1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_GENERIC_DMA_COHERENT 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 21config X86_64 22 def_bool y 23 depends on 64BIT 24 # Options that are inherently 64-bit kernel only: 25 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select NEED_DMA_MAP_STATE 31 select SWIOTLB 32 select X86_DEV_DMA_OPS 33 select ARCH_HAS_SYSCALL_WRAPPER 34 35# 36# Arch settings 37# 38# ( Note that options that are marked 'if X86_64' could in principle be 39# ported to 32-bit as well. ) 40# 41config X86 42 def_bool y 43 # 44 # Note: keep this list sorted alphabetically 45 # 46 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 47 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 48 select ANON_INODES 49 select ARCH_CLOCKSOURCE_DATA 50 select ARCH_DISCARD_MEMBLOCK 51 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 52 select ARCH_HAS_DEBUG_VIRTUAL 53 select ARCH_HAS_DEVMEM_IS_ALLOWED 54 select ARCH_HAS_ELF_RANDOMIZE 55 select ARCH_HAS_FAST_MULTIPLIER 56 select ARCH_HAS_FILTER_PGPROT 57 select ARCH_HAS_FORTIFY_SOURCE 58 select ARCH_HAS_GCOV_PROFILE_ALL 59 select ARCH_HAS_KCOV if X86_64 60 select ARCH_HAS_MEMBARRIER_SYNC_CORE 61 select ARCH_HAS_PMEM_API if X86_64 62 select ARCH_HAS_PTE_SPECIAL 63 select ARCH_HAS_REFCOUNT 64 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 65 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 66 select ARCH_HAS_SET_MEMORY 67 select ARCH_HAS_SG_CHAIN 68 select ARCH_HAS_STRICT_KERNEL_RWX 69 select ARCH_HAS_STRICT_MODULE_RWX 70 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 71 select ARCH_HAS_UBSAN_SANITIZE_ALL 72 select ARCH_HAS_ZONE_DEVICE if X86_64 73 select ARCH_HAVE_NMI_SAFE_CMPXCHG 74 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 75 select ARCH_MIGHT_HAVE_PC_PARPORT 76 select ARCH_MIGHT_HAVE_PC_SERIO 77 select ARCH_SUPPORTS_ACPI 78 select ARCH_SUPPORTS_ATOMIC_RMW 79 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 80 select ARCH_USE_BUILTIN_BSWAP 81 select ARCH_USE_QUEUED_RWLOCKS 82 select ARCH_USE_QUEUED_SPINLOCKS 83 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 84 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 85 select ARCH_WANTS_THP_SWAP if X86_64 86 select BUILDTIME_EXTABLE_SORT 87 select CLKEVT_I8253 88 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 89 select CLOCKSOURCE_WATCHDOG 90 select DCACHE_WORD_ACCESS 91 select DMA_DIRECT_OPS 92 select EDAC_ATOMIC_SCRUB 93 select EDAC_SUPPORT 94 select GENERIC_CLOCKEVENTS 95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 96 select GENERIC_CLOCKEVENTS_MIN_ADJUST 97 select GENERIC_CMOS_UPDATE 98 select GENERIC_CPU_AUTOPROBE 99 select GENERIC_CPU_VULNERABILITIES 100 select GENERIC_EARLY_IOREMAP 101 select GENERIC_FIND_FIRST_BIT 102 select GENERIC_IOMAP 103 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 104 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 105 select GENERIC_IRQ_MIGRATION if SMP 106 select GENERIC_IRQ_PROBE 107 select GENERIC_IRQ_RESERVATION_MODE 108 select GENERIC_IRQ_SHOW 109 select GENERIC_PENDING_IRQ if SMP 110 select GENERIC_SMP_IDLE_THREAD 111 select GENERIC_STRNCPY_FROM_USER 112 select GENERIC_STRNLEN_USER 113 select GENERIC_TIME_VSYSCALL 114 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 115 select HAVE_ACPI_APEI if ACPI 116 select HAVE_ACPI_APEI_NMI if ACPI 117 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 118 select HAVE_ARCH_AUDITSYSCALL 119 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 120 select HAVE_ARCH_JUMP_LABEL 121 select HAVE_ARCH_KASAN if X86_64 122 select HAVE_ARCH_KGDB 123 select HAVE_ARCH_MMAP_RND_BITS if MMU 124 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 125 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 126 select HAVE_ARCH_PREL32_RELOCATIONS 127 select HAVE_ARCH_SECCOMP_FILTER 128 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 129 select HAVE_ARCH_TRACEHOOK 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 132 select HAVE_ARCH_VMAP_STACK if X86_64 133 select HAVE_ARCH_WITHIN_STACK_FRAMES 134 select HAVE_CMPXCHG_DOUBLE 135 select HAVE_CMPXCHG_LOCAL 136 select HAVE_CONTEXT_TRACKING if X86_64 137 select HAVE_COPY_THREAD_TLS 138 select HAVE_C_RECORDMCOUNT 139 select HAVE_DEBUG_KMEMLEAK 140 select HAVE_DEBUG_STACKOVERFLOW 141 select HAVE_DMA_CONTIGUOUS 142 select HAVE_DYNAMIC_FTRACE 143 select HAVE_DYNAMIC_FTRACE_WITH_REGS 144 select HAVE_EBPF_JIT 145 select HAVE_EFFICIENT_UNALIGNED_ACCESS 146 select HAVE_EXIT_THREAD 147 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 148 select HAVE_FTRACE_MCOUNT_RECORD 149 select HAVE_FUNCTION_GRAPH_TRACER 150 select HAVE_FUNCTION_TRACER 151 select HAVE_GCC_PLUGINS 152 select HAVE_HW_BREAKPOINT 153 select HAVE_IDE 154 select HAVE_IOREMAP_PROT 155 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 156 select HAVE_IRQ_TIME_ACCOUNTING 157 select HAVE_KERNEL_BZIP2 158 select HAVE_KERNEL_GZIP 159 select HAVE_KERNEL_LZ4 160 select HAVE_KERNEL_LZMA 161 select HAVE_KERNEL_LZO 162 select HAVE_KERNEL_XZ 163 select HAVE_KPROBES 164 select HAVE_KPROBES_ON_FTRACE 165 select HAVE_FUNCTION_ERROR_INJECTION 166 select HAVE_KRETPROBES 167 select HAVE_KVM 168 select HAVE_LIVEPATCH if X86_64 169 select HAVE_MEMBLOCK 170 select HAVE_MEMBLOCK_NODE_MAP 171 select HAVE_MIXED_BREAKPOINTS_REGS 172 select HAVE_MOD_ARCH_SPECIFIC 173 select HAVE_NMI 174 select HAVE_OPROFILE 175 select HAVE_OPTPROBES 176 select HAVE_PCSPKR_PLATFORM 177 select HAVE_PERF_EVENTS 178 select HAVE_PERF_EVENTS_NMI 179 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 180 select HAVE_PERF_REGS 181 select HAVE_PERF_USER_STACK_DUMP 182 select HAVE_RCU_TABLE_FREE if PARAVIRT 183 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 184 select HAVE_REGS_AND_STACK_ACCESS_API 185 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 186 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 187 select HAVE_STACK_VALIDATION if X86_64 188 select HAVE_RSEQ 189 select HAVE_SYSCALL_TRACEPOINTS 190 select HAVE_UNSTABLE_SCHED_CLOCK 191 select HAVE_USER_RETURN_NOTIFIER 192 select HOTPLUG_SMT if SMP 193 select IRQ_FORCED_THREADING 194 select NEED_SG_DMA_LENGTH 195 select PCI_LOCKLESS_CONFIG 196 select PERF_EVENTS 197 select RTC_LIB 198 select RTC_MC146818_LIB 199 select SPARSE_IRQ 200 select SRCU 201 select SYSCTL_EXCEPTION_TRACE 202 select THREAD_INFO_IN_TASK 203 select USER_STACKTRACE_SUPPORT 204 select VIRT_TO_BUS 205 select X86_FEATURE_NAMES if PROC_FS 206 207config INSTRUCTION_DECODER 208 def_bool y 209 depends on KPROBES || PERF_EVENTS || UPROBES 210 211config OUTPUT_FORMAT 212 string 213 default "elf32-i386" if X86_32 214 default "elf64-x86-64" if X86_64 215 216config ARCH_DEFCONFIG 217 string 218 default "arch/x86/configs/i386_defconfig" if X86_32 219 default "arch/x86/configs/x86_64_defconfig" if X86_64 220 221config LOCKDEP_SUPPORT 222 def_bool y 223 224config STACKTRACE_SUPPORT 225 def_bool y 226 227config MMU 228 def_bool y 229 230config ARCH_MMAP_RND_BITS_MIN 231 default 28 if 64BIT 232 default 8 233 234config ARCH_MMAP_RND_BITS_MAX 235 default 32 if 64BIT 236 default 16 237 238config ARCH_MMAP_RND_COMPAT_BITS_MIN 239 default 8 240 241config ARCH_MMAP_RND_COMPAT_BITS_MAX 242 default 16 243 244config SBUS 245 bool 246 247config GENERIC_ISA_DMA 248 def_bool y 249 depends on ISA_DMA_API 250 251config GENERIC_BUG 252 def_bool y 253 depends on BUG 254 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 255 256config GENERIC_BUG_RELATIVE_POINTERS 257 bool 258 259config GENERIC_HWEIGHT 260 def_bool y 261 262config ARCH_MAY_HAVE_PC_FDC 263 def_bool y 264 depends on ISA_DMA_API 265 266config RWSEM_XCHGADD_ALGORITHM 267 def_bool y 268 269config GENERIC_CALIBRATE_DELAY 270 def_bool y 271 272config ARCH_HAS_CPU_RELAX 273 def_bool y 274 275config ARCH_HAS_CACHE_LINE_SIZE 276 def_bool y 277 278config ARCH_HAS_FILTER_PGPROT 279 def_bool y 280 281config HAVE_SETUP_PER_CPU_AREA 282 def_bool y 283 284config NEED_PER_CPU_EMBED_FIRST_CHUNK 285 def_bool y 286 287config NEED_PER_CPU_PAGE_FIRST_CHUNK 288 def_bool y 289 290config ARCH_HIBERNATION_POSSIBLE 291 def_bool y 292 293config ARCH_SUSPEND_POSSIBLE 294 def_bool y 295 296config ARCH_WANT_HUGE_PMD_SHARE 297 def_bool y 298 299config ARCH_WANT_GENERAL_HUGETLB 300 def_bool y 301 302config ZONE_DMA32 303 def_bool y if X86_64 304 305config AUDIT_ARCH 306 def_bool y if X86_64 307 308config ARCH_SUPPORTS_OPTIMIZED_INLINING 309 def_bool y 310 311config ARCH_SUPPORTS_DEBUG_PAGEALLOC 312 def_bool y 313 314config KASAN_SHADOW_OFFSET 315 hex 316 depends on KASAN 317 default 0xdffffc0000000000 318 319config HAVE_INTEL_TXT 320 def_bool y 321 depends on INTEL_IOMMU && ACPI 322 323config X86_32_SMP 324 def_bool y 325 depends on X86_32 && SMP 326 327config X86_64_SMP 328 def_bool y 329 depends on X86_64 && SMP 330 331config X86_32_LAZY_GS 332 def_bool y 333 depends on X86_32 && !STACKPROTECTOR 334 335config ARCH_SUPPORTS_UPROBES 336 def_bool y 337 338config FIX_EARLYCON_MEM 339 def_bool y 340 341config DYNAMIC_PHYSICAL_MASK 342 bool 343 344config PGTABLE_LEVELS 345 int 346 default 5 if X86_5LEVEL 347 default 4 if X86_64 348 default 3 if X86_PAE 349 default 2 350 351config CC_HAS_SANE_STACKPROTECTOR 352 bool 353 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 354 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 355 help 356 We have to make sure stack protector is unconditionally disabled if 357 the compiler produces broken code. 358 359menu "Processor type and features" 360 361config ZONE_DMA 362 bool "DMA memory allocation support" if EXPERT 363 default y 364 help 365 DMA memory allocation support allows devices with less than 32-bit 366 addressing to allocate within the first 16MB of address space. 367 Disable if no such devices will be used. 368 369 If unsure, say Y. 370 371config SMP 372 bool "Symmetric multi-processing support" 373 ---help--- 374 This enables support for systems with more than one CPU. If you have 375 a system with only one CPU, say N. If you have a system with more 376 than one CPU, say Y. 377 378 If you say N here, the kernel will run on uni- and multiprocessor 379 machines, but will use only one CPU of a multiprocessor machine. If 380 you say Y here, the kernel will run on many, but not all, 381 uniprocessor machines. On a uniprocessor machine, the kernel 382 will run faster if you say N here. 383 384 Note that if you say Y here and choose architecture "586" or 385 "Pentium" under "Processor family", the kernel will not work on 486 386 architectures. Similarly, multiprocessor kernels for the "PPro" 387 architecture may not work on all Pentium based boards. 388 389 People using multiprocessor machines who say Y here should also say 390 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 391 Management" code will be disabled if you say Y here. 392 393 See also <file:Documentation/x86/i386/IO-APIC.txt>, 394 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 395 <http://www.tldp.org/docs.html#howto>. 396 397 If you don't know what to do here, say N. 398 399config X86_FEATURE_NAMES 400 bool "Processor feature human-readable names" if EMBEDDED 401 default y 402 ---help--- 403 This option compiles in a table of x86 feature bits and corresponding 404 names. This is required to support /proc/cpuinfo and a few kernel 405 messages. You can disable this to save space, at the expense of 406 making those few kernel messages show numeric feature bits instead. 407 408 If in doubt, say Y. 409 410config X86_X2APIC 411 bool "Support x2apic" 412 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 413 ---help--- 414 This enables x2apic support on CPUs that have this feature. 415 416 This allows 32-bit apic IDs (so it can support very large systems), 417 and accesses the local apic via MSRs not via mmio. 418 419 If you don't know what to do here, say N. 420 421config X86_MPPARSE 422 bool "Enable MPS table" if ACPI || SFI 423 default y 424 depends on X86_LOCAL_APIC 425 ---help--- 426 For old smp systems that do not have proper acpi support. Newer systems 427 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 428 429config GOLDFISH 430 def_bool y 431 depends on X86_GOLDFISH 432 433config RETPOLINE 434 bool "Avoid speculative indirect branches in kernel" 435 default y 436 select STACK_VALIDATION if HAVE_STACK_VALIDATION 437 help 438 Compile kernel with the retpoline compiler options to guard against 439 kernel-to-user data leaks by avoiding speculative indirect 440 branches. Requires a compiler with -mindirect-branch=thunk-extern 441 support for full protection. The kernel may run slower. 442 443config INTEL_RDT 444 bool "Intel Resource Director Technology support" 445 default n 446 depends on X86 && CPU_SUP_INTEL 447 select KERNFS 448 help 449 Select to enable resource allocation and monitoring which are 450 sub-features of Intel Resource Director Technology(RDT). More 451 information about RDT can be found in the Intel x86 452 Architecture Software Developer Manual. 453 454 Say N if unsure. 455 456if X86_32 457config X86_BIGSMP 458 bool "Support for big SMP systems with more than 8 CPUs" 459 depends on SMP 460 ---help--- 461 This option is needed for the systems that have more than 8 CPUs 462 463config X86_EXTENDED_PLATFORM 464 bool "Support for extended (non-PC) x86 platforms" 465 default y 466 ---help--- 467 If you disable this option then the kernel will only support 468 standard PC platforms. (which covers the vast majority of 469 systems out there.) 470 471 If you enable this option then you'll be able to select support 472 for the following (non-PC) 32 bit x86 platforms: 473 Goldfish (Android emulator) 474 AMD Elan 475 RDC R-321x SoC 476 SGI 320/540 (Visual Workstation) 477 STA2X11-based (e.g. Northville) 478 Moorestown MID devices 479 480 If you have one of these systems, or if you want to build a 481 generic distribution kernel, say Y here - otherwise say N. 482endif 483 484if X86_64 485config X86_EXTENDED_PLATFORM 486 bool "Support for extended (non-PC) x86 platforms" 487 default y 488 ---help--- 489 If you disable this option then the kernel will only support 490 standard PC platforms. (which covers the vast majority of 491 systems out there.) 492 493 If you enable this option then you'll be able to select support 494 for the following (non-PC) 64 bit x86 platforms: 495 Numascale NumaChip 496 ScaleMP vSMP 497 SGI Ultraviolet 498 499 If you have one of these systems, or if you want to build a 500 generic distribution kernel, say Y here - otherwise say N. 501endif 502# This is an alphabetically sorted list of 64 bit extended platforms 503# Please maintain the alphabetic order if and when there are additions 504config X86_NUMACHIP 505 bool "Numascale NumaChip" 506 depends on X86_64 507 depends on X86_EXTENDED_PLATFORM 508 depends on NUMA 509 depends on SMP 510 depends on X86_X2APIC 511 depends on PCI_MMCONFIG 512 ---help--- 513 Adds support for Numascale NumaChip large-SMP systems. Needed to 514 enable more than ~168 cores. 515 If you don't have one of these, you should say N here. 516 517config X86_VSMP 518 bool "ScaleMP vSMP" 519 select HYPERVISOR_GUEST 520 select PARAVIRT 521 depends on X86_64 && PCI 522 depends on X86_EXTENDED_PLATFORM 523 depends on SMP 524 ---help--- 525 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 526 supposed to run on these EM64T-based machines. Only choose this option 527 if you have one of these machines. 528 529config X86_UV 530 bool "SGI Ultraviolet" 531 depends on X86_64 532 depends on X86_EXTENDED_PLATFORM 533 depends on NUMA 534 depends on EFI 535 depends on X86_X2APIC 536 depends on PCI 537 ---help--- 538 This option is needed in order to support SGI Ultraviolet systems. 539 If you don't have one of these, you should say N here. 540 541# Following is an alphabetically sorted list of 32 bit extended platforms 542# Please maintain the alphabetic order if and when there are additions 543 544config X86_GOLDFISH 545 bool "Goldfish (Virtual Platform)" 546 depends on X86_EXTENDED_PLATFORM 547 ---help--- 548 Enable support for the Goldfish virtual platform used primarily 549 for Android development. Unless you are building for the Android 550 Goldfish emulator say N here. 551 552config X86_INTEL_CE 553 bool "CE4100 TV platform" 554 depends on PCI 555 depends on PCI_GODIRECT 556 depends on X86_IO_APIC 557 depends on X86_32 558 depends on X86_EXTENDED_PLATFORM 559 select X86_REBOOTFIXUPS 560 select OF 561 select OF_EARLY_FLATTREE 562 ---help--- 563 Select for the Intel CE media processor (CE4100) SOC. 564 This option compiles in support for the CE4100 SOC for settop 565 boxes and media devices. 566 567config X86_INTEL_MID 568 bool "Intel MID platform support" 569 depends on X86_EXTENDED_PLATFORM 570 depends on X86_PLATFORM_DEVICES 571 depends on PCI 572 depends on X86_64 || (PCI_GOANY && X86_32) 573 depends on X86_IO_APIC 574 select SFI 575 select I2C 576 select DW_APB_TIMER 577 select APB_TIMER 578 select INTEL_SCU_IPC 579 select MFD_INTEL_MSIC 580 ---help--- 581 Select to build a kernel capable of supporting Intel MID (Mobile 582 Internet Device) platform systems which do not have the PCI legacy 583 interfaces. If you are building for a PC class system say N here. 584 585 Intel MID platforms are based on an Intel processor and chipset which 586 consume less power than most of the x86 derivatives. 587 588config X86_INTEL_QUARK 589 bool "Intel Quark platform support" 590 depends on X86_32 591 depends on X86_EXTENDED_PLATFORM 592 depends on X86_PLATFORM_DEVICES 593 depends on X86_TSC 594 depends on PCI 595 depends on PCI_GOANY 596 depends on X86_IO_APIC 597 select IOSF_MBI 598 select INTEL_IMR 599 select COMMON_CLK 600 ---help--- 601 Select to include support for Quark X1000 SoC. 602 Say Y here if you have a Quark based system such as the Arduino 603 compatible Intel Galileo. 604 605config X86_INTEL_LPSS 606 bool "Intel Low Power Subsystem Support" 607 depends on X86 && ACPI 608 select COMMON_CLK 609 select PINCTRL 610 select IOSF_MBI 611 ---help--- 612 Select to build support for Intel Low Power Subsystem such as 613 found on Intel Lynxpoint PCH. Selecting this option enables 614 things like clock tree (common clock framework) and pincontrol 615 which are needed by the LPSS peripheral drivers. 616 617config X86_AMD_PLATFORM_DEVICE 618 bool "AMD ACPI2Platform devices support" 619 depends on ACPI 620 select COMMON_CLK 621 select PINCTRL 622 ---help--- 623 Select to interpret AMD specific ACPI device to platform device 624 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 625 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 626 implemented under PINCTRL subsystem. 627 628config IOSF_MBI 629 tristate "Intel SoC IOSF Sideband support for SoC platforms" 630 depends on PCI 631 ---help--- 632 This option enables sideband register access support for Intel SoC 633 platforms. On these platforms the IOSF sideband is used in lieu of 634 MSR's for some register accesses, mostly but not limited to thermal 635 and power. Drivers may query the availability of this device to 636 determine if they need the sideband in order to work on these 637 platforms. The sideband is available on the following SoC products. 638 This list is not meant to be exclusive. 639 - BayTrail 640 - Braswell 641 - Quark 642 643 You should say Y if you are running a kernel on one of these SoC's. 644 645config IOSF_MBI_DEBUG 646 bool "Enable IOSF sideband access through debugfs" 647 depends on IOSF_MBI && DEBUG_FS 648 ---help--- 649 Select this option to expose the IOSF sideband access registers (MCR, 650 MDR, MCRX) through debugfs to write and read register information from 651 different units on the SoC. This is most useful for obtaining device 652 state information for debug and analysis. As this is a general access 653 mechanism, users of this option would have specific knowledge of the 654 device they want to access. 655 656 If you don't require the option or are in doubt, say N. 657 658config X86_RDC321X 659 bool "RDC R-321x SoC" 660 depends on X86_32 661 depends on X86_EXTENDED_PLATFORM 662 select M486 663 select X86_REBOOTFIXUPS 664 ---help--- 665 This option is needed for RDC R-321x system-on-chip, also known 666 as R-8610-(G). 667 If you don't have one of these chips, you should say N here. 668 669config X86_32_NON_STANDARD 670 bool "Support non-standard 32-bit SMP architectures" 671 depends on X86_32 && SMP 672 depends on X86_EXTENDED_PLATFORM 673 ---help--- 674 This option compiles in the bigsmp and STA2X11 default 675 subarchitectures. It is intended for a generic binary 676 kernel. If you select them all, kernel will probe it one by 677 one and will fallback to default. 678 679# Alphabetically sorted list of Non standard 32 bit platforms 680 681config X86_SUPPORTS_MEMORY_FAILURE 682 def_bool y 683 # MCE code calls memory_failure(): 684 depends on X86_MCE 685 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 686 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 687 depends on X86_64 || !SPARSEMEM 688 select ARCH_SUPPORTS_MEMORY_FAILURE 689 690config STA2X11 691 bool "STA2X11 Companion Chip Support" 692 depends on X86_32_NON_STANDARD && PCI 693 select ARCH_HAS_PHYS_TO_DMA 694 select X86_DEV_DMA_OPS 695 select X86_DMA_REMAP 696 select SWIOTLB 697 select MFD_STA2X11 698 select GPIOLIB 699 default n 700 ---help--- 701 This adds support for boards based on the STA2X11 IO-Hub, 702 a.k.a. "ConneXt". The chip is used in place of the standard 703 PC chipset, so all "standard" peripherals are missing. If this 704 option is selected the kernel will still be able to boot on 705 standard PC machines. 706 707config X86_32_IRIS 708 tristate "Eurobraille/Iris poweroff module" 709 depends on X86_32 710 ---help--- 711 The Iris machines from EuroBraille do not have APM or ACPI support 712 to shut themselves down properly. A special I/O sequence is 713 needed to do so, which is what this module does at 714 kernel shutdown. 715 716 This is only for Iris machines from EuroBraille. 717 718 If unused, say N. 719 720config SCHED_OMIT_FRAME_POINTER 721 def_bool y 722 prompt "Single-depth WCHAN output" 723 depends on X86 724 ---help--- 725 Calculate simpler /proc/<PID>/wchan values. If this option 726 is disabled then wchan values will recurse back to the 727 caller function. This provides more accurate wchan values, 728 at the expense of slightly more scheduling overhead. 729 730 If in doubt, say "Y". 731 732menuconfig HYPERVISOR_GUEST 733 bool "Linux guest support" 734 ---help--- 735 Say Y here to enable options for running Linux under various hyper- 736 visors. This option enables basic hypervisor detection and platform 737 setup. 738 739 If you say N, all options in this submenu will be skipped and 740 disabled, and Linux guest support won't be built in. 741 742if HYPERVISOR_GUEST 743 744config PARAVIRT 745 bool "Enable paravirtualization code" 746 ---help--- 747 This changes the kernel so it can modify itself when it is run 748 under a hypervisor, potentially improving performance significantly 749 over full virtualization. However, when run without a hypervisor 750 the kernel is theoretically slower and slightly larger. 751 752config PARAVIRT_DEBUG 753 bool "paravirt-ops debugging" 754 depends on PARAVIRT && DEBUG_KERNEL 755 ---help--- 756 Enable to debug paravirt_ops internals. Specifically, BUG if 757 a paravirt_op is missing when it is called. 758 759config PARAVIRT_SPINLOCKS 760 bool "Paravirtualization layer for spinlocks" 761 depends on PARAVIRT && SMP 762 ---help--- 763 Paravirtualized spinlocks allow a pvops backend to replace the 764 spinlock implementation with something virtualization-friendly 765 (for example, block the virtual CPU rather than spinning). 766 767 It has a minimal impact on native kernels and gives a nice performance 768 benefit on paravirtualized KVM / Xen kernels. 769 770 If you are unsure how to answer this question, answer Y. 771 772config QUEUED_LOCK_STAT 773 bool "Paravirt queued spinlock statistics" 774 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 775 ---help--- 776 Enable the collection of statistical data on the slowpath 777 behavior of paravirtualized queued spinlocks and report 778 them on debugfs. 779 780source "arch/x86/xen/Kconfig" 781 782config KVM_GUEST 783 bool "KVM Guest support (including kvmclock)" 784 depends on PARAVIRT 785 select PARAVIRT_CLOCK 786 default y 787 ---help--- 788 This option enables various optimizations for running under the KVM 789 hypervisor. It includes a paravirtualized clock, so that instead 790 of relying on a PIT (or probably other) emulation by the 791 underlying device model, the host provides the guest with 792 timing infrastructure such as time of day, and system time 793 794config KVM_DEBUG_FS 795 bool "Enable debug information for KVM Guests in debugfs" 796 depends on KVM_GUEST && DEBUG_FS 797 default n 798 ---help--- 799 This option enables collection of various statistics for KVM guest. 800 Statistics are displayed in debugfs filesystem. Enabling this option 801 may incur significant overhead. 802 803config PARAVIRT_TIME_ACCOUNTING 804 bool "Paravirtual steal time accounting" 805 depends on PARAVIRT 806 default n 807 ---help--- 808 Select this option to enable fine granularity task steal time 809 accounting. Time spent executing other tasks in parallel with 810 the current vCPU is discounted from the vCPU power. To account for 811 that, there can be a small performance impact. 812 813 If in doubt, say N here. 814 815config PARAVIRT_CLOCK 816 bool 817 818config JAILHOUSE_GUEST 819 bool "Jailhouse non-root cell support" 820 depends on X86_64 && PCI 821 select X86_PM_TIMER 822 ---help--- 823 This option allows to run Linux as guest in a Jailhouse non-root 824 cell. You can leave this option disabled if you only want to start 825 Jailhouse and run Linux afterwards in the root cell. 826 827endif #HYPERVISOR_GUEST 828 829config NO_BOOTMEM 830 def_bool y 831 832source "arch/x86/Kconfig.cpu" 833 834config HPET_TIMER 835 def_bool X86_64 836 prompt "HPET Timer Support" if X86_32 837 ---help--- 838 Use the IA-PC HPET (High Precision Event Timer) to manage 839 time in preference to the PIT and RTC, if a HPET is 840 present. 841 HPET is the next generation timer replacing legacy 8254s. 842 The HPET provides a stable time base on SMP 843 systems, unlike the TSC, but it is more expensive to access, 844 as it is off-chip. The interface used is documented 845 in the HPET spec, revision 1. 846 847 You can safely choose Y here. However, HPET will only be 848 activated if the platform and the BIOS support this feature. 849 Otherwise the 8254 will be used for timing services. 850 851 Choose N to continue using the legacy 8254 timer. 852 853config HPET_EMULATE_RTC 854 def_bool y 855 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 856 857config APB_TIMER 858 def_bool y if X86_INTEL_MID 859 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 860 select DW_APB_TIMER 861 depends on X86_INTEL_MID && SFI 862 help 863 APB timer is the replacement for 8254, HPET on X86 MID platforms. 864 The APBT provides a stable time base on SMP 865 systems, unlike the TSC, but it is more expensive to access, 866 as it is off-chip. APB timers are always running regardless of CPU 867 C states, they are used as per CPU clockevent device when possible. 868 869# Mark as expert because too many people got it wrong. 870# The code disables itself when not needed. 871config DMI 872 default y 873 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 874 bool "Enable DMI scanning" if EXPERT 875 ---help--- 876 Enabled scanning of DMI to identify machine quirks. Say Y 877 here unless you have verified that your setup is not 878 affected by entries in the DMI blacklist. Required by PNP 879 BIOS code. 880 881config GART_IOMMU 882 bool "Old AMD GART IOMMU support" 883 select IOMMU_HELPER 884 select SWIOTLB 885 depends on X86_64 && PCI && AMD_NB 886 ---help--- 887 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 888 GART based hardware IOMMUs. 889 890 The GART supports full DMA access for devices with 32-bit access 891 limitations, on systems with more than 3 GB. This is usually needed 892 for USB, sound, many IDE/SATA chipsets and some other devices. 893 894 Newer systems typically have a modern AMD IOMMU, supported via 895 the CONFIG_AMD_IOMMU=y config option. 896 897 In normal configurations this driver is only active when needed: 898 there's more than 3 GB of memory and the system contains a 899 32-bit limited device. 900 901 If unsure, say Y. 902 903config CALGARY_IOMMU 904 bool "IBM Calgary IOMMU support" 905 select IOMMU_HELPER 906 select SWIOTLB 907 depends on X86_64 && PCI 908 ---help--- 909 Support for hardware IOMMUs in IBM's xSeries x366 and x460 910 systems. Needed to run systems with more than 3GB of memory 911 properly with 32-bit PCI devices that do not support DAC 912 (Double Address Cycle). Calgary also supports bus level 913 isolation, where all DMAs pass through the IOMMU. This 914 prevents them from going anywhere except their intended 915 destination. This catches hard-to-find kernel bugs and 916 mis-behaving drivers and devices that do not use the DMA-API 917 properly to set up their DMA buffers. The IOMMU can be 918 turned off at boot time with the iommu=off parameter. 919 Normally the kernel will make the right choice by itself. 920 If unsure, say Y. 921 922config CALGARY_IOMMU_ENABLED_BY_DEFAULT 923 def_bool y 924 prompt "Should Calgary be enabled by default?" 925 depends on CALGARY_IOMMU 926 ---help--- 927 Should Calgary be enabled by default? if you choose 'y', Calgary 928 will be used (if it exists). If you choose 'n', Calgary will not be 929 used even if it exists. If you choose 'n' and would like to use 930 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 931 If unsure, say Y. 932 933config MAXSMP 934 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 935 depends on X86_64 && SMP && DEBUG_KERNEL 936 select CPUMASK_OFFSTACK 937 ---help--- 938 Enable maximum number of CPUS and NUMA Nodes for this architecture. 939 If unsure, say N. 940 941# 942# The maximum number of CPUs supported: 943# 944# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 945# and which can be configured interactively in the 946# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 947# 948# The ranges are different on 32-bit and 64-bit kernels, depending on 949# hardware capabilities and scalability features of the kernel. 950# 951# ( If MAXSMP is enabled we just use the highest possible value and disable 952# interactive configuration. ) 953# 954 955config NR_CPUS_RANGE_BEGIN 956 int 957 default NR_CPUS_RANGE_END if MAXSMP 958 default 1 if !SMP 959 default 2 960 961config NR_CPUS_RANGE_END 962 int 963 depends on X86_32 964 default 64 if SMP && X86_BIGSMP 965 default 8 if SMP && !X86_BIGSMP 966 default 1 if !SMP 967 968config NR_CPUS_RANGE_END 969 int 970 depends on X86_64 971 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 972 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 973 default 1 if !SMP 974 975config NR_CPUS_DEFAULT 976 int 977 depends on X86_32 978 default 32 if X86_BIGSMP 979 default 8 if SMP 980 default 1 if !SMP 981 982config NR_CPUS_DEFAULT 983 int 984 depends on X86_64 985 default 8192 if MAXSMP 986 default 64 if SMP 987 default 1 if !SMP 988 989config NR_CPUS 990 int "Maximum number of CPUs" if SMP && !MAXSMP 991 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 992 default NR_CPUS_DEFAULT 993 ---help--- 994 This allows you to specify the maximum number of CPUs which this 995 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 996 supported value is 8192, otherwise the maximum value is 512. The 997 minimum value which makes sense is 2. 998 999 This is purely to save memory: each supported CPU adds about 8KB 1000 to the kernel image. 1001 1002config SCHED_SMT 1003 def_bool y if SMP 1004 1005config SCHED_MC 1006 def_bool y 1007 prompt "Multi-core scheduler support" 1008 depends on SMP 1009 ---help--- 1010 Multi-core scheduler support improves the CPU scheduler's decision 1011 making when dealing with multi-core CPU chips at a cost of slightly 1012 increased overhead in some places. If unsure say N here. 1013 1014config SCHED_MC_PRIO 1015 bool "CPU core priorities scheduler support" 1016 depends on SCHED_MC && CPU_SUP_INTEL 1017 select X86_INTEL_PSTATE 1018 select CPU_FREQ 1019 default y 1020 ---help--- 1021 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1022 core ordering determined at manufacturing time, which allows 1023 certain cores to reach higher turbo frequencies (when running 1024 single threaded workloads) than others. 1025 1026 Enabling this kernel feature teaches the scheduler about 1027 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1028 scheduler's CPU selection logic accordingly, so that higher 1029 overall system performance can be achieved. 1030 1031 This feature will have no effect on CPUs without this feature. 1032 1033 If unsure say Y here. 1034 1035config UP_LATE_INIT 1036 def_bool y 1037 depends on !SMP && X86_LOCAL_APIC 1038 1039config X86_UP_APIC 1040 bool "Local APIC support on uniprocessors" if !PCI_MSI 1041 default PCI_MSI 1042 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1043 ---help--- 1044 A local APIC (Advanced Programmable Interrupt Controller) is an 1045 integrated interrupt controller in the CPU. If you have a single-CPU 1046 system which has a processor with a local APIC, you can say Y here to 1047 enable and use it. If you say Y here even though your machine doesn't 1048 have a local APIC, then the kernel will still run with no slowdown at 1049 all. The local APIC supports CPU-generated self-interrupts (timer, 1050 performance counters), and the NMI watchdog which detects hard 1051 lockups. 1052 1053config X86_UP_IOAPIC 1054 bool "IO-APIC support on uniprocessors" 1055 depends on X86_UP_APIC 1056 ---help--- 1057 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1058 SMP-capable replacement for PC-style interrupt controllers. Most 1059 SMP systems and many recent uniprocessor systems have one. 1060 1061 If you have a single-CPU system with an IO-APIC, you can say Y here 1062 to use it. If you say Y here even though your machine doesn't have 1063 an IO-APIC, then the kernel will still run with no slowdown at all. 1064 1065config X86_LOCAL_APIC 1066 def_bool y 1067 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1068 select IRQ_DOMAIN_HIERARCHY 1069 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1070 1071config X86_IO_APIC 1072 def_bool y 1073 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1074 1075config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1076 bool "Reroute for broken boot IRQs" 1077 depends on X86_IO_APIC 1078 ---help--- 1079 This option enables a workaround that fixes a source of 1080 spurious interrupts. This is recommended when threaded 1081 interrupt handling is used on systems where the generation of 1082 superfluous "boot interrupts" cannot be disabled. 1083 1084 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1085 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1086 kernel does during interrupt handling). On chipsets where this 1087 boot IRQ generation cannot be disabled, this workaround keeps 1088 the original IRQ line masked so that only the equivalent "boot 1089 IRQ" is delivered to the CPUs. The workaround also tells the 1090 kernel to set up the IRQ handler on the boot IRQ line. In this 1091 way only one interrupt is delivered to the kernel. Otherwise 1092 the spurious second interrupt may cause the kernel to bring 1093 down (vital) interrupt lines. 1094 1095 Only affects "broken" chipsets. Interrupt sharing may be 1096 increased on these systems. 1097 1098config X86_MCE 1099 bool "Machine Check / overheating reporting" 1100 select GENERIC_ALLOCATOR 1101 default y 1102 ---help--- 1103 Machine Check support allows the processor to notify the 1104 kernel if it detects a problem (e.g. overheating, data corruption). 1105 The action the kernel takes depends on the severity of the problem, 1106 ranging from warning messages to halting the machine. 1107 1108config X86_MCELOG_LEGACY 1109 bool "Support for deprecated /dev/mcelog character device" 1110 depends on X86_MCE 1111 ---help--- 1112 Enable support for /dev/mcelog which is needed by the old mcelog 1113 userspace logging daemon. Consider switching to the new generation 1114 rasdaemon solution. 1115 1116config X86_MCE_INTEL 1117 def_bool y 1118 prompt "Intel MCE features" 1119 depends on X86_MCE && X86_LOCAL_APIC 1120 ---help--- 1121 Additional support for intel specific MCE features such as 1122 the thermal monitor. 1123 1124config X86_MCE_AMD 1125 def_bool y 1126 prompt "AMD MCE features" 1127 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1128 ---help--- 1129 Additional support for AMD specific MCE features such as 1130 the DRAM Error Threshold. 1131 1132config X86_ANCIENT_MCE 1133 bool "Support for old Pentium 5 / WinChip machine checks" 1134 depends on X86_32 && X86_MCE 1135 ---help--- 1136 Include support for machine check handling on old Pentium 5 or WinChip 1137 systems. These typically need to be enabled explicitly on the command 1138 line. 1139 1140config X86_MCE_THRESHOLD 1141 depends on X86_MCE_AMD || X86_MCE_INTEL 1142 def_bool y 1143 1144config X86_MCE_INJECT 1145 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1146 tristate "Machine check injector support" 1147 ---help--- 1148 Provide support for injecting machine checks for testing purposes. 1149 If you don't know what a machine check is and you don't do kernel 1150 QA it is safe to say n. 1151 1152config X86_THERMAL_VECTOR 1153 def_bool y 1154 depends on X86_MCE_INTEL 1155 1156source "arch/x86/events/Kconfig" 1157 1158config X86_LEGACY_VM86 1159 bool "Legacy VM86 support" 1160 default n 1161 depends on X86_32 1162 ---help--- 1163 This option allows user programs to put the CPU into V8086 1164 mode, which is an 80286-era approximation of 16-bit real mode. 1165 1166 Some very old versions of X and/or vbetool require this option 1167 for user mode setting. Similarly, DOSEMU will use it if 1168 available to accelerate real mode DOS programs. However, any 1169 recent version of DOSEMU, X, or vbetool should be fully 1170 functional even without kernel VM86 support, as they will all 1171 fall back to software emulation. Nevertheless, if you are using 1172 a 16-bit DOS program where 16-bit performance matters, vm86 1173 mode might be faster than emulation and you might want to 1174 enable this option. 1175 1176 Note that any app that works on a 64-bit kernel is unlikely to 1177 need this option, as 64-bit kernels don't, and can't, support 1178 V8086 mode. This option is also unrelated to 16-bit protected 1179 mode and is not needed to run most 16-bit programs under Wine. 1180 1181 Enabling this option increases the complexity of the kernel 1182 and slows down exception handling a tiny bit. 1183 1184 If unsure, say N here. 1185 1186config VM86 1187 bool 1188 default X86_LEGACY_VM86 1189 1190config X86_16BIT 1191 bool "Enable support for 16-bit segments" if EXPERT 1192 default y 1193 depends on MODIFY_LDT_SYSCALL 1194 ---help--- 1195 This option is required by programs like Wine to run 16-bit 1196 protected mode legacy code on x86 processors. Disabling 1197 this option saves about 300 bytes on i386, or around 6K text 1198 plus 16K runtime memory on x86-64, 1199 1200config X86_ESPFIX32 1201 def_bool y 1202 depends on X86_16BIT && X86_32 1203 1204config X86_ESPFIX64 1205 def_bool y 1206 depends on X86_16BIT && X86_64 1207 1208config X86_VSYSCALL_EMULATION 1209 bool "Enable vsyscall emulation" if EXPERT 1210 default y 1211 depends on X86_64 1212 ---help--- 1213 This enables emulation of the legacy vsyscall page. Disabling 1214 it is roughly equivalent to booting with vsyscall=none, except 1215 that it will also disable the helpful warning if a program 1216 tries to use a vsyscall. With this option set to N, offending 1217 programs will just segfault, citing addresses of the form 1218 0xffffffffff600?00. 1219 1220 This option is required by many programs built before 2013, and 1221 care should be used even with newer programs if set to N. 1222 1223 Disabling this option saves about 7K of kernel size and 1224 possibly 4K of additional runtime pagetable memory. 1225 1226config TOSHIBA 1227 tristate "Toshiba Laptop support" 1228 depends on X86_32 1229 ---help--- 1230 This adds a driver to safely access the System Management Mode of 1231 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1232 not work on models with a Phoenix BIOS. The System Management Mode 1233 is used to set the BIOS and power saving options on Toshiba portables. 1234 1235 For information on utilities to make use of this driver see the 1236 Toshiba Linux utilities web site at: 1237 <http://www.buzzard.org.uk/toshiba/>. 1238 1239 Say Y if you intend to run this kernel on a Toshiba portable. 1240 Say N otherwise. 1241 1242config I8K 1243 tristate "Dell i8k legacy laptop support" 1244 select HWMON 1245 select SENSORS_DELL_SMM 1246 ---help--- 1247 This option enables legacy /proc/i8k userspace interface in hwmon 1248 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1249 temperature and allows controlling fan speeds of Dell laptops via 1250 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1251 it reports also power and hotkey status. For fan speed control is 1252 needed userspace package i8kutils. 1253 1254 Say Y if you intend to run this kernel on old Dell laptops or want to 1255 use userspace package i8kutils. 1256 Say N otherwise. 1257 1258config X86_REBOOTFIXUPS 1259 bool "Enable X86 board specific fixups for reboot" 1260 depends on X86_32 1261 ---help--- 1262 This enables chipset and/or board specific fixups to be done 1263 in order to get reboot to work correctly. This is only needed on 1264 some combinations of hardware and BIOS. The symptom, for which 1265 this config is intended, is when reboot ends with a stalled/hung 1266 system. 1267 1268 Currently, the only fixup is for the Geode machines using 1269 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1270 1271 Say Y if you want to enable the fixup. Currently, it's safe to 1272 enable this option even if you don't need it. 1273 Say N otherwise. 1274 1275config MICROCODE 1276 bool "CPU microcode loading support" 1277 default y 1278 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1279 select FW_LOADER 1280 ---help--- 1281 If you say Y here, you will be able to update the microcode on 1282 Intel and AMD processors. The Intel support is for the IA32 family, 1283 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1284 AMD support is for families 0x10 and later. You will obviously need 1285 the actual microcode binary data itself which is not shipped with 1286 the Linux kernel. 1287 1288 The preferred method to load microcode from a detached initrd is described 1289 in Documentation/x86/microcode.txt. For that you need to enable 1290 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1291 initrd for microcode blobs. 1292 1293 In addition, you can build the microcode into the kernel. For that you 1294 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1295 config option. 1296 1297config MICROCODE_INTEL 1298 bool "Intel microcode loading support" 1299 depends on MICROCODE 1300 default MICROCODE 1301 select FW_LOADER 1302 ---help--- 1303 This options enables microcode patch loading support for Intel 1304 processors. 1305 1306 For the current Intel microcode data package go to 1307 <https://downloadcenter.intel.com> and search for 1308 'Linux Processor Microcode Data File'. 1309 1310config MICROCODE_AMD 1311 bool "AMD microcode loading support" 1312 depends on MICROCODE 1313 select FW_LOADER 1314 ---help--- 1315 If you select this option, microcode patch loading support for AMD 1316 processors will be enabled. 1317 1318config MICROCODE_OLD_INTERFACE 1319 def_bool y 1320 depends on MICROCODE 1321 1322config X86_MSR 1323 tristate "/dev/cpu/*/msr - Model-specific register support" 1324 ---help--- 1325 This device gives privileged processes access to the x86 1326 Model-Specific Registers (MSRs). It is a character device with 1327 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1328 MSR accesses are directed to a specific CPU on multi-processor 1329 systems. 1330 1331config X86_CPUID 1332 tristate "/dev/cpu/*/cpuid - CPU information support" 1333 ---help--- 1334 This device gives processes access to the x86 CPUID instruction to 1335 be executed on a specific processor. It is a character device 1336 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1337 /dev/cpu/31/cpuid. 1338 1339choice 1340 prompt "High Memory Support" 1341 default HIGHMEM4G 1342 depends on X86_32 1343 1344config NOHIGHMEM 1345 bool "off" 1346 ---help--- 1347 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1348 However, the address space of 32-bit x86 processors is only 4 1349 Gigabytes large. That means that, if you have a large amount of 1350 physical memory, not all of it can be "permanently mapped" by the 1351 kernel. The physical memory that's not permanently mapped is called 1352 "high memory". 1353 1354 If you are compiling a kernel which will never run on a machine with 1355 more than 1 Gigabyte total physical RAM, answer "off" here (default 1356 choice and suitable for most users). This will result in a "3GB/1GB" 1357 split: 3GB are mapped so that each process sees a 3GB virtual memory 1358 space and the remaining part of the 4GB virtual memory space is used 1359 by the kernel to permanently map as much physical memory as 1360 possible. 1361 1362 If the machine has between 1 and 4 Gigabytes physical RAM, then 1363 answer "4GB" here. 1364 1365 If more than 4 Gigabytes is used then answer "64GB" here. This 1366 selection turns Intel PAE (Physical Address Extension) mode on. 1367 PAE implements 3-level paging on IA32 processors. PAE is fully 1368 supported by Linux, PAE mode is implemented on all recent Intel 1369 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1370 then the kernel will not boot on CPUs that don't support PAE! 1371 1372 The actual amount of total physical memory will either be 1373 auto detected or can be forced by using a kernel command line option 1374 such as "mem=256M". (Try "man bootparam" or see the documentation of 1375 your boot loader (lilo or loadlin) about how to pass options to the 1376 kernel at boot time.) 1377 1378 If unsure, say "off". 1379 1380config HIGHMEM4G 1381 bool "4GB" 1382 ---help--- 1383 Select this if you have a 32-bit processor and between 1 and 4 1384 gigabytes of physical RAM. 1385 1386config HIGHMEM64G 1387 bool "64GB" 1388 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1389 select X86_PAE 1390 ---help--- 1391 Select this if you have a 32-bit processor and more than 4 1392 gigabytes of physical RAM. 1393 1394endchoice 1395 1396choice 1397 prompt "Memory split" if EXPERT 1398 default VMSPLIT_3G 1399 depends on X86_32 1400 ---help--- 1401 Select the desired split between kernel and user memory. 1402 1403 If the address range available to the kernel is less than the 1404 physical memory installed, the remaining memory will be available 1405 as "high memory". Accessing high memory is a little more costly 1406 than low memory, as it needs to be mapped into the kernel first. 1407 Note that increasing the kernel address space limits the range 1408 available to user programs, making the address space there 1409 tighter. Selecting anything other than the default 3G/1G split 1410 will also likely make your kernel incompatible with binary-only 1411 kernel modules. 1412 1413 If you are not absolutely sure what you are doing, leave this 1414 option alone! 1415 1416 config VMSPLIT_3G 1417 bool "3G/1G user/kernel split" 1418 config VMSPLIT_3G_OPT 1419 depends on !X86_PAE 1420 bool "3G/1G user/kernel split (for full 1G low memory)" 1421 config VMSPLIT_2G 1422 bool "2G/2G user/kernel split" 1423 config VMSPLIT_2G_OPT 1424 depends on !X86_PAE 1425 bool "2G/2G user/kernel split (for full 2G low memory)" 1426 config VMSPLIT_1G 1427 bool "1G/3G user/kernel split" 1428endchoice 1429 1430config PAGE_OFFSET 1431 hex 1432 default 0xB0000000 if VMSPLIT_3G_OPT 1433 default 0x80000000 if VMSPLIT_2G 1434 default 0x78000000 if VMSPLIT_2G_OPT 1435 default 0x40000000 if VMSPLIT_1G 1436 default 0xC0000000 1437 depends on X86_32 1438 1439config HIGHMEM 1440 def_bool y 1441 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1442 1443config X86_PAE 1444 bool "PAE (Physical Address Extension) Support" 1445 depends on X86_32 && !HIGHMEM4G 1446 select PHYS_ADDR_T_64BIT 1447 select SWIOTLB 1448 ---help--- 1449 PAE is required for NX support, and furthermore enables 1450 larger swapspace support for non-overcommit purposes. It 1451 has the cost of more pagetable lookup overhead, and also 1452 consumes more pagetable space per process. 1453 1454config X86_5LEVEL 1455 bool "Enable 5-level page tables support" 1456 select DYNAMIC_MEMORY_LAYOUT 1457 select SPARSEMEM_VMEMMAP 1458 depends on X86_64 1459 ---help--- 1460 5-level paging enables access to larger address space: 1461 upto 128 PiB of virtual address space and 4 PiB of 1462 physical address space. 1463 1464 It will be supported by future Intel CPUs. 1465 1466 A kernel with the option enabled can be booted on machines that 1467 support 4- or 5-level paging. 1468 1469 See Documentation/x86/x86_64/5level-paging.txt for more 1470 information. 1471 1472 Say N if unsure. 1473 1474config X86_DIRECT_GBPAGES 1475 def_bool y 1476 depends on X86_64 && !DEBUG_PAGEALLOC 1477 ---help--- 1478 Certain kernel features effectively disable kernel 1479 linear 1 GB mappings (even if the CPU otherwise 1480 supports them), so don't confuse the user by printing 1481 that we have them enabled. 1482 1483config ARCH_HAS_MEM_ENCRYPT 1484 def_bool y 1485 1486config AMD_MEM_ENCRYPT 1487 bool "AMD Secure Memory Encryption (SME) support" 1488 depends on X86_64 && CPU_SUP_AMD 1489 select DYNAMIC_PHYSICAL_MASK 1490 ---help--- 1491 Say yes to enable support for the encryption of system memory. 1492 This requires an AMD processor that supports Secure Memory 1493 Encryption (SME). 1494 1495config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1496 bool "Activate AMD Secure Memory Encryption (SME) by default" 1497 default y 1498 depends on AMD_MEM_ENCRYPT 1499 ---help--- 1500 Say yes to have system memory encrypted by default if running on 1501 an AMD processor that supports Secure Memory Encryption (SME). 1502 1503 If set to Y, then the encryption of system memory can be 1504 deactivated with the mem_encrypt=off command line option. 1505 1506 If set to N, then the encryption of system memory can be 1507 activated with the mem_encrypt=on command line option. 1508 1509config ARCH_USE_MEMREMAP_PROT 1510 def_bool y 1511 depends on AMD_MEM_ENCRYPT 1512 1513# Common NUMA Features 1514config NUMA 1515 bool "Numa Memory Allocation and Scheduler Support" 1516 depends on SMP 1517 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1518 default y if X86_BIGSMP 1519 ---help--- 1520 Enable NUMA (Non Uniform Memory Access) support. 1521 1522 The kernel will try to allocate memory used by a CPU on the 1523 local memory controller of the CPU and add some more 1524 NUMA awareness to the kernel. 1525 1526 For 64-bit this is recommended if the system is Intel Core i7 1527 (or later), AMD Opteron, or EM64T NUMA. 1528 1529 For 32-bit this is only needed if you boot a 32-bit 1530 kernel on a 64-bit NUMA platform. 1531 1532 Otherwise, you should say N. 1533 1534config AMD_NUMA 1535 def_bool y 1536 prompt "Old style AMD Opteron NUMA detection" 1537 depends on X86_64 && NUMA && PCI 1538 ---help--- 1539 Enable AMD NUMA node topology detection. You should say Y here if 1540 you have a multi processor AMD system. This uses an old method to 1541 read the NUMA configuration directly from the builtin Northbridge 1542 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1543 which also takes priority if both are compiled in. 1544 1545config X86_64_ACPI_NUMA 1546 def_bool y 1547 prompt "ACPI NUMA detection" 1548 depends on X86_64 && NUMA && ACPI && PCI 1549 select ACPI_NUMA 1550 ---help--- 1551 Enable ACPI SRAT based node topology detection. 1552 1553# Some NUMA nodes have memory ranges that span 1554# other nodes. Even though a pfn is valid and 1555# between a node's start and end pfns, it may not 1556# reside on that node. See memmap_init_zone() 1557# for details. 1558config NODES_SPAN_OTHER_NODES 1559 def_bool y 1560 depends on X86_64_ACPI_NUMA 1561 1562config NUMA_EMU 1563 bool "NUMA emulation" 1564 depends on NUMA 1565 ---help--- 1566 Enable NUMA emulation. A flat machine will be split 1567 into virtual nodes when booted with "numa=fake=N", where N is the 1568 number of nodes. This is only useful for debugging. 1569 1570config NODES_SHIFT 1571 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1572 range 1 10 1573 default "10" if MAXSMP 1574 default "6" if X86_64 1575 default "3" 1576 depends on NEED_MULTIPLE_NODES 1577 ---help--- 1578 Specify the maximum number of NUMA Nodes available on the target 1579 system. Increases memory reserved to accommodate various tables. 1580 1581config ARCH_HAVE_MEMORY_PRESENT 1582 def_bool y 1583 depends on X86_32 && DISCONTIGMEM 1584 1585config ARCH_FLATMEM_ENABLE 1586 def_bool y 1587 depends on X86_32 && !NUMA 1588 1589config ARCH_DISCONTIGMEM_ENABLE 1590 def_bool y 1591 depends on NUMA && X86_32 1592 1593config ARCH_DISCONTIGMEM_DEFAULT 1594 def_bool y 1595 depends on NUMA && X86_32 1596 1597config ARCH_SPARSEMEM_ENABLE 1598 def_bool y 1599 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1600 select SPARSEMEM_STATIC if X86_32 1601 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1602 1603config ARCH_SPARSEMEM_DEFAULT 1604 def_bool y 1605 depends on X86_64 1606 1607config ARCH_SELECT_MEMORY_MODEL 1608 def_bool y 1609 depends on ARCH_SPARSEMEM_ENABLE 1610 1611config ARCH_MEMORY_PROBE 1612 bool "Enable sysfs memory/probe interface" 1613 depends on X86_64 && MEMORY_HOTPLUG 1614 help 1615 This option enables a sysfs memory/probe interface for testing. 1616 See Documentation/memory-hotplug.txt for more information. 1617 If you are unsure how to answer this question, answer N. 1618 1619config ARCH_PROC_KCORE_TEXT 1620 def_bool y 1621 depends on X86_64 && PROC_KCORE 1622 1623config ILLEGAL_POINTER_VALUE 1624 hex 1625 default 0 if X86_32 1626 default 0xdead000000000000 if X86_64 1627 1628config X86_PMEM_LEGACY_DEVICE 1629 bool 1630 1631config X86_PMEM_LEGACY 1632 tristate "Support non-standard NVDIMMs and ADR protected memory" 1633 depends on PHYS_ADDR_T_64BIT 1634 depends on BLK_DEV 1635 select X86_PMEM_LEGACY_DEVICE 1636 select LIBNVDIMM 1637 help 1638 Treat memory marked using the non-standard e820 type of 12 as used 1639 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1640 The kernel will offer these regions to the 'pmem' driver so 1641 they can be used for persistent storage. 1642 1643 Say Y if unsure. 1644 1645config HIGHPTE 1646 bool "Allocate 3rd-level pagetables from highmem" 1647 depends on HIGHMEM 1648 ---help--- 1649 The VM uses one page table entry for each page of physical memory. 1650 For systems with a lot of RAM, this can be wasteful of precious 1651 low memory. Setting this option will put user-space page table 1652 entries in high memory. 1653 1654config X86_CHECK_BIOS_CORRUPTION 1655 bool "Check for low memory corruption" 1656 ---help--- 1657 Periodically check for memory corruption in low memory, which 1658 is suspected to be caused by BIOS. Even when enabled in the 1659 configuration, it is disabled at runtime. Enable it by 1660 setting "memory_corruption_check=1" on the kernel command 1661 line. By default it scans the low 64k of memory every 60 1662 seconds; see the memory_corruption_check_size and 1663 memory_corruption_check_period parameters in 1664 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1665 1666 When enabled with the default parameters, this option has 1667 almost no overhead, as it reserves a relatively small amount 1668 of memory and scans it infrequently. It both detects corruption 1669 and prevents it from affecting the running system. 1670 1671 It is, however, intended as a diagnostic tool; if repeatable 1672 BIOS-originated corruption always affects the same memory, 1673 you can use memmap= to prevent the kernel from using that 1674 memory. 1675 1676config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1677 bool "Set the default setting of memory_corruption_check" 1678 depends on X86_CHECK_BIOS_CORRUPTION 1679 default y 1680 ---help--- 1681 Set whether the default state of memory_corruption_check is 1682 on or off. 1683 1684config X86_RESERVE_LOW 1685 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1686 default 64 1687 range 4 640 1688 ---help--- 1689 Specify the amount of low memory to reserve for the BIOS. 1690 1691 The first page contains BIOS data structures that the kernel 1692 must not use, so that page must always be reserved. 1693 1694 By default we reserve the first 64K of physical RAM, as a 1695 number of BIOSes are known to corrupt that memory range 1696 during events such as suspend/resume or monitor cable 1697 insertion, so it must not be used by the kernel. 1698 1699 You can set this to 4 if you are absolutely sure that you 1700 trust the BIOS to get all its memory reservations and usages 1701 right. If you know your BIOS have problems beyond the 1702 default 64K area, you can set this to 640 to avoid using the 1703 entire low memory range. 1704 1705 If you have doubts about the BIOS (e.g. suspend/resume does 1706 not work or there's kernel crashes after certain hardware 1707 hotplug events) then you might want to enable 1708 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1709 typical corruption patterns. 1710 1711 Leave this to the default value of 64 if you are unsure. 1712 1713config MATH_EMULATION 1714 bool 1715 depends on MODIFY_LDT_SYSCALL 1716 prompt "Math emulation" if X86_32 1717 ---help--- 1718 Linux can emulate a math coprocessor (used for floating point 1719 operations) if you don't have one. 486DX and Pentium processors have 1720 a math coprocessor built in, 486SX and 386 do not, unless you added 1721 a 487DX or 387, respectively. (The messages during boot time can 1722 give you some hints here ["man dmesg"].) Everyone needs either a 1723 coprocessor or this emulation. 1724 1725 If you don't have a math coprocessor, you need to say Y here; if you 1726 say Y here even though you have a coprocessor, the coprocessor will 1727 be used nevertheless. (This behavior can be changed with the kernel 1728 command line option "no387", which comes handy if your coprocessor 1729 is broken. Try "man bootparam" or see the documentation of your boot 1730 loader (lilo or loadlin) about how to pass options to the kernel at 1731 boot time.) This means that it is a good idea to say Y here if you 1732 intend to use this kernel on different machines. 1733 1734 More information about the internals of the Linux math coprocessor 1735 emulation can be found in <file:arch/x86/math-emu/README>. 1736 1737 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1738 kernel, it won't hurt. 1739 1740config MTRR 1741 def_bool y 1742 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1743 ---help--- 1744 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1745 the Memory Type Range Registers (MTRRs) may be used to control 1746 processor access to memory ranges. This is most useful if you have 1747 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1748 allows bus write transfers to be combined into a larger transfer 1749 before bursting over the PCI/AGP bus. This can increase performance 1750 of image write operations 2.5 times or more. Saying Y here creates a 1751 /proc/mtrr file which may be used to manipulate your processor's 1752 MTRRs. Typically the X server should use this. 1753 1754 This code has a reasonably generic interface so that similar 1755 control registers on other processors can be easily supported 1756 as well: 1757 1758 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1759 Registers (ARRs) which provide a similar functionality to MTRRs. For 1760 these, the ARRs are used to emulate the MTRRs. 1761 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1762 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1763 write-combining. All of these processors are supported by this code 1764 and it makes sense to say Y here if you have one of them. 1765 1766 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1767 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1768 can lead to all sorts of problems, so it's good to say Y here. 1769 1770 You can safely say Y even if your machine doesn't have MTRRs, you'll 1771 just add about 9 KB to your kernel. 1772 1773 See <file:Documentation/x86/mtrr.txt> for more information. 1774 1775config MTRR_SANITIZER 1776 def_bool y 1777 prompt "MTRR cleanup support" 1778 depends on MTRR 1779 ---help--- 1780 Convert MTRR layout from continuous to discrete, so X drivers can 1781 add writeback entries. 1782 1783 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1784 The largest mtrr entry size for a continuous block can be set with 1785 mtrr_chunk_size. 1786 1787 If unsure, say Y. 1788 1789config MTRR_SANITIZER_ENABLE_DEFAULT 1790 int "MTRR cleanup enable value (0-1)" 1791 range 0 1 1792 default "0" 1793 depends on MTRR_SANITIZER 1794 ---help--- 1795 Enable mtrr cleanup default value 1796 1797config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1798 int "MTRR cleanup spare reg num (0-7)" 1799 range 0 7 1800 default "1" 1801 depends on MTRR_SANITIZER 1802 ---help--- 1803 mtrr cleanup spare entries default, it can be changed via 1804 mtrr_spare_reg_nr=N on the kernel command line. 1805 1806config X86_PAT 1807 def_bool y 1808 prompt "x86 PAT support" if EXPERT 1809 depends on MTRR 1810 ---help--- 1811 Use PAT attributes to setup page level cache control. 1812 1813 PATs are the modern equivalents of MTRRs and are much more 1814 flexible than MTRRs. 1815 1816 Say N here if you see bootup problems (boot crash, boot hang, 1817 spontaneous reboots) or a non-working video driver. 1818 1819 If unsure, say Y. 1820 1821config ARCH_USES_PG_UNCACHED 1822 def_bool y 1823 depends on X86_PAT 1824 1825config ARCH_RANDOM 1826 def_bool y 1827 prompt "x86 architectural random number generator" if EXPERT 1828 ---help--- 1829 Enable the x86 architectural RDRAND instruction 1830 (Intel Bull Mountain technology) to generate random numbers. 1831 If supported, this is a high bandwidth, cryptographically 1832 secure hardware random number generator. 1833 1834config X86_SMAP 1835 def_bool y 1836 prompt "Supervisor Mode Access Prevention" if EXPERT 1837 ---help--- 1838 Supervisor Mode Access Prevention (SMAP) is a security 1839 feature in newer Intel processors. There is a small 1840 performance cost if this enabled and turned on; there is 1841 also a small increase in the kernel size if this is enabled. 1842 1843 If unsure, say Y. 1844 1845config X86_INTEL_UMIP 1846 def_bool y 1847 depends on CPU_SUP_INTEL 1848 prompt "Intel User Mode Instruction Prevention" if EXPERT 1849 ---help--- 1850 The User Mode Instruction Prevention (UMIP) is a security 1851 feature in newer Intel processors. If enabled, a general 1852 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1853 or STR instructions are executed in user mode. These instructions 1854 unnecessarily expose information about the hardware state. 1855 1856 The vast majority of applications do not use these instructions. 1857 For the very few that do, software emulation is provided in 1858 specific cases in protected and virtual-8086 modes. Emulated 1859 results are dummy. 1860 1861config X86_INTEL_MPX 1862 prompt "Intel MPX (Memory Protection Extensions)" 1863 def_bool n 1864 # Note: only available in 64-bit mode due to VMA flags shortage 1865 depends on CPU_SUP_INTEL && X86_64 1866 select ARCH_USES_HIGH_VMA_FLAGS 1867 ---help--- 1868 MPX provides hardware features that can be used in 1869 conjunction with compiler-instrumented code to check 1870 memory references. It is designed to detect buffer 1871 overflow or underflow bugs. 1872 1873 This option enables running applications which are 1874 instrumented or otherwise use MPX. It does not use MPX 1875 itself inside the kernel or to protect the kernel 1876 against bad memory references. 1877 1878 Enabling this option will make the kernel larger: 1879 ~8k of kernel text and 36 bytes of data on a 64-bit 1880 defconfig. It adds a long to the 'mm_struct' which 1881 will increase the kernel memory overhead of each 1882 process and adds some branches to paths used during 1883 exec() and munmap(). 1884 1885 For details, see Documentation/x86/intel_mpx.txt 1886 1887 If unsure, say N. 1888 1889config X86_INTEL_MEMORY_PROTECTION_KEYS 1890 prompt "Intel Memory Protection Keys" 1891 def_bool y 1892 # Note: only available in 64-bit mode 1893 depends on CPU_SUP_INTEL && X86_64 1894 select ARCH_USES_HIGH_VMA_FLAGS 1895 select ARCH_HAS_PKEYS 1896 ---help--- 1897 Memory Protection Keys provides a mechanism for enforcing 1898 page-based protections, but without requiring modification of the 1899 page tables when an application changes protection domains. 1900 1901 For details, see Documentation/x86/protection-keys.txt 1902 1903 If unsure, say y. 1904 1905choice 1906 prompt "TSX enable mode" 1907 depends on CPU_SUP_INTEL 1908 default X86_INTEL_TSX_MODE_OFF 1909 help 1910 Intel's TSX (Transactional Synchronization Extensions) feature 1911 allows to optimize locking protocols through lock elision which 1912 can lead to a noticeable performance boost. 1913 1914 On the other hand it has been shown that TSX can be exploited 1915 to form side channel attacks (e.g. TAA) and chances are there 1916 will be more of those attacks discovered in the future. 1917 1918 Therefore TSX is not enabled by default (aka tsx=off). An admin 1919 might override this decision by tsx=on the command line parameter. 1920 Even with TSX enabled, the kernel will attempt to enable the best 1921 possible TAA mitigation setting depending on the microcode available 1922 for the particular machine. 1923 1924 This option allows to set the default tsx mode between tsx=on, =off 1925 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1926 details. 1927 1928 Say off if not sure, auto if TSX is in use but it should be used on safe 1929 platforms or on if TSX is in use and the security aspect of tsx is not 1930 relevant. 1931 1932config X86_INTEL_TSX_MODE_OFF 1933 bool "off" 1934 help 1935 TSX is disabled if possible - equals to tsx=off command line parameter. 1936 1937config X86_INTEL_TSX_MODE_ON 1938 bool "on" 1939 help 1940 TSX is always enabled on TSX capable HW - equals the tsx=on command 1941 line parameter. 1942 1943config X86_INTEL_TSX_MODE_AUTO 1944 bool "auto" 1945 help 1946 TSX is enabled on TSX capable HW that is believed to be safe against 1947 side channel attacks- equals the tsx=auto command line parameter. 1948endchoice 1949 1950config EFI 1951 bool "EFI runtime service support" 1952 depends on ACPI 1953 select UCS2_STRING 1954 select EFI_RUNTIME_WRAPPERS 1955 ---help--- 1956 This enables the kernel to use EFI runtime services that are 1957 available (such as the EFI variable services). 1958 1959 This option is only useful on systems that have EFI firmware. 1960 In addition, you should use the latest ELILO loader available 1961 at <http://elilo.sourceforge.net> in order to take advantage 1962 of EFI runtime services. However, even with this option, the 1963 resultant kernel should continue to boot on existing non-EFI 1964 platforms. 1965 1966config EFI_STUB 1967 bool "EFI stub support" 1968 depends on EFI && !X86_USE_3DNOW 1969 select RELOCATABLE 1970 ---help--- 1971 This kernel feature allows a bzImage to be loaded directly 1972 by EFI firmware without the use of a bootloader. 1973 1974 See Documentation/efi-stub.txt for more information. 1975 1976config EFI_MIXED 1977 bool "EFI mixed-mode support" 1978 depends on EFI_STUB && X86_64 1979 ---help--- 1980 Enabling this feature allows a 64-bit kernel to be booted 1981 on a 32-bit firmware, provided that your CPU supports 64-bit 1982 mode. 1983 1984 Note that it is not possible to boot a mixed-mode enabled 1985 kernel via the EFI boot stub - a bootloader that supports 1986 the EFI handover protocol must be used. 1987 1988 If unsure, say N. 1989 1990config SECCOMP 1991 def_bool y 1992 prompt "Enable seccomp to safely compute untrusted bytecode" 1993 ---help--- 1994 This kernel feature is useful for number crunching applications 1995 that may need to compute untrusted bytecode during their 1996 execution. By using pipes or other transports made available to 1997 the process as file descriptors supporting the read/write 1998 syscalls, it's possible to isolate those applications in 1999 their own address space using seccomp. Once seccomp is 2000 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 2001 and the task is only allowed to execute a few safe syscalls 2002 defined by each seccomp mode. 2003 2004 If unsure, say Y. Only embedded should say N here. 2005 2006source kernel/Kconfig.hz 2007 2008config KEXEC 2009 bool "kexec system call" 2010 select KEXEC_CORE 2011 ---help--- 2012 kexec is a system call that implements the ability to shutdown your 2013 current kernel, and to start another kernel. It is like a reboot 2014 but it is independent of the system firmware. And like a reboot 2015 you can start any kernel with it, not just Linux. 2016 2017 The name comes from the similarity to the exec system call. 2018 2019 It is an ongoing process to be certain the hardware in a machine 2020 is properly shutdown, so do not be surprised if this code does not 2021 initially work for you. As of this writing the exact hardware 2022 interface is strongly in flux, so no good recommendation can be 2023 made. 2024 2025config KEXEC_FILE 2026 bool "kexec file based system call" 2027 select KEXEC_CORE 2028 select BUILD_BIN2C 2029 depends on X86_64 2030 depends on CRYPTO=y 2031 depends on CRYPTO_SHA256=y 2032 ---help--- 2033 This is new version of kexec system call. This system call is 2034 file based and takes file descriptors as system call argument 2035 for kernel and initramfs as opposed to list of segments as 2036 accepted by previous system call. 2037 2038config ARCH_HAS_KEXEC_PURGATORY 2039 def_bool KEXEC_FILE 2040 2041config KEXEC_VERIFY_SIG 2042 bool "Verify kernel signature during kexec_file_load() syscall" 2043 depends on KEXEC_FILE 2044 ---help--- 2045 This option makes kernel signature verification mandatory for 2046 the kexec_file_load() syscall. 2047 2048 In addition to that option, you need to enable signature 2049 verification for the corresponding kernel image type being 2050 loaded in order for this to work. 2051 2052config KEXEC_BZIMAGE_VERIFY_SIG 2053 bool "Enable bzImage signature verification support" 2054 depends on KEXEC_VERIFY_SIG 2055 depends on SIGNED_PE_FILE_VERIFICATION 2056 select SYSTEM_TRUSTED_KEYRING 2057 ---help--- 2058 Enable bzImage signature verification support. 2059 2060config CRASH_DUMP 2061 bool "kernel crash dumps" 2062 depends on X86_64 || (X86_32 && HIGHMEM) 2063 ---help--- 2064 Generate crash dump after being started by kexec. 2065 This should be normally only set in special crash dump kernels 2066 which are loaded in the main kernel with kexec-tools into 2067 a specially reserved region and then later executed after 2068 a crash by kdump/kexec. The crash dump kernel must be compiled 2069 to a memory address not used by the main kernel or BIOS using 2070 PHYSICAL_START, or it must be built as a relocatable image 2071 (CONFIG_RELOCATABLE=y). 2072 For more details see Documentation/kdump/kdump.txt 2073 2074config KEXEC_JUMP 2075 bool "kexec jump" 2076 depends on KEXEC && HIBERNATION 2077 ---help--- 2078 Jump between original kernel and kexeced kernel and invoke 2079 code in physical address mode via KEXEC 2080 2081config PHYSICAL_START 2082 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2083 default "0x1000000" 2084 ---help--- 2085 This gives the physical address where the kernel is loaded. 2086 2087 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2088 bzImage will decompress itself to above physical address and 2089 run from there. Otherwise, bzImage will run from the address where 2090 it has been loaded by the boot loader and will ignore above physical 2091 address. 2092 2093 In normal kdump cases one does not have to set/change this option 2094 as now bzImage can be compiled as a completely relocatable image 2095 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2096 address. This option is mainly useful for the folks who don't want 2097 to use a bzImage for capturing the crash dump and want to use a 2098 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2099 to be specifically compiled to run from a specific memory area 2100 (normally a reserved region) and this option comes handy. 2101 2102 So if you are using bzImage for capturing the crash dump, 2103 leave the value here unchanged to 0x1000000 and set 2104 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2105 for capturing the crash dump change this value to start of 2106 the reserved region. In other words, it can be set based on 2107 the "X" value as specified in the "crashkernel=YM@XM" 2108 command line boot parameter passed to the panic-ed 2109 kernel. Please take a look at Documentation/kdump/kdump.txt 2110 for more details about crash dumps. 2111 2112 Usage of bzImage for capturing the crash dump is recommended as 2113 one does not have to build two kernels. Same kernel can be used 2114 as production kernel and capture kernel. Above option should have 2115 gone away after relocatable bzImage support is introduced. But it 2116 is present because there are users out there who continue to use 2117 vmlinux for dump capture. This option should go away down the 2118 line. 2119 2120 Don't change this unless you know what you are doing. 2121 2122config RELOCATABLE 2123 bool "Build a relocatable kernel" 2124 default y 2125 ---help--- 2126 This builds a kernel image that retains relocation information 2127 so it can be loaded someplace besides the default 1MB. 2128 The relocations tend to make the kernel binary about 10% larger, 2129 but are discarded at runtime. 2130 2131 One use is for the kexec on panic case where the recovery kernel 2132 must live at a different physical address than the primary 2133 kernel. 2134 2135 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2136 it has been loaded at and the compile time physical address 2137 (CONFIG_PHYSICAL_START) is used as the minimum location. 2138 2139config RANDOMIZE_BASE 2140 bool "Randomize the address of the kernel image (KASLR)" 2141 depends on RELOCATABLE 2142 default y 2143 ---help--- 2144 In support of Kernel Address Space Layout Randomization (KASLR), 2145 this randomizes the physical address at which the kernel image 2146 is decompressed and the virtual address where the kernel 2147 image is mapped, as a security feature that deters exploit 2148 attempts relying on knowledge of the location of kernel 2149 code internals. 2150 2151 On 64-bit, the kernel physical and virtual addresses are 2152 randomized separately. The physical address will be anywhere 2153 between 16MB and the top of physical memory (up to 64TB). The 2154 virtual address will be randomized from 16MB up to 1GB (9 bits 2155 of entropy). Note that this also reduces the memory space 2156 available to kernel modules from 1.5GB to 1GB. 2157 2158 On 32-bit, the kernel physical and virtual addresses are 2159 randomized together. They will be randomized from 16MB up to 2160 512MB (8 bits of entropy). 2161 2162 Entropy is generated using the RDRAND instruction if it is 2163 supported. If RDTSC is supported, its value is mixed into 2164 the entropy pool as well. If neither RDRAND nor RDTSC are 2165 supported, then entropy is read from the i8254 timer. The 2166 usable entropy is limited by the kernel being built using 2167 2GB addressing, and that PHYSICAL_ALIGN must be at a 2168 minimum of 2MB. As a result, only 10 bits of entropy are 2169 theoretically possible, but the implementations are further 2170 limited due to memory layouts. 2171 2172 If unsure, say Y. 2173 2174# Relocation on x86 needs some additional build support 2175config X86_NEED_RELOCS 2176 def_bool y 2177 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2178 2179config PHYSICAL_ALIGN 2180 hex "Alignment value to which kernel should be aligned" 2181 default "0x200000" 2182 range 0x2000 0x1000000 if X86_32 2183 range 0x200000 0x1000000 if X86_64 2184 ---help--- 2185 This value puts the alignment restrictions on physical address 2186 where kernel is loaded and run from. Kernel is compiled for an 2187 address which meets above alignment restriction. 2188 2189 If bootloader loads the kernel at a non-aligned address and 2190 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2191 address aligned to above value and run from there. 2192 2193 If bootloader loads the kernel at a non-aligned address and 2194 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2195 load address and decompress itself to the address it has been 2196 compiled for and run from there. The address for which kernel is 2197 compiled already meets above alignment restrictions. Hence the 2198 end result is that kernel runs from a physical address meeting 2199 above alignment restrictions. 2200 2201 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2202 this value must be a multiple of 0x200000. 2203 2204 Don't change this unless you know what you are doing. 2205 2206config DYNAMIC_MEMORY_LAYOUT 2207 bool 2208 ---help--- 2209 This option makes base addresses of vmalloc and vmemmap as well as 2210 __PAGE_OFFSET movable during boot. 2211 2212config RANDOMIZE_MEMORY 2213 bool "Randomize the kernel memory sections" 2214 depends on X86_64 2215 depends on RANDOMIZE_BASE 2216 select DYNAMIC_MEMORY_LAYOUT 2217 default RANDOMIZE_BASE 2218 ---help--- 2219 Randomizes the base virtual address of kernel memory sections 2220 (physical memory mapping, vmalloc & vmemmap). This security feature 2221 makes exploits relying on predictable memory locations less reliable. 2222 2223 The order of allocations remains unchanged. Entropy is generated in 2224 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2225 configuration have in average 30,000 different possible virtual 2226 addresses for each memory section. 2227 2228 If unsure, say Y. 2229 2230config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2231 hex "Physical memory mapping padding" if EXPERT 2232 depends on RANDOMIZE_MEMORY 2233 default "0xa" if MEMORY_HOTPLUG 2234 default "0x0" 2235 range 0x1 0x40 if MEMORY_HOTPLUG 2236 range 0x0 0x40 2237 ---help--- 2238 Define the padding in terabytes added to the existing physical 2239 memory size during kernel memory randomization. It is useful 2240 for memory hotplug support but reduces the entropy available for 2241 address randomization. 2242 2243 If unsure, leave at the default value. 2244 2245config HOTPLUG_CPU 2246 def_bool y 2247 depends on SMP 2248 2249config BOOTPARAM_HOTPLUG_CPU0 2250 bool "Set default setting of cpu0_hotpluggable" 2251 default n 2252 depends on HOTPLUG_CPU 2253 ---help--- 2254 Set whether default state of cpu0_hotpluggable is on or off. 2255 2256 Say Y here to enable CPU0 hotplug by default. If this switch 2257 is turned on, there is no need to give cpu0_hotplug kernel 2258 parameter and the CPU0 hotplug feature is enabled by default. 2259 2260 Please note: there are two known CPU0 dependencies if you want 2261 to enable the CPU0 hotplug feature either by this switch or by 2262 cpu0_hotplug kernel parameter. 2263 2264 First, resume from hibernate or suspend always starts from CPU0. 2265 So hibernate and suspend are prevented if CPU0 is offline. 2266 2267 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2268 offline if any interrupt can not migrate out of CPU0. There may 2269 be other CPU0 dependencies. 2270 2271 Please make sure the dependencies are under your control before 2272 you enable this feature. 2273 2274 Say N if you don't want to enable CPU0 hotplug feature by default. 2275 You still can enable the CPU0 hotplug feature at boot by kernel 2276 parameter cpu0_hotplug. 2277 2278config DEBUG_HOTPLUG_CPU0 2279 def_bool n 2280 prompt "Debug CPU0 hotplug" 2281 depends on HOTPLUG_CPU 2282 ---help--- 2283 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2284 soon as possible and boots up userspace with CPU0 offlined. User 2285 can online CPU0 back after boot time. 2286 2287 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2288 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2289 compilation or giving cpu0_hotplug kernel parameter at boot. 2290 2291 If unsure, say N. 2292 2293config COMPAT_VDSO 2294 def_bool n 2295 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2296 depends on COMPAT_32 2297 ---help--- 2298 Certain buggy versions of glibc will crash if they are 2299 presented with a 32-bit vDSO that is not mapped at the address 2300 indicated in its segment table. 2301 2302 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2303 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2304 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2305 the only released version with the bug, but OpenSUSE 9 2306 contains a buggy "glibc 2.3.2". 2307 2308 The symptom of the bug is that everything crashes on startup, saying: 2309 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2310 2311 Saying Y here changes the default value of the vdso32 boot 2312 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2313 This works around the glibc bug but hurts performance. 2314 2315 If unsure, say N: if you are compiling your own kernel, you 2316 are unlikely to be using a buggy version of glibc. 2317 2318choice 2319 prompt "vsyscall table for legacy applications" 2320 depends on X86_64 2321 default LEGACY_VSYSCALL_EMULATE 2322 help 2323 Legacy user code that does not know how to find the vDSO expects 2324 to be able to issue three syscalls by calling fixed addresses in 2325 kernel space. Since this location is not randomized with ASLR, 2326 it can be used to assist security vulnerability exploitation. 2327 2328 This setting can be changed at boot time via the kernel command 2329 line parameter vsyscall=[emulate|none]. 2330 2331 On a system with recent enough glibc (2.14 or newer) and no 2332 static binaries, you can say None without a performance penalty 2333 to improve security. 2334 2335 If unsure, select "Emulate". 2336 2337 config LEGACY_VSYSCALL_EMULATE 2338 bool "Emulate" 2339 help 2340 The kernel traps and emulates calls into the fixed 2341 vsyscall address mapping. This makes the mapping 2342 non-executable, but it still contains known contents, 2343 which could be used in certain rare security vulnerability 2344 exploits. This configuration is recommended when userspace 2345 still uses the vsyscall area. 2346 2347 config LEGACY_VSYSCALL_NONE 2348 bool "None" 2349 help 2350 There will be no vsyscall mapping at all. This will 2351 eliminate any risk of ASLR bypass due to the vsyscall 2352 fixed address mapping. Attempts to use the vsyscalls 2353 will be reported to dmesg, so that either old or 2354 malicious userspace programs can be identified. 2355 2356endchoice 2357 2358config CMDLINE_BOOL 2359 bool "Built-in kernel command line" 2360 ---help--- 2361 Allow for specifying boot arguments to the kernel at 2362 build time. On some systems (e.g. embedded ones), it is 2363 necessary or convenient to provide some or all of the 2364 kernel boot arguments with the kernel itself (that is, 2365 to not rely on the boot loader to provide them.) 2366 2367 To compile command line arguments into the kernel, 2368 set this option to 'Y', then fill in the 2369 boot arguments in CONFIG_CMDLINE. 2370 2371 Systems with fully functional boot loaders (i.e. non-embedded) 2372 should leave this option set to 'N'. 2373 2374config CMDLINE 2375 string "Built-in kernel command string" 2376 depends on CMDLINE_BOOL 2377 default "" 2378 ---help--- 2379 Enter arguments here that should be compiled into the kernel 2380 image and used at boot time. If the boot loader provides a 2381 command line at boot time, it is appended to this string to 2382 form the full kernel command line, when the system boots. 2383 2384 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2385 change this behavior. 2386 2387 In most cases, the command line (whether built-in or provided 2388 by the boot loader) should specify the device for the root 2389 file system. 2390 2391config CMDLINE_OVERRIDE 2392 bool "Built-in command line overrides boot loader arguments" 2393 depends on CMDLINE_BOOL 2394 ---help--- 2395 Set this option to 'Y' to have the kernel ignore the boot loader 2396 command line, and use ONLY the built-in command line. 2397 2398 This is used to work around broken boot loaders. This should 2399 be set to 'N' under normal conditions. 2400 2401config MODIFY_LDT_SYSCALL 2402 bool "Enable the LDT (local descriptor table)" if EXPERT 2403 default y 2404 ---help--- 2405 Linux can allow user programs to install a per-process x86 2406 Local Descriptor Table (LDT) using the modify_ldt(2) system 2407 call. This is required to run 16-bit or segmented code such as 2408 DOSEMU or some Wine programs. It is also used by some very old 2409 threading libraries. 2410 2411 Enabling this feature adds a small amount of overhead to 2412 context switches and increases the low-level kernel attack 2413 surface. Disabling it removes the modify_ldt(2) system call. 2414 2415 Saying 'N' here may make sense for embedded or server kernels. 2416 2417source "kernel/livepatch/Kconfig" 2418 2419endmenu 2420 2421config ARCH_HAS_ADD_PAGES 2422 def_bool y 2423 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2424 2425config ARCH_ENABLE_MEMORY_HOTPLUG 2426 def_bool y 2427 depends on X86_64 || (X86_32 && HIGHMEM) 2428 2429config ARCH_ENABLE_MEMORY_HOTREMOVE 2430 def_bool y 2431 depends on MEMORY_HOTPLUG 2432 2433config USE_PERCPU_NUMA_NODE_ID 2434 def_bool y 2435 depends on NUMA 2436 2437config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2438 def_bool y 2439 depends on X86_64 || X86_PAE 2440 2441config ARCH_ENABLE_HUGEPAGE_MIGRATION 2442 def_bool y 2443 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2444 2445config ARCH_ENABLE_THP_MIGRATION 2446 def_bool y 2447 depends on X86_64 && TRANSPARENT_HUGEPAGE 2448 2449menu "Power management and ACPI options" 2450 2451config ARCH_HIBERNATION_HEADER 2452 def_bool y 2453 depends on X86_64 && HIBERNATION 2454 2455source "kernel/power/Kconfig" 2456 2457source "drivers/acpi/Kconfig" 2458 2459source "drivers/sfi/Kconfig" 2460 2461config X86_APM_BOOT 2462 def_bool y 2463 depends on APM 2464 2465menuconfig APM 2466 tristate "APM (Advanced Power Management) BIOS support" 2467 depends on X86_32 && PM_SLEEP 2468 ---help--- 2469 APM is a BIOS specification for saving power using several different 2470 techniques. This is mostly useful for battery powered laptops with 2471 APM compliant BIOSes. If you say Y here, the system time will be 2472 reset after a RESUME operation, the /proc/apm device will provide 2473 battery status information, and user-space programs will receive 2474 notification of APM "events" (e.g. battery status change). 2475 2476 If you select "Y" here, you can disable actual use of the APM 2477 BIOS by passing the "apm=off" option to the kernel at boot time. 2478 2479 Note that the APM support is almost completely disabled for 2480 machines with more than one CPU. 2481 2482 In order to use APM, you will need supporting software. For location 2483 and more information, read <file:Documentation/power/apm-acpi.txt> 2484 and the Battery Powered Linux mini-HOWTO, available from 2485 <http://www.tldp.org/docs.html#howto>. 2486 2487 This driver does not spin down disk drives (see the hdparm(8) 2488 manpage ("man 8 hdparm") for that), and it doesn't turn off 2489 VESA-compliant "green" monitors. 2490 2491 This driver does not support the TI 4000M TravelMate and the ACER 2492 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2493 desktop machines also don't have compliant BIOSes, and this driver 2494 may cause those machines to panic during the boot phase. 2495 2496 Generally, if you don't have a battery in your machine, there isn't 2497 much point in using this driver and you should say N. If you get 2498 random kernel OOPSes or reboots that don't seem to be related to 2499 anything, try disabling/enabling this option (or disabling/enabling 2500 APM in your BIOS). 2501 2502 Some other things you should try when experiencing seemingly random, 2503 "weird" problems: 2504 2505 1) make sure that you have enough swap space and that it is 2506 enabled. 2507 2) pass the "no-hlt" option to the kernel 2508 3) switch on floating point emulation in the kernel and pass 2509 the "no387" option to the kernel 2510 4) pass the "floppy=nodma" option to the kernel 2511 5) pass the "mem=4M" option to the kernel (thereby disabling 2512 all but the first 4 MB of RAM) 2513 6) make sure that the CPU is not over clocked. 2514 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2515 8) disable the cache from your BIOS settings 2516 9) install a fan for the video card or exchange video RAM 2517 10) install a better fan for the CPU 2518 11) exchange RAM chips 2519 12) exchange the motherboard. 2520 2521 To compile this driver as a module, choose M here: the 2522 module will be called apm. 2523 2524if APM 2525 2526config APM_IGNORE_USER_SUSPEND 2527 bool "Ignore USER SUSPEND" 2528 ---help--- 2529 This option will ignore USER SUSPEND requests. On machines with a 2530 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2531 series notebooks, it is necessary to say Y because of a BIOS bug. 2532 2533config APM_DO_ENABLE 2534 bool "Enable PM at boot time" 2535 ---help--- 2536 Enable APM features at boot time. From page 36 of the APM BIOS 2537 specification: "When disabled, the APM BIOS does not automatically 2538 power manage devices, enter the Standby State, enter the Suspend 2539 State, or take power saving steps in response to CPU Idle calls." 2540 This driver will make CPU Idle calls when Linux is idle (unless this 2541 feature is turned off -- see "Do CPU IDLE calls", below). This 2542 should always save battery power, but more complicated APM features 2543 will be dependent on your BIOS implementation. You may need to turn 2544 this option off if your computer hangs at boot time when using APM 2545 support, or if it beeps continuously instead of suspending. Turn 2546 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2547 T400CDT. This is off by default since most machines do fine without 2548 this feature. 2549 2550config APM_CPU_IDLE 2551 depends on CPU_IDLE 2552 bool "Make CPU Idle calls when idle" 2553 ---help--- 2554 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2555 On some machines, this can activate improved power savings, such as 2556 a slowed CPU clock rate, when the machine is idle. These idle calls 2557 are made after the idle loop has run for some length of time (e.g., 2558 333 mS). On some machines, this will cause a hang at boot time or 2559 whenever the CPU becomes idle. (On machines with more than one CPU, 2560 this option does nothing.) 2561 2562config APM_DISPLAY_BLANK 2563 bool "Enable console blanking using APM" 2564 ---help--- 2565 Enable console blanking using the APM. Some laptops can use this to 2566 turn off the LCD backlight when the screen blanker of the Linux 2567 virtual console blanks the screen. Note that this is only used by 2568 the virtual console screen blanker, and won't turn off the backlight 2569 when using the X Window system. This also doesn't have anything to 2570 do with your VESA-compliant power-saving monitor. Further, this 2571 option doesn't work for all laptops -- it might not turn off your 2572 backlight at all, or it might print a lot of errors to the console, 2573 especially if you are using gpm. 2574 2575config APM_ALLOW_INTS 2576 bool "Allow interrupts during APM BIOS calls" 2577 ---help--- 2578 Normally we disable external interrupts while we are making calls to 2579 the APM BIOS as a measure to lessen the effects of a badly behaving 2580 BIOS implementation. The BIOS should reenable interrupts if it 2581 needs to. Unfortunately, some BIOSes do not -- especially those in 2582 many of the newer IBM Thinkpads. If you experience hangs when you 2583 suspend, try setting this to Y. Otherwise, say N. 2584 2585endif # APM 2586 2587source "drivers/cpufreq/Kconfig" 2588 2589source "drivers/cpuidle/Kconfig" 2590 2591source "drivers/idle/Kconfig" 2592 2593endmenu 2594 2595 2596menu "Bus options (PCI etc.)" 2597 2598config PCI 2599 bool "PCI support" 2600 default y 2601 ---help--- 2602 Find out whether you have a PCI motherboard. PCI is the name of a 2603 bus system, i.e. the way the CPU talks to the other stuff inside 2604 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2605 VESA. If you have PCI, say Y, otherwise N. 2606 2607choice 2608 prompt "PCI access mode" 2609 depends on X86_32 && PCI 2610 default PCI_GOANY 2611 ---help--- 2612 On PCI systems, the BIOS can be used to detect the PCI devices and 2613 determine their configuration. However, some old PCI motherboards 2614 have BIOS bugs and may crash if this is done. Also, some embedded 2615 PCI-based systems don't have any BIOS at all. Linux can also try to 2616 detect the PCI hardware directly without using the BIOS. 2617 2618 With this option, you can specify how Linux should detect the 2619 PCI devices. If you choose "BIOS", the BIOS will be used, 2620 if you choose "Direct", the BIOS won't be used, and if you 2621 choose "MMConfig", then PCI Express MMCONFIG will be used. 2622 If you choose "Any", the kernel will try MMCONFIG, then the 2623 direct access method and falls back to the BIOS if that doesn't 2624 work. If unsure, go with the default, which is "Any". 2625 2626config PCI_GOBIOS 2627 bool "BIOS" 2628 2629config PCI_GOMMCONFIG 2630 bool "MMConfig" 2631 2632config PCI_GODIRECT 2633 bool "Direct" 2634 2635config PCI_GOOLPC 2636 bool "OLPC XO-1" 2637 depends on OLPC 2638 2639config PCI_GOANY 2640 bool "Any" 2641 2642endchoice 2643 2644config PCI_BIOS 2645 def_bool y 2646 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2647 2648# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2649config PCI_DIRECT 2650 def_bool y 2651 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2652 2653config PCI_MMCONFIG 2654 bool "Support mmconfig PCI config space access" if X86_64 2655 default y 2656 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2657 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2658 2659config PCI_OLPC 2660 def_bool y 2661 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2662 2663config PCI_XEN 2664 def_bool y 2665 depends on PCI && XEN 2666 select SWIOTLB_XEN 2667 2668config PCI_DOMAINS 2669 def_bool y 2670 depends on PCI 2671 2672config MMCONF_FAM10H 2673 def_bool y 2674 depends on X86_64 && PCI_MMCONFIG && ACPI 2675 2676config PCI_CNB20LE_QUIRK 2677 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2678 depends on PCI 2679 help 2680 Read the PCI windows out of the CNB20LE host bridge. This allows 2681 PCI hotplug to work on systems with the CNB20LE chipset which do 2682 not have ACPI. 2683 2684 There's no public spec for this chipset, and this functionality 2685 is known to be incomplete. 2686 2687 You should say N unless you know you need this. 2688 2689source "drivers/pci/Kconfig" 2690 2691config ISA_BUS 2692 bool "ISA bus support on modern systems" if EXPERT 2693 help 2694 Expose ISA bus device drivers and options available for selection and 2695 configuration. Enable this option if your target machine has an ISA 2696 bus. ISA is an older system, displaced by PCI and newer bus 2697 architectures -- if your target machine is modern, it probably does 2698 not have an ISA bus. 2699 2700 If unsure, say N. 2701 2702# x86_64 have no ISA slots, but can have ISA-style DMA. 2703config ISA_DMA_API 2704 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2705 default y 2706 help 2707 Enables ISA-style DMA support for devices requiring such controllers. 2708 If unsure, say Y. 2709 2710if X86_32 2711 2712config ISA 2713 bool "ISA support" 2714 ---help--- 2715 Find out whether you have ISA slots on your motherboard. ISA is the 2716 name of a bus system, i.e. the way the CPU talks to the other stuff 2717 inside your box. Other bus systems are PCI, EISA, MicroChannel 2718 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2719 newer boards don't support it. If you have ISA, say Y, otherwise N. 2720 2721config EISA 2722 bool "EISA support" 2723 depends on ISA 2724 ---help--- 2725 The Extended Industry Standard Architecture (EISA) bus was 2726 developed as an open alternative to the IBM MicroChannel bus. 2727 2728 The EISA bus provided some of the features of the IBM MicroChannel 2729 bus while maintaining backward compatibility with cards made for 2730 the older ISA bus. The EISA bus saw limited use between 1988 and 2731 1995 when it was made obsolete by the PCI bus. 2732 2733 Say Y here if you are building a kernel for an EISA-based machine. 2734 2735 Otherwise, say N. 2736 2737source "drivers/eisa/Kconfig" 2738 2739config SCx200 2740 tristate "NatSemi SCx200 support" 2741 ---help--- 2742 This provides basic support for National Semiconductor's 2743 (now AMD's) Geode processors. The driver probes for the 2744 PCI-IDs of several on-chip devices, so its a good dependency 2745 for other scx200_* drivers. 2746 2747 If compiled as a module, the driver is named scx200. 2748 2749config SCx200HR_TIMER 2750 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2751 depends on SCx200 2752 default y 2753 ---help--- 2754 This driver provides a clocksource built upon the on-chip 2755 27MHz high-resolution timer. Its also a workaround for 2756 NSC Geode SC-1100's buggy TSC, which loses time when the 2757 processor goes idle (as is done by the scheduler). The 2758 other workaround is idle=poll boot option. 2759 2760config OLPC 2761 bool "One Laptop Per Child support" 2762 depends on !X86_PAE 2763 select GPIOLIB 2764 select OF 2765 select OF_PROMTREE 2766 select IRQ_DOMAIN 2767 ---help--- 2768 Add support for detecting the unique features of the OLPC 2769 XO hardware. 2770 2771config OLPC_XO1_PM 2772 bool "OLPC XO-1 Power Management" 2773 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2774 ---help--- 2775 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2776 2777config OLPC_XO1_RTC 2778 bool "OLPC XO-1 Real Time Clock" 2779 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2780 ---help--- 2781 Add support for the XO-1 real time clock, which can be used as a 2782 programmable wakeup source. 2783 2784config OLPC_XO1_SCI 2785 bool "OLPC XO-1 SCI extras" 2786 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2787 depends on INPUT=y 2788 select POWER_SUPPLY 2789 ---help--- 2790 Add support for SCI-based features of the OLPC XO-1 laptop: 2791 - EC-driven system wakeups 2792 - Power button 2793 - Ebook switch 2794 - Lid switch 2795 - AC adapter status updates 2796 - Battery status updates 2797 2798config OLPC_XO15_SCI 2799 bool "OLPC XO-1.5 SCI extras" 2800 depends on OLPC && ACPI 2801 select POWER_SUPPLY 2802 ---help--- 2803 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2804 - EC-driven system wakeups 2805 - AC adapter status updates 2806 - Battery status updates 2807 2808config ALIX 2809 bool "PCEngines ALIX System Support (LED setup)" 2810 select GPIOLIB 2811 ---help--- 2812 This option enables system support for the PCEngines ALIX. 2813 At present this just sets up LEDs for GPIO control on 2814 ALIX2/3/6 boards. However, other system specific setup should 2815 get added here. 2816 2817 Note: You must still enable the drivers for GPIO and LED support 2818 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2819 2820 Note: You have to set alix.force=1 for boards with Award BIOS. 2821 2822config NET5501 2823 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2824 select GPIOLIB 2825 ---help--- 2826 This option enables system support for the Soekris Engineering net5501. 2827 2828config GEOS 2829 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2830 select GPIOLIB 2831 depends on DMI 2832 ---help--- 2833 This option enables system support for the Traverse Technologies GEOS. 2834 2835config TS5500 2836 bool "Technologic Systems TS-5500 platform support" 2837 depends on MELAN 2838 select CHECK_SIGNATURE 2839 select NEW_LEDS 2840 select LEDS_CLASS 2841 ---help--- 2842 This option enables system support for the Technologic Systems TS-5500. 2843 2844endif # X86_32 2845 2846config AMD_NB 2847 def_bool y 2848 depends on CPU_SUP_AMD && PCI 2849 2850source "drivers/pcmcia/Kconfig" 2851 2852config RAPIDIO 2853 tristate "RapidIO support" 2854 depends on PCI 2855 default n 2856 help 2857 If enabled this option will include drivers and the core 2858 infrastructure code to support RapidIO interconnect devices. 2859 2860source "drivers/rapidio/Kconfig" 2861 2862config X86_SYSFB 2863 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2864 help 2865 Firmwares often provide initial graphics framebuffers so the BIOS, 2866 bootloader or kernel can show basic video-output during boot for 2867 user-guidance and debugging. Historically, x86 used the VESA BIOS 2868 Extensions and EFI-framebuffers for this, which are mostly limited 2869 to x86. 2870 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2871 framebuffers so the new generic system-framebuffer drivers can be 2872 used on x86. If the framebuffer is not compatible with the generic 2873 modes, it is advertised as fallback platform framebuffer so legacy 2874 drivers like efifb, vesafb and uvesafb can pick it up. 2875 If this option is not selected, all system framebuffers are always 2876 marked as fallback platform framebuffers as usual. 2877 2878 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2879 not be able to pick up generic system framebuffers if this option 2880 is selected. You are highly encouraged to enable simplefb as 2881 replacement if you select this option. simplefb can correctly deal 2882 with generic system framebuffers. But you should still keep vesafb 2883 and others enabled as fallback if a system framebuffer is 2884 incompatible with simplefb. 2885 2886 If unsure, say Y. 2887 2888endmenu 2889 2890 2891menu "Binary Emulations" 2892 2893config IA32_EMULATION 2894 bool "IA32 Emulation" 2895 depends on X86_64 2896 select ARCH_WANT_OLD_COMPAT_IPC 2897 select BINFMT_ELF 2898 select COMPAT_BINFMT_ELF 2899 select COMPAT_OLD_SIGACTION 2900 ---help--- 2901 Include code to run legacy 32-bit programs under a 2902 64-bit kernel. You should likely turn this on, unless you're 2903 100% sure that you don't have any 32-bit programs left. 2904 2905config IA32_AOUT 2906 tristate "IA32 a.out support" 2907 depends on IA32_EMULATION 2908 depends on BROKEN 2909 ---help--- 2910 Support old a.out binaries in the 32bit emulation. 2911 2912config X86_X32 2913 bool "x32 ABI for 64-bit mode" 2914 depends on X86_64 2915 ---help--- 2916 Include code to run binaries for the x32 native 32-bit ABI 2917 for 64-bit processors. An x32 process gets access to the 2918 full 64-bit register file and wide data path while leaving 2919 pointers at 32 bits for smaller memory footprint. 2920 2921 You will need a recent binutils (2.22 or later) with 2922 elf32_x86_64 support enabled to compile a kernel with this 2923 option set. 2924 2925config COMPAT_32 2926 def_bool y 2927 depends on IA32_EMULATION || X86_32 2928 select HAVE_UID16 2929 select OLD_SIGSUSPEND3 2930 2931config COMPAT 2932 def_bool y 2933 depends on IA32_EMULATION || X86_X32 2934 2935if COMPAT 2936config COMPAT_FOR_U64_ALIGNMENT 2937 def_bool y 2938 2939config SYSVIPC_COMPAT 2940 def_bool y 2941 depends on SYSVIPC 2942endif 2943 2944endmenu 2945 2946 2947config HAVE_ATOMIC_IOMAP 2948 def_bool y 2949 depends on X86_32 2950 2951config X86_DEV_DMA_OPS 2952 bool 2953 depends on X86_64 || STA2X11 2954 2955config X86_DMA_REMAP 2956 bool 2957 depends on STA2X11 2958 2959config HAVE_GENERIC_GUP 2960 def_bool y 2961 2962source "drivers/firmware/Kconfig" 2963 2964source "arch/x86/kvm/Kconfig" 2965