1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2daa93fabSSam Ravnborg# Select 32 or 64 bit 3daa93fabSSam Ravnborgconfig 64BIT 4104daea1SMasahiro Yamada bool "64-bit kernel" if "$(ARCH)" = "x86" 5104daea1SMasahiro Yamada default "$(ARCH)" != "i386" 6a7f7f624SMasahiro Yamada help 7daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 8daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 9daa93fabSSam Ravnborg 10daa93fabSSam Ravnborgconfig X86_32 113120e25eSJan Beulich def_bool y 123120e25eSJan Beulich depends on !64BIT 13341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 14341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 15341c787eSIngo Molnar select CLKSRC_I8253 16341c787eSIngo Molnar select CLONE_BACKWARDS 17157e118bSThomas Gleixner select GENERIC_VDSO_32 18117ed454SThomas Gleixner select HAVE_DEBUG_STACKOVERFLOW 19157e118bSThomas Gleixner select KMAP_LOCAL 20341c787eSIngo Molnar select MODULES_USE_ELF_REL 21341c787eSIngo Molnar select OLD_SIGACTION 222ca408d9SBrian Gerst select ARCH_SPLIT_ARG64 23daa93fabSSam Ravnborg 24daa93fabSSam Ravnborgconfig X86_64 253120e25eSJan Beulich def_bool y 263120e25eSJan Beulich depends on 64BIT 27d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 284eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 29c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 30d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 31d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 32d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 33f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 3409230cbcSChristoph Hellwig select SWIOTLB 357facdc42SAl Viro select ARCH_HAS_ELFCORE_COMPAT 3663703f37SKefeng Wang select ZONE_DMA32 371032c0baSSam Ravnborg 38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 39518049d9SSteven Rostedt (VMware) def_bool y 40518049d9SSteven Rostedt (VMware) depends on X86_32 41518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 42518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 43518049d9SSteven Rostedt (VMware) help 44518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 45518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 46518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 47518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 48518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 49d94e0685SIngo Molnar# 50d94e0685SIngo Molnar# Arch settings 51d94e0685SIngo Molnar# 52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 53d94e0685SIngo Molnar# ported to 32-bit as well. ) 54d94e0685SIngo Molnar# 558d5fffb9SSam Ravnborgconfig X86 563c2362e6SHarvey Harrison def_bool y 57c763ea26SIngo Molnar # 58c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 59c763ea26SIngo Molnar # 606471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 616e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 62942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 632a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 641f6d3a8fSMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 651e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 665c11f00bSDavid Hildenbrand select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 6791024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 68cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 691e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 7091dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 71c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 72fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 73399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 7421266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 75b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 766471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 7772d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 78316d097cSDave Hansen select ARCH_HAS_FILTER_PGPROT 796974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 80957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 810f1441b4SPeter Zijlstra select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 820c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 8310bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 840ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 85c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 8617596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 873010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 880aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 89ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 90d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 91d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 92ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 93ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 94ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 9525c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 96c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 977e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 9863703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 996471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 1006471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10177fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1025e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1033599fe12SThomas Gleixner select ARCH_STACKWALK 1042c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1056471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1065d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 1076471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 10814df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 109583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 110583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1116471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 112dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1136471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1146471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1152ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 116ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 11781c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 118c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 11951c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 1203876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 12159612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 12238d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 123b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 12410916706SShile Zhang select BUILDTIME_TABLE_SORT 1256471b825SIngo Molnar select CLKEVT_I8253 1266471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1276471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1286471b825SIngo Molnar select DCACHE_WORD_ACCESS 1293aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 13045471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 13145471cd9SLinus Torvalds select EDAC_SUPPORT 1326471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1336471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1346471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1356471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 13661dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1376471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 13827d6b4d1SThomas Gleixner select GENERIC_ENTRY 1396471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 1406471b825SIngo Molnar select GENERIC_IOMAP 141c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1420fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 143ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1446471b825SIngo Molnar select GENERIC_IRQ_PROBE 145c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1466471b825SIngo Molnar select GENERIC_IRQ_SHOW 1476471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1482ae27137SSteven Price select GENERIC_PTDUMP 1496471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1506471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1517ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 152550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 15339656e83SChristoph Hellwig select GUP_GET_PTE_LOW_HIGH if X86_PAE 15417e5888eSHans de Goede select HARDIRQS_SW_RESEND 1557edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 1566471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1576471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1586471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1596471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1606471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 1616471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 162b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 163d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1640609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1651dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1666471b825SIngo Molnar select HAVE_ARCH_KGDB 1679e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1689e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1691b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 170271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1716471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 172f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 173afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1746471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1756471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 176a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 177b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1787677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 179e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 180fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 181c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1822ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1836471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1846471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1856471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 186d1f250e2SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 1876471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1886dafca97SSami Tolvanen select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION 1896471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1909c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 191677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 19206aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 19302a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 194562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 195c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 196503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 19703f5781bSWang YanQing select HAVE_EBPF_JIT 19858340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1996630a8e5SChristoph Hellwig select HAVE_EISA 2005f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 20167a929e0SChristoph Hellwig select HAVE_FAST_GUP 202644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 2036471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 2044a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2056471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2066b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2070067f129SK.Prasad select HAVE_HW_BREAKPOINT 2086471b825SIngo Molnar select HAVE_IOREMAP_PROT 209624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2106471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2116471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2126471b825SIngo Molnar select HAVE_KERNEL_GZIP 2136471b825SIngo Molnar select HAVE_KERNEL_LZ4 2146471b825SIngo Molnar select HAVE_KERNEL_LZMA 2156471b825SIngo Molnar select HAVE_KERNEL_LZO 2166471b825SIngo Molnar select HAVE_KERNEL_XZ 217fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2186471b825SIngo Molnar select HAVE_KPROBES 2196471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 220540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2216471b825SIngo Molnar select HAVE_KRETPROBES 2226471b825SIngo Molnar select HAVE_KVM 2236471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2240102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 225ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2269f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 227be37c98dSKalesh Singh select HAVE_MOVE_PUD 22842a0bb3fSPetr Mladek select HAVE_NMI 2296471b825SIngo Molnar select HAVE_OPTPROBES 2306471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2316471b825SIngo Molnar select HAVE_PERF_EVENTS 232c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 23392e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 234eb01d42aSChristoph Hellwig select HAVE_PCI 235c5e63197SJiri Olsa select HAVE_PERF_REGS 236c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 237ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 23800998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2396471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 2406415b38bSJiri Slaby select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 2413c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 242*7ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 243cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 244d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 245c763ea26SIngo Molnar select HAVE_STACK_VALIDATION if X86_64 246e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 2471e7e4788SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 2486ef869e0SMichal Hocko select HAVE_PREEMPT_DYNAMIC 249d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2506471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2516471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2527c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2537ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 25405736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 255c0185808SThomas Gleixner select IRQ_FORCED_THREADING 256*7ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 257*7ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 25886596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2592eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 260625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2616471b825SIngo Molnar select PERF_EVENTS 2623195ef59SPrarit Bhargava select RTC_LIB 263d6faca40SArnd Bergmann select RTC_MC146818_LIB 2646471b825SIngo Molnar select SPARSE_IRQ 26583fe27eaSPranith Kumar select SRCU 2661e7e4788SJosh Poimboeuf select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 2676471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 26815f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2694aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2706471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2716471b825SIngo Molnar select VIRT_TO_BUS 2723b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2736471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2740c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 2759e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2767d8330a5SBalbir Singh 277ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2783120e25eSJan Beulich def_bool y 2793120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 280ba7e4d13SIngo Molnar 28151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 28251b26adaSLinus Torvalds string 28351b26adaSLinus Torvalds default "elf32-i386" if X86_32 28451b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 28551b26adaSLinus Torvalds 2868d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2873c2362e6SHarvey Harrison def_bool y 2888d5fffb9SSam Ravnborg 2898d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2903c2362e6SHarvey Harrison def_bool y 2918d5fffb9SSam Ravnborg 2928d5fffb9SSam Ravnborgconfig MMU 2933c2362e6SHarvey Harrison def_bool y 2948d5fffb9SSam Ravnborg 2959e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 2969e08f57dSDaniel Cashman default 28 if 64BIT 2979e08f57dSDaniel Cashman default 8 2989e08f57dSDaniel Cashman 2999e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3009e08f57dSDaniel Cashman default 32 if 64BIT 3019e08f57dSDaniel Cashman default 16 3029e08f57dSDaniel Cashman 3039e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3049e08f57dSDaniel Cashman default 8 3059e08f57dSDaniel Cashman 3069e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3079e08f57dSDaniel Cashman default 16 3089e08f57dSDaniel Cashman 3098d5fffb9SSam Ravnborgconfig SBUS 3108d5fffb9SSam Ravnborg bool 3118d5fffb9SSam Ravnborg 3128d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3133120e25eSJan Beulich def_bool y 3143120e25eSJan Beulich depends on ISA_DMA_API 3158d5fffb9SSam Ravnborg 3168d5fffb9SSam Ravnborgconfig GENERIC_BUG 3173c2362e6SHarvey Harrison def_bool y 3188d5fffb9SSam Ravnborg depends on BUG 319b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 320b93a531eSJan Beulich 321b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 322b93a531eSJan Beulich bool 3238d5fffb9SSam Ravnborg 3248d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3253120e25eSJan Beulich def_bool y 3263120e25eSJan Beulich depends on ISA_DMA_API 3278d5fffb9SSam Ravnborg 3281032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3291032c0baSSam Ravnborg def_bool y 3301032c0baSSam Ravnborg 3319a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3329a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3338d5fffb9SSam Ravnborg 334316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT 335316d097cSDave Hansen def_bool y 336316d097cSDave Hansen 337801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 338801e4062SJohannes Berg def_bool y 339801e4062SJohannes Berg 340d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 341d7109fe3SAndy Shevchenko int 342d7109fe3SAndy Shevchenko default 1024 if X86_64 343d7109fe3SAndy Shevchenko default 512 344d7109fe3SAndy Shevchenko 345f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 346f4cb5700SJohannes Berg def_bool y 347f4cb5700SJohannes Berg 34853313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 34953313b2cSSteve Capper def_bool y 35053313b2cSSteve Capper 3518d5fffb9SSam Ravnborgconfig AUDIT_ARCH 352e0fd24a3SJan Beulich def_bool y if X86_64 3538d5fffb9SSam Ravnborg 354d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 355d6f2d75aSAndrey Ryabinin hex 356d6f2d75aSAndrey Ryabinin depends on KASAN 357d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 358d6f2d75aSAndrey Ryabinin 35969575d38SShane Wangconfig HAVE_INTEL_TXT 36069575d38SShane Wang def_bool y 3616ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36269575d38SShane Wang 3636b0c3d44SSam Ravnborgconfig X86_32_SMP 3646b0c3d44SSam Ravnborg def_bool y 3656b0c3d44SSam Ravnborg depends on X86_32 && SMP 3666b0c3d44SSam Ravnborg 3676b0c3d44SSam Ravnborgconfig X86_64_SMP 3686b0c3d44SSam Ravnborg def_bool y 3696b0c3d44SSam Ravnborg depends on X86_64 && SMP 3706b0c3d44SSam Ravnborg 3712b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3722b144498SSrikar Dronamraju def_bool y 3732b144498SSrikar Dronamraju 374d20642f0SRob Herringconfig FIX_EARLYCON_MEM 375d20642f0SRob Herring def_bool y 376d20642f0SRob Herring 37794d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 37894d49eb3SKirill A. Shutemov bool 37994d49eb3SKirill A. Shutemov 38098233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38198233368SKirill A. Shutemov int 38277ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38398233368SKirill A. Shutemov default 4 if X86_64 38498233368SKirill A. Shutemov default 3 if X86_PAE 38598233368SKirill A. Shutemov default 2 38698233368SKirill A. Shutemov 3872a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3882a61f474SMasahiro Yamada bool 3892a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3902a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3912a61f474SMasahiro Yamada help 3922a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3933fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 3943fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 3952a61f474SMasahiro Yamada 396506f1d07SSam Ravnborgmenu "Processor type and features" 397506f1d07SSam Ravnborg 398506f1d07SSam Ravnborgconfig SMP 399506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 400a7f7f624SMasahiro Yamada help 401506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4024a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4034a474157SRobert Graffham than one CPU, say Y. 404506f1d07SSam Ravnborg 4054a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 406506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 407506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4084a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 409506f1d07SSam Ravnborg will run faster if you say N here. 410506f1d07SSam Ravnborg 411506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 412506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 413506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 414506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 415506f1d07SSam Ravnborg 416506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 417506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 418506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 419506f1d07SSam Ravnborg 420cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4214f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 422506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 423506f1d07SSam Ravnborg 424506f1d07SSam Ravnborg If you don't know what to do here, say N. 425506f1d07SSam Ravnborg 4269def39beSJosh Triplettconfig X86_FEATURE_NAMES 4279def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4289def39beSJosh Triplett default y 429a7f7f624SMasahiro Yamada help 4309def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4319def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4329def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4339def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4349def39beSJosh Triplett 4359def39beSJosh Triplett If in doubt, say Y. 4369def39beSJosh Triplett 43706cd9a7dSYinghai Luconfig X86_X2APIC 43806cd9a7dSYinghai Lu bool "Support x2apic" 43919e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 440a7f7f624SMasahiro Yamada help 44106cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44206cd9a7dSYinghai Lu 44306cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44406cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 44506cd9a7dSYinghai Lu 44606cd9a7dSYinghai Lu If you don't know what to do here, say N. 44706cd9a7dSYinghai Lu 4486695c85bSYinghai Luconfig X86_MPPARSE 4494590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4507a527688SJan Beulich default y 4515ab74722SIngo Molnar depends on X86_LOCAL_APIC 452a7f7f624SMasahiro Yamada help 4536695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4546695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4556695c85bSYinghai Lu 456ddd70cf9SJun Nakajimaconfig GOLDFISH 457ddd70cf9SJun Nakajima def_bool y 458ddd70cf9SJun Nakajima depends on X86_GOLDFISH 459ddd70cf9SJun Nakajima 46076b04384SDavid Woodhouseconfig RETPOLINE 46176b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 46276b04384SDavid Woodhouse default y 46376b04384SDavid Woodhouse help 46476b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 46576b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 46676b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 46776b04384SDavid Woodhouse support for full protection. The kernel may run slower. 46876b04384SDavid Woodhouse 469e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 470e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4716fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 47259fe5a77SThomas Gleixner select KERNFS 473e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 47478e99b4aSFenghua Yu help 475e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4766fe07ce3SBabu Moger 4776fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4786fe07ce3SBabu Moger usage by the CPU. 4796fe07ce3SBabu Moger 4806fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4816fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4826fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4836fe07ce3SBabu Moger 4846fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4856fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4866fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 48778e99b4aSFenghua Yu 48878e99b4aSFenghua Yu Say N if unsure. 48978e99b4aSFenghua Yu 4908425091fSRavikiran G Thirumalaiif X86_32 491a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 492a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 493a0d0bb4dSRandy Dunlap depends on SMP 494a7f7f624SMasahiro Yamada help 495e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 496a0d0bb4dSRandy Dunlap 497c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 498c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 499c5c606d9SRavikiran G Thirumalai default y 500a7f7f624SMasahiro Yamada help 50106ac8346SIngo Molnar If you disable this option then the kernel will only support 50206ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 50306ac8346SIngo Molnar systems out there.) 50406ac8346SIngo Molnar 5058425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5068425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 507cb7b8023SBen Hutchings Goldfish (Android emulator) 5088425091fSRavikiran G Thirumalai AMD Elan 5098425091fSRavikiran G Thirumalai RDC R-321x SoC 5108425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 51183125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5123f4110a4SThomas Gleixner Moorestown MID devices 51306ac8346SIngo Molnar 51406ac8346SIngo Molnar If you have one of these systems, or if you want to build a 51506ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5168425091fSRavikiran G Thirumalaiendif 51706ac8346SIngo Molnar 5188425091fSRavikiran G Thirumalaiif X86_64 5198425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5208425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5218425091fSRavikiran G Thirumalai default y 522a7f7f624SMasahiro Yamada help 5238425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5248425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5258425091fSRavikiran G Thirumalai systems out there.) 5268425091fSRavikiran G Thirumalai 5278425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5288425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 52944b111b5SSteffen Persvold Numascale NumaChip 5308425091fSRavikiran G Thirumalai ScaleMP vSMP 5318425091fSRavikiran G Thirumalai SGI Ultraviolet 5328425091fSRavikiran G Thirumalai 5338425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5348425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5358425091fSRavikiran G Thirumalaiendif 536c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 537c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 53844b111b5SSteffen Persvoldconfig X86_NUMACHIP 53944b111b5SSteffen Persvold bool "Numascale NumaChip" 54044b111b5SSteffen Persvold depends on X86_64 54144b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 54244b111b5SSteffen Persvold depends on NUMA 54344b111b5SSteffen Persvold depends on SMP 54444b111b5SSteffen Persvold depends on X86_X2APIC 545f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 546a7f7f624SMasahiro Yamada help 54744b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 54844b111b5SSteffen Persvold enable more than ~168 cores. 54944b111b5SSteffen Persvold If you don't have one of these, you should say N here. 55003b48632SNick Piggin 5516a48565eSIngo Molnarconfig X86_VSMP 552c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5536276a074SBorislav Petkov select HYPERVISOR_GUEST 5546a48565eSIngo Molnar select PARAVIRT 5556a48565eSIngo Molnar depends on X86_64 && PCI 556c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 557ead91d4bSShai Fultheim depends on SMP 558a7f7f624SMasahiro Yamada help 5596a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5606a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5616a48565eSIngo Molnar if you have one of these machines. 5626a48565eSIngo Molnar 563c5c606d9SRavikiran G Thirumalaiconfig X86_UV 564c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 565c5c606d9SRavikiran G Thirumalai depends on X86_64 566c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 56754c28d29SJack Steiner depends on NUMA 5681ecb4ae5SAndrew Morton depends on EFI 569c2209ea5SIngo Molnar depends on KEXEC_CORE 5709d6c26e7SSuresh Siddha depends on X86_X2APIC 5711222e564SIngo Molnar depends on PCI 572a7f7f624SMasahiro Yamada help 573c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 574c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 575c5c606d9SRavikiran G Thirumalai 576c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 577c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 578506f1d07SSam Ravnborg 579ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 580ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 581cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 582a7f7f624SMasahiro Yamada help 583ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 584ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 585ddd70cf9SJun Nakajima Goldfish emulator say N here. 586ddd70cf9SJun Nakajima 587c751e17bSThomas Gleixnerconfig X86_INTEL_CE 588c751e17bSThomas Gleixner bool "CE4100 TV platform" 589c751e17bSThomas Gleixner depends on PCI 590c751e17bSThomas Gleixner depends on PCI_GODIRECT 5916084a6e2SJiang Liu depends on X86_IO_APIC 592c751e17bSThomas Gleixner depends on X86_32 593c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 59437bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 595da6b737bSSebastian Andrzej Siewior select OF 596da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 597a7f7f624SMasahiro Yamada help 598c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 599c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 600c751e17bSThomas Gleixner boxes and media devices. 601c751e17bSThomas Gleixner 6024cb9b00fSDavid Cohenconfig X86_INTEL_MID 60343605ef1SAlan Cox bool "Intel MID platform support" 60443605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 605edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6061ea7c673SAlan Cox depends on PCI 6073fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6081ea7c673SAlan Cox depends on X86_IO_APIC 6094cb9b00fSDavid Cohen select I2C 6107c9c3a1eSAlan Cox select DW_APB_TIMER 61154b34aa0SMika Westerberg select INTEL_SCU_PCI 612a7f7f624SMasahiro Yamada help 6134cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6144cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6154cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6161ea7c673SAlan Cox 6174cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6184cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 61943605ef1SAlan Cox 6208bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6218bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6228bbc2a13SBryan O'Donoghue depends on X86_32 6238bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6248bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6258bbc2a13SBryan O'Donoghue depends on X86_TSC 6268bbc2a13SBryan O'Donoghue depends on PCI 6278bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6288bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6298bbc2a13SBryan O'Donoghue select IOSF_MBI 6308bbc2a13SBryan O'Donoghue select INTEL_IMR 6319ab6eb51SAndy Shevchenko select COMMON_CLK 632a7f7f624SMasahiro Yamada help 6338bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6348bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6358bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6368bbc2a13SBryan O'Donoghue 6373d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6383d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6395962dd22SSinan Kaya depends on X86 && ACPI && PCI 6403d48aab1SMika Westerberg select COMMON_CLK 6410f531431SMathias Nyman select PINCTRL 642eebb3e8dSAndy Shevchenko select IOSF_MBI 643a7f7f624SMasahiro Yamada help 6443d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6453d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6460f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6470f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6483d48aab1SMika Westerberg 64992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 65092082a88SKen Xue bool "AMD ACPI2Platform devices support" 65192082a88SKen Xue depends on ACPI 65292082a88SKen Xue select COMMON_CLK 65392082a88SKen Xue select PINCTRL 654a7f7f624SMasahiro Yamada help 65592082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 65692082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 65792082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 65892082a88SKen Xue implemented under PINCTRL subsystem. 65992082a88SKen Xue 660ced3ce76SDavid E. Boxconfig IOSF_MBI 661ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 662ced3ce76SDavid E. Box depends on PCI 663a7f7f624SMasahiro Yamada help 664ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 665ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 666ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 667ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 668ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 669ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 670ced3ce76SDavid E. Box This list is not meant to be exclusive. 671ced3ce76SDavid E. Box - BayTrail 672ced3ce76SDavid E. Box - Braswell 673ced3ce76SDavid E. Box - Quark 674ced3ce76SDavid E. Box 675ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 676ced3ce76SDavid E. Box 677ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 678ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 679ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 680a7f7f624SMasahiro Yamada help 681ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 682ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 683ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 684ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 685ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 686ed2226bdSDavid E. Box device they want to access. 687ed2226bdSDavid E. Box 688ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 689ed2226bdSDavid E. Box 690c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 691c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 692506f1d07SSam Ravnborg depends on X86_32 693c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 694c5c606d9SRavikiran G Thirumalai select M486 695c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 696a7f7f624SMasahiro Yamada help 697c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 698c5c606d9SRavikiran G Thirumalai as R-8610-(G). 699c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 700c5c606d9SRavikiran G Thirumalai 701e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7029c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7039c398017SIngo Molnar depends on X86_32 && SMP 704c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 705a7f7f624SMasahiro Yamada help 706b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 707b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 708b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 709b5660ba7SH. Peter Anvin one and will fallback to default. 710d49c4288SYinghai Lu 711c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 712d49c4288SYinghai Lu 713d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7146fc108a0SJan Beulich def_bool y 715d949f36fSLinus Torvalds # MCE code calls memory_failure(): 716d949f36fSLinus Torvalds depends on X86_MCE 717d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 718d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 719d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 720d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 721d949f36fSLinus Torvalds 72283125a3aSAlessandro Rubiniconfig STA2X11 72383125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 72483125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 72583125a3aSAlessandro Rubini select SWIOTLB 72683125a3aSAlessandro Rubini select MFD_STA2X11 7270145071bSLinus Walleij select GPIOLIB 728a7f7f624SMasahiro Yamada help 72983125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 73083125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 73183125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 73283125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 73383125a3aSAlessandro Rubini standard PC machines. 73483125a3aSAlessandro Rubini 73582148d1dSShérabconfig X86_32_IRIS 73682148d1dSShérab tristate "Eurobraille/Iris poweroff module" 73782148d1dSShérab depends on X86_32 738a7f7f624SMasahiro Yamada help 73982148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 74082148d1dSShérab to shut themselves down properly. A special I/O sequence is 74182148d1dSShérab needed to do so, which is what this module does at 74282148d1dSShérab kernel shutdown. 74382148d1dSShérab 74482148d1dSShérab This is only for Iris machines from EuroBraille. 74582148d1dSShérab 74682148d1dSShérab If unused, say N. 74782148d1dSShérab 748ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7493c2362e6SHarvey Harrison def_bool y 7503c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 751a87d0914SKen Chen depends on X86 752a7f7f624SMasahiro Yamada help 753506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 754506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 755506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 756506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 757506f1d07SSam Ravnborg 758506f1d07SSam Ravnborg If in doubt, say "Y". 759506f1d07SSam Ravnborg 7606276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7616276a074SBorislav Petkov bool "Linux guest support" 762a7f7f624SMasahiro Yamada help 7636276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7646276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7656276a074SBorislav Petkov setup. 766506f1d07SSam Ravnborg 7676276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7686276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 769506f1d07SSam Ravnborg 7706276a074SBorislav Petkovif HYPERVISOR_GUEST 771506f1d07SSam Ravnborg 772e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 773e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 774a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 775a7f7f624SMasahiro Yamada help 776e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 777e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 778e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 779e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 780e61bd94aSEduardo Pereira Habkost 781c00a280aSJuergen Grossconfig PARAVIRT_XXL 782c00a280aSJuergen Gross bool 783c00a280aSJuergen Gross 7846276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7856276a074SBorislav Petkov bool "paravirt-ops debugging" 7866276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 787a7f7f624SMasahiro Yamada help 7886276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7896276a074SBorislav Petkov a paravirt_op is missing when it is called. 7906276a074SBorislav Petkov 791b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 792b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7936ea30386SKees Cook depends on PARAVIRT && SMP 794a7f7f624SMasahiro Yamada help 795b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 796b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 797b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 798b4ecc126SJeremy Fitzhardinge 7994c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8004c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 801b4ecc126SJeremy Fitzhardinge 8024c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 803b4ecc126SJeremy Fitzhardinge 804ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 805ecca2502SZhao Yakui def_bool n 806ecca2502SZhao Yakui 8076276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8086276a074SBorislav Petkov 8096276a074SBorislav Petkovconfig KVM_GUEST 8106276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8116276a074SBorislav Petkov depends on PARAVIRT 8126276a074SBorislav Petkov select PARAVIRT_CLOCK 813a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 814b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8156276a074SBorislav Petkov default y 816a7f7f624SMasahiro Yamada help 8176276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8186276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8196276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8206276a074SBorislav Petkov underlying device model, the host provides the guest with 8216276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8226276a074SBorislav Petkov 823a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 824a1c4423bSMarcelo Tosatti def_bool n 825a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 826a1c4423bSMarcelo Tosatti help 827a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 828a1c4423bSMarcelo Tosatti 8297733607fSMaran Wilsonconfig PVH 8307733607fSMaran Wilson bool "Support for running PVH guests" 831a7f7f624SMasahiro Yamada help 8327733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8337733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8347733607fSMaran Wilson 8356276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8366276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8376276a074SBorislav Petkov depends on PARAVIRT 838a7f7f624SMasahiro Yamada help 8396276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8406276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8416276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8426276a074SBorislav Petkov that, there can be a small performance impact. 8436276a074SBorislav Petkov 8446276a074SBorislav Petkov If in doubt, say N here. 8456276a074SBorislav Petkov 8467af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8477af192c9SGerd Hoffmann bool 8487af192c9SGerd Hoffmann 8494a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8504a362601SJan Kiszka bool "Jailhouse non-root cell support" 851abde587bSArnd Bergmann depends on X86_64 && PCI 85287e65d05SJan Kiszka select X86_PM_TIMER 853a7f7f624SMasahiro Yamada help 8544a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8554a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8564a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8574a362601SJan Kiszka 858ec7972c9SZhao Yakuiconfig ACRN_GUEST 859ec7972c9SZhao Yakui bool "ACRN Guest support" 860ec7972c9SZhao Yakui depends on X86_64 861498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 862ec7972c9SZhao Yakui help 863ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 864ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 865ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 866ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 867ec7972c9SZhao Yakui found in https://projectacrn.org/. 868ec7972c9SZhao Yakui 8696276a074SBorislav Petkovendif #HYPERVISOR_GUEST 87097349135SJeremy Fitzhardinge 871506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 872506f1d07SSam Ravnborg 873506f1d07SSam Ravnborgconfig HPET_TIMER 8743c2362e6SHarvey Harrison def_bool X86_64 875506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 876a7f7f624SMasahiro Yamada help 877506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 878506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 879506f1d07SSam Ravnborg present. 880506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 881506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 882506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8834e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8844e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 885506f1d07SSam Ravnborg 886506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 887506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 888506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 889506f1d07SSam Ravnborg 890506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 891506f1d07SSam Ravnborg 892506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8933c2362e6SHarvey Harrison def_bool y 8943228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 895506f1d07SSam Ravnborg 8966a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 897506f1d07SSam Ravnborg# The code disables itself when not needed. 8987ae9392cSThomas Petazzoniconfig DMI 8997ae9392cSThomas Petazzoni default y 900cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9016a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 902a7f7f624SMasahiro Yamada help 9037ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9047ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9057ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9067ae9392cSThomas Petazzoni BIOS code. 9077ae9392cSThomas Petazzoni 908506f1d07SSam Ravnborgconfig GART_IOMMU 90938901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9102f9237d4SChristoph Hellwig select DMA_OPS 911a4ce5a48SChristoph Hellwig select IOMMU_HELPER 912506f1d07SSam Ravnborg select SWIOTLB 91323ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 914a7f7f624SMasahiro Yamada help 915ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 916ced3c42cSIngo Molnar GART based hardware IOMMUs. 917ced3c42cSIngo Molnar 918ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 919ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 920ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 921ced3c42cSIngo Molnar 922ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 923ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 924ced3c42cSIngo Molnar 925ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 926ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 927ced3c42cSIngo Molnar 32-bit limited device. 928ced3c42cSIngo Molnar 929ced3c42cSIngo Molnar If unsure, say Y. 930506f1d07SSam Ravnborg 9311184dc2fSMike Travisconfig MAXSMP 932ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9336ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 93436f5101aSMike Travis select CPUMASK_OFFSTACK 935a7f7f624SMasahiro Yamada help 936ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9371184dc2fSMike Travis If unsure, say N. 938506f1d07SSam Ravnborg 939aec6487eSIngo Molnar# 940aec6487eSIngo Molnar# The maximum number of CPUs supported: 941aec6487eSIngo Molnar# 942aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 943aec6487eSIngo Molnar# and which can be configured interactively in the 944aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 945aec6487eSIngo Molnar# 946aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 947aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 948aec6487eSIngo Molnar# 949aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 950aec6487eSIngo Molnar# interactive configuration. ) 951aec6487eSIngo Molnar# 952a0d0bb4dSRandy Dunlap 953aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 954a0d0bb4dSRandy Dunlap int 955aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 956a0d0bb4dSRandy Dunlap default 1 if !SMP 957a0d0bb4dSRandy Dunlap default 2 958a0d0bb4dSRandy Dunlap 959aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 960a0d0bb4dSRandy Dunlap int 961a0d0bb4dSRandy Dunlap depends on X86_32 962aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 963aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 964a0d0bb4dSRandy Dunlap default 1 if !SMP 965a0d0bb4dSRandy Dunlap 966aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 967a0d0bb4dSRandy Dunlap int 968a0d0bb4dSRandy Dunlap depends on X86_64 9691edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9701edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 971a0d0bb4dSRandy Dunlap default 1 if !SMP 972aec6487eSIngo Molnar 973aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 974aec6487eSIngo Molnar int 975aec6487eSIngo Molnar depends on X86_32 976aec6487eSIngo Molnar default 32 if X86_BIGSMP 977aec6487eSIngo Molnar default 8 if SMP 978aec6487eSIngo Molnar default 1 if !SMP 979aec6487eSIngo Molnar 980aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 981aec6487eSIngo Molnar int 982aec6487eSIngo Molnar depends on X86_64 983a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 984a0d0bb4dSRandy Dunlap default 64 if SMP 985aec6487eSIngo Molnar default 1 if !SMP 986a0d0bb4dSRandy Dunlap 987506f1d07SSam Ravnborgconfig NR_CPUS 98836f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 989aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 990aec6487eSIngo Molnar default NR_CPUS_DEFAULT 991a7f7f624SMasahiro Yamada help 992506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 993bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 994cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 995506f1d07SSam Ravnborg minimum value which makes sense is 2. 996506f1d07SSam Ravnborg 997aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 998aec6487eSIngo Molnar to the kernel image. 999506f1d07SSam Ravnborg 100066558b73STim Chenconfig SCHED_CLUSTER 100166558b73STim Chen bool "Cluster scheduler support" 100266558b73STim Chen depends on SMP 100366558b73STim Chen default y 100466558b73STim Chen help 100566558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 100666558b73STim Chen making when dealing with machines that have clusters of CPUs. 100766558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 100866558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 100966558b73STim Chen busses. 101066558b73STim Chen 1011506f1d07SSam Ravnborgconfig SCHED_SMT 1012dbe73364SThomas Gleixner def_bool y if SMP 1013506f1d07SSam Ravnborg 1014506f1d07SSam Ravnborgconfig SCHED_MC 10153c2362e6SHarvey Harrison def_bool y 10163c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1017c8e56d20SBorislav Petkov depends on SMP 1018a7f7f624SMasahiro Yamada help 1019506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1020506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1021506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1022506f1d07SSam Ravnborg 1023de966cf4STim Chenconfig SCHED_MC_PRIO 1024de966cf4STim Chen bool "CPU core priorities scheduler support" 10250a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10260a21fc12SIngo Molnar select X86_INTEL_PSTATE 10270a21fc12SIngo Molnar select CPU_FREQ 1028de966cf4STim Chen default y 1029a7f7f624SMasahiro Yamada help 1030de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1031de966cf4STim Chen core ordering determined at manufacturing time, which allows 1032de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1033de966cf4STim Chen single threaded workloads) than others. 1034de966cf4STim Chen 1035de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1036de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1037de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1038de966cf4STim Chen overall system performance can be achieved. 1039de966cf4STim Chen 1040de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1041de966cf4STim Chen 1042de966cf4STim Chen If unsure say Y here. 10435e76b2abSTim Chen 104430b8b006SThomas Gleixnerconfig UP_LATE_INIT 104530b8b006SThomas Gleixner def_bool y 1046ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 104730b8b006SThomas Gleixner 1048506f1d07SSam Ravnborgconfig X86_UP_APIC 104950849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 105050849eefSJan Beulich default PCI_MSI 105138a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1052a7f7f624SMasahiro Yamada help 1053506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1054506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1055506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1056506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1057506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1058506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1059506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1060506f1d07SSam Ravnborg lockups. 1061506f1d07SSam Ravnborg 1062506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1063506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1064506f1d07SSam Ravnborg depends on X86_UP_APIC 1065a7f7f624SMasahiro Yamada help 1066506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1067506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1068506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1069506f1d07SSam Ravnborg 1070506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1071506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1072506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1073506f1d07SSam Ravnborg 1074506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10753c2362e6SHarvey Harrison def_bool y 10760dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1077b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 107852f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1079506f1d07SSam Ravnborg 1080506f1d07SSam Ravnborgconfig X86_IO_APIC 1081b1da1e71SJan Beulich def_bool y 1082b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1083506f1d07SSam Ravnborg 108441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 108541b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 108641b9eb26SStefan Assmann depends on X86_IO_APIC 1087a7f7f624SMasahiro Yamada help 108841b9eb26SStefan Assmann This option enables a workaround that fixes a source of 108941b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 109041b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 109141b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 109241b9eb26SStefan Assmann 109341b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 109441b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 109541b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 109641b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 109741b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 109841b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 109941b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 110041b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 110141b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 110241b9eb26SStefan Assmann down (vital) interrupt lines. 110341b9eb26SStefan Assmann 110441b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 110541b9eb26SStefan Assmann increased on these systems. 110641b9eb26SStefan Assmann 1107506f1d07SSam Ravnborgconfig X86_MCE 1108bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1109648ed940SChen, Gong select GENERIC_ALLOCATOR 1110e57dbaf7SBorislav Petkov default y 1111a7f7f624SMasahiro Yamada help 1112bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1113bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1114506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1115bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11164efc0670SAndi Kleen 11175de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11185de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11195de97c9fSTony Luck depends on X86_MCE 1120a7f7f624SMasahiro Yamada help 11215de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11225de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11235de97c9fSTony Luck rasdaemon solution. 11245de97c9fSTony Luck 1125506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11263c2362e6SHarvey Harrison def_bool y 11273c2362e6SHarvey Harrison prompt "Intel MCE features" 1128c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1129a7f7f624SMasahiro Yamada help 1130506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1131506f1d07SSam Ravnborg the thermal monitor. 1132506f1d07SSam Ravnborg 1133506f1d07SSam Ravnborgconfig X86_MCE_AMD 11343c2362e6SHarvey Harrison def_bool y 11353c2362e6SHarvey Harrison prompt "AMD MCE features" 1136f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1137a7f7f624SMasahiro Yamada help 1138506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1139506f1d07SSam Ravnborg the DRAM Error Threshold. 1140506f1d07SSam Ravnborg 11414efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11426fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1143c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1144a7f7f624SMasahiro Yamada help 11454efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11465065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11474efc0670SAndi Kleen line. 11484efc0670SAndi Kleen 1149b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1150b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11516fc108a0SJan Beulich def_bool y 1152b2762686SAndi Kleen 1153ea149b36SAndi Kleenconfig X86_MCE_INJECT 1154bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1155ea149b36SAndi Kleen tristate "Machine check injector support" 1156a7f7f624SMasahiro Yamada help 1157ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1158ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1159ea149b36SAndi Kleen QA it is safe to say n. 1160ea149b36SAndi Kleen 116107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1162e633c65aSKan Liang 11635aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11641e642812SIngo Molnar bool "Legacy VM86 support" 1165506f1d07SSam Ravnborg depends on X86_32 1166a7f7f624SMasahiro Yamada help 11675aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11685aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11695aef51c3SAndy Lutomirski 11705aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11715aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11725aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11735aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11745aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11751e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11761e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11771e642812SIngo Molnar mode might be faster than emulation and you might want to 11781e642812SIngo Molnar enable this option. 11795aef51c3SAndy Lutomirski 11801e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11811e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11821e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 11831e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 11845aef51c3SAndy Lutomirski 11851e642812SIngo Molnar Enabling this option increases the complexity of the kernel 11861e642812SIngo Molnar and slows down exception handling a tiny bit. 11875aef51c3SAndy Lutomirski 11881e642812SIngo Molnar If unsure, say N here. 11895aef51c3SAndy Lutomirski 11905aef51c3SAndy Lutomirskiconfig VM86 11915aef51c3SAndy Lutomirski bool 11925aef51c3SAndy Lutomirski default X86_LEGACY_VM86 119334273f41SH. Peter Anvin 119434273f41SH. Peter Anvinconfig X86_16BIT 119534273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 119634273f41SH. Peter Anvin default y 1197a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1198a7f7f624SMasahiro Yamada help 119934273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 120034273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 120134273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 120234273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 120334273f41SH. Peter Anvin 120434273f41SH. Peter Anvinconfig X86_ESPFIX32 120534273f41SH. Peter Anvin def_bool y 120634273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1207506f1d07SSam Ravnborg 1208197725deSH. Peter Anvinconfig X86_ESPFIX64 1209197725deSH. Peter Anvin def_bool y 121034273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1211506f1d07SSam Ravnborg 12121ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12131ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12141ad83c85SAndy Lutomirski default y 12151ad83c85SAndy Lutomirski depends on X86_64 1216a7f7f624SMasahiro Yamada help 12171ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12181ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12191ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12201ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12211ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12221ad83c85SAndy Lutomirski 0xffffffffff600?00. 12231ad83c85SAndy Lutomirski 12241ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12251ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12261ad83c85SAndy Lutomirski 12271ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12281ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12291ad83c85SAndy Lutomirski 1230111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1231111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1232a24ca997SThomas Gleixner default y 1233a7f7f624SMasahiro Yamada help 1234111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1235111e7b15SThomas Gleixner for legacy applications. 1236111e7b15SThomas Gleixner 1237c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1238c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1239c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1240c8137aceSThomas Gleixner capabilities and permission from potentially active security 1241c8137aceSThomas Gleixner modules. 1242c8137aceSThomas Gleixner 1243c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1244c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1245a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1246a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1247c8137aceSThomas Gleixner 1248506f1d07SSam Ravnborgconfig TOSHIBA 1249506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1250506f1d07SSam Ravnborg depends on X86_32 1251a7f7f624SMasahiro Yamada help 1252506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1253506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1254506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1255506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1256506f1d07SSam Ravnborg 1257506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1258506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1259506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1260506f1d07SSam Ravnborg 1261506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1262506f1d07SSam Ravnborg Say N otherwise. 1263506f1d07SSam Ravnborg 1264506f1d07SSam Ravnborgconfig I8K 1265039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1266ef775a0eSRandy Dunlap depends on HWMON 1267ef775a0eSRandy Dunlap depends on PROC_FS 1268039ae585SPali Rohár select SENSORS_DELL_SMM 1269a7f7f624SMasahiro Yamada help 1270039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1271039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1272039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1273039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1274039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1275039ae585SPali Rohár needed userspace package i8kutils. 1276506f1d07SSam Ravnborg 1277039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1278039ae585SPali Rohár use userspace package i8kutils. 1279506f1d07SSam Ravnborg Say N otherwise. 1280506f1d07SSam Ravnborg 1281506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12829ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12839ba16087SJan Beulich depends on X86_32 1284a7f7f624SMasahiro Yamada help 1285506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1286506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1287506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1288506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1289506f1d07SSam Ravnborg system. 1290506f1d07SSam Ravnborg 1291506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12925e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1293506f1d07SSam Ravnborg 1294506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1295506f1d07SSam Ravnborg enable this option even if you don't need it. 1296506f1d07SSam Ravnborg Say N otherwise. 1297506f1d07SSam Ravnborg 1298506f1d07SSam Ravnborgconfig MICROCODE 12999a2bc335SBorislav Petkov bool "CPU microcode loading support" 13009a2bc335SBorislav Petkov default y 130180030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1302a7f7f624SMasahiro Yamada help 1303506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13045f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13055f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13065f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13075f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13085f9c01aaSBorislav Petkov the Linux kernel. 1309506f1d07SSam Ravnborg 13105f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1311cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13125f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13135f9c01aaSBorislav Petkov initrd for microcode blobs. 1314506f1d07SSam Ravnborg 1315c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1316c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1317c508c46eSBenjamin Gilbert config option. 1318506f1d07SSam Ravnborg 13198d86f390SPeter Orubaconfig MICROCODE_INTEL 1320e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13218d86f390SPeter Oruba depends on MICROCODE 13228d86f390SPeter Oruba default MICROCODE 1323a7f7f624SMasahiro Yamada help 13248d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13258d86f390SPeter Oruba processors. 13268d86f390SPeter Oruba 1327b8989db9SAlan For the current Intel microcode data package go to 1328b8989db9SAlan <https://downloadcenter.intel.com> and search for 1329b8989db9SAlan 'Linux Processor Microcode Data File'. 13308d86f390SPeter Oruba 133180cc9f10SPeter Orubaconfig MICROCODE_AMD 1332e43f6e67SBorislav Petkov bool "AMD microcode loading support" 133380cc9f10SPeter Oruba depends on MICROCODE 1334a7f7f624SMasahiro Yamada help 133580cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 133680cc9f10SPeter Oruba processors will be enabled. 133780cc9f10SPeter Oruba 1338506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1339c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1340c02f48e0SBorislav Petkov default n 1341506f1d07SSam Ravnborg depends on MICROCODE 1342a7f7f624SMasahiro Yamada help 1343c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1344c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1345c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1346c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1347c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1348cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1349506f1d07SSam Ravnborg 1350506f1d07SSam Ravnborgconfig X86_MSR 1351506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1352a7f7f624SMasahiro Yamada help 1353506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1354506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1355506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1356506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1357506f1d07SSam Ravnborg systems. 1358506f1d07SSam Ravnborg 1359506f1d07SSam Ravnborgconfig X86_CPUID 1360506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1361a7f7f624SMasahiro Yamada help 1362506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1363506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1364506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1365506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1366506f1d07SSam Ravnborg 1367506f1d07SSam Ravnborgchoice 1368506f1d07SSam Ravnborg prompt "High Memory Support" 13696fc108a0SJan Beulich default HIGHMEM4G 1370506f1d07SSam Ravnborg depends on X86_32 1371506f1d07SSam Ravnborg 1372506f1d07SSam Ravnborgconfig NOHIGHMEM 1373506f1d07SSam Ravnborg bool "off" 1374a7f7f624SMasahiro Yamada help 1375506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1376506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1377506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1378506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1379506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1380506f1d07SSam Ravnborg "high memory". 1381506f1d07SSam Ravnborg 1382506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1383506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1384506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1385506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1386506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1387506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1388506f1d07SSam Ravnborg possible. 1389506f1d07SSam Ravnborg 1390506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1391506f1d07SSam Ravnborg answer "4GB" here. 1392506f1d07SSam Ravnborg 1393506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1394506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1395506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1396506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1397506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1398506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1399506f1d07SSam Ravnborg 1400506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1401506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1402506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1403506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1404506f1d07SSam Ravnborg kernel at boot time.) 1405506f1d07SSam Ravnborg 1406506f1d07SSam Ravnborg If unsure, say "off". 1407506f1d07SSam Ravnborg 1408506f1d07SSam Ravnborgconfig HIGHMEM4G 1409506f1d07SSam Ravnborg bool "4GB" 1410a7f7f624SMasahiro Yamada help 1411506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1412506f1d07SSam Ravnborg gigabytes of physical RAM. 1413506f1d07SSam Ravnborg 1414506f1d07SSam Ravnborgconfig HIGHMEM64G 1415506f1d07SSam Ravnborg bool "64GB" 1416225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1417506f1d07SSam Ravnborg select X86_PAE 1418a7f7f624SMasahiro Yamada help 1419506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1420506f1d07SSam Ravnborg gigabytes of physical RAM. 1421506f1d07SSam Ravnborg 1422506f1d07SSam Ravnborgendchoice 1423506f1d07SSam Ravnborg 1424506f1d07SSam Ravnborgchoice 14256a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1426506f1d07SSam Ravnborg default VMSPLIT_3G 1427506f1d07SSam Ravnborg depends on X86_32 1428a7f7f624SMasahiro Yamada help 1429506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1430506f1d07SSam Ravnborg 1431506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1432506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1433506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1434506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1435506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1436506f1d07SSam Ravnborg available to user programs, making the address space there 1437506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1438506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1439506f1d07SSam Ravnborg kernel modules. 1440506f1d07SSam Ravnborg 1441506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1442506f1d07SSam Ravnborg option alone! 1443506f1d07SSam Ravnborg 1444506f1d07SSam Ravnborg config VMSPLIT_3G 1445506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1446506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1447506f1d07SSam Ravnborg depends on !X86_PAE 1448506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1449506f1d07SSam Ravnborg config VMSPLIT_2G 1450506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1451506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1452506f1d07SSam Ravnborg depends on !X86_PAE 1453506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1454506f1d07SSam Ravnborg config VMSPLIT_1G 1455506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1456506f1d07SSam Ravnborgendchoice 1457506f1d07SSam Ravnborg 1458506f1d07SSam Ravnborgconfig PAGE_OFFSET 1459506f1d07SSam Ravnborg hex 1460506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1461506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1462506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1463506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1464506f1d07SSam Ravnborg default 0xC0000000 1465506f1d07SSam Ravnborg depends on X86_32 1466506f1d07SSam Ravnborg 1467506f1d07SSam Ravnborgconfig HIGHMEM 14683c2362e6SHarvey Harrison def_bool y 1469506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1470506f1d07SSam Ravnborg 1471506f1d07SSam Ravnborgconfig X86_PAE 14729ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1473506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1474d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14759d99c712SChristian Melki select SWIOTLB 1476a7f7f624SMasahiro Yamada help 1477506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1478506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1479506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1480506f1d07SSam Ravnborg consumes more pagetable space per process. 1481506f1d07SSam Ravnborg 148277ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148377ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148418ec1eafSKirill A. Shutemov default y 1485eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1486162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148777ef56e4SKirill A. Shutemov depends on X86_64 1488a7f7f624SMasahiro Yamada help 148977ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 149077ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 149177ef56e4SKirill A. Shutemov physical address space. 149277ef56e4SKirill A. Shutemov 149377ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149477ef56e4SKirill A. Shutemov 14956657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14966657fca0SKirill A. Shutemov support 4- or 5-level paging. 149777ef56e4SKirill A. Shutemov 1498cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 149977ef56e4SKirill A. Shutemov information. 150077ef56e4SKirill A. Shutemov 150177ef56e4SKirill A. Shutemov Say N if unsure. 150277ef56e4SKirill A. Shutemov 150310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1504e5008abeSLuis R. Rodriguez def_bool y 15052e1da13fSVlastimil Babka depends on X86_64 1506a7f7f624SMasahiro Yamada help 150710971ab2SIngo Molnar Certain kernel features effectively disable kernel 150810971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 150910971ab2SIngo Molnar supports them), so don't confuse the user by printing 151010971ab2SIngo Molnar that we have them enabled. 15119e899816SNick Piggin 15125c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15135c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15145c280cf6SThomas Gleixner depends on DEBUG_FS 1515a7f7f624SMasahiro Yamada help 1516b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1517a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15185c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15195c280cf6SThomas Gleixner 15207744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15217744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15227744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 152382fef0adSDavid Rientjes select DMA_COHERENT_POOL 152494d49eb3SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 1525ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 15269087c375STom Lendacky select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1527597cfe48SJoerg Roedel select INSTRUCTION_DECODER 152822916417STom Lendacky select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 1529aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 1530a7f7f624SMasahiro Yamada help 15317744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15327744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15337744ccdbSTom Lendacky Encryption (SME). 15347744ccdbSTom Lendacky 15357744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15367744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15377744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1538a7f7f624SMasahiro Yamada help 15397744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15407744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15417744ccdbSTom Lendacky 15427744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15437744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15447744ccdbSTom Lendacky 15457744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15467744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15477744ccdbSTom Lendacky 1548506f1d07SSam Ravnborg# Common NUMA Features 1549506f1d07SSam Ravnborgconfig NUMA 1550e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1551506f1d07SSam Ravnborg depends on SMP 1552b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1553b5660ba7SH. Peter Anvin default y if X86_BIGSMP 1554*7ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 1555a7f7f624SMasahiro Yamada help 1556e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1557fd51b2d7SKOSAKI Motohiro 1558506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1559506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1560506f1d07SSam Ravnborg NUMA awareness to the kernel. 1561506f1d07SSam Ravnborg 1562c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1563fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1564fd51b2d7SKOSAKI Motohiro 1565b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15667cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1567fd51b2d7SKOSAKI Motohiro 1568fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1569506f1d07SSam Ravnborg 1570eec1d4faSHans Rosenfeldconfig AMD_NUMA 15713c2362e6SHarvey Harrison def_bool y 15723c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15735da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1574a7f7f624SMasahiro Yamada help 1575eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1576eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1577eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1578eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1579eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1580506f1d07SSam Ravnborg 1581506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15823c2362e6SHarvey Harrison def_bool y 15833c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1584506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1585506f1d07SSam Ravnborg select ACPI_NUMA 1586a7f7f624SMasahiro Yamada help 1587506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1588506f1d07SSam Ravnborg 1589506f1d07SSam Ravnborgconfig NUMA_EMU 1590506f1d07SSam Ravnborg bool "NUMA emulation" 15911b7e03efSTejun Heo depends on NUMA 1592a7f7f624SMasahiro Yamada help 1593506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1594506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1595506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1596506f1d07SSam Ravnborg 1597506f1d07SSam Ravnborgconfig NODES_SHIFT 1598d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 159951591e31SDavid Rientjes range 1 10 160051591e31SDavid Rientjes default "10" if MAXSMP 1601506f1d07SSam Ravnborg default "6" if X86_64 1602506f1d07SSam Ravnborg default "3" 1603a9ee6cf5SMike Rapoport depends on NUMA 1604a7f7f624SMasahiro Yamada help 16051184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1606692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1607506f1d07SSam Ravnborg 1608506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1609506f1d07SSam Ravnborg def_bool y 16103b16651fSTejun Heo depends on X86_32 && !NUMA 1611506f1d07SSam Ravnborg 1612506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1613506f1d07SSam Ravnborg def_bool y 16146ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1615506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1616506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1617506f1d07SSam Ravnborg 16183b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16196ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16203b16651fSTejun Heo 1621506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1622506f1d07SSam Ravnborg def_bool y 1623b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1624506f1d07SSam Ravnborg 1625506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1626a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16275c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1628a0842b70SToshi Kani help 1629a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1630cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1631a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1632506f1d07SSam Ravnborg 16333b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16343b16651fSTejun Heo def_bool y 16353b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16363b16651fSTejun Heo 1637a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1638a29815a3SAvi Kivity hex 1639a29815a3SAvi Kivity default 0 if X86_32 1640a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1641a29815a3SAvi Kivity 16427a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16437a67832cSDan Williams bool 16447a67832cSDan Williams 1645ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16467a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16479f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16489f53f9faSDan Williams depends on BLK_DEV 16497a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16507b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16519f53f9faSDan Williams select LIBNVDIMM 1652ec776ef6SChristoph Hellwig help 1653ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1654ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1655ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1656ec776ef6SChristoph Hellwig they can be used for persistent storage. 1657ec776ef6SChristoph Hellwig 1658ec776ef6SChristoph Hellwig Say Y if unsure. 1659ec776ef6SChristoph Hellwig 1660506f1d07SSam Ravnborgconfig HIGHPTE 1661506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16626fc108a0SJan Beulich depends on HIGHMEM 1663a7f7f624SMasahiro Yamada help 1664506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1665506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1666506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1667506f1d07SSam Ravnborg entries in high memory. 1668506f1d07SSam Ravnborg 16699f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16709f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1671a7f7f624SMasahiro Yamada help 16729f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16739f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16749f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16759f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16769f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16779f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16789f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16798c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16809f077871SJeremy Fitzhardinge 16819f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16829f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16839f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16849f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16859f077871SJeremy Fitzhardinge 16869f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16879f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16889f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16899f077871SJeremy Fitzhardinge memory. 16909f077871SJeremy Fitzhardinge 1691c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1692c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1693c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1694c885df50SJeremy Fitzhardinge default y 1695a7f7f624SMasahiro Yamada help 1696c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1697c885df50SJeremy Fitzhardinge on or off. 1698c885df50SJeremy Fitzhardinge 1699506f1d07SSam Ravnborgconfig MATH_EMULATION 1700506f1d07SSam Ravnborg bool 1701a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 170287d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1703a7f7f624SMasahiro Yamada help 1704506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1705506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1706506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1707506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1708506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1709506f1d07SSam Ravnborg coprocessor or this emulation. 1710506f1d07SSam Ravnborg 1711506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1712506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1713506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1714506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1715506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1716506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1717506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1718506f1d07SSam Ravnborg intend to use this kernel on different machines. 1719506f1d07SSam Ravnborg 1720506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1721506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1722506f1d07SSam Ravnborg 1723506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1724506f1d07SSam Ravnborg kernel, it won't hurt. 1725506f1d07SSam Ravnborg 1726506f1d07SSam Ravnborgconfig MTRR 17276fc108a0SJan Beulich def_bool y 17286a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1729a7f7f624SMasahiro Yamada help 1730506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1731506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1732506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1733506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1734506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1735506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1736506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1737506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1738506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1739506f1d07SSam Ravnborg 1740506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1741506f1d07SSam Ravnborg control registers on other processors can be easily supported 1742506f1d07SSam Ravnborg as well: 1743506f1d07SSam Ravnborg 1744506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1745506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1746506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1747506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1748506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1749506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1750506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1751506f1d07SSam Ravnborg 1752506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1753506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1754506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1755506f1d07SSam Ravnborg 1756506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1757506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1758506f1d07SSam Ravnborg 1759cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1760506f1d07SSam Ravnborg 176195ffa243SYinghai Luconfig MTRR_SANITIZER 17622ffb3501SYinghai Lu def_bool y 176395ffa243SYinghai Lu prompt "MTRR cleanup support" 176495ffa243SYinghai Lu depends on MTRR 1765a7f7f624SMasahiro Yamada help 1766aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1767aba3728cSThomas Gleixner add writeback entries. 176895ffa243SYinghai Lu 1769aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1770692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1771aba3728cSThomas Gleixner mtrr_chunk_size. 177295ffa243SYinghai Lu 17732ffb3501SYinghai Lu If unsure, say Y. 177495ffa243SYinghai Lu 177595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1776f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1777f5098d62SYinghai Lu range 0 1 1778f5098d62SYinghai Lu default "0" 177995ffa243SYinghai Lu depends on MTRR_SANITIZER 1780a7f7f624SMasahiro Yamada help 1781f5098d62SYinghai Lu Enable mtrr cleanup default value 178295ffa243SYinghai Lu 178312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 178412031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 178512031a62SYinghai Lu range 0 7 178612031a62SYinghai Lu default "1" 178712031a62SYinghai Lu depends on MTRR_SANITIZER 1788a7f7f624SMasahiro Yamada help 178912031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1790aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 179112031a62SYinghai Lu 17922e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17936fc108a0SJan Beulich def_bool y 17946a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 17952a8a2719SIngo Molnar depends on MTRR 1796a7f7f624SMasahiro Yamada help 17972e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1798042b78e4SVenki Pallipadi 17992e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18002e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18012e5d9c85Svenkatesh.pallipadi@intel.com 18022e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1803042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18042e5d9c85Svenkatesh.pallipadi@intel.com 18052e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18062e5d9c85Svenkatesh.pallipadi@intel.com 180746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 180846cf98cdSVenkatesh Pallipadi def_bool y 180946cf98cdSVenkatesh Pallipadi depends on X86_PAT 181046cf98cdSVenkatesh Pallipadi 1811628c6246SH. Peter Anvinconfig ARCH_RANDOM 1812628c6246SH. Peter Anvin def_bool y 1813628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1814a7f7f624SMasahiro Yamada help 1815628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1816628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1817628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1818628c6246SH. Peter Anvin secure hardware random number generator. 1819628c6246SH. Peter Anvin 182051ae4a2dSH. Peter Anvinconfig X86_SMAP 182151ae4a2dSH. Peter Anvin def_bool y 182251ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1823a7f7f624SMasahiro Yamada help 182451ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 182551ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 182651ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 182751ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 182851ae4a2dSH. Peter Anvin 182951ae4a2dSH. Peter Anvin If unsure, say Y. 183051ae4a2dSH. Peter Anvin 1831b971880fSBabu Mogerconfig X86_UMIP 1832796ebc81SRicardo Neri def_bool y 1833b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1834a7f7f624SMasahiro Yamada help 1835b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1836b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1837b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1838b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1839b971880fSBabu Moger information about the hardware state. 1840796ebc81SRicardo Neri 1841796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1842796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1843796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1844796ebc81SRicardo Neri results are dummy. 1845aa35f896SRicardo Neri 184635e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 184738f3e775SBabu Moger prompt "Memory Protection Keys" 184835e97790SDave Hansen def_bool y 1849284244a9SDave Hansen # Note: only available in 64-bit mode 185038f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 185152c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 185252c8e601SIngo Molnar select ARCH_HAS_PKEYS 1853a7f7f624SMasahiro Yamada help 1854284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1855284244a9SDave Hansen page-based protections, but without requiring modification of the 1856284244a9SDave Hansen page tables when an application changes protection domains. 1857284244a9SDave Hansen 18581eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1859284244a9SDave Hansen 1860284244a9SDave Hansen If unsure, say y. 186135e97790SDave Hansen 1862db616173SMichal Hockochoice 1863db616173SMichal Hocko prompt "TSX enable mode" 1864db616173SMichal Hocko depends on CPU_SUP_INTEL 1865db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1866db616173SMichal Hocko help 1867db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1868db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1869db616173SMichal Hocko can lead to a noticeable performance boost. 1870db616173SMichal Hocko 1871db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1872db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1873db616173SMichal Hocko will be more of those attacks discovered in the future. 1874db616173SMichal Hocko 1875db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1876db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1877db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1878db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1879db616173SMichal Hocko for the particular machine. 1880db616173SMichal Hocko 1881db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1882db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1883db616173SMichal Hocko details. 1884db616173SMichal Hocko 1885db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1886db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1887db616173SMichal Hocko relevant. 1888db616173SMichal Hocko 1889db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1890db616173SMichal Hocko bool "off" 1891db616173SMichal Hocko help 1892db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1893db616173SMichal Hocko 1894db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1895db616173SMichal Hocko bool "on" 1896db616173SMichal Hocko help 1897db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1898db616173SMichal Hocko line parameter. 1899db616173SMichal Hocko 1900db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1901db616173SMichal Hocko bool "auto" 1902db616173SMichal Hocko help 1903db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1904db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1905db616173SMichal Hockoendchoice 1906db616173SMichal Hocko 1907e7e05452SSean Christophersonconfig X86_SGX 1908e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1909e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1910e7e05452SSean Christopherson depends on CRYPTO=y 1911e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1912e7e05452SSean Christopherson select SRCU 1913e7e05452SSean Christopherson select MMU_NOTIFIER 1914901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 1915e7e05452SSean Christopherson help 1916e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1917e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1918e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1919e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1920e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1921e7e05452SSean Christopherson hardware. 1922e7e05452SSean Christopherson 1923e7e05452SSean Christopherson If unsure, say N. 1924e7e05452SSean Christopherson 1925506f1d07SSam Ravnborgconfig EFI 19269ba16087SJan Beulich bool "EFI runtime service support" 19275b83683fSHuang, Ying depends on ACPI 1928f6ce5002SSergey Vlasov select UCS2_STRING 1929022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19301ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1931a7f7f624SMasahiro Yamada help 19328b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1933506f1d07SSam Ravnborg available (such as the EFI variable services). 1934506f1d07SSam Ravnborg 19358b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19368b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19378b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19388b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19398b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19408b2cb7a8SHuang, Ying platforms. 1941506f1d07SSam Ravnborg 1942291f3632SMatt Flemingconfig EFI_STUB 1943291f3632SMatt Fleming bool "EFI stub support" 1944b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 19458f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19467b2a583aSMatt Fleming select RELOCATABLE 1947a7f7f624SMasahiro Yamada help 1948291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1949291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1950291f3632SMatt Fleming 19514f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19520c759662SMatt Fleming 19537d453eeeSMatt Flemingconfig EFI_MIXED 19547d453eeeSMatt Fleming bool "EFI mixed-mode support" 19557d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1956a7f7f624SMasahiro Yamada help 19577d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19587d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19597d453eeeSMatt Fleming mode. 19607d453eeeSMatt Fleming 19617d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19627d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19637d453eeeSMatt Fleming the EFI handover protocol must be used. 19647d453eeeSMatt Fleming 19657d453eeeSMatt Fleming If unsure, say N. 19667d453eeeSMatt Fleming 19678636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 1968506f1d07SSam Ravnborg 1969506f1d07SSam Ravnborgconfig KEXEC 1970506f1d07SSam Ravnborg bool "kexec system call" 19712965faa5SDave Young select KEXEC_CORE 1972a7f7f624SMasahiro Yamada help 1973506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1974506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1975506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1976506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1977506f1d07SSam Ravnborg 1978506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1979506f1d07SSam Ravnborg 1980506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1981506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1982bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1983bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1984bf220695SGeert Uytterhoeven made. 1985506f1d07SSam Ravnborg 198674ca317cSVivek Goyalconfig KEXEC_FILE 198774ca317cSVivek Goyal bool "kexec file based system call" 19882965faa5SDave Young select KEXEC_CORE 198974ca317cSVivek Goyal select BUILD_BIN2C 199074ca317cSVivek Goyal depends on X86_64 199174ca317cSVivek Goyal depends on CRYPTO=y 199274ca317cSVivek Goyal depends on CRYPTO_SHA256=y 1993a7f7f624SMasahiro Yamada help 199474ca317cSVivek Goyal This is new version of kexec system call. This system call is 199574ca317cSVivek Goyal file based and takes file descriptors as system call argument 199674ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 199774ca317cSVivek Goyal accepted by previous system call. 199874ca317cSVivek Goyal 1999b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2000b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2001b799a09fSAKASHI Takahiro 200299d5cadfSJiri Bohacconfig KEXEC_SIG 20038e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 200474ca317cSVivek Goyal depends on KEXEC_FILE 2005a7f7f624SMasahiro Yamada help 200699d5cadfSJiri Bohac 200799d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 200899d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 200999d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 201099d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 201199d5cadfSJiri Bohac 201299d5cadfSJiri Bohac In addition to this option, you need to enable signature 201399d5cadfSJiri Bohac verification for the corresponding kernel image type being 201499d5cadfSJiri Bohac loaded in order for this to work. 201599d5cadfSJiri Bohac 201699d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 201799d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 201899d5cadfSJiri Bohac depends on KEXEC_SIG 2019a7f7f624SMasahiro Yamada help 20208e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2021d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20228e7d8381SVivek Goyal 20238e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20248e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 202599d5cadfSJiri Bohac depends on KEXEC_SIG 20268e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20278e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2028a7f7f624SMasahiro Yamada help 20298e7d8381SVivek Goyal Enable bzImage signature verification support. 20308e7d8381SVivek Goyal 2031506f1d07SSam Ravnborgconfig CRASH_DUMP 203204b69447SPavel Machek bool "kernel crash dumps" 2033506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2034a7f7f624SMasahiro Yamada help 2035506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2036506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2037506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2038506f1d07SSam Ravnborg a specially reserved region and then later executed after 2039506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2040506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2041506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2042506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2043330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2044506f1d07SSam Ravnborg 20453ab83521SHuang Yingconfig KEXEC_JUMP 20466ea30386SKees Cook bool "kexec jump" 2047fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2048a7f7f624SMasahiro Yamada help 204989081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 205089081d17SHuang Ying code in physical address mode via KEXEC 20513ab83521SHuang Ying 2052506f1d07SSam Ravnborgconfig PHYSICAL_START 20536a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2054ceefccc9SH. Peter Anvin default "0x1000000" 2055a7f7f624SMasahiro Yamada help 2056506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2057506f1d07SSam Ravnborg 2058506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2059506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2060506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2061506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2062506f1d07SSam Ravnborg address. 2063506f1d07SSam Ravnborg 2064506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2065506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2066506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2067506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2068506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2069506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2070506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2071506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2072506f1d07SSam Ravnborg 2073ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2074ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2075ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2076ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2077ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2078ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2079ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2080330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2081ceefccc9SH. Peter Anvin for more details about crash dumps. 2082506f1d07SSam Ravnborg 2083506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2084506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2085506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2086506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2087506f1d07SSam Ravnborg is present because there are users out there who continue to use 2088506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2089506f1d07SSam Ravnborg line. 2090506f1d07SSam Ravnborg 2091506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2092506f1d07SSam Ravnborg 2093506f1d07SSam Ravnborgconfig RELOCATABLE 209426717808SH. Peter Anvin bool "Build a relocatable kernel" 209526717808SH. Peter Anvin default y 2096a7f7f624SMasahiro Yamada help 2097506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2098506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2099506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2100506f1d07SSam Ravnborg but are discarded at runtime. 2101506f1d07SSam Ravnborg 2102506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2103506f1d07SSam Ravnborg must live at a different physical address than the primary 2104506f1d07SSam Ravnborg kernel. 2105506f1d07SSam Ravnborg 2106506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2107506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21088ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2109506f1d07SSam Ravnborg 21108ab3820fSKees Cookconfig RANDOMIZE_BASE 2111e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21128ab3820fSKees Cook depends on RELOCATABLE 21136807c846SIngo Molnar default y 2114a7f7f624SMasahiro Yamada help 2115e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2116e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2117e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2118e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2119e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2120e8581e3dSBaoquan He code internals. 2121e8581e3dSBaoquan He 2122ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2123ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2124ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2125ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2126ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2127ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2128ed9f007eSKees Cook 2129ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2130ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2131ed9f007eSKees Cook 512MB (8 bits of entropy). 21328ab3820fSKees Cook 2133a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2134e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2135e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2136ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2137ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2138ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2139ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2140ed9f007eSKees Cook theoretically possible, but the implementations are further 2141ed9f007eSKees Cook limited due to memory layouts. 2142e8581e3dSBaoquan He 21436807c846SIngo Molnar If unsure, say Y. 2144da2b6fb9SKees Cook 21458ab3820fSKees Cook# Relocation on x86 needs some additional build support 2146845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2147845adf72SH. Peter Anvin def_bool y 21488ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2149845adf72SH. Peter Anvin 2150506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2151a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21528ab3820fSKees Cook default "0x200000" 2153a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2154a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2155a7f7f624SMasahiro Yamada help 2156506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2157506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2158506f1d07SSam Ravnborg address which meets above alignment restriction. 2159506f1d07SSam Ravnborg 2160506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2161506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2162506f1d07SSam Ravnborg address aligned to above value and run from there. 2163506f1d07SSam Ravnborg 2164506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2165506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2166506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2167506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2168506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2169506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2170506f1d07SSam Ravnborg above alignment restrictions. 2171506f1d07SSam Ravnborg 2172a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2173a0215061SKees Cook this value must be a multiple of 0x200000. 2174a0215061SKees Cook 2175506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2176506f1d07SSam Ravnborg 2177eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2178eedb92abSKirill A. Shutemov bool 2179a7f7f624SMasahiro Yamada help 2180eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2181eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2182eedb92abSKirill A. Shutemov 21830483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 21840483e1faSThomas Garnier bool "Randomize the kernel memory sections" 21850483e1faSThomas Garnier depends on X86_64 21860483e1faSThomas Garnier depends on RANDOMIZE_BASE 2187eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 21880483e1faSThomas Garnier default RANDOMIZE_BASE 2189a7f7f624SMasahiro Yamada help 21900483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 21910483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 21920483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 21930483e1faSThomas Garnier 21940483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 21950483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 21960483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 21970483e1faSThomas Garnier addresses for each memory section. 21980483e1faSThomas Garnier 21996807c846SIngo Molnar If unsure, say Y. 22000483e1faSThomas Garnier 220190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 220290397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 220390397a41SThomas Garnier depends on RANDOMIZE_MEMORY 220490397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 220590397a41SThomas Garnier default "0x0" 220690397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 220790397a41SThomas Garnier range 0x0 0x40 2208a7f7f624SMasahiro Yamada help 220990397a41SThomas Garnier Define the padding in terabytes added to the existing physical 221090397a41SThomas Garnier memory size during kernel memory randomization. It is useful 221190397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 221290397a41SThomas Garnier address randomization. 221390397a41SThomas Garnier 221490397a41SThomas Garnier If unsure, leave at the default value. 221590397a41SThomas Garnier 2216506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2217bebd024eSThomas Gleixner def_bool y 221840b31360SStephen Rothwell depends on SMP 2219506f1d07SSam Ravnborg 222080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 222180aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22222c922cd0SKees Cook depends on HOTPLUG_CPU 2223a7f7f624SMasahiro Yamada help 222480aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 222580aa1dffSFenghua Yu 222680aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 222780aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 222880aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 222980aa1dffSFenghua Yu 223080aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 223180aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 223280aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 223380aa1dffSFenghua Yu 223480aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 223580aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 223680aa1dffSFenghua Yu 223780aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 223880aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 223980aa1dffSFenghua Yu be other CPU0 dependencies. 224080aa1dffSFenghua Yu 224180aa1dffSFenghua Yu Please make sure the dependencies are under your control before 224280aa1dffSFenghua Yu you enable this feature. 224380aa1dffSFenghua Yu 224480aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 224580aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 224680aa1dffSFenghua Yu parameter cpu0_hotplug. 224780aa1dffSFenghua Yu 2248a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2249a71c8bc5SFenghua Yu def_bool n 2250a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22512c922cd0SKees Cook depends on HOTPLUG_CPU 2252a7f7f624SMasahiro Yamada help 2253a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2254a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2255a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2256a71c8bc5SFenghua Yu 2257a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2258a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2259a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2260a71c8bc5SFenghua Yu 2261a71c8bc5SFenghua Yu If unsure, say N. 2262a71c8bc5SFenghua Yu 2263506f1d07SSam Ravnborgconfig COMPAT_VDSO 2264b0b49f26SAndy Lutomirski def_bool n 2265b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2266953fee1dSIngo Molnar depends on COMPAT_32 2267a7f7f624SMasahiro Yamada help 2268b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2269b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2270b0b49f26SAndy Lutomirski indicated in its segment table. 2271e84446deSRandy Dunlap 2272b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2273b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2274b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2275b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2276b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2277506f1d07SSam Ravnborg 2278b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2279b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2280b0b49f26SAndy Lutomirski 2281b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2282b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2283b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2284b0b49f26SAndy Lutomirski 2285b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2286b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2287506f1d07SSam Ravnborg 22883dc33bd3SKees Cookchoice 22893dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 22903dc33bd3SKees Cook depends on X86_64 2291625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 22923dc33bd3SKees Cook help 22933dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 22943dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 22953dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 22963dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 22973dc33bd3SKees Cook 22983dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2299bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23003dc33bd3SKees Cook 23013dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23023dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23033dc33bd3SKees Cook to improve security. 23043dc33bd3SKees Cook 2305bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23063dc33bd3SKees Cook 23073dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2308bd49e16eSAndy Lutomirski bool "Full emulation" 23093dc33bd3SKees Cook help 2310bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2311bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2312bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2313bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2314bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2315bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2316bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2317bd49e16eSAndy Lutomirski 2318bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2319bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2320bd49e16eSAndy Lutomirski 2321bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2322bd49e16eSAndy Lutomirski bool "Emulate execution only" 2323bd49e16eSAndy Lutomirski help 2324bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2325bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2326bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2327bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2328bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2329bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2330bd49e16eSAndy Lutomirski buffer. 23313dc33bd3SKees Cook 23323dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23333dc33bd3SKees Cook bool "None" 23343dc33bd3SKees Cook help 23353dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23363dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23373dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23383dc33bd3SKees Cook will be reported to dmesg, so that either old or 23393dc33bd3SKees Cook malicious userspace programs can be identified. 23403dc33bd3SKees Cook 23413dc33bd3SKees Cookendchoice 23423dc33bd3SKees Cook 2343516cbf37STim Birdconfig CMDLINE_BOOL 2344516cbf37STim Bird bool "Built-in kernel command line" 2345a7f7f624SMasahiro Yamada help 2346516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2347516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2348516cbf37STim Bird necessary or convenient to provide some or all of the 2349516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2350516cbf37STim Bird to not rely on the boot loader to provide them.) 2351516cbf37STim Bird 2352516cbf37STim Bird To compile command line arguments into the kernel, 2353516cbf37STim Bird set this option to 'Y', then fill in the 235469711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2355516cbf37STim Bird 2356516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2357516cbf37STim Bird should leave this option set to 'N'. 2358516cbf37STim Bird 2359516cbf37STim Birdconfig CMDLINE 2360516cbf37STim Bird string "Built-in kernel command string" 2361516cbf37STim Bird depends on CMDLINE_BOOL 2362516cbf37STim Bird default "" 2363a7f7f624SMasahiro Yamada help 2364516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2365516cbf37STim Bird image and used at boot time. If the boot loader provides a 2366516cbf37STim Bird command line at boot time, it is appended to this string to 2367516cbf37STim Bird form the full kernel command line, when the system boots. 2368516cbf37STim Bird 2369516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2370516cbf37STim Bird change this behavior. 2371516cbf37STim Bird 2372516cbf37STim Bird In most cases, the command line (whether built-in or provided 2373516cbf37STim Bird by the boot loader) should specify the device for the root 2374516cbf37STim Bird file system. 2375516cbf37STim Bird 2376516cbf37STim Birdconfig CMDLINE_OVERRIDE 2377516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2378645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2379a7f7f624SMasahiro Yamada help 2380516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2381516cbf37STim Bird command line, and use ONLY the built-in command line. 2382516cbf37STim Bird 2383516cbf37STim Bird This is used to work around broken boot loaders. This should 2384516cbf37STim Bird be set to 'N' under normal conditions. 2385516cbf37STim Bird 2386a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2387a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2388a5b9e5a2SAndy Lutomirski default y 2389a7f7f624SMasahiro Yamada help 2390a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2391a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2392a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2393a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2394a5b9e5a2SAndy Lutomirski threading libraries. 2395a5b9e5a2SAndy Lutomirski 2396a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2397a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2398a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2399a5b9e5a2SAndy Lutomirski 2400a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2401a5b9e5a2SAndy Lutomirski 24023aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24033aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24043aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24053aac3ebeSThomas Gleixner help 24063aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24073aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24083aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24093aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24103aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24113aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24123aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24133aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24143aac3ebeSThomas Gleixner never get a signal delivered. 24153aac3ebeSThomas Gleixner 24163aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24173aac3ebeSThomas Gleixner 2418b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2419b700e7f0SSeth Jennings 2420506f1d07SSam Ravnborgendmenu 2421506f1d07SSam Ravnborg 24223072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24233072e413SMichal Hocko def_bool y 24245c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24253072e413SMichal Hocko 2426f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2427f91ef222SOscar Salvador def_bool y 2428f91ef222SOscar Salvador 2429da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2430e279b6c1SSam Ravnborg 2431e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24323c2362e6SHarvey Harrison def_bool y 243344556530SZhimin Gu depends on HIBERNATION 2434e279b6c1SSam Ravnborg 2435e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2436e279b6c1SSam Ravnborg 2437e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2438e279b6c1SSam Ravnborg 2439a6b68076SAndi Kleenconfig X86_APM_BOOT 24406fc108a0SJan Beulich def_bool y 2441282e5aabSPaul Bolle depends on APM 2442a6b68076SAndi Kleen 2443e279b6c1SSam Ravnborgmenuconfig APM 2444e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2445efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2446a7f7f624SMasahiro Yamada help 2447e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2448e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2449e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2450e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2451e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2452e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2453e279b6c1SSam Ravnborg 2454e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2455e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2456e279b6c1SSam Ravnborg 2457e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2458e279b6c1SSam Ravnborg machines with more than one CPU. 2459e279b6c1SSam Ravnborg 2460e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2461151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24622dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2463e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2464e279b6c1SSam Ravnborg 2465e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2466e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2467e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2468e279b6c1SSam Ravnborg 2469e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2470e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2471e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2472e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2473e279b6c1SSam Ravnborg 2474e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2475e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2476e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2477e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2478e279b6c1SSam Ravnborg APM in your BIOS). 2479e279b6c1SSam Ravnborg 2480e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2481e279b6c1SSam Ravnborg "weird" problems: 2482e279b6c1SSam Ravnborg 2483e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2484e279b6c1SSam Ravnborg enabled. 2485e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2486e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2487e279b6c1SSam Ravnborg the "no387" option to the kernel 2488e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2489e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2490e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2491e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2492e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2493e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2494e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2495e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2496e279b6c1SSam Ravnborg 11) exchange RAM chips 2497e279b6c1SSam Ravnborg 12) exchange the motherboard. 2498e279b6c1SSam Ravnborg 2499e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2500e279b6c1SSam Ravnborg module will be called apm. 2501e279b6c1SSam Ravnborg 2502e279b6c1SSam Ravnborgif APM 2503e279b6c1SSam Ravnborg 2504e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2505e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2506a7f7f624SMasahiro Yamada help 2507e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2508e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2509e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2510e279b6c1SSam Ravnborg 2511e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2512e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2513a7f7f624SMasahiro Yamada help 2514e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2515e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2516e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2517e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2518e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2519e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2520e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2521e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2522e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2523e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2524e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2525e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2526e279b6c1SSam Ravnborg this feature. 2527e279b6c1SSam Ravnborg 2528e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2529dd8af076SLen Brown depends on CPU_IDLE 2530e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2531a7f7f624SMasahiro Yamada help 2532e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2533e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2534e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2535e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2536e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2537e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2538e279b6c1SSam Ravnborg this option does nothing.) 2539e279b6c1SSam Ravnborg 2540e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2541e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2542a7f7f624SMasahiro Yamada help 2543e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2544e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2545e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2546e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2547e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2548e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2549e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2550e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2551e279b6c1SSam Ravnborg especially if you are using gpm. 2552e279b6c1SSam Ravnborg 2553e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2554e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2555a7f7f624SMasahiro Yamada help 2556e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2557e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2558e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2559e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2560e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2561e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2562e279b6c1SSam Ravnborg 2563e279b6c1SSam Ravnborgendif # APM 2564e279b6c1SSam Ravnborg 2565bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2566e279b6c1SSam Ravnborg 2567e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2568e279b6c1SSam Ravnborg 256927471fdbSAndy Henroidsource "drivers/idle/Kconfig" 257027471fdbSAndy Henroid 2571e279b6c1SSam Ravnborgendmenu 2572e279b6c1SSam Ravnborg 2573e279b6c1SSam Ravnborg 2574e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2575e279b6c1SSam Ravnborg 2576e279b6c1SSam Ravnborgchoice 2577e279b6c1SSam Ravnborg prompt "PCI access mode" 2578efefa6f6SIngo Molnar depends on X86_32 && PCI 2579e279b6c1SSam Ravnborg default PCI_GOANY 2580a7f7f624SMasahiro Yamada help 2581e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2582e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2583e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2584e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2585e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2586e279b6c1SSam Ravnborg 2587e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2588e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2589e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2590e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2591e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2592e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2593e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2594e279b6c1SSam Ravnborg 2595e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2596e279b6c1SSam Ravnborg bool "BIOS" 2597e279b6c1SSam Ravnborg 2598e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2599e279b6c1SSam Ravnborg bool "MMConfig" 2600e279b6c1SSam Ravnborg 2601e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2602e279b6c1SSam Ravnborg bool "Direct" 2603e279b6c1SSam Ravnborg 26043ef0e1f8SAndres Salomonconfig PCI_GOOLPC 260576fb6570SDaniel Drake bool "OLPC XO-1" 26063ef0e1f8SAndres Salomon depends on OLPC 26073ef0e1f8SAndres Salomon 26082bdd1b03SAndres Salomonconfig PCI_GOANY 26092bdd1b03SAndres Salomon bool "Any" 26102bdd1b03SAndres Salomon 2611e279b6c1SSam Ravnborgendchoice 2612e279b6c1SSam Ravnborg 2613e279b6c1SSam Ravnborgconfig PCI_BIOS 26143c2362e6SHarvey Harrison def_bool y 2615efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2616e279b6c1SSam Ravnborg 2617e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2618e279b6c1SSam Ravnborgconfig PCI_DIRECT 26193c2362e6SHarvey Harrison def_bool y 26200aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2621e279b6c1SSam Ravnborg 2622e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2623b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2624b45c9f36SJan Kiszka default y 26254590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2626b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2627e279b6c1SSam Ravnborg 26283ef0e1f8SAndres Salomonconfig PCI_OLPC 26292bdd1b03SAndres Salomon def_bool y 26302bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26313ef0e1f8SAndres Salomon 2632b5401a96SAlex Nixonconfig PCI_XEN 2633b5401a96SAlex Nixon def_bool y 2634b5401a96SAlex Nixon depends on PCI && XEN 2635b5401a96SAlex Nixon 26368364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26378364e1f8SJan Kiszka def_bool y 26388364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2639e279b6c1SSam Ravnborg 26403f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26416a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26426ea30386SKees Cook depends on PCI 26433f6ea84aSIra W. Snyder help 26443f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26453f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26463f6ea84aSIra W. Snyder not have ACPI. 26473f6ea84aSIra W. Snyder 264864a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 264964a5fed6SBjorn Helgaas is known to be incomplete. 265064a5fed6SBjorn Helgaas 265164a5fed6SBjorn Helgaas You should say N unless you know you need this. 265264a5fed6SBjorn Helgaas 26533a495511SWilliam Breathitt Grayconfig ISA_BUS 265417a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26553a495511SWilliam Breathitt Gray help 265617a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 265717a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 265817a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 265917a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 266017a2a129SWilliam Breathitt Gray not have an ISA bus. 26613a495511SWilliam Breathitt Gray 26623a495511SWilliam Breathitt Gray If unsure, say N. 26633a495511SWilliam Breathitt Gray 26641c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2665e279b6c1SSam Ravnborgconfig ISA_DMA_API 26661c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 26671c00f016SDavid Rientjes default y 26681c00f016SDavid Rientjes help 26691c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 26701c00f016SDavid Rientjes If unsure, say Y. 2671e279b6c1SSam Ravnborg 267251e68d05SLinus Torvaldsif X86_32 267351e68d05SLinus Torvalds 2674e279b6c1SSam Ravnborgconfig ISA 2675e279b6c1SSam Ravnborg bool "ISA support" 2676a7f7f624SMasahiro Yamada help 2677e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2678e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2679e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2680e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2681e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2682e279b6c1SSam Ravnborg 2683e279b6c1SSam Ravnborgconfig SCx200 2684e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2685a7f7f624SMasahiro Yamada help 2686e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2687e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2688e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2689e279b6c1SSam Ravnborg for other scx200_* drivers. 2690e279b6c1SSam Ravnborg 2691e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2692e279b6c1SSam Ravnborg 2693e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2694e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2695592913ecSJohn Stultz depends on SCx200 2696e279b6c1SSam Ravnborg default y 2697a7f7f624SMasahiro Yamada help 2698e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2699e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2700e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2701e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2702e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2703e279b6c1SSam Ravnborg 27043ef0e1f8SAndres Salomonconfig OLPC 27053ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 270654008979SThomas Gleixner depends on !X86_PAE 27073c554946SAndres Salomon select GPIOLIB 2708dc3119e7SThomas Gleixner select OF 270945bb1674SDaniel Drake select OF_PROMTREE 2710b4e51854SGrant Likely select IRQ_DOMAIN 27110c3d931bSLubomir Rintel select OLPC_EC 2712a7f7f624SMasahiro Yamada help 27133ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27143ef0e1f8SAndres Salomon XO hardware. 27153ef0e1f8SAndres Salomon 2716a3128588SDaniel Drakeconfig OLPC_XO1_PM 2717a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2718fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2719a7f7f624SMasahiro Yamada help 272097c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2721bf1ebf00SDaniel Drake 2722cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2723cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2724cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2725a7f7f624SMasahiro Yamada help 2726cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2727cfee9597SDaniel Drake programmable wakeup source. 2728cfee9597SDaniel Drake 27297feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27307feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 273192e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2732ed8e47feSRandy Dunlap depends on INPUT=y 2733d8d01a63SDaniel Drake select POWER_SUPPLY 2734a7f7f624SMasahiro Yamada help 27357feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27367bc74b3dSDaniel Drake - EC-driven system wakeups 27377feda8e9SDaniel Drake - Power button 27387bc74b3dSDaniel Drake - Ebook switch 27392cf2baeaSDaniel Drake - Lid switch 2740e1040ac6SDaniel Drake - AC adapter status updates 2741e1040ac6SDaniel Drake - Battery status updates 27427feda8e9SDaniel Drake 2743a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2744a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2745d8d01a63SDaniel Drake depends on OLPC && ACPI 2746d8d01a63SDaniel Drake select POWER_SUPPLY 2747a7f7f624SMasahiro Yamada help 2748a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2749a0f30f59SDaniel Drake - EC-driven system wakeups 2750a0f30f59SDaniel Drake - AC adapter status updates 2751a0f30f59SDaniel Drake - Battery status updates 2752e279b6c1SSam Ravnborg 2753d4f3e350SEd Wildgooseconfig ALIX 2754d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2755d4f3e350SEd Wildgoose select GPIOLIB 2756a7f7f624SMasahiro Yamada help 2757d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2758d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2759d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2760d4f3e350SEd Wildgoose get added here. 2761d4f3e350SEd Wildgoose 2762d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2763d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2764d4f3e350SEd Wildgoose 2765d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2766d4f3e350SEd Wildgoose 2767da4e3302SPhilip Prindevilleconfig NET5501 2768da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2769da4e3302SPhilip Prindeville select GPIOLIB 2770a7f7f624SMasahiro Yamada help 2771da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2772da4e3302SPhilip Prindeville 27733197059aSPhilip A. Prindevilleconfig GEOS 27743197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 27753197059aSPhilip A. Prindeville select GPIOLIB 27763197059aSPhilip A. Prindeville depends on DMI 2777a7f7f624SMasahiro Yamada help 27783197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 27793197059aSPhilip A. Prindeville 27807d029125SVivien Didelotconfig TS5500 27817d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 27827d029125SVivien Didelot depends on MELAN 27837d029125SVivien Didelot select CHECK_SIGNATURE 27847d029125SVivien Didelot select NEW_LEDS 27857d029125SVivien Didelot select LEDS_CLASS 2786a7f7f624SMasahiro Yamada help 27877d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 27887d029125SVivien Didelot 2789e279b6c1SSam Ravnborgendif # X86_32 2790e279b6c1SSam Ravnborg 279123ac4ae8SAndreas Herrmannconfig AMD_NB 2792e279b6c1SSam Ravnborg def_bool y 27930e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2794e279b6c1SSam Ravnborg 2795e279b6c1SSam Ravnborgendmenu 2796e279b6c1SSam Ravnborg 2797e279b6c1SSam Ravnborg 27981572497cSChristoph Hellwigmenu "Binary Emulations" 2799e279b6c1SSam Ravnborg 2800e279b6c1SSam Ravnborgconfig IA32_EMULATION 2801e279b6c1SSam Ravnborg bool "IA32 Emulation" 2802e279b6c1SSam Ravnborg depends on X86_64 280339f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2804d1603990SRandy Dunlap select BINFMT_ELF 280539f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2806a7f7f624SMasahiro Yamada help 28075fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28085fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28095fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2810e279b6c1SSam Ravnborg 2811e279b6c1SSam Ravnborgconfig IA32_AOUT 2812e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28136b213e1bSDavid Woodhouse depends on IA32_EMULATION 2814eac61655SBorislav Petkov depends on BROKEN 2815a7f7f624SMasahiro Yamada help 2816e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2817e279b6c1SSam Ravnborg 28180bf62763SH. Peter Anvinconfig X86_X32 28196ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28209b54050bSBrian Gerst depends on X86_64 2821a7f7f624SMasahiro Yamada help 28225fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28235fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28245fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28255fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28265fd92e65SH. J. Lu 28275fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 28285fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 28295fd92e65SH. J. Lu option set. 28305fd92e65SH. J. Lu 2831953fee1dSIngo Molnarconfig COMPAT_32 2832953fee1dSIngo Molnar def_bool y 2833953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2834953fee1dSIngo Molnar select HAVE_UID16 2835953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2836953fee1dSIngo Molnar 2837e279b6c1SSam Ravnborgconfig COMPAT 28383c2362e6SHarvey Harrison def_bool y 28390bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2840e279b6c1SSam Ravnborg 28413120e25eSJan Beulichif COMPAT 2842e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28433120e25eSJan Beulich def_bool y 2844e279b6c1SSam Ravnborg 2845e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28463c2362e6SHarvey Harrison def_bool y 28473120e25eSJan Beulich depends on SYSVIPC 28483120e25eSJan Beulichendif 2849ee009e4aSDavid Howells 2850e279b6c1SSam Ravnborgendmenu 2851e279b6c1SSam Ravnborg 2852e279b6c1SSam Ravnborg 2853e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2854e5beae16SKeith Packard def_bool y 2855e5beae16SKeith Packard depends on X86_32 2856e5beae16SKeith Packard 2857edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28585e8ebd84SJason A. Donenfeld 28595e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2860