Kconfig 90 KB

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  1. # Select 32 or 64 bit
  2. config 64BIT
  3. bool "64-bit kernel" if ARCH = "x86"
  4. default ARCH != "i386"
  5. ---help---
  6. Say yes to build a 64-bit kernel - formerly known as x86_64
  7. Say no to build a 32-bit kernel - formerly known as i386
  8. config X86_32
  9. def_bool y
  10. depends on !64BIT
  11. # Options that are inherently 32-bit kernel only:
  12. select ARCH_WANT_IPC_PARSE_VERSION
  13. select CLKSRC_I8253
  14. select CLONE_BACKWARDS
  15. select HAVE_AOUT
  16. select HAVE_GENERIC_DMA_COHERENT
  17. select MODULES_USE_ELF_REL
  18. select OLD_SIGACTION
  19. config X86_64
  20. def_bool y
  21. depends on 64BIT
  22. # Options that are inherently 64-bit kernel only:
  23. select ARCH_HAS_GIGANTIC_PAGE
  24. select ARCH_SUPPORTS_INT128
  25. select ARCH_USE_CMPXCHG_LOCKREF
  26. select HAVE_ARCH_SOFT_DIRTY
  27. select MODULES_USE_ELF_RELA
  28. select X86_DEV_DMA_OPS
  29. #
  30. # Arch settings
  31. #
  32. # ( Note that options that are marked 'if X86_64' could in principle be
  33. # ported to 32-bit as well. )
  34. #
  35. config X86
  36. def_bool y
  37. #
  38. # Note: keep this list sorted alphabetically
  39. #
  40. select ACPI_LEGACY_TABLES_LOOKUP if ACPI
  41. select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
  42. select ANON_INODES
  43. select ARCH_CLOCKSOURCE_DATA
  44. select ARCH_DISCARD_MEMBLOCK
  45. select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
  46. select ARCH_HAS_DEBUG_VIRTUAL
  47. select ARCH_HAS_DEVMEM_IS_ALLOWED
  48. select ARCH_HAS_ELF_RANDOMIZE
  49. select ARCH_HAS_FAST_MULTIPLIER
  50. select ARCH_HAS_GCOV_PROFILE_ALL
  51. select ARCH_HAS_KCOV if X86_64
  52. select ARCH_HAS_MMIO_FLUSH
  53. select ARCH_HAS_PMEM_API if X86_64
  54. select ARCH_HAS_SET_MEMORY
  55. select ARCH_HAS_SG_CHAIN
  56. select ARCH_HAS_STRICT_KERNEL_RWX
  57. select ARCH_HAS_STRICT_MODULE_RWX
  58. select ARCH_HAS_UBSAN_SANITIZE_ALL
  59. select ARCH_HAVE_NMI_SAFE_CMPXCHG
  60. select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
  61. select ARCH_MIGHT_HAVE_PC_PARPORT
  62. select ARCH_MIGHT_HAVE_PC_SERIO
  63. select ARCH_SUPPORTS_ATOMIC_RMW
  64. select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
  65. select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
  66. select ARCH_USE_BUILTIN_BSWAP
  67. select ARCH_USE_QUEUED_RWLOCKS
  68. select ARCH_USE_QUEUED_SPINLOCKS
  69. select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
  70. select ARCH_WANT_FRAME_POINTERS
  71. select ARCH_WANTS_DYNAMIC_TASK_STRUCT
  72. select BUILDTIME_EXTABLE_SORT
  73. select CLKEVT_I8253
  74. select CLOCKSOURCE_VALIDATE_LAST_CYCLE
  75. select CLOCKSOURCE_WATCHDOG
  76. select DCACHE_WORD_ACCESS
  77. select EDAC_ATOMIC_SCRUB
  78. select EDAC_SUPPORT
  79. select GENERIC_CLOCKEVENTS
  80. select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
  81. select GENERIC_CLOCKEVENTS_MIN_ADJUST
  82. select GENERIC_CMOS_UPDATE
  83. select GENERIC_CPU_AUTOPROBE
  84. select GENERIC_EARLY_IOREMAP
  85. select GENERIC_FIND_FIRST_BIT
  86. select GENERIC_IOMAP
  87. select GENERIC_IRQ_PROBE
  88. select GENERIC_IRQ_SHOW
  89. select GENERIC_PENDING_IRQ if SMP
  90. select GENERIC_SMP_IDLE_THREAD
  91. select GENERIC_STRNCPY_FROM_USER
  92. select GENERIC_STRNLEN_USER
  93. select GENERIC_TIME_VSYSCALL
  94. select HAVE_ACPI_APEI if ACPI
  95. select HAVE_ACPI_APEI_NMI if ACPI
  96. select HAVE_ALIGNED_STRUCT_PAGE if SLUB
  97. select HAVE_ARCH_AUDITSYSCALL
  98. select HAVE_ARCH_HARDENED_USERCOPY
  99. select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
  100. select HAVE_ARCH_JUMP_LABEL
  101. select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
  102. select HAVE_ARCH_KGDB
  103. select HAVE_ARCH_KMEMCHECK
  104. select HAVE_ARCH_MMAP_RND_BITS if MMU
  105. select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
  106. select HAVE_ARCH_SECCOMP_FILTER
  107. select HAVE_ARCH_TRACEHOOK
  108. select HAVE_ARCH_TRANSPARENT_HUGEPAGE
  109. select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
  110. select HAVE_ARCH_VMAP_STACK if X86_64
  111. select HAVE_ARCH_WITHIN_STACK_FRAMES
  112. select HAVE_CC_STACKPROTECTOR
  113. select HAVE_CMPXCHG_DOUBLE
  114. select HAVE_CMPXCHG_LOCAL
  115. select HAVE_CONTEXT_TRACKING if X86_64
  116. select HAVE_COPY_THREAD_TLS
  117. select HAVE_C_RECORDMCOUNT
  118. select HAVE_DEBUG_KMEMLEAK
  119. select HAVE_DEBUG_STACKOVERFLOW
  120. select HAVE_DMA_API_DEBUG
  121. select HAVE_DMA_CONTIGUOUS
  122. select HAVE_DYNAMIC_FTRACE
  123. select HAVE_DYNAMIC_FTRACE_WITH_REGS
  124. select HAVE_EBPF_JIT if X86_64
  125. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  126. select HAVE_EXIT_THREAD
  127. select HAVE_FENTRY if X86_64
  128. select HAVE_FTRACE_MCOUNT_RECORD
  129. select HAVE_FUNCTION_GRAPH_TRACER
  130. select HAVE_FUNCTION_TRACER
  131. select HAVE_GCC_PLUGINS
  132. select HAVE_HW_BREAKPOINT
  133. select HAVE_IDE
  134. select HAVE_IOREMAP_PROT
  135. select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
  136. select HAVE_IRQ_TIME_ACCOUNTING
  137. select HAVE_KERNEL_BZIP2
  138. select HAVE_KERNEL_GZIP
  139. select HAVE_KERNEL_LZ4
  140. select HAVE_KERNEL_LZMA
  141. select HAVE_KERNEL_LZO
  142. select HAVE_KERNEL_XZ
  143. select HAVE_KPROBES
  144. select HAVE_KPROBES_ON_FTRACE
  145. select HAVE_KRETPROBES
  146. select HAVE_KVM
  147. select HAVE_LIVEPATCH if X86_64
  148. select HAVE_MEMBLOCK
  149. select HAVE_MEMBLOCK_NODE_MAP
  150. select HAVE_MIXED_BREAKPOINTS_REGS
  151. select HAVE_NMI
  152. select HAVE_OPROFILE
  153. select HAVE_OPTPROBES
  154. select HAVE_PCSPKR_PLATFORM
  155. select HAVE_PERF_EVENTS
  156. select HAVE_PERF_EVENTS_NMI
  157. select HAVE_PERF_REGS
  158. select HAVE_PERF_USER_STACK_DUMP
  159. select HAVE_REGS_AND_STACK_ACCESS_API
  160. select HAVE_STACK_VALIDATION if X86_64
  161. select HAVE_SYSCALL_TRACEPOINTS
  162. select HAVE_UNSTABLE_SCHED_CLOCK
  163. select HAVE_USER_RETURN_NOTIFIER
  164. select IRQ_FORCED_THREADING
  165. select PERF_EVENTS
  166. select RTC_LIB
  167. select RTC_MC146818_LIB
  168. select SPARSE_IRQ
  169. select SRCU
  170. select SYSCTL_EXCEPTION_TRACE
  171. select THREAD_INFO_IN_TASK
  172. select USER_STACKTRACE_SUPPORT
  173. select VIRT_TO_BUS
  174. select X86_FEATURE_NAMES if PROC_FS
  175. config INSTRUCTION_DECODER
  176. def_bool y
  177. depends on KPROBES || PERF_EVENTS || UPROBES
  178. config OUTPUT_FORMAT
  179. string
  180. default "elf32-i386" if X86_32
  181. default "elf64-x86-64" if X86_64
  182. config ARCH_DEFCONFIG
  183. string
  184. default "arch/x86/configs/i386_defconfig" if X86_32
  185. default "arch/x86/configs/x86_64_defconfig" if X86_64
  186. config LOCKDEP_SUPPORT
  187. def_bool y
  188. config STACKTRACE_SUPPORT
  189. def_bool y
  190. config MMU
  191. def_bool y
  192. config ARCH_MMAP_RND_BITS_MIN
  193. default 28 if 64BIT
  194. default 8
  195. config ARCH_MMAP_RND_BITS_MAX
  196. default 32 if 64BIT
  197. default 16
  198. config ARCH_MMAP_RND_COMPAT_BITS_MIN
  199. default 8
  200. config ARCH_MMAP_RND_COMPAT_BITS_MAX
  201. default 16
  202. config SBUS
  203. bool
  204. config NEED_DMA_MAP_STATE
  205. def_bool y
  206. depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
  207. config NEED_SG_DMA_LENGTH
  208. def_bool y
  209. config GENERIC_ISA_DMA
  210. def_bool y
  211. depends on ISA_DMA_API
  212. config GENERIC_BUG
  213. def_bool y
  214. depends on BUG
  215. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  216. config GENERIC_BUG_RELATIVE_POINTERS
  217. bool
  218. config GENERIC_HWEIGHT
  219. def_bool y
  220. config ARCH_MAY_HAVE_PC_FDC
  221. def_bool y
  222. depends on ISA_DMA_API
  223. config RWSEM_XCHGADD_ALGORITHM
  224. def_bool y
  225. config GENERIC_CALIBRATE_DELAY
  226. def_bool y
  227. config ARCH_HAS_CPU_RELAX
  228. def_bool y
  229. config ARCH_HAS_CACHE_LINE_SIZE
  230. def_bool y
  231. config HAVE_SETUP_PER_CPU_AREA
  232. def_bool y
  233. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  234. def_bool y
  235. config NEED_PER_CPU_PAGE_FIRST_CHUNK
  236. def_bool y
  237. config ARCH_HIBERNATION_POSSIBLE
  238. def_bool y
  239. config ARCH_SUSPEND_POSSIBLE
  240. def_bool y
  241. config ARCH_WANT_HUGE_PMD_SHARE
  242. def_bool y
  243. config ARCH_WANT_GENERAL_HUGETLB
  244. def_bool y
  245. config ZONE_DMA32
  246. def_bool y if X86_64
  247. config AUDIT_ARCH
  248. def_bool y if X86_64
  249. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  250. def_bool y
  251. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  252. def_bool y
  253. config KASAN_SHADOW_OFFSET
  254. hex
  255. depends on KASAN
  256. default 0xdffffc0000000000
  257. config HAVE_INTEL_TXT
  258. def_bool y
  259. depends on INTEL_IOMMU && ACPI
  260. config X86_32_SMP
  261. def_bool y
  262. depends on X86_32 && SMP
  263. config X86_64_SMP
  264. def_bool y
  265. depends on X86_64 && SMP
  266. config X86_32_LAZY_GS
  267. def_bool y
  268. depends on X86_32 && !CC_STACKPROTECTOR
  269. config ARCH_SUPPORTS_UPROBES
  270. def_bool y
  271. config FIX_EARLYCON_MEM
  272. def_bool y
  273. config PGTABLE_LEVELS
  274. int
  275. default 4 if X86_64
  276. default 3 if X86_PAE
  277. default 2
  278. source "init/Kconfig"
  279. source "kernel/Kconfig.freezer"
  280. menu "Processor type and features"
  281. config ZONE_DMA
  282. bool "DMA memory allocation support" if EXPERT
  283. default y
  284. help
  285. DMA memory allocation support allows devices with less than 32-bit
  286. addressing to allocate within the first 16MB of address space.
  287. Disable if no such devices will be used.
  288. If unsure, say Y.
  289. config SMP
  290. bool "Symmetric multi-processing support"
  291. ---help---
  292. This enables support for systems with more than one CPU. If you have
  293. a system with only one CPU, say N. If you have a system with more
  294. than one CPU, say Y.
  295. If you say N here, the kernel will run on uni- and multiprocessor
  296. machines, but will use only one CPU of a multiprocessor machine. If
  297. you say Y here, the kernel will run on many, but not all,
  298. uniprocessor machines. On a uniprocessor machine, the kernel
  299. will run faster if you say N here.
  300. Note that if you say Y here and choose architecture "586" or
  301. "Pentium" under "Processor family", the kernel will not work on 486
  302. architectures. Similarly, multiprocessor kernels for the "PPro"
  303. architecture may not work on all Pentium based boards.
  304. People using multiprocessor machines who say Y here should also say
  305. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  306. Management" code will be disabled if you say Y here.
  307. See also <file:Documentation/x86/i386/IO-APIC.txt>,
  308. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  309. <http://www.tldp.org/docs.html#howto>.
  310. If you don't know what to do here, say N.
  311. config X86_FEATURE_NAMES
  312. bool "Processor feature human-readable names" if EMBEDDED
  313. default y
  314. ---help---
  315. This option compiles in a table of x86 feature bits and corresponding
  316. names. This is required to support /proc/cpuinfo and a few kernel
  317. messages. You can disable this to save space, at the expense of
  318. making those few kernel messages show numeric feature bits instead.
  319. If in doubt, say Y.
  320. config X86_FAST_FEATURE_TESTS
  321. bool "Fast CPU feature tests" if EMBEDDED
  322. default y
  323. ---help---
  324. Some fast-paths in the kernel depend on the capabilities of the CPU.
  325. Say Y here for the kernel to patch in the appropriate code at runtime
  326. based on the capabilities of the CPU. The infrastructure for patching
  327. code at runtime takes up some additional space; space-constrained
  328. embedded systems may wish to say N here to produce smaller, slightly
  329. slower code.
  330. config X86_X2APIC
  331. bool "Support x2apic"
  332. depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
  333. ---help---
  334. This enables x2apic support on CPUs that have this feature.
  335. This allows 32-bit apic IDs (so it can support very large systems),
  336. and accesses the local apic via MSRs not via mmio.
  337. If you don't know what to do here, say N.
  338. config X86_MPPARSE
  339. bool "Enable MPS table" if ACPI || SFI
  340. default y
  341. depends on X86_LOCAL_APIC
  342. ---help---
  343. For old smp systems that do not have proper acpi support. Newer systems
  344. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  345. config X86_BIGSMP
  346. bool "Support for big SMP systems with more than 8 CPUs"
  347. depends on X86_32 && SMP
  348. ---help---
  349. This option is needed for the systems that have more than 8 CPUs
  350. config GOLDFISH
  351. def_bool y
  352. depends on X86_GOLDFISH
  353. config INTEL_RDT_A
  354. bool "Intel Resource Director Technology Allocation support"
  355. default n
  356. depends on X86 && CPU_SUP_INTEL
  357. select KERNFS
  358. help
  359. Select to enable resource allocation which is a sub-feature of
  360. Intel Resource Director Technology(RDT). More information about
  361. RDT can be found in the Intel x86 Architecture Software
  362. Developer Manual.
  363. Say N if unsure.
  364. if X86_32
  365. config X86_EXTENDED_PLATFORM
  366. bool "Support for extended (non-PC) x86 platforms"
  367. default y
  368. ---help---
  369. If you disable this option then the kernel will only support
  370. standard PC platforms. (which covers the vast majority of
  371. systems out there.)
  372. If you enable this option then you'll be able to select support
  373. for the following (non-PC) 32 bit x86 platforms:
  374. Goldfish (Android emulator)
  375. AMD Elan
  376. RDC R-321x SoC
  377. SGI 320/540 (Visual Workstation)
  378. STA2X11-based (e.g. Northville)
  379. Moorestown MID devices
  380. If you have one of these systems, or if you want to build a
  381. generic distribution kernel, say Y here - otherwise say N.
  382. endif
  383. if X86_64
  384. config X86_EXTENDED_PLATFORM
  385. bool "Support for extended (non-PC) x86 platforms"
  386. default y
  387. ---help---
  388. If you disable this option then the kernel will only support
  389. standard PC platforms. (which covers the vast majority of
  390. systems out there.)
  391. If you enable this option then you'll be able to select support
  392. for the following (non-PC) 64 bit x86 platforms:
  393. Numascale NumaChip
  394. ScaleMP vSMP
  395. SGI Ultraviolet
  396. If you have one of these systems, or if you want to build a
  397. generic distribution kernel, say Y here - otherwise say N.
  398. endif
  399. # This is an alphabetically sorted list of 64 bit extended platforms
  400. # Please maintain the alphabetic order if and when there are additions
  401. config X86_NUMACHIP
  402. bool "Numascale NumaChip"
  403. depends on X86_64
  404. depends on X86_EXTENDED_PLATFORM
  405. depends on NUMA
  406. depends on SMP
  407. depends on X86_X2APIC
  408. depends on PCI_MMCONFIG
  409. ---help---
  410. Adds support for Numascale NumaChip large-SMP systems. Needed to
  411. enable more than ~168 cores.
  412. If you don't have one of these, you should say N here.
  413. config X86_VSMP
  414. bool "ScaleMP vSMP"
  415. select HYPERVISOR_GUEST
  416. select PARAVIRT
  417. depends on X86_64 && PCI
  418. depends on X86_EXTENDED_PLATFORM
  419. depends on SMP
  420. ---help---
  421. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  422. supposed to run on these EM64T-based machines. Only choose this option
  423. if you have one of these machines.
  424. config X86_UV
  425. bool "SGI Ultraviolet"
  426. depends on X86_64
  427. depends on X86_EXTENDED_PLATFORM
  428. depends on NUMA
  429. depends on EFI
  430. depends on X86_X2APIC
  431. depends on PCI
  432. ---help---
  433. This option is needed in order to support SGI Ultraviolet systems.
  434. If you don't have one of these, you should say N here.
  435. # Following is an alphabetically sorted list of 32 bit extended platforms
  436. # Please maintain the alphabetic order if and when there are additions
  437. config X86_GOLDFISH
  438. bool "Goldfish (Virtual Platform)"
  439. depends on X86_EXTENDED_PLATFORM
  440. ---help---
  441. Enable support for the Goldfish virtual platform used primarily
  442. for Android development. Unless you are building for the Android
  443. Goldfish emulator say N here.
  444. config X86_INTEL_CE
  445. bool "CE4100 TV platform"
  446. depends on PCI
  447. depends on PCI_GODIRECT
  448. depends on X86_IO_APIC
  449. depends on X86_32
  450. depends on X86_EXTENDED_PLATFORM
  451. select X86_REBOOTFIXUPS
  452. select OF
  453. select OF_EARLY_FLATTREE
  454. ---help---
  455. Select for the Intel CE media processor (CE4100) SOC.
  456. This option compiles in support for the CE4100 SOC for settop
  457. boxes and media devices.
  458. config X86_INTEL_MID
  459. bool "Intel MID platform support"
  460. depends on X86_EXTENDED_PLATFORM
  461. depends on X86_PLATFORM_DEVICES
  462. depends on PCI
  463. depends on X86_64 || (PCI_GOANY && X86_32)
  464. depends on X86_IO_APIC
  465. select SFI
  466. select I2C
  467. select DW_APB_TIMER
  468. select APB_TIMER
  469. select INTEL_SCU_IPC
  470. select MFD_INTEL_MSIC
  471. ---help---
  472. Select to build a kernel capable of supporting Intel MID (Mobile
  473. Internet Device) platform systems which do not have the PCI legacy
  474. interfaces. If you are building for a PC class system say N here.
  475. Intel MID platforms are based on an Intel processor and chipset which
  476. consume less power than most of the x86 derivatives.
  477. config X86_INTEL_QUARK
  478. bool "Intel Quark platform support"
  479. depends on X86_32
  480. depends on X86_EXTENDED_PLATFORM
  481. depends on X86_PLATFORM_DEVICES
  482. depends on X86_TSC
  483. depends on PCI
  484. depends on PCI_GOANY
  485. depends on X86_IO_APIC
  486. select IOSF_MBI
  487. select INTEL_IMR
  488. select COMMON_CLK
  489. ---help---
  490. Select to include support for Quark X1000 SoC.
  491. Say Y here if you have a Quark based system such as the Arduino
  492. compatible Intel Galileo.
  493. config X86_INTEL_LPSS
  494. bool "Intel Low Power Subsystem Support"
  495. depends on X86 && ACPI
  496. select COMMON_CLK
  497. select PINCTRL
  498. select IOSF_MBI
  499. ---help---
  500. Select to build support for Intel Low Power Subsystem such as
  501. found on Intel Lynxpoint PCH. Selecting this option enables
  502. things like clock tree (common clock framework) and pincontrol
  503. which are needed by the LPSS peripheral drivers.
  504. config X86_AMD_PLATFORM_DEVICE
  505. bool "AMD ACPI2Platform devices support"
  506. depends on ACPI
  507. select COMMON_CLK
  508. select PINCTRL
  509. ---help---
  510. Select to interpret AMD specific ACPI device to platform device
  511. such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
  512. I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
  513. implemented under PINCTRL subsystem.
  514. config IOSF_MBI
  515. tristate "Intel SoC IOSF Sideband support for SoC platforms"
  516. depends on PCI
  517. ---help---
  518. This option enables sideband register access support for Intel SoC
  519. platforms. On these platforms the IOSF sideband is used in lieu of
  520. MSR's for some register accesses, mostly but not limited to thermal
  521. and power. Drivers may query the availability of this device to
  522. determine if they need the sideband in order to work on these
  523. platforms. The sideband is available on the following SoC products.
  524. This list is not meant to be exclusive.
  525. - BayTrail
  526. - Braswell
  527. - Quark
  528. You should say Y if you are running a kernel on one of these SoC's.
  529. config IOSF_MBI_DEBUG
  530. bool "Enable IOSF sideband access through debugfs"
  531. depends on IOSF_MBI && DEBUG_FS
  532. ---help---
  533. Select this option to expose the IOSF sideband access registers (MCR,
  534. MDR, MCRX) through debugfs to write and read register information from
  535. different units on the SoC. This is most useful for obtaining device
  536. state information for debug and analysis. As this is a general access
  537. mechanism, users of this option would have specific knowledge of the
  538. device they want to access.
  539. If you don't require the option or are in doubt, say N.
  540. config X86_RDC321X
  541. bool "RDC R-321x SoC"
  542. depends on X86_32
  543. depends on X86_EXTENDED_PLATFORM
  544. select M486
  545. select X86_REBOOTFIXUPS
  546. ---help---
  547. This option is needed for RDC R-321x system-on-chip, also known
  548. as R-8610-(G).
  549. If you don't have one of these chips, you should say N here.
  550. config X86_32_NON_STANDARD
  551. bool "Support non-standard 32-bit SMP architectures"
  552. depends on X86_32 && SMP
  553. depends on X86_EXTENDED_PLATFORM
  554. ---help---
  555. This option compiles in the bigsmp and STA2X11 default
  556. subarchitectures. It is intended for a generic binary
  557. kernel. If you select them all, kernel will probe it one by
  558. one and will fallback to default.
  559. # Alphabetically sorted list of Non standard 32 bit platforms
  560. config X86_SUPPORTS_MEMORY_FAILURE
  561. def_bool y
  562. # MCE code calls memory_failure():
  563. depends on X86_MCE
  564. # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
  565. # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
  566. depends on X86_64 || !SPARSEMEM
  567. select ARCH_SUPPORTS_MEMORY_FAILURE
  568. config STA2X11
  569. bool "STA2X11 Companion Chip Support"
  570. depends on X86_32_NON_STANDARD && PCI
  571. select X86_DEV_DMA_OPS
  572. select X86_DMA_REMAP
  573. select SWIOTLB
  574. select MFD_STA2X11
  575. select GPIOLIB
  576. default n
  577. ---help---
  578. This adds support for boards based on the STA2X11 IO-Hub,
  579. a.k.a. "ConneXt". The chip is used in place of the standard
  580. PC chipset, so all "standard" peripherals are missing. If this
  581. option is selected the kernel will still be able to boot on
  582. standard PC machines.
  583. config X86_32_IRIS
  584. tristate "Eurobraille/Iris poweroff module"
  585. depends on X86_32
  586. ---help---
  587. The Iris machines from EuroBraille do not have APM or ACPI support
  588. to shut themselves down properly. A special I/O sequence is
  589. needed to do so, which is what this module does at
  590. kernel shutdown.
  591. This is only for Iris machines from EuroBraille.
  592. If unused, say N.
  593. config SCHED_OMIT_FRAME_POINTER
  594. def_bool y
  595. prompt "Single-depth WCHAN output"
  596. depends on X86
  597. ---help---
  598. Calculate simpler /proc/<PID>/wchan values. If this option
  599. is disabled then wchan values will recurse back to the
  600. caller function. This provides more accurate wchan values,
  601. at the expense of slightly more scheduling overhead.
  602. If in doubt, say "Y".
  603. menuconfig HYPERVISOR_GUEST
  604. bool "Linux guest support"
  605. ---help---
  606. Say Y here to enable options for running Linux under various hyper-
  607. visors. This option enables basic hypervisor detection and platform
  608. setup.
  609. If you say N, all options in this submenu will be skipped and
  610. disabled, and Linux guest support won't be built in.
  611. if HYPERVISOR_GUEST
  612. config PARAVIRT
  613. bool "Enable paravirtualization code"
  614. ---help---
  615. This changes the kernel so it can modify itself when it is run
  616. under a hypervisor, potentially improving performance significantly
  617. over full virtualization. However, when run without a hypervisor
  618. the kernel is theoretically slower and slightly larger.
  619. config PARAVIRT_DEBUG
  620. bool "paravirt-ops debugging"
  621. depends on PARAVIRT && DEBUG_KERNEL
  622. ---help---
  623. Enable to debug paravirt_ops internals. Specifically, BUG if
  624. a paravirt_op is missing when it is called.
  625. config PARAVIRT_SPINLOCKS
  626. bool "Paravirtualization layer for spinlocks"
  627. depends on PARAVIRT && SMP
  628. ---help---
  629. Paravirtualized spinlocks allow a pvops backend to replace the
  630. spinlock implementation with something virtualization-friendly
  631. (for example, block the virtual CPU rather than spinning).
  632. It has a minimal impact on native kernels and gives a nice performance
  633. benefit on paravirtualized KVM / Xen kernels.
  634. If you are unsure how to answer this question, answer Y.
  635. config QUEUED_LOCK_STAT
  636. bool "Paravirt queued spinlock statistics"
  637. depends on PARAVIRT_SPINLOCKS && DEBUG_FS
  638. ---help---
  639. Enable the collection of statistical data on the slowpath
  640. behavior of paravirtualized queued spinlocks and report
  641. them on debugfs.
  642. source "arch/x86/xen/Kconfig"
  643. config KVM_GUEST
  644. bool "KVM Guest support (including kvmclock)"
  645. depends on PARAVIRT
  646. select PARAVIRT_CLOCK
  647. default y
  648. ---help---
  649. This option enables various optimizations for running under the KVM
  650. hypervisor. It includes a paravirtualized clock, so that instead
  651. of relying on a PIT (or probably other) emulation by the
  652. underlying device model, the host provides the guest with
  653. timing infrastructure such as time of day, and system time
  654. config KVM_DEBUG_FS
  655. bool "Enable debug information for KVM Guests in debugfs"
  656. depends on KVM_GUEST && DEBUG_FS
  657. default n
  658. ---help---
  659. This option enables collection of various statistics for KVM guest.
  660. Statistics are displayed in debugfs filesystem. Enabling this option
  661. may incur significant overhead.
  662. source "arch/x86/lguest/Kconfig"
  663. config PARAVIRT_TIME_ACCOUNTING
  664. bool "Paravirtual steal time accounting"
  665. depends on PARAVIRT
  666. default n
  667. ---help---
  668. Select this option to enable fine granularity task steal time
  669. accounting. Time spent executing other tasks in parallel with
  670. the current vCPU is discounted from the vCPU power. To account for
  671. that, there can be a small performance impact.
  672. If in doubt, say N here.
  673. config PARAVIRT_CLOCK
  674. bool
  675. endif #HYPERVISOR_GUEST
  676. config NO_BOOTMEM
  677. def_bool y
  678. source "arch/x86/Kconfig.cpu"
  679. config HPET_TIMER
  680. def_bool X86_64
  681. prompt "HPET Timer Support" if X86_32
  682. ---help---
  683. Use the IA-PC HPET (High Precision Event Timer) to manage
  684. time in preference to the PIT and RTC, if a HPET is
  685. present.
  686. HPET is the next generation timer replacing legacy 8254s.
  687. The HPET provides a stable time base on SMP
  688. systems, unlike the TSC, but it is more expensive to access,
  689. as it is off-chip. The interface used is documented
  690. in the HPET spec, revision 1.
  691. You can safely choose Y here. However, HPET will only be
  692. activated if the platform and the BIOS support this feature.
  693. Otherwise the 8254 will be used for timing services.
  694. Choose N to continue using the legacy 8254 timer.
  695. config HPET_EMULATE_RTC
  696. def_bool y
  697. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  698. config APB_TIMER
  699. def_bool y if X86_INTEL_MID
  700. prompt "Intel MID APB Timer Support" if X86_INTEL_MID
  701. select DW_APB_TIMER
  702. depends on X86_INTEL_MID && SFI
  703. help
  704. APB timer is the replacement for 8254, HPET on X86 MID platforms.
  705. The APBT provides a stable time base on SMP
  706. systems, unlike the TSC, but it is more expensive to access,
  707. as it is off-chip. APB timers are always running regardless of CPU
  708. C states, they are used as per CPU clockevent device when possible.
  709. # Mark as expert because too many people got it wrong.
  710. # The code disables itself when not needed.
  711. config DMI
  712. default y
  713. select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
  714. bool "Enable DMI scanning" if EXPERT
  715. ---help---
  716. Enabled scanning of DMI to identify machine quirks. Say Y
  717. here unless you have verified that your setup is not
  718. affected by entries in the DMI blacklist. Required by PNP
  719. BIOS code.
  720. config GART_IOMMU
  721. bool "Old AMD GART IOMMU support"
  722. select SWIOTLB
  723. depends on X86_64 && PCI && AMD_NB
  724. ---help---
  725. Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
  726. GART based hardware IOMMUs.
  727. The GART supports full DMA access for devices with 32-bit access
  728. limitations, on systems with more than 3 GB. This is usually needed
  729. for USB, sound, many IDE/SATA chipsets and some other devices.
  730. Newer systems typically have a modern AMD IOMMU, supported via
  731. the CONFIG_AMD_IOMMU=y config option.
  732. In normal configurations this driver is only active when needed:
  733. there's more than 3 GB of memory and the system contains a
  734. 32-bit limited device.
  735. If unsure, say Y.
  736. config CALGARY_IOMMU
  737. bool "IBM Calgary IOMMU support"
  738. select SWIOTLB
  739. depends on X86_64 && PCI
  740. ---help---
  741. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  742. systems. Needed to run systems with more than 3GB of memory
  743. properly with 32-bit PCI devices that do not support DAC
  744. (Double Address Cycle). Calgary also supports bus level
  745. isolation, where all DMAs pass through the IOMMU. This
  746. prevents them from going anywhere except their intended
  747. destination. This catches hard-to-find kernel bugs and
  748. mis-behaving drivers and devices that do not use the DMA-API
  749. properly to set up their DMA buffers. The IOMMU can be
  750. turned off at boot time with the iommu=off parameter.
  751. Normally the kernel will make the right choice by itself.
  752. If unsure, say Y.
  753. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  754. def_bool y
  755. prompt "Should Calgary be enabled by default?"
  756. depends on CALGARY_IOMMU
  757. ---help---
  758. Should Calgary be enabled by default? if you choose 'y', Calgary
  759. will be used (if it exists). If you choose 'n', Calgary will not be
  760. used even if it exists. If you choose 'n' and would like to use
  761. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  762. If unsure, say Y.
  763. # need this always selected by IOMMU for the VIA workaround
  764. config SWIOTLB
  765. def_bool y if X86_64
  766. ---help---
  767. Support for software bounce buffers used on x86-64 systems
  768. which don't have a hardware IOMMU. Using this PCI devices
  769. which can only access 32-bits of memory can be used on systems
  770. with more than 3 GB of memory.
  771. If unsure, say Y.
  772. config IOMMU_HELPER
  773. def_bool y
  774. depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
  775. config MAXSMP
  776. bool "Enable Maximum number of SMP Processors and NUMA Nodes"
  777. depends on X86_64 && SMP && DEBUG_KERNEL
  778. select CPUMASK_OFFSTACK
  779. ---help---
  780. Enable maximum number of CPUS and NUMA Nodes for this architecture.
  781. If unsure, say N.
  782. config NR_CPUS
  783. int "Maximum number of CPUs" if SMP && !MAXSMP
  784. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  785. range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
  786. range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
  787. default "1" if !SMP
  788. default "8192" if MAXSMP
  789. default "32" if SMP && X86_BIGSMP
  790. default "8" if SMP && X86_32
  791. default "64" if SMP
  792. ---help---
  793. This allows you to specify the maximum number of CPUs which this
  794. kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
  795. supported value is 8192, otherwise the maximum value is 512. The
  796. minimum value which makes sense is 2.
  797. This is purely to save memory - each supported CPU adds
  798. approximately eight kilobytes to the kernel image.
  799. config SCHED_SMT
  800. bool "SMT (Hyperthreading) scheduler support"
  801. depends on SMP
  802. ---help---
  803. SMT scheduler support improves the CPU scheduler's decision making
  804. when dealing with Intel Pentium 4 chips with HyperThreading at a
  805. cost of slightly increased overhead in some places. If unsure say
  806. N here.
  807. config SCHED_MC
  808. def_bool y
  809. prompt "Multi-core scheduler support"
  810. depends on SMP
  811. ---help---
  812. Multi-core scheduler support improves the CPU scheduler's decision
  813. making when dealing with multi-core CPU chips at a cost of slightly
  814. increased overhead in some places. If unsure say N here.
  815. config SCHED_MC_PRIO
  816. bool "CPU core priorities scheduler support"
  817. depends on SCHED_MC && CPU_SUP_INTEL
  818. select X86_INTEL_PSTATE
  819. select CPU_FREQ
  820. default y
  821. ---help---
  822. Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
  823. core ordering determined at manufacturing time, which allows
  824. certain cores to reach higher turbo frequencies (when running
  825. single threaded workloads) than others.
  826. Enabling this kernel feature teaches the scheduler about
  827. the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
  828. scheduler's CPU selection logic accordingly, so that higher
  829. overall system performance can be achieved.
  830. This feature will have no effect on CPUs without this feature.
  831. If unsure say Y here.
  832. source "kernel/Kconfig.preempt"
  833. config UP_LATE_INIT
  834. def_bool y
  835. depends on !SMP && X86_LOCAL_APIC
  836. config X86_UP_APIC
  837. bool "Local APIC support on uniprocessors" if !PCI_MSI
  838. default PCI_MSI
  839. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  840. ---help---
  841. A local APIC (Advanced Programmable Interrupt Controller) is an
  842. integrated interrupt controller in the CPU. If you have a single-CPU
  843. system which has a processor with a local APIC, you can say Y here to
  844. enable and use it. If you say Y here even though your machine doesn't
  845. have a local APIC, then the kernel will still run with no slowdown at
  846. all. The local APIC supports CPU-generated self-interrupts (timer,
  847. performance counters), and the NMI watchdog which detects hard
  848. lockups.
  849. config X86_UP_IOAPIC
  850. bool "IO-APIC support on uniprocessors"
  851. depends on X86_UP_APIC
  852. ---help---
  853. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  854. SMP-capable replacement for PC-style interrupt controllers. Most
  855. SMP systems and many recent uniprocessor systems have one.
  856. If you have a single-CPU system with an IO-APIC, you can say Y here
  857. to use it. If you say Y here even though your machine doesn't have
  858. an IO-APIC, then the kernel will still run with no slowdown at all.
  859. config X86_LOCAL_APIC
  860. def_bool y
  861. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
  862. select IRQ_DOMAIN_HIERARCHY
  863. select PCI_MSI_IRQ_DOMAIN if PCI_MSI
  864. config X86_IO_APIC
  865. def_bool y
  866. depends on X86_LOCAL_APIC || X86_UP_IOAPIC
  867. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  868. bool "Reroute for broken boot IRQs"
  869. depends on X86_IO_APIC
  870. ---help---
  871. This option enables a workaround that fixes a source of
  872. spurious interrupts. This is recommended when threaded
  873. interrupt handling is used on systems where the generation of
  874. superfluous "boot interrupts" cannot be disabled.
  875. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  876. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  877. kernel does during interrupt handling). On chipsets where this
  878. boot IRQ generation cannot be disabled, this workaround keeps
  879. the original IRQ line masked so that only the equivalent "boot
  880. IRQ" is delivered to the CPUs. The workaround also tells the
  881. kernel to set up the IRQ handler on the boot IRQ line. In this
  882. way only one interrupt is delivered to the kernel. Otherwise
  883. the spurious second interrupt may cause the kernel to bring
  884. down (vital) interrupt lines.
  885. Only affects "broken" chipsets. Interrupt sharing may be
  886. increased on these systems.
  887. config X86_MCE
  888. bool "Machine Check / overheating reporting"
  889. select GENERIC_ALLOCATOR
  890. default y
  891. ---help---
  892. Machine Check support allows the processor to notify the
  893. kernel if it detects a problem (e.g. overheating, data corruption).
  894. The action the kernel takes depends on the severity of the problem,
  895. ranging from warning messages to halting the machine.
  896. config X86_MCE_INTEL
  897. def_bool y
  898. prompt "Intel MCE features"
  899. depends on X86_MCE && X86_LOCAL_APIC
  900. ---help---
  901. Additional support for intel specific MCE features such as
  902. the thermal monitor.
  903. config X86_MCE_AMD
  904. def_bool y
  905. prompt "AMD MCE features"
  906. depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
  907. ---help---
  908. Additional support for AMD specific MCE features such as
  909. the DRAM Error Threshold.
  910. config X86_ANCIENT_MCE
  911. bool "Support for old Pentium 5 / WinChip machine checks"
  912. depends on X86_32 && X86_MCE
  913. ---help---
  914. Include support for machine check handling on old Pentium 5 or WinChip
  915. systems. These typically need to be enabled explicitly on the command
  916. line.
  917. config X86_MCE_THRESHOLD
  918. depends on X86_MCE_AMD || X86_MCE_INTEL
  919. def_bool y
  920. config X86_MCE_INJECT
  921. depends on X86_MCE && X86_LOCAL_APIC
  922. tristate "Machine check injector support"
  923. ---help---
  924. Provide support for injecting machine checks for testing purposes.
  925. If you don't know what a machine check is and you don't do kernel
  926. QA it is safe to say n.
  927. config X86_THERMAL_VECTOR
  928. def_bool y
  929. depends on X86_MCE_INTEL
  930. source "arch/x86/events/Kconfig"
  931. config X86_LEGACY_VM86
  932. bool "Legacy VM86 support"
  933. default n
  934. depends on X86_32
  935. ---help---
  936. This option allows user programs to put the CPU into V8086
  937. mode, which is an 80286-era approximation of 16-bit real mode.
  938. Some very old versions of X and/or vbetool require this option
  939. for user mode setting. Similarly, DOSEMU will use it if
  940. available to accelerate real mode DOS programs. However, any
  941. recent version of DOSEMU, X, or vbetool should be fully
  942. functional even without kernel VM86 support, as they will all
  943. fall back to software emulation. Nevertheless, if you are using
  944. a 16-bit DOS program where 16-bit performance matters, vm86
  945. mode might be faster than emulation and you might want to
  946. enable this option.
  947. Note that any app that works on a 64-bit kernel is unlikely to
  948. need this option, as 64-bit kernels don't, and can't, support
  949. V8086 mode. This option is also unrelated to 16-bit protected
  950. mode and is not needed to run most 16-bit programs under Wine.
  951. Enabling this option increases the complexity of the kernel
  952. and slows down exception handling a tiny bit.
  953. If unsure, say N here.
  954. config VM86
  955. bool
  956. default X86_LEGACY_VM86
  957. config X86_16BIT
  958. bool "Enable support for 16-bit segments" if EXPERT
  959. default y
  960. depends on MODIFY_LDT_SYSCALL
  961. ---help---
  962. This option is required by programs like Wine to run 16-bit
  963. protected mode legacy code on x86 processors. Disabling
  964. this option saves about 300 bytes on i386, or around 6K text
  965. plus 16K runtime memory on x86-64,
  966. config X86_ESPFIX32
  967. def_bool y
  968. depends on X86_16BIT && X86_32
  969. config X86_ESPFIX64
  970. def_bool y
  971. depends on X86_16BIT && X86_64
  972. config X86_VSYSCALL_EMULATION
  973. bool "Enable vsyscall emulation" if EXPERT
  974. default y
  975. depends on X86_64
  976. ---help---
  977. This enables emulation of the legacy vsyscall page. Disabling
  978. it is roughly equivalent to booting with vsyscall=none, except
  979. that it will also disable the helpful warning if a program
  980. tries to use a vsyscall. With this option set to N, offending
  981. programs will just segfault, citing addresses of the form
  982. 0xffffffffff600?00.
  983. This option is required by many programs built before 2013, and
  984. care should be used even with newer programs if set to N.
  985. Disabling this option saves about 7K of kernel size and
  986. possibly 4K of additional runtime pagetable memory.
  987. config TOSHIBA
  988. tristate "Toshiba Laptop support"
  989. depends on X86_32
  990. ---help---
  991. This adds a driver to safely access the System Management Mode of
  992. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  993. not work on models with a Phoenix BIOS. The System Management Mode
  994. is used to set the BIOS and power saving options on Toshiba portables.
  995. For information on utilities to make use of this driver see the
  996. Toshiba Linux utilities web site at:
  997. <http://www.buzzard.org.uk/toshiba/>.
  998. Say Y if you intend to run this kernel on a Toshiba portable.
  999. Say N otherwise.
  1000. config I8K
  1001. tristate "Dell i8k legacy laptop support"
  1002. select HWMON
  1003. select SENSORS_DELL_SMM
  1004. ---help---
  1005. This option enables legacy /proc/i8k userspace interface in hwmon
  1006. dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
  1007. temperature and allows controlling fan speeds of Dell laptops via
  1008. System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
  1009. it reports also power and hotkey status. For fan speed control is
  1010. needed userspace package i8kutils.
  1011. Say Y if you intend to run this kernel on old Dell laptops or want to
  1012. use userspace package i8kutils.
  1013. Say N otherwise.
  1014. config X86_REBOOTFIXUPS
  1015. bool "Enable X86 board specific fixups for reboot"
  1016. depends on X86_32
  1017. ---help---
  1018. This enables chipset and/or board specific fixups to be done
  1019. in order to get reboot to work correctly. This is only needed on
  1020. some combinations of hardware and BIOS. The symptom, for which
  1021. this config is intended, is when reboot ends with a stalled/hung
  1022. system.
  1023. Currently, the only fixup is for the Geode machines using
  1024. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  1025. Say Y if you want to enable the fixup. Currently, it's safe to
  1026. enable this option even if you don't need it.
  1027. Say N otherwise.
  1028. config MICROCODE
  1029. bool "CPU microcode loading support"
  1030. default y
  1031. depends on CPU_SUP_AMD || CPU_SUP_INTEL
  1032. select FW_LOADER
  1033. ---help---
  1034. If you say Y here, you will be able to update the microcode on
  1035. Intel and AMD processors. The Intel support is for the IA32 family,
  1036. e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
  1037. AMD support is for families 0x10 and later. You will obviously need
  1038. the actual microcode binary data itself which is not shipped with
  1039. the Linux kernel.
  1040. The preferred method to load microcode from a detached initrd is described
  1041. in Documentation/x86/early-microcode.txt. For that you need to enable
  1042. CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
  1043. initrd for microcode blobs.
  1044. In addition, you can build-in the microcode into the kernel. For that you
  1045. need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
  1046. to the CONFIG_EXTRA_FIRMWARE config option.
  1047. config MICROCODE_INTEL
  1048. bool "Intel microcode loading support"
  1049. depends on MICROCODE
  1050. default MICROCODE
  1051. select FW_LOADER
  1052. ---help---
  1053. This options enables microcode patch loading support for Intel
  1054. processors.
  1055. For the current Intel microcode data package go to
  1056. <https://downloadcenter.intel.com> and search for
  1057. 'Linux Processor Microcode Data File'.
  1058. config MICROCODE_AMD
  1059. bool "AMD microcode loading support"
  1060. depends on MICROCODE
  1061. select FW_LOADER
  1062. ---help---
  1063. If you select this option, microcode patch loading support for AMD
  1064. processors will be enabled.
  1065. config MICROCODE_OLD_INTERFACE
  1066. def_bool y
  1067. depends on MICROCODE
  1068. config X86_MSR
  1069. tristate "/dev/cpu/*/msr - Model-specific register support"
  1070. ---help---
  1071. This device gives privileged processes access to the x86
  1072. Model-Specific Registers (MSRs). It is a character device with
  1073. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  1074. MSR accesses are directed to a specific CPU on multi-processor
  1075. systems.
  1076. config X86_CPUID
  1077. tristate "/dev/cpu/*/cpuid - CPU information support"
  1078. ---help---
  1079. This device gives processes access to the x86 CPUID instruction to
  1080. be executed on a specific processor. It is a character device
  1081. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  1082. /dev/cpu/31/cpuid.
  1083. choice
  1084. prompt "High Memory Support"
  1085. default HIGHMEM4G
  1086. depends on X86_32
  1087. config NOHIGHMEM
  1088. bool "off"
  1089. ---help---
  1090. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  1091. However, the address space of 32-bit x86 processors is only 4
  1092. Gigabytes large. That means that, if you have a large amount of
  1093. physical memory, not all of it can be "permanently mapped" by the
  1094. kernel. The physical memory that's not permanently mapped is called
  1095. "high memory".
  1096. If you are compiling a kernel which will never run on a machine with
  1097. more than 1 Gigabyte total physical RAM, answer "off" here (default
  1098. choice and suitable for most users). This will result in a "3GB/1GB"
  1099. split: 3GB are mapped so that each process sees a 3GB virtual memory
  1100. space and the remaining part of the 4GB virtual memory space is used
  1101. by the kernel to permanently map as much physical memory as
  1102. possible.
  1103. If the machine has between 1 and 4 Gigabytes physical RAM, then
  1104. answer "4GB" here.
  1105. If more than 4 Gigabytes is used then answer "64GB" here. This
  1106. selection turns Intel PAE (Physical Address Extension) mode on.
  1107. PAE implements 3-level paging on IA32 processors. PAE is fully
  1108. supported by Linux, PAE mode is implemented on all recent Intel
  1109. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  1110. then the kernel will not boot on CPUs that don't support PAE!
  1111. The actual amount of total physical memory will either be
  1112. auto detected or can be forced by using a kernel command line option
  1113. such as "mem=256M". (Try "man bootparam" or see the documentation of
  1114. your boot loader (lilo or loadlin) about how to pass options to the
  1115. kernel at boot time.)
  1116. If unsure, say "off".
  1117. config HIGHMEM4G
  1118. bool "4GB"
  1119. ---help---
  1120. Select this if you have a 32-bit processor and between 1 and 4
  1121. gigabytes of physical RAM.
  1122. config HIGHMEM64G
  1123. bool "64GB"
  1124. depends on !M486
  1125. select X86_PAE
  1126. ---help---
  1127. Select this if you have a 32-bit processor and more than 4
  1128. gigabytes of physical RAM.
  1129. endchoice
  1130. choice
  1131. prompt "Memory split" if EXPERT
  1132. default VMSPLIT_3G
  1133. depends on X86_32
  1134. ---help---
  1135. Select the desired split between kernel and user memory.
  1136. If the address range available to the kernel is less than the
  1137. physical memory installed, the remaining memory will be available
  1138. as "high memory". Accessing high memory is a little more costly
  1139. than low memory, as it needs to be mapped into the kernel first.
  1140. Note that increasing the kernel address space limits the range
  1141. available to user programs, making the address space there
  1142. tighter. Selecting anything other than the default 3G/1G split
  1143. will also likely make your kernel incompatible with binary-only
  1144. kernel modules.
  1145. If you are not absolutely sure what you are doing, leave this
  1146. option alone!
  1147. config VMSPLIT_3G
  1148. bool "3G/1G user/kernel split"
  1149. config VMSPLIT_3G_OPT
  1150. depends on !X86_PAE
  1151. bool "3G/1G user/kernel split (for full 1G low memory)"
  1152. config VMSPLIT_2G
  1153. bool "2G/2G user/kernel split"
  1154. config VMSPLIT_2G_OPT
  1155. depends on !X86_PAE
  1156. bool "2G/2G user/kernel split (for full 2G low memory)"
  1157. config VMSPLIT_1G
  1158. bool "1G/3G user/kernel split"
  1159. endchoice
  1160. config PAGE_OFFSET
  1161. hex
  1162. default 0xB0000000 if VMSPLIT_3G_OPT
  1163. default 0x80000000 if VMSPLIT_2G
  1164. default 0x78000000 if VMSPLIT_2G_OPT
  1165. default 0x40000000 if VMSPLIT_1G
  1166. default 0xC0000000
  1167. depends on X86_32
  1168. config HIGHMEM
  1169. def_bool y
  1170. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  1171. config X86_PAE
  1172. bool "PAE (Physical Address Extension) Support"
  1173. depends on X86_32 && !HIGHMEM4G
  1174. select SWIOTLB
  1175. ---help---
  1176. PAE is required for NX support, and furthermore enables
  1177. larger swapspace support for non-overcommit purposes. It
  1178. has the cost of more pagetable lookup overhead, and also
  1179. consumes more pagetable space per process.
  1180. config ARCH_PHYS_ADDR_T_64BIT
  1181. def_bool y
  1182. depends on X86_64 || X86_PAE
  1183. config ARCH_DMA_ADDR_T_64BIT
  1184. def_bool y
  1185. depends on X86_64 || HIGHMEM64G
  1186. config X86_DIRECT_GBPAGES
  1187. def_bool y
  1188. depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
  1189. ---help---
  1190. Certain kernel features effectively disable kernel
  1191. linear 1 GB mappings (even if the CPU otherwise
  1192. supports them), so don't confuse the user by printing
  1193. that we have them enabled.
  1194. # Common NUMA Features
  1195. config NUMA
  1196. bool "Numa Memory Allocation and Scheduler Support"
  1197. depends on SMP
  1198. depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
  1199. default y if X86_BIGSMP
  1200. ---help---
  1201. Enable NUMA (Non Uniform Memory Access) support.
  1202. The kernel will try to allocate memory used by a CPU on the
  1203. local memory controller of the CPU and add some more
  1204. NUMA awareness to the kernel.
  1205. For 64-bit this is recommended if the system is Intel Core i7
  1206. (or later), AMD Opteron, or EM64T NUMA.
  1207. For 32-bit this is only needed if you boot a 32-bit
  1208. kernel on a 64-bit NUMA platform.
  1209. Otherwise, you should say N.
  1210. config AMD_NUMA
  1211. def_bool y
  1212. prompt "Old style AMD Opteron NUMA detection"
  1213. depends on X86_64 && NUMA && PCI
  1214. ---help---
  1215. Enable AMD NUMA node topology detection. You should say Y here if
  1216. you have a multi processor AMD system. This uses an old method to
  1217. read the NUMA configuration directly from the builtin Northbridge
  1218. of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
  1219. which also takes priority if both are compiled in.
  1220. config X86_64_ACPI_NUMA
  1221. def_bool y
  1222. prompt "ACPI NUMA detection"
  1223. depends on X86_64 && NUMA && ACPI && PCI
  1224. select ACPI_NUMA
  1225. ---help---
  1226. Enable ACPI SRAT based node topology detection.
  1227. # Some NUMA nodes have memory ranges that span
  1228. # other nodes. Even though a pfn is valid and
  1229. # between a node's start and end pfns, it may not
  1230. # reside on that node. See memmap_init_zone()
  1231. # for details.
  1232. config NODES_SPAN_OTHER_NODES
  1233. def_bool y
  1234. depends on X86_64_ACPI_NUMA
  1235. config NUMA_EMU
  1236. bool "NUMA emulation"
  1237. depends on NUMA
  1238. ---help---
  1239. Enable NUMA emulation. A flat machine will be split
  1240. into virtual nodes when booted with "numa=fake=N", where N is the
  1241. number of nodes. This is only useful for debugging.
  1242. config NODES_SHIFT
  1243. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  1244. range 1 10
  1245. default "10" if MAXSMP
  1246. default "6" if X86_64
  1247. default "3"
  1248. depends on NEED_MULTIPLE_NODES
  1249. ---help---
  1250. Specify the maximum number of NUMA Nodes available on the target
  1251. system. Increases memory reserved to accommodate various tables.
  1252. config ARCH_HAVE_MEMORY_PRESENT
  1253. def_bool y
  1254. depends on X86_32 && DISCONTIGMEM
  1255. config NEED_NODE_MEMMAP_SIZE
  1256. def_bool y
  1257. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1258. config ARCH_FLATMEM_ENABLE
  1259. def_bool y
  1260. depends on X86_32 && !NUMA
  1261. config ARCH_DISCONTIGMEM_ENABLE
  1262. def_bool y
  1263. depends on NUMA && X86_32
  1264. config ARCH_DISCONTIGMEM_DEFAULT
  1265. def_bool y
  1266. depends on NUMA && X86_32
  1267. config ARCH_SPARSEMEM_ENABLE
  1268. def_bool y
  1269. depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
  1270. select SPARSEMEM_STATIC if X86_32
  1271. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1272. config ARCH_SPARSEMEM_DEFAULT
  1273. def_bool y
  1274. depends on X86_64
  1275. config ARCH_SELECT_MEMORY_MODEL
  1276. def_bool y
  1277. depends on ARCH_SPARSEMEM_ENABLE
  1278. config ARCH_MEMORY_PROBE
  1279. bool "Enable sysfs memory/probe interface"
  1280. depends on X86_64 && MEMORY_HOTPLUG
  1281. help
  1282. This option enables a sysfs memory/probe interface for testing.
  1283. See Documentation/memory-hotplug.txt for more information.
  1284. If you are unsure how to answer this question, answer N.
  1285. config ARCH_PROC_KCORE_TEXT
  1286. def_bool y
  1287. depends on X86_64 && PROC_KCORE
  1288. config ILLEGAL_POINTER_VALUE
  1289. hex
  1290. default 0 if X86_32
  1291. default 0xdead000000000000 if X86_64
  1292. source "mm/Kconfig"
  1293. config X86_PMEM_LEGACY_DEVICE
  1294. bool
  1295. config X86_PMEM_LEGACY
  1296. tristate "Support non-standard NVDIMMs and ADR protected memory"
  1297. depends on PHYS_ADDR_T_64BIT
  1298. depends on BLK_DEV
  1299. select X86_PMEM_LEGACY_DEVICE
  1300. select LIBNVDIMM
  1301. help
  1302. Treat memory marked using the non-standard e820 type of 12 as used
  1303. by the Intel Sandy Bridge-EP reference BIOS as protected memory.
  1304. The kernel will offer these regions to the 'pmem' driver so
  1305. they can be used for persistent storage.
  1306. Say Y if unsure.
  1307. config HIGHPTE
  1308. bool "Allocate 3rd-level pagetables from highmem"
  1309. depends on HIGHMEM
  1310. ---help---
  1311. The VM uses one page table entry for each page of physical memory.
  1312. For systems with a lot of RAM, this can be wasteful of precious
  1313. low memory. Setting this option will put user-space page table
  1314. entries in high memory.
  1315. config X86_CHECK_BIOS_CORRUPTION
  1316. bool "Check for low memory corruption"
  1317. ---help---
  1318. Periodically check for memory corruption in low memory, which
  1319. is suspected to be caused by BIOS. Even when enabled in the
  1320. configuration, it is disabled at runtime. Enable it by
  1321. setting "memory_corruption_check=1" on the kernel command
  1322. line. By default it scans the low 64k of memory every 60
  1323. seconds; see the memory_corruption_check_size and
  1324. memory_corruption_check_period parameters in
  1325. Documentation/admin-guide/kernel-parameters.rst to adjust this.
  1326. When enabled with the default parameters, this option has
  1327. almost no overhead, as it reserves a relatively small amount
  1328. of memory and scans it infrequently. It both detects corruption
  1329. and prevents it from affecting the running system.
  1330. It is, however, intended as a diagnostic tool; if repeatable
  1331. BIOS-originated corruption always affects the same memory,
  1332. you can use memmap= to prevent the kernel from using that
  1333. memory.
  1334. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1335. bool "Set the default setting of memory_corruption_check"
  1336. depends on X86_CHECK_BIOS_CORRUPTION
  1337. default y
  1338. ---help---
  1339. Set whether the default state of memory_corruption_check is
  1340. on or off.
  1341. config X86_RESERVE_LOW
  1342. int "Amount of low memory, in kilobytes, to reserve for the BIOS"
  1343. default 64
  1344. range 4 640
  1345. ---help---
  1346. Specify the amount of low memory to reserve for the BIOS.
  1347. The first page contains BIOS data structures that the kernel
  1348. must not use, so that page must always be reserved.
  1349. By default we reserve the first 64K of physical RAM, as a
  1350. number of BIOSes are known to corrupt that memory range
  1351. during events such as suspend/resume or monitor cable
  1352. insertion, so it must not be used by the kernel.
  1353. You can set this to 4 if you are absolutely sure that you
  1354. trust the BIOS to get all its memory reservations and usages
  1355. right. If you know your BIOS have problems beyond the
  1356. default 64K area, you can set this to 640 to avoid using the
  1357. entire low memory range.
  1358. If you have doubts about the BIOS (e.g. suspend/resume does
  1359. not work or there's kernel crashes after certain hardware
  1360. hotplug events) then you might want to enable
  1361. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
  1362. typical corruption patterns.
  1363. Leave this to the default value of 64 if you are unsure.
  1364. config MATH_EMULATION
  1365. bool
  1366. depends on MODIFY_LDT_SYSCALL
  1367. prompt "Math emulation" if X86_32
  1368. ---help---
  1369. Linux can emulate a math coprocessor (used for floating point
  1370. operations) if you don't have one. 486DX and Pentium processors have
  1371. a math coprocessor built in, 486SX and 386 do not, unless you added
  1372. a 487DX or 387, respectively. (The messages during boot time can
  1373. give you some hints here ["man dmesg"].) Everyone needs either a
  1374. coprocessor or this emulation.
  1375. If you don't have a math coprocessor, you need to say Y here; if you
  1376. say Y here even though you have a coprocessor, the coprocessor will
  1377. be used nevertheless. (This behavior can be changed with the kernel
  1378. command line option "no387", which comes handy if your coprocessor
  1379. is broken. Try "man bootparam" or see the documentation of your boot
  1380. loader (lilo or loadlin) about how to pass options to the kernel at
  1381. boot time.) This means that it is a good idea to say Y here if you
  1382. intend to use this kernel on different machines.
  1383. More information about the internals of the Linux math coprocessor
  1384. emulation can be found in <file:arch/x86/math-emu/README>.
  1385. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1386. kernel, it won't hurt.
  1387. config MTRR
  1388. def_bool y
  1389. prompt "MTRR (Memory Type Range Register) support" if EXPERT
  1390. ---help---
  1391. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1392. the Memory Type Range Registers (MTRRs) may be used to control
  1393. processor access to memory ranges. This is most useful if you have
  1394. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1395. allows bus write transfers to be combined into a larger transfer
  1396. before bursting over the PCI/AGP bus. This can increase performance
  1397. of image write operations 2.5 times or more. Saying Y here creates a
  1398. /proc/mtrr file which may be used to manipulate your processor's
  1399. MTRRs. Typically the X server should use this.
  1400. This code has a reasonably generic interface so that similar
  1401. control registers on other processors can be easily supported
  1402. as well:
  1403. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1404. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1405. these, the ARRs are used to emulate the MTRRs.
  1406. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1407. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1408. write-combining. All of these processors are supported by this code
  1409. and it makes sense to say Y here if you have one of them.
  1410. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1411. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1412. can lead to all sorts of problems, so it's good to say Y here.
  1413. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1414. just add about 9 KB to your kernel.
  1415. See <file:Documentation/x86/mtrr.txt> for more information.
  1416. config MTRR_SANITIZER
  1417. def_bool y
  1418. prompt "MTRR cleanup support"
  1419. depends on MTRR
  1420. ---help---
  1421. Convert MTRR layout from continuous to discrete, so X drivers can
  1422. add writeback entries.
  1423. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1424. The largest mtrr entry size for a continuous block can be set with
  1425. mtrr_chunk_size.
  1426. If unsure, say Y.
  1427. config MTRR_SANITIZER_ENABLE_DEFAULT
  1428. int "MTRR cleanup enable value (0-1)"
  1429. range 0 1
  1430. default "0"
  1431. depends on MTRR_SANITIZER
  1432. ---help---
  1433. Enable mtrr cleanup default value
  1434. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1435. int "MTRR cleanup spare reg num (0-7)"
  1436. range 0 7
  1437. default "1"
  1438. depends on MTRR_SANITIZER
  1439. ---help---
  1440. mtrr cleanup spare entries default, it can be changed via
  1441. mtrr_spare_reg_nr=N on the kernel command line.
  1442. config X86_PAT
  1443. def_bool y
  1444. prompt "x86 PAT support" if EXPERT
  1445. depends on MTRR
  1446. ---help---
  1447. Use PAT attributes to setup page level cache control.
  1448. PATs are the modern equivalents of MTRRs and are much more
  1449. flexible than MTRRs.
  1450. Say N here if you see bootup problems (boot crash, boot hang,
  1451. spontaneous reboots) or a non-working video driver.
  1452. If unsure, say Y.
  1453. config ARCH_USES_PG_UNCACHED
  1454. def_bool y
  1455. depends on X86_PAT
  1456. config ARCH_RANDOM
  1457. def_bool y
  1458. prompt "x86 architectural random number generator" if EXPERT
  1459. ---help---
  1460. Enable the x86 architectural RDRAND instruction
  1461. (Intel Bull Mountain technology) to generate random numbers.
  1462. If supported, this is a high bandwidth, cryptographically
  1463. secure hardware random number generator.
  1464. config X86_SMAP
  1465. def_bool y
  1466. prompt "Supervisor Mode Access Prevention" if EXPERT
  1467. ---help---
  1468. Supervisor Mode Access Prevention (SMAP) is a security
  1469. feature in newer Intel processors. There is a small
  1470. performance cost if this enabled and turned on; there is
  1471. also a small increase in the kernel size if this is enabled.
  1472. If unsure, say Y.
  1473. config X86_INTEL_MPX
  1474. prompt "Intel MPX (Memory Protection Extensions)"
  1475. def_bool n
  1476. depends on CPU_SUP_INTEL
  1477. ---help---
  1478. MPX provides hardware features that can be used in
  1479. conjunction with compiler-instrumented code to check
  1480. memory references. It is designed to detect buffer
  1481. overflow or underflow bugs.
  1482. This option enables running applications which are
  1483. instrumented or otherwise use MPX. It does not use MPX
  1484. itself inside the kernel or to protect the kernel
  1485. against bad memory references.
  1486. Enabling this option will make the kernel larger:
  1487. ~8k of kernel text and 36 bytes of data on a 64-bit
  1488. defconfig. It adds a long to the 'mm_struct' which
  1489. will increase the kernel memory overhead of each
  1490. process and adds some branches to paths used during
  1491. exec() and munmap().
  1492. For details, see Documentation/x86/intel_mpx.txt
  1493. If unsure, say N.
  1494. config X86_INTEL_MEMORY_PROTECTION_KEYS
  1495. prompt "Intel Memory Protection Keys"
  1496. def_bool y
  1497. # Note: only available in 64-bit mode
  1498. depends on CPU_SUP_INTEL && X86_64
  1499. select ARCH_USES_HIGH_VMA_FLAGS
  1500. select ARCH_HAS_PKEYS
  1501. ---help---
  1502. Memory Protection Keys provides a mechanism for enforcing
  1503. page-based protections, but without requiring modification of the
  1504. page tables when an application changes protection domains.
  1505. For details, see Documentation/x86/protection-keys.txt
  1506. If unsure, say y.
  1507. config EFI
  1508. bool "EFI runtime service support"
  1509. depends on ACPI
  1510. select UCS2_STRING
  1511. select EFI_RUNTIME_WRAPPERS
  1512. ---help---
  1513. This enables the kernel to use EFI runtime services that are
  1514. available (such as the EFI variable services).
  1515. This option is only useful on systems that have EFI firmware.
  1516. In addition, you should use the latest ELILO loader available
  1517. at <http://elilo.sourceforge.net> in order to take advantage
  1518. of EFI runtime services. However, even with this option, the
  1519. resultant kernel should continue to boot on existing non-EFI
  1520. platforms.
  1521. config EFI_STUB
  1522. bool "EFI stub support"
  1523. depends on EFI && !X86_USE_3DNOW
  1524. select RELOCATABLE
  1525. ---help---
  1526. This kernel feature allows a bzImage to be loaded directly
  1527. by EFI firmware without the use of a bootloader.
  1528. See Documentation/efi-stub.txt for more information.
  1529. config EFI_MIXED
  1530. bool "EFI mixed-mode support"
  1531. depends on EFI_STUB && X86_64
  1532. ---help---
  1533. Enabling this feature allows a 64-bit kernel to be booted
  1534. on a 32-bit firmware, provided that your CPU supports 64-bit
  1535. mode.
  1536. Note that it is not possible to boot a mixed-mode enabled
  1537. kernel via the EFI boot stub - a bootloader that supports
  1538. the EFI handover protocol must be used.
  1539. If unsure, say N.
  1540. config SECCOMP
  1541. def_bool y
  1542. prompt "Enable seccomp to safely compute untrusted bytecode"
  1543. ---help---
  1544. This kernel feature is useful for number crunching applications
  1545. that may need to compute untrusted bytecode during their
  1546. execution. By using pipes or other transports made available to
  1547. the process as file descriptors supporting the read/write
  1548. syscalls, it's possible to isolate those applications in
  1549. their own address space using seccomp. Once seccomp is
  1550. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1551. and the task is only allowed to execute a few safe syscalls
  1552. defined by each seccomp mode.
  1553. If unsure, say Y. Only embedded should say N here.
  1554. source kernel/Kconfig.hz
  1555. config KEXEC
  1556. bool "kexec system call"
  1557. select KEXEC_CORE
  1558. ---help---
  1559. kexec is a system call that implements the ability to shutdown your
  1560. current kernel, and to start another kernel. It is like a reboot
  1561. but it is independent of the system firmware. And like a reboot
  1562. you can start any kernel with it, not just Linux.
  1563. The name comes from the similarity to the exec system call.
  1564. It is an ongoing process to be certain the hardware in a machine
  1565. is properly shutdown, so do not be surprised if this code does not
  1566. initially work for you. As of this writing the exact hardware
  1567. interface is strongly in flux, so no good recommendation can be
  1568. made.
  1569. config KEXEC_FILE
  1570. bool "kexec file based system call"
  1571. select KEXEC_CORE
  1572. select BUILD_BIN2C
  1573. depends on X86_64
  1574. depends on CRYPTO=y
  1575. depends on CRYPTO_SHA256=y
  1576. ---help---
  1577. This is new version of kexec system call. This system call is
  1578. file based and takes file descriptors as system call argument
  1579. for kernel and initramfs as opposed to list of segments as
  1580. accepted by previous system call.
  1581. config KEXEC_VERIFY_SIG
  1582. bool "Verify kernel signature during kexec_file_load() syscall"
  1583. depends on KEXEC_FILE
  1584. ---help---
  1585. This option makes kernel signature verification mandatory for
  1586. the kexec_file_load() syscall.
  1587. In addition to that option, you need to enable signature
  1588. verification for the corresponding kernel image type being
  1589. loaded in order for this to work.
  1590. config KEXEC_BZIMAGE_VERIFY_SIG
  1591. bool "Enable bzImage signature verification support"
  1592. depends on KEXEC_VERIFY_SIG
  1593. depends on SIGNED_PE_FILE_VERIFICATION
  1594. select SYSTEM_TRUSTED_KEYRING
  1595. ---help---
  1596. Enable bzImage signature verification support.
  1597. config CRASH_DUMP
  1598. bool "kernel crash dumps"
  1599. depends on X86_64 || (X86_32 && HIGHMEM)
  1600. ---help---
  1601. Generate crash dump after being started by kexec.
  1602. This should be normally only set in special crash dump kernels
  1603. which are loaded in the main kernel with kexec-tools into
  1604. a specially reserved region and then later executed after
  1605. a crash by kdump/kexec. The crash dump kernel must be compiled
  1606. to a memory address not used by the main kernel or BIOS using
  1607. PHYSICAL_START, or it must be built as a relocatable image
  1608. (CONFIG_RELOCATABLE=y).
  1609. For more details see Documentation/kdump/kdump.txt
  1610. config KEXEC_JUMP
  1611. bool "kexec jump"
  1612. depends on KEXEC && HIBERNATION
  1613. ---help---
  1614. Jump between original kernel and kexeced kernel and invoke
  1615. code in physical address mode via KEXEC
  1616. config PHYSICAL_START
  1617. hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
  1618. default "0x1000000"
  1619. ---help---
  1620. This gives the physical address where the kernel is loaded.
  1621. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1622. bzImage will decompress itself to above physical address and
  1623. run from there. Otherwise, bzImage will run from the address where
  1624. it has been loaded by the boot loader and will ignore above physical
  1625. address.
  1626. In normal kdump cases one does not have to set/change this option
  1627. as now bzImage can be compiled as a completely relocatable image
  1628. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1629. address. This option is mainly useful for the folks who don't want
  1630. to use a bzImage for capturing the crash dump and want to use a
  1631. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1632. to be specifically compiled to run from a specific memory area
  1633. (normally a reserved region) and this option comes handy.
  1634. So if you are using bzImage for capturing the crash dump,
  1635. leave the value here unchanged to 0x1000000 and set
  1636. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1637. for capturing the crash dump change this value to start of
  1638. the reserved region. In other words, it can be set based on
  1639. the "X" value as specified in the "crashkernel=YM@XM"
  1640. command line boot parameter passed to the panic-ed
  1641. kernel. Please take a look at Documentation/kdump/kdump.txt
  1642. for more details about crash dumps.
  1643. Usage of bzImage for capturing the crash dump is recommended as
  1644. one does not have to build two kernels. Same kernel can be used
  1645. as production kernel and capture kernel. Above option should have
  1646. gone away after relocatable bzImage support is introduced. But it
  1647. is present because there are users out there who continue to use
  1648. vmlinux for dump capture. This option should go away down the
  1649. line.
  1650. Don't change this unless you know what you are doing.
  1651. config RELOCATABLE
  1652. bool "Build a relocatable kernel"
  1653. default y
  1654. ---help---
  1655. This builds a kernel image that retains relocation information
  1656. so it can be loaded someplace besides the default 1MB.
  1657. The relocations tend to make the kernel binary about 10% larger,
  1658. but are discarded at runtime.
  1659. One use is for the kexec on panic case where the recovery kernel
  1660. must live at a different physical address than the primary
  1661. kernel.
  1662. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1663. it has been loaded at and the compile time physical address
  1664. (CONFIG_PHYSICAL_START) is used as the minimum location.
  1665. config RANDOMIZE_BASE
  1666. bool "Randomize the address of the kernel image (KASLR)"
  1667. depends on RELOCATABLE
  1668. default n
  1669. ---help---
  1670. In support of Kernel Address Space Layout Randomization (KASLR),
  1671. this randomizes the physical address at which the kernel image
  1672. is decompressed and the virtual address where the kernel
  1673. image is mapped, as a security feature that deters exploit
  1674. attempts relying on knowledge of the location of kernel
  1675. code internals.
  1676. On 64-bit, the kernel physical and virtual addresses are
  1677. randomized separately. The physical address will be anywhere
  1678. between 16MB and the top of physical memory (up to 64TB). The
  1679. virtual address will be randomized from 16MB up to 1GB (9 bits
  1680. of entropy). Note that this also reduces the memory space
  1681. available to kernel modules from 1.5GB to 1GB.
  1682. On 32-bit, the kernel physical and virtual addresses are
  1683. randomized together. They will be randomized from 16MB up to
  1684. 512MB (8 bits of entropy).
  1685. Entropy is generated using the RDRAND instruction if it is
  1686. supported. If RDTSC is supported, its value is mixed into
  1687. the entropy pool as well. If neither RDRAND nor RDTSC are
  1688. supported, then entropy is read from the i8254 timer. The
  1689. usable entropy is limited by the kernel being built using
  1690. 2GB addressing, and that PHYSICAL_ALIGN must be at a
  1691. minimum of 2MB. As a result, only 10 bits of entropy are
  1692. theoretically possible, but the implementations are further
  1693. limited due to memory layouts.
  1694. If unsure, say N.
  1695. # Relocation on x86 needs some additional build support
  1696. config X86_NEED_RELOCS
  1697. def_bool y
  1698. depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
  1699. config PHYSICAL_ALIGN
  1700. hex "Alignment value to which kernel should be aligned"
  1701. default "0x200000"
  1702. range 0x2000 0x1000000 if X86_32
  1703. range 0x200000 0x1000000 if X86_64
  1704. ---help---
  1705. This value puts the alignment restrictions on physical address
  1706. where kernel is loaded and run from. Kernel is compiled for an
  1707. address which meets above alignment restriction.
  1708. If bootloader loads the kernel at a non-aligned address and
  1709. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1710. address aligned to above value and run from there.
  1711. If bootloader loads the kernel at a non-aligned address and
  1712. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1713. load address and decompress itself to the address it has been
  1714. compiled for and run from there. The address for which kernel is
  1715. compiled already meets above alignment restrictions. Hence the
  1716. end result is that kernel runs from a physical address meeting
  1717. above alignment restrictions.
  1718. On 32-bit this value must be a multiple of 0x2000. On 64-bit
  1719. this value must be a multiple of 0x200000.
  1720. Don't change this unless you know what you are doing.
  1721. config RANDOMIZE_MEMORY
  1722. bool "Randomize the kernel memory sections"
  1723. depends on X86_64
  1724. depends on RANDOMIZE_BASE
  1725. default RANDOMIZE_BASE
  1726. ---help---
  1727. Randomizes the base virtual address of kernel memory sections
  1728. (physical memory mapping, vmalloc & vmemmap). This security feature
  1729. makes exploits relying on predictable memory locations less reliable.
  1730. The order of allocations remains unchanged. Entropy is generated in
  1731. the same way as RANDOMIZE_BASE. Current implementation in the optimal
  1732. configuration have in average 30,000 different possible virtual
  1733. addresses for each memory section.
  1734. If unsure, say N.
  1735. config RANDOMIZE_MEMORY_PHYSICAL_PADDING
  1736. hex "Physical memory mapping padding" if EXPERT
  1737. depends on RANDOMIZE_MEMORY
  1738. default "0xa" if MEMORY_HOTPLUG
  1739. default "0x0"
  1740. range 0x1 0x40 if MEMORY_HOTPLUG
  1741. range 0x0 0x40
  1742. ---help---
  1743. Define the padding in terabytes added to the existing physical
  1744. memory size during kernel memory randomization. It is useful
  1745. for memory hotplug support but reduces the entropy available for
  1746. address randomization.
  1747. If unsure, leave at the default value.
  1748. config HOTPLUG_CPU
  1749. bool "Support for hot-pluggable CPUs"
  1750. depends on SMP
  1751. ---help---
  1752. Say Y here to allow turning CPUs off and on. CPUs can be
  1753. controlled through /sys/devices/system/cpu.
  1754. ( Note: power management support will enable this option
  1755. automatically on SMP systems. )
  1756. Say N if you want to disable CPU hotplug.
  1757. config BOOTPARAM_HOTPLUG_CPU0
  1758. bool "Set default setting of cpu0_hotpluggable"
  1759. default n
  1760. depends on HOTPLUG_CPU
  1761. ---help---
  1762. Set whether default state of cpu0_hotpluggable is on or off.
  1763. Say Y here to enable CPU0 hotplug by default. If this switch
  1764. is turned on, there is no need to give cpu0_hotplug kernel
  1765. parameter and the CPU0 hotplug feature is enabled by default.
  1766. Please note: there are two known CPU0 dependencies if you want
  1767. to enable the CPU0 hotplug feature either by this switch or by
  1768. cpu0_hotplug kernel parameter.
  1769. First, resume from hibernate or suspend always starts from CPU0.
  1770. So hibernate and suspend are prevented if CPU0 is offline.
  1771. Second dependency is PIC interrupts always go to CPU0. CPU0 can not
  1772. offline if any interrupt can not migrate out of CPU0. There may
  1773. be other CPU0 dependencies.
  1774. Please make sure the dependencies are under your control before
  1775. you enable this feature.
  1776. Say N if you don't want to enable CPU0 hotplug feature by default.
  1777. You still can enable the CPU0 hotplug feature at boot by kernel
  1778. parameter cpu0_hotplug.
  1779. config DEBUG_HOTPLUG_CPU0
  1780. def_bool n
  1781. prompt "Debug CPU0 hotplug"
  1782. depends on HOTPLUG_CPU
  1783. ---help---
  1784. Enabling this option offlines CPU0 (if CPU0 can be offlined) as
  1785. soon as possible and boots up userspace with CPU0 offlined. User
  1786. can online CPU0 back after boot time.
  1787. To debug CPU0 hotplug, you need to enable CPU0 offline/online
  1788. feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
  1789. compilation or giving cpu0_hotplug kernel parameter at boot.
  1790. If unsure, say N.
  1791. config COMPAT_VDSO
  1792. def_bool n
  1793. prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
  1794. depends on COMPAT_32
  1795. ---help---
  1796. Certain buggy versions of glibc will crash if they are
  1797. presented with a 32-bit vDSO that is not mapped at the address
  1798. indicated in its segment table.
  1799. The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
  1800. and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
  1801. 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
  1802. the only released version with the bug, but OpenSUSE 9
  1803. contains a buggy "glibc 2.3.2".
  1804. The symptom of the bug is that everything crashes on startup, saying:
  1805. dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
  1806. Saying Y here changes the default value of the vdso32 boot
  1807. option from 1 to 0, which turns off the 32-bit vDSO entirely.
  1808. This works around the glibc bug but hurts performance.
  1809. If unsure, say N: if you are compiling your own kernel, you
  1810. are unlikely to be using a buggy version of glibc.
  1811. choice
  1812. prompt "vsyscall table for legacy applications"
  1813. depends on X86_64
  1814. default LEGACY_VSYSCALL_EMULATE
  1815. help
  1816. Legacy user code that does not know how to find the vDSO expects
  1817. to be able to issue three syscalls by calling fixed addresses in
  1818. kernel space. Since this location is not randomized with ASLR,
  1819. it can be used to assist security vulnerability exploitation.
  1820. This setting can be changed at boot time via the kernel command
  1821. line parameter vsyscall=[native|emulate|none].
  1822. On a system with recent enough glibc (2.14 or newer) and no
  1823. static binaries, you can say None without a performance penalty
  1824. to improve security.
  1825. If unsure, select "Emulate".
  1826. config LEGACY_VSYSCALL_NATIVE
  1827. bool "Native"
  1828. help
  1829. Actual executable code is located in the fixed vsyscall
  1830. address mapping, implementing time() efficiently. Since
  1831. this makes the mapping executable, it can be used during
  1832. security vulnerability exploitation (traditionally as
  1833. ROP gadgets). This configuration is not recommended.
  1834. config LEGACY_VSYSCALL_EMULATE
  1835. bool "Emulate"
  1836. help
  1837. The kernel traps and emulates calls into the fixed
  1838. vsyscall address mapping. This makes the mapping
  1839. non-executable, but it still contains known contents,
  1840. which could be used in certain rare security vulnerability
  1841. exploits. This configuration is recommended when userspace
  1842. still uses the vsyscall area.
  1843. config LEGACY_VSYSCALL_NONE
  1844. bool "None"
  1845. help
  1846. There will be no vsyscall mapping at all. This will
  1847. eliminate any risk of ASLR bypass due to the vsyscall
  1848. fixed address mapping. Attempts to use the vsyscalls
  1849. will be reported to dmesg, so that either old or
  1850. malicious userspace programs can be identified.
  1851. endchoice
  1852. config CMDLINE_BOOL
  1853. bool "Built-in kernel command line"
  1854. ---help---
  1855. Allow for specifying boot arguments to the kernel at
  1856. build time. On some systems (e.g. embedded ones), it is
  1857. necessary or convenient to provide some or all of the
  1858. kernel boot arguments with the kernel itself (that is,
  1859. to not rely on the boot loader to provide them.)
  1860. To compile command line arguments into the kernel,
  1861. set this option to 'Y', then fill in the
  1862. boot arguments in CONFIG_CMDLINE.
  1863. Systems with fully functional boot loaders (i.e. non-embedded)
  1864. should leave this option set to 'N'.
  1865. config CMDLINE
  1866. string "Built-in kernel command string"
  1867. depends on CMDLINE_BOOL
  1868. default ""
  1869. ---help---
  1870. Enter arguments here that should be compiled into the kernel
  1871. image and used at boot time. If the boot loader provides a
  1872. command line at boot time, it is appended to this string to
  1873. form the full kernel command line, when the system boots.
  1874. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1875. change this behavior.
  1876. In most cases, the command line (whether built-in or provided
  1877. by the boot loader) should specify the device for the root
  1878. file system.
  1879. config CMDLINE_OVERRIDE
  1880. bool "Built-in command line overrides boot loader arguments"
  1881. depends on CMDLINE_BOOL
  1882. ---help---
  1883. Set this option to 'Y' to have the kernel ignore the boot loader
  1884. command line, and use ONLY the built-in command line.
  1885. This is used to work around broken boot loaders. This should
  1886. be set to 'N' under normal conditions.
  1887. config MODIFY_LDT_SYSCALL
  1888. bool "Enable the LDT (local descriptor table)" if EXPERT
  1889. default y
  1890. ---help---
  1891. Linux can allow user programs to install a per-process x86
  1892. Local Descriptor Table (LDT) using the modify_ldt(2) system
  1893. call. This is required to run 16-bit or segmented code such as
  1894. DOSEMU or some Wine programs. It is also used by some very old
  1895. threading libraries.
  1896. Enabling this feature adds a small amount of overhead to
  1897. context switches and increases the low-level kernel attack
  1898. surface. Disabling it removes the modify_ldt(2) system call.
  1899. Saying 'N' here may make sense for embedded or server kernels.
  1900. source "kernel/livepatch/Kconfig"
  1901. endmenu
  1902. config ARCH_ENABLE_MEMORY_HOTPLUG
  1903. def_bool y
  1904. depends on X86_64 || (X86_32 && HIGHMEM)
  1905. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1906. def_bool y
  1907. depends on MEMORY_HOTPLUG
  1908. config USE_PERCPU_NUMA_NODE_ID
  1909. def_bool y
  1910. depends on NUMA
  1911. config ARCH_ENABLE_SPLIT_PMD_PTLOCK
  1912. def_bool y
  1913. depends on X86_64 || X86_PAE
  1914. config ARCH_ENABLE_HUGEPAGE_MIGRATION
  1915. def_bool y
  1916. depends on X86_64 && HUGETLB_PAGE && MIGRATION
  1917. menu "Power management and ACPI options"
  1918. config ARCH_HIBERNATION_HEADER
  1919. def_bool y
  1920. depends on X86_64 && HIBERNATION
  1921. source "kernel/power/Kconfig"
  1922. source "drivers/acpi/Kconfig"
  1923. source "drivers/sfi/Kconfig"
  1924. config X86_APM_BOOT
  1925. def_bool y
  1926. depends on APM
  1927. menuconfig APM
  1928. tristate "APM (Advanced Power Management) BIOS support"
  1929. depends on X86_32 && PM_SLEEP
  1930. ---help---
  1931. APM is a BIOS specification for saving power using several different
  1932. techniques. This is mostly useful for battery powered laptops with
  1933. APM compliant BIOSes. If you say Y here, the system time will be
  1934. reset after a RESUME operation, the /proc/apm device will provide
  1935. battery status information, and user-space programs will receive
  1936. notification of APM "events" (e.g. battery status change).
  1937. If you select "Y" here, you can disable actual use of the APM
  1938. BIOS by passing the "apm=off" option to the kernel at boot time.
  1939. Note that the APM support is almost completely disabled for
  1940. machines with more than one CPU.
  1941. In order to use APM, you will need supporting software. For location
  1942. and more information, read <file:Documentation/power/apm-acpi.txt>
  1943. and the Battery Powered Linux mini-HOWTO, available from
  1944. <http://www.tldp.org/docs.html#howto>.
  1945. This driver does not spin down disk drives (see the hdparm(8)
  1946. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1947. VESA-compliant "green" monitors.
  1948. This driver does not support the TI 4000M TravelMate and the ACER
  1949. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1950. desktop machines also don't have compliant BIOSes, and this driver
  1951. may cause those machines to panic during the boot phase.
  1952. Generally, if you don't have a battery in your machine, there isn't
  1953. much point in using this driver and you should say N. If you get
  1954. random kernel OOPSes or reboots that don't seem to be related to
  1955. anything, try disabling/enabling this option (or disabling/enabling
  1956. APM in your BIOS).
  1957. Some other things you should try when experiencing seemingly random,
  1958. "weird" problems:
  1959. 1) make sure that you have enough swap space and that it is
  1960. enabled.
  1961. 2) pass the "no-hlt" option to the kernel
  1962. 3) switch on floating point emulation in the kernel and pass
  1963. the "no387" option to the kernel
  1964. 4) pass the "floppy=nodma" option to the kernel
  1965. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1966. all but the first 4 MB of RAM)
  1967. 6) make sure that the CPU is not over clocked.
  1968. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1969. 8) disable the cache from your BIOS settings
  1970. 9) install a fan for the video card or exchange video RAM
  1971. 10) install a better fan for the CPU
  1972. 11) exchange RAM chips
  1973. 12) exchange the motherboard.
  1974. To compile this driver as a module, choose M here: the
  1975. module will be called apm.
  1976. if APM
  1977. config APM_IGNORE_USER_SUSPEND
  1978. bool "Ignore USER SUSPEND"
  1979. ---help---
  1980. This option will ignore USER SUSPEND requests. On machines with a
  1981. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1982. series notebooks, it is necessary to say Y because of a BIOS bug.
  1983. config APM_DO_ENABLE
  1984. bool "Enable PM at boot time"
  1985. ---help---
  1986. Enable APM features at boot time. From page 36 of the APM BIOS
  1987. specification: "When disabled, the APM BIOS does not automatically
  1988. power manage devices, enter the Standby State, enter the Suspend
  1989. State, or take power saving steps in response to CPU Idle calls."
  1990. This driver will make CPU Idle calls when Linux is idle (unless this
  1991. feature is turned off -- see "Do CPU IDLE calls", below). This
  1992. should always save battery power, but more complicated APM features
  1993. will be dependent on your BIOS implementation. You may need to turn
  1994. this option off if your computer hangs at boot time when using APM
  1995. support, or if it beeps continuously instead of suspending. Turn
  1996. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1997. T400CDT. This is off by default since most machines do fine without
  1998. this feature.
  1999. config APM_CPU_IDLE
  2000. depends on CPU_IDLE
  2001. bool "Make CPU Idle calls when idle"
  2002. ---help---
  2003. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  2004. On some machines, this can activate improved power savings, such as
  2005. a slowed CPU clock rate, when the machine is idle. These idle calls
  2006. are made after the idle loop has run for some length of time (e.g.,
  2007. 333 mS). On some machines, this will cause a hang at boot time or
  2008. whenever the CPU becomes idle. (On machines with more than one CPU,
  2009. this option does nothing.)
  2010. config APM_DISPLAY_BLANK
  2011. bool "Enable console blanking using APM"
  2012. ---help---
  2013. Enable console blanking using the APM. Some laptops can use this to
  2014. turn off the LCD backlight when the screen blanker of the Linux
  2015. virtual console blanks the screen. Note that this is only used by
  2016. the virtual console screen blanker, and won't turn off the backlight
  2017. when using the X Window system. This also doesn't have anything to
  2018. do with your VESA-compliant power-saving monitor. Further, this
  2019. option doesn't work for all laptops -- it might not turn off your
  2020. backlight at all, or it might print a lot of errors to the console,
  2021. especially if you are using gpm.
  2022. config APM_ALLOW_INTS
  2023. bool "Allow interrupts during APM BIOS calls"
  2024. ---help---
  2025. Normally we disable external interrupts while we are making calls to
  2026. the APM BIOS as a measure to lessen the effects of a badly behaving
  2027. BIOS implementation. The BIOS should reenable interrupts if it
  2028. needs to. Unfortunately, some BIOSes do not -- especially those in
  2029. many of the newer IBM Thinkpads. If you experience hangs when you
  2030. suspend, try setting this to Y. Otherwise, say N.
  2031. endif # APM
  2032. source "drivers/cpufreq/Kconfig"
  2033. source "drivers/cpuidle/Kconfig"
  2034. source "drivers/idle/Kconfig"
  2035. endmenu
  2036. menu "Bus options (PCI etc.)"
  2037. config PCI
  2038. bool "PCI support"
  2039. default y
  2040. ---help---
  2041. Find out whether you have a PCI motherboard. PCI is the name of a
  2042. bus system, i.e. the way the CPU talks to the other stuff inside
  2043. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  2044. VESA. If you have PCI, say Y, otherwise N.
  2045. choice
  2046. prompt "PCI access mode"
  2047. depends on X86_32 && PCI
  2048. default PCI_GOANY
  2049. ---help---
  2050. On PCI systems, the BIOS can be used to detect the PCI devices and
  2051. determine their configuration. However, some old PCI motherboards
  2052. have BIOS bugs and may crash if this is done. Also, some embedded
  2053. PCI-based systems don't have any BIOS at all. Linux can also try to
  2054. detect the PCI hardware directly without using the BIOS.
  2055. With this option, you can specify how Linux should detect the
  2056. PCI devices. If you choose "BIOS", the BIOS will be used,
  2057. if you choose "Direct", the BIOS won't be used, and if you
  2058. choose "MMConfig", then PCI Express MMCONFIG will be used.
  2059. If you choose "Any", the kernel will try MMCONFIG, then the
  2060. direct access method and falls back to the BIOS if that doesn't
  2061. work. If unsure, go with the default, which is "Any".
  2062. config PCI_GOBIOS
  2063. bool "BIOS"
  2064. config PCI_GOMMCONFIG
  2065. bool "MMConfig"
  2066. config PCI_GODIRECT
  2067. bool "Direct"
  2068. config PCI_GOOLPC
  2069. bool "OLPC XO-1"
  2070. depends on OLPC
  2071. config PCI_GOANY
  2072. bool "Any"
  2073. endchoice
  2074. config PCI_BIOS
  2075. def_bool y
  2076. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  2077. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  2078. config PCI_DIRECT
  2079. def_bool y
  2080. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
  2081. config PCI_MMCONFIG
  2082. def_bool y
  2083. depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
  2084. config PCI_OLPC
  2085. def_bool y
  2086. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  2087. config PCI_XEN
  2088. def_bool y
  2089. depends on PCI && XEN
  2090. select SWIOTLB_XEN
  2091. config PCI_DOMAINS
  2092. def_bool y
  2093. depends on PCI
  2094. config PCI_MMCONFIG
  2095. bool "Support mmconfig PCI config space access"
  2096. depends on X86_64 && PCI && ACPI
  2097. config PCI_CNB20LE_QUIRK
  2098. bool "Read CNB20LE Host Bridge Windows" if EXPERT
  2099. depends on PCI
  2100. help
  2101. Read the PCI windows out of the CNB20LE host bridge. This allows
  2102. PCI hotplug to work on systems with the CNB20LE chipset which do
  2103. not have ACPI.
  2104. There's no public spec for this chipset, and this functionality
  2105. is known to be incomplete.
  2106. You should say N unless you know you need this.
  2107. source "drivers/pci/Kconfig"
  2108. config ISA_BUS
  2109. bool "ISA-style bus support on modern systems" if EXPERT
  2110. select ISA_BUS_API
  2111. help
  2112. Enables ISA-style drivers on modern systems. This is necessary to
  2113. support PC/104 devices on X86_64 platforms.
  2114. If unsure, say N.
  2115. # x86_64 have no ISA slots, but can have ISA-style DMA.
  2116. config ISA_DMA_API
  2117. bool "ISA-style DMA support" if (X86_64 && EXPERT)
  2118. default y
  2119. help
  2120. Enables ISA-style DMA support for devices requiring such controllers.
  2121. If unsure, say Y.
  2122. if X86_32
  2123. config ISA
  2124. bool "ISA support"
  2125. ---help---
  2126. Find out whether you have ISA slots on your motherboard. ISA is the
  2127. name of a bus system, i.e. the way the CPU talks to the other stuff
  2128. inside your box. Other bus systems are PCI, EISA, MicroChannel
  2129. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  2130. newer boards don't support it. If you have ISA, say Y, otherwise N.
  2131. config EISA
  2132. bool "EISA support"
  2133. depends on ISA
  2134. ---help---
  2135. The Extended Industry Standard Architecture (EISA) bus was
  2136. developed as an open alternative to the IBM MicroChannel bus.
  2137. The EISA bus provided some of the features of the IBM MicroChannel
  2138. bus while maintaining backward compatibility with cards made for
  2139. the older ISA bus. The EISA bus saw limited use between 1988 and
  2140. 1995 when it was made obsolete by the PCI bus.
  2141. Say Y here if you are building a kernel for an EISA-based machine.
  2142. Otherwise, say N.
  2143. source "drivers/eisa/Kconfig"
  2144. config SCx200
  2145. tristate "NatSemi SCx200 support"
  2146. ---help---
  2147. This provides basic support for National Semiconductor's
  2148. (now AMD's) Geode processors. The driver probes for the
  2149. PCI-IDs of several on-chip devices, so its a good dependency
  2150. for other scx200_* drivers.
  2151. If compiled as a module, the driver is named scx200.
  2152. config SCx200HR_TIMER
  2153. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  2154. depends on SCx200
  2155. default y
  2156. ---help---
  2157. This driver provides a clocksource built upon the on-chip
  2158. 27MHz high-resolution timer. Its also a workaround for
  2159. NSC Geode SC-1100's buggy TSC, which loses time when the
  2160. processor goes idle (as is done by the scheduler). The
  2161. other workaround is idle=poll boot option.
  2162. config OLPC
  2163. bool "One Laptop Per Child support"
  2164. depends on !X86_PAE
  2165. select GPIOLIB
  2166. select OF
  2167. select OF_PROMTREE
  2168. select IRQ_DOMAIN
  2169. ---help---
  2170. Add support for detecting the unique features of the OLPC
  2171. XO hardware.
  2172. config OLPC_XO1_PM
  2173. bool "OLPC XO-1 Power Management"
  2174. depends on OLPC && MFD_CS5535 && PM_SLEEP
  2175. select MFD_CORE
  2176. ---help---
  2177. Add support for poweroff and suspend of the OLPC XO-1 laptop.
  2178. config OLPC_XO1_RTC
  2179. bool "OLPC XO-1 Real Time Clock"
  2180. depends on OLPC_XO1_PM && RTC_DRV_CMOS
  2181. ---help---
  2182. Add support for the XO-1 real time clock, which can be used as a
  2183. programmable wakeup source.
  2184. config OLPC_XO1_SCI
  2185. bool "OLPC XO-1 SCI extras"
  2186. depends on OLPC && OLPC_XO1_PM
  2187. depends on INPUT=y
  2188. select POWER_SUPPLY
  2189. select GPIO_CS5535
  2190. select MFD_CORE
  2191. ---help---
  2192. Add support for SCI-based features of the OLPC XO-1 laptop:
  2193. - EC-driven system wakeups
  2194. - Power button
  2195. - Ebook switch
  2196. - Lid switch
  2197. - AC adapter status updates
  2198. - Battery status updates
  2199. config OLPC_XO15_SCI
  2200. bool "OLPC XO-1.5 SCI extras"
  2201. depends on OLPC && ACPI
  2202. select POWER_SUPPLY
  2203. ---help---
  2204. Add support for SCI-based features of the OLPC XO-1.5 laptop:
  2205. - EC-driven system wakeups
  2206. - AC adapter status updates
  2207. - Battery status updates
  2208. config ALIX
  2209. bool "PCEngines ALIX System Support (LED setup)"
  2210. select GPIOLIB
  2211. ---help---
  2212. This option enables system support for the PCEngines ALIX.
  2213. At present this just sets up LEDs for GPIO control on
  2214. ALIX2/3/6 boards. However, other system specific setup should
  2215. get added here.
  2216. Note: You must still enable the drivers for GPIO and LED support
  2217. (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
  2218. Note: You have to set alix.force=1 for boards with Award BIOS.
  2219. config NET5501
  2220. bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
  2221. select GPIOLIB
  2222. ---help---
  2223. This option enables system support for the Soekris Engineering net5501.
  2224. config GEOS
  2225. bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
  2226. select GPIOLIB
  2227. depends on DMI
  2228. ---help---
  2229. This option enables system support for the Traverse Technologies GEOS.
  2230. config TS5500
  2231. bool "Technologic Systems TS-5500 platform support"
  2232. depends on MELAN
  2233. select CHECK_SIGNATURE
  2234. select NEW_LEDS
  2235. select LEDS_CLASS
  2236. ---help---
  2237. This option enables system support for the Technologic Systems TS-5500.
  2238. endif # X86_32
  2239. config AMD_NB
  2240. def_bool y
  2241. depends on CPU_SUP_AMD && PCI
  2242. source "drivers/pcmcia/Kconfig"
  2243. config RAPIDIO
  2244. tristate "RapidIO support"
  2245. depends on PCI
  2246. default n
  2247. help
  2248. If enabled this option will include drivers and the core
  2249. infrastructure code to support RapidIO interconnect devices.
  2250. source "drivers/rapidio/Kconfig"
  2251. config X86_SYSFB
  2252. bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
  2253. help
  2254. Firmwares often provide initial graphics framebuffers so the BIOS,
  2255. bootloader or kernel can show basic video-output during boot for
  2256. user-guidance and debugging. Historically, x86 used the VESA BIOS
  2257. Extensions and EFI-framebuffers for this, which are mostly limited
  2258. to x86.
  2259. This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
  2260. framebuffers so the new generic system-framebuffer drivers can be
  2261. used on x86. If the framebuffer is not compatible with the generic
  2262. modes, it is adverticed as fallback platform framebuffer so legacy
  2263. drivers like efifb, vesafb and uvesafb can pick it up.
  2264. If this option is not selected, all system framebuffers are always
  2265. marked as fallback platform framebuffers as usual.
  2266. Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
  2267. not be able to pick up generic system framebuffers if this option
  2268. is selected. You are highly encouraged to enable simplefb as
  2269. replacement if you select this option. simplefb can correctly deal
  2270. with generic system framebuffers. But you should still keep vesafb
  2271. and others enabled as fallback if a system framebuffer is
  2272. incompatible with simplefb.
  2273. If unsure, say Y.
  2274. endmenu
  2275. menu "Executable file formats / Emulations"
  2276. source "fs/Kconfig.binfmt"
  2277. config IA32_EMULATION
  2278. bool "IA32 Emulation"
  2279. depends on X86_64
  2280. select ARCH_WANT_OLD_COMPAT_IPC
  2281. select BINFMT_ELF
  2282. select COMPAT_BINFMT_ELF
  2283. select COMPAT_OLD_SIGACTION
  2284. ---help---
  2285. Include code to run legacy 32-bit programs under a
  2286. 64-bit kernel. You should likely turn this on, unless you're
  2287. 100% sure that you don't have any 32-bit programs left.
  2288. config IA32_AOUT
  2289. tristate "IA32 a.out support"
  2290. depends on IA32_EMULATION
  2291. ---help---
  2292. Support old a.out binaries in the 32bit emulation.
  2293. config X86_X32
  2294. bool "x32 ABI for 64-bit mode"
  2295. depends on X86_64
  2296. ---help---
  2297. Include code to run binaries for the x32 native 32-bit ABI
  2298. for 64-bit processors. An x32 process gets access to the
  2299. full 64-bit register file and wide data path while leaving
  2300. pointers at 32 bits for smaller memory footprint.
  2301. You will need a recent binutils (2.22 or later) with
  2302. elf32_x86_64 support enabled to compile a kernel with this
  2303. option set.
  2304. config COMPAT_32
  2305. def_bool y
  2306. depends on IA32_EMULATION || X86_32
  2307. select HAVE_UID16
  2308. select OLD_SIGSUSPEND3
  2309. config COMPAT
  2310. def_bool y
  2311. depends on IA32_EMULATION || X86_X32
  2312. if COMPAT
  2313. config COMPAT_FOR_U64_ALIGNMENT
  2314. def_bool y
  2315. config SYSVIPC_COMPAT
  2316. def_bool y
  2317. depends on SYSVIPC
  2318. config KEYS_COMPAT
  2319. def_bool y
  2320. depends on KEYS
  2321. endif
  2322. endmenu
  2323. config HAVE_ATOMIC_IOMAP
  2324. def_bool y
  2325. depends on X86_32
  2326. config X86_DEV_DMA_OPS
  2327. bool
  2328. depends on X86_64 || STA2X11
  2329. config X86_DMA_REMAP
  2330. bool
  2331. depends on STA2X11
  2332. source "net/Kconfig"
  2333. source "drivers/Kconfig"
  2334. source "drivers/firmware/Kconfig"
  2335. source "fs/Kconfig"
  2336. source "arch/x86/Kconfig.debug"
  2337. source "security/Kconfig"
  2338. source "crypto/Kconfig"
  2339. source "arch/x86/kvm/Kconfig"
  2340. source "lib/Kconfig"