1daa93fabSSam Ravnborg# Select 32 or 64 bit 2daa93fabSSam Ravnborgconfig 64BIT 36840999bSSam Ravnborg bool "64-bit kernel" if ARCH = "x86" 4ffee0de4SDavid Woodhouse default ARCH != "i386" 58f9ca475SIngo Molnar ---help--- 6daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 7daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 8daa93fabSSam Ravnborg 9daa93fabSSam Ravnborgconfig X86_32 103120e25eSJan Beulich def_bool y 113120e25eSJan Beulich depends on !64BIT 12daa93fabSSam Ravnborg 13daa93fabSSam Ravnborgconfig X86_64 143120e25eSJan Beulich def_bool y 153120e25eSJan Beulich depends on 64BIT 161032c0baSSam Ravnborg 171032c0baSSam Ravnborg### Arch settings 188d5fffb9SSam Ravnborgconfig X86 193c2362e6SHarvey Harrison def_bool y 206471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 216e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 226471b825SIngo Molnar select ANON_INODES 236471b825SIngo Molnar select ARCH_CLOCKSOURCE_DATA 246471b825SIngo Molnar select ARCH_DISCARD_MEMBLOCK 256471b825SIngo Molnar select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 26446f24d1SStephen Boyd select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 276471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 2872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 29957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 3096601adbSDan Williams select ARCH_HAS_PMEM_API if X86_64 3167a3e8feSRoss Zwisler select ARCH_HAS_MMIO_FLUSH 326471b825SIngo Molnar select ARCH_HAS_SG_CHAIN 336471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 346471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 3577fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 365e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 376471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 383b242c66SMel Gorman select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 39be5e610cSPeter Zijlstra select ARCH_SUPPORTS_INT128 if X86_64 406471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 416471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 426471b825SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF if X86_64 436471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 446471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 4572b252aeSMel Gorman select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 465aaeb5c0SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 47da4276b8SIngo Molnar select ARCH_WANT_FRAME_POINTERS 486471b825SIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION if X86_32 496471b825SIngo Molnar select ARCH_WANT_OPTIONAL_GPIOLIB 506471b825SIngo Molnar select BUILDTIME_EXTABLE_SORT 516471b825SIngo Molnar select CLKEVT_I8253 526471b825SIngo Molnar select CLKSRC_I8253 if X86_32 536471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 546471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 556471b825SIngo Molnar select CLONE_BACKWARDS if X86_32 566471b825SIngo Molnar select COMPAT_OLD_SIGACTION if IA32_EMULATION 576471b825SIngo Molnar select DCACHE_WORD_ACCESS 5845471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 5945471cd9SLinus Torvalds select EDAC_SUPPORT 606471b825SIngo Molnar select GENERIC_CLOCKEVENTS 616471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 626471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 636471b825SIngo Molnar select GENERIC_CMOS_UPDATE 646471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 656471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 666471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 676471b825SIngo Molnar select GENERIC_IOMAP 686471b825SIngo Molnar select GENERIC_IRQ_PROBE 696471b825SIngo Molnar select GENERIC_IRQ_SHOW 706471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 716471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 726471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 736471b825SIngo Molnar select GENERIC_STRNLEN_USER 746471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 756471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 766471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 776471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 786471b825SIngo Molnar select HAVE_AOUT if X86_32 796471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 806471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 816471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 826471b825SIngo Molnar select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 836471b825SIngo Molnar select HAVE_ARCH_KGDB 846471b825SIngo Molnar select HAVE_ARCH_KMEMCHECK 856471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 866471b825SIngo Molnar select HAVE_ARCH_SOFT_DIRTY if X86_64 876471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 886471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 896471b825SIngo Molnar select HAVE_BPF_JIT if X86_64 906471b825SIngo Molnar select HAVE_CC_STACKPROTECTOR 916471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 926471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 936471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 94c1bd55f9SJosh Triplett select HAVE_COPY_THREAD_TLS 956471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 966471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 976471b825SIngo Molnar select HAVE_DEBUG_STACKOVERFLOW 986471b825SIngo Molnar select HAVE_DMA_API_DEBUG 997c095e46SFUJITA Tomonori select HAVE_DMA_ATTRS 1009c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 101677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 10206aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 10358340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1046471b825SIngo Molnar select HAVE_FENTRY if X86_64 1056471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1066471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_FP_TEST 1076471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1086471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1096471b825SIngo Molnar select HAVE_GENERIC_DMA_COHERENT if X86_32 1100067f129SK.Prasad select HAVE_HW_BREAKPOINT 1116471b825SIngo Molnar select HAVE_IDE 1126471b825SIngo Molnar select HAVE_IOREMAP_PROT 1136471b825SIngo Molnar select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 1146471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1156471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1166471b825SIngo Molnar select HAVE_KERNEL_GZIP 1176471b825SIngo Molnar select HAVE_KERNEL_LZ4 1186471b825SIngo Molnar select HAVE_KERNEL_LZMA 1196471b825SIngo Molnar select HAVE_KERNEL_LZO 1206471b825SIngo Molnar select HAVE_KERNEL_XZ 1216471b825SIngo Molnar select HAVE_KPROBES 1226471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 1236471b825SIngo Molnar select HAVE_KRETPROBES 1246471b825SIngo Molnar select HAVE_KVM 1256471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 1266471b825SIngo Molnar select HAVE_MEMBLOCK 1276471b825SIngo Molnar select HAVE_MEMBLOCK_NODE_MAP 1280102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 1296471b825SIngo Molnar select HAVE_OPROFILE 1306471b825SIngo Molnar select HAVE_OPTPROBES 1316471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 1326471b825SIngo Molnar select HAVE_PERF_EVENTS 133c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 134c5e63197SJiri Olsa select HAVE_PERF_REGS 135c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 1366471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 1376471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 1380c3619eaSBrian Gerst select HAVE_UID16 if X86_32 || IA32_EMULATION 1396471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 1407c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 141c0185808SThomas Gleixner select IRQ_FORCED_THREADING 142786d35d4SDavid Howells select MODULES_USE_ELF_RELA if X86_64 1436471b825SIngo Molnar select MODULES_USE_ELF_REL if X86_32 1445b3eb3adSAl Viro select OLD_SIGACTION if X86_32 1456471b825SIngo Molnar select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 1466471b825SIngo Molnar select PERF_EVENTS 1473195ef59SPrarit Bhargava select RTC_LIB 1486471b825SIngo Molnar select SPARSE_IRQ 14983fe27eaSPranith Kumar select SRCU 1506471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 1516471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 1526471b825SIngo Molnar select VIRT_TO_BUS 1536471b825SIngo Molnar select X86_DEV_DMA_OPS if X86_64 1546471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 1557d8330a5SBalbir Singh 156ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 1573120e25eSJan Beulich def_bool y 1583120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 159ba7e4d13SIngo Molnar 1607fb0f1deSPeter Zijlstraconfig PERF_EVENTS_INTEL_UNCORE 1617fb0f1deSPeter Zijlstra def_bool y 162ce5686d4SPeter Zijlstra (Intel) depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 1637fb0f1deSPeter Zijlstra 16451b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 16551b26adaSLinus Torvalds string 16651b26adaSLinus Torvalds default "elf32-i386" if X86_32 16751b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 16851b26adaSLinus Torvalds 16973531905SSam Ravnborgconfig ARCH_DEFCONFIG 170b9b39bfbSSam Ravnborg string 17173531905SSam Ravnborg default "arch/x86/configs/i386_defconfig" if X86_32 17273531905SSam Ravnborg default "arch/x86/configs/x86_64_defconfig" if X86_64 173b9b39bfbSSam Ravnborg 1748d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 1753c2362e6SHarvey Harrison def_bool y 1768d5fffb9SSam Ravnborg 1778d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 1783c2362e6SHarvey Harrison def_bool y 1798d5fffb9SSam Ravnborg 180aa7d9350SHeiko Carstensconfig HAVE_LATENCYTOP_SUPPORT 181aa7d9350SHeiko Carstens def_bool y 182aa7d9350SHeiko Carstens 1838d5fffb9SSam Ravnborgconfig MMU 1843c2362e6SHarvey Harrison def_bool y 1858d5fffb9SSam Ravnborg 1868d5fffb9SSam Ravnborgconfig SBUS 1878d5fffb9SSam Ravnborg bool 1888d5fffb9SSam Ravnborg 1893bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE 1903120e25eSJan Beulich def_bool y 191a6dfa128SKonrad Rzeszutek Wilk depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 1923bc4e459SFUJITA Tomonori 19318e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH 1944a14d84eSAndrew Morton def_bool y 19518e98307SFUJITA Tomonori 1968d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 1973120e25eSJan Beulich def_bool y 1983120e25eSJan Beulich depends on ISA_DMA_API 1998d5fffb9SSam Ravnborg 2008d5fffb9SSam Ravnborgconfig GENERIC_BUG 2013c2362e6SHarvey Harrison def_bool y 2028d5fffb9SSam Ravnborg depends on BUG 203b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 204b93a531eSJan Beulich 205b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 206b93a531eSJan Beulich bool 2078d5fffb9SSam Ravnborg 2088d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT 2093c2362e6SHarvey Harrison def_bool y 2108d5fffb9SSam Ravnborg 2118d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2123120e25eSJan Beulich def_bool y 2133120e25eSJan Beulich depends on ISA_DMA_API 2148d5fffb9SSam Ravnborg 2151032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM 2163120e25eSJan Beulich def_bool y 2171032c0baSSam Ravnborg 2181032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2191032c0baSSam Ravnborg def_bool y 2201032c0baSSam Ravnborg 2219a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 2229a0b8415Svenkatesh.pallipadi@intel.com def_bool y 2238d5fffb9SSam Ravnborg 2241b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 2251b27d05bSPekka Enberg def_bool y 2261b27d05bSPekka Enberg 227dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 22889c9c4c5SBrian Gerst def_bool y 229b32ef636Stravis@sgi.com 23008fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 23108fc4580STejun Heo def_bool y 23208fc4580STejun Heo 23308fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 23411124411STejun Heo def_bool y 23511124411STejun Heo 236801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 237801e4062SJohannes Berg def_bool y 238801e4062SJohannes Berg 239f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 240f4cb5700SJohannes Berg def_bool y 241f4cb5700SJohannes Berg 242cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE 243cfe28c5dSSteve Capper def_bool y 244cfe28c5dSSteve Capper 24553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 24653313b2cSSteve Capper def_bool y 24753313b2cSSteve Capper 2488d5fffb9SSam Ravnborgconfig ZONE_DMA32 249e0fd24a3SJan Beulich def_bool y if X86_64 2508d5fffb9SSam Ravnborg 2518d5fffb9SSam Ravnborgconfig AUDIT_ARCH 252e0fd24a3SJan Beulich def_bool y if X86_64 2538d5fffb9SSam Ravnborg 254765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING 255765c68bdSIngo Molnar def_bool y 256765c68bdSIngo Molnar 2576a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 2586a11f75bSAkinobu Mita def_bool y 2596a11f75bSAkinobu Mita 260d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 261d6f2d75aSAndrey Ryabinin hex 262d6f2d75aSAndrey Ryabinin depends on KASAN 263d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 264d6f2d75aSAndrey Ryabinin 26569575d38SShane Wangconfig HAVE_INTEL_TXT 26669575d38SShane Wang def_bool y 2676ea30386SKees Cook depends on INTEL_IOMMU && ACPI 26869575d38SShane Wang 2696b0c3d44SSam Ravnborgconfig X86_32_SMP 2706b0c3d44SSam Ravnborg def_bool y 2716b0c3d44SSam Ravnborg depends on X86_32 && SMP 2726b0c3d44SSam Ravnborg 2736b0c3d44SSam Ravnborgconfig X86_64_SMP 2746b0c3d44SSam Ravnborg def_bool y 2756b0c3d44SSam Ravnborg depends on X86_64 && SMP 2766b0c3d44SSam Ravnborg 277ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 278ccbeed3aSTejun Heo def_bool y 27960a5317fSTejun Heo depends on X86_32 && !CC_STACKPROTECTOR 280ccbeed3aSTejun Heo 281d61931d8SBorislav Petkovconfig ARCH_HWEIGHT_CFLAGS 282d61931d8SBorislav Petkov string 283d61931d8SBorislav Petkov default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 284d61931d8SBorislav Petkov default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 285d61931d8SBorislav Petkov 2862b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 2872b144498SSrikar Dronamraju def_bool y 2882b144498SSrikar Dronamraju 289d20642f0SRob Herringconfig FIX_EARLYCON_MEM 290d20642f0SRob Herring def_bool y 291d20642f0SRob Herring 29298233368SKirill A. Shutemovconfig PGTABLE_LEVELS 29398233368SKirill A. Shutemov int 29498233368SKirill A. Shutemov default 4 if X86_64 29598233368SKirill A. Shutemov default 3 if X86_PAE 29698233368SKirill A. Shutemov default 2 29798233368SKirill A. Shutemov 298506f1d07SSam Ravnborgsource "init/Kconfig" 299dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer" 3008d5fffb9SSam Ravnborg 301506f1d07SSam Ravnborgmenu "Processor type and features" 302506f1d07SSam Ravnborg 3035ee71535SRandy Dunlapconfig ZONE_DMA 3045ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3055ee71535SRandy Dunlap default y 3065ee71535SRandy Dunlap help 3075ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3085ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3095ee71535SRandy Dunlap Disable if no such devices will be used. 3105ee71535SRandy Dunlap 3115ee71535SRandy Dunlap If unsure, say Y. 3125ee71535SRandy Dunlap 313506f1d07SSam Ravnborgconfig SMP 314506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 315506f1d07SSam Ravnborg ---help--- 316506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3174a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3184a474157SRobert Graffham than one CPU, say Y. 319506f1d07SSam Ravnborg 3204a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 321506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 322506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 3234a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 324506f1d07SSam Ravnborg will run faster if you say N here. 325506f1d07SSam Ravnborg 326506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 327506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 328506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 329506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 330506f1d07SSam Ravnborg 331506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 332506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 333506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 334506f1d07SSam Ravnborg 335395cf969SPaul Bolle See also <file:Documentation/x86/i386/IO-APIC.txt>, 336506f1d07SSam Ravnborg <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 337506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 338506f1d07SSam Ravnborg 339506f1d07SSam Ravnborg If you don't know what to do here, say N. 340506f1d07SSam Ravnborg 3419def39beSJosh Triplettconfig X86_FEATURE_NAMES 3429def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 3439def39beSJosh Triplett default y 3449def39beSJosh Triplett ---help--- 3459def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 3469def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 3479def39beSJosh Triplett messages. You can disable this to save space, at the expense of 3489def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 3499def39beSJosh Triplett 3509def39beSJosh Triplett If in doubt, say Y. 3519def39beSJosh Triplett 35206cd9a7dSYinghai Luconfig X86_X2APIC 35306cd9a7dSYinghai Lu bool "Support x2apic" 35419e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 35506cd9a7dSYinghai Lu ---help--- 35606cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 35706cd9a7dSYinghai Lu 35806cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 35906cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 36006cd9a7dSYinghai Lu 36106cd9a7dSYinghai Lu If you don't know what to do here, say N. 36206cd9a7dSYinghai Lu 3636695c85bSYinghai Luconfig X86_MPPARSE 3646e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 3657a527688SJan Beulich default y 3665ab74722SIngo Molnar depends on X86_LOCAL_APIC 3678f9ca475SIngo Molnar ---help--- 3686695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 3696695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 3706695c85bSYinghai Lu 37126f7ef14SYinghai Luconfig X86_BIGSMP 37226f7ef14SYinghai Lu bool "Support for big SMP systems with more than 8 CPUs" 37326f7ef14SYinghai Lu depends on X86_32 && SMP 3748f9ca475SIngo Molnar ---help--- 37526f7ef14SYinghai Lu This option is needed for the systems that have more than 8 CPUs 376506f1d07SSam Ravnborg 377ddd70cf9SJun Nakajimaconfig GOLDFISH 378ddd70cf9SJun Nakajima def_bool y 379ddd70cf9SJun Nakajima depends on X86_GOLDFISH 380ddd70cf9SJun Nakajima 3818425091fSRavikiran G Thirumalaiif X86_32 382c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 383c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 384c5c606d9SRavikiran G Thirumalai default y 3858f9ca475SIngo Molnar ---help--- 38606ac8346SIngo Molnar If you disable this option then the kernel will only support 38706ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 38806ac8346SIngo Molnar systems out there.) 38906ac8346SIngo Molnar 3908425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 3918425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 392cb7b8023SBen Hutchings Goldfish (Android emulator) 3938425091fSRavikiran G Thirumalai AMD Elan 3948425091fSRavikiran G Thirumalai RDC R-321x SoC 3958425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 39683125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 3973f4110a4SThomas Gleixner Moorestown MID devices 39806ac8346SIngo Molnar 39906ac8346SIngo Molnar If you have one of these systems, or if you want to build a 40006ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 4018425091fSRavikiran G Thirumalaiendif 40206ac8346SIngo Molnar 4038425091fSRavikiran G Thirumalaiif X86_64 4048425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 4058425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 4068425091fSRavikiran G Thirumalai default y 4078425091fSRavikiran G Thirumalai ---help--- 4088425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 4098425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 4108425091fSRavikiran G Thirumalai systems out there.) 4118425091fSRavikiran G Thirumalai 4128425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 4138425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 41444b111b5SSteffen Persvold Numascale NumaChip 4158425091fSRavikiran G Thirumalai ScaleMP vSMP 4168425091fSRavikiran G Thirumalai SGI Ultraviolet 4178425091fSRavikiran G Thirumalai 4188425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 4198425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 4208425091fSRavikiran G Thirumalaiendif 421c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 422c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 42344b111b5SSteffen Persvoldconfig X86_NUMACHIP 42444b111b5SSteffen Persvold bool "Numascale NumaChip" 42544b111b5SSteffen Persvold depends on X86_64 42644b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 42744b111b5SSteffen Persvold depends on NUMA 42844b111b5SSteffen Persvold depends on SMP 42944b111b5SSteffen Persvold depends on X86_X2APIC 430f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 43144b111b5SSteffen Persvold ---help--- 43244b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 43344b111b5SSteffen Persvold enable more than ~168 cores. 43444b111b5SSteffen Persvold If you don't have one of these, you should say N here. 43503b48632SNick Piggin 4366a48565eSIngo Molnarconfig X86_VSMP 437c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 4386276a074SBorislav Petkov select HYPERVISOR_GUEST 4396a48565eSIngo Molnar select PARAVIRT 4406a48565eSIngo Molnar depends on X86_64 && PCI 441c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 442ead91d4bSShai Fultheim depends on SMP 4438f9ca475SIngo Molnar ---help--- 4446a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 4456a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 4466a48565eSIngo Molnar if you have one of these machines. 4476a48565eSIngo Molnar 448c5c606d9SRavikiran G Thirumalaiconfig X86_UV 449c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 450c5c606d9SRavikiran G Thirumalai depends on X86_64 451c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 45254c28d29SJack Steiner depends on NUMA 4539d6c26e7SSuresh Siddha depends on X86_X2APIC 4541222e564SIngo Molnar depends on PCI 455c5c606d9SRavikiran G Thirumalai ---help--- 456c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 457c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 458c5c606d9SRavikiran G Thirumalai 459c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 460c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 461506f1d07SSam Ravnborg 462ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 463ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 464cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 465ddd70cf9SJun Nakajima ---help--- 466ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 467ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 468ddd70cf9SJun Nakajima Goldfish emulator say N here. 469ddd70cf9SJun Nakajima 470c751e17bSThomas Gleixnerconfig X86_INTEL_CE 471c751e17bSThomas Gleixner bool "CE4100 TV platform" 472c751e17bSThomas Gleixner depends on PCI 473c751e17bSThomas Gleixner depends on PCI_GODIRECT 4746084a6e2SJiang Liu depends on X86_IO_APIC 475c751e17bSThomas Gleixner depends on X86_32 476c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 47737bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 478da6b737bSSebastian Andrzej Siewior select OF 479da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 480c751e17bSThomas Gleixner ---help--- 481c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 482c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 483c751e17bSThomas Gleixner boxes and media devices. 484c751e17bSThomas Gleixner 4854cb9b00fSDavid Cohenconfig X86_INTEL_MID 48643605ef1SAlan Cox bool "Intel MID platform support" 48743605ef1SAlan Cox depends on X86_32 48843605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 489edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 4901ea7c673SAlan Cox depends on PCI 4911ea7c673SAlan Cox depends on PCI_GOANY 4921ea7c673SAlan Cox depends on X86_IO_APIC 4937c9c3a1eSAlan Cox select SFI 4944cb9b00fSDavid Cohen select I2C 4957c9c3a1eSAlan Cox select DW_APB_TIMER 4961ea7c673SAlan Cox select APB_TIMER 4971ea7c673SAlan Cox select INTEL_SCU_IPC 49815a713dfSMika Westerberg select MFD_INTEL_MSIC 4991ea7c673SAlan Cox ---help--- 5004cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 5014cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 5024cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 5031ea7c673SAlan Cox 5044cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 5054cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 50643605ef1SAlan Cox 5078bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 5088bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 5098bbc2a13SBryan O'Donoghue depends on X86_32 5108bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 5118bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 5128bbc2a13SBryan O'Donoghue depends on X86_TSC 5138bbc2a13SBryan O'Donoghue depends on PCI 5148bbc2a13SBryan O'Donoghue depends on PCI_GOANY 5158bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 5168bbc2a13SBryan O'Donoghue select IOSF_MBI 5178bbc2a13SBryan O'Donoghue select INTEL_IMR 5189ab6eb51SAndy Shevchenko select COMMON_CLK 5198bbc2a13SBryan O'Donoghue ---help--- 5208bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 5218bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 5228bbc2a13SBryan O'Donoghue compatible Intel Galileo. 5238bbc2a13SBryan O'Donoghue 5243d48aab1SMika Westerbergconfig X86_INTEL_LPSS 5253d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 5263d48aab1SMika Westerberg depends on ACPI 5273d48aab1SMika Westerberg select COMMON_CLK 5280f531431SMathias Nyman select PINCTRL 5293d48aab1SMika Westerberg ---help--- 5303d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 5313d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 5320f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 5330f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 5343d48aab1SMika Westerberg 53592082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 53692082a88SKen Xue bool "AMD ACPI2Platform devices support" 53792082a88SKen Xue depends on ACPI 53892082a88SKen Xue select COMMON_CLK 53992082a88SKen Xue select PINCTRL 54092082a88SKen Xue ---help--- 54192082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 54292082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 54392082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 54492082a88SKen Xue implemented under PINCTRL subsystem. 54592082a88SKen Xue 546ced3ce76SDavid E. Boxconfig IOSF_MBI 547ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 548ced3ce76SDavid E. Box depends on PCI 549ced3ce76SDavid E. Box ---help--- 550ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 551ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 552ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 553ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 554ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 555ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 556ced3ce76SDavid E. Box This list is not meant to be exclusive. 557ced3ce76SDavid E. Box - BayTrail 558ced3ce76SDavid E. Box - Braswell 559ced3ce76SDavid E. Box - Quark 560ced3ce76SDavid E. Box 561ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 562ced3ce76SDavid E. Box 563ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 564ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 565ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 566ed2226bdSDavid E. Box ---help--- 567ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 568ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 569ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 570ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 571ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 572ed2226bdSDavid E. Box device they want to access. 573ed2226bdSDavid E. Box 574ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 575ed2226bdSDavid E. Box 576c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 577c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 578506f1d07SSam Ravnborg depends on X86_32 579c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 580c5c606d9SRavikiran G Thirumalai select M486 581c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 582c5c606d9SRavikiran G Thirumalai ---help--- 583c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 584c5c606d9SRavikiran G Thirumalai as R-8610-(G). 585c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 586c5c606d9SRavikiran G Thirumalai 587e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 5889c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 5899c398017SIngo Molnar depends on X86_32 && SMP 590c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 5918f9ca475SIngo Molnar ---help--- 592b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 593b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 594b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 595b5660ba7SH. Peter Anvin one and will fallback to default. 596d49c4288SYinghai Lu 597c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 598d49c4288SYinghai Lu 599d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 6006fc108a0SJan Beulich def_bool y 601d949f36fSLinus Torvalds # MCE code calls memory_failure(): 602d949f36fSLinus Torvalds depends on X86_MCE 603d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 604d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 605d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 606d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 607d949f36fSLinus Torvalds 60883125a3aSAlessandro Rubiniconfig STA2X11 60983125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 61083125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 61183125a3aSAlessandro Rubini select X86_DEV_DMA_OPS 61283125a3aSAlessandro Rubini select X86_DMA_REMAP 61383125a3aSAlessandro Rubini select SWIOTLB 61483125a3aSAlessandro Rubini select MFD_STA2X11 61583125a3aSAlessandro Rubini select ARCH_REQUIRE_GPIOLIB 61683125a3aSAlessandro Rubini default n 61783125a3aSAlessandro Rubini ---help--- 61883125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 61983125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 62083125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 62183125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 62283125a3aSAlessandro Rubini standard PC machines. 62383125a3aSAlessandro Rubini 62482148d1dSShérabconfig X86_32_IRIS 62582148d1dSShérab tristate "Eurobraille/Iris poweroff module" 62682148d1dSShérab depends on X86_32 62782148d1dSShérab ---help--- 62882148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 62982148d1dSShérab to shut themselves down properly. A special I/O sequence is 63082148d1dSShérab needed to do so, which is what this module does at 63182148d1dSShérab kernel shutdown. 63282148d1dSShérab 63382148d1dSShérab This is only for Iris machines from EuroBraille. 63482148d1dSShérab 63582148d1dSShérab If unused, say N. 63682148d1dSShérab 637ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 6383c2362e6SHarvey Harrison def_bool y 6393c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 640a87d0914SKen Chen depends on X86 6418f9ca475SIngo Molnar ---help--- 642506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 643506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 644506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 645506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 646506f1d07SSam Ravnborg 647506f1d07SSam Ravnborg If in doubt, say "Y". 648506f1d07SSam Ravnborg 6496276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 6506276a074SBorislav Petkov bool "Linux guest support" 6518f9ca475SIngo Molnar ---help--- 6526276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 6536276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 6546276a074SBorislav Petkov setup. 655506f1d07SSam Ravnborg 6566276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 6576276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 658506f1d07SSam Ravnborg 6596276a074SBorislav Petkovif HYPERVISOR_GUEST 660506f1d07SSam Ravnborg 661e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 662e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 6638f9ca475SIngo Molnar ---help--- 664e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 665e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 666e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 667e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 668e61bd94aSEduardo Pereira Habkost 6696276a074SBorislav Petkovconfig PARAVIRT_DEBUG 6706276a074SBorislav Petkov bool "paravirt-ops debugging" 6716276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 6726276a074SBorislav Petkov ---help--- 6736276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 6746276a074SBorislav Petkov a paravirt_op is missing when it is called. 6756276a074SBorislav Petkov 676b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 677b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 6786ea30386SKees Cook depends on PARAVIRT && SMP 67962c7a1e9SIngo Molnar select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 680b4ecc126SJeremy Fitzhardinge ---help--- 681b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 682b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 683b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 684b4ecc126SJeremy Fitzhardinge 6854c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 6864c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 687b4ecc126SJeremy Fitzhardinge 6884c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 689b4ecc126SJeremy Fitzhardinge 690*45e898b7SWaiman Longconfig QUEUED_LOCK_STAT 691*45e898b7SWaiman Long bool "Paravirt queued spinlock statistics" 692*45e898b7SWaiman Long depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS 693*45e898b7SWaiman Long ---help--- 694*45e898b7SWaiman Long Enable the collection of statistical data on the slowpath 695*45e898b7SWaiman Long behavior of paravirtualized queued spinlocks and report 696*45e898b7SWaiman Long them on debugfs. 697*45e898b7SWaiman Long 6986276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 6996276a074SBorislav Petkov 7006276a074SBorislav Petkovconfig KVM_GUEST 7016276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 7026276a074SBorislav Petkov depends on PARAVIRT 7036276a074SBorislav Petkov select PARAVIRT_CLOCK 7046276a074SBorislav Petkov default y 7056276a074SBorislav Petkov ---help--- 7066276a074SBorislav Petkov This option enables various optimizations for running under the KVM 7076276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 7086276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 7096276a074SBorislav Petkov underlying device model, the host provides the guest with 7106276a074SBorislav Petkov timing infrastructure such as time of day, and system time 7116276a074SBorislav Petkov 7121e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS 7131e20eb85SSrivatsa Vaddagiri bool "Enable debug information for KVM Guests in debugfs" 7141e20eb85SSrivatsa Vaddagiri depends on KVM_GUEST && DEBUG_FS 7151e20eb85SSrivatsa Vaddagiri default n 7161e20eb85SSrivatsa Vaddagiri ---help--- 7171e20eb85SSrivatsa Vaddagiri This option enables collection of various statistics for KVM guest. 7181e20eb85SSrivatsa Vaddagiri Statistics are displayed in debugfs filesystem. Enabling this option 7191e20eb85SSrivatsa Vaddagiri may incur significant overhead. 7201e20eb85SSrivatsa Vaddagiri 7216276a074SBorislav Petkovsource "arch/x86/lguest/Kconfig" 7226276a074SBorislav Petkov 7236276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 7246276a074SBorislav Petkov bool "Paravirtual steal time accounting" 7256276a074SBorislav Petkov depends on PARAVIRT 7266276a074SBorislav Petkov default n 7276276a074SBorislav Petkov ---help--- 7286276a074SBorislav Petkov Select this option to enable fine granularity task steal time 7296276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 7306276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 7316276a074SBorislav Petkov that, there can be a small performance impact. 7326276a074SBorislav Petkov 7336276a074SBorislav Petkov If in doubt, say N here. 7346276a074SBorislav Petkov 7357af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 7367af192c9SGerd Hoffmann bool 7377af192c9SGerd Hoffmann 7386276a074SBorislav Petkovendif #HYPERVISOR_GUEST 73997349135SJeremy Fitzhardinge 74008677214SYinghai Luconfig NO_BOOTMEM 741774ea0bcSYinghai Lu def_bool y 74208677214SYinghai Lu 743506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 744506f1d07SSam Ravnborg 745506f1d07SSam Ravnborgconfig HPET_TIMER 7463c2362e6SHarvey Harrison def_bool X86_64 747506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 7488f9ca475SIngo Molnar ---help--- 749506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 750506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 751506f1d07SSam Ravnborg present. 752506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 753506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 754506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 755506f1d07SSam Ravnborg as it is off-chip. You can find the HPET spec at 756e45f2c07SDenis V. Lunev <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 757506f1d07SSam Ravnborg 758506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 759506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 760506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 761506f1d07SSam Ravnborg 762506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 763506f1d07SSam Ravnborg 764506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 7653c2362e6SHarvey Harrison def_bool y 7669d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 767506f1d07SSam Ravnborg 768bb24c471SJacob Panconfig APB_TIMER 769933b9463SAlan Cox def_bool y if X86_INTEL_MID 770933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 77106c3df49SJamie Iles select DW_APB_TIMER 772a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 773bb24c471SJacob Pan help 774bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 775bb24c471SJacob Pan The APBT provides a stable time base on SMP 776bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 777bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 778bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 779bb24c471SJacob Pan 7806a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 781506f1d07SSam Ravnborg# The code disables itself when not needed. 7827ae9392cSThomas Petazzoniconfig DMI 7837ae9392cSThomas Petazzoni default y 784cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 7856a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 7868f9ca475SIngo Molnar ---help--- 7877ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 7887ae9392cSThomas Petazzoni here unless you have verified that your setup is not 7897ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 7907ae9392cSThomas Petazzoni BIOS code. 7917ae9392cSThomas Petazzoni 792506f1d07SSam Ravnborgconfig GART_IOMMU 79338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 794506f1d07SSam Ravnborg select SWIOTLB 79523ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 7968f9ca475SIngo Molnar ---help--- 797ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 798ced3c42cSIngo Molnar GART based hardware IOMMUs. 799ced3c42cSIngo Molnar 800ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 801ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 802ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 803ced3c42cSIngo Molnar 804ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 805ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 806ced3c42cSIngo Molnar 807ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 808ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 809ced3c42cSIngo Molnar 32-bit limited device. 810ced3c42cSIngo Molnar 811ced3c42cSIngo Molnar If unsure, say Y. 812506f1d07SSam Ravnborg 813506f1d07SSam Ravnborgconfig CALGARY_IOMMU 814506f1d07SSam Ravnborg bool "IBM Calgary IOMMU support" 815506f1d07SSam Ravnborg select SWIOTLB 8166ea30386SKees Cook depends on X86_64 && PCI 8178f9ca475SIngo Molnar ---help--- 818506f1d07SSam Ravnborg Support for hardware IOMMUs in IBM's xSeries x366 and x460 819506f1d07SSam Ravnborg systems. Needed to run systems with more than 3GB of memory 820506f1d07SSam Ravnborg properly with 32-bit PCI devices that do not support DAC 821506f1d07SSam Ravnborg (Double Address Cycle). Calgary also supports bus level 822506f1d07SSam Ravnborg isolation, where all DMAs pass through the IOMMU. This 823506f1d07SSam Ravnborg prevents them from going anywhere except their intended 824506f1d07SSam Ravnborg destination. This catches hard-to-find kernel bugs and 825506f1d07SSam Ravnborg mis-behaving drivers and devices that do not use the DMA-API 826506f1d07SSam Ravnborg properly to set up their DMA buffers. The IOMMU can be 827506f1d07SSam Ravnborg turned off at boot time with the iommu=off parameter. 828506f1d07SSam Ravnborg Normally the kernel will make the right choice by itself. 829506f1d07SSam Ravnborg If unsure, say Y. 830506f1d07SSam Ravnborg 831506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT 8323c2362e6SHarvey Harrison def_bool y 8333c2362e6SHarvey Harrison prompt "Should Calgary be enabled by default?" 834506f1d07SSam Ravnborg depends on CALGARY_IOMMU 8358f9ca475SIngo Molnar ---help--- 836506f1d07SSam Ravnborg Should Calgary be enabled by default? if you choose 'y', Calgary 837506f1d07SSam Ravnborg will be used (if it exists). If you choose 'n', Calgary will not be 838506f1d07SSam Ravnborg used even if it exists. If you choose 'n' and would like to use 839506f1d07SSam Ravnborg Calgary anyway, pass 'iommu=calgary' on the kernel command line. 840506f1d07SSam Ravnborg If unsure, say Y. 841506f1d07SSam Ravnborg 842506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround 843506f1d07SSam Ravnborgconfig SWIOTLB 844a1afd01cSJoerg Roedel def_bool y if X86_64 8458f9ca475SIngo Molnar ---help--- 846506f1d07SSam Ravnborg Support for software bounce buffers used on x86-64 systems 8474454d327SJoe Millenbach which don't have a hardware IOMMU. Using this PCI devices 8484454d327SJoe Millenbach which can only access 32-bits of memory can be used on systems 8494454d327SJoe Millenbach with more than 3 GB of memory. 8504454d327SJoe Millenbach If unsure, say Y. 851506f1d07SSam Ravnborg 852a8522509SFUJITA Tomonoriconfig IOMMU_HELPER 8533120e25eSJan Beulich def_bool y 8543120e25eSJan Beulich depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 855d25e26b6SLinus Torvalds 8561184dc2fSMike Travisconfig MAXSMP 857ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 8586ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 85936f5101aSMike Travis select CPUMASK_OFFSTACK 8608f9ca475SIngo Molnar ---help--- 861ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 8621184dc2fSMike Travis If unsure, say N. 863506f1d07SSam Ravnborg 864506f1d07SSam Ravnborgconfig NR_CPUS 86536f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 8662a3313f4SMichael K. Johnson range 2 8 if SMP && X86_32 && !X86_BIGSMP 867bb61ccc7SJosh Boyer range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 868b53b5edaSJosh Boyer range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 86978637a97SMike Travis default "1" if !SMP 870b53b5edaSJosh Boyer default "8192" if MAXSMP 871b5660ba7SH. Peter Anvin default "32" if SMP && X86_BIGSMP 872c5c19941SKirill A. Shutemov default "8" if SMP && X86_32 873c5c19941SKirill A. Shutemov default "64" if SMP 8748f9ca475SIngo Molnar ---help--- 875506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 876bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 877cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 878506f1d07SSam Ravnborg minimum value which makes sense is 2. 879506f1d07SSam Ravnborg 880506f1d07SSam Ravnborg This is purely to save memory - each supported CPU adds 881506f1d07SSam Ravnborg approximately eight kilobytes to the kernel image. 882506f1d07SSam Ravnborg 883506f1d07SSam Ravnborgconfig SCHED_SMT 884506f1d07SSam Ravnborg bool "SMT (Hyperthreading) scheduler support" 885c8e56d20SBorislav Petkov depends on SMP 8868f9ca475SIngo Molnar ---help--- 887506f1d07SSam Ravnborg SMT scheduler support improves the CPU scheduler's decision making 888506f1d07SSam Ravnborg when dealing with Intel Pentium 4 chips with HyperThreading at a 889506f1d07SSam Ravnborg cost of slightly increased overhead in some places. If unsure say 890506f1d07SSam Ravnborg N here. 891506f1d07SSam Ravnborg 892506f1d07SSam Ravnborgconfig SCHED_MC 8933c2362e6SHarvey Harrison def_bool y 8943c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 895c8e56d20SBorislav Petkov depends on SMP 8968f9ca475SIngo Molnar ---help--- 897506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 898506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 899506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 900506f1d07SSam Ravnborg 901506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt" 902506f1d07SSam Ravnborg 90330b8b006SThomas Gleixnerconfig UP_LATE_INIT 90430b8b006SThomas Gleixner def_bool y 905ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 90630b8b006SThomas Gleixner 907506f1d07SSam Ravnborgconfig X86_UP_APIC 90850849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 90950849eefSJan Beulich default PCI_MSI 91038a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 9118f9ca475SIngo Molnar ---help--- 912506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 913506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 914506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 915506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 916506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 917506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 918506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 919506f1d07SSam Ravnborg lockups. 920506f1d07SSam Ravnborg 921506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 922506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 923506f1d07SSam Ravnborg depends on X86_UP_APIC 9248f9ca475SIngo Molnar ---help--- 925506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 926506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 927506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 928506f1d07SSam Ravnborg 929506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 930506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 931506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 932506f1d07SSam Ravnborg 933506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 9343c2362e6SHarvey Harrison def_bool y 9350dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 936b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 93752f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 938506f1d07SSam Ravnborg 939506f1d07SSam Ravnborgconfig X86_IO_APIC 940b1da1e71SJan Beulich def_bool y 941b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 942506f1d07SSam Ravnborg 94341b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 94441b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 94541b9eb26SStefan Assmann depends on X86_IO_APIC 9468f9ca475SIngo Molnar ---help--- 94741b9eb26SStefan Assmann This option enables a workaround that fixes a source of 94841b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 94941b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 95041b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 95141b9eb26SStefan Assmann 95241b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 95341b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 95441b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 95541b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 95641b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 95741b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 95841b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 95941b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 96041b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 96141b9eb26SStefan Assmann down (vital) interrupt lines. 96241b9eb26SStefan Assmann 96341b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 96441b9eb26SStefan Assmann increased on these systems. 96541b9eb26SStefan Assmann 966506f1d07SSam Ravnborgconfig X86_MCE 967bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 968648ed940SChen, Gong select GENERIC_ALLOCATOR 969e57dbaf7SBorislav Petkov default y 970506f1d07SSam Ravnborg ---help--- 971bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 972bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 973506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 974bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 9754efc0670SAndi Kleen 976506f1d07SSam Ravnborgconfig X86_MCE_INTEL 9773c2362e6SHarvey Harrison def_bool y 9783c2362e6SHarvey Harrison prompt "Intel MCE features" 979c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9808f9ca475SIngo Molnar ---help--- 981506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 982506f1d07SSam Ravnborg the thermal monitor. 983506f1d07SSam Ravnborg 984506f1d07SSam Ravnborgconfig X86_MCE_AMD 9853c2362e6SHarvey Harrison def_bool y 9863c2362e6SHarvey Harrison prompt "AMD MCE features" 987c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 9888f9ca475SIngo Molnar ---help--- 989506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 990506f1d07SSam Ravnborg the DRAM Error Threshold. 991506f1d07SSam Ravnborg 9924efc0670SAndi Kleenconfig X86_ANCIENT_MCE 9936fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 994c31d9633SAndi Kleen depends on X86_32 && X86_MCE 9954efc0670SAndi Kleen ---help--- 9964efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 9975065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 9984efc0670SAndi Kleen line. 9994efc0670SAndi Kleen 1000b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1001b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 10026fc108a0SJan Beulich def_bool y 1003b2762686SAndi Kleen 1004ea149b36SAndi Kleenconfig X86_MCE_INJECT 1005c1ebf835SAndi Kleen depends on X86_MCE 1006ea149b36SAndi Kleen tristate "Machine check injector support" 1007ea149b36SAndi Kleen ---help--- 1008ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1009ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1010ea149b36SAndi Kleen QA it is safe to say n. 1011ea149b36SAndi Kleen 10124efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 10134efc0670SAndi Kleen def_bool y 10145bb38adcSAndi Kleen depends on X86_MCE_INTEL 10154efc0670SAndi Kleen 10165aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 10171e642812SIngo Molnar bool "Legacy VM86 support" 10185aef51c3SAndy Lutomirski default n 1019506f1d07SSam Ravnborg depends on X86_32 10208f9ca475SIngo Molnar ---help--- 10215aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 10225aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 10235aef51c3SAndy Lutomirski 10245aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 10255aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 10265aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 10275aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 10285aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 10291e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 10301e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 10311e642812SIngo Molnar mode might be faster than emulation and you might want to 10321e642812SIngo Molnar enable this option. 10335aef51c3SAndy Lutomirski 10341e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 10351e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 10361e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 10371e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 10385aef51c3SAndy Lutomirski 10391e642812SIngo Molnar Enabling this option increases the complexity of the kernel 10401e642812SIngo Molnar and slows down exception handling a tiny bit. 10415aef51c3SAndy Lutomirski 10421e642812SIngo Molnar If unsure, say N here. 10435aef51c3SAndy Lutomirski 10445aef51c3SAndy Lutomirskiconfig VM86 10455aef51c3SAndy Lutomirski bool 10465aef51c3SAndy Lutomirski default X86_LEGACY_VM86 104734273f41SH. Peter Anvin 104834273f41SH. Peter Anvinconfig X86_16BIT 104934273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 105034273f41SH. Peter Anvin default y 1051a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 105234273f41SH. Peter Anvin ---help--- 105334273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 105434273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 105534273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 105634273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 105734273f41SH. Peter Anvin 105834273f41SH. Peter Anvinconfig X86_ESPFIX32 105934273f41SH. Peter Anvin def_bool y 106034273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1061506f1d07SSam Ravnborg 1062197725deSH. Peter Anvinconfig X86_ESPFIX64 1063197725deSH. Peter Anvin def_bool y 106434273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1065506f1d07SSam Ravnborg 10661ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 10671ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 10681ad83c85SAndy Lutomirski default y 10691ad83c85SAndy Lutomirski depends on X86_64 10701ad83c85SAndy Lutomirski ---help--- 10711ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 10721ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 10731ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 10741ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 10751ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 10761ad83c85SAndy Lutomirski 0xffffffffff600?00. 10771ad83c85SAndy Lutomirski 10781ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 10791ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 10801ad83c85SAndy Lutomirski 10811ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 10821ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 10831ad83c85SAndy Lutomirski 1084506f1d07SSam Ravnborgconfig TOSHIBA 1085506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1086506f1d07SSam Ravnborg depends on X86_32 1087506f1d07SSam Ravnborg ---help--- 1088506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1089506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1090506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1091506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1092506f1d07SSam Ravnborg 1093506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1094506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1095506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1096506f1d07SSam Ravnborg 1097506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1098506f1d07SSam Ravnborg Say N otherwise. 1099506f1d07SSam Ravnborg 1100506f1d07SSam Ravnborgconfig I8K 1101039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1102949a9d70SJean Delvare select HWMON 1103039ae585SPali Rohár select SENSORS_DELL_SMM 1104506f1d07SSam Ravnborg ---help--- 1105039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1106039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1107039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1108039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1109039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1110039ae585SPali Rohár needed userspace package i8kutils. 1111506f1d07SSam Ravnborg 1112039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1113039ae585SPali Rohár use userspace package i8kutils. 1114506f1d07SSam Ravnborg Say N otherwise. 1115506f1d07SSam Ravnborg 1116506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 11179ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 11189ba16087SJan Beulich depends on X86_32 1119506f1d07SSam Ravnborg ---help--- 1120506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1121506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1122506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1123506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1124506f1d07SSam Ravnborg system. 1125506f1d07SSam Ravnborg 1126506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 11275e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1128506f1d07SSam Ravnborg 1129506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1130506f1d07SSam Ravnborg enable this option even if you don't need it. 1131506f1d07SSam Ravnborg Say N otherwise. 1132506f1d07SSam Ravnborg 1133506f1d07SSam Ravnborgconfig MICROCODE 11349a2bc335SBorislav Petkov bool "CPU microcode loading support" 11359a2bc335SBorislav Petkov default y 113680030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1137fe055896SBorislav Petkov depends on BLK_DEV_INITRD 1138506f1d07SSam Ravnborg select FW_LOADER 1139506f1d07SSam Ravnborg ---help--- 1140e43f6e67SBorislav Petkov 1141506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 114280cc9f10SPeter Oruba certain Intel and AMD processors. The Intel support is for the 1143e43f6e67SBorislav Petkov IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1144e43f6e67SBorislav Petkov Xeon etc. The AMD support is for families 0x10 and later. You will 1145e43f6e67SBorislav Petkov obviously need the actual microcode binary data itself which is not 1146e43f6e67SBorislav Petkov shipped with the Linux kernel. 1147506f1d07SSam Ravnborg 11488d86f390SPeter Oruba This option selects the general module only, you need to select 11498d86f390SPeter Oruba at least one vendor specific module as well. 1150506f1d07SSam Ravnborg 1151e43f6e67SBorislav Petkov To compile this driver as a module, choose M here: the module 1152e43f6e67SBorislav Petkov will be called microcode. 1153506f1d07SSam Ravnborg 11548d86f390SPeter Orubaconfig MICROCODE_INTEL 1155e43f6e67SBorislav Petkov bool "Intel microcode loading support" 11568d86f390SPeter Oruba depends on MICROCODE 11578d86f390SPeter Oruba default MICROCODE 11588d86f390SPeter Oruba select FW_LOADER 11598f9ca475SIngo Molnar ---help--- 11608d86f390SPeter Oruba This options enables microcode patch loading support for Intel 11618d86f390SPeter Oruba processors. 11628d86f390SPeter Oruba 1163b8989db9SAlan For the current Intel microcode data package go to 1164b8989db9SAlan <https://downloadcenter.intel.com> and search for 1165b8989db9SAlan 'Linux Processor Microcode Data File'. 11668d86f390SPeter Oruba 116780cc9f10SPeter Orubaconfig MICROCODE_AMD 1168e43f6e67SBorislav Petkov bool "AMD microcode loading support" 116980cc9f10SPeter Oruba depends on MICROCODE 117080cc9f10SPeter Oruba select FW_LOADER 11718f9ca475SIngo Molnar ---help--- 117280cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 117380cc9f10SPeter Oruba processors will be enabled. 117480cc9f10SPeter Oruba 1175506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 11763c2362e6SHarvey Harrison def_bool y 1177506f1d07SSam Ravnborg depends on MICROCODE 1178506f1d07SSam Ravnborg 1179506f1d07SSam Ravnborgconfig X86_MSR 1180506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 11818f9ca475SIngo Molnar ---help--- 1182506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1183506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1184506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1185506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1186506f1d07SSam Ravnborg systems. 1187506f1d07SSam Ravnborg 1188506f1d07SSam Ravnborgconfig X86_CPUID 1189506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 11908f9ca475SIngo Molnar ---help--- 1191506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1192506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1193506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1194506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1195506f1d07SSam Ravnborg 1196506f1d07SSam Ravnborgchoice 1197506f1d07SSam Ravnborg prompt "High Memory Support" 11986fc108a0SJan Beulich default HIGHMEM4G 1199506f1d07SSam Ravnborg depends on X86_32 1200506f1d07SSam Ravnborg 1201506f1d07SSam Ravnborgconfig NOHIGHMEM 1202506f1d07SSam Ravnborg bool "off" 1203506f1d07SSam Ravnborg ---help--- 1204506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1205506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1206506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1207506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1208506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1209506f1d07SSam Ravnborg "high memory". 1210506f1d07SSam Ravnborg 1211506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1212506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1213506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1214506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1215506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1216506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1217506f1d07SSam Ravnborg possible. 1218506f1d07SSam Ravnborg 1219506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1220506f1d07SSam Ravnborg answer "4GB" here. 1221506f1d07SSam Ravnborg 1222506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1223506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1224506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1225506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1226506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1227506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1228506f1d07SSam Ravnborg 1229506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1230506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1231506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1232506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1233506f1d07SSam Ravnborg kernel at boot time.) 1234506f1d07SSam Ravnborg 1235506f1d07SSam Ravnborg If unsure, say "off". 1236506f1d07SSam Ravnborg 1237506f1d07SSam Ravnborgconfig HIGHMEM4G 1238506f1d07SSam Ravnborg bool "4GB" 12398f9ca475SIngo Molnar ---help--- 1240506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1241506f1d07SSam Ravnborg gigabytes of physical RAM. 1242506f1d07SSam Ravnborg 1243506f1d07SSam Ravnborgconfig HIGHMEM64G 1244506f1d07SSam Ravnborg bool "64GB" 1245eb068e78SH. Peter Anvin depends on !M486 1246506f1d07SSam Ravnborg select X86_PAE 12478f9ca475SIngo Molnar ---help--- 1248506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1249506f1d07SSam Ravnborg gigabytes of physical RAM. 1250506f1d07SSam Ravnborg 1251506f1d07SSam Ravnborgendchoice 1252506f1d07SSam Ravnborg 1253506f1d07SSam Ravnborgchoice 12546a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1255506f1d07SSam Ravnborg default VMSPLIT_3G 1256506f1d07SSam Ravnborg depends on X86_32 12578f9ca475SIngo Molnar ---help--- 1258506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1259506f1d07SSam Ravnborg 1260506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1261506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1262506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1263506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1264506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1265506f1d07SSam Ravnborg available to user programs, making the address space there 1266506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1267506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1268506f1d07SSam Ravnborg kernel modules. 1269506f1d07SSam Ravnborg 1270506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1271506f1d07SSam Ravnborg option alone! 1272506f1d07SSam Ravnborg 1273506f1d07SSam Ravnborg config VMSPLIT_3G 1274506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1275506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1276506f1d07SSam Ravnborg depends on !X86_PAE 1277506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1278506f1d07SSam Ravnborg config VMSPLIT_2G 1279506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1280506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1281506f1d07SSam Ravnborg depends on !X86_PAE 1282506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1283506f1d07SSam Ravnborg config VMSPLIT_1G 1284506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1285506f1d07SSam Ravnborgendchoice 1286506f1d07SSam Ravnborg 1287506f1d07SSam Ravnborgconfig PAGE_OFFSET 1288506f1d07SSam Ravnborg hex 1289506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1290506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1291506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1292506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1293506f1d07SSam Ravnborg default 0xC0000000 1294506f1d07SSam Ravnborg depends on X86_32 1295506f1d07SSam Ravnborg 1296506f1d07SSam Ravnborgconfig HIGHMEM 12973c2362e6SHarvey Harrison def_bool y 1298506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1299506f1d07SSam Ravnborg 1300506f1d07SSam Ravnborgconfig X86_PAE 13019ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1302506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 13039d99c712SChristian Melki select SWIOTLB 13048f9ca475SIngo Molnar ---help--- 1305506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1306506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1307506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1308506f1d07SSam Ravnborg consumes more pagetable space per process. 1309506f1d07SSam Ravnborg 1310600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT 13113120e25eSJan Beulich def_bool y 13123120e25eSJan Beulich depends on X86_64 || X86_PAE 1313600715dcSJeremy Fitzhardinge 131466f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT 13153120e25eSJan Beulich def_bool y 13163120e25eSJan Beulich depends on X86_64 || HIGHMEM64G 131766f2b061SFUJITA Tomonori 131810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1319e5008abeSLuis R. Rodriguez def_bool y 1320e5008abeSLuis R. Rodriguez depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 13218f9ca475SIngo Molnar ---help--- 132210971ab2SIngo Molnar Certain kernel features effectively disable kernel 132310971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 132410971ab2SIngo Molnar supports them), so don't confuse the user by printing 132510971ab2SIngo Molnar that we have them enabled. 13269e899816SNick Piggin 1327506f1d07SSam Ravnborg# Common NUMA Features 1328506f1d07SSam Ravnborgconfig NUMA 1329fd51b2d7SKOSAKI Motohiro bool "Numa Memory Allocation and Scheduler Support" 1330506f1d07SSam Ravnborg depends on SMP 1331b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1332b5660ba7SH. Peter Anvin default y if X86_BIGSMP 13338f9ca475SIngo Molnar ---help--- 1334506f1d07SSam Ravnborg Enable NUMA (Non Uniform Memory Access) support. 1335fd51b2d7SKOSAKI Motohiro 1336506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1337506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1338506f1d07SSam Ravnborg NUMA awareness to the kernel. 1339506f1d07SSam Ravnborg 1340c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1341fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1342fd51b2d7SKOSAKI Motohiro 1343b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 13447cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1345fd51b2d7SKOSAKI Motohiro 1346fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1347506f1d07SSam Ravnborg 1348eec1d4faSHans Rosenfeldconfig AMD_NUMA 13493c2362e6SHarvey Harrison def_bool y 13503c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 13515da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 13528f9ca475SIngo Molnar ---help--- 1353eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1354eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1355eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1356eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1357eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1358506f1d07SSam Ravnborg 1359506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 13603c2362e6SHarvey Harrison def_bool y 13613c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1362506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1363506f1d07SSam Ravnborg select ACPI_NUMA 13648f9ca475SIngo Molnar ---help--- 1365506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1366506f1d07SSam Ravnborg 13676ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span 13686ec6e0d9SSuresh Siddha# other nodes. Even though a pfn is valid and 13696ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not 13706ec6e0d9SSuresh Siddha# reside on that node. See memmap_init_zone() 13716ec6e0d9SSuresh Siddha# for details. 13726ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES 13736ec6e0d9SSuresh Siddha def_bool y 13746ec6e0d9SSuresh Siddha depends on X86_64_ACPI_NUMA 13756ec6e0d9SSuresh Siddha 1376506f1d07SSam Ravnborgconfig NUMA_EMU 1377506f1d07SSam Ravnborg bool "NUMA emulation" 13781b7e03efSTejun Heo depends on NUMA 13798f9ca475SIngo Molnar ---help--- 1380506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1381506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1382506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1383506f1d07SSam Ravnborg 1384506f1d07SSam Ravnborgconfig NODES_SHIFT 1385d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 138651591e31SDavid Rientjes range 1 10 138751591e31SDavid Rientjes default "10" if MAXSMP 1388506f1d07SSam Ravnborg default "6" if X86_64 1389506f1d07SSam Ravnborg default "3" 1390506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 13918f9ca475SIngo Molnar ---help--- 13921184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1393692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1394506f1d07SSam Ravnborg 1395506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT 13963c2362e6SHarvey Harrison def_bool y 1397506f1d07SSam Ravnborg depends on X86_32 && DISCONTIGMEM 1398506f1d07SSam Ravnborg 1399506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE 14003c2362e6SHarvey Harrison def_bool y 1401506f1d07SSam Ravnborg depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1402506f1d07SSam Ravnborg 1403506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1404506f1d07SSam Ravnborg def_bool y 14053b16651fSTejun Heo depends on X86_32 && !NUMA 1406506f1d07SSam Ravnborg 1407506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE 1408506f1d07SSam Ravnborg def_bool y 1409b263295dSChristoph Lameter depends on NUMA && X86_32 1410506f1d07SSam Ravnborg 1411506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT 1412506f1d07SSam Ravnborg def_bool y 1413b263295dSChristoph Lameter depends on NUMA && X86_32 1414b263295dSChristoph Lameter 1415506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1416506f1d07SSam Ravnborg def_bool y 14176ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1418506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1419506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1420506f1d07SSam Ravnborg 14213b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 14223b16651fSTejun Heo def_bool y 14233b16651fSTejun Heo depends on X86_64 14243b16651fSTejun Heo 1425506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1426506f1d07SSam Ravnborg def_bool y 1427b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1428506f1d07SSam Ravnborg 1429506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1430a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 14313120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1432a0842b70SToshi Kani help 1433a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1434a0842b70SToshi Kani See Documentation/memory-hotplug.txt for more information. 1435a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1436506f1d07SSam Ravnborg 14373b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 14383b16651fSTejun Heo def_bool y 14393b16651fSTejun Heo depends on X86_64 && PROC_KCORE 14403b16651fSTejun Heo 1441a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1442a29815a3SAvi Kivity hex 1443a29815a3SAvi Kivity default 0 if X86_32 1444a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1445a29815a3SAvi Kivity 1446506f1d07SSam Ravnborgsource "mm/Kconfig" 1447506f1d07SSam Ravnborg 14487a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 14497a67832cSDan Williams bool 14507a67832cSDan Williams 1451ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 14527a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 14539f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 14549f53f9faSDan Williams depends on BLK_DEV 14557a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 14569f53f9faSDan Williams select LIBNVDIMM 1457ec776ef6SChristoph Hellwig help 1458ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1459ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1460ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1461ec776ef6SChristoph Hellwig they can be used for persistent storage. 1462ec776ef6SChristoph Hellwig 1463ec776ef6SChristoph Hellwig Say Y if unsure. 1464ec776ef6SChristoph Hellwig 1465506f1d07SSam Ravnborgconfig HIGHPTE 1466506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 14676fc108a0SJan Beulich depends on HIGHMEM 14688f9ca475SIngo Molnar ---help--- 1469506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1470506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1471506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1472506f1d07SSam Ravnborg entries in high memory. 1473506f1d07SSam Ravnborg 14749f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 14759f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 14768f9ca475SIngo Molnar ---help--- 14779f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 14789f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 14799f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 14809f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 14819f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 14829f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 14839f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 14849f077871SJeremy Fitzhardinge Documentation/kernel-parameters.txt to adjust this. 14859f077871SJeremy Fitzhardinge 14869f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 14879f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 14889f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 14899f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 14909f077871SJeremy Fitzhardinge 14919f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 14929f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 14939f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 14949f077871SJeremy Fitzhardinge memory. 14959f077871SJeremy Fitzhardinge 1496c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1497c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1498c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1499c885df50SJeremy Fitzhardinge default y 15008f9ca475SIngo Molnar ---help--- 1501c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1502c885df50SJeremy Fitzhardinge on or off. 1503c885df50SJeremy Fitzhardinge 15049ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1505d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1506d0cd7425SH. Peter Anvin default 64 1507d0cd7425SH. Peter Anvin range 4 640 15088f9ca475SIngo Molnar ---help--- 1509d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1510fc381519SIngo Molnar 1511d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1512d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1513fc381519SIngo Molnar 1514d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1515d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1516d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1517d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1518fc381519SIngo Molnar 1519d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1520d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1521d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1522d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1523d0cd7425SH. Peter Anvin entire low memory range. 1524d0cd7425SH. Peter Anvin 1525d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1526d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1527d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1528d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1529d0cd7425SH. Peter Anvin typical corruption patterns. 1530d0cd7425SH. Peter Anvin 1531d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1532fc381519SIngo Molnar 1533506f1d07SSam Ravnborgconfig MATH_EMULATION 1534506f1d07SSam Ravnborg bool 1535a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1536506f1d07SSam Ravnborg prompt "Math emulation" if X86_32 1537506f1d07SSam Ravnborg ---help--- 1538506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1539506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1540506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1541506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1542506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1543506f1d07SSam Ravnborg coprocessor or this emulation. 1544506f1d07SSam Ravnborg 1545506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1546506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1547506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1548506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1549506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1550506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1551506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1552506f1d07SSam Ravnborg intend to use this kernel on different machines. 1553506f1d07SSam Ravnborg 1554506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1555506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1556506f1d07SSam Ravnborg 1557506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1558506f1d07SSam Ravnborg kernel, it won't hurt. 1559506f1d07SSam Ravnborg 1560506f1d07SSam Ravnborgconfig MTRR 15616fc108a0SJan Beulich def_bool y 15626a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1563506f1d07SSam Ravnborg ---help--- 1564506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1565506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1566506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1567506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1568506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1569506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1570506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1571506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1572506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1573506f1d07SSam Ravnborg 1574506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1575506f1d07SSam Ravnborg control registers on other processors can be easily supported 1576506f1d07SSam Ravnborg as well: 1577506f1d07SSam Ravnborg 1578506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1579506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1580506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1581506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1582506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1583506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1584506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1585506f1d07SSam Ravnborg 1586506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1587506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1588506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1589506f1d07SSam Ravnborg 1590506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1591506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1592506f1d07SSam Ravnborg 15937225e751SRandy Dunlap See <file:Documentation/x86/mtrr.txt> for more information. 1594506f1d07SSam Ravnborg 159595ffa243SYinghai Luconfig MTRR_SANITIZER 15962ffb3501SYinghai Lu def_bool y 159795ffa243SYinghai Lu prompt "MTRR cleanup support" 159895ffa243SYinghai Lu depends on MTRR 15998f9ca475SIngo Molnar ---help--- 1600aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1601aba3728cSThomas Gleixner add writeback entries. 160295ffa243SYinghai Lu 1603aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1604692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1605aba3728cSThomas Gleixner mtrr_chunk_size. 160695ffa243SYinghai Lu 16072ffb3501SYinghai Lu If unsure, say Y. 160895ffa243SYinghai Lu 160995ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1610f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1611f5098d62SYinghai Lu range 0 1 1612f5098d62SYinghai Lu default "0" 161395ffa243SYinghai Lu depends on MTRR_SANITIZER 16148f9ca475SIngo Molnar ---help--- 1615f5098d62SYinghai Lu Enable mtrr cleanup default value 161695ffa243SYinghai Lu 161712031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 161812031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 161912031a62SYinghai Lu range 0 7 162012031a62SYinghai Lu default "1" 162112031a62SYinghai Lu depends on MTRR_SANITIZER 16228f9ca475SIngo Molnar ---help--- 162312031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1624aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 162512031a62SYinghai Lu 16262e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 16276fc108a0SJan Beulich def_bool y 16286a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 16292a8a2719SIngo Molnar depends on MTRR 16308f9ca475SIngo Molnar ---help--- 16312e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1632042b78e4SVenki Pallipadi 16332e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 16342e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 16352e5d9c85Svenkatesh.pallipadi@intel.com 16362e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1637042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 16382e5d9c85Svenkatesh.pallipadi@intel.com 16392e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 16402e5d9c85Svenkatesh.pallipadi@intel.com 164146cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 164246cf98cdSVenkatesh Pallipadi def_bool y 164346cf98cdSVenkatesh Pallipadi depends on X86_PAT 164446cf98cdSVenkatesh Pallipadi 1645628c6246SH. Peter Anvinconfig ARCH_RANDOM 1646628c6246SH. Peter Anvin def_bool y 1647628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1648628c6246SH. Peter Anvin ---help--- 1649628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1650628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1651628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1652628c6246SH. Peter Anvin secure hardware random number generator. 1653628c6246SH. Peter Anvin 165451ae4a2dSH. Peter Anvinconfig X86_SMAP 165551ae4a2dSH. Peter Anvin def_bool y 165651ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 165751ae4a2dSH. Peter Anvin ---help--- 165851ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 165951ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 166051ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 166151ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 166251ae4a2dSH. Peter Anvin 166351ae4a2dSH. Peter Anvin If unsure, say Y. 166451ae4a2dSH. Peter Anvin 166572e9b5feSDave Hansenconfig X86_INTEL_MPX 166672e9b5feSDave Hansen prompt "Intel MPX (Memory Protection Extensions)" 166772e9b5feSDave Hansen def_bool n 166872e9b5feSDave Hansen depends on CPU_SUP_INTEL 166972e9b5feSDave Hansen ---help--- 167072e9b5feSDave Hansen MPX provides hardware features that can be used in 167172e9b5feSDave Hansen conjunction with compiler-instrumented code to check 167272e9b5feSDave Hansen memory references. It is designed to detect buffer 167372e9b5feSDave Hansen overflow or underflow bugs. 167472e9b5feSDave Hansen 167572e9b5feSDave Hansen This option enables running applications which are 167672e9b5feSDave Hansen instrumented or otherwise use MPX. It does not use MPX 167772e9b5feSDave Hansen itself inside the kernel or to protect the kernel 167872e9b5feSDave Hansen against bad memory references. 167972e9b5feSDave Hansen 168072e9b5feSDave Hansen Enabling this option will make the kernel larger: 168172e9b5feSDave Hansen ~8k of kernel text and 36 bytes of data on a 64-bit 168272e9b5feSDave Hansen defconfig. It adds a long to the 'mm_struct' which 168372e9b5feSDave Hansen will increase the kernel memory overhead of each 168472e9b5feSDave Hansen process and adds some branches to paths used during 168572e9b5feSDave Hansen exec() and munmap(). 168672e9b5feSDave Hansen 168772e9b5feSDave Hansen For details, see Documentation/x86/intel_mpx.txt 168872e9b5feSDave Hansen 168972e9b5feSDave Hansen If unsure, say N. 169072e9b5feSDave Hansen 1691506f1d07SSam Ravnborgconfig EFI 16929ba16087SJan Beulich bool "EFI runtime service support" 16935b83683fSHuang, Ying depends on ACPI 1694f6ce5002SSergey Vlasov select UCS2_STRING 1695022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1696506f1d07SSam Ravnborg ---help--- 16978b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1698506f1d07SSam Ravnborg available (such as the EFI variable services). 1699506f1d07SSam Ravnborg 17008b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 17018b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 17028b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 17038b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 17048b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 17058b2cb7a8SHuang, Ying platforms. 1706506f1d07SSam Ravnborg 1707291f3632SMatt Flemingconfig EFI_STUB 1708291f3632SMatt Fleming bool "EFI stub support" 1709b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 17107b2a583aSMatt Fleming select RELOCATABLE 1711291f3632SMatt Fleming ---help--- 1712291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1713291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1714291f3632SMatt Fleming 17154172fe2fSRoy Franz See Documentation/efi-stub.txt for more information. 17160c759662SMatt Fleming 17177d453eeeSMatt Flemingconfig EFI_MIXED 17187d453eeeSMatt Fleming bool "EFI mixed-mode support" 17197d453eeeSMatt Fleming depends on EFI_STUB && X86_64 17207d453eeeSMatt Fleming ---help--- 17217d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 17227d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 17237d453eeeSMatt Fleming mode. 17247d453eeeSMatt Fleming 17257d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 17267d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 17277d453eeeSMatt Fleming the EFI handover protocol must be used. 17287d453eeeSMatt Fleming 17297d453eeeSMatt Fleming If unsure, say N. 17307d453eeeSMatt Fleming 1731506f1d07SSam Ravnborgconfig SECCOMP 17323c2362e6SHarvey Harrison def_bool y 17333c2362e6SHarvey Harrison prompt "Enable seccomp to safely compute untrusted bytecode" 17348f9ca475SIngo Molnar ---help--- 1735506f1d07SSam Ravnborg This kernel feature is useful for number crunching applications 1736506f1d07SSam Ravnborg that may need to compute untrusted bytecode during their 1737506f1d07SSam Ravnborg execution. By using pipes or other transports made available to 1738506f1d07SSam Ravnborg the process as file descriptors supporting the read/write 1739506f1d07SSam Ravnborg syscalls, it's possible to isolate those applications in 1740506f1d07SSam Ravnborg their own address space using seccomp. Once seccomp is 17419c0bbee8SAlexey Dobriyan enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1742506f1d07SSam Ravnborg and the task is only allowed to execute a few safe syscalls 1743506f1d07SSam Ravnborg defined by each seccomp mode. 1744506f1d07SSam Ravnborg 1745506f1d07SSam Ravnborg If unsure, say Y. Only embedded should say N here. 1746506f1d07SSam Ravnborg 1747506f1d07SSam Ravnborgsource kernel/Kconfig.hz 1748506f1d07SSam Ravnborg 1749506f1d07SSam Ravnborgconfig KEXEC 1750506f1d07SSam Ravnborg bool "kexec system call" 17512965faa5SDave Young select KEXEC_CORE 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" 17682965faa5SDave Young select KEXEC_CORE 176974ca317cSVivek Goyal select BUILD_BIN2C 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 20383dc33bd3SKees Cookchoice 20393dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 20403dc33bd3SKees Cook depends on X86_64 20413dc33bd3SKees Cook default LEGACY_VSYSCALL_EMULATE 20423dc33bd3SKees Cook help 20433dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 20443dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 20453dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 20463dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 20473dc33bd3SKees Cook 20483dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 20493dc33bd3SKees Cook line parameter vsyscall=[native|emulate|none]. 20503dc33bd3SKees Cook 20513dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 20523dc33bd3SKees Cook static binaries, you can say None without a performance penalty 20533dc33bd3SKees Cook to improve security. 20543dc33bd3SKees Cook 20553dc33bd3SKees Cook If unsure, select "Emulate". 20563dc33bd3SKees Cook 20573dc33bd3SKees Cook config LEGACY_VSYSCALL_NATIVE 20583dc33bd3SKees Cook bool "Native" 20593dc33bd3SKees Cook help 20603dc33bd3SKees Cook Actual executable code is located in the fixed vsyscall 20613dc33bd3SKees Cook address mapping, implementing time() efficiently. Since 20623dc33bd3SKees Cook this makes the mapping executable, it can be used during 20633dc33bd3SKees Cook security vulnerability exploitation (traditionally as 20643dc33bd3SKees Cook ROP gadgets). This configuration is not recommended. 20653dc33bd3SKees Cook 20663dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 20673dc33bd3SKees Cook bool "Emulate" 20683dc33bd3SKees Cook help 20693dc33bd3SKees Cook The kernel traps and emulates calls into the fixed 20703dc33bd3SKees Cook vsyscall address mapping. This makes the mapping 20713dc33bd3SKees Cook non-executable, but it still contains known contents, 20723dc33bd3SKees Cook which could be used in certain rare security vulnerability 20733dc33bd3SKees Cook exploits. This configuration is recommended when userspace 20743dc33bd3SKees Cook still uses the vsyscall area. 20753dc33bd3SKees Cook 20763dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 20773dc33bd3SKees Cook bool "None" 20783dc33bd3SKees Cook help 20793dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 20803dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 20813dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 20823dc33bd3SKees Cook will be reported to dmesg, so that either old or 20833dc33bd3SKees Cook malicious userspace programs can be identified. 20843dc33bd3SKees Cook 20853dc33bd3SKees Cookendchoice 20863dc33bd3SKees Cook 2087516cbf37STim Birdconfig CMDLINE_BOOL 2088516cbf37STim Bird bool "Built-in kernel command line" 20898f9ca475SIngo Molnar ---help--- 2090516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2091516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2092516cbf37STim Bird necessary or convenient to provide some or all of the 2093516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2094516cbf37STim Bird to not rely on the boot loader to provide them.) 2095516cbf37STim Bird 2096516cbf37STim Bird To compile command line arguments into the kernel, 2097516cbf37STim Bird set this option to 'Y', then fill in the 209869711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2099516cbf37STim Bird 2100516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2101516cbf37STim Bird should leave this option set to 'N'. 2102516cbf37STim Bird 2103516cbf37STim Birdconfig CMDLINE 2104516cbf37STim Bird string "Built-in kernel command string" 2105516cbf37STim Bird depends on CMDLINE_BOOL 2106516cbf37STim Bird default "" 21078f9ca475SIngo Molnar ---help--- 2108516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2109516cbf37STim Bird image and used at boot time. If the boot loader provides a 2110516cbf37STim Bird command line at boot time, it is appended to this string to 2111516cbf37STim Bird form the full kernel command line, when the system boots. 2112516cbf37STim Bird 2113516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2114516cbf37STim Bird change this behavior. 2115516cbf37STim Bird 2116516cbf37STim Bird In most cases, the command line (whether built-in or provided 2117516cbf37STim Bird by the boot loader) should specify the device for the root 2118516cbf37STim Bird file system. 2119516cbf37STim Bird 2120516cbf37STim Birdconfig CMDLINE_OVERRIDE 2121516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2122516cbf37STim Bird depends on CMDLINE_BOOL 21238f9ca475SIngo Molnar ---help--- 2124516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2125516cbf37STim Bird command line, and use ONLY the built-in command line. 2126516cbf37STim Bird 2127516cbf37STim Bird This is used to work around broken boot loaders. This should 2128516cbf37STim Bird be set to 'N' under normal conditions. 2129516cbf37STim Bird 2130a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2131a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2132a5b9e5a2SAndy Lutomirski default y 2133a5b9e5a2SAndy Lutomirski ---help--- 2134a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2135a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2136a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2137a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2138a5b9e5a2SAndy Lutomirski threading libraries. 2139a5b9e5a2SAndy Lutomirski 2140a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2141a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2142a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2143a5b9e5a2SAndy Lutomirski 2144a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2145a5b9e5a2SAndy Lutomirski 2146b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2147b700e7f0SSeth Jennings 2148506f1d07SSam Ravnborgendmenu 2149506f1d07SSam Ravnborg 2150506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2151506f1d07SSam Ravnborg def_bool y 2152506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2153506f1d07SSam Ravnborg 215435551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 215535551053SGary Hade def_bool y 215635551053SGary Hade depends on MEMORY_HOTPLUG 215735551053SGary Hade 2158e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2159645a7919STejun Heo def_bool y 2160e534c7c5SLee Schermerhorn depends on NUMA 2161e534c7c5SLee Schermerhorn 21629491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 21639491846fSKirill A. Shutemov def_bool y 21649491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 21659491846fSKirill A. Shutemov 2166c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2167c177c81eSNaoya Horiguchi def_bool y 2168c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2169c177c81eSNaoya Horiguchi 2170da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2171e279b6c1SSam Ravnborg 2172e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 21733c2362e6SHarvey Harrison def_bool y 2174e279b6c1SSam Ravnborg depends on X86_64 && HIBERNATION 2175e279b6c1SSam Ravnborg 2176e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2177e279b6c1SSam Ravnborg 2178e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2179e279b6c1SSam Ravnborg 2180efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2181efafc8b2SFeng Tang 2182a6b68076SAndi Kleenconfig X86_APM_BOOT 21836fc108a0SJan Beulich def_bool y 2184282e5aabSPaul Bolle depends on APM 2185a6b68076SAndi Kleen 2186e279b6c1SSam Ravnborgmenuconfig APM 2187e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2188efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2189e279b6c1SSam Ravnborg ---help--- 2190e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2191e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2192e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2193e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2194e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2195e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2196e279b6c1SSam Ravnborg 2197e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2198e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2199e279b6c1SSam Ravnborg 2200e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2201e279b6c1SSam Ravnborg machines with more than one CPU. 2202e279b6c1SSam Ravnborg 2203e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 22042dc98fd3SMichael Witten and more information, read <file:Documentation/power/apm-acpi.txt> 22052dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2206e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2207e279b6c1SSam Ravnborg 2208e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2209e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2210e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2211e279b6c1SSam Ravnborg 2212e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2213e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2214e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2215e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2216e279b6c1SSam Ravnborg 2217e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2218e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2219e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2220e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2221e279b6c1SSam Ravnborg APM in your BIOS). 2222e279b6c1SSam Ravnborg 2223e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2224e279b6c1SSam Ravnborg "weird" problems: 2225e279b6c1SSam Ravnborg 2226e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2227e279b6c1SSam Ravnborg enabled. 2228e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2229e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2230e279b6c1SSam Ravnborg the "no387" option to the kernel 2231e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2232e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2233e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2234e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2235e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2236e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2237e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2238e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2239e279b6c1SSam Ravnborg 11) exchange RAM chips 2240e279b6c1SSam Ravnborg 12) exchange the motherboard. 2241e279b6c1SSam Ravnborg 2242e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2243e279b6c1SSam Ravnborg module will be called apm. 2244e279b6c1SSam Ravnborg 2245e279b6c1SSam Ravnborgif APM 2246e279b6c1SSam Ravnborg 2247e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2248e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 22498f9ca475SIngo Molnar ---help--- 2250e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2251e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2252e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2253e279b6c1SSam Ravnborg 2254e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2255e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2256e279b6c1SSam Ravnborg ---help--- 2257e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2258e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2259e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2260e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2261e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2262e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2263e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2264e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2265e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2266e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2267e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2268e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2269e279b6c1SSam Ravnborg this feature. 2270e279b6c1SSam Ravnborg 2271e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2272dd8af076SLen Brown depends on CPU_IDLE 2273e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 22748f9ca475SIngo Molnar ---help--- 2275e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2276e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2277e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2278e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2279e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2280e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2281e279b6c1SSam Ravnborg this option does nothing.) 2282e279b6c1SSam Ravnborg 2283e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2284e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 22858f9ca475SIngo Molnar ---help--- 2286e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2287e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2288e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2289e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2290e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2291e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2292e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2293e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2294e279b6c1SSam Ravnborg especially if you are using gpm. 2295e279b6c1SSam Ravnborg 2296e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2297e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 22988f9ca475SIngo Molnar ---help--- 2299e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2300e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2301e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2302e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2303e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2304e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2305e279b6c1SSam Ravnborg 2306e279b6c1SSam Ravnborgendif # APM 2307e279b6c1SSam Ravnborg 2308bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2309e279b6c1SSam Ravnborg 2310e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2311e279b6c1SSam Ravnborg 231227471fdbSAndy Henroidsource "drivers/idle/Kconfig" 231327471fdbSAndy Henroid 2314e279b6c1SSam Ravnborgendmenu 2315e279b6c1SSam Ravnborg 2316e279b6c1SSam Ravnborg 2317e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2318e279b6c1SSam Ravnborg 2319e279b6c1SSam Ravnborgconfig PCI 23201ac97018SIngo Molnar bool "PCI support" 23211c858087SAdrian Bunk default y 23228f9ca475SIngo Molnar ---help--- 2323e279b6c1SSam Ravnborg Find out whether you have a PCI motherboard. PCI is the name of a 2324e279b6c1SSam Ravnborg bus system, i.e. the way the CPU talks to the other stuff inside 2325e279b6c1SSam Ravnborg your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2326e279b6c1SSam Ravnborg VESA. If you have PCI, say Y, otherwise N. 2327e279b6c1SSam Ravnborg 2328e279b6c1SSam Ravnborgchoice 2329e279b6c1SSam Ravnborg prompt "PCI access mode" 2330efefa6f6SIngo Molnar depends on X86_32 && PCI 2331e279b6c1SSam Ravnborg default PCI_GOANY 2332e279b6c1SSam Ravnborg ---help--- 2333e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2334e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2335e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2336e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2337e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2338e279b6c1SSam Ravnborg 2339e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2340e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2341e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2342e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2343e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2344e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2345e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2346e279b6c1SSam Ravnborg 2347e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2348e279b6c1SSam Ravnborg bool "BIOS" 2349e279b6c1SSam Ravnborg 2350e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2351e279b6c1SSam Ravnborg bool "MMConfig" 2352e279b6c1SSam Ravnborg 2353e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2354e279b6c1SSam Ravnborg bool "Direct" 2355e279b6c1SSam Ravnborg 23563ef0e1f8SAndres Salomonconfig PCI_GOOLPC 235776fb6570SDaniel Drake bool "OLPC XO-1" 23583ef0e1f8SAndres Salomon depends on OLPC 23593ef0e1f8SAndres Salomon 23602bdd1b03SAndres Salomonconfig PCI_GOANY 23612bdd1b03SAndres Salomon bool "Any" 23622bdd1b03SAndres Salomon 2363e279b6c1SSam Ravnborgendchoice 2364e279b6c1SSam Ravnborg 2365e279b6c1SSam Ravnborgconfig PCI_BIOS 23663c2362e6SHarvey Harrison def_bool y 2367efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2368e279b6c1SSam Ravnborg 2369e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2370e279b6c1SSam Ravnborgconfig PCI_DIRECT 23713c2362e6SHarvey Harrison def_bool y 23720aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2373e279b6c1SSam Ravnborg 2374e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 23753c2362e6SHarvey Harrison def_bool y 23765f0db7a2SFeng Tang depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2377e279b6c1SSam Ravnborg 23783ef0e1f8SAndres Salomonconfig PCI_OLPC 23792bdd1b03SAndres Salomon def_bool y 23802bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 23813ef0e1f8SAndres Salomon 2382b5401a96SAlex Nixonconfig PCI_XEN 2383b5401a96SAlex Nixon def_bool y 2384b5401a96SAlex Nixon depends on PCI && XEN 2385b5401a96SAlex Nixon select SWIOTLB_XEN 2386b5401a96SAlex Nixon 2387e279b6c1SSam Ravnborgconfig PCI_DOMAINS 23883c2362e6SHarvey Harrison def_bool y 2389e279b6c1SSam Ravnborg depends on PCI 2390e279b6c1SSam Ravnborg 2391e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2392e279b6c1SSam Ravnborg bool "Support mmconfig PCI config space access" 2393e279b6c1SSam Ravnborg depends on X86_64 && PCI && ACPI 2394e279b6c1SSam Ravnborg 23953f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 23966a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 23976ea30386SKees Cook depends on PCI 23983f6ea84aSIra W. Snyder help 23993f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 24003f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 24013f6ea84aSIra W. Snyder not have ACPI. 24023f6ea84aSIra W. Snyder 240364a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 240464a5fed6SBjorn Helgaas is known to be incomplete. 240564a5fed6SBjorn Helgaas 240664a5fed6SBjorn Helgaas You should say N unless you know you need this. 240764a5fed6SBjorn Helgaas 2408e279b6c1SSam Ravnborgsource "drivers/pci/pcie/Kconfig" 2409e279b6c1SSam Ravnborg 2410e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig" 2411e279b6c1SSam Ravnborg 24121c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2413e279b6c1SSam Ravnborgconfig ISA_DMA_API 24141c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 24151c00f016SDavid Rientjes default y 24161c00f016SDavid Rientjes help 24171c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 24181c00f016SDavid Rientjes If unsure, say Y. 2419e279b6c1SSam Ravnborg 2420e279b6c1SSam Ravnborgif X86_32 2421e279b6c1SSam Ravnborg 2422e279b6c1SSam Ravnborgconfig ISA 2423e279b6c1SSam Ravnborg bool "ISA support" 24248f9ca475SIngo Molnar ---help--- 2425e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2426e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2427e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2428e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2429e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2430e279b6c1SSam Ravnborg 2431e279b6c1SSam Ravnborgconfig EISA 2432e279b6c1SSam Ravnborg bool "EISA support" 2433e279b6c1SSam Ravnborg depends on ISA 2434e279b6c1SSam Ravnborg ---help--- 2435e279b6c1SSam Ravnborg The Extended Industry Standard Architecture (EISA) bus was 2436e279b6c1SSam Ravnborg developed as an open alternative to the IBM MicroChannel bus. 2437e279b6c1SSam Ravnborg 2438e279b6c1SSam Ravnborg The EISA bus provided some of the features of the IBM MicroChannel 2439e279b6c1SSam Ravnborg bus while maintaining backward compatibility with cards made for 2440e279b6c1SSam Ravnborg the older ISA bus. The EISA bus saw limited use between 1988 and 2441e279b6c1SSam Ravnborg 1995 when it was made obsolete by the PCI bus. 2442e279b6c1SSam Ravnborg 2443e279b6c1SSam Ravnborg Say Y here if you are building a kernel for an EISA-based machine. 2444e279b6c1SSam Ravnborg 2445e279b6c1SSam Ravnborg Otherwise, say N. 2446e279b6c1SSam Ravnborg 2447e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig" 2448e279b6c1SSam Ravnborg 2449e279b6c1SSam Ravnborgconfig SCx200 2450e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 24518f9ca475SIngo Molnar ---help--- 2452e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2453e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2454e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2455e279b6c1SSam Ravnborg for other scx200_* drivers. 2456e279b6c1SSam Ravnborg 2457e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2458e279b6c1SSam Ravnborg 2459e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2460e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2461592913ecSJohn Stultz depends on SCx200 2462e279b6c1SSam Ravnborg default y 24638f9ca475SIngo Molnar ---help--- 2464e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2465e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2466e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2467e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2468e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2469e279b6c1SSam Ravnborg 24703ef0e1f8SAndres Salomonconfig OLPC 24713ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 247254008979SThomas Gleixner depends on !X86_PAE 24733c554946SAndres Salomon select GPIOLIB 2474dc3119e7SThomas Gleixner select OF 247545bb1674SDaniel Drake select OF_PROMTREE 2476b4e51854SGrant Likely select IRQ_DOMAIN 24778f9ca475SIngo Molnar ---help--- 24783ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 24793ef0e1f8SAndres Salomon XO hardware. 24803ef0e1f8SAndres Salomon 2481a3128588SDaniel Drakeconfig OLPC_XO1_PM 2482a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 248397c4cb71SDaniel Drake depends on OLPC && MFD_CS5535 && PM_SLEEP 2484a3128588SDaniel Drake select MFD_CORE 2485bf1ebf00SDaniel Drake ---help--- 248697c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2487bf1ebf00SDaniel Drake 2488cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2489cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2490cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2491cfee9597SDaniel Drake ---help--- 2492cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2493cfee9597SDaniel Drake programmable wakeup source. 2494cfee9597SDaniel Drake 24957feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 24967feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 2497d8d01a63SDaniel Drake depends on OLPC && OLPC_XO1_PM 2498ed8e47feSRandy Dunlap depends on INPUT=y 2499d8d01a63SDaniel Drake select POWER_SUPPLY 25007feda8e9SDaniel Drake select GPIO_CS5535 25017feda8e9SDaniel Drake select MFD_CORE 25027feda8e9SDaniel Drake ---help--- 25037feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 25047bc74b3dSDaniel Drake - EC-driven system wakeups 25057feda8e9SDaniel Drake - Power button 25067bc74b3dSDaniel Drake - Ebook switch 25072cf2baeaSDaniel Drake - Lid switch 2508e1040ac6SDaniel Drake - AC adapter status updates 2509e1040ac6SDaniel Drake - Battery status updates 25107feda8e9SDaniel Drake 2511a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2512a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2513d8d01a63SDaniel Drake depends on OLPC && ACPI 2514d8d01a63SDaniel Drake select POWER_SUPPLY 2515a0f30f59SDaniel Drake ---help--- 2516a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2517a0f30f59SDaniel Drake - EC-driven system wakeups 2518a0f30f59SDaniel Drake - AC adapter status updates 2519a0f30f59SDaniel Drake - Battery status updates 2520e279b6c1SSam Ravnborg 2521d4f3e350SEd Wildgooseconfig ALIX 2522d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2523d4f3e350SEd Wildgoose select GPIOLIB 2524d4f3e350SEd Wildgoose ---help--- 2525d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2526d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2527d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2528d4f3e350SEd Wildgoose get added here. 2529d4f3e350SEd Wildgoose 2530d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2531d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2532d4f3e350SEd Wildgoose 2533d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2534d4f3e350SEd Wildgoose 2535da4e3302SPhilip Prindevilleconfig NET5501 2536da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2537da4e3302SPhilip Prindeville select GPIOLIB 2538da4e3302SPhilip Prindeville ---help--- 2539da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2540da4e3302SPhilip Prindeville 25413197059aSPhilip A. Prindevilleconfig GEOS 25423197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 25433197059aSPhilip A. Prindeville select GPIOLIB 25443197059aSPhilip A. Prindeville depends on DMI 25453197059aSPhilip A. Prindeville ---help--- 25463197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 25473197059aSPhilip A. Prindeville 25487d029125SVivien Didelotconfig TS5500 25497d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 25507d029125SVivien Didelot depends on MELAN 25517d029125SVivien Didelot select CHECK_SIGNATURE 25527d029125SVivien Didelot select NEW_LEDS 25537d029125SVivien Didelot select LEDS_CLASS 25547d029125SVivien Didelot ---help--- 25557d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 25567d029125SVivien Didelot 2557e279b6c1SSam Ravnborgendif # X86_32 2558e279b6c1SSam Ravnborg 255923ac4ae8SAndreas Herrmannconfig AMD_NB 2560e279b6c1SSam Ravnborg def_bool y 25610e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2562e279b6c1SSam Ravnborg 2563e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig" 2564e279b6c1SSam Ravnborg 2565e279b6c1SSam Ravnborgsource "drivers/pci/hotplug/Kconfig" 2566e279b6c1SSam Ravnborg 2567388b78adSAlexandre Bounineconfig RAPIDIO 2568fdf90abcSAlexandre Bounine tristate "RapidIO support" 2569388b78adSAlexandre Bounine depends on PCI 2570388b78adSAlexandre Bounine default n 2571388b78adSAlexandre Bounine help 2572fdf90abcSAlexandre Bounine If enabled this option will include drivers and the core 2573388b78adSAlexandre Bounine infrastructure code to support RapidIO interconnect devices. 2574388b78adSAlexandre Bounine 2575388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig" 2576388b78adSAlexandre Bounine 2577e3263ab3SDavid Herrmannconfig X86_SYSFB 2578e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2579e3263ab3SDavid Herrmann help 2580e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2581e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2582e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2583e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2584e3263ab3SDavid Herrmann to x86. 2585e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2586e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2587e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2588e3263ab3SDavid Herrmann modes, it is adverticed as fallback platform framebuffer so legacy 2589e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2590e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2591e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2592e3263ab3SDavid Herrmann 2593e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2594e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2595e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2596e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2597e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2598e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2599e3263ab3SDavid Herrmann incompatible with simplefb. 2600e3263ab3SDavid Herrmann 2601e3263ab3SDavid Herrmann If unsure, say Y. 2602e3263ab3SDavid Herrmann 2603e279b6c1SSam Ravnborgendmenu 2604e279b6c1SSam Ravnborg 2605e279b6c1SSam Ravnborg 2606e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations" 2607e279b6c1SSam Ravnborg 2608e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt" 2609e279b6c1SSam Ravnborg 2610e279b6c1SSam Ravnborgconfig IA32_EMULATION 2611e279b6c1SSam Ravnborg bool "IA32 Emulation" 2612e279b6c1SSam Ravnborg depends on X86_64 2613d1603990SRandy Dunlap select BINFMT_ELF 2614a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 26153bead553SBrian Gerst select ARCH_WANT_OLD_COMPAT_IPC 26168f9ca475SIngo Molnar ---help--- 26175fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 26185fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 26195fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2620e279b6c1SSam Ravnborg 2621e279b6c1SSam Ravnborgconfig IA32_AOUT 2622e279b6c1SSam Ravnborg tristate "IA32 a.out support" 26236b213e1bSDavid Woodhouse depends on IA32_EMULATION 26248f9ca475SIngo Molnar ---help--- 2625e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2626e279b6c1SSam Ravnborg 26270bf62763SH. Peter Anvinconfig X86_X32 26286ea30386SKees Cook bool "x32 ABI for 64-bit mode" 26299b54050bSBrian Gerst depends on X86_64 26305fd92e65SH. J. Lu ---help--- 26315fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 26325fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 26335fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 26345fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 26355fd92e65SH. J. Lu 26365fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 26375fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 26385fd92e65SH. J. Lu option set. 26395fd92e65SH. J. Lu 2640e279b6c1SSam Ravnborgconfig COMPAT 26413c2362e6SHarvey Harrison def_bool y 26420bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2643e279b6c1SSam Ravnborg 26443120e25eSJan Beulichif COMPAT 2645e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 26463120e25eSJan Beulich def_bool y 2647e279b6c1SSam Ravnborg 2648e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 26493c2362e6SHarvey Harrison def_bool y 26503120e25eSJan Beulich depends on SYSVIPC 2651e279b6c1SSam Ravnborg 2652ee009e4aSDavid Howellsconfig KEYS_COMPAT 26533120e25eSJan Beulich def_bool y 26543120e25eSJan Beulich depends on KEYS 26553120e25eSJan Beulichendif 2656ee009e4aSDavid Howells 2657e279b6c1SSam Ravnborgendmenu 2658e279b6c1SSam Ravnborg 2659e279b6c1SSam Ravnborg 2660e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2661e5beae16SKeith Packard def_bool y 2662e5beae16SKeith Packard depends on X86_32 2663e5beae16SKeith Packard 26644692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS 26654692d77fSAlessandro Rubini bool 266683125a3aSAlessandro Rubini depends on X86_64 || STA2X11 26674692d77fSAlessandro Rubini 2668f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP 2669f7219a53SAlessandro Rubini bool 267083125a3aSAlessandro Rubini depends on STA2X11 2671f7219a53SAlessandro Rubini 267293e5eaddSLi, Aubreyconfig PMC_ATOM 267393e5eaddSLi, Aubrey def_bool y 267493e5eaddSLi, Aubrey depends on PCI 267593e5eaddSLi, Aubrey 2676e279b6c1SSam Ravnborgsource "net/Kconfig" 2677e279b6c1SSam Ravnborg 2678e279b6c1SSam Ravnborgsource "drivers/Kconfig" 2679e279b6c1SSam Ravnborg 2680e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2681e279b6c1SSam Ravnborg 2682e279b6c1SSam Ravnborgsource "fs/Kconfig" 2683e279b6c1SSam Ravnborg 2684e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug" 2685e279b6c1SSam Ravnborg 2686e279b6c1SSam Ravnborgsource "security/Kconfig" 2687e279b6c1SSam Ravnborg 2688e279b6c1SSam Ravnborgsource "crypto/Kconfig" 2689e279b6c1SSam Ravnborg 2690edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 2691edf88417SAvi Kivity 2692e279b6c1SSam Ravnborgsource "lib/Kconfig" 2693