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 641e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 6591024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM) 6691024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 67cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 681e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 6991dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 70c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 71fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 72399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 7321266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 74b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 756471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 7672d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 77316d097cSDave Hansen select ARCH_HAS_FILTER_PGPROT 786974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 79957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 800f1441b4SPeter Zijlstra select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 810c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 8210bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 830ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 84c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 8517596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 863010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 870aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 88ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 89d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 90d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 91ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 92ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 93ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 9425c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 95c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 967e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 9763703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 986471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 996471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10077fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1015e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1023599fe12SThomas Gleixner select ARCH_STACKWALK 1032c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1046471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1055d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 1066471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 10714df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 108583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 109583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1106471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 111dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1126471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1136471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1142ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 115ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 11681c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 117c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 11851c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 1193876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 12059612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 12138d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 122b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 12310916706SShile Zhang select BUILDTIME_TABLE_SORT 1246471b825SIngo Molnar select CLKEVT_I8253 1256471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1266471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1276471b825SIngo Molnar select DCACHE_WORD_ACCESS 12845471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 12945471cd9SLinus Torvalds select EDAC_SUPPORT 1306471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1316471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1326471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1336471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 13461dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1356471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 13627d6b4d1SThomas Gleixner select GENERIC_ENTRY 1376471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 1386471b825SIngo Molnar select GENERIC_IOMAP 139c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1400fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 141ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1426471b825SIngo Molnar select GENERIC_IRQ_PROBE 143c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1446471b825SIngo Molnar select GENERIC_IRQ_SHOW 1456471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1462ae27137SSteven Price select GENERIC_PTDUMP 1476471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1486471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1497ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 150550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 15139656e83SChristoph Hellwig select GUP_GET_PTE_LOW_HIGH if X86_PAE 15217e5888eSHans de Goede select HARDIRQS_SW_RESEND 1537edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 1546471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1556471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1566471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1576471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1586471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 1596471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 160b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 161d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1620609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1631dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1646471b825SIngo Molnar select HAVE_ARCH_KGDB 1659e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1669e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1671b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 168271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1696471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 170f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 171afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1726471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1736471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 174a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 175b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1767677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 177e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 178fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 179c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1802ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1816471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1826471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1836471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 184d1f250e2SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 1856471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1866dafca97SSami Tolvanen select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION 1876471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1889c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 189677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 19006aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 19102a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 192562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 19303f5781bSWang YanQing select HAVE_EBPF_JIT 19458340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1956630a8e5SChristoph Hellwig select HAVE_EISA 1965f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 19767a929e0SChristoph Hellwig select HAVE_FAST_GUP 198644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 1996471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 2006471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 2016471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2026b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2030067f129SK.Prasad select HAVE_HW_BREAKPOINT 2046471b825SIngo Molnar select HAVE_IOREMAP_PROT 205624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2066471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2076471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2086471b825SIngo Molnar select HAVE_KERNEL_GZIP 2096471b825SIngo Molnar select HAVE_KERNEL_LZ4 2106471b825SIngo Molnar select HAVE_KERNEL_LZMA 2116471b825SIngo Molnar select HAVE_KERNEL_LZO 2126471b825SIngo Molnar select HAVE_KERNEL_XZ 213fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2146471b825SIngo Molnar select HAVE_KPROBES 2156471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 216540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2176471b825SIngo Molnar select HAVE_KRETPROBES 2186471b825SIngo Molnar select HAVE_KVM 2196471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2200102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 221ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2229f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 223be37c98dSKalesh Singh select HAVE_MOVE_PUD 22442a0bb3fSPetr Mladek select HAVE_NMI 2256471b825SIngo Molnar select HAVE_OPTPROBES 2266471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2276471b825SIngo Molnar select HAVE_PERF_EVENTS 228c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 22992e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 230eb01d42aSChristoph Hellwig select HAVE_PCI 231c5e63197SJiri Olsa select HAVE_PERF_REGS 232c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 233ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 23400998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2356471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 2366415b38bSJiri Slaby select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 2373c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 238cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 239d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 240c763ea26SIngo Molnar select HAVE_STACK_VALIDATION if X86_64 241e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 2421e7e4788SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 2436ef869e0SMichal Hocko select HAVE_PREEMPT_DYNAMIC 244d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2456471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2466471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2477c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2487ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 24905736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 250c0185808SThomas Gleixner select IRQ_FORCED_THREADING 25186596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2522eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 253625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2546471b825SIngo Molnar select PERF_EVENTS 2553195ef59SPrarit Bhargava select RTC_LIB 256d6faca40SArnd Bergmann select RTC_MC146818_LIB 2576471b825SIngo Molnar select SPARSE_IRQ 25883fe27eaSPranith Kumar select SRCU 2591e7e4788SJosh Poimboeuf select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 2606471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 26115f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2624aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2636471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2646471b825SIngo Molnar select VIRT_TO_BUS 2653b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2666471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2670c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 2689e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2697d8330a5SBalbir Singh 270ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2713120e25eSJan Beulich def_bool y 2723120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 273ba7e4d13SIngo Molnar 27451b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 27551b26adaSLinus Torvalds string 27651b26adaSLinus Torvalds default "elf32-i386" if X86_32 27751b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 27851b26adaSLinus Torvalds 2798d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2803c2362e6SHarvey Harrison def_bool y 2818d5fffb9SSam Ravnborg 2828d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2833c2362e6SHarvey Harrison def_bool y 2848d5fffb9SSam Ravnborg 2858d5fffb9SSam Ravnborgconfig MMU 2863c2362e6SHarvey Harrison def_bool y 2878d5fffb9SSam Ravnborg 2889e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 2899e08f57dSDaniel Cashman default 28 if 64BIT 2909e08f57dSDaniel Cashman default 8 2919e08f57dSDaniel Cashman 2929e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 2939e08f57dSDaniel Cashman default 32 if 64BIT 2949e08f57dSDaniel Cashman default 16 2959e08f57dSDaniel Cashman 2969e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 2979e08f57dSDaniel Cashman default 8 2989e08f57dSDaniel Cashman 2999e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3009e08f57dSDaniel Cashman default 16 3019e08f57dSDaniel Cashman 3028d5fffb9SSam Ravnborgconfig SBUS 3038d5fffb9SSam Ravnborg bool 3048d5fffb9SSam Ravnborg 3058d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3063120e25eSJan Beulich def_bool y 3073120e25eSJan Beulich depends on ISA_DMA_API 3088d5fffb9SSam Ravnborg 3098d5fffb9SSam Ravnborgconfig GENERIC_BUG 3103c2362e6SHarvey Harrison def_bool y 3118d5fffb9SSam Ravnborg depends on BUG 312b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 313b93a531eSJan Beulich 314b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 315b93a531eSJan Beulich bool 3168d5fffb9SSam Ravnborg 3178d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3183120e25eSJan Beulich def_bool y 3193120e25eSJan Beulich depends on ISA_DMA_API 3208d5fffb9SSam Ravnborg 3211032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3221032c0baSSam Ravnborg def_bool y 3231032c0baSSam Ravnborg 3249a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3259a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3268d5fffb9SSam Ravnborg 327316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT 328316d097cSDave Hansen def_bool y 329316d097cSDave Hansen 330dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 33189c9c4c5SBrian Gerst def_bool y 332b32ef636Stravis@sgi.com 33308fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 33408fc4580STejun Heo def_bool y 33508fc4580STejun Heo 33608fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 33711124411STejun Heo def_bool y 33811124411STejun Heo 339801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 340801e4062SJohannes Berg def_bool y 341801e4062SJohannes Berg 342d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 343d7109fe3SAndy Shevchenko int 344d7109fe3SAndy Shevchenko default 1024 if X86_64 345d7109fe3SAndy Shevchenko default 512 346d7109fe3SAndy Shevchenko 347f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 348f4cb5700SJohannes Berg def_bool y 349f4cb5700SJohannes Berg 35053313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 35153313b2cSSteve Capper def_bool y 35253313b2cSSteve Capper 3538d5fffb9SSam Ravnborgconfig AUDIT_ARCH 354e0fd24a3SJan Beulich def_bool y if X86_64 3558d5fffb9SSam Ravnborg 356d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 357d6f2d75aSAndrey Ryabinin hex 358d6f2d75aSAndrey Ryabinin depends on KASAN 359d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 360d6f2d75aSAndrey Ryabinin 36169575d38SShane Wangconfig HAVE_INTEL_TXT 36269575d38SShane Wang def_bool y 3636ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36469575d38SShane Wang 3656b0c3d44SSam Ravnborgconfig X86_32_SMP 3666b0c3d44SSam Ravnborg def_bool y 3676b0c3d44SSam Ravnborg depends on X86_32 && SMP 3686b0c3d44SSam Ravnborg 3696b0c3d44SSam Ravnborgconfig X86_64_SMP 3706b0c3d44SSam Ravnborg def_bool y 3716b0c3d44SSam Ravnborg depends on X86_64 && SMP 3726b0c3d44SSam Ravnborg 3732b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3742b144498SSrikar Dronamraju def_bool y 3752b144498SSrikar Dronamraju 376d20642f0SRob Herringconfig FIX_EARLYCON_MEM 377d20642f0SRob Herring def_bool y 378d20642f0SRob Herring 37994d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 38094d49eb3SKirill A. Shutemov bool 38194d49eb3SKirill A. Shutemov 38298233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38398233368SKirill A. Shutemov int 38477ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38598233368SKirill A. Shutemov default 4 if X86_64 38698233368SKirill A. Shutemov default 3 if X86_PAE 38798233368SKirill A. Shutemov default 2 38898233368SKirill A. Shutemov 3892a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3902a61f474SMasahiro Yamada bool 3912a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3922a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3932a61f474SMasahiro Yamada help 3942a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3953fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 3963fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 3972a61f474SMasahiro Yamada 398506f1d07SSam Ravnborgmenu "Processor type and features" 399506f1d07SSam Ravnborg 400506f1d07SSam Ravnborgconfig SMP 401506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 402a7f7f624SMasahiro Yamada help 403506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4044a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4054a474157SRobert Graffham than one CPU, say Y. 406506f1d07SSam Ravnborg 4074a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 408506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 409506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4104a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 411506f1d07SSam Ravnborg will run faster if you say N here. 412506f1d07SSam Ravnborg 413506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 414506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 415506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 416506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 417506f1d07SSam Ravnborg 418506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 419506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 420506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 421506f1d07SSam Ravnborg 422cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4234f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 424506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 425506f1d07SSam Ravnborg 426506f1d07SSam Ravnborg If you don't know what to do here, say N. 427506f1d07SSam Ravnborg 4289def39beSJosh Triplettconfig X86_FEATURE_NAMES 4299def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4309def39beSJosh Triplett default y 431a7f7f624SMasahiro Yamada help 4329def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4339def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4349def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4359def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4369def39beSJosh Triplett 4379def39beSJosh Triplett If in doubt, say Y. 4389def39beSJosh Triplett 43906cd9a7dSYinghai Luconfig X86_X2APIC 44006cd9a7dSYinghai Lu bool "Support x2apic" 44119e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 442a7f7f624SMasahiro Yamada help 44306cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44406cd9a7dSYinghai Lu 44506cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44606cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 44706cd9a7dSYinghai Lu 44806cd9a7dSYinghai Lu If you don't know what to do here, say N. 44906cd9a7dSYinghai Lu 4506695c85bSYinghai Luconfig X86_MPPARSE 4514590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4527a527688SJan Beulich default y 4535ab74722SIngo Molnar depends on X86_LOCAL_APIC 454a7f7f624SMasahiro Yamada help 4556695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4566695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4576695c85bSYinghai Lu 458ddd70cf9SJun Nakajimaconfig GOLDFISH 459ddd70cf9SJun Nakajima def_bool y 460ddd70cf9SJun Nakajima depends on X86_GOLDFISH 461ddd70cf9SJun Nakajima 46276b04384SDavid Woodhouseconfig RETPOLINE 46376b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 46476b04384SDavid Woodhouse default y 46576b04384SDavid Woodhouse help 46676b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 46776b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 46876b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 46976b04384SDavid Woodhouse support for full protection. The kernel may run slower. 47076b04384SDavid Woodhouse 471e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 472e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4736fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 47459fe5a77SThomas Gleixner select KERNFS 475e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 47678e99b4aSFenghua Yu help 477e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4786fe07ce3SBabu Moger 4796fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4806fe07ce3SBabu Moger usage by the CPU. 4816fe07ce3SBabu Moger 4826fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4836fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4846fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4856fe07ce3SBabu Moger 4866fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4876fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4886fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 48978e99b4aSFenghua Yu 49078e99b4aSFenghua Yu Say N if unsure. 49178e99b4aSFenghua Yu 4928425091fSRavikiran G Thirumalaiif X86_32 493a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 494a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 495a0d0bb4dSRandy Dunlap depends on SMP 496a7f7f624SMasahiro Yamada help 497e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 498a0d0bb4dSRandy Dunlap 499c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 500c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 501c5c606d9SRavikiran G Thirumalai default y 502a7f7f624SMasahiro Yamada help 50306ac8346SIngo Molnar If you disable this option then the kernel will only support 50406ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 50506ac8346SIngo Molnar systems out there.) 50606ac8346SIngo Molnar 5078425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5088425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 509cb7b8023SBen Hutchings Goldfish (Android emulator) 5108425091fSRavikiran G Thirumalai AMD Elan 5118425091fSRavikiran G Thirumalai RDC R-321x SoC 5128425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 51383125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5143f4110a4SThomas Gleixner Moorestown MID devices 51506ac8346SIngo Molnar 51606ac8346SIngo Molnar If you have one of these systems, or if you want to build a 51706ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5188425091fSRavikiran G Thirumalaiendif 51906ac8346SIngo Molnar 5208425091fSRavikiran G Thirumalaiif X86_64 5218425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5228425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5238425091fSRavikiran G Thirumalai default y 524a7f7f624SMasahiro Yamada help 5258425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5268425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5278425091fSRavikiran G Thirumalai systems out there.) 5288425091fSRavikiran G Thirumalai 5298425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5308425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 53144b111b5SSteffen Persvold Numascale NumaChip 5328425091fSRavikiran G Thirumalai ScaleMP vSMP 5338425091fSRavikiran G Thirumalai SGI Ultraviolet 5348425091fSRavikiran G Thirumalai 5358425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5368425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5378425091fSRavikiran G Thirumalaiendif 538c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 539c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 54044b111b5SSteffen Persvoldconfig X86_NUMACHIP 54144b111b5SSteffen Persvold bool "Numascale NumaChip" 54244b111b5SSteffen Persvold depends on X86_64 54344b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 54444b111b5SSteffen Persvold depends on NUMA 54544b111b5SSteffen Persvold depends on SMP 54644b111b5SSteffen Persvold depends on X86_X2APIC 547f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 548a7f7f624SMasahiro Yamada help 54944b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 55044b111b5SSteffen Persvold enable more than ~168 cores. 55144b111b5SSteffen Persvold If you don't have one of these, you should say N here. 55203b48632SNick Piggin 5536a48565eSIngo Molnarconfig X86_VSMP 554c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5556276a074SBorislav Petkov select HYPERVISOR_GUEST 5566a48565eSIngo Molnar select PARAVIRT 5576a48565eSIngo Molnar depends on X86_64 && PCI 558c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 559ead91d4bSShai Fultheim depends on SMP 560a7f7f624SMasahiro Yamada help 5616a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5626a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5636a48565eSIngo Molnar if you have one of these machines. 5646a48565eSIngo Molnar 565c5c606d9SRavikiran G Thirumalaiconfig X86_UV 566c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 567c5c606d9SRavikiran G Thirumalai depends on X86_64 568c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 56954c28d29SJack Steiner depends on NUMA 5701ecb4ae5SAndrew Morton depends on EFI 571c2209ea5SIngo Molnar depends on KEXEC_CORE 5729d6c26e7SSuresh Siddha depends on X86_X2APIC 5731222e564SIngo Molnar depends on PCI 574a7f7f624SMasahiro Yamada help 575c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 576c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 577c5c606d9SRavikiran G Thirumalai 578c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 579c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 580506f1d07SSam Ravnborg 581ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 582ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 583cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 584a7f7f624SMasahiro Yamada help 585ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 586ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 587ddd70cf9SJun Nakajima Goldfish emulator say N here. 588ddd70cf9SJun Nakajima 589c751e17bSThomas Gleixnerconfig X86_INTEL_CE 590c751e17bSThomas Gleixner bool "CE4100 TV platform" 591c751e17bSThomas Gleixner depends on PCI 592c751e17bSThomas Gleixner depends on PCI_GODIRECT 5936084a6e2SJiang Liu depends on X86_IO_APIC 594c751e17bSThomas Gleixner depends on X86_32 595c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 59637bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 597da6b737bSSebastian Andrzej Siewior select OF 598da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 599a7f7f624SMasahiro Yamada help 600c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 601c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 602c751e17bSThomas Gleixner boxes and media devices. 603c751e17bSThomas Gleixner 6044cb9b00fSDavid Cohenconfig X86_INTEL_MID 60543605ef1SAlan Cox bool "Intel MID platform support" 60643605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 607edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6081ea7c673SAlan Cox depends on PCI 6093fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6101ea7c673SAlan Cox depends on X86_IO_APIC 6114cb9b00fSDavid Cohen select I2C 6127c9c3a1eSAlan Cox select DW_APB_TIMER 6131ea7c673SAlan Cox select APB_TIMER 61454b34aa0SMika Westerberg select INTEL_SCU_PCI 61515a713dfSMika Westerberg select MFD_INTEL_MSIC 616a7f7f624SMasahiro Yamada help 6174cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6184cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6194cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6201ea7c673SAlan Cox 6214cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6224cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 62343605ef1SAlan Cox 6248bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6258bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6268bbc2a13SBryan O'Donoghue depends on X86_32 6278bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6288bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6298bbc2a13SBryan O'Donoghue depends on X86_TSC 6308bbc2a13SBryan O'Donoghue depends on PCI 6318bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6328bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6338bbc2a13SBryan O'Donoghue select IOSF_MBI 6348bbc2a13SBryan O'Donoghue select INTEL_IMR 6359ab6eb51SAndy Shevchenko select COMMON_CLK 636a7f7f624SMasahiro Yamada help 6378bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6388bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6398bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6408bbc2a13SBryan O'Donoghue 6413d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6423d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6435962dd22SSinan Kaya depends on X86 && ACPI && PCI 6443d48aab1SMika Westerberg select COMMON_CLK 6450f531431SMathias Nyman select PINCTRL 646eebb3e8dSAndy Shevchenko select IOSF_MBI 647a7f7f624SMasahiro Yamada help 6483d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6493d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6500f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6510f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6523d48aab1SMika Westerberg 65392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 65492082a88SKen Xue bool "AMD ACPI2Platform devices support" 65592082a88SKen Xue depends on ACPI 65692082a88SKen Xue select COMMON_CLK 65792082a88SKen Xue select PINCTRL 658a7f7f624SMasahiro Yamada help 65992082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 66092082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 66192082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 66292082a88SKen Xue implemented under PINCTRL subsystem. 66392082a88SKen Xue 664ced3ce76SDavid E. Boxconfig IOSF_MBI 665ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 666ced3ce76SDavid E. Box depends on PCI 667a7f7f624SMasahiro Yamada help 668ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 669ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 670ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 671ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 672ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 673ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 674ced3ce76SDavid E. Box This list is not meant to be exclusive. 675ced3ce76SDavid E. Box - BayTrail 676ced3ce76SDavid E. Box - Braswell 677ced3ce76SDavid E. Box - Quark 678ced3ce76SDavid E. Box 679ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 680ced3ce76SDavid E. Box 681ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 682ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 683ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 684a7f7f624SMasahiro Yamada help 685ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 686ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 687ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 688ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 689ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 690ed2226bdSDavid E. Box device they want to access. 691ed2226bdSDavid E. Box 692ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 693ed2226bdSDavid E. Box 694c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 695c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 696506f1d07SSam Ravnborg depends on X86_32 697c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 698c5c606d9SRavikiran G Thirumalai select M486 699c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 700a7f7f624SMasahiro Yamada help 701c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 702c5c606d9SRavikiran G Thirumalai as R-8610-(G). 703c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 704c5c606d9SRavikiran G Thirumalai 705e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7069c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7079c398017SIngo Molnar depends on X86_32 && SMP 708c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 709a7f7f624SMasahiro Yamada help 710b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 711b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 712b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 713b5660ba7SH. Peter Anvin one and will fallback to default. 714d49c4288SYinghai Lu 715c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 716d49c4288SYinghai Lu 717d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7186fc108a0SJan Beulich def_bool y 719d949f36fSLinus Torvalds # MCE code calls memory_failure(): 720d949f36fSLinus Torvalds depends on X86_MCE 721d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 722d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 723d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 724d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 725d949f36fSLinus Torvalds 72683125a3aSAlessandro Rubiniconfig STA2X11 72783125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 72883125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 72983125a3aSAlessandro Rubini select SWIOTLB 73083125a3aSAlessandro Rubini select MFD_STA2X11 7310145071bSLinus Walleij select GPIOLIB 732a7f7f624SMasahiro Yamada help 73383125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 73483125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 73583125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 73683125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 73783125a3aSAlessandro Rubini standard PC machines. 73883125a3aSAlessandro Rubini 73982148d1dSShérabconfig X86_32_IRIS 74082148d1dSShérab tristate "Eurobraille/Iris poweroff module" 74182148d1dSShérab depends on X86_32 742a7f7f624SMasahiro Yamada help 74382148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 74482148d1dSShérab to shut themselves down properly. A special I/O sequence is 74582148d1dSShérab needed to do so, which is what this module does at 74682148d1dSShérab kernel shutdown. 74782148d1dSShérab 74882148d1dSShérab This is only for Iris machines from EuroBraille. 74982148d1dSShérab 75082148d1dSShérab If unused, say N. 75182148d1dSShérab 752ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7533c2362e6SHarvey Harrison def_bool y 7543c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 755a87d0914SKen Chen depends on X86 756a7f7f624SMasahiro Yamada help 757506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 758506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 759506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 760506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 761506f1d07SSam Ravnborg 762506f1d07SSam Ravnborg If in doubt, say "Y". 763506f1d07SSam Ravnborg 7646276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7656276a074SBorislav Petkov bool "Linux guest support" 766a7f7f624SMasahiro Yamada help 7676276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7686276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7696276a074SBorislav Petkov setup. 770506f1d07SSam Ravnborg 7716276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7726276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 773506f1d07SSam Ravnborg 7746276a074SBorislav Petkovif HYPERVISOR_GUEST 775506f1d07SSam Ravnborg 776e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 777e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 778a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 779a7f7f624SMasahiro Yamada help 780e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 781e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 782e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 783e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 784e61bd94aSEduardo Pereira Habkost 785c00a280aSJuergen Grossconfig PARAVIRT_XXL 786c00a280aSJuergen Gross bool 787c00a280aSJuergen Gross 7886276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7896276a074SBorislav Petkov bool "paravirt-ops debugging" 7906276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 791a7f7f624SMasahiro Yamada help 7926276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7936276a074SBorislav Petkov a paravirt_op is missing when it is called. 7946276a074SBorislav Petkov 795b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 796b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7976ea30386SKees Cook depends on PARAVIRT && SMP 798a7f7f624SMasahiro Yamada help 799b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 800b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 801b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 802b4ecc126SJeremy Fitzhardinge 8034c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8044c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 805b4ecc126SJeremy Fitzhardinge 8064c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 807b4ecc126SJeremy Fitzhardinge 808ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 809ecca2502SZhao Yakui def_bool n 810ecca2502SZhao Yakui 8116276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8126276a074SBorislav Petkov 8136276a074SBorislav Petkovconfig KVM_GUEST 8146276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8156276a074SBorislav Petkov depends on PARAVIRT 8166276a074SBorislav Petkov select PARAVIRT_CLOCK 817a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 818b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8196276a074SBorislav Petkov default y 820a7f7f624SMasahiro Yamada help 8216276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8226276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8236276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8246276a074SBorislav Petkov underlying device model, the host provides the guest with 8256276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8266276a074SBorislav Petkov 827a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 828a1c4423bSMarcelo Tosatti def_bool n 829a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 830a1c4423bSMarcelo Tosatti help 831a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 832a1c4423bSMarcelo Tosatti 8337733607fSMaran Wilsonconfig PVH 8347733607fSMaran Wilson bool "Support for running PVH guests" 835a7f7f624SMasahiro Yamada help 8367733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8377733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8387733607fSMaran Wilson 8396276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8406276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8416276a074SBorislav Petkov depends on PARAVIRT 842a7f7f624SMasahiro Yamada help 8436276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8446276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8456276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8466276a074SBorislav Petkov that, there can be a small performance impact. 8476276a074SBorislav Petkov 8486276a074SBorislav Petkov If in doubt, say N here. 8496276a074SBorislav Petkov 8507af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8517af192c9SGerd Hoffmann bool 8527af192c9SGerd Hoffmann 8534a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8544a362601SJan Kiszka bool "Jailhouse non-root cell support" 855abde587bSArnd Bergmann depends on X86_64 && PCI 85687e65d05SJan Kiszka select X86_PM_TIMER 857a7f7f624SMasahiro Yamada help 8584a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8594a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8604a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8614a362601SJan Kiszka 862ec7972c9SZhao Yakuiconfig ACRN_GUEST 863ec7972c9SZhao Yakui bool "ACRN Guest support" 864ec7972c9SZhao Yakui depends on X86_64 865498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 866ec7972c9SZhao Yakui help 867ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 868ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 869ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 870ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 871ec7972c9SZhao Yakui found in https://projectacrn.org/. 872ec7972c9SZhao Yakui 8736276a074SBorislav Petkovendif #HYPERVISOR_GUEST 87497349135SJeremy Fitzhardinge 875506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 876506f1d07SSam Ravnborg 877506f1d07SSam Ravnborgconfig HPET_TIMER 8783c2362e6SHarvey Harrison def_bool X86_64 879506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 880a7f7f624SMasahiro Yamada help 881506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 882506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 883506f1d07SSam Ravnborg present. 884506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 885506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 886506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8874e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8884e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 889506f1d07SSam Ravnborg 890506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 891506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 892506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 893506f1d07SSam Ravnborg 894506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 895506f1d07SSam Ravnborg 896506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8973c2362e6SHarvey Harrison def_bool y 8983228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 899506f1d07SSam Ravnborg 9006a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 901506f1d07SSam Ravnborg# The code disables itself when not needed. 9027ae9392cSThomas Petazzoniconfig DMI 9037ae9392cSThomas Petazzoni default y 904cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9056a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 906a7f7f624SMasahiro Yamada help 9077ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9087ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9097ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9107ae9392cSThomas Petazzoni BIOS code. 9117ae9392cSThomas Petazzoni 912506f1d07SSam Ravnborgconfig GART_IOMMU 91338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9142f9237d4SChristoph Hellwig select DMA_OPS 915a4ce5a48SChristoph Hellwig select IOMMU_HELPER 916506f1d07SSam Ravnborg select SWIOTLB 91723ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 918a7f7f624SMasahiro Yamada help 919ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 920ced3c42cSIngo Molnar GART based hardware IOMMUs. 921ced3c42cSIngo Molnar 922ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 923ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 924ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 925ced3c42cSIngo Molnar 926ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 927ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 928ced3c42cSIngo Molnar 929ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 930ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 931ced3c42cSIngo Molnar 32-bit limited device. 932ced3c42cSIngo Molnar 933ced3c42cSIngo Molnar If unsure, say Y. 934506f1d07SSam Ravnborg 9351184dc2fSMike Travisconfig MAXSMP 936ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9376ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 93836f5101aSMike Travis select CPUMASK_OFFSTACK 939a7f7f624SMasahiro Yamada help 940ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9411184dc2fSMike Travis If unsure, say N. 942506f1d07SSam Ravnborg 943aec6487eSIngo Molnar# 944aec6487eSIngo Molnar# The maximum number of CPUs supported: 945aec6487eSIngo Molnar# 946aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 947aec6487eSIngo Molnar# and which can be configured interactively in the 948aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 949aec6487eSIngo Molnar# 950aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 951aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 952aec6487eSIngo Molnar# 953aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 954aec6487eSIngo Molnar# interactive configuration. ) 955aec6487eSIngo Molnar# 956a0d0bb4dSRandy Dunlap 957aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 958a0d0bb4dSRandy Dunlap int 959aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 960a0d0bb4dSRandy Dunlap default 1 if !SMP 961a0d0bb4dSRandy Dunlap default 2 962a0d0bb4dSRandy Dunlap 963aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 964a0d0bb4dSRandy Dunlap int 965a0d0bb4dSRandy Dunlap depends on X86_32 966aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 967aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 968a0d0bb4dSRandy Dunlap default 1 if !SMP 969a0d0bb4dSRandy Dunlap 970aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 971a0d0bb4dSRandy Dunlap int 972a0d0bb4dSRandy Dunlap depends on X86_64 9731edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9741edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 975a0d0bb4dSRandy Dunlap default 1 if !SMP 976aec6487eSIngo Molnar 977aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 978aec6487eSIngo Molnar int 979aec6487eSIngo Molnar depends on X86_32 980aec6487eSIngo Molnar default 32 if X86_BIGSMP 981aec6487eSIngo Molnar default 8 if SMP 982aec6487eSIngo Molnar default 1 if !SMP 983aec6487eSIngo Molnar 984aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 985aec6487eSIngo Molnar int 986aec6487eSIngo Molnar depends on X86_64 987a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 988a0d0bb4dSRandy Dunlap default 64 if SMP 989aec6487eSIngo Molnar default 1 if !SMP 990a0d0bb4dSRandy Dunlap 991506f1d07SSam Ravnborgconfig NR_CPUS 99236f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 993aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 994aec6487eSIngo Molnar default NR_CPUS_DEFAULT 995a7f7f624SMasahiro Yamada help 996506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 997bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 998cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 999506f1d07SSam Ravnborg minimum value which makes sense is 2. 1000506f1d07SSam Ravnborg 1001aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1002aec6487eSIngo Molnar to the kernel image. 1003506f1d07SSam Ravnborg 1004506f1d07SSam Ravnborgconfig SCHED_SMT 1005dbe73364SThomas Gleixner def_bool y if SMP 1006506f1d07SSam Ravnborg 1007506f1d07SSam Ravnborgconfig SCHED_MC 10083c2362e6SHarvey Harrison def_bool y 10093c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1010c8e56d20SBorislav Petkov depends on SMP 1011a7f7f624SMasahiro Yamada help 1012506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1013506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1014506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1015506f1d07SSam Ravnborg 1016de966cf4STim Chenconfig SCHED_MC_PRIO 1017de966cf4STim Chen bool "CPU core priorities scheduler support" 10180a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10190a21fc12SIngo Molnar select X86_INTEL_PSTATE 10200a21fc12SIngo Molnar select CPU_FREQ 1021de966cf4STim Chen default y 1022a7f7f624SMasahiro Yamada help 1023de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1024de966cf4STim Chen core ordering determined at manufacturing time, which allows 1025de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1026de966cf4STim Chen single threaded workloads) than others. 1027de966cf4STim Chen 1028de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1029de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1030de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1031de966cf4STim Chen overall system performance can be achieved. 1032de966cf4STim Chen 1033de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1034de966cf4STim Chen 1035de966cf4STim Chen If unsure say Y here. 10365e76b2abSTim Chen 103730b8b006SThomas Gleixnerconfig UP_LATE_INIT 103830b8b006SThomas Gleixner def_bool y 1039ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 104030b8b006SThomas Gleixner 1041506f1d07SSam Ravnborgconfig X86_UP_APIC 104250849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 104350849eefSJan Beulich default PCI_MSI 104438a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1045a7f7f624SMasahiro Yamada help 1046506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1047506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1048506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1049506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1050506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1051506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1052506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1053506f1d07SSam Ravnborg lockups. 1054506f1d07SSam Ravnborg 1055506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1056506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1057506f1d07SSam Ravnborg depends on X86_UP_APIC 1058a7f7f624SMasahiro Yamada help 1059506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1060506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1061506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1062506f1d07SSam Ravnborg 1063506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1064506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1065506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1066506f1d07SSam Ravnborg 1067506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10683c2362e6SHarvey Harrison def_bool y 10690dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1070b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 107152f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1072506f1d07SSam Ravnborg 1073506f1d07SSam Ravnborgconfig X86_IO_APIC 1074b1da1e71SJan Beulich def_bool y 1075b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1076506f1d07SSam Ravnborg 107741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 107841b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 107941b9eb26SStefan Assmann depends on X86_IO_APIC 1080a7f7f624SMasahiro Yamada help 108141b9eb26SStefan Assmann This option enables a workaround that fixes a source of 108241b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 108341b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 108441b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 108541b9eb26SStefan Assmann 108641b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 108741b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 108841b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 108941b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 109041b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 109141b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 109241b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 109341b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 109441b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 109541b9eb26SStefan Assmann down (vital) interrupt lines. 109641b9eb26SStefan Assmann 109741b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 109841b9eb26SStefan Assmann increased on these systems. 109941b9eb26SStefan Assmann 1100506f1d07SSam Ravnborgconfig X86_MCE 1101bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1102648ed940SChen, Gong select GENERIC_ALLOCATOR 1103e57dbaf7SBorislav Petkov default y 1104a7f7f624SMasahiro Yamada help 1105bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1106bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1107506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1108bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11094efc0670SAndi Kleen 11105de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11115de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11125de97c9fSTony Luck depends on X86_MCE 1113a7f7f624SMasahiro Yamada help 11145de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11155de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11165de97c9fSTony Luck rasdaemon solution. 11175de97c9fSTony Luck 1118506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11193c2362e6SHarvey Harrison def_bool y 11203c2362e6SHarvey Harrison prompt "Intel MCE features" 1121c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1122a7f7f624SMasahiro Yamada help 1123506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1124506f1d07SSam Ravnborg the thermal monitor. 1125506f1d07SSam Ravnborg 1126506f1d07SSam Ravnborgconfig X86_MCE_AMD 11273c2362e6SHarvey Harrison def_bool y 11283c2362e6SHarvey Harrison prompt "AMD MCE features" 1129f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1130a7f7f624SMasahiro Yamada help 1131506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1132506f1d07SSam Ravnborg the DRAM Error Threshold. 1133506f1d07SSam Ravnborg 11344efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11356fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1136c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1137a7f7f624SMasahiro Yamada help 11384efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11395065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11404efc0670SAndi Kleen line. 11414efc0670SAndi Kleen 1142b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1143b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11446fc108a0SJan Beulich def_bool y 1145b2762686SAndi Kleen 1146ea149b36SAndi Kleenconfig X86_MCE_INJECT 1147bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1148ea149b36SAndi Kleen tristate "Machine check injector support" 1149a7f7f624SMasahiro Yamada help 1150ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1151ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1152ea149b36SAndi Kleen QA it is safe to say n. 1153ea149b36SAndi Kleen 115407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1155e633c65aSKan Liang 11565aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11571e642812SIngo Molnar bool "Legacy VM86 support" 1158506f1d07SSam Ravnborg depends on X86_32 1159a7f7f624SMasahiro Yamada help 11605aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11615aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11625aef51c3SAndy Lutomirski 11635aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11645aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11655aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11665aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11675aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11681e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11691e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11701e642812SIngo Molnar mode might be faster than emulation and you might want to 11711e642812SIngo Molnar enable this option. 11725aef51c3SAndy Lutomirski 11731e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11741e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11751e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 11761e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 11775aef51c3SAndy Lutomirski 11781e642812SIngo Molnar Enabling this option increases the complexity of the kernel 11791e642812SIngo Molnar and slows down exception handling a tiny bit. 11805aef51c3SAndy Lutomirski 11811e642812SIngo Molnar If unsure, say N here. 11825aef51c3SAndy Lutomirski 11835aef51c3SAndy Lutomirskiconfig VM86 11845aef51c3SAndy Lutomirski bool 11855aef51c3SAndy Lutomirski default X86_LEGACY_VM86 118634273f41SH. Peter Anvin 118734273f41SH. Peter Anvinconfig X86_16BIT 118834273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 118934273f41SH. Peter Anvin default y 1190a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1191a7f7f624SMasahiro Yamada help 119234273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 119334273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 119434273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 119534273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 119634273f41SH. Peter Anvin 119734273f41SH. Peter Anvinconfig X86_ESPFIX32 119834273f41SH. Peter Anvin def_bool y 119934273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1200506f1d07SSam Ravnborg 1201197725deSH. Peter Anvinconfig X86_ESPFIX64 1202197725deSH. Peter Anvin def_bool y 120334273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1204506f1d07SSam Ravnborg 12051ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12061ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12071ad83c85SAndy Lutomirski default y 12081ad83c85SAndy Lutomirski depends on X86_64 1209a7f7f624SMasahiro Yamada help 12101ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12111ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12121ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12131ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12141ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12151ad83c85SAndy Lutomirski 0xffffffffff600?00. 12161ad83c85SAndy Lutomirski 12171ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12181ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12191ad83c85SAndy Lutomirski 12201ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12211ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12221ad83c85SAndy Lutomirski 1223111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1224111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1225a24ca997SThomas Gleixner default y 1226a7f7f624SMasahiro Yamada help 1227111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1228111e7b15SThomas Gleixner for legacy applications. 1229111e7b15SThomas Gleixner 1230c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1231c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1232c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1233c8137aceSThomas Gleixner capabilities and permission from potentially active security 1234c8137aceSThomas Gleixner modules. 1235c8137aceSThomas Gleixner 1236c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1237c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1238a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1239a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1240c8137aceSThomas Gleixner 1241506f1d07SSam Ravnborgconfig TOSHIBA 1242506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1243506f1d07SSam Ravnborg depends on X86_32 1244a7f7f624SMasahiro Yamada help 1245506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1246506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1247506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1248506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1249506f1d07SSam Ravnborg 1250506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1251506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1252506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1253506f1d07SSam Ravnborg 1254506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1255506f1d07SSam Ravnborg Say N otherwise. 1256506f1d07SSam Ravnborg 1257506f1d07SSam Ravnborgconfig I8K 1258039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1259*ef775a0eSRandy Dunlap depends on HWMON 1260*ef775a0eSRandy Dunlap depends on PROC_FS 1261039ae585SPali Rohár select SENSORS_DELL_SMM 1262a7f7f624SMasahiro Yamada help 1263039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1264039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1265039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1266039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1267039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1268039ae585SPali Rohár needed userspace package i8kutils. 1269506f1d07SSam Ravnborg 1270039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1271039ae585SPali Rohár use userspace package i8kutils. 1272506f1d07SSam Ravnborg Say N otherwise. 1273506f1d07SSam Ravnborg 1274506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12759ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12769ba16087SJan Beulich depends on X86_32 1277a7f7f624SMasahiro Yamada help 1278506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1279506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1280506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1281506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1282506f1d07SSam Ravnborg system. 1283506f1d07SSam Ravnborg 1284506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12855e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1286506f1d07SSam Ravnborg 1287506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1288506f1d07SSam Ravnborg enable this option even if you don't need it. 1289506f1d07SSam Ravnborg Say N otherwise. 1290506f1d07SSam Ravnborg 1291506f1d07SSam Ravnborgconfig MICROCODE 12929a2bc335SBorislav Petkov bool "CPU microcode loading support" 12939a2bc335SBorislav Petkov default y 129480030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1295a7f7f624SMasahiro Yamada help 1296506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 12975f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 12985f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 12995f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13005f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13015f9c01aaSBorislav Petkov the Linux kernel. 1302506f1d07SSam Ravnborg 13035f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1304cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13055f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13065f9c01aaSBorislav Petkov initrd for microcode blobs. 1307506f1d07SSam Ravnborg 1308c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1309c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1310c508c46eSBenjamin Gilbert config option. 1311506f1d07SSam Ravnborg 13128d86f390SPeter Orubaconfig MICROCODE_INTEL 1313e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13148d86f390SPeter Oruba depends on MICROCODE 13158d86f390SPeter Oruba default MICROCODE 1316a7f7f624SMasahiro Yamada help 13178d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13188d86f390SPeter Oruba processors. 13198d86f390SPeter Oruba 1320b8989db9SAlan For the current Intel microcode data package go to 1321b8989db9SAlan <https://downloadcenter.intel.com> and search for 1322b8989db9SAlan 'Linux Processor Microcode Data File'. 13238d86f390SPeter Oruba 132480cc9f10SPeter Orubaconfig MICROCODE_AMD 1325e43f6e67SBorislav Petkov bool "AMD microcode loading support" 132680cc9f10SPeter Oruba depends on MICROCODE 1327a7f7f624SMasahiro Yamada help 132880cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 132980cc9f10SPeter Oruba processors will be enabled. 133080cc9f10SPeter Oruba 1331506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1332c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1333c02f48e0SBorislav Petkov default n 1334506f1d07SSam Ravnborg depends on MICROCODE 1335a7f7f624SMasahiro Yamada help 1336c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1337c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1338c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1339c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1340c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1341cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1342506f1d07SSam Ravnborg 1343506f1d07SSam Ravnborgconfig X86_MSR 1344506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1345a7f7f624SMasahiro Yamada help 1346506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1347506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1348506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1349506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1350506f1d07SSam Ravnborg systems. 1351506f1d07SSam Ravnborg 1352506f1d07SSam Ravnborgconfig X86_CPUID 1353506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1354a7f7f624SMasahiro Yamada help 1355506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1356506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1357506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1358506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1359506f1d07SSam Ravnborg 1360506f1d07SSam Ravnborgchoice 1361506f1d07SSam Ravnborg prompt "High Memory Support" 13626fc108a0SJan Beulich default HIGHMEM4G 1363506f1d07SSam Ravnborg depends on X86_32 1364506f1d07SSam Ravnborg 1365506f1d07SSam Ravnborgconfig NOHIGHMEM 1366506f1d07SSam Ravnborg bool "off" 1367a7f7f624SMasahiro Yamada help 1368506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1369506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1370506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1371506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1372506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1373506f1d07SSam Ravnborg "high memory". 1374506f1d07SSam Ravnborg 1375506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1376506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1377506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1378506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1379506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1380506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1381506f1d07SSam Ravnborg possible. 1382506f1d07SSam Ravnborg 1383506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1384506f1d07SSam Ravnborg answer "4GB" here. 1385506f1d07SSam Ravnborg 1386506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1387506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1388506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1389506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1390506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1391506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1392506f1d07SSam Ravnborg 1393506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1394506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1395506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1396506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1397506f1d07SSam Ravnborg kernel at boot time.) 1398506f1d07SSam Ravnborg 1399506f1d07SSam Ravnborg If unsure, say "off". 1400506f1d07SSam Ravnborg 1401506f1d07SSam Ravnborgconfig HIGHMEM4G 1402506f1d07SSam Ravnborg bool "4GB" 1403a7f7f624SMasahiro Yamada help 1404506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1405506f1d07SSam Ravnborg gigabytes of physical RAM. 1406506f1d07SSam Ravnborg 1407506f1d07SSam Ravnborgconfig HIGHMEM64G 1408506f1d07SSam Ravnborg bool "64GB" 14090ef3439cSMaciej W. Rozycki depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1410506f1d07SSam Ravnborg select X86_PAE 1411a7f7f624SMasahiro Yamada help 1412506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1413506f1d07SSam Ravnborg gigabytes of physical RAM. 1414506f1d07SSam Ravnborg 1415506f1d07SSam Ravnborgendchoice 1416506f1d07SSam Ravnborg 1417506f1d07SSam Ravnborgchoice 14186a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1419506f1d07SSam Ravnborg default VMSPLIT_3G 1420506f1d07SSam Ravnborg depends on X86_32 1421a7f7f624SMasahiro Yamada help 1422506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1423506f1d07SSam Ravnborg 1424506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1425506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1426506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1427506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1428506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1429506f1d07SSam Ravnborg available to user programs, making the address space there 1430506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1431506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1432506f1d07SSam Ravnborg kernel modules. 1433506f1d07SSam Ravnborg 1434506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1435506f1d07SSam Ravnborg option alone! 1436506f1d07SSam Ravnborg 1437506f1d07SSam Ravnborg config VMSPLIT_3G 1438506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1439506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1440506f1d07SSam Ravnborg depends on !X86_PAE 1441506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1442506f1d07SSam Ravnborg config VMSPLIT_2G 1443506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1444506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1445506f1d07SSam Ravnborg depends on !X86_PAE 1446506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1447506f1d07SSam Ravnborg config VMSPLIT_1G 1448506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1449506f1d07SSam Ravnborgendchoice 1450506f1d07SSam Ravnborg 1451506f1d07SSam Ravnborgconfig PAGE_OFFSET 1452506f1d07SSam Ravnborg hex 1453506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1454506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1455506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1456506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1457506f1d07SSam Ravnborg default 0xC0000000 1458506f1d07SSam Ravnborg depends on X86_32 1459506f1d07SSam Ravnborg 1460506f1d07SSam Ravnborgconfig HIGHMEM 14613c2362e6SHarvey Harrison def_bool y 1462506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1463506f1d07SSam Ravnborg 1464506f1d07SSam Ravnborgconfig X86_PAE 14659ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1466506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1467d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14689d99c712SChristian Melki select SWIOTLB 1469a7f7f624SMasahiro Yamada help 1470506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1471506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1472506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1473506f1d07SSam Ravnborg consumes more pagetable space per process. 1474506f1d07SSam Ravnborg 147577ef56e4SKirill A. Shutemovconfig X86_5LEVEL 147677ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 147718ec1eafSKirill A. Shutemov default y 1478eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1479162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148077ef56e4SKirill A. Shutemov depends on X86_64 1481a7f7f624SMasahiro Yamada help 148277ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 148377ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 148477ef56e4SKirill A. Shutemov physical address space. 148577ef56e4SKirill A. Shutemov 148677ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 148777ef56e4SKirill A. Shutemov 14886657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14896657fca0SKirill A. Shutemov support 4- or 5-level paging. 149077ef56e4SKirill A. Shutemov 1491cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 149277ef56e4SKirill A. Shutemov information. 149377ef56e4SKirill A. Shutemov 149477ef56e4SKirill A. Shutemov Say N if unsure. 149577ef56e4SKirill A. Shutemov 149610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1497e5008abeSLuis R. Rodriguez def_bool y 14982e1da13fSVlastimil Babka depends on X86_64 1499a7f7f624SMasahiro Yamada help 150010971ab2SIngo Molnar Certain kernel features effectively disable kernel 150110971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 150210971ab2SIngo Molnar supports them), so don't confuse the user by printing 150310971ab2SIngo Molnar that we have them enabled. 15049e899816SNick Piggin 15055c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15065c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15075c280cf6SThomas Gleixner depends on DEBUG_FS 1508a7f7f624SMasahiro Yamada help 1509b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1510a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15115c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15125c280cf6SThomas Gleixner 15137744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15147744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15157744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 151682fef0adSDavid Rientjes select DMA_COHERENT_POOL 151794d49eb3SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 1518ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 15199087c375STom Lendacky select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1520597cfe48SJoerg Roedel select INSTRUCTION_DECODER 152122916417STom Lendacky select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 1522a7f7f624SMasahiro Yamada help 15237744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15247744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15257744ccdbSTom Lendacky Encryption (SME). 15267744ccdbSTom Lendacky 15277744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15287744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15297744ccdbSTom Lendacky default y 15307744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1531a7f7f624SMasahiro Yamada help 15327744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15337744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15347744ccdbSTom Lendacky 15357744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15367744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15377744ccdbSTom Lendacky 15387744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15397744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15407744ccdbSTom Lendacky 1541506f1d07SSam Ravnborg# Common NUMA Features 1542506f1d07SSam Ravnborgconfig NUMA 1543e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1544506f1d07SSam Ravnborg depends on SMP 1545b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1546b5660ba7SH. Peter Anvin default y if X86_BIGSMP 1547a7f7f624SMasahiro Yamada help 1548e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1549fd51b2d7SKOSAKI Motohiro 1550506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1551506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1552506f1d07SSam Ravnborg NUMA awareness to the kernel. 1553506f1d07SSam Ravnborg 1554c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1555fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1556fd51b2d7SKOSAKI Motohiro 1557b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15587cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1559fd51b2d7SKOSAKI Motohiro 1560fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1561506f1d07SSam Ravnborg 1562eec1d4faSHans Rosenfeldconfig AMD_NUMA 15633c2362e6SHarvey Harrison def_bool y 15643c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15655da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1566a7f7f624SMasahiro Yamada help 1567eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1568eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1569eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1570eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1571eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1572506f1d07SSam Ravnborg 1573506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15743c2362e6SHarvey Harrison def_bool y 15753c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1576506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1577506f1d07SSam Ravnborg select ACPI_NUMA 1578a7f7f624SMasahiro Yamada help 1579506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1580506f1d07SSam Ravnborg 1581506f1d07SSam Ravnborgconfig NUMA_EMU 1582506f1d07SSam Ravnborg bool "NUMA emulation" 15831b7e03efSTejun Heo depends on NUMA 1584a7f7f624SMasahiro Yamada help 1585506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1586506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1587506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1588506f1d07SSam Ravnborg 1589506f1d07SSam Ravnborgconfig NODES_SHIFT 1590d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 159151591e31SDavid Rientjes range 1 10 159251591e31SDavid Rientjes default "10" if MAXSMP 1593506f1d07SSam Ravnborg default "6" if X86_64 1594506f1d07SSam Ravnborg default "3" 1595a9ee6cf5SMike Rapoport depends on NUMA 1596a7f7f624SMasahiro Yamada help 15971184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1598692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1599506f1d07SSam Ravnborg 1600506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1601506f1d07SSam Ravnborg def_bool y 16023b16651fSTejun Heo depends on X86_32 && !NUMA 1603506f1d07SSam Ravnborg 1604506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1605506f1d07SSam Ravnborg def_bool y 16066ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1607506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1608506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1609506f1d07SSam Ravnborg 16103b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16116ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16123b16651fSTejun Heo 1613506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1614506f1d07SSam Ravnborg def_bool y 1615b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1616506f1d07SSam Ravnborg 1617506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1618a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16193120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1620a0842b70SToshi Kani help 1621a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1622cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1623a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1624506f1d07SSam Ravnborg 16253b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16263b16651fSTejun Heo def_bool y 16273b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16283b16651fSTejun Heo 1629a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1630a29815a3SAvi Kivity hex 1631a29815a3SAvi Kivity default 0 if X86_32 1632a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1633a29815a3SAvi Kivity 16347a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16357a67832cSDan Williams bool 16367a67832cSDan Williams 1637ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16387a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16399f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16409f53f9faSDan Williams depends on BLK_DEV 16417a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16427b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16439f53f9faSDan Williams select LIBNVDIMM 1644ec776ef6SChristoph Hellwig help 1645ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1646ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1647ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1648ec776ef6SChristoph Hellwig they can be used for persistent storage. 1649ec776ef6SChristoph Hellwig 1650ec776ef6SChristoph Hellwig Say Y if unsure. 1651ec776ef6SChristoph Hellwig 1652506f1d07SSam Ravnborgconfig HIGHPTE 1653506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16546fc108a0SJan Beulich depends on HIGHMEM 1655a7f7f624SMasahiro Yamada help 1656506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1657506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1658506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1659506f1d07SSam Ravnborg entries in high memory. 1660506f1d07SSam Ravnborg 16619f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16629f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1663a7f7f624SMasahiro Yamada help 16649f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16659f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16669f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16679f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16689f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16699f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16709f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16718c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16729f077871SJeremy Fitzhardinge 16739f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16749f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16759f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16769f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16779f077871SJeremy Fitzhardinge 16789f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16799f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16809f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16819f077871SJeremy Fitzhardinge memory. 16829f077871SJeremy Fitzhardinge 1683c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1684c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1685c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1686c885df50SJeremy Fitzhardinge default y 1687a7f7f624SMasahiro Yamada help 1688c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1689c885df50SJeremy Fitzhardinge on or off. 1690c885df50SJeremy Fitzhardinge 1691506f1d07SSam Ravnborgconfig MATH_EMULATION 1692506f1d07SSam Ravnborg bool 1693a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 169487d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1695a7f7f624SMasahiro Yamada help 1696506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1697506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1698506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1699506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1700506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1701506f1d07SSam Ravnborg coprocessor or this emulation. 1702506f1d07SSam Ravnborg 1703506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1704506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1705506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1706506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1707506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1708506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1709506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1710506f1d07SSam Ravnborg intend to use this kernel on different machines. 1711506f1d07SSam Ravnborg 1712506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1713506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1714506f1d07SSam Ravnborg 1715506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1716506f1d07SSam Ravnborg kernel, it won't hurt. 1717506f1d07SSam Ravnborg 1718506f1d07SSam Ravnborgconfig MTRR 17196fc108a0SJan Beulich def_bool y 17206a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1721a7f7f624SMasahiro Yamada help 1722506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1723506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1724506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1725506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1726506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1727506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1728506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1729506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1730506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1731506f1d07SSam Ravnborg 1732506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1733506f1d07SSam Ravnborg control registers on other processors can be easily supported 1734506f1d07SSam Ravnborg as well: 1735506f1d07SSam Ravnborg 1736506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1737506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1738506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1739506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1740506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1741506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1742506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1743506f1d07SSam Ravnborg 1744506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1745506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1746506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1749506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1750506f1d07SSam Ravnborg 1751cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1752506f1d07SSam Ravnborg 175395ffa243SYinghai Luconfig MTRR_SANITIZER 17542ffb3501SYinghai Lu def_bool y 175595ffa243SYinghai Lu prompt "MTRR cleanup support" 175695ffa243SYinghai Lu depends on MTRR 1757a7f7f624SMasahiro Yamada help 1758aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1759aba3728cSThomas Gleixner add writeback entries. 176095ffa243SYinghai Lu 1761aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1762692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1763aba3728cSThomas Gleixner mtrr_chunk_size. 176495ffa243SYinghai Lu 17652ffb3501SYinghai Lu If unsure, say Y. 176695ffa243SYinghai Lu 176795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1768f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1769f5098d62SYinghai Lu range 0 1 1770f5098d62SYinghai Lu default "0" 177195ffa243SYinghai Lu depends on MTRR_SANITIZER 1772a7f7f624SMasahiro Yamada help 1773f5098d62SYinghai Lu Enable mtrr cleanup default value 177495ffa243SYinghai Lu 177512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 177612031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 177712031a62SYinghai Lu range 0 7 177812031a62SYinghai Lu default "1" 177912031a62SYinghai Lu depends on MTRR_SANITIZER 1780a7f7f624SMasahiro Yamada help 178112031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1782aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 178312031a62SYinghai Lu 17842e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17856fc108a0SJan Beulich def_bool y 17866a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 17872a8a2719SIngo Molnar depends on MTRR 1788a7f7f624SMasahiro Yamada help 17892e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1790042b78e4SVenki Pallipadi 17912e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 17922e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 17932e5d9c85Svenkatesh.pallipadi@intel.com 17942e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1795042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 17962e5d9c85Svenkatesh.pallipadi@intel.com 17972e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 17982e5d9c85Svenkatesh.pallipadi@intel.com 179946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 180046cf98cdSVenkatesh Pallipadi def_bool y 180146cf98cdSVenkatesh Pallipadi depends on X86_PAT 180246cf98cdSVenkatesh Pallipadi 1803628c6246SH. Peter Anvinconfig ARCH_RANDOM 1804628c6246SH. Peter Anvin def_bool y 1805628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1806a7f7f624SMasahiro Yamada help 1807628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1808628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1809628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1810628c6246SH. Peter Anvin secure hardware random number generator. 1811628c6246SH. Peter Anvin 181251ae4a2dSH. Peter Anvinconfig X86_SMAP 181351ae4a2dSH. Peter Anvin def_bool y 181451ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1815a7f7f624SMasahiro Yamada help 181651ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 181751ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 181851ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 181951ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 182051ae4a2dSH. Peter Anvin 182151ae4a2dSH. Peter Anvin If unsure, say Y. 182251ae4a2dSH. Peter Anvin 1823b971880fSBabu Mogerconfig X86_UMIP 1824796ebc81SRicardo Neri def_bool y 1825b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1826a7f7f624SMasahiro Yamada help 1827b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1828b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1829b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1830b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1831b971880fSBabu Moger information about the hardware state. 1832796ebc81SRicardo Neri 1833796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1834796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1835796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1836796ebc81SRicardo Neri results are dummy. 1837aa35f896SRicardo Neri 183835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 183938f3e775SBabu Moger prompt "Memory Protection Keys" 184035e97790SDave Hansen def_bool y 1841284244a9SDave Hansen # Note: only available in 64-bit mode 184238f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 184352c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 184452c8e601SIngo Molnar select ARCH_HAS_PKEYS 1845a7f7f624SMasahiro Yamada help 1846284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1847284244a9SDave Hansen page-based protections, but without requiring modification of the 1848284244a9SDave Hansen page tables when an application changes protection domains. 1849284244a9SDave Hansen 18501eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1851284244a9SDave Hansen 1852284244a9SDave Hansen If unsure, say y. 185335e97790SDave Hansen 1854db616173SMichal Hockochoice 1855db616173SMichal Hocko prompt "TSX enable mode" 1856db616173SMichal Hocko depends on CPU_SUP_INTEL 1857db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1858db616173SMichal Hocko help 1859db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1860db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1861db616173SMichal Hocko can lead to a noticeable performance boost. 1862db616173SMichal Hocko 1863db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1864db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1865db616173SMichal Hocko will be more of those attacks discovered in the future. 1866db616173SMichal Hocko 1867db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1868db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1869db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1870db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1871db616173SMichal Hocko for the particular machine. 1872db616173SMichal Hocko 1873db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1874db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1875db616173SMichal Hocko details. 1876db616173SMichal Hocko 1877db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1878db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1879db616173SMichal Hocko relevant. 1880db616173SMichal Hocko 1881db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1882db616173SMichal Hocko bool "off" 1883db616173SMichal Hocko help 1884db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1885db616173SMichal Hocko 1886db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1887db616173SMichal Hocko bool "on" 1888db616173SMichal Hocko help 1889db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1890db616173SMichal Hocko line parameter. 1891db616173SMichal Hocko 1892db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1893db616173SMichal Hocko bool "auto" 1894db616173SMichal Hocko help 1895db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1896db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1897db616173SMichal Hockoendchoice 1898db616173SMichal Hocko 1899e7e05452SSean Christophersonconfig X86_SGX 1900e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1901e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1902e7e05452SSean Christopherson depends on CRYPTO=y 1903e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1904e7e05452SSean Christopherson select SRCU 1905e7e05452SSean Christopherson select MMU_NOTIFIER 1906901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 1907e7e05452SSean Christopherson help 1908e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1909e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1910e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1911e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1912e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1913e7e05452SSean Christopherson hardware. 1914e7e05452SSean Christopherson 1915e7e05452SSean Christopherson If unsure, say N. 1916e7e05452SSean Christopherson 1917506f1d07SSam Ravnborgconfig EFI 19189ba16087SJan Beulich bool "EFI runtime service support" 19195b83683fSHuang, Ying depends on ACPI 1920f6ce5002SSergey Vlasov select UCS2_STRING 1921022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1922a7f7f624SMasahiro Yamada help 19238b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1924506f1d07SSam Ravnborg available (such as the EFI variable services). 1925506f1d07SSam Ravnborg 19268b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19278b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19288b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19298b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19308b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19318b2cb7a8SHuang, Ying platforms. 1932506f1d07SSam Ravnborg 1933291f3632SMatt Flemingconfig EFI_STUB 1934291f3632SMatt Fleming bool "EFI stub support" 1935b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 19368f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19377b2a583aSMatt Fleming select RELOCATABLE 1938a7f7f624SMasahiro Yamada help 1939291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1940291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1941291f3632SMatt Fleming 19424f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19430c759662SMatt Fleming 19447d453eeeSMatt Flemingconfig EFI_MIXED 19457d453eeeSMatt Fleming bool "EFI mixed-mode support" 19467d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1947a7f7f624SMasahiro Yamada help 19487d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19497d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19507d453eeeSMatt Fleming mode. 19517d453eeeSMatt Fleming 19527d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19537d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19547d453eeeSMatt Fleming the EFI handover protocol must be used. 19557d453eeeSMatt Fleming 19567d453eeeSMatt Fleming If unsure, say N. 19577d453eeeSMatt Fleming 19588636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 1959506f1d07SSam Ravnborg 1960506f1d07SSam Ravnborgconfig KEXEC 1961506f1d07SSam Ravnborg bool "kexec system call" 19622965faa5SDave Young select KEXEC_CORE 1963a7f7f624SMasahiro Yamada help 1964506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1965506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1966506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1967506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1968506f1d07SSam Ravnborg 1969506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1970506f1d07SSam Ravnborg 1971506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1972506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1973bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1974bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1975bf220695SGeert Uytterhoeven made. 1976506f1d07SSam Ravnborg 197774ca317cSVivek Goyalconfig KEXEC_FILE 197874ca317cSVivek Goyal bool "kexec file based system call" 19792965faa5SDave Young select KEXEC_CORE 198074ca317cSVivek Goyal select BUILD_BIN2C 198174ca317cSVivek Goyal depends on X86_64 198274ca317cSVivek Goyal depends on CRYPTO=y 198374ca317cSVivek Goyal depends on CRYPTO_SHA256=y 1984a7f7f624SMasahiro Yamada help 198574ca317cSVivek Goyal This is new version of kexec system call. This system call is 198674ca317cSVivek Goyal file based and takes file descriptors as system call argument 198774ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 198874ca317cSVivek Goyal accepted by previous system call. 198974ca317cSVivek Goyal 1990b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 1991b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 1992b799a09fSAKASHI Takahiro 199399d5cadfSJiri Bohacconfig KEXEC_SIG 19948e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 199574ca317cSVivek Goyal depends on KEXEC_FILE 1996a7f7f624SMasahiro Yamada help 199799d5cadfSJiri Bohac 199899d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 199999d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 200099d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 200199d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 200299d5cadfSJiri Bohac 200399d5cadfSJiri Bohac In addition to this option, you need to enable signature 200499d5cadfSJiri Bohac verification for the corresponding kernel image type being 200599d5cadfSJiri Bohac loaded in order for this to work. 200699d5cadfSJiri Bohac 200799d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 200899d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 200999d5cadfSJiri Bohac depends on KEXEC_SIG 2010a7f7f624SMasahiro Yamada help 20118e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2012d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20138e7d8381SVivek Goyal 20148e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20158e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 201699d5cadfSJiri Bohac depends on KEXEC_SIG 20178e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20188e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2019a7f7f624SMasahiro Yamada help 20208e7d8381SVivek Goyal Enable bzImage signature verification support. 20218e7d8381SVivek Goyal 2022506f1d07SSam Ravnborgconfig CRASH_DUMP 202304b69447SPavel Machek bool "kernel crash dumps" 2024506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2025a7f7f624SMasahiro Yamada help 2026506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2027506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2028506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2029506f1d07SSam Ravnborg a specially reserved region and then later executed after 2030506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2031506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2032506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2033506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2034330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2035506f1d07SSam Ravnborg 20363ab83521SHuang Yingconfig KEXEC_JUMP 20376ea30386SKees Cook bool "kexec jump" 2038fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2039a7f7f624SMasahiro Yamada help 204089081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 204189081d17SHuang Ying code in physical address mode via KEXEC 20423ab83521SHuang Ying 2043506f1d07SSam Ravnborgconfig PHYSICAL_START 20446a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2045ceefccc9SH. Peter Anvin default "0x1000000" 2046a7f7f624SMasahiro Yamada help 2047506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2048506f1d07SSam Ravnborg 2049506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2050506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2051506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2052506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2053506f1d07SSam Ravnborg address. 2054506f1d07SSam Ravnborg 2055506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2056506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2057506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2058506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2059506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2060506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2061506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2062506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2063506f1d07SSam Ravnborg 2064ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2065ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2066ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2067ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2068ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2069ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2070ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2071330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2072ceefccc9SH. Peter Anvin for more details about crash dumps. 2073506f1d07SSam Ravnborg 2074506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2075506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2076506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2077506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2078506f1d07SSam Ravnborg is present because there are users out there who continue to use 2079506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2080506f1d07SSam Ravnborg line. 2081506f1d07SSam Ravnborg 2082506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2083506f1d07SSam Ravnborg 2084506f1d07SSam Ravnborgconfig RELOCATABLE 208526717808SH. Peter Anvin bool "Build a relocatable kernel" 208626717808SH. Peter Anvin default y 2087a7f7f624SMasahiro Yamada help 2088506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2089506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2090506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2091506f1d07SSam Ravnborg but are discarded at runtime. 2092506f1d07SSam Ravnborg 2093506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2094506f1d07SSam Ravnborg must live at a different physical address than the primary 2095506f1d07SSam Ravnborg kernel. 2096506f1d07SSam Ravnborg 2097506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2098506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 20998ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2100506f1d07SSam Ravnborg 21018ab3820fSKees Cookconfig RANDOMIZE_BASE 2102e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21038ab3820fSKees Cook depends on RELOCATABLE 21046807c846SIngo Molnar default y 2105a7f7f624SMasahiro Yamada help 2106e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2107e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2108e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2109e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2110e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2111e8581e3dSBaoquan He code internals. 2112e8581e3dSBaoquan He 2113ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2114ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2115ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2116ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2117ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2118ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2119ed9f007eSKees Cook 2120ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2121ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2122ed9f007eSKees Cook 512MB (8 bits of entropy). 21238ab3820fSKees Cook 2124a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2125e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2126e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2127ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2128ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2129ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2130ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2131ed9f007eSKees Cook theoretically possible, but the implementations are further 2132ed9f007eSKees Cook limited due to memory layouts. 2133e8581e3dSBaoquan He 21346807c846SIngo Molnar If unsure, say Y. 2135da2b6fb9SKees Cook 21368ab3820fSKees Cook# Relocation on x86 needs some additional build support 2137845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2138845adf72SH. Peter Anvin def_bool y 21398ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2140845adf72SH. Peter Anvin 2141506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2142a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21438ab3820fSKees Cook default "0x200000" 2144a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2145a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2146a7f7f624SMasahiro Yamada help 2147506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2148506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2149506f1d07SSam Ravnborg address which meets above alignment restriction. 2150506f1d07SSam Ravnborg 2151506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2152506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2153506f1d07SSam Ravnborg address aligned to above value and run from there. 2154506f1d07SSam Ravnborg 2155506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2156506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2157506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2158506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2159506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2160506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2161506f1d07SSam Ravnborg above alignment restrictions. 2162506f1d07SSam Ravnborg 2163a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2164a0215061SKees Cook this value must be a multiple of 0x200000. 2165a0215061SKees Cook 2166506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2167506f1d07SSam Ravnborg 2168eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2169eedb92abSKirill A. Shutemov bool 2170a7f7f624SMasahiro Yamada help 2171eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2172eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2173eedb92abSKirill A. Shutemov 21740483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 21750483e1faSThomas Garnier bool "Randomize the kernel memory sections" 21760483e1faSThomas Garnier depends on X86_64 21770483e1faSThomas Garnier depends on RANDOMIZE_BASE 2178eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 21790483e1faSThomas Garnier default RANDOMIZE_BASE 2180a7f7f624SMasahiro Yamada help 21810483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 21820483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 21830483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 21840483e1faSThomas Garnier 21850483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 21860483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 21870483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 21880483e1faSThomas Garnier addresses for each memory section. 21890483e1faSThomas Garnier 21906807c846SIngo Molnar If unsure, say Y. 21910483e1faSThomas Garnier 219290397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 219390397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 219490397a41SThomas Garnier depends on RANDOMIZE_MEMORY 219590397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 219690397a41SThomas Garnier default "0x0" 219790397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 219890397a41SThomas Garnier range 0x0 0x40 2199a7f7f624SMasahiro Yamada help 220090397a41SThomas Garnier Define the padding in terabytes added to the existing physical 220190397a41SThomas Garnier memory size during kernel memory randomization. It is useful 220290397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 220390397a41SThomas Garnier address randomization. 220490397a41SThomas Garnier 220590397a41SThomas Garnier If unsure, leave at the default value. 220690397a41SThomas Garnier 2207506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2208bebd024eSThomas Gleixner def_bool y 220940b31360SStephen Rothwell depends on SMP 2210506f1d07SSam Ravnborg 221180aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 221280aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22132c922cd0SKees Cook depends on HOTPLUG_CPU 2214a7f7f624SMasahiro Yamada help 221580aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 221680aa1dffSFenghua Yu 221780aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 221880aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 221980aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 222080aa1dffSFenghua Yu 222180aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 222280aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 222380aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 222480aa1dffSFenghua Yu 222580aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 222680aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 222780aa1dffSFenghua Yu 222880aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 222980aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 223080aa1dffSFenghua Yu be other CPU0 dependencies. 223180aa1dffSFenghua Yu 223280aa1dffSFenghua Yu Please make sure the dependencies are under your control before 223380aa1dffSFenghua Yu you enable this feature. 223480aa1dffSFenghua Yu 223580aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 223680aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 223780aa1dffSFenghua Yu parameter cpu0_hotplug. 223880aa1dffSFenghua Yu 2239a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2240a71c8bc5SFenghua Yu def_bool n 2241a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22422c922cd0SKees Cook depends on HOTPLUG_CPU 2243a7f7f624SMasahiro Yamada help 2244a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2245a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2246a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2247a71c8bc5SFenghua Yu 2248a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2249a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2250a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2251a71c8bc5SFenghua Yu 2252a71c8bc5SFenghua Yu If unsure, say N. 2253a71c8bc5SFenghua Yu 2254506f1d07SSam Ravnborgconfig COMPAT_VDSO 2255b0b49f26SAndy Lutomirski def_bool n 2256b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2257953fee1dSIngo Molnar depends on COMPAT_32 2258a7f7f624SMasahiro Yamada help 2259b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2260b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2261b0b49f26SAndy Lutomirski indicated in its segment table. 2262e84446deSRandy Dunlap 2263b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2264b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2265b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2266b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2267b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2268506f1d07SSam Ravnborg 2269b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2270b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2271b0b49f26SAndy Lutomirski 2272b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2273b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2274b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2275b0b49f26SAndy Lutomirski 2276b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2277b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2278506f1d07SSam Ravnborg 22793dc33bd3SKees Cookchoice 22803dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 22813dc33bd3SKees Cook depends on X86_64 2282625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 22833dc33bd3SKees Cook help 22843dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 22853dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 22863dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 22873dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 22883dc33bd3SKees Cook 22893dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2290bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 22913dc33bd3SKees Cook 22923dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 22933dc33bd3SKees Cook static binaries, you can say None without a performance penalty 22943dc33bd3SKees Cook to improve security. 22953dc33bd3SKees Cook 2296bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 22973dc33bd3SKees Cook 22983dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2299bd49e16eSAndy Lutomirski bool "Full emulation" 23003dc33bd3SKees Cook help 2301bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2302bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2303bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2304bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2305bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2306bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2307bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2308bd49e16eSAndy Lutomirski 2309bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2310bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2311bd49e16eSAndy Lutomirski 2312bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2313bd49e16eSAndy Lutomirski bool "Emulate execution only" 2314bd49e16eSAndy Lutomirski help 2315bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2316bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2317bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2318bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2319bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2320bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2321bd49e16eSAndy Lutomirski buffer. 23223dc33bd3SKees Cook 23233dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23243dc33bd3SKees Cook bool "None" 23253dc33bd3SKees Cook help 23263dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23273dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23283dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23293dc33bd3SKees Cook will be reported to dmesg, so that either old or 23303dc33bd3SKees Cook malicious userspace programs can be identified. 23313dc33bd3SKees Cook 23323dc33bd3SKees Cookendchoice 23333dc33bd3SKees Cook 2334516cbf37STim Birdconfig CMDLINE_BOOL 2335516cbf37STim Bird bool "Built-in kernel command line" 2336a7f7f624SMasahiro Yamada help 2337516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2338516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2339516cbf37STim Bird necessary or convenient to provide some or all of the 2340516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2341516cbf37STim Bird to not rely on the boot loader to provide them.) 2342516cbf37STim Bird 2343516cbf37STim Bird To compile command line arguments into the kernel, 2344516cbf37STim Bird set this option to 'Y', then fill in the 234569711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2346516cbf37STim Bird 2347516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2348516cbf37STim Bird should leave this option set to 'N'. 2349516cbf37STim Bird 2350516cbf37STim Birdconfig CMDLINE 2351516cbf37STim Bird string "Built-in kernel command string" 2352516cbf37STim Bird depends on CMDLINE_BOOL 2353516cbf37STim Bird default "" 2354a7f7f624SMasahiro Yamada help 2355516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2356516cbf37STim Bird image and used at boot time. If the boot loader provides a 2357516cbf37STim Bird command line at boot time, it is appended to this string to 2358516cbf37STim Bird form the full kernel command line, when the system boots. 2359516cbf37STim Bird 2360516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2361516cbf37STim Bird change this behavior. 2362516cbf37STim Bird 2363516cbf37STim Bird In most cases, the command line (whether built-in or provided 2364516cbf37STim Bird by the boot loader) should specify the device for the root 2365516cbf37STim Bird file system. 2366516cbf37STim Bird 2367516cbf37STim Birdconfig CMDLINE_OVERRIDE 2368516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2369645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2370a7f7f624SMasahiro Yamada help 2371516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2372516cbf37STim Bird command line, and use ONLY the built-in command line. 2373516cbf37STim Bird 2374516cbf37STim Bird This is used to work around broken boot loaders. This should 2375516cbf37STim Bird be set to 'N' under normal conditions. 2376516cbf37STim Bird 2377a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2378a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2379a5b9e5a2SAndy Lutomirski default y 2380a7f7f624SMasahiro Yamada help 2381a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2382a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2383a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2384a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2385a5b9e5a2SAndy Lutomirski threading libraries. 2386a5b9e5a2SAndy Lutomirski 2387a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2388a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2389a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2390a5b9e5a2SAndy Lutomirski 2391a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2392a5b9e5a2SAndy Lutomirski 2393b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2394b700e7f0SSeth Jennings 2395506f1d07SSam Ravnborgendmenu 2396506f1d07SSam Ravnborg 23973072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 23983072e413SMichal Hocko def_bool y 23993072e413SMichal Hocko depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 24003072e413SMichal Hocko 2401f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2402f91ef222SOscar Salvador def_bool y 2403f91ef222SOscar Salvador 2404e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2405645a7919STejun Heo def_bool y 2406e534c7c5SLee Schermerhorn depends on NUMA 2407e534c7c5SLee Schermerhorn 2408da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2409e279b6c1SSam Ravnborg 2410e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24113c2362e6SHarvey Harrison def_bool y 241244556530SZhimin Gu depends on HIBERNATION 2413e279b6c1SSam Ravnborg 2414e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2415e279b6c1SSam Ravnborg 2416e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2417e279b6c1SSam Ravnborg 2418a6b68076SAndi Kleenconfig X86_APM_BOOT 24196fc108a0SJan Beulich def_bool y 2420282e5aabSPaul Bolle depends on APM 2421a6b68076SAndi Kleen 2422e279b6c1SSam Ravnborgmenuconfig APM 2423e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2424efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2425a7f7f624SMasahiro Yamada help 2426e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2427e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2428e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2429e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2430e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2431e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2432e279b6c1SSam Ravnborg 2433e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2434e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2435e279b6c1SSam Ravnborg 2436e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2437e279b6c1SSam Ravnborg machines with more than one CPU. 2438e279b6c1SSam Ravnborg 2439e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2440151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24412dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2442e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2443e279b6c1SSam Ravnborg 2444e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2445e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2446e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2447e279b6c1SSam Ravnborg 2448e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2449e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2450e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2451e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2452e279b6c1SSam Ravnborg 2453e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2454e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2455e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2456e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2457e279b6c1SSam Ravnborg APM in your BIOS). 2458e279b6c1SSam Ravnborg 2459e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2460e279b6c1SSam Ravnborg "weird" problems: 2461e279b6c1SSam Ravnborg 2462e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2463e279b6c1SSam Ravnborg enabled. 2464e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2465e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2466e279b6c1SSam Ravnborg the "no387" option to the kernel 2467e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2468e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2469e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2470e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2471e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2472e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2473e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2474e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2475e279b6c1SSam Ravnborg 11) exchange RAM chips 2476e279b6c1SSam Ravnborg 12) exchange the motherboard. 2477e279b6c1SSam Ravnborg 2478e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2479e279b6c1SSam Ravnborg module will be called apm. 2480e279b6c1SSam Ravnborg 2481e279b6c1SSam Ravnborgif APM 2482e279b6c1SSam Ravnborg 2483e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2484e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2485a7f7f624SMasahiro Yamada help 2486e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2487e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2488e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2489e279b6c1SSam Ravnborg 2490e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2491e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2492a7f7f624SMasahiro Yamada help 2493e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2494e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2495e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2496e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2497e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2498e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2499e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2500e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2501e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2502e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2503e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2504e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2505e279b6c1SSam Ravnborg this feature. 2506e279b6c1SSam Ravnborg 2507e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2508dd8af076SLen Brown depends on CPU_IDLE 2509e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2510a7f7f624SMasahiro Yamada help 2511e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2512e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2513e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2514e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2515e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2516e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2517e279b6c1SSam Ravnborg this option does nothing.) 2518e279b6c1SSam Ravnborg 2519e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2520e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2521a7f7f624SMasahiro Yamada help 2522e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2523e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2524e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2525e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2526e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2527e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2528e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2529e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2530e279b6c1SSam Ravnborg especially if you are using gpm. 2531e279b6c1SSam Ravnborg 2532e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2533e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2534a7f7f624SMasahiro Yamada help 2535e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2536e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2537e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2538e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2539e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2540e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2541e279b6c1SSam Ravnborg 2542e279b6c1SSam Ravnborgendif # APM 2543e279b6c1SSam Ravnborg 2544bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2545e279b6c1SSam Ravnborg 2546e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2547e279b6c1SSam Ravnborg 254827471fdbSAndy Henroidsource "drivers/idle/Kconfig" 254927471fdbSAndy Henroid 2550e279b6c1SSam Ravnborgendmenu 2551e279b6c1SSam Ravnborg 2552e279b6c1SSam Ravnborg 2553e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2554e279b6c1SSam Ravnborg 2555e279b6c1SSam Ravnborgchoice 2556e279b6c1SSam Ravnborg prompt "PCI access mode" 2557efefa6f6SIngo Molnar depends on X86_32 && PCI 2558e279b6c1SSam Ravnborg default PCI_GOANY 2559a7f7f624SMasahiro Yamada help 2560e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2561e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2562e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2563e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2564e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2565e279b6c1SSam Ravnborg 2566e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2567e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2568e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2569e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2570e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2571e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2572e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2573e279b6c1SSam Ravnborg 2574e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2575e279b6c1SSam Ravnborg bool "BIOS" 2576e279b6c1SSam Ravnborg 2577e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2578e279b6c1SSam Ravnborg bool "MMConfig" 2579e279b6c1SSam Ravnborg 2580e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2581e279b6c1SSam Ravnborg bool "Direct" 2582e279b6c1SSam Ravnborg 25833ef0e1f8SAndres Salomonconfig PCI_GOOLPC 258476fb6570SDaniel Drake bool "OLPC XO-1" 25853ef0e1f8SAndres Salomon depends on OLPC 25863ef0e1f8SAndres Salomon 25872bdd1b03SAndres Salomonconfig PCI_GOANY 25882bdd1b03SAndres Salomon bool "Any" 25892bdd1b03SAndres Salomon 2590e279b6c1SSam Ravnborgendchoice 2591e279b6c1SSam Ravnborg 2592e279b6c1SSam Ravnborgconfig PCI_BIOS 25933c2362e6SHarvey Harrison def_bool y 2594efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2595e279b6c1SSam Ravnborg 2596e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2597e279b6c1SSam Ravnborgconfig PCI_DIRECT 25983c2362e6SHarvey Harrison def_bool y 25990aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2600e279b6c1SSam Ravnborg 2601e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2602b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2603b45c9f36SJan Kiszka default y 26044590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2605b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2606e279b6c1SSam Ravnborg 26073ef0e1f8SAndres Salomonconfig PCI_OLPC 26082bdd1b03SAndres Salomon def_bool y 26092bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26103ef0e1f8SAndres Salomon 2611b5401a96SAlex Nixonconfig PCI_XEN 2612b5401a96SAlex Nixon def_bool y 2613b5401a96SAlex Nixon depends on PCI && XEN 2614b5401a96SAlex Nixon 26158364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26168364e1f8SJan Kiszka def_bool y 26178364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2618e279b6c1SSam Ravnborg 26193f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26206a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26216ea30386SKees Cook depends on PCI 26223f6ea84aSIra W. Snyder help 26233f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26243f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26253f6ea84aSIra W. Snyder not have ACPI. 26263f6ea84aSIra W. Snyder 262764a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 262864a5fed6SBjorn Helgaas is known to be incomplete. 262964a5fed6SBjorn Helgaas 263064a5fed6SBjorn Helgaas You should say N unless you know you need this. 263164a5fed6SBjorn Helgaas 26323a495511SWilliam Breathitt Grayconfig ISA_BUS 263317a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26343a495511SWilliam Breathitt Gray help 263517a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 263617a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 263717a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 263817a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 263917a2a129SWilliam Breathitt Gray not have an ISA bus. 26403a495511SWilliam Breathitt Gray 26413a495511SWilliam Breathitt Gray If unsure, say N. 26423a495511SWilliam Breathitt Gray 26431c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2644e279b6c1SSam Ravnborgconfig ISA_DMA_API 26451c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 26461c00f016SDavid Rientjes default y 26471c00f016SDavid Rientjes help 26481c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 26491c00f016SDavid Rientjes If unsure, say Y. 2650e279b6c1SSam Ravnborg 265151e68d05SLinus Torvaldsif X86_32 265251e68d05SLinus Torvalds 2653e279b6c1SSam Ravnborgconfig ISA 2654e279b6c1SSam Ravnborg bool "ISA support" 2655a7f7f624SMasahiro Yamada help 2656e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2657e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2658e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2659e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2660e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2661e279b6c1SSam Ravnborg 2662e279b6c1SSam Ravnborgconfig SCx200 2663e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2664a7f7f624SMasahiro Yamada help 2665e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2666e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2667e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2668e279b6c1SSam Ravnborg for other scx200_* drivers. 2669e279b6c1SSam Ravnborg 2670e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2671e279b6c1SSam Ravnborg 2672e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2673e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2674592913ecSJohn Stultz depends on SCx200 2675e279b6c1SSam Ravnborg default y 2676a7f7f624SMasahiro Yamada help 2677e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2678e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2679e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2680e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2681e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2682e279b6c1SSam Ravnborg 26833ef0e1f8SAndres Salomonconfig OLPC 26843ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 268554008979SThomas Gleixner depends on !X86_PAE 26863c554946SAndres Salomon select GPIOLIB 2687dc3119e7SThomas Gleixner select OF 268845bb1674SDaniel Drake select OF_PROMTREE 2689b4e51854SGrant Likely select IRQ_DOMAIN 26900c3d931bSLubomir Rintel select OLPC_EC 2691a7f7f624SMasahiro Yamada help 26923ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 26933ef0e1f8SAndres Salomon XO hardware. 26943ef0e1f8SAndres Salomon 2695a3128588SDaniel Drakeconfig OLPC_XO1_PM 2696a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2697fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2698a7f7f624SMasahiro Yamada help 269997c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2700bf1ebf00SDaniel Drake 2701cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2702cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2703cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2704a7f7f624SMasahiro Yamada help 2705cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2706cfee9597SDaniel Drake programmable wakeup source. 2707cfee9597SDaniel Drake 27087feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27097feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 271092e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2711ed8e47feSRandy Dunlap depends on INPUT=y 2712d8d01a63SDaniel Drake select POWER_SUPPLY 2713a7f7f624SMasahiro Yamada help 27147feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27157bc74b3dSDaniel Drake - EC-driven system wakeups 27167feda8e9SDaniel Drake - Power button 27177bc74b3dSDaniel Drake - Ebook switch 27182cf2baeaSDaniel Drake - Lid switch 2719e1040ac6SDaniel Drake - AC adapter status updates 2720e1040ac6SDaniel Drake - Battery status updates 27217feda8e9SDaniel Drake 2722a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2723a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2724d8d01a63SDaniel Drake depends on OLPC && ACPI 2725d8d01a63SDaniel Drake select POWER_SUPPLY 2726a7f7f624SMasahiro Yamada help 2727a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2728a0f30f59SDaniel Drake - EC-driven system wakeups 2729a0f30f59SDaniel Drake - AC adapter status updates 2730a0f30f59SDaniel Drake - Battery status updates 2731e279b6c1SSam Ravnborg 2732d4f3e350SEd Wildgooseconfig ALIX 2733d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2734d4f3e350SEd Wildgoose select GPIOLIB 2735a7f7f624SMasahiro Yamada help 2736d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2737d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2738d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2739d4f3e350SEd Wildgoose get added here. 2740d4f3e350SEd Wildgoose 2741d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2742d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2743d4f3e350SEd Wildgoose 2744d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2745d4f3e350SEd Wildgoose 2746da4e3302SPhilip Prindevilleconfig NET5501 2747da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2748da4e3302SPhilip Prindeville select GPIOLIB 2749a7f7f624SMasahiro Yamada help 2750da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2751da4e3302SPhilip Prindeville 27523197059aSPhilip A. Prindevilleconfig GEOS 27533197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 27543197059aSPhilip A. Prindeville select GPIOLIB 27553197059aSPhilip A. Prindeville depends on DMI 2756a7f7f624SMasahiro Yamada help 27573197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 27583197059aSPhilip A. Prindeville 27597d029125SVivien Didelotconfig TS5500 27607d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 27617d029125SVivien Didelot depends on MELAN 27627d029125SVivien Didelot select CHECK_SIGNATURE 27637d029125SVivien Didelot select NEW_LEDS 27647d029125SVivien Didelot select LEDS_CLASS 2765a7f7f624SMasahiro Yamada help 27667d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 27677d029125SVivien Didelot 2768e279b6c1SSam Ravnborgendif # X86_32 2769e279b6c1SSam Ravnborg 277023ac4ae8SAndreas Herrmannconfig AMD_NB 2771e279b6c1SSam Ravnborg def_bool y 27720e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2773e279b6c1SSam Ravnborg 2774e279b6c1SSam Ravnborgendmenu 2775e279b6c1SSam Ravnborg 2776e279b6c1SSam Ravnborg 27771572497cSChristoph Hellwigmenu "Binary Emulations" 2778e279b6c1SSam Ravnborg 2779e279b6c1SSam Ravnborgconfig IA32_EMULATION 2780e279b6c1SSam Ravnborg bool "IA32 Emulation" 2781e279b6c1SSam Ravnborg depends on X86_64 278239f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2783d1603990SRandy Dunlap select BINFMT_ELF 278439f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2785a7f7f624SMasahiro Yamada help 27865fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 27875fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 27885fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2789e279b6c1SSam Ravnborg 2790e279b6c1SSam Ravnborgconfig IA32_AOUT 2791e279b6c1SSam Ravnborg tristate "IA32 a.out support" 27926b213e1bSDavid Woodhouse depends on IA32_EMULATION 2793eac61655SBorislav Petkov depends on BROKEN 2794a7f7f624SMasahiro Yamada help 2795e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2796e279b6c1SSam Ravnborg 27970bf62763SH. Peter Anvinconfig X86_X32 27986ea30386SKees Cook bool "x32 ABI for 64-bit mode" 27999b54050bSBrian Gerst depends on X86_64 2800a7f7f624SMasahiro Yamada help 28015fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28025fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28035fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28045fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28055fd92e65SH. J. Lu 28065fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 28075fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 28085fd92e65SH. J. Lu option set. 28095fd92e65SH. J. Lu 2810953fee1dSIngo Molnarconfig COMPAT_32 2811953fee1dSIngo Molnar def_bool y 2812953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2813953fee1dSIngo Molnar select HAVE_UID16 2814953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2815953fee1dSIngo Molnar 2816e279b6c1SSam Ravnborgconfig COMPAT 28173c2362e6SHarvey Harrison def_bool y 28180bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2819e279b6c1SSam Ravnborg 28203120e25eSJan Beulichif COMPAT 2821e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28223120e25eSJan Beulich def_bool y 2823e279b6c1SSam Ravnborg 2824e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28253c2362e6SHarvey Harrison def_bool y 28263120e25eSJan Beulich depends on SYSVIPC 28273120e25eSJan Beulichendif 2828ee009e4aSDavid Howells 2829e279b6c1SSam Ravnborgendmenu 2830e279b6c1SSam Ravnborg 2831e279b6c1SSam Ravnborg 2832e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2833e5beae16SKeith Packard def_bool y 2834e5beae16SKeith Packard depends on X86_32 2835e5beae16SKeith Packard 2836e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2837e279b6c1SSam Ravnborg 2838edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28395e8ebd84SJason A. Donenfeld 28405e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2841