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 22daa93fabSSam Ravnborg 23daa93fabSSam Ravnborgconfig X86_64 243120e25eSJan Beulich def_bool y 253120e25eSJan Beulich depends on 64BIT 26d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 274eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 28c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 29d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 30d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 31d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 32f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 3309230cbcSChristoph Hellwig select SWIOTLB 341032c0baSSam Ravnborg 35518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 36518049d9SSteven Rostedt (VMware) def_bool y 37518049d9SSteven Rostedt (VMware) depends on X86_32 38518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 39518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 40518049d9SSteven Rostedt (VMware) help 41518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 42518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 43518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 44518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 45518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 46d94e0685SIngo Molnar# 47d94e0685SIngo Molnar# Arch settings 48d94e0685SIngo Molnar# 49d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 50d94e0685SIngo Molnar# ported to 32-bit as well. ) 51d94e0685SIngo Molnar# 528d5fffb9SSam Ravnborgconfig X86 533c2362e6SHarvey Harrison def_bool y 54c763ea26SIngo Molnar # 55c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 56c763ea26SIngo Molnar # 576471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 586e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 59942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 602a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 6191dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 62fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 63399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 6421266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 65b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 666471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 6772d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 68316d097cSDave Hansen select ARCH_HAS_FILTER_PGPROT 696974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 70957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 710f1441b4SPeter Zijlstra select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 720c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 7310bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 740ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 75c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 7617596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 773010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 780aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 79ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 80d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 81d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 82ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 83ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 84ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 8525c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 86c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 877e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 886471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 896471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 9077fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 915e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 923599fe12SThomas Gleixner select ARCH_STACKWALK 932c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 946471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 956471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 96*14df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 976471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 986471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 996471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1002ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 101ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 10281c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 103c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 1043876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 10538d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 10610916706SShile Zhang select BUILDTIME_TABLE_SORT 1076471b825SIngo Molnar select CLKEVT_I8253 1086471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1096471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1106471b825SIngo Molnar select DCACHE_WORD_ACCESS 11145471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 11245471cd9SLinus Torvalds select EDAC_SUPPORT 1136471b825SIngo Molnar select GENERIC_CLOCKEVENTS 1146471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1156471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1166471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1176471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 11861dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1196471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 12027d6b4d1SThomas Gleixner select GENERIC_ENTRY 1216471b825SIngo Molnar select GENERIC_FIND_FIRST_BIT 1226471b825SIngo Molnar select GENERIC_IOMAP 123c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1240fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 125ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1266471b825SIngo Molnar select GENERIC_IRQ_PROBE 127c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1286471b825SIngo Molnar select GENERIC_IRQ_SHOW 1296471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1302ae27137SSteven Price select GENERIC_PTDUMP 1316471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1326471b825SIngo Molnar select GENERIC_STRNCPY_FROM_USER 1336471b825SIngo Molnar select GENERIC_STRNLEN_USER 1346471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1357ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 136550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 13739656e83SChristoph Hellwig select GUP_GET_PTE_LOW_HIGH if X86_PAE 13817e5888eSHans de Goede select HARDIRQS_SW_RESEND 1397edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 1406471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1416471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1426471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1436471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1446471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 1456471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 146b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 147d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1480609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1496471b825SIngo Molnar select HAVE_ARCH_KGDB 1509e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1519e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1521b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 153271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1546471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 155f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 156afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1576471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1586471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 159a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 160b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 161e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 162c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1632ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1646471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1656471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1666471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 1676471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 1686471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1699c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 170677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 17106aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 172562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 17303f5781bSWang YanQing select HAVE_EBPF_JIT 17458340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 1756630a8e5SChristoph Hellwig select HAVE_EISA 1765f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 17767a929e0SChristoph Hellwig select HAVE_FAST_GUP 178644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 1796471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 1806471b825SIngo Molnar select HAVE_FUNCTION_GRAPH_TRACER 1816471b825SIngo Molnar select HAVE_FUNCTION_TRACER 1826b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 1830067f129SK.Prasad select HAVE_HW_BREAKPOINT 1846471b825SIngo Molnar select HAVE_IDE 1856471b825SIngo Molnar select HAVE_IOREMAP_PROT 1866471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 1876471b825SIngo Molnar select HAVE_KERNEL_BZIP2 1886471b825SIngo Molnar select HAVE_KERNEL_GZIP 1896471b825SIngo Molnar select HAVE_KERNEL_LZ4 1906471b825SIngo Molnar select HAVE_KERNEL_LZMA 1916471b825SIngo Molnar select HAVE_KERNEL_LZO 1926471b825SIngo Molnar select HAVE_KERNEL_XZ 193fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 1946471b825SIngo Molnar select HAVE_KPROBES 1956471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 196540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 1976471b825SIngo Molnar select HAVE_KRETPROBES 1986471b825SIngo Molnar select HAVE_KVM 1996471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2000102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 201ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2029f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 20342a0bb3fSPetr Mladek select HAVE_NMI 2046471b825SIngo Molnar select HAVE_OPROFILE 2056471b825SIngo Molnar select HAVE_OPTPROBES 2066471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2076471b825SIngo Molnar select HAVE_PERF_EVENTS 208c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 20992e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 210eb01d42aSChristoph Hellwig select HAVE_PCI 211c5e63197SJiri Olsa select HAVE_PERF_REGS 212c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 213ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 21400998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2156471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 2166415b38bSJiri Slaby select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 2173c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 218d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 219c763ea26SIngo Molnar select HAVE_STACK_VALIDATION if X86_64 220e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 2211e7e4788SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 222d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2236471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2246471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2257c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2267ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 22705736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 228c0185808SThomas Gleixner select IRQ_FORCED_THREADING 22986596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2302eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 231625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2326471b825SIngo Molnar select PERF_EVENTS 2333195ef59SPrarit Bhargava select RTC_LIB 234d6faca40SArnd Bergmann select RTC_MC146818_LIB 2356471b825SIngo Molnar select SPARSE_IRQ 23683fe27eaSPranith Kumar select SRCU 2371e7e4788SJosh Poimboeuf select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 2386471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 23915f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2406471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2416471b825SIngo Molnar select VIRT_TO_BUS 2423b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2436471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2440c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 2459e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2467d8330a5SBalbir Singh 247ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2483120e25eSJan Beulich def_bool y 2493120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 250ba7e4d13SIngo Molnar 25151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 25251b26adaSLinus Torvalds string 25351b26adaSLinus Torvalds default "elf32-i386" if X86_32 25451b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 25551b26adaSLinus Torvalds 2568d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2573c2362e6SHarvey Harrison def_bool y 2588d5fffb9SSam Ravnborg 2598d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 2603c2362e6SHarvey Harrison def_bool y 2618d5fffb9SSam Ravnborg 2628d5fffb9SSam Ravnborgconfig MMU 2633c2362e6SHarvey Harrison def_bool y 2648d5fffb9SSam Ravnborg 2659e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 2669e08f57dSDaniel Cashman default 28 if 64BIT 2679e08f57dSDaniel Cashman default 8 2689e08f57dSDaniel Cashman 2699e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 2709e08f57dSDaniel Cashman default 32 if 64BIT 2719e08f57dSDaniel Cashman default 16 2729e08f57dSDaniel Cashman 2739e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 2749e08f57dSDaniel Cashman default 8 2759e08f57dSDaniel Cashman 2769e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 2779e08f57dSDaniel Cashman default 16 2789e08f57dSDaniel Cashman 2798d5fffb9SSam Ravnborgconfig SBUS 2808d5fffb9SSam Ravnborg bool 2818d5fffb9SSam Ravnborg 2828d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 2833120e25eSJan Beulich def_bool y 2843120e25eSJan Beulich depends on ISA_DMA_API 2858d5fffb9SSam Ravnborg 2868d5fffb9SSam Ravnborgconfig GENERIC_BUG 2873c2362e6SHarvey Harrison def_bool y 2888d5fffb9SSam Ravnborg depends on BUG 289b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 290b93a531eSJan Beulich 291b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 292b93a531eSJan Beulich bool 2938d5fffb9SSam Ravnborg 2948d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 2953120e25eSJan Beulich def_bool y 2963120e25eSJan Beulich depends on ISA_DMA_API 2978d5fffb9SSam Ravnborg 2981032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 2991032c0baSSam Ravnborg def_bool y 3001032c0baSSam Ravnborg 3019a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3029a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3038d5fffb9SSam Ravnborg 3041b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE 3051b27d05bSPekka Enberg def_bool y 3061b27d05bSPekka Enberg 307316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT 308316d097cSDave Hansen def_bool y 309316d097cSDave Hansen 310dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA 31189c9c4c5SBrian Gerst def_bool y 312b32ef636Stravis@sgi.com 31308fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK 31408fc4580STejun Heo def_bool y 31508fc4580STejun Heo 31608fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK 31711124411STejun Heo def_bool y 31811124411STejun Heo 319801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 320801e4062SJohannes Berg def_bool y 321801e4062SJohannes Berg 322f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 323f4cb5700SJohannes Berg def_bool y 324f4cb5700SJohannes Berg 32553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB 32653313b2cSSteve Capper def_bool y 32753313b2cSSteve Capper 3288d5fffb9SSam Ravnborgconfig ZONE_DMA32 329e0fd24a3SJan Beulich def_bool y if X86_64 3308d5fffb9SSam Ravnborg 3318d5fffb9SSam Ravnborgconfig AUDIT_ARCH 332e0fd24a3SJan Beulich def_bool y if X86_64 3338d5fffb9SSam Ravnborg 3346a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 3356a11f75bSAkinobu Mita def_bool y 3366a11f75bSAkinobu Mita 337d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 338d6f2d75aSAndrey Ryabinin hex 339d6f2d75aSAndrey Ryabinin depends on KASAN 340d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 341d6f2d75aSAndrey Ryabinin 34269575d38SShane Wangconfig HAVE_INTEL_TXT 34369575d38SShane Wang def_bool y 3446ea30386SKees Cook depends on INTEL_IOMMU && ACPI 34569575d38SShane Wang 3466b0c3d44SSam Ravnborgconfig X86_32_SMP 3476b0c3d44SSam Ravnborg def_bool y 3486b0c3d44SSam Ravnborg depends on X86_32 && SMP 3496b0c3d44SSam Ravnborg 3506b0c3d44SSam Ravnborgconfig X86_64_SMP 3516b0c3d44SSam Ravnborg def_bool y 3526b0c3d44SSam Ravnborg depends on X86_64 && SMP 3536b0c3d44SSam Ravnborg 354ccbeed3aSTejun Heoconfig X86_32_LAZY_GS 355ccbeed3aSTejun Heo def_bool y 3568458f8c2SMasahiro Yamada depends on X86_32 && !STACKPROTECTOR 357ccbeed3aSTejun Heo 3582b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3592b144498SSrikar Dronamraju def_bool y 3602b144498SSrikar Dronamraju 361d20642f0SRob Herringconfig FIX_EARLYCON_MEM 362d20642f0SRob Herring def_bool y 363d20642f0SRob Herring 36494d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 36594d49eb3SKirill A. Shutemov bool 36694d49eb3SKirill A. Shutemov 36798233368SKirill A. Shutemovconfig PGTABLE_LEVELS 36898233368SKirill A. Shutemov int 36977ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 37098233368SKirill A. Shutemov default 4 if X86_64 37198233368SKirill A. Shutemov default 3 if X86_PAE 37298233368SKirill A. Shutemov default 2 37398233368SKirill A. Shutemov 3742a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3752a61f474SMasahiro Yamada bool 3762a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 3772a61f474SMasahiro Yamada default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 3782a61f474SMasahiro Yamada help 3792a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3802a61f474SMasahiro Yamada the compiler produces broken code. 3812a61f474SMasahiro Yamada 382506f1d07SSam Ravnborgmenu "Processor type and features" 383506f1d07SSam Ravnborg 3845ee71535SRandy Dunlapconfig ZONE_DMA 3855ee71535SRandy Dunlap bool "DMA memory allocation support" if EXPERT 3865ee71535SRandy Dunlap default y 3875ee71535SRandy Dunlap help 3885ee71535SRandy Dunlap DMA memory allocation support allows devices with less than 32-bit 3895ee71535SRandy Dunlap addressing to allocate within the first 16MB of address space. 3905ee71535SRandy Dunlap Disable if no such devices will be used. 3915ee71535SRandy Dunlap 3925ee71535SRandy Dunlap If unsure, say Y. 3935ee71535SRandy Dunlap 394506f1d07SSam Ravnborgconfig SMP 395506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 396a7f7f624SMasahiro Yamada help 397506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 3984a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 3994a474157SRobert Graffham than one CPU, say Y. 400506f1d07SSam Ravnborg 4014a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 402506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 403506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4044a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 405506f1d07SSam Ravnborg will run faster if you say N here. 406506f1d07SSam Ravnborg 407506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 408506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 409506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 410506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 411506f1d07SSam Ravnborg 412506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 413506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 414506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 415506f1d07SSam Ravnborg 416cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4174f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 418506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 419506f1d07SSam Ravnborg 420506f1d07SSam Ravnborg If you don't know what to do here, say N. 421506f1d07SSam Ravnborg 4229def39beSJosh Triplettconfig X86_FEATURE_NAMES 4239def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4249def39beSJosh Triplett default y 425a7f7f624SMasahiro Yamada help 4269def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4279def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4289def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4299def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4309def39beSJosh Triplett 4319def39beSJosh Triplett If in doubt, say Y. 4329def39beSJosh Triplett 43306cd9a7dSYinghai Luconfig X86_X2APIC 43406cd9a7dSYinghai Lu bool "Support x2apic" 43519e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 436a7f7f624SMasahiro Yamada help 43706cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 43806cd9a7dSYinghai Lu 43906cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44006cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 44106cd9a7dSYinghai Lu 44206cd9a7dSYinghai Lu If you don't know what to do here, say N. 44306cd9a7dSYinghai Lu 4446695c85bSYinghai Luconfig X86_MPPARSE 4456e87f9b7SBin Gao bool "Enable MPS table" if ACPI || SFI 4467a527688SJan Beulich default y 4475ab74722SIngo Molnar depends on X86_LOCAL_APIC 448a7f7f624SMasahiro Yamada help 4496695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4506695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4516695c85bSYinghai Lu 452ddd70cf9SJun Nakajimaconfig GOLDFISH 453ddd70cf9SJun Nakajima def_bool y 454ddd70cf9SJun Nakajima depends on X86_GOLDFISH 455ddd70cf9SJun Nakajima 45676b04384SDavid Woodhouseconfig RETPOLINE 45776b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 45876b04384SDavid Woodhouse default y 45976b04384SDavid Woodhouse help 46076b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 46176b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 46276b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 46376b04384SDavid Woodhouse support for full protection. The kernel may run slower. 46476b04384SDavid Woodhouse 465e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 466e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4676fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 46859fe5a77SThomas Gleixner select KERNFS 469e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 47078e99b4aSFenghua Yu help 471e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4726fe07ce3SBabu Moger 4736fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4746fe07ce3SBabu Moger usage by the CPU. 4756fe07ce3SBabu Moger 4766fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4776fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4786fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4796fe07ce3SBabu Moger 4806fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4816fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4826fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 48378e99b4aSFenghua Yu 48478e99b4aSFenghua Yu Say N if unsure. 48578e99b4aSFenghua Yu 4868425091fSRavikiran G Thirumalaiif X86_32 487a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 488a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 489a0d0bb4dSRandy Dunlap depends on SMP 490a7f7f624SMasahiro Yamada help 491e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 492a0d0bb4dSRandy Dunlap 493c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 494c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 495c5c606d9SRavikiran G Thirumalai default y 496a7f7f624SMasahiro Yamada help 49706ac8346SIngo Molnar If you disable this option then the kernel will only support 49806ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 49906ac8346SIngo Molnar systems out there.) 50006ac8346SIngo Molnar 5018425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5028425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 503cb7b8023SBen Hutchings Goldfish (Android emulator) 5048425091fSRavikiran G Thirumalai AMD Elan 5058425091fSRavikiran G Thirumalai RDC R-321x SoC 5068425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 50783125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5083f4110a4SThomas Gleixner Moorestown MID devices 50906ac8346SIngo Molnar 51006ac8346SIngo Molnar If you have one of these systems, or if you want to build a 51106ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 5128425091fSRavikiran G Thirumalaiendif 51306ac8346SIngo Molnar 5148425091fSRavikiran G Thirumalaiif X86_64 5158425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5168425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5178425091fSRavikiran G Thirumalai default y 518a7f7f624SMasahiro Yamada help 5198425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5208425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5218425091fSRavikiran G Thirumalai systems out there.) 5228425091fSRavikiran G Thirumalai 5238425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5248425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 52544b111b5SSteffen Persvold Numascale NumaChip 5268425091fSRavikiran G Thirumalai ScaleMP vSMP 5278425091fSRavikiran G Thirumalai SGI Ultraviolet 5288425091fSRavikiran G Thirumalai 5298425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5308425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 5318425091fSRavikiran G Thirumalaiendif 532c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 533c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 53444b111b5SSteffen Persvoldconfig X86_NUMACHIP 53544b111b5SSteffen Persvold bool "Numascale NumaChip" 53644b111b5SSteffen Persvold depends on X86_64 53744b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 53844b111b5SSteffen Persvold depends on NUMA 53944b111b5SSteffen Persvold depends on SMP 54044b111b5SSteffen Persvold depends on X86_X2APIC 541f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 542a7f7f624SMasahiro Yamada help 54344b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 54444b111b5SSteffen Persvold enable more than ~168 cores. 54544b111b5SSteffen Persvold If you don't have one of these, you should say N here. 54603b48632SNick Piggin 5476a48565eSIngo Molnarconfig X86_VSMP 548c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5496276a074SBorislav Petkov select HYPERVISOR_GUEST 5506a48565eSIngo Molnar select PARAVIRT 5516a48565eSIngo Molnar depends on X86_64 && PCI 552c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 553ead91d4bSShai Fultheim depends on SMP 554a7f7f624SMasahiro Yamada help 5556a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5566a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5576a48565eSIngo Molnar if you have one of these machines. 5586a48565eSIngo Molnar 559c5c606d9SRavikiran G Thirumalaiconfig X86_UV 560c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 561c5c606d9SRavikiran G Thirumalai depends on X86_64 562c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 56354c28d29SJack Steiner depends on NUMA 5641ecb4ae5SAndrew Morton depends on EFI 5659d6c26e7SSuresh Siddha depends on X86_X2APIC 5661222e564SIngo Molnar depends on PCI 567a7f7f624SMasahiro Yamada help 568c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 569c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 570c5c606d9SRavikiran G Thirumalai 571c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 572c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 573506f1d07SSam Ravnborg 574ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 575ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 576cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 577a7f7f624SMasahiro Yamada help 578ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 579ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 580ddd70cf9SJun Nakajima Goldfish emulator say N here. 581ddd70cf9SJun Nakajima 582c751e17bSThomas Gleixnerconfig X86_INTEL_CE 583c751e17bSThomas Gleixner bool "CE4100 TV platform" 584c751e17bSThomas Gleixner depends on PCI 585c751e17bSThomas Gleixner depends on PCI_GODIRECT 5866084a6e2SJiang Liu depends on X86_IO_APIC 587c751e17bSThomas Gleixner depends on X86_32 588c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 58937bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 590da6b737bSSebastian Andrzej Siewior select OF 591da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 592a7f7f624SMasahiro Yamada help 593c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 594c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 595c751e17bSThomas Gleixner boxes and media devices. 596c751e17bSThomas Gleixner 5974cb9b00fSDavid Cohenconfig X86_INTEL_MID 59843605ef1SAlan Cox bool "Intel MID platform support" 59943605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 600edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6011ea7c673SAlan Cox depends on PCI 6023fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6031ea7c673SAlan Cox depends on X86_IO_APIC 6047c9c3a1eSAlan Cox select SFI 6054cb9b00fSDavid Cohen select I2C 6067c9c3a1eSAlan Cox select DW_APB_TIMER 6071ea7c673SAlan Cox select APB_TIMER 60854b34aa0SMika Westerberg select INTEL_SCU_PCI 60915a713dfSMika Westerberg select MFD_INTEL_MSIC 610a7f7f624SMasahiro Yamada help 6114cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6124cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6134cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6141ea7c673SAlan Cox 6154cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6164cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 61743605ef1SAlan Cox 6188bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6198bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6208bbc2a13SBryan O'Donoghue depends on X86_32 6218bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6228bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6238bbc2a13SBryan O'Donoghue depends on X86_TSC 6248bbc2a13SBryan O'Donoghue depends on PCI 6258bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6268bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6278bbc2a13SBryan O'Donoghue select IOSF_MBI 6288bbc2a13SBryan O'Donoghue select INTEL_IMR 6299ab6eb51SAndy Shevchenko select COMMON_CLK 630a7f7f624SMasahiro Yamada help 6318bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6328bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6338bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6348bbc2a13SBryan O'Donoghue 6353d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6363d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6375962dd22SSinan Kaya depends on X86 && ACPI && PCI 6383d48aab1SMika Westerberg select COMMON_CLK 6390f531431SMathias Nyman select PINCTRL 640eebb3e8dSAndy Shevchenko select IOSF_MBI 641a7f7f624SMasahiro Yamada help 6423d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6433d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6440f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6450f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6463d48aab1SMika Westerberg 64792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 64892082a88SKen Xue bool "AMD ACPI2Platform devices support" 64992082a88SKen Xue depends on ACPI 65092082a88SKen Xue select COMMON_CLK 65192082a88SKen Xue select PINCTRL 652a7f7f624SMasahiro Yamada help 65392082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 65492082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 65592082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 65692082a88SKen Xue implemented under PINCTRL subsystem. 65792082a88SKen Xue 658ced3ce76SDavid E. Boxconfig IOSF_MBI 659ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 660ced3ce76SDavid E. Box depends on PCI 661a7f7f624SMasahiro Yamada help 662ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 663ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 664ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 665ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 666ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 667ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 668ced3ce76SDavid E. Box This list is not meant to be exclusive. 669ced3ce76SDavid E. Box - BayTrail 670ced3ce76SDavid E. Box - Braswell 671ced3ce76SDavid E. Box - Quark 672ced3ce76SDavid E. Box 673ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 674ced3ce76SDavid E. Box 675ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 676ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 677ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 678a7f7f624SMasahiro Yamada help 679ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 680ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 681ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 682ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 683ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 684ed2226bdSDavid E. Box device they want to access. 685ed2226bdSDavid E. Box 686ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 687ed2226bdSDavid E. Box 688c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 689c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 690506f1d07SSam Ravnborg depends on X86_32 691c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 692c5c606d9SRavikiran G Thirumalai select M486 693c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 694a7f7f624SMasahiro Yamada help 695c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 696c5c606d9SRavikiran G Thirumalai as R-8610-(G). 697c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 698c5c606d9SRavikiran G Thirumalai 699e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7009c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7019c398017SIngo Molnar depends on X86_32 && SMP 702c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 703a7f7f624SMasahiro Yamada help 704b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 705b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 706b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 707b5660ba7SH. Peter Anvin one and will fallback to default. 708d49c4288SYinghai Lu 709c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 710d49c4288SYinghai Lu 711d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7126fc108a0SJan Beulich def_bool y 713d949f36fSLinus Torvalds # MCE code calls memory_failure(): 714d949f36fSLinus Torvalds depends on X86_MCE 715d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 716d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 717d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 718d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 719d949f36fSLinus Torvalds 72083125a3aSAlessandro Rubiniconfig STA2X11 72183125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 72283125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 72383125a3aSAlessandro Rubini select SWIOTLB 72483125a3aSAlessandro Rubini select MFD_STA2X11 7250145071bSLinus Walleij select GPIOLIB 726a7f7f624SMasahiro Yamada help 72783125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 72883125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 72983125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 73083125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 73183125a3aSAlessandro Rubini standard PC machines. 73283125a3aSAlessandro Rubini 73382148d1dSShérabconfig X86_32_IRIS 73482148d1dSShérab tristate "Eurobraille/Iris poweroff module" 73582148d1dSShérab depends on X86_32 736a7f7f624SMasahiro Yamada help 73782148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 73882148d1dSShérab to shut themselves down properly. A special I/O sequence is 73982148d1dSShérab needed to do so, which is what this module does at 74082148d1dSShérab kernel shutdown. 74182148d1dSShérab 74282148d1dSShérab This is only for Iris machines from EuroBraille. 74382148d1dSShérab 74482148d1dSShérab If unused, say N. 74582148d1dSShérab 746ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7473c2362e6SHarvey Harrison def_bool y 7483c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 749a87d0914SKen Chen depends on X86 750a7f7f624SMasahiro Yamada help 751506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 752506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 753506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 754506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 755506f1d07SSam Ravnborg 756506f1d07SSam Ravnborg If in doubt, say "Y". 757506f1d07SSam Ravnborg 7586276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7596276a074SBorislav Petkov bool "Linux guest support" 760a7f7f624SMasahiro Yamada help 7616276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7626276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7636276a074SBorislav Petkov setup. 764506f1d07SSam Ravnborg 7656276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7666276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 767506f1d07SSam Ravnborg 7686276a074SBorislav Petkovif HYPERVISOR_GUEST 769506f1d07SSam Ravnborg 770e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 771e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 772a7f7f624SMasahiro Yamada help 773e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 774e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 775e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 776e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 777e61bd94aSEduardo Pereira Habkost 778c00a280aSJuergen Grossconfig PARAVIRT_XXL 779c00a280aSJuergen Gross bool 780c00a280aSJuergen Gross 7816276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7826276a074SBorislav Petkov bool "paravirt-ops debugging" 7836276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 784a7f7f624SMasahiro Yamada help 7856276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7866276a074SBorislav Petkov a paravirt_op is missing when it is called. 7876276a074SBorislav Petkov 788b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 789b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 7906ea30386SKees Cook depends on PARAVIRT && SMP 791a7f7f624SMasahiro Yamada help 792b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 793b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 794b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 795b4ecc126SJeremy Fitzhardinge 7964c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 7974c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 798b4ecc126SJeremy Fitzhardinge 7994c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 800b4ecc126SJeremy Fitzhardinge 801ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 802ecca2502SZhao Yakui def_bool n 803ecca2502SZhao Yakui 8046276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8056276a074SBorislav Petkov 8066276a074SBorislav Petkovconfig KVM_GUEST 8076276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8086276a074SBorislav Petkov depends on PARAVIRT 8096276a074SBorislav Petkov select PARAVIRT_CLOCK 810a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 811b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8126276a074SBorislav Petkov default y 813a7f7f624SMasahiro Yamada help 8146276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8156276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8166276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8176276a074SBorislav Petkov underlying device model, the host provides the guest with 8186276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8196276a074SBorislav Petkov 820a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 821a1c4423bSMarcelo Tosatti def_bool n 822a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 823a1c4423bSMarcelo Tosatti help 824a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 825a1c4423bSMarcelo Tosatti 8267733607fSMaran Wilsonconfig PVH 8277733607fSMaran Wilson bool "Support for running PVH guests" 828a7f7f624SMasahiro Yamada help 8297733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8307733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8317733607fSMaran Wilson 8326276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8336276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8346276a074SBorislav Petkov depends on PARAVIRT 835a7f7f624SMasahiro Yamada help 8366276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8376276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8386276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8396276a074SBorislav Petkov that, there can be a small performance impact. 8406276a074SBorislav Petkov 8416276a074SBorislav Petkov If in doubt, say N here. 8426276a074SBorislav Petkov 8437af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8447af192c9SGerd Hoffmann bool 8457af192c9SGerd Hoffmann 8464a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8474a362601SJan Kiszka bool "Jailhouse non-root cell support" 848abde587bSArnd Bergmann depends on X86_64 && PCI 84987e65d05SJan Kiszka select X86_PM_TIMER 850a7f7f624SMasahiro Yamada help 8514a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8524a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8534a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8544a362601SJan Kiszka 855ec7972c9SZhao Yakuiconfig ACRN_GUEST 856ec7972c9SZhao Yakui bool "ACRN Guest support" 857ec7972c9SZhao Yakui depends on X86_64 858498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 859ec7972c9SZhao Yakui help 860ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 861ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 862ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 863ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 864ec7972c9SZhao Yakui found in https://projectacrn.org/. 865ec7972c9SZhao Yakui 8666276a074SBorislav Petkovendif #HYPERVISOR_GUEST 86797349135SJeremy Fitzhardinge 868506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 869506f1d07SSam Ravnborg 870506f1d07SSam Ravnborgconfig HPET_TIMER 8713c2362e6SHarvey Harrison def_bool X86_64 872506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 873a7f7f624SMasahiro Yamada help 874506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 875506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 876506f1d07SSam Ravnborg present. 877506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 878506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 879506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 8804e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 8814e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 882506f1d07SSam Ravnborg 883506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 884506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 885506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 886506f1d07SSam Ravnborg 887506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 888506f1d07SSam Ravnborg 889506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 8903c2362e6SHarvey Harrison def_bool y 8919d8af78bSBernhard Walle depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 892506f1d07SSam Ravnborg 893bb24c471SJacob Panconfig APB_TIMER 894933b9463SAlan Cox def_bool y if X86_INTEL_MID 895933b9463SAlan Cox prompt "Intel MID APB Timer Support" if X86_INTEL_MID 89606c3df49SJamie Iles select DW_APB_TIMER 897a0c3832aSAlan Cox depends on X86_INTEL_MID && SFI 898bb24c471SJacob Pan help 899bb24c471SJacob Pan APB timer is the replacement for 8254, HPET on X86 MID platforms. 900bb24c471SJacob Pan The APBT provides a stable time base on SMP 901bb24c471SJacob Pan systems, unlike the TSC, but it is more expensive to access, 902bb24c471SJacob Pan as it is off-chip. APB timers are always running regardless of CPU 903bb24c471SJacob Pan C states, they are used as per CPU clockevent device when possible. 904bb24c471SJacob Pan 9056a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 906506f1d07SSam Ravnborg# The code disables itself when not needed. 9077ae9392cSThomas Petazzoniconfig DMI 9087ae9392cSThomas Petazzoni default y 909cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9106a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 911a7f7f624SMasahiro Yamada help 9127ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9137ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9147ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9157ae9392cSThomas Petazzoni BIOS code. 9167ae9392cSThomas Petazzoni 917506f1d07SSam Ravnborgconfig GART_IOMMU 91838901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9192f9237d4SChristoph Hellwig select DMA_OPS 920a4ce5a48SChristoph Hellwig select IOMMU_HELPER 921506f1d07SSam Ravnborg select SWIOTLB 92223ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 923a7f7f624SMasahiro Yamada help 924ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 925ced3c42cSIngo Molnar GART based hardware IOMMUs. 926ced3c42cSIngo Molnar 927ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 928ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 929ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 930ced3c42cSIngo Molnar 931ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 932ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 933ced3c42cSIngo Molnar 934ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 935ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 936ced3c42cSIngo Molnar 32-bit limited device. 937ced3c42cSIngo Molnar 938ced3c42cSIngo Molnar If unsure, say Y. 939506f1d07SSam Ravnborg 9401184dc2fSMike Travisconfig MAXSMP 941ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9426ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 94336f5101aSMike Travis select CPUMASK_OFFSTACK 944a7f7f624SMasahiro Yamada help 945ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9461184dc2fSMike Travis If unsure, say N. 947506f1d07SSam Ravnborg 948aec6487eSIngo Molnar# 949aec6487eSIngo Molnar# The maximum number of CPUs supported: 950aec6487eSIngo Molnar# 951aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 952aec6487eSIngo Molnar# and which can be configured interactively in the 953aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 954aec6487eSIngo Molnar# 955aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 956aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 957aec6487eSIngo Molnar# 958aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 959aec6487eSIngo Molnar# interactive configuration. ) 960aec6487eSIngo Molnar# 961a0d0bb4dSRandy Dunlap 962aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 963a0d0bb4dSRandy Dunlap int 964aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 965a0d0bb4dSRandy Dunlap default 1 if !SMP 966a0d0bb4dSRandy Dunlap default 2 967a0d0bb4dSRandy Dunlap 968aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 969a0d0bb4dSRandy Dunlap int 970a0d0bb4dSRandy Dunlap depends on X86_32 971aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 972aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 973a0d0bb4dSRandy Dunlap default 1 if !SMP 974a0d0bb4dSRandy Dunlap 975aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 976a0d0bb4dSRandy Dunlap int 977a0d0bb4dSRandy Dunlap depends on X86_64 9781edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 9791edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 980a0d0bb4dSRandy Dunlap default 1 if !SMP 981aec6487eSIngo Molnar 982aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 983aec6487eSIngo Molnar int 984aec6487eSIngo Molnar depends on X86_32 985aec6487eSIngo Molnar default 32 if X86_BIGSMP 986aec6487eSIngo Molnar default 8 if SMP 987aec6487eSIngo Molnar default 1 if !SMP 988aec6487eSIngo Molnar 989aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 990aec6487eSIngo Molnar int 991aec6487eSIngo Molnar depends on X86_64 992a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 993a0d0bb4dSRandy Dunlap default 64 if SMP 994aec6487eSIngo Molnar default 1 if !SMP 995a0d0bb4dSRandy Dunlap 996506f1d07SSam Ravnborgconfig NR_CPUS 99736f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 998aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 999aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1000a7f7f624SMasahiro Yamada help 1001506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1002bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1003cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1004506f1d07SSam Ravnborg minimum value which makes sense is 2. 1005506f1d07SSam Ravnborg 1006aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1007aec6487eSIngo Molnar to the kernel image. 1008506f1d07SSam Ravnborg 1009506f1d07SSam Ravnborgconfig SCHED_SMT 1010dbe73364SThomas Gleixner def_bool y if SMP 1011506f1d07SSam Ravnborg 1012506f1d07SSam Ravnborgconfig SCHED_MC 10133c2362e6SHarvey Harrison def_bool y 10143c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1015c8e56d20SBorislav Petkov depends on SMP 1016a7f7f624SMasahiro Yamada help 1017506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1018506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1019506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1020506f1d07SSam Ravnborg 1021de966cf4STim Chenconfig SCHED_MC_PRIO 1022de966cf4STim Chen bool "CPU core priorities scheduler support" 10230a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10240a21fc12SIngo Molnar select X86_INTEL_PSTATE 10250a21fc12SIngo Molnar select CPU_FREQ 1026de966cf4STim Chen default y 1027a7f7f624SMasahiro Yamada help 1028de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1029de966cf4STim Chen core ordering determined at manufacturing time, which allows 1030de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1031de966cf4STim Chen single threaded workloads) than others. 1032de966cf4STim Chen 1033de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1034de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1035de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1036de966cf4STim Chen overall system performance can be achieved. 1037de966cf4STim Chen 1038de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1039de966cf4STim Chen 1040de966cf4STim Chen If unsure say Y here. 10415e76b2abSTim Chen 104230b8b006SThomas Gleixnerconfig UP_LATE_INIT 104330b8b006SThomas Gleixner def_bool y 1044ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 104530b8b006SThomas Gleixner 1046506f1d07SSam Ravnborgconfig X86_UP_APIC 104750849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 104850849eefSJan Beulich default PCI_MSI 104938a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1050a7f7f624SMasahiro Yamada help 1051506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1052506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1053506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1054506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1055506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1056506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1057506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1058506f1d07SSam Ravnborg lockups. 1059506f1d07SSam Ravnborg 1060506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1061506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1062506f1d07SSam Ravnborg depends on X86_UP_APIC 1063a7f7f624SMasahiro Yamada help 1064506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1065506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1066506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1067506f1d07SSam Ravnborg 1068506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1069506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1070506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1071506f1d07SSam Ravnborg 1072506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 10733c2362e6SHarvey Harrison def_bool y 10740dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1075b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 107652f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1077506f1d07SSam Ravnborg 1078506f1d07SSam Ravnborgconfig X86_IO_APIC 1079b1da1e71SJan Beulich def_bool y 1080b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1081506f1d07SSam Ravnborg 108241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 108341b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 108441b9eb26SStefan Assmann depends on X86_IO_APIC 1085a7f7f624SMasahiro Yamada help 108641b9eb26SStefan Assmann This option enables a workaround that fixes a source of 108741b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 108841b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 108941b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 109041b9eb26SStefan Assmann 109141b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 109241b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 109341b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 109441b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 109541b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 109641b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 109741b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 109841b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 109941b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 110041b9eb26SStefan Assmann down (vital) interrupt lines. 110141b9eb26SStefan Assmann 110241b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 110341b9eb26SStefan Assmann increased on these systems. 110441b9eb26SStefan Assmann 1105506f1d07SSam Ravnborgconfig X86_MCE 1106bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1107648ed940SChen, Gong select GENERIC_ALLOCATOR 1108e57dbaf7SBorislav Petkov default y 1109a7f7f624SMasahiro Yamada help 1110bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1111bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1112506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1113bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11144efc0670SAndi Kleen 11155de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11165de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11175de97c9fSTony Luck depends on X86_MCE 1118a7f7f624SMasahiro Yamada help 11195de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11205de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11215de97c9fSTony Luck rasdaemon solution. 11225de97c9fSTony Luck 1123506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11243c2362e6SHarvey Harrison def_bool y 11253c2362e6SHarvey Harrison prompt "Intel MCE features" 1126c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1127a7f7f624SMasahiro Yamada help 1128506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1129506f1d07SSam Ravnborg the thermal monitor. 1130506f1d07SSam Ravnborg 1131506f1d07SSam Ravnborgconfig X86_MCE_AMD 11323c2362e6SHarvey Harrison def_bool y 11333c2362e6SHarvey Harrison prompt "AMD MCE features" 1134f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1135a7f7f624SMasahiro Yamada help 1136506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1137506f1d07SSam Ravnborg the DRAM Error Threshold. 1138506f1d07SSam Ravnborg 11394efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11406fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1141c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1142a7f7f624SMasahiro Yamada help 11434efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11445065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11454efc0670SAndi Kleen line. 11464efc0670SAndi Kleen 1147b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1148b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11496fc108a0SJan Beulich def_bool y 1150b2762686SAndi Kleen 1151ea149b36SAndi Kleenconfig X86_MCE_INJECT 1152bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1153ea149b36SAndi Kleen tristate "Machine check injector support" 1154a7f7f624SMasahiro Yamada help 1155ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1156ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1157ea149b36SAndi Kleen QA it is safe to say n. 1158ea149b36SAndi Kleen 11594efc0670SAndi Kleenconfig X86_THERMAL_VECTOR 11604efc0670SAndi Kleen def_bool y 11615bb38adcSAndi Kleen depends on X86_MCE_INTEL 11624efc0670SAndi Kleen 116307dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1164e633c65aSKan Liang 11655aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11661e642812SIngo Molnar bool "Legacy VM86 support" 1167506f1d07SSam Ravnborg depends on X86_32 1168a7f7f624SMasahiro Yamada help 11695aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11705aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11715aef51c3SAndy Lutomirski 11725aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 11735aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 11745aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 11755aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 11765aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 11771e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 11781e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 11791e642812SIngo Molnar mode might be faster than emulation and you might want to 11801e642812SIngo Molnar enable this option. 11815aef51c3SAndy Lutomirski 11821e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 11831e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 11841e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 11851e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 11865aef51c3SAndy Lutomirski 11871e642812SIngo Molnar Enabling this option increases the complexity of the kernel 11881e642812SIngo Molnar and slows down exception handling a tiny bit. 11895aef51c3SAndy Lutomirski 11901e642812SIngo Molnar If unsure, say N here. 11915aef51c3SAndy Lutomirski 11925aef51c3SAndy Lutomirskiconfig VM86 11935aef51c3SAndy Lutomirski bool 11945aef51c3SAndy Lutomirski default X86_LEGACY_VM86 119534273f41SH. Peter Anvin 119634273f41SH. Peter Anvinconfig X86_16BIT 119734273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 119834273f41SH. Peter Anvin default y 1199a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1200a7f7f624SMasahiro Yamada help 120134273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 120234273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 120334273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 120434273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 120534273f41SH. Peter Anvin 120634273f41SH. Peter Anvinconfig X86_ESPFIX32 120734273f41SH. Peter Anvin def_bool y 120834273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1209506f1d07SSam Ravnborg 1210197725deSH. Peter Anvinconfig X86_ESPFIX64 1211197725deSH. Peter Anvin def_bool y 121234273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1213506f1d07SSam Ravnborg 12141ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12151ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12161ad83c85SAndy Lutomirski default y 12171ad83c85SAndy Lutomirski depends on X86_64 1218a7f7f624SMasahiro Yamada help 12191ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12201ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12211ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12221ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12231ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12241ad83c85SAndy Lutomirski 0xffffffffff600?00. 12251ad83c85SAndy Lutomirski 12261ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12271ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12281ad83c85SAndy Lutomirski 12291ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12301ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12311ad83c85SAndy Lutomirski 1232111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1233111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1234a24ca997SThomas Gleixner default y 1235a7f7f624SMasahiro Yamada help 1236111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1237111e7b15SThomas Gleixner for legacy applications. 1238111e7b15SThomas Gleixner 1239c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1240c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1241c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1242c8137aceSThomas Gleixner capabilities and permission from potentially active security 1243c8137aceSThomas Gleixner modules. 1244c8137aceSThomas Gleixner 1245c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1246c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1247a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1248a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1249c8137aceSThomas Gleixner 1250506f1d07SSam Ravnborgconfig TOSHIBA 1251506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1252506f1d07SSam Ravnborg depends on X86_32 1253a7f7f624SMasahiro Yamada help 1254506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1255506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1256506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1257506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1258506f1d07SSam Ravnborg 1259506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1260506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1261506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1262506f1d07SSam Ravnborg 1263506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1264506f1d07SSam Ravnborg Say N otherwise. 1265506f1d07SSam Ravnborg 1266506f1d07SSam Ravnborgconfig I8K 1267039ae585SPali Rohár tristate "Dell i8k legacy laptop support" 1268949a9d70SJean Delvare select HWMON 1269039ae585SPali Rohár select SENSORS_DELL_SMM 1270a7f7f624SMasahiro Yamada help 1271039ae585SPali Rohár This option enables legacy /proc/i8k userspace interface in hwmon 1272039ae585SPali Rohár dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1273039ae585SPali Rohár temperature and allows controlling fan speeds of Dell laptops via 1274039ae585SPali Rohár System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1275039ae585SPali Rohár it reports also power and hotkey status. For fan speed control is 1276039ae585SPali Rohár needed userspace package i8kutils. 1277506f1d07SSam Ravnborg 1278039ae585SPali Rohár Say Y if you intend to run this kernel on old Dell laptops or want to 1279039ae585SPali Rohár use userspace package i8kutils. 1280506f1d07SSam Ravnborg Say N otherwise. 1281506f1d07SSam Ravnborg 1282506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12839ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12849ba16087SJan Beulich depends on X86_32 1285a7f7f624SMasahiro Yamada help 1286506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1287506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1288506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1289506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1290506f1d07SSam Ravnborg system. 1291506f1d07SSam Ravnborg 1292506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 12935e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1294506f1d07SSam Ravnborg 1295506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1296506f1d07SSam Ravnborg enable this option even if you don't need it. 1297506f1d07SSam Ravnborg Say N otherwise. 1298506f1d07SSam Ravnborg 1299506f1d07SSam Ravnborgconfig MICROCODE 13009a2bc335SBorislav Petkov bool "CPU microcode loading support" 13019a2bc335SBorislav Petkov default y 130280030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1303a7f7f624SMasahiro Yamada help 1304506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13055f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13065f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13075f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13085f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13095f9c01aaSBorislav Petkov the Linux kernel. 1310506f1d07SSam Ravnborg 13115f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1312cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13135f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13145f9c01aaSBorislav Petkov initrd for microcode blobs. 1315506f1d07SSam Ravnborg 1316c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1317c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1318c508c46eSBenjamin Gilbert config option. 1319506f1d07SSam Ravnborg 13208d86f390SPeter Orubaconfig MICROCODE_INTEL 1321e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13228d86f390SPeter Oruba depends on MICROCODE 13238d86f390SPeter Oruba default MICROCODE 1324a7f7f624SMasahiro Yamada help 13258d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13268d86f390SPeter Oruba processors. 13278d86f390SPeter Oruba 1328b8989db9SAlan For the current Intel microcode data package go to 1329b8989db9SAlan <https://downloadcenter.intel.com> and search for 1330b8989db9SAlan 'Linux Processor Microcode Data File'. 13318d86f390SPeter Oruba 133280cc9f10SPeter Orubaconfig MICROCODE_AMD 1333e43f6e67SBorislav Petkov bool "AMD microcode loading support" 133480cc9f10SPeter Oruba depends on MICROCODE 1335a7f7f624SMasahiro Yamada help 133680cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 133780cc9f10SPeter Oruba processors will be enabled. 133880cc9f10SPeter Oruba 1339506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE 1340c02f48e0SBorislav Petkov bool "Ancient loading interface (DEPRECATED)" 1341c02f48e0SBorislav Petkov default n 1342506f1d07SSam Ravnborg depends on MICROCODE 1343a7f7f624SMasahiro Yamada help 1344c02f48e0SBorislav Petkov DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1345c02f48e0SBorislav Petkov which was used by userspace tools like iucode_tool and microcode.ctl. 1346c02f48e0SBorislav Petkov It is inadequate because it runs too late to be able to properly 1347c02f48e0SBorislav Petkov load microcode on a machine and it needs special tools. Instead, you 1348c02f48e0SBorislav Petkov should've switched to the early loading method with the initrd or 1349cb1aaebeSMauro Carvalho Chehab builtin microcode by now: Documentation/x86/microcode.rst 1350506f1d07SSam Ravnborg 1351506f1d07SSam Ravnborgconfig X86_MSR 1352506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1353a7f7f624SMasahiro Yamada help 1354506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1355506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1356506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1357506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1358506f1d07SSam Ravnborg systems. 1359506f1d07SSam Ravnborg 1360506f1d07SSam Ravnborgconfig X86_CPUID 1361506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1362a7f7f624SMasahiro Yamada help 1363506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1364506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1365506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1366506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1367506f1d07SSam Ravnborg 1368506f1d07SSam Ravnborgchoice 1369506f1d07SSam Ravnborg prompt "High Memory Support" 13706fc108a0SJan Beulich default HIGHMEM4G 1371506f1d07SSam Ravnborg depends on X86_32 1372506f1d07SSam Ravnborg 1373506f1d07SSam Ravnborgconfig NOHIGHMEM 1374506f1d07SSam Ravnborg bool "off" 1375a7f7f624SMasahiro Yamada help 1376506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1377506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1378506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1379506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1380506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1381506f1d07SSam Ravnborg "high memory". 1382506f1d07SSam Ravnborg 1383506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1384506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1385506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1386506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1387506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1388506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1389506f1d07SSam Ravnborg possible. 1390506f1d07SSam Ravnborg 1391506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1392506f1d07SSam Ravnborg answer "4GB" here. 1393506f1d07SSam Ravnborg 1394506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1395506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1396506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1397506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1398506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1399506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1400506f1d07SSam Ravnborg 1401506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1402506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1403506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1404506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1405506f1d07SSam Ravnborg kernel at boot time.) 1406506f1d07SSam Ravnborg 1407506f1d07SSam Ravnborg If unsure, say "off". 1408506f1d07SSam Ravnborg 1409506f1d07SSam Ravnborgconfig HIGHMEM4G 1410506f1d07SSam Ravnborg bool "4GB" 1411a7f7f624SMasahiro Yamada help 1412506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1413506f1d07SSam Ravnborg gigabytes of physical RAM. 1414506f1d07SSam Ravnborg 1415506f1d07SSam Ravnborgconfig HIGHMEM64G 1416506f1d07SSam Ravnborg bool "64GB" 141769b8d3fcSMatthew Whitehead depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1418506f1d07SSam Ravnborg select X86_PAE 1419a7f7f624SMasahiro Yamada help 1420506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1421506f1d07SSam Ravnborg gigabytes of physical RAM. 1422506f1d07SSam Ravnborg 1423506f1d07SSam Ravnborgendchoice 1424506f1d07SSam Ravnborg 1425506f1d07SSam Ravnborgchoice 14266a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1427506f1d07SSam Ravnborg default VMSPLIT_3G 1428506f1d07SSam Ravnborg depends on X86_32 1429a7f7f624SMasahiro Yamada help 1430506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1431506f1d07SSam Ravnborg 1432506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1433506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1434506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1435506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1436506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1437506f1d07SSam Ravnborg available to user programs, making the address space there 1438506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1439506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1440506f1d07SSam Ravnborg kernel modules. 1441506f1d07SSam Ravnborg 1442506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1443506f1d07SSam Ravnborg option alone! 1444506f1d07SSam Ravnborg 1445506f1d07SSam Ravnborg config VMSPLIT_3G 1446506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1447506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1448506f1d07SSam Ravnborg depends on !X86_PAE 1449506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1450506f1d07SSam Ravnborg config VMSPLIT_2G 1451506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1452506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1453506f1d07SSam Ravnborg depends on !X86_PAE 1454506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1455506f1d07SSam Ravnborg config VMSPLIT_1G 1456506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1457506f1d07SSam Ravnborgendchoice 1458506f1d07SSam Ravnborg 1459506f1d07SSam Ravnborgconfig PAGE_OFFSET 1460506f1d07SSam Ravnborg hex 1461506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1462506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1463506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1464506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1465506f1d07SSam Ravnborg default 0xC0000000 1466506f1d07SSam Ravnborg depends on X86_32 1467506f1d07SSam Ravnborg 1468506f1d07SSam Ravnborgconfig HIGHMEM 14693c2362e6SHarvey Harrison def_bool y 1470506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1471506f1d07SSam Ravnborg 1472506f1d07SSam Ravnborgconfig X86_PAE 14739ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1474506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1475d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14769d99c712SChristian Melki select SWIOTLB 1477a7f7f624SMasahiro Yamada help 1478506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1479506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1480506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1481506f1d07SSam Ravnborg consumes more pagetable space per process. 1482506f1d07SSam Ravnborg 148377ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148477ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148518ec1eafSKirill A. Shutemov default y 1486eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1487162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148877ef56e4SKirill A. Shutemov depends on X86_64 1489a7f7f624SMasahiro Yamada help 149077ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 149177ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 149277ef56e4SKirill A. Shutemov physical address space. 149377ef56e4SKirill A. Shutemov 149477ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149577ef56e4SKirill A. Shutemov 14966657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14976657fca0SKirill A. Shutemov support 4- or 5-level paging. 149877ef56e4SKirill A. Shutemov 1499cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 150077ef56e4SKirill A. Shutemov information. 150177ef56e4SKirill A. Shutemov 150277ef56e4SKirill A. Shutemov Say N if unsure. 150377ef56e4SKirill A. Shutemov 150410971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1505e5008abeSLuis R. Rodriguez def_bool y 15062e1da13fSVlastimil Babka depends on X86_64 1507a7f7f624SMasahiro Yamada help 150810971ab2SIngo Molnar Certain kernel features effectively disable kernel 150910971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 151010971ab2SIngo Molnar supports them), so don't confuse the user by printing 151110971ab2SIngo Molnar that we have them enabled. 15129e899816SNick Piggin 15135c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15145c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15155c280cf6SThomas Gleixner depends on DEBUG_FS 1516a7f7f624SMasahiro Yamada help 1517b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1518a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15195c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15205c280cf6SThomas Gleixner 15217744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15227744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15237744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 152482fef0adSDavid Rientjes select DMA_COHERENT_POOL 152594d49eb3SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 1526ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 15279087c375STom Lendacky select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1528597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1529a7f7f624SMasahiro Yamada help 15307744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15317744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15327744ccdbSTom Lendacky Encryption (SME). 15337744ccdbSTom Lendacky 15347744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15357744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15367744ccdbSTom Lendacky default y 15377744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1538a7f7f624SMasahiro Yamada help 15397744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15407744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15417744ccdbSTom Lendacky 15427744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15437744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15447744ccdbSTom Lendacky 15457744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15467744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15477744ccdbSTom Lendacky 1548506f1d07SSam Ravnborg# Common NUMA Features 1549506f1d07SSam Ravnborgconfig NUMA 1550e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1551506f1d07SSam Ravnborg depends on SMP 1552b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1553b5660ba7SH. Peter Anvin default y if X86_BIGSMP 1554a7f7f624SMasahiro Yamada help 1555e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1556fd51b2d7SKOSAKI Motohiro 1557506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1558506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1559506f1d07SSam Ravnborg NUMA awareness to the kernel. 1560506f1d07SSam Ravnborg 1561c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1562fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1563fd51b2d7SKOSAKI Motohiro 1564b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15657cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1566fd51b2d7SKOSAKI Motohiro 1567fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1568506f1d07SSam Ravnborg 1569eec1d4faSHans Rosenfeldconfig AMD_NUMA 15703c2362e6SHarvey Harrison def_bool y 15713c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15725da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1573a7f7f624SMasahiro Yamada help 1574eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1575eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1576eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1577eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1578eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1579506f1d07SSam Ravnborg 1580506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15813c2362e6SHarvey Harrison def_bool y 15823c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1583506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1584506f1d07SSam Ravnborg select ACPI_NUMA 1585a7f7f624SMasahiro Yamada help 1586506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1587506f1d07SSam Ravnborg 1588506f1d07SSam Ravnborgconfig NUMA_EMU 1589506f1d07SSam Ravnborg bool "NUMA emulation" 15901b7e03efSTejun Heo depends on NUMA 1591a7f7f624SMasahiro Yamada help 1592506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1593506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1594506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1595506f1d07SSam Ravnborg 1596506f1d07SSam Ravnborgconfig NODES_SHIFT 1597d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 159851591e31SDavid Rientjes range 1 10 159951591e31SDavid Rientjes default "10" if MAXSMP 1600506f1d07SSam Ravnborg default "6" if X86_64 1601506f1d07SSam Ravnborg default "3" 1602506f1d07SSam Ravnborg depends on NEED_MULTIPLE_NODES 1603a7f7f624SMasahiro Yamada help 16041184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1605692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1606506f1d07SSam Ravnborg 1607506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1608506f1d07SSam Ravnborg def_bool y 16093b16651fSTejun Heo depends on X86_32 && !NUMA 1610506f1d07SSam Ravnborg 1611506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1612506f1d07SSam Ravnborg def_bool y 16136ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1614506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1615506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1616506f1d07SSam Ravnborg 16173b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16186ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16193b16651fSTejun Heo 1620506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1621506f1d07SSam Ravnborg def_bool y 1622b263295dSChristoph Lameter depends on ARCH_SPARSEMEM_ENABLE 1623506f1d07SSam Ravnborg 1624506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1625a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16263120e25eSJan Beulich depends on X86_64 && MEMORY_HOTPLUG 1627a0842b70SToshi Kani help 1628a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1629cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1630a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1631506f1d07SSam Ravnborg 16323b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16333b16651fSTejun Heo def_bool y 16343b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16353b16651fSTejun Heo 1636a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1637a29815a3SAvi Kivity hex 1638a29815a3SAvi Kivity default 0 if X86_32 1639a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1640a29815a3SAvi Kivity 16417a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16427a67832cSDan Williams bool 16437a67832cSDan Williams 1644ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16457a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16469f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16479f53f9faSDan Williams depends on BLK_DEV 16487a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16497b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16509f53f9faSDan Williams select LIBNVDIMM 1651ec776ef6SChristoph Hellwig help 1652ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1653ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1654ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1655ec776ef6SChristoph Hellwig they can be used for persistent storage. 1656ec776ef6SChristoph Hellwig 1657ec776ef6SChristoph Hellwig Say Y if unsure. 1658ec776ef6SChristoph Hellwig 1659506f1d07SSam Ravnborgconfig HIGHPTE 1660506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16616fc108a0SJan Beulich depends on HIGHMEM 1662a7f7f624SMasahiro Yamada help 1663506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1664506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1665506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1666506f1d07SSam Ravnborg entries in high memory. 1667506f1d07SSam Ravnborg 16689f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16699f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1670a7f7f624SMasahiro Yamada help 16719f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16729f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16739f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16749f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16759f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16769f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16779f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16788c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16799f077871SJeremy Fitzhardinge 16809f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16819f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16829f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16839f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16849f077871SJeremy Fitzhardinge 16859f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16869f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16879f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16889f077871SJeremy Fitzhardinge memory. 16899f077871SJeremy Fitzhardinge 1690c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1691c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1692c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1693c885df50SJeremy Fitzhardinge default y 1694a7f7f624SMasahiro Yamada help 1695c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1696c885df50SJeremy Fitzhardinge on or off. 1697c885df50SJeremy Fitzhardinge 16989ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW 1699d0cd7425SH. Peter Anvin int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1700d0cd7425SH. Peter Anvin default 64 1701d0cd7425SH. Peter Anvin range 4 640 1702a7f7f624SMasahiro Yamada help 1703d0cd7425SH. Peter Anvin Specify the amount of low memory to reserve for the BIOS. 1704fc381519SIngo Molnar 1705d0cd7425SH. Peter Anvin The first page contains BIOS data structures that the kernel 1706d0cd7425SH. Peter Anvin must not use, so that page must always be reserved. 1707fc381519SIngo Molnar 1708d0cd7425SH. Peter Anvin By default we reserve the first 64K of physical RAM, as a 1709d0cd7425SH. Peter Anvin number of BIOSes are known to corrupt that memory range 1710d0cd7425SH. Peter Anvin during events such as suspend/resume or monitor cable 1711d0cd7425SH. Peter Anvin insertion, so it must not be used by the kernel. 1712fc381519SIngo Molnar 1713d0cd7425SH. Peter Anvin You can set this to 4 if you are absolutely sure that you 1714d0cd7425SH. Peter Anvin trust the BIOS to get all its memory reservations and usages 1715d0cd7425SH. Peter Anvin right. If you know your BIOS have problems beyond the 1716d0cd7425SH. Peter Anvin default 64K area, you can set this to 640 to avoid using the 1717d0cd7425SH. Peter Anvin entire low memory range. 1718d0cd7425SH. Peter Anvin 1719d0cd7425SH. Peter Anvin If you have doubts about the BIOS (e.g. suspend/resume does 1720d0cd7425SH. Peter Anvin not work or there's kernel crashes after certain hardware 1721d0cd7425SH. Peter Anvin hotplug events) then you might want to enable 1722d0cd7425SH. Peter Anvin X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1723d0cd7425SH. Peter Anvin typical corruption patterns. 1724d0cd7425SH. Peter Anvin 1725d0cd7425SH. Peter Anvin Leave this to the default value of 64 if you are unsure. 1726fc381519SIngo Molnar 1727506f1d07SSam Ravnborgconfig MATH_EMULATION 1728506f1d07SSam Ravnborg bool 1729a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 173087d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1731a7f7f624SMasahiro Yamada help 1732506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1733506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1734506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1735506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1736506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1737506f1d07SSam Ravnborg coprocessor or this emulation. 1738506f1d07SSam Ravnborg 1739506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1740506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1741506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1742506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1743506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1744506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1745506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1746506f1d07SSam Ravnborg intend to use this kernel on different machines. 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1749506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1750506f1d07SSam Ravnborg 1751506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1752506f1d07SSam Ravnborg kernel, it won't hurt. 1753506f1d07SSam Ravnborg 1754506f1d07SSam Ravnborgconfig MTRR 17556fc108a0SJan Beulich def_bool y 17566a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1757a7f7f624SMasahiro Yamada help 1758506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1759506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1760506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1761506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1762506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1763506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1764506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1765506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1766506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1767506f1d07SSam Ravnborg 1768506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1769506f1d07SSam Ravnborg control registers on other processors can be easily supported 1770506f1d07SSam Ravnborg as well: 1771506f1d07SSam Ravnborg 1772506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1773506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1774506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1775506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1776506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1777506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1778506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1779506f1d07SSam Ravnborg 1780506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1781506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1782506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1783506f1d07SSam Ravnborg 1784506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1785506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1786506f1d07SSam Ravnborg 1787cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1788506f1d07SSam Ravnborg 178995ffa243SYinghai Luconfig MTRR_SANITIZER 17902ffb3501SYinghai Lu def_bool y 179195ffa243SYinghai Lu prompt "MTRR cleanup support" 179295ffa243SYinghai Lu depends on MTRR 1793a7f7f624SMasahiro Yamada help 1794aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1795aba3728cSThomas Gleixner add writeback entries. 179695ffa243SYinghai Lu 1797aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1798692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1799aba3728cSThomas Gleixner mtrr_chunk_size. 180095ffa243SYinghai Lu 18012ffb3501SYinghai Lu If unsure, say Y. 180295ffa243SYinghai Lu 180395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1804f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1805f5098d62SYinghai Lu range 0 1 1806f5098d62SYinghai Lu default "0" 180795ffa243SYinghai Lu depends on MTRR_SANITIZER 1808a7f7f624SMasahiro Yamada help 1809f5098d62SYinghai Lu Enable mtrr cleanup default value 181095ffa243SYinghai Lu 181112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 181212031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 181312031a62SYinghai Lu range 0 7 181412031a62SYinghai Lu default "1" 181512031a62SYinghai Lu depends on MTRR_SANITIZER 1816a7f7f624SMasahiro Yamada help 181712031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1818aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 181912031a62SYinghai Lu 18202e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 18216fc108a0SJan Beulich def_bool y 18226a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18232a8a2719SIngo Molnar depends on MTRR 1824a7f7f624SMasahiro Yamada help 18252e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1826042b78e4SVenki Pallipadi 18272e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18282e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18292e5d9c85Svenkatesh.pallipadi@intel.com 18302e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1831042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18322e5d9c85Svenkatesh.pallipadi@intel.com 18332e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18342e5d9c85Svenkatesh.pallipadi@intel.com 183546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 183646cf98cdSVenkatesh Pallipadi def_bool y 183746cf98cdSVenkatesh Pallipadi depends on X86_PAT 183846cf98cdSVenkatesh Pallipadi 1839628c6246SH. Peter Anvinconfig ARCH_RANDOM 1840628c6246SH. Peter Anvin def_bool y 1841628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1842a7f7f624SMasahiro Yamada help 1843628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1844628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1845628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1846628c6246SH. Peter Anvin secure hardware random number generator. 1847628c6246SH. Peter Anvin 184851ae4a2dSH. Peter Anvinconfig X86_SMAP 184951ae4a2dSH. Peter Anvin def_bool y 185051ae4a2dSH. Peter Anvin prompt "Supervisor Mode Access Prevention" if EXPERT 1851a7f7f624SMasahiro Yamada help 185251ae4a2dSH. Peter Anvin Supervisor Mode Access Prevention (SMAP) is a security 185351ae4a2dSH. Peter Anvin feature in newer Intel processors. There is a small 185451ae4a2dSH. Peter Anvin performance cost if this enabled and turned on; there is 185551ae4a2dSH. Peter Anvin also a small increase in the kernel size if this is enabled. 185651ae4a2dSH. Peter Anvin 185751ae4a2dSH. Peter Anvin If unsure, say Y. 185851ae4a2dSH. Peter Anvin 1859b971880fSBabu Mogerconfig X86_UMIP 1860796ebc81SRicardo Neri def_bool y 1861b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1862a7f7f624SMasahiro Yamada help 1863b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1864b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1865b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1866b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1867b971880fSBabu Moger information about the hardware state. 1868796ebc81SRicardo Neri 1869796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1870796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1871796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1872796ebc81SRicardo Neri results are dummy. 1873aa35f896SRicardo Neri 187435e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 187538f3e775SBabu Moger prompt "Memory Protection Keys" 187635e97790SDave Hansen def_bool y 1877284244a9SDave Hansen # Note: only available in 64-bit mode 187838f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 187952c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 188052c8e601SIngo Molnar select ARCH_HAS_PKEYS 1881a7f7f624SMasahiro Yamada help 1882284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1883284244a9SDave Hansen page-based protections, but without requiring modification of the 1884284244a9SDave Hansen page tables when an application changes protection domains. 1885284244a9SDave Hansen 18861eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1887284244a9SDave Hansen 1888284244a9SDave Hansen If unsure, say y. 188935e97790SDave Hansen 1890db616173SMichal Hockochoice 1891db616173SMichal Hocko prompt "TSX enable mode" 1892db616173SMichal Hocko depends on CPU_SUP_INTEL 1893db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1894db616173SMichal Hocko help 1895db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1896db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1897db616173SMichal Hocko can lead to a noticeable performance boost. 1898db616173SMichal Hocko 1899db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1900db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1901db616173SMichal Hocko will be more of those attacks discovered in the future. 1902db616173SMichal Hocko 1903db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1904db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1905db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1906db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1907db616173SMichal Hocko for the particular machine. 1908db616173SMichal Hocko 1909db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1910db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1911db616173SMichal Hocko details. 1912db616173SMichal Hocko 1913db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1914db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1915db616173SMichal Hocko relevant. 1916db616173SMichal Hocko 1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1918db616173SMichal Hocko bool "off" 1919db616173SMichal Hocko help 1920db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1921db616173SMichal Hocko 1922db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1923db616173SMichal Hocko bool "on" 1924db616173SMichal Hocko help 1925db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1926db616173SMichal Hocko line parameter. 1927db616173SMichal Hocko 1928db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1929db616173SMichal Hocko bool "auto" 1930db616173SMichal Hocko help 1931db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1932db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1933db616173SMichal Hockoendchoice 1934db616173SMichal Hocko 1935506f1d07SSam Ravnborgconfig EFI 19369ba16087SJan Beulich bool "EFI runtime service support" 19375b83683fSHuang, Ying depends on ACPI 1938f6ce5002SSergey Vlasov select UCS2_STRING 1939022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 1940a7f7f624SMasahiro Yamada help 19418b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1942506f1d07SSam Ravnborg available (such as the EFI variable services). 1943506f1d07SSam Ravnborg 19448b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19458b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19468b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19478b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19488b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19498b2cb7a8SHuang, Ying platforms. 1950506f1d07SSam Ravnborg 1951291f3632SMatt Flemingconfig EFI_STUB 1952291f3632SMatt Fleming bool "EFI stub support" 1953b16d8c23SMatt Fleming depends on EFI && !X86_USE_3DNOW 19548f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19557b2a583aSMatt Fleming select RELOCATABLE 1956a7f7f624SMasahiro Yamada help 1957291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1958291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1959291f3632SMatt Fleming 19604f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19610c759662SMatt Fleming 19627d453eeeSMatt Flemingconfig EFI_MIXED 19637d453eeeSMatt Fleming bool "EFI mixed-mode support" 19647d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1965a7f7f624SMasahiro Yamada help 19667d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19677d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 19687d453eeeSMatt Fleming mode. 19697d453eeeSMatt Fleming 19707d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 19717d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 19727d453eeeSMatt Fleming the EFI handover protocol must be used. 19737d453eeeSMatt Fleming 19747d453eeeSMatt Fleming If unsure, say N. 19757d453eeeSMatt Fleming 19768636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 1977506f1d07SSam Ravnborg 1978506f1d07SSam Ravnborgconfig KEXEC 1979506f1d07SSam Ravnborg bool "kexec system call" 19802965faa5SDave Young select KEXEC_CORE 1981a7f7f624SMasahiro Yamada help 1982506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 1983506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 1984506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 1985506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 1986506f1d07SSam Ravnborg 1987506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 1988506f1d07SSam Ravnborg 1989506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 1990506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 1991bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 1992bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 1993bf220695SGeert Uytterhoeven made. 1994506f1d07SSam Ravnborg 199574ca317cSVivek Goyalconfig KEXEC_FILE 199674ca317cSVivek Goyal bool "kexec file based system call" 19972965faa5SDave Young select KEXEC_CORE 199874ca317cSVivek Goyal select BUILD_BIN2C 199974ca317cSVivek Goyal depends on X86_64 200074ca317cSVivek Goyal depends on CRYPTO=y 200174ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2002a7f7f624SMasahiro Yamada help 200374ca317cSVivek Goyal This is new version of kexec system call. This system call is 200474ca317cSVivek Goyal file based and takes file descriptors as system call argument 200574ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 200674ca317cSVivek Goyal accepted by previous system call. 200774ca317cSVivek Goyal 2008b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2009b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2010b799a09fSAKASHI Takahiro 201199d5cadfSJiri Bohacconfig KEXEC_SIG 20128e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 201374ca317cSVivek Goyal depends on KEXEC_FILE 2014a7f7f624SMasahiro Yamada help 201599d5cadfSJiri Bohac 201699d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 201799d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 201899d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 201999d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 202099d5cadfSJiri Bohac 202199d5cadfSJiri Bohac In addition to this option, you need to enable signature 202299d5cadfSJiri Bohac verification for the corresponding kernel image type being 202399d5cadfSJiri Bohac loaded in order for this to work. 202499d5cadfSJiri Bohac 202599d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 202699d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 202799d5cadfSJiri Bohac depends on KEXEC_SIG 2028a7f7f624SMasahiro Yamada help 20298e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2030d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20318e7d8381SVivek Goyal 20328e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20338e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 203499d5cadfSJiri Bohac depends on KEXEC_SIG 20358e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20368e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2037a7f7f624SMasahiro Yamada help 20388e7d8381SVivek Goyal Enable bzImage signature verification support. 20398e7d8381SVivek Goyal 2040506f1d07SSam Ravnborgconfig CRASH_DUMP 204104b69447SPavel Machek bool "kernel crash dumps" 2042506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2043a7f7f624SMasahiro Yamada help 2044506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2045506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2046506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2047506f1d07SSam Ravnborg a specially reserved region and then later executed after 2048506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2049506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2050506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2051506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2052330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2053506f1d07SSam Ravnborg 20543ab83521SHuang Yingconfig KEXEC_JUMP 20556ea30386SKees Cook bool "kexec jump" 2056fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2057a7f7f624SMasahiro Yamada help 205889081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 205989081d17SHuang Ying code in physical address mode via KEXEC 20603ab83521SHuang Ying 2061506f1d07SSam Ravnborgconfig PHYSICAL_START 20626a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2063ceefccc9SH. Peter Anvin default "0x1000000" 2064a7f7f624SMasahiro Yamada help 2065506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2066506f1d07SSam Ravnborg 2067506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2068506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2069506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2070506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2071506f1d07SSam Ravnborg address. 2072506f1d07SSam Ravnborg 2073506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2074506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2075506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2076506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2077506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2078506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2079506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2080506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2081506f1d07SSam Ravnborg 2082ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2083ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2084ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2085ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2086ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2087ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2088ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2089330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2090ceefccc9SH. Peter Anvin for more details about crash dumps. 2091506f1d07SSam Ravnborg 2092506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2093506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2094506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2095506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2096506f1d07SSam Ravnborg is present because there are users out there who continue to use 2097506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2098506f1d07SSam Ravnborg line. 2099506f1d07SSam Ravnborg 2100506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2101506f1d07SSam Ravnborg 2102506f1d07SSam Ravnborgconfig RELOCATABLE 210326717808SH. Peter Anvin bool "Build a relocatable kernel" 210426717808SH. Peter Anvin default y 2105a7f7f624SMasahiro Yamada help 2106506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2107506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2108506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2109506f1d07SSam Ravnborg but are discarded at runtime. 2110506f1d07SSam Ravnborg 2111506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2112506f1d07SSam Ravnborg must live at a different physical address than the primary 2113506f1d07SSam Ravnborg kernel. 2114506f1d07SSam Ravnborg 2115506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2116506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21178ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2118506f1d07SSam Ravnborg 21198ab3820fSKees Cookconfig RANDOMIZE_BASE 2120e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21218ab3820fSKees Cook depends on RELOCATABLE 21226807c846SIngo Molnar default y 2123a7f7f624SMasahiro Yamada help 2124e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2125e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2126e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2127e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2128e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2129e8581e3dSBaoquan He code internals. 2130e8581e3dSBaoquan He 2131ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2132ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2133ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2134ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2135ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2136ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2137ed9f007eSKees Cook 2138ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2139ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2140ed9f007eSKees Cook 512MB (8 bits of entropy). 21418ab3820fSKees Cook 2142a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2143e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2144e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2145ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2146ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2147ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2148ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2149ed9f007eSKees Cook theoretically possible, but the implementations are further 2150ed9f007eSKees Cook limited due to memory layouts. 2151e8581e3dSBaoquan He 21526807c846SIngo Molnar If unsure, say Y. 2153da2b6fb9SKees Cook 21548ab3820fSKees Cook# Relocation on x86 needs some additional build support 2155845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2156845adf72SH. Peter Anvin def_bool y 21578ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2158845adf72SH. Peter Anvin 2159506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2160a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21618ab3820fSKees Cook default "0x200000" 2162a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2163a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2164a7f7f624SMasahiro Yamada help 2165506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2166506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2167506f1d07SSam Ravnborg address which meets above alignment restriction. 2168506f1d07SSam Ravnborg 2169506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2170506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2171506f1d07SSam Ravnborg address aligned to above value and run from there. 2172506f1d07SSam Ravnborg 2173506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2174506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2175506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2176506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2177506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2178506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2179506f1d07SSam Ravnborg above alignment restrictions. 2180506f1d07SSam Ravnborg 2181a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2182a0215061SKees Cook this value must be a multiple of 0x200000. 2183a0215061SKees Cook 2184506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2185506f1d07SSam Ravnborg 2186eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2187eedb92abSKirill A. Shutemov bool 2188a7f7f624SMasahiro Yamada help 2189eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2190eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2191eedb92abSKirill A. Shutemov 21920483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 21930483e1faSThomas Garnier bool "Randomize the kernel memory sections" 21940483e1faSThomas Garnier depends on X86_64 21950483e1faSThomas Garnier depends on RANDOMIZE_BASE 2196eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 21970483e1faSThomas Garnier default RANDOMIZE_BASE 2198a7f7f624SMasahiro Yamada help 21990483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22000483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22010483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22020483e1faSThomas Garnier 22030483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22040483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22050483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22060483e1faSThomas Garnier addresses for each memory section. 22070483e1faSThomas Garnier 22086807c846SIngo Molnar If unsure, say Y. 22090483e1faSThomas Garnier 221090397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 221190397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 221290397a41SThomas Garnier depends on RANDOMIZE_MEMORY 221390397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 221490397a41SThomas Garnier default "0x0" 221590397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 221690397a41SThomas Garnier range 0x0 0x40 2217a7f7f624SMasahiro Yamada help 221890397a41SThomas Garnier Define the padding in terabytes added to the existing physical 221990397a41SThomas Garnier memory size during kernel memory randomization. It is useful 222090397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 222190397a41SThomas Garnier address randomization. 222290397a41SThomas Garnier 222390397a41SThomas Garnier If unsure, leave at the default value. 222490397a41SThomas Garnier 2225506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2226bebd024eSThomas Gleixner def_bool y 222740b31360SStephen Rothwell depends on SMP 2228506f1d07SSam Ravnborg 222980aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 223080aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22312c922cd0SKees Cook depends on HOTPLUG_CPU 2232a7f7f624SMasahiro Yamada help 223380aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 223480aa1dffSFenghua Yu 223580aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 223680aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 223780aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 223880aa1dffSFenghua Yu 223980aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 224080aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 224180aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 224280aa1dffSFenghua Yu 224380aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 224480aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 224580aa1dffSFenghua Yu 224680aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 224780aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 224880aa1dffSFenghua Yu be other CPU0 dependencies. 224980aa1dffSFenghua Yu 225080aa1dffSFenghua Yu Please make sure the dependencies are under your control before 225180aa1dffSFenghua Yu you enable this feature. 225280aa1dffSFenghua Yu 225380aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 225480aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 225580aa1dffSFenghua Yu parameter cpu0_hotplug. 225680aa1dffSFenghua Yu 2257a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2258a71c8bc5SFenghua Yu def_bool n 2259a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22602c922cd0SKees Cook depends on HOTPLUG_CPU 2261a7f7f624SMasahiro Yamada help 2262a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2263a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2264a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2265a71c8bc5SFenghua Yu 2266a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2267a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2268a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2269a71c8bc5SFenghua Yu 2270a71c8bc5SFenghua Yu If unsure, say N. 2271a71c8bc5SFenghua Yu 2272506f1d07SSam Ravnborgconfig COMPAT_VDSO 2273b0b49f26SAndy Lutomirski def_bool n 2274b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2275953fee1dSIngo Molnar depends on COMPAT_32 2276a7f7f624SMasahiro Yamada help 2277b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2278b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2279b0b49f26SAndy Lutomirski indicated in its segment table. 2280e84446deSRandy Dunlap 2281b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2282b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2283b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2284b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2285b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2286506f1d07SSam Ravnborg 2287b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2288b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2289b0b49f26SAndy Lutomirski 2290b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2291b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2292b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2293b0b49f26SAndy Lutomirski 2294b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2295b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2296506f1d07SSam Ravnborg 22973dc33bd3SKees Cookchoice 22983dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 22993dc33bd3SKees Cook depends on X86_64 2300625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23013dc33bd3SKees Cook help 23023dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23033dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23043dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23053dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23063dc33bd3SKees Cook 23073dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2308bd49e16eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. 23093dc33bd3SKees Cook 23103dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23113dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23123dc33bd3SKees Cook to improve security. 23133dc33bd3SKees Cook 2314bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23153dc33bd3SKees Cook 23163dc33bd3SKees Cook config LEGACY_VSYSCALL_EMULATE 2317bd49e16eSAndy Lutomirski bool "Full emulation" 23183dc33bd3SKees Cook help 2319bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2320bd49e16eSAndy Lutomirski address mapping. This makes the mapping non-executable, but 2321bd49e16eSAndy Lutomirski it still contains readable known contents, which could be 2322bd49e16eSAndy Lutomirski used in certain rare security vulnerability exploits. This 2323bd49e16eSAndy Lutomirski configuration is recommended when using legacy userspace 2324bd49e16eSAndy Lutomirski that still uses vsyscalls along with legacy binary 2325bd49e16eSAndy Lutomirski instrumentation tools that require code to be readable. 2326bd49e16eSAndy Lutomirski 2327bd49e16eSAndy Lutomirski An example of this type of legacy userspace is running 2328bd49e16eSAndy Lutomirski Pin on an old binary that still uses vsyscalls. 2329bd49e16eSAndy Lutomirski 2330bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2331bd49e16eSAndy Lutomirski bool "Emulate execution only" 2332bd49e16eSAndy Lutomirski help 2333bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2334bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2335bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2336bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2337bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2338bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2339bd49e16eSAndy Lutomirski buffer. 23403dc33bd3SKees Cook 23413dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23423dc33bd3SKees Cook bool "None" 23433dc33bd3SKees Cook help 23443dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23453dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23463dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23473dc33bd3SKees Cook will be reported to dmesg, so that either old or 23483dc33bd3SKees Cook malicious userspace programs can be identified. 23493dc33bd3SKees Cook 23503dc33bd3SKees Cookendchoice 23513dc33bd3SKees Cook 2352516cbf37STim Birdconfig CMDLINE_BOOL 2353516cbf37STim Bird bool "Built-in kernel command line" 2354a7f7f624SMasahiro Yamada help 2355516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2356516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2357516cbf37STim Bird necessary or convenient to provide some or all of the 2358516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2359516cbf37STim Bird to not rely on the boot loader to provide them.) 2360516cbf37STim Bird 2361516cbf37STim Bird To compile command line arguments into the kernel, 2362516cbf37STim Bird set this option to 'Y', then fill in the 236369711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2364516cbf37STim Bird 2365516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2366516cbf37STim Bird should leave this option set to 'N'. 2367516cbf37STim Bird 2368516cbf37STim Birdconfig CMDLINE 2369516cbf37STim Bird string "Built-in kernel command string" 2370516cbf37STim Bird depends on CMDLINE_BOOL 2371516cbf37STim Bird default "" 2372a7f7f624SMasahiro Yamada help 2373516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2374516cbf37STim Bird image and used at boot time. If the boot loader provides a 2375516cbf37STim Bird command line at boot time, it is appended to this string to 2376516cbf37STim Bird form the full kernel command line, when the system boots. 2377516cbf37STim Bird 2378516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2379516cbf37STim Bird change this behavior. 2380516cbf37STim Bird 2381516cbf37STim Bird In most cases, the command line (whether built-in or provided 2382516cbf37STim Bird by the boot loader) should specify the device for the root 2383516cbf37STim Bird file system. 2384516cbf37STim Bird 2385516cbf37STim Birdconfig CMDLINE_OVERRIDE 2386516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2387645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2388a7f7f624SMasahiro Yamada help 2389516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2390516cbf37STim Bird command line, and use ONLY the built-in command line. 2391516cbf37STim Bird 2392516cbf37STim Bird This is used to work around broken boot loaders. This should 2393516cbf37STim Bird be set to 'N' under normal conditions. 2394516cbf37STim Bird 2395a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2396a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2397a5b9e5a2SAndy Lutomirski default y 2398a7f7f624SMasahiro Yamada help 2399a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2400a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2401a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2402a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2403a5b9e5a2SAndy Lutomirski threading libraries. 2404a5b9e5a2SAndy Lutomirski 2405a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2406a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2407a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2408a5b9e5a2SAndy Lutomirski 2409a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2410a5b9e5a2SAndy Lutomirski 2411b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2412b700e7f0SSeth Jennings 2413506f1d07SSam Ravnborgendmenu 2414506f1d07SSam Ravnborg 24153072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24163072e413SMichal Hocko def_bool y 24173072e413SMichal Hocko depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 24183072e413SMichal Hocko 2419506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG 2420506f1d07SSam Ravnborg def_bool y 2421506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2422506f1d07SSam Ravnborg 242335551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE 242435551053SGary Hade def_bool y 242535551053SGary Hade depends on MEMORY_HOTPLUG 242635551053SGary Hade 2427e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID 2428645a7919STejun Heo def_bool y 2429e534c7c5SLee Schermerhorn depends on NUMA 2430e534c7c5SLee Schermerhorn 24319491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK 24329491846fSKirill A. Shutemov def_bool y 24339491846fSKirill A. Shutemov depends on X86_64 || X86_PAE 24349491846fSKirill A. Shutemov 2435c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION 2436c177c81eSNaoya Horiguchi def_bool y 2437c177c81eSNaoya Horiguchi depends on X86_64 && HUGETLB_PAGE && MIGRATION 2438c177c81eSNaoya Horiguchi 24399c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION 24409c670ea3SNaoya Horiguchi def_bool y 24419c670ea3SNaoya Horiguchi depends on X86_64 && TRANSPARENT_HUGEPAGE 24429c670ea3SNaoya Horiguchi 2443da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2444e279b6c1SSam Ravnborg 2445e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24463c2362e6SHarvey Harrison def_bool y 244744556530SZhimin Gu depends on HIBERNATION 2448e279b6c1SSam Ravnborg 2449e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2450e279b6c1SSam Ravnborg 2451e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2452e279b6c1SSam Ravnborg 2453efafc8b2SFeng Tangsource "drivers/sfi/Kconfig" 2454efafc8b2SFeng Tang 2455a6b68076SAndi Kleenconfig X86_APM_BOOT 24566fc108a0SJan Beulich def_bool y 2457282e5aabSPaul Bolle depends on APM 2458a6b68076SAndi Kleen 2459e279b6c1SSam Ravnborgmenuconfig APM 2460e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2461efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2462a7f7f624SMasahiro Yamada help 2463e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2464e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2465e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2466e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2467e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2468e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2469e279b6c1SSam Ravnborg 2470e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2471e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2472e279b6c1SSam Ravnborg 2473e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2474e279b6c1SSam Ravnborg machines with more than one CPU. 2475e279b6c1SSam Ravnborg 2476e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2477151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24782dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2479e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2480e279b6c1SSam Ravnborg 2481e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2482e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2483e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2484e279b6c1SSam Ravnborg 2485e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2486e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2487e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2488e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2489e279b6c1SSam Ravnborg 2490e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2491e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2492e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2493e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2494e279b6c1SSam Ravnborg APM in your BIOS). 2495e279b6c1SSam Ravnborg 2496e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2497e279b6c1SSam Ravnborg "weird" problems: 2498e279b6c1SSam Ravnborg 2499e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2500e279b6c1SSam Ravnborg enabled. 2501e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2502e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2503e279b6c1SSam Ravnborg the "no387" option to the kernel 2504e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2505e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2506e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2507e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2508e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2509e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2510e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2511e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2512e279b6c1SSam Ravnborg 11) exchange RAM chips 2513e279b6c1SSam Ravnborg 12) exchange the motherboard. 2514e279b6c1SSam Ravnborg 2515e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2516e279b6c1SSam Ravnborg module will be called apm. 2517e279b6c1SSam Ravnborg 2518e279b6c1SSam Ravnborgif APM 2519e279b6c1SSam Ravnborg 2520e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2521e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2522a7f7f624SMasahiro Yamada help 2523e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2524e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2525e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2526e279b6c1SSam Ravnborg 2527e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2528e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2529a7f7f624SMasahiro Yamada help 2530e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2531e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2532e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2533e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2534e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2535e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2536e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2537e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2538e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2539e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2540e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2541e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2542e279b6c1SSam Ravnborg this feature. 2543e279b6c1SSam Ravnborg 2544e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2545dd8af076SLen Brown depends on CPU_IDLE 2546e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2547a7f7f624SMasahiro Yamada help 2548e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2549e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2550e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2551e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2552e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2553e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2554e279b6c1SSam Ravnborg this option does nothing.) 2555e279b6c1SSam Ravnborg 2556e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2557e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2558a7f7f624SMasahiro Yamada help 2559e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2560e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2561e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2562e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2563e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2564e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2565e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2566e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2567e279b6c1SSam Ravnborg especially if you are using gpm. 2568e279b6c1SSam Ravnborg 2569e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2570e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2571a7f7f624SMasahiro Yamada help 2572e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2573e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2574e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2575e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2576e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2577e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2578e279b6c1SSam Ravnborg 2579e279b6c1SSam Ravnborgendif # APM 2580e279b6c1SSam Ravnborg 2581bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2582e279b6c1SSam Ravnborg 2583e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2584e279b6c1SSam Ravnborg 258527471fdbSAndy Henroidsource "drivers/idle/Kconfig" 258627471fdbSAndy Henroid 2587e279b6c1SSam Ravnborgendmenu 2588e279b6c1SSam Ravnborg 2589e279b6c1SSam Ravnborg 2590e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2591e279b6c1SSam Ravnborg 2592e279b6c1SSam Ravnborgchoice 2593e279b6c1SSam Ravnborg prompt "PCI access mode" 2594efefa6f6SIngo Molnar depends on X86_32 && PCI 2595e279b6c1SSam Ravnborg default PCI_GOANY 2596a7f7f624SMasahiro Yamada help 2597e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2598e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2599e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2600e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2601e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2602e279b6c1SSam Ravnborg 2603e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2604e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2605e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2606e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2607e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2608e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2609e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2610e279b6c1SSam Ravnborg 2611e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2612e279b6c1SSam Ravnborg bool "BIOS" 2613e279b6c1SSam Ravnborg 2614e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2615e279b6c1SSam Ravnborg bool "MMConfig" 2616e279b6c1SSam Ravnborg 2617e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2618e279b6c1SSam Ravnborg bool "Direct" 2619e279b6c1SSam Ravnborg 26203ef0e1f8SAndres Salomonconfig PCI_GOOLPC 262176fb6570SDaniel Drake bool "OLPC XO-1" 26223ef0e1f8SAndres Salomon depends on OLPC 26233ef0e1f8SAndres Salomon 26242bdd1b03SAndres Salomonconfig PCI_GOANY 26252bdd1b03SAndres Salomon bool "Any" 26262bdd1b03SAndres Salomon 2627e279b6c1SSam Ravnborgendchoice 2628e279b6c1SSam Ravnborg 2629e279b6c1SSam Ravnborgconfig PCI_BIOS 26303c2362e6SHarvey Harrison def_bool y 2631efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2632e279b6c1SSam Ravnborg 2633e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2634e279b6c1SSam Ravnborgconfig PCI_DIRECT 26353c2362e6SHarvey Harrison def_bool y 26360aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2637e279b6c1SSam Ravnborg 2638e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2639b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2640b45c9f36SJan Kiszka default y 26418364e1f8SJan Kiszka depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2642b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2643e279b6c1SSam Ravnborg 26443ef0e1f8SAndres Salomonconfig PCI_OLPC 26452bdd1b03SAndres Salomon def_bool y 26462bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26473ef0e1f8SAndres Salomon 2648b5401a96SAlex Nixonconfig PCI_XEN 2649b5401a96SAlex Nixon def_bool y 2650b5401a96SAlex Nixon depends on PCI && XEN 2651b5401a96SAlex Nixon select SWIOTLB_XEN 2652b5401a96SAlex Nixon 26538364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26548364e1f8SJan Kiszka def_bool y 26558364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2656e279b6c1SSam Ravnborg 26573f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26586a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26596ea30386SKees Cook depends on PCI 26603f6ea84aSIra W. Snyder help 26613f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26623f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26633f6ea84aSIra W. Snyder not have ACPI. 26643f6ea84aSIra W. Snyder 266564a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 266664a5fed6SBjorn Helgaas is known to be incomplete. 266764a5fed6SBjorn Helgaas 266864a5fed6SBjorn Helgaas You should say N unless you know you need this. 266964a5fed6SBjorn Helgaas 26703a495511SWilliam Breathitt Grayconfig ISA_BUS 267117a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26723a495511SWilliam Breathitt Gray help 267317a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 267417a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 267517a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 267617a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 267717a2a129SWilliam Breathitt Gray not have an ISA bus. 26783a495511SWilliam Breathitt Gray 26793a495511SWilliam Breathitt Gray If unsure, say N. 26803a495511SWilliam Breathitt Gray 26811c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2682e279b6c1SSam Ravnborgconfig ISA_DMA_API 26831c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 26841c00f016SDavid Rientjes default y 26851c00f016SDavid Rientjes help 26861c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 26871c00f016SDavid Rientjes If unsure, say Y. 2688e279b6c1SSam Ravnborg 268951e68d05SLinus Torvaldsif X86_32 269051e68d05SLinus Torvalds 2691e279b6c1SSam Ravnborgconfig ISA 2692e279b6c1SSam Ravnborg bool "ISA support" 2693a7f7f624SMasahiro Yamada help 2694e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2695e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2696e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2697e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2698e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2699e279b6c1SSam Ravnborg 2700e279b6c1SSam Ravnborgconfig SCx200 2701e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2702a7f7f624SMasahiro Yamada help 2703e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2704e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2705e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2706e279b6c1SSam Ravnborg for other scx200_* drivers. 2707e279b6c1SSam Ravnborg 2708e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2709e279b6c1SSam Ravnborg 2710e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2711e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2712592913ecSJohn Stultz depends on SCx200 2713e279b6c1SSam Ravnborg default y 2714a7f7f624SMasahiro Yamada help 2715e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2716e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2717e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2718e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2719e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2720e279b6c1SSam Ravnborg 27213ef0e1f8SAndres Salomonconfig OLPC 27223ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 272354008979SThomas Gleixner depends on !X86_PAE 27243c554946SAndres Salomon select GPIOLIB 2725dc3119e7SThomas Gleixner select OF 272645bb1674SDaniel Drake select OF_PROMTREE 2727b4e51854SGrant Likely select IRQ_DOMAIN 27280c3d931bSLubomir Rintel select OLPC_EC 2729a7f7f624SMasahiro Yamada help 27303ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27313ef0e1f8SAndres Salomon XO hardware. 27323ef0e1f8SAndres Salomon 2733a3128588SDaniel Drakeconfig OLPC_XO1_PM 2734a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2735fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2736a7f7f624SMasahiro Yamada help 273797c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2738bf1ebf00SDaniel Drake 2739cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2740cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2741cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2742a7f7f624SMasahiro Yamada help 2743cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2744cfee9597SDaniel Drake programmable wakeup source. 2745cfee9597SDaniel Drake 27467feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27477feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 274892e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2749ed8e47feSRandy Dunlap depends on INPUT=y 2750d8d01a63SDaniel Drake select POWER_SUPPLY 2751a7f7f624SMasahiro Yamada help 27527feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27537bc74b3dSDaniel Drake - EC-driven system wakeups 27547feda8e9SDaniel Drake - Power button 27557bc74b3dSDaniel Drake - Ebook switch 27562cf2baeaSDaniel Drake - Lid switch 2757e1040ac6SDaniel Drake - AC adapter status updates 2758e1040ac6SDaniel Drake - Battery status updates 27597feda8e9SDaniel Drake 2760a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2761a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2762d8d01a63SDaniel Drake depends on OLPC && ACPI 2763d8d01a63SDaniel Drake select POWER_SUPPLY 2764a7f7f624SMasahiro Yamada help 2765a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2766a0f30f59SDaniel Drake - EC-driven system wakeups 2767a0f30f59SDaniel Drake - AC adapter status updates 2768a0f30f59SDaniel Drake - Battery status updates 2769e279b6c1SSam Ravnborg 2770d4f3e350SEd Wildgooseconfig ALIX 2771d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2772d4f3e350SEd Wildgoose select GPIOLIB 2773a7f7f624SMasahiro Yamada help 2774d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2775d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2776d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2777d4f3e350SEd Wildgoose get added here. 2778d4f3e350SEd Wildgoose 2779d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2780d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2781d4f3e350SEd Wildgoose 2782d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2783d4f3e350SEd Wildgoose 2784da4e3302SPhilip Prindevilleconfig NET5501 2785da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2786da4e3302SPhilip Prindeville select GPIOLIB 2787a7f7f624SMasahiro Yamada help 2788da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2789da4e3302SPhilip Prindeville 27903197059aSPhilip A. Prindevilleconfig GEOS 27913197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 27923197059aSPhilip A. Prindeville select GPIOLIB 27933197059aSPhilip A. Prindeville depends on DMI 2794a7f7f624SMasahiro Yamada help 27953197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 27963197059aSPhilip A. Prindeville 27977d029125SVivien Didelotconfig TS5500 27987d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 27997d029125SVivien Didelot depends on MELAN 28007d029125SVivien Didelot select CHECK_SIGNATURE 28017d029125SVivien Didelot select NEW_LEDS 28027d029125SVivien Didelot select LEDS_CLASS 2803a7f7f624SMasahiro Yamada help 28047d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 28057d029125SVivien Didelot 2806e279b6c1SSam Ravnborgendif # X86_32 2807e279b6c1SSam Ravnborg 280823ac4ae8SAndreas Herrmannconfig AMD_NB 2809e279b6c1SSam Ravnborg def_bool y 28100e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2811e279b6c1SSam Ravnborg 2812e3263ab3SDavid Herrmannconfig X86_SYSFB 2813e3263ab3SDavid Herrmann bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2814e3263ab3SDavid Herrmann help 2815e3263ab3SDavid Herrmann Firmwares often provide initial graphics framebuffers so the BIOS, 2816e3263ab3SDavid Herrmann bootloader or kernel can show basic video-output during boot for 2817e3263ab3SDavid Herrmann user-guidance and debugging. Historically, x86 used the VESA BIOS 2818e3263ab3SDavid Herrmann Extensions and EFI-framebuffers for this, which are mostly limited 2819e3263ab3SDavid Herrmann to x86. 2820e3263ab3SDavid Herrmann This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2821e3263ab3SDavid Herrmann framebuffers so the new generic system-framebuffer drivers can be 2822e3263ab3SDavid Herrmann used on x86. If the framebuffer is not compatible with the generic 2823e3a5dc08SNikolas Nyby modes, it is advertised as fallback platform framebuffer so legacy 2824e3263ab3SDavid Herrmann drivers like efifb, vesafb and uvesafb can pick it up. 2825e3263ab3SDavid Herrmann If this option is not selected, all system framebuffers are always 2826e3263ab3SDavid Herrmann marked as fallback platform framebuffers as usual. 2827e3263ab3SDavid Herrmann 2828e3263ab3SDavid Herrmann Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2829e3263ab3SDavid Herrmann not be able to pick up generic system framebuffers if this option 2830e3263ab3SDavid Herrmann is selected. You are highly encouraged to enable simplefb as 2831e3263ab3SDavid Herrmann replacement if you select this option. simplefb can correctly deal 2832e3263ab3SDavid Herrmann with generic system framebuffers. But you should still keep vesafb 2833e3263ab3SDavid Herrmann and others enabled as fallback if a system framebuffer is 2834e3263ab3SDavid Herrmann incompatible with simplefb. 2835e3263ab3SDavid Herrmann 2836e3263ab3SDavid Herrmann If unsure, say Y. 2837e3263ab3SDavid Herrmann 2838e279b6c1SSam Ravnborgendmenu 2839e279b6c1SSam Ravnborg 2840e279b6c1SSam Ravnborg 28411572497cSChristoph Hellwigmenu "Binary Emulations" 2842e279b6c1SSam Ravnborg 2843e279b6c1SSam Ravnborgconfig IA32_EMULATION 2844e279b6c1SSam Ravnborg bool "IA32 Emulation" 2845e279b6c1SSam Ravnborg depends on X86_64 284639f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2847d1603990SRandy Dunlap select BINFMT_ELF 2848a97f52e6SRoland McGrath select COMPAT_BINFMT_ELF 284939f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2850a7f7f624SMasahiro Yamada help 28515fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28525fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28535fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2854e279b6c1SSam Ravnborg 2855e279b6c1SSam Ravnborgconfig IA32_AOUT 2856e279b6c1SSam Ravnborg tristate "IA32 a.out support" 28576b213e1bSDavid Woodhouse depends on IA32_EMULATION 2858eac61655SBorislav Petkov depends on BROKEN 2859a7f7f624SMasahiro Yamada help 2860e279b6c1SSam Ravnborg Support old a.out binaries in the 32bit emulation. 2861e279b6c1SSam Ravnborg 28620bf62763SH. Peter Anvinconfig X86_X32 28636ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28649b54050bSBrian Gerst depends on X86_64 2865a7f7f624SMasahiro Yamada help 28665fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28675fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28685fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28695fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28705fd92e65SH. J. Lu 28715fd92e65SH. J. Lu You will need a recent binutils (2.22 or later) with 28725fd92e65SH. J. Lu elf32_x86_64 support enabled to compile a kernel with this 28735fd92e65SH. J. Lu option set. 28745fd92e65SH. J. Lu 2875953fee1dSIngo Molnarconfig COMPAT_32 2876953fee1dSIngo Molnar def_bool y 2877953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2878953fee1dSIngo Molnar select HAVE_UID16 2879953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2880953fee1dSIngo Molnar 2881e279b6c1SSam Ravnborgconfig COMPAT 28823c2362e6SHarvey Harrison def_bool y 28830bf62763SH. Peter Anvin depends on IA32_EMULATION || X86_X32 2884e279b6c1SSam Ravnborg 28853120e25eSJan Beulichif COMPAT 2886e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28873120e25eSJan Beulich def_bool y 2888e279b6c1SSam Ravnborg 2889e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT 28903c2362e6SHarvey Harrison def_bool y 28913120e25eSJan Beulich depends on SYSVIPC 28923120e25eSJan Beulichendif 2893ee009e4aSDavid Howells 2894e279b6c1SSam Ravnborgendmenu 2895e279b6c1SSam Ravnborg 2896e279b6c1SSam Ravnborg 2897e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2898e5beae16SKeith Packard def_bool y 2899e5beae16SKeith Packard depends on X86_32 2900e5beae16SKeith Packard 2901e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig" 2902e279b6c1SSam Ravnborg 2903edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 29045e8ebd84SJason A. Donenfeld 29055e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2906