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 19103f16cd0SJosh 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 2154ab7674fSJosh Poimboeuf select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 2166471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2176471b825SIngo Molnar select HAVE_KERNEL_GZIP 2186471b825SIngo Molnar select HAVE_KERNEL_LZ4 2196471b825SIngo Molnar select HAVE_KERNEL_LZMA 2206471b825SIngo Molnar select HAVE_KERNEL_LZO 2216471b825SIngo Molnar select HAVE_KERNEL_XZ 222fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2236471b825SIngo Molnar select HAVE_KPROBES 2246471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 225540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2266471b825SIngo Molnar select HAVE_KRETPROBES 227f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2286471b825SIngo Molnar select HAVE_KVM 2296471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2300102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 231ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2329f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 233be37c98dSKalesh Singh select HAVE_MOVE_PUD 23422102f45SJosh Poimboeuf select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 23542a0bb3fSPetr Mladek select HAVE_NMI 236*489e355bSJosh Poimboeuf select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 23703f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2386471b825SIngo Molnar select HAVE_OPTPROBES 2396471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2406471b825SIngo Molnar select HAVE_PERF_EVENTS 241c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 24292e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 243eb01d42aSChristoph Hellwig select HAVE_PCI 244c5e63197SJiri Olsa select HAVE_PERF_REGS 245c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 246ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 24700998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2486471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 24903f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2503c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2517ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 252cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 253d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 25403f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 255e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 25603f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 25799cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 258d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2596471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2606471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2617c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2627ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 26305736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 264c0185808SThomas Gleixner select IRQ_FORCED_THREADING 2657ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 2667ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 26786596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2682eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 269625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2706471b825SIngo Molnar select PERF_EVENTS 2713195ef59SPrarit Bhargava select RTC_LIB 272d6faca40SArnd Bergmann select RTC_MC146818_LIB 2736471b825SIngo Molnar select SPARSE_IRQ 27483fe27eaSPranith Kumar select SRCU 2756471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 27615f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2774aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2786471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2796471b825SIngo Molnar select VIRT_TO_BUS 2803b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2816471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2820c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 28350468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 2849e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2857d8330a5SBalbir Singh 286ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2873120e25eSJan Beulich def_bool y 2883120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 289ba7e4d13SIngo Molnar 29051b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 29151b26adaSLinus Torvalds string 29251b26adaSLinus Torvalds default "elf32-i386" if X86_32 29351b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 29451b26adaSLinus Torvalds 2958d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2963c2362e6SHarvey Harrison def_bool y 2978d5fffb9SSam Ravnborg 2988d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2993c2362e6SHarvey Harrison def_bool y 3008d5fffb9SSam Ravnborg 3018d5fffb9SSam Ravnborgconfig MMU 3023c2362e6SHarvey Harrison def_bool y 3038d5fffb9SSam Ravnborg 3049e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3059e08f57dSDaniel Cashman default 28 if 64BIT 3069e08f57dSDaniel Cashman default 8 3079e08f57dSDaniel Cashman 3089e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3099e08f57dSDaniel Cashman default 32 if 64BIT 3109e08f57dSDaniel Cashman default 16 3119e08f57dSDaniel Cashman 3129e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3139e08f57dSDaniel Cashman default 8 3149e08f57dSDaniel Cashman 3159e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3169e08f57dSDaniel Cashman default 16 3179e08f57dSDaniel Cashman 3188d5fffb9SSam Ravnborgconfig SBUS 3198d5fffb9SSam Ravnborg bool 3208d5fffb9SSam Ravnborg 3218d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3223120e25eSJan Beulich def_bool y 3233120e25eSJan Beulich depends on ISA_DMA_API 3248d5fffb9SSam Ravnborg 3258d5fffb9SSam Ravnborgconfig GENERIC_BUG 3263c2362e6SHarvey Harrison def_bool y 3278d5fffb9SSam Ravnborg depends on BUG 328b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 329b93a531eSJan Beulich 330b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 331b93a531eSJan Beulich bool 3328d5fffb9SSam Ravnborg 3338d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3343120e25eSJan Beulich def_bool y 3353120e25eSJan Beulich depends on ISA_DMA_API 3368d5fffb9SSam Ravnborg 3371032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3381032c0baSSam Ravnborg def_bool y 3391032c0baSSam Ravnborg 3409a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3419a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3428d5fffb9SSam Ravnborg 343801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 344801e4062SJohannes Berg def_bool y 345801e4062SJohannes Berg 346d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 347d7109fe3SAndy Shevchenko int 348d7109fe3SAndy Shevchenko default 1024 if X86_64 349d7109fe3SAndy Shevchenko default 512 350d7109fe3SAndy Shevchenko 351f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 352f4cb5700SJohannes Berg def_bool y 353f4cb5700SJohannes Berg 3548d5fffb9SSam Ravnborgconfig AUDIT_ARCH 355e0fd24a3SJan Beulich def_bool y if X86_64 3568d5fffb9SSam Ravnborg 357d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 358d6f2d75aSAndrey Ryabinin hex 359d6f2d75aSAndrey Ryabinin depends on KASAN 360d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 361d6f2d75aSAndrey Ryabinin 36269575d38SShane Wangconfig HAVE_INTEL_TXT 36369575d38SShane Wang def_bool y 3646ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36569575d38SShane Wang 3666b0c3d44SSam Ravnborgconfig X86_32_SMP 3676b0c3d44SSam Ravnborg def_bool y 3686b0c3d44SSam Ravnborg depends on X86_32 && SMP 3696b0c3d44SSam Ravnborg 3706b0c3d44SSam Ravnborgconfig X86_64_SMP 3716b0c3d44SSam Ravnborg def_bool y 3726b0c3d44SSam Ravnborg depends on X86_64 && SMP 3736b0c3d44SSam Ravnborg 3742b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3752b144498SSrikar Dronamraju def_bool y 3762b144498SSrikar Dronamraju 377d20642f0SRob Herringconfig FIX_EARLYCON_MEM 378d20642f0SRob Herring def_bool y 379d20642f0SRob Herring 38094d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 38194d49eb3SKirill A. Shutemov bool 38294d49eb3SKirill A. Shutemov 38398233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38498233368SKirill A. Shutemov int 38577ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38698233368SKirill A. Shutemov default 4 if X86_64 38798233368SKirill A. Shutemov default 3 if X86_PAE 38898233368SKirill A. Shutemov default 2 38998233368SKirill A. Shutemov 3902a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3912a61f474SMasahiro Yamada bool 3922a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3932a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3942a61f474SMasahiro Yamada help 3952a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3963fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 3973fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 3982a61f474SMasahiro Yamada 399506f1d07SSam Ravnborgmenu "Processor type and features" 400506f1d07SSam Ravnborg 401506f1d07SSam Ravnborgconfig SMP 402506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 403a7f7f624SMasahiro Yamada help 404506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4054a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4064a474157SRobert Graffham than one CPU, say Y. 407506f1d07SSam Ravnborg 4084a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 409506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 410506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4114a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 412506f1d07SSam Ravnborg will run faster if you say N here. 413506f1d07SSam Ravnborg 414506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 415506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 416506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 417506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 418506f1d07SSam Ravnborg 419506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 420506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 421506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 422506f1d07SSam Ravnborg 423cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4244f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 425506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 426506f1d07SSam Ravnborg 427506f1d07SSam Ravnborg If you don't know what to do here, say N. 428506f1d07SSam Ravnborg 4299def39beSJosh Triplettconfig X86_FEATURE_NAMES 4309def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4319def39beSJosh Triplett default y 432a7f7f624SMasahiro Yamada help 4339def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4349def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4359def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4369def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4379def39beSJosh Triplett 4389def39beSJosh Triplett If in doubt, say Y. 4399def39beSJosh Triplett 44006cd9a7dSYinghai Luconfig X86_X2APIC 44106cd9a7dSYinghai Lu bool "Support x2apic" 44219e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 443a7f7f624SMasahiro Yamada help 44406cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44506cd9a7dSYinghai Lu 44606cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44706cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 44806cd9a7dSYinghai Lu 44906cd9a7dSYinghai Lu If you don't know what to do here, say N. 45006cd9a7dSYinghai Lu 4516695c85bSYinghai Luconfig X86_MPPARSE 4524590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4537a527688SJan Beulich default y 4545ab74722SIngo Molnar depends on X86_LOCAL_APIC 455a7f7f624SMasahiro Yamada help 4566695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4576695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4586695c85bSYinghai Lu 459ddd70cf9SJun Nakajimaconfig GOLDFISH 460ddd70cf9SJun Nakajima def_bool y 461ddd70cf9SJun Nakajima depends on X86_GOLDFISH 462ddd70cf9SJun Nakajima 46376b04384SDavid Woodhouseconfig RETPOLINE 46476b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 46503f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 46676b04384SDavid Woodhouse default y 46776b04384SDavid Woodhouse help 46876b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 46976b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 47076b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 47176b04384SDavid Woodhouse support for full protection. The kernel may run slower. 47276b04384SDavid Woodhouse 473e463a09aSPeter Zijlstraconfig CC_HAS_SLS 474e463a09aSPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 475e463a09aSPeter Zijlstra 476e463a09aSPeter Zijlstraconfig SLS 477e463a09aSPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 478e463a09aSPeter Zijlstra depends on CC_HAS_SLS && X86_64 47903f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 480e463a09aSPeter Zijlstra default n 481e463a09aSPeter Zijlstra help 482e463a09aSPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 483e463a09aSPeter Zijlstra against straight line speculation. The kernel image might be slightly 484e463a09aSPeter Zijlstra larger. 485e463a09aSPeter Zijlstra 486e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 487e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4886fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 48959fe5a77SThomas Gleixner select KERNFS 490e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 49178e99b4aSFenghua Yu help 492e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4936fe07ce3SBabu Moger 4946fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4956fe07ce3SBabu Moger usage by the CPU. 4966fe07ce3SBabu Moger 4976fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4986fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4996fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 5006fe07ce3SBabu Moger 5016fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 5026fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 5036fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 50478e99b4aSFenghua Yu 50578e99b4aSFenghua Yu Say N if unsure. 50678e99b4aSFenghua Yu 5078425091fSRavikiran G Thirumalaiif X86_32 508a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 509a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 510a0d0bb4dSRandy Dunlap depends on SMP 511a7f7f624SMasahiro Yamada help 512e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 513a0d0bb4dSRandy Dunlap 514c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 515c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 516c5c606d9SRavikiran G Thirumalai default y 517a7f7f624SMasahiro Yamada help 51806ac8346SIngo Molnar If you disable this option then the kernel will only support 51906ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 52006ac8346SIngo Molnar systems out there.) 52106ac8346SIngo Molnar 5228425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5238425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 524cb7b8023SBen Hutchings Goldfish (Android emulator) 5258425091fSRavikiran G Thirumalai AMD Elan 5268425091fSRavikiran G Thirumalai RDC R-321x SoC 5278425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 52883125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5293f4110a4SThomas Gleixner Moorestown MID devices 53006ac8346SIngo Molnar 53106ac8346SIngo Molnar If you have one of these systems, or if you want to build a 53206ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5338425091fSRavikiran G Thirumalaiendif 53406ac8346SIngo Molnar 5358425091fSRavikiran G Thirumalaiif X86_64 5368425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5378425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5388425091fSRavikiran G Thirumalai default y 539a7f7f624SMasahiro Yamada help 5408425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5418425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5428425091fSRavikiran G Thirumalai systems out there.) 5438425091fSRavikiran G Thirumalai 5448425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5458425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 54644b111b5SSteffen Persvold Numascale NumaChip 5478425091fSRavikiran G Thirumalai ScaleMP vSMP 5488425091fSRavikiran G Thirumalai SGI Ultraviolet 5498425091fSRavikiran G Thirumalai 5508425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5518425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5528425091fSRavikiran G Thirumalaiendif 553c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 554c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 55544b111b5SSteffen Persvoldconfig X86_NUMACHIP 55644b111b5SSteffen Persvold bool "Numascale NumaChip" 55744b111b5SSteffen Persvold depends on X86_64 55844b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 55944b111b5SSteffen Persvold depends on NUMA 56044b111b5SSteffen Persvold depends on SMP 56144b111b5SSteffen Persvold depends on X86_X2APIC 562f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 563a7f7f624SMasahiro Yamada help 56444b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 56544b111b5SSteffen Persvold enable more than ~168 cores. 56644b111b5SSteffen Persvold If you don't have one of these, you should say N here. 56703b48632SNick Piggin 5686a48565eSIngo Molnarconfig X86_VSMP 569c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5706276a074SBorislav Petkov select HYPERVISOR_GUEST 5716a48565eSIngo Molnar select PARAVIRT 5726a48565eSIngo Molnar depends on X86_64 && PCI 573c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 574ead91d4bSShai Fultheim depends on SMP 575a7f7f624SMasahiro Yamada help 5766a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5776a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5786a48565eSIngo Molnar if you have one of these machines. 5796a48565eSIngo Molnar 580c5c606d9SRavikiran G Thirumalaiconfig X86_UV 581c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 582c5c606d9SRavikiran G Thirumalai depends on X86_64 583c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 58454c28d29SJack Steiner depends on NUMA 5851ecb4ae5SAndrew Morton depends on EFI 586c2209ea5SIngo Molnar depends on KEXEC_CORE 5879d6c26e7SSuresh Siddha depends on X86_X2APIC 5881222e564SIngo Molnar depends on PCI 589a7f7f624SMasahiro Yamada help 590c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 591c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 592c5c606d9SRavikiran G Thirumalai 593c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 594c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 595506f1d07SSam Ravnborg 596ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 597ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 598cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 599a7f7f624SMasahiro Yamada help 600ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 601ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 602ddd70cf9SJun Nakajima Goldfish emulator say N here. 603ddd70cf9SJun Nakajima 604c751e17bSThomas Gleixnerconfig X86_INTEL_CE 605c751e17bSThomas Gleixner bool "CE4100 TV platform" 606c751e17bSThomas Gleixner depends on PCI 607c751e17bSThomas Gleixner depends on PCI_GODIRECT 6086084a6e2SJiang Liu depends on X86_IO_APIC 609c751e17bSThomas Gleixner depends on X86_32 610c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 61137bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 612da6b737bSSebastian Andrzej Siewior select OF 613da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 614a7f7f624SMasahiro Yamada help 615c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 616c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 617c751e17bSThomas Gleixner boxes and media devices. 618c751e17bSThomas Gleixner 6194cb9b00fSDavid Cohenconfig X86_INTEL_MID 62043605ef1SAlan Cox bool "Intel MID platform support" 62143605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 622edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6231ea7c673SAlan Cox depends on PCI 6243fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6251ea7c673SAlan Cox depends on X86_IO_APIC 6264cb9b00fSDavid Cohen select I2C 6277c9c3a1eSAlan Cox select DW_APB_TIMER 62854b34aa0SMika Westerberg select INTEL_SCU_PCI 629a7f7f624SMasahiro Yamada help 6304cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6314cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6324cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6331ea7c673SAlan Cox 6344cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6354cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 63643605ef1SAlan Cox 6378bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6388bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6398bbc2a13SBryan O'Donoghue depends on X86_32 6408bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6418bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6428bbc2a13SBryan O'Donoghue depends on X86_TSC 6438bbc2a13SBryan O'Donoghue depends on PCI 6448bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6458bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6468bbc2a13SBryan O'Donoghue select IOSF_MBI 6478bbc2a13SBryan O'Donoghue select INTEL_IMR 6489ab6eb51SAndy Shevchenko select COMMON_CLK 649a7f7f624SMasahiro Yamada help 6508bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6518bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6528bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6538bbc2a13SBryan O'Donoghue 6543d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6553d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6565962dd22SSinan Kaya depends on X86 && ACPI && PCI 6573d48aab1SMika Westerberg select COMMON_CLK 6580f531431SMathias Nyman select PINCTRL 659eebb3e8dSAndy Shevchenko select IOSF_MBI 660a7f7f624SMasahiro Yamada help 6613d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6623d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6630f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6640f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6653d48aab1SMika Westerberg 66692082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 66792082a88SKen Xue bool "AMD ACPI2Platform devices support" 66892082a88SKen Xue depends on ACPI 66992082a88SKen Xue select COMMON_CLK 67092082a88SKen Xue select PINCTRL 671a7f7f624SMasahiro Yamada help 67292082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 67392082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 67492082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 67592082a88SKen Xue implemented under PINCTRL subsystem. 67692082a88SKen Xue 677ced3ce76SDavid E. Boxconfig IOSF_MBI 678ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 679ced3ce76SDavid E. Box depends on PCI 680a7f7f624SMasahiro Yamada help 681ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 682ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 683ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 684ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 685ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 686ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 687ced3ce76SDavid E. Box This list is not meant to be exclusive. 688ced3ce76SDavid E. Box - BayTrail 689ced3ce76SDavid E. Box - Braswell 690ced3ce76SDavid E. Box - Quark 691ced3ce76SDavid E. Box 692ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 693ced3ce76SDavid E. Box 694ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 695ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 696ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 697a7f7f624SMasahiro Yamada help 698ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 699ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 700ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 701ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 702ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 703ed2226bdSDavid E. Box device they want to access. 704ed2226bdSDavid E. Box 705ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 706ed2226bdSDavid E. Box 707c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 708c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 709506f1d07SSam Ravnborg depends on X86_32 710c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 711c5c606d9SRavikiran G Thirumalai select M486 712c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 713a7f7f624SMasahiro Yamada help 714c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 715c5c606d9SRavikiran G Thirumalai as R-8610-(G). 716c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 717c5c606d9SRavikiran G Thirumalai 718e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7199c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7209c398017SIngo Molnar depends on X86_32 && SMP 721c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 722a7f7f624SMasahiro Yamada help 723b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 724b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 725b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 726b5660ba7SH. Peter Anvin one and will fallback to default. 727d49c4288SYinghai Lu 728c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 729d49c4288SYinghai Lu 730d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7316fc108a0SJan Beulich def_bool y 732d949f36fSLinus Torvalds # MCE code calls memory_failure(): 733d949f36fSLinus Torvalds depends on X86_MCE 734d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 735d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 736d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 737d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 738d949f36fSLinus Torvalds 73983125a3aSAlessandro Rubiniconfig STA2X11 74083125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 74183125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 74283125a3aSAlessandro Rubini select SWIOTLB 74383125a3aSAlessandro Rubini select MFD_STA2X11 7440145071bSLinus Walleij select GPIOLIB 745a7f7f624SMasahiro Yamada help 74683125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 74783125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 74883125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 74983125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 75083125a3aSAlessandro Rubini standard PC machines. 75183125a3aSAlessandro Rubini 75282148d1dSShérabconfig X86_32_IRIS 75382148d1dSShérab tristate "Eurobraille/Iris poweroff module" 75482148d1dSShérab depends on X86_32 755a7f7f624SMasahiro Yamada help 75682148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 75782148d1dSShérab to shut themselves down properly. A special I/O sequence is 75882148d1dSShérab needed to do so, which is what this module does at 75982148d1dSShérab kernel shutdown. 76082148d1dSShérab 76182148d1dSShérab This is only for Iris machines from EuroBraille. 76282148d1dSShérab 76382148d1dSShérab If unused, say N. 76482148d1dSShérab 765ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7663c2362e6SHarvey Harrison def_bool y 7673c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 768a87d0914SKen Chen depends on X86 769a7f7f624SMasahiro Yamada help 770506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 771506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 772506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 773506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 774506f1d07SSam Ravnborg 775506f1d07SSam Ravnborg If in doubt, say "Y". 776506f1d07SSam Ravnborg 7776276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7786276a074SBorislav Petkov bool "Linux guest support" 779a7f7f624SMasahiro Yamada help 7806276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7816276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7826276a074SBorislav Petkov setup. 783506f1d07SSam Ravnborg 7846276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7856276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 786506f1d07SSam Ravnborg 7876276a074SBorislav Petkovif HYPERVISOR_GUEST 788506f1d07SSam Ravnborg 789e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 790e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 791a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 792a7f7f624SMasahiro Yamada help 793e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 794e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 795e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 796e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 797e61bd94aSEduardo Pereira Habkost 798c00a280aSJuergen Grossconfig PARAVIRT_XXL 799c00a280aSJuergen Gross bool 800c00a280aSJuergen Gross 8016276a074SBorislav Petkovconfig PARAVIRT_DEBUG 8026276a074SBorislav Petkov bool "paravirt-ops debugging" 8036276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 804a7f7f624SMasahiro Yamada help 8056276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8066276a074SBorislav Petkov a paravirt_op is missing when it is called. 8076276a074SBorislav Petkov 808b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 809b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8106ea30386SKees Cook depends on PARAVIRT && SMP 811a7f7f624SMasahiro Yamada help 812b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 813b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 814b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 815b4ecc126SJeremy Fitzhardinge 8164c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8174c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 818b4ecc126SJeremy Fitzhardinge 8194c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 820b4ecc126SJeremy Fitzhardinge 821ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 822ecca2502SZhao Yakui def_bool n 823ecca2502SZhao Yakui 8246276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8256276a074SBorislav Petkov 8266276a074SBorislav Petkovconfig KVM_GUEST 8276276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8286276a074SBorislav Petkov depends on PARAVIRT 8296276a074SBorislav Petkov select PARAVIRT_CLOCK 830a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 831b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8326276a074SBorislav Petkov default y 833a7f7f624SMasahiro Yamada help 8346276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8356276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8366276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8376276a074SBorislav Petkov underlying device model, the host provides the guest with 8386276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8396276a074SBorislav Petkov 840a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 841a1c4423bSMarcelo Tosatti def_bool n 842a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 843a1c4423bSMarcelo Tosatti help 844a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 845a1c4423bSMarcelo Tosatti 8467733607fSMaran Wilsonconfig PVH 8477733607fSMaran Wilson bool "Support for running PVH guests" 848a7f7f624SMasahiro Yamada help 8497733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8507733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8517733607fSMaran Wilson 8526276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8536276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8546276a074SBorislav Petkov depends on PARAVIRT 855a7f7f624SMasahiro Yamada help 8566276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8576276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8586276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8596276a074SBorislav Petkov that, there can be a small performance impact. 8606276a074SBorislav Petkov 8616276a074SBorislav Petkov If in doubt, say N here. 8626276a074SBorislav Petkov 8637af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8647af192c9SGerd Hoffmann bool 8657af192c9SGerd Hoffmann 8664a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8674a362601SJan Kiszka bool "Jailhouse non-root cell support" 868abde587bSArnd Bergmann depends on X86_64 && PCI 86987e65d05SJan Kiszka select X86_PM_TIMER 870a7f7f624SMasahiro Yamada help 8714a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8724a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8734a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8744a362601SJan Kiszka 875ec7972c9SZhao Yakuiconfig ACRN_GUEST 876ec7972c9SZhao Yakui bool "ACRN Guest support" 877ec7972c9SZhao Yakui depends on X86_64 878498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 879ec7972c9SZhao Yakui help 880ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 881ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 882ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 883ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 884ec7972c9SZhao Yakui found in https://projectacrn.org/. 885ec7972c9SZhao Yakui 8866276a074SBorislav Petkovendif #HYPERVISOR_GUEST 88797349135SJeremy Fitzhardinge 888506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 889506f1d07SSam Ravnborg 890506f1d07SSam Ravnborgconfig HPET_TIMER 8913c2362e6SHarvey Harrison def_bool X86_64 892506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 893a7f7f624SMasahiro Yamada help 894506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 895506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 896506f1d07SSam Ravnborg present. 897506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 898506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 899506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9004e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9014e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 902506f1d07SSam Ravnborg 903506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 904506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 905506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 906506f1d07SSam Ravnborg 907506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 908506f1d07SSam Ravnborg 909506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9103c2362e6SHarvey Harrison def_bool y 9113228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 912506f1d07SSam Ravnborg 9136a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 914506f1d07SSam Ravnborg# The code disables itself when not needed. 9157ae9392cSThomas Petazzoniconfig DMI 9167ae9392cSThomas Petazzoni default y 917cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9186a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 919a7f7f624SMasahiro Yamada help 9207ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9217ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9227ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9237ae9392cSThomas Petazzoni BIOS code. 9247ae9392cSThomas Petazzoni 925506f1d07SSam Ravnborgconfig GART_IOMMU 92638901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9272f9237d4SChristoph Hellwig select DMA_OPS 928a4ce5a48SChristoph Hellwig select IOMMU_HELPER 929506f1d07SSam Ravnborg select SWIOTLB 93023ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 931a7f7f624SMasahiro Yamada help 932ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 933ced3c42cSIngo Molnar GART based hardware IOMMUs. 934ced3c42cSIngo Molnar 935ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 936ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 937ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 938ced3c42cSIngo Molnar 939ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 940ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 941ced3c42cSIngo Molnar 942ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 943ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 944ced3c42cSIngo Molnar 32-bit limited device. 945ced3c42cSIngo Molnar 946ced3c42cSIngo Molnar If unsure, say Y. 947506f1d07SSam Ravnborg 9481184dc2fSMike Travisconfig MAXSMP 949ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9506ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 95136f5101aSMike Travis select CPUMASK_OFFSTACK 952a7f7f624SMasahiro Yamada help 953ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9541184dc2fSMike Travis If unsure, say N. 955506f1d07SSam Ravnborg 956aec6487eSIngo Molnar# 957aec6487eSIngo Molnar# The maximum number of CPUs supported: 958aec6487eSIngo Molnar# 959aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 960aec6487eSIngo Molnar# and which can be configured interactively in the 961aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 962aec6487eSIngo Molnar# 963aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 964aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 965aec6487eSIngo Molnar# 966aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 967aec6487eSIngo Molnar# interactive configuration. ) 968aec6487eSIngo Molnar# 969a0d0bb4dSRandy Dunlap 970aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 971a0d0bb4dSRandy Dunlap int 972aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 973a0d0bb4dSRandy Dunlap default 1 if !SMP 974a0d0bb4dSRandy Dunlap default 2 975a0d0bb4dSRandy Dunlap 976aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 977a0d0bb4dSRandy Dunlap int 978a0d0bb4dSRandy Dunlap depends on X86_32 979aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 980aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 981a0d0bb4dSRandy Dunlap default 1 if !SMP 982a0d0bb4dSRandy Dunlap 983aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 984a0d0bb4dSRandy Dunlap int 985a0d0bb4dSRandy Dunlap depends on X86_64 9861edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9871edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 988a0d0bb4dSRandy Dunlap default 1 if !SMP 989aec6487eSIngo Molnar 990aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 991aec6487eSIngo Molnar int 992aec6487eSIngo Molnar depends on X86_32 993aec6487eSIngo Molnar default 32 if X86_BIGSMP 994aec6487eSIngo Molnar default 8 if SMP 995aec6487eSIngo Molnar default 1 if !SMP 996aec6487eSIngo Molnar 997aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 998aec6487eSIngo Molnar int 999aec6487eSIngo Molnar depends on X86_64 1000a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1001a0d0bb4dSRandy Dunlap default 64 if SMP 1002aec6487eSIngo Molnar default 1 if !SMP 1003a0d0bb4dSRandy Dunlap 1004506f1d07SSam Ravnborgconfig NR_CPUS 100536f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1006aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1007aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1008a7f7f624SMasahiro Yamada help 1009506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1010bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1011cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1012506f1d07SSam Ravnborg minimum value which makes sense is 2. 1013506f1d07SSam Ravnborg 1014aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1015aec6487eSIngo Molnar to the kernel image. 1016506f1d07SSam Ravnborg 101766558b73STim Chenconfig SCHED_CLUSTER 101866558b73STim Chen bool "Cluster scheduler support" 101966558b73STim Chen depends on SMP 102066558b73STim Chen default y 102166558b73STim Chen help 102266558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 102366558b73STim Chen making when dealing with machines that have clusters of CPUs. 102466558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 102566558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 102666558b73STim Chen busses. 102766558b73STim Chen 1028506f1d07SSam Ravnborgconfig SCHED_SMT 1029dbe73364SThomas Gleixner def_bool y if SMP 1030506f1d07SSam Ravnborg 1031506f1d07SSam Ravnborgconfig SCHED_MC 10323c2362e6SHarvey Harrison def_bool y 10333c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1034c8e56d20SBorislav Petkov depends on SMP 1035a7f7f624SMasahiro Yamada help 1036506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1037506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1038506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1039506f1d07SSam Ravnborg 1040de966cf4STim Chenconfig SCHED_MC_PRIO 1041de966cf4STim Chen bool "CPU core priorities scheduler support" 10420a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10430a21fc12SIngo Molnar select X86_INTEL_PSTATE 10440a21fc12SIngo Molnar select CPU_FREQ 1045de966cf4STim Chen default y 1046a7f7f624SMasahiro Yamada help 1047de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1048de966cf4STim Chen core ordering determined at manufacturing time, which allows 1049de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1050de966cf4STim Chen single threaded workloads) than others. 1051de966cf4STim Chen 1052de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1053de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1054de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1055de966cf4STim Chen overall system performance can be achieved. 1056de966cf4STim Chen 1057de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1058de966cf4STim Chen 1059de966cf4STim Chen If unsure say Y here. 10605e76b2abSTim Chen 106130b8b006SThomas Gleixnerconfig UP_LATE_INIT 106230b8b006SThomas Gleixner def_bool y 1063ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 106430b8b006SThomas Gleixner 1065506f1d07SSam Ravnborgconfig X86_UP_APIC 106650849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 106750849eefSJan Beulich default PCI_MSI 106838a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1069a7f7f624SMasahiro Yamada help 1070506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1071506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1072506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1073506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1074506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1075506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1076506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1077506f1d07SSam Ravnborg lockups. 1078506f1d07SSam Ravnborg 1079506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1080506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1081506f1d07SSam Ravnborg depends on X86_UP_APIC 1082a7f7f624SMasahiro Yamada help 1083506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1084506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1085506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1086506f1d07SSam Ravnborg 1087506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1088506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1089506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1090506f1d07SSam Ravnborg 1091506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10923c2362e6SHarvey Harrison def_bool y 10930dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1094b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 109552f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1096506f1d07SSam Ravnborg 1097506f1d07SSam Ravnborgconfig X86_IO_APIC 1098b1da1e71SJan Beulich def_bool y 1099b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1100506f1d07SSam Ravnborg 110141b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 110241b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 110341b9eb26SStefan Assmann depends on X86_IO_APIC 1104a7f7f624SMasahiro Yamada help 110541b9eb26SStefan Assmann This option enables a workaround that fixes a source of 110641b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 110741b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 110841b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 110941b9eb26SStefan Assmann 111041b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 111141b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 111241b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 111341b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 111441b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 111541b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 111641b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 111741b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 111841b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 111941b9eb26SStefan Assmann down (vital) interrupt lines. 112041b9eb26SStefan Assmann 112141b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 112241b9eb26SStefan Assmann increased on these systems. 112341b9eb26SStefan Assmann 1124506f1d07SSam Ravnborgconfig X86_MCE 1125bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1126648ed940SChen, Gong select GENERIC_ALLOCATOR 1127e57dbaf7SBorislav Petkov default y 1128a7f7f624SMasahiro Yamada help 1129bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1130bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1131506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1132bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11334efc0670SAndi Kleen 11345de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11355de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11365de97c9fSTony Luck depends on X86_MCE 1137a7f7f624SMasahiro Yamada help 11385de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11395de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11405de97c9fSTony Luck rasdaemon solution. 11415de97c9fSTony Luck 1142506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11433c2362e6SHarvey Harrison def_bool y 11443c2362e6SHarvey Harrison prompt "Intel MCE features" 1145c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1146a7f7f624SMasahiro Yamada help 1147506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1148506f1d07SSam Ravnborg the thermal monitor. 1149506f1d07SSam Ravnborg 1150506f1d07SSam Ravnborgconfig X86_MCE_AMD 11513c2362e6SHarvey Harrison def_bool y 11523c2362e6SHarvey Harrison prompt "AMD MCE features" 1153f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1154a7f7f624SMasahiro Yamada help 1155506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1156506f1d07SSam Ravnborg the DRAM Error Threshold. 1157506f1d07SSam Ravnborg 11584efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11596fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1160c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1161a7f7f624SMasahiro Yamada help 11624efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11635065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11644efc0670SAndi Kleen line. 11654efc0670SAndi Kleen 1166b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1167b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11686fc108a0SJan Beulich def_bool y 1169b2762686SAndi Kleen 1170ea149b36SAndi Kleenconfig X86_MCE_INJECT 1171bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1172ea149b36SAndi Kleen tristate "Machine check injector support" 1173a7f7f624SMasahiro Yamada help 1174ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1175ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1176ea149b36SAndi Kleen QA it is safe to say n. 1177ea149b36SAndi Kleen 117807dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1179e633c65aSKan Liang 11805aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11811e642812SIngo Molnar bool "Legacy VM86 support" 1182506f1d07SSam Ravnborg depends on X86_32 1183a7f7f624SMasahiro Yamada help 11845aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11855aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11865aef51c3SAndy Lutomirski 11875aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11885aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11895aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11905aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11915aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11921e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11931e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11941e642812SIngo Molnar mode might be faster than emulation and you might want to 11951e642812SIngo Molnar enable this option. 11965aef51c3SAndy Lutomirski 11971e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11981e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11991e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12001e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12015aef51c3SAndy Lutomirski 12021e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12031e642812SIngo Molnar and slows down exception handling a tiny bit. 12045aef51c3SAndy Lutomirski 12051e642812SIngo Molnar If unsure, say N here. 12065aef51c3SAndy Lutomirski 12075aef51c3SAndy Lutomirskiconfig VM86 12085aef51c3SAndy Lutomirski bool 12095aef51c3SAndy Lutomirski default X86_LEGACY_VM86 121034273f41SH. Peter Anvin 121134273f41SH. Peter Anvinconfig X86_16BIT 121234273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 121334273f41SH. Peter Anvin default y 1214a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1215a7f7f624SMasahiro Yamada help 121634273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 121734273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 121834273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 121934273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 122034273f41SH. Peter Anvin 122134273f41SH. Peter Anvinconfig X86_ESPFIX32 122234273f41SH. Peter Anvin def_bool y 122334273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1224506f1d07SSam Ravnborg 1225197725deSH. Peter Anvinconfig X86_ESPFIX64 1226197725deSH. Peter Anvin def_bool y 122734273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1228506f1d07SSam Ravnborg 12291ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12301ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12311ad83c85SAndy Lutomirski default y 12321ad83c85SAndy Lutomirski depends on X86_64 1233a7f7f624SMasahiro Yamada help 12341ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12351ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12361ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12371ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12381ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12391ad83c85SAndy Lutomirski 0xffffffffff600?00. 12401ad83c85SAndy Lutomirski 12411ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12421ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12431ad83c85SAndy Lutomirski 12441ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12451ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12461ad83c85SAndy Lutomirski 1247111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1248111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1249a24ca997SThomas Gleixner default y 1250a7f7f624SMasahiro Yamada help 1251111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1252111e7b15SThomas Gleixner for legacy applications. 1253111e7b15SThomas Gleixner 1254c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1255c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1256c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1257c8137aceSThomas Gleixner capabilities and permission from potentially active security 1258c8137aceSThomas Gleixner modules. 1259c8137aceSThomas Gleixner 1260c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1261c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1262a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1263a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1264c8137aceSThomas Gleixner 1265506f1d07SSam Ravnborgconfig TOSHIBA 1266506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1267506f1d07SSam Ravnborg depends on X86_32 1268a7f7f624SMasahiro Yamada help 1269506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1270506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1271506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1272506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1273506f1d07SSam Ravnborg 1274506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1275506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1276506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1277506f1d07SSam Ravnborg 1278506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1279506f1d07SSam Ravnborg Say N otherwise. 1280506f1d07SSam Ravnborg 1281506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12829ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12839ba16087SJan Beulich depends on X86_32 1284a7f7f624SMasahiro Yamada help 1285506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1286506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1287506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1288506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1289506f1d07SSam Ravnborg system. 1290506f1d07SSam Ravnborg 1291506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12925e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1293506f1d07SSam Ravnborg 1294506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1295506f1d07SSam Ravnborg enable this option even if you don't need it. 1296506f1d07SSam Ravnborg Say N otherwise. 1297506f1d07SSam Ravnborg 1298506f1d07SSam Ravnborgconfig MICROCODE 12999a2bc335SBorislav Petkov bool "CPU microcode loading support" 13009a2bc335SBorislav Petkov default y 130180030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1302a7f7f624SMasahiro Yamada help 1303506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13045f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13055f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13065f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13075f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13085f9c01aaSBorislav Petkov the Linux kernel. 1309506f1d07SSam Ravnborg 13105f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1311cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13125f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13135f9c01aaSBorislav Petkov initrd for microcode blobs. 1314506f1d07SSam Ravnborg 1315c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1316c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1317c508c46eSBenjamin Gilbert config option. 1318506f1d07SSam Ravnborg 13198d86f390SPeter Orubaconfig MICROCODE_INTEL 1320e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13218d86f390SPeter Oruba depends on MICROCODE 13228d86f390SPeter Oruba default MICROCODE 1323a7f7f624SMasahiro Yamada help 13248d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13258d86f390SPeter Oruba processors. 13268d86f390SPeter Oruba 1327b8989db9SAlan For the current Intel microcode data package go to 1328b8989db9SAlan <https://downloadcenter.intel.com> and search for 1329b8989db9SAlan 'Linux Processor Microcode Data File'. 13308d86f390SPeter Oruba 133180cc9f10SPeter Orubaconfig MICROCODE_AMD 1332e43f6e67SBorislav Petkov bool "AMD microcode loading support" 133380cc9f10SPeter Oruba depends on MICROCODE 1334a7f7f624SMasahiro Yamada help 133580cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 133680cc9f10SPeter Oruba processors will be enabled. 133780cc9f10SPeter Oruba 1338506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1339c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1340c02f48e0SBorislav Petkov default n 1341506f1d07SSam Ravnborg depends on MICROCODE 1342a7f7f624SMasahiro Yamada help 1343c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1344c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1345c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1346c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1347c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1348cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1349506f1d07SSam Ravnborg 1350506f1d07SSam Ravnborgconfig X86_MSR 1351506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1352a7f7f624SMasahiro Yamada help 1353506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1354506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1355506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1356506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1357506f1d07SSam Ravnborg systems. 1358506f1d07SSam Ravnborg 1359506f1d07SSam Ravnborgconfig X86_CPUID 1360506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1361a7f7f624SMasahiro Yamada help 1362506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1363506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1364506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1365506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1366506f1d07SSam Ravnborg 1367506f1d07SSam Ravnborgchoice 1368506f1d07SSam Ravnborg prompt "High Memory Support" 13696fc108a0SJan Beulich default HIGHMEM4G 1370506f1d07SSam Ravnborg depends on X86_32 1371506f1d07SSam Ravnborg 1372506f1d07SSam Ravnborgconfig NOHIGHMEM 1373506f1d07SSam Ravnborg bool "off" 1374a7f7f624SMasahiro Yamada help 1375506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1376506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1377506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1378506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1379506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1380506f1d07SSam Ravnborg "high memory". 1381506f1d07SSam Ravnborg 1382506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1383506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1384506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1385506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1386506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1387506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1388506f1d07SSam Ravnborg possible. 1389506f1d07SSam Ravnborg 1390506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1391506f1d07SSam Ravnborg answer "4GB" here. 1392506f1d07SSam Ravnborg 1393506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1394506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1395506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1396506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1397506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1398506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1399506f1d07SSam Ravnborg 1400506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1401506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1402506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1403506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1404506f1d07SSam Ravnborg kernel at boot time.) 1405506f1d07SSam Ravnborg 1406506f1d07SSam Ravnborg If unsure, say "off". 1407506f1d07SSam Ravnborg 1408506f1d07SSam Ravnborgconfig HIGHMEM4G 1409506f1d07SSam Ravnborg bool "4GB" 1410a7f7f624SMasahiro Yamada help 1411506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1412506f1d07SSam Ravnborg gigabytes of physical RAM. 1413506f1d07SSam Ravnborg 1414506f1d07SSam Ravnborgconfig HIGHMEM64G 1415506f1d07SSam Ravnborg bool "64GB" 1416225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1417506f1d07SSam Ravnborg select X86_PAE 1418a7f7f624SMasahiro Yamada help 1419506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1420506f1d07SSam Ravnborg gigabytes of physical RAM. 1421506f1d07SSam Ravnborg 1422506f1d07SSam Ravnborgendchoice 1423506f1d07SSam Ravnborg 1424506f1d07SSam Ravnborgchoice 14256a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1426506f1d07SSam Ravnborg default VMSPLIT_3G 1427506f1d07SSam Ravnborg depends on X86_32 1428a7f7f624SMasahiro Yamada help 1429506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1430506f1d07SSam Ravnborg 1431506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1432506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1433506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1434506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1435506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1436506f1d07SSam Ravnborg available to user programs, making the address space there 1437506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1438506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1439506f1d07SSam Ravnborg kernel modules. 1440506f1d07SSam Ravnborg 1441506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1442506f1d07SSam Ravnborg option alone! 1443506f1d07SSam Ravnborg 1444506f1d07SSam Ravnborg config VMSPLIT_3G 1445506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1446506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1447506f1d07SSam Ravnborg depends on !X86_PAE 1448506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1449506f1d07SSam Ravnborg config VMSPLIT_2G 1450506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1451506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1452506f1d07SSam Ravnborg depends on !X86_PAE 1453506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1454506f1d07SSam Ravnborg config VMSPLIT_1G 1455506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1456506f1d07SSam Ravnborgendchoice 1457506f1d07SSam Ravnborg 1458506f1d07SSam Ravnborgconfig PAGE_OFFSET 1459506f1d07SSam Ravnborg hex 1460506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1461506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1462506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1463506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1464506f1d07SSam Ravnborg default 0xC0000000 1465506f1d07SSam Ravnborg depends on X86_32 1466506f1d07SSam Ravnborg 1467506f1d07SSam Ravnborgconfig HIGHMEM 14683c2362e6SHarvey Harrison def_bool y 1469506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1470506f1d07SSam Ravnborg 1471506f1d07SSam Ravnborgconfig X86_PAE 14729ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1473506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1474d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14759d99c712SChristian Melki select SWIOTLB 1476a7f7f624SMasahiro Yamada help 1477506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1478506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1479506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1480506f1d07SSam Ravnborg consumes more pagetable space per process. 1481506f1d07SSam Ravnborg 148277ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148377ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148418ec1eafSKirill A. Shutemov default y 1485eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1486162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148777ef56e4SKirill A. Shutemov depends on X86_64 1488a7f7f624SMasahiro Yamada help 148977ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 149077ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 149177ef56e4SKirill A. Shutemov physical address space. 149277ef56e4SKirill A. Shutemov 149377ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149477ef56e4SKirill A. Shutemov 14956657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14966657fca0SKirill A. Shutemov support 4- or 5-level paging. 149777ef56e4SKirill A. Shutemov 1498cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 149977ef56e4SKirill A. Shutemov information. 150077ef56e4SKirill A. Shutemov 150177ef56e4SKirill A. Shutemov Say N if unsure. 150277ef56e4SKirill A. Shutemov 150310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1504e5008abeSLuis R. Rodriguez def_bool y 15052e1da13fSVlastimil Babka depends on X86_64 1506a7f7f624SMasahiro Yamada help 150710971ab2SIngo Molnar Certain kernel features effectively disable kernel 150810971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 150910971ab2SIngo Molnar supports them), so don't confuse the user by printing 151010971ab2SIngo Molnar that we have them enabled. 15119e899816SNick Piggin 15125c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15135c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15145c280cf6SThomas Gleixner depends on DEBUG_FS 1515a7f7f624SMasahiro Yamada help 1516b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1517a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15185c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15195c280cf6SThomas Gleixner 152020f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 152120f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 152220f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 152320f07a04SKirill A. Shutemov select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 152420f07a04SKirill A. Shutemov def_bool n 152520f07a04SKirill A. Shutemov 15267744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15277744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15287744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 152982fef0adSDavid Rientjes select DMA_COHERENT_POOL 1530ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1531597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1532aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 153320f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 1534a7f7f624SMasahiro Yamada help 15357744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15367744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15377744ccdbSTom Lendacky Encryption (SME). 15387744ccdbSTom Lendacky 15397744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15407744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15417744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1542a7f7f624SMasahiro Yamada help 15437744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15447744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15457744ccdbSTom Lendacky 15467744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15477744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15487744ccdbSTom Lendacky 15497744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15507744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15517744ccdbSTom Lendacky 1552506f1d07SSam Ravnborg# Common NUMA Features 1553506f1d07SSam Ravnborgconfig NUMA 1554e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1555506f1d07SSam Ravnborg depends on SMP 1556b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1557b5660ba7SH. Peter Anvin default y if X86_BIGSMP 15587ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 1559a7f7f624SMasahiro Yamada help 1560e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1561fd51b2d7SKOSAKI Motohiro 1562506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1563506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1564506f1d07SSam Ravnborg NUMA awareness to the kernel. 1565506f1d07SSam Ravnborg 1566c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1567fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1568fd51b2d7SKOSAKI Motohiro 1569b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15707cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1571fd51b2d7SKOSAKI Motohiro 1572fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1573506f1d07SSam Ravnborg 1574eec1d4faSHans Rosenfeldconfig AMD_NUMA 15753c2362e6SHarvey Harrison def_bool y 15763c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15775da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1578a7f7f624SMasahiro Yamada help 1579eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1580eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1581eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1582eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1583eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1584506f1d07SSam Ravnborg 1585506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15863c2362e6SHarvey Harrison def_bool y 15873c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1588506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1589506f1d07SSam Ravnborg select ACPI_NUMA 1590a7f7f624SMasahiro Yamada help 1591506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1592506f1d07SSam Ravnborg 1593506f1d07SSam Ravnborgconfig NUMA_EMU 1594506f1d07SSam Ravnborg bool "NUMA emulation" 15951b7e03efSTejun Heo depends on NUMA 1596a7f7f624SMasahiro Yamada help 1597506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1598506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1599506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1600506f1d07SSam Ravnborg 1601506f1d07SSam Ravnborgconfig NODES_SHIFT 1602d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 160351591e31SDavid Rientjes range 1 10 160451591e31SDavid Rientjes default "10" if MAXSMP 1605506f1d07SSam Ravnborg default "6" if X86_64 1606506f1d07SSam Ravnborg default "3" 1607a9ee6cf5SMike Rapoport depends on NUMA 1608a7f7f624SMasahiro Yamada help 16091184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1610692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1611506f1d07SSam Ravnborg 1612506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1613506f1d07SSam Ravnborg def_bool y 16143b16651fSTejun Heo depends on X86_32 && !NUMA 1615506f1d07SSam Ravnborg 1616506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1617506f1d07SSam Ravnborg def_bool y 16186ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1619506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1620506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1621506f1d07SSam Ravnborg 16223b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16236ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16243b16651fSTejun Heo 1625506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1626506f1d07SSam Ravnborg def_bool y 16274eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1628506f1d07SSam Ravnborg 1629506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1630a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16315c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1632a0842b70SToshi Kani help 1633a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1634cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1635a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1636506f1d07SSam Ravnborg 16373b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16383b16651fSTejun Heo def_bool y 16393b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16403b16651fSTejun Heo 1641a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1642a29815a3SAvi Kivity hex 1643a29815a3SAvi Kivity default 0 if X86_32 1644a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1645a29815a3SAvi Kivity 16467a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16477a67832cSDan Williams bool 16487a67832cSDan Williams 1649ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16507a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16519f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16529f53f9faSDan Williams depends on BLK_DEV 16537a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16547b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16559f53f9faSDan Williams select LIBNVDIMM 1656ec776ef6SChristoph Hellwig help 1657ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1658ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1659ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1660ec776ef6SChristoph Hellwig they can be used for persistent storage. 1661ec776ef6SChristoph Hellwig 1662ec776ef6SChristoph Hellwig Say Y if unsure. 1663ec776ef6SChristoph Hellwig 1664506f1d07SSam Ravnborgconfig HIGHPTE 1665506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16666fc108a0SJan Beulich depends on HIGHMEM 1667a7f7f624SMasahiro Yamada help 1668506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1669506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1670506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1671506f1d07SSam Ravnborg entries in high memory. 1672506f1d07SSam Ravnborg 16739f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16749f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1675a7f7f624SMasahiro Yamada help 16769f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16779f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16789f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16799f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16809f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16819f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16829f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16838c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16849f077871SJeremy Fitzhardinge 16859f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16869f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16879f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16889f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16899f077871SJeremy Fitzhardinge 16909f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16919f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16929f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16939f077871SJeremy Fitzhardinge memory. 16949f077871SJeremy Fitzhardinge 1695c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1696c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1697c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1698c885df50SJeremy Fitzhardinge default y 1699a7f7f624SMasahiro Yamada help 1700c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1701c885df50SJeremy Fitzhardinge on or off. 1702c885df50SJeremy Fitzhardinge 1703506f1d07SSam Ravnborgconfig MATH_EMULATION 1704506f1d07SSam Ravnborg bool 1705a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 170687d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1707a7f7f624SMasahiro Yamada help 1708506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1709506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1710506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1711506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1712506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1713506f1d07SSam Ravnborg coprocessor or this emulation. 1714506f1d07SSam Ravnborg 1715506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1716506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1717506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1718506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1719506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1720506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1721506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1722506f1d07SSam Ravnborg intend to use this kernel on different machines. 1723506f1d07SSam Ravnborg 1724506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1725506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1726506f1d07SSam Ravnborg 1727506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1728506f1d07SSam Ravnborg kernel, it won't hurt. 1729506f1d07SSam Ravnborg 1730506f1d07SSam Ravnborgconfig MTRR 17316fc108a0SJan Beulich def_bool y 17326a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1733a7f7f624SMasahiro Yamada help 1734506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1735506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1736506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1737506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1738506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1739506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1740506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1741506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1742506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1743506f1d07SSam Ravnborg 1744506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1745506f1d07SSam Ravnborg control registers on other processors can be easily supported 1746506f1d07SSam Ravnborg as well: 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1749506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1750506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1751506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1752506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1753506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1754506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1755506f1d07SSam Ravnborg 1756506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1757506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1758506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1759506f1d07SSam Ravnborg 1760506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1761506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1762506f1d07SSam Ravnborg 1763cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1764506f1d07SSam Ravnborg 176595ffa243SYinghai Luconfig MTRR_SANITIZER 17662ffb3501SYinghai Lu def_bool y 176795ffa243SYinghai Lu prompt "MTRR cleanup support" 176895ffa243SYinghai Lu depends on MTRR 1769a7f7f624SMasahiro Yamada help 1770aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1771aba3728cSThomas Gleixner add writeback entries. 177295ffa243SYinghai Lu 1773aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1774692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1775aba3728cSThomas Gleixner mtrr_chunk_size. 177695ffa243SYinghai Lu 17772ffb3501SYinghai Lu If unsure, say Y. 177895ffa243SYinghai Lu 177995ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1780f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1781f5098d62SYinghai Lu range 0 1 1782f5098d62SYinghai Lu default "0" 178395ffa243SYinghai Lu depends on MTRR_SANITIZER 1784a7f7f624SMasahiro Yamada help 1785f5098d62SYinghai Lu Enable mtrr cleanup default value 178695ffa243SYinghai Lu 178712031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 178812031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 178912031a62SYinghai Lu range 0 7 179012031a62SYinghai Lu default "1" 179112031a62SYinghai Lu depends on MTRR_SANITIZER 1792a7f7f624SMasahiro Yamada help 179312031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1794aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 179512031a62SYinghai Lu 17962e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17976fc108a0SJan Beulich def_bool y 17986a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 17992a8a2719SIngo Molnar depends on MTRR 1800a7f7f624SMasahiro Yamada help 18012e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1802042b78e4SVenki Pallipadi 18032e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18042e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18052e5d9c85Svenkatesh.pallipadi@intel.com 18062e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1807042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18082e5d9c85Svenkatesh.pallipadi@intel.com 18092e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18102e5d9c85Svenkatesh.pallipadi@intel.com 181146cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 181246cf98cdSVenkatesh Pallipadi def_bool y 181346cf98cdSVenkatesh Pallipadi depends on X86_PAT 181446cf98cdSVenkatesh Pallipadi 1815628c6246SH. Peter Anvinconfig ARCH_RANDOM 1816628c6246SH. Peter Anvin def_bool y 1817628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1818a7f7f624SMasahiro Yamada help 1819628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1820628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1821628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1822628c6246SH. Peter Anvin secure hardware random number generator. 1823628c6246SH. Peter Anvin 182451ae4a2dSH. Peter Anvinconfig X86_SMAP 182551ae4a2dSH. Peter Anvin def_bool y 182651ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 182703f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 1828a7f7f624SMasahiro Yamada help 182951ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 183051ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 183151ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 183251ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 183351ae4a2dSH. Peter Anvin 183451ae4a2dSH. Peter Anvin If unsure, say Y. 183551ae4a2dSH. Peter Anvin 1836b971880fSBabu Mogerconfig X86_UMIP 1837796ebc81SRicardo Neri def_bool y 1838b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1839a7f7f624SMasahiro Yamada help 1840b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1841b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1842b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1843b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1844b971880fSBabu Moger information about the hardware state. 1845796ebc81SRicardo Neri 1846796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1847796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1848796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1849796ebc81SRicardo Neri results are dummy. 1850aa35f896SRicardo Neri 1851156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1852156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1853156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1854156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1855262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1856262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1857156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1858262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1859156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1860156ff4a5SPeter Zijlstra 1861156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1862156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 1863156ff4a5SPeter Zijlstra bool 186403f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1865f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1866f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 186703f16cd0SJosh Poimboeuf select OBJTOOL 1868156ff4a5SPeter Zijlstra help 1869156ff4a5SPeter Zijlstra Build the kernel with support for Indirect Branch Tracking, a 1870156ff4a5SPeter Zijlstra hardware support course-grain forward-edge Control Flow Integrity 1871156ff4a5SPeter Zijlstra protection. It enforces that all indirect calls must land on 1872156ff4a5SPeter Zijlstra an ENDBR instruction, as such, the compiler will instrument the 1873156ff4a5SPeter Zijlstra code with them to make this happen. 1874156ff4a5SPeter Zijlstra 1875ed53a0d9SPeter Zijlstra In addition to building the kernel with IBT, seal all functions that 18764cdfc11bSNur Hussein are not indirect call targets, avoiding them ever becoming one. 1877ed53a0d9SPeter Zijlstra 1878ed53a0d9SPeter Zijlstra This requires LTO like objtool runs and will slow down the build. It 1879ed53a0d9SPeter Zijlstra does significantly reduce the number of ENDBR instructions in the 1880ed53a0d9SPeter Zijlstra kernel image. 1881ed53a0d9SPeter Zijlstra 188235e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 188338f3e775SBabu Moger prompt "Memory Protection Keys" 188435e97790SDave Hansen def_bool y 1885284244a9SDave Hansen # Note: only available in 64-bit mode 188638f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 188752c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 188852c8e601SIngo Molnar select ARCH_HAS_PKEYS 1889a7f7f624SMasahiro Yamada help 1890284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1891284244a9SDave Hansen page-based protections, but without requiring modification of the 1892284244a9SDave Hansen page tables when an application changes protection domains. 1893284244a9SDave Hansen 18941eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1895284244a9SDave Hansen 1896284244a9SDave Hansen If unsure, say y. 189735e97790SDave Hansen 1898db616173SMichal Hockochoice 1899db616173SMichal Hocko prompt "TSX enable mode" 1900db616173SMichal Hocko depends on CPU_SUP_INTEL 1901db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1902db616173SMichal Hocko help 1903db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1904db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1905db616173SMichal Hocko can lead to a noticeable performance boost. 1906db616173SMichal Hocko 1907db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1908db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1909db616173SMichal Hocko will be more of those attacks discovered in the future. 1910db616173SMichal Hocko 1911db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1912db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1913db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1914db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1915db616173SMichal Hocko for the particular machine. 1916db616173SMichal Hocko 1917db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1918db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1919db616173SMichal Hocko details. 1920db616173SMichal Hocko 1921db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1922db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1923db616173SMichal Hocko relevant. 1924db616173SMichal Hocko 1925db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1926db616173SMichal Hocko bool "off" 1927db616173SMichal Hocko help 1928db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1929db616173SMichal Hocko 1930db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1931db616173SMichal Hocko bool "on" 1932db616173SMichal Hocko help 1933db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1934db616173SMichal Hocko line parameter. 1935db616173SMichal Hocko 1936db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1937db616173SMichal Hocko bool "auto" 1938db616173SMichal Hocko help 1939db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1940db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1941db616173SMichal Hockoendchoice 1942db616173SMichal Hocko 1943e7e05452SSean Christophersonconfig X86_SGX 1944e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1945e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1946e7e05452SSean Christopherson depends on CRYPTO=y 1947e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1948e7e05452SSean Christopherson select SRCU 1949e7e05452SSean Christopherson select MMU_NOTIFIER 1950901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 195140e0e784STony Luck select XARRAY_MULTI 1952e7e05452SSean Christopherson help 1953e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1954e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1955e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1956e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1957e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1958e7e05452SSean Christopherson hardware. 1959e7e05452SSean Christopherson 1960e7e05452SSean Christopherson If unsure, say N. 1961e7e05452SSean Christopherson 1962506f1d07SSam Ravnborgconfig EFI 19639ba16087SJan Beulich bool "EFI runtime service support" 19645b83683fSHuang, Ying depends on ACPI 1965f6ce5002SSergey Vlasov select UCS2_STRING 1966022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19671ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1968a7f7f624SMasahiro Yamada help 19698b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1970506f1d07SSam Ravnborg available (such as the EFI variable services). 1971506f1d07SSam Ravnborg 19728b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19738b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19748b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19758b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19768b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19778b2cb7a8SHuang, Ying platforms. 1978506f1d07SSam Ravnborg 1979291f3632SMatt Flemingconfig EFI_STUB 1980291f3632SMatt Fleming bool "EFI stub support" 1981c6dbd3e5SPeter Zijlstra depends on EFI 19828f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19837b2a583aSMatt Fleming select RELOCATABLE 1984a7f7f624SMasahiro Yamada help 1985291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1986291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1987291f3632SMatt Fleming 19884f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19890c759662SMatt Fleming 19907d453eeeSMatt Flemingconfig EFI_MIXED 19917d453eeeSMatt Fleming bool "EFI mixed-mode support" 19927d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1993a7f7f624SMasahiro Yamada help 19947d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19957d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19967d453eeeSMatt Fleming mode. 19977d453eeeSMatt Fleming 19987d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19997d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 20007d453eeeSMatt Fleming the EFI handover protocol must be used. 20017d453eeeSMatt Fleming 20027d453eeeSMatt Fleming If unsure, say N. 20037d453eeeSMatt Fleming 20048636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2005506f1d07SSam Ravnborg 2006506f1d07SSam Ravnborgconfig KEXEC 2007506f1d07SSam Ravnborg bool "kexec system call" 20082965faa5SDave Young select KEXEC_CORE 2009a7f7f624SMasahiro Yamada help 2010506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 2011506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 2012506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 2013506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 2014506f1d07SSam Ravnborg 2015506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 2016506f1d07SSam Ravnborg 2017506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 2018506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 2019bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 2020bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 2021bf220695SGeert Uytterhoeven made. 2022506f1d07SSam Ravnborg 202374ca317cSVivek Goyalconfig KEXEC_FILE 202474ca317cSVivek Goyal bool "kexec file based system call" 20252965faa5SDave Young select KEXEC_CORE 202674ca317cSVivek Goyal select BUILD_BIN2C 202774ca317cSVivek Goyal depends on X86_64 202874ca317cSVivek Goyal depends on CRYPTO=y 202974ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2030a7f7f624SMasahiro Yamada help 203174ca317cSVivek Goyal This is new version of kexec system call. This system call is 203274ca317cSVivek Goyal file based and takes file descriptors as system call argument 203374ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 203474ca317cSVivek Goyal accepted by previous system call. 203574ca317cSVivek Goyal 2036b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2037b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2038b799a09fSAKASHI Takahiro 203999d5cadfSJiri Bohacconfig KEXEC_SIG 20408e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 204174ca317cSVivek Goyal depends on KEXEC_FILE 2042a7f7f624SMasahiro Yamada help 204399d5cadfSJiri Bohac 204499d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 204599d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 204699d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 204799d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 204899d5cadfSJiri Bohac 204999d5cadfSJiri Bohac In addition to this option, you need to enable signature 205099d5cadfSJiri Bohac verification for the corresponding kernel image type being 205199d5cadfSJiri Bohac loaded in order for this to work. 205299d5cadfSJiri Bohac 205399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 205499d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 205599d5cadfSJiri Bohac depends on KEXEC_SIG 2056a7f7f624SMasahiro Yamada help 20578e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2058d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20598e7d8381SVivek Goyal 20608e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20618e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 206299d5cadfSJiri Bohac depends on KEXEC_SIG 20638e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20648e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2065a7f7f624SMasahiro Yamada help 20668e7d8381SVivek Goyal Enable bzImage signature verification support. 20678e7d8381SVivek Goyal 2068506f1d07SSam Ravnborgconfig CRASH_DUMP 206904b69447SPavel Machek bool "kernel crash dumps" 2070506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2071a7f7f624SMasahiro Yamada help 2072506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2073506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2074506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2075506f1d07SSam Ravnborg a specially reserved region and then later executed after 2076506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2077506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2078506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2079506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2080330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2081506f1d07SSam Ravnborg 20823ab83521SHuang Yingconfig KEXEC_JUMP 20836ea30386SKees Cook bool "kexec jump" 2084fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2085a7f7f624SMasahiro Yamada help 208689081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 208789081d17SHuang Ying code in physical address mode via KEXEC 20883ab83521SHuang Ying 2089506f1d07SSam Ravnborgconfig PHYSICAL_START 20906a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2091ceefccc9SH. Peter Anvin default "0x1000000" 2092a7f7f624SMasahiro Yamada help 2093506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2094506f1d07SSam Ravnborg 2095506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2096506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2097506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2098506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2099506f1d07SSam Ravnborg address. 2100506f1d07SSam Ravnborg 2101506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2102506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2103506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2104506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2105506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2106506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2107506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2108506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2109506f1d07SSam Ravnborg 2110ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2111ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2112ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2113ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2114ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2115ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2116ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2117330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2118ceefccc9SH. Peter Anvin for more details about crash dumps. 2119506f1d07SSam Ravnborg 2120506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2121506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2122506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2123506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2124506f1d07SSam Ravnborg is present because there are users out there who continue to use 2125506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2126506f1d07SSam Ravnborg line. 2127506f1d07SSam Ravnborg 2128506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2129506f1d07SSam Ravnborg 2130506f1d07SSam Ravnborgconfig RELOCATABLE 213126717808SH. Peter Anvin bool "Build a relocatable kernel" 213226717808SH. Peter Anvin default y 2133a7f7f624SMasahiro Yamada help 2134506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2135506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2136506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2137506f1d07SSam Ravnborg but are discarded at runtime. 2138506f1d07SSam Ravnborg 2139506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2140506f1d07SSam Ravnborg must live at a different physical address than the primary 2141506f1d07SSam Ravnborg kernel. 2142506f1d07SSam Ravnborg 2143506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2144506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21458ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2146506f1d07SSam Ravnborg 21478ab3820fSKees Cookconfig RANDOMIZE_BASE 2148e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21498ab3820fSKees Cook depends on RELOCATABLE 21506807c846SIngo Molnar default y 2151a7f7f624SMasahiro Yamada help 2152e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2153e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2154e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2155e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2156e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2157e8581e3dSBaoquan He code internals. 2158e8581e3dSBaoquan He 2159ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2160ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2161ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2162ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2163ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2164ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2165ed9f007eSKees Cook 2166ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2167ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2168ed9f007eSKees Cook 512MB (8 bits of entropy). 21698ab3820fSKees Cook 2170a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2171e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2172e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2173ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2174ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2175ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2176ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2177ed9f007eSKees Cook theoretically possible, but the implementations are further 2178ed9f007eSKees Cook limited due to memory layouts. 2179e8581e3dSBaoquan He 21806807c846SIngo Molnar If unsure, say Y. 2181da2b6fb9SKees Cook 21828ab3820fSKees Cook# Relocation on x86 needs some additional build support 2183845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2184845adf72SH. Peter Anvin def_bool y 21858ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2186845adf72SH. Peter Anvin 2187506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2188a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21898ab3820fSKees Cook default "0x200000" 2190a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2191a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2192a7f7f624SMasahiro Yamada help 2193506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2194506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2195506f1d07SSam Ravnborg address which meets above alignment restriction. 2196506f1d07SSam Ravnborg 2197506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2198506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2199506f1d07SSam Ravnborg address aligned to above value and run from there. 2200506f1d07SSam Ravnborg 2201506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2202506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2203506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2204506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2205506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2206506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2207506f1d07SSam Ravnborg above alignment restrictions. 2208506f1d07SSam Ravnborg 2209a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2210a0215061SKees Cook this value must be a multiple of 0x200000. 2211a0215061SKees Cook 2212506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2213506f1d07SSam Ravnborg 2214eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2215eedb92abSKirill A. Shutemov bool 2216a7f7f624SMasahiro Yamada help 2217eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2218eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2219eedb92abSKirill A. Shutemov 22200483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22210483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22220483e1faSThomas Garnier depends on X86_64 22230483e1faSThomas Garnier depends on RANDOMIZE_BASE 2224eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22250483e1faSThomas Garnier default RANDOMIZE_BASE 2226a7f7f624SMasahiro Yamada help 22270483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22280483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22290483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22300483e1faSThomas Garnier 22310483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22320483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22330483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22340483e1faSThomas Garnier addresses for each memory section. 22350483e1faSThomas Garnier 22366807c846SIngo Molnar If unsure, say Y. 22370483e1faSThomas Garnier 223890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 223990397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 224090397a41SThomas Garnier depends on RANDOMIZE_MEMORY 224190397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 224290397a41SThomas Garnier default "0x0" 224390397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 224490397a41SThomas Garnier range 0x0 0x40 2245a7f7f624SMasahiro Yamada help 224690397a41SThomas Garnier Define the padding in terabytes added to the existing physical 224790397a41SThomas Garnier memory size during kernel memory randomization. It is useful 224890397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 224990397a41SThomas Garnier address randomization. 225090397a41SThomas Garnier 225190397a41SThomas Garnier If unsure, leave at the default value. 225290397a41SThomas Garnier 2253506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2254bebd024eSThomas Gleixner def_bool y 225540b31360SStephen Rothwell depends on SMP 2256506f1d07SSam Ravnborg 225780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 225880aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22592c922cd0SKees Cook depends on HOTPLUG_CPU 2260a7f7f624SMasahiro Yamada help 226180aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 226280aa1dffSFenghua Yu 226380aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 226480aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 226580aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 226680aa1dffSFenghua Yu 226780aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 226880aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 226980aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 227080aa1dffSFenghua Yu 227180aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 227280aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 227380aa1dffSFenghua Yu 227480aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 227580aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 227680aa1dffSFenghua Yu be other CPU0 dependencies. 227780aa1dffSFenghua Yu 227880aa1dffSFenghua Yu Please make sure the dependencies are under your control before 227980aa1dffSFenghua Yu you enable this feature. 228080aa1dffSFenghua Yu 228180aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 228280aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 228380aa1dffSFenghua Yu parameter cpu0_hotplug. 228480aa1dffSFenghua Yu 2285a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2286a71c8bc5SFenghua Yu def_bool n 2287a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22882c922cd0SKees Cook depends on HOTPLUG_CPU 2289a7f7f624SMasahiro Yamada help 2290a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2291a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2292a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2293a71c8bc5SFenghua Yu 2294a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2295a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2296a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2297a71c8bc5SFenghua Yu 2298a71c8bc5SFenghua Yu If unsure, say N. 2299a71c8bc5SFenghua Yu 2300506f1d07SSam Ravnborgconfig COMPAT_VDSO 2301b0b49f26SAndy Lutomirski def_bool n 2302b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2303953fee1dSIngo Molnar depends on COMPAT_32 2304a7f7f624SMasahiro Yamada help 2305b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2306b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2307b0b49f26SAndy Lutomirski indicated in its segment table. 2308e84446deSRandy Dunlap 2309b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2310b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2311b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2312b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2313b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2314506f1d07SSam Ravnborg 2315b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2316b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2317b0b49f26SAndy Lutomirski 2318b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2319b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2320b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2321b0b49f26SAndy Lutomirski 2322b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2323b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2324506f1d07SSam Ravnborg 23253dc33bd3SKees Cookchoice 23263dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23273dc33bd3SKees Cook depends on X86_64 2328625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23293dc33bd3SKees Cook help 23303dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23313dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23323dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23333dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23343dc33bd3SKees Cook 23353dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2336bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23373dc33bd3SKees Cook 23383dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23393dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23403dc33bd3SKees Cook to improve security. 23413dc33bd3SKees Cook 2342bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23433dc33bd3SKees Cook 23443dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2345bd49e16eSAndy Lutomirski bool "Full emulation" 23463dc33bd3SKees Cook help 2347bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2348bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2349bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2350bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2351bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2352bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2353bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2354bd49e16eSAndy Lutomirski 2355bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2356bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2357bd49e16eSAndy Lutomirski 2358bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2359bd49e16eSAndy Lutomirski bool "Emulate execution only" 2360bd49e16eSAndy Lutomirski help 2361bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2362bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2363bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2364bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2365bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2366bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2367bd49e16eSAndy Lutomirski buffer. 23683dc33bd3SKees Cook 23693dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23703dc33bd3SKees Cook bool "None" 23713dc33bd3SKees Cook help 23723dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23733dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23743dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23753dc33bd3SKees Cook will be reported to dmesg, so that either old or 23763dc33bd3SKees Cook malicious userspace programs can be identified. 23773dc33bd3SKees Cook 23783dc33bd3SKees Cookendchoice 23793dc33bd3SKees Cook 2380516cbf37STim Birdconfig CMDLINE_BOOL 2381516cbf37STim Bird bool "Built-in kernel command line" 2382a7f7f624SMasahiro Yamada help 2383516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2384516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2385516cbf37STim Bird necessary or convenient to provide some or all of the 2386516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2387516cbf37STim Bird to not rely on the boot loader to provide them.) 2388516cbf37STim Bird 2389516cbf37STim Bird To compile command line arguments into the kernel, 2390516cbf37STim Bird set this option to 'Y', then fill in the 239169711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2392516cbf37STim Bird 2393516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2394516cbf37STim Bird should leave this option set to 'N'. 2395516cbf37STim Bird 2396516cbf37STim Birdconfig CMDLINE 2397516cbf37STim Bird string "Built-in kernel command string" 2398516cbf37STim Bird depends on CMDLINE_BOOL 2399516cbf37STim Bird default "" 2400a7f7f624SMasahiro Yamada help 2401516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2402516cbf37STim Bird image and used at boot time. If the boot loader provides a 2403516cbf37STim Bird command line at boot time, it is appended to this string to 2404516cbf37STim Bird form the full kernel command line, when the system boots. 2405516cbf37STim Bird 2406516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2407516cbf37STim Bird change this behavior. 2408516cbf37STim Bird 2409516cbf37STim Bird In most cases, the command line (whether built-in or provided 2410516cbf37STim Bird by the boot loader) should specify the device for the root 2411516cbf37STim Bird file system. 2412516cbf37STim Bird 2413516cbf37STim Birdconfig CMDLINE_OVERRIDE 2414516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2415645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2416a7f7f624SMasahiro Yamada help 2417516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2418516cbf37STim Bird command line, and use ONLY the built-in command line. 2419516cbf37STim Bird 2420516cbf37STim Bird This is used to work around broken boot loaders. This should 2421516cbf37STim Bird be set to 'N' under normal conditions. 2422516cbf37STim Bird 2423a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2424a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2425a5b9e5a2SAndy Lutomirski default y 2426a7f7f624SMasahiro Yamada help 2427a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2428a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2429a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2430a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2431a5b9e5a2SAndy Lutomirski threading libraries. 2432a5b9e5a2SAndy Lutomirski 2433a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2434a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2435a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2436a5b9e5a2SAndy Lutomirski 2437a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2438a5b9e5a2SAndy Lutomirski 24393aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24403aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24413aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24423aac3ebeSThomas Gleixner help 24433aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24443aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24453aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24463aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24473aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24483aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24493aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24503aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24513aac3ebeSThomas Gleixner never get a signal delivered. 24523aac3ebeSThomas Gleixner 24533aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24543aac3ebeSThomas Gleixner 2455b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2456b700e7f0SSeth Jennings 2457506f1d07SSam Ravnborgendmenu 2458506f1d07SSam Ravnborg 24593072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24603072e413SMichal Hocko def_bool y 24615c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24623072e413SMichal Hocko 2463f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2464f91ef222SOscar Salvador def_bool y 2465f91ef222SOscar Salvador 2466da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2467e279b6c1SSam Ravnborg 2468e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24693c2362e6SHarvey Harrison def_bool y 247044556530SZhimin Gu depends on HIBERNATION 2471e279b6c1SSam Ravnborg 2472e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2473e279b6c1SSam Ravnborg 2474e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2475e279b6c1SSam Ravnborg 2476a6b68076SAndi Kleenconfig X86_APM_BOOT 24776fc108a0SJan Beulich def_bool y 2478282e5aabSPaul Bolle depends on APM 2479a6b68076SAndi Kleen 2480e279b6c1SSam Ravnborgmenuconfig APM 2481e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2482efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2483a7f7f624SMasahiro Yamada help 2484e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2485e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2486e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2487e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2488e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2489e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2490e279b6c1SSam Ravnborg 2491e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2492e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2493e279b6c1SSam Ravnborg 2494e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2495e279b6c1SSam Ravnborg machines with more than one CPU. 2496e279b6c1SSam Ravnborg 2497e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2498151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24992dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2500e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2501e279b6c1SSam Ravnborg 2502e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2503e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2504e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2505e279b6c1SSam Ravnborg 2506e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2507e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2508e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2509e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2510e279b6c1SSam Ravnborg 2511e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2512e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2513e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2514e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2515e279b6c1SSam Ravnborg APM in your BIOS). 2516e279b6c1SSam Ravnborg 2517e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2518e279b6c1SSam Ravnborg "weird" problems: 2519e279b6c1SSam Ravnborg 2520e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2521e279b6c1SSam Ravnborg enabled. 2522e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2523e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2524e279b6c1SSam Ravnborg the "no387" option to the kernel 2525e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2526e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2527e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2528e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2529e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2530e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2531e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2532e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2533e279b6c1SSam Ravnborg 11) exchange RAM chips 2534e279b6c1SSam Ravnborg 12) exchange the motherboard. 2535e279b6c1SSam Ravnborg 2536e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2537e279b6c1SSam Ravnborg module will be called apm. 2538e279b6c1SSam Ravnborg 2539e279b6c1SSam Ravnborgif APM 2540e279b6c1SSam Ravnborg 2541e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2542e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2543a7f7f624SMasahiro Yamada help 2544e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2545e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2546e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2547e279b6c1SSam Ravnborg 2548e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2549e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2550a7f7f624SMasahiro Yamada help 2551e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2552e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2553e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2554e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2555e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2556e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2557e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2558e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2559e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2560e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2561e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2562e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2563e279b6c1SSam Ravnborg this feature. 2564e279b6c1SSam Ravnborg 2565e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2566dd8af076SLen Brown depends on CPU_IDLE 2567e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2568a7f7f624SMasahiro Yamada help 2569e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2570e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2571e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2572e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2573e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2574e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2575e279b6c1SSam Ravnborg this option does nothing.) 2576e279b6c1SSam Ravnborg 2577e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2578e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2579a7f7f624SMasahiro Yamada help 2580e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2581e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2582e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2583e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2584e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2585e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2586e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2587e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2588e279b6c1SSam Ravnborg especially if you are using gpm. 2589e279b6c1SSam Ravnborg 2590e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2591e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2592a7f7f624SMasahiro Yamada help 2593e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2594e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2595e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2596e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2597e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2598e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2599e279b6c1SSam Ravnborg 2600e279b6c1SSam Ravnborgendif # APM 2601e279b6c1SSam Ravnborg 2602bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2603e279b6c1SSam Ravnborg 2604e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2605e279b6c1SSam Ravnborg 260627471fdbSAndy Henroidsource "drivers/idle/Kconfig" 260727471fdbSAndy Henroid 2608e279b6c1SSam Ravnborgendmenu 2609e279b6c1SSam Ravnborg 2610e279b6c1SSam Ravnborg 2611e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2612e279b6c1SSam Ravnborg 2613e279b6c1SSam Ravnborgchoice 2614e279b6c1SSam Ravnborg prompt "PCI access mode" 2615efefa6f6SIngo Molnar depends on X86_32 && PCI 2616e279b6c1SSam Ravnborg default PCI_GOANY 2617a7f7f624SMasahiro Yamada help 2618e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2619e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2620e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2621e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2622e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2623e279b6c1SSam Ravnborg 2624e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2625e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2626e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2627e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2628e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2629e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2630e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2631e279b6c1SSam Ravnborg 2632e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2633e279b6c1SSam Ravnborg bool "BIOS" 2634e279b6c1SSam Ravnborg 2635e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2636e279b6c1SSam Ravnborg bool "MMConfig" 2637e279b6c1SSam Ravnborg 2638e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2639e279b6c1SSam Ravnborg bool "Direct" 2640e279b6c1SSam Ravnborg 26413ef0e1f8SAndres Salomonconfig PCI_GOOLPC 264276fb6570SDaniel Drake bool "OLPC XO-1" 26433ef0e1f8SAndres Salomon depends on OLPC 26443ef0e1f8SAndres Salomon 26452bdd1b03SAndres Salomonconfig PCI_GOANY 26462bdd1b03SAndres Salomon bool "Any" 26472bdd1b03SAndres Salomon 2648e279b6c1SSam Ravnborgendchoice 2649e279b6c1SSam Ravnborg 2650e279b6c1SSam Ravnborgconfig PCI_BIOS 26513c2362e6SHarvey Harrison def_bool y 2652efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2653e279b6c1SSam Ravnborg 2654e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2655e279b6c1SSam Ravnborgconfig PCI_DIRECT 26563c2362e6SHarvey Harrison def_bool y 26570aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2658e279b6c1SSam Ravnborg 2659e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2660b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2661b45c9f36SJan Kiszka default y 26624590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2663b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2664e279b6c1SSam Ravnborg 26653ef0e1f8SAndres Salomonconfig PCI_OLPC 26662bdd1b03SAndres Salomon def_bool y 26672bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26683ef0e1f8SAndres Salomon 2669b5401a96SAlex Nixonconfig PCI_XEN 2670b5401a96SAlex Nixon def_bool y 2671b5401a96SAlex Nixon depends on PCI && XEN 2672b5401a96SAlex Nixon 26738364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26748364e1f8SJan Kiszka def_bool y 26758364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2676e279b6c1SSam Ravnborg 26773f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26786a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26796ea30386SKees Cook depends on PCI 26803f6ea84aSIra W. Snyder help 26813f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26823f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26833f6ea84aSIra W. Snyder not have ACPI. 26843f6ea84aSIra W. Snyder 268564a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 268664a5fed6SBjorn Helgaas is known to be incomplete. 268764a5fed6SBjorn Helgaas 268864a5fed6SBjorn Helgaas You should say N unless you know you need this. 268964a5fed6SBjorn Helgaas 26903a495511SWilliam Breathitt Grayconfig ISA_BUS 269117a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26923a495511SWilliam Breathitt Gray help 269317a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 269417a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 269517a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 269617a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 269717a2a129SWilliam Breathitt Gray not have an ISA bus. 26983a495511SWilliam Breathitt Gray 26993a495511SWilliam Breathitt Gray If unsure, say N. 27003a495511SWilliam Breathitt Gray 27011c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2702e279b6c1SSam Ravnborgconfig ISA_DMA_API 27031c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 27041c00f016SDavid Rientjes default y 27051c00f016SDavid Rientjes help 27061c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 27071c00f016SDavid Rientjes If unsure, say Y. 2708e279b6c1SSam Ravnborg 270951e68d05SLinus Torvaldsif X86_32 271051e68d05SLinus Torvalds 2711e279b6c1SSam Ravnborgconfig ISA 2712e279b6c1SSam Ravnborg bool "ISA support" 2713a7f7f624SMasahiro Yamada help 2714e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2715e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2716e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2717e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2718e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2719e279b6c1SSam Ravnborg 2720e279b6c1SSam Ravnborgconfig SCx200 2721e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2722a7f7f624SMasahiro Yamada help 2723e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2724e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2725e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2726e279b6c1SSam Ravnborg for other scx200_* drivers. 2727e279b6c1SSam Ravnborg 2728e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2729e279b6c1SSam Ravnborg 2730e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2731e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2732592913ecSJohn Stultz depends on SCx200 2733e279b6c1SSam Ravnborg default y 2734a7f7f624SMasahiro Yamada help 2735e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2736e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2737e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2738e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2739e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2740e279b6c1SSam Ravnborg 27413ef0e1f8SAndres Salomonconfig OLPC 27423ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 274354008979SThomas Gleixner depends on !X86_PAE 27443c554946SAndres Salomon select GPIOLIB 2745dc3119e7SThomas Gleixner select OF 274645bb1674SDaniel Drake select OF_PROMTREE 2747b4e51854SGrant Likely select IRQ_DOMAIN 27480c3d931bSLubomir Rintel select OLPC_EC 2749a7f7f624SMasahiro Yamada help 27503ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27513ef0e1f8SAndres Salomon XO hardware. 27523ef0e1f8SAndres Salomon 2753a3128588SDaniel Drakeconfig OLPC_XO1_PM 2754a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2755fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2756a7f7f624SMasahiro Yamada help 275797c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2758bf1ebf00SDaniel Drake 2759cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2760cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2761cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2762a7f7f624SMasahiro Yamada help 2763cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2764cfee9597SDaniel Drake programmable wakeup source. 2765cfee9597SDaniel Drake 27667feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27677feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 276892e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2769ed8e47feSRandy Dunlap depends on INPUT=y 2770d8d01a63SDaniel Drake select POWER_SUPPLY 2771a7f7f624SMasahiro Yamada help 27727feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27737bc74b3dSDaniel Drake - EC-driven system wakeups 27747feda8e9SDaniel Drake - Power button 27757bc74b3dSDaniel Drake - Ebook switch 27762cf2baeaSDaniel Drake - Lid switch 2777e1040ac6SDaniel Drake - AC adapter status updates 2778e1040ac6SDaniel Drake - Battery status updates 27797feda8e9SDaniel Drake 2780a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2781a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2782d8d01a63SDaniel Drake depends on OLPC && ACPI 2783d8d01a63SDaniel Drake select POWER_SUPPLY 2784a7f7f624SMasahiro Yamada help 2785a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2786a0f30f59SDaniel Drake - EC-driven system wakeups 2787a0f30f59SDaniel Drake - AC adapter status updates 2788a0f30f59SDaniel Drake - Battery status updates 2789e279b6c1SSam Ravnborg 2790d4f3e350SEd Wildgooseconfig ALIX 2791d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2792d4f3e350SEd Wildgoose select GPIOLIB 2793a7f7f624SMasahiro Yamada help 2794d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2795d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2796d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2797d4f3e350SEd Wildgoose get added here. 2798d4f3e350SEd Wildgoose 2799d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2800d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2801d4f3e350SEd Wildgoose 2802d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2803d4f3e350SEd Wildgoose 2804da4e3302SPhilip Prindevilleconfig NET5501 2805da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2806da4e3302SPhilip Prindeville select GPIOLIB 2807a7f7f624SMasahiro Yamada help 2808da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2809da4e3302SPhilip Prindeville 28103197059aSPhilip A. Prindevilleconfig GEOS 28113197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 28123197059aSPhilip A. Prindeville select GPIOLIB 28133197059aSPhilip A. Prindeville depends on DMI 2814a7f7f624SMasahiro Yamada help 28153197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 28163197059aSPhilip A. Prindeville 28177d029125SVivien Didelotconfig TS5500 28187d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 28197d029125SVivien Didelot depends on MELAN 28207d029125SVivien Didelot select CHECK_SIGNATURE 28217d029125SVivien Didelot select NEW_LEDS 28227d029125SVivien Didelot select LEDS_CLASS 2823a7f7f624SMasahiro Yamada help 28247d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 28257d029125SVivien Didelot 2826e279b6c1SSam Ravnborgendif # X86_32 2827e279b6c1SSam Ravnborg 282823ac4ae8SAndreas Herrmannconfig AMD_NB 2829e279b6c1SSam Ravnborg def_bool y 28300e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2831e279b6c1SSam Ravnborg 2832e279b6c1SSam Ravnborgendmenu 2833e279b6c1SSam Ravnborg 2834e279b6c1SSam Ravnborg 28351572497cSChristoph Hellwigmenu "Binary Emulations" 2836e279b6c1SSam Ravnborg 2837e279b6c1SSam Ravnborgconfig IA32_EMULATION 2838e279b6c1SSam Ravnborg bool "IA32 Emulation" 2839e279b6c1SSam Ravnborg depends on X86_64 284039f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2841d1603990SRandy Dunlap select BINFMT_ELF 284239f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2843a7f7f624SMasahiro Yamada help 28445fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28455fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28465fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2847e279b6c1SSam Ravnborg 2848e279b6c1SSam Ravnborgconfig IA32_AOUT 2849e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28506b213e1bSDavid Woodhouse depends on IA32_EMULATION 2851eac61655SBorislav Petkov depends on BROKEN 2852a7f7f624SMasahiro Yamada help 2853e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2854e279b6c1SSam Ravnborg 285583a44a4fSMasahiro Yamadaconfig X86_X32_ABI 28566ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28579b54050bSBrian Gerst depends on X86_64 2858aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 2859aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 2860aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 2861aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 2862aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 2863a7f7f624SMasahiro Yamada help 28645fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28655fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28665fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28675fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28685fd92e65SH. J. Lu 2869953fee1dSIngo Molnarconfig COMPAT_32 2870953fee1dSIngo Molnar def_bool y 2871953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2872953fee1dSIngo Molnar select HAVE_UID16 2873953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2874953fee1dSIngo Molnar 2875e279b6c1SSam Ravnborgconfig COMPAT 28763c2362e6SHarvey Harrison def_bool y 287783a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 2878e279b6c1SSam Ravnborg 28793120e25eSJan Beulichif COMPAT 2880e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28813120e25eSJan Beulich def_bool y 2882e279b6c1SSam Ravnborg 2883e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28843c2362e6SHarvey Harrison def_bool y 28853120e25eSJan Beulich depends on SYSVIPC 28863120e25eSJan Beulichendif 2887ee009e4aSDavid Howells 2888e279b6c1SSam Ravnborgendmenu 2889e279b6c1SSam Ravnborg 2890e279b6c1SSam Ravnborg 2891e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2892e5beae16SKeith Packard def_bool y 2893e5beae16SKeith Packard depends on X86_32 2894e5beae16SKeith Packard 2895edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28965e8ebd84SJason A. Donenfeld 28975e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2898