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 242cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 243d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 244c763ea26SIngo Molnar select HAVE_STACK_VALIDATION if X86_64 245e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 2461e7e4788SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 2476ef869e0SMichal Hocko select HAVE_PREEMPT_DYNAMIC 248d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2496471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2506471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2517c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2527ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 25305736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 254c0185808SThomas Gleixner select IRQ_FORCED_THREADING 25586596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2562eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 257625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2586471b825SIngo Molnar select PERF_EVENTS 2593195ef59SPrarit Bhargava select RTC_LIB 260d6faca40SArnd Bergmann select RTC_MC146818_LIB 2616471b825SIngo Molnar select SPARSE_IRQ 26283fe27eaSPranith Kumar select SRCU 2631e7e4788SJosh Poimboeuf select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 2646471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 26515f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2664aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2676471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2686471b825SIngo Molnar select VIRT_TO_BUS 2693b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2706471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2710c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 2729e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2737d8330a5SBalbir Singh 274ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2753120e25eSJan Beulich def_bool y 2763120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 277ba7e4d13SIngo Molnar 27851b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 27951b26adaSLinus Torvalds string 28051b26adaSLinus Torvalds default "elf32-i386" if X86_32 28151b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 28251b26adaSLinus Torvalds 2838d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2843c2362e6SHarvey Harrison def_bool y 2858d5fffb9SSam Ravnborg 2868d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2873c2362e6SHarvey Harrison def_bool y 2888d5fffb9SSam Ravnborg 2898d5fffb9SSam Ravnborgconfig MMU 2903c2362e6SHarvey Harrison def_bool y 2918d5fffb9SSam Ravnborg 2929e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 2939e08f57dSDaniel Cashman default 28 if 64BIT 2949e08f57dSDaniel Cashman default 8 2959e08f57dSDaniel Cashman 2969e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 2979e08f57dSDaniel Cashman default 32 if 64BIT 2989e08f57dSDaniel Cashman default 16 2999e08f57dSDaniel Cashman 3009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3019e08f57dSDaniel Cashman default 8 3029e08f57dSDaniel Cashman 3039e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3049e08f57dSDaniel Cashman default 16 3059e08f57dSDaniel Cashman 3068d5fffb9SSam Ravnborgconfig SBUS 3078d5fffb9SSam Ravnborg bool 3088d5fffb9SSam Ravnborg 3098d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3103120e25eSJan Beulich def_bool y 3113120e25eSJan Beulich depends on ISA_DMA_API 3128d5fffb9SSam Ravnborg 3138d5fffb9SSam Ravnborgconfig GENERIC_BUG 3143c2362e6SHarvey Harrison def_bool y 3158d5fffb9SSam Ravnborg depends on BUG 316b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 317b93a531eSJan Beulich 318b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 319b93a531eSJan Beulich bool 3208d5fffb9SSam Ravnborg 3218d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3223120e25eSJan Beulich def_bool y 3233120e25eSJan Beulich depends on ISA_DMA_API 3248d5fffb9SSam Ravnborg 3251032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3261032c0baSSam Ravnborg def_bool y 3271032c0baSSam Ravnborg 3289a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3299a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3308d5fffb9SSam Ravnborg 331316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT 332316d097cSDave Hansen def_bool y 333316d097cSDave Hansen 334dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 33589c9c4c5SBrian Gerst def_bool y 336b32ef636Stravis@sgi.com 33708fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 33808fc4580STejun Heo def_bool y 33908fc4580STejun Heo 34008fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 34111124411STejun Heo def_bool y 34211124411STejun Heo 343801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 344801e4062SJohannes Berg def_bool y 345801e4062SJohannes Berg 346d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 347d7109fe3SAndy Shevchenko int 348d7109fe3SAndy Shevchenko default 1024 if X86_64 349d7109fe3SAndy Shevchenko default 512 350d7109fe3SAndy Shevchenko 351f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 352f4cb5700SJohannes Berg def_bool y 353f4cb5700SJohannes Berg 35453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 35553313b2cSSteve Capper def_bool y 35653313b2cSSteve Capper 3578d5fffb9SSam Ravnborgconfig AUDIT_ARCH 358e0fd24a3SJan Beulich def_bool y if X86_64 3598d5fffb9SSam Ravnborg 360d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 361d6f2d75aSAndrey Ryabinin hex 362d6f2d75aSAndrey Ryabinin depends on KASAN 363d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 364d6f2d75aSAndrey Ryabinin 36569575d38SShane Wangconfig HAVE_INTEL_TXT 36669575d38SShane Wang def_bool y 3676ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36869575d38SShane Wang 3696b0c3d44SSam Ravnborgconfig X86_32_SMP 3706b0c3d44SSam Ravnborg def_bool y 3716b0c3d44SSam Ravnborg depends on X86_32 && SMP 3726b0c3d44SSam Ravnborg 3736b0c3d44SSam Ravnborgconfig X86_64_SMP 3746b0c3d44SSam Ravnborg def_bool y 3756b0c3d44SSam Ravnborg depends on X86_64 && SMP 3766b0c3d44SSam Ravnborg 3772b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3782b144498SSrikar Dronamraju def_bool y 3792b144498SSrikar Dronamraju 380d20642f0SRob Herringconfig FIX_EARLYCON_MEM 381d20642f0SRob Herring def_bool y 382d20642f0SRob Herring 38394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 38494d49eb3SKirill A. Shutemov bool 38594d49eb3SKirill A. Shutemov 38698233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38798233368SKirill A. Shutemov int 38877ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38998233368SKirill A. Shutemov default 4 if X86_64 39098233368SKirill A. Shutemov default 3 if X86_PAE 39198233368SKirill A. Shutemov default 2 39298233368SKirill A. Shutemov 3932a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3942a61f474SMasahiro Yamada bool 3952a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3962a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3972a61f474SMasahiro Yamada help 3982a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3993fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 4003fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 4012a61f474SMasahiro Yamada 402506f1d07SSam Ravnborgmenu "Processor type and features" 403506f1d07SSam Ravnborg 404506f1d07SSam Ravnborgconfig SMP 405506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 406a7f7f624SMasahiro Yamada help 407506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4084a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4094a474157SRobert Graffham than one CPU, say Y. 410506f1d07SSam Ravnborg 4114a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 412506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 413506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4144a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 415506f1d07SSam Ravnborg will run faster if you say N here. 416506f1d07SSam Ravnborg 417506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 418506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 419506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 420506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 421506f1d07SSam Ravnborg 422506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 423506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 424506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 425506f1d07SSam Ravnborg 426cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4274f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 428506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 429506f1d07SSam Ravnborg 430506f1d07SSam Ravnborg If you don't know what to do here, say N. 431506f1d07SSam Ravnborg 4329def39beSJosh Triplettconfig X86_FEATURE_NAMES 4339def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4349def39beSJosh Triplett default y 435a7f7f624SMasahiro Yamada help 4369def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4379def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4389def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4399def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4409def39beSJosh Triplett 4419def39beSJosh Triplett If in doubt, say Y. 4429def39beSJosh Triplett 44306cd9a7dSYinghai Luconfig X86_X2APIC 44406cd9a7dSYinghai Lu bool "Support x2apic" 44519e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 446a7f7f624SMasahiro Yamada help 44706cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44806cd9a7dSYinghai Lu 44906cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 45006cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 45106cd9a7dSYinghai Lu 45206cd9a7dSYinghai Lu If you don't know what to do here, say N. 45306cd9a7dSYinghai Lu 4546695c85bSYinghai Luconfig X86_MPPARSE 4554590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4567a527688SJan Beulich default y 4575ab74722SIngo Molnar depends on X86_LOCAL_APIC 458a7f7f624SMasahiro Yamada help 4596695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4606695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4616695c85bSYinghai Lu 462ddd70cf9SJun Nakajimaconfig GOLDFISH 463ddd70cf9SJun Nakajima def_bool y 464ddd70cf9SJun Nakajima depends on X86_GOLDFISH 465ddd70cf9SJun Nakajima 46676b04384SDavid Woodhouseconfig RETPOLINE 46776b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 46876b04384SDavid Woodhouse default y 46976b04384SDavid Woodhouse help 47076b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 47176b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 47276b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 47376b04384SDavid Woodhouse support for full protection. The kernel may run slower. 47476b04384SDavid Woodhouse 475e463a09aSPeter Zijlstraconfig CC_HAS_SLS 476e463a09aSPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 477e463a09aSPeter Zijlstra 478e463a09aSPeter Zijlstraconfig SLS 479e463a09aSPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 480e463a09aSPeter Zijlstra depends on CC_HAS_SLS && X86_64 481e463a09aSPeter Zijlstra default n 482e463a09aSPeter Zijlstra help 483e463a09aSPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 484e463a09aSPeter Zijlstra against straight line speculation. The kernel image might be slightly 485e463a09aSPeter Zijlstra larger. 486e463a09aSPeter Zijlstra 487e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 488e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4896fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 49059fe5a77SThomas Gleixner select KERNFS 491e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 49278e99b4aSFenghua Yu help 493e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4946fe07ce3SBabu Moger 4956fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4966fe07ce3SBabu Moger usage by the CPU. 4976fe07ce3SBabu Moger 4986fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4996fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 5006fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 5016fe07ce3SBabu Moger 5026fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 5036fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 5046fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 50578e99b4aSFenghua Yu 50678e99b4aSFenghua Yu Say N if unsure. 50778e99b4aSFenghua Yu 5088425091fSRavikiran G Thirumalaiif X86_32 509a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 510a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 511a0d0bb4dSRandy Dunlap depends on SMP 512a7f7f624SMasahiro Yamada help 513e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 514a0d0bb4dSRandy Dunlap 515c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 516c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 517c5c606d9SRavikiran G Thirumalai default y 518a7f7f624SMasahiro Yamada help 51906ac8346SIngo Molnar If you disable this option then the kernel will only support 52006ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 52106ac8346SIngo Molnar systems out there.) 52206ac8346SIngo Molnar 5238425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5248425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 525cb7b8023SBen Hutchings Goldfish (Android emulator) 5268425091fSRavikiran G Thirumalai AMD Elan 5278425091fSRavikiran G Thirumalai RDC R-321x SoC 5288425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 52983125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5303f4110a4SThomas Gleixner Moorestown MID devices 53106ac8346SIngo Molnar 53206ac8346SIngo Molnar If you have one of these systems, or if you want to build a 53306ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5348425091fSRavikiran G Thirumalaiendif 53506ac8346SIngo Molnar 5368425091fSRavikiran G Thirumalaiif X86_64 5378425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5388425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5398425091fSRavikiran G Thirumalai default y 540a7f7f624SMasahiro Yamada help 5418425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5428425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5438425091fSRavikiran G Thirumalai systems out there.) 5448425091fSRavikiran G Thirumalai 5458425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5468425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 54744b111b5SSteffen Persvold Numascale NumaChip 5488425091fSRavikiran G Thirumalai ScaleMP vSMP 5498425091fSRavikiran G Thirumalai SGI Ultraviolet 5508425091fSRavikiran G Thirumalai 5518425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5528425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5538425091fSRavikiran G Thirumalaiendif 554c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 555c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 55644b111b5SSteffen Persvoldconfig X86_NUMACHIP 55744b111b5SSteffen Persvold bool "Numascale NumaChip" 55844b111b5SSteffen Persvold depends on X86_64 55944b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 56044b111b5SSteffen Persvold depends on NUMA 56144b111b5SSteffen Persvold depends on SMP 56244b111b5SSteffen Persvold depends on X86_X2APIC 563f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 564a7f7f624SMasahiro Yamada help 56544b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 56644b111b5SSteffen Persvold enable more than ~168 cores. 56744b111b5SSteffen Persvold If you don't have one of these, you should say N here. 56803b48632SNick Piggin 5696a48565eSIngo Molnarconfig X86_VSMP 570c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5716276a074SBorislav Petkov select HYPERVISOR_GUEST 5726a48565eSIngo Molnar select PARAVIRT 5736a48565eSIngo Molnar depends on X86_64 && PCI 574c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 575ead91d4bSShai Fultheim depends on SMP 576a7f7f624SMasahiro Yamada help 5776a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5786a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5796a48565eSIngo Molnar if you have one of these machines. 5806a48565eSIngo Molnar 581c5c606d9SRavikiran G Thirumalaiconfig X86_UV 582c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 583c5c606d9SRavikiran G Thirumalai depends on X86_64 584c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 58554c28d29SJack Steiner depends on NUMA 5861ecb4ae5SAndrew Morton depends on EFI 587c2209ea5SIngo Molnar depends on KEXEC_CORE 5889d6c26e7SSuresh Siddha depends on X86_X2APIC 5891222e564SIngo Molnar depends on PCI 590a7f7f624SMasahiro Yamada help 591c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 592c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 593c5c606d9SRavikiran G Thirumalai 594c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 595c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 596506f1d07SSam Ravnborg 597ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 598ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 599cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 600a7f7f624SMasahiro Yamada help 601ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 602ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 603ddd70cf9SJun Nakajima Goldfish emulator say N here. 604ddd70cf9SJun Nakajima 605c751e17bSThomas Gleixnerconfig X86_INTEL_CE 606c751e17bSThomas Gleixner bool "CE4100 TV platform" 607c751e17bSThomas Gleixner depends on PCI 608c751e17bSThomas Gleixner depends on PCI_GODIRECT 6096084a6e2SJiang Liu depends on X86_IO_APIC 610c751e17bSThomas Gleixner depends on X86_32 611c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 61237bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 613da6b737bSSebastian Andrzej Siewior select OF 614da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 615a7f7f624SMasahiro Yamada help 616c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 617c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 618c751e17bSThomas Gleixner boxes and media devices. 619c751e17bSThomas Gleixner 6204cb9b00fSDavid Cohenconfig X86_INTEL_MID 62143605ef1SAlan Cox bool "Intel MID platform support" 62243605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 623edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6241ea7c673SAlan Cox depends on PCI 6253fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6261ea7c673SAlan Cox depends on X86_IO_APIC 6274cb9b00fSDavid Cohen select I2C 6287c9c3a1eSAlan Cox select DW_APB_TIMER 62954b34aa0SMika Westerberg select INTEL_SCU_PCI 630a7f7f624SMasahiro Yamada help 6314cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6324cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6334cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6341ea7c673SAlan Cox 6354cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6364cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 63743605ef1SAlan Cox 6388bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6398bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6408bbc2a13SBryan O'Donoghue depends on X86_32 6418bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6428bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6438bbc2a13SBryan O'Donoghue depends on X86_TSC 6448bbc2a13SBryan O'Donoghue depends on PCI 6458bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6468bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6478bbc2a13SBryan O'Donoghue select IOSF_MBI 6488bbc2a13SBryan O'Donoghue select INTEL_IMR 6499ab6eb51SAndy Shevchenko select COMMON_CLK 650a7f7f624SMasahiro Yamada help 6518bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6528bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6538bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6548bbc2a13SBryan O'Donoghue 6553d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6563d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6575962dd22SSinan Kaya depends on X86 && ACPI && PCI 6583d48aab1SMika Westerberg select COMMON_CLK 6590f531431SMathias Nyman select PINCTRL 660eebb3e8dSAndy Shevchenko select IOSF_MBI 661a7f7f624SMasahiro Yamada help 6623d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6633d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6640f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6650f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6663d48aab1SMika Westerberg 66792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 66892082a88SKen Xue bool "AMD ACPI2Platform devices support" 66992082a88SKen Xue depends on ACPI 67092082a88SKen Xue select COMMON_CLK 67192082a88SKen Xue select PINCTRL 672a7f7f624SMasahiro Yamada help 67392082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 67492082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 67592082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 67692082a88SKen Xue implemented under PINCTRL subsystem. 67792082a88SKen Xue 678ced3ce76SDavid E. Boxconfig IOSF_MBI 679ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 680ced3ce76SDavid E. Box depends on PCI 681a7f7f624SMasahiro Yamada help 682ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 683ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 684ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 685ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 686ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 687ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 688ced3ce76SDavid E. Box This list is not meant to be exclusive. 689ced3ce76SDavid E. Box - BayTrail 690ced3ce76SDavid E. Box - Braswell 691ced3ce76SDavid E. Box - Quark 692ced3ce76SDavid E. Box 693ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 694ced3ce76SDavid E. Box 695ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 696ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 697ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 698a7f7f624SMasahiro Yamada help 699ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 700ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 701ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 702ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 703ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 704ed2226bdSDavid E. Box device they want to access. 705ed2226bdSDavid E. Box 706ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 707ed2226bdSDavid E. Box 708c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 709c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 710506f1d07SSam Ravnborg depends on X86_32 711c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 712c5c606d9SRavikiran G Thirumalai select M486 713c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 714a7f7f624SMasahiro Yamada help 715c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 716c5c606d9SRavikiran G Thirumalai as R-8610-(G). 717c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 718c5c606d9SRavikiran G Thirumalai 719e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7209c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7219c398017SIngo Molnar depends on X86_32 && SMP 722c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 723a7f7f624SMasahiro Yamada help 724b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 725b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 726b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 727b5660ba7SH. Peter Anvin one and will fallback to default. 728d49c4288SYinghai Lu 729c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 730d49c4288SYinghai Lu 731d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7326fc108a0SJan Beulich def_bool y 733d949f36fSLinus Torvalds # MCE code calls memory_failure(): 734d949f36fSLinus Torvalds depends on X86_MCE 735d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 736d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 737d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 738d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 739d949f36fSLinus Torvalds 74083125a3aSAlessandro Rubiniconfig STA2X11 74183125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 74283125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 74383125a3aSAlessandro Rubini select SWIOTLB 74483125a3aSAlessandro Rubini select MFD_STA2X11 7450145071bSLinus Walleij select GPIOLIB 746a7f7f624SMasahiro Yamada help 74783125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 74883125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 74983125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 75083125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 75183125a3aSAlessandro Rubini standard PC machines. 75283125a3aSAlessandro Rubini 75382148d1dSShérabconfig X86_32_IRIS 75482148d1dSShérab tristate "Eurobraille/Iris poweroff module" 75582148d1dSShérab depends on X86_32 756a7f7f624SMasahiro Yamada help 75782148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 75882148d1dSShérab to shut themselves down properly. A special I/O sequence is 75982148d1dSShérab needed to do so, which is what this module does at 76082148d1dSShérab kernel shutdown. 76182148d1dSShérab 76282148d1dSShérab This is only for Iris machines from EuroBraille. 76382148d1dSShérab 76482148d1dSShérab If unused, say N. 76582148d1dSShérab 766ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7673c2362e6SHarvey Harrison def_bool y 7683c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 769a87d0914SKen Chen depends on X86 770a7f7f624SMasahiro Yamada help 771506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 772506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 773506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 774506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 775506f1d07SSam Ravnborg 776506f1d07SSam Ravnborg If in doubt, say "Y". 777506f1d07SSam Ravnborg 7786276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7796276a074SBorislav Petkov bool "Linux guest support" 780a7f7f624SMasahiro Yamada help 7816276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7826276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7836276a074SBorislav Petkov setup. 784506f1d07SSam Ravnborg 7856276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7866276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 787506f1d07SSam Ravnborg 7886276a074SBorislav Petkovif HYPERVISOR_GUEST 789506f1d07SSam Ravnborg 790e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 791e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 792a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 793a7f7f624SMasahiro Yamada help 794e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 795e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 796e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 797e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 798e61bd94aSEduardo Pereira Habkost 799c00a280aSJuergen Grossconfig PARAVIRT_XXL 800c00a280aSJuergen Gross bool 801c00a280aSJuergen Gross 8026276a074SBorislav Petkovconfig PARAVIRT_DEBUG 8036276a074SBorislav Petkov bool "paravirt-ops debugging" 8046276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 805a7f7f624SMasahiro Yamada help 8066276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8076276a074SBorislav Petkov a paravirt_op is missing when it is called. 8086276a074SBorislav Petkov 809b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 810b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8116ea30386SKees Cook depends on PARAVIRT && SMP 812a7f7f624SMasahiro Yamada help 813b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 814b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 815b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 816b4ecc126SJeremy Fitzhardinge 8174c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8184c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 819b4ecc126SJeremy Fitzhardinge 8204c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 821b4ecc126SJeremy Fitzhardinge 822ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 823ecca2502SZhao Yakui def_bool n 824ecca2502SZhao Yakui 8256276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8266276a074SBorislav Petkov 8276276a074SBorislav Petkovconfig KVM_GUEST 8286276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8296276a074SBorislav Petkov depends on PARAVIRT 8306276a074SBorislav Petkov select PARAVIRT_CLOCK 831a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 832b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8336276a074SBorislav Petkov default y 834a7f7f624SMasahiro Yamada help 8356276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8366276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8376276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8386276a074SBorislav Petkov underlying device model, the host provides the guest with 8396276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8406276a074SBorislav Petkov 841a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 842a1c4423bSMarcelo Tosatti def_bool n 843a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 844a1c4423bSMarcelo Tosatti help 845a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 846a1c4423bSMarcelo Tosatti 8477733607fSMaran Wilsonconfig PVH 8487733607fSMaran Wilson bool "Support for running PVH guests" 849a7f7f624SMasahiro Yamada help 8507733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8517733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8527733607fSMaran Wilson 8536276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8546276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8556276a074SBorislav Petkov depends on PARAVIRT 856a7f7f624SMasahiro Yamada help 8576276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8586276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8596276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8606276a074SBorislav Petkov that, there can be a small performance impact. 8616276a074SBorislav Petkov 8626276a074SBorislav Petkov If in doubt, say N here. 8636276a074SBorislav Petkov 8647af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8657af192c9SGerd Hoffmann bool 8667af192c9SGerd Hoffmann 8674a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8684a362601SJan Kiszka bool "Jailhouse non-root cell support" 869abde587bSArnd Bergmann depends on X86_64 && PCI 87087e65d05SJan Kiszka select X86_PM_TIMER 871a7f7f624SMasahiro Yamada help 8724a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8734a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8744a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8754a362601SJan Kiszka 876ec7972c9SZhao Yakuiconfig ACRN_GUEST 877ec7972c9SZhao Yakui bool "ACRN Guest support" 878ec7972c9SZhao Yakui depends on X86_64 879498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 880ec7972c9SZhao Yakui help 881ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 882ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 883ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 884ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 885ec7972c9SZhao Yakui found in https://projectacrn.org/. 886ec7972c9SZhao Yakui 8876276a074SBorislav Petkovendif #HYPERVISOR_GUEST 88897349135SJeremy Fitzhardinge 889506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 890506f1d07SSam Ravnborg 891506f1d07SSam Ravnborgconfig HPET_TIMER 8923c2362e6SHarvey Harrison def_bool X86_64 893506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 894a7f7f624SMasahiro Yamada help 895506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 896506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 897506f1d07SSam Ravnborg present. 898506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 899506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 900506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9014e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9024e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 903506f1d07SSam Ravnborg 904506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 905506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 906506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 907506f1d07SSam Ravnborg 908506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 909506f1d07SSam Ravnborg 910506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9113c2362e6SHarvey Harrison def_bool y 9123228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 913506f1d07SSam Ravnborg 9146a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 915506f1d07SSam Ravnborg# The code disables itself when not needed. 9167ae9392cSThomas Petazzoniconfig DMI 9177ae9392cSThomas Petazzoni default y 918cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9196a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 920a7f7f624SMasahiro Yamada help 9217ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9227ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9237ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9247ae9392cSThomas Petazzoni BIOS code. 9257ae9392cSThomas Petazzoni 926506f1d07SSam Ravnborgconfig GART_IOMMU 92738901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9282f9237d4SChristoph Hellwig select DMA_OPS 929a4ce5a48SChristoph Hellwig select IOMMU_HELPER 930506f1d07SSam Ravnborg select SWIOTLB 93123ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 932a7f7f624SMasahiro Yamada help 933ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 934ced3c42cSIngo Molnar GART based hardware IOMMUs. 935ced3c42cSIngo Molnar 936ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 937ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 938ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 939ced3c42cSIngo Molnar 940ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 941ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 942ced3c42cSIngo Molnar 943ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 944ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 945ced3c42cSIngo Molnar 32-bit limited device. 946ced3c42cSIngo Molnar 947ced3c42cSIngo Molnar If unsure, say Y. 948506f1d07SSam Ravnborg 9491184dc2fSMike Travisconfig MAXSMP 950ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9516ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 95236f5101aSMike Travis select CPUMASK_OFFSTACK 953a7f7f624SMasahiro Yamada help 954ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9551184dc2fSMike Travis If unsure, say N. 956506f1d07SSam Ravnborg 957aec6487eSIngo Molnar# 958aec6487eSIngo Molnar# The maximum number of CPUs supported: 959aec6487eSIngo Molnar# 960aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 961aec6487eSIngo Molnar# and which can be configured interactively in the 962aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 963aec6487eSIngo Molnar# 964aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 965aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 966aec6487eSIngo Molnar# 967aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 968aec6487eSIngo Molnar# interactive configuration. ) 969aec6487eSIngo Molnar# 970a0d0bb4dSRandy Dunlap 971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 972a0d0bb4dSRandy Dunlap int 973aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 974a0d0bb4dSRandy Dunlap default 1 if !SMP 975a0d0bb4dSRandy Dunlap default 2 976a0d0bb4dSRandy Dunlap 977aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 978a0d0bb4dSRandy Dunlap int 979a0d0bb4dSRandy Dunlap depends on X86_32 980aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 981aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 982a0d0bb4dSRandy Dunlap default 1 if !SMP 983a0d0bb4dSRandy Dunlap 984aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 985a0d0bb4dSRandy Dunlap int 986a0d0bb4dSRandy Dunlap depends on X86_64 9871edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9881edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 989a0d0bb4dSRandy Dunlap default 1 if !SMP 990aec6487eSIngo Molnar 991aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 992aec6487eSIngo Molnar int 993aec6487eSIngo Molnar depends on X86_32 994aec6487eSIngo Molnar default 32 if X86_BIGSMP 995aec6487eSIngo Molnar default 8 if SMP 996aec6487eSIngo Molnar default 1 if !SMP 997aec6487eSIngo Molnar 998aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 999aec6487eSIngo Molnar int 1000aec6487eSIngo Molnar depends on X86_64 1001a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1002a0d0bb4dSRandy Dunlap default 64 if SMP 1003aec6487eSIngo Molnar default 1 if !SMP 1004a0d0bb4dSRandy Dunlap 1005506f1d07SSam Ravnborgconfig NR_CPUS 100636f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1007aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1008aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1009a7f7f624SMasahiro Yamada help 1010506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1011bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1012cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1013506f1d07SSam Ravnborg minimum value which makes sense is 2. 1014506f1d07SSam Ravnborg 1015aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1016aec6487eSIngo Molnar to the kernel image. 1017506f1d07SSam Ravnborg 101866558b73STim Chenconfig SCHED_CLUSTER 101966558b73STim Chen bool "Cluster scheduler support" 102066558b73STim Chen depends on SMP 102166558b73STim Chen default y 102266558b73STim Chen help 102366558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 102466558b73STim Chen making when dealing with machines that have clusters of CPUs. 102566558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 102666558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 102766558b73STim Chen busses. 102866558b73STim Chen 1029506f1d07SSam Ravnborgconfig SCHED_SMT 1030dbe73364SThomas Gleixner def_bool y if SMP 1031506f1d07SSam Ravnborg 1032506f1d07SSam Ravnborgconfig SCHED_MC 10333c2362e6SHarvey Harrison def_bool y 10343c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1035c8e56d20SBorislav Petkov depends on SMP 1036a7f7f624SMasahiro Yamada help 1037506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1038506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1039506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1040506f1d07SSam Ravnborg 1041de966cf4STim Chenconfig SCHED_MC_PRIO 1042de966cf4STim Chen bool "CPU core priorities scheduler support" 10430a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10440a21fc12SIngo Molnar select X86_INTEL_PSTATE 10450a21fc12SIngo Molnar select CPU_FREQ 1046de966cf4STim Chen default y 1047a7f7f624SMasahiro Yamada help 1048de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1049de966cf4STim Chen core ordering determined at manufacturing time, which allows 1050de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1051de966cf4STim Chen single threaded workloads) than others. 1052de966cf4STim Chen 1053de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1054de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1055de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1056de966cf4STim Chen overall system performance can be achieved. 1057de966cf4STim Chen 1058de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1059de966cf4STim Chen 1060de966cf4STim Chen If unsure say Y here. 10615e76b2abSTim Chen 106230b8b006SThomas Gleixnerconfig UP_LATE_INIT 106330b8b006SThomas Gleixner def_bool y 1064ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 106530b8b006SThomas Gleixner 1066506f1d07SSam Ravnborgconfig X86_UP_APIC 106750849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 106850849eefSJan Beulich default PCI_MSI 106938a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1070a7f7f624SMasahiro Yamada help 1071506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1072506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1073506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1074506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1075506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1076506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1077506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1078506f1d07SSam Ravnborg lockups. 1079506f1d07SSam Ravnborg 1080506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1081506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1082506f1d07SSam Ravnborg depends on X86_UP_APIC 1083a7f7f624SMasahiro Yamada help 1084506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1085506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1086506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1087506f1d07SSam Ravnborg 1088506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1089506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1090506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1091506f1d07SSam Ravnborg 1092506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10933c2362e6SHarvey Harrison def_bool y 10940dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1095b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 109652f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1097506f1d07SSam Ravnborg 1098506f1d07SSam Ravnborgconfig X86_IO_APIC 1099b1da1e71SJan Beulich def_bool y 1100b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1101506f1d07SSam Ravnborg 110241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 110341b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 110441b9eb26SStefan Assmann depends on X86_IO_APIC 1105a7f7f624SMasahiro Yamada help 110641b9eb26SStefan Assmann This option enables a workaround that fixes a source of 110741b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 110841b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 110941b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 111041b9eb26SStefan Assmann 111141b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 111241b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 111341b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 111441b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 111541b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 111641b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 111741b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 111841b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 111941b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 112041b9eb26SStefan Assmann down (vital) interrupt lines. 112141b9eb26SStefan Assmann 112241b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 112341b9eb26SStefan Assmann increased on these systems. 112441b9eb26SStefan Assmann 1125506f1d07SSam Ravnborgconfig X86_MCE 1126bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1127648ed940SChen, Gong select GENERIC_ALLOCATOR 1128e57dbaf7SBorislav Petkov default y 1129a7f7f624SMasahiro Yamada help 1130bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1131bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1132506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1133bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11344efc0670SAndi Kleen 11355de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11365de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11375de97c9fSTony Luck depends on X86_MCE 1138a7f7f624SMasahiro Yamada help 11395de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11405de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11415de97c9fSTony Luck rasdaemon solution. 11425de97c9fSTony Luck 1143506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11443c2362e6SHarvey Harrison def_bool y 11453c2362e6SHarvey Harrison prompt "Intel MCE features" 1146c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1147a7f7f624SMasahiro Yamada help 1148506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1149506f1d07SSam Ravnborg the thermal monitor. 1150506f1d07SSam Ravnborg 1151506f1d07SSam Ravnborgconfig X86_MCE_AMD 11523c2362e6SHarvey Harrison def_bool y 11533c2362e6SHarvey Harrison prompt "AMD MCE features" 1154f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1155a7f7f624SMasahiro Yamada help 1156506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1157506f1d07SSam Ravnborg the DRAM Error Threshold. 1158506f1d07SSam Ravnborg 11594efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11606fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1161c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1162a7f7f624SMasahiro Yamada help 11634efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11645065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11654efc0670SAndi Kleen line. 11664efc0670SAndi Kleen 1167b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1168b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11696fc108a0SJan Beulich def_bool y 1170b2762686SAndi Kleen 1171ea149b36SAndi Kleenconfig X86_MCE_INJECT 1172bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1173ea149b36SAndi Kleen tristate "Machine check injector support" 1174a7f7f624SMasahiro Yamada help 1175ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1176ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1177ea149b36SAndi Kleen QA it is safe to say n. 1178ea149b36SAndi Kleen 117907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1180e633c65aSKan Liang 11815aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11821e642812SIngo Molnar bool "Legacy VM86 support" 1183506f1d07SSam Ravnborg depends on X86_32 1184a7f7f624SMasahiro Yamada help 11855aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11865aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11875aef51c3SAndy Lutomirski 11885aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11895aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11905aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11915aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11925aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11931e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11941e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11951e642812SIngo Molnar mode might be faster than emulation and you might want to 11961e642812SIngo Molnar enable this option. 11975aef51c3SAndy Lutomirski 11981e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11991e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 12001e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12011e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12025aef51c3SAndy Lutomirski 12031e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12041e642812SIngo Molnar and slows down exception handling a tiny bit. 12055aef51c3SAndy Lutomirski 12061e642812SIngo Molnar If unsure, say N here. 12075aef51c3SAndy Lutomirski 12085aef51c3SAndy Lutomirskiconfig VM86 12095aef51c3SAndy Lutomirski bool 12105aef51c3SAndy Lutomirski default X86_LEGACY_VM86 121134273f41SH. Peter Anvin 121234273f41SH. Peter Anvinconfig X86_16BIT 121334273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 121434273f41SH. Peter Anvin default y 1215a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1216a7f7f624SMasahiro Yamada help 121734273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 121834273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 121934273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 122034273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 122134273f41SH. Peter Anvin 122234273f41SH. Peter Anvinconfig X86_ESPFIX32 122334273f41SH. Peter Anvin def_bool y 122434273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1225506f1d07SSam Ravnborg 1226197725deSH. Peter Anvinconfig X86_ESPFIX64 1227197725deSH. Peter Anvin def_bool y 122834273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1229506f1d07SSam Ravnborg 12301ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12311ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12321ad83c85SAndy Lutomirski default y 12331ad83c85SAndy Lutomirski depends on X86_64 1234a7f7f624SMasahiro Yamada help 12351ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12361ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12371ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12381ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12391ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12401ad83c85SAndy Lutomirski 0xffffffffff600?00. 12411ad83c85SAndy Lutomirski 12421ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12431ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12441ad83c85SAndy Lutomirski 12451ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12461ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12471ad83c85SAndy Lutomirski 1248111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1249111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1250a24ca997SThomas Gleixner default y 1251a7f7f624SMasahiro Yamada help 1252111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1253111e7b15SThomas Gleixner for legacy applications. 1254111e7b15SThomas Gleixner 1255c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1256c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1257c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1258c8137aceSThomas Gleixner capabilities and permission from potentially active security 1259c8137aceSThomas Gleixner modules. 1260c8137aceSThomas Gleixner 1261c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1262c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1263a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1264a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1265c8137aceSThomas Gleixner 1266506f1d07SSam Ravnborgconfig TOSHIBA 1267506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1268506f1d07SSam Ravnborg depends on X86_32 1269a7f7f624SMasahiro Yamada help 1270506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1271506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1272506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1273506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1274506f1d07SSam Ravnborg 1275506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1276506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1277506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1278506f1d07SSam Ravnborg 1279506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1280506f1d07SSam Ravnborg Say N otherwise. 1281506f1d07SSam Ravnborg 1282506f1d07SSam Ravnborgconfig I8K 1283039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1284ef775a0eSRandy Dunlap depends on HWMON 1285ef775a0eSRandy Dunlap depends on PROC_FS 1286039ae585SPali Rohár select SENSORS_DELL_SMM 1287a7f7f624SMasahiro Yamada help 1288039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1289039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1290039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1291039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1292039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1293039ae585SPali Rohár needed userspace package i8kutils. 1294506f1d07SSam Ravnborg 1295039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1296039ae585SPali Rohár use userspace package i8kutils. 1297506f1d07SSam Ravnborg Say N otherwise. 1298506f1d07SSam Ravnborg 1299506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 13009ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 13019ba16087SJan Beulich depends on X86_32 1302a7f7f624SMasahiro Yamada help 1303506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1304506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1305506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1306506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1307506f1d07SSam Ravnborg system. 1308506f1d07SSam Ravnborg 1309506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 13105e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1311506f1d07SSam Ravnborg 1312506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1313506f1d07SSam Ravnborg enable this option even if you don't need it. 1314506f1d07SSam Ravnborg Say N otherwise. 1315506f1d07SSam Ravnborg 1316506f1d07SSam Ravnborgconfig MICROCODE 13179a2bc335SBorislav Petkov bool "CPU microcode loading support" 13189a2bc335SBorislav Petkov default y 131980030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1320a7f7f624SMasahiro Yamada help 1321506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13225f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13235f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13245f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13255f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13265f9c01aaSBorislav Petkov the Linux kernel. 1327506f1d07SSam Ravnborg 13285f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1329cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13305f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13315f9c01aaSBorislav Petkov initrd for microcode blobs. 1332506f1d07SSam Ravnborg 1333c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1334c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1335c508c46eSBenjamin Gilbert config option. 1336506f1d07SSam Ravnborg 13378d86f390SPeter Orubaconfig MICROCODE_INTEL 1338e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13398d86f390SPeter Oruba depends on MICROCODE 13408d86f390SPeter Oruba default MICROCODE 1341a7f7f624SMasahiro Yamada help 13428d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13438d86f390SPeter Oruba processors. 13448d86f390SPeter Oruba 1345b8989db9SAlan For the current Intel microcode data package go to 1346b8989db9SAlan <https://downloadcenter.intel.com> and search for 1347b8989db9SAlan 'Linux Processor Microcode Data File'. 13488d86f390SPeter Oruba 134980cc9f10SPeter Orubaconfig MICROCODE_AMD 1350e43f6e67SBorislav Petkov bool "AMD microcode loading support" 135180cc9f10SPeter Oruba depends on MICROCODE 1352a7f7f624SMasahiro Yamada help 135380cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 135480cc9f10SPeter Oruba processors will be enabled. 135580cc9f10SPeter Oruba 1356506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1357c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1358c02f48e0SBorislav Petkov default n 1359506f1d07SSam Ravnborg depends on MICROCODE 1360a7f7f624SMasahiro Yamada help 1361c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1362c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1363c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1364c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1365c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1366cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1367506f1d07SSam Ravnborg 1368506f1d07SSam Ravnborgconfig X86_MSR 1369506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1370a7f7f624SMasahiro Yamada help 1371506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1372506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1373506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1374506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1375506f1d07SSam Ravnborg systems. 1376506f1d07SSam Ravnborg 1377506f1d07SSam Ravnborgconfig X86_CPUID 1378506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1379a7f7f624SMasahiro Yamada help 1380506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1381506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1382506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1383506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1384506f1d07SSam Ravnborg 1385506f1d07SSam Ravnborgchoice 1386506f1d07SSam Ravnborg prompt "High Memory Support" 13876fc108a0SJan Beulich default HIGHMEM4G 1388506f1d07SSam Ravnborg depends on X86_32 1389506f1d07SSam Ravnborg 1390506f1d07SSam Ravnborgconfig NOHIGHMEM 1391506f1d07SSam Ravnborg bool "off" 1392a7f7f624SMasahiro Yamada help 1393506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1394506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1395506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1396506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1397506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1398506f1d07SSam Ravnborg "high memory". 1399506f1d07SSam Ravnborg 1400506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1401506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1402506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1403506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1404506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1405506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1406506f1d07SSam Ravnborg possible. 1407506f1d07SSam Ravnborg 1408506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1409506f1d07SSam Ravnborg answer "4GB" here. 1410506f1d07SSam Ravnborg 1411506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1412506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1413506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1414506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1415506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1416506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1417506f1d07SSam Ravnborg 1418506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1419506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1420506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1421506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1422506f1d07SSam Ravnborg kernel at boot time.) 1423506f1d07SSam Ravnborg 1424506f1d07SSam Ravnborg If unsure, say "off". 1425506f1d07SSam Ravnborg 1426506f1d07SSam Ravnborgconfig HIGHMEM4G 1427506f1d07SSam Ravnborg bool "4GB" 1428a7f7f624SMasahiro Yamada help 1429506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1430506f1d07SSam Ravnborg gigabytes of physical RAM. 1431506f1d07SSam Ravnborg 1432506f1d07SSam Ravnborgconfig HIGHMEM64G 1433506f1d07SSam Ravnborg bool "64GB" 1434225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1435506f1d07SSam Ravnborg select X86_PAE 1436a7f7f624SMasahiro Yamada help 1437506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1438506f1d07SSam Ravnborg gigabytes of physical RAM. 1439506f1d07SSam Ravnborg 1440506f1d07SSam Ravnborgendchoice 1441506f1d07SSam Ravnborg 1442506f1d07SSam Ravnborgchoice 14436a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1444506f1d07SSam Ravnborg default VMSPLIT_3G 1445506f1d07SSam Ravnborg depends on X86_32 1446a7f7f624SMasahiro Yamada help 1447506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1448506f1d07SSam Ravnborg 1449506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1450506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1451506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1452506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1453506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1454506f1d07SSam Ravnborg available to user programs, making the address space there 1455506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1456506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1457506f1d07SSam Ravnborg kernel modules. 1458506f1d07SSam Ravnborg 1459506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1460506f1d07SSam Ravnborg option alone! 1461506f1d07SSam Ravnborg 1462506f1d07SSam Ravnborg config VMSPLIT_3G 1463506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1464506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1465506f1d07SSam Ravnborg depends on !X86_PAE 1466506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1467506f1d07SSam Ravnborg config VMSPLIT_2G 1468506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1469506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1470506f1d07SSam Ravnborg depends on !X86_PAE 1471506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1472506f1d07SSam Ravnborg config VMSPLIT_1G 1473506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1474506f1d07SSam Ravnborgendchoice 1475506f1d07SSam Ravnborg 1476506f1d07SSam Ravnborgconfig PAGE_OFFSET 1477506f1d07SSam Ravnborg hex 1478506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1479506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1480506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1481506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1482506f1d07SSam Ravnborg default 0xC0000000 1483506f1d07SSam Ravnborg depends on X86_32 1484506f1d07SSam Ravnborg 1485506f1d07SSam Ravnborgconfig HIGHMEM 14863c2362e6SHarvey Harrison def_bool y 1487506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1488506f1d07SSam Ravnborg 1489506f1d07SSam Ravnborgconfig X86_PAE 14909ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1491506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1492d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14939d99c712SChristian Melki select SWIOTLB 1494a7f7f624SMasahiro Yamada help 1495506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1496506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1497506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1498506f1d07SSam Ravnborg consumes more pagetable space per process. 1499506f1d07SSam Ravnborg 150077ef56e4SKirill A. Shutemovconfig X86_5LEVEL 150177ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 150218ec1eafSKirill A. Shutemov default y 1503eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1504162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 150577ef56e4SKirill A. Shutemov depends on X86_64 1506a7f7f624SMasahiro Yamada help 150777ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 150877ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 150977ef56e4SKirill A. Shutemov physical address space. 151077ef56e4SKirill A. Shutemov 151177ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 151277ef56e4SKirill A. Shutemov 15136657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 15146657fca0SKirill A. Shutemov support 4- or 5-level paging. 151577ef56e4SKirill A. Shutemov 1516cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 151777ef56e4SKirill A. Shutemov information. 151877ef56e4SKirill A. Shutemov 151977ef56e4SKirill A. Shutemov Say N if unsure. 152077ef56e4SKirill A. Shutemov 152110971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1522e5008abeSLuis R. Rodriguez def_bool y 15232e1da13fSVlastimil Babka depends on X86_64 1524a7f7f624SMasahiro Yamada help 152510971ab2SIngo Molnar Certain kernel features effectively disable kernel 152610971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 152710971ab2SIngo Molnar supports them), so don't confuse the user by printing 152810971ab2SIngo Molnar that we have them enabled. 15299e899816SNick Piggin 15305c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15315c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15325c280cf6SThomas Gleixner depends on DEBUG_FS 1533a7f7f624SMasahiro Yamada help 1534b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1535a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15365c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15375c280cf6SThomas Gleixner 15387744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15397744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15407744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 154182fef0adSDavid Rientjes select DMA_COHERENT_POOL 154294d49eb3SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 1543ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 15449087c375STom Lendacky select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1545597cfe48SJoerg Roedel select INSTRUCTION_DECODER 154622916417STom Lendacky select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 1547aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 1548a7f7f624SMasahiro Yamada help 15497744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15507744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15517744ccdbSTom Lendacky Encryption (SME). 15527744ccdbSTom Lendacky 15537744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15547744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15557744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1556a7f7f624SMasahiro Yamada help 15577744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15587744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15597744ccdbSTom Lendacky 15607744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15617744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15627744ccdbSTom Lendacky 15637744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15647744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15657744ccdbSTom Lendacky 1566506f1d07SSam Ravnborg# Common NUMA Features 1567506f1d07SSam Ravnborgconfig NUMA 1568e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1569506f1d07SSam Ravnborg depends on SMP 1570b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1571b5660ba7SH. Peter Anvin default y if X86_BIGSMP 1572a7f7f624SMasahiro Yamada help 1573e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1574fd51b2d7SKOSAKI Motohiro 1575506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1576506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1577506f1d07SSam Ravnborg NUMA awareness to the kernel. 1578506f1d07SSam Ravnborg 1579c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1580fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1581fd51b2d7SKOSAKI Motohiro 1582b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15837cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1584fd51b2d7SKOSAKI Motohiro 1585fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1586506f1d07SSam Ravnborg 1587eec1d4faSHans Rosenfeldconfig AMD_NUMA 15883c2362e6SHarvey Harrison def_bool y 15893c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15905da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1591a7f7f624SMasahiro Yamada help 1592eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1593eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1594eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1595eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1596eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1597506f1d07SSam Ravnborg 1598506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15993c2362e6SHarvey Harrison def_bool y 16003c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1601506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1602506f1d07SSam Ravnborg select ACPI_NUMA 1603a7f7f624SMasahiro Yamada help 1604506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1605506f1d07SSam Ravnborg 1606506f1d07SSam Ravnborgconfig NUMA_EMU 1607506f1d07SSam Ravnborg bool "NUMA emulation" 16081b7e03efSTejun Heo depends on NUMA 1609a7f7f624SMasahiro Yamada help 1610506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1611506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1612506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1613506f1d07SSam Ravnborg 1614506f1d07SSam Ravnborgconfig NODES_SHIFT 1615d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 161651591e31SDavid Rientjes range 1 10 161751591e31SDavid Rientjes default "10" if MAXSMP 1618506f1d07SSam Ravnborg default "6" if X86_64 1619506f1d07SSam Ravnborg default "3" 1620a9ee6cf5SMike Rapoport depends on NUMA 1621a7f7f624SMasahiro Yamada help 16221184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1623692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1624506f1d07SSam Ravnborg 1625506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1626506f1d07SSam Ravnborg def_bool y 16273b16651fSTejun Heo depends on X86_32 && !NUMA 1628506f1d07SSam Ravnborg 1629506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1630506f1d07SSam Ravnborg def_bool y 16316ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1632506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1633506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1634506f1d07SSam Ravnborg 16353b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16366ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16373b16651fSTejun Heo 1638506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1639506f1d07SSam Ravnborg def_bool y 1640b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1641506f1d07SSam Ravnborg 1642506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1643a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16445c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1645a0842b70SToshi Kani help 1646a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1647cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1648a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1649506f1d07SSam Ravnborg 16503b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16513b16651fSTejun Heo def_bool y 16523b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16533b16651fSTejun Heo 1654a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1655a29815a3SAvi Kivity hex 1656a29815a3SAvi Kivity default 0 if X86_32 1657a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1658a29815a3SAvi Kivity 16597a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16607a67832cSDan Williams bool 16617a67832cSDan Williams 1662ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16637a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16649f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16659f53f9faSDan Williams depends on BLK_DEV 16667a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16677b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16689f53f9faSDan Williams select LIBNVDIMM 1669ec776ef6SChristoph Hellwig help 1670ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1671ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1672ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1673ec776ef6SChristoph Hellwig they can be used for persistent storage. 1674ec776ef6SChristoph Hellwig 1675ec776ef6SChristoph Hellwig Say Y if unsure. 1676ec776ef6SChristoph Hellwig 1677506f1d07SSam Ravnborgconfig HIGHPTE 1678506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16796fc108a0SJan Beulich depends on HIGHMEM 1680a7f7f624SMasahiro Yamada help 1681506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1682506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1683506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1684506f1d07SSam Ravnborg entries in high memory. 1685506f1d07SSam Ravnborg 16869f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16879f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1688a7f7f624SMasahiro Yamada help 16899f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16909f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16919f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16929f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16939f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16949f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16959f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16968c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16979f077871SJeremy Fitzhardinge 16989f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16999f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 17009f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 17019f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 17029f077871SJeremy Fitzhardinge 17039f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 17049f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 17059f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 17069f077871SJeremy Fitzhardinge memory. 17079f077871SJeremy Fitzhardinge 1708c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1709c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1710c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1711c885df50SJeremy Fitzhardinge default y 1712a7f7f624SMasahiro Yamada help 1713c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1714c885df50SJeremy Fitzhardinge on or off. 1715c885df50SJeremy Fitzhardinge 1716506f1d07SSam Ravnborgconfig MATH_EMULATION 1717506f1d07SSam Ravnborg bool 1718a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 171987d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1720a7f7f624SMasahiro Yamada help 1721506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1722506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1723506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1724506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1725506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1726506f1d07SSam Ravnborg coprocessor or this emulation. 1727506f1d07SSam Ravnborg 1728506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1729506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1730506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1731506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1732506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1733506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1734506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1735506f1d07SSam Ravnborg intend to use this kernel on different machines. 1736506f1d07SSam Ravnborg 1737506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1738506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1739506f1d07SSam Ravnborg 1740506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1741506f1d07SSam Ravnborg kernel, it won't hurt. 1742506f1d07SSam Ravnborg 1743506f1d07SSam Ravnborgconfig MTRR 17446fc108a0SJan Beulich def_bool y 17456a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1746a7f7f624SMasahiro Yamada help 1747506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1748506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1749506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1750506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1751506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1752506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1753506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1754506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1755506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1756506f1d07SSam Ravnborg 1757506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1758506f1d07SSam Ravnborg control registers on other processors can be easily supported 1759506f1d07SSam Ravnborg as well: 1760506f1d07SSam Ravnborg 1761506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1762506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1763506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1764506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1765506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1766506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1767506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1768506f1d07SSam Ravnborg 1769506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1770506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1771506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1772506f1d07SSam Ravnborg 1773506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1774506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1775506f1d07SSam Ravnborg 1776cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1777506f1d07SSam Ravnborg 177895ffa243SYinghai Luconfig MTRR_SANITIZER 17792ffb3501SYinghai Lu def_bool y 178095ffa243SYinghai Lu prompt "MTRR cleanup support" 178195ffa243SYinghai Lu depends on MTRR 1782a7f7f624SMasahiro Yamada help 1783aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1784aba3728cSThomas Gleixner add writeback entries. 178595ffa243SYinghai Lu 1786aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1787692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1788aba3728cSThomas Gleixner mtrr_chunk_size. 178995ffa243SYinghai Lu 17902ffb3501SYinghai Lu If unsure, say Y. 179195ffa243SYinghai Lu 179295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1793f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1794f5098d62SYinghai Lu range 0 1 1795f5098d62SYinghai Lu default "0" 179695ffa243SYinghai Lu depends on MTRR_SANITIZER 1797a7f7f624SMasahiro Yamada help 1798f5098d62SYinghai Lu Enable mtrr cleanup default value 179995ffa243SYinghai Lu 180012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 180112031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 180212031a62SYinghai Lu range 0 7 180312031a62SYinghai Lu default "1" 180412031a62SYinghai Lu depends on MTRR_SANITIZER 1805a7f7f624SMasahiro Yamada help 180612031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1807aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 180812031a62SYinghai Lu 18092e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 18106fc108a0SJan Beulich def_bool y 18116a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18122a8a2719SIngo Molnar depends on MTRR 1813a7f7f624SMasahiro Yamada help 18142e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1815042b78e4SVenki Pallipadi 18162e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18172e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18182e5d9c85Svenkatesh.pallipadi@intel.com 18192e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1820042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18212e5d9c85Svenkatesh.pallipadi@intel.com 18222e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18232e5d9c85Svenkatesh.pallipadi@intel.com 182446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 182546cf98cdSVenkatesh Pallipadi def_bool y 182646cf98cdSVenkatesh Pallipadi depends on X86_PAT 182746cf98cdSVenkatesh Pallipadi 1828628c6246SH. Peter Anvinconfig ARCH_RANDOM 1829628c6246SH. Peter Anvin def_bool y 1830628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1831a7f7f624SMasahiro Yamada help 1832628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1833628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1834628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1835628c6246SH. Peter Anvin secure hardware random number generator. 1836628c6246SH. Peter Anvin 183751ae4a2dSH. Peter Anvinconfig X86_SMAP 183851ae4a2dSH. Peter Anvin def_bool y 183951ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1840a7f7f624SMasahiro Yamada help 184151ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 184251ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 184351ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 184451ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 184551ae4a2dSH. Peter Anvin 184651ae4a2dSH. Peter Anvin If unsure, say Y. 184751ae4a2dSH. Peter Anvin 1848b971880fSBabu Mogerconfig X86_UMIP 1849796ebc81SRicardo Neri def_bool y 1850b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1851a7f7f624SMasahiro Yamada help 1852b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1853b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1854b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1855b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1856b971880fSBabu Moger information about the hardware state. 1857796ebc81SRicardo Neri 1858796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1859796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1860796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1861796ebc81SRicardo Neri results are dummy. 1862aa35f896SRicardo Neri 186335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 186438f3e775SBabu Moger prompt "Memory Protection Keys" 186535e97790SDave Hansen def_bool y 1866284244a9SDave Hansen # Note: only available in 64-bit mode 186738f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 186852c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 186952c8e601SIngo Molnar select ARCH_HAS_PKEYS 1870a7f7f624SMasahiro Yamada help 1871284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1872284244a9SDave Hansen page-based protections, but without requiring modification of the 1873284244a9SDave Hansen page tables when an application changes protection domains. 1874284244a9SDave Hansen 18751eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1876284244a9SDave Hansen 1877284244a9SDave Hansen If unsure, say y. 187835e97790SDave Hansen 1879db616173SMichal Hockochoice 1880db616173SMichal Hocko prompt "TSX enable mode" 1881db616173SMichal Hocko depends on CPU_SUP_INTEL 1882db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1883db616173SMichal Hocko help 1884db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1885db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1886db616173SMichal Hocko can lead to a noticeable performance boost. 1887db616173SMichal Hocko 1888db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1889db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1890db616173SMichal Hocko will be more of those attacks discovered in the future. 1891db616173SMichal Hocko 1892db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1893db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1894db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1895db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1896db616173SMichal Hocko for the particular machine. 1897db616173SMichal Hocko 1898db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1899db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1900db616173SMichal Hocko details. 1901db616173SMichal Hocko 1902db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1903db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1904db616173SMichal Hocko relevant. 1905db616173SMichal Hocko 1906db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1907db616173SMichal Hocko bool "off" 1908db616173SMichal Hocko help 1909db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1910db616173SMichal Hocko 1911db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1912db616173SMichal Hocko bool "on" 1913db616173SMichal Hocko help 1914db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1915db616173SMichal Hocko line parameter. 1916db616173SMichal Hocko 1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1918db616173SMichal Hocko bool "auto" 1919db616173SMichal Hocko help 1920db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1921db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1922db616173SMichal Hockoendchoice 1923db616173SMichal Hocko 1924e7e05452SSean Christophersonconfig X86_SGX 1925e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1926e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1927e7e05452SSean Christopherson depends on CRYPTO=y 1928e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1929e7e05452SSean Christopherson select SRCU 1930e7e05452SSean Christopherson select MMU_NOTIFIER 1931901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 1932e7e05452SSean Christopherson help 1933e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1934e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1935e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1936e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1937e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1938e7e05452SSean Christopherson hardware. 1939e7e05452SSean Christopherson 1940e7e05452SSean Christopherson If unsure, say N. 1941e7e05452SSean Christopherson 1942506f1d07SSam Ravnborgconfig EFI 19439ba16087SJan Beulich bool "EFI runtime service support" 19445b83683fSHuang, Ying depends on ACPI 1945f6ce5002SSergey Vlasov select UCS2_STRING 1946022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1947a7f7f624SMasahiro Yamada help 19488b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1949506f1d07SSam Ravnborg available (such as the EFI variable services). 1950506f1d07SSam Ravnborg 19518b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19528b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19538b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19548b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19558b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19568b2cb7a8SHuang, Ying platforms. 1957506f1d07SSam Ravnborg 1958291f3632SMatt Flemingconfig EFI_STUB 1959291f3632SMatt Fleming bool "EFI stub support" 1960*c6dbd3e5SPeter Zijlstra depends on EFI 19618f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19627b2a583aSMatt Fleming select RELOCATABLE 1963a7f7f624SMasahiro Yamada help 1964291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1965291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1966291f3632SMatt Fleming 19674f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19680c759662SMatt Fleming 19697d453eeeSMatt Flemingconfig EFI_MIXED 19707d453eeeSMatt Fleming bool "EFI mixed-mode support" 19717d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1972a7f7f624SMasahiro Yamada help 19737d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19747d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19757d453eeeSMatt Fleming mode. 19767d453eeeSMatt Fleming 19777d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19787d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19797d453eeeSMatt Fleming the EFI handover protocol must be used. 19807d453eeeSMatt Fleming 19817d453eeeSMatt Fleming If unsure, say N. 19827d453eeeSMatt Fleming 19838636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 1984506f1d07SSam Ravnborg 1985506f1d07SSam Ravnborgconfig KEXEC 1986506f1d07SSam Ravnborg bool "kexec system call" 19872965faa5SDave Young select KEXEC_CORE 1988a7f7f624SMasahiro Yamada help 1989506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1990506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1991506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1992506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1993506f1d07SSam Ravnborg 1994506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1995506f1d07SSam Ravnborg 1996506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1997506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1998bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1999bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 2000bf220695SGeert Uytterhoeven made. 2001506f1d07SSam Ravnborg 200274ca317cSVivek Goyalconfig KEXEC_FILE 200374ca317cSVivek Goyal bool "kexec file based system call" 20042965faa5SDave Young select KEXEC_CORE 200574ca317cSVivek Goyal select BUILD_BIN2C 200674ca317cSVivek Goyal depends on X86_64 200774ca317cSVivek Goyal depends on CRYPTO=y 200874ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2009a7f7f624SMasahiro Yamada help 201074ca317cSVivek Goyal This is new version of kexec system call. This system call is 201174ca317cSVivek Goyal file based and takes file descriptors as system call argument 201274ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 201374ca317cSVivek Goyal accepted by previous system call. 201474ca317cSVivek Goyal 2015b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2016b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2017b799a09fSAKASHI Takahiro 201899d5cadfSJiri Bohacconfig KEXEC_SIG 20198e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 202074ca317cSVivek Goyal depends on KEXEC_FILE 2021a7f7f624SMasahiro Yamada help 202299d5cadfSJiri Bohac 202399d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 202499d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 202599d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 202699d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 202799d5cadfSJiri Bohac 202899d5cadfSJiri Bohac In addition to this option, you need to enable signature 202999d5cadfSJiri Bohac verification for the corresponding kernel image type being 203099d5cadfSJiri Bohac loaded in order for this to work. 203199d5cadfSJiri Bohac 203299d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 203399d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 203499d5cadfSJiri Bohac depends on KEXEC_SIG 2035a7f7f624SMasahiro Yamada help 20368e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2037d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20388e7d8381SVivek Goyal 20398e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20408e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 204199d5cadfSJiri Bohac depends on KEXEC_SIG 20428e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20438e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2044a7f7f624SMasahiro Yamada help 20458e7d8381SVivek Goyal Enable bzImage signature verification support. 20468e7d8381SVivek Goyal 2047506f1d07SSam Ravnborgconfig CRASH_DUMP 204804b69447SPavel Machek bool "kernel crash dumps" 2049506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2050a7f7f624SMasahiro Yamada help 2051506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2052506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2053506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2054506f1d07SSam Ravnborg a specially reserved region and then later executed after 2055506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2056506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2057506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2058506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2059330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2060506f1d07SSam Ravnborg 20613ab83521SHuang Yingconfig KEXEC_JUMP 20626ea30386SKees Cook bool "kexec jump" 2063fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2064a7f7f624SMasahiro Yamada help 206589081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 206689081d17SHuang Ying code in physical address mode via KEXEC 20673ab83521SHuang Ying 2068506f1d07SSam Ravnborgconfig PHYSICAL_START 20696a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2070ceefccc9SH. Peter Anvin default "0x1000000" 2071a7f7f624SMasahiro Yamada help 2072506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2073506f1d07SSam Ravnborg 2074506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2075506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2076506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2077506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2078506f1d07SSam Ravnborg address. 2079506f1d07SSam Ravnborg 2080506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2081506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2082506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2083506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2084506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2085506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2086506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2087506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2088506f1d07SSam Ravnborg 2089ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2090ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2091ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2092ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2093ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2094ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2095ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2096330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2097ceefccc9SH. Peter Anvin for more details about crash dumps. 2098506f1d07SSam Ravnborg 2099506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2100506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2101506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2102506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2103506f1d07SSam Ravnborg is present because there are users out there who continue to use 2104506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2105506f1d07SSam Ravnborg line. 2106506f1d07SSam Ravnborg 2107506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2108506f1d07SSam Ravnborg 2109506f1d07SSam Ravnborgconfig RELOCATABLE 211026717808SH. Peter Anvin bool "Build a relocatable kernel" 211126717808SH. Peter Anvin default y 2112a7f7f624SMasahiro Yamada help 2113506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2114506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2115506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2116506f1d07SSam Ravnborg but are discarded at runtime. 2117506f1d07SSam Ravnborg 2118506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2119506f1d07SSam Ravnborg must live at a different physical address than the primary 2120506f1d07SSam Ravnborg kernel. 2121506f1d07SSam Ravnborg 2122506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2123506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21248ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2125506f1d07SSam Ravnborg 21268ab3820fSKees Cookconfig RANDOMIZE_BASE 2127e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21288ab3820fSKees Cook depends on RELOCATABLE 21296807c846SIngo Molnar default y 2130a7f7f624SMasahiro Yamada help 2131e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2132e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2133e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2134e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2135e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2136e8581e3dSBaoquan He code internals. 2137e8581e3dSBaoquan He 2138ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2139ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2140ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2141ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2142ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2143ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2144ed9f007eSKees Cook 2145ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2146ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2147ed9f007eSKees Cook 512MB (8 bits of entropy). 21488ab3820fSKees Cook 2149a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2150e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2151e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2152ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2153ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2154ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2155ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2156ed9f007eSKees Cook theoretically possible, but the implementations are further 2157ed9f007eSKees Cook limited due to memory layouts. 2158e8581e3dSBaoquan He 21596807c846SIngo Molnar If unsure, say Y. 2160da2b6fb9SKees Cook 21618ab3820fSKees Cook# Relocation on x86 needs some additional build support 2162845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2163845adf72SH. Peter Anvin def_bool y 21648ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2165845adf72SH. Peter Anvin 2166506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2167a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21688ab3820fSKees Cook default "0x200000" 2169a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2170a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2171a7f7f624SMasahiro Yamada help 2172506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2173506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2174506f1d07SSam Ravnborg address which meets above alignment restriction. 2175506f1d07SSam Ravnborg 2176506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2177506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2178506f1d07SSam Ravnborg address aligned to above value and run from there. 2179506f1d07SSam Ravnborg 2180506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2181506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2182506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2183506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2184506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2185506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2186506f1d07SSam Ravnborg above alignment restrictions. 2187506f1d07SSam Ravnborg 2188a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2189a0215061SKees Cook this value must be a multiple of 0x200000. 2190a0215061SKees Cook 2191506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2192506f1d07SSam Ravnborg 2193eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2194eedb92abSKirill A. Shutemov bool 2195a7f7f624SMasahiro Yamada help 2196eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2197eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2198eedb92abSKirill A. Shutemov 21990483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22000483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22010483e1faSThomas Garnier depends on X86_64 22020483e1faSThomas Garnier depends on RANDOMIZE_BASE 2203eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22040483e1faSThomas Garnier default RANDOMIZE_BASE 2205a7f7f624SMasahiro Yamada help 22060483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22070483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22080483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22090483e1faSThomas Garnier 22100483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22110483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22120483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22130483e1faSThomas Garnier addresses for each memory section. 22140483e1faSThomas Garnier 22156807c846SIngo Molnar If unsure, say Y. 22160483e1faSThomas Garnier 221790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 221890397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 221990397a41SThomas Garnier depends on RANDOMIZE_MEMORY 222090397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 222190397a41SThomas Garnier default "0x0" 222290397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 222390397a41SThomas Garnier range 0x0 0x40 2224a7f7f624SMasahiro Yamada help 222590397a41SThomas Garnier Define the padding in terabytes added to the existing physical 222690397a41SThomas Garnier memory size during kernel memory randomization. It is useful 222790397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 222890397a41SThomas Garnier address randomization. 222990397a41SThomas Garnier 223090397a41SThomas Garnier If unsure, leave at the default value. 223190397a41SThomas Garnier 2232506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2233bebd024eSThomas Gleixner def_bool y 223440b31360SStephen Rothwell depends on SMP 2235506f1d07SSam Ravnborg 223680aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 223780aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22382c922cd0SKees Cook depends on HOTPLUG_CPU 2239a7f7f624SMasahiro Yamada help 224080aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 224180aa1dffSFenghua Yu 224280aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 224380aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 224480aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 224580aa1dffSFenghua Yu 224680aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 224780aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 224880aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 224980aa1dffSFenghua Yu 225080aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 225180aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 225280aa1dffSFenghua Yu 225380aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 225480aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 225580aa1dffSFenghua Yu be other CPU0 dependencies. 225680aa1dffSFenghua Yu 225780aa1dffSFenghua Yu Please make sure the dependencies are under your control before 225880aa1dffSFenghua Yu you enable this feature. 225980aa1dffSFenghua Yu 226080aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 226180aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 226280aa1dffSFenghua Yu parameter cpu0_hotplug. 226380aa1dffSFenghua Yu 2264a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2265a71c8bc5SFenghua Yu def_bool n 2266a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22672c922cd0SKees Cook depends on HOTPLUG_CPU 2268a7f7f624SMasahiro Yamada help 2269a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2270a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2271a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2272a71c8bc5SFenghua Yu 2273a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2274a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2275a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2276a71c8bc5SFenghua Yu 2277a71c8bc5SFenghua Yu If unsure, say N. 2278a71c8bc5SFenghua Yu 2279506f1d07SSam Ravnborgconfig COMPAT_VDSO 2280b0b49f26SAndy Lutomirski def_bool n 2281b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2282953fee1dSIngo Molnar depends on COMPAT_32 2283a7f7f624SMasahiro Yamada help 2284b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2285b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2286b0b49f26SAndy Lutomirski indicated in its segment table. 2287e84446deSRandy Dunlap 2288b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2289b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2290b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2291b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2292b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2293506f1d07SSam Ravnborg 2294b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2295b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2296b0b49f26SAndy Lutomirski 2297b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2298b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2299b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2300b0b49f26SAndy Lutomirski 2301b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2302b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2303506f1d07SSam Ravnborg 23043dc33bd3SKees Cookchoice 23053dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23063dc33bd3SKees Cook depends on X86_64 2307625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23083dc33bd3SKees Cook help 23093dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23103dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23113dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23123dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23133dc33bd3SKees Cook 23143dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2315bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23163dc33bd3SKees Cook 23173dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23183dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23193dc33bd3SKees Cook to improve security. 23203dc33bd3SKees Cook 2321bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23223dc33bd3SKees Cook 23233dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2324bd49e16eSAndy Lutomirski bool "Full emulation" 23253dc33bd3SKees Cook help 2326bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2327bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2328bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2329bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2330bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2331bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2332bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2333bd49e16eSAndy Lutomirski 2334bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2335bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2336bd49e16eSAndy Lutomirski 2337bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2338bd49e16eSAndy Lutomirski bool "Emulate execution only" 2339bd49e16eSAndy Lutomirski help 2340bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2341bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2342bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2343bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2344bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2345bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2346bd49e16eSAndy Lutomirski buffer. 23473dc33bd3SKees Cook 23483dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23493dc33bd3SKees Cook bool "None" 23503dc33bd3SKees Cook help 23513dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23523dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23533dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23543dc33bd3SKees Cook will be reported to dmesg, so that either old or 23553dc33bd3SKees Cook malicious userspace programs can be identified. 23563dc33bd3SKees Cook 23573dc33bd3SKees Cookendchoice 23583dc33bd3SKees Cook 2359516cbf37STim Birdconfig CMDLINE_BOOL 2360516cbf37STim Bird bool "Built-in kernel command line" 2361a7f7f624SMasahiro Yamada help 2362516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2363516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2364516cbf37STim Bird necessary or convenient to provide some or all of the 2365516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2366516cbf37STim Bird to not rely on the boot loader to provide them.) 2367516cbf37STim Bird 2368516cbf37STim Bird To compile command line arguments into the kernel, 2369516cbf37STim Bird set this option to 'Y', then fill in the 237069711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2371516cbf37STim Bird 2372516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2373516cbf37STim Bird should leave this option set to 'N'. 2374516cbf37STim Bird 2375516cbf37STim Birdconfig CMDLINE 2376516cbf37STim Bird string "Built-in kernel command string" 2377516cbf37STim Bird depends on CMDLINE_BOOL 2378516cbf37STim Bird default "" 2379a7f7f624SMasahiro Yamada help 2380516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2381516cbf37STim Bird image and used at boot time. If the boot loader provides a 2382516cbf37STim Bird command line at boot time, it is appended to this string to 2383516cbf37STim Bird form the full kernel command line, when the system boots. 2384516cbf37STim Bird 2385516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2386516cbf37STim Bird change this behavior. 2387516cbf37STim Bird 2388516cbf37STim Bird In most cases, the command line (whether built-in or provided 2389516cbf37STim Bird by the boot loader) should specify the device for the root 2390516cbf37STim Bird file system. 2391516cbf37STim Bird 2392516cbf37STim Birdconfig CMDLINE_OVERRIDE 2393516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2394645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2395a7f7f624SMasahiro Yamada help 2396516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2397516cbf37STim Bird command line, and use ONLY the built-in command line. 2398516cbf37STim Bird 2399516cbf37STim Bird This is used to work around broken boot loaders. This should 2400516cbf37STim Bird be set to 'N' under normal conditions. 2401516cbf37STim Bird 2402a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2403a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2404a5b9e5a2SAndy Lutomirski default y 2405a7f7f624SMasahiro Yamada help 2406a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2407a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2408a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2409a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2410a5b9e5a2SAndy Lutomirski threading libraries. 2411a5b9e5a2SAndy Lutomirski 2412a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2413a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2414a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2415a5b9e5a2SAndy Lutomirski 2416a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2417a5b9e5a2SAndy Lutomirski 24183aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24193aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24203aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24213aac3ebeSThomas Gleixner help 24223aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24233aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24243aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24253aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24263aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24273aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24283aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24293aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24303aac3ebeSThomas Gleixner never get a signal delivered. 24313aac3ebeSThomas Gleixner 24323aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24333aac3ebeSThomas Gleixner 2434b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2435b700e7f0SSeth Jennings 2436506f1d07SSam Ravnborgendmenu 2437506f1d07SSam Ravnborg 24383072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24393072e413SMichal Hocko def_bool y 24405c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24413072e413SMichal Hocko 2442f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2443f91ef222SOscar Salvador def_bool y 2444f91ef222SOscar Salvador 2445e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2446645a7919STejun Heo def_bool y 2447e534c7c5SLee Schermerhorn depends on NUMA 2448e534c7c5SLee Schermerhorn 2449da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2450e279b6c1SSam Ravnborg 2451e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24523c2362e6SHarvey Harrison def_bool y 245344556530SZhimin Gu depends on HIBERNATION 2454e279b6c1SSam Ravnborg 2455e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2456e279b6c1SSam Ravnborg 2457e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2458e279b6c1SSam Ravnborg 2459a6b68076SAndi Kleenconfig X86_APM_BOOT 24606fc108a0SJan Beulich def_bool y 2461282e5aabSPaul Bolle depends on APM 2462a6b68076SAndi Kleen 2463e279b6c1SSam Ravnborgmenuconfig APM 2464e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2465efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2466a7f7f624SMasahiro Yamada help 2467e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2468e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2469e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2470e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2471e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2472e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2473e279b6c1SSam Ravnborg 2474e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2475e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2476e279b6c1SSam Ravnborg 2477e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2478e279b6c1SSam Ravnborg machines with more than one CPU. 2479e279b6c1SSam Ravnborg 2480e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2481151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24822dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2483e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2484e279b6c1SSam Ravnborg 2485e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2486e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2487e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2488e279b6c1SSam Ravnborg 2489e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2490e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2491e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2492e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2493e279b6c1SSam Ravnborg 2494e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2495e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2496e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2497e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2498e279b6c1SSam Ravnborg APM in your BIOS). 2499e279b6c1SSam Ravnborg 2500e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2501e279b6c1SSam Ravnborg "weird" problems: 2502e279b6c1SSam Ravnborg 2503e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2504e279b6c1SSam Ravnborg enabled. 2505e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2506e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2507e279b6c1SSam Ravnborg the "no387" option to the kernel 2508e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2509e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2510e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2511e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2512e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2513e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2514e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2515e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2516e279b6c1SSam Ravnborg 11) exchange RAM chips 2517e279b6c1SSam Ravnborg 12) exchange the motherboard. 2518e279b6c1SSam Ravnborg 2519e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2520e279b6c1SSam Ravnborg module will be called apm. 2521e279b6c1SSam Ravnborg 2522e279b6c1SSam Ravnborgif APM 2523e279b6c1SSam Ravnborg 2524e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2525e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2526a7f7f624SMasahiro Yamada help 2527e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2528e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2529e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2530e279b6c1SSam Ravnborg 2531e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2532e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2533a7f7f624SMasahiro Yamada help 2534e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2535e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2536e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2537e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2538e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2539e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2540e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2541e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2542e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2543e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2544e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2545e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2546e279b6c1SSam Ravnborg this feature. 2547e279b6c1SSam Ravnborg 2548e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2549dd8af076SLen Brown depends on CPU_IDLE 2550e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2551a7f7f624SMasahiro Yamada help 2552e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2553e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2554e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2555e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2556e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2557e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2558e279b6c1SSam Ravnborg this option does nothing.) 2559e279b6c1SSam Ravnborg 2560e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2561e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2562a7f7f624SMasahiro Yamada help 2563e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2564e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2565e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2566e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2567e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2568e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2569e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2570e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2571e279b6c1SSam Ravnborg especially if you are using gpm. 2572e279b6c1SSam Ravnborg 2573e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2574e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2575a7f7f624SMasahiro Yamada help 2576e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2577e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2578e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2579e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2580e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2581e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2582e279b6c1SSam Ravnborg 2583e279b6c1SSam Ravnborgendif # APM 2584e279b6c1SSam Ravnborg 2585bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2586e279b6c1SSam Ravnborg 2587e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2588e279b6c1SSam Ravnborg 258927471fdbSAndy Henroidsource "drivers/idle/Kconfig" 259027471fdbSAndy Henroid 2591e279b6c1SSam Ravnborgendmenu 2592e279b6c1SSam Ravnborg 2593e279b6c1SSam Ravnborg 2594e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2595e279b6c1SSam Ravnborg 2596e279b6c1SSam Ravnborgchoice 2597e279b6c1SSam Ravnborg prompt "PCI access mode" 2598efefa6f6SIngo Molnar depends on X86_32 && PCI 2599e279b6c1SSam Ravnborg default PCI_GOANY 2600a7f7f624SMasahiro Yamada help 2601e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2602e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2603e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2604e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2605e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2606e279b6c1SSam Ravnborg 2607e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2608e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2609e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2610e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2611e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2612e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2613e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2614e279b6c1SSam Ravnborg 2615e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2616e279b6c1SSam Ravnborg bool "BIOS" 2617e279b6c1SSam Ravnborg 2618e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2619e279b6c1SSam Ravnborg bool "MMConfig" 2620e279b6c1SSam Ravnborg 2621e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2622e279b6c1SSam Ravnborg bool "Direct" 2623e279b6c1SSam Ravnborg 26243ef0e1f8SAndres Salomonconfig PCI_GOOLPC 262576fb6570SDaniel Drake bool "OLPC XO-1" 26263ef0e1f8SAndres Salomon depends on OLPC 26273ef0e1f8SAndres Salomon 26282bdd1b03SAndres Salomonconfig PCI_GOANY 26292bdd1b03SAndres Salomon bool "Any" 26302bdd1b03SAndres Salomon 2631e279b6c1SSam Ravnborgendchoice 2632e279b6c1SSam Ravnborg 2633e279b6c1SSam Ravnborgconfig PCI_BIOS 26343c2362e6SHarvey Harrison def_bool y 2635efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2636e279b6c1SSam Ravnborg 2637e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2638e279b6c1SSam Ravnborgconfig PCI_DIRECT 26393c2362e6SHarvey Harrison def_bool y 26400aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2641e279b6c1SSam Ravnborg 2642e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2643b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2644b45c9f36SJan Kiszka default y 26454590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2646b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2647e279b6c1SSam Ravnborg 26483ef0e1f8SAndres Salomonconfig PCI_OLPC 26492bdd1b03SAndres Salomon def_bool y 26502bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26513ef0e1f8SAndres Salomon 2652b5401a96SAlex Nixonconfig PCI_XEN 2653b5401a96SAlex Nixon def_bool y 2654b5401a96SAlex Nixon depends on PCI && XEN 2655b5401a96SAlex Nixon 26568364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26578364e1f8SJan Kiszka def_bool y 26588364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2659e279b6c1SSam Ravnborg 26603f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26616a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26626ea30386SKees Cook depends on PCI 26633f6ea84aSIra W. Snyder help 26643f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26653f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26663f6ea84aSIra W. Snyder not have ACPI. 26673f6ea84aSIra W. Snyder 266864a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 266964a5fed6SBjorn Helgaas is known to be incomplete. 267064a5fed6SBjorn Helgaas 267164a5fed6SBjorn Helgaas You should say N unless you know you need this. 267264a5fed6SBjorn Helgaas 26733a495511SWilliam Breathitt Grayconfig ISA_BUS 267417a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26753a495511SWilliam Breathitt Gray help 267617a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 267717a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 267817a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 267917a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 268017a2a129SWilliam Breathitt Gray not have an ISA bus. 26813a495511SWilliam Breathitt Gray 26823a495511SWilliam Breathitt Gray If unsure, say N. 26833a495511SWilliam Breathitt Gray 26841c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2685e279b6c1SSam Ravnborgconfig ISA_DMA_API 26861c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 26871c00f016SDavid Rientjes default y 26881c00f016SDavid Rientjes help 26891c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 26901c00f016SDavid Rientjes If unsure, say Y. 2691e279b6c1SSam Ravnborg 269251e68d05SLinus Torvaldsif X86_32 269351e68d05SLinus Torvalds 2694e279b6c1SSam Ravnborgconfig ISA 2695e279b6c1SSam Ravnborg bool "ISA support" 2696a7f7f624SMasahiro Yamada help 2697e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2698e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2699e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2700e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2701e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2702e279b6c1SSam Ravnborg 2703e279b6c1SSam Ravnborgconfig SCx200 2704e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2705a7f7f624SMasahiro Yamada help 2706e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2707e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2708e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2709e279b6c1SSam Ravnborg for other scx200_* drivers. 2710e279b6c1SSam Ravnborg 2711e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2712e279b6c1SSam Ravnborg 2713e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2714e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2715592913ecSJohn Stultz depends on SCx200 2716e279b6c1SSam Ravnborg default y 2717a7f7f624SMasahiro Yamada help 2718e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2719e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2720e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2721e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2722e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2723e279b6c1SSam Ravnborg 27243ef0e1f8SAndres Salomonconfig OLPC 27253ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 272654008979SThomas Gleixner depends on !X86_PAE 27273c554946SAndres Salomon select GPIOLIB 2728dc3119e7SThomas Gleixner select OF 272945bb1674SDaniel Drake select OF_PROMTREE 2730b4e51854SGrant Likely select IRQ_DOMAIN 27310c3d931bSLubomir Rintel select OLPC_EC 2732a7f7f624SMasahiro Yamada help 27333ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27343ef0e1f8SAndres Salomon XO hardware. 27353ef0e1f8SAndres Salomon 2736a3128588SDaniel Drakeconfig OLPC_XO1_PM 2737a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2738fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2739a7f7f624SMasahiro Yamada help 274097c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2741bf1ebf00SDaniel Drake 2742cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2743cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2744cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2745a7f7f624SMasahiro Yamada help 2746cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2747cfee9597SDaniel Drake programmable wakeup source. 2748cfee9597SDaniel Drake 27497feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27507feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 275192e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2752ed8e47feSRandy Dunlap depends on INPUT=y 2753d8d01a63SDaniel Drake select POWER_SUPPLY 2754a7f7f624SMasahiro Yamada help 27557feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27567bc74b3dSDaniel Drake - EC-driven system wakeups 27577feda8e9SDaniel Drake - Power button 27587bc74b3dSDaniel Drake - Ebook switch 27592cf2baeaSDaniel Drake - Lid switch 2760e1040ac6SDaniel Drake - AC adapter status updates 2761e1040ac6SDaniel Drake - Battery status updates 27627feda8e9SDaniel Drake 2763a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2764a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2765d8d01a63SDaniel Drake depends on OLPC && ACPI 2766d8d01a63SDaniel Drake select POWER_SUPPLY 2767a7f7f624SMasahiro Yamada help 2768a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2769a0f30f59SDaniel Drake - EC-driven system wakeups 2770a0f30f59SDaniel Drake - AC adapter status updates 2771a0f30f59SDaniel Drake - Battery status updates 2772e279b6c1SSam Ravnborg 2773d4f3e350SEd Wildgooseconfig ALIX 2774d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2775d4f3e350SEd Wildgoose select GPIOLIB 2776a7f7f624SMasahiro Yamada help 2777d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2778d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2779d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2780d4f3e350SEd Wildgoose get added here. 2781d4f3e350SEd Wildgoose 2782d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2783d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2784d4f3e350SEd Wildgoose 2785d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2786d4f3e350SEd Wildgoose 2787da4e3302SPhilip Prindevilleconfig NET5501 2788da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2789da4e3302SPhilip Prindeville select GPIOLIB 2790a7f7f624SMasahiro Yamada help 2791da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2792da4e3302SPhilip Prindeville 27933197059aSPhilip A. Prindevilleconfig GEOS 27943197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 27953197059aSPhilip A. Prindeville select GPIOLIB 27963197059aSPhilip A. Prindeville depends on DMI 2797a7f7f624SMasahiro Yamada help 27983197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 27993197059aSPhilip A. Prindeville 28007d029125SVivien Didelotconfig TS5500 28017d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 28027d029125SVivien Didelot depends on MELAN 28037d029125SVivien Didelot select CHECK_SIGNATURE 28047d029125SVivien Didelot select NEW_LEDS 28057d029125SVivien Didelot select LEDS_CLASS 2806a7f7f624SMasahiro Yamada help 28077d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 28087d029125SVivien Didelot 2809e279b6c1SSam Ravnborgendif # X86_32 2810e279b6c1SSam Ravnborg 281123ac4ae8SAndreas Herrmannconfig AMD_NB 2812e279b6c1SSam Ravnborg def_bool y 28130e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2814e279b6c1SSam Ravnborg 2815e279b6c1SSam Ravnborgendmenu 2816e279b6c1SSam Ravnborg 2817e279b6c1SSam Ravnborg 28181572497cSChristoph Hellwigmenu "Binary Emulations" 2819e279b6c1SSam Ravnborg 2820e279b6c1SSam Ravnborgconfig IA32_EMULATION 2821e279b6c1SSam Ravnborg bool "IA32 Emulation" 2822e279b6c1SSam Ravnborg depends on X86_64 282339f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2824d1603990SRandy Dunlap select BINFMT_ELF 282539f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2826a7f7f624SMasahiro Yamada help 28275fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28285fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28295fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2830e279b6c1SSam Ravnborg 2831e279b6c1SSam Ravnborgconfig IA32_AOUT 2832e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28336b213e1bSDavid Woodhouse depends on IA32_EMULATION 2834eac61655SBorislav Petkov depends on BROKEN 2835a7f7f624SMasahiro Yamada help 2836e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2837e279b6c1SSam Ravnborg 28380bf62763SH. Peter Anvinconfig X86_X32 28396ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28409b54050bSBrian Gerst depends on X86_64 2841a7f7f624SMasahiro Yamada help 28425fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28435fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28445fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28455fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28465fd92e65SH. J. Lu 28475fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 28485fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 28495fd92e65SH. J. Lu option set. 28505fd92e65SH. J. Lu 2851953fee1dSIngo Molnarconfig COMPAT_32 2852953fee1dSIngo Molnar def_bool y 2853953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2854953fee1dSIngo Molnar select HAVE_UID16 2855953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2856953fee1dSIngo Molnar 2857e279b6c1SSam Ravnborgconfig COMPAT 28583c2362e6SHarvey Harrison def_bool y 28590bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2860e279b6c1SSam Ravnborg 28613120e25eSJan Beulichif COMPAT 2862e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28633120e25eSJan Beulich def_bool y 2864e279b6c1SSam Ravnborg 2865e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28663c2362e6SHarvey Harrison def_bool y 28673120e25eSJan Beulich depends on SYSVIPC 28683120e25eSJan Beulichendif 2869ee009e4aSDavid Howells 2870e279b6c1SSam Ravnborgendmenu 2871e279b6c1SSam Ravnborg 2872e279b6c1SSam Ravnborg 2873e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2874e5beae16SKeith Packard def_bool y 2875e5beae16SKeith Packard depends on X86_32 2876e5beae16SKeith Packard 2877edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28785e8ebd84SJason A. Donenfeld 28795e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2880