1daa93fabSSam Ravnborg# Select 32 or 64 bit 2daa93fabSSam Ravnborgconfig 64BIT 36840999bSSam Ravnborg bool "64-bit kernel" if ARCH = "x86" 4ffee0de4SDavid Woodhouse default ARCH != "i386" 58f9ca475SIngo Molnar ---help--- 6daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 7daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 8daa93fabSSam Ravnborg 9daa93fabSSam Ravnborgconfig X86_32 103120e25eSJan Beulich def_bool y 113120e25eSJan Beulich depends on !64BIT 12daa93fabSSam Ravnborg 13daa93fabSSam Ravnborgconfig X86_64 143120e25eSJan Beulich def_bool y 153120e25eSJan Beulich depends on 64BIT 161032c0baSSam Ravnborg 171032c0baSSam Ravnborg### Arch settings 188d5fffb9SSam Ravnborgconfig X86 193c2362e6SHarvey Harrison def_bool y 206471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 216e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 226471b825SIngo Molnar select ANON_INODES 236471b825SIngo Molnar select ARCH_CLOCKSOURCE_DATA 246471b825SIngo Molnar select ARCH_DISCARD_MEMBLOCK 256471b825SIngo Molnar select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 26446f24d1SStephen Boyd select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 276471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 2872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 29957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 3096601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 3167a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 326471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 336471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 346471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3577fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 365e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 376471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 383b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 39be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 406471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 416471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 426471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 436471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 446471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 4572b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 465aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 47da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 486471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 496471b825SIngo Molnar select ARCH_WANT_OPTIONAL_GPIOLIB 506471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 516471b825SIngo Molnar select CLKEVT_I8253 526471b825SIngo Molnar select CLKSRC_I8253 if X86_32 536471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 546471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 556471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 566471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 576471b825SIngo Molnar select DCACHE_WORD_ACCESS 5845471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 5945471cd9SLinus Torvalds select EDAC_SUPPORT 606471b825SIngo Molnar select GENERIC_CLOCKEVENTS 616471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 626471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 636471b825SIngo Molnar select GENERIC_CMOS_UPDATE 646471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 656471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 666471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 676471b825SIngo Molnar select GENERIC_IOMAP 686471b825SIngo Molnar select GENERIC_IRQ_PROBE 696471b825SIngo Molnar select GENERIC_IRQ_SHOW 706471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 716471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 726471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 736471b825SIngo Molnar select GENERIC_STRNLEN_USER 746471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 756471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 766471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 776471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 786471b825SIngo Molnar select HAVE_AOUT if X86_32 796471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 806471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 816471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 826471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 836471b825SIngo Molnar select HAVE_ARCH_KGDB 846471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 856471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 866471b825SIngo Molnar select HAVE_ARCH_SOFT_DIRTY if X86_64 876471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 886471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 896471b825SIngo Molnar select HAVE_BPF_JIT if X86_64 906471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 916471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 926471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 936471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 94c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 956471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 966471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 976471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 986471b825SIngo Molnar select HAVE_DMA_API_DEBUG 997c095e46SFUJITA Tomonori select HAVE_DMA_ATTRS 1009c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 101677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10206aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10358340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1046471b825SIngo Molnar select HAVE_FENTRY if X86_64 1056471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1066471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_FP_TEST 1076471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1086471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1096471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1100067f129SK.Prasad select HAVE_HW_BREAKPOINT 1116471b825SIngo Molnar select HAVE_IDE 1126471b825SIngo Molnar select HAVE_IOREMAP_PROT 1136471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1146471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1156471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1166471b825SIngo Molnar select HAVE_KERNEL_GZIP 1176471b825SIngo Molnar select HAVE_KERNEL_LZ4 1186471b825SIngo Molnar select HAVE_KERNEL_LZMA 1196471b825SIngo Molnar select HAVE_KERNEL_LZO 1206471b825SIngo Molnar select HAVE_KERNEL_XZ 1216471b825SIngo Molnar select HAVE_KPROBES 1226471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1236471b825SIngo Molnar select HAVE_KRETPROBES 1246471b825SIngo Molnar select HAVE_KVM 1256471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1266471b825SIngo Molnar select HAVE_MEMBLOCK 1276471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1280102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 1296471b825SIngo Molnar select HAVE_OPROFILE 1306471b825SIngo Molnar select HAVE_OPTPROBES 1316471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1326471b825SIngo Molnar select HAVE_PERF_EVENTS 133c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 134c5e63197SJiri Olsa select HAVE_PERF_REGS 135c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1366471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1376471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1380c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1396471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1407c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 141c0185808SThomas Gleixner select IRQ_FORCED_THREADING 142786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1436471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1445b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1456471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1466471b825SIngo Molnar select PERF_EVENTS 1473195ef59SPrarit Bhargava select RTC_LIB 1486471b825SIngo Molnar select SPARSE_IRQ 14983fe27eaSPranith Kumar select SRCU 1506471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 1516471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1526471b825SIngo Molnar select VIRT_TO_BUS 1536471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1546471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 1557d8330a5SBalbir Singh 156ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1573120e25eSJan Beulich def_bool y 1583120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 159ba7e4d13SIngo Molnar 1607fb0f1deSPeter Zijlstraconfig PERF_EVENTS_INTEL_UNCORE 1617fb0f1deSPeter Zijlstra def_bool y 162ce5686d4SPeter Zijlstra (Intel) depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 1637fb0f1deSPeter Zijlstra 16451b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 16551b26adaSLinus Torvalds string 16651b26adaSLinus Torvalds default "elf32-i386" if X86_32 16751b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 16851b26adaSLinus Torvalds 16973531905SSam Ravnborgconfig ARCH_DEFCONFIG 170b9b39bfbSSam Ravnborg string 17173531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 17273531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 173b9b39bfbSSam Ravnborg 1748d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1753c2362e6SHarvey Harrison def_bool y 1768d5fffb9SSam Ravnborg 1778d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1783c2362e6SHarvey Harrison def_bool y 1798d5fffb9SSam Ravnborg 180aa7d9350SHeiko Carstensconfig HAVE_LATENCYTOP_SUPPORT 181aa7d9350SHeiko Carstens def_bool y 182aa7d9350SHeiko Carstens 1838d5fffb9SSam Ravnborgconfig MMU 1843c2362e6SHarvey Harrison def_bool y 1858d5fffb9SSam Ravnborg 1868d5fffb9SSam Ravnborgconfig SBUS 1878d5fffb9SSam Ravnborg bool 1888d5fffb9SSam Ravnborg 1893bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 1903120e25eSJan Beulich def_bool y 191a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 1923bc4e459SFUJITA Tomonori 19318e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 1944a14d84eSAndrew Morton def_bool y 19518e98307SFUJITA Tomonori 1968d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 1973120e25eSJan Beulich def_bool y 1983120e25eSJan Beulich depends on ISA_DMA_API 1998d5fffb9SSam Ravnborg 2008d5fffb9SSam Ravnborgconfig GENERIC_BUG 2013c2362e6SHarvey Harrison def_bool y 2028d5fffb9SSam Ravnborg depends on BUG 203b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 204b93a531eSJan Beulich 205b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 206b93a531eSJan Beulich bool 2078d5fffb9SSam Ravnborg 2088d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2093c2362e6SHarvey Harrison def_bool y 2108d5fffb9SSam Ravnborg 2118d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2123120e25eSJan Beulich def_bool y 2133120e25eSJan Beulich depends on ISA_DMA_API 2148d5fffb9SSam Ravnborg 2151032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2163120e25eSJan Beulich def_bool y 2171032c0baSSam Ravnborg 2181032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2191032c0baSSam Ravnborg def_bool y 2201032c0baSSam Ravnborg 2219a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2229a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2238d5fffb9SSam Ravnborg 2241b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2251b27d05bSPekka Enberg def_bool y 2261b27d05bSPekka Enberg 227dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 22889c9c4c5SBrian Gerst def_bool y 229b32ef636Stravis@sgi.com 23008fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 23108fc4580STejun Heo def_bool y 23208fc4580STejun Heo 23308fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 23411124411STejun Heo def_bool y 23511124411STejun Heo 236801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 237801e4062SJohannes Berg def_bool y 238801e4062SJohannes Berg 239f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 240f4cb5700SJohannes Berg def_bool y 241f4cb5700SJohannes Berg 242cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 243cfe28c5dSSteve Capper def_bool y 244cfe28c5dSSteve Capper 24553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 24653313b2cSSteve Capper def_bool y 24753313b2cSSteve Capper 2488d5fffb9SSam Ravnborgconfig ZONE_DMA32 249e0fd24a3SJan Beulich def_bool y if X86_64 2508d5fffb9SSam Ravnborg 2518d5fffb9SSam Ravnborgconfig AUDIT_ARCH 252e0fd24a3SJan Beulich def_bool y if X86_64 2538d5fffb9SSam Ravnborg 254765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 255765c68bdSIngo Molnar def_bool y 256765c68bdSIngo Molnar 2576a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2586a11f75bSAkinobu Mita def_bool y 2596a11f75bSAkinobu Mita 260d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 261d6f2d75aSAndrey Ryabinin hex 262d6f2d75aSAndrey Ryabinin depends on KASAN 263d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 264d6f2d75aSAndrey Ryabinin 26569575d38SShane Wangconfig HAVE_INTEL_TXT 26669575d38SShane Wang def_bool y 2676ea30386SKees Cook depends on INTEL_IOMMU && ACPI 26869575d38SShane Wang 2696b0c3d44SSam Ravnborgconfig X86_32_SMP 2706b0c3d44SSam Ravnborg def_bool y 2716b0c3d44SSam Ravnborg depends on X86_32 && SMP 2726b0c3d44SSam Ravnborg 2736b0c3d44SSam Ravnborgconfig X86_64_SMP 2746b0c3d44SSam Ravnborg def_bool y 2756b0c3d44SSam Ravnborg depends on X86_64 && SMP 2766b0c3d44SSam Ravnborg 277ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 278ccbeed3aSTejun Heo def_bool y 27960a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 280ccbeed3aSTejun Heo 281d61931d8SBorislav Petkovconfig ARCH_HWEIGHT_CFLAGS 282d61931d8SBorislav Petkov string 283d61931d8SBorislav Petkov default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 284d61931d8SBorislav Petkov default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 285d61931d8SBorislav Petkov 2862b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 2872b144498SSrikar Dronamraju def_bool y 2882b144498SSrikar Dronamraju 289d20642f0SRob Herringconfig FIX_EARLYCON_MEM 290d20642f0SRob Herring def_bool y 291d20642f0SRob Herring 29298233368SKirill A. Shutemovconfig PGTABLE_LEVELS 29398233368SKirill A. Shutemov int 29498233368SKirill A. Shutemov default 4 if X86_64 29598233368SKirill A. Shutemov default 3 if X86_PAE 29698233368SKirill A. Shutemov default 2 29798233368SKirill A. Shutemov 298506f1d07SSam Ravnborgsource "init/Kconfig" 299dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3008d5fffb9SSam Ravnborg 301506f1d07SSam Ravnborgmenu "Processor type and features" 302506f1d07SSam Ravnborg 3035ee71535SRandy Dunlapconfig ZONE_DMA 3045ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3055ee71535SRandy Dunlap default y 3065ee71535SRandy Dunlap help 3075ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3085ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3095ee71535SRandy Dunlap Disable if no such devices will be used. 3105ee71535SRandy Dunlap 3115ee71535SRandy Dunlap If unsure, say Y. 3125ee71535SRandy Dunlap 313506f1d07SSam Ravnborgconfig SMP 314506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 315506f1d07SSam Ravnborg ---help--- 316506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3174a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3184a474157SRobert Graffham than one CPU, say Y. 319506f1d07SSam Ravnborg 3204a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 321506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 322506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3234a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 324506f1d07SSam Ravnborg will run faster if you say N here. 325506f1d07SSam Ravnborg 326506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 327506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 328506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 329506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 330506f1d07SSam Ravnborg 331506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 332506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 333506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 334506f1d07SSam Ravnborg 335395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 336506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 337506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 338506f1d07SSam Ravnborg 339506f1d07SSam Ravnborg If you don't know what to do here, say N. 340506f1d07SSam Ravnborg 3419def39beSJosh Triplettconfig X86_FEATURE_NAMES 3429def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3439def39beSJosh Triplett default y 3449def39beSJosh Triplett ---help--- 3459def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3469def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3479def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3489def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3499def39beSJosh Triplett 3509def39beSJosh Triplett If in doubt, say Y. 3519def39beSJosh Triplett 352*6e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS 353*6e1315feSBorislav Petkov bool "Fast CPU feature tests" if EMBEDDED 354*6e1315feSBorislav Petkov default y 355*6e1315feSBorislav Petkov ---help--- 356*6e1315feSBorislav Petkov Some fast-paths in the kernel depend on the capabilities of the CPU. 357*6e1315feSBorislav Petkov Say Y here for the kernel to patch in the appropriate code at runtime 358*6e1315feSBorislav Petkov based on the capabilities of the CPU. The infrastructure for patching 359*6e1315feSBorislav Petkov code at runtime takes up some additional space; space-constrained 360*6e1315feSBorislav Petkov embedded systems may wish to say N here to produce smaller, slightly 361*6e1315feSBorislav Petkov slower code. 362*6e1315feSBorislav Petkov 36306cd9a7dSYinghai Luconfig X86_X2APIC 36406cd9a7dSYinghai Lu bool "Support x2apic" 36519e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 36606cd9a7dSYinghai Lu ---help--- 36706cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 36806cd9a7dSYinghai Lu 36906cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 37006cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 37106cd9a7dSYinghai Lu 37206cd9a7dSYinghai Lu If you don't know what to do here, say N. 37306cd9a7dSYinghai Lu 3746695c85bSYinghai Luconfig X86_MPPARSE 3756e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3767a527688SJan Beulich default y 3775ab74722SIngo Molnar depends on X86_LOCAL_APIC 3788f9ca475SIngo Molnar ---help--- 3796695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 3806695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 3816695c85bSYinghai Lu 38226f7ef14SYinghai Luconfig X86_BIGSMP 38326f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 38426f7ef14SYinghai Lu depends on X86_32 && SMP 3858f9ca475SIngo Molnar ---help--- 38626f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 387506f1d07SSam Ravnborg 388ddd70cf9SJun Nakajimaconfig GOLDFISH 389ddd70cf9SJun Nakajima def_bool y 390ddd70cf9SJun Nakajima depends on X86_GOLDFISH 391ddd70cf9SJun Nakajima 3928425091fSRavikiran G Thirumalaiif X86_32 393c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 394c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 395c5c606d9SRavikiran G Thirumalai default y 3968f9ca475SIngo Molnar ---help--- 39706ac8346SIngo Molnar If you disable this option then the kernel will only support 39806ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 39906ac8346SIngo Molnar systems out there.) 40006ac8346SIngo Molnar 4018425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4028425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 403cb7b8023SBen Hutchings Goldfish (Android emulator) 4048425091fSRavikiran G Thirumalai AMD Elan 4058425091fSRavikiran G Thirumalai RDC R-321x SoC 4068425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 40783125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 4083f4110a4SThomas Gleixner Moorestown MID devices 40906ac8346SIngo Molnar 41006ac8346SIngo Molnar If you have one of these systems, or if you want to build a 41106ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4128425091fSRavikiran G Thirumalaiendif 41306ac8346SIngo Molnar 4148425091fSRavikiran G Thirumalaiif X86_64 4158425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4168425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4178425091fSRavikiran G Thirumalai default y 4188425091fSRavikiran G Thirumalai ---help--- 4198425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4208425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4218425091fSRavikiran G Thirumalai systems out there.) 4228425091fSRavikiran G Thirumalai 4238425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4248425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 42544b111b5SSteffen Persvold Numascale NumaChip 4268425091fSRavikiran G Thirumalai ScaleMP vSMP 4278425091fSRavikiran G Thirumalai SGI Ultraviolet 4288425091fSRavikiran G Thirumalai 4298425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4308425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4318425091fSRavikiran G Thirumalaiendif 432c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 433c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 43444b111b5SSteffen Persvoldconfig X86_NUMACHIP 43544b111b5SSteffen Persvold bool "Numascale NumaChip" 43644b111b5SSteffen Persvold depends on X86_64 43744b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 43844b111b5SSteffen Persvold depends on NUMA 43944b111b5SSteffen Persvold depends on SMP 44044b111b5SSteffen Persvold depends on X86_X2APIC 441f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 44244b111b5SSteffen Persvold ---help--- 44344b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 44444b111b5SSteffen Persvold enable more than ~168 cores. 44544b111b5SSteffen Persvold If you don't have one of these, you should say N here. 44603b48632SNick Piggin 4476a48565eSIngo Molnarconfig X86_VSMP 448c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4496276a074SBorislav Petkov select HYPERVISOR_GUEST 4506a48565eSIngo Molnar select PARAVIRT 4516a48565eSIngo Molnar depends on X86_64 && PCI 452c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 453ead91d4bSShai Fultheim depends on SMP 4548f9ca475SIngo Molnar ---help--- 4556a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4566a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4576a48565eSIngo Molnar if you have one of these machines. 4586a48565eSIngo Molnar 459c5c606d9SRavikiran G Thirumalaiconfig X86_UV 460c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 461c5c606d9SRavikiran G Thirumalai depends on X86_64 462c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 46354c28d29SJack Steiner depends on NUMA 4649d6c26e7SSuresh Siddha depends on X86_X2APIC 4651222e564SIngo Molnar depends on PCI 466c5c606d9SRavikiran G Thirumalai ---help--- 467c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 468c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 469c5c606d9SRavikiran G Thirumalai 470c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 471c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 472506f1d07SSam Ravnborg 473ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 474ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 475cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 476ddd70cf9SJun Nakajima ---help--- 477ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 478ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 479ddd70cf9SJun Nakajima Goldfish emulator say N here. 480ddd70cf9SJun Nakajima 481c751e17bSThomas Gleixnerconfig X86_INTEL_CE 482c751e17bSThomas Gleixner bool "CE4100 TV platform" 483c751e17bSThomas Gleixner depends on PCI 484c751e17bSThomas Gleixner depends on PCI_GODIRECT 4856084a6e2SJiang Liu depends on X86_IO_APIC 486c751e17bSThomas Gleixner depends on X86_32 487c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 48837bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 489da6b737bSSebastian Andrzej Siewior select OF 490da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 491c751e17bSThomas Gleixner ---help--- 492c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 493c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 494c751e17bSThomas Gleixner boxes and media devices. 495c751e17bSThomas Gleixner 4964cb9b00fSDavid Cohenconfig X86_INTEL_MID 49743605ef1SAlan Cox bool "Intel MID platform support" 49843605ef1SAlan Cox depends on X86_32 49943605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 500edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 5011ea7c673SAlan Cox depends on PCI 5021ea7c673SAlan Cox depends on PCI_GOANY 5031ea7c673SAlan Cox depends on X86_IO_APIC 5047c9c3a1eSAlan Cox select SFI 5054cb9b00fSDavid Cohen select I2C 5067c9c3a1eSAlan Cox select DW_APB_TIMER 5071ea7c673SAlan Cox select APB_TIMER 5081ea7c673SAlan Cox select INTEL_SCU_IPC 50915a713dfSMika Westerberg select MFD_INTEL_MSIC 5101ea7c673SAlan Cox ---help--- 5114cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5124cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5134cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5141ea7c673SAlan Cox 5154cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5164cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 51743605ef1SAlan Cox 5188bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5198bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5208bbc2a13SBryan O'Donoghue depends on X86_32 5218bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5228bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5238bbc2a13SBryan O'Donoghue depends on X86_TSC 5248bbc2a13SBryan O'Donoghue depends on PCI 5258bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5268bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5278bbc2a13SBryan O'Donoghue select IOSF_MBI 5288bbc2a13SBryan O'Donoghue select INTEL_IMR 5299ab6eb51SAndy Shevchenko select COMMON_CLK 5308bbc2a13SBryan O'Donoghue ---help--- 5318bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5328bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5338bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5348bbc2a13SBryan O'Donoghue 5353d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5363d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 5373d48aab1SMika Westerberg depends on ACPI 5383d48aab1SMika Westerberg select COMMON_CLK 5390f531431SMathias Nyman select PINCTRL 5403d48aab1SMika Westerberg ---help--- 5413d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5423d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5430f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5440f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5453d48aab1SMika Westerberg 54692082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 54792082a88SKen Xue bool "AMD ACPI2Platform devices support" 54892082a88SKen Xue depends on ACPI 54992082a88SKen Xue select COMMON_CLK 55092082a88SKen Xue select PINCTRL 55192082a88SKen Xue ---help--- 55292082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 55392082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 55492082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 55592082a88SKen Xue implemented under PINCTRL subsystem. 55692082a88SKen Xue 557ced3ce76SDavid E. Boxconfig IOSF_MBI 558ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 559ced3ce76SDavid E. Box depends on PCI 560ced3ce76SDavid E. Box ---help--- 561ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 562ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 563ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 564ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 565ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 566ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 567ced3ce76SDavid E. Box This list is not meant to be exclusive. 568ced3ce76SDavid E. Box - BayTrail 569ced3ce76SDavid E. Box - Braswell 570ced3ce76SDavid E. Box - Quark 571ced3ce76SDavid E. Box 572ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 573ced3ce76SDavid E. Box 574ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 575ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 576ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 577ed2226bdSDavid E. Box ---help--- 578ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 579ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 580ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 581ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 582ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 583ed2226bdSDavid E. Box device they want to access. 584ed2226bdSDavid E. Box 585ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 586ed2226bdSDavid E. Box 587c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 588c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 589506f1d07SSam Ravnborg depends on X86_32 590c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 591c5c606d9SRavikiran G Thirumalai select M486 592c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 593c5c606d9SRavikiran G Thirumalai ---help--- 594c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 595c5c606d9SRavikiran G Thirumalai as R-8610-(G). 596c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 597c5c606d9SRavikiran G Thirumalai 598e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 5999c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 6009c398017SIngo Molnar depends on X86_32 && SMP 601c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 6028f9ca475SIngo Molnar ---help--- 603b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 604b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 605b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 606b5660ba7SH. Peter Anvin one and will fallback to default. 607d49c4288SYinghai Lu 608c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 609d49c4288SYinghai Lu 610d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6116fc108a0SJan Beulich def_bool y 612d949f36fSLinus Torvalds # MCE code calls memory_failure(): 613d949f36fSLinus Torvalds depends on X86_MCE 614d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 615d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 616d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 617d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 618d949f36fSLinus Torvalds 61983125a3aSAlessandro Rubiniconfig STA2X11 62083125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 62183125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 62283125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 62383125a3aSAlessandro Rubini select X86_DMA_REMAP 62483125a3aSAlessandro Rubini select SWIOTLB 62583125a3aSAlessandro Rubini select MFD_STA2X11 62683125a3aSAlessandro Rubini select ARCH_REQUIRE_GPIOLIB 62783125a3aSAlessandro Rubini default n 62883125a3aSAlessandro Rubini ---help--- 62983125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 63083125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 63183125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 63283125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 63383125a3aSAlessandro Rubini standard PC machines. 63483125a3aSAlessandro Rubini 63582148d1dSShérabconfig X86_32_IRIS 63682148d1dSShérab tristate "Eurobraille/Iris poweroff module" 63782148d1dSShérab depends on X86_32 63882148d1dSShérab ---help--- 63982148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 64082148d1dSShérab to shut themselves down properly. A special I/O sequence is 64182148d1dSShérab needed to do so, which is what this module does at 64282148d1dSShérab kernel shutdown. 64382148d1dSShérab 64482148d1dSShérab This is only for Iris machines from EuroBraille. 64582148d1dSShérab 64682148d1dSShérab If unused, say N. 64782148d1dSShérab 648ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6493c2362e6SHarvey Harrison def_bool y 6503c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 651a87d0914SKen Chen depends on X86 6528f9ca475SIngo Molnar ---help--- 653506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 654506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 655506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 656506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 657506f1d07SSam Ravnborg 658506f1d07SSam Ravnborg If in doubt, say "Y". 659506f1d07SSam Ravnborg 6606276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6616276a074SBorislav Petkov bool "Linux guest support" 6628f9ca475SIngo Molnar ---help--- 6636276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6646276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6656276a074SBorislav Petkov setup. 666506f1d07SSam Ravnborg 6676276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6686276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 669506f1d07SSam Ravnborg 6706276a074SBorislav Petkovif HYPERVISOR_GUEST 671506f1d07SSam Ravnborg 672e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 673e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 6748f9ca475SIngo Molnar ---help--- 675e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 676e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 677e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 678e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 679e61bd94aSEduardo Pereira Habkost 6806276a074SBorislav Petkovconfig PARAVIRT_DEBUG 6816276a074SBorislav Petkov bool "paravirt-ops debugging" 6826276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 6836276a074SBorislav Petkov ---help--- 6846276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 6856276a074SBorislav Petkov a paravirt_op is missing when it is called. 6866276a074SBorislav Petkov 687b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 688b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 6896ea30386SKees Cook depends on PARAVIRT && SMP 69062c7a1e9SIngo Molnar select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 691b4ecc126SJeremy Fitzhardinge ---help--- 692b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 693b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 694b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 695b4ecc126SJeremy Fitzhardinge 6964c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 6974c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 698b4ecc126SJeremy Fitzhardinge 6994c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 700b4ecc126SJeremy Fitzhardinge 7016276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 7026276a074SBorislav Petkov 7036276a074SBorislav Petkovconfig KVM_GUEST 7046276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7056276a074SBorislav Petkov depends on PARAVIRT 7066276a074SBorislav Petkov select PARAVIRT_CLOCK 7076276a074SBorislav Petkov default y 7086276a074SBorislav Petkov ---help--- 7096276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7106276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7116276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7126276a074SBorislav Petkov underlying device model, the host provides the guest with 7136276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7146276a074SBorislav Petkov 7151e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7161e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7171e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7181e20eb85SSrivatsa Vaddagiri default n 7191e20eb85SSrivatsa Vaddagiri ---help--- 7201e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7211e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7221e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7231e20eb85SSrivatsa Vaddagiri 7246276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7256276a074SBorislav Petkov 7266276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7276276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7286276a074SBorislav Petkov depends on PARAVIRT 7296276a074SBorislav Petkov default n 7306276a074SBorislav Petkov ---help--- 7316276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7326276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7336276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7346276a074SBorislav Petkov that, there can be a small performance impact. 7356276a074SBorislav Petkov 7366276a074SBorislav Petkov If in doubt, say N here. 7376276a074SBorislav Petkov 7387af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7397af192c9SGerd Hoffmann bool 7407af192c9SGerd Hoffmann 7416276a074SBorislav Petkovendif #HYPERVISOR_GUEST 74297349135SJeremy Fitzhardinge 74308677214SYinghai Luconfig NO_BOOTMEM 744774ea0bcSYinghai Lu def_bool y 74508677214SYinghai Lu 746506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 747506f1d07SSam Ravnborg 748506f1d07SSam Ravnborgconfig HPET_TIMER 7493c2362e6SHarvey Harrison def_bool X86_64 750506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7518f9ca475SIngo Molnar ---help--- 752506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 753506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 754506f1d07SSam Ravnborg present. 755506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 756506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 757506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 758506f1d07SSam Ravnborg as it is off-chip. You can find the HPET spec at 759e45f2c07SDenis V. Lunev <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 760506f1d07SSam Ravnborg 761506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 762506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 763506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 764506f1d07SSam Ravnborg 765506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 766506f1d07SSam Ravnborg 767506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 7683c2362e6SHarvey Harrison def_bool y 7699d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 770506f1d07SSam Ravnborg 771bb24c471SJacob Panconfig APB_TIMER 772933b9463SAlan Cox def_bool y if X86_INTEL_MID 773933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 77406c3df49SJamie Iles select DW_APB_TIMER 775a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 776bb24c471SJacob Pan help 777bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 778bb24c471SJacob Pan The APBT provides a stable time base on SMP 779bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 780bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 781bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 782bb24c471SJacob Pan 7836a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 784506f1d07SSam Ravnborg# The code disables itself when not needed. 7857ae9392cSThomas Petazzoniconfig DMI 7867ae9392cSThomas Petazzoni default y 787cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 7886a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 7898f9ca475SIngo Molnar ---help--- 7907ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 7917ae9392cSThomas Petazzoni here unless you have verified that your setup is not 7927ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 7937ae9392cSThomas Petazzoni BIOS code. 7947ae9392cSThomas Petazzoni 795506f1d07SSam Ravnborgconfig GART_IOMMU 79638901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 797506f1d07SSam Ravnborg select SWIOTLB 79823ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 7998f9ca475SIngo Molnar ---help--- 800ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 801ced3c42cSIngo Molnar GART based hardware IOMMUs. 802ced3c42cSIngo Molnar 803ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 804ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 805ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 806ced3c42cSIngo Molnar 807ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 808ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 809ced3c42cSIngo Molnar 810ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 811ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 812ced3c42cSIngo Molnar 32-bit limited device. 813ced3c42cSIngo Molnar 814ced3c42cSIngo Molnar If unsure, say Y. 815506f1d07SSam Ravnborg 816506f1d07SSam Ravnborgconfig CALGARY_IOMMU 817506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 818506f1d07SSam Ravnborg select SWIOTLB 8196ea30386SKees Cook depends on X86_64 && PCI 8208f9ca475SIngo Molnar ---help--- 821506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 822506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 823506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 824506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 825506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 826506f1d07SSam Ravnborg prevents them from going anywhere except their intended 827506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 828506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 829506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 830506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 831506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 832506f1d07SSam Ravnborg If unsure, say Y. 833506f1d07SSam Ravnborg 834506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8353c2362e6SHarvey Harrison def_bool y 8363c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 837506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8388f9ca475SIngo Molnar ---help--- 839506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 840506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 841506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 842506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 843506f1d07SSam Ravnborg If unsure, say Y. 844506f1d07SSam Ravnborg 845506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 846506f1d07SSam Ravnborgconfig SWIOTLB 847a1afd01cSJoerg Roedel def_bool y if X86_64 8488f9ca475SIngo Molnar ---help--- 849506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8504454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8514454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8524454d327SJoe Millenbach with more than 3 GB of memory. 8534454d327SJoe Millenbach If unsure, say Y. 854506f1d07SSam Ravnborg 855a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8563120e25eSJan Beulich def_bool y 8573120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 858d25e26b6SLinus Torvalds 8591184dc2fSMike Travisconfig MAXSMP 860ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8616ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 86236f5101aSMike Travis select CPUMASK_OFFSTACK 8638f9ca475SIngo Molnar ---help--- 864ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 8651184dc2fSMike Travis If unsure, say N. 866506f1d07SSam Ravnborg 867506f1d07SSam Ravnborgconfig NR_CPUS 86836f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 8692a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 870bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 871b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 87278637a97SMike Travis default "1" if !SMP 873b53b5edaSJosh Boyer default "8192" if MAXSMP 874b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 875c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 876c5c19941SKirill A. Shutemov default "64" if SMP 8778f9ca475SIngo Molnar ---help--- 878506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 879bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 880cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 881506f1d07SSam Ravnborg minimum value which makes sense is 2. 882506f1d07SSam Ravnborg 883506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 884506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 885506f1d07SSam Ravnborg 886506f1d07SSam Ravnborgconfig SCHED_SMT 887506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 888c8e56d20SBorislav Petkov depends on SMP 8898f9ca475SIngo Molnar ---help--- 890506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 891506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 892506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 893506f1d07SSam Ravnborg N here. 894506f1d07SSam Ravnborg 895506f1d07SSam Ravnborgconfig SCHED_MC 8963c2362e6SHarvey Harrison def_bool y 8973c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 898c8e56d20SBorislav Petkov depends on SMP 8998f9ca475SIngo Molnar ---help--- 900506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 901506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 902506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 903506f1d07SSam Ravnborg 904506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 905506f1d07SSam Ravnborg 90630b8b006SThomas Gleixnerconfig UP_LATE_INIT 90730b8b006SThomas Gleixner def_bool y 908ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 90930b8b006SThomas Gleixner 910506f1d07SSam Ravnborgconfig X86_UP_APIC 91150849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 91250849eefSJan Beulich default PCI_MSI 91338a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9148f9ca475SIngo Molnar ---help--- 915506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 916506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 917506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 918506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 919506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 920506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 921506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 922506f1d07SSam Ravnborg lockups. 923506f1d07SSam Ravnborg 924506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 925506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 926506f1d07SSam Ravnborg depends on X86_UP_APIC 9278f9ca475SIngo Molnar ---help--- 928506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 929506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 930506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 931506f1d07SSam Ravnborg 932506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 933506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 934506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 935506f1d07SSam Ravnborg 936506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9373c2362e6SHarvey Harrison def_bool y 9380dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 939b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 94052f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 941506f1d07SSam Ravnborg 942506f1d07SSam Ravnborgconfig X86_IO_APIC 943b1da1e71SJan Beulich def_bool y 944b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 945506f1d07SSam Ravnborg 94641b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 94741b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 94841b9eb26SStefan Assmann depends on X86_IO_APIC 9498f9ca475SIngo Molnar ---help--- 95041b9eb26SStefan Assmann This option enables a workaround that fixes a source of 95141b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 95241b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 95341b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 95441b9eb26SStefan Assmann 95541b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 95641b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 95741b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 95841b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 95941b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 96041b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 96141b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 96241b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 96341b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 96441b9eb26SStefan Assmann down (vital) interrupt lines. 96541b9eb26SStefan Assmann 96641b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 96741b9eb26SStefan Assmann increased on these systems. 96841b9eb26SStefan Assmann 969506f1d07SSam Ravnborgconfig X86_MCE 970bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 971648ed940SChen, Gong select GENERIC_ALLOCATOR 972e57dbaf7SBorislav Petkov default y 973506f1d07SSam Ravnborg ---help--- 974bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 975bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 976506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 977bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 9784efc0670SAndi Kleen 979506f1d07SSam Ravnborgconfig X86_MCE_INTEL 9803c2362e6SHarvey Harrison def_bool y 9813c2362e6SHarvey Harrison prompt "Intel MCE features" 982c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9838f9ca475SIngo Molnar ---help--- 984506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 985506f1d07SSam Ravnborg the thermal monitor. 986506f1d07SSam Ravnborg 987506f1d07SSam Ravnborgconfig X86_MCE_AMD 9883c2362e6SHarvey Harrison def_bool y 9893c2362e6SHarvey Harrison prompt "AMD MCE features" 990c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9918f9ca475SIngo Molnar ---help--- 992506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 993506f1d07SSam Ravnborg the DRAM Error Threshold. 994506f1d07SSam Ravnborg 9954efc0670SAndi Kleenconfig X86_ANCIENT_MCE 9966fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 997c31d9633SAndi Kleen depends on X86_32 && X86_MCE 9984efc0670SAndi Kleen ---help--- 9994efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 10005065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 10014efc0670SAndi Kleen line. 10024efc0670SAndi Kleen 1003b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1004b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10056fc108a0SJan Beulich def_bool y 1006b2762686SAndi Kleen 1007ea149b36SAndi Kleenconfig X86_MCE_INJECT 1008c1ebf835SAndi Kleen depends on X86_MCE 1009ea149b36SAndi Kleen tristate "Machine check injector support" 1010ea149b36SAndi Kleen ---help--- 1011ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1012ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1013ea149b36SAndi Kleen QA it is safe to say n. 1014ea149b36SAndi Kleen 10154efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10164efc0670SAndi Kleen def_bool y 10175bb38adcSAndi Kleen depends on X86_MCE_INTEL 10184efc0670SAndi Kleen 10195aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10201e642812SIngo Molnar bool "Legacy VM86 support" 10215aef51c3SAndy Lutomirski default n 1022506f1d07SSam Ravnborg depends on X86_32 10238f9ca475SIngo Molnar ---help--- 10245aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10255aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10265aef51c3SAndy Lutomirski 10275aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10285aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10295aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10305aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10315aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10321e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10331e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10341e642812SIngo Molnar mode might be faster than emulation and you might want to 10351e642812SIngo Molnar enable this option. 10365aef51c3SAndy Lutomirski 10371e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10381e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10391e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10401e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10415aef51c3SAndy Lutomirski 10421e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10431e642812SIngo Molnar and slows down exception handling a tiny bit. 10445aef51c3SAndy Lutomirski 10451e642812SIngo Molnar If unsure, say N here. 10465aef51c3SAndy Lutomirski 10475aef51c3SAndy Lutomirskiconfig VM86 10485aef51c3SAndy Lutomirski bool 10495aef51c3SAndy Lutomirski default X86_LEGACY_VM86 105034273f41SH. Peter Anvin 105134273f41SH. Peter Anvinconfig X86_16BIT 105234273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 105334273f41SH. Peter Anvin default y 1054a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 105534273f41SH. Peter Anvin ---help--- 105634273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 105734273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 105834273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 105934273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 106034273f41SH. Peter Anvin 106134273f41SH. Peter Anvinconfig X86_ESPFIX32 106234273f41SH. Peter Anvin def_bool y 106334273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1064506f1d07SSam Ravnborg 1065197725deSH. Peter Anvinconfig X86_ESPFIX64 1066197725deSH. Peter Anvin def_bool y 106734273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1068506f1d07SSam Ravnborg 10691ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 10701ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 10711ad83c85SAndy Lutomirski default y 10721ad83c85SAndy Lutomirski depends on X86_64 10731ad83c85SAndy Lutomirski ---help--- 10741ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 10751ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 10761ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 10771ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 10781ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 10791ad83c85SAndy Lutomirski 0xffffffffff600?00. 10801ad83c85SAndy Lutomirski 10811ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 10821ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 10831ad83c85SAndy Lutomirski 10841ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 10851ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 10861ad83c85SAndy Lutomirski 1087506f1d07SSam Ravnborgconfig TOSHIBA 1088506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1089506f1d07SSam Ravnborg depends on X86_32 1090506f1d07SSam Ravnborg ---help--- 1091506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1092506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1093506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1094506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1095506f1d07SSam Ravnborg 1096506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1097506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1098506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1099506f1d07SSam Ravnborg 1100506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1101506f1d07SSam Ravnborg Say N otherwise. 1102506f1d07SSam Ravnborg 1103506f1d07SSam Ravnborgconfig I8K 1104039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1105949a9d70SJean Delvare select HWMON 1106039ae585SPali Rohár select SENSORS_DELL_SMM 1107506f1d07SSam Ravnborg ---help--- 1108039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1109039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1110039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1111039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1112039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1113039ae585SPali Rohár needed userspace package i8kutils. 1114506f1d07SSam Ravnborg 1115039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1116039ae585SPali Rohár use userspace package i8kutils. 1117506f1d07SSam Ravnborg Say N otherwise. 1118506f1d07SSam Ravnborg 1119506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11209ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11219ba16087SJan Beulich depends on X86_32 1122506f1d07SSam Ravnborg ---help--- 1123506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1124506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1125506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1126506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1127506f1d07SSam Ravnborg system. 1128506f1d07SSam Ravnborg 1129506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11305e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1131506f1d07SSam Ravnborg 1132506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1133506f1d07SSam Ravnborg enable this option even if you don't need it. 1134506f1d07SSam Ravnborg Say N otherwise. 1135506f1d07SSam Ravnborg 1136506f1d07SSam Ravnborgconfig MICROCODE 11379a2bc335SBorislav Petkov bool "CPU microcode loading support" 11389a2bc335SBorislav Petkov default y 113980030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1140fe055896SBorislav Petkov depends on BLK_DEV_INITRD 1141506f1d07SSam Ravnborg select FW_LOADER 1142506f1d07SSam Ravnborg ---help--- 1143e43f6e67SBorislav Petkov 1144506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 114580cc9f10SPeter Oruba certain Intel and AMD processors. The Intel support is for the 1146e43f6e67SBorislav Petkov IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1147e43f6e67SBorislav Petkov Xeon etc. The AMD support is for families 0x10 and later. You will 1148e43f6e67SBorislav Petkov obviously need the actual microcode binary data itself which is not 1149e43f6e67SBorislav Petkov shipped with the Linux kernel. 1150506f1d07SSam Ravnborg 11518d86f390SPeter Oruba This option selects the general module only, you need to select 11528d86f390SPeter Oruba at least one vendor specific module as well. 1153506f1d07SSam Ravnborg 1154e43f6e67SBorislav Petkov To compile this driver as a module, choose M here: the module 1155e43f6e67SBorislav Petkov will be called microcode. 1156506f1d07SSam Ravnborg 11578d86f390SPeter Orubaconfig MICROCODE_INTEL 1158e43f6e67SBorislav Petkov bool "Intel microcode loading support" 11598d86f390SPeter Oruba depends on MICROCODE 11608d86f390SPeter Oruba default MICROCODE 11618d86f390SPeter Oruba select FW_LOADER 11628f9ca475SIngo Molnar ---help--- 11638d86f390SPeter Oruba This options enables microcode patch loading support for Intel 11648d86f390SPeter Oruba processors. 11658d86f390SPeter Oruba 1166b8989db9SAlan For the current Intel microcode data package go to 1167b8989db9SAlan <https://downloadcenter.intel.com> and search for 1168b8989db9SAlan 'Linux Processor Microcode Data File'. 11698d86f390SPeter Oruba 117080cc9f10SPeter Orubaconfig MICROCODE_AMD 1171e43f6e67SBorislav Petkov bool "AMD microcode loading support" 117280cc9f10SPeter Oruba depends on MICROCODE 117380cc9f10SPeter Oruba select FW_LOADER 11748f9ca475SIngo Molnar ---help--- 117580cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 117680cc9f10SPeter Oruba processors will be enabled. 117780cc9f10SPeter Oruba 1178506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 11793c2362e6SHarvey Harrison def_bool y 1180506f1d07SSam Ravnborg depends on MICROCODE 1181506f1d07SSam Ravnborg 1182506f1d07SSam Ravnborgconfig X86_MSR 1183506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 11848f9ca475SIngo Molnar ---help--- 1185506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1186506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1187506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1188506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1189506f1d07SSam Ravnborg systems. 1190506f1d07SSam Ravnborg 1191506f1d07SSam Ravnborgconfig X86_CPUID 1192506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 11938f9ca475SIngo Molnar ---help--- 1194506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1195506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1196506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1197506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1198506f1d07SSam Ravnborg 1199506f1d07SSam Ravnborgchoice 1200506f1d07SSam Ravnborg prompt "High Memory Support" 12016fc108a0SJan Beulich default HIGHMEM4G 1202506f1d07SSam Ravnborg depends on X86_32 1203506f1d07SSam Ravnborg 1204506f1d07SSam Ravnborgconfig NOHIGHMEM 1205506f1d07SSam Ravnborg bool "off" 1206506f1d07SSam Ravnborg ---help--- 1207506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1208506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1209506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1210506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1211506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1212506f1d07SSam Ravnborg "high memory". 1213506f1d07SSam Ravnborg 1214506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1215506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1216506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1217506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1218506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1219506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1220506f1d07SSam Ravnborg possible. 1221506f1d07SSam Ravnborg 1222506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1223506f1d07SSam Ravnborg answer "4GB" here. 1224506f1d07SSam Ravnborg 1225506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1226506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1227506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1228506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1229506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1230506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1231506f1d07SSam Ravnborg 1232506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1233506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1234506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1235506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1236506f1d07SSam Ravnborg kernel at boot time.) 1237506f1d07SSam Ravnborg 1238506f1d07SSam Ravnborg If unsure, say "off". 1239506f1d07SSam Ravnborg 1240506f1d07SSam Ravnborgconfig HIGHMEM4G 1241506f1d07SSam Ravnborg bool "4GB" 12428f9ca475SIngo Molnar ---help--- 1243506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1244506f1d07SSam Ravnborg gigabytes of physical RAM. 1245506f1d07SSam Ravnborg 1246506f1d07SSam Ravnborgconfig HIGHMEM64G 1247506f1d07SSam Ravnborg bool "64GB" 1248eb068e78SH. Peter Anvin depends on !M486 1249506f1d07SSam Ravnborg select X86_PAE 12508f9ca475SIngo Molnar ---help--- 1251506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1252506f1d07SSam Ravnborg gigabytes of physical RAM. 1253506f1d07SSam Ravnborg 1254506f1d07SSam Ravnborgendchoice 1255506f1d07SSam Ravnborg 1256506f1d07SSam Ravnborgchoice 12576a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1258506f1d07SSam Ravnborg default VMSPLIT_3G 1259506f1d07SSam Ravnborg depends on X86_32 12608f9ca475SIngo Molnar ---help--- 1261506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1262506f1d07SSam Ravnborg 1263506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1264506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1265506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1266506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1267506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1268506f1d07SSam Ravnborg available to user programs, making the address space there 1269506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1270506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1271506f1d07SSam Ravnborg kernel modules. 1272506f1d07SSam Ravnborg 1273506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1274506f1d07SSam Ravnborg option alone! 1275506f1d07SSam Ravnborg 1276506f1d07SSam Ravnborg config VMSPLIT_3G 1277506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1278506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1279506f1d07SSam Ravnborg depends on !X86_PAE 1280506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1281506f1d07SSam Ravnborg config VMSPLIT_2G 1282506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1283506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1284506f1d07SSam Ravnborg depends on !X86_PAE 1285506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1286506f1d07SSam Ravnborg config VMSPLIT_1G 1287506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1288506f1d07SSam Ravnborgendchoice 1289506f1d07SSam Ravnborg 1290506f1d07SSam Ravnborgconfig PAGE_OFFSET 1291506f1d07SSam Ravnborg hex 1292506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1293506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1294506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1295506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1296506f1d07SSam Ravnborg default 0xC0000000 1297506f1d07SSam Ravnborg depends on X86_32 1298506f1d07SSam Ravnborg 1299506f1d07SSam Ravnborgconfig HIGHMEM 13003c2362e6SHarvey Harrison def_bool y 1301506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1302506f1d07SSam Ravnborg 1303506f1d07SSam Ravnborgconfig X86_PAE 13049ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1305506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13069d99c712SChristian Melki select SWIOTLB 13078f9ca475SIngo Molnar ---help--- 1308506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1309506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1310506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1311506f1d07SSam Ravnborg consumes more pagetable space per process. 1312506f1d07SSam Ravnborg 1313600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13143120e25eSJan Beulich def_bool y 13153120e25eSJan Beulich depends on X86_64 || X86_PAE 1316600715dcSJeremy Fitzhardinge 131766f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13183120e25eSJan Beulich def_bool y 13193120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 132066f2b061SFUJITA Tomonori 132110971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1322e5008abeSLuis R. Rodriguez def_bool y 1323e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13248f9ca475SIngo Molnar ---help--- 132510971ab2SIngo Molnar Certain kernel features effectively disable kernel 132610971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 132710971ab2SIngo Molnar supports them), so don't confuse the user by printing 132810971ab2SIngo Molnar that we have them enabled. 13299e899816SNick Piggin 1330506f1d07SSam Ravnborg# Common NUMA Features 1331506f1d07SSam Ravnborgconfig NUMA 1332fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1333506f1d07SSam Ravnborg depends on SMP 1334b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1335b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13368f9ca475SIngo Molnar ---help--- 1337506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1338fd51b2d7SKOSAKI Motohiro 1339506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1340506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1341506f1d07SSam Ravnborg NUMA awareness to the kernel. 1342506f1d07SSam Ravnborg 1343c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1344fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1345fd51b2d7SKOSAKI Motohiro 1346b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13477cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1348fd51b2d7SKOSAKI Motohiro 1349fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1350506f1d07SSam Ravnborg 1351eec1d4faSHans Rosenfeldconfig AMD_NUMA 13523c2362e6SHarvey Harrison def_bool y 13533c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13545da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13558f9ca475SIngo Molnar ---help--- 1356eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1357eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1358eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1359eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1360eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1361506f1d07SSam Ravnborg 1362506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 13633c2362e6SHarvey Harrison def_bool y 13643c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1365506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1366506f1d07SSam Ravnborg select ACPI_NUMA 13678f9ca475SIngo Molnar ---help--- 1368506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1369506f1d07SSam Ravnborg 13706ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 13716ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 13726ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 13736ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 13746ec6e0d9SSuresh Siddha# for details. 13756ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 13766ec6e0d9SSuresh Siddha def_bool y 13776ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 13786ec6e0d9SSuresh Siddha 1379506f1d07SSam Ravnborgconfig NUMA_EMU 1380506f1d07SSam Ravnborg bool "NUMA emulation" 13811b7e03efSTejun Heo depends on NUMA 13828f9ca475SIngo Molnar ---help--- 1383506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1384506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1385506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1386506f1d07SSam Ravnborg 1387506f1d07SSam Ravnborgconfig NODES_SHIFT 1388d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 138951591e31SDavid Rientjes range 1 10 139051591e31SDavid Rientjes default "10" if MAXSMP 1391506f1d07SSam Ravnborg default "6" if X86_64 1392506f1d07SSam Ravnborg default "3" 1393506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 13948f9ca475SIngo Molnar ---help--- 13951184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1396692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1397506f1d07SSam Ravnborg 1398506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 13993c2362e6SHarvey Harrison def_bool y 1400506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1401506f1d07SSam Ravnborg 1402506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14033c2362e6SHarvey Harrison def_bool y 1404506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1405506f1d07SSam Ravnborg 1406506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1407506f1d07SSam Ravnborg def_bool y 14083b16651fSTejun Heo depends on X86_32 && !NUMA 1409506f1d07SSam Ravnborg 1410506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1411506f1d07SSam Ravnborg def_bool y 1412b263295dSChristoph Lameter depends on NUMA && X86_32 1413506f1d07SSam Ravnborg 1414506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1415506f1d07SSam Ravnborg def_bool y 1416b263295dSChristoph Lameter depends on NUMA && X86_32 1417b263295dSChristoph Lameter 1418506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1419506f1d07SSam Ravnborg def_bool y 14206ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1421506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1422506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1423506f1d07SSam Ravnborg 14243b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14253b16651fSTejun Heo def_bool y 14263b16651fSTejun Heo depends on X86_64 14273b16651fSTejun Heo 1428506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1429506f1d07SSam Ravnborg def_bool y 1430b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1431506f1d07SSam Ravnborg 1432506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1433a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14343120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1435a0842b70SToshi Kani help 1436a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1437a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1438a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1439506f1d07SSam Ravnborg 14403b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14413b16651fSTejun Heo def_bool y 14423b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14433b16651fSTejun Heo 1444a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1445a29815a3SAvi Kivity hex 1446a29815a3SAvi Kivity default 0 if X86_32 1447a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1448a29815a3SAvi Kivity 1449506f1d07SSam Ravnborgsource "mm/Kconfig" 1450506f1d07SSam Ravnborg 14517a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14527a67832cSDan Williams bool 14537a67832cSDan Williams 1454ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 14557a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 14569f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14579f53f9faSDan Williams depends on BLK_DEV 14587a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 14599f53f9faSDan Williams select LIBNVDIMM 1460ec776ef6SChristoph Hellwig help 1461ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1462ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1463ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1464ec776ef6SChristoph Hellwig they can be used for persistent storage. 1465ec776ef6SChristoph Hellwig 1466ec776ef6SChristoph Hellwig Say Y if unsure. 1467ec776ef6SChristoph Hellwig 1468506f1d07SSam Ravnborgconfig HIGHPTE 1469506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 14706fc108a0SJan Beulich depends on HIGHMEM 14718f9ca475SIngo Molnar ---help--- 1472506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1473506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1474506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1475506f1d07SSam Ravnborg entries in high memory. 1476506f1d07SSam Ravnborg 14779f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 14789f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 14798f9ca475SIngo Molnar ---help--- 14809f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 14819f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 14829f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 14839f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 14849f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 14859f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 14869f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 14879f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 14889f077871SJeremy Fitzhardinge 14899f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 14909f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 14919f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 14929f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 14939f077871SJeremy Fitzhardinge 14949f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 14959f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 14969f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 14979f077871SJeremy Fitzhardinge memory. 14989f077871SJeremy Fitzhardinge 1499c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1500c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1501c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1502c885df50SJeremy Fitzhardinge default y 15038f9ca475SIngo Molnar ---help--- 1504c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1505c885df50SJeremy Fitzhardinge on or off. 1506c885df50SJeremy Fitzhardinge 15079ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1508d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1509d0cd7425SH. Peter Anvin default 64 1510d0cd7425SH. Peter Anvin range 4 640 15118f9ca475SIngo Molnar ---help--- 1512d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1513fc381519SIngo Molnar 1514d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1515d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1516fc381519SIngo Molnar 1517d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1518d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1519d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1520d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1521fc381519SIngo Molnar 1522d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1523d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1524d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1525d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1526d0cd7425SH. Peter Anvin entire low memory range. 1527d0cd7425SH. Peter Anvin 1528d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1529d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1530d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1531d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1532d0cd7425SH. Peter Anvin typical corruption patterns. 1533d0cd7425SH. Peter Anvin 1534d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1535fc381519SIngo Molnar 1536506f1d07SSam Ravnborgconfig MATH_EMULATION 1537506f1d07SSam Ravnborg bool 1538a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1539506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1540506f1d07SSam Ravnborg ---help--- 1541506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1542506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1543506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1544506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1545506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1546506f1d07SSam Ravnborg coprocessor or this emulation. 1547506f1d07SSam Ravnborg 1548506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1549506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1550506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1551506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1552506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1553506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1554506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1555506f1d07SSam Ravnborg intend to use this kernel on different machines. 1556506f1d07SSam Ravnborg 1557506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1558506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1559506f1d07SSam Ravnborg 1560506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1561506f1d07SSam Ravnborg kernel, it won't hurt. 1562506f1d07SSam Ravnborg 1563506f1d07SSam Ravnborgconfig MTRR 15646fc108a0SJan Beulich def_bool y 15656a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1566506f1d07SSam Ravnborg ---help--- 1567506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1568506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1569506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1570506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1571506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1572506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1573506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1574506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1575506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1576506f1d07SSam Ravnborg 1577506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1578506f1d07SSam Ravnborg control registers on other processors can be easily supported 1579506f1d07SSam Ravnborg as well: 1580506f1d07SSam Ravnborg 1581506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1582506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1583506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1584506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1585506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1586506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1587506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1588506f1d07SSam Ravnborg 1589506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1590506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1591506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1592506f1d07SSam Ravnborg 1593506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1594506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1595506f1d07SSam Ravnborg 15967225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1597506f1d07SSam Ravnborg 159895ffa243SYinghai Luconfig MTRR_SANITIZER 15992ffb3501SYinghai Lu def_bool y 160095ffa243SYinghai Lu prompt "MTRR cleanup support" 160195ffa243SYinghai Lu depends on MTRR 16028f9ca475SIngo Molnar ---help--- 1603aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1604aba3728cSThomas Gleixner add writeback entries. 160595ffa243SYinghai Lu 1606aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1607692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1608aba3728cSThomas Gleixner mtrr_chunk_size. 160995ffa243SYinghai Lu 16102ffb3501SYinghai Lu If unsure, say Y. 161195ffa243SYinghai Lu 161295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1613f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1614f5098d62SYinghai Lu range 0 1 1615f5098d62SYinghai Lu default "0" 161695ffa243SYinghai Lu depends on MTRR_SANITIZER 16178f9ca475SIngo Molnar ---help--- 1618f5098d62SYinghai Lu Enable mtrr cleanup default value 161995ffa243SYinghai Lu 162012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 162112031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 162212031a62SYinghai Lu range 0 7 162312031a62SYinghai Lu default "1" 162412031a62SYinghai Lu depends on MTRR_SANITIZER 16258f9ca475SIngo Molnar ---help--- 162612031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1627aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 162812031a62SYinghai Lu 16292e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16306fc108a0SJan Beulich def_bool y 16316a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16322a8a2719SIngo Molnar depends on MTRR 16338f9ca475SIngo Molnar ---help--- 16342e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1635042b78e4SVenki Pallipadi 16362e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16372e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16382e5d9c85Svenkatesh.pallipadi@intel.com 16392e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1640042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16412e5d9c85Svenkatesh.pallipadi@intel.com 16422e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16432e5d9c85Svenkatesh.pallipadi@intel.com 164446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 164546cf98cdSVenkatesh Pallipadi def_bool y 164646cf98cdSVenkatesh Pallipadi depends on X86_PAT 164746cf98cdSVenkatesh Pallipadi 1648628c6246SH. Peter Anvinconfig ARCH_RANDOM 1649628c6246SH. Peter Anvin def_bool y 1650628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1651628c6246SH. Peter Anvin ---help--- 1652628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1653628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1654628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1655628c6246SH. Peter Anvin secure hardware random number generator. 1656628c6246SH. Peter Anvin 165751ae4a2dSH. Peter Anvinconfig X86_SMAP 165851ae4a2dSH. Peter Anvin def_bool y 165951ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 166051ae4a2dSH. Peter Anvin ---help--- 166151ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 166251ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 166351ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 166451ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 166551ae4a2dSH. Peter Anvin 166651ae4a2dSH. Peter Anvin If unsure, say Y. 166751ae4a2dSH. Peter Anvin 166872e9b5feSDave Hansenconfig X86_INTEL_MPX 166972e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 167072e9b5feSDave Hansen def_bool n 167172e9b5feSDave Hansen depends on CPU_SUP_INTEL 167272e9b5feSDave Hansen ---help--- 167372e9b5feSDave Hansen MPX provides hardware features that can be used in 167472e9b5feSDave Hansen conjunction with compiler-instrumented code to check 167572e9b5feSDave Hansen memory references. It is designed to detect buffer 167672e9b5feSDave Hansen overflow or underflow bugs. 167772e9b5feSDave Hansen 167872e9b5feSDave Hansen This option enables running applications which are 167972e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 168072e9b5feSDave Hansen itself inside the kernel or to protect the kernel 168172e9b5feSDave Hansen against bad memory references. 168272e9b5feSDave Hansen 168372e9b5feSDave Hansen Enabling this option will make the kernel larger: 168472e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 168572e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 168672e9b5feSDave Hansen will increase the kernel memory overhead of each 168772e9b5feSDave Hansen process and adds some branches to paths used during 168872e9b5feSDave Hansen exec() and munmap(). 168972e9b5feSDave Hansen 169072e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 169172e9b5feSDave Hansen 169272e9b5feSDave Hansen If unsure, say N. 169372e9b5feSDave Hansen 1694506f1d07SSam Ravnborgconfig EFI 16959ba16087SJan Beulich bool "EFI runtime service support" 16965b83683fSHuang, Ying depends on ACPI 1697f6ce5002SSergey Vlasov select UCS2_STRING 1698022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1699506f1d07SSam Ravnborg ---help--- 17008b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1701506f1d07SSam Ravnborg available (such as the EFI variable services). 1702506f1d07SSam Ravnborg 17038b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17048b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17058b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17068b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17078b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17088b2cb7a8SHuang, Ying platforms. 1709506f1d07SSam Ravnborg 1710291f3632SMatt Flemingconfig EFI_STUB 1711291f3632SMatt Fleming bool "EFI stub support" 1712b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17137b2a583aSMatt Fleming select RELOCATABLE 1714291f3632SMatt Fleming ---help--- 1715291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1716291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1717291f3632SMatt Fleming 17184172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17190c759662SMatt Fleming 17207d453eeeSMatt Flemingconfig EFI_MIXED 17217d453eeeSMatt Fleming bool "EFI mixed-mode support" 17227d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17237d453eeeSMatt Fleming ---help--- 17247d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17257d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17267d453eeeSMatt Fleming mode. 17277d453eeeSMatt Fleming 17287d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17297d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17307d453eeeSMatt Fleming the EFI handover protocol must be used. 17317d453eeeSMatt Fleming 17327d453eeeSMatt Fleming If unsure, say N. 17337d453eeeSMatt Fleming 1734506f1d07SSam Ravnborgconfig SECCOMP 17353c2362e6SHarvey Harrison def_bool y 17363c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17378f9ca475SIngo Molnar ---help--- 1738506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1739506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1740506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1741506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1742506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1743506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17449c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1745506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1746506f1d07SSam Ravnborg defined by each seccomp mode. 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1749506f1d07SSam Ravnborg 1750506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1751506f1d07SSam Ravnborg 1752506f1d07SSam Ravnborgconfig KEXEC 1753506f1d07SSam Ravnborg bool "kexec system call" 17542965faa5SDave Young select KEXEC_CORE 17558f9ca475SIngo Molnar ---help--- 1756506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1757506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1758506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1759506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1760506f1d07SSam Ravnborg 1761506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1762506f1d07SSam Ravnborg 1763506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1764506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1765bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1766bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1767bf220695SGeert Uytterhoeven made. 1768506f1d07SSam Ravnborg 176974ca317cSVivek Goyalconfig KEXEC_FILE 177074ca317cSVivek Goyal bool "kexec file based system call" 17712965faa5SDave Young select KEXEC_CORE 177274ca317cSVivek Goyal select BUILD_BIN2C 177374ca317cSVivek Goyal depends on X86_64 177474ca317cSVivek Goyal depends on CRYPTO=y 177574ca317cSVivek Goyal depends on CRYPTO_SHA256=y 177674ca317cSVivek Goyal ---help--- 177774ca317cSVivek Goyal This is new version of kexec system call. This system call is 177874ca317cSVivek Goyal file based and takes file descriptors as system call argument 177974ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 178074ca317cSVivek Goyal accepted by previous system call. 178174ca317cSVivek Goyal 17828e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 17838e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 178474ca317cSVivek Goyal depends on KEXEC_FILE 17858e7d8381SVivek Goyal ---help--- 17868e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1787d8eb8940SBorislav Petkov the kexec_file_load() syscall. 17888e7d8381SVivek Goyal 1789d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1790d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1791d8eb8940SBorislav Petkov loaded in order for this to work. 17928e7d8381SVivek Goyal 17938e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 17948e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 17958e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 17968e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 17978e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 17988e7d8381SVivek Goyal ---help--- 17998e7d8381SVivek Goyal Enable bzImage signature verification support. 18008e7d8381SVivek Goyal 1801506f1d07SSam Ravnborgconfig CRASH_DUMP 180204b69447SPavel Machek bool "kernel crash dumps" 1803506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18048f9ca475SIngo Molnar ---help--- 1805506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1806506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1807506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1808506f1d07SSam Ravnborg a specially reserved region and then later executed after 1809506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1810506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1811506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1812506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1813506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1814506f1d07SSam Ravnborg 18153ab83521SHuang Yingconfig KEXEC_JUMP 18166ea30386SKees Cook bool "kexec jump" 1817fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18188f9ca475SIngo Molnar ---help--- 181989081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 182089081d17SHuang Ying code in physical address mode via KEXEC 18213ab83521SHuang Ying 1822506f1d07SSam Ravnborgconfig PHYSICAL_START 18236a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1824ceefccc9SH. Peter Anvin default "0x1000000" 18258f9ca475SIngo Molnar ---help--- 1826506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1827506f1d07SSam Ravnborg 1828506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1829506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1830506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1831506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1832506f1d07SSam Ravnborg address. 1833506f1d07SSam Ravnborg 1834506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1835506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1836506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1837506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1838506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1839506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1840506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1841506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1842506f1d07SSam Ravnborg 1843ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1844ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1845ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1846ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1847ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1848ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1849ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1850ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1851ceefccc9SH. Peter Anvin for more details about crash dumps. 1852506f1d07SSam Ravnborg 1853506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1854506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1855506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1856506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1857506f1d07SSam Ravnborg is present because there are users out there who continue to use 1858506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1859506f1d07SSam Ravnborg line. 1860506f1d07SSam Ravnborg 1861506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1862506f1d07SSam Ravnborg 1863506f1d07SSam Ravnborgconfig RELOCATABLE 186426717808SH. Peter Anvin bool "Build a relocatable kernel" 186526717808SH. Peter Anvin default y 18668f9ca475SIngo Molnar ---help--- 1867506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1868506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1869506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1870506f1d07SSam Ravnborg but are discarded at runtime. 1871506f1d07SSam Ravnborg 1872506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1873506f1d07SSam Ravnborg must live at a different physical address than the primary 1874506f1d07SSam Ravnborg kernel. 1875506f1d07SSam Ravnborg 1876506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1877506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 18788ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1879506f1d07SSam Ravnborg 18808ab3820fSKees Cookconfig RANDOMIZE_BASE 18818ab3820fSKees Cook bool "Randomize the address of the kernel image" 18828ab3820fSKees Cook depends on RELOCATABLE 18838ab3820fSKees Cook default n 18848ab3820fSKees Cook ---help--- 18858ab3820fSKees Cook Randomizes the physical and virtual address at which the 18868ab3820fSKees Cook kernel image is decompressed, as a security feature that 18878ab3820fSKees Cook deters exploit attempts relying on knowledge of the location 18888ab3820fSKees Cook of kernel internals. 18898ab3820fSKees Cook 1890a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1891a653f356SKees Cook supported. If RDTSC is supported, it is used as well. If 1892a653f356SKees Cook neither RDRAND nor RDTSC are supported, then randomness is 1893a653f356SKees Cook read from the i8254 timer. 18948ab3820fSKees Cook 18958ab3820fSKees Cook The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1896a653f356SKees Cook and aligned according to PHYSICAL_ALIGN. Since the kernel is 1897a653f356SKees Cook built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1898a653f356SKees Cook minimum of 2MiB, only 10 bits of entropy is theoretically 1899a653f356SKees Cook possible. At best, due to page table layouts, 64-bit can use 1900a653f356SKees Cook 9 bits of entropy and 32-bit uses 8 bits. 19018ab3820fSKees Cook 1902da2b6fb9SKees Cook If unsure, say N. 1903da2b6fb9SKees Cook 19048ab3820fSKees Cookconfig RANDOMIZE_BASE_MAX_OFFSET 1905da2b6fb9SKees Cook hex "Maximum kASLR offset allowed" if EXPERT 19068ab3820fSKees Cook depends on RANDOMIZE_BASE 19076145cfe3SKees Cook range 0x0 0x20000000 if X86_32 19086145cfe3SKees Cook default "0x20000000" if X86_32 19096145cfe3SKees Cook range 0x0 0x40000000 if X86_64 19106145cfe3SKees Cook default "0x40000000" if X86_64 19118ab3820fSKees Cook ---help--- 1912da2b6fb9SKees Cook The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1913da2b6fb9SKees Cook memory is used to determine the maximal offset in bytes that will 1914da2b6fb9SKees Cook be applied to the kernel when kernel Address Space Layout 1915da2b6fb9SKees Cook Randomization (kASLR) is active. This must be a multiple of 1916da2b6fb9SKees Cook PHYSICAL_ALIGN. 19176145cfe3SKees Cook 1918da2b6fb9SKees Cook On 32-bit this is limited to 512MiB by page table layouts. The 1919da2b6fb9SKees Cook default is 512MiB. 19206145cfe3SKees Cook 19216145cfe3SKees Cook On 64-bit this is limited by how the kernel fixmap page table is 1922da2b6fb9SKees Cook positioned, so this cannot be larger than 1GiB currently. Without 1923da2b6fb9SKees Cook RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1924da2b6fb9SKees Cook and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1925da2b6fb9SKees Cook modules area will shrink to compensate, up to the current maximum 1926da2b6fb9SKees Cook 1GiB to 1GiB split. The default is 1GiB. 1927da2b6fb9SKees Cook 1928da2b6fb9SKees Cook If unsure, leave at the default value. 19298ab3820fSKees Cook 19308ab3820fSKees Cook# Relocation on x86 needs some additional build support 1931845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1932845adf72SH. Peter Anvin def_bool y 19338ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1934845adf72SH. Peter Anvin 1935506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1936a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19378ab3820fSKees Cook default "0x200000" 1938a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1939a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19408f9ca475SIngo Molnar ---help--- 1941506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1942506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1943506f1d07SSam Ravnborg address which meets above alignment restriction. 1944506f1d07SSam Ravnborg 1945506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1946506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1947506f1d07SSam Ravnborg address aligned to above value and run from there. 1948506f1d07SSam Ravnborg 1949506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1950506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1951506f1d07SSam Ravnborg load address and decompress itself to the address it has been 1952506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 1953506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 1954506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 1955506f1d07SSam Ravnborg above alignment restrictions. 1956506f1d07SSam Ravnborg 1957a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 1958a0215061SKees Cook this value must be a multiple of 0x200000. 1959a0215061SKees Cook 1960506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1961506f1d07SSam Ravnborg 1962506f1d07SSam Ravnborgconfig HOTPLUG_CPU 19637c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 196440b31360SStephen Rothwell depends on SMP 1965506f1d07SSam Ravnborg ---help--- 19667c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 19677c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 19687c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 19697c13e6a3SDimitri Sivanich automatically on SMP systems. ) 19707c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 1971506f1d07SSam Ravnborg 197280aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 197380aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 197480aa1dffSFenghua Yu default n 19752c922cd0SKees Cook depends on HOTPLUG_CPU 197680aa1dffSFenghua Yu ---help--- 197780aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 197880aa1dffSFenghua Yu 197980aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 198080aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 198180aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 198280aa1dffSFenghua Yu 198380aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 198480aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 198580aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 198680aa1dffSFenghua Yu 198780aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 198880aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 198980aa1dffSFenghua Yu 199080aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 199180aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 199280aa1dffSFenghua Yu be other CPU0 dependencies. 199380aa1dffSFenghua Yu 199480aa1dffSFenghua Yu Please make sure the dependencies are under your control before 199580aa1dffSFenghua Yu you enable this feature. 199680aa1dffSFenghua Yu 199780aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 199880aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 199980aa1dffSFenghua Yu parameter cpu0_hotplug. 200080aa1dffSFenghua Yu 2001a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2002a71c8bc5SFenghua Yu def_bool n 2003a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20042c922cd0SKees Cook depends on HOTPLUG_CPU 2005a71c8bc5SFenghua Yu ---help--- 2006a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2007a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2008a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2009a71c8bc5SFenghua Yu 2010a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2011a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2012a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2013a71c8bc5SFenghua Yu 2014a71c8bc5SFenghua Yu If unsure, say N. 2015a71c8bc5SFenghua Yu 2016506f1d07SSam Ravnborgconfig COMPAT_VDSO 2017b0b49f26SAndy Lutomirski def_bool n 2018b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2019af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 20208f9ca475SIngo Molnar ---help--- 2021b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2022b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2023b0b49f26SAndy Lutomirski indicated in its segment table. 2024e84446deSRandy Dunlap 2025b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2026b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2027b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2028b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2029b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2030506f1d07SSam Ravnborg 2031b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2032b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2033b0b49f26SAndy Lutomirski 2034b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2035b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2036b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2037b0b49f26SAndy Lutomirski 2038b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2039b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2040506f1d07SSam Ravnborg 20413dc33bd3SKees Cookchoice 20423dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 20433dc33bd3SKees Cook depends on X86_64 20443dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 20453dc33bd3SKees Cook help 20463dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 20473dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 20483dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 20493dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 20503dc33bd3SKees Cook 20513dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 20523dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 20533dc33bd3SKees Cook 20543dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 20553dc33bd3SKees Cook static binaries, you can say None without a performance penalty 20563dc33bd3SKees Cook to improve security. 20573dc33bd3SKees Cook 20583dc33bd3SKees Cook If unsure, select "Emulate". 20593dc33bd3SKees Cook 20603dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 20613dc33bd3SKees Cook bool "Native" 20623dc33bd3SKees Cook help 20633dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 20643dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 20653dc33bd3SKees Cook this makes the mapping executable, it can be used during 20663dc33bd3SKees Cook security vulnerability exploitation (traditionally as 20673dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 20683dc33bd3SKees Cook 20693dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 20703dc33bd3SKees Cook bool "Emulate" 20713dc33bd3SKees Cook help 20723dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 20733dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 20743dc33bd3SKees Cook non-executable, but it still contains known contents, 20753dc33bd3SKees Cook which could be used in certain rare security vulnerability 20763dc33bd3SKees Cook exploits. This configuration is recommended when userspace 20773dc33bd3SKees Cook still uses the vsyscall area. 20783dc33bd3SKees Cook 20793dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 20803dc33bd3SKees Cook bool "None" 20813dc33bd3SKees Cook help 20823dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 20833dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 20843dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 20853dc33bd3SKees Cook will be reported to dmesg, so that either old or 20863dc33bd3SKees Cook malicious userspace programs can be identified. 20873dc33bd3SKees Cook 20883dc33bd3SKees Cookendchoice 20893dc33bd3SKees Cook 2090516cbf37STim Birdconfig CMDLINE_BOOL 2091516cbf37STim Bird bool "Built-in kernel command line" 20928f9ca475SIngo Molnar ---help--- 2093516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2094516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2095516cbf37STim Bird necessary or convenient to provide some or all of the 2096516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2097516cbf37STim Bird to not rely on the boot loader to provide them.) 2098516cbf37STim Bird 2099516cbf37STim Bird To compile command line arguments into the kernel, 2100516cbf37STim Bird set this option to 'Y', then fill in the 210169711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2102516cbf37STim Bird 2103516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2104516cbf37STim Bird should leave this option set to 'N'. 2105516cbf37STim Bird 2106516cbf37STim Birdconfig CMDLINE 2107516cbf37STim Bird string "Built-in kernel command string" 2108516cbf37STim Bird depends on CMDLINE_BOOL 2109516cbf37STim Bird default "" 21108f9ca475SIngo Molnar ---help--- 2111516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2112516cbf37STim Bird image and used at boot time. If the boot loader provides a 2113516cbf37STim Bird command line at boot time, it is appended to this string to 2114516cbf37STim Bird form the full kernel command line, when the system boots. 2115516cbf37STim Bird 2116516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2117516cbf37STim Bird change this behavior. 2118516cbf37STim Bird 2119516cbf37STim Bird In most cases, the command line (whether built-in or provided 2120516cbf37STim Bird by the boot loader) should specify the device for the root 2121516cbf37STim Bird file system. 2122516cbf37STim Bird 2123516cbf37STim Birdconfig CMDLINE_OVERRIDE 2124516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2125516cbf37STim Bird depends on CMDLINE_BOOL 21268f9ca475SIngo Molnar ---help--- 2127516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2128516cbf37STim Bird command line, and use ONLY the built-in command line. 2129516cbf37STim Bird 2130516cbf37STim Bird This is used to work around broken boot loaders. This should 2131516cbf37STim Bird be set to 'N' under normal conditions. 2132516cbf37STim Bird 2133a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2134a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2135a5b9e5a2SAndy Lutomirski default y 2136a5b9e5a2SAndy Lutomirski ---help--- 2137a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2138a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2139a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2140a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2141a5b9e5a2SAndy Lutomirski threading libraries. 2142a5b9e5a2SAndy Lutomirski 2143a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2144a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2145a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2146a5b9e5a2SAndy Lutomirski 2147a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2148a5b9e5a2SAndy Lutomirski 2149b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2150b700e7f0SSeth Jennings 2151506f1d07SSam Ravnborgendmenu 2152506f1d07SSam Ravnborg 2153506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2154506f1d07SSam Ravnborg def_bool y 2155506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2156506f1d07SSam Ravnborg 215735551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 215835551053SGary Hade def_bool y 215935551053SGary Hade depends on MEMORY_HOTPLUG 216035551053SGary Hade 2161e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2162645a7919STejun Heo def_bool y 2163e534c7c5SLee Schermerhorn depends on NUMA 2164e534c7c5SLee Schermerhorn 21659491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 21669491846fSKirill A. Shutemov def_bool y 21679491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 21689491846fSKirill A. Shutemov 2169c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2170c177c81eSNaoya Horiguchi def_bool y 2171c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2172c177c81eSNaoya Horiguchi 2173da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2174e279b6c1SSam Ravnborg 2175e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 21763c2362e6SHarvey Harrison def_bool y 2177e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2178e279b6c1SSam Ravnborg 2179e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2180e279b6c1SSam Ravnborg 2181e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2182e279b6c1SSam Ravnborg 2183efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2184efafc8b2SFeng Tang 2185a6b68076SAndi Kleenconfig X86_APM_BOOT 21866fc108a0SJan Beulich def_bool y 2187282e5aabSPaul Bolle depends on APM 2188a6b68076SAndi Kleen 2189e279b6c1SSam Ravnborgmenuconfig APM 2190e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2191efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2192e279b6c1SSam Ravnborg ---help--- 2193e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2194e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2195e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2196e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2197e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2198e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2199e279b6c1SSam Ravnborg 2200e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2201e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2202e279b6c1SSam Ravnborg 2203e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2204e279b6c1SSam Ravnborg machines with more than one CPU. 2205e279b6c1SSam Ravnborg 2206e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22072dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22082dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2209e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2210e279b6c1SSam Ravnborg 2211e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2212e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2213e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2214e279b6c1SSam Ravnborg 2215e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2216e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2217e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2218e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2219e279b6c1SSam Ravnborg 2220e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2221e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2222e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2223e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2224e279b6c1SSam Ravnborg APM in your BIOS). 2225e279b6c1SSam Ravnborg 2226e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2227e279b6c1SSam Ravnborg "weird" problems: 2228e279b6c1SSam Ravnborg 2229e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2230e279b6c1SSam Ravnborg enabled. 2231e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2232e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2233e279b6c1SSam Ravnborg the "no387" option to the kernel 2234e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2235e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2236e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2237e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2238e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2239e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2240e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2241e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2242e279b6c1SSam Ravnborg 11) exchange RAM chips 2243e279b6c1SSam Ravnborg 12) exchange the motherboard. 2244e279b6c1SSam Ravnborg 2245e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2246e279b6c1SSam Ravnborg module will be called apm. 2247e279b6c1SSam Ravnborg 2248e279b6c1SSam Ravnborgif APM 2249e279b6c1SSam Ravnborg 2250e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2251e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 22528f9ca475SIngo Molnar ---help--- 2253e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2254e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2255e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2256e279b6c1SSam Ravnborg 2257e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2258e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2259e279b6c1SSam Ravnborg ---help--- 2260e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2261e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2262e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2263e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2264e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2265e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2266e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2267e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2268e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2269e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2270e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2271e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2272e279b6c1SSam Ravnborg this feature. 2273e279b6c1SSam Ravnborg 2274e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2275dd8af076SLen Brown depends on CPU_IDLE 2276e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 22778f9ca475SIngo Molnar ---help--- 2278e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2279e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2280e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2281e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2282e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2283e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2284e279b6c1SSam Ravnborg this option does nothing.) 2285e279b6c1SSam Ravnborg 2286e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2287e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 22888f9ca475SIngo Molnar ---help--- 2289e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2290e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2291e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2292e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2293e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2294e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2295e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2296e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2297e279b6c1SSam Ravnborg especially if you are using gpm. 2298e279b6c1SSam Ravnborg 2299e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2300e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 23018f9ca475SIngo Molnar ---help--- 2302e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2303e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2304e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2305e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2306e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2307e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2308e279b6c1SSam Ravnborg 2309e279b6c1SSam Ravnborgendif # APM 2310e279b6c1SSam Ravnborg 2311bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2312e279b6c1SSam Ravnborg 2313e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2314e279b6c1SSam Ravnborg 231527471fdbSAndy Henroidsource "drivers/idle/Kconfig" 231627471fdbSAndy Henroid 2317e279b6c1SSam Ravnborgendmenu 2318e279b6c1SSam Ravnborg 2319e279b6c1SSam Ravnborg 2320e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2321e279b6c1SSam Ravnborg 2322e279b6c1SSam Ravnborgconfig PCI 23231ac97018SIngo Molnar bool "PCI support" 23241c858087SAdrian Bunk default y 23258f9ca475SIngo Molnar ---help--- 2326e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2327e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2328e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2329e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2330e279b6c1SSam Ravnborg 2331e279b6c1SSam Ravnborgchoice 2332e279b6c1SSam Ravnborg prompt "PCI access mode" 2333efefa6f6SIngo Molnar depends on X86_32 && PCI 2334e279b6c1SSam Ravnborg default PCI_GOANY 2335e279b6c1SSam Ravnborg ---help--- 2336e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2337e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2338e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2339e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2340e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2341e279b6c1SSam Ravnborg 2342e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2343e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2344e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2345e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2346e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2347e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2348e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2349e279b6c1SSam Ravnborg 2350e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2351e279b6c1SSam Ravnborg bool "BIOS" 2352e279b6c1SSam Ravnborg 2353e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2354e279b6c1SSam Ravnborg bool "MMConfig" 2355e279b6c1SSam Ravnborg 2356e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2357e279b6c1SSam Ravnborg bool "Direct" 2358e279b6c1SSam Ravnborg 23593ef0e1f8SAndres Salomonconfig PCI_GOOLPC 236076fb6570SDaniel Drake bool "OLPC XO-1" 23613ef0e1f8SAndres Salomon depends on OLPC 23623ef0e1f8SAndres Salomon 23632bdd1b03SAndres Salomonconfig PCI_GOANY 23642bdd1b03SAndres Salomon bool "Any" 23652bdd1b03SAndres Salomon 2366e279b6c1SSam Ravnborgendchoice 2367e279b6c1SSam Ravnborg 2368e279b6c1SSam Ravnborgconfig PCI_BIOS 23693c2362e6SHarvey Harrison def_bool y 2370efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2371e279b6c1SSam Ravnborg 2372e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2373e279b6c1SSam Ravnborgconfig PCI_DIRECT 23743c2362e6SHarvey Harrison def_bool y 23750aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2376e279b6c1SSam Ravnborg 2377e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 23783c2362e6SHarvey Harrison def_bool y 23795f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2380e279b6c1SSam Ravnborg 23813ef0e1f8SAndres Salomonconfig PCI_OLPC 23822bdd1b03SAndres Salomon def_bool y 23832bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 23843ef0e1f8SAndres Salomon 2385b5401a96SAlex Nixonconfig PCI_XEN 2386b5401a96SAlex Nixon def_bool y 2387b5401a96SAlex Nixon depends on PCI && XEN 2388b5401a96SAlex Nixon select SWIOTLB_XEN 2389b5401a96SAlex Nixon 2390e279b6c1SSam Ravnborgconfig PCI_DOMAINS 23913c2362e6SHarvey Harrison def_bool y 2392e279b6c1SSam Ravnborg depends on PCI 2393e279b6c1SSam Ravnborg 2394e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2395e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2396e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2397e279b6c1SSam Ravnborg 23983f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 23996a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 24006ea30386SKees Cook depends on PCI 24013f6ea84aSIra W. Snyder help 24023f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24033f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24043f6ea84aSIra W. Snyder not have ACPI. 24053f6ea84aSIra W. Snyder 240664a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 240764a5fed6SBjorn Helgaas is known to be incomplete. 240864a5fed6SBjorn Helgaas 240964a5fed6SBjorn Helgaas You should say N unless you know you need this. 241064a5fed6SBjorn Helgaas 2411e279b6c1SSam Ravnborgsource "drivers/pci/pcie/Kconfig" 2412e279b6c1SSam Ravnborg 2413e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2414e279b6c1SSam Ravnborg 24151c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2416e279b6c1SSam Ravnborgconfig ISA_DMA_API 24171c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 24181c00f016SDavid Rientjes default y 24191c00f016SDavid Rientjes help 24201c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 24211c00f016SDavid Rientjes If unsure, say Y. 2422e279b6c1SSam Ravnborg 2423e279b6c1SSam Ravnborgif X86_32 2424e279b6c1SSam Ravnborg 2425e279b6c1SSam Ravnborgconfig ISA 2426e279b6c1SSam Ravnborg bool "ISA support" 24278f9ca475SIngo Molnar ---help--- 2428e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2429e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2430e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2431e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2432e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2433e279b6c1SSam Ravnborg 2434e279b6c1SSam Ravnborgconfig EISA 2435e279b6c1SSam Ravnborg bool "EISA support" 2436e279b6c1SSam Ravnborg depends on ISA 2437e279b6c1SSam Ravnborg ---help--- 2438e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2439e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2440e279b6c1SSam Ravnborg 2441e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2442e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2443e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2444e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2445e279b6c1SSam Ravnborg 2446e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2447e279b6c1SSam Ravnborg 2448e279b6c1SSam Ravnborg Otherwise, say N. 2449e279b6c1SSam Ravnborg 2450e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2451e279b6c1SSam Ravnborg 2452e279b6c1SSam Ravnborgconfig SCx200 2453e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 24548f9ca475SIngo Molnar ---help--- 2455e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2456e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2457e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2458e279b6c1SSam Ravnborg for other scx200_* drivers. 2459e279b6c1SSam Ravnborg 2460e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2461e279b6c1SSam Ravnborg 2462e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2463e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2464592913ecSJohn Stultz depends on SCx200 2465e279b6c1SSam Ravnborg default y 24668f9ca475SIngo Molnar ---help--- 2467e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2468e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2469e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2470e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2471e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2472e279b6c1SSam Ravnborg 24733ef0e1f8SAndres Salomonconfig OLPC 24743ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 247554008979SThomas Gleixner depends on !X86_PAE 24763c554946SAndres Salomon select GPIOLIB 2477dc3119e7SThomas Gleixner select OF 247845bb1674SDaniel Drake select OF_PROMTREE 2479b4e51854SGrant Likely select IRQ_DOMAIN 24808f9ca475SIngo Molnar ---help--- 24813ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 24823ef0e1f8SAndres Salomon XO hardware. 24833ef0e1f8SAndres Salomon 2484a3128588SDaniel Drakeconfig OLPC_XO1_PM 2485a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 248697c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2487a3128588SDaniel Drake select MFD_CORE 2488bf1ebf00SDaniel Drake ---help--- 248997c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2490bf1ebf00SDaniel Drake 2491cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2492cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2493cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2494cfee9597SDaniel Drake ---help--- 2495cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2496cfee9597SDaniel Drake programmable wakeup source. 2497cfee9597SDaniel Drake 24987feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 24997feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2500d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2501ed8e47feSRandy Dunlap depends on INPUT=y 2502d8d01a63SDaniel Drake select POWER_SUPPLY 25037feda8e9SDaniel Drake select GPIO_CS5535 25047feda8e9SDaniel Drake select MFD_CORE 25057feda8e9SDaniel Drake ---help--- 25067feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25077bc74b3dSDaniel Drake - EC-driven system wakeups 25087feda8e9SDaniel Drake - Power button 25097bc74b3dSDaniel Drake - Ebook switch 25102cf2baeaSDaniel Drake - Lid switch 2511e1040ac6SDaniel Drake - AC adapter status updates 2512e1040ac6SDaniel Drake - Battery status updates 25137feda8e9SDaniel Drake 2514a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2515a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2516d8d01a63SDaniel Drake depends on OLPC && ACPI 2517d8d01a63SDaniel Drake select POWER_SUPPLY 2518a0f30f59SDaniel Drake ---help--- 2519a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2520a0f30f59SDaniel Drake - EC-driven system wakeups 2521a0f30f59SDaniel Drake - AC adapter status updates 2522a0f30f59SDaniel Drake - Battery status updates 2523e279b6c1SSam Ravnborg 2524d4f3e350SEd Wildgooseconfig ALIX 2525d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2526d4f3e350SEd Wildgoose select GPIOLIB 2527d4f3e350SEd Wildgoose ---help--- 2528d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2529d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2530d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2531d4f3e350SEd Wildgoose get added here. 2532d4f3e350SEd Wildgoose 2533d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2534d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2535d4f3e350SEd Wildgoose 2536d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2537d4f3e350SEd Wildgoose 2538da4e3302SPhilip Prindevilleconfig NET5501 2539da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2540da4e3302SPhilip Prindeville select GPIOLIB 2541da4e3302SPhilip Prindeville ---help--- 2542da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2543da4e3302SPhilip Prindeville 25443197059aSPhilip A. Prindevilleconfig GEOS 25453197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 25463197059aSPhilip A. Prindeville select GPIOLIB 25473197059aSPhilip A. Prindeville depends on DMI 25483197059aSPhilip A. Prindeville ---help--- 25493197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 25503197059aSPhilip A. Prindeville 25517d029125SVivien Didelotconfig TS5500 25527d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 25537d029125SVivien Didelot depends on MELAN 25547d029125SVivien Didelot select CHECK_SIGNATURE 25557d029125SVivien Didelot select NEW_LEDS 25567d029125SVivien Didelot select LEDS_CLASS 25577d029125SVivien Didelot ---help--- 25587d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 25597d029125SVivien Didelot 2560e279b6c1SSam Ravnborgendif # X86_32 2561e279b6c1SSam Ravnborg 256223ac4ae8SAndreas Herrmannconfig AMD_NB 2563e279b6c1SSam Ravnborg def_bool y 25640e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2565e279b6c1SSam Ravnborg 2566e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2567e279b6c1SSam Ravnborg 2568e279b6c1SSam Ravnborgsource "drivers/pci/hotplug/Kconfig" 2569e279b6c1SSam Ravnborg 2570388b78adSAlexandre Bounineconfig RAPIDIO 2571fdf90abcSAlexandre Bounine tristate "RapidIO support" 2572388b78adSAlexandre Bounine depends on PCI 2573388b78adSAlexandre Bounine default n 2574388b78adSAlexandre Bounine help 2575fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2576388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2577388b78adSAlexandre Bounine 2578388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2579388b78adSAlexandre Bounine 2580e3263ab3SDavid Herrmannconfig X86_SYSFB 2581e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2582e3263ab3SDavid Herrmann help 2583e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2584e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2585e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2586e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2587e3263ab3SDavid Herrmann to x86. 2588e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2589e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2590e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2591e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2592e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2593e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2594e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2595e3263ab3SDavid Herrmann 2596e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2597e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2598e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2599e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2600e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2601e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2602e3263ab3SDavid Herrmann incompatible with simplefb. 2603e3263ab3SDavid Herrmann 2604e3263ab3SDavid Herrmann If unsure, say Y. 2605e3263ab3SDavid Herrmann 2606e279b6c1SSam Ravnborgendmenu 2607e279b6c1SSam Ravnborg 2608e279b6c1SSam Ravnborg 2609e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2610e279b6c1SSam Ravnborg 2611e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2612e279b6c1SSam Ravnborg 2613e279b6c1SSam Ravnborgconfig IA32_EMULATION 2614e279b6c1SSam Ravnborg bool "IA32 Emulation" 2615e279b6c1SSam Ravnborg depends on X86_64 2616d1603990SRandy Dunlap select BINFMT_ELF 2617a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 26183bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 26198f9ca475SIngo Molnar ---help--- 26205fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 26215fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 26225fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2623e279b6c1SSam Ravnborg 2624e279b6c1SSam Ravnborgconfig IA32_AOUT 2625e279b6c1SSam Ravnborg tristate "IA32 a.out support" 26266b213e1bSDavid Woodhouse depends on IA32_EMULATION 26278f9ca475SIngo Molnar ---help--- 2628e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2629e279b6c1SSam Ravnborg 26300bf62763SH. Peter Anvinconfig X86_X32 26316ea30386SKees Cook bool "x32 ABI for 64-bit mode" 26329b54050bSBrian Gerst depends on X86_64 26335fd92e65SH. J. Lu ---help--- 26345fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 26355fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 26365fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 26375fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 26385fd92e65SH. J. Lu 26395fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 26405fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 26415fd92e65SH. J. Lu option set. 26425fd92e65SH. J. Lu 2643e279b6c1SSam Ravnborgconfig COMPAT 26443c2362e6SHarvey Harrison def_bool y 26450bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2646e279b6c1SSam Ravnborg 26473120e25eSJan Beulichif COMPAT 2648e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 26493120e25eSJan Beulich def_bool y 2650e279b6c1SSam Ravnborg 2651e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 26523c2362e6SHarvey Harrison def_bool y 26533120e25eSJan Beulich depends on SYSVIPC 2654e279b6c1SSam Ravnborg 2655ee009e4aSDavid Howellsconfig KEYS_COMPAT 26563120e25eSJan Beulich def_bool y 26573120e25eSJan Beulich depends on KEYS 26583120e25eSJan Beulichendif 2659ee009e4aSDavid Howells 2660e279b6c1SSam Ravnborgendmenu 2661e279b6c1SSam Ravnborg 2662e279b6c1SSam Ravnborg 2663e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2664e5beae16SKeith Packard def_bool y 2665e5beae16SKeith Packard depends on X86_32 2666e5beae16SKeith Packard 26674692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 26684692d77fSAlessandro Rubini bool 266983125a3aSAlessandro Rubini depends on X86_64 || STA2X11 26704692d77fSAlessandro Rubini 2671f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2672f7219a53SAlessandro Rubini bool 267383125a3aSAlessandro Rubini depends on STA2X11 2674f7219a53SAlessandro Rubini 267593e5eaddSLi, Aubreyconfig PMC_ATOM 267693e5eaddSLi, Aubrey def_bool y 267793e5eaddSLi, Aubrey depends on PCI 267893e5eaddSLi, Aubrey 2679e279b6c1SSam Ravnborgsource "net/Kconfig" 2680e279b6c1SSam Ravnborg 2681e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2682e279b6c1SSam Ravnborg 2683e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2684e279b6c1SSam Ravnborg 2685e279b6c1SSam Ravnborgsource "fs/Kconfig" 2686e279b6c1SSam Ravnborg 2687e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2688e279b6c1SSam Ravnborg 2689e279b6c1SSam Ravnborgsource "security/Kconfig" 2690e279b6c1SSam Ravnborg 2691e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2692e279b6c1SSam Ravnborg 2693edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2694edf88417SAvi Kivity 2695e279b6c1SSam Ravnborgsource "lib/Kconfig" 2696