1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2daa93fabSSam Ravnborg# Select 32 or 64 bit 3daa93fabSSam Ravnborgconfig 64BIT 4104daea1SMasahiro Yamada bool "64-bit kernel" if "$(ARCH)" = "x86" 5104daea1SMasahiro Yamada default "$(ARCH)" != "i386" 6a7f7f624SMasahiro Yamada help 7daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 8daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 9daa93fabSSam Ravnborg 10daa93fabSSam Ravnborgconfig X86_32 113120e25eSJan Beulich def_bool y 123120e25eSJan Beulich depends on !64BIT 13341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 14341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 15341c787eSIngo Molnar select CLKSRC_I8253 16341c787eSIngo Molnar select CLONE_BACKWARDS 17157e118bSThomas Gleixner select GENERIC_VDSO_32 18117ed454SThomas Gleixner select HAVE_DEBUG_STACKOVERFLOW 19157e118bSThomas Gleixner select KMAP_LOCAL 20341c787eSIngo Molnar select MODULES_USE_ELF_REL 21341c787eSIngo Molnar select OLD_SIGACTION 222ca408d9SBrian Gerst select ARCH_SPLIT_ARG64 23daa93fabSSam Ravnborg 24daa93fabSSam Ravnborgconfig X86_64 253120e25eSJan Beulich def_bool y 263120e25eSJan Beulich depends on 64BIT 27d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 284eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 29c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 30d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 31d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 32d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 33f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 3409230cbcSChristoph Hellwig select SWIOTLB 357facdc42SAl Viro select ARCH_HAS_ELFCORE_COMPAT 3663703f37SKefeng Wang select ZONE_DMA32 371032c0baSSam Ravnborg 38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 39518049d9SSteven Rostedt (VMware) def_bool y 40518049d9SSteven Rostedt (VMware) depends on X86_32 41518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 42518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 43518049d9SSteven Rostedt (VMware) help 44518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 45518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 46518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 47518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 48518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 49d94e0685SIngo Molnar# 50d94e0685SIngo Molnar# Arch settings 51d94e0685SIngo Molnar# 52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 53d94e0685SIngo Molnar# ported to 32-bit as well. ) 54d94e0685SIngo Molnar# 558d5fffb9SSam Ravnborgconfig X86 563c2362e6SHarvey Harrison def_bool y 57c763ea26SIngo Molnar # 58c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 59c763ea26SIngo Molnar # 606471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 616e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 62942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 632a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 641f6d3a8fSMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 651e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 665c11f00bSDavid Hildenbrand select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 6791024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 68cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 691e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 7091dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 71c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 722792d84eSKees Cook select ARCH_HAS_CURRENT_STACK_POINTER 73fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 74399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 7521266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 76b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 776471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 7872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 79316d097cSDave Hansen select ARCH_HAS_FILTER_PGPROT 806974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 81957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 82bece04b5SMarco Elver select ARCH_HAS_KCOV if X86_64 830c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 8410bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 850ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 86c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 8717596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 883010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 890aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 90ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 91d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 92d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 93ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 94ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 95ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 9625c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 97c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 987e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 9963703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 1006471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 1016471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10277fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1035e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1043599fe12SThomas Gleixner select ARCH_STACKWALK 1052c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1066471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1075d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 108d283d422SPasha Tatashin select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 1096471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 11014df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 111583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 112583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1136471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 114dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1156471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1166471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1172ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 118ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 11981c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 120c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 12151c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 12207431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 1233876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 12459612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 12538d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 126b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 12710916706SShile Zhang select BUILDTIME_TABLE_SORT 1286471b825SIngo Molnar select CLKEVT_I8253 1296471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1306471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1316471b825SIngo Molnar select DCACHE_WORD_ACCESS 1323aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 13345471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 13445471cd9SLinus Torvalds select EDAC_SUPPORT 1356471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1366471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1376471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1386471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 13961dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1406471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 14127d6b4d1SThomas Gleixner select GENERIC_ENTRY 1426471b825SIngo Molnar select GENERIC_IOMAP 143c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1440fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 145ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1466471b825SIngo Molnar select GENERIC_IRQ_PROBE 147c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1486471b825SIngo Molnar select GENERIC_IRQ_SHOW 1496471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1502ae27137SSteven Price select GENERIC_PTDUMP 1516471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1526471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1537ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 154550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 15539656e83SChristoph Hellwig select GUP_GET_PTE_LOW_HIGH if X86_PAE 15617e5888eSHans de Goede select HARDIRQS_SW_RESEND 1577edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 1586471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1596471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1606471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1616471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1626471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 163eed1fceeSSong Liu select HAVE_ARCH_HUGE_VMALLOC if X86_64 1646471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 165b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 166d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1670609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1681dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1696471b825SIngo Molnar select HAVE_ARCH_KGDB 1709e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1719e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1721b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 173271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1746471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 175f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 176afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1776471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1786471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 179a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 180b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1817677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 182e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 183fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 184c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1852ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1866471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1876471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1886471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 189d1f250e2SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 1906471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 191*03f16cd0SJosh Poimboeuf select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 1924ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 1936471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1949c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 195677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 19606aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 19702a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 198562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 199c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 200503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 20103f5781bSWang YanQing select HAVE_EBPF_JIT 20258340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 2036630a8e5SChristoph Hellwig select HAVE_EISA 2045f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 20567a929e0SChristoph Hellwig select HAVE_FAST_GUP 206644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 2076471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 2084a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2096471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2106b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2110067f129SK.Prasad select HAVE_HW_BREAKPOINT 2126471b825SIngo Molnar select HAVE_IOREMAP_PROT 213624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2146471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2156471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2166471b825SIngo Molnar select HAVE_KERNEL_GZIP 2176471b825SIngo Molnar select HAVE_KERNEL_LZ4 2186471b825SIngo Molnar select HAVE_KERNEL_LZMA 2196471b825SIngo Molnar select HAVE_KERNEL_LZO 2206471b825SIngo Molnar select HAVE_KERNEL_XZ 221fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2226471b825SIngo Molnar select HAVE_KPROBES 2236471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 224540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2256471b825SIngo Molnar select HAVE_KRETPROBES 226f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2276471b825SIngo Molnar select HAVE_KVM 2286471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2290102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 230ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2319f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 232be37c98dSKalesh Singh select HAVE_MOVE_PUD 23342a0bb3fSPetr Mladek select HAVE_NMI 234*03f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2356471b825SIngo Molnar select HAVE_OPTPROBES 2366471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2376471b825SIngo Molnar select HAVE_PERF_EVENTS 238c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 23992e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 240eb01d42aSChristoph Hellwig select HAVE_PCI 241c5e63197SJiri Olsa select HAVE_PERF_REGS 242c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 243ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 24400998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2456471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 246*03f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2473c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2487ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 249cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 250d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 251*03f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 252e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 253*03f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 25499cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 255d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2566471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2576471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2587c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2597ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 26005736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 261c0185808SThomas Gleixner select IRQ_FORCED_THREADING 2627ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 2637ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 26486596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2652eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 266625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2676471b825SIngo Molnar select PERF_EVENTS 2683195ef59SPrarit Bhargava select RTC_LIB 269d6faca40SArnd Bergmann select RTC_MC146818_LIB 2706471b825SIngo Molnar select SPARSE_IRQ 27183fe27eaSPranith Kumar select SRCU 2726471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 27315f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2744aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2756471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2766471b825SIngo Molnar select VIRT_TO_BUS 2773b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2786471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2790c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 28050468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 2819e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2827d8330a5SBalbir Singh 283ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2843120e25eSJan Beulich def_bool y 2853120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 286ba7e4d13SIngo Molnar 28751b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 28851b26adaSLinus Torvalds string 28951b26adaSLinus Torvalds default "elf32-i386" if X86_32 29051b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 29151b26adaSLinus Torvalds 2928d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2933c2362e6SHarvey Harrison def_bool y 2948d5fffb9SSam Ravnborg 2958d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2963c2362e6SHarvey Harrison def_bool y 2978d5fffb9SSam Ravnborg 2988d5fffb9SSam Ravnborgconfig MMU 2993c2362e6SHarvey Harrison def_bool y 3008d5fffb9SSam Ravnborg 3019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3029e08f57dSDaniel Cashman default 28 if 64BIT 3039e08f57dSDaniel Cashman default 8 3049e08f57dSDaniel Cashman 3059e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3069e08f57dSDaniel Cashman default 32 if 64BIT 3079e08f57dSDaniel Cashman default 16 3089e08f57dSDaniel Cashman 3099e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3109e08f57dSDaniel Cashman default 8 3119e08f57dSDaniel Cashman 3129e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3139e08f57dSDaniel Cashman default 16 3149e08f57dSDaniel Cashman 3158d5fffb9SSam Ravnborgconfig SBUS 3168d5fffb9SSam Ravnborg bool 3178d5fffb9SSam Ravnborg 3188d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3193120e25eSJan Beulich def_bool y 3203120e25eSJan Beulich depends on ISA_DMA_API 3218d5fffb9SSam Ravnborg 3228d5fffb9SSam Ravnborgconfig GENERIC_BUG 3233c2362e6SHarvey Harrison def_bool y 3248d5fffb9SSam Ravnborg depends on BUG 325b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 326b93a531eSJan Beulich 327b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 328b93a531eSJan Beulich bool 3298d5fffb9SSam Ravnborg 3308d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3313120e25eSJan Beulich def_bool y 3323120e25eSJan Beulich depends on ISA_DMA_API 3338d5fffb9SSam Ravnborg 3341032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3351032c0baSSam Ravnborg def_bool y 3361032c0baSSam Ravnborg 3379a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3389a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3398d5fffb9SSam Ravnborg 340801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 341801e4062SJohannes Berg def_bool y 342801e4062SJohannes Berg 343d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 344d7109fe3SAndy Shevchenko int 345d7109fe3SAndy Shevchenko default 1024 if X86_64 346d7109fe3SAndy Shevchenko default 512 347d7109fe3SAndy Shevchenko 348f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 349f4cb5700SJohannes Berg def_bool y 350f4cb5700SJohannes Berg 3518d5fffb9SSam Ravnborgconfig AUDIT_ARCH 352e0fd24a3SJan Beulich def_bool y if X86_64 3538d5fffb9SSam Ravnborg 354d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 355d6f2d75aSAndrey Ryabinin hex 356d6f2d75aSAndrey Ryabinin depends on KASAN 357d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 358d6f2d75aSAndrey Ryabinin 35969575d38SShane Wangconfig HAVE_INTEL_TXT 36069575d38SShane Wang def_bool y 3616ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36269575d38SShane Wang 3636b0c3d44SSam Ravnborgconfig X86_32_SMP 3646b0c3d44SSam Ravnborg def_bool y 3656b0c3d44SSam Ravnborg depends on X86_32 && SMP 3666b0c3d44SSam Ravnborg 3676b0c3d44SSam Ravnborgconfig X86_64_SMP 3686b0c3d44SSam Ravnborg def_bool y 3696b0c3d44SSam Ravnborg depends on X86_64 && SMP 3706b0c3d44SSam Ravnborg 3712b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3722b144498SSrikar Dronamraju def_bool y 3732b144498SSrikar Dronamraju 374d20642f0SRob Herringconfig FIX_EARLYCON_MEM 375d20642f0SRob Herring def_bool y 376d20642f0SRob Herring 37794d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 37894d49eb3SKirill A. Shutemov bool 37994d49eb3SKirill A. Shutemov 38098233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38198233368SKirill A. Shutemov int 38277ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38398233368SKirill A. Shutemov default 4 if X86_64 38498233368SKirill A. Shutemov default 3 if X86_PAE 38598233368SKirill A. Shutemov default 2 38698233368SKirill A. Shutemov 3872a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3882a61f474SMasahiro Yamada bool 3892a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3902a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3912a61f474SMasahiro Yamada help 3922a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3933fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 3943fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 3952a61f474SMasahiro Yamada 396506f1d07SSam Ravnborgmenu "Processor type and features" 397506f1d07SSam Ravnborg 398506f1d07SSam Ravnborgconfig SMP 399506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 400a7f7f624SMasahiro Yamada help 401506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4024a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4034a474157SRobert Graffham than one CPU, say Y. 404506f1d07SSam Ravnborg 4054a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 406506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 407506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4084a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 409506f1d07SSam Ravnborg will run faster if you say N here. 410506f1d07SSam Ravnborg 411506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 412506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 413506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 414506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 415506f1d07SSam Ravnborg 416506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 417506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 418506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 419506f1d07SSam Ravnborg 420cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4214f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 422506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 423506f1d07SSam Ravnborg 424506f1d07SSam Ravnborg If you don't know what to do here, say N. 425506f1d07SSam Ravnborg 4269def39beSJosh Triplettconfig X86_FEATURE_NAMES 4279def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4289def39beSJosh Triplett default y 429a7f7f624SMasahiro Yamada help 4309def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4319def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4329def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4339def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4349def39beSJosh Triplett 4359def39beSJosh Triplett If in doubt, say Y. 4369def39beSJosh Triplett 43706cd9a7dSYinghai Luconfig X86_X2APIC 43806cd9a7dSYinghai Lu bool "Support x2apic" 43919e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 440a7f7f624SMasahiro Yamada help 44106cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44206cd9a7dSYinghai Lu 44306cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44406cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 44506cd9a7dSYinghai Lu 44606cd9a7dSYinghai Lu If you don't know what to do here, say N. 44706cd9a7dSYinghai Lu 4486695c85bSYinghai Luconfig X86_MPPARSE 4494590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4507a527688SJan Beulich default y 4515ab74722SIngo Molnar depends on X86_LOCAL_APIC 452a7f7f624SMasahiro Yamada help 4536695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4546695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4556695c85bSYinghai Lu 456ddd70cf9SJun Nakajimaconfig GOLDFISH 457ddd70cf9SJun Nakajima def_bool y 458ddd70cf9SJun Nakajima depends on X86_GOLDFISH 459ddd70cf9SJun Nakajima 46076b04384SDavid Woodhouseconfig RETPOLINE 46176b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 462*03f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 46376b04384SDavid Woodhouse default y 46476b04384SDavid Woodhouse help 46576b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 46676b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 46776b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 46876b04384SDavid Woodhouse support for full protection. The kernel may run slower. 46976b04384SDavid Woodhouse 470e463a09aSPeter Zijlstraconfig CC_HAS_SLS 471e463a09aSPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 472e463a09aSPeter Zijlstra 473e463a09aSPeter Zijlstraconfig SLS 474e463a09aSPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 475e463a09aSPeter Zijlstra depends on CC_HAS_SLS && X86_64 476*03f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 477e463a09aSPeter Zijlstra default n 478e463a09aSPeter Zijlstra help 479e463a09aSPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 480e463a09aSPeter Zijlstra against straight line speculation. The kernel image might be slightly 481e463a09aSPeter Zijlstra larger. 482e463a09aSPeter Zijlstra 483e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 484e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4856fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 48659fe5a77SThomas Gleixner select KERNFS 487e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 48878e99b4aSFenghua Yu help 489e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4906fe07ce3SBabu Moger 4916fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4926fe07ce3SBabu Moger usage by the CPU. 4936fe07ce3SBabu Moger 4946fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4956fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4966fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4976fe07ce3SBabu Moger 4986fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4996fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 5006fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 50178e99b4aSFenghua Yu 50278e99b4aSFenghua Yu Say N if unsure. 50378e99b4aSFenghua Yu 5048425091fSRavikiran G Thirumalaiif X86_32 505a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 506a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 507a0d0bb4dSRandy Dunlap depends on SMP 508a7f7f624SMasahiro Yamada help 509e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 510a0d0bb4dSRandy Dunlap 511c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 512c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 513c5c606d9SRavikiran G Thirumalai default y 514a7f7f624SMasahiro Yamada help 51506ac8346SIngo Molnar If you disable this option then the kernel will only support 51606ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 51706ac8346SIngo Molnar systems out there.) 51806ac8346SIngo Molnar 5198425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5208425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 521cb7b8023SBen Hutchings Goldfish (Android emulator) 5228425091fSRavikiran G Thirumalai AMD Elan 5238425091fSRavikiran G Thirumalai RDC R-321x SoC 5248425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 52583125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5263f4110a4SThomas Gleixner Moorestown MID devices 52706ac8346SIngo Molnar 52806ac8346SIngo Molnar If you have one of these systems, or if you want to build a 52906ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5308425091fSRavikiran G Thirumalaiendif 53106ac8346SIngo Molnar 5328425091fSRavikiran G Thirumalaiif X86_64 5338425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5348425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5358425091fSRavikiran G Thirumalai default y 536a7f7f624SMasahiro Yamada help 5378425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5388425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5398425091fSRavikiran G Thirumalai systems out there.) 5408425091fSRavikiran G Thirumalai 5418425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5428425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 54344b111b5SSteffen Persvold Numascale NumaChip 5448425091fSRavikiran G Thirumalai ScaleMP vSMP 5458425091fSRavikiran G Thirumalai SGI Ultraviolet 5468425091fSRavikiran G Thirumalai 5478425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5488425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5498425091fSRavikiran G Thirumalaiendif 550c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 551c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 55244b111b5SSteffen Persvoldconfig X86_NUMACHIP 55344b111b5SSteffen Persvold bool "Numascale NumaChip" 55444b111b5SSteffen Persvold depends on X86_64 55544b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 55644b111b5SSteffen Persvold depends on NUMA 55744b111b5SSteffen Persvold depends on SMP 55844b111b5SSteffen Persvold depends on X86_X2APIC 559f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 560a7f7f624SMasahiro Yamada help 56144b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 56244b111b5SSteffen Persvold enable more than ~168 cores. 56344b111b5SSteffen Persvold If you don't have one of these, you should say N here. 56403b48632SNick Piggin 5656a48565eSIngo Molnarconfig X86_VSMP 566c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5676276a074SBorislav Petkov select HYPERVISOR_GUEST 5686a48565eSIngo Molnar select PARAVIRT 5696a48565eSIngo Molnar depends on X86_64 && PCI 570c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 571ead91d4bSShai Fultheim depends on SMP 572a7f7f624SMasahiro Yamada help 5736a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5746a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5756a48565eSIngo Molnar if you have one of these machines. 5766a48565eSIngo Molnar 577c5c606d9SRavikiran G Thirumalaiconfig X86_UV 578c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 579c5c606d9SRavikiran G Thirumalai depends on X86_64 580c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 58154c28d29SJack Steiner depends on NUMA 5821ecb4ae5SAndrew Morton depends on EFI 583c2209ea5SIngo Molnar depends on KEXEC_CORE 5849d6c26e7SSuresh Siddha depends on X86_X2APIC 5851222e564SIngo Molnar depends on PCI 586a7f7f624SMasahiro Yamada help 587c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 588c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 589c5c606d9SRavikiran G Thirumalai 590c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 591c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 592506f1d07SSam Ravnborg 593ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 594ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 595cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 596a7f7f624SMasahiro Yamada help 597ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 598ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 599ddd70cf9SJun Nakajima Goldfish emulator say N here. 600ddd70cf9SJun Nakajima 601c751e17bSThomas Gleixnerconfig X86_INTEL_CE 602c751e17bSThomas Gleixner bool "CE4100 TV platform" 603c751e17bSThomas Gleixner depends on PCI 604c751e17bSThomas Gleixner depends on PCI_GODIRECT 6056084a6e2SJiang Liu depends on X86_IO_APIC 606c751e17bSThomas Gleixner depends on X86_32 607c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 60837bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 609da6b737bSSebastian Andrzej Siewior select OF 610da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 611a7f7f624SMasahiro Yamada help 612c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 613c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 614c751e17bSThomas Gleixner boxes and media devices. 615c751e17bSThomas Gleixner 6164cb9b00fSDavid Cohenconfig X86_INTEL_MID 61743605ef1SAlan Cox bool "Intel MID platform support" 61843605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 619edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6201ea7c673SAlan Cox depends on PCI 6213fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6221ea7c673SAlan Cox depends on X86_IO_APIC 6234cb9b00fSDavid Cohen select I2C 6247c9c3a1eSAlan Cox select DW_APB_TIMER 62554b34aa0SMika Westerberg select INTEL_SCU_PCI 626a7f7f624SMasahiro Yamada help 6274cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6284cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6294cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6301ea7c673SAlan Cox 6314cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6324cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 63343605ef1SAlan Cox 6348bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6358bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6368bbc2a13SBryan O'Donoghue depends on X86_32 6378bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6388bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6398bbc2a13SBryan O'Donoghue depends on X86_TSC 6408bbc2a13SBryan O'Donoghue depends on PCI 6418bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6428bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6438bbc2a13SBryan O'Donoghue select IOSF_MBI 6448bbc2a13SBryan O'Donoghue select INTEL_IMR 6459ab6eb51SAndy Shevchenko select COMMON_CLK 646a7f7f624SMasahiro Yamada help 6478bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6488bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6498bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6508bbc2a13SBryan O'Donoghue 6513d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6523d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6535962dd22SSinan Kaya depends on X86 && ACPI && PCI 6543d48aab1SMika Westerberg select COMMON_CLK 6550f531431SMathias Nyman select PINCTRL 656eebb3e8dSAndy Shevchenko select IOSF_MBI 657a7f7f624SMasahiro Yamada help 6583d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6593d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6600f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6610f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6623d48aab1SMika Westerberg 66392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 66492082a88SKen Xue bool "AMD ACPI2Platform devices support" 66592082a88SKen Xue depends on ACPI 66692082a88SKen Xue select COMMON_CLK 66792082a88SKen Xue select PINCTRL 668a7f7f624SMasahiro Yamada help 66992082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 67092082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 67192082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 67292082a88SKen Xue implemented under PINCTRL subsystem. 67392082a88SKen Xue 674ced3ce76SDavid E. Boxconfig IOSF_MBI 675ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 676ced3ce76SDavid E. Box depends on PCI 677a7f7f624SMasahiro Yamada help 678ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 679ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 680ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 681ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 682ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 683ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 684ced3ce76SDavid E. Box This list is not meant to be exclusive. 685ced3ce76SDavid E. Box - BayTrail 686ced3ce76SDavid E. Box - Braswell 687ced3ce76SDavid E. Box - Quark 688ced3ce76SDavid E. Box 689ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 690ced3ce76SDavid E. Box 691ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 692ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 693ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 694a7f7f624SMasahiro Yamada help 695ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 696ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 697ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 698ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 699ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 700ed2226bdSDavid E. Box device they want to access. 701ed2226bdSDavid E. Box 702ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 703ed2226bdSDavid E. Box 704c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 705c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 706506f1d07SSam Ravnborg depends on X86_32 707c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 708c5c606d9SRavikiran G Thirumalai select M486 709c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 710a7f7f624SMasahiro Yamada help 711c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 712c5c606d9SRavikiran G Thirumalai as R-8610-(G). 713c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 714c5c606d9SRavikiran G Thirumalai 715e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7169c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7179c398017SIngo Molnar depends on X86_32 && SMP 718c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 719a7f7f624SMasahiro Yamada help 720b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 721b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 722b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 723b5660ba7SH. Peter Anvin one and will fallback to default. 724d49c4288SYinghai Lu 725c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 726d49c4288SYinghai Lu 727d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7286fc108a0SJan Beulich def_bool y 729d949f36fSLinus Torvalds # MCE code calls memory_failure(): 730d949f36fSLinus Torvalds depends on X86_MCE 731d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 732d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 733d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 734d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 735d949f36fSLinus Torvalds 73683125a3aSAlessandro Rubiniconfig STA2X11 73783125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 73883125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 73983125a3aSAlessandro Rubini select SWIOTLB 74083125a3aSAlessandro Rubini select MFD_STA2X11 7410145071bSLinus Walleij select GPIOLIB 742a7f7f624SMasahiro Yamada help 74383125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 74483125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 74583125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 74683125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 74783125a3aSAlessandro Rubini standard PC machines. 74883125a3aSAlessandro Rubini 74982148d1dSShérabconfig X86_32_IRIS 75082148d1dSShérab tristate "Eurobraille/Iris poweroff module" 75182148d1dSShérab depends on X86_32 752a7f7f624SMasahiro Yamada help 75382148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 75482148d1dSShérab to shut themselves down properly. A special I/O sequence is 75582148d1dSShérab needed to do so, which is what this module does at 75682148d1dSShérab kernel shutdown. 75782148d1dSShérab 75882148d1dSShérab This is only for Iris machines from EuroBraille. 75982148d1dSShérab 76082148d1dSShérab If unused, say N. 76182148d1dSShérab 762ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7633c2362e6SHarvey Harrison def_bool y 7643c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 765a87d0914SKen Chen depends on X86 766a7f7f624SMasahiro Yamada help 767506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 768506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 769506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 770506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 771506f1d07SSam Ravnborg 772506f1d07SSam Ravnborg If in doubt, say "Y". 773506f1d07SSam Ravnborg 7746276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7756276a074SBorislav Petkov bool "Linux guest support" 776a7f7f624SMasahiro Yamada help 7776276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7786276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7796276a074SBorislav Petkov setup. 780506f1d07SSam Ravnborg 7816276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7826276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 783506f1d07SSam Ravnborg 7846276a074SBorislav Petkovif HYPERVISOR_GUEST 785506f1d07SSam Ravnborg 786e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 787e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 788a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 789a7f7f624SMasahiro Yamada help 790e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 791e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 792e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 793e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 794e61bd94aSEduardo Pereira Habkost 795c00a280aSJuergen Grossconfig PARAVIRT_XXL 796c00a280aSJuergen Gross bool 797c00a280aSJuergen Gross 7986276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7996276a074SBorislav Petkov bool "paravirt-ops debugging" 8006276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 801a7f7f624SMasahiro Yamada help 8026276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8036276a074SBorislav Petkov a paravirt_op is missing when it is called. 8046276a074SBorislav Petkov 805b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 806b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8076ea30386SKees Cook depends on PARAVIRT && SMP 808a7f7f624SMasahiro Yamada help 809b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 810b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 811b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 812b4ecc126SJeremy Fitzhardinge 8134c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8144c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 815b4ecc126SJeremy Fitzhardinge 8164c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 817b4ecc126SJeremy Fitzhardinge 818ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 819ecca2502SZhao Yakui def_bool n 820ecca2502SZhao Yakui 8216276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8226276a074SBorislav Petkov 8236276a074SBorislav Petkovconfig KVM_GUEST 8246276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8256276a074SBorislav Petkov depends on PARAVIRT 8266276a074SBorislav Petkov select PARAVIRT_CLOCK 827a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 828b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8296276a074SBorislav Petkov default y 830a7f7f624SMasahiro Yamada help 8316276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8326276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8336276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8346276a074SBorislav Petkov underlying device model, the host provides the guest with 8356276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8366276a074SBorislav Petkov 837a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 838a1c4423bSMarcelo Tosatti def_bool n 839a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 840a1c4423bSMarcelo Tosatti help 841a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 842a1c4423bSMarcelo Tosatti 8437733607fSMaran Wilsonconfig PVH 8447733607fSMaran Wilson bool "Support for running PVH guests" 845a7f7f624SMasahiro Yamada help 8467733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8477733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8487733607fSMaran Wilson 8496276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8506276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8516276a074SBorislav Petkov depends on PARAVIRT 852a7f7f624SMasahiro Yamada help 8536276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8546276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8556276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8566276a074SBorislav Petkov that, there can be a small performance impact. 8576276a074SBorislav Petkov 8586276a074SBorislav Petkov If in doubt, say N here. 8596276a074SBorislav Petkov 8607af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8617af192c9SGerd Hoffmann bool 8627af192c9SGerd Hoffmann 8634a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8644a362601SJan Kiszka bool "Jailhouse non-root cell support" 865abde587bSArnd Bergmann depends on X86_64 && PCI 86687e65d05SJan Kiszka select X86_PM_TIMER 867a7f7f624SMasahiro Yamada help 8684a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8694a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8704a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8714a362601SJan Kiszka 872ec7972c9SZhao Yakuiconfig ACRN_GUEST 873ec7972c9SZhao Yakui bool "ACRN Guest support" 874ec7972c9SZhao Yakui depends on X86_64 875498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 876ec7972c9SZhao Yakui help 877ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 878ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 879ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 880ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 881ec7972c9SZhao Yakui found in https://projectacrn.org/. 882ec7972c9SZhao Yakui 8836276a074SBorislav Petkovendif #HYPERVISOR_GUEST 88497349135SJeremy Fitzhardinge 885506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 886506f1d07SSam Ravnborg 887506f1d07SSam Ravnborgconfig HPET_TIMER 8883c2362e6SHarvey Harrison def_bool X86_64 889506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 890a7f7f624SMasahiro Yamada help 891506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 892506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 893506f1d07SSam Ravnborg present. 894506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 895506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 896506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8974e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8984e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 899506f1d07SSam Ravnborg 900506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 901506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 902506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 903506f1d07SSam Ravnborg 904506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 905506f1d07SSam Ravnborg 906506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9073c2362e6SHarvey Harrison def_bool y 9083228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 909506f1d07SSam Ravnborg 9106a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 911506f1d07SSam Ravnborg# The code disables itself when not needed. 9127ae9392cSThomas Petazzoniconfig DMI 9137ae9392cSThomas Petazzoni default y 914cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9156a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 916a7f7f624SMasahiro Yamada help 9177ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9187ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9197ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9207ae9392cSThomas Petazzoni BIOS code. 9217ae9392cSThomas Petazzoni 922506f1d07SSam Ravnborgconfig GART_IOMMU 92338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9242f9237d4SChristoph Hellwig select DMA_OPS 925a4ce5a48SChristoph Hellwig select IOMMU_HELPER 926506f1d07SSam Ravnborg select SWIOTLB 92723ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 928a7f7f624SMasahiro Yamada help 929ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 930ced3c42cSIngo Molnar GART based hardware IOMMUs. 931ced3c42cSIngo Molnar 932ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 933ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 934ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 935ced3c42cSIngo Molnar 936ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 937ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 938ced3c42cSIngo Molnar 939ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 940ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 941ced3c42cSIngo Molnar 32-bit limited device. 942ced3c42cSIngo Molnar 943ced3c42cSIngo Molnar If unsure, say Y. 944506f1d07SSam Ravnborg 9451184dc2fSMike Travisconfig MAXSMP 946ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9476ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 94836f5101aSMike Travis select CPUMASK_OFFSTACK 949a7f7f624SMasahiro Yamada help 950ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9511184dc2fSMike Travis If unsure, say N. 952506f1d07SSam Ravnborg 953aec6487eSIngo Molnar# 954aec6487eSIngo Molnar# The maximum number of CPUs supported: 955aec6487eSIngo Molnar# 956aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 957aec6487eSIngo Molnar# and which can be configured interactively in the 958aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 959aec6487eSIngo Molnar# 960aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 961aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 962aec6487eSIngo Molnar# 963aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 964aec6487eSIngo Molnar# interactive configuration. ) 965aec6487eSIngo Molnar# 966a0d0bb4dSRandy Dunlap 967aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 968a0d0bb4dSRandy Dunlap int 969aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 970a0d0bb4dSRandy Dunlap default 1 if !SMP 971a0d0bb4dSRandy Dunlap default 2 972a0d0bb4dSRandy Dunlap 973aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 974a0d0bb4dSRandy Dunlap int 975a0d0bb4dSRandy Dunlap depends on X86_32 976aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 977aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 978a0d0bb4dSRandy Dunlap default 1 if !SMP 979a0d0bb4dSRandy Dunlap 980aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 981a0d0bb4dSRandy Dunlap int 982a0d0bb4dSRandy Dunlap depends on X86_64 9831edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9841edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 985a0d0bb4dSRandy Dunlap default 1 if !SMP 986aec6487eSIngo Molnar 987aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 988aec6487eSIngo Molnar int 989aec6487eSIngo Molnar depends on X86_32 990aec6487eSIngo Molnar default 32 if X86_BIGSMP 991aec6487eSIngo Molnar default 8 if SMP 992aec6487eSIngo Molnar default 1 if !SMP 993aec6487eSIngo Molnar 994aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 995aec6487eSIngo Molnar int 996aec6487eSIngo Molnar depends on X86_64 997a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 998a0d0bb4dSRandy Dunlap default 64 if SMP 999aec6487eSIngo Molnar default 1 if !SMP 1000a0d0bb4dSRandy Dunlap 1001506f1d07SSam Ravnborgconfig NR_CPUS 100236f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1003aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1004aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1005a7f7f624SMasahiro Yamada help 1006506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1007bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1008cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1009506f1d07SSam Ravnborg minimum value which makes sense is 2. 1010506f1d07SSam Ravnborg 1011aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1012aec6487eSIngo Molnar to the kernel image. 1013506f1d07SSam Ravnborg 101466558b73STim Chenconfig SCHED_CLUSTER 101566558b73STim Chen bool "Cluster scheduler support" 101666558b73STim Chen depends on SMP 101766558b73STim Chen default y 101866558b73STim Chen help 101966558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 102066558b73STim Chen making when dealing with machines that have clusters of CPUs. 102166558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 102266558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 102366558b73STim Chen busses. 102466558b73STim Chen 1025506f1d07SSam Ravnborgconfig SCHED_SMT 1026dbe73364SThomas Gleixner def_bool y if SMP 1027506f1d07SSam Ravnborg 1028506f1d07SSam Ravnborgconfig SCHED_MC 10293c2362e6SHarvey Harrison def_bool y 10303c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1031c8e56d20SBorislav Petkov depends on SMP 1032a7f7f624SMasahiro Yamada help 1033506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1034506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1035506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1036506f1d07SSam Ravnborg 1037de966cf4STim Chenconfig SCHED_MC_PRIO 1038de966cf4STim Chen bool "CPU core priorities scheduler support" 10390a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10400a21fc12SIngo Molnar select X86_INTEL_PSTATE 10410a21fc12SIngo Molnar select CPU_FREQ 1042de966cf4STim Chen default y 1043a7f7f624SMasahiro Yamada help 1044de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1045de966cf4STim Chen core ordering determined at manufacturing time, which allows 1046de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1047de966cf4STim Chen single threaded workloads) than others. 1048de966cf4STim Chen 1049de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1050de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1051de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1052de966cf4STim Chen overall system performance can be achieved. 1053de966cf4STim Chen 1054de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1055de966cf4STim Chen 1056de966cf4STim Chen If unsure say Y here. 10575e76b2abSTim Chen 105830b8b006SThomas Gleixnerconfig UP_LATE_INIT 105930b8b006SThomas Gleixner def_bool y 1060ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 106130b8b006SThomas Gleixner 1062506f1d07SSam Ravnborgconfig X86_UP_APIC 106350849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 106450849eefSJan Beulich default PCI_MSI 106538a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1066a7f7f624SMasahiro Yamada help 1067506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1068506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1069506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1070506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1071506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1072506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1073506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1074506f1d07SSam Ravnborg lockups. 1075506f1d07SSam Ravnborg 1076506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1077506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1078506f1d07SSam Ravnborg depends on X86_UP_APIC 1079a7f7f624SMasahiro Yamada help 1080506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1081506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1082506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1083506f1d07SSam Ravnborg 1084506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1085506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1086506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1087506f1d07SSam Ravnborg 1088506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10893c2362e6SHarvey Harrison def_bool y 10900dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1091b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 109252f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1093506f1d07SSam Ravnborg 1094506f1d07SSam Ravnborgconfig X86_IO_APIC 1095b1da1e71SJan Beulich def_bool y 1096b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1097506f1d07SSam Ravnborg 109841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 109941b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 110041b9eb26SStefan Assmann depends on X86_IO_APIC 1101a7f7f624SMasahiro Yamada help 110241b9eb26SStefan Assmann This option enables a workaround that fixes a source of 110341b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 110441b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 110541b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 110641b9eb26SStefan Assmann 110741b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 110841b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 110941b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 111041b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 111141b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 111241b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 111341b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 111441b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 111541b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 111641b9eb26SStefan Assmann down (vital) interrupt lines. 111741b9eb26SStefan Assmann 111841b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 111941b9eb26SStefan Assmann increased on these systems. 112041b9eb26SStefan Assmann 1121506f1d07SSam Ravnborgconfig X86_MCE 1122bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1123648ed940SChen, Gong select GENERIC_ALLOCATOR 1124e57dbaf7SBorislav Petkov default y 1125a7f7f624SMasahiro Yamada help 1126bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1127bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1128506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1129bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11304efc0670SAndi Kleen 11315de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11325de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11335de97c9fSTony Luck depends on X86_MCE 1134a7f7f624SMasahiro Yamada help 11355de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11365de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11375de97c9fSTony Luck rasdaemon solution. 11385de97c9fSTony Luck 1139506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11403c2362e6SHarvey Harrison def_bool y 11413c2362e6SHarvey Harrison prompt "Intel MCE features" 1142c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1143a7f7f624SMasahiro Yamada help 1144506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1145506f1d07SSam Ravnborg the thermal monitor. 1146506f1d07SSam Ravnborg 1147506f1d07SSam Ravnborgconfig X86_MCE_AMD 11483c2362e6SHarvey Harrison def_bool y 11493c2362e6SHarvey Harrison prompt "AMD MCE features" 1150f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1151a7f7f624SMasahiro Yamada help 1152506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1153506f1d07SSam Ravnborg the DRAM Error Threshold. 1154506f1d07SSam Ravnborg 11554efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11566fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1157c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1158a7f7f624SMasahiro Yamada help 11594efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11605065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11614efc0670SAndi Kleen line. 11624efc0670SAndi Kleen 1163b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1164b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11656fc108a0SJan Beulich def_bool y 1166b2762686SAndi Kleen 1167ea149b36SAndi Kleenconfig X86_MCE_INJECT 1168bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1169ea149b36SAndi Kleen tristate "Machine check injector support" 1170a7f7f624SMasahiro Yamada help 1171ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1172ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1173ea149b36SAndi Kleen QA it is safe to say n. 1174ea149b36SAndi Kleen 117507dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1176e633c65aSKan Liang 11775aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11781e642812SIngo Molnar bool "Legacy VM86 support" 1179506f1d07SSam Ravnborg depends on X86_32 1180a7f7f624SMasahiro Yamada help 11815aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11825aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11835aef51c3SAndy Lutomirski 11845aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11855aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11865aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11875aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11885aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11891e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11901e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11911e642812SIngo Molnar mode might be faster than emulation and you might want to 11921e642812SIngo Molnar enable this option. 11935aef51c3SAndy Lutomirski 11941e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11951e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11961e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 11971e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 11985aef51c3SAndy Lutomirski 11991e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12001e642812SIngo Molnar and slows down exception handling a tiny bit. 12015aef51c3SAndy Lutomirski 12021e642812SIngo Molnar If unsure, say N here. 12035aef51c3SAndy Lutomirski 12045aef51c3SAndy Lutomirskiconfig VM86 12055aef51c3SAndy Lutomirski bool 12065aef51c3SAndy Lutomirski default X86_LEGACY_VM86 120734273f41SH. Peter Anvin 120834273f41SH. Peter Anvinconfig X86_16BIT 120934273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 121034273f41SH. Peter Anvin default y 1211a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1212a7f7f624SMasahiro Yamada help 121334273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 121434273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 121534273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 121634273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 121734273f41SH. Peter Anvin 121834273f41SH. Peter Anvinconfig X86_ESPFIX32 121934273f41SH. Peter Anvin def_bool y 122034273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1221506f1d07SSam Ravnborg 1222197725deSH. Peter Anvinconfig X86_ESPFIX64 1223197725deSH. Peter Anvin def_bool y 122434273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1225506f1d07SSam Ravnborg 12261ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12271ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12281ad83c85SAndy Lutomirski default y 12291ad83c85SAndy Lutomirski depends on X86_64 1230a7f7f624SMasahiro Yamada help 12311ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12321ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12331ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12341ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12351ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12361ad83c85SAndy Lutomirski 0xffffffffff600?00. 12371ad83c85SAndy Lutomirski 12381ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12391ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12401ad83c85SAndy Lutomirski 12411ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12421ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12431ad83c85SAndy Lutomirski 1244111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1245111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1246a24ca997SThomas Gleixner default y 1247a7f7f624SMasahiro Yamada help 1248111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1249111e7b15SThomas Gleixner for legacy applications. 1250111e7b15SThomas Gleixner 1251c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1252c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1253c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1254c8137aceSThomas Gleixner capabilities and permission from potentially active security 1255c8137aceSThomas Gleixner modules. 1256c8137aceSThomas Gleixner 1257c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1258c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1259a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1260a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1261c8137aceSThomas Gleixner 1262506f1d07SSam Ravnborgconfig TOSHIBA 1263506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1264506f1d07SSam Ravnborg depends on X86_32 1265a7f7f624SMasahiro Yamada help 1266506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1267506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1268506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1269506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1270506f1d07SSam Ravnborg 1271506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1272506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1273506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1274506f1d07SSam Ravnborg 1275506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1276506f1d07SSam Ravnborg Say N otherwise. 1277506f1d07SSam Ravnborg 1278506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12799ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12809ba16087SJan Beulich depends on X86_32 1281a7f7f624SMasahiro Yamada help 1282506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1283506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1284506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1285506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1286506f1d07SSam Ravnborg system. 1287506f1d07SSam Ravnborg 1288506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12895e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1290506f1d07SSam Ravnborg 1291506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1292506f1d07SSam Ravnborg enable this option even if you don't need it. 1293506f1d07SSam Ravnborg Say N otherwise. 1294506f1d07SSam Ravnborg 1295506f1d07SSam Ravnborgconfig MICROCODE 12969a2bc335SBorislav Petkov bool "CPU microcode loading support" 12979a2bc335SBorislav Petkov default y 129880030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1299a7f7f624SMasahiro Yamada help 1300506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13015f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13025f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13035f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13045f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13055f9c01aaSBorislav Petkov the Linux kernel. 1306506f1d07SSam Ravnborg 13075f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1308cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13095f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13105f9c01aaSBorislav Petkov initrd for microcode blobs. 1311506f1d07SSam Ravnborg 1312c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1313c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1314c508c46eSBenjamin Gilbert config option. 1315506f1d07SSam Ravnborg 13168d86f390SPeter Orubaconfig MICROCODE_INTEL 1317e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13188d86f390SPeter Oruba depends on MICROCODE 13198d86f390SPeter Oruba default MICROCODE 1320a7f7f624SMasahiro Yamada help 13218d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13228d86f390SPeter Oruba processors. 13238d86f390SPeter Oruba 1324b8989db9SAlan For the current Intel microcode data package go to 1325b8989db9SAlan <https://downloadcenter.intel.com> and search for 1326b8989db9SAlan 'Linux Processor Microcode Data File'. 13278d86f390SPeter Oruba 132880cc9f10SPeter Orubaconfig MICROCODE_AMD 1329e43f6e67SBorislav Petkov bool "AMD microcode loading support" 133080cc9f10SPeter Oruba depends on MICROCODE 1331a7f7f624SMasahiro Yamada help 133280cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 133380cc9f10SPeter Oruba processors will be enabled. 133480cc9f10SPeter Oruba 1335506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1336c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1337c02f48e0SBorislav Petkov default n 1338506f1d07SSam Ravnborg depends on MICROCODE 1339a7f7f624SMasahiro Yamada help 1340c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1341c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1342c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1343c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1344c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1345cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1346506f1d07SSam Ravnborg 1347506f1d07SSam Ravnborgconfig X86_MSR 1348506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1349a7f7f624SMasahiro Yamada help 1350506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1351506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1352506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1353506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1354506f1d07SSam Ravnborg systems. 1355506f1d07SSam Ravnborg 1356506f1d07SSam Ravnborgconfig X86_CPUID 1357506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1358a7f7f624SMasahiro Yamada help 1359506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1360506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1361506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1362506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1363506f1d07SSam Ravnborg 1364506f1d07SSam Ravnborgchoice 1365506f1d07SSam Ravnborg prompt "High Memory Support" 13666fc108a0SJan Beulich default HIGHMEM4G 1367506f1d07SSam Ravnborg depends on X86_32 1368506f1d07SSam Ravnborg 1369506f1d07SSam Ravnborgconfig NOHIGHMEM 1370506f1d07SSam Ravnborg bool "off" 1371a7f7f624SMasahiro Yamada help 1372506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1373506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1374506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1375506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1376506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1377506f1d07SSam Ravnborg "high memory". 1378506f1d07SSam Ravnborg 1379506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1380506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1381506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1382506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1383506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1384506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1385506f1d07SSam Ravnborg possible. 1386506f1d07SSam Ravnborg 1387506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1388506f1d07SSam Ravnborg answer "4GB" here. 1389506f1d07SSam Ravnborg 1390506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1391506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1392506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1393506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1394506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1395506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1396506f1d07SSam Ravnborg 1397506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1398506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1399506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1400506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1401506f1d07SSam Ravnborg kernel at boot time.) 1402506f1d07SSam Ravnborg 1403506f1d07SSam Ravnborg If unsure, say "off". 1404506f1d07SSam Ravnborg 1405506f1d07SSam Ravnborgconfig HIGHMEM4G 1406506f1d07SSam Ravnborg bool "4GB" 1407a7f7f624SMasahiro Yamada help 1408506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1409506f1d07SSam Ravnborg gigabytes of physical RAM. 1410506f1d07SSam Ravnborg 1411506f1d07SSam Ravnborgconfig HIGHMEM64G 1412506f1d07SSam Ravnborg bool "64GB" 1413225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1414506f1d07SSam Ravnborg select X86_PAE 1415a7f7f624SMasahiro Yamada help 1416506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1417506f1d07SSam Ravnborg gigabytes of physical RAM. 1418506f1d07SSam Ravnborg 1419506f1d07SSam Ravnborgendchoice 1420506f1d07SSam Ravnborg 1421506f1d07SSam Ravnborgchoice 14226a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1423506f1d07SSam Ravnborg default VMSPLIT_3G 1424506f1d07SSam Ravnborg depends on X86_32 1425a7f7f624SMasahiro Yamada help 1426506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1427506f1d07SSam Ravnborg 1428506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1429506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1430506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1431506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1432506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1433506f1d07SSam Ravnborg available to user programs, making the address space there 1434506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1435506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1436506f1d07SSam Ravnborg kernel modules. 1437506f1d07SSam Ravnborg 1438506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1439506f1d07SSam Ravnborg option alone! 1440506f1d07SSam Ravnborg 1441506f1d07SSam Ravnborg config VMSPLIT_3G 1442506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1443506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1444506f1d07SSam Ravnborg depends on !X86_PAE 1445506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1446506f1d07SSam Ravnborg config VMSPLIT_2G 1447506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1448506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1449506f1d07SSam Ravnborg depends on !X86_PAE 1450506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1451506f1d07SSam Ravnborg config VMSPLIT_1G 1452506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1453506f1d07SSam Ravnborgendchoice 1454506f1d07SSam Ravnborg 1455506f1d07SSam Ravnborgconfig PAGE_OFFSET 1456506f1d07SSam Ravnborg hex 1457506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1458506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1459506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1460506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1461506f1d07SSam Ravnborg default 0xC0000000 1462506f1d07SSam Ravnborg depends on X86_32 1463506f1d07SSam Ravnborg 1464506f1d07SSam Ravnborgconfig HIGHMEM 14653c2362e6SHarvey Harrison def_bool y 1466506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1467506f1d07SSam Ravnborg 1468506f1d07SSam Ravnborgconfig X86_PAE 14699ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1470506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1471d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14729d99c712SChristian Melki select SWIOTLB 1473a7f7f624SMasahiro Yamada help 1474506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1475506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1476506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1477506f1d07SSam Ravnborg consumes more pagetable space per process. 1478506f1d07SSam Ravnborg 147977ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148077ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148118ec1eafSKirill A. Shutemov default y 1482eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1483162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148477ef56e4SKirill A. Shutemov depends on X86_64 1485a7f7f624SMasahiro Yamada help 148677ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 148777ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 148877ef56e4SKirill A. Shutemov physical address space. 148977ef56e4SKirill A. Shutemov 149077ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149177ef56e4SKirill A. Shutemov 14926657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14936657fca0SKirill A. Shutemov support 4- or 5-level paging. 149477ef56e4SKirill A. Shutemov 1495cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 149677ef56e4SKirill A. Shutemov information. 149777ef56e4SKirill A. Shutemov 149877ef56e4SKirill A. Shutemov Say N if unsure. 149977ef56e4SKirill A. Shutemov 150010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1501e5008abeSLuis R. Rodriguez def_bool y 15022e1da13fSVlastimil Babka depends on X86_64 1503a7f7f624SMasahiro Yamada help 150410971ab2SIngo Molnar Certain kernel features effectively disable kernel 150510971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 150610971ab2SIngo Molnar supports them), so don't confuse the user by printing 150710971ab2SIngo Molnar that we have them enabled. 15089e899816SNick Piggin 15095c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15105c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15115c280cf6SThomas Gleixner depends on DEBUG_FS 1512a7f7f624SMasahiro Yamada help 1513b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1514a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15155c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15165c280cf6SThomas Gleixner 151720f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 151820f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 151920f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 152020f07a04SKirill A. Shutemov select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 152120f07a04SKirill A. Shutemov def_bool n 152220f07a04SKirill A. Shutemov 15237744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15247744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15257744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 152682fef0adSDavid Rientjes select DMA_COHERENT_POOL 1527ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1528597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1529aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 153020f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 1531a7f7f624SMasahiro Yamada help 15327744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15337744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15347744ccdbSTom Lendacky Encryption (SME). 15357744ccdbSTom Lendacky 15367744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15377744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15387744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1539a7f7f624SMasahiro Yamada help 15407744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15417744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15427744ccdbSTom Lendacky 15437744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15447744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15457744ccdbSTom Lendacky 15467744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15477744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15487744ccdbSTom Lendacky 1549506f1d07SSam Ravnborg# Common NUMA Features 1550506f1d07SSam Ravnborgconfig NUMA 1551e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1552506f1d07SSam Ravnborg depends on SMP 1553b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1554b5660ba7SH. Peter Anvin default y if X86_BIGSMP 15557ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 1556a7f7f624SMasahiro Yamada help 1557e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1558fd51b2d7SKOSAKI Motohiro 1559506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1560506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1561506f1d07SSam Ravnborg NUMA awareness to the kernel. 1562506f1d07SSam Ravnborg 1563c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1564fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1565fd51b2d7SKOSAKI Motohiro 1566b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15677cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1568fd51b2d7SKOSAKI Motohiro 1569fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1570506f1d07SSam Ravnborg 1571eec1d4faSHans Rosenfeldconfig AMD_NUMA 15723c2362e6SHarvey Harrison def_bool y 15733c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15745da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1575a7f7f624SMasahiro Yamada help 1576eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1577eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1578eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1579eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1580eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1581506f1d07SSam Ravnborg 1582506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15833c2362e6SHarvey Harrison def_bool y 15843c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1585506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1586506f1d07SSam Ravnborg select ACPI_NUMA 1587a7f7f624SMasahiro Yamada help 1588506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1589506f1d07SSam Ravnborg 1590506f1d07SSam Ravnborgconfig NUMA_EMU 1591506f1d07SSam Ravnborg bool "NUMA emulation" 15921b7e03efSTejun Heo depends on NUMA 1593a7f7f624SMasahiro Yamada help 1594506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1595506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1596506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1597506f1d07SSam Ravnborg 1598506f1d07SSam Ravnborgconfig NODES_SHIFT 1599d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 160051591e31SDavid Rientjes range 1 10 160151591e31SDavid Rientjes default "10" if MAXSMP 1602506f1d07SSam Ravnborg default "6" if X86_64 1603506f1d07SSam Ravnborg default "3" 1604a9ee6cf5SMike Rapoport depends on NUMA 1605a7f7f624SMasahiro Yamada help 16061184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1607692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1608506f1d07SSam Ravnborg 1609506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1610506f1d07SSam Ravnborg def_bool y 16113b16651fSTejun Heo depends on X86_32 && !NUMA 1612506f1d07SSam Ravnborg 1613506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1614506f1d07SSam Ravnborg def_bool y 16156ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1616506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1617506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1618506f1d07SSam Ravnborg 16193b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16206ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16213b16651fSTejun Heo 1622506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1623506f1d07SSam Ravnborg def_bool y 16244eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1625506f1d07SSam Ravnborg 1626506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1627a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16285c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1629a0842b70SToshi Kani help 1630a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1631cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1632a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1633506f1d07SSam Ravnborg 16343b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16353b16651fSTejun Heo def_bool y 16363b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16373b16651fSTejun Heo 1638a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1639a29815a3SAvi Kivity hex 1640a29815a3SAvi Kivity default 0 if X86_32 1641a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1642a29815a3SAvi Kivity 16437a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16447a67832cSDan Williams bool 16457a67832cSDan Williams 1646ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16477a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16489f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16499f53f9faSDan Williams depends on BLK_DEV 16507a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16517b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16529f53f9faSDan Williams select LIBNVDIMM 1653ec776ef6SChristoph Hellwig help 1654ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1655ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1656ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1657ec776ef6SChristoph Hellwig they can be used for persistent storage. 1658ec776ef6SChristoph Hellwig 1659ec776ef6SChristoph Hellwig Say Y if unsure. 1660ec776ef6SChristoph Hellwig 1661506f1d07SSam Ravnborgconfig HIGHPTE 1662506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16636fc108a0SJan Beulich depends on HIGHMEM 1664a7f7f624SMasahiro Yamada help 1665506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1666506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1667506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1668506f1d07SSam Ravnborg entries in high memory. 1669506f1d07SSam Ravnborg 16709f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16719f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1672a7f7f624SMasahiro Yamada help 16739f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16749f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16759f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16769f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16779f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16789f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16799f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16808c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16819f077871SJeremy Fitzhardinge 16829f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16839f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16849f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16859f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16869f077871SJeremy Fitzhardinge 16879f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16889f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16899f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16909f077871SJeremy Fitzhardinge memory. 16919f077871SJeremy Fitzhardinge 1692c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1693c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1694c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1695c885df50SJeremy Fitzhardinge default y 1696a7f7f624SMasahiro Yamada help 1697c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1698c885df50SJeremy Fitzhardinge on or off. 1699c885df50SJeremy Fitzhardinge 1700506f1d07SSam Ravnborgconfig MATH_EMULATION 1701506f1d07SSam Ravnborg bool 1702a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 170387d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1704a7f7f624SMasahiro Yamada help 1705506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1706506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1707506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1708506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1709506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1710506f1d07SSam Ravnborg coprocessor or this emulation. 1711506f1d07SSam Ravnborg 1712506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1713506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1714506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1715506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1716506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1717506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1718506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1719506f1d07SSam Ravnborg intend to use this kernel on different machines. 1720506f1d07SSam Ravnborg 1721506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1722506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1723506f1d07SSam Ravnborg 1724506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1725506f1d07SSam Ravnborg kernel, it won't hurt. 1726506f1d07SSam Ravnborg 1727506f1d07SSam Ravnborgconfig MTRR 17286fc108a0SJan Beulich def_bool y 17296a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1730a7f7f624SMasahiro Yamada help 1731506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1732506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1733506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1734506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1735506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1736506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1737506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1738506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1739506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1740506f1d07SSam Ravnborg 1741506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1742506f1d07SSam Ravnborg control registers on other processors can be easily supported 1743506f1d07SSam Ravnborg as well: 1744506f1d07SSam Ravnborg 1745506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1746506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1747506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1748506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1749506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1750506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1751506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1752506f1d07SSam Ravnborg 1753506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1754506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1755506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1756506f1d07SSam Ravnborg 1757506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1758506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1759506f1d07SSam Ravnborg 1760cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1761506f1d07SSam Ravnborg 176295ffa243SYinghai Luconfig MTRR_SANITIZER 17632ffb3501SYinghai Lu def_bool y 176495ffa243SYinghai Lu prompt "MTRR cleanup support" 176595ffa243SYinghai Lu depends on MTRR 1766a7f7f624SMasahiro Yamada help 1767aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1768aba3728cSThomas Gleixner add writeback entries. 176995ffa243SYinghai Lu 1770aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1771692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1772aba3728cSThomas Gleixner mtrr_chunk_size. 177395ffa243SYinghai Lu 17742ffb3501SYinghai Lu If unsure, say Y. 177595ffa243SYinghai Lu 177695ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1777f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1778f5098d62SYinghai Lu range 0 1 1779f5098d62SYinghai Lu default "0" 178095ffa243SYinghai Lu depends on MTRR_SANITIZER 1781a7f7f624SMasahiro Yamada help 1782f5098d62SYinghai Lu Enable mtrr cleanup default value 178395ffa243SYinghai Lu 178412031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 178512031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 178612031a62SYinghai Lu range 0 7 178712031a62SYinghai Lu default "1" 178812031a62SYinghai Lu depends on MTRR_SANITIZER 1789a7f7f624SMasahiro Yamada help 179012031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1791aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 179212031a62SYinghai Lu 17932e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17946fc108a0SJan Beulich def_bool y 17956a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 17962a8a2719SIngo Molnar depends on MTRR 1797a7f7f624SMasahiro Yamada help 17982e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1799042b78e4SVenki Pallipadi 18002e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18012e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18022e5d9c85Svenkatesh.pallipadi@intel.com 18032e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1804042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18052e5d9c85Svenkatesh.pallipadi@intel.com 18062e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18072e5d9c85Svenkatesh.pallipadi@intel.com 180846cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 180946cf98cdSVenkatesh Pallipadi def_bool y 181046cf98cdSVenkatesh Pallipadi depends on X86_PAT 181146cf98cdSVenkatesh Pallipadi 1812628c6246SH. Peter Anvinconfig ARCH_RANDOM 1813628c6246SH. Peter Anvin def_bool y 1814628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1815a7f7f624SMasahiro Yamada help 1816628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1817628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1818628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1819628c6246SH. Peter Anvin secure hardware random number generator. 1820628c6246SH. Peter Anvin 182151ae4a2dSH. Peter Anvinconfig X86_SMAP 182251ae4a2dSH. Peter Anvin def_bool y 182351ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1824*03f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 1825a7f7f624SMasahiro Yamada help 182651ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 182751ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 182851ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 182951ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 183051ae4a2dSH. Peter Anvin 183151ae4a2dSH. Peter Anvin If unsure, say Y. 183251ae4a2dSH. Peter Anvin 1833b971880fSBabu Mogerconfig X86_UMIP 1834796ebc81SRicardo Neri def_bool y 1835b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1836a7f7f624SMasahiro Yamada help 1837b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1838b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1839b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1840b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1841b971880fSBabu Moger information about the hardware state. 1842796ebc81SRicardo Neri 1843796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1844796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1845796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1846796ebc81SRicardo Neri results are dummy. 1847aa35f896SRicardo Neri 1848156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1849156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1850156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1851156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1852262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1853262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1854156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1855262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1856156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1857156ff4a5SPeter Zijlstra 1858156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1859156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 1860156ff4a5SPeter Zijlstra bool 1861*03f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1862f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1863f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 1864*03f16cd0SJosh Poimboeuf select OBJTOOL 1865156ff4a5SPeter Zijlstra help 1866156ff4a5SPeter Zijlstra Build the kernel with support for Indirect Branch Tracking, a 1867156ff4a5SPeter Zijlstra hardware support course-grain forward-edge Control Flow Integrity 1868156ff4a5SPeter Zijlstra protection. It enforces that all indirect calls must land on 1869156ff4a5SPeter Zijlstra an ENDBR instruction, as such, the compiler will instrument the 1870156ff4a5SPeter Zijlstra code with them to make this happen. 1871156ff4a5SPeter Zijlstra 1872ed53a0d9SPeter Zijlstra In addition to building the kernel with IBT, seal all functions that 18734cdfc11bSNur Hussein are not indirect call targets, avoiding them ever becoming one. 1874ed53a0d9SPeter Zijlstra 1875ed53a0d9SPeter Zijlstra This requires LTO like objtool runs and will slow down the build. It 1876ed53a0d9SPeter Zijlstra does significantly reduce the number of ENDBR instructions in the 1877ed53a0d9SPeter Zijlstra kernel image. 1878ed53a0d9SPeter Zijlstra 187935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 188038f3e775SBabu Moger prompt "Memory Protection Keys" 188135e97790SDave Hansen def_bool y 1882284244a9SDave Hansen # Note: only available in 64-bit mode 188338f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 188452c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 188552c8e601SIngo Molnar select ARCH_HAS_PKEYS 1886a7f7f624SMasahiro Yamada help 1887284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1888284244a9SDave Hansen page-based protections, but without requiring modification of the 1889284244a9SDave Hansen page tables when an application changes protection domains. 1890284244a9SDave Hansen 18911eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1892284244a9SDave Hansen 1893284244a9SDave Hansen If unsure, say y. 189435e97790SDave Hansen 1895db616173SMichal Hockochoice 1896db616173SMichal Hocko prompt "TSX enable mode" 1897db616173SMichal Hocko depends on CPU_SUP_INTEL 1898db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1899db616173SMichal Hocko help 1900db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1901db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1902db616173SMichal Hocko can lead to a noticeable performance boost. 1903db616173SMichal Hocko 1904db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1905db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1906db616173SMichal Hocko will be more of those attacks discovered in the future. 1907db616173SMichal Hocko 1908db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1909db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1910db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1911db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1912db616173SMichal Hocko for the particular machine. 1913db616173SMichal Hocko 1914db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1915db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1916db616173SMichal Hocko details. 1917db616173SMichal Hocko 1918db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1919db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1920db616173SMichal Hocko relevant. 1921db616173SMichal Hocko 1922db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1923db616173SMichal Hocko bool "off" 1924db616173SMichal Hocko help 1925db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1926db616173SMichal Hocko 1927db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1928db616173SMichal Hocko bool "on" 1929db616173SMichal Hocko help 1930db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1931db616173SMichal Hocko line parameter. 1932db616173SMichal Hocko 1933db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1934db616173SMichal Hocko bool "auto" 1935db616173SMichal Hocko help 1936db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1937db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1938db616173SMichal Hockoendchoice 1939db616173SMichal Hocko 1940e7e05452SSean Christophersonconfig X86_SGX 1941e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1942e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1943e7e05452SSean Christopherson depends on CRYPTO=y 1944e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1945e7e05452SSean Christopherson select SRCU 1946e7e05452SSean Christopherson select MMU_NOTIFIER 1947901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 194840e0e784STony Luck select XARRAY_MULTI 1949e7e05452SSean Christopherson help 1950e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1951e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1952e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1953e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1954e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1955e7e05452SSean Christopherson hardware. 1956e7e05452SSean Christopherson 1957e7e05452SSean Christopherson If unsure, say N. 1958e7e05452SSean Christopherson 1959506f1d07SSam Ravnborgconfig EFI 19609ba16087SJan Beulich bool "EFI runtime service support" 19615b83683fSHuang, Ying depends on ACPI 1962f6ce5002SSergey Vlasov select UCS2_STRING 1963022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19641ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1965a7f7f624SMasahiro Yamada help 19668b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1967506f1d07SSam Ravnborg available (such as the EFI variable services). 1968506f1d07SSam Ravnborg 19698b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19708b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19718b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19728b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19738b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19748b2cb7a8SHuang, Ying platforms. 1975506f1d07SSam Ravnborg 1976291f3632SMatt Flemingconfig EFI_STUB 1977291f3632SMatt Fleming bool "EFI stub support" 1978c6dbd3e5SPeter Zijlstra depends on EFI 19798f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19807b2a583aSMatt Fleming select RELOCATABLE 1981a7f7f624SMasahiro Yamada help 1982291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1983291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1984291f3632SMatt Fleming 19854f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19860c759662SMatt Fleming 19877d453eeeSMatt Flemingconfig EFI_MIXED 19887d453eeeSMatt Fleming bool "EFI mixed-mode support" 19897d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1990a7f7f624SMasahiro Yamada help 19917d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19927d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19937d453eeeSMatt Fleming mode. 19947d453eeeSMatt Fleming 19957d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19967d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19977d453eeeSMatt Fleming the EFI handover protocol must be used. 19987d453eeeSMatt Fleming 19997d453eeeSMatt Fleming If unsure, say N. 20007d453eeeSMatt Fleming 20018636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2002506f1d07SSam Ravnborg 2003506f1d07SSam Ravnborgconfig KEXEC 2004506f1d07SSam Ravnborg bool "kexec system call" 20052965faa5SDave Young select KEXEC_CORE 2006a7f7f624SMasahiro Yamada help 2007506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 2008506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 2009506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 2010506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 2011506f1d07SSam Ravnborg 2012506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 2013506f1d07SSam Ravnborg 2014506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 2015506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 2016bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 2017bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 2018bf220695SGeert Uytterhoeven made. 2019506f1d07SSam Ravnborg 202074ca317cSVivek Goyalconfig KEXEC_FILE 202174ca317cSVivek Goyal bool "kexec file based system call" 20222965faa5SDave Young select KEXEC_CORE 202374ca317cSVivek Goyal select BUILD_BIN2C 202474ca317cSVivek Goyal depends on X86_64 202574ca317cSVivek Goyal depends on CRYPTO=y 202674ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2027a7f7f624SMasahiro Yamada help 202874ca317cSVivek Goyal This is new version of kexec system call. This system call is 202974ca317cSVivek Goyal file based and takes file descriptors as system call argument 203074ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 203174ca317cSVivek Goyal accepted by previous system call. 203274ca317cSVivek Goyal 2033b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2034b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2035b799a09fSAKASHI Takahiro 203699d5cadfSJiri Bohacconfig KEXEC_SIG 20378e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 203874ca317cSVivek Goyal depends on KEXEC_FILE 2039a7f7f624SMasahiro Yamada help 204099d5cadfSJiri Bohac 204199d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 204299d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 204399d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 204499d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 204599d5cadfSJiri Bohac 204699d5cadfSJiri Bohac In addition to this option, you need to enable signature 204799d5cadfSJiri Bohac verification for the corresponding kernel image type being 204899d5cadfSJiri Bohac loaded in order for this to work. 204999d5cadfSJiri Bohac 205099d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 205199d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 205299d5cadfSJiri Bohac depends on KEXEC_SIG 2053a7f7f624SMasahiro Yamada help 20548e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2055d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20568e7d8381SVivek Goyal 20578e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20588e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 205999d5cadfSJiri Bohac depends on KEXEC_SIG 20608e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20618e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2062a7f7f624SMasahiro Yamada help 20638e7d8381SVivek Goyal Enable bzImage signature verification support. 20648e7d8381SVivek Goyal 2065506f1d07SSam Ravnborgconfig CRASH_DUMP 206604b69447SPavel Machek bool "kernel crash dumps" 2067506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2068a7f7f624SMasahiro Yamada help 2069506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2070506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2071506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2072506f1d07SSam Ravnborg a specially reserved region and then later executed after 2073506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2074506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2075506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2076506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2077330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2078506f1d07SSam Ravnborg 20793ab83521SHuang Yingconfig KEXEC_JUMP 20806ea30386SKees Cook bool "kexec jump" 2081fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2082a7f7f624SMasahiro Yamada help 208389081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 208489081d17SHuang Ying code in physical address mode via KEXEC 20853ab83521SHuang Ying 2086506f1d07SSam Ravnborgconfig PHYSICAL_START 20876a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2088ceefccc9SH. Peter Anvin default "0x1000000" 2089a7f7f624SMasahiro Yamada help 2090506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2091506f1d07SSam Ravnborg 2092506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2093506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2094506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2095506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2096506f1d07SSam Ravnborg address. 2097506f1d07SSam Ravnborg 2098506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2099506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2100506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2101506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2102506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2103506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2104506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2105506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2106506f1d07SSam Ravnborg 2107ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2108ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2109ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2110ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2111ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2112ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2113ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2114330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2115ceefccc9SH. Peter Anvin for more details about crash dumps. 2116506f1d07SSam Ravnborg 2117506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2118506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2119506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2120506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2121506f1d07SSam Ravnborg is present because there are users out there who continue to use 2122506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2123506f1d07SSam Ravnborg line. 2124506f1d07SSam Ravnborg 2125506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2126506f1d07SSam Ravnborg 2127506f1d07SSam Ravnborgconfig RELOCATABLE 212826717808SH. Peter Anvin bool "Build a relocatable kernel" 212926717808SH. Peter Anvin default y 2130a7f7f624SMasahiro Yamada help 2131506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2132506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2133506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2134506f1d07SSam Ravnborg but are discarded at runtime. 2135506f1d07SSam Ravnborg 2136506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2137506f1d07SSam Ravnborg must live at a different physical address than the primary 2138506f1d07SSam Ravnborg kernel. 2139506f1d07SSam Ravnborg 2140506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2141506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21428ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2143506f1d07SSam Ravnborg 21448ab3820fSKees Cookconfig RANDOMIZE_BASE 2145e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21468ab3820fSKees Cook depends on RELOCATABLE 21476807c846SIngo Molnar default y 2148a7f7f624SMasahiro Yamada help 2149e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2150e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2151e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2152e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2153e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2154e8581e3dSBaoquan He code internals. 2155e8581e3dSBaoquan He 2156ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2157ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2158ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2159ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2160ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2161ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2162ed9f007eSKees Cook 2163ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2164ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2165ed9f007eSKees Cook 512MB (8 bits of entropy). 21668ab3820fSKees Cook 2167a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2168e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2169e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2170ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2171ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2172ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2173ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2174ed9f007eSKees Cook theoretically possible, but the implementations are further 2175ed9f007eSKees Cook limited due to memory layouts. 2176e8581e3dSBaoquan He 21776807c846SIngo Molnar If unsure, say Y. 2178da2b6fb9SKees Cook 21798ab3820fSKees Cook# Relocation on x86 needs some additional build support 2180845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2181845adf72SH. Peter Anvin def_bool y 21828ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2183845adf72SH. Peter Anvin 2184506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2185a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21868ab3820fSKees Cook default "0x200000" 2187a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2188a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2189a7f7f624SMasahiro Yamada help 2190506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2191506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2192506f1d07SSam Ravnborg address which meets above alignment restriction. 2193506f1d07SSam Ravnborg 2194506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2195506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2196506f1d07SSam Ravnborg address aligned to above value and run from there. 2197506f1d07SSam Ravnborg 2198506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2199506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2200506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2201506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2202506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2203506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2204506f1d07SSam Ravnborg above alignment restrictions. 2205506f1d07SSam Ravnborg 2206a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2207a0215061SKees Cook this value must be a multiple of 0x200000. 2208a0215061SKees Cook 2209506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2210506f1d07SSam Ravnborg 2211eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2212eedb92abSKirill A. Shutemov bool 2213a7f7f624SMasahiro Yamada help 2214eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2215eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2216eedb92abSKirill A. Shutemov 22170483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22180483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22190483e1faSThomas Garnier depends on X86_64 22200483e1faSThomas Garnier depends on RANDOMIZE_BASE 2221eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22220483e1faSThomas Garnier default RANDOMIZE_BASE 2223a7f7f624SMasahiro Yamada help 22240483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22250483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22260483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22270483e1faSThomas Garnier 22280483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22290483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22300483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22310483e1faSThomas Garnier addresses for each memory section. 22320483e1faSThomas Garnier 22336807c846SIngo Molnar If unsure, say Y. 22340483e1faSThomas Garnier 223590397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 223690397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 223790397a41SThomas Garnier depends on RANDOMIZE_MEMORY 223890397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 223990397a41SThomas Garnier default "0x0" 224090397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 224190397a41SThomas Garnier range 0x0 0x40 2242a7f7f624SMasahiro Yamada help 224390397a41SThomas Garnier Define the padding in terabytes added to the existing physical 224490397a41SThomas Garnier memory size during kernel memory randomization. It is useful 224590397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 224690397a41SThomas Garnier address randomization. 224790397a41SThomas Garnier 224890397a41SThomas Garnier If unsure, leave at the default value. 224990397a41SThomas Garnier 2250506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2251bebd024eSThomas Gleixner def_bool y 225240b31360SStephen Rothwell depends on SMP 2253506f1d07SSam Ravnborg 225480aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 225580aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22562c922cd0SKees Cook depends on HOTPLUG_CPU 2257a7f7f624SMasahiro Yamada help 225880aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 225980aa1dffSFenghua Yu 226080aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 226180aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 226280aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 226380aa1dffSFenghua Yu 226480aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 226580aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 226680aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 226780aa1dffSFenghua Yu 226880aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 226980aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 227080aa1dffSFenghua Yu 227180aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 227280aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 227380aa1dffSFenghua Yu be other CPU0 dependencies. 227480aa1dffSFenghua Yu 227580aa1dffSFenghua Yu Please make sure the dependencies are under your control before 227680aa1dffSFenghua Yu you enable this feature. 227780aa1dffSFenghua Yu 227880aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 227980aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 228080aa1dffSFenghua Yu parameter cpu0_hotplug. 228180aa1dffSFenghua Yu 2282a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2283a71c8bc5SFenghua Yu def_bool n 2284a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22852c922cd0SKees Cook depends on HOTPLUG_CPU 2286a7f7f624SMasahiro Yamada help 2287a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2288a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2289a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2290a71c8bc5SFenghua Yu 2291a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2292a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2293a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2294a71c8bc5SFenghua Yu 2295a71c8bc5SFenghua Yu If unsure, say N. 2296a71c8bc5SFenghua Yu 2297506f1d07SSam Ravnborgconfig COMPAT_VDSO 2298b0b49f26SAndy Lutomirski def_bool n 2299b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2300953fee1dSIngo Molnar depends on COMPAT_32 2301a7f7f624SMasahiro Yamada help 2302b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2303b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2304b0b49f26SAndy Lutomirski indicated in its segment table. 2305e84446deSRandy Dunlap 2306b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2307b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2308b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2309b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2310b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2311506f1d07SSam Ravnborg 2312b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2313b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2314b0b49f26SAndy Lutomirski 2315b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2316b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2317b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2318b0b49f26SAndy Lutomirski 2319b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2320b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2321506f1d07SSam Ravnborg 23223dc33bd3SKees Cookchoice 23233dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23243dc33bd3SKees Cook depends on X86_64 2325625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23263dc33bd3SKees Cook help 23273dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23283dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23293dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23303dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23313dc33bd3SKees Cook 23323dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2333bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23343dc33bd3SKees Cook 23353dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23363dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23373dc33bd3SKees Cook to improve security. 23383dc33bd3SKees Cook 2339bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23403dc33bd3SKees Cook 23413dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2342bd49e16eSAndy Lutomirski bool "Full emulation" 23433dc33bd3SKees Cook help 2344bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2345bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2346bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2347bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2348bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2349bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2350bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2351bd49e16eSAndy Lutomirski 2352bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2353bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2354bd49e16eSAndy Lutomirski 2355bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2356bd49e16eSAndy Lutomirski bool "Emulate execution only" 2357bd49e16eSAndy Lutomirski help 2358bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2359bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2360bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2361bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2362bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2363bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2364bd49e16eSAndy Lutomirski buffer. 23653dc33bd3SKees Cook 23663dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23673dc33bd3SKees Cook bool "None" 23683dc33bd3SKees Cook help 23693dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23703dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23713dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23723dc33bd3SKees Cook will be reported to dmesg, so that either old or 23733dc33bd3SKees Cook malicious userspace programs can be identified. 23743dc33bd3SKees Cook 23753dc33bd3SKees Cookendchoice 23763dc33bd3SKees Cook 2377516cbf37STim Birdconfig CMDLINE_BOOL 2378516cbf37STim Bird bool "Built-in kernel command line" 2379a7f7f624SMasahiro Yamada help 2380516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2381516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2382516cbf37STim Bird necessary or convenient to provide some or all of the 2383516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2384516cbf37STim Bird to not rely on the boot loader to provide them.) 2385516cbf37STim Bird 2386516cbf37STim Bird To compile command line arguments into the kernel, 2387516cbf37STim Bird set this option to 'Y', then fill in the 238869711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2389516cbf37STim Bird 2390516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2391516cbf37STim Bird should leave this option set to 'N'. 2392516cbf37STim Bird 2393516cbf37STim Birdconfig CMDLINE 2394516cbf37STim Bird string "Built-in kernel command string" 2395516cbf37STim Bird depends on CMDLINE_BOOL 2396516cbf37STim Bird default "" 2397a7f7f624SMasahiro Yamada help 2398516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2399516cbf37STim Bird image and used at boot time. If the boot loader provides a 2400516cbf37STim Bird command line at boot time, it is appended to this string to 2401516cbf37STim Bird form the full kernel command line, when the system boots. 2402516cbf37STim Bird 2403516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2404516cbf37STim Bird change this behavior. 2405516cbf37STim Bird 2406516cbf37STim Bird In most cases, the command line (whether built-in or provided 2407516cbf37STim Bird by the boot loader) should specify the device for the root 2408516cbf37STim Bird file system. 2409516cbf37STim Bird 2410516cbf37STim Birdconfig CMDLINE_OVERRIDE 2411516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2412645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2413a7f7f624SMasahiro Yamada help 2414516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2415516cbf37STim Bird command line, and use ONLY the built-in command line. 2416516cbf37STim Bird 2417516cbf37STim Bird This is used to work around broken boot loaders. This should 2418516cbf37STim Bird be set to 'N' under normal conditions. 2419516cbf37STim Bird 2420a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2421a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2422a5b9e5a2SAndy Lutomirski default y 2423a7f7f624SMasahiro Yamada help 2424a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2425a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2426a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2427a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2428a5b9e5a2SAndy Lutomirski threading libraries. 2429a5b9e5a2SAndy Lutomirski 2430a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2431a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2432a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2433a5b9e5a2SAndy Lutomirski 2434a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2435a5b9e5a2SAndy Lutomirski 24363aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24373aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24383aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24393aac3ebeSThomas Gleixner help 24403aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24413aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24423aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24433aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24443aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24453aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24463aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24473aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24483aac3ebeSThomas Gleixner never get a signal delivered. 24493aac3ebeSThomas Gleixner 24503aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24513aac3ebeSThomas Gleixner 2452b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2453b700e7f0SSeth Jennings 2454506f1d07SSam Ravnborgendmenu 2455506f1d07SSam Ravnborg 24563072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24573072e413SMichal Hocko def_bool y 24585c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24593072e413SMichal Hocko 2460f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2461f91ef222SOscar Salvador def_bool y 2462f91ef222SOscar Salvador 2463da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2464e279b6c1SSam Ravnborg 2465e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24663c2362e6SHarvey Harrison def_bool y 246744556530SZhimin Gu depends on HIBERNATION 2468e279b6c1SSam Ravnborg 2469e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2470e279b6c1SSam Ravnborg 2471e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2472e279b6c1SSam Ravnborg 2473a6b68076SAndi Kleenconfig X86_APM_BOOT 24746fc108a0SJan Beulich def_bool y 2475282e5aabSPaul Bolle depends on APM 2476a6b68076SAndi Kleen 2477e279b6c1SSam Ravnborgmenuconfig APM 2478e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2479efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2480a7f7f624SMasahiro Yamada help 2481e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2482e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2483e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2484e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2485e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2486e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2487e279b6c1SSam Ravnborg 2488e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2489e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2490e279b6c1SSam Ravnborg 2491e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2492e279b6c1SSam Ravnborg machines with more than one CPU. 2493e279b6c1SSam Ravnborg 2494e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2495151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24962dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2497e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2498e279b6c1SSam Ravnborg 2499e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2500e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2501e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2502e279b6c1SSam Ravnborg 2503e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2504e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2505e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2506e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2507e279b6c1SSam Ravnborg 2508e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2509e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2510e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2511e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2512e279b6c1SSam Ravnborg APM in your BIOS). 2513e279b6c1SSam Ravnborg 2514e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2515e279b6c1SSam Ravnborg "weird" problems: 2516e279b6c1SSam Ravnborg 2517e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2518e279b6c1SSam Ravnborg enabled. 2519e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2520e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2521e279b6c1SSam Ravnborg the "no387" option to the kernel 2522e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2523e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2524e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2525e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2526e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2527e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2528e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2529e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2530e279b6c1SSam Ravnborg 11) exchange RAM chips 2531e279b6c1SSam Ravnborg 12) exchange the motherboard. 2532e279b6c1SSam Ravnborg 2533e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2534e279b6c1SSam Ravnborg module will be called apm. 2535e279b6c1SSam Ravnborg 2536e279b6c1SSam Ravnborgif APM 2537e279b6c1SSam Ravnborg 2538e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2539e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2540a7f7f624SMasahiro Yamada help 2541e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2542e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2543e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2544e279b6c1SSam Ravnborg 2545e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2546e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2547a7f7f624SMasahiro Yamada help 2548e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2549e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2550e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2551e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2552e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2553e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2554e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2555e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2556e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2557e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2558e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2559e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2560e279b6c1SSam Ravnborg this feature. 2561e279b6c1SSam Ravnborg 2562e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2563dd8af076SLen Brown depends on CPU_IDLE 2564e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2565a7f7f624SMasahiro Yamada help 2566e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2567e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2568e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2569e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2570e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2571e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2572e279b6c1SSam Ravnborg this option does nothing.) 2573e279b6c1SSam Ravnborg 2574e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2575e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2576a7f7f624SMasahiro Yamada help 2577e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2578e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2579e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2580e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2581e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2582e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2583e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2584e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2585e279b6c1SSam Ravnborg especially if you are using gpm. 2586e279b6c1SSam Ravnborg 2587e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2588e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2589a7f7f624SMasahiro Yamada help 2590e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2591e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2592e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2593e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2594e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2595e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2596e279b6c1SSam Ravnborg 2597e279b6c1SSam Ravnborgendif # APM 2598e279b6c1SSam Ravnborg 2599bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2600e279b6c1SSam Ravnborg 2601e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2602e279b6c1SSam Ravnborg 260327471fdbSAndy Henroidsource "drivers/idle/Kconfig" 260427471fdbSAndy Henroid 2605e279b6c1SSam Ravnborgendmenu 2606e279b6c1SSam Ravnborg 2607e279b6c1SSam Ravnborg 2608e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2609e279b6c1SSam Ravnborg 2610e279b6c1SSam Ravnborgchoice 2611e279b6c1SSam Ravnborg prompt "PCI access mode" 2612efefa6f6SIngo Molnar depends on X86_32 && PCI 2613e279b6c1SSam Ravnborg default PCI_GOANY 2614a7f7f624SMasahiro Yamada help 2615e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2616e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2617e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2618e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2619e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2620e279b6c1SSam Ravnborg 2621e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2622e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2623e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2624e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2625e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2626e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2627e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2628e279b6c1SSam Ravnborg 2629e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2630e279b6c1SSam Ravnborg bool "BIOS" 2631e279b6c1SSam Ravnborg 2632e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2633e279b6c1SSam Ravnborg bool "MMConfig" 2634e279b6c1SSam Ravnborg 2635e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2636e279b6c1SSam Ravnborg bool "Direct" 2637e279b6c1SSam Ravnborg 26383ef0e1f8SAndres Salomonconfig PCI_GOOLPC 263976fb6570SDaniel Drake bool "OLPC XO-1" 26403ef0e1f8SAndres Salomon depends on OLPC 26413ef0e1f8SAndres Salomon 26422bdd1b03SAndres Salomonconfig PCI_GOANY 26432bdd1b03SAndres Salomon bool "Any" 26442bdd1b03SAndres Salomon 2645e279b6c1SSam Ravnborgendchoice 2646e279b6c1SSam Ravnborg 2647e279b6c1SSam Ravnborgconfig PCI_BIOS 26483c2362e6SHarvey Harrison def_bool y 2649efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2650e279b6c1SSam Ravnborg 2651e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2652e279b6c1SSam Ravnborgconfig PCI_DIRECT 26533c2362e6SHarvey Harrison def_bool y 26540aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2655e279b6c1SSam Ravnborg 2656e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2657b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2658b45c9f36SJan Kiszka default y 26594590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2660b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2661e279b6c1SSam Ravnborg 26623ef0e1f8SAndres Salomonconfig PCI_OLPC 26632bdd1b03SAndres Salomon def_bool y 26642bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26653ef0e1f8SAndres Salomon 2666b5401a96SAlex Nixonconfig PCI_XEN 2667b5401a96SAlex Nixon def_bool y 2668b5401a96SAlex Nixon depends on PCI && XEN 2669b5401a96SAlex Nixon 26708364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26718364e1f8SJan Kiszka def_bool y 26728364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2673e279b6c1SSam Ravnborg 26743f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26756a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26766ea30386SKees Cook depends on PCI 26773f6ea84aSIra W. Snyder help 26783f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26793f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26803f6ea84aSIra W. Snyder not have ACPI. 26813f6ea84aSIra W. Snyder 268264a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 268364a5fed6SBjorn Helgaas is known to be incomplete. 268464a5fed6SBjorn Helgaas 268564a5fed6SBjorn Helgaas You should say N unless you know you need this. 268664a5fed6SBjorn Helgaas 26873a495511SWilliam Breathitt Grayconfig ISA_BUS 268817a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26893a495511SWilliam Breathitt Gray help 269017a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 269117a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 269217a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 269317a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 269417a2a129SWilliam Breathitt Gray not have an ISA bus. 26953a495511SWilliam Breathitt Gray 26963a495511SWilliam Breathitt Gray If unsure, say N. 26973a495511SWilliam Breathitt Gray 26981c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2699e279b6c1SSam Ravnborgconfig ISA_DMA_API 27001c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 27011c00f016SDavid Rientjes default y 27021c00f016SDavid Rientjes help 27031c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 27041c00f016SDavid Rientjes If unsure, say Y. 2705e279b6c1SSam Ravnborg 270651e68d05SLinus Torvaldsif X86_32 270751e68d05SLinus Torvalds 2708e279b6c1SSam Ravnborgconfig ISA 2709e279b6c1SSam Ravnborg bool "ISA support" 2710a7f7f624SMasahiro Yamada help 2711e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2712e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2713e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2714e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2715e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2716e279b6c1SSam Ravnborg 2717e279b6c1SSam Ravnborgconfig SCx200 2718e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2719a7f7f624SMasahiro Yamada help 2720e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2721e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2722e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2723e279b6c1SSam Ravnborg for other scx200_* drivers. 2724e279b6c1SSam Ravnborg 2725e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2726e279b6c1SSam Ravnborg 2727e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2728e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2729592913ecSJohn Stultz depends on SCx200 2730e279b6c1SSam Ravnborg default y 2731a7f7f624SMasahiro Yamada help 2732e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2733e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2734e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2735e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2736e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2737e279b6c1SSam Ravnborg 27383ef0e1f8SAndres Salomonconfig OLPC 27393ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 274054008979SThomas Gleixner depends on !X86_PAE 27413c554946SAndres Salomon select GPIOLIB 2742dc3119e7SThomas Gleixner select OF 274345bb1674SDaniel Drake select OF_PROMTREE 2744b4e51854SGrant Likely select IRQ_DOMAIN 27450c3d931bSLubomir Rintel select OLPC_EC 2746a7f7f624SMasahiro Yamada help 27473ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27483ef0e1f8SAndres Salomon XO hardware. 27493ef0e1f8SAndres Salomon 2750a3128588SDaniel Drakeconfig OLPC_XO1_PM 2751a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2752fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2753a7f7f624SMasahiro Yamada help 275497c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2755bf1ebf00SDaniel Drake 2756cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2757cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2758cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2759a7f7f624SMasahiro Yamada help 2760cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2761cfee9597SDaniel Drake programmable wakeup source. 2762cfee9597SDaniel Drake 27637feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27647feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 276592e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2766ed8e47feSRandy Dunlap depends on INPUT=y 2767d8d01a63SDaniel Drake select POWER_SUPPLY 2768a7f7f624SMasahiro Yamada help 27697feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27707bc74b3dSDaniel Drake - EC-driven system wakeups 27717feda8e9SDaniel Drake - Power button 27727bc74b3dSDaniel Drake - Ebook switch 27732cf2baeaSDaniel Drake - Lid switch 2774e1040ac6SDaniel Drake - AC adapter status updates 2775e1040ac6SDaniel Drake - Battery status updates 27767feda8e9SDaniel Drake 2777a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2778a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2779d8d01a63SDaniel Drake depends on OLPC && ACPI 2780d8d01a63SDaniel Drake select POWER_SUPPLY 2781a7f7f624SMasahiro Yamada help 2782a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2783a0f30f59SDaniel Drake - EC-driven system wakeups 2784a0f30f59SDaniel Drake - AC adapter status updates 2785a0f30f59SDaniel Drake - Battery status updates 2786e279b6c1SSam Ravnborg 2787d4f3e350SEd Wildgooseconfig ALIX 2788d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2789d4f3e350SEd Wildgoose select GPIOLIB 2790a7f7f624SMasahiro Yamada help 2791d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2792d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2793d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2794d4f3e350SEd Wildgoose get added here. 2795d4f3e350SEd Wildgoose 2796d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2797d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2798d4f3e350SEd Wildgoose 2799d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2800d4f3e350SEd Wildgoose 2801da4e3302SPhilip Prindevilleconfig NET5501 2802da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2803da4e3302SPhilip Prindeville select GPIOLIB 2804a7f7f624SMasahiro Yamada help 2805da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2806da4e3302SPhilip Prindeville 28073197059aSPhilip A. Prindevilleconfig GEOS 28083197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 28093197059aSPhilip A. Prindeville select GPIOLIB 28103197059aSPhilip A. Prindeville depends on DMI 2811a7f7f624SMasahiro Yamada help 28123197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 28133197059aSPhilip A. Prindeville 28147d029125SVivien Didelotconfig TS5500 28157d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 28167d029125SVivien Didelot depends on MELAN 28177d029125SVivien Didelot select CHECK_SIGNATURE 28187d029125SVivien Didelot select NEW_LEDS 28197d029125SVivien Didelot select LEDS_CLASS 2820a7f7f624SMasahiro Yamada help 28217d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 28227d029125SVivien Didelot 2823e279b6c1SSam Ravnborgendif # X86_32 2824e279b6c1SSam Ravnborg 282523ac4ae8SAndreas Herrmannconfig AMD_NB 2826e279b6c1SSam Ravnborg def_bool y 28270e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2828e279b6c1SSam Ravnborg 2829e279b6c1SSam Ravnborgendmenu 2830e279b6c1SSam Ravnborg 2831e279b6c1SSam Ravnborg 28321572497cSChristoph Hellwigmenu "Binary Emulations" 2833e279b6c1SSam Ravnborg 2834e279b6c1SSam Ravnborgconfig IA32_EMULATION 2835e279b6c1SSam Ravnborg bool "IA32 Emulation" 2836e279b6c1SSam Ravnborg depends on X86_64 283739f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2838d1603990SRandy Dunlap select BINFMT_ELF 283939f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2840a7f7f624SMasahiro Yamada help 28415fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28425fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28435fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2844e279b6c1SSam Ravnborg 2845e279b6c1SSam Ravnborgconfig IA32_AOUT 2846e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28476b213e1bSDavid Woodhouse depends on IA32_EMULATION 2848eac61655SBorislav Petkov depends on BROKEN 2849a7f7f624SMasahiro Yamada help 2850e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2851e279b6c1SSam Ravnborg 285283a44a4fSMasahiro Yamadaconfig X86_X32_ABI 28536ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28549b54050bSBrian Gerst depends on X86_64 2855aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 2856aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 2857aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 2858aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 2859aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 2860a7f7f624SMasahiro Yamada help 28615fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28625fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28635fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28645fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28655fd92e65SH. J. Lu 2866953fee1dSIngo Molnarconfig COMPAT_32 2867953fee1dSIngo Molnar def_bool y 2868953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2869953fee1dSIngo Molnar select HAVE_UID16 2870953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2871953fee1dSIngo Molnar 2872e279b6c1SSam Ravnborgconfig COMPAT 28733c2362e6SHarvey Harrison def_bool y 287483a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 2875e279b6c1SSam Ravnborg 28763120e25eSJan Beulichif COMPAT 2877e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28783120e25eSJan Beulich def_bool y 2879e279b6c1SSam Ravnborg 2880e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28813c2362e6SHarvey Harrison def_bool y 28823120e25eSJan Beulich depends on SYSVIPC 28833120e25eSJan Beulichendif 2884ee009e4aSDavid Howells 2885e279b6c1SSam Ravnborgendmenu 2886e279b6c1SSam Ravnborg 2887e279b6c1SSam Ravnborg 2888e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2889e5beae16SKeith Packard def_bool y 2890e5beae16SKeith Packard depends on X86_32 2891e5beae16SKeith Packard 2892edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28935e8ebd84SJason A. Donenfeld 28945e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2895