc381519SIngo Molnar 1567506f1d07SSam Ravnborgconfig MATH_EMULATION 1568506f1d07SSam Ravnborg bool 1569a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1570506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1571506f1d07SSam Ravnborg ---help--- 1572506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1573506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1574506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1575506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1576506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1577506f1d07SSam Ravnborg coprocessor or this emulation. 1578506f1d07SSam Ravnborg 1579506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1580506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1581506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1582506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1583506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1584506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1585506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1586506f1d07SSam Ravnborg intend to use this kernel on different machines. 1587506f1d07SSam Ravnborg 1588506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1589506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1590506f1d07SSam Ravnborg 1591506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1592506f1d07SSam Ravnborg kernel, it won't hurt. 1593506f1d07SSam Ravnborg 1594506f1d07SSam Ravnborgconfig MTRR 15956fc108a0SJan Beulich def_bool y 15966a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1597506f1d07SSam Ravnborg ---help--- 1598506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1599506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1600506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1601506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1602506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1603506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1604506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1605506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1606506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1607506f1d07SSam Ravnborg 1608506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1609506f1d07SSam Ravnborg control registers on other processors can be easily supported 1610506f1d07SSam Ravnborg as well: 1611506f1d07SSam Ravnborg 1612506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1613506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1614506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1615506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1616506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1617506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1618506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1619506f1d07SSam Ravnborg 1620506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1621506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1622506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1623506f1d07SSam Ravnborg 1624506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1625506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1626506f1d07SSam Ravnborg 16277225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1628506f1d07SSam Ravnborg 162995ffa243SYinghai Luconfig MTRR_SANITIZER 16302ffb3501SYinghai Lu def_bool y 163195ffa243SYinghai Lu prompt "MTRR cleanup support" 163295ffa243SYinghai Lu depends on MTRR 16338f9ca475SIngo Molnar ---help--- 1634aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1635aba3728cSThomas Gleixner add writeback entries. 163695ffa243SYinghai Lu 1637aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1638692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1639aba3728cSThomas Gleixner mtrr_chunk_size. 164095ffa243SYinghai Lu 16412ffb3501SYinghai Lu If unsure, say Y. 164295ffa243SYinghai Lu 164395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1644f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1645f5098d62SYinghai Lu range 0 1 1646f5098d62SYinghai Lu default "0" 164795ffa243SYinghai Lu depends on MTRR_SANITIZER 16488f9ca475SIngo Molnar ---help--- 1649f5098d62SYinghai Lu Enable mtrr cleanup default value 165095ffa243SYinghai Lu 165112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 165212031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 165312031a62SYinghai Lu range 0 7 165412031a62SYinghai Lu default "1" 165512031a62SYinghai Lu depends on MTRR_SANITIZER 16568f9ca475SIngo Molnar ---help--- 165712031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1658aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 165912031a62SYinghai Lu 16602e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16616fc108a0SJan Beulich def_bool y 16626a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16632a8a2719SIngo Molnar depends on MTRR 16648f9ca475SIngo Molnar ---help--- 16652e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1666042b78e4SVenki Pallipadi 16672e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16682e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16692e5d9c85Svenkatesh.pallipadi@intel.com 16702e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1671042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16722e5d9c85Svenkatesh.pallipadi@intel.com 16732e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16742e5d9c85Svenkatesh.pallipadi@intel.com 167546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 167646cf98cdSVenkatesh Pallipadi def_bool y 167746cf98cdSVenkatesh Pallipadi depends on X86_PAT 167846cf98cdSVenkatesh Pallipadi 1679628c6246SH. Peter Anvinconfig ARCH_RANDOM 1680628c6246SH. Peter Anvin def_bool y 1681628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1682628c6246SH. Peter Anvin ---help--- 1683628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1684628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1685628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1686628c6246SH. Peter Anvin secure hardware random number generator. 1687628c6246SH. Peter Anvin 168851ae4a2dSH. Peter Anvinconfig X86_SMAP 168951ae4a2dSH. Peter Anvin def_bool y 169051ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 169151ae4a2dSH. Peter Anvin ---help--- 169251ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 169351ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 169451ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 169551ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 169651ae4a2dSH. Peter Anvin 169751ae4a2dSH. Peter Anvin If unsure, say Y. 169851ae4a2dSH. Peter Anvin 169972e9b5feSDave Hansenconfig X86_INTEL_MPX 170072e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 170172e9b5feSDave Hansen def_bool n 170272e9b5feSDave Hansen depends on CPU_SUP_INTEL 170372e9b5feSDave Hansen ---help--- 170472e9b5feSDave Hansen MPX provides hardware features that can be used in 170572e9b5feSDave Hansen conjunction with compiler-instrumented code to check 170672e9b5feSDave Hansen memory references. It is designed to detect buffer 170772e9b5feSDave Hansen overflow or underflow bugs. 170872e9b5feSDave Hansen 170972e9b5feSDave Hansen This option enables running applications which are 171072e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 171172e9b5feSDave Hansen itself inside the kernel or to protect the kernel 171272e9b5feSDave Hansen against bad memory references. 171372e9b5feSDave Hansen 171472e9b5feSDave Hansen Enabling this option will make the kernel larger: 171572e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 171672e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 171772e9b5feSDave Hansen will increase the kernel memory overhead of each 171872e9b5feSDave Hansen process and adds some branches to paths used during 171972e9b5feSDave Hansen exec() and munmap(). 172072e9b5feSDave Hansen 172172e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 172272e9b5feSDave Hansen 172372e9b5feSDave Hansen If unsure, say N. 172472e9b5feSDave Hansen 172535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 1726284244a9SDave Hansen prompt "Intel Memory Protection Keys" 172735e97790SDave Hansen def_bool y 1728284244a9SDave Hansen # Note: only available in 64-bit mode 172935e97790SDave Hansen depends on CPU_SUP_INTEL && X86_64 1730284244a9SDave Hansen ---help--- 1731284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1732284244a9SDave Hansen page-based protections, but without requiring modification of the 1733284244a9SDave Hansen page tables when an application changes protection domains. 1734284244a9SDave Hansen 1735284244a9SDave Hansen For details, see Documentation/x86/protection-keys.txt 1736284244a9SDave Hansen 1737284244a9SDave Hansen If unsure, say y. 173835e97790SDave Hansen 1739506f1d07SSam Ravnborgconfig EFI 17409ba16087SJan Beulich bool "EFI runtime service support" 17415b83683fSHuang, Ying depends on ACPI 1742f6ce5002SSergey Vlasov select UCS2_STRING 1743022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1744506f1d07SSam Ravnborg ---help--- 17458b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1746506f1d07SSam Ravnborg available (such as the EFI variable services). 1747506f1d07SSam Ravnborg 17488b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17498b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17508b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17518b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17528b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17538b2cb7a8SHuang, Ying platforms. 1754506f1d07SSam Ravnborg 1755291f3632SMatt Flemingconfig EFI_STUB 1756291f3632SMatt Fleming bool "EFI stub support" 1757b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17587b2a583aSMatt Fleming select RELOCATABLE 1759291f3632SMatt Fleming ---help--- 1760291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1761291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1762291f3632SMatt Fleming 17634172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17640c759662SMatt Fleming 17657d453eeeSMatt Flemingconfig EFI_MIXED 17667d453eeeSMatt Fleming bool "EFI mixed-mode support" 17677d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17687d453eeeSMatt Fleming ---help--- 17697d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17707d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17717d453eeeSMatt Fleming mode. 17727d453eeeSMatt Fleming 17737d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17747d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17757d453eeeSMatt Fleming the EFI handover protocol must be used. 17767d453eeeSMatt Fleming 17777d453eeeSMatt Fleming If unsure, say N. 17787d453eeeSMatt Fleming 1779506f1d07SSam Ravnborgconfig SECCOMP 17803c2362e6SHarvey Harrison def_bool y 17813c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17828f9ca475SIngo Molnar ---help--- 1783506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1784506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1785506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1786506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1787506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1788506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17899c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1790506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1791506f1d07SSam Ravnborg defined by each seccomp mode. 1792506f1d07SSam Ravnborg 1793506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1794506f1d07SSam Ravnborg 1795506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1796506f1d07SSam Ravnborg 1797506f1d07SSam Ravnborgconfig KEXEC 1798506f1d07SSam Ravnborg bool "kexec system call" 17992965faa5SDave Young select KEXEC_CORE 18008f9ca475SIngo Molnar ---help--- 1801506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1802506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1803506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1804506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1805506f1d07SSam Ravnborg 1806506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1807506f1d07SSam Ravnborg 1808506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1809506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1810bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1811bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1812bf220695SGeert Uytterhoeven made. 1813506f1d07SSam Ravnborg 181474ca317cSVivek Goyalconfig KEXEC_FILE 181574ca317cSVivek Goyal bool "kexec file based system call" 18162965faa5SDave Young select KEXEC_CORE 181774ca317cSVivek Goyal select BUILD_BIN2C 181874ca317cSVivek Goyal depends on X86_64 181974ca317cSVivek Goyal depends on CRYPTO=y 182074ca317cSVivek Goyal depends on CRYPTO_SHA256=y 182174ca317cSVivek Goyal ---help--- 182274ca317cSVivek Goyal This is new version of kexec system call. This system call is 182374ca317cSVivek Goyal file based and takes file descriptors as system call argument 182474ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 182574ca317cSVivek Goyal accepted by previous system call. 182674ca317cSVivek Goyal 18278e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 18288e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 182974ca317cSVivek Goyal depends on KEXEC_FILE 18308e7d8381SVivek Goyal ---help--- 18318e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1832d8eb8940SBorislav Petkov the kexec_file_load() syscall. 18338e7d8381SVivek Goyal 1834d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1835d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1836d8eb8940SBorislav Petkov loaded in order for this to work. 18378e7d8381SVivek Goyal 18388e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 18398e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 18408e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 18418e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 18428e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 18438e7d8381SVivek Goyal ---help--- 18448e7d8381SVivek Goyal Enable bzImage signature verification support. 18458e7d8381SVivek Goyal 1846506f1d07SSam Ravnborgconfig CRASH_DUMP 184704b69447SPavel Machek bool "kernel crash dumps" 1848506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18498f9ca475SIngo Molnar ---help--- 1850506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1851506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1852506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1853506f1d07SSam Ravnborg a specially reserved region and then later executed after 1854506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1855506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1856506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1857506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1858506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1859506f1d07SSam Ravnborg 18603ab83521SHuang Yingconfig KEXEC_JUMP 18616ea30386SKees Cook bool "kexec jump" 1862fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18638f9ca475SIngo Molnar ---help--- 186489081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 186589081d17SHuang Ying code in physical address mode via KEXEC 18663ab83521SHuang Ying 1867506f1d07SSam Ravnborgconfig PHYSICAL_START 18686a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1869ceefccc9SH. Peter Anvin default "0x1000000" 18708f9ca475SIngo Molnar ---help--- 1871506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1872506f1d07SSam Ravnborg 1873506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1874506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1875506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1876506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1877506f1d07SSam Ravnborg address. 1878506f1d07SSam Ravnborg 1879506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1880506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1881506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1882506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1883506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1884506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1885506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1886506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1887506f1d07SSam Ravnborg 1888ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1889ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1890ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1891ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1892ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1893ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1894ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1895ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1896ceefccc9SH. Peter Anvin for more details about crash dumps. 1897506f1d07SSam Ravnborg 1898506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1899506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1900506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1901506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1902506f1d07SSam Ravnborg is present because there are users out there who continue to use 1903506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1904506f1d07SSam Ravnborg line. 1905506f1d07SSam Ravnborg 1906506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1907506f1d07SSam Ravnborg 1908506f1d07SSam Ravnborgconfig RELOCATABLE 190926717808SH. Peter Anvin bool "Build a relocatable kernel" 191026717808SH. Peter Anvin default y 19118f9ca475SIngo Molnar ---help--- 1912506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1913506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1914506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1915506f1d07SSam Ravnborg but are discarded at runtime. 1916506f1d07SSam Ravnborg 1917506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1918506f1d07SSam Ravnborg must live at a different physical address than the primary 1919506f1d07SSam Ravnborg kernel. 1920506f1d07SSam Ravnborg 1921506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1922506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 19238ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1924506f1d07SSam Ravnborg 19258ab3820fSKees Cookconfig RANDOMIZE_BASE 19268ab3820fSKees Cook bool "Randomize the address of the kernel image" 19278ab3820fSKees Cook depends on RELOCATABLE 19288ab3820fSKees Cook default n 19298ab3820fSKees Cook ---help--- 19308ab3820fSKees Cook Randomizes the physical and virtual address at which the 19318ab3820fSKees Cook kernel image is decompressed, as a security feature that 19328ab3820fSKees Cook deters exploit attempts relying on knowledge of the location 19338ab3820fSKees Cook of kernel internals. 19348ab3820fSKees Cook 1935a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1936a653f356SKees Cook supported. If RDTSC is supported, it is used as well. If 1937a653f356SKees Cook neither RDRAND nor RDTSC are supported, then randomness is 1938a653f356SKees Cook read from the i8254 timer. 19398ab3820fSKees Cook 19408ab3820fSKees Cook The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1941a653f356SKees Cook and aligned according to PHYSICAL_ALIGN. Since the kernel is 1942a653f356SKees Cook built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1943a653f356SKees Cook minimum of 2MiB, only 10 bits of entropy is theoretically 1944a653f356SKees Cook possible. At best, due to page table layouts, 64-bit can use 1945a653f356SKees Cook 9 bits of entropy and 32-bit uses 8 bits. 19468ab3820fSKees Cook 1947da2b6fb9SKees Cook If unsure, say N. 1948da2b6fb9SKees Cook 19498ab3820fSKees Cookconfig RANDOMIZE_BASE_MAX_OFFSET 1950da2b6fb9SKees Cook hex "Maximum kASLR offset allowed" if EXPERT 19518ab3820fSKees Cook depends on RANDOMIZE_BASE 19526145cfe3SKees Cook range 0x0 0x20000000 if X86_32 19536145cfe3SKees Cook default "0x20000000" if X86_32 19546145cfe3SKees Cook range 0x0 0x40000000 if X86_64 19556145cfe3SKees Cook default "0x40000000" if X86_64 19568ab3820fSKees Cook ---help--- 1957da2b6fb9SKees Cook The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1958da2b6fb9SKees Cook memory is used to determine the maximal offset in bytes that will 1959da2b6fb9SKees Cook be applied to the kernel when kernel Address Space Layout 1960da2b6fb9SKees Cook Randomization (kASLR) is active. This must be a multiple of 1961da2b6fb9SKees Cook PHYSICAL_ALIGN. 19626145cfe3SKees Cook 1963da2b6fb9SKees Cook On 32-bit this is limited to 512MiB by page table layouts. The 1964da2b6fb9SKees Cook default is 512MiB. 19656145cfe3SKees Cook 19666145cfe3SKees Cook On 64-bit this is limited by how the kernel fixmap page table is 1967da2b6fb9SKees Cook positioned, so this cannot be larger than 1GiB currently. Without 1968da2b6fb9SKees Cook RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1969da2b6fb9SKees Cook and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1970da2b6fb9SKees Cook modules area will shrink to compensate, up to the current maximum 1971da2b6fb9SKees Cook 1GiB to 1GiB split. The default is 1GiB. 1972da2b6fb9SKees Cook 1973da2b6fb9SKees Cook If unsure, leave at the default value. 19748ab3820fSKees Cook 19758ab3820fSKees Cook# Relocation on x86 needs some additional build support 1976845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1977845adf72SH. Peter Anvin def_bool y 19788ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1979845adf72SH. Peter Anvin 1980506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1981a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19828ab3820fSKees Cook default "0x200000" 1983a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1984a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19858f9ca475SIngo Molnar ---help--- 1986506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1987506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1988506f1d07SSam Ravnborg address which meets above alignment restriction. 1989506f1d07SSam Ravnborg 1990506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1991506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1992506f1d07SSam Ravnborg address aligned to above value and run from there. 1993506f1d07SSam Ravnborg 1994506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1995506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1996506f1d07SSam Ravnborg load address and decompress itself to the address it has been 1997506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 1998506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 1999506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2000506f1d07SSam Ravnborg above alignment restrictions. 2001506f1d07SSam Ravnborg 2002a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2003a0215061SKees Cook this value must be a multiple of 0x200000. 2004a0215061SKees Cook 2005506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2006506f1d07SSam Ravnborg 2007506f1d07SSam Ravnborgconfig HOTPLUG_CPU 20087c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 200940b31360SStephen Rothwell depends on SMP 2010506f1d07SSam Ravnborg ---help--- 20117c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 20127c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 20137c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 20147c13e6a3SDimitri Sivanich automatically on SMP systems. ) 20157c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 2016506f1d07SSam Ravnborg 201780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 201880aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 201980aa1dffSFenghua Yu default n 20202c922cd0SKees Cook depends on HOTPLUG_CPU 202180aa1dffSFenghua Yu ---help--- 202280aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 202380aa1dffSFenghua Yu 202480aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 202580aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 202680aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 202780aa1dffSFenghua Yu 202880aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 202980aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 203080aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 203180aa1dffSFenghua Yu 203280aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 203380aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 203480aa1dffSFenghua Yu 203580aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 203680aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 203780aa1dffSFenghua Yu be other CPU0 dependencies. 203880aa1dffSFenghua Yu 203980aa1dffSFenghua Yu Please make sure the dependencies are under your control before 204080aa1dffSFenghua Yu you enable this feature. 204180aa1dffSFenghua Yu 204280aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 204380aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 204480aa1dffSFenghua Yu parameter cpu0_hotplug. 204580aa1dffSFenghua Yu 2046a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2047a71c8bc5SFenghua Yu def_bool n 2048a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20492c922cd0SKees Cook depends on HOTPLUG_CPU 2050a71c8bc5SFenghua Yu ---help--- 2051a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2052a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2053a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2054a71c8bc5SFenghua Yu 2055a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2056a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2057a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2058a71c8bc5SFenghua Yu 2059a71c8bc5SFenghua Yu If unsure, say N. 2060a71c8bc5SFenghua Yu 2061506f1d07SSam Ravnborgconfig COMPAT_VDSO 2062b0b49f26SAndy Lutomirski def_bool n 2063b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2064af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 20658f9ca475SIngo Molnar ---help--- 2066b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2067b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2068b0b49f26SAndy Lutomirski indicated in its segment table. 2069e84446deSRandy Dunlap 2070b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2071b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2072b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2073b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2074b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2075506f1d07SSam Ravnborg 2076b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2077b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2078b0b49f26SAndy Lutomirski 2079b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2080b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2081b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2082b0b49f26SAndy Lutomirski 2083b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2084b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2085506f1d07SSam Ravnborg 20863dc33bd3SKees Cookchoice 20873dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 20883dc33bd3SKees Cook depends on X86_64 20893dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 20903dc33bd3SKees Cook help 20913dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 20923dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 20933dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 20943dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 20953dc33bd3SKees Cook 20963dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 20973dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 20983dc33bd3SKees Cook 20993dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 21003dc33bd3SKees Cook static binaries, you can say None without a performance penalty 21013dc33bd3SKees Cook to improve security. 21023dc33bd3SKees Cook 21033dc33bd3SKees Cook If unsure, select "Emulate". 21043dc33bd3SKees Cook 21053dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 21063dc33bd3SKees Cook bool "Native" 21073dc33bd3SKees Cook help 21083dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 21093dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 21103dc33bd3SKees Cook this makes the mapping executable, it can be used during 21113dc33bd3SKees Cook security vulnerability exploitation (traditionally as 21123dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 21133dc33bd3SKees Cook 21143dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 21153dc33bd3SKees Cook bool "Emulate" 21163dc33bd3SKees Cook help 21173dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 21183dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 21193dc33bd3SKees Cook non-executable, but it still contains known contents, 21203dc33bd3SKees Cook which could be used in certain rare security vulnerability 21213dc33bd3SKees Cook exploits. This configuration is recommended when userspace 21223dc33bd3SKees Cook still uses the vsyscall area. 21233dc33bd3SKees Cook 21243dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 21253dc33bd3SKees Cook bool "None" 21263dc33bd3SKees Cook help 21273dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 21283dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 21293dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 21303dc33bd3SKees Cook will be reported to dmesg, so that either old or 21313dc33bd3SKees Cook malicious userspace programs can be identified. 21323dc33bd3SKees Cook 21333dc33bd3SKees Cookendchoice 21343dc33bd3SKees Cook 2135516cbf37STim Birdconfig CMDLINE_BOOL 2136516cbf37STim Bird bool "Built-in kernel command line" 21378f9ca475SIngo Molnar ---help--- 2138516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2139516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2140516cbf37STim Bird necessary or convenient to provide some or all of the 2141516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2142516cbf37STim Bird to not rely on the boot loader to provide them.) 2143516cbf37STim Bird 2144516cbf37STim Bird To compile command line arguments into the kernel, 2145516cbf37STim Bird set this option to 'Y', then fill in the 214669711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2147516cbf37STim Bird 2148516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2149516cbf37STim Bird should leave this option set to 'N'. 2150516cbf37STim Bird 2151516cbf37STim Birdconfig CMDLINE 2152516cbf37STim Bird string "Built-in kernel command string" 2153516cbf37STim Bird depends on CMDLINE_BOOL 2154516cbf37STim Bird default "" 21558f9ca475SIngo Molnar ---help--- 2156516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2157516cbf37STim Bird image and used at boot time. If the boot loader provides a 2158516cbf37STim Bird command line at boot time, it is appended to this string to 2159516cbf37STim Bird form the full kernel command line, when the system boots. 2160516cbf37STim Bird 2161516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2162516cbf37STim Bird change this behavior. 2163516cbf37STim Bird 2164516cbf37STim Bird In most cases, the command line (whether built-in or provided 2165516cbf37STim Bird by the boot loader) should specify the device for the root 2166516cbf37STim Bird file system. 2167516cbf37STim Bird 2168516cbf37STim Birdconfig CMDLINE_OVERRIDE 2169516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2170516cbf37STim Bird depends on CMDLINE_BOOL 21718f9ca475SIngo Molnar ---help--- 2172516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2173516cbf37STim Bird command line, and use ONLY the built-in command line. 2174516cbf37STim Bird 2175516cbf37STim Bird This is used to work around broken boot loaders. This should 2176516cbf37STim Bird be set to 'N' under normal conditions. 2177516cbf37STim Bird 2178a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2179a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2180a5b9e5a2SAndy Lutomirski default y 2181a5b9e5a2SAndy Lutomirski ---help--- 2182a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2183a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2184a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2185a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2186a5b9e5a2SAndy Lutomirski threading libraries. 2187a5b9e5a2SAndy Lutomirski 2188a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2189a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2190a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2191a5b9e5a2SAndy Lutomirski 2192a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2193a5b9e5a2SAndy Lutomirski 2194b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2195b700e7f0SSeth Jennings 2196506f1d07SSam Ravnborgendmenu 2197506f1d07SSam Ravnborg 2198506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2199506f1d07SSam Ravnborg def_bool y 2200506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2201506f1d07SSam Ravnborg 220235551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 220335551053SGary Hade def_bool y 220435551053SGary Hade depends on MEMORY_HOTPLUG 220535551053SGary Hade 2206e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2207645a7919STejun Heo def_bool y 2208e534c7c5SLee Schermerhorn depends on NUMA 2209e534c7c5SLee Schermerhorn 22109491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 22119491846fSKirill A. Shutemov def_bool y 22129491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 22139491846fSKirill A. Shutemov 2214c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2215c177c81eSNaoya Horiguchi def_bool y 2216c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2217c177c81eSNaoya Horiguchi 2218da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2219e279b6c1SSam Ravnborg 2220e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 22213c2362e6SHarvey Harrison def_bool y 2222e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2223e279b6c1SSam Ravnborg 2224e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2225e279b6c1SSam Ravnborg 2226e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2227e279b6c1SSam Ravnborg 2228efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2229efafc8b2SFeng Tang 2230a6b68076SAndi Kleenconfig X86_APM_BOOT 22316fc108a0SJan Beulich def_bool y 2232282e5aabSPaul Bolle depends on APM 2233a6b68076SAndi Kleen 2234e279b6c1SSam Ravnborgmenuconfig APM 2235e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2236efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2237e279b6c1SSam Ravnborg ---help--- 2238e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2239e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2240e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2241e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2242e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2243e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2244e279b6c1SSam Ravnborg 2245e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2246e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2247e279b6c1SSam Ravnborg 2248e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2249e279b6c1SSam Ravnborg machines with more than one CPU. 2250e279b6c1SSam Ravnborg 2251e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22522dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22532dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2254e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2255e279b6c1SSam Ravnborg 2256e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2257e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2258e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2259e279b6c1SSam Ravnborg 2260e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2261e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2262e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2263e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2264e279b6c1SSam Ravnborg 2265e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2266e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2267e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2268e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2269e279b6c1SSam Ravnborg APM in your BIOS). 2270e279b6c1SSam Ravnborg 2271e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2272e279b6c1SSam Ravnborg "weird" problems: 2273e279b6c1SSam Ravnborg 2274e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2275e279b6c1SSam Ravnborg enabled. 2276e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2277e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2278e279b6c1SSam Ravnborg the "no387" option to the kernel 2279e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2280e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2281e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2282e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2283e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2284e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2285e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2286e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2287e279b6c1SSam Ravnborg 11) exchange RAM chips 2288e279b6c1SSam Ravnborg 12) exchange the motherboard. 2289e279b6c1SSam Ravnborg 2290e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2291e279b6c1SSam Ravnborg module will be called apm. 2292e279b6c1SSam Ravnborg 2293e279b6c1SSam Ravnborgif APM 2294e279b6c1SSam Ravnborg 2295e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2296e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 22978f9ca475SIngo Molnar ---help--- 2298e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2299e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2300e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2301e279b6c1SSam Ravnborg 2302e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2303e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2304e279b6c1SSam Ravnborg ---help--- 2305e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2306e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2307e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2308e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2309e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2310e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2311e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2312e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2313e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2314e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2315e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2316e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2317e279b6c1SSam Ravnborg this feature. 2318e279b6c1SSam Ravnborg 2319e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2320dd8af076SLen Brown depends on CPU_IDLE 2321e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 23228f9ca475SIngo Molnar ---help--- 2323e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2324e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2325e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2326e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2327e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2328e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2329e279b6c1SSam Ravnborg this option does nothing.) 2330e279b6c1SSam Ravnborg 2331e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2332e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 23338f9ca475SIngo Molnar ---help--- 2334e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2335e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2336e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2337e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2338e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2339e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2340e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2341e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2342e279b6c1SSam Ravnborg especially if you are using gpm. 2343e279b6c1SSam Ravnborg 2344e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2345e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 23468f9ca475SIngo Molnar ---help--- 2347e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2348e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2349e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2350e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2351e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2352e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2353e279b6c1SSam Ravnborg 2354e279b6c1SSam Ravnborgendif # APM 2355e279b6c1SSam Ravnborg 2356bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2357e279b6c1SSam Ravnborg 2358e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2359e279b6c1SSam Ravnborg 236027471fdbSAndy Henroidsource "drivers/idle/Kconfig" 236127471fdbSAndy Henroid 2362e279b6c1SSam Ravnborgendmenu 2363e279b6c1SSam Ravnborg 2364e279b6c1SSam Ravnborg 2365e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2366e279b6c1SSam Ravnborg 2367e279b6c1SSam Ravnborgconfig PCI 23681ac97018SIngo Molnar bool "PCI support" 23691c858087SAdrian Bunk default y 23708f9ca475SIngo Molnar ---help--- 2371e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2372e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2373e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2374e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2375e279b6c1SSam Ravnborg 2376e279b6c1SSam Ravnborgchoice 2377e279b6c1SSam Ravnborg prompt "PCI access mode" 2378efefa6f6SIngo Molnar depends on X86_32 && PCI 2379e279b6c1SSam Ravnborg default PCI_GOANY 2380e279b6c1SSam Ravnborg ---help--- 2381e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2382e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2383e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2384e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2385e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2386e279b6c1SSam Ravnborg 2387e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2388e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2389e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2390e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2391e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2392e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2393e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2394e279b6c1SSam Ravnborg 2395e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2396e279b6c1SSam Ravnborg bool "BIOS" 2397e279b6c1SSam Ravnborg 2398e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2399e279b6c1SSam Ravnborg bool "MMConfig" 2400e279b6c1SSam Ravnborg 2401e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2402e279b6c1SSam Ravnborg bool "Direct" 2403e279b6c1SSam Ravnborg 24043ef0e1f8SAndres Salomonconfig PCI_GOOLPC 240576fb6570SDaniel Drake bool "OLPC XO-1" 24063ef0e1f8SAndres Salomon depends on OLPC 24073ef0e1f8SAndres Salomon 24082bdd1b03SAndres Salomonconfig PCI_GOANY 24092bdd1b03SAndres Salomon bool "Any" 24102bdd1b03SAndres Salomon 2411e279b6c1SSam Ravnborgendchoice 2412e279b6c1SSam Ravnborg 2413e279b6c1SSam Ravnborgconfig PCI_BIOS 24143c2362e6SHarvey Harrison def_bool y 2415efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2416e279b6c1SSam Ravnborg 2417e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2418e279b6c1SSam Ravnborgconfig PCI_DIRECT 24193c2362e6SHarvey Harrison def_bool y 24200aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2421e279b6c1SSam Ravnborg 2422e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 24233c2362e6SHarvey Harrison def_bool y 24245f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2425e279b6c1SSam Ravnborg 24263ef0e1f8SAndres Salomonconfig PCI_OLPC 24272bdd1b03SAndres Salomon def_bool y 24282bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 24293ef0e1f8SAndres Salomon 2430b5401a96SAlex Nixonconfig PCI_XEN 2431b5401a96SAlex Nixon def_bool y 2432b5401a96SAlex Nixon depends on PCI && XEN 2433b5401a96SAlex Nixon select SWIOTLB_XEN 2434b5401a96SAlex Nixon 2435e279b6c1SSam Ravnborgconfig PCI_DOMAINS 24363c2362e6SHarvey Harrison def_bool y 2437e279b6c1SSam Ravnborg depends on PCI 2438e279b6c1SSam Ravnborg 2439e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2440e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2441e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2442e279b6c1SSam Ravnborg 24433f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 24446a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 24456ea30386SKees Cook depends on PCI 24463f6ea84aSIra W. Snyder help 24473f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24483f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24493f6ea84aSIra W. Snyder not have ACPI. 24503f6ea84aSIra W. Snyder 245164a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 245264a5fed6SBjorn Helgaas is known to be incomplete. 245364a5fed6SBjorn Helgaas 245464a5fed6SBjorn Helgaas You should say N unless you know you need this. 245564a5fed6SBjorn Helgaas 2456e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2457e279b6c1SSam Ravnborg 24581c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2459e279b6c1SSam Ravnborgconfig ISA_DMA_API 24601c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 24611c00f016SDavid Rientjes default y 24621c00f016SDavid Rientjes help 24631c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 24641c00f016SDavid Rientjes If unsure, say Y. 2465e279b6c1SSam Ravnborg 2466e279b6c1SSam Ravnborgif X86_32 2467e279b6c1SSam Ravnborg 2468e279b6c1SSam Ravnborgconfig ISA 2469e279b6c1SSam Ravnborg bool "ISA support" 24708f9ca475SIngo Molnar ---help--- 2471e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2472e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2473e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2474e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2475e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2476e279b6c1SSam Ravnborg 2477e279b6c1SSam Ravnborgconfig EISA 2478e279b6c1SSam Ravnborg bool "EISA support" 2479e279b6c1SSam Ravnborg depends on ISA 2480e279b6c1SSam Ravnborg ---help--- 2481e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2482e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2483e279b6c1SSam Ravnborg 2484e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2485e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2486e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2487e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2488e279b6c1SSam Ravnborg 2489e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2490e279b6c1SSam Ravnborg 2491e279b6c1SSam Ravnborg Otherwise, say N. 2492e279b6c1SSam Ravnborg 2493e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2494e279b6c1SSam Ravnborg 2495e279b6c1SSam Ravnborgconfig SCx200 2496e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 24978f9ca475SIngo Molnar ---help--- 2498e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2499e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2500e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2501e279b6c1SSam Ravnborg for other scx200_* drivers. 2502e279b6c1SSam Ravnborg 2503e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2504e279b6c1SSam Ravnborg 2505e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2506e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2507592913ecSJohn Stultz depends on SCx200 2508e279b6c1SSam Ravnborg default y 25098f9ca475SIngo Molnar ---help--- 2510e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2511e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2512e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2513e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2514e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2515e279b6c1SSam Ravnborg 25163ef0e1f8SAndres Salomonconfig OLPC 25173ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 251854008979SThomas Gleixner depends on !X86_PAE 25193c554946SAndres Salomon select GPIOLIB 2520dc3119e7SThomas Gleixner select OF 252145bb1674SDaniel Drake select OF_PROMTREE 2522b4e51854SGrant Likely select IRQ_DOMAIN 25238f9ca475SIngo Molnar ---help--- 25243ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 25253ef0e1f8SAndres Salomon XO hardware. 25263ef0e1f8SAndres Salomon 2527a3128588SDaniel Drakeconfig OLPC_XO1_PM 2528a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 252997c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2530a3128588SDaniel Drake select MFD_CORE 2531bf1ebf00SDaniel Drake ---help--- 253297c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2533bf1ebf00SDaniel Drake 2534cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2535cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2536cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2537cfee9597SDaniel Drake ---help--- 2538cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2539cfee9597SDaniel Drake programmable wakeup source. 2540cfee9597SDaniel Drake 25417feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 25427feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2543d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2544ed8e47feSRandy Dunlap depends on INPUT=y 2545d8d01a63SDaniel Drake select POWER_SUPPLY 25467feda8e9SDaniel Drake select GPIO_CS5535 25477feda8e9SDaniel Drake select MFD_CORE 25487feda8e9SDaniel Drake ---help--- 25497feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25507bc74b3dSDaniel Drake - EC-driven system wakeups 25517feda8e9SDaniel Drake - Power button 25527bc74b3dSDaniel Drake - Ebook switch 25532cf2baeaSDaniel Drake - Lid switch 2554e1040ac6SDaniel Drake - AC adapter status updates 2555e1040ac6SDaniel Drake - Battery status updates 25567feda8e9SDaniel Drake 2557a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2558a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2559d8d01a63SDaniel Drake depends on OLPC && ACPI 2560d8d01a63SDaniel Drake select POWER_SUPPLY 2561a0f30f59SDaniel Drake ---help--- 2562a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2563a0f30f59SDaniel Drake - EC-driven system wakeups 2564a0f30f59SDaniel Drake - AC adapter status updates 2565a0f30f59SDaniel Drake - Battery status updates 2566e279b6c1SSam Ravnborg 2567d4f3e350SEd Wildgooseconfig ALIX 2568d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2569d4f3e350SEd Wildgoose select GPIOLIB 2570d4f3e350SEd Wildgoose ---help--- 2571d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2572d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2573d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2574d4f3e350SEd Wildgoose get added here. 2575d4f3e350SEd Wildgoose 2576d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2577d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2578d4f3e350SEd Wildgoose 2579d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2580d4f3e350SEd Wildgoose 2581da4e3302SPhilip Prindevilleconfig NET5501 2582da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2583da4e3302SPhilip Prindeville select GPIOLIB 2584da4e3302SPhilip Prindeville ---help--- 2585da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2586da4e3302SPhilip Prindeville 25873197059aSPhilip A. Prindevilleconfig GEOS 25883197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 25893197059aSPhilip A. Prindeville select GPIOLIB 25903197059aSPhilip A. Prindeville depends on DMI 25913197059aSPhilip A. Prindeville ---help--- 25923197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 25933197059aSPhilip A. Prindeville 25947d029125SVivien Didelotconfig TS5500 25957d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 25967d029125SVivien Didelot depends on MELAN 25977d029125SVivien Didelot select CHECK_SIGNATURE 25987d029125SVivien Didelot select NEW_LEDS 25997d029125SVivien Didelot select LEDS_CLASS 26007d029125SVivien Didelot ---help--- 26017d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 26027d029125SVivien Didelot 2603e279b6c1SSam Ravnborgendif # X86_32 2604e279b6c1SSam Ravnborg 260523ac4ae8SAndreas Herrmannconfig AMD_NB 2606e279b6c1SSam Ravnborg def_bool y 26070e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2608e279b6c1SSam Ravnborg 2609e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2610e279b6c1SSam Ravnborg 2611388b78adSAlexandre Bounineconfig RAPIDIO 2612fdf90abcSAlexandre Bounine tristate "RapidIO support" 2613388b78adSAlexandre Bounine depends on PCI 2614388b78adSAlexandre Bounine default n 2615388b78adSAlexandre Bounine help 2616fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2617388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2618388b78adSAlexandre Bounine 2619388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2620388b78adSAlexandre Bounine 2621e3263ab3SDavid Herrmannconfig X86_SYSFB 2622e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2623e3263ab3SDavid Herrmann help 2624e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2625e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2626e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2627e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2628e3263ab3SDavid Herrmann to x86. 2629e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2630e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2631e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2632e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2633e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2634e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2635e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2636e3263ab3SDavid Herrmann 2637e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2638e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2639e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2640e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2641e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2642e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2643e3263ab3SDavid Herrmann incompatible with simplefb. 2644e3263ab3SDavid Herrmann 2645e3263ab3SDavid Herrmann If unsure, say Y. 2646e3263ab3SDavid Herrmann 2647e279b6c1SSam Ravnborgendmenu 2648e279b6c1SSam Ravnborg 2649e279b6c1SSam Ravnborg 2650e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2651e279b6c1SSam Ravnborg 2652e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2653e279b6c1SSam Ravnborg 2654e279b6c1SSam Ravnborgconfig IA32_EMULATION 2655e279b6c1SSam Ravnborg bool "IA32 Emulation" 2656e279b6c1SSam Ravnborg depends on X86_64 2657d1603990SRandy Dunlap select BINFMT_ELF 2658a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 26593bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 26608f9ca475SIngo Molnar ---help--- 26615fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 26625fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 26635fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2664e279b6c1SSam Ravnborg 2665e279b6c1SSam Ravnborgconfig IA32_AOUT 2666e279b6c1SSam Ravnborg tristate "IA32 a.out support" 26676b213e1bSDavid Woodhouse depends on IA32_EMULATION 26688f9ca475SIngo Molnar ---help--- 2669e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2670e279b6c1SSam Ravnborg 26710bf62763SH. Peter Anvinconfig X86_X32 26726ea30386SKees Cook bool "x32 ABI for 64-bit mode" 26739b54050bSBrian Gerst depends on X86_64 26745fd92e65SH. J. Lu ---help--- 26755fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 26765fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 26775fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 26785fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 26795fd92e65SH. J. Lu 26805fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 26815fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 26825fd92e65SH. J. Lu option set. 26835fd92e65SH. J. Lu 2684e279b6c1SSam Ravnborgconfig COMPAT 26853c2362e6SHarvey Harrison def_bool y 26860bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2687e279b6c1SSam Ravnborg 26883120e25eSJan Beulichif COMPAT 2689e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 26903120e25eSJan Beulich def_bool y 2691e279b6c1SSam Ravnborg 2692e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 26933c2362e6SHarvey Harrison def_bool y 26943120e25eSJan Beulich depends on SYSVIPC 2695e279b6c1SSam Ravnborg 2696ee009e4aSDavid Howellsconfig KEYS_COMPAT 26973120e25eSJan Beulich def_bool y 26983120e25eSJan Beulich depends on KEYS 26993120e25eSJan Beulichendif 2700ee009e4aSDavid Howells 2701e279b6c1SSam Ravnborgendmenu 2702e279b6c1SSam Ravnborg 2703e279b6c1SSam Ravnborg 2704e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2705e5beae16SKeith Packard def_bool y 2706e5beae16SKeith Packard depends on X86_32 2707e5beae16SKeith Packard 27084692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 27094692d77fSAlessandro Rubini bool 271083125a3aSAlessandro Rubini depends on X86_64 || STA2X11 27114692d77fSAlessandro Rubini 2712f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2713f7219a53SAlessandro Rubini bool 271483125a3aSAlessandro Rubini depends on STA2X11 2715f7219a53SAlessandro Rubini 271693e5eaddSLi, Aubreyconfig PMC_ATOM 271793e5eaddSLi, Aubrey def_bool y 271893e5eaddSLi, Aubrey depends on PCI 271993e5eaddSLi, Aubrey 2720185a383aSKeith Buschconfig VMD 2721185a383aSKeith Busch depends on PCI_MSI 2722185a383aSKeith Busch tristate "Volume Management Device Driver" 2723185a383aSKeith Busch default N 2724185a383aSKeith Busch ---help--- 2725185a383aSKeith Busch Adds support for the Intel Volume Management Device (VMD). VMD is a 2726185a383aSKeith Busch secondary PCI host bridge that allows PCI Express root ports, 2727185a383aSKeith Busch and devices attached to them, to be removed from the default 2728185a383aSKeith Busch PCI domain and placed within the VMD domain. This provides 2729185a383aSKeith Busch more bus resources than are otherwise possible with a 2730185a383aSKeith Busch single domain. If you know your system provides one of these and 2731185a383aSKeith Busch has devices attached to it, say Y; if you are not sure, say N. 2732185a383aSKeith Busch 2733e279b6c1SSam Ravnborgsource "net/Kconfig" 2734e279b6c1SSam Ravnborg 2735e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2736e279b6c1SSam Ravnborg 2737e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2738e279b6c1SSam Ravnborg 2739e279b6c1SSam Ravnborgsource "fs/Kconfig" 2740e279b6c1SSam Ravnborg 2741e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2742e279b6c1SSam Ravnborg 2743e279b6c1SSam Ravnborgsource "security/Kconfig" 2744e279b6c1SSam Ravnborg 2745e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2746e279b6c1SSam Ravnborg 2747edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2748edf88417SAvi Kivity 2749e279b6c1SSam Ravnborgsource "lib/Kconfig" 2750