Kconfig 91 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_UACCESS_FLUSHCACHE if X86_64
  55. select ARCH_HAS_SET_MEMORY
  56. select ARCH_HAS_SG_CHAIN
  57. select ARCH_HAS_STRICT_KERNEL_RWX
  58. select ARCH_HAS_STRICT_MODULE_RWX
  59. select ARCH_HAS_UBSAN_SANITIZE_ALL
  60. select ARCH_HAVE_NMI_SAFE_CMPXCHG
  61. select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
  62. select ARCH_MIGHT_HAVE_PC_PARPORT
  63. select ARCH_MIGHT_HAVE_PC_SERIO
  64. select ARCH_SUPPORTS_ATOMIC_RMW
  65. select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
  66. select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
  67. select ARCH_USE_BUILTIN_BSWAP
  68. select ARCH_USE_QUEUED_RWLOCKS
  69. select ARCH_USE_QUEUED_SPINLOCKS
  70. select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
  71. select ARCH_WANT_FRAME_POINTERS
  72. select ARCH_WANTS_DYNAMIC_TASK_STRUCT
  73. select BUILDTIME_EXTABLE_SORT
  74. select CLKEVT_I8253
  75. select CLOCKSOURCE_VALIDATE_LAST_CYCLE
  76. select CLOCKSOURCE_WATCHDOG
  77. select DCACHE_WORD_ACCESS
  78. select EDAC_ATOMIC_SCRUB
  79. select EDAC_SUPPORT
  80. select GENERIC_CLOCKEVENTS
  81. select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
  82. select GENERIC_CLOCKEVENTS_MIN_ADJUST
  83. select GENERIC_CMOS_UPDATE
  84. select GENERIC_CPU_AUTOPROBE
  85. select GENERIC_EARLY_IOREMAP
  86. select GENERIC_FIND_FIRST_BIT
  87. select GENERIC_IOMAP
  88. select GENERIC_IRQ_PROBE
  89. select GENERIC_IRQ_SHOW
  90. select GENERIC_PENDING_IRQ if SMP
  91. select GENERIC_SMP_IDLE_THREAD
  92. select GENERIC_STRNCPY_FROM_USER
  93. select GENERIC_STRNLEN_USER
  94. select GENERIC_TIME_VSYSCALL
  95. select HAVE_ACPI_APEI if ACPI
  96. select HAVE_ACPI_APEI_NMI if ACPI
  97. select HAVE_ALIGNED_STRUCT_PAGE if SLUB
  98. select HAVE_ARCH_AUDITSYSCALL
  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_COMPAT_MMAP_BASES if MMU && COMPAT
  107. select HAVE_ARCH_SECCOMP_FILTER
  108. select HAVE_ARCH_TRACEHOOK
  109. select HAVE_ARCH_TRANSPARENT_HUGEPAGE
  110. select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
  111. select HAVE_ARCH_VMAP_STACK if X86_64
  112. select HAVE_ARCH_WITHIN_STACK_FRAMES
  113. select HAVE_CC_STACKPROTECTOR
  114. select HAVE_CMPXCHG_DOUBLE
  115. select HAVE_CMPXCHG_LOCAL
  116. select HAVE_CONTEXT_TRACKING if X86_64
  117. select HAVE_COPY_THREAD_TLS
  118. select HAVE_C_RECORDMCOUNT
  119. select HAVE_DEBUG_KMEMLEAK
  120. select HAVE_DEBUG_STACKOVERFLOW
  121. select HAVE_DMA_API_DEBUG
  122. select HAVE_DMA_CONTIGUOUS
  123. select HAVE_DYNAMIC_FTRACE
  124. select HAVE_DYNAMIC_FTRACE_WITH_REGS
  125. select HAVE_EBPF_JIT if X86_64
  126. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  127. select HAVE_EXIT_THREAD
  128. select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
  129. select HAVE_FTRACE_MCOUNT_RECORD
  130. select HAVE_FUNCTION_GRAPH_TRACER
  131. select HAVE_FUNCTION_TRACER
  132. select HAVE_GCC_PLUGINS
  133. select HAVE_HW_BREAKPOINT
  134. select HAVE_IDE
  135. select HAVE_IOREMAP_PROT
  136. select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
  137. select HAVE_IRQ_TIME_ACCOUNTING
  138. select HAVE_KERNEL_BZIP2
  139. select HAVE_KERNEL_GZIP
  140. select HAVE_KERNEL_LZ4
  141. select HAVE_KERNEL_LZMA
  142. select HAVE_KERNEL_LZO
  143. select HAVE_KERNEL_XZ
  144. select HAVE_KPROBES
  145. select HAVE_KPROBES_ON_FTRACE
  146. select HAVE_KRETPROBES
  147. select HAVE_KVM
  148. select HAVE_LIVEPATCH if X86_64
  149. select HAVE_MEMBLOCK
  150. select HAVE_MEMBLOCK_NODE_MAP
  151. select HAVE_MIXED_BREAKPOINTS_REGS
  152. select HAVE_NMI
  153. select HAVE_OPROFILE
  154. select HAVE_OPTPROBES
  155. select HAVE_PCSPKR_PLATFORM
  156. select HAVE_PERF_EVENTS
  157. select HAVE_PERF_EVENTS_NMI
  158. select HAVE_PERF_REGS
  159. select HAVE_PERF_USER_STACK_DUMP
  160. select HAVE_REGS_AND_STACK_ACCESS_API
  161. select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER && STACK_VALIDATION
  162. select HAVE_STACK_VALIDATION if X86_64
  163. select HAVE_SYSCALL_TRACEPOINTS
  164. select HAVE_UNSTABLE_SCHED_CLOCK
  165. select HAVE_USER_RETURN_NOTIFIER
  166. select IRQ_FORCED_THREADING
  167. select PERF_EVENTS
  168. select RTC_LIB
  169. select RTC_MC146818_LIB
  170. select SPARSE_IRQ
  171. select SRCU
  172. select SYSCTL_EXCEPTION_TRACE
  173. select THREAD_INFO_IN_TASK
  174. select USER_STACKTRACE_SUPPORT
  175. select VIRT_TO_BUS
  176. select X86_FEATURE_NAMES if PROC_FS
  177. config INSTRUCTION_DECODER
  178. def_bool y
  179. depends on KPROBES || PERF_EVENTS || UPROBES
  180. config OUTPUT_FORMAT
  181. string
  182. default "elf32-i386" if X86_32
  183. default "elf64-x86-64" if X86_64
  184. config ARCH_DEFCONFIG
  185. string
  186. default "arch/x86/configs/i386_defconfig" if X86_32
  187. default "arch/x86/configs/x86_64_defconfig" if X86_64
  188. config LOCKDEP_SUPPORT
  189. def_bool y
  190. config STACKTRACE_SUPPORT
  191. def_bool y
  192. config MMU
  193. def_bool y
  194. config ARCH_MMAP_RND_BITS_MIN
  195. default 28 if 64BIT
  196. default 8
  197. config ARCH_MMAP_RND_BITS_MAX
  198. default 32 if 64BIT
  199. default 16
  200. config ARCH_MMAP_RND_COMPAT_BITS_MIN
  201. default 8
  202. config ARCH_MMAP_RND_COMPAT_BITS_MAX
  203. default 16
  204. config SBUS
  205. bool
  206. config NEED_DMA_MAP_STATE
  207. def_bool y
  208. depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
  209. config NEED_SG_DMA_LENGTH
  210. def_bool y
  211. config GENERIC_ISA_DMA
  212. def_bool y
  213. depends on ISA_DMA_API
  214. config GENERIC_BUG
  215. def_bool y
  216. depends on BUG
  217. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  218. config GENERIC_BUG_RELATIVE_POINTERS
  219. bool
  220. config GENERIC_HWEIGHT
  221. def_bool y
  222. config ARCH_MAY_HAVE_PC_FDC
  223. def_bool y
  224. depends on ISA_DMA_API
  225. config RWSEM_XCHGADD_ALGORITHM
  226. def_bool y
  227. config GENERIC_CALIBRATE_DELAY
  228. def_bool y
  229. config ARCH_HAS_CPU_RELAX
  230. def_bool y
  231. config ARCH_HAS_CACHE_LINE_SIZE
  232. def_bool y
  233. config HAVE_SETUP_PER_CPU_AREA
  234. def_bool y
  235. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  236. def_bool y
  237. config NEED_PER_CPU_PAGE_FIRST_CHUNK
  238. def_bool y
  239. config ARCH_HIBERNATION_POSSIBLE
  240. def_bool y
  241. config ARCH_SUSPEND_POSSIBLE
  242. def_bool y
  243. config ARCH_WANT_HUGE_PMD_SHARE
  244. def_bool y
  245. config ARCH_WANT_GENERAL_HUGETLB
  246. def_bool y
  247. config ZONE_DMA32
  248. def_bool y if X86_64
  249. config AUDIT_ARCH
  250. def_bool y if X86_64
  251. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  252. def_bool y
  253. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  254. def_bool y
  255. config KASAN_SHADOW_OFFSET
  256. hex
  257. depends on KASAN
  258. default 0xdff8000000000000 if X86_5LEVEL
  259. default 0xdffffc0000000000
  260. config HAVE_INTEL_TXT
  261. def_bool y
  262. depends on INTEL_IOMMU && ACPI
  263. config X86_32_SMP
  264. def_bool y
  265. depends on X86_32 && SMP
  266. config X86_64_SMP
  267. def_bool y
  268. depends on X86_64 && SMP
  269. config X86_32_LAZY_GS
  270. def_bool y
  271. depends on X86_32 && !CC_STACKPROTECTOR
  272. config ARCH_SUPPORTS_UPROBES
  273. def_bool y
  274. config FIX_EARLYCON_MEM
  275. def_bool y
  276. config PGTABLE_LEVELS
  277. int
  278. default 4 if X86_64
  279. default 3 if X86_PAE
  280. default 2
  281. source "init/Kconfig"
  282. source "kernel/Kconfig.freezer"
  283. menu "Processor type and features"
  284. config ZONE_DMA
  285. bool "DMA memory allocation support" if EXPERT
  286. default y
  287. help
  288. DMA memory allocation support allows devices with less than 32-bit
  289. addressing to allocate within the first 16MB of address space.
  290. Disable if no such devices will be used.
  291. If unsure, say Y.
  292. config SMP
  293. bool "Symmetric multi-processing support"
  294. ---help---
  295. This enables support for systems with more than one CPU. If you have
  296. a system with only one CPU, say N. If you have a system with more
  297. than one CPU, say Y.
  298. If you say N here, the kernel will run on uni- and multiprocessor
  299. machines, but will use only one CPU of a multiprocessor machine. If
  300. you say Y here, the kernel will run on many, but not all,
  301. uniprocessor machines. On a uniprocessor machine, the kernel
  302. will run faster if you say N here.
  303. Note that if you say Y here and choose architecture "586" or
  304. "Pentium" under "Processor family", the kernel will not work on 486
  305. architectures. Similarly, multiprocessor kernels for the "PPro"
  306. architecture may not work on all Pentium based boards.
  307. People using multiprocessor machines who say Y here should also say
  308. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  309. Management" code will be disabled if you say Y here.
  310. See also <file:Documentation/x86/i386/IO-APIC.txt>,
  311. <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
  312. <http://www.tldp.org/docs.html#howto>.
  313. If you don't know what to do here, say N.
  314. config X86_FEATURE_NAMES
  315. bool "Processor feature human-readable names" if EMBEDDED
  316. default y
  317. ---help---
  318. This option compiles in a table of x86 feature bits and corresponding
  319. names. This is required to support /proc/cpuinfo and a few kernel
  320. messages. You can disable this to save space, at the expense of
  321. making those few kernel messages show numeric feature bits instead.
  322. If in doubt, say Y.
  323. config X86_FAST_FEATURE_TESTS
  324. bool "Fast CPU feature tests" if EMBEDDED
  325. default y
  326. ---help---
  327. Some fast-paths in the kernel depend on the capabilities of the CPU.
  328. Say Y here for the kernel to patch in the appropriate code at runtime
  329. based on the capabilities of the CPU. The infrastructure for patching
  330. code at runtime takes up some additional space; space-constrained
  331. embedded systems may wish to say N here to produce smaller, slightly
  332. slower code.
  333. config X86_X2APIC
  334. bool "Support x2apic"
  335. depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
  336. ---help---
  337. This enables x2apic support on CPUs that have this feature.
  338. This allows 32-bit apic IDs (so it can support very large systems),
  339. and accesses the local apic via MSRs not via mmio.
  340. If you don't know what to do here, say N.
  341. config X86_MPPARSE
  342. bool "Enable MPS table" if ACPI || SFI
  343. default y
  344. depends on X86_LOCAL_APIC
  345. ---help---
  346. For old smp systems that do not have proper acpi support. Newer systems
  347. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  348. config X86_BIGSMP
  349. bool "Support for big SMP systems with more than 8 CPUs"
  350. depends on X86_32 && SMP
  351. ---help---
  352. This option is needed for the systems that have more than 8 CPUs
  353. config GOLDFISH
  354. def_bool y
  355. depends on X86_GOLDFISH
  356. config INTEL_RDT_A
  357. bool "Intel Resource Director Technology Allocation support"
  358. default n
  359. depends on X86 && CPU_SUP_INTEL
  360. select KERNFS
  361. help
  362. Select to enable resource allocation which is a sub-feature of
  363. Intel Resource Director Technology(RDT). More information about
  364. RDT can be found in the Intel x86 Architecture Software
  365. Developer Manual.
  366. Say N if unsure.
  367. if X86_32
  368. config X86_EXTENDED_PLATFORM
  369. bool "Support for extended (non-PC) x86 platforms"
  370. default y
  371. ---help---
  372. If you disable this option then the kernel will only support
  373. standard PC platforms. (which covers the vast majority of
  374. systems out there.)
  375. If you enable this option then you'll be able to select support
  376. for the following (non-PC) 32 bit x86 platforms:
  377. Goldfish (Android emulator)
  378. AMD Elan
  379. RDC R-321x SoC
  380. SGI 320/540 (Visual Workstation)
  381. STA2X11-based (e.g. Northville)
  382. Moorestown MID devices
  383. If you have one of these systems, or if you want to build a
  384. generic distribution kernel, say Y here - otherwise say N.
  385. endif
  386. if X86_64
  387. config X86_EXTENDED_PLATFORM
  388. bool "Support for extended (non-PC) x86 platforms"
  389. default y
  390. ---help---
  391. If you disable this option then the kernel will only support
  392. standard PC platforms. (which covers the vast majority of
  393. systems out there.)
  394. If you enable this option then you'll be able to select support
  395. for the following (non-PC) 64 bit x86 platforms:
  396. Numascale NumaChip
  397. ScaleMP vSMP
  398. SGI Ultraviolet
  399. If you have one of these systems, or if you want to build a
  400. generic distribution kernel, say Y here - otherwise say N.
  401. endif
  402. # This is an alphabetically sorted list of 64 bit extended platforms
  403. # Please maintain the alphabetic order if and when there are additions
  404. config X86_NUMACHIP
  405. bool "Numascale NumaChip"
  406. depends on X86_64
  407. depends on X86_EXTENDED_PLATFORM
  408. depends on NUMA
  409. depends on SMP
  410. depends on X86_X2APIC
  411. depends on PCI_MMCONFIG
  412. ---help---
  413. Adds support for Numascale NumaChip large-SMP systems. Needed to
  414. enable more than ~168 cores.
  415. If you don't have one of these, you should say N here.
  416. config X86_VSMP
  417. bool "ScaleMP vSMP"
  418. select HYPERVISOR_GUEST
  419. select PARAVIRT
  420. depends on X86_64 && PCI
  421. depends on X86_EXTENDED_PLATFORM
  422. depends on SMP
  423. ---help---
  424. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  425. supposed to run on these EM64T-based machines. Only choose this option
  426. if you have one of these machines.
  427. config X86_UV
  428. bool "SGI Ultraviolet"
  429. depends on X86_64
  430. depends on X86_EXTENDED_PLATFORM
  431. depends on NUMA
  432. depends on EFI
  433. depends on X86_X2APIC
  434. depends on PCI
  435. ---help---
  436. This option is needed in order to support SGI Ultraviolet systems.
  437. If you don't have one of these, you should say N here.
  438. # Following is an alphabetically sorted list of 32 bit extended platforms
  439. # Please maintain the alphabetic order if and when there are additions
  440. config X86_GOLDFISH
  441. bool "Goldfish (Virtual Platform)"
  442. depends on X86_EXTENDED_PLATFORM
  443. ---help---
  444. Enable support for the Goldfish virtual platform used primarily
  445. for Android development. Unless you are building for the Android
  446. Goldfish emulator say N here.
  447. config X86_INTEL_CE
  448. bool "CE4100 TV platform"
  449. depends on PCI
  450. depends on PCI_GODIRECT
  451. depends on X86_IO_APIC
  452. depends on X86_32
  453. depends on X86_EXTENDED_PLATFORM
  454. select X86_REBOOTFIXUPS
  455. select OF
  456. select OF_EARLY_FLATTREE
  457. ---help---
  458. Select for the Intel CE media processor (CE4100) SOC.
  459. This option compiles in support for the CE4100 SOC for settop
  460. boxes and media devices.
  461. config X86_INTEL_MID
  462. bool "Intel MID platform support"
  463. depends on X86_EXTENDED_PLATFORM
  464. depends on X86_PLATFORM_DEVICES
  465. depends on PCI
  466. depends on X86_64 || (PCI_GOANY && X86_32)
  467. depends on X86_IO_APIC
  468. select SFI
  469. select I2C
  470. select DW_APB_TIMER
  471. select APB_TIMER
  472. select INTEL_SCU_IPC
  473. select MFD_INTEL_MSIC
  474. ---help---
  475. Select to build a kernel capable of supporting Intel MID (Mobile
  476. Internet Device) platform systems which do not have the PCI legacy
  477. interfaces. If you are building for a PC class system say N here.
  478. Intel MID platforms are based on an Intel processor and chipset which
  479. consume less power than most of the x86 derivatives.
  480. config X86_INTEL_QUARK
  481. bool "Intel Quark platform support"
  482. depends on X86_32
  483. depends on X86_EXTENDED_PLATFORM
  484. depends on X86_PLATFORM_DEVICES
  485. depends on X86_TSC
  486. depends on PCI
  487. depends on PCI_GOANY
  488. depends on X86_IO_APIC
  489. select IOSF_MBI
  490. select INTEL_IMR
  491. select COMMON_CLK
  492. ---help---
  493. Select to include support for Quark X1000 SoC.
  494. Say Y here if you have a Quark based system such as the Arduino
  495. compatible Intel Galileo.
  496. config X86_INTEL_LPSS
  497. bool "Intel Low Power Subsystem Support"
  498. depends on X86 && ACPI
  499. select COMMON_CLK
  500. select PINCTRL
  501. select IOSF_MBI
  502. ---help---
  503. Select to build support for Intel Low Power Subsystem such as
  504. found on Intel Lynxpoint PCH. Selecting this option enables
  505. things like clock tree (common clock framework) and pincontrol
  506. which are needed by the LPSS peripheral drivers.
  507. config X86_AMD_PLATFORM_DEVICE
  508. bool "AMD ACPI2Platform devices support"
  509. depends on ACPI
  510. select COMMON_CLK
  511. select PINCTRL
  512. ---help---
  513. Select to interpret AMD specific ACPI device to platform device
  514. such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
  515. I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
  516. implemented under PINCTRL subsystem.
  517. config IOSF_MBI
  518. tristate "Intel SoC IOSF Sideband support for SoC platforms"
  519. depends on PCI
  520. ---help---
  521. This option enables sideband register access support for Intel SoC
  522. platforms. On these platforms the IOSF sideband is used in lieu of
  523. MSR's for some register accesses, mostly but not limited to thermal
  524. and power. Drivers may query the availability of this device to
  525. determine if they need the sideband in order to work on these
  526. platforms. The sideband is available on the following SoC products.
  527. This list is not meant to be exclusive.
  528. - BayTrail
  529. - Braswell
  530. - Quark
  531. You should say Y if you are running a kernel on one of these SoC's.
  532. config IOSF_MBI_DEBUG
  533. bool "Enable IOSF sideband access through debugfs"
  534. depends on IOSF_MBI && DEBUG_FS
  535. ---help---
  536. Select this option to expose the IOSF sideband access registers (MCR,
  537. MDR, MCRX) through debugfs to write and read register information from
  538. different units on the SoC. This is most useful for obtaining device
  539. state information for debug and analysis. As this is a general access
  540. mechanism, users of this option would have specific knowledge of the
  541. device they want to access.
  542. If you don't require the option or are in doubt, say N.
  543. config X86_RDC321X
  544. bool "RDC R-321x SoC"
  545. depends on X86_32
  546. depends on X86_EXTENDED_PLATFORM
  547. select M486
  548. select X86_REBOOTFIXUPS
  549. ---help---
  550. This option is needed for RDC R-321x system-on-chip, also known
  551. as R-8610-(G).
  552. If you don't have one of these chips, you should say N here.
  553. config X86_32_NON_STANDARD
  554. bool "Support non-standard 32-bit SMP architectures"
  555. depends on X86_32 && SMP
  556. depends on X86_EXTENDED_PLATFORM
  557. ---help---
  558. This option compiles in the bigsmp and STA2X11 default
  559. subarchitectures. It is intended for a generic binary
  560. kernel. If you select them all, kernel will probe it one by
  561. one and will fallback to default.
  562. # Alphabetically sorted list of Non standard 32 bit platforms
  563. config X86_SUPPORTS_MEMORY_FAILURE
  564. def_bool y
  565. # MCE code calls memory_failure():
  566. depends on X86_MCE
  567. # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
  568. # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
  569. depends on X86_64 || !SPARSEMEM
  570. select ARCH_SUPPORTS_MEMORY_FAILURE
  571. config STA2X11
  572. bool "STA2X11 Companion Chip Support"
  573. depends on X86_32_NON_STANDARD && PCI
  574. select X86_DEV_DMA_OPS
  575. select X86_DMA_REMAP
  576. select SWIOTLB
  577. select MFD_STA2X11
  578. select GPIOLIB
  579. default n
  580. ---help---
  581. This adds support for boards based on the STA2X11 IO-Hub,
  582. a.k.a. "ConneXt". The chip is used in place of the standard
  583. PC chipset, so all "standard" peripherals are missing. If this
  584. option is selected the kernel will still be able to boot on
  585. standard PC machines.
  586. config X86_32_IRIS
  587. tristate "Eurobraille/Iris poweroff module"
  588. depends on X86_32
  589. ---help---
  590. The Iris machines from EuroBraille do not have APM or ACPI support
  591. to shut themselves down properly. A special I/O sequence is
  592. needed to do so, which is what this module does at
  593. kernel shutdown.
  594. This is only for Iris machines from EuroBraille.
  595. If unused, say N.
  596. config SCHED_OMIT_FRAME_POINTER
  597. def_bool y
  598. prompt "Single-depth WCHAN output"
  599. depends on X86
  600. ---help---
  601. Calculate simpler /proc/<PID>/wchan values. If this option
  602. is disabled then wchan values will recurse back to the
  603. caller function. This provides more accurate wchan values,
  604. at the expense of slightly more scheduling overhead.
  605. If in doubt, say "Y".
  606. menuconfig HYPERVISOR_GUEST
  607. bool "Linux guest support"
  608. ---help---
  609. Say Y here to enable options for running Linux under various hyper-
  610. visors. This option enables basic hypervisor detection and platform
  611. setup.
  612. If you say N, all options in this submenu will be skipped and
  613. disabled, and Linux guest support won't be built in.
  614. if HYPERVISOR_GUEST
  615. config PARAVIRT
  616. bool "Enable paravirtualization code"
  617. ---help---
  618. This changes the kernel so it can modify itself when it is run
  619. under a hypervisor, potentially improving performance significantly
  620. over full virtualization. However, when run without a hypervisor
  621. the kernel is theoretically slower and slightly larger.
  622. config PARAVIRT_DEBUG
  623. bool "paravirt-ops debugging"
  624. depends on PARAVIRT && DEBUG_KERNEL
  625. ---help---
  626. Enable to debug paravirt_ops internals. Specifically, BUG if
  627. a paravirt_op is missing when it is called.
  628. config PARAVIRT_SPINLOCKS
  629. bool "Paravirtualization layer for spinlocks"
  630. depends on PARAVIRT && SMP
  631. ---help---
  632. Paravirtualized spinlocks allow a pvops backend to replace the
  633. spinlock implementation with something virtualization-friendly
  634. (for example, block the virtual CPU rather than spinning).
  635. It has a minimal impact on native kernels and gives a nice performance
  636. benefit on paravirtualized KVM / Xen kernels.
  637. If you are unsure how to answer this question, answer Y.
  638. config QUEUED_LOCK_STAT
  639. bool "Paravirt queued spinlock statistics"
  640. depends on PARAVIRT_SPINLOCKS && DEBUG_FS
  641. ---help---
  642. Enable the collection of statistical data on the slowpath
  643. behavior of paravirtualized queued spinlocks and report
  644. them on debugfs.
  645. source "arch/x86/xen/Kconfig"
  646. config KVM_GUEST
  647. bool "KVM Guest support (including kvmclock)"
  648. depends on PARAVIRT
  649. select PARAVIRT_CLOCK
  650. default y
  651. ---help---
  652. This option enables various optimizations for running under the KVM
  653. hypervisor. It includes a paravirtualized clock, so that instead
  654. of relying on a PIT (or probably other) emulation by the
  655. underlying device model, the host provides the guest with
  656. timing infrastructure such as time of day, and system time
  657. config KVM_DEBUG_FS
  658. bool "Enable debug information for KVM Guests in debugfs"
  659. depends on KVM_GUEST && DEBUG_FS
  660. default n
  661. ---help---
  662. This option enables collection of various statistics for KVM guest.
  663. Statistics are displayed in debugfs filesystem. Enabling this option
  664. may incur significant overhead.
  665. source "arch/x86/lguest/Kconfig"
  666. config PARAVIRT_TIME_ACCOUNTING
  667. bool "Paravirtual steal time accounting"
  668. depends on PARAVIRT
  669. default n
  670. ---help---
  671. Select this option to enable fine granularity task steal time
  672. accounting. Time spent executing other tasks in parallel with
  673. the current vCPU is discounted from the vCPU power. To account for
  674. that, there can be a small performance impact.
  675. If in doubt, say N here.
  676. config PARAVIRT_CLOCK
  677. bool
  678. endif #HYPERVISOR_GUEST
  679. config NO_BOOTMEM
  680. def_bool y
  681. source "arch/x86/Kconfig.cpu"
  682. config HPET_TIMER
  683. def_bool X86_64
  684. prompt "HPET Timer Support" if X86_32
  685. ---help---
  686. Use the IA-PC HPET (High Precision Event Timer) to manage
  687. time in preference to the PIT and RTC, if a HPET is
  688. present.
  689. HPET is the next generation timer replacing legacy 8254s.
  690. The HPET provides a stable time base on SMP
  691. systems, unlike the TSC, but it is more expensive to access,
  692. as it is off-chip. The interface used is documented
  693. in the HPET spec, revision 1.
  694. You can safely choose Y here. However, HPET will only be
  695. activated if the platform and the BIOS support this feature.
  696. Otherwise the 8254 will be used for timing services.
  697. Choose N to continue using the legacy 8254 timer.
  698. config HPET_EMULATE_RTC
  699. def_bool y
  700. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  701. config APB_TIMER
  702. def_bool y if X86_INTEL_MID
  703. prompt "Intel MID APB Timer Support" if X86_INTEL_MID
  704. select DW_APB_TIMER
  705. depends on X86_INTEL_MID && SFI
  706. help
  707. APB timer is the replacement for 8254, HPET on X86 MID platforms.
  708. The APBT provides a stable time base on SMP
  709. systems, unlike the TSC, but it is more expensive to access,
  710. as it is off-chip. APB timers are always running regardless of CPU
  711. C states, they are used as per CPU clockevent device when possible.
  712. # Mark as expert because too many people got it wrong.
  713. # The code disables itself when not needed.
  714. config DMI
  715. default y
  716. select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
  717. bool "Enable DMI scanning" if EXPERT
  718. ---help---
  719. Enabled scanning of DMI to identify machine quirks. Say Y
  720. here unless you have verified that your setup is not
  721. affected by entries in the DMI blacklist. Required by PNP
  722. BIOS code.
  723. config GART_IOMMU
  724. bool "Old AMD GART IOMMU support"
  725. select SWIOTLB
  726. depends on X86_64 && PCI && AMD_NB
  727. ---help---
  728. Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
  729. GART based hardware IOMMUs.
  730. The GART supports full DMA access for devices with 32-bit access
  731. limitations, on systems with more than 3 GB. This is usually needed
  732. for USB, sound, many IDE/SATA chipsets and some other devices.
  733. Newer systems typically have a modern AMD IOMMU, supported via
  734. the CONFIG_AMD_IOMMU=y config option.
  735. In normal configurations this driver is only active when needed:
  736. there's more than 3 GB of memory and the system contains a
  737. 32-bit limited device.
  738. If unsure, say Y.
  739. config CALGARY_IOMMU
  740. bool "IBM Calgary IOMMU support"
  741. select SWIOTLB
  742. depends on X86_64 && PCI
  743. ---help---
  744. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  745. systems. Needed to run systems with more than 3GB of memory
  746. properly with 32-bit PCI devices that do not support DAC
  747. (Double Address Cycle). Calgary also supports bus level
  748. isolation, where all DMAs pass through the IOMMU. This
  749. prevents them from going anywhere except their intended
  750. destination. This catches hard-to-find kernel bugs and
  751. mis-behaving drivers and devices that do not use the DMA-API
  752. properly to set up their DMA buffers. The IOMMU can be
  753. turned off at boot time with the iommu=off parameter.
  754. Normally the kernel will make the right choice by itself.
  755. If unsure, say Y.
  756. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  757. def_bool y
  758. prompt "Should Calgary be enabled by default?"
  759. depends on CALGARY_IOMMU
  760. ---help---
  761. Should Calgary be enabled by default? if you choose 'y', Calgary
  762. will be used (if it exists). If you choose 'n', Calgary will not be
  763. used even if it exists. If you choose 'n' and would like to use
  764. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  765. If unsure, say Y.
  766. # need this always selected by IOMMU for the VIA workaround
  767. config SWIOTLB
  768. def_bool y if X86_64
  769. ---help---
  770. Support for software bounce buffers used on x86-64 systems
  771. which don't have a hardware IOMMU. Using this PCI devices
  772. which can only access 32-bits of memory can be used on systems
  773. with more than 3 GB of memory.
  774. If unsure, say Y.
  775. config IOMMU_HELPER
  776. def_bool y
  777. depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
  778. config MAXSMP
  779. bool "Enable Maximum number of SMP Processors and NUMA Nodes"
  780. depends on X86_64 && SMP && DEBUG_KERNEL
  781. select CPUMASK_OFFSTACK
  782. ---help---
  783. Enable maximum number of CPUS and NUMA Nodes for this architecture.
  784. If unsure, say N.
  785. config NR_CPUS
  786. int "Maximum number of CPUs" if SMP && !MAXSMP
  787. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  788. range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
  789. range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
  790. default "1" if !SMP
  791. default "8192" if MAXSMP
  792. default "32" if SMP && X86_BIGSMP
  793. default "8" if SMP && X86_32
  794. default "64" if SMP
  795. ---help---
  796. This allows you to specify the maximum number of CPUs which this
  797. kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
  798. supported value is 8192, otherwise the maximum value is 512. The
  799. minimum value which makes sense is 2.
  800. This is purely to save memory - each supported CPU adds
  801. approximately eight kilobytes to the kernel image.
  802. config SCHED_SMT
  803. bool "SMT (Hyperthreading) scheduler support"
  804. depends on SMP
  805. ---help---
  806. SMT scheduler support improves the CPU scheduler's decision making
  807. when dealing with Intel Pentium 4 chips with HyperThreading at a
  808. cost of slightly increased overhead in some places. If unsure say
  809. N here.
  810. config SCHED_MC
  811. def_bool y
  812. prompt "Multi-core scheduler support"
  813. depends on SMP
  814. ---help---
  815. Multi-core scheduler support improves the CPU scheduler's decision
  816. making when dealing with multi-core CPU chips at a cost of slightly
  817. increased overhead in some places. If unsure say N here.
  818. config SCHED_MC_PRIO
  819. bool "CPU core priorities scheduler support"
  820. depends on SCHED_MC && CPU_SUP_INTEL
  821. select X86_INTEL_PSTATE
  822. select CPU_FREQ
  823. default y
  824. ---help---
  825. Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
  826. core ordering determined at manufacturing time, which allows
  827. certain cores to reach higher turbo frequencies (when running
  828. single threaded workloads) than others.
  829. Enabling this kernel feature teaches the scheduler about
  830. the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
  831. scheduler's CPU selection logic accordingly, so that higher
  832. overall system performance can be achieved.
  833. This feature will have no effect on CPUs without this feature.
  834. If unsure say Y here.
  835. source "kernel/Kconfig.preempt"
  836. config UP_LATE_INIT
  837. def_bool y
  838. depends on !SMP && X86_LOCAL_APIC
  839. config X86_UP_APIC
  840. bool "Local APIC support on uniprocessors" if !PCI_MSI
  841. default PCI_MSI
  842. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  843. ---help---
  844. A local APIC (Advanced Programmable Interrupt Controller) is an
  845. integrated interrupt controller in the CPU. If you have a single-CPU
  846. system which has a processor with a local APIC, you can say Y here to
  847. enable and use it. If you say Y here even though your machine doesn't
  848. have a local APIC, then the kernel will still run with no slowdown at
  849. all. The local APIC supports CPU-generated self-interrupts (timer,
  850. performance counters), and the NMI watchdog which detects hard
  851. lockups.
  852. config X86_UP_IOAPIC
  853. bool "IO-APIC support on uniprocessors"
  854. depends on X86_UP_APIC
  855. ---help---
  856. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  857. SMP-capable replacement for PC-style interrupt controllers. Most
  858. SMP systems and many recent uniprocessor systems have one.
  859. If you have a single-CPU system with an IO-APIC, you can say Y here
  860. to use it. If you say Y here even though your machine doesn't have
  861. an IO-APIC, then the kernel will still run with no slowdown at all.
  862. config X86_LOCAL_APIC
  863. def_bool y
  864. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
  865. select IRQ_DOMAIN_HIERARCHY
  866. select PCI_MSI_IRQ_DOMAIN if PCI_MSI
  867. config X86_IO_APIC
  868. def_bool y
  869. depends on X86_LOCAL_APIC || X86_UP_IOAPIC
  870. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  871. bool "Reroute for broken boot IRQs"
  872. depends on X86_IO_APIC
  873. ---help---
  874. This option enables a workaround that fixes a source of
  875. spurious interrupts. This is recommended when threaded
  876. interrupt handling is used on systems where the generation of
  877. superfluous "boot interrupts" cannot be disabled.
  878. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  879. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  880. kernel does during interrupt handling). On chipsets where this
  881. boot IRQ generation cannot be disabled, this workaround keeps
  882. the original IRQ line masked so that only the equivalent "boot
  883. IRQ" is delivered to the CPUs. The workaround also tells the
  884. kernel to set up the IRQ handler on the boot IRQ line. In this
  885. way only one interrupt is delivered to the kernel. Otherwise
  886. the spurious second interrupt may cause the kernel to bring
  887. down (vital) interrupt lines.
  888. Only affects "broken" chipsets. Interrupt sharing may be
  889. increased on these systems.
  890. config X86_MCE
  891. bool "Machine Check / overheating reporting"
  892. select GENERIC_ALLOCATOR
  893. default y
  894. ---help---
  895. Machine Check support allows the processor to notify the
  896. kernel if it detects a problem (e.g. overheating, data corruption).
  897. The action the kernel takes depends on the severity of the problem,
  898. ranging from warning messages to halting the machine.
  899. config X86_MCELOG_LEGACY
  900. bool "Support for deprecated /dev/mcelog character device"
  901. depends on X86_MCE
  902. ---help---
  903. Enable support for /dev/mcelog which is needed by the old mcelog
  904. userspace logging daemon. Consider switching to the new generation
  905. rasdaemon solution.
  906. config X86_MCE_INTEL
  907. def_bool y
  908. prompt "Intel MCE features"
  909. depends on X86_MCE && X86_LOCAL_APIC
  910. ---help---
  911. Additional support for intel specific MCE features such as
  912. the thermal monitor.
  913. config X86_MCE_AMD
  914. def_bool y
  915. prompt "AMD MCE features"
  916. depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
  917. ---help---
  918. Additional support for AMD specific MCE features such as
  919. the DRAM Error Threshold.
  920. config X86_ANCIENT_MCE
  921. bool "Support for old Pentium 5 / WinChip machine checks"
  922. depends on X86_32 && X86_MCE
  923. ---help---
  924. Include support for machine check handling on old Pentium 5 or WinChip
  925. systems. These typically need to be enabled explicitly on the command
  926. line.
  927. config X86_MCE_THRESHOLD
  928. depends on X86_MCE_AMD || X86_MCE_INTEL
  929. def_bool y
  930. config X86_MCE_INJECT
  931. depends on X86_MCE && X86_LOCAL_APIC && X86_MCELOG_LEGACY
  932. tristate "Machine check injector support"
  933. ---help---
  934. Provide support for injecting machine checks for testing purposes.
  935. If you don't know what a machine check is and you don't do kernel
  936. QA it is safe to say n.
  937. config X86_THERMAL_VECTOR
  938. def_bool y
  939. depends on X86_MCE_INTEL
  940. source "arch/x86/events/Kconfig"
  941. config X86_LEGACY_VM86
  942. bool "Legacy VM86 support"
  943. default n
  944. depends on X86_32
  945. ---help---
  946. This option allows user programs to put the CPU into V8086
  947. mode, which is an 80286-era approximation of 16-bit real mode.
  948. Some very old versions of X and/or vbetool require this option
  949. for user mode setting. Similarly, DOSEMU will use it if
  950. available to accelerate real mode DOS programs. However, any
  951. recent version of DOSEMU, X, or vbetool should be fully
  952. functional even without kernel VM86 support, as they will all
  953. fall back to software emulation. Nevertheless, if you are using
  954. a 16-bit DOS program where 16-bit performance matters, vm86
  955. mode might be faster than emulation and you might want to
  956. enable this option.
  957. Note that any app that works on a 64-bit kernel is unlikely to
  958. need this option, as 64-bit kernels don't, and can't, support
  959. V8086 mode. This option is also unrelated to 16-bit protected
  960. mode and is not needed to run most 16-bit programs under Wine.
  961. Enabling this option increases the complexity of the kernel
  962. and slows down exception handling a tiny bit.
  963. If unsure, say N here.
  964. config VM86
  965. bool
  966. default X86_LEGACY_VM86
  967. config X86_16BIT
  968. bool "Enable support for 16-bit segments" if EXPERT
  969. default y
  970. depends on MODIFY_LDT_SYSCALL
  971. ---help---
  972. This option is required by programs like Wine to run 16-bit
  973. protected mode legacy code on x86 processors. Disabling
  974. this option saves about 300 bytes on i386, or around 6K text
  975. plus 16K runtime memory on x86-64,
  976. config X86_ESPFIX32
  977. def_bool y
  978. depends on X86_16BIT && X86_32
  979. config X86_ESPFIX64
  980. def_bool y
  981. depends on X86_16BIT && X86_64
  982. config X86_VSYSCALL_EMULATION
  983. bool "Enable vsyscall emulation" if EXPERT
  984. default y
  985. depends on X86_64
  986. ---help---
  987. This enables emulation of the legacy vsyscall page. Disabling
  988. it is roughly equivalent to booting with vsyscall=none, except
  989. that it will also disable the helpful warning if a program
  990. tries to use a vsyscall. With this option set to N, offending
  991. programs will just segfault, citing addresses of the form
  992. 0xffffffffff600?00.
  993. This option is required by many programs built before 2013, and
  994. care should be used even with newer programs if set to N.
  995. Disabling this option saves about 7K of kernel size and
  996. possibly 4K of additional runtime pagetable memory.
  997. config TOSHIBA
  998. tristate "Toshiba Laptop support"
  999. depends on X86_32
  1000. ---help---
  1001. This adds a driver to safely access the System Management Mode of
  1002. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  1003. not work on models with a Phoenix BIOS. The System Management Mode
  1004. is used to set the BIOS and power saving options on Toshiba portables.
  1005. For information on utilities to make use of this driver see the
  1006. Toshiba Linux utilities web site at:
  1007. <http://www.buzzard.org.uk/toshiba/>.
  1008. Say Y if you intend to run this kernel on a Toshiba portable.
  1009. Say N otherwise.
  1010. config I8K
  1011. tristate "Dell i8k legacy laptop support"
  1012. select HWMON
  1013. select SENSORS_DELL_SMM
  1014. ---help---
  1015. This option enables legacy /proc/i8k userspace interface in hwmon
  1016. dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
  1017. temperature and allows controlling fan speeds of Dell laptops via
  1018. System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
  1019. it reports also power and hotkey status. For fan speed control is
  1020. needed userspace package i8kutils.
  1021. Say Y if you intend to run this kernel on old Dell laptops or want to
  1022. use userspace package i8kutils.
  1023. Say N otherwise.
  1024. config X86_REBOOTFIXUPS
  1025. bool "Enable X86 board specific fixups for reboot"
  1026. depends on X86_32
  1027. ---help---
  1028. This enables chipset and/or board specific fixups to be done
  1029. in order to get reboot to work correctly. This is only needed on
  1030. some combinations of hardware and BIOS. The symptom, for which
  1031. this config is intended, is when reboot ends with a stalled/hung
  1032. system.
  1033. Currently, the only fixup is for the Geode machines using
  1034. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  1035. Say Y if you want to enable the fixup. Currently, it's safe to
  1036. enable this option even if you don't need it.
  1037. Say N otherwise.
  1038. config MICROCODE
  1039. bool "CPU microcode loading support"
  1040. default y
  1041. depends on CPU_SUP_AMD || CPU_SUP_INTEL
  1042. select FW_LOADER
  1043. ---help---
  1044. If you say Y here, you will be able to update the microcode on
  1045. Intel and AMD processors. The Intel support is for the IA32 family,
  1046. e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
  1047. AMD support is for families 0x10 and later. You will obviously need
  1048. the actual microcode binary data itself which is not shipped with
  1049. the Linux kernel.
  1050. The preferred method to load microcode from a detached initrd is described
  1051. in Documentation/x86/early-microcode.txt. For that you need to enable
  1052. CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
  1053. initrd for microcode blobs.
  1054. In addition, you can build-in the microcode into the kernel. For that you
  1055. need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
  1056. to the CONFIG_EXTRA_FIRMWARE config option.
  1057. config MICROCODE_INTEL
  1058. bool "Intel microcode loading support"
  1059. depends on MICROCODE
  1060. default MICROCODE
  1061. select FW_LOADER
  1062. ---help---
  1063. This options enables microcode patch loading support for Intel
  1064. processors.
  1065. For the current Intel microcode data package go to
  1066. <https://downloadcenter.intel.com> and search for
  1067. 'Linux Processor Microcode Data File'.
  1068. config MICROCODE_AMD
  1069. bool "AMD microcode loading support"
  1070. depends on MICROCODE
  1071. select FW_LOADER
  1072. ---help---
  1073. If you select this option, microcode patch loading support for AMD
  1074. processors will be enabled.
  1075. config MICROCODE_OLD_INTERFACE
  1076. def_bool y
  1077. depends on MICROCODE
  1078. config X86_MSR
  1079. tristate "/dev/cpu/*/msr - Model-specific register support"
  1080. ---help---
  1081. This device gives privileged processes access to the x86
  1082. Model-Specific Registers (MSRs). It is a character device with
  1083. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  1084. MSR accesses are directed to a specific CPU on multi-processor
  1085. systems.
  1086. config X86_CPUID
  1087. tristate "/dev/cpu/*/cpuid - CPU information support"
  1088. ---help---
  1089. This device gives processes access to the x86 CPUID instruction to
  1090. be executed on a specific processor. It is a character device
  1091. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  1092. /dev/cpu/31/cpuid.
  1093. choice
  1094. prompt "High Memory Support"
  1095. default HIGHMEM4G
  1096. depends on X86_32
  1097. config NOHIGHMEM
  1098. bool "off"
  1099. ---help---
  1100. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  1101. However, the address space of 32-bit x86 processors is only 4
  1102. Gigabytes large. That means that, if you have a large amount of
  1103. physical memory, not all of it can be "permanently mapped" by the
  1104. kernel. The physical memory that's not permanently mapped is called
  1105. "high memory".
  1106. If you are compiling a kernel which will never run on a machine with
  1107. more than 1 Gigabyte total physical RAM, answer "off" here (default
  1108. choice and suitable for most users). This will result in a "3GB/1GB"
  1109. split: 3GB are mapped so that each process sees a 3GB virtual memory
  1110. space and the remaining part of the 4GB virtual memory space is used
  1111. by the kernel to permanently map as much physical memory as
  1112. possible.
  1113. If the machine has between 1 and 4 Gigabytes physical RAM, then
  1114. answer "4GB" here.
  1115. If more than 4 Gigabytes is used then answer "64GB" here. This
  1116. selection turns Intel PAE (Physical Address Extension) mode on.
  1117. PAE implements 3-level paging on IA32 processors. PAE is fully
  1118. supported by Linux, PAE mode is implemented on all recent Intel
  1119. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  1120. then the kernel will not boot on CPUs that don't support PAE!
  1121. The actual amount of total physical memory will either be
  1122. auto detected or can be forced by using a kernel command line option
  1123. such as "mem=256M". (Try "man bootparam" or see the documentation of
  1124. your boot loader (lilo or loadlin) about how to pass options to the
  1125. kernel at boot time.)
  1126. If unsure, say "off".
  1127. config HIGHMEM4G
  1128. bool "4GB"
  1129. ---help---
  1130. Select this if you have a 32-bit processor and between 1 and 4
  1131. gigabytes of physical RAM.
  1132. config HIGHMEM64G
  1133. bool "64GB"
  1134. depends on !M486
  1135. select X86_PAE
  1136. ---help---
  1137. Select this if you have a 32-bit processor and more than 4
  1138. gigabytes of physical RAM.
  1139. endchoice
  1140. choice
  1141. prompt "Memory split" if EXPERT
  1142. default VMSPLIT_3G
  1143. depends on X86_32
  1144. ---help---
  1145. Select the desired split between kernel and user memory.
  1146. If the address range available to the kernel is less than the
  1147. physical memory installed, the remaining memory will be available
  1148. as "high memory". Accessing high memory is a little more costly
  1149. than low memory, as it needs to be mapped into the kernel first.
  1150. Note that increasing the kernel address space limits the range
  1151. available to user programs, making the address space there
  1152. tighter. Selecting anything other than the default 3G/1G split
  1153. will also likely make your kernel incompatible with binary-only
  1154. kernel modules.
  1155. If you are not absolutely sure what you are doing, leave this
  1156. option alone!
  1157. config VMSPLIT_3G
  1158. bool "3G/1G user/kernel split"
  1159. config VMSPLIT_3G_OPT
  1160. depends on !X86_PAE
  1161. bool "3G/1G user/kernel split (for full 1G low memory)"
  1162. config VMSPLIT_2G
  1163. bool "2G/2G user/kernel split"
  1164. config VMSPLIT_2G_OPT
  1165. depends on !X86_PAE
  1166. bool "2G/2G user/kernel split (for full 2G low memory)"
  1167. config VMSPLIT_1G
  1168. bool "1G/3G user/kernel split"
  1169. endchoice
  1170. config PAGE_OFFSET
  1171. hex
  1172. default 0xB0000000 if VMSPLIT_3G_OPT
  1173. default 0x80000000 if VMSPLIT_2G
  1174. default 0x78000000 if VMSPLIT_2G_OPT
  1175. default 0x40000000 if VMSPLIT_1G
  1176. default 0xC0000000
  1177. depends on X86_32
  1178. config HIGHMEM
  1179. def_bool y
  1180. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  1181. config X86_PAE
  1182. bool "PAE (Physical Address Extension) Support"
  1183. depends on X86_32 && !HIGHMEM4G
  1184. select SWIOTLB
  1185. ---help---
  1186. PAE is required for NX support, and furthermore enables
  1187. larger swapspace support for non-overcommit purposes. It
  1188. has the cost of more pagetable lookup overhead, and also
  1189. consumes more pagetable space per process.
  1190. config ARCH_PHYS_ADDR_T_64BIT
  1191. def_bool y
  1192. depends on X86_64 || X86_PAE
  1193. config ARCH_DMA_ADDR_T_64BIT
  1194. def_bool y
  1195. depends on X86_64 || HIGHMEM64G
  1196. config X86_DIRECT_GBPAGES
  1197. def_bool y
  1198. depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
  1199. ---help---
  1200. Certain kernel features effectively disable kernel
  1201. linear 1 GB mappings (even if the CPU otherwise
  1202. supports them), so don't confuse the user by printing
  1203. that we have them enabled.
  1204. # Common NUMA Features
  1205. config NUMA
  1206. bool "Numa Memory Allocation and Scheduler Support"
  1207. depends on SMP
  1208. depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
  1209. default y if X86_BIGSMP
  1210. ---help---
  1211. Enable NUMA (Non Uniform Memory Access) support.
  1212. The kernel will try to allocate memory used by a CPU on the
  1213. local memory controller of the CPU and add some more
  1214. NUMA awareness to the kernel.
  1215. For 64-bit this is recommended if the system is Intel Core i7
  1216. (or later), AMD Opteron, or EM64T NUMA.
  1217. For 32-bit this is only needed if you boot a 32-bit
  1218. kernel on a 64-bit NUMA platform.
  1219. Otherwise, you should say N.
  1220. config AMD_NUMA
  1221. def_bool y
  1222. prompt "Old style AMD Opteron NUMA detection"
  1223. depends on X86_64 && NUMA && PCI
  1224. ---help---
  1225. Enable AMD NUMA node topology detection. You should say Y here if
  1226. you have a multi processor AMD system. This uses an old method to
  1227. read the NUMA configuration directly from the builtin Northbridge
  1228. of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
  1229. which also takes priority if both are compiled in.
  1230. config X86_64_ACPI_NUMA
  1231. def_bool y
  1232. prompt "ACPI NUMA detection"
  1233. depends on X86_64 && NUMA && ACPI && PCI
  1234. select ACPI_NUMA
  1235. ---help---
  1236. Enable ACPI SRAT based node topology detection.
  1237. # Some NUMA nodes have memory ranges that span
  1238. # other nodes. Even though a pfn is valid and
  1239. # between a node's start and end pfns, it may not
  1240. # reside on that node. See memmap_init_zone()
  1241. # for details.
  1242. config NODES_SPAN_OTHER_NODES
  1243. def_bool y
  1244. depends on X86_64_ACPI_NUMA
  1245. config NUMA_EMU
  1246. bool "NUMA emulation"
  1247. depends on NUMA
  1248. ---help---
  1249. Enable NUMA emulation. A flat machine will be split
  1250. into virtual nodes when booted with "numa=fake=N", where N is the
  1251. number of nodes. This is only useful for debugging.
  1252. config NODES_SHIFT
  1253. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  1254. range 1 10
  1255. default "10" if MAXSMP
  1256. default "6" if X86_64
  1257. default "3"
  1258. depends on NEED_MULTIPLE_NODES
  1259. ---help---
  1260. Specify the maximum number of NUMA Nodes available on the target
  1261. system. Increases memory reserved to accommodate various tables.
  1262. config ARCH_HAVE_MEMORY_PRESENT
  1263. def_bool y
  1264. depends on X86_32 && DISCONTIGMEM
  1265. config NEED_NODE_MEMMAP_SIZE
  1266. def_bool y
  1267. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1268. config ARCH_FLATMEM_ENABLE
  1269. def_bool y
  1270. depends on X86_32 && !NUMA
  1271. config ARCH_DISCONTIGMEM_ENABLE
  1272. def_bool y
  1273. depends on NUMA && X86_32
  1274. config ARCH_DISCONTIGMEM_DEFAULT
  1275. def_bool y
  1276. depends on NUMA && X86_32
  1277. config ARCH_SPARSEMEM_ENABLE
  1278. def_bool y
  1279. depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
  1280. select SPARSEMEM_STATIC if X86_32
  1281. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1282. config ARCH_SPARSEMEM_DEFAULT
  1283. def_bool y
  1284. depends on X86_64
  1285. config ARCH_SELECT_MEMORY_MODEL
  1286. def_bool y
  1287. depends on ARCH_SPARSEMEM_ENABLE
  1288. config ARCH_MEMORY_PROBE
  1289. bool "Enable sysfs memory/probe interface"
  1290. depends on X86_64 && MEMORY_HOTPLUG
  1291. help
  1292. This option enables a sysfs memory/probe interface for testing.
  1293. See Documentation/memory-hotplug.txt for more information.
  1294. If you are unsure how to answer this question, answer N.
  1295. config ARCH_PROC_KCORE_TEXT
  1296. def_bool y
  1297. depends on X86_64 && PROC_KCORE
  1298. config ILLEGAL_POINTER_VALUE
  1299. hex
  1300. default 0 if X86_32
  1301. default 0xdead000000000000 if X86_64
  1302. source "mm/Kconfig"
  1303. config X86_PMEM_LEGACY_DEVICE
  1304. bool
  1305. config X86_PMEM_LEGACY
  1306. tristate "Support non-standard NVDIMMs and ADR protected memory"
  1307. depends on PHYS_ADDR_T_64BIT
  1308. depends on BLK_DEV
  1309. select X86_PMEM_LEGACY_DEVICE
  1310. select LIBNVDIMM
  1311. help
  1312. Treat memory marked using the non-standard e820 type of 12 as used
  1313. by the Intel Sandy Bridge-EP reference BIOS as protected memory.
  1314. The kernel will offer these regions to the 'pmem' driver so
  1315. they can be used for persistent storage.
  1316. Say Y if unsure.
  1317. config HIGHPTE
  1318. bool "Allocate 3rd-level pagetables from highmem"
  1319. depends on HIGHMEM
  1320. ---help---
  1321. The VM uses one page table entry for each page of physical memory.
  1322. For systems with a lot of RAM, this can be wasteful of precious
  1323. low memory. Setting this option will put user-space page table
  1324. entries in high memory.
  1325. config X86_CHECK_BIOS_CORRUPTION
  1326. bool "Check for low memory corruption"
  1327. ---help---
  1328. Periodically check for memory corruption in low memory, which
  1329. is suspected to be caused by BIOS. Even when enabled in the
  1330. configuration, it is disabled at runtime. Enable it by
  1331. setting "memory_corruption_check=1" on the kernel command
  1332. line. By default it scans the low 64k of memory every 60
  1333. seconds; see the memory_corruption_check_size and
  1334. memory_corruption_check_period parameters in
  1335. Documentation/admin-guide/kernel-parameters.rst to adjust this.
  1336. When enabled with the default parameters, this option has
  1337. almost no overhead, as it reserves a relatively small amount
  1338. of memory and scans it infrequently. It both detects corruption
  1339. and prevents it from affecting the running system.
  1340. It is, however, intended as a diagnostic tool; if repeatable
  1341. BIOS-originated corruption always affects the same memory,
  1342. you can use memmap= to prevent the kernel from using that
  1343. memory.
  1344. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1345. bool "Set the default setting of memory_corruption_check"
  1346. depends on X86_CHECK_BIOS_CORRUPTION
  1347. default y
  1348. ---help---
  1349. Set whether the default state of memory_corruption_check is
  1350. on or off.
  1351. config X86_RESERVE_LOW
  1352. int "Amount of low memory, in kilobytes, to reserve for the BIOS"
  1353. default 64
  1354. range 4 640
  1355. ---help---
  1356. Specify the amount of low memory to reserve for the BIOS.
  1357. The first page contains BIOS data structures that the kernel
  1358. must not use, so that page must always be reserved.
  1359. By default we reserve the first 64K of physical RAM, as a
  1360. number of BIOSes are known to corrupt that memory range
  1361. during events such as suspend/resume or monitor cable
  1362. insertion, so it must not be used by the kernel.
  1363. You can set this to 4 if you are absolutely sure that you
  1364. trust the BIOS to get all its memory reservations and usages
  1365. right. If you know your BIOS have problems beyond the
  1366. default 64K area, you can set this to 640 to avoid using the
  1367. entire low memory range.
  1368. If you have doubts about the BIOS (e.g. suspend/resume does
  1369. not work or there's kernel crashes after certain hardware
  1370. hotplug events) then you might want to enable
  1371. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
  1372. typical corruption patterns.
  1373. Leave this to the default value of 64 if you are unsure.
  1374. config MATH_EMULATION
  1375. bool
  1376. depends on MODIFY_LDT_SYSCALL
  1377. prompt "Math emulation" if X86_32
  1378. ---help---
  1379. Linux can emulate a math coprocessor (used for floating point
  1380. operations) if you don't have one. 486DX and Pentium processors have
  1381. a math coprocessor built in, 486SX and 386 do not, unless you added
  1382. a 487DX or 387, respectively. (The messages during boot time can
  1383. give you some hints here ["man dmesg"].) Everyone needs either a
  1384. coprocessor or this emulation.
  1385. If you don't have a math coprocessor, you need to say Y here; if you
  1386. say Y here even though you have a coprocessor, the coprocessor will
  1387. be used nevertheless. (This behavior can be changed with the kernel
  1388. command line option "no387", which comes handy if your coprocessor
  1389. is broken. Try "man bootparam" or see the documentation of your boot
  1390. loader (lilo or loadlin) about how to pass options to the kernel at
  1391. boot time.) This means that it is a good idea to say Y here if you
  1392. intend to use this kernel on different machines.
  1393. More information about the internals of the Linux math coprocessor
  1394. emulation can be found in <file:arch/x86/math-emu/README>.
  1395. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1396. kernel, it won't hurt.
  1397. config MTRR
  1398. def_bool y
  1399. prompt "MTRR (Memory Type Range Register) support" if EXPERT
  1400. ---help---
  1401. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1402. the Memory Type Range Registers (MTRRs) may be used to control
  1403. processor access to memory ranges. This is most useful if you have
  1404. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1405. allows bus write transfers to be combined into a larger transfer
  1406. before bursting over the PCI/AGP bus. This can increase performance
  1407. of image write operations 2.5 times or more. Saying Y here creates a
  1408. /proc/mtrr file which may be used to manipulate your processor's
  1409. MTRRs. Typically the X server should use this.
  1410. This code has a reasonably generic interface so that similar
  1411. control registers on other processors can be easily supported
  1412. as well:
  1413. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1414. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1415. these, the ARRs are used to emulate the MTRRs.
  1416. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1417. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1418. write-combining. All of these processors are supported by this code
  1419. and it makes sense to say Y here if you have one of them.
  1420. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1421. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1422. can lead to all sorts of problems, so it's good to say Y here.
  1423. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1424. just add about 9 KB to your kernel.
  1425. See <file:Documentation/x86/mtrr.txt> for more information.
  1426. config MTRR_SANITIZER
  1427. def_bool y
  1428. prompt "MTRR cleanup support"
  1429. depends on MTRR
  1430. ---help---
  1431. Convert MTRR layout from continuous to discrete, so X drivers can
  1432. add writeback entries.
  1433. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1434. The largest mtrr entry size for a continuous block can be set with
  1435. mtrr_chunk_size.
  1436. If unsure, say Y.
  1437. config MTRR_SANITIZER_ENABLE_DEFAULT
  1438. int "MTRR cleanup enable value (0-1)"
  1439. range 0 1
  1440. default "0"
  1441. depends on MTRR_SANITIZER
  1442. ---help---
  1443. Enable mtrr cleanup default value
  1444. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1445. int "MTRR cleanup spare reg num (0-7)"
  1446. range 0 7
  1447. default "1"
  1448. depends on MTRR_SANITIZER
  1449. ---help---
  1450. mtrr cleanup spare entries default, it can be changed via
  1451. mtrr_spare_reg_nr=N on the kernel command line.
  1452. config X86_PAT
  1453. def_bool y
  1454. prompt "x86 PAT support" if EXPERT
  1455. depends on MTRR
  1456. ---help---
  1457. Use PAT attributes to setup page level cache control.
  1458. PATs are the modern equivalents of MTRRs and are much more
  1459. flexible than MTRRs.
  1460. Say N here if you see bootup problems (boot crash, boot hang,
  1461. spontaneous reboots) or a non-working video driver.
  1462. If unsure, say Y.
  1463. config ARCH_USES_PG_UNCACHED
  1464. def_bool y
  1465. depends on X86_PAT
  1466. config ARCH_RANDOM
  1467. def_bool y
  1468. prompt "x86 architectural random number generator" if EXPERT
  1469. ---help---
  1470. Enable the x86 architectural RDRAND instruction
  1471. (Intel Bull Mountain technology) to generate random numbers.
  1472. If supported, this is a high bandwidth, cryptographically
  1473. secure hardware random number generator.
  1474. config X86_SMAP
  1475. def_bool y
  1476. prompt "Supervisor Mode Access Prevention" if EXPERT
  1477. ---help---
  1478. Supervisor Mode Access Prevention (SMAP) is a security
  1479. feature in newer Intel processors. There is a small
  1480. performance cost if this enabled and turned on; there is
  1481. also a small increase in the kernel size if this is enabled.
  1482. If unsure, say Y.
  1483. config X86_INTEL_MPX
  1484. prompt "Intel MPX (Memory Protection Extensions)"
  1485. def_bool n
  1486. depends on CPU_SUP_INTEL
  1487. ---help---
  1488. MPX provides hardware features that can be used in
  1489. conjunction with compiler-instrumented code to check
  1490. memory references. It is designed to detect buffer
  1491. overflow or underflow bugs.
  1492. This option enables running applications which are
  1493. instrumented or otherwise use MPX. It does not use MPX
  1494. itself inside the kernel or to protect the kernel
  1495. against bad memory references.
  1496. Enabling this option will make the kernel larger:
  1497. ~8k of kernel text and 36 bytes of data on a 64-bit
  1498. defconfig. It adds a long to the 'mm_struct' which
  1499. will increase the kernel memory overhead of each
  1500. process and adds some branches to paths used during
  1501. exec() and munmap().
  1502. For details, see Documentation/x86/intel_mpx.txt
  1503. If unsure, say N.
  1504. config X86_INTEL_MEMORY_PROTECTION_KEYS
  1505. prompt "Intel Memory Protection Keys"
  1506. def_bool y
  1507. # Note: only available in 64-bit mode
  1508. depends on CPU_SUP_INTEL && X86_64
  1509. select ARCH_USES_HIGH_VMA_FLAGS
  1510. select ARCH_HAS_PKEYS
  1511. ---help---
  1512. Memory Protection Keys provides a mechanism for enforcing
  1513. page-based protections, but without requiring modification of the
  1514. page tables when an application changes protection domains.
  1515. For details, see Documentation/x86/protection-keys.txt
  1516. If unsure, say y.
  1517. config EFI
  1518. bool "EFI runtime service support"
  1519. depends on ACPI
  1520. select UCS2_STRING
  1521. select EFI_RUNTIME_WRAPPERS
  1522. ---help---
  1523. This enables the kernel to use EFI runtime services that are
  1524. available (such as the EFI variable services).
  1525. This option is only useful on systems that have EFI firmware.
  1526. In addition, you should use the latest ELILO loader available
  1527. at <http://elilo.sourceforge.net> in order to take advantage
  1528. of EFI runtime services. However, even with this option, the
  1529. resultant kernel should continue to boot on existing non-EFI
  1530. platforms.
  1531. config EFI_STUB
  1532. bool "EFI stub support"
  1533. depends on EFI && !X86_USE_3DNOW
  1534. select RELOCATABLE
  1535. ---help---
  1536. This kernel feature allows a bzImage to be loaded directly
  1537. by EFI firmware without the use of a bootloader.
  1538. See Documentation/efi-stub.txt for more information.
  1539. config EFI_MIXED
  1540. bool "EFI mixed-mode support"
  1541. depends on EFI_STUB && X86_64
  1542. ---help---
  1543. Enabling this feature allows a 64-bit kernel to be booted
  1544. on a 32-bit firmware, provided that your CPU supports 64-bit
  1545. mode.
  1546. Note that it is not possible to boot a mixed-mode enabled
  1547. kernel via the EFI boot stub - a bootloader that supports
  1548. the EFI handover protocol must be used.
  1549. If unsure, say N.
  1550. config SECCOMP
  1551. def_bool y
  1552. prompt "Enable seccomp to safely compute untrusted bytecode"
  1553. ---help---
  1554. This kernel feature is useful for number crunching applications
  1555. that may need to compute untrusted bytecode during their
  1556. execution. By using pipes or other transports made available to
  1557. the process as file descriptors supporting the read/write
  1558. syscalls, it's possible to isolate those applications in
  1559. their own address space using seccomp. Once seccomp is
  1560. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1561. and the task is only allowed to execute a few safe syscalls
  1562. defined by each seccomp mode.
  1563. If unsure, say Y. Only embedded should say N here.
  1564. source kernel/Kconfig.hz
  1565. config KEXEC
  1566. bool "kexec system call"
  1567. select KEXEC_CORE
  1568. ---help---
  1569. kexec is a system call that implements the ability to shutdown your
  1570. current kernel, and to start another kernel. It is like a reboot
  1571. but it is independent of the system firmware. And like a reboot
  1572. you can start any kernel with it, not just Linux.
  1573. The name comes from the similarity to the exec system call.
  1574. It is an ongoing process to be certain the hardware in a machine
  1575. is properly shutdown, so do not be surprised if this code does not
  1576. initially work for you. As of this writing the exact hardware
  1577. interface is strongly in flux, so no good recommendation can be
  1578. made.
  1579. config KEXEC_FILE
  1580. bool "kexec file based system call"
  1581. select KEXEC_CORE
  1582. select BUILD_BIN2C
  1583. depends on X86_64
  1584. depends on CRYPTO=y
  1585. depends on CRYPTO_SHA256=y
  1586. ---help---
  1587. This is new version of kexec system call. This system call is
  1588. file based and takes file descriptors as system call argument
  1589. for kernel and initramfs as opposed to list of segments as
  1590. accepted by previous system call.
  1591. config KEXEC_VERIFY_SIG
  1592. bool "Verify kernel signature during kexec_file_load() syscall"
  1593. depends on KEXEC_FILE
  1594. ---help---
  1595. This option makes kernel signature verification mandatory for
  1596. the kexec_file_load() syscall.
  1597. In addition to that option, you need to enable signature
  1598. verification for the corresponding kernel image type being
  1599. loaded in order for this to work.
  1600. config KEXEC_BZIMAGE_VERIFY_SIG
  1601. bool "Enable bzImage signature verification support"
  1602. depends on KEXEC_VERIFY_SIG
  1603. depends on SIGNED_PE_FILE_VERIFICATION
  1604. select SYSTEM_TRUSTED_KEYRING
  1605. ---help---
  1606. Enable bzImage signature verification support.
  1607. config CRASH_DUMP
  1608. bool "kernel crash dumps"
  1609. depends on X86_64 || (X86_32 && HIGHMEM)
  1610. ---help---
  1611. Generate crash dump after being started by kexec.
  1612. This should be normally only set in special crash dump kernels
  1613. which are loaded in the main kernel with kexec-tools into
  1614. a specially reserved region and then later executed after
  1615. a crash by kdump/kexec. The crash dump kernel must be compiled
  1616. to a memory address not used by the main kernel or BIOS using
  1617. PHYSICAL_START, or it must be built as a relocatable image
  1618. (CONFIG_RELOCATABLE=y).
  1619. For more details see Documentation/kdump/kdump.txt
  1620. config KEXEC_JUMP
  1621. bool "kexec jump"
  1622. depends on KEXEC && HIBERNATION
  1623. ---help---
  1624. Jump between original kernel and kexeced kernel and invoke
  1625. code in physical address mode via KEXEC
  1626. config PHYSICAL_START
  1627. hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
  1628. default "0x1000000"
  1629. ---help---
  1630. This gives the physical address where the kernel is loaded.
  1631. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1632. bzImage will decompress itself to above physical address and
  1633. run from there. Otherwise, bzImage will run from the address where
  1634. it has been loaded by the boot loader and will ignore above physical
  1635. address.
  1636. In normal kdump cases one does not have to set/change this option
  1637. as now bzImage can be compiled as a completely relocatable image
  1638. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1639. address. This option is mainly useful for the folks who don't want
  1640. to use a bzImage for capturing the crash dump and want to use a
  1641. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1642. to be specifically compiled to run from a specific memory area
  1643. (normally a reserved region) and this option comes handy.
  1644. So if you are using bzImage for capturing the crash dump,
  1645. leave the value here unchanged to 0x1000000 and set
  1646. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1647. for capturing the crash dump change this value to start of
  1648. the reserved region. In other words, it can be set based on
  1649. the "X" value as specified in the "crashkernel=YM@XM"
  1650. command line boot parameter passed to the panic-ed
  1651. kernel. Please take a look at Documentation/kdump/kdump.txt
  1652. for more details about crash dumps.
  1653. Usage of bzImage for capturing the crash dump is recommended as
  1654. one does not have to build two kernels. Same kernel can be used
  1655. as production kernel and capture kernel. Above option should have
  1656. gone away after relocatable bzImage support is introduced. But it
  1657. is present because there are users out there who continue to use
  1658. vmlinux for dump capture. This option should go away down the
  1659. line.
  1660. Don't change this unless you know what you are doing.
  1661. config RELOCATABLE
  1662. bool "Build a relocatable kernel"
  1663. default y
  1664. ---help---
  1665. This builds a kernel image that retains relocation information
  1666. so it can be loaded someplace besides the default 1MB.
  1667. The relocations tend to make the kernel binary about 10% larger,
  1668. but are discarded at runtime.
  1669. One use is for the kexec on panic case where the recovery kernel
  1670. must live at a different physical address than the primary
  1671. kernel.
  1672. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1673. it has been loaded at and the compile time physical address
  1674. (CONFIG_PHYSICAL_START) is used as the minimum location.
  1675. config RANDOMIZE_BASE
  1676. bool "Randomize the address of the kernel image (KASLR)"
  1677. depends on RELOCATABLE
  1678. default y
  1679. ---help---
  1680. In support of Kernel Address Space Layout Randomization (KASLR),
  1681. this randomizes the physical address at which the kernel image
  1682. is decompressed and the virtual address where the kernel
  1683. image is mapped, as a security feature that deters exploit
  1684. attempts relying on knowledge of the location of kernel
  1685. code internals.
  1686. On 64-bit, the kernel physical and virtual addresses are
  1687. randomized separately. The physical address will be anywhere
  1688. between 16MB and the top of physical memory (up to 64TB). The
  1689. virtual address will be randomized from 16MB up to 1GB (9 bits
  1690. of entropy). Note that this also reduces the memory space
  1691. available to kernel modules from 1.5GB to 1GB.
  1692. On 32-bit, the kernel physical and virtual addresses are
  1693. randomized together. They will be randomized from 16MB up to
  1694. 512MB (8 bits of entropy).
  1695. Entropy is generated using the RDRAND instruction if it is
  1696. supported. If RDTSC is supported, its value is mixed into
  1697. the entropy pool as well. If neither RDRAND nor RDTSC are
  1698. supported, then entropy is read from the i8254 timer. The
  1699. usable entropy is limited by the kernel being built using
  1700. 2GB addressing, and that PHYSICAL_ALIGN must be at a
  1701. minimum of 2MB. As a result, only 10 bits of entropy are
  1702. theoretically possible, but the implementations are further
  1703. limited due to memory layouts.
  1704. If unsure, say Y.
  1705. # Relocation on x86 needs some additional build support
  1706. config X86_NEED_RELOCS
  1707. def_bool y
  1708. depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
  1709. config PHYSICAL_ALIGN
  1710. hex "Alignment value to which kernel should be aligned"
  1711. default "0x200000"
  1712. range 0x2000 0x1000000 if X86_32
  1713. range 0x200000 0x1000000 if X86_64
  1714. ---help---
  1715. This value puts the alignment restrictions on physical address
  1716. where kernel is loaded and run from. Kernel is compiled for an
  1717. address which meets above alignment restriction.
  1718. If bootloader loads the kernel at a non-aligned address and
  1719. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1720. address aligned to above value and run from there.
  1721. If bootloader loads the kernel at a non-aligned address and
  1722. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1723. load address and decompress itself to the address it has been
  1724. compiled for and run from there. The address for which kernel is
  1725. compiled already meets above alignment restrictions. Hence the
  1726. end result is that kernel runs from a physical address meeting
  1727. above alignment restrictions.
  1728. On 32-bit this value must be a multiple of 0x2000. On 64-bit
  1729. this value must be a multiple of 0x200000.
  1730. Don't change this unless you know what you are doing.
  1731. config RANDOMIZE_MEMORY
  1732. bool "Randomize the kernel memory sections"
  1733. depends on X86_64
  1734. depends on RANDOMIZE_BASE
  1735. default RANDOMIZE_BASE
  1736. ---help---
  1737. Randomizes the base virtual address of kernel memory sections
  1738. (physical memory mapping, vmalloc & vmemmap). This security feature
  1739. makes exploits relying on predictable memory locations less reliable.
  1740. The order of allocations remains unchanged. Entropy is generated in
  1741. the same way as RANDOMIZE_BASE. Current implementation in the optimal
  1742. configuration have in average 30,000 different possible virtual
  1743. addresses for each memory section.
  1744. If unsure, say Y.
  1745. config RANDOMIZE_MEMORY_PHYSICAL_PADDING
  1746. hex "Physical memory mapping padding" if EXPERT
  1747. depends on RANDOMIZE_MEMORY
  1748. default "0xa" if MEMORY_HOTPLUG
  1749. default "0x0"
  1750. range 0x1 0x40 if MEMORY_HOTPLUG
  1751. range 0x0 0x40
  1752. ---help---
  1753. Define the padding in terabytes added to the existing physical
  1754. memory size during kernel memory randomization. It is useful
  1755. for memory hotplug support but reduces the entropy available for
  1756. address randomization.
  1757. If unsure, leave at the default value.
  1758. config HOTPLUG_CPU
  1759. bool "Support for hot-pluggable CPUs"
  1760. depends on SMP
  1761. ---help---
  1762. Say Y here to allow turning CPUs off and on. CPUs can be
  1763. controlled through /sys/devices/system/cpu.
  1764. ( Note: power management support will enable this option
  1765. automatically on SMP systems. )
  1766. Say N if you want to disable CPU hotplug.
  1767. config BOOTPARAM_HOTPLUG_CPU0
  1768. bool "Set default setting of cpu0_hotpluggable"
  1769. default n
  1770. depends on HOTPLUG_CPU
  1771. ---help---
  1772. Set whether default state of cpu0_hotpluggable is on or off.
  1773. Say Y here to enable CPU0 hotplug by default. If this switch
  1774. is turned on, there is no need to give cpu0_hotplug kernel
  1775. parameter and the CPU0 hotplug feature is enabled by default.
  1776. Please note: there are two known CPU0 dependencies if you want
  1777. to enable the CPU0 hotplug feature either by this switch or by
  1778. cpu0_hotplug kernel parameter.
  1779. First, resume from hibernate or suspend always starts from CPU0.
  1780. So hibernate and suspend are prevented if CPU0 is offline.
  1781. Second dependency is PIC interrupts always go to CPU0. CPU0 can not
  1782. offline if any interrupt can not migrate out of CPU0. There may
  1783. be other CPU0 dependencies.
  1784. Please make sure the dependencies are under your control before
  1785. you enable this feature.
  1786. Say N if you don't want to enable CPU0 hotplug feature by default.
  1787. You still can enable the CPU0 hotplug feature at boot by kernel
  1788. parameter cpu0_hotplug.
  1789. config DEBUG_HOTPLUG_CPU0
  1790. def_bool n
  1791. prompt "Debug CPU0 hotplug"
  1792. depends on HOTPLUG_CPU
  1793. ---help---
  1794. Enabling this option offlines CPU0 (if CPU0 can be offlined) as
  1795. soon as possible and boots up userspace with CPU0 offlined. User
  1796. can online CPU0 back after boot time.
  1797. To debug CPU0 hotplug, you need to enable CPU0 offline/online
  1798. feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
  1799. compilation or giving cpu0_hotplug kernel parameter at boot.
  1800. If unsure, say N.
  1801. config COMPAT_VDSO
  1802. def_bool n
  1803. prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
  1804. depends on COMPAT_32
  1805. ---help---
  1806. Certain buggy versions of glibc will crash if they are
  1807. presented with a 32-bit vDSO that is not mapped at the address
  1808. indicated in its segment table.
  1809. The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
  1810. and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
  1811. 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
  1812. the only released version with the bug, but OpenSUSE 9
  1813. contains a buggy "glibc 2.3.2".
  1814. The symptom of the bug is that everything crashes on startup, saying:
  1815. dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
  1816. Saying Y here changes the default value of the vdso32 boot
  1817. option from 1 to 0, which turns off the 32-bit vDSO entirely.
  1818. This works around the glibc bug but hurts performance.
  1819. If unsure, say N: if you are compiling your own kernel, you
  1820. are unlikely to be using a buggy version of glibc.
  1821. choice
  1822. prompt "vsyscall table for legacy applications"
  1823. depends on X86_64
  1824. default LEGACY_VSYSCALL_EMULATE
  1825. help
  1826. Legacy user code that does not know how to find the vDSO expects
  1827. to be able to issue three syscalls by calling fixed addresses in
  1828. kernel space. Since this location is not randomized with ASLR,
  1829. it can be used to assist security vulnerability exploitation.
  1830. This setting can be changed at boot time via the kernel command
  1831. line parameter vsyscall=[native|emulate|none].
  1832. On a system with recent enough glibc (2.14 or newer) and no
  1833. static binaries, you can say None without a performance penalty
  1834. to improve security.
  1835. If unsure, select "Emulate".
  1836. config LEGACY_VSYSCALL_NATIVE
  1837. bool "Native"
  1838. help
  1839. Actual executable code is located in the fixed vsyscall
  1840. address mapping, implementing time() efficiently. Since
  1841. this makes the mapping executable, it can be used during
  1842. security vulnerability exploitation (traditionally as
  1843. ROP gadgets). This configuration is not recommended.
  1844. config LEGACY_VSYSCALL_EMULATE
  1845. bool "Emulate"
  1846. help
  1847. The kernel traps and emulates calls into the fixed
  1848. vsyscall address mapping. This makes the mapping
  1849. non-executable, but it still contains known contents,
  1850. which could be used in certain rare security vulnerability
  1851. exploits. This configuration is recommended when userspace
  1852. still uses the vsyscall area.
  1853. config LEGACY_VSYSCALL_NONE
  1854. bool "None"
  1855. help
  1856. There will be no vsyscall mapping at all. This will
  1857. eliminate any risk of ASLR bypass due to the vsyscall
  1858. fixed address mapping. Attempts to use the vsyscalls
  1859. will be reported to dmesg, so that either old or
  1860. malicious userspace programs can be identified.
  1861. endchoice
  1862. config CMDLINE_BOOL
  1863. bool "Built-in kernel command line"
  1864. ---help---
  1865. Allow for specifying boot arguments to the kernel at
  1866. build time. On some systems (e.g. embedded ones), it is
  1867. necessary or convenient to provide some or all of the
  1868. kernel boot arguments with the kernel itself (that is,
  1869. to not rely on the boot loader to provide them.)
  1870. To compile command line arguments into the kernel,
  1871. set this option to 'Y', then fill in the
  1872. boot arguments in CONFIG_CMDLINE.
  1873. Systems with fully functional boot loaders (i.e. non-embedded)
  1874. should leave this option set to 'N'.
  1875. config CMDLINE
  1876. string "Built-in kernel command string"
  1877. depends on CMDLINE_BOOL
  1878. default ""
  1879. ---help---
  1880. Enter arguments here that should be compiled into the kernel
  1881. image and used at boot time. If the boot loader provides a
  1882. command line at boot time, it is appended to this string to
  1883. form the full kernel command line, when the system boots.
  1884. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1885. change this behavior.
  1886. In most cases, the command line (whether built-in or provided
  1887. by the boot loader) should specify the device for the root
  1888. file system.
  1889. config CMDLINE_OVERRIDE
  1890. bool "Built-in command line overrides boot loader arguments"
  1891. depends on CMDLINE_BOOL
  1892. ---help---
  1893. Set this option to 'Y' to have the kernel ignore the boot loader
  1894. command line, and use ONLY the built-in command line.
  1895. This is used to work around broken boot loaders. This should
  1896. be set to 'N' under normal conditions.
  1897. config MODIFY_LDT_SYSCALL
  1898. bool "Enable the LDT (local descriptor table)" if EXPERT
  1899. default y
  1900. ---help---
  1901. Linux can allow user programs to install a per-process x86
  1902. Local Descriptor Table (LDT) using the modify_ldt(2) system
  1903. call. This is required to run 16-bit or segmented code such as
  1904. DOSEMU or some Wine programs. It is also used by some very old
  1905. threading libraries.
  1906. Enabling this feature adds a small amount of overhead to
  1907. context switches and increases the low-level kernel attack
  1908. surface. Disabling it removes the modify_ldt(2) system call.
  1909. Saying 'N' here may make sense for embedded or server kernels.
  1910. source "kernel/livepatch/Kconfig"
  1911. endmenu
  1912. config ARCH_ENABLE_MEMORY_HOTPLUG
  1913. def_bool y
  1914. depends on X86_64 || (X86_32 && HIGHMEM)
  1915. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1916. def_bool y
  1917. depends on MEMORY_HOTPLUG
  1918. config USE_PERCPU_NUMA_NODE_ID
  1919. def_bool y
  1920. depends on NUMA
  1921. config ARCH_ENABLE_SPLIT_PMD_PTLOCK
  1922. def_bool y
  1923. depends on X86_64 || X86_PAE
  1924. config ARCH_ENABLE_HUGEPAGE_MIGRATION
  1925. def_bool y
  1926. depends on X86_64 && HUGETLB_PAGE && MIGRATION
  1927. menu "Power management and ACPI options"
  1928. config ARCH_HIBERNATION_HEADER
  1929. def_bool y
  1930. depends on X86_64 && HIBERNATION
  1931. source "kernel/power/Kconfig"
  1932. source "drivers/acpi/Kconfig"
  1933. source "drivers/sfi/Kconfig"
  1934. config X86_APM_BOOT
  1935. def_bool y
  1936. depends on APM
  1937. menuconfig APM
  1938. tristate "APM (Advanced Power Management) BIOS support"
  1939. depends on X86_32 && PM_SLEEP
  1940. ---help---
  1941. APM is a BIOS specification for saving power using several different
  1942. techniques. This is mostly useful for battery powered laptops with
  1943. APM compliant BIOSes. If you say Y here, the system time will be
  1944. reset after a RESUME operation, the /proc/apm device will provide
  1945. battery status information, and user-space programs will receive
  1946. notification of APM "events" (e.g. battery status change).
  1947. If you select "Y" here, you can disable actual use of the APM
  1948. BIOS by passing the "apm=off" option to the kernel at boot time.
  1949. Note that the APM support is almost completely disabled for
  1950. machines with more than one CPU.
  1951. In order to use APM, you will need supporting software. For location
  1952. and more information, read <file:Documentation/power/apm-acpi.txt>
  1953. and the Battery Powered Linux mini-HOWTO, available from
  1954. <http://www.tldp.org/docs.html#howto>.
  1955. This driver does not spin down disk drives (see the hdparm(8)
  1956. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1957. VESA-compliant "green" monitors.
  1958. This driver does not support the TI 4000M TravelMate and the ACER
  1959. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1960. desktop machines also don't have compliant BIOSes, and this driver
  1961. may cause those machines to panic during the boot phase.
  1962. Generally, if you don't have a battery in your machine, there isn't
  1963. much point in using this driver and you should say N. If you get
  1964. random kernel OOPSes or reboots that don't seem to be related to
  1965. anything, try disabling/enabling this option (or disabling/enabling
  1966. APM in your BIOS).
  1967. Some other things you should try when experiencing seemingly random,
  1968. "weird" problems:
  1969. 1) make sure that you have enough swap space and that it is
  1970. enabled.
  1971. 2) pass the "no-hlt" option to the kernel
  1972. 3) switch on floating point emulation in the kernel and pass
  1973. the "no387" option to the kernel
  1974. 4) pass the "floppy=nodma" option to the kernel
  1975. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1976. all but the first 4 MB of RAM)
  1977. 6) make sure that the CPU is not over clocked.
  1978. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1979. 8) disable the cache from your BIOS settings
  1980. 9) install a fan for the video card or exchange video RAM
  1981. 10) install a better fan for the CPU
  1982. 11) exchange RAM chips
  1983. 12) exchange the motherboard.
  1984. To compile this driver as a module, choose M here: the
  1985. module will be called apm.
  1986. if APM
  1987. config APM_IGNORE_USER_SUSPEND
  1988. bool "Ignore USER SUSPEND"
  1989. ---help---
  1990. This option will ignore USER SUSPEND requests. On machines with a
  1991. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1992. series notebooks, it is necessary to say Y because of a BIOS bug.
  1993. config APM_DO_ENABLE
  1994. bool "Enable PM at boot time"
  1995. ---help---
  1996. Enable APM features at boot time. From page 36 of the APM BIOS
  1997. specification: "When disabled, the APM BIOS does not automatically
  1998. power manage devices, enter the Standby State, enter the Suspend
  1999. State, or take power saving steps in response to CPU Idle calls."
  2000. This driver will make CPU Idle calls when Linux is idle (unless this
  2001. feature is turned off -- see "Do CPU IDLE calls", below). This
  2002. should always save battery power, but more complicated APM features
  2003. will be dependent on your BIOS implementation. You may need to turn
  2004. this option off if your computer hangs at boot time when using APM
  2005. support, or if it beeps continuously instead of suspending. Turn
  2006. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  2007. T400CDT. This is off by default since most machines do fine without
  2008. this feature.
  2009. config APM_CPU_IDLE
  2010. depends on CPU_IDLE
  2011. bool "Make CPU Idle calls when idle"
  2012. ---help---
  2013. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  2014. On some machines, this can activate improved power savings, such as
  2015. a slowed CPU clock rate, when the machine is idle. These idle calls
  2016. are made after the idle loop has run for some length of time (e.g.,
  2017. 333 mS). On some machines, this will cause a hang at boot time or
  2018. whenever the CPU becomes idle. (On machines with more than one CPU,
  2019. this option does nothing.)
  2020. config APM_DISPLAY_BLANK
  2021. bool "Enable console blanking using APM"
  2022. ---help---
  2023. Enable console blanking using the APM. Some laptops can use this to
  2024. turn off the LCD backlight when the screen blanker of the Linux
  2025. virtual console blanks the screen. Note that this is only used by
  2026. the virtual console screen blanker, and won't turn off the backlight
  2027. when using the X Window system. This also doesn't have anything to
  2028. do with your VESA-compliant power-saving monitor. Further, this
  2029. option doesn't work for all laptops -- it might not turn off your
  2030. backlight at all, or it might print a lot of errors to the console,
  2031. especially if you are using gpm.
  2032. config APM_ALLOW_INTS
  2033. bool "Allow interrupts during APM BIOS calls"
  2034. ---help---
  2035. Normally we disable external interrupts while we are making calls to
  2036. the APM BIOS as a measure to lessen the effects of a badly behaving
  2037. BIOS implementation. The BIOS should reenable interrupts if it
  2038. needs to. Unfortunately, some BIOSes do not -- especially those in
  2039. many of the newer IBM Thinkpads. If you experience hangs when you
  2040. suspend, try setting this to Y. Otherwise, say N.
  2041. endif # APM
  2042. source "drivers/cpufreq/Kconfig"
  2043. source "drivers/cpuidle/Kconfig"
  2044. source "drivers/idle/Kconfig"
  2045. endmenu
  2046. menu "Bus options (PCI etc.)"
  2047. config PCI
  2048. bool "PCI support"
  2049. default y
  2050. ---help---
  2051. Find out whether you have a PCI motherboard. PCI is the name of a
  2052. bus system, i.e. the way the CPU talks to the other stuff inside
  2053. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  2054. VESA. If you have PCI, say Y, otherwise N.
  2055. choice
  2056. prompt "PCI access mode"
  2057. depends on X86_32 && PCI
  2058. default PCI_GOANY
  2059. ---help---
  2060. On PCI systems, the BIOS can be used to detect the PCI devices and
  2061. determine their configuration. However, some old PCI motherboards
  2062. have BIOS bugs and may crash if this is done. Also, some embedded
  2063. PCI-based systems don't have any BIOS at all. Linux can also try to
  2064. detect the PCI hardware directly without using the BIOS.
  2065. With this option, you can specify how Linux should detect the
  2066. PCI devices. If you choose "BIOS", the BIOS will be used,
  2067. if you choose "Direct", the BIOS won't be used, and if you
  2068. choose "MMConfig", then PCI Express MMCONFIG will be used.
  2069. If you choose "Any", the kernel will try MMCONFIG, then the
  2070. direct access method and falls back to the BIOS if that doesn't
  2071. work. If unsure, go with the default, which is "Any".
  2072. config PCI_GOBIOS
  2073. bool "BIOS"
  2074. config PCI_GOMMCONFIG
  2075. bool "MMConfig"
  2076. config PCI_GODIRECT
  2077. bool "Direct"
  2078. config PCI_GOOLPC
  2079. bool "OLPC XO-1"
  2080. depends on OLPC
  2081. config PCI_GOANY
  2082. bool "Any"
  2083. endchoice
  2084. config PCI_BIOS
  2085. def_bool y
  2086. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  2087. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  2088. config PCI_DIRECT
  2089. def_bool y
  2090. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
  2091. config PCI_MMCONFIG
  2092. def_bool y
  2093. depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
  2094. config PCI_OLPC
  2095. def_bool y
  2096. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  2097. config PCI_XEN
  2098. def_bool y
  2099. depends on PCI && XEN
  2100. select SWIOTLB_XEN
  2101. config PCI_DOMAINS
  2102. def_bool y
  2103. depends on PCI
  2104. config PCI_MMCONFIG
  2105. bool "Support mmconfig PCI config space access"
  2106. depends on X86_64 && PCI && ACPI
  2107. config PCI_CNB20LE_QUIRK
  2108. bool "Read CNB20LE Host Bridge Windows" if EXPERT
  2109. depends on PCI
  2110. help
  2111. Read the PCI windows out of the CNB20LE host bridge. This allows
  2112. PCI hotplug to work on systems with the CNB20LE chipset which do
  2113. not have ACPI.
  2114. There's no public spec for this chipset, and this functionality
  2115. is known to be incomplete.
  2116. You should say N unless you know you need this.
  2117. source "drivers/pci/Kconfig"
  2118. config ISA_BUS
  2119. bool "ISA-style bus support on modern systems" if EXPERT
  2120. select ISA_BUS_API
  2121. help
  2122. Enables ISA-style drivers on modern systems. This is necessary to
  2123. support PC/104 devices on X86_64 platforms.
  2124. If unsure, say N.
  2125. # x86_64 have no ISA slots, but can have ISA-style DMA.
  2126. config ISA_DMA_API
  2127. bool "ISA-style DMA support" if (X86_64 && EXPERT)
  2128. default y
  2129. help
  2130. Enables ISA-style DMA support for devices requiring such controllers.
  2131. If unsure, say Y.
  2132. if X86_32
  2133. config ISA
  2134. bool "ISA support"
  2135. ---help---
  2136. Find out whether you have ISA slots on your motherboard. ISA is the
  2137. name of a bus system, i.e. the way the CPU talks to the other stuff
  2138. inside your box. Other bus systems are PCI, EISA, MicroChannel
  2139. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  2140. newer boards don't support it. If you have ISA, say Y, otherwise N.
  2141. config EISA
  2142. bool "EISA support"
  2143. depends on ISA
  2144. ---help---
  2145. The Extended Industry Standard Architecture (EISA) bus was
  2146. developed as an open alternative to the IBM MicroChannel bus.
  2147. The EISA bus provided some of the features of the IBM MicroChannel
  2148. bus while maintaining backward compatibility with cards made for
  2149. the older ISA bus. The EISA bus saw limited use between 1988 and
  2150. 1995 when it was made obsolete by the PCI bus.
  2151. Say Y here if you are building a kernel for an EISA-based machine.
  2152. Otherwise, say N.
  2153. source "drivers/eisa/Kconfig"
  2154. config SCx200
  2155. tristate "NatSemi SCx200 support"
  2156. ---help---
  2157. This provides basic support for National Semiconductor's
  2158. (now AMD's) Geode processors. The driver probes for the
  2159. PCI-IDs of several on-chip devices, so its a good dependency
  2160. for other scx200_* drivers.
  2161. If compiled as a module, the driver is named scx200.
  2162. config SCx200HR_TIMER
  2163. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  2164. depends on SCx200
  2165. default y
  2166. ---help---
  2167. This driver provides a clocksource built upon the on-chip
  2168. 27MHz high-resolution timer. Its also a workaround for
  2169. NSC Geode SC-1100's buggy TSC, which loses time when the
  2170. processor goes idle (as is done by the scheduler). The
  2171. other workaround is idle=poll boot option.
  2172. config OLPC
  2173. bool "One Laptop Per Child support"
  2174. depends on !X86_PAE
  2175. select GPIOLIB
  2176. select OF
  2177. select OF_PROMTREE
  2178. select IRQ_DOMAIN
  2179. ---help---
  2180. Add support for detecting the unique features of the OLPC
  2181. XO hardware.
  2182. config OLPC_XO1_PM
  2183. bool "OLPC XO-1 Power Management"
  2184. depends on OLPC && MFD_CS5535 && PM_SLEEP
  2185. select MFD_CORE
  2186. ---help---
  2187. Add support for poweroff and suspend of the OLPC XO-1 laptop.
  2188. config OLPC_XO1_RTC
  2189. bool "OLPC XO-1 Real Time Clock"
  2190. depends on OLPC_XO1_PM && RTC_DRV_CMOS
  2191. ---help---
  2192. Add support for the XO-1 real time clock, which can be used as a
  2193. programmable wakeup source.
  2194. config OLPC_XO1_SCI
  2195. bool "OLPC XO-1 SCI extras"
  2196. depends on OLPC && OLPC_XO1_PM
  2197. depends on INPUT=y
  2198. select POWER_SUPPLY
  2199. select GPIO_CS5535
  2200. select MFD_CORE
  2201. ---help---
  2202. Add support for SCI-based features of the OLPC XO-1 laptop:
  2203. - EC-driven system wakeups
  2204. - Power button
  2205. - Ebook switch
  2206. - Lid switch
  2207. - AC adapter status updates
  2208. - Battery status updates
  2209. config OLPC_XO15_SCI
  2210. bool "OLPC XO-1.5 SCI extras"
  2211. depends on OLPC && ACPI
  2212. select POWER_SUPPLY
  2213. ---help---
  2214. Add support for SCI-based features of the OLPC XO-1.5 laptop:
  2215. - EC-driven system wakeups
  2216. - AC adapter status updates
  2217. - Battery status updates
  2218. config ALIX
  2219. bool "PCEngines ALIX System Support (LED setup)"
  2220. select GPIOLIB
  2221. ---help---
  2222. This option enables system support for the PCEngines ALIX.
  2223. At present this just sets up LEDs for GPIO control on
  2224. ALIX2/3/6 boards. However, other system specific setup should
  2225. get added here.
  2226. Note: You must still enable the drivers for GPIO and LED support
  2227. (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
  2228. Note: You have to set alix.force=1 for boards with Award BIOS.
  2229. config NET5501
  2230. bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
  2231. select GPIOLIB
  2232. ---help---
  2233. This option enables system support for the Soekris Engineering net5501.
  2234. config GEOS
  2235. bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
  2236. select GPIOLIB
  2237. depends on DMI
  2238. ---help---
  2239. This option enables system support for the Traverse Technologies GEOS.
  2240. config TS5500
  2241. bool "Technologic Systems TS-5500 platform support"
  2242. depends on MELAN
  2243. select CHECK_SIGNATURE
  2244. select NEW_LEDS
  2245. select LEDS_CLASS
  2246. ---help---
  2247. This option enables system support for the Technologic Systems TS-5500.
  2248. endif # X86_32
  2249. config AMD_NB
  2250. def_bool y
  2251. depends on CPU_SUP_AMD && PCI
  2252. source "drivers/pcmcia/Kconfig"
  2253. config RAPIDIO
  2254. tristate "RapidIO support"
  2255. depends on PCI
  2256. default n
  2257. help
  2258. If enabled this option will include drivers and the core
  2259. infrastructure code to support RapidIO interconnect devices.
  2260. source "drivers/rapidio/Kconfig"
  2261. config X86_SYSFB
  2262. bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
  2263. help
  2264. Firmwares often provide initial graphics framebuffers so the BIOS,
  2265. bootloader or kernel can show basic video-output during boot for
  2266. user-guidance and debugging. Historically, x86 used the VESA BIOS
  2267. Extensions and EFI-framebuffers for this, which are mostly limited
  2268. to x86.
  2269. This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
  2270. framebuffers so the new generic system-framebuffer drivers can be
  2271. used on x86. If the framebuffer is not compatible with the generic
  2272. modes, it is adverticed as fallback platform framebuffer so legacy
  2273. drivers like efifb, vesafb and uvesafb can pick it up.
  2274. If this option is not selected, all system framebuffers are always
  2275. marked as fallback platform framebuffers as usual.
  2276. Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
  2277. not be able to pick up generic system framebuffers if this option
  2278. is selected. You are highly encouraged to enable simplefb as
  2279. replacement if you select this option. simplefb can correctly deal
  2280. with generic system framebuffers. But you should still keep vesafb
  2281. and others enabled as fallback if a system framebuffer is
  2282. incompatible with simplefb.
  2283. If unsure, say Y.
  2284. endmenu
  2285. menu "Executable file formats / Emulations"
  2286. source "fs/Kconfig.binfmt"
  2287. config IA32_EMULATION
  2288. bool "IA32 Emulation"
  2289. depends on X86_64
  2290. select ARCH_WANT_OLD_COMPAT_IPC
  2291. select BINFMT_ELF
  2292. select COMPAT_BINFMT_ELF
  2293. select COMPAT_OLD_SIGACTION
  2294. ---help---
  2295. Include code to run legacy 32-bit programs under a
  2296. 64-bit kernel. You should likely turn this on, unless you're
  2297. 100% sure that you don't have any 32-bit programs left.
  2298. config IA32_AOUT
  2299. tristate "IA32 a.out support"
  2300. depends on IA32_EMULATION
  2301. ---help---
  2302. Support old a.out binaries in the 32bit emulation.
  2303. config X86_X32
  2304. bool "x32 ABI for 64-bit mode"
  2305. depends on X86_64
  2306. ---help---
  2307. Include code to run binaries for the x32 native 32-bit ABI
  2308. for 64-bit processors. An x32 process gets access to the
  2309. full 64-bit register file and wide data path while leaving
  2310. pointers at 32 bits for smaller memory footprint.
  2311. You will need a recent binutils (2.22 or later) with
  2312. elf32_x86_64 support enabled to compile a kernel with this
  2313. option set.
  2314. config COMPAT_32
  2315. def_bool y
  2316. depends on IA32_EMULATION || X86_32
  2317. select HAVE_UID16
  2318. select OLD_SIGSUSPEND3
  2319. config COMPAT
  2320. def_bool y
  2321. depends on IA32_EMULATION || X86_X32
  2322. if COMPAT
  2323. config COMPAT_FOR_U64_ALIGNMENT
  2324. def_bool y
  2325. config SYSVIPC_COMPAT
  2326. def_bool y
  2327. depends on SYSVIPC
  2328. config KEYS_COMPAT
  2329. def_bool y
  2330. depends on KEYS
  2331. endif
  2332. endmenu
  2333. config HAVE_ATOMIC_IOMAP
  2334. def_bool y
  2335. depends on X86_32
  2336. config X86_DEV_DMA_OPS
  2337. bool
  2338. depends on X86_64 || STA2X11
  2339. config X86_DMA_REMAP
  2340. bool
  2341. depends on STA2X11
  2342. source "net/Kconfig"
  2343. source "drivers/Kconfig"
  2344. source "drivers/firmware/Kconfig"
  2345. source "fs/Kconfig"
  2346. source "arch/x86/Kconfig.debug"
  2347. source "security/Kconfig"
  2348. source "crypto/Kconfig"
  2349. source "arch/x86/kvm/Kconfig"
  2350. source "lib/Kconfig"