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 3061031952SRoss Zwisler select ARCH_HAS_PMEM_API 316471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 326471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 336471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3477fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 355e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 366471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 373b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 38be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 396471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 406471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 416471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 426471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 436471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 445aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 45da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 466471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 476471b825SIngo Molnar select ARCH_WANT_OPTIONAL_GPIOLIB 486471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 496471b825SIngo Molnar select CLKEVT_I8253 506471b825SIngo Molnar select CLKSRC_I8253 if X86_32 516471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 526471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 536471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 546471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 556471b825SIngo Molnar select DCACHE_WORD_ACCESS 5645471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 5745471cd9SLinus Torvalds select EDAC_SUPPORT 586471b825SIngo Molnar select GENERIC_CLOCKEVENTS 596471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 606471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 616471b825SIngo Molnar select GENERIC_CMOS_UPDATE 626471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 636471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 646471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 656471b825SIngo Molnar select GENERIC_IOMAP 666471b825SIngo Molnar select GENERIC_IRQ_PROBE 676471b825SIngo Molnar select GENERIC_IRQ_SHOW 686471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 696471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 706471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 716471b825SIngo Molnar select GENERIC_STRNLEN_USER 726471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 736471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 746471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 756471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 766471b825SIngo Molnar select HAVE_AOUT if X86_32 776471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 786471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 796471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 806471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 816471b825SIngo Molnar select HAVE_ARCH_KGDB 826471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 836471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 846471b825SIngo Molnar select HAVE_ARCH_SOFT_DIRTY if X86_64 856471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 866471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 876471b825SIngo Molnar select HAVE_BPF_JIT if X86_64 886471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 896471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 906471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 916471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 92c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 936471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 946471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 956471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 966471b825SIngo Molnar select HAVE_DMA_API_DEBUG 977c095e46SFUJITA Tomonori select HAVE_DMA_ATTRS 989c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 99677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10006aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10158340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1026471b825SIngo Molnar select HAVE_FENTRY if X86_64 1036471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1046471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_FP_TEST 1056471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1066471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1076471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1080067f129SK.Prasad select HAVE_HW_BREAKPOINT 1096471b825SIngo Molnar select HAVE_IDE 1106471b825SIngo Molnar select HAVE_IOREMAP_PROT 1116471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1126471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1136471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1146471b825SIngo Molnar select HAVE_KERNEL_GZIP 1156471b825SIngo Molnar select HAVE_KERNEL_LZ4 1166471b825SIngo Molnar select HAVE_KERNEL_LZMA 1176471b825SIngo Molnar select HAVE_KERNEL_LZO 1186471b825SIngo Molnar select HAVE_KERNEL_XZ 1196471b825SIngo Molnar select HAVE_KPROBES 1206471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1216471b825SIngo Molnar select HAVE_KRETPROBES 1226471b825SIngo Molnar select HAVE_KVM 1236471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1246471b825SIngo Molnar select HAVE_MEMBLOCK 1256471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1260102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 1276471b825SIngo Molnar select HAVE_OPROFILE 1286471b825SIngo Molnar select HAVE_OPTPROBES 1296471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1306471b825SIngo Molnar select HAVE_PERF_EVENTS 131c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 132c5e63197SJiri Olsa select HAVE_PERF_REGS 133c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1346471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1356471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1360c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1376471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1387c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 139c0185808SThomas Gleixner select IRQ_FORCED_THREADING 140786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1416471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1425b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1436471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1446471b825SIngo Molnar select PERF_EVENTS 1453195ef59SPrarit Bhargava select RTC_LIB 1466471b825SIngo Molnar select SPARSE_IRQ 14783fe27eaSPranith Kumar select SRCU 1486471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 1496471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1506471b825SIngo Molnar select VIRT_TO_BUS 1516471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1526471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 1537d8330a5SBalbir Singh 154ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1553120e25eSJan Beulich def_bool y 1563120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 157ba7e4d13SIngo Molnar 1587fb0f1deSPeter Zijlstraconfig PERF_EVENTS_INTEL_UNCORE 1597fb0f1deSPeter Zijlstra def_bool y 160ce5686d4SPeter Zijlstra (Intel) depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 1617fb0f1deSPeter Zijlstra 16251b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 16351b26adaSLinus Torvalds string 16451b26adaSLinus Torvalds default "elf32-i386" if X86_32 16551b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 16651b26adaSLinus Torvalds 16773531905SSam Ravnborgconfig ARCH_DEFCONFIG 168b9b39bfbSSam Ravnborg string 16973531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 17073531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 171b9b39bfbSSam Ravnborg 1728d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1733c2362e6SHarvey Harrison def_bool y 1748d5fffb9SSam Ravnborg 1758d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1763c2362e6SHarvey Harrison def_bool y 1778d5fffb9SSam Ravnborg 178aa7d9350SHeiko Carstensconfig HAVE_LATENCYTOP_SUPPORT 179aa7d9350SHeiko Carstens def_bool y 180aa7d9350SHeiko Carstens 1818d5fffb9SSam Ravnborgconfig MMU 1823c2362e6SHarvey Harrison def_bool y 1838d5fffb9SSam Ravnborg 1848d5fffb9SSam Ravnborgconfig SBUS 1858d5fffb9SSam Ravnborg bool 1868d5fffb9SSam Ravnborg 1873bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 1883120e25eSJan Beulich def_bool y 189a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 1903bc4e459SFUJITA Tomonori 19118e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 1924a14d84eSAndrew Morton def_bool y 19318e98307SFUJITA Tomonori 1948d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 1953120e25eSJan Beulich def_bool y 1963120e25eSJan Beulich depends on ISA_DMA_API 1978d5fffb9SSam Ravnborg 1988d5fffb9SSam Ravnborgconfig GENERIC_BUG 1993c2362e6SHarvey Harrison def_bool y 2008d5fffb9SSam Ravnborg depends on BUG 201b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 202b93a531eSJan Beulich 203b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 204b93a531eSJan Beulich bool 2058d5fffb9SSam Ravnborg 2068d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2073c2362e6SHarvey Harrison def_bool y 2088d5fffb9SSam Ravnborg 2098d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2103120e25eSJan Beulich def_bool y 2113120e25eSJan Beulich depends on ISA_DMA_API 2128d5fffb9SSam Ravnborg 2131032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2143120e25eSJan Beulich def_bool y 2151032c0baSSam Ravnborg 2161032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2171032c0baSSam Ravnborg def_bool y 2181032c0baSSam Ravnborg 2199a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2209a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2218d5fffb9SSam Ravnborg 2221b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2231b27d05bSPekka Enberg def_bool y 2241b27d05bSPekka Enberg 225dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 22689c9c4c5SBrian Gerst def_bool y 227b32ef636Stravis@sgi.com 22808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 22908fc4580STejun Heo def_bool y 23008fc4580STejun Heo 23108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 23211124411STejun Heo def_bool y 23311124411STejun Heo 234801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 235801e4062SJohannes Berg def_bool y 236801e4062SJohannes Berg 237f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 238f4cb5700SJohannes Berg def_bool y 239f4cb5700SJohannes Berg 240cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 241cfe28c5dSSteve Capper def_bool y 242cfe28c5dSSteve Capper 24353313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 24453313b2cSSteve Capper def_bool y 24553313b2cSSteve Capper 2468d5fffb9SSam Ravnborgconfig ZONE_DMA32 247e0fd24a3SJan Beulich def_bool y if X86_64 2488d5fffb9SSam Ravnborg 2498d5fffb9SSam Ravnborgconfig AUDIT_ARCH 250e0fd24a3SJan Beulich def_bool y if X86_64 2518d5fffb9SSam Ravnborg 252765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 253765c68bdSIngo Molnar def_bool y 254765c68bdSIngo Molnar 2556a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2566a11f75bSAkinobu Mita def_bool y 2576a11f75bSAkinobu Mita 258d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 259d6f2d75aSAndrey Ryabinin hex 260d6f2d75aSAndrey Ryabinin depends on KASAN 261d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 262d6f2d75aSAndrey Ryabinin 26369575d38SShane Wangconfig HAVE_INTEL_TXT 26469575d38SShane Wang def_bool y 2656ea30386SKees Cook depends on INTEL_IOMMU && ACPI 26669575d38SShane Wang 2676b0c3d44SSam Ravnborgconfig X86_32_SMP 2686b0c3d44SSam Ravnborg def_bool y 2696b0c3d44SSam Ravnborg depends on X86_32 && SMP 2706b0c3d44SSam Ravnborg 2716b0c3d44SSam Ravnborgconfig X86_64_SMP 2726b0c3d44SSam Ravnborg def_bool y 2736b0c3d44SSam Ravnborg depends on X86_64 && SMP 2746b0c3d44SSam Ravnborg 275ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 276ccbeed3aSTejun Heo def_bool y 27760a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 278ccbeed3aSTejun Heo 279d61931d8SBorislav Petkovconfig ARCH_HWEIGHT_CFLAGS 280d61931d8SBorislav Petkov string 281d61931d8SBorislav Petkov default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 282d61931d8SBorislav 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 283d61931d8SBorislav Petkov 2842b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 2852b144498SSrikar Dronamraju def_bool y 2862b144498SSrikar Dronamraju 287d20642f0SRob Herringconfig FIX_EARLYCON_MEM 288d20642f0SRob Herring def_bool y 289d20642f0SRob Herring 29098233368SKirill A. Shutemovconfig PGTABLE_LEVELS 29198233368SKirill A. Shutemov int 29298233368SKirill A. Shutemov default 4 if X86_64 29398233368SKirill A. Shutemov default 3 if X86_PAE 29498233368SKirill A. Shutemov default 2 29598233368SKirill A. Shutemov 296506f1d07SSam Ravnborgsource "init/Kconfig" 297dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 2988d5fffb9SSam Ravnborg 299506f1d07SSam Ravnborgmenu "Processor type and features" 300506f1d07SSam Ravnborg 3015ee71535SRandy Dunlapconfig ZONE_DMA 3025ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3035ee71535SRandy Dunlap default y 3045ee71535SRandy Dunlap help 3055ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3065ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3075ee71535SRandy Dunlap Disable if no such devices will be used. 3085ee71535SRandy Dunlap 3095ee71535SRandy Dunlap If unsure, say Y. 3105ee71535SRandy Dunlap 311506f1d07SSam Ravnborgconfig SMP 312506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 313506f1d07SSam Ravnborg ---help--- 314506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3154a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3164a474157SRobert Graffham than one CPU, say Y. 317506f1d07SSam Ravnborg 3184a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 319506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 320506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3214a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 322506f1d07SSam Ravnborg will run faster if you say N here. 323506f1d07SSam Ravnborg 324506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 325506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 326506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 327506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 328506f1d07SSam Ravnborg 329506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 330506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 331506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 332506f1d07SSam Ravnborg 333395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 334506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 335506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 336506f1d07SSam Ravnborg 337506f1d07SSam Ravnborg If you don't know what to do here, say N. 338506f1d07SSam Ravnborg 3399def39beSJosh Triplettconfig X86_FEATURE_NAMES 3409def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3419def39beSJosh Triplett default y 3429def39beSJosh Triplett ---help--- 3439def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3449def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3459def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3469def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3479def39beSJosh Triplett 3489def39beSJosh Triplett If in doubt, say Y. 3499def39beSJosh Triplett 35006cd9a7dSYinghai Luconfig X86_X2APIC 35106cd9a7dSYinghai Lu bool "Support x2apic" 35219e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 35306cd9a7dSYinghai Lu ---help--- 35406cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 35506cd9a7dSYinghai Lu 35606cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 35706cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 35806cd9a7dSYinghai Lu 35906cd9a7dSYinghai Lu If you don't know what to do here, say N. 36006cd9a7dSYinghai Lu 3616695c85bSYinghai Luconfig X86_MPPARSE 3626e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3637a527688SJan Beulich default y 3645ab74722SIngo Molnar depends on X86_LOCAL_APIC 3658f9ca475SIngo Molnar ---help--- 3666695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 3676695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 3686695c85bSYinghai Lu 36926f7ef14SYinghai Luconfig X86_BIGSMP 37026f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 37126f7ef14SYinghai Lu depends on X86_32 && SMP 3728f9ca475SIngo Molnar ---help--- 37326f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 374506f1d07SSam Ravnborg 375ddd70cf9SJun Nakajimaconfig GOLDFISH 376ddd70cf9SJun Nakajima def_bool y 377ddd70cf9SJun Nakajima depends on X86_GOLDFISH 378ddd70cf9SJun Nakajima 3798425091fSRavikiran G Thirumalaiif X86_32 380c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 381c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 382c5c606d9SRavikiran G Thirumalai default y 3838f9ca475SIngo Molnar ---help--- 38406ac8346SIngo Molnar If you disable this option then the kernel will only support 38506ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 38606ac8346SIngo Molnar systems out there.) 38706ac8346SIngo Molnar 3888425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 3898425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 390cb7b8023SBen Hutchings Goldfish (Android emulator) 3918425091fSRavikiran G Thirumalai AMD Elan 3928425091fSRavikiran G Thirumalai RDC R-321x SoC 3938425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 39483125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 3953f4110a4SThomas Gleixner Moorestown MID devices 39606ac8346SIngo Molnar 39706ac8346SIngo Molnar If you have one of these systems, or if you want to build a 39806ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 3998425091fSRavikiran G Thirumalaiendif 40006ac8346SIngo Molnar 4018425091fSRavikiran G Thirumalaiif X86_64 4028425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4038425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4048425091fSRavikiran G Thirumalai default y 4058425091fSRavikiran G Thirumalai ---help--- 4068425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4078425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4088425091fSRavikiran G Thirumalai systems out there.) 4098425091fSRavikiran G Thirumalai 4108425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4118425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 41244b111b5SSteffen Persvold Numascale NumaChip 4138425091fSRavikiran G Thirumalai ScaleMP vSMP 4148425091fSRavikiran G Thirumalai SGI Ultraviolet 4158425091fSRavikiran G Thirumalai 4168425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4178425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4188425091fSRavikiran G Thirumalaiendif 419c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 420c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 42144b111b5SSteffen Persvoldconfig X86_NUMACHIP 42244b111b5SSteffen Persvold bool "Numascale NumaChip" 42344b111b5SSteffen Persvold depends on X86_64 42444b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 42544b111b5SSteffen Persvold depends on NUMA 42644b111b5SSteffen Persvold depends on SMP 42744b111b5SSteffen Persvold depends on X86_X2APIC 428f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 42944b111b5SSteffen Persvold ---help--- 43044b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 43144b111b5SSteffen Persvold enable more than ~168 cores. 43244b111b5SSteffen Persvold If you don't have one of these, you should say N here. 43303b48632SNick Piggin 4346a48565eSIngo Molnarconfig X86_VSMP 435c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4366276a074SBorislav Petkov select HYPERVISOR_GUEST 4376a48565eSIngo Molnar select PARAVIRT 4386a48565eSIngo Molnar depends on X86_64 && PCI 439c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 440ead91d4bSShai Fultheim depends on SMP 4418f9ca475SIngo Molnar ---help--- 4426a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4436a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4446a48565eSIngo Molnar if you have one of these machines. 4456a48565eSIngo Molnar 446c5c606d9SRavikiran G Thirumalaiconfig X86_UV 447c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 448c5c606d9SRavikiran G Thirumalai depends on X86_64 449c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 45054c28d29SJack Steiner depends on NUMA 4519d6c26e7SSuresh Siddha depends on X86_X2APIC 4521222e564SIngo Molnar depends on PCI 453c5c606d9SRavikiran G Thirumalai ---help--- 454c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 455c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 456c5c606d9SRavikiran G Thirumalai 457c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 458c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 459506f1d07SSam Ravnborg 460ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 461ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 462cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 463ddd70cf9SJun Nakajima ---help--- 464ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 465ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 466ddd70cf9SJun Nakajima Goldfish emulator say N here. 467ddd70cf9SJun Nakajima 468c751e17bSThomas Gleixnerconfig X86_INTEL_CE 469c751e17bSThomas Gleixner bool "CE4100 TV platform" 470c751e17bSThomas Gleixner depends on PCI 471c751e17bSThomas Gleixner depends on PCI_GODIRECT 4726084a6e2SJiang Liu depends on X86_IO_APIC 473c751e17bSThomas Gleixner depends on X86_32 474c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 47537bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 476da6b737bSSebastian Andrzej Siewior select OF 477da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 478c751e17bSThomas Gleixner ---help--- 479c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 480c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 481c751e17bSThomas Gleixner boxes and media devices. 482c751e17bSThomas Gleixner 4834cb9b00fSDavid Cohenconfig X86_INTEL_MID 48443605ef1SAlan Cox bool "Intel MID platform support" 48543605ef1SAlan Cox depends on X86_32 48643605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 487edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 4881ea7c673SAlan Cox depends on PCI 4891ea7c673SAlan Cox depends on PCI_GOANY 4901ea7c673SAlan Cox depends on X86_IO_APIC 4917c9c3a1eSAlan Cox select SFI 4924cb9b00fSDavid Cohen select I2C 4937c9c3a1eSAlan Cox select DW_APB_TIMER 4941ea7c673SAlan Cox select APB_TIMER 4951ea7c673SAlan Cox select INTEL_SCU_IPC 49615a713dfSMika Westerberg select MFD_INTEL_MSIC 4971ea7c673SAlan Cox ---help--- 4984cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 4994cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5004cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5011ea7c673SAlan Cox 5024cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5034cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 50443605ef1SAlan Cox 5058bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5068bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5078bbc2a13SBryan O'Donoghue depends on X86_32 5088bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5098bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5108bbc2a13SBryan O'Donoghue depends on X86_TSC 5118bbc2a13SBryan O'Donoghue depends on PCI 5128bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5138bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5148bbc2a13SBryan O'Donoghue select IOSF_MBI 5158bbc2a13SBryan O'Donoghue select INTEL_IMR 5169ab6eb51SAndy Shevchenko select COMMON_CLK 5178bbc2a13SBryan O'Donoghue ---help--- 5188bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5198bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5208bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5218bbc2a13SBryan O'Donoghue 5223d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5233d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 5243d48aab1SMika Westerberg depends on ACPI 5253d48aab1SMika Westerberg select COMMON_CLK 5260f531431SMathias Nyman select PINCTRL 5273d48aab1SMika Westerberg ---help--- 5283d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5293d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5300f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5310f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5323d48aab1SMika Westerberg 53392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 53492082a88SKen Xue bool "AMD ACPI2Platform devices support" 53592082a88SKen Xue depends on ACPI 53692082a88SKen Xue select COMMON_CLK 53792082a88SKen Xue select PINCTRL 53892082a88SKen Xue ---help--- 53992082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 54092082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 54192082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 54292082a88SKen Xue implemented under PINCTRL subsystem. 54392082a88SKen Xue 544ced3ce76SDavid E. Boxconfig IOSF_MBI 545ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 546ced3ce76SDavid E. Box depends on PCI 547ced3ce76SDavid E. Box ---help--- 548ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 549ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 550ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 551ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 552ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 553ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 554ced3ce76SDavid E. Box This list is not meant to be exclusive. 555ced3ce76SDavid E. Box - BayTrail 556ced3ce76SDavid E. Box - Braswell 557ced3ce76SDavid E. Box - Quark 558ced3ce76SDavid E. Box 559ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 560ced3ce76SDavid E. Box 561ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 562ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 563ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 564ed2226bdSDavid E. Box ---help--- 565ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 566ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 567ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 568ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 569ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 570ed2226bdSDavid E. Box device they want to access. 571ed2226bdSDavid E. Box 572ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 573ed2226bdSDavid E. Box 574c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 575c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 576506f1d07SSam Ravnborg depends on X86_32 577c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 578c5c606d9SRavikiran G Thirumalai select M486 579c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 580c5c606d9SRavikiran G Thirumalai ---help--- 581c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 582c5c606d9SRavikiran G Thirumalai as R-8610-(G). 583c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 584c5c606d9SRavikiran G Thirumalai 585e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 5869c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 5879c398017SIngo Molnar depends on X86_32 && SMP 588c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 5898f9ca475SIngo Molnar ---help--- 590b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 591b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 592b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 593b5660ba7SH. Peter Anvin one and will fallback to default. 594d49c4288SYinghai Lu 595c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 596d49c4288SYinghai Lu 597d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 5986fc108a0SJan Beulich def_bool y 599d949f36fSLinus Torvalds # MCE code calls memory_failure(): 600d949f36fSLinus Torvalds depends on X86_MCE 601d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 602d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 603d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 604d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 605d949f36fSLinus Torvalds 60683125a3aSAlessandro Rubiniconfig STA2X11 60783125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 60883125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 60983125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 61083125a3aSAlessandro Rubini select X86_DMA_REMAP 61183125a3aSAlessandro Rubini select SWIOTLB 61283125a3aSAlessandro Rubini select MFD_STA2X11 61383125a3aSAlessandro Rubini select ARCH_REQUIRE_GPIOLIB 61483125a3aSAlessandro Rubini default n 61583125a3aSAlessandro Rubini ---help--- 61683125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 61783125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 61883125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 61983125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 62083125a3aSAlessandro Rubini standard PC machines. 62183125a3aSAlessandro Rubini 62282148d1dSShérabconfig X86_32_IRIS 62382148d1dSShérab tristate "Eurobraille/Iris poweroff module" 62482148d1dSShérab depends on X86_32 62582148d1dSShérab ---help--- 62682148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 62782148d1dSShérab to shut themselves down properly. A special I/O sequence is 62882148d1dSShérab needed to do so, which is what this module does at 62982148d1dSShérab kernel shutdown. 63082148d1dSShérab 63182148d1dSShérab This is only for Iris machines from EuroBraille. 63282148d1dSShérab 63382148d1dSShérab If unused, say N. 63482148d1dSShérab 635ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6363c2362e6SHarvey Harrison def_bool y 6373c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 638a87d0914SKen Chen depends on X86 6398f9ca475SIngo Molnar ---help--- 640506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 641506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 642506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 643506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 644506f1d07SSam Ravnborg 645506f1d07SSam Ravnborg If in doubt, say "Y". 646506f1d07SSam Ravnborg 6476276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6486276a074SBorislav Petkov bool "Linux guest support" 6498f9ca475SIngo Molnar ---help--- 6506276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6516276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6526276a074SBorislav Petkov setup. 653506f1d07SSam Ravnborg 6546276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6556276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 656506f1d07SSam Ravnborg 6576276a074SBorislav Petkovif HYPERVISOR_GUEST 658506f1d07SSam Ravnborg 659e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 660e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 6618f9ca475SIngo Molnar ---help--- 662e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 663e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 664e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 665e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 666e61bd94aSEduardo Pereira Habkost 6676276a074SBorislav Petkovconfig PARAVIRT_DEBUG 6686276a074SBorislav Petkov bool "paravirt-ops debugging" 6696276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 6706276a074SBorislav Petkov ---help--- 6716276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 6726276a074SBorislav Petkov a paravirt_op is missing when it is called. 6736276a074SBorislav Petkov 674b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 675b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 6766ea30386SKees Cook depends on PARAVIRT && SMP 67762c7a1e9SIngo Molnar select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 678b4ecc126SJeremy Fitzhardinge ---help--- 679b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 680b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 681b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 682b4ecc126SJeremy Fitzhardinge 6834c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 6844c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 685b4ecc126SJeremy Fitzhardinge 6864c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 687b4ecc126SJeremy Fitzhardinge 6886276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 6896276a074SBorislav Petkov 6906276a074SBorislav Petkovconfig KVM_GUEST 6916276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 6926276a074SBorislav Petkov depends on PARAVIRT 6936276a074SBorislav Petkov select PARAVIRT_CLOCK 6946276a074SBorislav Petkov default y 6956276a074SBorislav Petkov ---help--- 6966276a074SBorislav Petkov This option enables various optimizations for running under the KVM 6976276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 6986276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 6996276a074SBorislav Petkov underlying device model, the host provides the guest with 7006276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7016276a074SBorislav Petkov 7021e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7031e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7041e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7051e20eb85SSrivatsa Vaddagiri default n 7061e20eb85SSrivatsa Vaddagiri ---help--- 7071e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7081e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7091e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7101e20eb85SSrivatsa Vaddagiri 7116276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7126276a074SBorislav Petkov 7136276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7146276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7156276a074SBorislav Petkov depends on PARAVIRT 7166276a074SBorislav Petkov default n 7176276a074SBorislav Petkov ---help--- 7186276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7196276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7206276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7216276a074SBorislav Petkov that, there can be a small performance impact. 7226276a074SBorislav Petkov 7236276a074SBorislav Petkov If in doubt, say N here. 7246276a074SBorislav Petkov 7257af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7267af192c9SGerd Hoffmann bool 7277af192c9SGerd Hoffmann 7286276a074SBorislav Petkovendif #HYPERVISOR_GUEST 72997349135SJeremy Fitzhardinge 73008677214SYinghai Luconfig NO_BOOTMEM 731774ea0bcSYinghai Lu def_bool y 73208677214SYinghai Lu 733506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 734506f1d07SSam Ravnborg 735506f1d07SSam Ravnborgconfig HPET_TIMER 7363c2362e6SHarvey Harrison def_bool X86_64 737506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7388f9ca475SIngo Molnar ---help--- 739506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 740506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 741506f1d07SSam Ravnborg present. 742506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 743506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 744506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 745506f1d07SSam Ravnborg as it is off-chip. You can find the HPET spec at 746e45f2c07SDenis V. Lunev <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 747506f1d07SSam Ravnborg 748506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 749506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 750506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 751506f1d07SSam Ravnborg 752506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 753506f1d07SSam Ravnborg 754506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 7553c2362e6SHarvey Harrison def_bool y 7569d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 757506f1d07SSam Ravnborg 758bb24c471SJacob Panconfig APB_TIMER 759933b9463SAlan Cox def_bool y if X86_INTEL_MID 760933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 76106c3df49SJamie Iles select DW_APB_TIMER 762a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 763bb24c471SJacob Pan help 764bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 765bb24c471SJacob Pan The APBT provides a stable time base on SMP 766bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 767bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 768bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 769bb24c471SJacob Pan 7706a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 771506f1d07SSam Ravnborg# The code disables itself when not needed. 7727ae9392cSThomas Petazzoniconfig DMI 7737ae9392cSThomas Petazzoni default y 774cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 7756a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 7768f9ca475SIngo Molnar ---help--- 7777ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 7787ae9392cSThomas Petazzoni here unless you have verified that your setup is not 7797ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 7807ae9392cSThomas Petazzoni BIOS code. 7817ae9392cSThomas Petazzoni 782506f1d07SSam Ravnborgconfig GART_IOMMU 78338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 784506f1d07SSam Ravnborg select SWIOTLB 78523ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 7868f9ca475SIngo Molnar ---help--- 787ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 788ced3c42cSIngo Molnar GART based hardware IOMMUs. 789ced3c42cSIngo Molnar 790ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 791ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 792ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 793ced3c42cSIngo Molnar 794ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 795ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 796ced3c42cSIngo Molnar 797ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 798ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 799ced3c42cSIngo Molnar 32-bit limited device. 800ced3c42cSIngo Molnar 801ced3c42cSIngo Molnar If unsure, say Y. 802506f1d07SSam Ravnborg 803506f1d07SSam Ravnborgconfig CALGARY_IOMMU 804506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 805506f1d07SSam Ravnborg select SWIOTLB 8066ea30386SKees Cook depends on X86_64 && PCI 8078f9ca475SIngo Molnar ---help--- 808506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 809506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 810506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 811506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 812506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 813506f1d07SSam Ravnborg prevents them from going anywhere except their intended 814506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 815506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 816506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 817506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 818506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 819506f1d07SSam Ravnborg If unsure, say Y. 820506f1d07SSam Ravnborg 821506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8223c2362e6SHarvey Harrison def_bool y 8233c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 824506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8258f9ca475SIngo Molnar ---help--- 826506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 827506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 828506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 829506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 830506f1d07SSam Ravnborg If unsure, say Y. 831506f1d07SSam Ravnborg 832506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 833506f1d07SSam Ravnborgconfig SWIOTLB 834a1afd01cSJoerg Roedel def_bool y if X86_64 8358f9ca475SIngo Molnar ---help--- 836506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8374454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8384454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8394454d327SJoe Millenbach with more than 3 GB of memory. 8404454d327SJoe Millenbach If unsure, say Y. 841506f1d07SSam Ravnborg 842a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8433120e25eSJan Beulich def_bool y 8443120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 845d25e26b6SLinus Torvalds 8461184dc2fSMike Travisconfig MAXSMP 847ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8486ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 84936f5101aSMike Travis select CPUMASK_OFFSTACK 8508f9ca475SIngo Molnar ---help--- 851ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 8521184dc2fSMike Travis If unsure, say N. 853506f1d07SSam Ravnborg 854506f1d07SSam Ravnborgconfig NR_CPUS 85536f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 8562a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 857bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 858b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 85978637a97SMike Travis default "1" if !SMP 860b53b5edaSJosh Boyer default "8192" if MAXSMP 861b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 862c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 863c5c19941SKirill A. Shutemov default "64" if SMP 8648f9ca475SIngo Molnar ---help--- 865506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 866bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 867cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 868506f1d07SSam Ravnborg minimum value which makes sense is 2. 869506f1d07SSam Ravnborg 870506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 871506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 872506f1d07SSam Ravnborg 873506f1d07SSam Ravnborgconfig SCHED_SMT 874506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 875c8e56d20SBorislav Petkov depends on SMP 8768f9ca475SIngo Molnar ---help--- 877506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 878506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 879506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 880506f1d07SSam Ravnborg N here. 881506f1d07SSam Ravnborg 882506f1d07SSam Ravnborgconfig SCHED_MC 8833c2362e6SHarvey Harrison def_bool y 8843c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 885c8e56d20SBorislav Petkov depends on SMP 8868f9ca475SIngo Molnar ---help--- 887506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 888506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 889506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 890506f1d07SSam Ravnborg 891506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 892506f1d07SSam Ravnborg 89330b8b006SThomas Gleixnerconfig UP_LATE_INIT 89430b8b006SThomas Gleixner def_bool y 895ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 89630b8b006SThomas Gleixner 897506f1d07SSam Ravnborgconfig X86_UP_APIC 89850849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 89950849eefSJan Beulich default PCI_MSI 90038a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9018f9ca475SIngo Molnar ---help--- 902506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 903506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 904506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 905506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 906506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 907506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 908506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 909506f1d07SSam Ravnborg lockups. 910506f1d07SSam Ravnborg 911506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 912506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 913506f1d07SSam Ravnborg depends on X86_UP_APIC 9148f9ca475SIngo Molnar ---help--- 915506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 916506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 917506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 918506f1d07SSam Ravnborg 919506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 920506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 921506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 922506f1d07SSam Ravnborg 923506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9243c2362e6SHarvey Harrison def_bool y 9250dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 926b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 92752f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 928506f1d07SSam Ravnborg 929506f1d07SSam Ravnborgconfig X86_IO_APIC 930b1da1e71SJan Beulich def_bool y 931b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 932506f1d07SSam Ravnborg 93341b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 93441b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 93541b9eb26SStefan Assmann depends on X86_IO_APIC 9368f9ca475SIngo Molnar ---help--- 93741b9eb26SStefan Assmann This option enables a workaround that fixes a source of 93841b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 93941b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 94041b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 94141b9eb26SStefan Assmann 94241b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 94341b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 94441b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 94541b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 94641b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 94741b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 94841b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 94941b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 95041b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 95141b9eb26SStefan Assmann down (vital) interrupt lines. 95241b9eb26SStefan Assmann 95341b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 95441b9eb26SStefan Assmann increased on these systems. 95541b9eb26SStefan Assmann 956506f1d07SSam Ravnborgconfig X86_MCE 957bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 958648ed940SChen, Gong select GENERIC_ALLOCATOR 959e57dbaf7SBorislav Petkov default y 960506f1d07SSam Ravnborg ---help--- 961bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 962bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 963506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 964bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 9654efc0670SAndi Kleen 966506f1d07SSam Ravnborgconfig X86_MCE_INTEL 9673c2362e6SHarvey Harrison def_bool y 9683c2362e6SHarvey Harrison prompt "Intel MCE features" 969c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9708f9ca475SIngo Molnar ---help--- 971506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 972506f1d07SSam Ravnborg the thermal monitor. 973506f1d07SSam Ravnborg 974506f1d07SSam Ravnborgconfig X86_MCE_AMD 9753c2362e6SHarvey Harrison def_bool y 9763c2362e6SHarvey Harrison prompt "AMD MCE features" 977c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9788f9ca475SIngo Molnar ---help--- 979506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 980506f1d07SSam Ravnborg the DRAM Error Threshold. 981506f1d07SSam Ravnborg 9824efc0670SAndi Kleenconfig X86_ANCIENT_MCE 9836fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 984c31d9633SAndi Kleen depends on X86_32 && X86_MCE 9854efc0670SAndi Kleen ---help--- 9864efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 9875065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 9884efc0670SAndi Kleen line. 9894efc0670SAndi Kleen 990b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 991b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 9926fc108a0SJan Beulich def_bool y 993b2762686SAndi Kleen 994ea149b36SAndi Kleenconfig X86_MCE_INJECT 995c1ebf835SAndi Kleen depends on X86_MCE 996ea149b36SAndi Kleen tristate "Machine check injector support" 997ea149b36SAndi Kleen ---help--- 998ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 999ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1000ea149b36SAndi Kleen QA it is safe to say n. 1001ea149b36SAndi Kleen 10024efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10034efc0670SAndi Kleen def_bool y 10045bb38adcSAndi Kleen depends on X86_MCE_INTEL 10054efc0670SAndi Kleen 10065aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 1007*1e642812SIngo Molnar bool "Legacy VM86 support" 10085aef51c3SAndy Lutomirski default n 1009506f1d07SSam Ravnborg depends on X86_32 10108f9ca475SIngo Molnar ---help--- 10115aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10125aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10135aef51c3SAndy Lutomirski 10145aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10155aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10165aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10175aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10185aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 1019*1e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 1020*1e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 1021*1e642812SIngo Molnar mode might be faster than emulation and you might want to 1022*1e642812SIngo Molnar enable this option. 10235aef51c3SAndy Lutomirski 1024*1e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 1025*1e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 1026*1e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 1027*1e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10285aef51c3SAndy Lutomirski 1029*1e642812SIngo Molnar Enabling this option increases the complexity of the kernel 1030*1e642812SIngo Molnar and slows down exception handling a tiny bit. 10315aef51c3SAndy Lutomirski 1032*1e642812SIngo Molnar If unsure, say N here. 10335aef51c3SAndy Lutomirski 10345aef51c3SAndy Lutomirskiconfig VM86 10355aef51c3SAndy Lutomirski bool 10365aef51c3SAndy Lutomirski default X86_LEGACY_VM86 103734273f41SH. Peter Anvin 103834273f41SH. Peter Anvinconfig X86_16BIT 103934273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 104034273f41SH. Peter Anvin default y 1041a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 104234273f41SH. Peter Anvin ---help--- 104334273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 104434273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 104534273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 104634273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 104734273f41SH. Peter Anvin 104834273f41SH. Peter Anvinconfig X86_ESPFIX32 104934273f41SH. Peter Anvin def_bool y 105034273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1051506f1d07SSam Ravnborg 1052197725deSH. Peter Anvinconfig X86_ESPFIX64 1053197725deSH. Peter Anvin def_bool y 105434273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1055506f1d07SSam Ravnborg 10561ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 10571ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 10581ad83c85SAndy Lutomirski default y 10591ad83c85SAndy Lutomirski depends on X86_64 10601ad83c85SAndy Lutomirski ---help--- 10611ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 10621ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 10631ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 10641ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 10651ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 10661ad83c85SAndy Lutomirski 0xffffffffff600?00. 10671ad83c85SAndy Lutomirski 10681ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 10691ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 10701ad83c85SAndy Lutomirski 10711ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 10721ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 10731ad83c85SAndy Lutomirski 1074506f1d07SSam Ravnborgconfig TOSHIBA 1075506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1076506f1d07SSam Ravnborg depends on X86_32 1077506f1d07SSam Ravnborg ---help--- 1078506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1079506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1080506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1081506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1082506f1d07SSam Ravnborg 1083506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1084506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1085506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1086506f1d07SSam Ravnborg 1087506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1088506f1d07SSam Ravnborg Say N otherwise. 1089506f1d07SSam Ravnborg 1090506f1d07SSam Ravnborgconfig I8K 1091039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1092949a9d70SJean Delvare select HWMON 1093039ae585SPali Rohár select SENSORS_DELL_SMM 1094506f1d07SSam Ravnborg ---help--- 1095039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1096039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1097039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1098039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1099039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1100039ae585SPali Rohár needed userspace package i8kutils. 1101506f1d07SSam Ravnborg 1102039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1103039ae585SPali Rohár use userspace package i8kutils. 1104506f1d07SSam Ravnborg Say N otherwise. 1105506f1d07SSam Ravnborg 1106506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11079ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11089ba16087SJan Beulich depends on X86_32 1109506f1d07SSam Ravnborg ---help--- 1110506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1111506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1112506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1113506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1114506f1d07SSam Ravnborg system. 1115506f1d07SSam Ravnborg 1116506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11175e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1118506f1d07SSam Ravnborg 1119506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1120506f1d07SSam Ravnborg enable this option even if you don't need it. 1121506f1d07SSam Ravnborg Say N otherwise. 1122506f1d07SSam Ravnborg 1123506f1d07SSam Ravnborgconfig MICROCODE 1124e43f6e67SBorislav Petkov tristate "CPU microcode loading support" 112580030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1126506f1d07SSam Ravnborg select FW_LOADER 1127506f1d07SSam Ravnborg ---help--- 1128e43f6e67SBorislav Petkov 1129506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 113080cc9f10SPeter Oruba certain Intel and AMD processors. The Intel support is for the 1131e43f6e67SBorislav Petkov IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1132e43f6e67SBorislav Petkov Xeon etc. The AMD support is for families 0x10 and later. You will 1133e43f6e67SBorislav Petkov obviously need the actual microcode binary data itself which is not 1134e43f6e67SBorislav Petkov shipped with the Linux kernel. 1135506f1d07SSam Ravnborg 11368d86f390SPeter Oruba This option selects the general module only, you need to select 11378d86f390SPeter Oruba at least one vendor specific module as well. 1138506f1d07SSam Ravnborg 1139e43f6e67SBorislav Petkov To compile this driver as a module, choose M here: the module 1140e43f6e67SBorislav Petkov will be called microcode. 1141506f1d07SSam Ravnborg 11428d86f390SPeter Orubaconfig MICROCODE_INTEL 1143e43f6e67SBorislav Petkov bool "Intel microcode loading support" 11448d86f390SPeter Oruba depends on MICROCODE 11458d86f390SPeter Oruba default MICROCODE 11468d86f390SPeter Oruba select FW_LOADER 11478f9ca475SIngo Molnar ---help--- 11488d86f390SPeter Oruba This options enables microcode patch loading support for Intel 11498d86f390SPeter Oruba processors. 11508d86f390SPeter Oruba 1151b8989db9SAlan For the current Intel microcode data package go to 1152b8989db9SAlan <https://downloadcenter.intel.com> and search for 1153b8989db9SAlan 'Linux Processor Microcode Data File'. 11548d86f390SPeter Oruba 115580cc9f10SPeter Orubaconfig MICROCODE_AMD 1156e43f6e67SBorislav Petkov bool "AMD microcode loading support" 115780cc9f10SPeter Oruba depends on MICROCODE 115880cc9f10SPeter Oruba select FW_LOADER 11598f9ca475SIngo Molnar ---help--- 116080cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 116180cc9f10SPeter Oruba processors will be enabled. 116280cc9f10SPeter Oruba 1163506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 11643c2362e6SHarvey Harrison def_bool y 1165506f1d07SSam Ravnborg depends on MICROCODE 1166506f1d07SSam Ravnborg 1167da76f64eSFenghua Yuconfig MICROCODE_INTEL_EARLY 1168e0fd24a3SJan Beulich bool 1169757885e9SJacob Shin 1170757885e9SJacob Shinconfig MICROCODE_AMD_EARLY 1171e0fd24a3SJan Beulich bool 1172757885e9SJacob Shin 1173757885e9SJacob Shinconfig MICROCODE_EARLY 1174da76f64eSFenghua Yu bool "Early load microcode" 11756b3389acSJacob Shin depends on MICROCODE=y && BLK_DEV_INITRD 1176757885e9SJacob Shin select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1177757885e9SJacob Shin select MICROCODE_AMD_EARLY if MICROCODE_AMD 1178da76f64eSFenghua Yu default y 1179da76f64eSFenghua Yu help 1180da76f64eSFenghua Yu This option provides functionality to read additional microcode data 1181da76f64eSFenghua Yu at the beginning of initrd image. The data tells kernel to load 1182da76f64eSFenghua Yu microcode to CPU's as early as possible. No functional change if no 1183da76f64eSFenghua Yu microcode data is glued to the initrd, therefore it's safe to say Y. 1184da76f64eSFenghua Yu 1185506f1d07SSam Ravnborgconfig X86_MSR 1186506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 11878f9ca475SIngo Molnar ---help--- 1188506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1189506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1190506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1191506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1192506f1d07SSam Ravnborg systems. 1193506f1d07SSam Ravnborg 1194506f1d07SSam Ravnborgconfig X86_CPUID 1195506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 11968f9ca475SIngo Molnar ---help--- 1197506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1198506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1199506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1200506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1201506f1d07SSam Ravnborg 1202506f1d07SSam Ravnborgchoice 1203506f1d07SSam Ravnborg prompt "High Memory Support" 12046fc108a0SJan Beulich default HIGHMEM4G 1205506f1d07SSam Ravnborg depends on X86_32 1206506f1d07SSam Ravnborg 1207506f1d07SSam Ravnborgconfig NOHIGHMEM 1208506f1d07SSam Ravnborg bool "off" 1209506f1d07SSam Ravnborg ---help--- 1210506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1211506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1212506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1213506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1214506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1215506f1d07SSam Ravnborg "high memory". 1216506f1d07SSam Ravnborg 1217506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1218506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1219506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1220506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1221506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1222506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1223506f1d07SSam Ravnborg possible. 1224506f1d07SSam Ravnborg 1225506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1226506f1d07SSam Ravnborg answer "4GB" here. 1227506f1d07SSam Ravnborg 1228506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1229506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1230506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1231506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1232506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1233506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1234506f1d07SSam Ravnborg 1235506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1236506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1237506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1238506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1239506f1d07SSam Ravnborg kernel at boot time.) 1240506f1d07SSam Ravnborg 1241506f1d07SSam Ravnborg If unsure, say "off". 1242506f1d07SSam Ravnborg 1243506f1d07SSam Ravnborgconfig HIGHMEM4G 1244506f1d07SSam Ravnborg bool "4GB" 12458f9ca475SIngo Molnar ---help--- 1246506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1247506f1d07SSam Ravnborg gigabytes of physical RAM. 1248506f1d07SSam Ravnborg 1249506f1d07SSam Ravnborgconfig HIGHMEM64G 1250506f1d07SSam Ravnborg bool "64GB" 1251eb068e78SH. Peter Anvin depends on !M486 1252506f1d07SSam Ravnborg select X86_PAE 12538f9ca475SIngo Molnar ---help--- 1254506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1255506f1d07SSam Ravnborg gigabytes of physical RAM. 1256506f1d07SSam Ravnborg 1257506f1d07SSam Ravnborgendchoice 1258506f1d07SSam Ravnborg 1259506f1d07SSam Ravnborgchoice 12606a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1261506f1d07SSam Ravnborg default VMSPLIT_3G 1262506f1d07SSam Ravnborg depends on X86_32 12638f9ca475SIngo Molnar ---help--- 1264506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1265506f1d07SSam Ravnborg 1266506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1267506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1268506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1269506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1270506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1271506f1d07SSam Ravnborg available to user programs, making the address space there 1272506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1273506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1274506f1d07SSam Ravnborg kernel modules. 1275506f1d07SSam Ravnborg 1276506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1277506f1d07SSam Ravnborg option alone! 1278506f1d07SSam Ravnborg 1279506f1d07SSam Ravnborg config VMSPLIT_3G 1280506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1281506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1282506f1d07SSam Ravnborg depends on !X86_PAE 1283506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1284506f1d07SSam Ravnborg config VMSPLIT_2G 1285506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1286506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1287506f1d07SSam Ravnborg depends on !X86_PAE 1288506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1289506f1d07SSam Ravnborg config VMSPLIT_1G 1290506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1291506f1d07SSam Ravnborgendchoice 1292506f1d07SSam Ravnborg 1293506f1d07SSam Ravnborgconfig PAGE_OFFSET 1294506f1d07SSam Ravnborg hex 1295506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1296506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1297506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1298506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1299506f1d07SSam Ravnborg default 0xC0000000 1300506f1d07SSam Ravnborg depends on X86_32 1301506f1d07SSam Ravnborg 1302506f1d07SSam Ravnborgconfig HIGHMEM 13033c2362e6SHarvey Harrison def_bool y 1304506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1305506f1d07SSam Ravnborg 1306506f1d07SSam Ravnborgconfig X86_PAE 13079ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1308506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13098f9ca475SIngo Molnar ---help--- 1310506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1311506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1312506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1313506f1d07SSam Ravnborg consumes more pagetable space per process. 1314506f1d07SSam Ravnborg 1315600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13163120e25eSJan Beulich def_bool y 13173120e25eSJan Beulich depends on X86_64 || X86_PAE 1318600715dcSJeremy Fitzhardinge 131966f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13203120e25eSJan Beulich def_bool y 13213120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 132266f2b061SFUJITA Tomonori 132310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1324e5008abeSLuis R. Rodriguez def_bool y 1325e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13268f9ca475SIngo Molnar ---help--- 132710971ab2SIngo Molnar Certain kernel features effectively disable kernel 132810971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 132910971ab2SIngo Molnar supports them), so don't confuse the user by printing 133010971ab2SIngo Molnar that we have them enabled. 13319e899816SNick Piggin 1332506f1d07SSam Ravnborg# Common NUMA Features 1333506f1d07SSam Ravnborgconfig NUMA 1334fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1335506f1d07SSam Ravnborg depends on SMP 1336b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1337b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13388f9ca475SIngo Molnar ---help--- 1339506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1340fd51b2d7SKOSAKI Motohiro 1341506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1342506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1343506f1d07SSam Ravnborg NUMA awareness to the kernel. 1344506f1d07SSam Ravnborg 1345c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1346fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1347fd51b2d7SKOSAKI Motohiro 1348b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13497cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1350fd51b2d7SKOSAKI Motohiro 1351fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1352506f1d07SSam Ravnborg 1353eec1d4faSHans Rosenfeldconfig AMD_NUMA 13543c2362e6SHarvey Harrison def_bool y 13553c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13565da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13578f9ca475SIngo Molnar ---help--- 1358eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1359eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1360eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1361eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1362eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1363506f1d07SSam Ravnborg 1364506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 13653c2362e6SHarvey Harrison def_bool y 13663c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1367506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1368506f1d07SSam Ravnborg select ACPI_NUMA 13698f9ca475SIngo Molnar ---help--- 1370506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1371506f1d07SSam Ravnborg 13726ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 13736ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 13746ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 13756ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 13766ec6e0d9SSuresh Siddha# for details. 13776ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 13786ec6e0d9SSuresh Siddha def_bool y 13796ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 13806ec6e0d9SSuresh Siddha 1381506f1d07SSam Ravnborgconfig NUMA_EMU 1382506f1d07SSam Ravnborg bool "NUMA emulation" 13831b7e03efSTejun Heo depends on NUMA 13848f9ca475SIngo Molnar ---help--- 1385506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1386506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1387506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1388506f1d07SSam Ravnborg 1389506f1d07SSam Ravnborgconfig NODES_SHIFT 1390d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 139151591e31SDavid Rientjes range 1 10 139251591e31SDavid Rientjes default "10" if MAXSMP 1393506f1d07SSam Ravnborg default "6" if X86_64 1394506f1d07SSam Ravnborg default "3" 1395506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 13968f9ca475SIngo Molnar ---help--- 13971184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1398692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1399506f1d07SSam Ravnborg 1400506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 14013c2362e6SHarvey Harrison def_bool y 1402506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1403506f1d07SSam Ravnborg 1404506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14053c2362e6SHarvey Harrison def_bool y 1406506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1407506f1d07SSam Ravnborg 1408506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1409506f1d07SSam Ravnborg def_bool y 14103b16651fSTejun Heo depends on X86_32 && !NUMA 1411506f1d07SSam Ravnborg 1412506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1413506f1d07SSam Ravnborg def_bool y 1414b263295dSChristoph Lameter depends on NUMA && X86_32 1415506f1d07SSam Ravnborg 1416506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1417506f1d07SSam Ravnborg def_bool y 1418b263295dSChristoph Lameter depends on NUMA && X86_32 1419b263295dSChristoph Lameter 1420506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1421506f1d07SSam Ravnborg def_bool y 14226ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1423506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1424506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1425506f1d07SSam Ravnborg 14263b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14273b16651fSTejun Heo def_bool y 14283b16651fSTejun Heo depends on X86_64 14293b16651fSTejun Heo 1430506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1431506f1d07SSam Ravnborg def_bool y 1432b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1433506f1d07SSam Ravnborg 1434506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1435a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14363120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1437a0842b70SToshi Kani help 1438a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1439a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1440a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1441506f1d07SSam Ravnborg 14423b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14433b16651fSTejun Heo def_bool y 14443b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14453b16651fSTejun Heo 1446a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1447a29815a3SAvi Kivity hex 1448a29815a3SAvi Kivity default 0 if X86_32 1449a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1450a29815a3SAvi Kivity 1451506f1d07SSam Ravnborgsource "mm/Kconfig" 1452506f1d07SSam Ravnborg 1453ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 1454ec776ef6SChristoph Hellwig bool "Support non-standard NVDIMMs and ADR protected memory" 14559f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14569f53f9faSDan Williams depends on BLK_DEV 14579f53f9faSDan Williams select LIBNVDIMM 1458ec776ef6SChristoph Hellwig help 1459ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1460ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1461ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1462ec776ef6SChristoph Hellwig they can be used for persistent storage. 1463ec776ef6SChristoph Hellwig 1464ec776ef6SChristoph Hellwig Say Y if unsure. 1465ec776ef6SChristoph Hellwig 1466506f1d07SSam Ravnborgconfig HIGHPTE 1467506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 14686fc108a0SJan Beulich depends on HIGHMEM 14698f9ca475SIngo Molnar ---help--- 1470506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1471506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1472506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1473506f1d07SSam Ravnborg entries in high memory. 1474506f1d07SSam Ravnborg 14759f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 14769f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 14778f9ca475SIngo Molnar ---help--- 14789f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 14799f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 14809f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 14819f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 14829f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 14839f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 14849f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 14859f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 14869f077871SJeremy Fitzhardinge 14879f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 14889f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 14899f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 14909f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 14919f077871SJeremy Fitzhardinge 14929f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 14939f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 14949f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 14959f077871SJeremy Fitzhardinge memory. 14969f077871SJeremy Fitzhardinge 1497c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1498c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1499c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1500c885df50SJeremy Fitzhardinge default y 15018f9ca475SIngo Molnar ---help--- 1502c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1503c885df50SJeremy Fitzhardinge on or off. 1504c885df50SJeremy Fitzhardinge 15059ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1506d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1507d0cd7425SH. Peter Anvin default 64 1508d0cd7425SH. Peter Anvin range 4 640 15098f9ca475SIngo Molnar ---help--- 1510d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1511fc381519SIngo Molnar 1512d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1513d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1514fc381519SIngo Molnar 1515d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1516d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1517d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1518d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1519fc381519SIngo Molnar 1520d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1521d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1522d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1523d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1524d0cd7425SH. Peter Anvin entire low memory range. 1525d0cd7425SH. Peter Anvin 1526d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1527d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1528d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1529d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1530d0cd7425SH. Peter Anvin typical corruption patterns. 1531d0cd7425SH. Peter Anvin 1532d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1533fc381519SIngo Molnar 1534506f1d07SSam Ravnborgconfig MATH_EMULATION 1535506f1d07SSam Ravnborg bool 1536a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1537506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1538506f1d07SSam Ravnborg ---help--- 1539506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1540506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1541506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1542506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1543506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1544506f1d07SSam Ravnborg coprocessor or this emulation. 1545506f1d07SSam Ravnborg 1546506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1547506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1548506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1549506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1550506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1551506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1552506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1553506f1d07SSam Ravnborg intend to use this kernel on different machines. 1554506f1d07SSam Ravnborg 1555506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1556506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1557506f1d07SSam Ravnborg 1558506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1559506f1d07SSam Ravnborg kernel, it won't hurt. 1560506f1d07SSam Ravnborg 1561506f1d07SSam Ravnborgconfig MTRR 15626fc108a0SJan Beulich def_bool y 15636a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1564506f1d07SSam Ravnborg ---help--- 1565506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1566506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1567506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1568506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1569506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1570506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1571506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1572506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1573506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1574506f1d07SSam Ravnborg 1575506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1576506f1d07SSam Ravnborg control registers on other processors can be easily supported 1577506f1d07SSam Ravnborg as well: 1578506f1d07SSam Ravnborg 1579506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1580506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1581506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1582506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1583506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1584506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1585506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1586506f1d07SSam Ravnborg 1587506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1588506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1589506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1590506f1d07SSam Ravnborg 1591506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1592506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1593506f1d07SSam Ravnborg 15947225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1595506f1d07SSam Ravnborg 159695ffa243SYinghai Luconfig MTRR_SANITIZER 15972ffb3501SYinghai Lu def_bool y 159895ffa243SYinghai Lu prompt "MTRR cleanup support" 159995ffa243SYinghai Lu depends on MTRR 16008f9ca475SIngo Molnar ---help--- 1601aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1602aba3728cSThomas Gleixner add writeback entries. 160395ffa243SYinghai Lu 1604aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1605692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1606aba3728cSThomas Gleixner mtrr_chunk_size. 160795ffa243SYinghai Lu 16082ffb3501SYinghai Lu If unsure, say Y. 160995ffa243SYinghai Lu 161095ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1611f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1612f5098d62SYinghai Lu range 0 1 1613f5098d62SYinghai Lu default "0" 161495ffa243SYinghai Lu depends on MTRR_SANITIZER 16158f9ca475SIngo Molnar ---help--- 1616f5098d62SYinghai Lu Enable mtrr cleanup default value 161795ffa243SYinghai Lu 161812031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 161912031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 162012031a62SYinghai Lu range 0 7 162112031a62SYinghai Lu default "1" 162212031a62SYinghai Lu depends on MTRR_SANITIZER 16238f9ca475SIngo Molnar ---help--- 162412031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1625aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 162612031a62SYinghai Lu 16272e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16286fc108a0SJan Beulich def_bool y 16296a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16302a8a2719SIngo Molnar depends on MTRR 16318f9ca475SIngo Molnar ---help--- 16322e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1633042b78e4SVenki Pallipadi 16342e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16352e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16362e5d9c85Svenkatesh.pallipadi@intel.com 16372e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1638042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16392e5d9c85Svenkatesh.pallipadi@intel.com 16402e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16412e5d9c85Svenkatesh.pallipadi@intel.com 164246cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 164346cf98cdSVenkatesh Pallipadi def_bool y 164446cf98cdSVenkatesh Pallipadi depends on X86_PAT 164546cf98cdSVenkatesh Pallipadi 1646628c6246SH. Peter Anvinconfig ARCH_RANDOM 1647628c6246SH. Peter Anvin def_bool y 1648628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1649628c6246SH. Peter Anvin ---help--- 1650628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1651628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1652628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1653628c6246SH. Peter Anvin secure hardware random number generator. 1654628c6246SH. Peter Anvin 165551ae4a2dSH. Peter Anvinconfig X86_SMAP 165651ae4a2dSH. Peter Anvin def_bool y 165751ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 165851ae4a2dSH. Peter Anvin ---help--- 165951ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 166051ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 166151ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 166251ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 166351ae4a2dSH. Peter Anvin 166451ae4a2dSH. Peter Anvin If unsure, say Y. 166551ae4a2dSH. Peter Anvin 166672e9b5feSDave Hansenconfig X86_INTEL_MPX 166772e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 166872e9b5feSDave Hansen def_bool n 166972e9b5feSDave Hansen depends on CPU_SUP_INTEL 167072e9b5feSDave Hansen ---help--- 167172e9b5feSDave Hansen MPX provides hardware features that can be used in 167272e9b5feSDave Hansen conjunction with compiler-instrumented code to check 167372e9b5feSDave Hansen memory references. It is designed to detect buffer 167472e9b5feSDave Hansen overflow or underflow bugs. 167572e9b5feSDave Hansen 167672e9b5feSDave Hansen This option enables running applications which are 167772e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 167872e9b5feSDave Hansen itself inside the kernel or to protect the kernel 167972e9b5feSDave Hansen against bad memory references. 168072e9b5feSDave Hansen 168172e9b5feSDave Hansen Enabling this option will make the kernel larger: 168272e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 168372e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 168472e9b5feSDave Hansen will increase the kernel memory overhead of each 168572e9b5feSDave Hansen process and adds some branches to paths used during 168672e9b5feSDave Hansen exec() and munmap(). 168772e9b5feSDave Hansen 168872e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 168972e9b5feSDave Hansen 169072e9b5feSDave Hansen If unsure, say N. 169172e9b5feSDave Hansen 1692506f1d07SSam Ravnborgconfig EFI 16939ba16087SJan Beulich bool "EFI runtime service support" 16945b83683fSHuang, Ying depends on ACPI 1695f6ce5002SSergey Vlasov select UCS2_STRING 1696022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1697506f1d07SSam Ravnborg ---help--- 16988b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1699506f1d07SSam Ravnborg available (such as the EFI variable services). 1700506f1d07SSam Ravnborg 17018b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17028b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17038b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17048b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17058b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17068b2cb7a8SHuang, Ying platforms. 1707506f1d07SSam Ravnborg 1708291f3632SMatt Flemingconfig EFI_STUB 1709291f3632SMatt Fleming bool "EFI stub support" 1710b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17117b2a583aSMatt Fleming select RELOCATABLE 1712291f3632SMatt Fleming ---help--- 1713291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1714291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1715291f3632SMatt Fleming 17164172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17170c759662SMatt Fleming 17187d453eeeSMatt Flemingconfig EFI_MIXED 17197d453eeeSMatt Fleming bool "EFI mixed-mode support" 17207d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17217d453eeeSMatt Fleming ---help--- 17227d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17237d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17247d453eeeSMatt Fleming mode. 17257d453eeeSMatt Fleming 17267d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17277d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17287d453eeeSMatt Fleming the EFI handover protocol must be used. 17297d453eeeSMatt Fleming 17307d453eeeSMatt Fleming If unsure, say N. 17317d453eeeSMatt Fleming 1732506f1d07SSam Ravnborgconfig SECCOMP 17333c2362e6SHarvey Harrison def_bool y 17343c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17358f9ca475SIngo Molnar ---help--- 1736506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1737506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1738506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1739506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1740506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1741506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17429c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1743506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1744506f1d07SSam Ravnborg defined by each seccomp mode. 1745506f1d07SSam Ravnborg 1746506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1749506f1d07SSam Ravnborg 1750506f1d07SSam Ravnborgconfig KEXEC 1751506f1d07SSam Ravnborg bool "kexec system call" 17528f9ca475SIngo Molnar ---help--- 1753506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1754506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1755506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1756506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1757506f1d07SSam Ravnborg 1758506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1759506f1d07SSam Ravnborg 1760506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1761506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1762bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1763bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1764bf220695SGeert Uytterhoeven made. 1765506f1d07SSam Ravnborg 176674ca317cSVivek Goyalconfig KEXEC_FILE 176774ca317cSVivek Goyal bool "kexec file based system call" 176874ca317cSVivek Goyal select BUILD_BIN2C 176974ca317cSVivek Goyal depends on KEXEC 177074ca317cSVivek Goyal depends on X86_64 177174ca317cSVivek Goyal depends on CRYPTO=y 177274ca317cSVivek Goyal depends on CRYPTO_SHA256=y 177374ca317cSVivek Goyal ---help--- 177474ca317cSVivek Goyal This is new version of kexec system call. This system call is 177574ca317cSVivek Goyal file based and takes file descriptors as system call argument 177674ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 177774ca317cSVivek Goyal accepted by previous system call. 177874ca317cSVivek Goyal 17798e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG 17808e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 178174ca317cSVivek Goyal depends on KEXEC_FILE 17828e7d8381SVivek Goyal ---help--- 17838e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 1784d8eb8940SBorislav Petkov the kexec_file_load() syscall. 17858e7d8381SVivek Goyal 1786d8eb8940SBorislav Petkov In addition to that option, you need to enable signature 1787d8eb8940SBorislav Petkov verification for the corresponding kernel image type being 1788d8eb8940SBorislav Petkov loaded in order for this to work. 17898e7d8381SVivek Goyal 17908e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 17918e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 17928e7d8381SVivek Goyal depends on KEXEC_VERIFY_SIG 17938e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 17948e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 17958e7d8381SVivek Goyal ---help--- 17968e7d8381SVivek Goyal Enable bzImage signature verification support. 17978e7d8381SVivek Goyal 1798506f1d07SSam Ravnborgconfig CRASH_DUMP 179904b69447SPavel Machek bool "kernel crash dumps" 1800506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 18018f9ca475SIngo Molnar ---help--- 1802506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 1803506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 1804506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 1805506f1d07SSam Ravnborg a specially reserved region and then later executed after 1806506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 1807506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 1808506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 1809506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 1810506f1d07SSam Ravnborg For more details see Documentation/kdump/kdump.txt 1811506f1d07SSam Ravnborg 18123ab83521SHuang Yingconfig KEXEC_JUMP 18136ea30386SKees Cook bool "kexec jump" 1814fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 18158f9ca475SIngo Molnar ---help--- 181689081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 181789081d17SHuang Ying code in physical address mode via KEXEC 18183ab83521SHuang Ying 1819506f1d07SSam Ravnborgconfig PHYSICAL_START 18206a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1821ceefccc9SH. Peter Anvin default "0x1000000" 18228f9ca475SIngo Molnar ---help--- 1823506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 1824506f1d07SSam Ravnborg 1825506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1826506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 1827506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 1828506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 1829506f1d07SSam Ravnborg address. 1830506f1d07SSam Ravnborg 1831506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 1832506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 1833506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1834506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 1835506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 1836506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 1837506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 1838506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 1839506f1d07SSam Ravnborg 1840ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 1841ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 1842ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1843ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 1844ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 1845ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 1846ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 1847ceefccc9SH. Peter Anvin kernel. Please take a look at Documentation/kdump/kdump.txt 1848ceefccc9SH. Peter Anvin for more details about crash dumps. 1849506f1d07SSam Ravnborg 1850506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 1851506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 1852506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 1853506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 1854506f1d07SSam Ravnborg is present because there are users out there who continue to use 1855506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 1856506f1d07SSam Ravnborg line. 1857506f1d07SSam Ravnborg 1858506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1859506f1d07SSam Ravnborg 1860506f1d07SSam Ravnborgconfig RELOCATABLE 186126717808SH. Peter Anvin bool "Build a relocatable kernel" 186226717808SH. Peter Anvin default y 18638f9ca475SIngo Molnar ---help--- 1864506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 1865506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 1866506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 1867506f1d07SSam Ravnborg but are discarded at runtime. 1868506f1d07SSam Ravnborg 1869506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 1870506f1d07SSam Ravnborg must live at a different physical address than the primary 1871506f1d07SSam Ravnborg kernel. 1872506f1d07SSam Ravnborg 1873506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1874506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 18758ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 1876506f1d07SSam Ravnborg 18778ab3820fSKees Cookconfig RANDOMIZE_BASE 18788ab3820fSKees Cook bool "Randomize the address of the kernel image" 18798ab3820fSKees Cook depends on RELOCATABLE 18808ab3820fSKees Cook default n 18818ab3820fSKees Cook ---help--- 18828ab3820fSKees Cook Randomizes the physical and virtual address at which the 18838ab3820fSKees Cook kernel image is decompressed, as a security feature that 18848ab3820fSKees Cook deters exploit attempts relying on knowledge of the location 18858ab3820fSKees Cook of kernel internals. 18868ab3820fSKees Cook 1887a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 1888a653f356SKees Cook supported. If RDTSC is supported, it is used as well. If 1889a653f356SKees Cook neither RDRAND nor RDTSC are supported, then randomness is 1890a653f356SKees Cook read from the i8254 timer. 18918ab3820fSKees Cook 18928ab3820fSKees Cook The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1893a653f356SKees Cook and aligned according to PHYSICAL_ALIGN. Since the kernel is 1894a653f356SKees Cook built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1895a653f356SKees Cook minimum of 2MiB, only 10 bits of entropy is theoretically 1896a653f356SKees Cook possible. At best, due to page table layouts, 64-bit can use 1897a653f356SKees Cook 9 bits of entropy and 32-bit uses 8 bits. 18988ab3820fSKees Cook 1899da2b6fb9SKees Cook If unsure, say N. 1900da2b6fb9SKees Cook 19018ab3820fSKees Cookconfig RANDOMIZE_BASE_MAX_OFFSET 1902da2b6fb9SKees Cook hex "Maximum kASLR offset allowed" if EXPERT 19038ab3820fSKees Cook depends on RANDOMIZE_BASE 19046145cfe3SKees Cook range 0x0 0x20000000 if X86_32 19056145cfe3SKees Cook default "0x20000000" if X86_32 19066145cfe3SKees Cook range 0x0 0x40000000 if X86_64 19076145cfe3SKees Cook default "0x40000000" if X86_64 19088ab3820fSKees Cook ---help--- 1909da2b6fb9SKees Cook The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1910da2b6fb9SKees Cook memory is used to determine the maximal offset in bytes that will 1911da2b6fb9SKees Cook be applied to the kernel when kernel Address Space Layout 1912da2b6fb9SKees Cook Randomization (kASLR) is active. This must be a multiple of 1913da2b6fb9SKees Cook PHYSICAL_ALIGN. 19146145cfe3SKees Cook 1915da2b6fb9SKees Cook On 32-bit this is limited to 512MiB by page table layouts. The 1916da2b6fb9SKees Cook default is 512MiB. 19176145cfe3SKees Cook 19186145cfe3SKees Cook On 64-bit this is limited by how the kernel fixmap page table is 1919da2b6fb9SKees Cook positioned, so this cannot be larger than 1GiB currently. Without 1920da2b6fb9SKees Cook RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1921da2b6fb9SKees Cook and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1922da2b6fb9SKees Cook modules area will shrink to compensate, up to the current maximum 1923da2b6fb9SKees Cook 1GiB to 1GiB split. The default is 1GiB. 1924da2b6fb9SKees Cook 1925da2b6fb9SKees Cook If unsure, leave at the default value. 19268ab3820fSKees Cook 19278ab3820fSKees Cook# Relocation on x86 needs some additional build support 1928845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 1929845adf72SH. Peter Anvin def_bool y 19308ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1931845adf72SH. Peter Anvin 1932506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 1933a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 19348ab3820fSKees Cook default "0x200000" 1935a0215061SKees Cook range 0x2000 0x1000000 if X86_32 1936a0215061SKees Cook range 0x200000 0x1000000 if X86_64 19378f9ca475SIngo Molnar ---help--- 1938506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 1939506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 1940506f1d07SSam Ravnborg address which meets above alignment restriction. 1941506f1d07SSam Ravnborg 1942506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1943506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1944506f1d07SSam Ravnborg address aligned to above value and run from there. 1945506f1d07SSam Ravnborg 1946506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 1947506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1948506f1d07SSam Ravnborg load address and decompress itself to the address it has been 1949506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 1950506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 1951506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 1952506f1d07SSam Ravnborg above alignment restrictions. 1953506f1d07SSam Ravnborg 1954a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 1955a0215061SKees Cook this value must be a multiple of 0x200000. 1956a0215061SKees Cook 1957506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 1958506f1d07SSam Ravnborg 1959506f1d07SSam Ravnborgconfig HOTPLUG_CPU 19607c13e6a3SDimitri Sivanich bool "Support for hot-pluggable CPUs" 196140b31360SStephen Rothwell depends on SMP 1962506f1d07SSam Ravnborg ---help--- 19637c13e6a3SDimitri Sivanich Say Y here to allow turning CPUs off and on. CPUs can be 19647c13e6a3SDimitri Sivanich controlled through /sys/devices/system/cpu. 19657c13e6a3SDimitri Sivanich ( Note: power management support will enable this option 19667c13e6a3SDimitri Sivanich automatically on SMP systems. ) 19677c13e6a3SDimitri Sivanich Say N if you want to disable CPU hotplug. 1968506f1d07SSam Ravnborg 196980aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 197080aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 197180aa1dffSFenghua Yu default n 19722c922cd0SKees Cook depends on HOTPLUG_CPU 197380aa1dffSFenghua Yu ---help--- 197480aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 197580aa1dffSFenghua Yu 197680aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 197780aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 197880aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 197980aa1dffSFenghua Yu 198080aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 198180aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 198280aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 198380aa1dffSFenghua Yu 198480aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 198580aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 198680aa1dffSFenghua Yu 198780aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 198880aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 198980aa1dffSFenghua Yu be other CPU0 dependencies. 199080aa1dffSFenghua Yu 199180aa1dffSFenghua Yu Please make sure the dependencies are under your control before 199280aa1dffSFenghua Yu you enable this feature. 199380aa1dffSFenghua Yu 199480aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 199580aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 199680aa1dffSFenghua Yu parameter cpu0_hotplug. 199780aa1dffSFenghua Yu 1998a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 1999a71c8bc5SFenghua Yu def_bool n 2000a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 20012c922cd0SKees Cook depends on HOTPLUG_CPU 2002a71c8bc5SFenghua Yu ---help--- 2003a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2004a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2005a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2006a71c8bc5SFenghua Yu 2007a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2008a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2009a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2010a71c8bc5SFenghua Yu 2011a71c8bc5SFenghua Yu If unsure, say N. 2012a71c8bc5SFenghua Yu 2013506f1d07SSam Ravnborgconfig COMPAT_VDSO 2014b0b49f26SAndy Lutomirski def_bool n 2015b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2016af65d648SRoland McGrath depends on X86_32 || IA32_EMULATION 20178f9ca475SIngo Molnar ---help--- 2018b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2019b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2020b0b49f26SAndy Lutomirski indicated in its segment table. 2021e84446deSRandy Dunlap 2022b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2023b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2024b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2025b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2026b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2027506f1d07SSam Ravnborg 2028b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2029b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2030b0b49f26SAndy Lutomirski 2031b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2032b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2033b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2034b0b49f26SAndy Lutomirski 2035b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2036b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2037506f1d07SSam Ravnborg 2038516cbf37STim Birdconfig CMDLINE_BOOL 2039516cbf37STim Bird bool "Built-in kernel command line" 20408f9ca475SIngo Molnar ---help--- 2041516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2042516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2043516cbf37STim Bird necessary or convenient to provide some or all of the 2044516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2045516cbf37STim Bird to not rely on the boot loader to provide them.) 2046516cbf37STim Bird 2047516cbf37STim Bird To compile command line arguments into the kernel, 2048516cbf37STim Bird set this option to 'Y', then fill in the 204969711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2050516cbf37STim Bird 2051516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2052516cbf37STim Bird should leave this option set to 'N'. 2053516cbf37STim Bird 2054516cbf37STim Birdconfig CMDLINE 2055516cbf37STim Bird string "Built-in kernel command string" 2056516cbf37STim Bird depends on CMDLINE_BOOL 2057516cbf37STim Bird default "" 20588f9ca475SIngo Molnar ---help--- 2059516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2060516cbf37STim Bird image and used at boot time. If the boot loader provides a 2061516cbf37STim Bird command line at boot time, it is appended to this string to 2062516cbf37STim Bird form the full kernel command line, when the system boots. 2063516cbf37STim Bird 2064516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2065516cbf37STim Bird change this behavior. 2066516cbf37STim Bird 2067516cbf37STim Bird In most cases, the command line (whether built-in or provided 2068516cbf37STim Bird by the boot loader) should specify the device for the root 2069516cbf37STim Bird file system. 2070516cbf37STim Bird 2071516cbf37STim Birdconfig CMDLINE_OVERRIDE 2072516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2073516cbf37STim Bird depends on CMDLINE_BOOL 20748f9ca475SIngo Molnar ---help--- 2075516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2076516cbf37STim Bird command line, and use ONLY the built-in command line. 2077516cbf37STim Bird 2078516cbf37STim Bird This is used to work around broken boot loaders. This should 2079516cbf37STim Bird be set to 'N' under normal conditions. 2080516cbf37STim Bird 2081a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2082a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2083a5b9e5a2SAndy Lutomirski default y 2084a5b9e5a2SAndy Lutomirski ---help--- 2085a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2086a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2087a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2088a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2089a5b9e5a2SAndy Lutomirski threading libraries. 2090a5b9e5a2SAndy Lutomirski 2091a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2092a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2093a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2094a5b9e5a2SAndy Lutomirski 2095a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2096a5b9e5a2SAndy Lutomirski 2097b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2098b700e7f0SSeth Jennings 2099506f1d07SSam Ravnborgendmenu 2100506f1d07SSam Ravnborg 2101506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2102506f1d07SSam Ravnborg def_bool y 2103506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2104506f1d07SSam Ravnborg 210535551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 210635551053SGary Hade def_bool y 210735551053SGary Hade depends on MEMORY_HOTPLUG 210835551053SGary Hade 2109e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2110645a7919STejun Heo def_bool y 2111e534c7c5SLee Schermerhorn depends on NUMA 2112e534c7c5SLee Schermerhorn 21139491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 21149491846fSKirill A. Shutemov def_bool y 21159491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 21169491846fSKirill A. Shutemov 2117c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2118c177c81eSNaoya Horiguchi def_bool y 2119c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2120c177c81eSNaoya Horiguchi 2121da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2122e279b6c1SSam Ravnborg 2123e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 21243c2362e6SHarvey Harrison def_bool y 2125e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2126e279b6c1SSam Ravnborg 2127e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2128e279b6c1SSam Ravnborg 2129e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2130e279b6c1SSam Ravnborg 2131efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2132efafc8b2SFeng Tang 2133a6b68076SAndi Kleenconfig X86_APM_BOOT 21346fc108a0SJan Beulich def_bool y 2135282e5aabSPaul Bolle depends on APM 2136a6b68076SAndi Kleen 2137e279b6c1SSam Ravnborgmenuconfig APM 2138e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2139efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2140e279b6c1SSam Ravnborg ---help--- 2141e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2142e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2143e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2144e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2145e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2146e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2147e279b6c1SSam Ravnborg 2148e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2149e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2150e279b6c1SSam Ravnborg 2151e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2152e279b6c1SSam Ravnborg machines with more than one CPU. 2153e279b6c1SSam Ravnborg 2154e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 21552dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 21562dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2157e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2158e279b6c1SSam Ravnborg 2159e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2160e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2161e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2162e279b6c1SSam Ravnborg 2163e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2164e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2165e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2166e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2167e279b6c1SSam Ravnborg 2168e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2169e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2170e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2171e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2172e279b6c1SSam Ravnborg APM in your BIOS). 2173e279b6c1SSam Ravnborg 2174e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2175e279b6c1SSam Ravnborg "weird" problems: 2176e279b6c1SSam Ravnborg 2177e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2178e279b6c1SSam Ravnborg enabled. 2179e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2180e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2181e279b6c1SSam Ravnborg the "no387" option to the kernel 2182e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2183e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2184e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2185e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2186e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2187e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2188e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2189e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2190e279b6c1SSam Ravnborg 11) exchange RAM chips 2191e279b6c1SSam Ravnborg 12) exchange the motherboard. 2192e279b6c1SSam Ravnborg 2193e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2194e279b6c1SSam Ravnborg module will be called apm. 2195e279b6c1SSam Ravnborg 2196e279b6c1SSam Ravnborgif APM 2197e279b6c1SSam Ravnborg 2198e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2199e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 22008f9ca475SIngo Molnar ---help--- 2201e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2202e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2203e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2204e279b6c1SSam Ravnborg 2205e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2206e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2207e279b6c1SSam Ravnborg ---help--- 2208e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2209e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2210e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2211e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2212e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2213e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2214e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2215e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2216e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2217e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2218e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2219e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2220e279b6c1SSam Ravnborg this feature. 2221e279b6c1SSam Ravnborg 2222e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2223dd8af076SLen Brown depends on CPU_IDLE 2224e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 22258f9ca475SIngo Molnar ---help--- 2226e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2227e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2228e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2229e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2230e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2231e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2232e279b6c1SSam Ravnborg this option does nothing.) 2233e279b6c1SSam Ravnborg 2234e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2235e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 22368f9ca475SIngo Molnar ---help--- 2237e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2238e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2239e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2240e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2241e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2242e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2243e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2244e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2245e279b6c1SSam Ravnborg especially if you are using gpm. 2246e279b6c1SSam Ravnborg 2247e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2248e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 22498f9ca475SIngo Molnar ---help--- 2250e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2251e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2252e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2253e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2254e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2255e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2256e279b6c1SSam Ravnborg 2257e279b6c1SSam Ravnborgendif # APM 2258e279b6c1SSam Ravnborg 2259bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2260e279b6c1SSam Ravnborg 2261e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2262e279b6c1SSam Ravnborg 226327471fdbSAndy Henroidsource "drivers/idle/Kconfig" 226427471fdbSAndy Henroid 2265e279b6c1SSam Ravnborgendmenu 2266e279b6c1SSam Ravnborg 2267e279b6c1SSam Ravnborg 2268e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2269e279b6c1SSam Ravnborg 2270e279b6c1SSam Ravnborgconfig PCI 22711ac97018SIngo Molnar bool "PCI support" 22721c858087SAdrian Bunk default y 22738f9ca475SIngo Molnar ---help--- 2274e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2275e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2276e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2277e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2278e279b6c1SSam Ravnborg 2279e279b6c1SSam Ravnborgchoice 2280e279b6c1SSam Ravnborg prompt "PCI access mode" 2281efefa6f6SIngo Molnar depends on X86_32 && PCI 2282e279b6c1SSam Ravnborg default PCI_GOANY 2283e279b6c1SSam Ravnborg ---help--- 2284e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2285e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2286e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2287e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2288e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2289e279b6c1SSam Ravnborg 2290e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2291e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2292e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2293e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2294e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2295e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2296e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2297e279b6c1SSam Ravnborg 2298e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2299e279b6c1SSam Ravnborg bool "BIOS" 2300e279b6c1SSam Ravnborg 2301e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2302e279b6c1SSam Ravnborg bool "MMConfig" 2303e279b6c1SSam Ravnborg 2304e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2305e279b6c1SSam Ravnborg bool "Direct" 2306e279b6c1SSam Ravnborg 23073ef0e1f8SAndres Salomonconfig PCI_GOOLPC 230876fb6570SDaniel Drake bool "OLPC XO-1" 23093ef0e1f8SAndres Salomon depends on OLPC 23103ef0e1f8SAndres Salomon 23112bdd1b03SAndres Salomonconfig PCI_GOANY 23122bdd1b03SAndres Salomon bool "Any" 23132bdd1b03SAndres Salomon 2314e279b6c1SSam Ravnborgendchoice 2315e279b6c1SSam Ravnborg 2316e279b6c1SSam Ravnborgconfig PCI_BIOS 23173c2362e6SHarvey Harrison def_bool y 2318efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2319e279b6c1SSam Ravnborg 2320e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2321e279b6c1SSam Ravnborgconfig PCI_DIRECT 23223c2362e6SHarvey Harrison def_bool y 23230aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2324e279b6c1SSam Ravnborg 2325e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 23263c2362e6SHarvey Harrison def_bool y 23275f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2328e279b6c1SSam Ravnborg 23293ef0e1f8SAndres Salomonconfig PCI_OLPC 23302bdd1b03SAndres Salomon def_bool y 23312bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 23323ef0e1f8SAndres Salomon 2333b5401a96SAlex Nixonconfig PCI_XEN 2334b5401a96SAlex Nixon def_bool y 2335b5401a96SAlex Nixon depends on PCI && XEN 2336b5401a96SAlex Nixon select SWIOTLB_XEN 2337b5401a96SAlex Nixon 2338e279b6c1SSam Ravnborgconfig PCI_DOMAINS 23393c2362e6SHarvey Harrison def_bool y 2340e279b6c1SSam Ravnborg depends on PCI 2341e279b6c1SSam Ravnborg 2342e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2343e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2344e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2345e279b6c1SSam Ravnborg 23463f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 23476a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 23486ea30386SKees Cook depends on PCI 23493f6ea84aSIra W. Snyder help 23503f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 23513f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 23523f6ea84aSIra W. Snyder not have ACPI. 23533f6ea84aSIra W. Snyder 235464a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 235564a5fed6SBjorn Helgaas is known to be incomplete. 235664a5fed6SBjorn Helgaas 235764a5fed6SBjorn Helgaas You should say N unless you know you need this. 235864a5fed6SBjorn Helgaas 2359e279b6c1SSam Ravnborgsource "drivers/pci/pcie/Kconfig" 2360e279b6c1SSam Ravnborg 2361e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2362e279b6c1SSam Ravnborg 23631c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2364e279b6c1SSam Ravnborgconfig ISA_DMA_API 23651c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 23661c00f016SDavid Rientjes default y 23671c00f016SDavid Rientjes help 23681c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 23691c00f016SDavid Rientjes If unsure, say Y. 2370e279b6c1SSam Ravnborg 2371e279b6c1SSam Ravnborgif X86_32 2372e279b6c1SSam Ravnborg 2373e279b6c1SSam Ravnborgconfig ISA 2374e279b6c1SSam Ravnborg bool "ISA support" 23758f9ca475SIngo Molnar ---help--- 2376e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2377e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2378e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2379e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2380e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2381e279b6c1SSam Ravnborg 2382e279b6c1SSam Ravnborgconfig EISA 2383e279b6c1SSam Ravnborg bool "EISA support" 2384e279b6c1SSam Ravnborg depends on ISA 2385e279b6c1SSam Ravnborg ---help--- 2386e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2387e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2388e279b6c1SSam Ravnborg 2389e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2390e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2391e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2392e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2393e279b6c1SSam Ravnborg 2394e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2395e279b6c1SSam Ravnborg 2396e279b6c1SSam Ravnborg Otherwise, say N. 2397e279b6c1SSam Ravnborg 2398e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2399e279b6c1SSam Ravnborg 2400e279b6c1SSam Ravnborgconfig SCx200 2401e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 24028f9ca475SIngo Molnar ---help--- 2403e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2404e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2405e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2406e279b6c1SSam Ravnborg for other scx200_* drivers. 2407e279b6c1SSam Ravnborg 2408e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2409e279b6c1SSam Ravnborg 2410e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2411e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2412592913ecSJohn Stultz depends on SCx200 2413e279b6c1SSam Ravnborg default y 24148f9ca475SIngo Molnar ---help--- 2415e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2416e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2417e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2418e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2419e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2420e279b6c1SSam Ravnborg 24213ef0e1f8SAndres Salomonconfig OLPC 24223ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 242354008979SThomas Gleixner depends on !X86_PAE 24243c554946SAndres Salomon select GPIOLIB 2425dc3119e7SThomas Gleixner select OF 242645bb1674SDaniel Drake select OF_PROMTREE 2427b4e51854SGrant Likely select IRQ_DOMAIN 24288f9ca475SIngo Molnar ---help--- 24293ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 24303ef0e1f8SAndres Salomon XO hardware. 24313ef0e1f8SAndres Salomon 2432a3128588SDaniel Drakeconfig OLPC_XO1_PM 2433a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 243497c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2435a3128588SDaniel Drake select MFD_CORE 2436bf1ebf00SDaniel Drake ---help--- 243797c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2438bf1ebf00SDaniel Drake 2439cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2440cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2441cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2442cfee9597SDaniel Drake ---help--- 2443cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2444cfee9597SDaniel Drake programmable wakeup source. 2445cfee9597SDaniel Drake 24467feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 24477feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2448d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2449ed8e47feSRandy Dunlap depends on INPUT=y 2450d8d01a63SDaniel Drake select POWER_SUPPLY 24517feda8e9SDaniel Drake select GPIO_CS5535 24527feda8e9SDaniel Drake select MFD_CORE 24537feda8e9SDaniel Drake ---help--- 24547feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 24557bc74b3dSDaniel Drake - EC-driven system wakeups 24567feda8e9SDaniel Drake - Power button 24577bc74b3dSDaniel Drake - Ebook switch 24582cf2baeaSDaniel Drake - Lid switch 2459e1040ac6SDaniel Drake - AC adapter status updates 2460e1040ac6SDaniel Drake - Battery status updates 24617feda8e9SDaniel Drake 2462a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2463a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2464d8d01a63SDaniel Drake depends on OLPC && ACPI 2465d8d01a63SDaniel Drake select POWER_SUPPLY 2466a0f30f59SDaniel Drake ---help--- 2467a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2468a0f30f59SDaniel Drake - EC-driven system wakeups 2469a0f30f59SDaniel Drake - AC adapter status updates 2470a0f30f59SDaniel Drake - Battery status updates 2471e279b6c1SSam Ravnborg 2472d4f3e350SEd Wildgooseconfig ALIX 2473d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2474d4f3e350SEd Wildgoose select GPIOLIB 2475d4f3e350SEd Wildgoose ---help--- 2476d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2477d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2478d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2479d4f3e350SEd Wildgoose get added here. 2480d4f3e350SEd Wildgoose 2481d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2482d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2483d4f3e350SEd Wildgoose 2484d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2485d4f3e350SEd Wildgoose 2486da4e3302SPhilip Prindevilleconfig NET5501 2487da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2488da4e3302SPhilip Prindeville select GPIOLIB 2489da4e3302SPhilip Prindeville ---help--- 2490da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2491da4e3302SPhilip Prindeville 24923197059aSPhilip A. Prindevilleconfig GEOS 24933197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 24943197059aSPhilip A. Prindeville select GPIOLIB 24953197059aSPhilip A. Prindeville depends on DMI 24963197059aSPhilip A. Prindeville ---help--- 24973197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 24983197059aSPhilip A. Prindeville 24997d029125SVivien Didelotconfig TS5500 25007d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 25017d029125SVivien Didelot depends on MELAN 25027d029125SVivien Didelot select CHECK_SIGNATURE 25037d029125SVivien Didelot select NEW_LEDS 25047d029125SVivien Didelot select LEDS_CLASS 25057d029125SVivien Didelot ---help--- 25067d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 25077d029125SVivien Didelot 2508e279b6c1SSam Ravnborgendif # X86_32 2509e279b6c1SSam Ravnborg 251023ac4ae8SAndreas Herrmannconfig AMD_NB 2511e279b6c1SSam Ravnborg def_bool y 25120e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2513e279b6c1SSam Ravnborg 2514e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2515e279b6c1SSam Ravnborg 2516e279b6c1SSam Ravnborgsource "drivers/pci/hotplug/Kconfig" 2517e279b6c1SSam Ravnborg 2518388b78adSAlexandre Bounineconfig RAPIDIO 2519fdf90abcSAlexandre Bounine tristate "RapidIO support" 2520388b78adSAlexandre Bounine depends on PCI 2521388b78adSAlexandre Bounine default n 2522388b78adSAlexandre Bounine help 2523fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2524388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2525388b78adSAlexandre Bounine 2526388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2527388b78adSAlexandre Bounine 2528e3263ab3SDavid Herrmannconfig X86_SYSFB 2529e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2530e3263ab3SDavid Herrmann help 2531e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2532e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2533e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2534e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2535e3263ab3SDavid Herrmann to x86. 2536e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2537e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2538e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2539e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2540e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2541e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2542e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2543e3263ab3SDavid Herrmann 2544e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2545e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2546e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2547e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2548e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2549e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2550e3263ab3SDavid Herrmann incompatible with simplefb. 2551e3263ab3SDavid Herrmann 2552e3263ab3SDavid Herrmann If unsure, say Y. 2553e3263ab3SDavid Herrmann 2554e279b6c1SSam Ravnborgendmenu 2555e279b6c1SSam Ravnborg 2556e279b6c1SSam Ravnborg 2557e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2558e279b6c1SSam Ravnborg 2559e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2560e279b6c1SSam Ravnborg 2561e279b6c1SSam Ravnborgconfig IA32_EMULATION 2562e279b6c1SSam Ravnborg bool "IA32 Emulation" 2563e279b6c1SSam Ravnborg depends on X86_64 2564d1603990SRandy Dunlap select BINFMT_ELF 2565a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 25663bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 25678f9ca475SIngo Molnar ---help--- 25685fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 25695fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 25705fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2571e279b6c1SSam Ravnborg 2572e279b6c1SSam Ravnborgconfig IA32_AOUT 2573e279b6c1SSam Ravnborg tristate "IA32 a.out support" 25746b213e1bSDavid Woodhouse depends on IA32_EMULATION 25758f9ca475SIngo Molnar ---help--- 2576e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2577e279b6c1SSam Ravnborg 25780bf62763SH. Peter Anvinconfig X86_X32 25796ea30386SKees Cook bool "x32 ABI for 64-bit mode" 25809b54050bSBrian Gerst depends on X86_64 25815fd92e65SH. J. Lu ---help--- 25825fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 25835fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 25845fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 25855fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 25865fd92e65SH. J. Lu 25875fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 25885fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 25895fd92e65SH. J. Lu option set. 25905fd92e65SH. J. Lu 2591e279b6c1SSam Ravnborgconfig COMPAT 25923c2362e6SHarvey Harrison def_bool y 25930bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2594e279b6c1SSam Ravnborg 25953120e25eSJan Beulichif COMPAT 2596e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 25973120e25eSJan Beulich def_bool y 2598e279b6c1SSam Ravnborg 2599e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 26003c2362e6SHarvey Harrison def_bool y 26013120e25eSJan Beulich depends on SYSVIPC 2602e279b6c1SSam Ravnborg 2603ee009e4aSDavid Howellsconfig KEYS_COMPAT 26043120e25eSJan Beulich def_bool y 26053120e25eSJan Beulich depends on KEYS 26063120e25eSJan Beulichendif 2607ee009e4aSDavid Howells 2608e279b6c1SSam Ravnborgendmenu 2609e279b6c1SSam Ravnborg 2610e279b6c1SSam Ravnborg 2611e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2612e5beae16SKeith Packard def_bool y 2613e5beae16SKeith Packard depends on X86_32 2614e5beae16SKeith Packard 26154692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 26164692d77fSAlessandro Rubini bool 261783125a3aSAlessandro Rubini depends on X86_64 || STA2X11 26184692d77fSAlessandro Rubini 2619f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2620f7219a53SAlessandro Rubini bool 262183125a3aSAlessandro Rubini depends on STA2X11 2622f7219a53SAlessandro Rubini 262393e5eaddSLi, Aubreyconfig PMC_ATOM 262493e5eaddSLi, Aubrey def_bool y 262593e5eaddSLi, Aubrey depends on PCI 262693e5eaddSLi, Aubrey 2627e279b6c1SSam Ravnborgsource "net/Kconfig" 2628e279b6c1SSam Ravnborg 2629e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2630e279b6c1SSam Ravnborg 2631e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2632e279b6c1SSam Ravnborg 2633e279b6c1SSam Ravnborgsource "fs/Kconfig" 2634e279b6c1SSam Ravnborg 2635e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2636e279b6c1SSam Ravnborg 2637e279b6c1SSam Ravnborgsource "security/Kconfig" 2638e279b6c1SSam Ravnborg 2639e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2640e279b6c1SSam Ravnborg 2641edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2642edf88417SAvi Kivity 2643e279b6c1SSam Ravnborgsource "lib/Kconfig" 2644