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 2591dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 2621266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 276471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 2872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 29957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 30461a7184SYisheng Xie select ARCH_HAS_GIGANTIC_PAGE if X86_64 315c9a8750SDmitry Vyukov select ARCH_HAS_KCOV if X86_64 3296601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 3367a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 346471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 35c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 366471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 376471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3877fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 395e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 406471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 413b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 42be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 436471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 446471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 456471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 466471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 476471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 4872b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 495aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 50da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 516471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 526471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 536471b825SIngo Molnar select CLKEVT_I8253 546471b825SIngo Molnar select CLKSRC_I8253 if X86_32 556471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 566471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 576471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 586471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 596471b825SIngo Molnar select DCACHE_WORD_ACCESS 6045471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 6145471cd9SLinus Torvalds select EDAC_SUPPORT 626471b825SIngo Molnar select GENERIC_CLOCKEVENTS 636471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 646471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 656471b825SIngo Molnar select GENERIC_CMOS_UPDATE 666471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 676471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 686471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 696471b825SIngo Molnar select GENERIC_IOMAP 706471b825SIngo Molnar select GENERIC_IRQ_PROBE 716471b825SIngo Molnar select GENERIC_IRQ_SHOW 726471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 736471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 746471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 756471b825SIngo Molnar select GENERIC_STRNLEN_USER 766471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 776471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 786471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 796471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 806471b825SIngo Molnar select HAVE_AOUT if X86_32 816471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 825b710f34SKees Cook select HAVE_ARCH_HARDENED_USERCOPY 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 940f60a8efSKees Cook select HAVE_ARCH_WITHIN_STACK_FRAMES 956077776bSDaniel Borkmann select HAVE_EBPF_JIT if X86_64 96e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 976471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 986471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 996471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1006471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 101c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 1026471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1036471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1046471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 1056471b825SIngo Molnar select HAVE_DMA_API_DEBUG 1069c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 107677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10806aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10958340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1105f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 1116471b825SIngo Molnar select HAVE_FENTRY if X86_64 1126471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1136471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1146471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1156b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 1166471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1170067f129SK.Prasad select HAVE_HW_BREAKPOINT 1186471b825SIngo Molnar select HAVE_IDE 1196471b825SIngo Molnar select HAVE_IOREMAP_PROT 1206471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1216471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1226471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1236471b825SIngo Molnar select HAVE_KERNEL_GZIP 1246471b825SIngo Molnar select HAVE_KERNEL_LZ4 1256471b825SIngo Molnar select HAVE_KERNEL_LZMA 1266471b825SIngo Molnar select HAVE_KERNEL_LZO 1276471b825SIngo Molnar select HAVE_KERNEL_XZ 1286471b825SIngo Molnar select HAVE_KPROBES 1296471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1306471b825SIngo Molnar select HAVE_KRETPROBES 1316471b825SIngo Molnar select HAVE_KVM 1326471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1336471b825SIngo Molnar select HAVE_MEMBLOCK 1346471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1350102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 13642a0bb3fSPetr Mladek select HAVE_NMI 1376471b825SIngo Molnar select HAVE_OPROFILE 1386471b825SIngo Molnar select HAVE_OPTPROBES 1396471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1406471b825SIngo Molnar select HAVE_PERF_EVENTS 141c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 142c5e63197SJiri Olsa select HAVE_PERF_REGS 143c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1446471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1456471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1460c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1476471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1487c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 149c0185808SThomas Gleixner select IRQ_FORCED_THREADING 150786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1516471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1525b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1536471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1546471b825SIngo Molnar select PERF_EVENTS 1553195ef59SPrarit Bhargava select RTC_LIB 156d6faca40SArnd Bergmann select RTC_MC146818_LIB 1576471b825SIngo Molnar select SPARSE_IRQ 15883fe27eaSPranith Kumar select SRCU 1596471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 16015f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 1616471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1626471b825SIngo Molnar select VIRT_TO_BUS 1636471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1646471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 165d4883d5dSJosh Poimboeuf select HAVE_STACK_VALIDATION if X86_64 16663c17fb8SDave Hansen select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS 16766d37570SDave Hansen select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS 1687d8330a5SBalbir Singh 169ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1703120e25eSJan Beulich def_bool y 1713120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 172ba7e4d13SIngo Molnar 17351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 17451b26adaSLinus Torvalds string 17551b26adaSLinus Torvalds default "elf32-i386" if X86_32 17651b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 17751b26adaSLinus Torvalds 17873531905SSam Ravnborgconfig ARCH_DEFCONFIG 179b9b39bfbSSam Ravnborg string 18073531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 18173531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 182b9b39bfbSSam Ravnborg 1838d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1843c2362e6SHarvey Harrison def_bool y 1858d5fffb9SSam Ravnborg 1868d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1873c2362e6SHarvey Harrison def_bool y 1888d5fffb9SSam Ravnborg 1898d5fffb9SSam Ravnborgconfig MMU 1903c2362e6SHarvey Harrison def_bool y 1918d5fffb9SSam Ravnborg 1929e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 1939e08f57dSDaniel Cashman default 28 if 64BIT 1949e08f57dSDaniel Cashman default 8 1959e08f57dSDaniel Cashman 1969e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 1979e08f57dSDaniel Cashman default 32 if 64BIT 1989e08f57dSDaniel Cashman default 16 1999e08f57dSDaniel Cashman 2009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 2019e08f57dSDaniel Cashman default 8 2029e08f57dSDaniel Cashman 2039e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 2049e08f57dSDaniel Cashman default 16 2059e08f57dSDaniel Cashman 2068d5fffb9SSam Ravnborgconfig SBUS 2078d5fffb9SSam Ravnborg bool 2088d5fffb9SSam Ravnborg 2093bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 2103120e25eSJan Beulich def_bool y 211a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 2123bc4e459SFUJITA Tomonori 21318e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 2144a14d84eSAndrew Morton def_bool y 21518e98307SFUJITA Tomonori 2168d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 2173120e25eSJan Beulich def_bool y 2183120e25eSJan Beulich depends on ISA_DMA_API 2198d5fffb9SSam Ravnborg 2208d5fffb9SSam Ravnborgconfig GENERIC_BUG 2213c2362e6SHarvey Harrison def_bool y 2228d5fffb9SSam Ravnborg depends on BUG 223b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 224b93a531eSJan Beulich 225b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 226b93a531eSJan Beulich bool 2278d5fffb9SSam Ravnborg 2288d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2293c2362e6SHarvey Harrison def_bool y 2308d5fffb9SSam Ravnborg 2318d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2323120e25eSJan Beulich def_bool y 2333120e25eSJan Beulich depends on ISA_DMA_API 2348d5fffb9SSam Ravnborg 2351032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2363120e25eSJan Beulich def_bool y 2371032c0baSSam Ravnborg 2381032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2391032c0baSSam Ravnborg def_bool y 2401032c0baSSam Ravnborg 2419a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2429a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2438d5fffb9SSam Ravnborg 2441b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2451b27d05bSPekka Enberg def_bool y 2461b27d05bSPekka Enberg 247dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 24889c9c4c5SBrian Gerst def_bool y 249b32ef636Stravis@sgi.com 25008fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 25108fc4580STejun Heo def_bool y 25208fc4580STejun Heo 25308fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 25411124411STejun Heo def_bool y 25511124411STejun Heo 256801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 257801e4062SJohannes Berg def_bool y 258801e4062SJohannes Berg 259f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 260f4cb5700SJohannes Berg def_bool y 261f4cb5700SJohannes Berg 262cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 263cfe28c5dSSteve Capper def_bool y 264cfe28c5dSSteve Capper 26553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 26653313b2cSSteve Capper def_bool y 26753313b2cSSteve Capper 2688d5fffb9SSam Ravnborgconfig ZONE_DMA32 269e0fd24a3SJan Beulich def_bool y if X86_64 2708d5fffb9SSam Ravnborg 2718d5fffb9SSam Ravnborgconfig AUDIT_ARCH 272e0fd24a3SJan Beulich def_bool y if X86_64 2738d5fffb9SSam Ravnborg 274765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 275765c68bdSIngo Molnar def_bool y 276765c68bdSIngo Molnar 2776a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2786a11f75bSAkinobu Mita def_bool y 2796a11f75bSAkinobu Mita 280d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 281d6f2d75aSAndrey Ryabinin hex 282d6f2d75aSAndrey Ryabinin depends on KASAN 283d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 284d6f2d75aSAndrey Ryabinin 28569575d38SShane Wangconfig HAVE_INTEL_TXT 28669575d38SShane Wang def_bool y 2876ea30386SKees Cook depends on INTEL_IOMMU && ACPI 28869575d38SShane Wang 2896b0c3d44SSam Ravnborgconfig X86_32_SMP 2906b0c3d44SSam Ravnborg def_bool y 2916b0c3d44SSam Ravnborg depends on X86_32 && SMP 2926b0c3d44SSam Ravnborg 2936b0c3d44SSam Ravnborgconfig X86_64_SMP 2946b0c3d44SSam Ravnborg def_bool y 2956b0c3d44SSam Ravnborg depends on X86_64 && SMP 2966b0c3d44SSam Ravnborg 297ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 298ccbeed3aSTejun Heo def_bool y 29960a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 300ccbeed3aSTejun Heo 3012b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3022b144498SSrikar Dronamraju def_bool y 3032b144498SSrikar Dronamraju 304d20642f0SRob Herringconfig FIX_EARLYCON_MEM 305d20642f0SRob Herring def_bool y 306d20642f0SRob Herring 3079ccaf77cSKees Cookconfig DEBUG_RODATA 3089ccaf77cSKees Cook def_bool y 3099ccaf77cSKees Cook 31098233368SKirill A. Shutemovconfig PGTABLE_LEVELS 31198233368SKirill A. Shutemov int 31298233368SKirill A. Shutemov default 4 if X86_64 31398233368SKirill A. Shutemov default 3 if X86_PAE 31498233368SKirill A. Shutemov default 2 31598233368SKirill A. Shutemov 316506f1d07SSam Ravnborgsource "init/Kconfig" 317dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3188d5fffb9SSam Ravnborg 319506f1d07SSam Ravnborgmenu "Processor type and features" 320506f1d07SSam Ravnborg 3215ee71535SRandy Dunlapconfig ZONE_DMA 3225ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3235ee71535SRandy Dunlap default y 3245ee71535SRandy Dunlap help 3255ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3265ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3275ee71535SRandy Dunlap Disable if no such devices will be used. 3285ee71535SRandy Dunlap 3295ee71535SRandy Dunlap If unsure, say Y. 3305ee71535SRandy Dunlap 331506f1d07SSam Ravnborgconfig SMP 332506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 333506f1d07SSam Ravnborg ---help--- 334506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3354a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3364a474157SRobert Graffham than one CPU, say Y. 337506f1d07SSam Ravnborg 3384a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 339506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 340506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3414a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 342506f1d07SSam Ravnborg will run faster if you say N here. 343506f1d07SSam Ravnborg 344506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 345506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 346506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 347506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 348506f1d07SSam Ravnborg 349506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 350506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 351506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 352506f1d07SSam Ravnborg 353395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 354506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 355506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 356506f1d07SSam Ravnborg 357506f1d07SSam Ravnborg If you don't know what to do here, say N. 358506f1d07SSam Ravnborg 3599def39beSJosh Triplettconfig X86_FEATURE_NAMES 3609def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3619def39beSJosh Triplett default y 3629def39beSJosh Triplett ---help--- 3639def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3649def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3659def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3669def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3679def39beSJosh Triplett 3689def39beSJosh Triplett If in doubt, say Y. 3699def39beSJosh Triplett 3706e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS 3716e1315feSBorislav Petkov bool "Fast CPU feature tests" if EMBEDDED 3726e1315feSBorislav Petkov default y 3736e1315feSBorislav Petkov ---help--- 3746e1315feSBorislav Petkov Some fast-paths in the kernel depend on the capabilities of the CPU. 3756e1315feSBorislav Petkov Say Y here for the kernel to patch in the appropriate code at runtime 3766e1315feSBorislav Petkov based on the capabilities of the CPU. The infrastructure for patching 3776e1315feSBorislav Petkov code at runtime takes up some additional space; space-constrained 3786e1315feSBorislav Petkov embedded systems may wish to say N here to produce smaller, slightly 3796e1315feSBorislav Petkov slower code. 3806e1315feSBorislav Petkov 38106cd9a7dSYinghai Luconfig X86_X2APIC 38206cd9a7dSYinghai Lu bool "Support x2apic" 38319e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 38406cd9a7dSYinghai Lu ---help--- 38506cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 38606cd9a7dSYinghai Lu 38706cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 38806cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 38906cd9a7dSYinghai Lu 39006cd9a7dSYinghai Lu If you don't know what to do here, say N. 39106cd9a7dSYinghai Lu 3926695c85bSYinghai Luconfig X86_MPPARSE 3936e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3947a527688SJan Beulich default y 3955ab74722SIngo Molnar depends on X86_LOCAL_APIC 3968f9ca475SIngo Molnar ---help--- 3976695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 3986695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 3996695c85bSYinghai Lu 40026f7ef14SYinghai Luconfig X86_BIGSMP 40126f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 40226f7ef14SYinghai Lu depends on X86_32 && SMP 4038f9ca475SIngo Molnar ---help--- 40426f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 405506f1d07SSam Ravnborg 406ddd70cf9SJun Nakajimaconfig GOLDFISH 407ddd70cf9SJun Nakajima def_bool y 408ddd70cf9SJun Nakajima depends on X86_GOLDFISH 409ddd70cf9SJun Nakajima 4108425091fSRavikiran G Thirumalaiif X86_32 411c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 412c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 413c5c606d9SRavikiran G Thirumalai default y 4148f9ca475SIngo Molnar ---help--- 41506ac8346SIngo Molnar If you disable this option then the kernel will only support 41606ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 41706ac8346SIngo Molnar systems out there.) 41806ac8346SIngo Molnar 4198425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4208425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 421cb7b8023SBen Hutchings Goldfish (Android emulator) 4228425091fSRavikiran G Thirumalai AMD Elan 4238425091fSRavikiran G Thirumalai RDC R-321x SoC 4248425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 42583125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 4263f4110a4SThomas Gleixner Moorestown MID devices 42706ac8346SIngo Molnar 42806ac8346SIngo Molnar If you have one of these systems, or if you want to build a 42906ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4308425091fSRavikiran G Thirumalaiendif 43106ac8346SIngo Molnar 4328425091fSRavikiran G Thirumalaiif X86_64 4338425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4348425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4358425091fSRavikiran G Thirumalai default y 4368425091fSRavikiran G Thirumalai ---help--- 4378425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4388425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4398425091fSRavikiran G Thirumalai systems out there.) 4408425091fSRavikiran G Thirumalai 4418425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4428425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 44344b111b5SSteffen Persvold Numascale NumaChip 4448425091fSRavikiran G Thirumalai ScaleMP vSMP 4458425091fSRavikiran G Thirumalai SGI Ultraviolet 4468425091fSRavikiran G Thirumalai 4478425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4488425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4498425091fSRavikiran G Thirumalaiendif 450c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 451c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 45244b111b5SSteffen Persvoldconfig X86_NUMACHIP 45344b111b5SSteffen Persvold bool "Numascale NumaChip" 45444b111b5SSteffen Persvold depends on X86_64 45544b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 45644b111b5SSteffen Persvold depends on NUMA 45744b111b5SSteffen Persvold depends on SMP 45844b111b5SSteffen Persvold depends on X86_X2APIC 459f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 46044b111b5SSteffen Persvold ---help--- 46144b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 46244b111b5SSteffen Persvold enable more than ~168 cores. 46344b111b5SSteffen Persvold If you don't have one of these, you should say N here. 46403b48632SNick Piggin 4656a48565eSIngo Molnarconfig X86_VSMP 466c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4676276a074SBorislav Petkov select HYPERVISOR_GUEST 4686a48565eSIngo Molnar select PARAVIRT 4696a48565eSIngo Molnar depends on X86_64 && PCI 470c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 471ead91d4bSShai Fultheim depends on SMP 4728f9ca475SIngo Molnar ---help--- 4736a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4746a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4756a48565eSIngo Molnar if you have one of these machines. 4766a48565eSIngo Molnar 477c5c606d9SRavikiran G Thirumalaiconfig X86_UV 478c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 479c5c606d9SRavikiran G Thirumalai depends on X86_64 480c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 48154c28d29SJack Steiner depends on NUMA 4821ecb4ae5SAndrew Morton depends on EFI 4839d6c26e7SSuresh Siddha depends on X86_X2APIC 4841222e564SIngo Molnar depends on PCI 485c5c606d9SRavikiran G Thirumalai ---help--- 486c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 487c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 488c5c606d9SRavikiran G Thirumalai 489c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 490c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 491506f1d07SSam Ravnborg 492ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 493ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 494cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 495ddd70cf9SJun Nakajima ---help--- 496ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 497ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 498ddd70cf9SJun Nakajima Goldfish emulator say N here. 499ddd70cf9SJun Nakajima 500c751e17bSThomas Gleixnerconfig X86_INTEL_CE 501c751e17bSThomas Gleixner bool "CE4100 TV platform" 502c751e17bSThomas Gleixner depends on PCI 503c751e17bSThomas Gleixner depends on PCI_GODIRECT 5046084a6e2SJiang Liu depends on X86_IO_APIC 505c751e17bSThomas Gleixner depends on X86_32 506c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 50737bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 508da6b737bSSebastian Andrzej Siewior select OF 509da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 510c751e17bSThomas Gleixner ---help--- 511c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 512c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 513c751e17bSThomas Gleixner boxes and media devices. 514c751e17bSThomas Gleixner 5154cb9b00fSDavid Cohenconfig X86_INTEL_MID 51643605ef1SAlan Cox bool "Intel MID platform support" 51743605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 518edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 5191ea7c673SAlan Cox depends on PCI 5203fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 5211ea7c673SAlan Cox depends on X86_IO_APIC 5227c9c3a1eSAlan Cox select SFI 5234cb9b00fSDavid Cohen select I2C 5247c9c3a1eSAlan Cox select DW_APB_TIMER 5251ea7c673SAlan Cox select APB_TIMER 5261ea7c673SAlan Cox select INTEL_SCU_IPC 52715a713dfSMika Westerberg select MFD_INTEL_MSIC 5281ea7c673SAlan Cox ---help--- 5294cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5304cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5314cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5321ea7c673SAlan Cox 5334cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5344cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 53543605ef1SAlan Cox 5368bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5378bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5388bbc2a13SBryan O'Donoghue depends on X86_32 5398bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5408bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5418bbc2a13SBryan O'Donoghue depends on X86_TSC 5428bbc2a13SBryan O'Donoghue depends on PCI 5438bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5448bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5458bbc2a13SBryan O'Donoghue select IOSF_MBI 5468bbc2a13SBryan O'Donoghue select INTEL_IMR 5479ab6eb51SAndy Shevchenko select COMMON_CLK 5488bbc2a13SBryan O'Donoghue ---help--- 5498bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5508bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5518bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5528bbc2a13SBryan O'Donoghue 55358cbbee2SVadim Pasternakconfig MLX_PLATFORM 55458cbbee2SVadim Pasternak tristate "Mellanox Technologies platform support" 55558cbbee2SVadim Pasternak depends on X86_64 55658cbbee2SVadim Pasternak depends on X86_EXTENDED_PLATFORM 55758cbbee2SVadim Pasternak ---help--- 55858cbbee2SVadim Pasternak This option enables system support for the Mellanox Technologies 55958cbbee2SVadim Pasternak platform. 56058cbbee2SVadim Pasternak 56158cbbee2SVadim Pasternak Say Y here if you are building a kernel for Mellanox system. 56258cbbee2SVadim Pasternak 56358cbbee2SVadim Pasternak Otherwise, say N. 56458cbbee2SVadim Pasternak 5653d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5663d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 567eebb3e8dSAndy Shevchenko depends on X86 && ACPI 5683d48aab1SMika Westerberg select COMMON_CLK 5690f531431SMathias Nyman select PINCTRL 570eebb3e8dSAndy Shevchenko select IOSF_MBI 5713d48aab1SMika Westerberg ---help--- 5723d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5733d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5740f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5750f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5763d48aab1SMika Westerberg 57792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 57892082a88SKen Xue bool "AMD ACPI2Platform devices support" 57992082a88SKen Xue depends on ACPI 58092082a88SKen Xue select COMMON_CLK 58192082a88SKen Xue select PINCTRL 58292082a88SKen Xue ---help--- 58392082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 58492082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 58592082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 58692082a88SKen Xue implemented under PINCTRL subsystem. 58792082a88SKen Xue 588ced3ce76SDavid E. Boxconfig IOSF_MBI 589ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 590ced3ce76SDavid E. Box depends on PCI 591ced3ce76SDavid E. Box ---help--- 592ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 593ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 594ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 595ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 596ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 597ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 598ced3ce76SDavid E. Box This list is not meant to be exclusive. 599ced3ce76SDavid E. Box - BayTrail 600ced3ce76SDavid E. Box - Braswell 601ced3ce76SDavid E. Box - Quark 602ced3ce76SDavid E. Box 603ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 604ced3ce76SDavid E. Box 605ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 606ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 607ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 608ed2226bdSDavid E. Box ---help--- 609ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 610ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 611ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 612ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 613ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 614ed2226bdSDavid E. Box device they want to access. 615ed2226bdSDavid E. Box 616ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 617ed2226bdSDavid E. Box 618c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 619c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 620506f1d07SSam Ravnborg depends on X86_32 621c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 622c5c606d9SRavikiran G Thirumalai select M486 623c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 624c5c606d9SRavikiran G Thirumalai ---help--- 625c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 626c5c606d9SRavikiran G Thirumalai as R-8610-(G). 627c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 628c5c606d9SRavikiran G Thirumalai 629e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 6309c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 6319c398017SIngo Molnar depends on X86_32 && SMP 632c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 6338f9ca475SIngo Molnar ---help--- 634b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 635b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 636b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 637b5660ba7SH. Peter Anvin one and will fallback to default. 638d49c4288SYinghai Lu 639c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 640d49c4288SYinghai Lu 641d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6426fc108a0SJan Beulich def_bool y 643d949f36fSLinus Torvalds # MCE code calls memory_failure(): 644d949f36fSLinus Torvalds depends on X86_MCE 645d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 646d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 647d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 648d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 649d949f36fSLinus Torvalds 65083125a3aSAlessandro Rubiniconfig STA2X11 65183125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 65283125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 65383125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 65483125a3aSAlessandro Rubini select X86_DMA_REMAP 65583125a3aSAlessandro Rubini select SWIOTLB 65683125a3aSAlessandro Rubini select MFD_STA2X11 6570145071bSLinus Walleij select GPIOLIB 65883125a3aSAlessandro Rubini default n 65983125a3aSAlessandro Rubini ---help--- 66083125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 66183125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 66283125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 66383125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 66483125a3aSAlessandro Rubini standard PC machines. 66583125a3aSAlessandro Rubini 66682148d1dSShérabconfig X86_32_IRIS 66782148d1dSShérab tristate "Eurobraille/Iris poweroff module" 66882148d1dSShérab depends on X86_32 66982148d1dSShérab ---help--- 67082148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 67182148d1dSShérab to shut themselves down properly. A special I/O sequence is 67282148d1dSShérab needed to do so, which is what this module does at 67382148d1dSShérab kernel shutdown. 67482148d1dSShérab 67582148d1dSShérab This is only for Iris machines from EuroBraille. 67682148d1dSShérab 67782148d1dSShérab If unused, say N. 67882148d1dSShérab 679ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6803c2362e6SHarvey Harrison def_bool y 6813c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 682a87d0914SKen Chen depends on X86 6838f9ca475SIngo Molnar ---help--- 684506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 685506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 686506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 687506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 688506f1d07SSam Ravnborg 689506f1d07SSam Ravnborg If in doubt, say "Y". 690506f1d07SSam Ravnborg 6916276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6926276a074SBorislav Petkov bool "Linux guest support" 6938f9ca475SIngo Molnar ---help--- 6946276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6956276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6966276a074SBorislav Petkov setup. 697506f1d07SSam Ravnborg 6986276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6996276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 700506f1d07SSam Ravnborg 7016276a074SBorislav Petkovif HYPERVISOR_GUEST 702506f1d07SSam Ravnborg 703e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 704e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 7058f9ca475SIngo Molnar ---help--- 706e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 707e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 708e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 709e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 710e61bd94aSEduardo Pereira Habkost 7116276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7126276a074SBorislav Petkov bool "paravirt-ops debugging" 7136276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 7146276a074SBorislav Petkov ---help--- 7156276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7166276a074SBorislav Petkov a paravirt_op is missing when it is called. 7176276a074SBorislav Petkov 718b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 719b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7206ea30386SKees Cook depends on PARAVIRT && SMP 721b4ecc126SJeremy Fitzhardinge ---help--- 722b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 723b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 724b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 725b4ecc126SJeremy Fitzhardinge 7264c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 7274c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 728b4ecc126SJeremy Fitzhardinge 7294c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 730b4ecc126SJeremy Fitzhardinge 73145e898b7SWaiman Longconfig QUEUED_LOCK_STAT 73245e898b7SWaiman Long bool "Paravirt queued spinlock statistics" 733cfd8983fSPeter Zijlstra depends on PARAVIRT_SPINLOCKS && DEBUG_FS 73445e898b7SWaiman Long ---help--- 73545e898b7SWaiman Long Enable the collection of statistical data on the slowpath 73645e898b7SWaiman Long behavior of paravirtualized queued spinlocks and report 73745e898b7SWaiman Long them on debugfs. 73845e898b7SWaiman Long 7396276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 7406276a074SBorislav Petkov 7416276a074SBorislav Petkovconfig KVM_GUEST 7426276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7436276a074SBorislav Petkov depends on PARAVIRT 7446276a074SBorislav Petkov select PARAVIRT_CLOCK 7456276a074SBorislav Petkov default y 7466276a074SBorislav Petkov ---help--- 7476276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7486276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7496276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7506276a074SBorislav Petkov underlying device model, the host provides the guest with 7516276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7526276a074SBorislav Petkov 7531e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7541e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7551e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7561e20eb85SSrivatsa Vaddagiri default n 7571e20eb85SSrivatsa Vaddagiri ---help--- 7581e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7591e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7601e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7611e20eb85SSrivatsa Vaddagiri 7626276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7636276a074SBorislav Petkov 7646276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7656276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7666276a074SBorislav Petkov depends on PARAVIRT 7676276a074SBorislav Petkov default n 7686276a074SBorislav Petkov ---help--- 7696276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7706276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7716276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7726276a074SBorislav Petkov that, there can be a small performance impact. 7736276a074SBorislav Petkov 7746276a074SBorislav Petkov If in doubt, say N here. 7756276a074SBorislav Petkov 7767af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7777af192c9SGerd Hoffmann bool 7787af192c9SGerd Hoffmann 7796276a074SBorislav Petkovendif #HYPERVISOR_GUEST 78097349135SJeremy Fitzhardinge 78108677214SYinghai Luconfig NO_BOOTMEM 782774ea0bcSYinghai Lu def_bool y 78308677214SYinghai Lu 784506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 785506f1d07SSam Ravnborg 786506f1d07SSam Ravnborgconfig HPET_TIMER 7873c2362e6SHarvey Harrison def_bool X86_64 788506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7898f9ca475SIngo Molnar ---help--- 790506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 791506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 792506f1d07SSam Ravnborg present. 793506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 794506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 795506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 7964e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 7974e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 798506f1d07SSam Ravnborg 799506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 800506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 801506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 802506f1d07SSam Ravnborg 803506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 804506f1d07SSam Ravnborg 805506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8063c2362e6SHarvey Harrison def_bool y 8079d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 808506f1d07SSam Ravnborg 809bb24c471SJacob Panconfig APB_TIMER 810933b9463SAlan Cox def_bool y if X86_INTEL_MID 811933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 81206c3df49SJamie Iles select DW_APB_TIMER 813a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 814bb24c471SJacob Pan help 815bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 816bb24c471SJacob Pan The APBT provides a stable time base on SMP 817bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 818bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 819bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 820bb24c471SJacob Pan 8216a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 822506f1d07SSam Ravnborg# The code disables itself when not needed. 8237ae9392cSThomas Petazzoniconfig DMI 8247ae9392cSThomas Petazzoni default y 825cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 8266a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 8278f9ca475SIngo Molnar ---help--- 8287ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 8297ae9392cSThomas Petazzoni here unless you have verified that your setup is not 8307ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 8317ae9392cSThomas Petazzoni BIOS code. 8327ae9392cSThomas Petazzoni 833506f1d07SSam Ravnborgconfig GART_IOMMU 83438901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 835506f1d07SSam Ravnborg select SWIOTLB 83623ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 8378f9ca475SIngo Molnar ---help--- 838ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 839ced3c42cSIngo Molnar GART based hardware IOMMUs. 840ced3c42cSIngo Molnar 841ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 842ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 843ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 844ced3c42cSIngo Molnar 845ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 846ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 847ced3c42cSIngo Molnar 848ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 849ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 850ced3c42cSIngo Molnar 32-bit limited device. 851ced3c42cSIngo Molnar 852ced3c42cSIngo Molnar If unsure, say Y. 853506f1d07SSam Ravnborg 854506f1d07SSam Ravnborgconfig CALGARY_IOMMU 855506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 856506f1d07SSam Ravnborg select SWIOTLB 8576ea30386SKees Cook depends on X86_64 && PCI 8588f9ca475SIngo Molnar ---help--- 859506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 860506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 861506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 862506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 863506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 864506f1d07SSam Ravnborg prevents them from going anywhere except their intended 865506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 866506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 867506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 868506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 869506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 870506f1d07SSam Ravnborg If unsure, say Y. 871506f1d07SSam Ravnborg 872506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8733c2362e6SHarvey Harrison def_bool y 8743c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 875506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8768f9ca475SIngo Molnar ---help--- 877506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 878506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 879506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 880506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 881506f1d07SSam Ravnborg If unsure, say Y. 882506f1d07SSam Ravnborg 883506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 884506f1d07SSam Ravnborgconfig SWIOTLB 885a1afd01cSJoerg Roedel def_bool y if X86_64 8868f9ca475SIngo Molnar ---help--- 887506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8884454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8894454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8904454d327SJoe Millenbach with more than 3 GB of memory. 8914454d327SJoe Millenbach If unsure, say Y. 892506f1d07SSam Ravnborg 893a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8943120e25eSJan Beulich def_bool y 8953120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 896d25e26b6SLinus Torvalds 8971184dc2fSMike Travisconfig MAXSMP 898ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8996ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 90036f5101aSMike Travis select CPUMASK_OFFSTACK 9018f9ca475SIngo Molnar ---help--- 902ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9031184dc2fSMike Travis If unsure, say N. 904506f1d07SSam Ravnborg 905506f1d07SSam Ravnborgconfig NR_CPUS 90636f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 9072a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 908bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 909b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 91078637a97SMike Travis default "1" if !SMP 911b53b5edaSJosh Boyer default "8192" if MAXSMP 912b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 913c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 914c5c19941SKirill A. Shutemov default "64" if SMP 9158f9ca475SIngo Molnar ---help--- 916506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 917bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 918cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 919506f1d07SSam Ravnborg minimum value which makes sense is 2. 920506f1d07SSam Ravnborg 921506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 922506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 923506f1d07SSam Ravnborg 924506f1d07SSam Ravnborgconfig SCHED_SMT 925506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 926c8e56d20SBorislav Petkov depends on SMP 9278f9ca475SIngo Molnar ---help--- 928506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 929506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 930506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 931506f1d07SSam Ravnborg N here. 932506f1d07SSam Ravnborg 933506f1d07SSam Ravnborgconfig SCHED_MC 9343c2362e6SHarvey Harrison def_bool y 9353c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 936c8e56d20SBorislav Petkov depends on SMP 9378f9ca475SIngo Molnar ---help--- 938506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 939506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 940506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 941506f1d07SSam Ravnborg 942506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 943506f1d07SSam Ravnborg 94430b8b006SThomas Gleixnerconfig UP_LATE_INIT 94530b8b006SThomas Gleixner def_bool y 946ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 94730b8b006SThomas Gleixner 948506f1d07SSam Ravnborgconfig X86_UP_APIC 94950849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 95050849eefSJan Beulich default PCI_MSI 95138a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9528f9ca475SIngo Molnar ---help--- 953506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 954506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 955506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 956506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 957506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 958506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 959506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 960506f1d07SSam Ravnborg lockups. 961506f1d07SSam Ravnborg 962506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 963506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 964506f1d07SSam Ravnborg depends on X86_UP_APIC 9658f9ca475SIngo Molnar ---help--- 966506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 967506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 968506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 969506f1d07SSam Ravnborg 970506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 971506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 972506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 973506f1d07SSam Ravnborg 974506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9753c2362e6SHarvey Harrison def_bool y 9760dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 977b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 97852f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 979506f1d07SSam Ravnborg 980506f1d07SSam Ravnborgconfig X86_IO_APIC 981b1da1e71SJan Beulich def_bool y 982b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 983506f1d07SSam Ravnborg 98441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 98541b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 98641b9eb26SStefan Assmann depends on X86_IO_APIC 9878f9ca475SIngo Molnar ---help--- 98841b9eb26SStefan Assmann This option enables a workaround that fixes a source of 98941b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 99041b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 99141b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 99241b9eb26SStefan Assmann 99341b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 99441b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 99541b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 99641b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 99741b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 99841b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 99941b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 100041b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 100141b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 100241b9eb26SStefan Assmann down (vital) interrupt lines. 100341b9eb26SStefan Assmann 100441b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 100541b9eb26SStefan Assmann increased on these systems. 100641b9eb26SStefan Assmann 1007506f1d07SSam Ravnborgconfig X86_MCE 1008bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1009648ed940SChen, Gong select GENERIC_ALLOCATOR 1010e57dbaf7SBorislav Petkov default y 1011506f1d07SSam Ravnborg ---help--- 1012bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1013bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1014506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1015bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 10164efc0670SAndi Kleen 1017506f1d07SSam Ravnborgconfig X86_MCE_INTEL 10183c2362e6SHarvey Harrison def_bool y 10193c2362e6SHarvey Harrison prompt "Intel MCE features" 1020c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10218f9ca475SIngo Molnar ---help--- 1022506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1023506f1d07SSam Ravnborg the thermal monitor. 1024506f1d07SSam Ravnborg 1025506f1d07SSam Ravnborgconfig X86_MCE_AMD 10263c2362e6SHarvey Harrison def_bool y 10273c2362e6SHarvey Harrison prompt "AMD MCE features" 1028c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 10298f9ca475SIngo Molnar ---help--- 1030506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1031506f1d07SSam Ravnborg the DRAM Error Threshold. 1032506f1d07SSam Ravnborg 10334efc0670SAndi Kleenconfig X86_ANCIENT_MCE 10346fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1035c31d9633SAndi Kleen depends on X86_32 && X86_MCE 10364efc0670SAndi Kleen ---help--- 10374efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 10385065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 10394efc0670SAndi Kleen line. 10404efc0670SAndi Kleen 1041b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1042b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10436fc108a0SJan Beulich def_bool y 1044b2762686SAndi Kleen 1045ea149b36SAndi Kleenconfig X86_MCE_INJECT 1046c1ebf835SAndi Kleen depends on X86_MCE 1047ea149b36SAndi Kleen tristate "Machine check injector support" 1048ea149b36SAndi Kleen ---help--- 1049ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1050ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1051ea149b36SAndi Kleen QA it is safe to say n. 1052ea149b36SAndi Kleen 10534efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10544efc0670SAndi Kleen def_bool y 10555bb38adcSAndi Kleen depends on X86_MCE_INTEL 10564efc0670SAndi Kleen 105707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1058e633c65aSKan Liang 10595aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10601e642812SIngo Molnar bool "Legacy VM86 support" 10615aef51c3SAndy Lutomirski default n 1062506f1d07SSam Ravnborg depends on X86_32 10638f9ca475SIngo Molnar ---help--- 10645aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10655aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10665aef51c3SAndy Lutomirski 10675aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10685aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10695aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10705aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10715aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10721e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10731e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10741e642812SIngo Molnar mode might be faster than emulation and you might want to 10751e642812SIngo Molnar enable this option. 10765aef51c3SAndy Lutomirski 10771e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10781e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10791e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10801e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10815aef51c3SAndy Lutomirski 10821e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10831e642812SIngo Molnar and slows down exception handling a tiny bit. 10845aef51c3SAndy Lutomirski 10851e642812SIngo Molnar If unsure, say N here. 10865aef51c3SAndy Lutomirski 10875aef51c3SAndy Lutomirskiconfig VM86 10885aef51c3SAndy Lutomirski bool 10895aef51c3SAndy Lutomirski default X86_LEGACY_VM86 109034273f41SH. Peter Anvin 109134273f41SH. Peter Anvinconfig X86_16BIT 109234273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 109334273f41SH. Peter Anvin default y 1094a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 109534273f41SH. Peter Anvin ---help--- 109634273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 109734273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 109834273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 109934273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 110034273f41SH. Peter Anvin 110134273f41SH. Peter Anvinconfig X86_ESPFIX32 110234273f41SH. Peter Anvin def_bool y 110334273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1104506f1d07SSam Ravnborg 1105197725deSH. Peter Anvinconfig X86_ESPFIX64 1106197725deSH. Peter Anvin def_bool y 110734273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1108506f1d07SSam Ravnborg 11091ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 11101ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 11111ad83c85SAndy Lutomirski default y 11121ad83c85SAndy Lutomirski depends on X86_64 11131ad83c85SAndy Lutomirski ---help--- 11141ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 11151ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 11161ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 11171ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 11181ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 11191ad83c85SAndy Lutomirski 0xffffffffff600?00. 11201ad83c85SAndy Lutomirski 11211ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 11221ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 11231ad83c85SAndy Lutomirski 11241ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 11251ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 11261ad83c85SAndy Lutomirski 1127506f1d07SSam Ravnborgconfig TOSHIBA 1128506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1129506f1d07SSam Ravnborg depends on X86_32 1130506f1d07SSam Ravnborg ---help--- 1131506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1132506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1133506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1134506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1135506f1d07SSam Ravnborg 1136506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1137506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1138506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1139506f1d07SSam Ravnborg 1140506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1141506f1d07SSam Ravnborg Say N otherwise. 1142506f1d07SSam Ravnborg 1143506f1d07SSam Ravnborgconfig I8K 1144039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1145949a9d70SJean Delvare select HWMON 1146039ae585SPali Rohár select SENSORS_DELL_SMM 1147506f1d07SSam Ravnborg ---help--- 1148039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1149039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1150039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1151039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1152039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1153039ae585SPali Rohár needed userspace package i8kutils. 1154506f1d07SSam Ravnborg 1155039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1156039ae585SPali Rohár use userspace package i8kutils. 1157506f1d07SSam Ravnborg Say N otherwise. 1158506f1d07SSam Ravnborg 1159506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11609ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11619ba16087SJan Beulich depends on X86_32 1162506f1d07SSam Ravnborg ---help--- 1163506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1164506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1165506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1166506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1167506f1d07SSam Ravnborg system. 1168506f1d07SSam Ravnborg 1169506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11705e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1171506f1d07SSam Ravnborg 1172506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1173506f1d07SSam Ravnborg enable this option even if you don't need it. 1174506f1d07SSam Ravnborg Say N otherwise. 1175506f1d07SSam Ravnborg 1176506f1d07SSam Ravnborgconfig MICROCODE 11779a2bc335SBorislav Petkov bool "CPU microcode loading support" 11789a2bc335SBorislav Petkov default y 117980030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1180506f1d07SSam Ravnborg select FW_LOADER 1181506f1d07SSam Ravnborg ---help--- 1182506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 11835f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 11845f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 11855f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 11865f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 11875f9c01aaSBorislav Petkov the Linux kernel. 1188506f1d07SSam Ravnborg 11895f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 11905f9c01aaSBorislav Petkov in Documentation/x86/early-microcode.txt. For that you need to enable 11915f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 11925f9c01aaSBorislav Petkov initrd for microcode blobs. 1193506f1d07SSam Ravnborg 11945f9c01aaSBorislav Petkov In addition, you can build-in the microcode into the kernel. For that you 11955f9c01aaSBorislav Petkov need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 11965f9c01aaSBorislav Petkov to the CONFIG_EXTRA_FIRMWARE config option. 1197506f1d07SSam Ravnborg 11988d86f390SPeter Orubaconfig MICROCODE_INTEL 1199e43f6e67SBorislav Petkov bool "Intel microcode loading support" 12008d86f390SPeter Oruba depends on MICROCODE 12018d86f390SPeter Oruba default MICROCODE 12028d86f390SPeter Oruba select FW_LOADER 12038f9ca475SIngo Molnar ---help--- 12048d86f390SPeter Oruba This options enables microcode patch loading support for Intel 12058d86f390SPeter Oruba processors. 12068d86f390SPeter Oruba 1207b8989db9SAlan For the current Intel microcode data package go to 1208b8989db9SAlan <https://downloadcenter.intel.com> and search for 1209b8989db9SAlan 'Linux Processor Microcode Data File'. 12108d86f390SPeter Oruba 121180cc9f10SPeter Orubaconfig MICROCODE_AMD 1212e43f6e67SBorislav Petkov bool "AMD microcode loading support" 121380cc9f10SPeter Oruba depends on MICROCODE 121480cc9f10SPeter Oruba select FW_LOADER 12158f9ca475SIngo Molnar ---help--- 121680cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 121780cc9f10SPeter Oruba processors will be enabled. 121880cc9f10SPeter Oruba 1219506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 12203c2362e6SHarvey Harrison def_bool y 1221506f1d07SSam Ravnborg depends on MICROCODE 1222506f1d07SSam Ravnborg 1223506f1d07SSam Ravnborgconfig X86_MSR 1224506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 12258f9ca475SIngo Molnar ---help--- 1226506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1227506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1228506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1229506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1230506f1d07SSam Ravnborg systems. 1231506f1d07SSam Ravnborg 1232506f1d07SSam Ravnborgconfig X86_CPUID 1233506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 12348f9ca475SIngo Molnar ---help--- 1235506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1236506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1237506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1238506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1239506f1d07SSam Ravnborg 1240506f1d07SSam Ravnborgchoice 1241506f1d07SSam Ravnborg prompt "High Memory Support" 12426fc108a0SJan Beulich default HIGHMEM4G 1243506f1d07SSam Ravnborg depends on X86_32 1244506f1d07SSam Ravnborg 1245506f1d07SSam Ravnborgconfig NOHIGHMEM 1246506f1d07SSam Ravnborg bool "off" 1247506f1d07SSam Ravnborg ---help--- 1248506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1249506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1250506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1251506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1252506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1253506f1d07SSam Ravnborg "high memory". 1254506f1d07SSam Ravnborg 1255506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1256506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1257506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1258506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1259506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1260506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1261506f1d07SSam Ravnborg possible. 1262506f1d07SSam Ravnborg 1263506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1264506f1d07SSam Ravnborg answer "4GB" here. 1265506f1d07SSam Ravnborg 1266506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1267506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1268506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1269506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1270506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1271506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1272506f1d07SSam Ravnborg 1273506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1274506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1275506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1276506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1277506f1d07SSam Ravnborg kernel at boot time.) 1278506f1d07SSam Ravnborg 1279506f1d07SSam Ravnborg If unsure, say "off". 1280506f1d07SSam Ravnborg 1281506f1d07SSam Ravnborgconfig HIGHMEM4G 1282506f1d07SSam Ravnborg bool "4GB" 12838f9ca475SIngo Molnar ---help--- 1284506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1285506f1d07SSam Ravnborg gigabytes of physical RAM. 1286506f1d07SSam Ravnborg 1287506f1d07SSam Ravnborgconfig HIGHMEM64G 1288506f1d07SSam Ravnborg bool "64GB" 1289eb068e78SH. Peter Anvin depends on !M486 1290506f1d07SSam Ravnborg select X86_PAE 12918f9ca475SIngo Molnar ---help--- 1292506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1293506f1d07SSam Ravnborg gigabytes of physical RAM. 1294506f1d07SSam Ravnborg 1295506f1d07SSam Ravnborgendchoice 1296506f1d07SSam Ravnborg 1297506f1d07SSam Ravnborgchoice 12986a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1299506f1d07SSam Ravnborg default VMSPLIT_3G 1300506f1d07SSam Ravnborg depends on X86_32 13018f9ca475SIngo Molnar ---help--- 1302506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1303506f1d07SSam Ravnborg 1304506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1305506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1306506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1307506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1308506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1309506f1d07SSam Ravnborg available to user programs, making the address space there 1310506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1311506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1312506f1d07SSam Ravnborg kernel modules. 1313506f1d07SSam Ravnborg 1314506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1315506f1d07SSam Ravnborg option alone! 1316506f1d07SSam Ravnborg 1317506f1d07SSam Ravnborg config VMSPLIT_3G 1318506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1319506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1320506f1d07SSam Ravnborg depends on !X86_PAE 1321506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1322506f1d07SSam Ravnborg config VMSPLIT_2G 1323506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1324506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1325506f1d07SSam Ravnborg depends on !X86_PAE 1326506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1327506f1d07SSam Ravnborg config VMSPLIT_1G 1328506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1329506f1d07SSam Ravnborgendchoice 1330506f1d07SSam Ravnborg 1331506f1d07SSam Ravnborgconfig PAGE_OFFSET 1332506f1d07SSam Ravnborg hex 1333506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1334506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1335506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1336506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1337506f1d07SSam Ravnborg default 0xC0000000 1338506f1d07SSam Ravnborg depends on X86_32 1339506f1d07SSam Ravnborg 1340506f1d07SSam Ravnborgconfig HIGHMEM 13413c2362e6SHarvey Harrison def_bool y 1342506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1343506f1d07SSam Ravnborg 1344506f1d07SSam Ravnborgconfig X86_PAE 13459ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1346506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13479d99c712SChristian Melki select SWIOTLB 13488f9ca475SIngo Molnar ---help--- 1349506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1350506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1351506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1352506f1d07SSam Ravnborg consumes more pagetable space per process. 1353506f1d07SSam Ravnborg 1354600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13553120e25eSJan Beulich def_bool y 13563120e25eSJan Beulich depends on X86_64 || X86_PAE 1357600715dcSJeremy Fitzhardinge 135866f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13593120e25eSJan Beulich def_bool y 13603120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 136166f2b061SFUJITA Tomonori 136210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1363e5008abeSLuis R. Rodriguez def_bool y 1364e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13658f9ca475SIngo Molnar ---help--- 136610971ab2SIngo Molnar Certain kernel features effectively disable kernel 136710971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 136810971ab2SIngo Molnar supports them), so don't confuse the user by printing 136910971ab2SIngo Molnar that we have them enabled. 13709e899816SNick Piggin 1371506f1d07SSam Ravnborg# Common NUMA Features 1372506f1d07SSam Ravnborgconfig NUMA 1373fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1374506f1d07SSam Ravnborg depends on SMP 1375b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1376b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13778f9ca475SIngo Molnar ---help--- 1378506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1379fd51b2d7SKOSAKI Motohiro 1380506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1381506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1382506f1d07SSam Ravnborg NUMA awareness to the kernel. 1383506f1d07SSam Ravnborg 1384c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1385fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1386fd51b2d7SKOSAKI Motohiro 1387b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13887cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1389fd51b2d7SKOSAKI Motohiro 1390fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1391506f1d07SSam Ravnborg 1392eec1d4faSHans Rosenfeldconfig AMD_NUMA 13933c2362e6SHarvey Harrison def_bool y 13943c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13955da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13968f9ca475SIngo Molnar ---help--- 1397eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1398eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1399eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1400eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1401eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1402506f1d07SSam Ravnborg 1403506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 14043c2362e6SHarvey Harrison def_bool y 14053c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1406506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1407506f1d07SSam Ravnborg select ACPI_NUMA 14088f9ca475SIngo Molnar ---help--- 1409506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1410506f1d07SSam Ravnborg 14116ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 14126ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 14136ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 14146ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 14156ec6e0d9SSuresh Siddha# for details. 14166ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 14176ec6e0d9SSuresh Siddha def_bool y 14186ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 14196ec6e0d9SSuresh Siddha 1420506f1d07SSam Ravnborgconfig NUMA_EMU 1421506f1d07SSam Ravnborg bool "NUMA emulation" 14221b7e03efSTejun Heo depends on NUMA 14238f9ca475SIngo Molnar ---help--- 1424506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1425506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1426506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1427506f1d07SSam Ravnborg 1428506f1d07SSam Ravnborgconfig NODES_SHIFT 1429d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 143051591e31SDavid Rientjes range 1 10 143151591e31SDavid Rientjes default "10" if MAXSMP 1432506f1d07SSam Ravnborg default "6" if X86_64 1433506f1d07SSam Ravnborg default "3" 1434506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 14358f9ca475SIngo Molnar ---help--- 14361184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1437692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1438506f1d07SSam Ravnborg 1439506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 14403c2362e6SHarvey Harrison def_bool y 1441506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1442506f1d07SSam Ravnborg 1443506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14443c2362e6SHarvey Harrison def_bool y 1445506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1446506f1d07SSam Ravnborg 1447506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1448506f1d07SSam Ravnborg def_bool y 14493b16651fSTejun Heo depends on X86_32 && !NUMA 1450506f1d07SSam Ravnborg 1451506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1452506f1d07SSam Ravnborg def_bool y 1453b263295dSChristoph Lameter depends on NUMA && X86_32 1454506f1d07SSam Ravnborg 1455506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1456506f1d07SSam Ravnborg def_bool y 1457b263295dSChristoph Lameter depends on NUMA && X86_32 1458b263295dSChristoph Lameter 1459506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1460506f1d07SSam Ravnborg def_bool y 14616ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1462506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1463506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1464506f1d07SSam Ravnborg 14653b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14663b16651fSTejun Heo def_bool y 14673b16651fSTejun Heo depends on X86_64 14683b16651fSTejun Heo 1469506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1470506f1d07SSam Ravnborg def_bool y 1471b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1472506f1d07SSam Ravnborg 1473506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1474a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14753120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1476a0842b70SToshi Kani help 1477a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1478a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1479a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1480506f1d07SSam Ravnborg 14813b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14823b16651fSTejun Heo def_bool y 14833b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14843b16651fSTejun Heo 1485a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1486a29815a3SAvi Kivity hex 1487a29815a3SAvi Kivity default 0 if X86_32 1488a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1489a29815a3SAvi Kivity 1490506f1d07SSam Ravnborgsource "mm/Kconfig" 1491506f1d07SSam Ravnborg 14927a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14937a67832cSDan Williams bool 14947a67832cSDan Williams 1495ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 14967a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 14979f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14989f53f9faSDan Williams depends on BLK_DEV 14997a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 15009f53f9faSDan Williams select LIBNVDIMM 1501ec776ef6SChristoph Hellwig help 1502ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1503ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1504ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1505ec776ef6SChristoph Hellwig they can be used for persistent storage. 1506ec776ef6SChristoph Hellwig 1507ec776ef6SChristoph Hellwig Say Y if unsure. 1508ec776ef6SChristoph Hellwig 1509506f1d07SSam Ravnborgconfig HIGHPTE 1510506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 15116fc108a0SJan Beulich depends on HIGHMEM 15128f9ca475SIngo Molnar ---help--- 1513506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1514506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1515506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1516506f1d07SSam Ravnborg entries in high memory. 1517506f1d07SSam Ravnborg 15189f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 15199f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 15208f9ca475SIngo Molnar ---help--- 15219f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 15229f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 15239f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 15249f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 15259f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 15269f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 15279f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 1528*8c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 15299f077871SJeremy Fitzhardinge 15309f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 15319f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 15329f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 15339f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 15349f077871SJeremy Fitzhardinge 15359f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 15369f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 15379f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 15389f077871SJeremy Fitzhardinge memory. 15399f077871SJeremy Fitzhardinge 1540c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1541c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1542c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1543c885df50SJeremy Fitzhardinge default y 15448f9ca475SIngo Molnar ---help--- 1545c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1546c885df50SJeremy Fitzhardinge on or off. 1547c885df50SJeremy Fitzhardinge 15489ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1549d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1550d0cd7425SH. Peter Anvin default 64 1551d0cd7425SH. Peter Anvin range 4 640 15528f9ca475SIngo Molnar ---help--- 1553d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1554fc381519SIngo Molnar 1555d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1556d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1557fc381519SIngo Molnar 1558d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1559d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1560d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1561d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1562fc381519SIngo Molnar 1563d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1564d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1565d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1566d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1567d0cd7425SH. Peter Anvin entire low memory range. 1568d0cd7425SH. Peter Anvin 1569d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1570d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1571d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1572d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1573d0cd7425SH. Peter Anvin typical corruption patterns. 1574d0cd7425SH. Peter Anvin 1575d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1576fc381519SIngo Molnar 1577506f1d07SSam Ravnborgconfig MATH_EMULATION 1578506f1d07SSam Ravnborg bool 1579a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1580506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1581506f1d07SSam Ravnborg ---help--- 1582506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1583506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1584506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1585506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1586506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1587506f1d07SSam Ravnborg coprocessor or this emulation. 1588506f1d07SSam Ravnborg 1589506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1590506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1591506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1592506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1593506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1594506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1595506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1596506f1d07SSam Ravnborg intend to use this kernel on different machines. 1597506f1d07SSam Ravnborg 1598506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1599506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1600506f1d07SSam Ravnborg 1601506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1602506f1d07SSam Ravnborg kernel, it won't hurt. 1603506f1d07SSam Ravnborg 1604506f1d07SSam Ravnborgconfig MTRR 16056fc108a0SJan Beulich def_bool y 16066a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1607506f1d07SSam Ravnborg ---help--- 1608506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1609506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1610506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1611506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1612506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1613506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1614506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1615506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1616506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1617506f1d07SSam Ravnborg 1618506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1619506f1d07SSam Ravnborg control registers on other processors can be easily supported 1620506f1d07SSam Ravnborg as well: 1621506f1d07SSam Ravnborg 1622506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1623506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1624506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1625506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1626506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1627506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1628506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1629506f1d07SSam Ravnborg 1630506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1631506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1632506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1633506f1d07SSam Ravnborg 1634506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1635506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1636506f1d07SSam Ravnborg 16377225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1638506f1d07SSam Ravnborg 163995ffa243SYinghai Luconfig MTRR_SANITIZER 16402ffb3501SYinghai Lu def_bool y 164195ffa243SYinghai Lu prompt "MTRR cleanup support" 164295ffa243SYinghai Lu depends on MTRR 16438f9ca475SIngo Molnar ---help--- 1644aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1645aba3728cSThomas Gleixner add writeback entries. 164695ffa243SYinghai Lu 1647aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1648692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1649aba3728cSThomas Gleixner mtrr_chunk_size. 165095ffa243SYinghai Lu 16512ffb3501SYinghai Lu If unsure, say Y. 165295ffa243SYinghai Lu 165395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1654f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1655f5098d62SYinghai Lu range 0 1 1656f5098d62SYinghai Lu default "0" 165795ffa243SYinghai Lu depends on MTRR_SANITIZER 16588f9ca475SIngo Molnar ---help--- 1659f5098d62SYinghai Lu Enable mtrr cleanup default value 166095ffa243SYinghai Lu 166112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 166212031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 166312031a62SYinghai Lu range 0 7 166412031a62SYinghai Lu default "1" 166512031a62SYinghai Lu depends on MTRR_SANITIZER 16668f9ca475SIngo Molnar ---help--- 166712031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1668aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 166912031a62SYinghai Lu 16702e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16716fc108a0SJan Beulich def_bool y 16726a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16732a8a2719SIngo Molnar depends on MTRR 16748f9ca475SIngo Molnar ---help--- 16752e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1676042b78e4SVenki Pallipadi 16772e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16782e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16792e5d9c85Svenkatesh.pallipadi@intel.com 16802e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1681042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16822e5d9c85Svenkatesh.pallipadi@intel.com 16832e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16842e5d9c85Svenkatesh.pallipadi@intel.com 168546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 168646cf98cdSVenkatesh Pallipadi def_bool y 168746cf98cdSVenkatesh Pallipadi depends on X86_PAT 168846cf98cdSVenkatesh Pallipadi 1689628c6246SH. Peter Anvinconfig ARCH_RANDOM 1690628c6246SH. Peter Anvin def_bool y 1691628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1692628c6246SH. Peter Anvin ---help--- 1693628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1694628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1695628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1696628c6246SH. Peter Anvin secure hardware random number generator. 1697628c6246SH. Peter Anvin 169851ae4a2dSH. Peter Anvinconfig X86_SMAP 169951ae4a2dSH. Peter Anvin def_bool y 170051ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 170151ae4a2dSH. Peter Anvin ---help--- 170251ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 170351ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 170451ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 170551ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 170651ae4a2dSH. Peter Anvin 170751ae4a2dSH. Peter Anvin If unsure, say Y. 170851ae4a2dSH. Peter Anvin 170972e9b5feSDave Hansenconfig X86_INTEL_MPX 171072e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 171172e9b5feSDave Hansen def_bool n 171272e9b5feSDave Hansen depends on CPU_SUP_INTEL 171372e9b5feSDave Hansen ---help--- 171472e9b5feSDave Hansen MPX provides hardware features that can be used in 171572e9b5feSDave Hansen conjunction with compiler-instrumented code to check 171672e9b5feSDave Hansen memory references. It is designed to detect buffer 171772e9b5feSDave Hansen overflow or underflow bugs. 171872e9b5feSDave Hansen 171972e9b5feSDave Hansen This option enables running applications which are 172072e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 172172e9b5feSDave Hansen itself inside the kernel or to protect the kernel 172272e9b5feSDave Hansen against bad memory references. 172372e9b5feSDave Hansen 172472e9b5feSDave Hansen Enabling this option will make the kernel larger: 172572e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 172672e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 172772e9b5feSDave Hansen will increase the kernel memory overhead of each 172872e9b5feSDave Hansen process and adds some branches to paths used during 172972e9b5feSDave Hansen exec() and munmap(). 173072e9b5feSDave Hansen 173172e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 173272e9b5feSDave Hansen 173372e9b5feSDave Hansen If unsure, say N. 173472e9b5feSDave Hansen 173535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 1736284244a9SDave Hansen prompt "Intel Memory Protection Keys" 173735e97790SDave Hansen def_bool y 1738284244a9SDave Hansen # Note: only available in 64-bit mode 173935e97790SDave Hansen depends on CPU_SUP_INTEL && X86_64 1740284244a9SDave Hansen ---help--- 1741284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1742284244a9SDave Hansen page-based protections, but without requiring modification of the 1743284244a9SDave Hansen page tables when an application changes protection domains. 1744284244a9SDave Hansen 1745284244a9SDave Hansen For details, see Documentation/x86/protection-keys.txt 1746284244a9SDave Hansen 1747284244a9SDave Hansen If unsure, say y. 174835e97790SDave Hansen 1749506f1d07SSam Ravnborgconfig EFI 17509ba16087SJan Beulich bool "EFI runtime service support" 17515b83683fSHuang, Ying depends on ACPI 1752f6ce5002SSergey Vlasov select UCS2_STRING 1753022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1754506f1d07SSam Ravnborg ---help--- 17558b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1756506f1d07SSam Ravnborg available (such as the EFI variable services). 1757506f1d07SSam Ravnborg 17588b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17598b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17608b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17618b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17628b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17638b2cb7a8SHuang, Ying platforms. 1764506f1d07SSam Ravnborg 1765291f3632SMatt Flemingconfig EFI_STUB 1766291f3632SMatt Fleming bool "EFI stub support" 1767b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17687b2a583aSMatt Fleming select RELOCATABLE 1769291f3632SMatt Fleming ---help--- 1770291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1771291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1772291f3632SMatt Fleming 17734172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17740c759662SMatt Fleming 17757d453eeeSMatt Flemingconfig EFI_MIXED 17767d453eeeSMatt Fleming bool "EFI mixed-mode support" 17777d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17787d453eeeSMatt Fleming ---help--- 17797d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17807d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17817d453eeeSMatt Fleming mode. 17827d453eeeSMatt Fleming 17837d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17847d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17857d453eeeSMatt Fleming the EFI handover protocol must be used. 17867d453eeeSMatt Fleming 17877d453eeeSMatt Fleming If unsure, say N. 17887d453eeeSMatt Fleming 1789506f1d07SSam Ravnborgconfig SECCOMP 17903c2362e6SHarvey Harrison def_bool y 17913c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17928f9ca475SIngo Molnar ---help--- 1793506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1794506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1795506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1796506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1797506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1798506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17999c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1800506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1801506f1d07SSam Ravnborg defined by each seccomp mode. 1802506f1d07SSam Ravnborg 1803506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1804506f1d07SSam Ravnborg 1805506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1806506f1d07SSam Ravnborg 1807506f1d07SSam Ravnborgconfig KEXEC 1808506f1d07SSam Ravnborg bool "kexec system call" 18092965faa5SDave Young select KEXEC_CORE 18108f9ca475SIngo Molnar ---help--- 1811506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1812506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1813506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1814506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1815506f1d07SSam Ravnborg 1816506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1817506f1d07SSam Ravnborg 1818506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1819506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1820bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1821bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1822bf220695SGeert Uytterhoeven made. 1823506f1d07SSam Ravnborg 182474ca317cSVivek Goyalconfig KEXEC_FILE 182574ca317cSVivek Goyal bool "kexec file based system call" 18262965faa5SDave Young select KEXEC_CORE 182774ca317cSVivek Goyal select BUILD_BIN2C 182874ca317cSVivek Goyal depends on X86_64 182974ca317cSVivek Goyal depends on CRYPTO=y 183074ca317cSVivek Goyal depends on CRYPTO_SHA256=y 183174ca317cSVivek Goyal ---help--- 183274ca317cSVivek Goyal This is new version of kexec system call. This system call is 183374ca317cSVivek Goyal file based and takes file descriptors as system call argument 183474ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 183574ca317cSVivek Goyal accepted by previous system call. 183674ca317cSVivek Goyal 18378e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 18388e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 183974ca317cSVivek Goyal depends on KEXEC_FILE 18408e7d8381SVivek Goyal ---help--- 18418e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1842d8eb8940SBorislav Petkov the kexec_file_load() syscall. 18438e7d8381SVivek Goyal 1844d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1845d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1846d8eb8940SBorislav Petkov loaded in order for this to work. 18478e7d8381SVivek Goyal 18488e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 18498e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 18508e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 18518e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 18528e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 18538e7d8381SVivek Goyal ---help--- 18548e7d8381SVivek Goyal Enable bzImage signature verification support. 18558e7d8381SVivek Goyal 1856506f1d07SSam Ravnborgconfig CRASH_DUMP 185704b69447SPavel Machek bool "kernel crash dumps" 1858506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18598f9ca475SIngo Molnar ---help--- 1860506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1861506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1862506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1863506f1d07SSam Ravnborg a specially reserved region and then later executed after 1864506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1865506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1866506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1867506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1868506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1869506f1d07SSam Ravnborg 18703ab83521SHuang Yingconfig KEXEC_JUMP 18716ea30386SKees Cook bool "kexec jump" 1872fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18738f9ca475SIngo Molnar ---help--- 187489081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 187589081d17SHuang Ying code in physical address mode via KEXEC 18763ab83521SHuang Ying 1877506f1d07SSam Ravnborgconfig PHYSICAL_START 18786a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1879ceefccc9SH. Peter Anvin default "0x1000000" 18808f9ca475SIngo Molnar ---help--- 1881506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1882506f1d07SSam Ravnborg 1883506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1884506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1885506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1886506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1887506f1d07SSam Ravnborg address. 1888506f1d07SSam Ravnborg 1889506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1890506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1891506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1892506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1893506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1894506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1895506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1896506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1897506f1d07SSam Ravnborg 1898ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1899ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1900ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1901ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1902ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1903ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1904ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1905ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1906ceefccc9SH. Peter Anvin for more details about crash dumps. 1907506f1d07SSam Ravnborg 1908506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1909506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1910506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1911506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1912506f1d07SSam Ravnborg is present because there are users out there who continue to use 1913506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1914506f1d07SSam Ravnborg line. 1915506f1d07SSam Ravnborg 1916506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1917506f1d07SSam Ravnborg 1918506f1d07SSam Ravnborgconfig RELOCATABLE 191926717808SH. Peter Anvin bool "Build a relocatable kernel" 192026717808SH. Peter Anvin default y 19218f9ca475SIngo Molnar ---help--- 1922506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1923506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1924506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1925506f1d07SSam Ravnborg but are discarded at runtime. 1926506f1d07SSam Ravnborg 1927506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1928506f1d07SSam Ravnborg must live at a different physical address than the primary 1929506f1d07SSam Ravnborg kernel. 1930506f1d07SSam Ravnborg 1931506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1932506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 19338ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1934506f1d07SSam Ravnborg 19358ab3820fSKees Cookconfig RANDOMIZE_BASE 1936e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 19378ab3820fSKees Cook depends on RELOCATABLE 19388ab3820fSKees Cook default n 19398ab3820fSKees Cook ---help--- 1940e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 1941e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 1942e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 1943e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 1944e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 1945e8581e3dSBaoquan He code internals. 1946e8581e3dSBaoquan He 1947ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 1948ed9f007eSKees Cook randomized separately. The physical address will be anywhere 1949ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 1950ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 1951ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 1952ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 1953ed9f007eSKees Cook 1954ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 1955ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 1956ed9f007eSKees Cook 512MB (8 bits of entropy). 19578ab3820fSKees Cook 1958a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1959e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 1960e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 1961ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 1962ed9f007eSKees Cook usable entropy is limited by the kernel being built using 1963ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 1964ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 1965ed9f007eSKees Cook theoretically possible, but the implementations are further 1966ed9f007eSKees Cook limited due to memory layouts. 1967e8581e3dSBaoquan He 1968e8581e3dSBaoquan He If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot 1969e8581e3dSBaoquan He time. To enable it, boot with "kaslr" on the kernel command 1970e8581e3dSBaoquan He line (which will also disable hibernation). 19718ab3820fSKees Cook 1972da2b6fb9SKees Cook If unsure, say N. 1973da2b6fb9SKees Cook 19748ab3820fSKees Cook# Relocation on x86 needs some additional build support 1975845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1976845adf72SH. Peter Anvin def_bool y 19778ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1978845adf72SH. Peter Anvin 1979506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1980a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19818ab3820fSKees Cook default "0x200000" 1982a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1983a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19848f9ca475SIngo Molnar ---help--- 1985506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1986506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1987506f1d07SSam Ravnborg address which meets above alignment restriction. 1988506f1d07SSam Ravnborg 1989506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1990506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1991506f1d07SSam Ravnborg address aligned to above value and run from there. 1992506f1d07SSam Ravnborg 1993506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1994506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1995506f1d07SSam Ravnborg load address and decompress itself to the address it has been 1996506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 1997506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 1998506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 1999506f1d07SSam Ravnborg above alignment restrictions. 2000506f1d07SSam Ravnborg 2001a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2002a0215061SKees Cook this value must be a multiple of 0x200000. 2003a0215061SKees Cook 2004506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2005506f1d07SSam Ravnborg 20060483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 20070483e1faSThomas Garnier bool "Randomize the kernel memory sections" 20080483e1faSThomas Garnier depends on X86_64 20090483e1faSThomas Garnier depends on RANDOMIZE_BASE 20100483e1faSThomas Garnier default RANDOMIZE_BASE 20110483e1faSThomas Garnier ---help--- 20120483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 20130483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 20140483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 20150483e1faSThomas Garnier 20160483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 20170483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 20180483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 20190483e1faSThomas Garnier addresses for each memory section. 20200483e1faSThomas Garnier 20210483e1faSThomas Garnier If unsure, say N. 20220483e1faSThomas Garnier 202390397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 202490397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 202590397a41SThomas Garnier depends on RANDOMIZE_MEMORY 202690397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 202790397a41SThomas Garnier default "0x0" 202890397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 202990397a41SThomas Garnier range 0x0 0x40 203090397a41SThomas Garnier ---help--- 203190397a41SThomas Garnier Define the padding in terabytes added to the existing physical 203290397a41SThomas Garnier memory size during kernel memory randomization. It is useful 203390397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 203490397a41SThomas Garnier address randomization. 203590397a41SThomas Garnier 203690397a41SThomas Garnier If unsure, leave at the default value. 203790397a41SThomas Garnier 2038506f1d07SSam Ravnborgconfig HOTPLUG_CPU 20397c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 204040b31360SStephen Rothwell depends on SMP 2041506f1d07SSam Ravnborg ---help--- 20427c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 20437c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 20447c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 20457c13e6a3SDimitri Sivanich automatically on SMP systems. ) 20467c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 2047506f1d07SSam Ravnborg 204880aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 204980aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 205080aa1dffSFenghua Yu default n 20512c922cd0SKees Cook depends on HOTPLUG_CPU 205280aa1dffSFenghua Yu ---help--- 205380aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 205480aa1dffSFenghua Yu 205580aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 205680aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 205780aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 205880aa1dffSFenghua Yu 205980aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 206080aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 206180aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 206280aa1dffSFenghua Yu 206380aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 206480aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 206580aa1dffSFenghua Yu 206680aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 206780aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 206880aa1dffSFenghua Yu be other CPU0 dependencies. 206980aa1dffSFenghua Yu 207080aa1dffSFenghua Yu Please make sure the dependencies are under your control before 207180aa1dffSFenghua Yu you enable this feature. 207280aa1dffSFenghua Yu 207380aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 207480aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 207580aa1dffSFenghua Yu parameter cpu0_hotplug. 207680aa1dffSFenghua Yu 2077a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2078a71c8bc5SFenghua Yu def_bool n 2079a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20802c922cd0SKees Cook depends on HOTPLUG_CPU 2081a71c8bc5SFenghua Yu ---help--- 2082a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2083a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2084a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2085a71c8bc5SFenghua Yu 2086a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2087a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2088a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2089a71c8bc5SFenghua Yu 2090a71c8bc5SFenghua Yu If unsure, say N. 2091a71c8bc5SFenghua Yu 2092506f1d07SSam Ravnborgconfig COMPAT_VDSO 2093b0b49f26SAndy Lutomirski def_bool n 2094b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2095af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 20968f9ca475SIngo Molnar ---help--- 2097b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2098b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2099b0b49f26SAndy Lutomirski indicated in its segment table. 2100e84446deSRandy Dunlap 2101b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2102b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2103b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2104b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2105b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2106506f1d07SSam Ravnborg 2107b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2108b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2109b0b49f26SAndy Lutomirski 2110b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2111b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2112b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2113b0b49f26SAndy Lutomirski 2114b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2115b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2116506f1d07SSam Ravnborg 21173dc33bd3SKees Cookchoice 21183dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 21193dc33bd3SKees Cook depends on X86_64 21203dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 21213dc33bd3SKees Cook help 21223dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 21233dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 21243dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 21253dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 21263dc33bd3SKees Cook 21273dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 21283dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 21293dc33bd3SKees Cook 21303dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 21313dc33bd3SKees Cook static binaries, you can say None without a performance penalty 21323dc33bd3SKees Cook to improve security. 21333dc33bd3SKees Cook 21343dc33bd3SKees Cook If unsure, select "Emulate". 21353dc33bd3SKees Cook 21363dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 21373dc33bd3SKees Cook bool "Native" 21383dc33bd3SKees Cook help 21393dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 21403dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 21413dc33bd3SKees Cook this makes the mapping executable, it can be used during 21423dc33bd3SKees Cook security vulnerability exploitation (traditionally as 21433dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 21443dc33bd3SKees Cook 21453dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 21463dc33bd3SKees Cook bool "Emulate" 21473dc33bd3SKees Cook help 21483dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 21493dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 21503dc33bd3SKees Cook non-executable, but it still contains known contents, 21513dc33bd3SKees Cook which could be used in certain rare security vulnerability 21523dc33bd3SKees Cook exploits. This configuration is recommended when userspace 21533dc33bd3SKees Cook still uses the vsyscall area. 21543dc33bd3SKees Cook 21553dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 21563dc33bd3SKees Cook bool "None" 21573dc33bd3SKees Cook help 21583dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 21593dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 21603dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 21613dc33bd3SKees Cook will be reported to dmesg, so that either old or 21623dc33bd3SKees Cook malicious userspace programs can be identified. 21633dc33bd3SKees Cook 21643dc33bd3SKees Cookendchoice 21653dc33bd3SKees Cook 2166516cbf37STim Birdconfig CMDLINE_BOOL 2167516cbf37STim Bird bool "Built-in kernel command line" 21688f9ca475SIngo Molnar ---help--- 2169516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2170516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2171516cbf37STim Bird necessary or convenient to provide some or all of the 2172516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2173516cbf37STim Bird to not rely on the boot loader to provide them.) 2174516cbf37STim Bird 2175516cbf37STim Bird To compile command line arguments into the kernel, 2176516cbf37STim Bird set this option to 'Y', then fill in the 217769711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2178516cbf37STim Bird 2179516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2180516cbf37STim Bird should leave this option set to 'N'. 2181516cbf37STim Bird 2182516cbf37STim Birdconfig CMDLINE 2183516cbf37STim Bird string "Built-in kernel command string" 2184516cbf37STim Bird depends on CMDLINE_BOOL 2185516cbf37STim Bird default "" 21868f9ca475SIngo Molnar ---help--- 2187516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2188516cbf37STim Bird image and used at boot time. If the boot loader provides a 2189516cbf37STim Bird command line at boot time, it is appended to this string to 2190516cbf37STim Bird form the full kernel command line, when the system boots. 2191516cbf37STim Bird 2192516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2193516cbf37STim Bird change this behavior. 2194516cbf37STim Bird 2195516cbf37STim Bird In most cases, the command line (whether built-in or provided 2196516cbf37STim Bird by the boot loader) should specify the device for the root 2197516cbf37STim Bird file system. 2198516cbf37STim Bird 2199516cbf37STim Birdconfig CMDLINE_OVERRIDE 2200516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2201516cbf37STim Bird depends on CMDLINE_BOOL 22028f9ca475SIngo Molnar ---help--- 2203516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2204516cbf37STim Bird command line, and use ONLY the built-in command line. 2205516cbf37STim Bird 2206516cbf37STim Bird This is used to work around broken boot loaders. This should 2207516cbf37STim Bird be set to 'N' under normal conditions. 2208516cbf37STim Bird 2209a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2210a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2211a5b9e5a2SAndy Lutomirski default y 2212a5b9e5a2SAndy Lutomirski ---help--- 2213a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2214a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2215a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2216a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2217a5b9e5a2SAndy Lutomirski threading libraries. 2218a5b9e5a2SAndy Lutomirski 2219a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2220a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2221a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2222a5b9e5a2SAndy Lutomirski 2223a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2224a5b9e5a2SAndy Lutomirski 2225b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2226b700e7f0SSeth Jennings 2227506f1d07SSam Ravnborgendmenu 2228506f1d07SSam Ravnborg 2229506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2230506f1d07SSam Ravnborg def_bool y 2231506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2232506f1d07SSam Ravnborg 223335551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 223435551053SGary Hade def_bool y 223535551053SGary Hade depends on MEMORY_HOTPLUG 223635551053SGary Hade 2237e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2238645a7919STejun Heo def_bool y 2239e534c7c5SLee Schermerhorn depends on NUMA 2240e534c7c5SLee Schermerhorn 22419491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 22429491846fSKirill A. Shutemov def_bool y 22439491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 22449491846fSKirill A. Shutemov 2245c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2246c177c81eSNaoya Horiguchi def_bool y 2247c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2248c177c81eSNaoya Horiguchi 2249da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2250e279b6c1SSam Ravnborg 2251e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 22523c2362e6SHarvey Harrison def_bool y 2253e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2254e279b6c1SSam Ravnborg 2255e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2256e279b6c1SSam Ravnborg 2257e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2258e279b6c1SSam Ravnborg 2259efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2260efafc8b2SFeng Tang 2261a6b68076SAndi Kleenconfig X86_APM_BOOT 22626fc108a0SJan Beulich def_bool y 2263282e5aabSPaul Bolle depends on APM 2264a6b68076SAndi Kleen 2265e279b6c1SSam Ravnborgmenuconfig APM 2266e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2267efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2268e279b6c1SSam Ravnborg ---help--- 2269e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2270e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2271e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2272e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2273e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2274e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2275e279b6c1SSam Ravnborg 2276e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2277e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2278e279b6c1SSam Ravnborg 2279e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2280e279b6c1SSam Ravnborg machines with more than one CPU. 2281e279b6c1SSam Ravnborg 2282e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22832dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22842dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2285e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2286e279b6c1SSam Ravnborg 2287e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2288e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2289e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2290e279b6c1SSam Ravnborg 2291e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2292e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2293e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2294e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2295e279b6c1SSam Ravnborg 2296e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2297e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2298e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2299e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2300e279b6c1SSam Ravnborg APM in your BIOS). 2301e279b6c1SSam Ravnborg 2302e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2303e279b6c1SSam Ravnborg "weird" problems: 2304e279b6c1SSam Ravnborg 2305e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2306e279b6c1SSam Ravnborg enabled. 2307e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2308e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2309e279b6c1SSam Ravnborg the "no387" option to the kernel 2310e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2311e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2312e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2313e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2314e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2315e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2316e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2317e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2318e279b6c1SSam Ravnborg 11) exchange RAM chips 2319e279b6c1SSam Ravnborg 12) exchange the motherboard. 2320e279b6c1SSam Ravnborg 2321e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2322e279b6c1SSam Ravnborg module will be called apm. 2323e279b6c1SSam Ravnborg 2324e279b6c1SSam Ravnborgif APM 2325e279b6c1SSam Ravnborg 2326e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2327e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 23288f9ca475SIngo Molnar ---help--- 2329e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2330e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2331e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2332e279b6c1SSam Ravnborg 2333e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2334e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2335e279b6c1SSam Ravnborg ---help--- 2336e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2337e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2338e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2339e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2340e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2341e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2342e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2343e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2344e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2345e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2346e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2347e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2348e279b6c1SSam Ravnborg this feature. 2349e279b6c1SSam Ravnborg 2350e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2351dd8af076SLen Brown depends on CPU_IDLE 2352e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 23538f9ca475SIngo Molnar ---help--- 2354e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2355e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2356e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2357e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2358e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2359e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2360e279b6c1SSam Ravnborg this option does nothing.) 2361e279b6c1SSam Ravnborg 2362e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2363e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 23648f9ca475SIngo Molnar ---help--- 2365e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2366e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2367e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2368e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2369e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2370e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2371e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2372e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2373e279b6c1SSam Ravnborg especially if you are using gpm. 2374e279b6c1SSam Ravnborg 2375e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2376e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 23778f9ca475SIngo Molnar ---help--- 2378e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2379e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2380e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2381e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2382e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2383e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2384e279b6c1SSam Ravnborg 2385e279b6c1SSam Ravnborgendif # APM 2386e279b6c1SSam Ravnborg 2387bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2388e279b6c1SSam Ravnborg 2389e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2390e279b6c1SSam Ravnborg 239127471fdbSAndy Henroidsource "drivers/idle/Kconfig" 239227471fdbSAndy Henroid 2393e279b6c1SSam Ravnborgendmenu 2394e279b6c1SSam Ravnborg 2395e279b6c1SSam Ravnborg 2396e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2397e279b6c1SSam Ravnborg 2398e279b6c1SSam Ravnborgconfig PCI 23991ac97018SIngo Molnar bool "PCI support" 24001c858087SAdrian Bunk default y 24018f9ca475SIngo Molnar ---help--- 2402e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2403e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2404e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2405e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2406e279b6c1SSam Ravnborg 2407e279b6c1SSam Ravnborgchoice 2408e279b6c1SSam Ravnborg prompt "PCI access mode" 2409efefa6f6SIngo Molnar depends on X86_32 && PCI 2410e279b6c1SSam Ravnborg default PCI_GOANY 2411e279b6c1SSam Ravnborg ---help--- 2412e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2413e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2414e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2415e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2416e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2417e279b6c1SSam Ravnborg 2418e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2419e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2420e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2421e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2422e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2423e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2424e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2425e279b6c1SSam Ravnborg 2426e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2427e279b6c1SSam Ravnborg bool "BIOS" 2428e279b6c1SSam Ravnborg 2429e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2430e279b6c1SSam Ravnborg bool "MMConfig" 2431e279b6c1SSam Ravnborg 2432e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2433e279b6c1SSam Ravnborg bool "Direct" 2434e279b6c1SSam Ravnborg 24353ef0e1f8SAndres Salomonconfig PCI_GOOLPC 243676fb6570SDaniel Drake bool "OLPC XO-1" 24373ef0e1f8SAndres Salomon depends on OLPC 24383ef0e1f8SAndres Salomon 24392bdd1b03SAndres Salomonconfig PCI_GOANY 24402bdd1b03SAndres Salomon bool "Any" 24412bdd1b03SAndres Salomon 2442e279b6c1SSam Ravnborgendchoice 2443e279b6c1SSam Ravnborg 2444e279b6c1SSam Ravnborgconfig PCI_BIOS 24453c2362e6SHarvey Harrison def_bool y 2446efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2447e279b6c1SSam Ravnborg 2448e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2449e279b6c1SSam Ravnborgconfig PCI_DIRECT 24503c2362e6SHarvey Harrison def_bool y 24510aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2452e279b6c1SSam Ravnborg 2453e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 24543c2362e6SHarvey Harrison def_bool y 24555f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2456e279b6c1SSam Ravnborg 24573ef0e1f8SAndres Salomonconfig PCI_OLPC 24582bdd1b03SAndres Salomon def_bool y 24592bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 24603ef0e1f8SAndres Salomon 2461b5401a96SAlex Nixonconfig PCI_XEN 2462b5401a96SAlex Nixon def_bool y 2463b5401a96SAlex Nixon depends on PCI && XEN 2464b5401a96SAlex Nixon select SWIOTLB_XEN 2465b5401a96SAlex Nixon 2466e279b6c1SSam Ravnborgconfig PCI_DOMAINS 24673c2362e6SHarvey Harrison def_bool y 2468e279b6c1SSam Ravnborg depends on PCI 2469e279b6c1SSam Ravnborg 2470e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2471e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2472e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2473e279b6c1SSam Ravnborg 24743f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 24756a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 24766ea30386SKees Cook depends on PCI 24773f6ea84aSIra W. Snyder help 24783f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24793f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24803f6ea84aSIra W. Snyder not have ACPI. 24813f6ea84aSIra W. Snyder 248264a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 248364a5fed6SBjorn Helgaas is known to be incomplete. 248464a5fed6SBjorn Helgaas 248564a5fed6SBjorn Helgaas You should say N unless you know you need this. 248664a5fed6SBjorn Helgaas 2487e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2488e279b6c1SSam Ravnborg 24893a495511SWilliam Breathitt Grayconfig ISA_BUS 24903a495511SWilliam Breathitt Gray bool "ISA-style bus support on modern systems" if EXPERT 24913a495511SWilliam Breathitt Gray select ISA_BUS_API 24923a495511SWilliam Breathitt Gray help 24933a495511SWilliam Breathitt Gray Enables ISA-style drivers on modern systems. This is necessary to 24943a495511SWilliam Breathitt Gray support PC/104 devices on X86_64 platforms. 24953a495511SWilliam Breathitt Gray 24963a495511SWilliam Breathitt Gray If unsure, say N. 24973a495511SWilliam Breathitt Gray 24981c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2499e279b6c1SSam Ravnborgconfig ISA_DMA_API 25001c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 25011c00f016SDavid Rientjes default y 25021c00f016SDavid Rientjes help 25031c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 25041c00f016SDavid Rientjes If unsure, say Y. 2505e279b6c1SSam Ravnborg 250651e68d05SLinus Torvaldsif X86_32 250751e68d05SLinus Torvalds 2508e279b6c1SSam Ravnborgconfig ISA 2509e279b6c1SSam Ravnborg bool "ISA support" 25108f9ca475SIngo Molnar ---help--- 2511e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2512e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2513e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2514e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2515e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2516e279b6c1SSam Ravnborg 2517e279b6c1SSam Ravnborgconfig EISA 2518e279b6c1SSam Ravnborg bool "EISA support" 2519e279b6c1SSam Ravnborg depends on ISA 2520e279b6c1SSam Ravnborg ---help--- 2521e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2522e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2523e279b6c1SSam Ravnborg 2524e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2525e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2526e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2527e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2528e279b6c1SSam Ravnborg 2529e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2530e279b6c1SSam Ravnborg 2531e279b6c1SSam Ravnborg Otherwise, say N. 2532e279b6c1SSam Ravnborg 2533e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2534e279b6c1SSam Ravnborg 2535e279b6c1SSam Ravnborgconfig SCx200 2536e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 25378f9ca475SIngo Molnar ---help--- 2538e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2539e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2540e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2541e279b6c1SSam Ravnborg for other scx200_* drivers. 2542e279b6c1SSam Ravnborg 2543e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2544e279b6c1SSam Ravnborg 2545e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2546e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2547592913ecSJohn Stultz depends on SCx200 2548e279b6c1SSam Ravnborg default y 25498f9ca475SIngo Molnar ---help--- 2550e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2551e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2552e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2553e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2554e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2555e279b6c1SSam Ravnborg 25563ef0e1f8SAndres Salomonconfig OLPC 25573ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 255854008979SThomas Gleixner depends on !X86_PAE 25593c554946SAndres Salomon select GPIOLIB 2560dc3119e7SThomas Gleixner select OF 256145bb1674SDaniel Drake select OF_PROMTREE 2562b4e51854SGrant Likely select IRQ_DOMAIN 25638f9ca475SIngo Molnar ---help--- 25643ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 25653ef0e1f8SAndres Salomon XO hardware. 25663ef0e1f8SAndres Salomon 2567a3128588SDaniel Drakeconfig OLPC_XO1_PM 2568a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 256997c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2570a3128588SDaniel Drake select MFD_CORE 2571bf1ebf00SDaniel Drake ---help--- 257297c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2573bf1ebf00SDaniel Drake 2574cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2575cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2576cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2577cfee9597SDaniel Drake ---help--- 2578cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2579cfee9597SDaniel Drake programmable wakeup source. 2580cfee9597SDaniel Drake 25817feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 25827feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2583d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2584ed8e47feSRandy Dunlap depends on INPUT=y 2585d8d01a63SDaniel Drake select POWER_SUPPLY 25867feda8e9SDaniel Drake select GPIO_CS5535 25877feda8e9SDaniel Drake select MFD_CORE 25887feda8e9SDaniel Drake ---help--- 25897feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25907bc74b3dSDaniel Drake - EC-driven system wakeups 25917feda8e9SDaniel Drake - Power button 25927bc74b3dSDaniel Drake - Ebook switch 25932cf2baeaSDaniel Drake - Lid switch 2594e1040ac6SDaniel Drake - AC adapter status updates 2595e1040ac6SDaniel Drake - Battery status updates 25967feda8e9SDaniel Drake 2597a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2598a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2599d8d01a63SDaniel Drake depends on OLPC && ACPI 2600d8d01a63SDaniel Drake select POWER_SUPPLY 2601a0f30f59SDaniel Drake ---help--- 2602a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2603a0f30f59SDaniel Drake - EC-driven system wakeups 2604a0f30f59SDaniel Drake - AC adapter status updates 2605a0f30f59SDaniel Drake - Battery status updates 2606e279b6c1SSam Ravnborg 2607d4f3e350SEd Wildgooseconfig ALIX 2608d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2609d4f3e350SEd Wildgoose select GPIOLIB 2610d4f3e350SEd Wildgoose ---help--- 2611d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2612d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2613d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2614d4f3e350SEd Wildgoose get added here. 2615d4f3e350SEd Wildgoose 2616d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2617d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2618d4f3e350SEd Wildgoose 2619d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2620d4f3e350SEd Wildgoose 2621da4e3302SPhilip Prindevilleconfig NET5501 2622da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2623da4e3302SPhilip Prindeville select GPIOLIB 2624da4e3302SPhilip Prindeville ---help--- 2625da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2626da4e3302SPhilip Prindeville 26273197059aSPhilip A. Prindevilleconfig GEOS 26283197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 26293197059aSPhilip A. Prindeville select GPIOLIB 26303197059aSPhilip A. Prindeville depends on DMI 26313197059aSPhilip A. Prindeville ---help--- 26323197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 26333197059aSPhilip A. Prindeville 26347d029125SVivien Didelotconfig TS5500 26357d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 26367d029125SVivien Didelot depends on MELAN 26377d029125SVivien Didelot select CHECK_SIGNATURE 26387d029125SVivien Didelot select NEW_LEDS 26397d029125SVivien Didelot select LEDS_CLASS 26407d029125SVivien Didelot ---help--- 26417d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 26427d029125SVivien Didelot 2643e279b6c1SSam Ravnborgendif # X86_32 2644e279b6c1SSam Ravnborg 264523ac4ae8SAndreas Herrmannconfig AMD_NB 2646e279b6c1SSam Ravnborg def_bool y 26470e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2648e279b6c1SSam Ravnborg 2649e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2650e279b6c1SSam Ravnborg 2651388b78adSAlexandre Bounineconfig RAPIDIO 2652fdf90abcSAlexandre Bounine tristate "RapidIO support" 2653388b78adSAlexandre Bounine depends on PCI 2654388b78adSAlexandre Bounine default n 2655388b78adSAlexandre Bounine help 2656fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2657388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2658388b78adSAlexandre Bounine 2659388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2660388b78adSAlexandre Bounine 2661e3263ab3SDavid Herrmannconfig X86_SYSFB 2662e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2663e3263ab3SDavid Herrmann help 2664e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2665e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2666e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2667e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2668e3263ab3SDavid Herrmann to x86. 2669e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2670e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2671e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2672e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2673e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2674e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2675e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2676e3263ab3SDavid Herrmann 2677e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2678e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2679e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2680e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2681e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2682e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2683e3263ab3SDavid Herrmann incompatible with simplefb. 2684e3263ab3SDavid Herrmann 2685e3263ab3SDavid Herrmann If unsure, say Y. 2686e3263ab3SDavid Herrmann 2687e279b6c1SSam Ravnborgendmenu 2688e279b6c1SSam Ravnborg 2689e279b6c1SSam Ravnborg 2690e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2691e279b6c1SSam Ravnborg 2692e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2693e279b6c1SSam Ravnborg 2694e279b6c1SSam Ravnborgconfig IA32_EMULATION 2695e279b6c1SSam Ravnborg bool "IA32 Emulation" 2696e279b6c1SSam Ravnborg depends on X86_64 2697d1603990SRandy Dunlap select BINFMT_ELF 2698a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 26993bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 27008f9ca475SIngo Molnar ---help--- 27015fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 27025fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 27035fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2704e279b6c1SSam Ravnborg 2705e279b6c1SSam Ravnborgconfig IA32_AOUT 2706e279b6c1SSam Ravnborg tristate "IA32 a.out support" 27076b213e1bSDavid Woodhouse depends on IA32_EMULATION 27088f9ca475SIngo Molnar ---help--- 2709e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2710e279b6c1SSam Ravnborg 27110bf62763SH. Peter Anvinconfig X86_X32 27126ea30386SKees Cook bool "x32 ABI for 64-bit mode" 27139b54050bSBrian Gerst depends on X86_64 27145fd92e65SH. J. Lu ---help--- 27155fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 27165fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 27175fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 27185fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 27195fd92e65SH. J. Lu 27205fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 27215fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 27225fd92e65SH. J. Lu option set. 27235fd92e65SH. J. Lu 2724e279b6c1SSam Ravnborgconfig COMPAT 27253c2362e6SHarvey Harrison def_bool y 27260bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2727e279b6c1SSam Ravnborg 27283120e25eSJan Beulichif COMPAT 2729e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 27303120e25eSJan Beulich def_bool y 2731e279b6c1SSam Ravnborg 2732e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 27333c2362e6SHarvey Harrison def_bool y 27343120e25eSJan Beulich depends on SYSVIPC 2735e279b6c1SSam Ravnborg 2736ee009e4aSDavid Howellsconfig KEYS_COMPAT 27373120e25eSJan Beulich def_bool y 27383120e25eSJan Beulich depends on KEYS 27393120e25eSJan Beulichendif 2740ee009e4aSDavid Howells 2741e279b6c1SSam Ravnborgendmenu 2742e279b6c1SSam Ravnborg 2743e279b6c1SSam Ravnborg 2744e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2745e5beae16SKeith Packard def_bool y 2746e5beae16SKeith Packard depends on X86_32 2747e5beae16SKeith Packard 27484692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 27494692d77fSAlessandro Rubini bool 275083125a3aSAlessandro Rubini depends on X86_64 || STA2X11 27514692d77fSAlessandro Rubini 2752f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2753f7219a53SAlessandro Rubini bool 275483125a3aSAlessandro Rubini depends on STA2X11 2755f7219a53SAlessandro Rubini 275693e5eaddSLi, Aubreyconfig PMC_ATOM 275793e5eaddSLi, Aubrey def_bool y 275893e5eaddSLi, Aubrey depends on PCI 275993e5eaddSLi, Aubrey 2760e279b6c1SSam Ravnborgsource "net/Kconfig" 2761e279b6c1SSam Ravnborg 2762e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2763e279b6c1SSam Ravnborg 2764e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2765e279b6c1SSam Ravnborg 2766e279b6c1SSam Ravnborgsource "fs/Kconfig" 2767e279b6c1SSam Ravnborg 2768e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2769e279b6c1SSam Ravnborg 2770e279b6c1SSam Ravnborgsource "security/Kconfig" 2771e279b6c1SSam Ravnborg 2772e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2773e279b6c1SSam Ravnborg 2774edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2775edf88417SAvi Kivity 2776e279b6c1SSam Ravnborgsource "lib/Kconfig" 2777