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 1960b707e57SLinus Torvalds select HAVE_SAMPLE_FTRACE_MULTI_DIRECT 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 475e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 476e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4776fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 47859fe5a77SThomas Gleixner select KERNFS 479e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 48078e99b4aSFenghua Yu help 481e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4826fe07ce3SBabu Moger 4836fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4846fe07ce3SBabu Moger usage by the CPU. 4856fe07ce3SBabu Moger 4866fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4876fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4886fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4896fe07ce3SBabu Moger 4906fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4916fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4926fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 49378e99b4aSFenghua Yu 49478e99b4aSFenghua Yu Say N if unsure. 49578e99b4aSFenghua Yu 4968425091fSRavikiran G Thirumalaiif X86_32 497a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 498a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 499a0d0bb4dSRandy Dunlap depends on SMP 500a7f7f624SMasahiro Yamada help 501e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 502a0d0bb4dSRandy Dunlap 503c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 504c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 505c5c606d9SRavikiran G Thirumalai default y 506a7f7f624SMasahiro Yamada help 50706ac8346SIngo Molnar If you disable this option then the kernel will only support 50806ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 50906ac8346SIngo Molnar systems out there.) 51006ac8346SIngo Molnar 5118425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5128425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 513cb7b8023SBen Hutchings Goldfish (Android emulator) 5148425091fSRavikiran G Thirumalai AMD Elan 5158425091fSRavikiran G Thirumalai RDC R-321x SoC 5168425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 51783125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5183f4110a4SThomas Gleixner Moorestown MID devices 51906ac8346SIngo Molnar 52006ac8346SIngo Molnar If you have one of these systems, or if you want to build a 52106ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5228425091fSRavikiran G Thirumalaiendif 52306ac8346SIngo Molnar 5248425091fSRavikiran G Thirumalaiif X86_64 5258425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5268425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5278425091fSRavikiran G Thirumalai default y 528a7f7f624SMasahiro Yamada help 5298425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5308425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5318425091fSRavikiran G Thirumalai systems out there.) 5328425091fSRavikiran G Thirumalai 5338425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5348425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 53544b111b5SSteffen Persvold Numascale NumaChip 5368425091fSRavikiran G Thirumalai ScaleMP vSMP 5378425091fSRavikiran G Thirumalai SGI Ultraviolet 5388425091fSRavikiran G Thirumalai 5398425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5408425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5418425091fSRavikiran G Thirumalaiendif 542c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 543c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 54444b111b5SSteffen Persvoldconfig X86_NUMACHIP 54544b111b5SSteffen Persvold bool "Numascale NumaChip" 54644b111b5SSteffen Persvold depends on X86_64 54744b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 54844b111b5SSteffen Persvold depends on NUMA 54944b111b5SSteffen Persvold depends on SMP 55044b111b5SSteffen Persvold depends on X86_X2APIC 551f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 552a7f7f624SMasahiro Yamada help 55344b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 55444b111b5SSteffen Persvold enable more than ~168 cores. 55544b111b5SSteffen Persvold If you don't have one of these, you should say N here. 55603b48632SNick Piggin 5576a48565eSIngo Molnarconfig X86_VSMP 558c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5596276a074SBorislav Petkov select HYPERVISOR_GUEST 5606a48565eSIngo Molnar select PARAVIRT 5616a48565eSIngo Molnar depends on X86_64 && PCI 562c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 563ead91d4bSShai Fultheim depends on SMP 564a7f7f624SMasahiro Yamada help 5656a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5666a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5676a48565eSIngo Molnar if you have one of these machines. 5686a48565eSIngo Molnar 569c5c606d9SRavikiran G Thirumalaiconfig X86_UV 570c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 571c5c606d9SRavikiran G Thirumalai depends on X86_64 572c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 57354c28d29SJack Steiner depends on NUMA 5741ecb4ae5SAndrew Morton depends on EFI 575c2209ea5SIngo Molnar depends on KEXEC_CORE 5769d6c26e7SSuresh Siddha depends on X86_X2APIC 5771222e564SIngo Molnar depends on PCI 578a7f7f624SMasahiro Yamada help 579c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 580c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 581c5c606d9SRavikiran G Thirumalai 582c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 583c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 584506f1d07SSam Ravnborg 585ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 586ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 587cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 588a7f7f624SMasahiro Yamada help 589ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 590ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 591ddd70cf9SJun Nakajima Goldfish emulator say N here. 592ddd70cf9SJun Nakajima 593c751e17bSThomas Gleixnerconfig X86_INTEL_CE 594c751e17bSThomas Gleixner bool "CE4100 TV platform" 595c751e17bSThomas Gleixner depends on PCI 596c751e17bSThomas Gleixner depends on PCI_GODIRECT 5976084a6e2SJiang Liu depends on X86_IO_APIC 598c751e17bSThomas Gleixner depends on X86_32 599c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 60037bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 601da6b737bSSebastian Andrzej Siewior select OF 602da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 603a7f7f624SMasahiro Yamada help 604c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 605c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 606c751e17bSThomas Gleixner boxes and media devices. 607c751e17bSThomas Gleixner 6084cb9b00fSDavid Cohenconfig X86_INTEL_MID 60943605ef1SAlan Cox bool "Intel MID platform support" 61043605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 611edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6121ea7c673SAlan Cox depends on PCI 6133fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6141ea7c673SAlan Cox depends on X86_IO_APIC 6154cb9b00fSDavid Cohen select I2C 6167c9c3a1eSAlan Cox select DW_APB_TIMER 61754b34aa0SMika Westerberg select INTEL_SCU_PCI 618a7f7f624SMasahiro Yamada help 6194cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6204cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6214cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6221ea7c673SAlan Cox 6234cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6244cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 62543605ef1SAlan Cox 6268bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6278bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6288bbc2a13SBryan O'Donoghue depends on X86_32 6298bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6308bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6318bbc2a13SBryan O'Donoghue depends on X86_TSC 6328bbc2a13SBryan O'Donoghue depends on PCI 6338bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6348bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6358bbc2a13SBryan O'Donoghue select IOSF_MBI 6368bbc2a13SBryan O'Donoghue select INTEL_IMR 6379ab6eb51SAndy Shevchenko select COMMON_CLK 638a7f7f624SMasahiro Yamada help 6398bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6408bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6418bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6428bbc2a13SBryan O'Donoghue 6433d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6443d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6455962dd22SSinan Kaya depends on X86 && ACPI && PCI 6463d48aab1SMika Westerberg select COMMON_CLK 6470f531431SMathias Nyman select PINCTRL 648eebb3e8dSAndy Shevchenko select IOSF_MBI 649a7f7f624SMasahiro Yamada help 6503d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6513d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6520f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6530f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6543d48aab1SMika Westerberg 65592082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 65692082a88SKen Xue bool "AMD ACPI2Platform devices support" 65792082a88SKen Xue depends on ACPI 65892082a88SKen Xue select COMMON_CLK 65992082a88SKen Xue select PINCTRL 660a7f7f624SMasahiro Yamada help 66192082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 66292082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 66392082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 66492082a88SKen Xue implemented under PINCTRL subsystem. 66592082a88SKen Xue 666ced3ce76SDavid E. Boxconfig IOSF_MBI 667ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 668ced3ce76SDavid E. Box depends on PCI 669a7f7f624SMasahiro Yamada help 670ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 671ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 672ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 673ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 674ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 675ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 676ced3ce76SDavid E. Box This list is not meant to be exclusive. 677ced3ce76SDavid E. Box - BayTrail 678ced3ce76SDavid E. Box - Braswell 679ced3ce76SDavid E. Box - Quark 680ced3ce76SDavid E. Box 681ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 682ced3ce76SDavid E. Box 683ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 684ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 685ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 686a7f7f624SMasahiro Yamada help 687ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 688ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 689ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 690ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 691ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 692ed2226bdSDavid E. Box device they want to access. 693ed2226bdSDavid E. Box 694ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 695ed2226bdSDavid E. Box 696c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 697c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 698506f1d07SSam Ravnborg depends on X86_32 699c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 700c5c606d9SRavikiran G Thirumalai select M486 701c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 702a7f7f624SMasahiro Yamada help 703c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 704c5c606d9SRavikiran G Thirumalai as R-8610-(G). 705c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 706c5c606d9SRavikiran G Thirumalai 707e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7089c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7099c398017SIngo Molnar depends on X86_32 && SMP 710c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 711a7f7f624SMasahiro Yamada help 712b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 713b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 714b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 715b5660ba7SH. Peter Anvin one and will fallback to default. 716d49c4288SYinghai Lu 717c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 718d49c4288SYinghai Lu 719d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7206fc108a0SJan Beulich def_bool y 721d949f36fSLinus Torvalds # MCE code calls memory_failure(): 722d949f36fSLinus Torvalds depends on X86_MCE 723d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 724d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 725d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 726d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 727d949f36fSLinus Torvalds 72883125a3aSAlessandro Rubiniconfig STA2X11 72983125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 73083125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 73183125a3aSAlessandro Rubini select SWIOTLB 73283125a3aSAlessandro Rubini select MFD_STA2X11 7330145071bSLinus Walleij select GPIOLIB 734a7f7f624SMasahiro Yamada help 73583125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 73683125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 73783125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 73883125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 73983125a3aSAlessandro Rubini standard PC machines. 74083125a3aSAlessandro Rubini 74182148d1dSShérabconfig X86_32_IRIS 74282148d1dSShérab tristate "Eurobraille/Iris poweroff module" 74382148d1dSShérab depends on X86_32 744a7f7f624SMasahiro Yamada help 74582148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 74682148d1dSShérab to shut themselves down properly. A special I/O sequence is 74782148d1dSShérab needed to do so, which is what this module does at 74882148d1dSShérab kernel shutdown. 74982148d1dSShérab 75082148d1dSShérab This is only for Iris machines from EuroBraille. 75182148d1dSShérab 75282148d1dSShérab If unused, say N. 75382148d1dSShérab 754ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7553c2362e6SHarvey Harrison def_bool y 7563c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 757a87d0914SKen Chen depends on X86 758a7f7f624SMasahiro Yamada help 759506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 760506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 761506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 762506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 763506f1d07SSam Ravnborg 764506f1d07SSam Ravnborg If in doubt, say "Y". 765506f1d07SSam Ravnborg 7666276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7676276a074SBorislav Petkov bool "Linux guest support" 768a7f7f624SMasahiro Yamada help 7696276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7706276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7716276a074SBorislav Petkov setup. 772506f1d07SSam Ravnborg 7736276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7746276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 775506f1d07SSam Ravnborg 7766276a074SBorislav Petkovif HYPERVISOR_GUEST 777506f1d07SSam Ravnborg 778e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 779e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 780a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 781a7f7f624SMasahiro Yamada help 782e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 783e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 784e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 785e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 786e61bd94aSEduardo Pereira Habkost 787c00a280aSJuergen Grossconfig PARAVIRT_XXL 788c00a280aSJuergen Gross bool 789c00a280aSJuergen Gross 7906276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7916276a074SBorislav Petkov bool "paravirt-ops debugging" 7926276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 793a7f7f624SMasahiro Yamada help 7946276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7956276a074SBorislav Petkov a paravirt_op is missing when it is called. 7966276a074SBorislav Petkov 797b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 798b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7996ea30386SKees Cook depends on PARAVIRT && SMP 800a7f7f624SMasahiro Yamada help 801b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 802b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 803b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 804b4ecc126SJeremy Fitzhardinge 8054c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8064c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 807b4ecc126SJeremy Fitzhardinge 8084c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 809b4ecc126SJeremy Fitzhardinge 810ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 811ecca2502SZhao Yakui def_bool n 812ecca2502SZhao Yakui 8136276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8146276a074SBorislav Petkov 8156276a074SBorislav Petkovconfig KVM_GUEST 8166276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8176276a074SBorislav Petkov depends on PARAVIRT 8186276a074SBorislav Petkov select PARAVIRT_CLOCK 819a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 820b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8216276a074SBorislav Petkov default y 822a7f7f624SMasahiro Yamada help 8236276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8246276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8256276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8266276a074SBorislav Petkov underlying device model, the host provides the guest with 8276276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8286276a074SBorislav Petkov 829a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 830a1c4423bSMarcelo Tosatti def_bool n 831a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 832a1c4423bSMarcelo Tosatti help 833a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 834a1c4423bSMarcelo Tosatti 8357733607fSMaran Wilsonconfig PVH 8367733607fSMaran Wilson bool "Support for running PVH guests" 837a7f7f624SMasahiro Yamada help 8387733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8397733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8407733607fSMaran Wilson 8416276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8426276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8436276a074SBorislav Petkov depends on PARAVIRT 844a7f7f624SMasahiro Yamada help 8456276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8466276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8476276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8486276a074SBorislav Petkov that, there can be a small performance impact. 8496276a074SBorislav Petkov 8506276a074SBorislav Petkov If in doubt, say N here. 8516276a074SBorislav Petkov 8527af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8537af192c9SGerd Hoffmann bool 8547af192c9SGerd Hoffmann 8554a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8564a362601SJan Kiszka bool "Jailhouse non-root cell support" 857abde587bSArnd Bergmann depends on X86_64 && PCI 85887e65d05SJan Kiszka select X86_PM_TIMER 859a7f7f624SMasahiro Yamada help 8604a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8614a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8624a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8634a362601SJan Kiszka 864ec7972c9SZhao Yakuiconfig ACRN_GUEST 865ec7972c9SZhao Yakui bool "ACRN Guest support" 866ec7972c9SZhao Yakui depends on X86_64 867498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 868ec7972c9SZhao Yakui help 869ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 870ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 871ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 872ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 873ec7972c9SZhao Yakui found in https://projectacrn.org/. 874ec7972c9SZhao Yakui 8756276a074SBorislav Petkovendif #HYPERVISOR_GUEST 87697349135SJeremy Fitzhardinge 877506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 878506f1d07SSam Ravnborg 879506f1d07SSam Ravnborgconfig HPET_TIMER 8803c2362e6SHarvey Harrison def_bool X86_64 881506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 882a7f7f624SMasahiro Yamada help 883506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 884506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 885506f1d07SSam Ravnborg present. 886506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 887506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 888506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8894e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8904e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 891506f1d07SSam Ravnborg 892506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 893506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 894506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 895506f1d07SSam Ravnborg 896506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 897506f1d07SSam Ravnborg 898506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8993c2362e6SHarvey Harrison def_bool y 9003228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 901506f1d07SSam Ravnborg 9026a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 903506f1d07SSam Ravnborg# The code disables itself when not needed. 9047ae9392cSThomas Petazzoniconfig DMI 9057ae9392cSThomas Petazzoni default y 906cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9076a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 908a7f7f624SMasahiro Yamada help 9097ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9107ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9117ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9127ae9392cSThomas Petazzoni BIOS code. 9137ae9392cSThomas Petazzoni 914506f1d07SSam Ravnborgconfig GART_IOMMU 91538901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9162f9237d4SChristoph Hellwig select DMA_OPS 917a4ce5a48SChristoph Hellwig select IOMMU_HELPER 918506f1d07SSam Ravnborg select SWIOTLB 91923ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 920a7f7f624SMasahiro Yamada help 921ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 922ced3c42cSIngo Molnar GART based hardware IOMMUs. 923ced3c42cSIngo Molnar 924ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 925ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 926ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 927ced3c42cSIngo Molnar 928ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 929ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 930ced3c42cSIngo Molnar 931ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 932ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 933ced3c42cSIngo Molnar 32-bit limited device. 934ced3c42cSIngo Molnar 935ced3c42cSIngo Molnar If unsure, say Y. 936506f1d07SSam Ravnborg 9371184dc2fSMike Travisconfig MAXSMP 938ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9396ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 94036f5101aSMike Travis select CPUMASK_OFFSTACK 941a7f7f624SMasahiro Yamada help 942ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9431184dc2fSMike Travis If unsure, say N. 944506f1d07SSam Ravnborg 945aec6487eSIngo Molnar# 946aec6487eSIngo Molnar# The maximum number of CPUs supported: 947aec6487eSIngo Molnar# 948aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 949aec6487eSIngo Molnar# and which can be configured interactively in the 950aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 951aec6487eSIngo Molnar# 952aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 953aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 954aec6487eSIngo Molnar# 955aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 956aec6487eSIngo Molnar# interactive configuration. ) 957aec6487eSIngo Molnar# 958a0d0bb4dSRandy Dunlap 959aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 960a0d0bb4dSRandy Dunlap int 961aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 962a0d0bb4dSRandy Dunlap default 1 if !SMP 963a0d0bb4dSRandy Dunlap default 2 964a0d0bb4dSRandy Dunlap 965aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 966a0d0bb4dSRandy Dunlap int 967a0d0bb4dSRandy Dunlap depends on X86_32 968aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 969aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 970a0d0bb4dSRandy Dunlap default 1 if !SMP 971a0d0bb4dSRandy Dunlap 972aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 973a0d0bb4dSRandy Dunlap int 974a0d0bb4dSRandy Dunlap depends on X86_64 9751edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9761edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 977a0d0bb4dSRandy Dunlap default 1 if !SMP 978aec6487eSIngo Molnar 979aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 980aec6487eSIngo Molnar int 981aec6487eSIngo Molnar depends on X86_32 982aec6487eSIngo Molnar default 32 if X86_BIGSMP 983aec6487eSIngo Molnar default 8 if SMP 984aec6487eSIngo Molnar default 1 if !SMP 985aec6487eSIngo Molnar 986aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 987aec6487eSIngo Molnar int 988aec6487eSIngo Molnar depends on X86_64 989a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 990a0d0bb4dSRandy Dunlap default 64 if SMP 991aec6487eSIngo Molnar default 1 if !SMP 992a0d0bb4dSRandy Dunlap 993506f1d07SSam Ravnborgconfig NR_CPUS 99436f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 995aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 996aec6487eSIngo Molnar default NR_CPUS_DEFAULT 997a7f7f624SMasahiro Yamada help 998506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 999bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1000cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1001506f1d07SSam Ravnborg minimum value which makes sense is 2. 1002506f1d07SSam Ravnborg 1003aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1004aec6487eSIngo Molnar to the kernel image. 1005506f1d07SSam Ravnborg 100666558b73STim Chenconfig SCHED_CLUSTER 100766558b73STim Chen bool "Cluster scheduler support" 100866558b73STim Chen depends on SMP 100966558b73STim Chen default y 101066558b73STim Chen help 101166558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 101266558b73STim Chen making when dealing with machines that have clusters of CPUs. 101366558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 101466558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 101566558b73STim Chen busses. 101666558b73STim Chen 1017506f1d07SSam Ravnborgconfig SCHED_SMT 1018dbe73364SThomas Gleixner def_bool y if SMP 1019506f1d07SSam Ravnborg 1020506f1d07SSam Ravnborgconfig SCHED_MC 10213c2362e6SHarvey Harrison def_bool y 10223c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1023c8e56d20SBorislav Petkov depends on SMP 1024a7f7f624SMasahiro Yamada help 1025506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1026506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1027506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1028506f1d07SSam Ravnborg 1029de966cf4STim Chenconfig SCHED_MC_PRIO 1030de966cf4STim Chen bool "CPU core priorities scheduler support" 10310a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10320a21fc12SIngo Molnar select X86_INTEL_PSTATE 10330a21fc12SIngo Molnar select CPU_FREQ 1034de966cf4STim Chen default y 1035a7f7f624SMasahiro Yamada help 1036de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1037de966cf4STim Chen core ordering determined at manufacturing time, which allows 1038de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1039de966cf4STim Chen single threaded workloads) than others. 1040de966cf4STim Chen 1041de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1042de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1043de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1044de966cf4STim Chen overall system performance can be achieved. 1045de966cf4STim Chen 1046de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1047de966cf4STim Chen 1048de966cf4STim Chen If unsure say Y here. 10495e76b2abSTim Chen 105030b8b006SThomas Gleixnerconfig UP_LATE_INIT 105130b8b006SThomas Gleixner def_bool y 1052ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 105330b8b006SThomas Gleixner 1054506f1d07SSam Ravnborgconfig X86_UP_APIC 105550849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 105650849eefSJan Beulich default PCI_MSI 105738a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1058a7f7f624SMasahiro Yamada help 1059506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1060506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1061506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1062506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1063506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1064506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1065506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1066506f1d07SSam Ravnborg lockups. 1067506f1d07SSam Ravnborg 1068506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1069506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1070506f1d07SSam Ravnborg depends on X86_UP_APIC 1071a7f7f624SMasahiro Yamada help 1072506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1073506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1074506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1075506f1d07SSam Ravnborg 1076506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1077506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1078506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1079506f1d07SSam Ravnborg 1080506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10813c2362e6SHarvey Harrison def_bool y 10820dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1083b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 108452f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1085506f1d07SSam Ravnborg 1086506f1d07SSam Ravnborgconfig X86_IO_APIC 1087b1da1e71SJan Beulich def_bool y 1088b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1089506f1d07SSam Ravnborg 109041b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 109141b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 109241b9eb26SStefan Assmann depends on X86_IO_APIC 1093a7f7f624SMasahiro Yamada help 109441b9eb26SStefan Assmann This option enables a workaround that fixes a source of 109541b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 109641b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 109741b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 109841b9eb26SStefan Assmann 109941b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 110041b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 110141b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 110241b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 110341b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 110441b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 110541b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 110641b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 110741b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 110841b9eb26SStefan Assmann down (vital) interrupt lines. 110941b9eb26SStefan Assmann 111041b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 111141b9eb26SStefan Assmann increased on these systems. 111241b9eb26SStefan Assmann 1113506f1d07SSam Ravnborgconfig X86_MCE 1114bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1115648ed940SChen, Gong select GENERIC_ALLOCATOR 1116e57dbaf7SBorislav Petkov default y 1117a7f7f624SMasahiro Yamada help 1118bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1119bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1120506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1121bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11224efc0670SAndi Kleen 11235de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11245de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11255de97c9fSTony Luck depends on X86_MCE 1126a7f7f624SMasahiro Yamada help 11275de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11285de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11295de97c9fSTony Luck rasdaemon solution. 11305de97c9fSTony Luck 1131506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11323c2362e6SHarvey Harrison def_bool y 11333c2362e6SHarvey Harrison prompt "Intel MCE features" 1134c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1135a7f7f624SMasahiro Yamada help 1136506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1137506f1d07SSam Ravnborg the thermal monitor. 1138506f1d07SSam Ravnborg 1139506f1d07SSam Ravnborgconfig X86_MCE_AMD 11403c2362e6SHarvey Harrison def_bool y 11413c2362e6SHarvey Harrison prompt "AMD MCE features" 1142f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1143a7f7f624SMasahiro Yamada help 1144506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1145506f1d07SSam Ravnborg the DRAM Error Threshold. 1146506f1d07SSam Ravnborg 11474efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11486fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1149c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1150a7f7f624SMasahiro Yamada help 11514efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11525065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11534efc0670SAndi Kleen line. 11544efc0670SAndi Kleen 1155b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1156b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11576fc108a0SJan Beulich def_bool y 1158b2762686SAndi Kleen 1159ea149b36SAndi Kleenconfig X86_MCE_INJECT 1160bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1161ea149b36SAndi Kleen tristate "Machine check injector support" 1162a7f7f624SMasahiro Yamada help 1163ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1164ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1165ea149b36SAndi Kleen QA it is safe to say n. 1166ea149b36SAndi Kleen 116707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1168e633c65aSKan Liang 11695aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11701e642812SIngo Molnar bool "Legacy VM86 support" 1171506f1d07SSam Ravnborg depends on X86_32 1172a7f7f624SMasahiro Yamada help 11735aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11745aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11755aef51c3SAndy Lutomirski 11765aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11775aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11785aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11795aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11805aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11811e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11821e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11831e642812SIngo Molnar mode might be faster than emulation and you might want to 11841e642812SIngo Molnar enable this option. 11855aef51c3SAndy Lutomirski 11861e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11871e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11881e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 11891e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 11905aef51c3SAndy Lutomirski 11911e642812SIngo Molnar Enabling this option increases the complexity of the kernel 11921e642812SIngo Molnar and slows down exception handling a tiny bit. 11935aef51c3SAndy Lutomirski 11941e642812SIngo Molnar If unsure, say N here. 11955aef51c3SAndy Lutomirski 11965aef51c3SAndy Lutomirskiconfig VM86 11975aef51c3SAndy Lutomirski bool 11985aef51c3SAndy Lutomirski default X86_LEGACY_VM86 119934273f41SH. Peter Anvin 120034273f41SH. Peter Anvinconfig X86_16BIT 120134273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 120234273f41SH. Peter Anvin default y 1203a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1204a7f7f624SMasahiro Yamada help 120534273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 120634273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 120734273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 120834273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 120934273f41SH. Peter Anvin 121034273f41SH. Peter Anvinconfig X86_ESPFIX32 121134273f41SH. Peter Anvin def_bool y 121234273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1213506f1d07SSam Ravnborg 1214197725deSH. Peter Anvinconfig X86_ESPFIX64 1215197725deSH. Peter Anvin def_bool y 121634273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1217506f1d07SSam Ravnborg 12181ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12191ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12201ad83c85SAndy Lutomirski default y 12211ad83c85SAndy Lutomirski depends on X86_64 1222a7f7f624SMasahiro Yamada help 12231ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12241ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12251ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12261ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12271ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12281ad83c85SAndy Lutomirski 0xffffffffff600?00. 12291ad83c85SAndy Lutomirski 12301ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12311ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12321ad83c85SAndy Lutomirski 12331ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12341ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12351ad83c85SAndy Lutomirski 1236111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1237111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1238a24ca997SThomas Gleixner default y 1239a7f7f624SMasahiro Yamada help 1240111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1241111e7b15SThomas Gleixner for legacy applications. 1242111e7b15SThomas Gleixner 1243c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1244c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1245c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1246c8137aceSThomas Gleixner capabilities and permission from potentially active security 1247c8137aceSThomas Gleixner modules. 1248c8137aceSThomas Gleixner 1249c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1250c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1251a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1252a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1253c8137aceSThomas Gleixner 1254506f1d07SSam Ravnborgconfig TOSHIBA 1255506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1256506f1d07SSam Ravnborg depends on X86_32 1257a7f7f624SMasahiro Yamada help 1258506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1259506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1260506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1261506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1262506f1d07SSam Ravnborg 1263506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1264506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1265506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1266506f1d07SSam Ravnborg 1267506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1268506f1d07SSam Ravnborg Say N otherwise. 1269506f1d07SSam Ravnborg 1270506f1d07SSam Ravnborgconfig I8K 1271039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1272ef775a0eSRandy Dunlap depends on HWMON 1273ef775a0eSRandy Dunlap depends on PROC_FS 1274039ae585SPali Rohár select SENSORS_DELL_SMM 1275a7f7f624SMasahiro Yamada help 1276039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1277039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1278039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1279039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1280039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1281039ae585SPali Rohár needed userspace package i8kutils. 1282506f1d07SSam Ravnborg 1283039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1284039ae585SPali Rohár use userspace package i8kutils. 1285506f1d07SSam Ravnborg Say N otherwise. 1286506f1d07SSam Ravnborg 1287506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12889ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12899ba16087SJan Beulich depends on X86_32 1290a7f7f624SMasahiro Yamada help 1291506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1292506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1293506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1294506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1295506f1d07SSam Ravnborg system. 1296506f1d07SSam Ravnborg 1297506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12985e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1299506f1d07SSam Ravnborg 1300506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1301506f1d07SSam Ravnborg enable this option even if you don't need it. 1302506f1d07SSam Ravnborg Say N otherwise. 1303506f1d07SSam Ravnborg 1304506f1d07SSam Ravnborgconfig MICROCODE 13059a2bc335SBorislav Petkov bool "CPU microcode loading support" 13069a2bc335SBorislav Petkov default y 130780030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1308a7f7f624SMasahiro Yamada help 1309506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13105f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13115f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13125f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13135f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13145f9c01aaSBorislav Petkov the Linux kernel. 1315506f1d07SSam Ravnborg 13165f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1317cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13185f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13195f9c01aaSBorislav Petkov initrd for microcode blobs. 1320506f1d07SSam Ravnborg 1321c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1322c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1323c508c46eSBenjamin Gilbert config option. 1324506f1d07SSam Ravnborg 13258d86f390SPeter Orubaconfig MICROCODE_INTEL 1326e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13278d86f390SPeter Oruba depends on MICROCODE 13288d86f390SPeter Oruba default MICROCODE 1329a7f7f624SMasahiro Yamada help 13308d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13318d86f390SPeter Oruba processors. 13328d86f390SPeter Oruba 1333b8989db9SAlan For the current Intel microcode data package go to 1334b8989db9SAlan <https://downloadcenter.intel.com> and search for 1335b8989db9SAlan 'Linux Processor Microcode Data File'. 13368d86f390SPeter Oruba 133780cc9f10SPeter Orubaconfig MICROCODE_AMD 1338e43f6e67SBorislav Petkov bool "AMD microcode loading support" 133980cc9f10SPeter Oruba depends on MICROCODE 1340a7f7f624SMasahiro Yamada help 134180cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 134280cc9f10SPeter Oruba processors will be enabled. 134380cc9f10SPeter Oruba 1344506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1345c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1346c02f48e0SBorislav Petkov default n 1347506f1d07SSam Ravnborg depends on MICROCODE 1348a7f7f624SMasahiro Yamada help 1349c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1350c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1351c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1352c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1353c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1354cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1355506f1d07SSam Ravnborg 1356506f1d07SSam Ravnborgconfig X86_MSR 1357506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1358a7f7f624SMasahiro Yamada help 1359506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1360506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1361506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1362506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1363506f1d07SSam Ravnborg systems. 1364506f1d07SSam Ravnborg 1365506f1d07SSam Ravnborgconfig X86_CPUID 1366506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1367a7f7f624SMasahiro Yamada help 1368506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1369506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1370506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1371506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1372506f1d07SSam Ravnborg 1373506f1d07SSam Ravnborgchoice 1374506f1d07SSam Ravnborg prompt "High Memory Support" 13756fc108a0SJan Beulich default HIGHMEM4G 1376506f1d07SSam Ravnborg depends on X86_32 1377506f1d07SSam Ravnborg 1378506f1d07SSam Ravnborgconfig NOHIGHMEM 1379506f1d07SSam Ravnborg bool "off" 1380a7f7f624SMasahiro Yamada help 1381506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1382506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1383506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1384506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1385506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1386506f1d07SSam Ravnborg "high memory". 1387506f1d07SSam Ravnborg 1388506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1389506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1390506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1391506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1392506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1393506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1394506f1d07SSam Ravnborg possible. 1395506f1d07SSam Ravnborg 1396506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1397506f1d07SSam Ravnborg answer "4GB" here. 1398506f1d07SSam Ravnborg 1399506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1400506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1401506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1402506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1403506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1404506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1405506f1d07SSam Ravnborg 1406506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1407506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1408506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1409506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1410506f1d07SSam Ravnborg kernel at boot time.) 1411506f1d07SSam Ravnborg 1412506f1d07SSam Ravnborg If unsure, say "off". 1413506f1d07SSam Ravnborg 1414506f1d07SSam Ravnborgconfig HIGHMEM4G 1415506f1d07SSam Ravnborg bool "4GB" 1416a7f7f624SMasahiro Yamada help 1417506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1418506f1d07SSam Ravnborg gigabytes of physical RAM. 1419506f1d07SSam Ravnborg 1420506f1d07SSam Ravnborgconfig HIGHMEM64G 1421506f1d07SSam Ravnborg bool "64GB" 1422225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1423506f1d07SSam Ravnborg select X86_PAE 1424a7f7f624SMasahiro Yamada help 1425506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1426506f1d07SSam Ravnborg gigabytes of physical RAM. 1427506f1d07SSam Ravnborg 1428506f1d07SSam Ravnborgendchoice 1429506f1d07SSam Ravnborg 1430506f1d07SSam Ravnborgchoice 14316a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1432506f1d07SSam Ravnborg default VMSPLIT_3G 1433506f1d07SSam Ravnborg depends on X86_32 1434a7f7f624SMasahiro Yamada help 1435506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1436506f1d07SSam Ravnborg 1437506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1438506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1439506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1440506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1441506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1442506f1d07SSam Ravnborg available to user programs, making the address space there 1443506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1444506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1445506f1d07SSam Ravnborg kernel modules. 1446506f1d07SSam Ravnborg 1447506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1448506f1d07SSam Ravnborg option alone! 1449506f1d07SSam Ravnborg 1450506f1d07SSam Ravnborg config VMSPLIT_3G 1451506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1452506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1453506f1d07SSam Ravnborg depends on !X86_PAE 1454506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1455506f1d07SSam Ravnborg config VMSPLIT_2G 1456506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1457506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1458506f1d07SSam Ravnborg depends on !X86_PAE 1459506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1460506f1d07SSam Ravnborg config VMSPLIT_1G 1461506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1462506f1d07SSam Ravnborgendchoice 1463506f1d07SSam Ravnborg 1464506f1d07SSam Ravnborgconfig PAGE_OFFSET 1465506f1d07SSam Ravnborg hex 1466506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1467506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1468506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1469506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1470506f1d07SSam Ravnborg default 0xC0000000 1471506f1d07SSam Ravnborg depends on X86_32 1472506f1d07SSam Ravnborg 1473506f1d07SSam Ravnborgconfig HIGHMEM 14743c2362e6SHarvey Harrison def_bool y 1475506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1476506f1d07SSam Ravnborg 1477506f1d07SSam Ravnborgconfig X86_PAE 14789ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1479506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1480d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14819d99c712SChristian Melki select SWIOTLB 1482a7f7f624SMasahiro Yamada help 1483506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1484506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1485506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1486506f1d07SSam Ravnborg consumes more pagetable space per process. 1487506f1d07SSam Ravnborg 148877ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148977ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 149018ec1eafSKirill A. Shutemov default y 1491eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1492162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 149377ef56e4SKirill A. Shutemov depends on X86_64 1494a7f7f624SMasahiro Yamada help 149577ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 149677ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 149777ef56e4SKirill A. Shutemov physical address space. 149877ef56e4SKirill A. Shutemov 149977ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 150077ef56e4SKirill A. Shutemov 15016657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 15026657fca0SKirill A. Shutemov support 4- or 5-level paging. 150377ef56e4SKirill A. Shutemov 1504cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 150577ef56e4SKirill A. Shutemov information. 150677ef56e4SKirill A. Shutemov 150777ef56e4SKirill A. Shutemov Say N if unsure. 150877ef56e4SKirill A. Shutemov 150910971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1510e5008abeSLuis R. Rodriguez def_bool y 15112e1da13fSVlastimil Babka depends on X86_64 1512a7f7f624SMasahiro Yamada help 151310971ab2SIngo Molnar Certain kernel features effectively disable kernel 151410971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 151510971ab2SIngo Molnar supports them), so don't confuse the user by printing 151610971ab2SIngo Molnar that we have them enabled. 15179e899816SNick Piggin 15185c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15195c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15205c280cf6SThomas Gleixner depends on DEBUG_FS 1521a7f7f624SMasahiro Yamada help 1522b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1523a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15245c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15255c280cf6SThomas Gleixner 15267744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15277744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15287744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 152982fef0adSDavid Rientjes select DMA_COHERENT_POOL 153094d49eb3SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 1531ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 15329087c375STom Lendacky select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1533597cfe48SJoerg Roedel select INSTRUCTION_DECODER 153422916417STom Lendacky select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 1535aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 1536a7f7f624SMasahiro Yamada help 15377744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15387744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15397744ccdbSTom Lendacky Encryption (SME). 15407744ccdbSTom Lendacky 15417744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15427744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15437744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1544a7f7f624SMasahiro Yamada help 15457744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15467744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15477744ccdbSTom Lendacky 15487744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15497744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15507744ccdbSTom Lendacky 15517744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15527744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15537744ccdbSTom Lendacky 1554506f1d07SSam Ravnborg# Common NUMA Features 1555506f1d07SSam Ravnborgconfig NUMA 1556e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1557506f1d07SSam Ravnborg depends on SMP 1558b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1559b5660ba7SH. Peter Anvin default y if X86_BIGSMP 1560a7f7f624SMasahiro Yamada help 1561e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1562fd51b2d7SKOSAKI Motohiro 1563506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1564506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1565506f1d07SSam Ravnborg NUMA awareness to the kernel. 1566506f1d07SSam Ravnborg 1567c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1568fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1569fd51b2d7SKOSAKI Motohiro 1570b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15717cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1572fd51b2d7SKOSAKI Motohiro 1573fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1574506f1d07SSam Ravnborg 1575eec1d4faSHans Rosenfeldconfig AMD_NUMA 15763c2362e6SHarvey Harrison def_bool y 15773c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15785da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1579a7f7f624SMasahiro Yamada help 1580eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1581eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1582eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1583eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1584eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1585506f1d07SSam Ravnborg 1586506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15873c2362e6SHarvey Harrison def_bool y 15883c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1589506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1590506f1d07SSam Ravnborg select ACPI_NUMA 1591a7f7f624SMasahiro Yamada help 1592506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1593506f1d07SSam Ravnborg 1594506f1d07SSam Ravnborgconfig NUMA_EMU 1595506f1d07SSam Ravnborg bool "NUMA emulation" 15961b7e03efSTejun Heo depends on NUMA 1597a7f7f624SMasahiro Yamada help 1598506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1599506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1600506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1601506f1d07SSam Ravnborg 1602506f1d07SSam Ravnborgconfig NODES_SHIFT 1603d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 160451591e31SDavid Rientjes range 1 10 160551591e31SDavid Rientjes default "10" if MAXSMP 1606506f1d07SSam Ravnborg default "6" if X86_64 1607506f1d07SSam Ravnborg default "3" 1608a9ee6cf5SMike Rapoport depends on NUMA 1609a7f7f624SMasahiro Yamada help 16101184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1611692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1612506f1d07SSam Ravnborg 1613506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1614506f1d07SSam Ravnborg def_bool y 16153b16651fSTejun Heo depends on X86_32 && !NUMA 1616506f1d07SSam Ravnborg 1617506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1618506f1d07SSam Ravnborg def_bool y 16196ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1620506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1621506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1622506f1d07SSam Ravnborg 16233b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16246ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16253b16651fSTejun Heo 1626506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1627506f1d07SSam Ravnborg def_bool y 1628b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1629506f1d07SSam Ravnborg 1630506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1631a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16325c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1633a0842b70SToshi Kani help 1634a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1635cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1636a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1637506f1d07SSam Ravnborg 16383b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16393b16651fSTejun Heo def_bool y 16403b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16413b16651fSTejun Heo 1642a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1643a29815a3SAvi Kivity hex 1644a29815a3SAvi Kivity default 0 if X86_32 1645a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1646a29815a3SAvi Kivity 16477a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16487a67832cSDan Williams bool 16497a67832cSDan Williams 1650ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16517a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16529f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16539f53f9faSDan Williams depends on BLK_DEV 16547a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16557b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16569f53f9faSDan Williams select LIBNVDIMM 1657ec776ef6SChristoph Hellwig help 1658ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1659ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1660ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1661ec776ef6SChristoph Hellwig they can be used for persistent storage. 1662ec776ef6SChristoph Hellwig 1663ec776ef6SChristoph Hellwig Say Y if unsure. 1664ec776ef6SChristoph Hellwig 1665506f1d07SSam Ravnborgconfig HIGHPTE 1666506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16676fc108a0SJan Beulich depends on HIGHMEM 1668a7f7f624SMasahiro Yamada help 1669506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1670506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1671506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1672506f1d07SSam Ravnborg entries in high memory. 1673506f1d07SSam Ravnborg 16749f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16759f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1676a7f7f624SMasahiro Yamada help 16779f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16789f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16799f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16809f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16819f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16829f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16839f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16848c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16859f077871SJeremy Fitzhardinge 16869f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16879f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16889f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16899f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16909f077871SJeremy Fitzhardinge 16919f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16929f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16939f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16949f077871SJeremy Fitzhardinge memory. 16959f077871SJeremy Fitzhardinge 1696c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1697c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1698c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1699c885df50SJeremy Fitzhardinge default y 1700a7f7f624SMasahiro Yamada help 1701c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1702c885df50SJeremy Fitzhardinge on or off. 1703c885df50SJeremy Fitzhardinge 1704506f1d07SSam Ravnborgconfig MATH_EMULATION 1705506f1d07SSam Ravnborg bool 1706a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 170787d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1708a7f7f624SMasahiro Yamada help 1709506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1710506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1711506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1712506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1713506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1714506f1d07SSam Ravnborg coprocessor or this emulation. 1715506f1d07SSam Ravnborg 1716506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1717506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1718506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1719506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1720506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1721506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1722506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1723506f1d07SSam Ravnborg intend to use this kernel on different machines. 1724506f1d07SSam Ravnborg 1725506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1726506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1727506f1d07SSam Ravnborg 1728506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1729506f1d07SSam Ravnborg kernel, it won't hurt. 1730506f1d07SSam Ravnborg 1731506f1d07SSam Ravnborgconfig MTRR 17326fc108a0SJan Beulich def_bool y 17336a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1734a7f7f624SMasahiro Yamada help 1735506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1736506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1737506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1738506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1739506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1740506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1741506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1742506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1743506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1744506f1d07SSam Ravnborg 1745506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1746506f1d07SSam Ravnborg control registers on other processors can be easily supported 1747506f1d07SSam Ravnborg as well: 1748506f1d07SSam Ravnborg 1749506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1750506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1751506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1752506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1753506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1754506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1755506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1756506f1d07SSam Ravnborg 1757506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1758506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1759506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1760506f1d07SSam Ravnborg 1761506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1762506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1763506f1d07SSam Ravnborg 1764cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1765506f1d07SSam Ravnborg 176695ffa243SYinghai Luconfig MTRR_SANITIZER 17672ffb3501SYinghai Lu def_bool y 176895ffa243SYinghai Lu prompt "MTRR cleanup support" 176995ffa243SYinghai Lu depends on MTRR 1770a7f7f624SMasahiro Yamada help 1771aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1772aba3728cSThomas Gleixner add writeback entries. 177395ffa243SYinghai Lu 1774aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1775692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1776aba3728cSThomas Gleixner mtrr_chunk_size. 177795ffa243SYinghai Lu 17782ffb3501SYinghai Lu If unsure, say Y. 177995ffa243SYinghai Lu 178095ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1781f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1782f5098d62SYinghai Lu range 0 1 1783f5098d62SYinghai Lu default "0" 178495ffa243SYinghai Lu depends on MTRR_SANITIZER 1785a7f7f624SMasahiro Yamada help 1786f5098d62SYinghai Lu Enable mtrr cleanup default value 178795ffa243SYinghai Lu 178812031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 178912031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 179012031a62SYinghai Lu range 0 7 179112031a62SYinghai Lu default "1" 179212031a62SYinghai Lu depends on MTRR_SANITIZER 1793a7f7f624SMasahiro Yamada help 179412031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1795aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 179612031a62SYinghai Lu 17972e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17986fc108a0SJan Beulich def_bool y 17996a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18002a8a2719SIngo Molnar depends on MTRR 1801a7f7f624SMasahiro Yamada help 18022e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1803042b78e4SVenki Pallipadi 18042e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18052e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18062e5d9c85Svenkatesh.pallipadi@intel.com 18072e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1808042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18092e5d9c85Svenkatesh.pallipadi@intel.com 18102e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18112e5d9c85Svenkatesh.pallipadi@intel.com 181246cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 181346cf98cdSVenkatesh Pallipadi def_bool y 181446cf98cdSVenkatesh Pallipadi depends on X86_PAT 181546cf98cdSVenkatesh Pallipadi 1816628c6246SH. Peter Anvinconfig ARCH_RANDOM 1817628c6246SH. Peter Anvin def_bool y 1818628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1819a7f7f624SMasahiro Yamada help 1820628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1821628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1822628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1823628c6246SH. Peter Anvin secure hardware random number generator. 1824628c6246SH. Peter Anvin 182551ae4a2dSH. Peter Anvinconfig X86_SMAP 182651ae4a2dSH. Peter Anvin def_bool y 182751ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1828a7f7f624SMasahiro Yamada help 182951ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 183051ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 183151ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 183251ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 183351ae4a2dSH. Peter Anvin 183451ae4a2dSH. Peter Anvin If unsure, say Y. 183551ae4a2dSH. Peter Anvin 1836b971880fSBabu Mogerconfig X86_UMIP 1837796ebc81SRicardo Neri def_bool y 1838b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1839a7f7f624SMasahiro Yamada help 1840b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1841b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1842b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1843b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1844b971880fSBabu Moger information about the hardware state. 1845796ebc81SRicardo Neri 1846796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1847796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1848796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1849796ebc81SRicardo Neri results are dummy. 1850aa35f896SRicardo Neri 185135e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 185238f3e775SBabu Moger prompt "Memory Protection Keys" 185335e97790SDave Hansen def_bool y 1854284244a9SDave Hansen # Note: only available in 64-bit mode 185538f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 185652c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 185752c8e601SIngo Molnar select ARCH_HAS_PKEYS 1858a7f7f624SMasahiro Yamada help 1859284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1860284244a9SDave Hansen page-based protections, but without requiring modification of the 1861284244a9SDave Hansen page tables when an application changes protection domains. 1862284244a9SDave Hansen 18631eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1864284244a9SDave Hansen 1865284244a9SDave Hansen If unsure, say y. 186635e97790SDave Hansen 1867db616173SMichal Hockochoice 1868db616173SMichal Hocko prompt "TSX enable mode" 1869db616173SMichal Hocko depends on CPU_SUP_INTEL 1870db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1871db616173SMichal Hocko help 1872db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1873db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1874db616173SMichal Hocko can lead to a noticeable performance boost. 1875db616173SMichal Hocko 1876db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1877db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1878db616173SMichal Hocko will be more of those attacks discovered in the future. 1879db616173SMichal Hocko 1880db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1881db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1882db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1883db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1884db616173SMichal Hocko for the particular machine. 1885db616173SMichal Hocko 1886db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1887db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1888db616173SMichal Hocko details. 1889db616173SMichal Hocko 1890db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1891db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1892db616173SMichal Hocko relevant. 1893db616173SMichal Hocko 1894db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1895db616173SMichal Hocko bool "off" 1896db616173SMichal Hocko help 1897db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1898db616173SMichal Hocko 1899db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1900db616173SMichal Hocko bool "on" 1901db616173SMichal Hocko help 1902db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1903db616173SMichal Hocko line parameter. 1904db616173SMichal Hocko 1905db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1906db616173SMichal Hocko bool "auto" 1907db616173SMichal Hocko help 1908db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1909db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1910db616173SMichal Hockoendchoice 1911db616173SMichal Hocko 1912e7e05452SSean Christophersonconfig X86_SGX 1913e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1914e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1915e7e05452SSean Christopherson depends on CRYPTO=y 1916e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1917e7e05452SSean Christopherson select SRCU 1918e7e05452SSean Christopherson select MMU_NOTIFIER 1919901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 1920e7e05452SSean Christopherson help 1921e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1922e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1923e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1924e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1925e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1926e7e05452SSean Christopherson hardware. 1927e7e05452SSean Christopherson 1928e7e05452SSean Christopherson If unsure, say N. 1929e7e05452SSean Christopherson 1930506f1d07SSam Ravnborgconfig EFI 19319ba16087SJan Beulich bool "EFI runtime service support" 19325b83683fSHuang, Ying depends on ACPI 1933f6ce5002SSergey Vlasov select UCS2_STRING 1934022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1935*1ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1936a7f7f624SMasahiro Yamada help 19378b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1938506f1d07SSam Ravnborg available (such as the EFI variable services). 1939506f1d07SSam Ravnborg 19408b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19418b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19428b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19438b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19448b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19458b2cb7a8SHuang, Ying platforms. 1946506f1d07SSam Ravnborg 1947291f3632SMatt Flemingconfig EFI_STUB 1948291f3632SMatt Fleming bool "EFI stub support" 1949b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 19508f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19517b2a583aSMatt Fleming select RELOCATABLE 1952a7f7f624SMasahiro Yamada help 1953291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1954291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1955291f3632SMatt Fleming 19564f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19570c759662SMatt Fleming 19587d453eeeSMatt Flemingconfig EFI_MIXED 19597d453eeeSMatt Fleming bool "EFI mixed-mode support" 19607d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1961a7f7f624SMasahiro Yamada help 19627d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19637d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19647d453eeeSMatt Fleming mode. 19657d453eeeSMatt Fleming 19667d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19677d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19687d453eeeSMatt Fleming the EFI handover protocol must be used. 19697d453eeeSMatt Fleming 19707d453eeeSMatt Fleming If unsure, say N. 19717d453eeeSMatt Fleming 19728636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 1973506f1d07SSam Ravnborg 1974506f1d07SSam Ravnborgconfig KEXEC 1975506f1d07SSam Ravnborg bool "kexec system call" 19762965faa5SDave Young select KEXEC_CORE 1977a7f7f624SMasahiro Yamada help 1978506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1979506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1980506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1981506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1982506f1d07SSam Ravnborg 1983506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1984506f1d07SSam Ravnborg 1985506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1986506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1987bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1988bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1989bf220695SGeert Uytterhoeven made. 1990506f1d07SSam Ravnborg 199174ca317cSVivek Goyalconfig KEXEC_FILE 199274ca317cSVivek Goyal bool "kexec file based system call" 19932965faa5SDave Young select KEXEC_CORE 199474ca317cSVivek Goyal select BUILD_BIN2C 199574ca317cSVivek Goyal depends on X86_64 199674ca317cSVivek Goyal depends on CRYPTO=y 199774ca317cSVivek Goyal depends on CRYPTO_SHA256=y 1998a7f7f624SMasahiro Yamada help 199974ca317cSVivek Goyal This is new version of kexec system call. This system call is 200074ca317cSVivek Goyal file based and takes file descriptors as system call argument 200174ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 200274ca317cSVivek Goyal accepted by previous system call. 200374ca317cSVivek Goyal 2004b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2005b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2006b799a09fSAKASHI Takahiro 200799d5cadfSJiri Bohacconfig KEXEC_SIG 20088e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 200974ca317cSVivek Goyal depends on KEXEC_FILE 2010a7f7f624SMasahiro Yamada help 201199d5cadfSJiri Bohac 201299d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 201399d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 201499d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 201599d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 201699d5cadfSJiri Bohac 201799d5cadfSJiri Bohac In addition to this option, you need to enable signature 201899d5cadfSJiri Bohac verification for the corresponding kernel image type being 201999d5cadfSJiri Bohac loaded in order for this to work. 202099d5cadfSJiri Bohac 202199d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 202299d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 202399d5cadfSJiri Bohac depends on KEXEC_SIG 2024a7f7f624SMasahiro Yamada help 20258e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2026d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20278e7d8381SVivek Goyal 20288e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20298e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 203099d5cadfSJiri Bohac depends on KEXEC_SIG 20318e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20328e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2033a7f7f624SMasahiro Yamada help 20348e7d8381SVivek Goyal Enable bzImage signature verification support. 20358e7d8381SVivek Goyal 2036506f1d07SSam Ravnborgconfig CRASH_DUMP 203704b69447SPavel Machek bool "kernel crash dumps" 2038506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2039a7f7f624SMasahiro Yamada help 2040506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2041506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2042506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2043506f1d07SSam Ravnborg a specially reserved region and then later executed after 2044506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2045506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2046506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2047506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2048330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2049506f1d07SSam Ravnborg 20503ab83521SHuang Yingconfig KEXEC_JUMP 20516ea30386SKees Cook bool "kexec jump" 2052fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2053a7f7f624SMasahiro Yamada help 205489081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 205589081d17SHuang Ying code in physical address mode via KEXEC 20563ab83521SHuang Ying 2057506f1d07SSam Ravnborgconfig PHYSICAL_START 20586a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2059ceefccc9SH. Peter Anvin default "0x1000000" 2060a7f7f624SMasahiro Yamada help 2061506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2062506f1d07SSam Ravnborg 2063506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2064506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2065506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2066506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2067506f1d07SSam Ravnborg address. 2068506f1d07SSam Ravnborg 2069506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2070506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2071506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2072506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2073506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2074506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2075506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2076506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2077506f1d07SSam Ravnborg 2078ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2079ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2080ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2081ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2082ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2083ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2084ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2085330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2086ceefccc9SH. Peter Anvin for more details about crash dumps. 2087506f1d07SSam Ravnborg 2088506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2089506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2090506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2091506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2092506f1d07SSam Ravnborg is present because there are users out there who continue to use 2093506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2094506f1d07SSam Ravnborg line. 2095506f1d07SSam Ravnborg 2096506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2097506f1d07SSam Ravnborg 2098506f1d07SSam Ravnborgconfig RELOCATABLE 209926717808SH. Peter Anvin bool "Build a relocatable kernel" 210026717808SH. Peter Anvin default y 2101a7f7f624SMasahiro Yamada help 2102506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2103506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2104506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2105506f1d07SSam Ravnborg but are discarded at runtime. 2106506f1d07SSam Ravnborg 2107506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2108506f1d07SSam Ravnborg must live at a different physical address than the primary 2109506f1d07SSam Ravnborg kernel. 2110506f1d07SSam Ravnborg 2111506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2112506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21138ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2114506f1d07SSam Ravnborg 21158ab3820fSKees Cookconfig RANDOMIZE_BASE 2116e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21178ab3820fSKees Cook depends on RELOCATABLE 21186807c846SIngo Molnar default y 2119a7f7f624SMasahiro Yamada help 2120e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2121e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2122e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2123e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2124e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2125e8581e3dSBaoquan He code internals. 2126e8581e3dSBaoquan He 2127ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2128ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2129ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2130ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2131ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2132ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2133ed9f007eSKees Cook 2134ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2135ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2136ed9f007eSKees Cook 512MB (8 bits of entropy). 21378ab3820fSKees Cook 2138a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2139e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2140e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2141ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2142ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2143ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2144ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2145ed9f007eSKees Cook theoretically possible, but the implementations are further 2146ed9f007eSKees Cook limited due to memory layouts. 2147e8581e3dSBaoquan He 21486807c846SIngo Molnar If unsure, say Y. 2149da2b6fb9SKees Cook 21508ab3820fSKees Cook# Relocation on x86 needs some additional build support 2151845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2152845adf72SH. Peter Anvin def_bool y 21538ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2154845adf72SH. Peter Anvin 2155506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2156a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21578ab3820fSKees Cook default "0x200000" 2158a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2159a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2160a7f7f624SMasahiro Yamada help 2161506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2162506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2163506f1d07SSam Ravnborg address which meets above alignment restriction. 2164506f1d07SSam Ravnborg 2165506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2166506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2167506f1d07SSam Ravnborg address aligned to above value and run from there. 2168506f1d07SSam Ravnborg 2169506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2170506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2171506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2172506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2173506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2174506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2175506f1d07SSam Ravnborg above alignment restrictions. 2176506f1d07SSam Ravnborg 2177a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2178a0215061SKees Cook this value must be a multiple of 0x200000. 2179a0215061SKees Cook 2180506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2181506f1d07SSam Ravnborg 2182eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2183eedb92abSKirill A. Shutemov bool 2184a7f7f624SMasahiro Yamada help 2185eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2186eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2187eedb92abSKirill A. Shutemov 21880483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 21890483e1faSThomas Garnier bool "Randomize the kernel memory sections" 21900483e1faSThomas Garnier depends on X86_64 21910483e1faSThomas Garnier depends on RANDOMIZE_BASE 2192eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 21930483e1faSThomas Garnier default RANDOMIZE_BASE 2194a7f7f624SMasahiro Yamada help 21950483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 21960483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 21970483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 21980483e1faSThomas Garnier 21990483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22000483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22010483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22020483e1faSThomas Garnier addresses for each memory section. 22030483e1faSThomas Garnier 22046807c846SIngo Molnar If unsure, say Y. 22050483e1faSThomas Garnier 220690397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 220790397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 220890397a41SThomas Garnier depends on RANDOMIZE_MEMORY 220990397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 221090397a41SThomas Garnier default "0x0" 221190397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 221290397a41SThomas Garnier range 0x0 0x40 2213a7f7f624SMasahiro Yamada help 221490397a41SThomas Garnier Define the padding in terabytes added to the existing physical 221590397a41SThomas Garnier memory size during kernel memory randomization. It is useful 221690397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 221790397a41SThomas Garnier address randomization. 221890397a41SThomas Garnier 221990397a41SThomas Garnier If unsure, leave at the default value. 222090397a41SThomas Garnier 2221506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2222bebd024eSThomas Gleixner def_bool y 222340b31360SStephen Rothwell depends on SMP 2224506f1d07SSam Ravnborg 222580aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 222680aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22272c922cd0SKees Cook depends on HOTPLUG_CPU 2228a7f7f624SMasahiro Yamada help 222980aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 223080aa1dffSFenghua Yu 223180aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 223280aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 223380aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 223480aa1dffSFenghua Yu 223580aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 223680aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 223780aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 223880aa1dffSFenghua Yu 223980aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 224080aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 224180aa1dffSFenghua Yu 224280aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 224380aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 224480aa1dffSFenghua Yu be other CPU0 dependencies. 224580aa1dffSFenghua Yu 224680aa1dffSFenghua Yu Please make sure the dependencies are under your control before 224780aa1dffSFenghua Yu you enable this feature. 224880aa1dffSFenghua Yu 224980aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 225080aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 225180aa1dffSFenghua Yu parameter cpu0_hotplug. 225280aa1dffSFenghua Yu 2253a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2254a71c8bc5SFenghua Yu def_bool n 2255a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22562c922cd0SKees Cook depends on HOTPLUG_CPU 2257a7f7f624SMasahiro Yamada help 2258a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2259a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2260a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2261a71c8bc5SFenghua Yu 2262a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2263a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2264a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2265a71c8bc5SFenghua Yu 2266a71c8bc5SFenghua Yu If unsure, say N. 2267a71c8bc5SFenghua Yu 2268506f1d07SSam Ravnborgconfig COMPAT_VDSO 2269b0b49f26SAndy Lutomirski def_bool n 2270b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2271953fee1dSIngo Molnar depends on COMPAT_32 2272a7f7f624SMasahiro Yamada help 2273b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2274b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2275b0b49f26SAndy Lutomirski indicated in its segment table. 2276e84446deSRandy Dunlap 2277b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2278b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2279b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2280b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2281b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2282506f1d07SSam Ravnborg 2283b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2284b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2285b0b49f26SAndy Lutomirski 2286b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2287b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2288b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2289b0b49f26SAndy Lutomirski 2290b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2291b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2292506f1d07SSam Ravnborg 22933dc33bd3SKees Cookchoice 22943dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 22953dc33bd3SKees Cook depends on X86_64 2296625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 22973dc33bd3SKees Cook help 22983dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 22993dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23003dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23013dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23023dc33bd3SKees Cook 23033dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2304bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23053dc33bd3SKees Cook 23063dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23073dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23083dc33bd3SKees Cook to improve security. 23093dc33bd3SKees Cook 2310bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23113dc33bd3SKees Cook 23123dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2313bd49e16eSAndy Lutomirski bool "Full emulation" 23143dc33bd3SKees Cook help 2315bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2316bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2317bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2318bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2319bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2320bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2321bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2322bd49e16eSAndy Lutomirski 2323bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2324bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2325bd49e16eSAndy Lutomirski 2326bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2327bd49e16eSAndy Lutomirski bool "Emulate execution only" 2328bd49e16eSAndy Lutomirski help 2329bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2330bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2331bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2332bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2333bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2334bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2335bd49e16eSAndy Lutomirski buffer. 23363dc33bd3SKees Cook 23373dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23383dc33bd3SKees Cook bool "None" 23393dc33bd3SKees Cook help 23403dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23413dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23423dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23433dc33bd3SKees Cook will be reported to dmesg, so that either old or 23443dc33bd3SKees Cook malicious userspace programs can be identified. 23453dc33bd3SKees Cook 23463dc33bd3SKees Cookendchoice 23473dc33bd3SKees Cook 2348516cbf37STim Birdconfig CMDLINE_BOOL 2349516cbf37STim Bird bool "Built-in kernel command line" 2350a7f7f624SMasahiro Yamada help 2351516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2352516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2353516cbf37STim Bird necessary or convenient to provide some or all of the 2354516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2355516cbf37STim Bird to not rely on the boot loader to provide them.) 2356516cbf37STim Bird 2357516cbf37STim Bird To compile command line arguments into the kernel, 2358516cbf37STim Bird set this option to 'Y', then fill in the 235969711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2360516cbf37STim Bird 2361516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2362516cbf37STim Bird should leave this option set to 'N'. 2363516cbf37STim Bird 2364516cbf37STim Birdconfig CMDLINE 2365516cbf37STim Bird string "Built-in kernel command string" 2366516cbf37STim Bird depends on CMDLINE_BOOL 2367516cbf37STim Bird default "" 2368a7f7f624SMasahiro Yamada help 2369516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2370516cbf37STim Bird image and used at boot time. If the boot loader provides a 2371516cbf37STim Bird command line at boot time, it is appended to this string to 2372516cbf37STim Bird form the full kernel command line, when the system boots. 2373516cbf37STim Bird 2374516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2375516cbf37STim Bird change this behavior. 2376516cbf37STim Bird 2377516cbf37STim Bird In most cases, the command line (whether built-in or provided 2378516cbf37STim Bird by the boot loader) should specify the device for the root 2379516cbf37STim Bird file system. 2380516cbf37STim Bird 2381516cbf37STim Birdconfig CMDLINE_OVERRIDE 2382516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2383645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2384a7f7f624SMasahiro Yamada help 2385516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2386516cbf37STim Bird command line, and use ONLY the built-in command line. 2387516cbf37STim Bird 2388516cbf37STim Bird This is used to work around broken boot loaders. This should 2389516cbf37STim Bird be set to 'N' under normal conditions. 2390516cbf37STim Bird 2391a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2392a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2393a5b9e5a2SAndy Lutomirski default y 2394a7f7f624SMasahiro Yamada help 2395a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2396a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2397a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2398a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2399a5b9e5a2SAndy Lutomirski threading libraries. 2400a5b9e5a2SAndy Lutomirski 2401a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2402a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2403a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2404a5b9e5a2SAndy Lutomirski 2405a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2406a5b9e5a2SAndy Lutomirski 24073aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24083aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24093aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24103aac3ebeSThomas Gleixner help 24113aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24123aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24133aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24143aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24153aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24163aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24173aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24183aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24193aac3ebeSThomas Gleixner never get a signal delivered. 24203aac3ebeSThomas Gleixner 24213aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24223aac3ebeSThomas Gleixner 2423b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2424b700e7f0SSeth Jennings 2425506f1d07SSam Ravnborgendmenu 2426506f1d07SSam Ravnborg 24273072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24283072e413SMichal Hocko def_bool y 24295c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24303072e413SMichal Hocko 2431f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2432f91ef222SOscar Salvador def_bool y 2433f91ef222SOscar Salvador 2434e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2435645a7919STejun Heo def_bool y 2436e534c7c5SLee Schermerhorn depends on NUMA 2437e534c7c5SLee Schermerhorn 2438da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2439e279b6c1SSam Ravnborg 2440e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24413c2362e6SHarvey Harrison def_bool y 244244556530SZhimin Gu depends on HIBERNATION 2443e279b6c1SSam Ravnborg 2444e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2445e279b6c1SSam Ravnborg 2446e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2447e279b6c1SSam Ravnborg 2448a6b68076SAndi Kleenconfig X86_APM_BOOT 24496fc108a0SJan Beulich def_bool y 2450282e5aabSPaul Bolle depends on APM 2451a6b68076SAndi Kleen 2452e279b6c1SSam Ravnborgmenuconfig APM 2453e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2454efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2455a7f7f624SMasahiro Yamada help 2456e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2457e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2458e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2459e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2460e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2461e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2462e279b6c1SSam Ravnborg 2463e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2464e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2465e279b6c1SSam Ravnborg 2466e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2467e279b6c1SSam Ravnborg machines with more than one CPU. 2468e279b6c1SSam Ravnborg 2469e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2470151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24712dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2472e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2473e279b6c1SSam Ravnborg 2474e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2475e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2476e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2477e279b6c1SSam Ravnborg 2478e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2479e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2480e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2481e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2482e279b6c1SSam Ravnborg 2483e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2484e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2485e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2486e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2487e279b6c1SSam Ravnborg APM in your BIOS). 2488e279b6c1SSam Ravnborg 2489e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2490e279b6c1SSam Ravnborg "weird" problems: 2491e279b6c1SSam Ravnborg 2492e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2493e279b6c1SSam Ravnborg enabled. 2494e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2495e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2496e279b6c1SSam Ravnborg the "no387" option to the kernel 2497e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2498e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2499e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2500e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2501e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2502e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2503e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2504e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2505e279b6c1SSam Ravnborg 11) exchange RAM chips 2506e279b6c1SSam Ravnborg 12) exchange the motherboard. 2507e279b6c1SSam Ravnborg 2508e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2509e279b6c1SSam Ravnborg module will be called apm. 2510e279b6c1SSam Ravnborg 2511e279b6c1SSam Ravnborgif APM 2512e279b6c1SSam Ravnborg 2513e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2514e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2515a7f7f624SMasahiro Yamada help 2516e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2517e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2518e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2519e279b6c1SSam Ravnborg 2520e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2521e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2522a7f7f624SMasahiro Yamada help 2523e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2524e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2525e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2526e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2527e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2528e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2529e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2530e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2531e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2532e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2533e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2534e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2535e279b6c1SSam Ravnborg this feature. 2536e279b6c1SSam Ravnborg 2537e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2538dd8af076SLen Brown depends on CPU_IDLE 2539e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2540a7f7f624SMasahiro Yamada help 2541e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2542e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2543e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2544e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2545e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2546e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2547e279b6c1SSam Ravnborg this option does nothing.) 2548e279b6c1SSam Ravnborg 2549e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2550e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2551a7f7f624SMasahiro Yamada help 2552e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2553e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2554e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2555e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2556e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2557e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2558e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2559e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2560e279b6c1SSam Ravnborg especially if you are using gpm. 2561e279b6c1SSam Ravnborg 2562e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2563e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2564a7f7f624SMasahiro Yamada help 2565e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2566e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2567e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2568e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2569e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2570e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2571e279b6c1SSam Ravnborg 2572e279b6c1SSam Ravnborgendif # APM 2573e279b6c1SSam Ravnborg 2574bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2575e279b6c1SSam Ravnborg 2576e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2577e279b6c1SSam Ravnborg 257827471fdbSAndy Henroidsource "drivers/idle/Kconfig" 257927471fdbSAndy Henroid 2580e279b6c1SSam Ravnborgendmenu 2581e279b6c1SSam Ravnborg 2582e279b6c1SSam Ravnborg 2583e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2584e279b6c1SSam Ravnborg 2585e279b6c1SSam Ravnborgchoice 2586e279b6c1SSam Ravnborg prompt "PCI access mode" 2587efefa6f6SIngo Molnar depends on X86_32 && PCI 2588e279b6c1SSam Ravnborg default PCI_GOANY 2589a7f7f624SMasahiro Yamada help 2590e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2591e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2592e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2593e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2594e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2595e279b6c1SSam Ravnborg 2596e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2597e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2598e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2599e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2600e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2601e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2602e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2603e279b6c1SSam Ravnborg 2604e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2605e279b6c1SSam Ravnborg bool "BIOS" 2606e279b6c1SSam Ravnborg 2607e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2608e279b6c1SSam Ravnborg bool "MMConfig" 2609e279b6c1SSam Ravnborg 2610e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2611e279b6c1SSam Ravnborg bool "Direct" 2612e279b6c1SSam Ravnborg 26133ef0e1f8SAndres Salomonconfig PCI_GOOLPC 261476fb6570SDaniel Drake bool "OLPC XO-1" 26153ef0e1f8SAndres Salomon depends on OLPC 26163ef0e1f8SAndres Salomon 26172bdd1b03SAndres Salomonconfig PCI_GOANY 26182bdd1b03SAndres Salomon bool "Any" 26192bdd1b03SAndres Salomon 2620e279b6c1SSam Ravnborgendchoice 2621e279b6c1SSam Ravnborg 2622e279b6c1SSam Ravnborgconfig PCI_BIOS 26233c2362e6SHarvey Harrison def_bool y 2624efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2625e279b6c1SSam Ravnborg 2626e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2627e279b6c1SSam Ravnborgconfig PCI_DIRECT 26283c2362e6SHarvey Harrison def_bool y 26290aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2630e279b6c1SSam Ravnborg 2631e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2632b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2633b45c9f36SJan Kiszka default y 26344590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2635b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2636e279b6c1SSam Ravnborg 26373ef0e1f8SAndres Salomonconfig PCI_OLPC 26382bdd1b03SAndres Salomon def_bool y 26392bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26403ef0e1f8SAndres Salomon 2641b5401a96SAlex Nixonconfig PCI_XEN 2642b5401a96SAlex Nixon def_bool y 2643b5401a96SAlex Nixon depends on PCI && XEN 2644b5401a96SAlex Nixon 26458364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26468364e1f8SJan Kiszka def_bool y 26478364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2648e279b6c1SSam Ravnborg 26493f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26506a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26516ea30386SKees Cook depends on PCI 26523f6ea84aSIra W. Snyder help 26533f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26543f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26553f6ea84aSIra W. Snyder not have ACPI. 26563f6ea84aSIra W. Snyder 265764a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 265864a5fed6SBjorn Helgaas is known to be incomplete. 265964a5fed6SBjorn Helgaas 266064a5fed6SBjorn Helgaas You should say N unless you know you need this. 266164a5fed6SBjorn Helgaas 26623a495511SWilliam Breathitt Grayconfig ISA_BUS 266317a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26643a495511SWilliam Breathitt Gray help 266517a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 266617a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 266717a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 266817a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 266917a2a129SWilliam Breathitt Gray not have an ISA bus. 26703a495511SWilliam Breathitt Gray 26713a495511SWilliam Breathitt Gray If unsure, say N. 26723a495511SWilliam Breathitt Gray 26731c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2674e279b6c1SSam Ravnborgconfig ISA_DMA_API 26751c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 26761c00f016SDavid Rientjes default y 26771c00f016SDavid Rientjes help 26781c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 26791c00f016SDavid Rientjes If unsure, say Y. 2680e279b6c1SSam Ravnborg 268151e68d05SLinus Torvaldsif X86_32 268251e68d05SLinus Torvalds 2683e279b6c1SSam Ravnborgconfig ISA 2684e279b6c1SSam Ravnborg bool "ISA support" 2685a7f7f624SMasahiro Yamada help 2686e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2687e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2688e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2689e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2690e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2691e279b6c1SSam Ravnborg 2692e279b6c1SSam Ravnborgconfig SCx200 2693e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2694a7f7f624SMasahiro Yamada help 2695e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2696e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2697e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2698e279b6c1SSam Ravnborg for other scx200_* drivers. 2699e279b6c1SSam Ravnborg 2700e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2701e279b6c1SSam Ravnborg 2702e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2703e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2704592913ecSJohn Stultz depends on SCx200 2705e279b6c1SSam Ravnborg default y 2706a7f7f624SMasahiro Yamada help 2707e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2708e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2709e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2710e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2711e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2712e279b6c1SSam Ravnborg 27133ef0e1f8SAndres Salomonconfig OLPC 27143ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 271554008979SThomas Gleixner depends on !X86_PAE 27163c554946SAndres Salomon select GPIOLIB 2717dc3119e7SThomas Gleixner select OF 271845bb1674SDaniel Drake select OF_PROMTREE 2719b4e51854SGrant Likely select IRQ_DOMAIN 27200c3d931bSLubomir Rintel select OLPC_EC 2721a7f7f624SMasahiro Yamada help 27223ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27233ef0e1f8SAndres Salomon XO hardware. 27243ef0e1f8SAndres Salomon 2725a3128588SDaniel Drakeconfig OLPC_XO1_PM 2726a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2727fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2728a7f7f624SMasahiro Yamada help 272997c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2730bf1ebf00SDaniel Drake 2731cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2732cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2733cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2734a7f7f624SMasahiro Yamada help 2735cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2736cfee9597SDaniel Drake programmable wakeup source. 2737cfee9597SDaniel Drake 27387feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27397feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 274092e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2741ed8e47feSRandy Dunlap depends on INPUT=y 2742d8d01a63SDaniel Drake select POWER_SUPPLY 2743a7f7f624SMasahiro Yamada help 27447feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27457bc74b3dSDaniel Drake - EC-driven system wakeups 27467feda8e9SDaniel Drake - Power button 27477bc74b3dSDaniel Drake - Ebook switch 27482cf2baeaSDaniel Drake - Lid switch 2749e1040ac6SDaniel Drake - AC adapter status updates 2750e1040ac6SDaniel Drake - Battery status updates 27517feda8e9SDaniel Drake 2752a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2753a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2754d8d01a63SDaniel Drake depends on OLPC && ACPI 2755d8d01a63SDaniel Drake select POWER_SUPPLY 2756a7f7f624SMasahiro Yamada help 2757a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2758a0f30f59SDaniel Drake - EC-driven system wakeups 2759a0f30f59SDaniel Drake - AC adapter status updates 2760a0f30f59SDaniel Drake - Battery status updates 2761e279b6c1SSam Ravnborg 2762d4f3e350SEd Wildgooseconfig ALIX 2763d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2764d4f3e350SEd Wildgoose select GPIOLIB 2765a7f7f624SMasahiro Yamada help 2766d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2767d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2768d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2769d4f3e350SEd Wildgoose get added here. 2770d4f3e350SEd Wildgoose 2771d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2772d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2773d4f3e350SEd Wildgoose 2774d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2775d4f3e350SEd Wildgoose 2776da4e3302SPhilip Prindevilleconfig NET5501 2777da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2778da4e3302SPhilip Prindeville select GPIOLIB 2779a7f7f624SMasahiro Yamada help 2780da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2781da4e3302SPhilip Prindeville 27823197059aSPhilip A. Prindevilleconfig GEOS 27833197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 27843197059aSPhilip A. Prindeville select GPIOLIB 27853197059aSPhilip A. Prindeville depends on DMI 2786a7f7f624SMasahiro Yamada help 27873197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 27883197059aSPhilip A. Prindeville 27897d029125SVivien Didelotconfig TS5500 27907d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 27917d029125SVivien Didelot depends on MELAN 27927d029125SVivien Didelot select CHECK_SIGNATURE 27937d029125SVivien Didelot select NEW_LEDS 27947d029125SVivien Didelot select LEDS_CLASS 2795a7f7f624SMasahiro Yamada help 27967d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 27977d029125SVivien Didelot 2798e279b6c1SSam Ravnborgendif # X86_32 2799e279b6c1SSam Ravnborg 280023ac4ae8SAndreas Herrmannconfig AMD_NB 2801e279b6c1SSam Ravnborg def_bool y 28020e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2803e279b6c1SSam Ravnborg 2804e279b6c1SSam Ravnborgendmenu 2805e279b6c1SSam Ravnborg 2806e279b6c1SSam Ravnborg 28071572497cSChristoph Hellwigmenu "Binary Emulations" 2808e279b6c1SSam Ravnborg 2809e279b6c1SSam Ravnborgconfig IA32_EMULATION 2810e279b6c1SSam Ravnborg bool "IA32 Emulation" 2811e279b6c1SSam Ravnborg depends on X86_64 281239f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2813d1603990SRandy Dunlap select BINFMT_ELF 281439f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2815a7f7f624SMasahiro Yamada help 28165fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28175fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28185fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2819e279b6c1SSam Ravnborg 2820e279b6c1SSam Ravnborgconfig IA32_AOUT 2821e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28226b213e1bSDavid Woodhouse depends on IA32_EMULATION 2823eac61655SBorislav Petkov depends on BROKEN 2824a7f7f624SMasahiro Yamada help 2825e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2826e279b6c1SSam Ravnborg 28270bf62763SH. Peter Anvinconfig X86_X32 28286ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28299b54050bSBrian Gerst depends on X86_64 2830a7f7f624SMasahiro Yamada help 28315fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28325fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28335fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28345fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28355fd92e65SH. J. Lu 28365fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 28375fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 28385fd92e65SH. J. Lu option set. 28395fd92e65SH. J. Lu 2840953fee1dSIngo Molnarconfig COMPAT_32 2841953fee1dSIngo Molnar def_bool y 2842953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2843953fee1dSIngo Molnar select HAVE_UID16 2844953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2845953fee1dSIngo Molnar 2846e279b6c1SSam Ravnborgconfig COMPAT 28473c2362e6SHarvey Harrison def_bool y 28480bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2849e279b6c1SSam Ravnborg 28503120e25eSJan Beulichif COMPAT 2851e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28523120e25eSJan Beulich def_bool y 2853e279b6c1SSam Ravnborg 2854e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28553c2362e6SHarvey Harrison def_bool y 28563120e25eSJan Beulich depends on SYSVIPC 28573120e25eSJan Beulichendif 2858ee009e4aSDavid Howells 2859e279b6c1SSam Ravnborgendmenu 2860e279b6c1SSam Ravnborg 2861e279b6c1SSam Ravnborg 2862e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2863e5beae16SKeith Packard def_bool y 2864e5beae16SKeith Packard depends on X86_32 2865e5beae16SKeith Packard 2866edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28675e8ebd84SJason A. Donenfeld 28685e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2869