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 GENERIC_VDSO_32 18 select HAVE_DEBUG_STACKOVERFLOW 19 select KMAP_LOCAL 20 select MODULES_USE_ELF_REL 21 select OLD_SIGACTION 22 select ARCH_SPLIT_ARG64 23 24config X86_64 25 def_bool y 26 depends on 64BIT 27 # Options that are inherently 64-bit kernel only: 28 select ARCH_HAS_GIGANTIC_PAGE 29 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 30 select ARCH_USE_CMPXCHG_LOCKREF 31 select HAVE_ARCH_SOFT_DIRTY 32 select MODULES_USE_ELF_RELA 33 select NEED_DMA_MAP_STATE 34 select SWIOTLB 35 36config FORCE_DYNAMIC_FTRACE 37 def_bool y 38 depends on X86_32 39 depends on FUNCTION_TRACER 40 select DYNAMIC_FTRACE 41 help 42 We keep the static function tracing (!DYNAMIC_FTRACE) around 43 in order to test the non static function tracing in the 44 generic code, as other architectures still use it. But we 45 only need to keep it around for x86_64. No need to keep it 46 for x86_32. For x86_32, force DYNAMIC_FTRACE. 47# 48# Arch settings 49# 50# ( Note that options that are marked 'if X86_64' could in principle be 51# ported to 32-bit as well. ) 52# 53config X86 54 def_bool y 55 # 56 # Note: keep this list sorted alphabetically 57 # 58 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 59 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 60 select ARCH_32BIT_OFF_T if X86_32 61 select ARCH_CLOCKSOURCE_INIT 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 63 select ARCH_HAS_DEBUG_VIRTUAL 64 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 65 select ARCH_HAS_DEVMEM_IS_ALLOWED 66 select ARCH_HAS_EARLY_DEBUG if KGDB 67 select ARCH_HAS_ELF_RANDOMIZE 68 select ARCH_HAS_FAST_MULTIPLIER 69 select ARCH_HAS_FILTER_PGPROT 70 select ARCH_HAS_FORTIFY_SOURCE 71 select ARCH_HAS_GCOV_PROFILE_ALL 72 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 73 select ARCH_HAS_MEM_ENCRYPT 74 select ARCH_HAS_MEMBARRIER_SYNC_CORE 75 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 76 select ARCH_HAS_PMEM_API if X86_64 77 select ARCH_HAS_PTE_DEVMAP if X86_64 78 select ARCH_HAS_PTE_SPECIAL 79 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 80 select ARCH_HAS_COPY_MC if X86_64 81 select ARCH_HAS_SET_MEMORY 82 select ARCH_HAS_SET_DIRECT_MAP 83 select ARCH_HAS_STRICT_KERNEL_RWX 84 select ARCH_HAS_STRICT_MODULE_RWX 85 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 86 select ARCH_HAS_SYSCALL_WRAPPER 87 select ARCH_HAS_UBSAN_SANITIZE_ALL 88 select ARCH_HAS_DEBUG_WX 89 select ARCH_HAVE_NMI_SAFE_CMPXCHG 90 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 91 select ARCH_MIGHT_HAVE_PC_PARPORT 92 select ARCH_MIGHT_HAVE_PC_SERIO 93 select ARCH_STACKWALK 94 select ARCH_SUPPORTS_ACPI 95 select ARCH_SUPPORTS_ATOMIC_RMW 96 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 97 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 98 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 99 select ARCH_USE_BUILTIN_BSWAP 100 select ARCH_USE_QUEUED_RWLOCKS 101 select ARCH_USE_QUEUED_SPINLOCKS 102 select ARCH_USE_SYM_ANNOTATIONS 103 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 104 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 105 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 106 select ARCH_WANT_HUGE_PMD_SHARE 107 select ARCH_WANT_LD_ORPHAN_WARN 108 select ARCH_WANTS_THP_SWAP if X86_64 109 select BUILDTIME_TABLE_SORT 110 select CLKEVT_I8253 111 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 112 select CLOCKSOURCE_WATCHDOG 113 select DCACHE_WORD_ACCESS 114 select EDAC_ATOMIC_SCRUB 115 select EDAC_SUPPORT 116 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 117 select GENERIC_CLOCKEVENTS_MIN_ADJUST 118 select GENERIC_CMOS_UPDATE 119 select GENERIC_CPU_AUTOPROBE 120 select GENERIC_CPU_VULNERABILITIES 121 select GENERIC_EARLY_IOREMAP 122 select GENERIC_ENTRY 123 select GENERIC_FIND_FIRST_BIT 124 select GENERIC_IOMAP 125 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 126 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 127 select GENERIC_IRQ_MIGRATION if SMP 128 select GENERIC_IRQ_PROBE 129 select GENERIC_IRQ_RESERVATION_MODE 130 select GENERIC_IRQ_SHOW 131 select GENERIC_PENDING_IRQ if SMP 132 select GENERIC_PTDUMP 133 select GENERIC_SMP_IDLE_THREAD 134 select GENERIC_STRNCPY_FROM_USER 135 select GENERIC_STRNLEN_USER 136 select GENERIC_TIME_VSYSCALL 137 select GENERIC_GETTIMEOFDAY 138 select GENERIC_VDSO_TIME_NS 139 select GUP_GET_PTE_LOW_HIGH if X86_PAE 140 select HARDIRQS_SW_RESEND 141 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 142 select HAVE_ACPI_APEI if ACPI 143 select HAVE_ACPI_APEI_NMI if ACPI 144 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 145 select HAVE_ARCH_AUDITSYSCALL 146 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 147 select HAVE_ARCH_JUMP_LABEL 148 select HAVE_ARCH_JUMP_LABEL_RELATIVE 149 select HAVE_ARCH_KASAN if X86_64 150 select HAVE_ARCH_KASAN_VMALLOC if X86_64 151 select HAVE_ARCH_KGDB 152 select HAVE_ARCH_MMAP_RND_BITS if MMU 153 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 154 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 155 select HAVE_ARCH_PREL32_RELOCATIONS 156 select HAVE_ARCH_SECCOMP_FILTER 157 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 158 select HAVE_ARCH_STACKLEAK 159 select HAVE_ARCH_TRACEHOOK 160 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 161 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 162 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 163 select HAVE_ARCH_VMAP_STACK if X86_64 164 select HAVE_ARCH_WITHIN_STACK_FRAMES 165 select HAVE_ASM_MODVERSIONS 166 select HAVE_CMPXCHG_DOUBLE 167 select HAVE_CMPXCHG_LOCAL 168 select HAVE_CONTEXT_TRACKING if X86_64 169 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 170 select HAVE_C_RECORDMCOUNT 171 select HAVE_DEBUG_KMEMLEAK 172 select HAVE_DMA_CONTIGUOUS 173 select HAVE_DYNAMIC_FTRACE 174 select HAVE_DYNAMIC_FTRACE_WITH_REGS 175 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 176 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 177 select HAVE_EBPF_JIT 178 select HAVE_EFFICIENT_UNALIGNED_ACCESS 179 select HAVE_EISA 180 select HAVE_EXIT_THREAD 181 select HAVE_FAST_GUP 182 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 183 select HAVE_FTRACE_MCOUNT_RECORD 184 select HAVE_FUNCTION_GRAPH_TRACER 185 select HAVE_FUNCTION_TRACER 186 select HAVE_GCC_PLUGINS 187 select HAVE_HW_BREAKPOINT 188 select HAVE_IDE 189 select HAVE_IOREMAP_PROT 190 select HAVE_IRQ_TIME_ACCOUNTING 191 select HAVE_KERNEL_BZIP2 192 select HAVE_KERNEL_GZIP 193 select HAVE_KERNEL_LZ4 194 select HAVE_KERNEL_LZMA 195 select HAVE_KERNEL_LZO 196 select HAVE_KERNEL_XZ 197 select HAVE_KERNEL_ZSTD 198 select HAVE_KPROBES 199 select HAVE_KPROBES_ON_FTRACE 200 select HAVE_FUNCTION_ERROR_INJECTION 201 select HAVE_KRETPROBES 202 select HAVE_KVM 203 select HAVE_LIVEPATCH if X86_64 204 select HAVE_MIXED_BREAKPOINTS_REGS 205 select HAVE_MOD_ARCH_SPECIFIC 206 select HAVE_MOVE_PMD 207 select HAVE_MOVE_PUD 208 select HAVE_NMI 209 select HAVE_OPROFILE 210 select HAVE_OPTPROBES 211 select HAVE_PCSPKR_PLATFORM 212 select HAVE_PERF_EVENTS 213 select HAVE_PERF_EVENTS_NMI 214 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 215 select HAVE_PCI 216 select HAVE_PERF_REGS 217 select HAVE_PERF_USER_STACK_DUMP 218 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 219 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 220 select HAVE_REGS_AND_STACK_ACCESS_API 221 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 222 select HAVE_FUNCTION_ARG_ACCESS_API 223 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 224 select HAVE_STACK_VALIDATION if X86_64 225 select HAVE_STATIC_CALL 226 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 227 select HAVE_RSEQ 228 select HAVE_SYSCALL_TRACEPOINTS 229 select HAVE_UNSTABLE_SCHED_CLOCK 230 select HAVE_USER_RETURN_NOTIFIER 231 select HAVE_GENERIC_VDSO 232 select HOTPLUG_SMT if SMP 233 select IRQ_FORCED_THREADING 234 select NEED_SG_DMA_LENGTH 235 select PCI_DOMAINS if PCI 236 select PCI_LOCKLESS_CONFIG if PCI 237 select PERF_EVENTS 238 select RTC_LIB 239 select RTC_MC146818_LIB 240 select SPARSE_IRQ 241 select SRCU 242 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 243 select SYSCTL_EXCEPTION_TRACE 244 select THREAD_INFO_IN_TASK 245 select USER_STACKTRACE_SUPPORT 246 select VIRT_TO_BUS 247 select HAVE_ARCH_KCSAN if X86_64 248 select X86_FEATURE_NAMES if PROC_FS 249 select PROC_PID_ARCH_STATUS if PROC_FS 250 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 251 252config INSTRUCTION_DECODER 253 def_bool y 254 depends on KPROBES || PERF_EVENTS || UPROBES 255 256config OUTPUT_FORMAT 257 string 258 default "elf32-i386" if X86_32 259 default "elf64-x86-64" if X86_64 260 261config LOCKDEP_SUPPORT 262 def_bool y 263 264config STACKTRACE_SUPPORT 265 def_bool y 266 267config MMU 268 def_bool y 269 270config ARCH_MMAP_RND_BITS_MIN 271 default 28 if 64BIT 272 default 8 273 274config ARCH_MMAP_RND_BITS_MAX 275 default 32 if 64BIT 276 default 16 277 278config ARCH_MMAP_RND_COMPAT_BITS_MIN 279 default 8 280 281config ARCH_MMAP_RND_COMPAT_BITS_MAX 282 default 16 283 284config SBUS 285 bool 286 287config GENERIC_ISA_DMA 288 def_bool y 289 depends on ISA_DMA_API 290 291config GENERIC_BUG 292 def_bool y 293 depends on BUG 294 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 295 296config GENERIC_BUG_RELATIVE_POINTERS 297 bool 298 299config ARCH_MAY_HAVE_PC_FDC 300 def_bool y 301 depends on ISA_DMA_API 302 303config GENERIC_CALIBRATE_DELAY 304 def_bool y 305 306config ARCH_HAS_CPU_RELAX 307 def_bool y 308 309config ARCH_HAS_CACHE_LINE_SIZE 310 def_bool y 311 312config ARCH_HAS_FILTER_PGPROT 313 def_bool y 314 315config HAVE_SETUP_PER_CPU_AREA 316 def_bool y 317 318config NEED_PER_CPU_EMBED_FIRST_CHUNK 319 def_bool y 320 321config NEED_PER_CPU_PAGE_FIRST_CHUNK 322 def_bool y 323 324config ARCH_HIBERNATION_POSSIBLE 325 def_bool y 326 327config ARCH_SUSPEND_POSSIBLE 328 def_bool y 329 330config ARCH_WANT_GENERAL_HUGETLB 331 def_bool y 332 333config ZONE_DMA32 334 def_bool y if X86_64 335 336config AUDIT_ARCH 337 def_bool y if X86_64 338 339config KASAN_SHADOW_OFFSET 340 hex 341 depends on KASAN 342 default 0xdffffc0000000000 343 344config HAVE_INTEL_TXT 345 def_bool y 346 depends on INTEL_IOMMU && ACPI 347 348config X86_32_SMP 349 def_bool y 350 depends on X86_32 && SMP 351 352config X86_64_SMP 353 def_bool y 354 depends on X86_64 && SMP 355 356config X86_32_LAZY_GS 357 def_bool y 358 depends on X86_32 && !STACKPROTECTOR 359 360config ARCH_SUPPORTS_UPROBES 361 def_bool y 362 363config FIX_EARLYCON_MEM 364 def_bool y 365 366config DYNAMIC_PHYSICAL_MASK 367 bool 368 369config PGTABLE_LEVELS 370 int 371 default 5 if X86_5LEVEL 372 default 4 if X86_64 373 default 3 if X86_PAE 374 default 2 375 376config CC_HAS_SANE_STACKPROTECTOR 377 bool 378 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 379 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 380 help 381 We have to make sure stack protector is unconditionally disabled if 382 the compiler produces broken code. 383 384menu "Processor type and features" 385 386config ZONE_DMA 387 bool "DMA memory allocation support" if EXPERT 388 default y 389 help 390 DMA memory allocation support allows devices with less than 32-bit 391 addressing to allocate within the first 16MB of address space. 392 Disable if no such devices will be used. 393 394 If unsure, say Y. 395 396config SMP 397 bool "Symmetric multi-processing support" 398 help 399 This enables support for systems with more than one CPU. If you have 400 a system with only one CPU, say N. If you have a system with more 401 than one CPU, say Y. 402 403 If you say N here, the kernel will run on uni- and multiprocessor 404 machines, but will use only one CPU of a multiprocessor machine. If 405 you say Y here, the kernel will run on many, but not all, 406 uniprocessor machines. On a uniprocessor machine, the kernel 407 will run faster if you say N here. 408 409 Note that if you say Y here and choose architecture "586" or 410 "Pentium" under "Processor family", the kernel will not work on 486 411 architectures. Similarly, multiprocessor kernels for the "PPro" 412 architecture may not work on all Pentium based boards. 413 414 People using multiprocessor machines who say Y here should also say 415 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 416 Management" code will be disabled if you say Y here. 417 418 See also <file:Documentation/x86/i386/IO-APIC.rst>, 419 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 420 <http://www.tldp.org/docs.html#howto>. 421 422 If you don't know what to do here, say N. 423 424config X86_FEATURE_NAMES 425 bool "Processor feature human-readable names" if EMBEDDED 426 default y 427 help 428 This option compiles in a table of x86 feature bits and corresponding 429 names. This is required to support /proc/cpuinfo and a few kernel 430 messages. You can disable this to save space, at the expense of 431 making those few kernel messages show numeric feature bits instead. 432 433 If in doubt, say Y. 434 435config X86_X2APIC 436 bool "Support x2apic" 437 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 438 help 439 This enables x2apic support on CPUs that have this feature. 440 441 This allows 32-bit apic IDs (so it can support very large systems), 442 and accesses the local apic via MSRs not via mmio. 443 444 If you don't know what to do here, say N. 445 446config X86_MPPARSE 447 bool "Enable MPS table" if ACPI || SFI 448 default y 449 depends on X86_LOCAL_APIC 450 help 451 For old smp systems that do not have proper acpi support. Newer systems 452 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 453 454config GOLDFISH 455 def_bool y 456 depends on X86_GOLDFISH 457 458config RETPOLINE 459 bool "Avoid speculative indirect branches in kernel" 460 default y 461 help 462 Compile kernel with the retpoline compiler options to guard against 463 kernel-to-user data leaks by avoiding speculative indirect 464 branches. Requires a compiler with -mindirect-branch=thunk-extern 465 support for full protection. The kernel may run slower. 466 467config X86_CPU_RESCTRL 468 bool "x86 CPU resource control support" 469 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 470 select KERNFS 471 select PROC_CPU_RESCTRL if PROC_FS 472 help 473 Enable x86 CPU resource control support. 474 475 Provide support for the allocation and monitoring of system resources 476 usage by the CPU. 477 478 Intel calls this Intel Resource Director Technology 479 (Intel(R) RDT). More information about RDT can be found in the 480 Intel x86 Architecture Software Developer Manual. 481 482 AMD calls this AMD Platform Quality of Service (AMD QoS). 483 More information about AMD QoS can be found in the AMD64 Technology 484 Platform Quality of Service Extensions manual. 485 486 Say N if unsure. 487 488if X86_32 489config X86_BIGSMP 490 bool "Support for big SMP systems with more than 8 CPUs" 491 depends on SMP 492 help 493 This option is needed for the systems that have more than 8 CPUs. 494 495config X86_EXTENDED_PLATFORM 496 bool "Support for extended (non-PC) x86 platforms" 497 default y 498 help 499 If you disable this option then the kernel will only support 500 standard PC platforms. (which covers the vast majority of 501 systems out there.) 502 503 If you enable this option then you'll be able to select support 504 for the following (non-PC) 32 bit x86 platforms: 505 Goldfish (Android emulator) 506 AMD Elan 507 RDC R-321x SoC 508 SGI 320/540 (Visual Workstation) 509 STA2X11-based (e.g. Northville) 510 Moorestown MID devices 511 512 If you have one of these systems, or if you want to build a 513 generic distribution kernel, say Y here - otherwise say N. 514endif 515 516if X86_64 517config X86_EXTENDED_PLATFORM 518 bool "Support for extended (non-PC) x86 platforms" 519 default y 520 help 521 If you disable this option then the kernel will only support 522 standard PC platforms. (which covers the vast majority of 523 systems out there.) 524 525 If you enable this option then you'll be able to select support 526 for the following (non-PC) 64 bit x86 platforms: 527 Numascale NumaChip 528 ScaleMP vSMP 529 SGI Ultraviolet 530 531 If you have one of these systems, or if you want to build a 532 generic distribution kernel, say Y here - otherwise say N. 533endif 534# This is an alphabetically sorted list of 64 bit extended platforms 535# Please maintain the alphabetic order if and when there are additions 536config X86_NUMACHIP 537 bool "Numascale NumaChip" 538 depends on X86_64 539 depends on X86_EXTENDED_PLATFORM 540 depends on NUMA 541 depends on SMP 542 depends on X86_X2APIC 543 depends on PCI_MMCONFIG 544 help 545 Adds support for Numascale NumaChip large-SMP systems. Needed to 546 enable more than ~168 cores. 547 If you don't have one of these, you should say N here. 548 549config X86_VSMP 550 bool "ScaleMP vSMP" 551 select HYPERVISOR_GUEST 552 select PARAVIRT 553 depends on X86_64 && PCI 554 depends on X86_EXTENDED_PLATFORM 555 depends on SMP 556 help 557 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 558 supposed to run on these EM64T-based machines. Only choose this option 559 if you have one of these machines. 560 561config X86_UV 562 bool "SGI Ultraviolet" 563 depends on X86_64 564 depends on X86_EXTENDED_PLATFORM 565 depends on NUMA 566 depends on EFI 567 depends on X86_X2APIC 568 depends on PCI 569 help 570 This option is needed in order to support SGI Ultraviolet systems. 571 If you don't have one of these, you should say N here. 572 573# Following is an alphabetically sorted list of 32 bit extended platforms 574# Please maintain the alphabetic order if and when there are additions 575 576config X86_GOLDFISH 577 bool "Goldfish (Virtual Platform)" 578 depends on X86_EXTENDED_PLATFORM 579 help 580 Enable support for the Goldfish virtual platform used primarily 581 for Android development. Unless you are building for the Android 582 Goldfish emulator say N here. 583 584config X86_INTEL_CE 585 bool "CE4100 TV platform" 586 depends on PCI 587 depends on PCI_GODIRECT 588 depends on X86_IO_APIC 589 depends on X86_32 590 depends on X86_EXTENDED_PLATFORM 591 select X86_REBOOTFIXUPS 592 select OF 593 select OF_EARLY_FLATTREE 594 help 595 Select for the Intel CE media processor (CE4100) SOC. 596 This option compiles in support for the CE4100 SOC for settop 597 boxes and media devices. 598 599config X86_INTEL_MID 600 bool "Intel MID platform support" 601 depends on X86_EXTENDED_PLATFORM 602 depends on X86_PLATFORM_DEVICES 603 depends on PCI 604 depends on X86_64 || (PCI_GOANY && X86_32) 605 depends on X86_IO_APIC 606 select SFI 607 select I2C 608 select DW_APB_TIMER 609 select APB_TIMER 610 select INTEL_SCU_PCI 611 select MFD_INTEL_MSIC 612 help 613 Select to build a kernel capable of supporting Intel MID (Mobile 614 Internet Device) platform systems which do not have the PCI legacy 615 interfaces. If you are building for a PC class system say N here. 616 617 Intel MID platforms are based on an Intel processor and chipset which 618 consume less power than most of the x86 derivatives. 619 620config X86_INTEL_QUARK 621 bool "Intel Quark platform support" 622 depends on X86_32 623 depends on X86_EXTENDED_PLATFORM 624 depends on X86_PLATFORM_DEVICES 625 depends on X86_TSC 626 depends on PCI 627 depends on PCI_GOANY 628 depends on X86_IO_APIC 629 select IOSF_MBI 630 select INTEL_IMR 631 select COMMON_CLK 632 help 633 Select to include support for Quark X1000 SoC. 634 Say Y here if you have a Quark based system such as the Arduino 635 compatible Intel Galileo. 636 637config X86_INTEL_LPSS 638 bool "Intel Low Power Subsystem Support" 639 depends on X86 && ACPI && PCI 640 select COMMON_CLK 641 select PINCTRL 642 select IOSF_MBI 643 help 644 Select to build support for Intel Low Power Subsystem such as 645 found on Intel Lynxpoint PCH. Selecting this option enables 646 things like clock tree (common clock framework) and pincontrol 647 which are needed by the LPSS peripheral drivers. 648 649config X86_AMD_PLATFORM_DEVICE 650 bool "AMD ACPI2Platform devices support" 651 depends on ACPI 652 select COMMON_CLK 653 select PINCTRL 654 help 655 Select to interpret AMD specific ACPI device to platform device 656 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 657 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 658 implemented under PINCTRL subsystem. 659 660config IOSF_MBI 661 tristate "Intel SoC IOSF Sideband support for SoC platforms" 662 depends on PCI 663 help 664 This option enables sideband register access support for Intel SoC 665 platforms. On these platforms the IOSF sideband is used in lieu of 666 MSR's for some register accesses, mostly but not limited to thermal 667 and power. Drivers may query the availability of this device to 668 determine if they need the sideband in order to work on these 669 platforms. The sideband is available on the following SoC products. 670 This list is not meant to be exclusive. 671 - BayTrail 672 - Braswell 673 - Quark 674 675 You should say Y if you are running a kernel on one of these SoC's. 676 677config IOSF_MBI_DEBUG 678 bool "Enable IOSF sideband access through debugfs" 679 depends on IOSF_MBI && DEBUG_FS 680 help 681 Select this option to expose the IOSF sideband access registers (MCR, 682 MDR, MCRX) through debugfs to write and read register information from 683 different units on the SoC. This is most useful for obtaining device 684 state information for debug and analysis. As this is a general access 685 mechanism, users of this option would have specific knowledge of the 686 device they want to access. 687 688 If you don't require the option or are in doubt, say N. 689 690config X86_RDC321X 691 bool "RDC R-321x SoC" 692 depends on X86_32 693 depends on X86_EXTENDED_PLATFORM 694 select M486 695 select X86_REBOOTFIXUPS 696 help 697 This option is needed for RDC R-321x system-on-chip, also known 698 as R-8610-(G). 699 If you don't have one of these chips, you should say N here. 700 701config X86_32_NON_STANDARD 702 bool "Support non-standard 32-bit SMP architectures" 703 depends on X86_32 && SMP 704 depends on X86_EXTENDED_PLATFORM 705 help 706 This option compiles in the bigsmp and STA2X11 default 707 subarchitectures. It is intended for a generic binary 708 kernel. If you select them all, kernel will probe it one by 709 one and will fallback to default. 710 711# Alphabetically sorted list of Non standard 32 bit platforms 712 713config X86_SUPPORTS_MEMORY_FAILURE 714 def_bool y 715 # MCE code calls memory_failure(): 716 depends on X86_MCE 717 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 718 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 719 depends on X86_64 || !SPARSEMEM 720 select ARCH_SUPPORTS_MEMORY_FAILURE 721 722config STA2X11 723 bool "STA2X11 Companion Chip Support" 724 depends on X86_32_NON_STANDARD && PCI 725 select SWIOTLB 726 select MFD_STA2X11 727 select GPIOLIB 728 help 729 This adds support for boards based on the STA2X11 IO-Hub, 730 a.k.a. "ConneXt". The chip is used in place of the standard 731 PC chipset, so all "standard" peripherals are missing. If this 732 option is selected the kernel will still be able to boot on 733 standard PC machines. 734 735config X86_32_IRIS 736 tristate "Eurobraille/Iris poweroff module" 737 depends on X86_32 738 help 739 The Iris machines from EuroBraille do not have APM or ACPI support 740 to shut themselves down properly. A special I/O sequence is 741 needed to do so, which is what this module does at 742 kernel shutdown. 743 744 This is only for Iris machines from EuroBraille. 745 746 If unused, say N. 747 748config SCHED_OMIT_FRAME_POINTER 749 def_bool y 750 prompt "Single-depth WCHAN output" 751 depends on X86 752 help 753 Calculate simpler /proc/<PID>/wchan values. If this option 754 is disabled then wchan values will recurse back to the 755 caller function. This provides more accurate wchan values, 756 at the expense of slightly more scheduling overhead. 757 758 If in doubt, say "Y". 759 760menuconfig HYPERVISOR_GUEST 761 bool "Linux guest support" 762 help 763 Say Y here to enable options for running Linux under various hyper- 764 visors. This option enables basic hypervisor detection and platform 765 setup. 766 767 If you say N, all options in this submenu will be skipped and 768 disabled, and Linux guest support won't be built in. 769 770if HYPERVISOR_GUEST 771 772config PARAVIRT 773 bool "Enable paravirtualization code" 774 help 775 This changes the kernel so it can modify itself when it is run 776 under a hypervisor, potentially improving performance significantly 777 over full virtualization. However, when run without a hypervisor 778 the kernel is theoretically slower and slightly larger. 779 780config PARAVIRT_XXL 781 bool 782 783config PARAVIRT_DEBUG 784 bool "paravirt-ops debugging" 785 depends on PARAVIRT && DEBUG_KERNEL 786 help 787 Enable to debug paravirt_ops internals. Specifically, BUG if 788 a paravirt_op is missing when it is called. 789 790config PARAVIRT_SPINLOCKS 791 bool "Paravirtualization layer for spinlocks" 792 depends on PARAVIRT && SMP 793 help 794 Paravirtualized spinlocks allow a pvops backend to replace the 795 spinlock implementation with something virtualization-friendly 796 (for example, block the virtual CPU rather than spinning). 797 798 It has a minimal impact on native kernels and gives a nice performance 799 benefit on paravirtualized KVM / Xen kernels. 800 801 If you are unsure how to answer this question, answer Y. 802 803config X86_HV_CALLBACK_VECTOR 804 def_bool n 805 806source "arch/x86/xen/Kconfig" 807 808config KVM_GUEST 809 bool "KVM Guest support (including kvmclock)" 810 depends on PARAVIRT 811 select PARAVIRT_CLOCK 812 select ARCH_CPUIDLE_HALTPOLL 813 select X86_HV_CALLBACK_VECTOR 814 default y 815 help 816 This option enables various optimizations for running under the KVM 817 hypervisor. It includes a paravirtualized clock, so that instead 818 of relying on a PIT (or probably other) emulation by the 819 underlying device model, the host provides the guest with 820 timing infrastructure such as time of day, and system time 821 822config ARCH_CPUIDLE_HALTPOLL 823 def_bool n 824 prompt "Disable host haltpoll when loading haltpoll driver" 825 help 826 If virtualized under KVM, disable host haltpoll. 827 828config PVH 829 bool "Support for running PVH guests" 830 help 831 This option enables the PVH entry point for guest virtual machines 832 as specified in the x86/HVM direct boot ABI. 833 834config PARAVIRT_TIME_ACCOUNTING 835 bool "Paravirtual steal time accounting" 836 depends on PARAVIRT 837 help 838 Select this option to enable fine granularity task steal time 839 accounting. Time spent executing other tasks in parallel with 840 the current vCPU is discounted from the vCPU power. To account for 841 that, there can be a small performance impact. 842 843 If in doubt, say N here. 844 845config PARAVIRT_CLOCK 846 bool 847 848config JAILHOUSE_GUEST 849 bool "Jailhouse non-root cell support" 850 depends on X86_64 && PCI 851 select X86_PM_TIMER 852 help 853 This option allows to run Linux as guest in a Jailhouse non-root 854 cell. You can leave this option disabled if you only want to start 855 Jailhouse and run Linux afterwards in the root cell. 856 857config ACRN_GUEST 858 bool "ACRN Guest support" 859 depends on X86_64 860 select X86_HV_CALLBACK_VECTOR 861 help 862 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 863 a flexible, lightweight reference open-source hypervisor, built with 864 real-time and safety-criticality in mind. It is built for embedded 865 IOT with small footprint and real-time features. More details can be 866 found in https://projectacrn.org/. 867 868endif #HYPERVISOR_GUEST 869 870source "arch/x86/Kconfig.cpu" 871 872config HPET_TIMER 873 def_bool X86_64 874 prompt "HPET Timer Support" if X86_32 875 help 876 Use the IA-PC HPET (High Precision Event Timer) to manage 877 time in preference to the PIT and RTC, if a HPET is 878 present. 879 HPET is the next generation timer replacing legacy 8254s. 880 The HPET provides a stable time base on SMP 881 systems, unlike the TSC, but it is more expensive to access, 882 as it is off-chip. The interface used is documented 883 in the HPET spec, revision 1. 884 885 You can safely choose Y here. However, HPET will only be 886 activated if the platform and the BIOS support this feature. 887 Otherwise the 8254 will be used for timing services. 888 889 Choose N to continue using the legacy 8254 timer. 890 891config HPET_EMULATE_RTC 892 def_bool y 893 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 894 895config APB_TIMER 896 def_bool y if X86_INTEL_MID 897 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 898 select DW_APB_TIMER 899 depends on X86_INTEL_MID && SFI 900 help 901 APB timer is the replacement for 8254, HPET on X86 MID platforms. 902 The APBT provides a stable time base on SMP 903 systems, unlike the TSC, but it is more expensive to access, 904 as it is off-chip. APB timers are always running regardless of CPU 905 C states, they are used as per CPU clockevent device when possible. 906 907# Mark as expert because too many people got it wrong. 908# The code disables itself when not needed. 909config DMI 910 default y 911 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 912 bool "Enable DMI scanning" if EXPERT 913 help 914 Enabled scanning of DMI to identify machine quirks. Say Y 915 here unless you have verified that your setup is not 916 affected by entries in the DMI blacklist. Required by PNP 917 BIOS code. 918 919config GART_IOMMU 920 bool "Old AMD GART IOMMU support" 921 select DMA_OPS 922 select IOMMU_HELPER 923 select SWIOTLB 924 depends on X86_64 && PCI && AMD_NB 925 help 926 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 927 GART based hardware IOMMUs. 928 929 The GART supports full DMA access for devices with 32-bit access 930 limitations, on systems with more than 3 GB. This is usually needed 931 for USB, sound, many IDE/SATA chipsets and some other devices. 932 933 Newer systems typically have a modern AMD IOMMU, supported via 934 the CONFIG_AMD_IOMMU=y config option. 935 936 In normal configurations this driver is only active when needed: 937 there's more than 3 GB of memory and the system contains a 938 32-bit limited device. 939 940 If unsure, say Y. 941 942config MAXSMP 943 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 944 depends on X86_64 && SMP && DEBUG_KERNEL 945 select CPUMASK_OFFSTACK 946 help 947 Enable maximum number of CPUS and NUMA Nodes for this architecture. 948 If unsure, say N. 949 950# 951# The maximum number of CPUs supported: 952# 953# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 954# and which can be configured interactively in the 955# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 956# 957# The ranges are different on 32-bit and 64-bit kernels, depending on 958# hardware capabilities and scalability features of the kernel. 959# 960# ( If MAXSMP is enabled we just use the highest possible value and disable 961# interactive configuration. ) 962# 963 964config NR_CPUS_RANGE_BEGIN 965 int 966 default NR_CPUS_RANGE_END if MAXSMP 967 default 1 if !SMP 968 default 2 969 970config NR_CPUS_RANGE_END 971 int 972 depends on X86_32 973 default 64 if SMP && X86_BIGSMP 974 default 8 if SMP && !X86_BIGSMP 975 default 1 if !SMP 976 977config NR_CPUS_RANGE_END 978 int 979 depends on X86_64 980 default 8192 if SMP && CPUMASK_OFFSTACK 981 default 512 if SMP && !CPUMASK_OFFSTACK 982 default 1 if !SMP 983 984config NR_CPUS_DEFAULT 985 int 986 depends on X86_32 987 default 32 if X86_BIGSMP 988 default 8 if SMP 989 default 1 if !SMP 990 991config NR_CPUS_DEFAULT 992 int 993 depends on X86_64 994 default 8192 if MAXSMP 995 default 64 if SMP 996 default 1 if !SMP 997 998config NR_CPUS 999 int "Maximum number of CPUs" if SMP && !MAXSMP 1000 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1001 default NR_CPUS_DEFAULT 1002 help 1003 This allows you to specify the maximum number of CPUs which this 1004 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1005 supported value is 8192, otherwise the maximum value is 512. The 1006 minimum value which makes sense is 2. 1007 1008 This is purely to save memory: each supported CPU adds about 8KB 1009 to the kernel image. 1010 1011config SCHED_SMT 1012 def_bool y if SMP 1013 1014config SCHED_MC 1015 def_bool y 1016 prompt "Multi-core scheduler support" 1017 depends on SMP 1018 help 1019 Multi-core scheduler support improves the CPU scheduler's decision 1020 making when dealing with multi-core CPU chips at a cost of slightly 1021 increased overhead in some places. If unsure say N here. 1022 1023config SCHED_MC_PRIO 1024 bool "CPU core priorities scheduler support" 1025 depends on SCHED_MC && CPU_SUP_INTEL 1026 select X86_INTEL_PSTATE 1027 select CPU_FREQ 1028 default y 1029 help 1030 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1031 core ordering determined at manufacturing time, which allows 1032 certain cores to reach higher turbo frequencies (when running 1033 single threaded workloads) than others. 1034 1035 Enabling this kernel feature teaches the scheduler about 1036 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1037 scheduler's CPU selection logic accordingly, so that higher 1038 overall system performance can be achieved. 1039 1040 This feature will have no effect on CPUs without this feature. 1041 1042 If unsure say Y here. 1043 1044config UP_LATE_INIT 1045 def_bool y 1046 depends on !SMP && X86_LOCAL_APIC 1047 1048config X86_UP_APIC 1049 bool "Local APIC support on uniprocessors" if !PCI_MSI 1050 default PCI_MSI 1051 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1052 help 1053 A local APIC (Advanced Programmable Interrupt Controller) is an 1054 integrated interrupt controller in the CPU. If you have a single-CPU 1055 system which has a processor with a local APIC, you can say Y here to 1056 enable and use it. If you say Y here even though your machine doesn't 1057 have a local APIC, then the kernel will still run with no slowdown at 1058 all. The local APIC supports CPU-generated self-interrupts (timer, 1059 performance counters), and the NMI watchdog which detects hard 1060 lockups. 1061 1062config X86_UP_IOAPIC 1063 bool "IO-APIC support on uniprocessors" 1064 depends on X86_UP_APIC 1065 help 1066 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1067 SMP-capable replacement for PC-style interrupt controllers. Most 1068 SMP systems and many recent uniprocessor systems have one. 1069 1070 If you have a single-CPU system with an IO-APIC, you can say Y here 1071 to use it. If you say Y here even though your machine doesn't have 1072 an IO-APIC, then the kernel will still run with no slowdown at all. 1073 1074config X86_LOCAL_APIC 1075 def_bool y 1076 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1077 select IRQ_DOMAIN_HIERARCHY 1078 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1079 1080config X86_IO_APIC 1081 def_bool y 1082 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1083 1084config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1085 bool "Reroute for broken boot IRQs" 1086 depends on X86_IO_APIC 1087 help 1088 This option enables a workaround that fixes a source of 1089 spurious interrupts. This is recommended when threaded 1090 interrupt handling is used on systems where the generation of 1091 superfluous "boot interrupts" cannot be disabled. 1092 1093 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1094 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1095 kernel does during interrupt handling). On chipsets where this 1096 boot IRQ generation cannot be disabled, this workaround keeps 1097 the original IRQ line masked so that only the equivalent "boot 1098 IRQ" is delivered to the CPUs. The workaround also tells the 1099 kernel to set up the IRQ handler on the boot IRQ line. In this 1100 way only one interrupt is delivered to the kernel. Otherwise 1101 the spurious second interrupt may cause the kernel to bring 1102 down (vital) interrupt lines. 1103 1104 Only affects "broken" chipsets. Interrupt sharing may be 1105 increased on these systems. 1106 1107config X86_MCE 1108 bool "Machine Check / overheating reporting" 1109 select GENERIC_ALLOCATOR 1110 default y 1111 help 1112 Machine Check support allows the processor to notify the 1113 kernel if it detects a problem (e.g. overheating, data corruption). 1114 The action the kernel takes depends on the severity of the problem, 1115 ranging from warning messages to halting the machine. 1116 1117config X86_MCELOG_LEGACY 1118 bool "Support for deprecated /dev/mcelog character device" 1119 depends on X86_MCE 1120 help 1121 Enable support for /dev/mcelog which is needed by the old mcelog 1122 userspace logging daemon. Consider switching to the new generation 1123 rasdaemon solution. 1124 1125config X86_MCE_INTEL 1126 def_bool y 1127 prompt "Intel MCE features" 1128 depends on X86_MCE && X86_LOCAL_APIC 1129 help 1130 Additional support for intel specific MCE features such as 1131 the thermal monitor. 1132 1133config X86_MCE_AMD 1134 def_bool y 1135 prompt "AMD MCE features" 1136 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1137 help 1138 Additional support for AMD specific MCE features such as 1139 the DRAM Error Threshold. 1140 1141config X86_ANCIENT_MCE 1142 bool "Support for old Pentium 5 / WinChip machine checks" 1143 depends on X86_32 && X86_MCE 1144 help 1145 Include support for machine check handling on old Pentium 5 or WinChip 1146 systems. These typically need to be enabled explicitly on the command 1147 line. 1148 1149config X86_MCE_THRESHOLD 1150 depends on X86_MCE_AMD || X86_MCE_INTEL 1151 def_bool y 1152 1153config X86_MCE_INJECT 1154 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1155 tristate "Machine check injector support" 1156 help 1157 Provide support for injecting machine checks for testing purposes. 1158 If you don't know what a machine check is and you don't do kernel 1159 QA it is safe to say n. 1160 1161config X86_THERMAL_VECTOR 1162 def_bool y 1163 depends on X86_MCE_INTEL 1164 1165source "arch/x86/events/Kconfig" 1166 1167config X86_LEGACY_VM86 1168 bool "Legacy VM86 support" 1169 depends on X86_32 1170 help 1171 This option allows user programs to put the CPU into V8086 1172 mode, which is an 80286-era approximation of 16-bit real mode. 1173 1174 Some very old versions of X and/or vbetool require this option 1175 for user mode setting. Similarly, DOSEMU will use it if 1176 available to accelerate real mode DOS programs. However, any 1177 recent version of DOSEMU, X, or vbetool should be fully 1178 functional even without kernel VM86 support, as they will all 1179 fall back to software emulation. Nevertheless, if you are using 1180 a 16-bit DOS program where 16-bit performance matters, vm86 1181 mode might be faster than emulation and you might want to 1182 enable this option. 1183 1184 Note that any app that works on a 64-bit kernel is unlikely to 1185 need this option, as 64-bit kernels don't, and can't, support 1186 V8086 mode. This option is also unrelated to 16-bit protected 1187 mode and is not needed to run most 16-bit programs under Wine. 1188 1189 Enabling this option increases the complexity of the kernel 1190 and slows down exception handling a tiny bit. 1191 1192 If unsure, say N here. 1193 1194config VM86 1195 bool 1196 default X86_LEGACY_VM86 1197 1198config X86_16BIT 1199 bool "Enable support for 16-bit segments" if EXPERT 1200 default y 1201 depends on MODIFY_LDT_SYSCALL 1202 help 1203 This option is required by programs like Wine to run 16-bit 1204 protected mode legacy code on x86 processors. Disabling 1205 this option saves about 300 bytes on i386, or around 6K text 1206 plus 16K runtime memory on x86-64, 1207 1208config X86_ESPFIX32 1209 def_bool y 1210 depends on X86_16BIT && X86_32 1211 1212config X86_ESPFIX64 1213 def_bool y 1214 depends on X86_16BIT && X86_64 1215 1216config X86_VSYSCALL_EMULATION 1217 bool "Enable vsyscall emulation" if EXPERT 1218 default y 1219 depends on X86_64 1220 help 1221 This enables emulation of the legacy vsyscall page. Disabling 1222 it is roughly equivalent to booting with vsyscall=none, except 1223 that it will also disable the helpful warning if a program 1224 tries to use a vsyscall. With this option set to N, offending 1225 programs will just segfault, citing addresses of the form 1226 0xffffffffff600?00. 1227 1228 This option is required by many programs built before 2013, and 1229 care should be used even with newer programs if set to N. 1230 1231 Disabling this option saves about 7K of kernel size and 1232 possibly 4K of additional runtime pagetable memory. 1233 1234config X86_IOPL_IOPERM 1235 bool "IOPERM and IOPL Emulation" 1236 default y 1237 help 1238 This enables the ioperm() and iopl() syscalls which are necessary 1239 for legacy applications. 1240 1241 Legacy IOPL support is an overbroad mechanism which allows user 1242 space aside of accessing all 65536 I/O ports also to disable 1243 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1244 capabilities and permission from potentially active security 1245 modules. 1246 1247 The emulation restricts the functionality of the syscall to 1248 only allowing the full range I/O port access, but prevents the 1249 ability to disable interrupts from user space which would be 1250 granted if the hardware IOPL mechanism would be used. 1251 1252config TOSHIBA 1253 tristate "Toshiba Laptop support" 1254 depends on X86_32 1255 help 1256 This adds a driver to safely access the System Management Mode of 1257 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1258 not work on models with a Phoenix BIOS. The System Management Mode 1259 is used to set the BIOS and power saving options on Toshiba portables. 1260 1261 For information on utilities to make use of this driver see the 1262 Toshiba Linux utilities web site at: 1263 <http://www.buzzard.org.uk/toshiba/>. 1264 1265 Say Y if you intend to run this kernel on a Toshiba portable. 1266 Say N otherwise. 1267 1268config I8K 1269 tristate "Dell i8k legacy laptop support" 1270 select HWMON 1271 select SENSORS_DELL_SMM 1272 help 1273 This option enables legacy /proc/i8k userspace interface in hwmon 1274 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1275 temperature and allows controlling fan speeds of Dell laptops via 1276 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1277 it reports also power and hotkey status. For fan speed control is 1278 needed userspace package i8kutils. 1279 1280 Say Y if you intend to run this kernel on old Dell laptops or want to 1281 use userspace package i8kutils. 1282 Say N otherwise. 1283 1284config X86_REBOOTFIXUPS 1285 bool "Enable X86 board specific fixups for reboot" 1286 depends on X86_32 1287 help 1288 This enables chipset and/or board specific fixups to be done 1289 in order to get reboot to work correctly. This is only needed on 1290 some combinations of hardware and BIOS. The symptom, for which 1291 this config is intended, is when reboot ends with a stalled/hung 1292 system. 1293 1294 Currently, the only fixup is for the Geode machines using 1295 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1296 1297 Say Y if you want to enable the fixup. Currently, it's safe to 1298 enable this option even if you don't need it. 1299 Say N otherwise. 1300 1301config MICROCODE 1302 bool "CPU microcode loading support" 1303 default y 1304 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1305 help 1306 If you say Y here, you will be able to update the microcode on 1307 Intel and AMD processors. The Intel support is for the IA32 family, 1308 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1309 AMD support is for families 0x10 and later. You will obviously need 1310 the actual microcode binary data itself which is not shipped with 1311 the Linux kernel. 1312 1313 The preferred method to load microcode from a detached initrd is described 1314 in Documentation/x86/microcode.rst. For that you need to enable 1315 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1316 initrd for microcode blobs. 1317 1318 In addition, you can build the microcode into the kernel. For that you 1319 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1320 config option. 1321 1322config MICROCODE_INTEL 1323 bool "Intel microcode loading support" 1324 depends on MICROCODE 1325 default MICROCODE 1326 help 1327 This options enables microcode patch loading support for Intel 1328 processors. 1329 1330 For the current Intel microcode data package go to 1331 <https://downloadcenter.intel.com> and search for 1332 'Linux Processor Microcode Data File'. 1333 1334config MICROCODE_AMD 1335 bool "AMD microcode loading support" 1336 depends on MICROCODE 1337 help 1338 If you select this option, microcode patch loading support for AMD 1339 processors will be enabled. 1340 1341config MICROCODE_OLD_INTERFACE 1342 bool "Ancient loading interface (DEPRECATED)" 1343 default n 1344 depends on MICROCODE 1345 help 1346 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1347 which was used by userspace tools like iucode_tool and microcode.ctl. 1348 It is inadequate because it runs too late to be able to properly 1349 load microcode on a machine and it needs special tools. Instead, you 1350 should've switched to the early loading method with the initrd or 1351 builtin microcode by now: Documentation/x86/microcode.rst 1352 1353config X86_MSR 1354 tristate "/dev/cpu/*/msr - Model-specific register support" 1355 help 1356 This device gives privileged processes access to the x86 1357 Model-Specific Registers (MSRs). It is a character device with 1358 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1359 MSR accesses are directed to a specific CPU on multi-processor 1360 systems. 1361 1362config X86_CPUID 1363 tristate "/dev/cpu/*/cpuid - CPU information support" 1364 help 1365 This device gives processes access to the x86 CPUID instruction to 1366 be executed on a specific processor. It is a character device 1367 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1368 /dev/cpu/31/cpuid. 1369 1370choice 1371 prompt "High Memory Support" 1372 default HIGHMEM4G 1373 depends on X86_32 1374 1375config NOHIGHMEM 1376 bool "off" 1377 help 1378 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1379 However, the address space of 32-bit x86 processors is only 4 1380 Gigabytes large. That means that, if you have a large amount of 1381 physical memory, not all of it can be "permanently mapped" by the 1382 kernel. The physical memory that's not permanently mapped is called 1383 "high memory". 1384 1385 If you are compiling a kernel which will never run on a machine with 1386 more than 1 Gigabyte total physical RAM, answer "off" here (default 1387 choice and suitable for most users). This will result in a "3GB/1GB" 1388 split: 3GB are mapped so that each process sees a 3GB virtual memory 1389 space and the remaining part of the 4GB virtual memory space is used 1390 by the kernel to permanently map as much physical memory as 1391 possible. 1392 1393 If the machine has between 1 and 4 Gigabytes physical RAM, then 1394 answer "4GB" here. 1395 1396 If more than 4 Gigabytes is used then answer "64GB" here. This 1397 selection turns Intel PAE (Physical Address Extension) mode on. 1398 PAE implements 3-level paging on IA32 processors. PAE is fully 1399 supported by Linux, PAE mode is implemented on all recent Intel 1400 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1401 then the kernel will not boot on CPUs that don't support PAE! 1402 1403 The actual amount of total physical memory will either be 1404 auto detected or can be forced by using a kernel command line option 1405 such as "mem=256M". (Try "man bootparam" or see the documentation of 1406 your boot loader (lilo or loadlin) about how to pass options to the 1407 kernel at boot time.) 1408 1409 If unsure, say "off". 1410 1411config HIGHMEM4G 1412 bool "4GB" 1413 help 1414 Select this if you have a 32-bit processor and between 1 and 4 1415 gigabytes of physical RAM. 1416 1417config HIGHMEM64G 1418 bool "64GB" 1419 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1420 select X86_PAE 1421 help 1422 Select this if you have a 32-bit processor and more than 4 1423 gigabytes of physical RAM. 1424 1425endchoice 1426 1427choice 1428 prompt "Memory split" if EXPERT 1429 default VMSPLIT_3G 1430 depends on X86_32 1431 help 1432 Select the desired split between kernel and user memory. 1433 1434 If the address range available to the kernel is less than the 1435 physical memory installed, the remaining memory will be available 1436 as "high memory". Accessing high memory is a little more costly 1437 than low memory, as it needs to be mapped into the kernel first. 1438 Note that increasing the kernel address space limits the range 1439 available to user programs, making the address space there 1440 tighter. Selecting anything other than the default 3G/1G split 1441 will also likely make your kernel incompatible with binary-only 1442 kernel modules. 1443 1444 If you are not absolutely sure what you are doing, leave this 1445 option alone! 1446 1447 config VMSPLIT_3G 1448 bool "3G/1G user/kernel split" 1449 config VMSPLIT_3G_OPT 1450 depends on !X86_PAE 1451 bool "3G/1G user/kernel split (for full 1G low memory)" 1452 config VMSPLIT_2G 1453 bool "2G/2G user/kernel split" 1454 config VMSPLIT_2G_OPT 1455 depends on !X86_PAE 1456 bool "2G/2G user/kernel split (for full 2G low memory)" 1457 config VMSPLIT_1G 1458 bool "1G/3G user/kernel split" 1459endchoice 1460 1461config PAGE_OFFSET 1462 hex 1463 default 0xB0000000 if VMSPLIT_3G_OPT 1464 default 0x80000000 if VMSPLIT_2G 1465 default 0x78000000 if VMSPLIT_2G_OPT 1466 default 0x40000000 if VMSPLIT_1G 1467 default 0xC0000000 1468 depends on X86_32 1469 1470config HIGHMEM 1471 def_bool y 1472 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1473 1474config X86_PAE 1475 bool "PAE (Physical Address Extension) Support" 1476 depends on X86_32 && !HIGHMEM4G 1477 select PHYS_ADDR_T_64BIT 1478 select SWIOTLB 1479 help 1480 PAE is required for NX support, and furthermore enables 1481 larger swapspace support for non-overcommit purposes. It 1482 has the cost of more pagetable lookup overhead, and also 1483 consumes more pagetable space per process. 1484 1485config X86_5LEVEL 1486 bool "Enable 5-level page tables support" 1487 default y 1488 select DYNAMIC_MEMORY_LAYOUT 1489 select SPARSEMEM_VMEMMAP 1490 depends on X86_64 1491 help 1492 5-level paging enables access to larger address space: 1493 upto 128 PiB of virtual address space and 4 PiB of 1494 physical address space. 1495 1496 It will be supported by future Intel CPUs. 1497 1498 A kernel with the option enabled can be booted on machines that 1499 support 4- or 5-level paging. 1500 1501 See Documentation/x86/x86_64/5level-paging.rst for more 1502 information. 1503 1504 Say N if unsure. 1505 1506config X86_DIRECT_GBPAGES 1507 def_bool y 1508 depends on X86_64 1509 help 1510 Certain kernel features effectively disable kernel 1511 linear 1 GB mappings (even if the CPU otherwise 1512 supports them), so don't confuse the user by printing 1513 that we have them enabled. 1514 1515config X86_CPA_STATISTICS 1516 bool "Enable statistic for Change Page Attribute" 1517 depends on DEBUG_FS 1518 help 1519 Expose statistics about the Change Page Attribute mechanism, which 1520 helps to determine the effectiveness of preserving large and huge 1521 page mappings when mapping protections are changed. 1522 1523config AMD_MEM_ENCRYPT 1524 bool "AMD Secure Memory Encryption (SME) support" 1525 depends on X86_64 && CPU_SUP_AMD 1526 select DMA_COHERENT_POOL 1527 select DYNAMIC_PHYSICAL_MASK 1528 select ARCH_USE_MEMREMAP_PROT 1529 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1530 select INSTRUCTION_DECODER 1531 help 1532 Say yes to enable support for the encryption of system memory. 1533 This requires an AMD processor that supports Secure Memory 1534 Encryption (SME). 1535 1536config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1537 bool "Activate AMD Secure Memory Encryption (SME) by default" 1538 default y 1539 depends on AMD_MEM_ENCRYPT 1540 help 1541 Say yes to have system memory encrypted by default if running on 1542 an AMD processor that supports Secure Memory Encryption (SME). 1543 1544 If set to Y, then the encryption of system memory can be 1545 deactivated with the mem_encrypt=off command line option. 1546 1547 If set to N, then the encryption of system memory can be 1548 activated with the mem_encrypt=on command line option. 1549 1550# Common NUMA Features 1551config NUMA 1552 bool "NUMA Memory Allocation and Scheduler Support" 1553 depends on SMP 1554 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1555 default y if X86_BIGSMP 1556 help 1557 Enable NUMA (Non-Uniform Memory Access) support. 1558 1559 The kernel will try to allocate memory used by a CPU on the 1560 local memory controller of the CPU and add some more 1561 NUMA awareness to the kernel. 1562 1563 For 64-bit this is recommended if the system is Intel Core i7 1564 (or later), AMD Opteron, or EM64T NUMA. 1565 1566 For 32-bit this is only needed if you boot a 32-bit 1567 kernel on a 64-bit NUMA platform. 1568 1569 Otherwise, you should say N. 1570 1571config AMD_NUMA 1572 def_bool y 1573 prompt "Old style AMD Opteron NUMA detection" 1574 depends on X86_64 && NUMA && PCI 1575 help 1576 Enable AMD NUMA node topology detection. You should say Y here if 1577 you have a multi processor AMD system. This uses an old method to 1578 read the NUMA configuration directly from the builtin Northbridge 1579 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1580 which also takes priority if both are compiled in. 1581 1582config X86_64_ACPI_NUMA 1583 def_bool y 1584 prompt "ACPI NUMA detection" 1585 depends on X86_64 && NUMA && ACPI && PCI 1586 select ACPI_NUMA 1587 help 1588 Enable ACPI SRAT based node topology detection. 1589 1590config NUMA_EMU 1591 bool "NUMA emulation" 1592 depends on NUMA 1593 help 1594 Enable NUMA emulation. A flat machine will be split 1595 into virtual nodes when booted with "numa=fake=N", where N is the 1596 number of nodes. This is only useful for debugging. 1597 1598config NODES_SHIFT 1599 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1600 range 1 10 1601 default "10" if MAXSMP 1602 default "6" if X86_64 1603 default "3" 1604 depends on NEED_MULTIPLE_NODES 1605 help 1606 Specify the maximum number of NUMA Nodes available on the target 1607 system. Increases memory reserved to accommodate various tables. 1608 1609config ARCH_FLATMEM_ENABLE 1610 def_bool y 1611 depends on X86_32 && !NUMA 1612 1613config ARCH_SPARSEMEM_ENABLE 1614 def_bool y 1615 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1616 select SPARSEMEM_STATIC if X86_32 1617 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1618 1619config ARCH_SPARSEMEM_DEFAULT 1620 def_bool X86_64 || (NUMA && X86_32) 1621 1622config ARCH_SELECT_MEMORY_MODEL 1623 def_bool y 1624 depends on ARCH_SPARSEMEM_ENABLE 1625 1626config ARCH_MEMORY_PROBE 1627 bool "Enable sysfs memory/probe interface" 1628 depends on X86_64 && MEMORY_HOTPLUG 1629 help 1630 This option enables a sysfs memory/probe interface for testing. 1631 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1632 If you are unsure how to answer this question, answer N. 1633 1634config ARCH_PROC_KCORE_TEXT 1635 def_bool y 1636 depends on X86_64 && PROC_KCORE 1637 1638config ILLEGAL_POINTER_VALUE 1639 hex 1640 default 0 if X86_32 1641 default 0xdead000000000000 if X86_64 1642 1643config X86_PMEM_LEGACY_DEVICE 1644 bool 1645 1646config X86_PMEM_LEGACY 1647 tristate "Support non-standard NVDIMMs and ADR protected memory" 1648 depends on PHYS_ADDR_T_64BIT 1649 depends on BLK_DEV 1650 select X86_PMEM_LEGACY_DEVICE 1651 select NUMA_KEEP_MEMINFO if NUMA 1652 select LIBNVDIMM 1653 help 1654 Treat memory marked using the non-standard e820 type of 12 as used 1655 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1656 The kernel will offer these regions to the 'pmem' driver so 1657 they can be used for persistent storage. 1658 1659 Say Y if unsure. 1660 1661config HIGHPTE 1662 bool "Allocate 3rd-level pagetables from highmem" 1663 depends on HIGHMEM 1664 help 1665 The VM uses one page table entry for each page of physical memory. 1666 For systems with a lot of RAM, this can be wasteful of precious 1667 low memory. Setting this option will put user-space page table 1668 entries in high memory. 1669 1670config X86_CHECK_BIOS_CORRUPTION 1671 bool "Check for low memory corruption" 1672 help 1673 Periodically check for memory corruption in low memory, which 1674 is suspected to be caused by BIOS. Even when enabled in the 1675 configuration, it is disabled at runtime. Enable it by 1676 setting "memory_corruption_check=1" on the kernel command 1677 line. By default it scans the low 64k of memory every 60 1678 seconds; see the memory_corruption_check_size and 1679 memory_corruption_check_period parameters in 1680 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1681 1682 When enabled with the default parameters, this option has 1683 almost no overhead, as it reserves a relatively small amount 1684 of memory and scans it infrequently. It both detects corruption 1685 and prevents it from affecting the running system. 1686 1687 It is, however, intended as a diagnostic tool; if repeatable 1688 BIOS-originated corruption always affects the same memory, 1689 you can use memmap= to prevent the kernel from using that 1690 memory. 1691 1692config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1693 bool "Set the default setting of memory_corruption_check" 1694 depends on X86_CHECK_BIOS_CORRUPTION 1695 default y 1696 help 1697 Set whether the default state of memory_corruption_check is 1698 on or off. 1699 1700config X86_RESERVE_LOW 1701 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1702 default 64 1703 range 4 640 1704 help 1705 Specify the amount of low memory to reserve for the BIOS. 1706 1707 The first page contains BIOS data structures that the kernel 1708 must not use, so that page must always be reserved. 1709 1710 By default we reserve the first 64K of physical RAM, as a 1711 number of BIOSes are known to corrupt that memory range 1712 during events such as suspend/resume or monitor cable 1713 insertion, so it must not be used by the kernel. 1714 1715 You can set this to 4 if you are absolutely sure that you 1716 trust the BIOS to get all its memory reservations and usages 1717 right. If you know your BIOS have problems beyond the 1718 default 64K area, you can set this to 640 to avoid using the 1719 entire low memory range. 1720 1721 If you have doubts about the BIOS (e.g. suspend/resume does 1722 not work or there's kernel crashes after certain hardware 1723 hotplug events) then you might want to enable 1724 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1725 typical corruption patterns. 1726 1727 Leave this to the default value of 64 if you are unsure. 1728 1729config MATH_EMULATION 1730 bool 1731 depends on MODIFY_LDT_SYSCALL 1732 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1733 help 1734 Linux can emulate a math coprocessor (used for floating point 1735 operations) if you don't have one. 486DX and Pentium processors have 1736 a math coprocessor built in, 486SX and 386 do not, unless you added 1737 a 487DX or 387, respectively. (The messages during boot time can 1738 give you some hints here ["man dmesg"].) Everyone needs either a 1739 coprocessor or this emulation. 1740 1741 If you don't have a math coprocessor, you need to say Y here; if you 1742 say Y here even though you have a coprocessor, the coprocessor will 1743 be used nevertheless. (This behavior can be changed with the kernel 1744 command line option "no387", which comes handy if your coprocessor 1745 is broken. Try "man bootparam" or see the documentation of your boot 1746 loader (lilo or loadlin) about how to pass options to the kernel at 1747 boot time.) This means that it is a good idea to say Y here if you 1748 intend to use this kernel on different machines. 1749 1750 More information about the internals of the Linux math coprocessor 1751 emulation can be found in <file:arch/x86/math-emu/README>. 1752 1753 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1754 kernel, it won't hurt. 1755 1756config MTRR 1757 def_bool y 1758 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1759 help 1760 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1761 the Memory Type Range Registers (MTRRs) may be used to control 1762 processor access to memory ranges. This is most useful if you have 1763 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1764 allows bus write transfers to be combined into a larger transfer 1765 before bursting over the PCI/AGP bus. This can increase performance 1766 of image write operations 2.5 times or more. Saying Y here creates a 1767 /proc/mtrr file which may be used to manipulate your processor's 1768 MTRRs. Typically the X server should use this. 1769 1770 This code has a reasonably generic interface so that similar 1771 control registers on other processors can be easily supported 1772 as well: 1773 1774 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1775 Registers (ARRs) which provide a similar functionality to MTRRs. For 1776 these, the ARRs are used to emulate the MTRRs. 1777 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1778 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1779 write-combining. All of these processors are supported by this code 1780 and it makes sense to say Y here if you have one of them. 1781 1782 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1783 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1784 can lead to all sorts of problems, so it's good to say Y here. 1785 1786 You can safely say Y even if your machine doesn't have MTRRs, you'll 1787 just add about 9 KB to your kernel. 1788 1789 See <file:Documentation/x86/mtrr.rst> for more information. 1790 1791config MTRR_SANITIZER 1792 def_bool y 1793 prompt "MTRR cleanup support" 1794 depends on MTRR 1795 help 1796 Convert MTRR layout from continuous to discrete, so X drivers can 1797 add writeback entries. 1798 1799 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1800 The largest mtrr entry size for a continuous block can be set with 1801 mtrr_chunk_size. 1802 1803 If unsure, say Y. 1804 1805config MTRR_SANITIZER_ENABLE_DEFAULT 1806 int "MTRR cleanup enable value (0-1)" 1807 range 0 1 1808 default "0" 1809 depends on MTRR_SANITIZER 1810 help 1811 Enable mtrr cleanup default value 1812 1813config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1814 int "MTRR cleanup spare reg num (0-7)" 1815 range 0 7 1816 default "1" 1817 depends on MTRR_SANITIZER 1818 help 1819 mtrr cleanup spare entries default, it can be changed via 1820 mtrr_spare_reg_nr=N on the kernel command line. 1821 1822config X86_PAT 1823 def_bool y 1824 prompt "x86 PAT support" if EXPERT 1825 depends on MTRR 1826 help 1827 Use PAT attributes to setup page level cache control. 1828 1829 PATs are the modern equivalents of MTRRs and are much more 1830 flexible than MTRRs. 1831 1832 Say N here if you see bootup problems (boot crash, boot hang, 1833 spontaneous reboots) or a non-working video driver. 1834 1835 If unsure, say Y. 1836 1837config ARCH_USES_PG_UNCACHED 1838 def_bool y 1839 depends on X86_PAT 1840 1841config ARCH_RANDOM 1842 def_bool y 1843 prompt "x86 architectural random number generator" if EXPERT 1844 help 1845 Enable the x86 architectural RDRAND instruction 1846 (Intel Bull Mountain technology) to generate random numbers. 1847 If supported, this is a high bandwidth, cryptographically 1848 secure hardware random number generator. 1849 1850config X86_SMAP 1851 def_bool y 1852 prompt "Supervisor Mode Access Prevention" if EXPERT 1853 help 1854 Supervisor Mode Access Prevention (SMAP) is a security 1855 feature in newer Intel processors. There is a small 1856 performance cost if this enabled and turned on; there is 1857 also a small increase in the kernel size if this is enabled. 1858 1859 If unsure, say Y. 1860 1861config X86_UMIP 1862 def_bool y 1863 prompt "User Mode Instruction Prevention" if EXPERT 1864 help 1865 User Mode Instruction Prevention (UMIP) is a security feature in 1866 some x86 processors. If enabled, a general protection fault is 1867 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1868 executed in user mode. These instructions unnecessarily expose 1869 information about the hardware state. 1870 1871 The vast majority of applications do not use these instructions. 1872 For the very few that do, software emulation is provided in 1873 specific cases in protected and virtual-8086 modes. Emulated 1874 results are dummy. 1875 1876config X86_INTEL_MEMORY_PROTECTION_KEYS 1877 prompt "Memory Protection Keys" 1878 def_bool y 1879 # Note: only available in 64-bit mode 1880 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1881 select ARCH_USES_HIGH_VMA_FLAGS 1882 select ARCH_HAS_PKEYS 1883 help 1884 Memory Protection Keys provides a mechanism for enforcing 1885 page-based protections, but without requiring modification of the 1886 page tables when an application changes protection domains. 1887 1888 For details, see Documentation/core-api/protection-keys.rst 1889 1890 If unsure, say y. 1891 1892choice 1893 prompt "TSX enable mode" 1894 depends on CPU_SUP_INTEL 1895 default X86_INTEL_TSX_MODE_OFF 1896 help 1897 Intel's TSX (Transactional Synchronization Extensions) feature 1898 allows to optimize locking protocols through lock elision which 1899 can lead to a noticeable performance boost. 1900 1901 On the other hand it has been shown that TSX can be exploited 1902 to form side channel attacks (e.g. TAA) and chances are there 1903 will be more of those attacks discovered in the future. 1904 1905 Therefore TSX is not enabled by default (aka tsx=off). An admin 1906 might override this decision by tsx=on the command line parameter. 1907 Even with TSX enabled, the kernel will attempt to enable the best 1908 possible TAA mitigation setting depending on the microcode available 1909 for the particular machine. 1910 1911 This option allows to set the default tsx mode between tsx=on, =off 1912 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1913 details. 1914 1915 Say off if not sure, auto if TSX is in use but it should be used on safe 1916 platforms or on if TSX is in use and the security aspect of tsx is not 1917 relevant. 1918 1919config X86_INTEL_TSX_MODE_OFF 1920 bool "off" 1921 help 1922 TSX is disabled if possible - equals to tsx=off command line parameter. 1923 1924config X86_INTEL_TSX_MODE_ON 1925 bool "on" 1926 help 1927 TSX is always enabled on TSX capable HW - equals the tsx=on command 1928 line parameter. 1929 1930config X86_INTEL_TSX_MODE_AUTO 1931 bool "auto" 1932 help 1933 TSX is enabled on TSX capable HW that is believed to be safe against 1934 side channel attacks- equals the tsx=auto command line parameter. 1935endchoice 1936 1937config X86_SGX 1938 bool "Software Guard eXtensions (SGX)" 1939 depends on X86_64 && CPU_SUP_INTEL 1940 depends on CRYPTO=y 1941 depends on CRYPTO_SHA256=y 1942 select SRCU 1943 select MMU_NOTIFIER 1944 help 1945 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1946 that can be used by applications to set aside private regions of code 1947 and data, referred to as enclaves. An enclave's private memory can 1948 only be accessed by code running within the enclave. Accesses from 1949 outside the enclave, including other enclaves, are disallowed by 1950 hardware. 1951 1952 If unsure, say N. 1953 1954config EFI 1955 bool "EFI runtime service support" 1956 depends on ACPI 1957 select UCS2_STRING 1958 select EFI_RUNTIME_WRAPPERS 1959 help 1960 This enables the kernel to use EFI runtime services that are 1961 available (such as the EFI variable services). 1962 1963 This option is only useful on systems that have EFI firmware. 1964 In addition, you should use the latest ELILO loader available 1965 at <http://elilo.sourceforge.net> in order to take advantage 1966 of EFI runtime services. However, even with this option, the 1967 resultant kernel should continue to boot on existing non-EFI 1968 platforms. 1969 1970config EFI_STUB 1971 bool "EFI stub support" 1972 depends on EFI && !X86_USE_3DNOW 1973 depends on $(cc-option,-mabi=ms) || X86_32 1974 select RELOCATABLE 1975 help 1976 This kernel feature allows a bzImage to be loaded directly 1977 by EFI firmware without the use of a bootloader. 1978 1979 See Documentation/admin-guide/efi-stub.rst for more information. 1980 1981config EFI_MIXED 1982 bool "EFI mixed-mode support" 1983 depends on EFI_STUB && X86_64 1984 help 1985 Enabling this feature allows a 64-bit kernel to be booted 1986 on a 32-bit firmware, provided that your CPU supports 64-bit 1987 mode. 1988 1989 Note that it is not possible to boot a mixed-mode enabled 1990 kernel via the EFI boot stub - a bootloader that supports 1991 the EFI handover protocol must be used. 1992 1993 If unsure, say N. 1994 1995source "kernel/Kconfig.hz" 1996 1997config KEXEC 1998 bool "kexec system call" 1999 select KEXEC_CORE 2000 help 2001 kexec is a system call that implements the ability to shutdown your 2002 current kernel, and to start another kernel. It is like a reboot 2003 but it is independent of the system firmware. And like a reboot 2004 you can start any kernel with it, not just Linux. 2005 2006 The name comes from the similarity to the exec system call. 2007 2008 It is an ongoing process to be certain the hardware in a machine 2009 is properly shutdown, so do not be surprised if this code does not 2010 initially work for you. As of this writing the exact hardware 2011 interface is strongly in flux, so no good recommendation can be 2012 made. 2013 2014config KEXEC_FILE 2015 bool "kexec file based system call" 2016 select KEXEC_CORE 2017 select BUILD_BIN2C 2018 depends on X86_64 2019 depends on CRYPTO=y 2020 depends on CRYPTO_SHA256=y 2021 help 2022 This is new version of kexec system call. This system call is 2023 file based and takes file descriptors as system call argument 2024 for kernel and initramfs as opposed to list of segments as 2025 accepted by previous system call. 2026 2027config ARCH_HAS_KEXEC_PURGATORY 2028 def_bool KEXEC_FILE 2029 2030config KEXEC_SIG 2031 bool "Verify kernel signature during kexec_file_load() syscall" 2032 depends on KEXEC_FILE 2033 help 2034 2035 This option makes the kexec_file_load() syscall check for a valid 2036 signature of the kernel image. The image can still be loaded without 2037 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2038 there's a signature that we can check, then it must be valid. 2039 2040 In addition to this option, you need to enable signature 2041 verification for the corresponding kernel image type being 2042 loaded in order for this to work. 2043 2044config KEXEC_SIG_FORCE 2045 bool "Require a valid signature in kexec_file_load() syscall" 2046 depends on KEXEC_SIG 2047 help 2048 This option makes kernel signature verification mandatory for 2049 the kexec_file_load() syscall. 2050 2051config KEXEC_BZIMAGE_VERIFY_SIG 2052 bool "Enable bzImage signature verification support" 2053 depends on KEXEC_SIG 2054 depends on SIGNED_PE_FILE_VERIFICATION 2055 select SYSTEM_TRUSTED_KEYRING 2056 help 2057 Enable bzImage signature verification support. 2058 2059config CRASH_DUMP 2060 bool "kernel crash dumps" 2061 depends on X86_64 || (X86_32 && HIGHMEM) 2062 help 2063 Generate crash dump after being started by kexec. 2064 This should be normally only set in special crash dump kernels 2065 which are loaded in the main kernel with kexec-tools into 2066 a specially reserved region and then later executed after 2067 a crash by kdump/kexec. The crash dump kernel must be compiled 2068 to a memory address not used by the main kernel or BIOS using 2069 PHYSICAL_START, or it must be built as a relocatable image 2070 (CONFIG_RELOCATABLE=y). 2071 For more details see Documentation/admin-guide/kdump/kdump.rst 2072 2073config KEXEC_JUMP 2074 bool "kexec jump" 2075 depends on KEXEC && HIBERNATION 2076 help 2077 Jump between original kernel and kexeced kernel and invoke 2078 code in physical address mode via KEXEC 2079 2080config PHYSICAL_START 2081 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2082 default "0x1000000" 2083 help 2084 This gives the physical address where the kernel is loaded. 2085 2086 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2087 bzImage will decompress itself to above physical address and 2088 run from there. Otherwise, bzImage will run from the address where 2089 it has been loaded by the boot loader and will ignore above physical 2090 address. 2091 2092 In normal kdump cases one does not have to set/change this option 2093 as now bzImage can be compiled as a completely relocatable image 2094 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2095 address. This option is mainly useful for the folks who don't want 2096 to use a bzImage for capturing the crash dump and want to use a 2097 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2098 to be specifically compiled to run from a specific memory area 2099 (normally a reserved region) and this option comes handy. 2100 2101 So if you are using bzImage for capturing the crash dump, 2102 leave the value here unchanged to 0x1000000 and set 2103 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2104 for capturing the crash dump change this value to start of 2105 the reserved region. In other words, it can be set based on 2106 the "X" value as specified in the "crashkernel=YM@XM" 2107 command line boot parameter passed to the panic-ed 2108 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2109 for more details about crash dumps. 2110 2111 Usage of bzImage for capturing the crash dump is recommended as 2112 one does not have to build two kernels. Same kernel can be used 2113 as production kernel and capture kernel. Above option should have 2114 gone away after relocatable bzImage support is introduced. But it 2115 is present because there are users out there who continue to use 2116 vmlinux for dump capture. This option should go away down the 2117 line. 2118 2119 Don't change this unless you know what you are doing. 2120 2121config RELOCATABLE 2122 bool "Build a relocatable kernel" 2123 default y 2124 help 2125 This builds a kernel image that retains relocation information 2126 so it can be loaded someplace besides the default 1MB. 2127 The relocations tend to make the kernel binary about 10% larger, 2128 but are discarded at runtime. 2129 2130 One use is for the kexec on panic case where the recovery kernel 2131 must live at a different physical address than the primary 2132 kernel. 2133 2134 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2135 it has been loaded at and the compile time physical address 2136 (CONFIG_PHYSICAL_START) is used as the minimum location. 2137 2138config RANDOMIZE_BASE 2139 bool "Randomize the address of the kernel image (KASLR)" 2140 depends on RELOCATABLE 2141 default y 2142 help 2143 In support of Kernel Address Space Layout Randomization (KASLR), 2144 this randomizes the physical address at which the kernel image 2145 is decompressed and the virtual address where the kernel 2146 image is mapped, as a security feature that deters exploit 2147 attempts relying on knowledge of the location of kernel 2148 code internals. 2149 2150 On 64-bit, the kernel physical and virtual addresses are 2151 randomized separately. The physical address will be anywhere 2152 between 16MB and the top of physical memory (up to 64TB). The 2153 virtual address will be randomized from 16MB up to 1GB (9 bits 2154 of entropy). Note that this also reduces the memory space 2155 available to kernel modules from 1.5GB to 1GB. 2156 2157 On 32-bit, the kernel physical and virtual addresses are 2158 randomized together. They will be randomized from 16MB up to 2159 512MB (8 bits of entropy). 2160 2161 Entropy is generated using the RDRAND instruction if it is 2162 supported. If RDTSC is supported, its value is mixed into 2163 the entropy pool as well. If neither RDRAND nor RDTSC are 2164 supported, then entropy is read from the i8254 timer. The 2165 usable entropy is limited by the kernel being built using 2166 2GB addressing, and that PHYSICAL_ALIGN must be at a 2167 minimum of 2MB. As a result, only 10 bits of entropy are 2168 theoretically possible, but the implementations are further 2169 limited due to memory layouts. 2170 2171 If unsure, say Y. 2172 2173# Relocation on x86 needs some additional build support 2174config X86_NEED_RELOCS 2175 def_bool y 2176 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2177 2178config PHYSICAL_ALIGN 2179 hex "Alignment value to which kernel should be aligned" 2180 default "0x200000" 2181 range 0x2000 0x1000000 if X86_32 2182 range 0x200000 0x1000000 if X86_64 2183 help 2184 This value puts the alignment restrictions on physical address 2185 where kernel is loaded and run from. Kernel is compiled for an 2186 address which meets above alignment restriction. 2187 2188 If bootloader loads the kernel at a non-aligned address and 2189 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2190 address aligned to above value and run from there. 2191 2192 If bootloader loads the kernel at a non-aligned address and 2193 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2194 load address and decompress itself to the address it has been 2195 compiled for and run from there. The address for which kernel is 2196 compiled already meets above alignment restrictions. Hence the 2197 end result is that kernel runs from a physical address meeting 2198 above alignment restrictions. 2199 2200 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2201 this value must be a multiple of 0x200000. 2202 2203 Don't change this unless you know what you are doing. 2204 2205config DYNAMIC_MEMORY_LAYOUT 2206 bool 2207 help 2208 This option makes base addresses of vmalloc and vmemmap as well as 2209 __PAGE_OFFSET movable during boot. 2210 2211config RANDOMIZE_MEMORY 2212 bool "Randomize the kernel memory sections" 2213 depends on X86_64 2214 depends on RANDOMIZE_BASE 2215 select DYNAMIC_MEMORY_LAYOUT 2216 default RANDOMIZE_BASE 2217 help 2218 Randomizes the base virtual address of kernel memory sections 2219 (physical memory mapping, vmalloc & vmemmap). This security feature 2220 makes exploits relying on predictable memory locations less reliable. 2221 2222 The order of allocations remains unchanged. Entropy is generated in 2223 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2224 configuration have in average 30,000 different possible virtual 2225 addresses for each memory section. 2226 2227 If unsure, say Y. 2228 2229config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2230 hex "Physical memory mapping padding" if EXPERT 2231 depends on RANDOMIZE_MEMORY 2232 default "0xa" if MEMORY_HOTPLUG 2233 default "0x0" 2234 range 0x1 0x40 if MEMORY_HOTPLUG 2235 range 0x0 0x40 2236 help 2237 Define the padding in terabytes added to the existing physical 2238 memory size during kernel memory randomization. It is useful 2239 for memory hotplug support but reduces the entropy available for 2240 address randomization. 2241 2242 If unsure, leave at the default value. 2243 2244config HOTPLUG_CPU 2245 def_bool y 2246 depends on SMP 2247 2248config BOOTPARAM_HOTPLUG_CPU0 2249 bool "Set default setting of cpu0_hotpluggable" 2250 depends on HOTPLUG_CPU 2251 help 2252 Set whether default state of cpu0_hotpluggable is on or off. 2253 2254 Say Y here to enable CPU0 hotplug by default. If this switch 2255 is turned on, there is no need to give cpu0_hotplug kernel 2256 parameter and the CPU0 hotplug feature is enabled by default. 2257 2258 Please note: there are two known CPU0 dependencies if you want 2259 to enable the CPU0 hotplug feature either by this switch or by 2260 cpu0_hotplug kernel parameter. 2261 2262 First, resume from hibernate or suspend always starts from CPU0. 2263 So hibernate and suspend are prevented if CPU0 is offline. 2264 2265 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2266 offline if any interrupt can not migrate out of CPU0. There may 2267 be other CPU0 dependencies. 2268 2269 Please make sure the dependencies are under your control before 2270 you enable this feature. 2271 2272 Say N if you don't want to enable CPU0 hotplug feature by default. 2273 You still can enable the CPU0 hotplug feature at boot by kernel 2274 parameter cpu0_hotplug. 2275 2276config DEBUG_HOTPLUG_CPU0 2277 def_bool n 2278 prompt "Debug CPU0 hotplug" 2279 depends on HOTPLUG_CPU 2280 help 2281 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2282 soon as possible and boots up userspace with CPU0 offlined. User 2283 can online CPU0 back after boot time. 2284 2285 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2286 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2287 compilation or giving cpu0_hotplug kernel parameter at boot. 2288 2289 If unsure, say N. 2290 2291config COMPAT_VDSO 2292 def_bool n 2293 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2294 depends on COMPAT_32 2295 help 2296 Certain buggy versions of glibc will crash if they are 2297 presented with a 32-bit vDSO that is not mapped at the address 2298 indicated in its segment table. 2299 2300 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2301 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2302 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2303 the only released version with the bug, but OpenSUSE 9 2304 contains a buggy "glibc 2.3.2". 2305 2306 The symptom of the bug is that everything crashes on startup, saying: 2307 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2308 2309 Saying Y here changes the default value of the vdso32 boot 2310 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2311 This works around the glibc bug but hurts performance. 2312 2313 If unsure, say N: if you are compiling your own kernel, you 2314 are unlikely to be using a buggy version of glibc. 2315 2316choice 2317 prompt "vsyscall table for legacy applications" 2318 depends on X86_64 2319 default LEGACY_VSYSCALL_XONLY 2320 help 2321 Legacy user code that does not know how to find the vDSO expects 2322 to be able to issue three syscalls by calling fixed addresses in 2323 kernel space. Since this location is not randomized with ASLR, 2324 it can be used to assist security vulnerability exploitation. 2325 2326 This setting can be changed at boot time via the kernel command 2327 line parameter vsyscall=[emulate|xonly|none]. 2328 2329 On a system with recent enough glibc (2.14 or newer) and no 2330 static binaries, you can say None without a performance penalty 2331 to improve security. 2332 2333 If unsure, select "Emulate execution only". 2334 2335 config LEGACY_VSYSCALL_EMULATE 2336 bool "Full emulation" 2337 help 2338 The kernel traps and emulates calls into the fixed vsyscall 2339 address mapping. This makes the mapping non-executable, but 2340 it still contains readable known contents, which could be 2341 used in certain rare security vulnerability exploits. This 2342 configuration is recommended when using legacy userspace 2343 that still uses vsyscalls along with legacy binary 2344 instrumentation tools that require code to be readable. 2345 2346 An example of this type of legacy userspace is running 2347 Pin on an old binary that still uses vsyscalls. 2348 2349 config LEGACY_VSYSCALL_XONLY 2350 bool "Emulate execution only" 2351 help 2352 The kernel traps and emulates calls into the fixed vsyscall 2353 address mapping and does not allow reads. This 2354 configuration is recommended when userspace might use the 2355 legacy vsyscall area but support for legacy binary 2356 instrumentation of legacy code is not needed. It mitigates 2357 certain uses of the vsyscall area as an ASLR-bypassing 2358 buffer. 2359 2360 config LEGACY_VSYSCALL_NONE 2361 bool "None" 2362 help 2363 There will be no vsyscall mapping at all. This will 2364 eliminate any risk of ASLR bypass due to the vsyscall 2365 fixed address mapping. Attempts to use the vsyscalls 2366 will be reported to dmesg, so that either old or 2367 malicious userspace programs can be identified. 2368 2369endchoice 2370 2371config CMDLINE_BOOL 2372 bool "Built-in kernel command line" 2373 help 2374 Allow for specifying boot arguments to the kernel at 2375 build time. On some systems (e.g. embedded ones), it is 2376 necessary or convenient to provide some or all of the 2377 kernel boot arguments with the kernel itself (that is, 2378 to not rely on the boot loader to provide them.) 2379 2380 To compile command line arguments into the kernel, 2381 set this option to 'Y', then fill in the 2382 boot arguments in CONFIG_CMDLINE. 2383 2384 Systems with fully functional boot loaders (i.e. non-embedded) 2385 should leave this option set to 'N'. 2386 2387config CMDLINE 2388 string "Built-in kernel command string" 2389 depends on CMDLINE_BOOL 2390 default "" 2391 help 2392 Enter arguments here that should be compiled into the kernel 2393 image and used at boot time. If the boot loader provides a 2394 command line at boot time, it is appended to this string to 2395 form the full kernel command line, when the system boots. 2396 2397 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2398 change this behavior. 2399 2400 In most cases, the command line (whether built-in or provided 2401 by the boot loader) should specify the device for the root 2402 file system. 2403 2404config CMDLINE_OVERRIDE 2405 bool "Built-in command line overrides boot loader arguments" 2406 depends on CMDLINE_BOOL && CMDLINE != "" 2407 help 2408 Set this option to 'Y' to have the kernel ignore the boot loader 2409 command line, and use ONLY the built-in command line. 2410 2411 This is used to work around broken boot loaders. This should 2412 be set to 'N' under normal conditions. 2413 2414config MODIFY_LDT_SYSCALL 2415 bool "Enable the LDT (local descriptor table)" if EXPERT 2416 default y 2417 help 2418 Linux can allow user programs to install a per-process x86 2419 Local Descriptor Table (LDT) using the modify_ldt(2) system 2420 call. This is required to run 16-bit or segmented code such as 2421 DOSEMU or some Wine programs. It is also used by some very old 2422 threading libraries. 2423 2424 Enabling this feature adds a small amount of overhead to 2425 context switches and increases the low-level kernel attack 2426 surface. Disabling it removes the modify_ldt(2) system call. 2427 2428 Saying 'N' here may make sense for embedded or server kernels. 2429 2430source "kernel/livepatch/Kconfig" 2431 2432endmenu 2433 2434config ARCH_HAS_ADD_PAGES 2435 def_bool y 2436 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2437 2438config ARCH_ENABLE_MEMORY_HOTPLUG 2439 def_bool y 2440 depends on X86_64 || (X86_32 && HIGHMEM) 2441 2442config ARCH_ENABLE_MEMORY_HOTREMOVE 2443 def_bool y 2444 depends on MEMORY_HOTPLUG 2445 2446config USE_PERCPU_NUMA_NODE_ID 2447 def_bool y 2448 depends on NUMA 2449 2450config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2451 def_bool y 2452 depends on X86_64 || X86_PAE 2453 2454config ARCH_ENABLE_HUGEPAGE_MIGRATION 2455 def_bool y 2456 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2457 2458config ARCH_ENABLE_THP_MIGRATION 2459 def_bool y 2460 depends on X86_64 && TRANSPARENT_HUGEPAGE 2461 2462menu "Power management and ACPI options" 2463 2464config ARCH_HIBERNATION_HEADER 2465 def_bool y 2466 depends on HIBERNATION 2467 2468source "kernel/power/Kconfig" 2469 2470source "drivers/acpi/Kconfig" 2471 2472source "drivers/sfi/Kconfig" 2473 2474config X86_APM_BOOT 2475 def_bool y 2476 depends on APM 2477 2478menuconfig APM 2479 tristate "APM (Advanced Power Management) BIOS support" 2480 depends on X86_32 && PM_SLEEP 2481 help 2482 APM is a BIOS specification for saving power using several different 2483 techniques. This is mostly useful for battery powered laptops with 2484 APM compliant BIOSes. If you say Y here, the system time will be 2485 reset after a RESUME operation, the /proc/apm device will provide 2486 battery status information, and user-space programs will receive 2487 notification of APM "events" (e.g. battery status change). 2488 2489 If you select "Y" here, you can disable actual use of the APM 2490 BIOS by passing the "apm=off" option to the kernel at boot time. 2491 2492 Note that the APM support is almost completely disabled for 2493 machines with more than one CPU. 2494 2495 In order to use APM, you will need supporting software. For location 2496 and more information, read <file:Documentation/power/apm-acpi.rst> 2497 and the Battery Powered Linux mini-HOWTO, available from 2498 <http://www.tldp.org/docs.html#howto>. 2499 2500 This driver does not spin down disk drives (see the hdparm(8) 2501 manpage ("man 8 hdparm") for that), and it doesn't turn off 2502 VESA-compliant "green" monitors. 2503 2504 This driver does not support the TI 4000M TravelMate and the ACER 2505 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2506 desktop machines also don't have compliant BIOSes, and this driver 2507 may cause those machines to panic during the boot phase. 2508 2509 Generally, if you don't have a battery in your machine, there isn't 2510 much point in using this driver and you should say N. If you get 2511 random kernel OOPSes or reboots that don't seem to be related to 2512 anything, try disabling/enabling this option (or disabling/enabling 2513 APM in your BIOS). 2514 2515 Some other things you should try when experiencing seemingly random, 2516 "weird" problems: 2517 2518 1) make sure that you have enough swap space and that it is 2519 enabled. 2520 2) pass the "no-hlt" option to the kernel 2521 3) switch on floating point emulation in the kernel and pass 2522 the "no387" option to the kernel 2523 4) pass the "floppy=nodma" option to the kernel 2524 5) pass the "mem=4M" option to the kernel (thereby disabling 2525 all but the first 4 MB of RAM) 2526 6) make sure that the CPU is not over clocked. 2527 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2528 8) disable the cache from your BIOS settings 2529 9) install a fan for the video card or exchange video RAM 2530 10) install a better fan for the CPU 2531 11) exchange RAM chips 2532 12) exchange the motherboard. 2533 2534 To compile this driver as a module, choose M here: the 2535 module will be called apm. 2536 2537if APM 2538 2539config APM_IGNORE_USER_SUSPEND 2540 bool "Ignore USER SUSPEND" 2541 help 2542 This option will ignore USER SUSPEND requests. On machines with a 2543 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2544 series notebooks, it is necessary to say Y because of a BIOS bug. 2545 2546config APM_DO_ENABLE 2547 bool "Enable PM at boot time" 2548 help 2549 Enable APM features at boot time. From page 36 of the APM BIOS 2550 specification: "When disabled, the APM BIOS does not automatically 2551 power manage devices, enter the Standby State, enter the Suspend 2552 State, or take power saving steps in response to CPU Idle calls." 2553 This driver will make CPU Idle calls when Linux is idle (unless this 2554 feature is turned off -- see "Do CPU IDLE calls", below). This 2555 should always save battery power, but more complicated APM features 2556 will be dependent on your BIOS implementation. You may need to turn 2557 this option off if your computer hangs at boot time when using APM 2558 support, or if it beeps continuously instead of suspending. Turn 2559 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2560 T400CDT. This is off by default since most machines do fine without 2561 this feature. 2562 2563config APM_CPU_IDLE 2564 depends on CPU_IDLE 2565 bool "Make CPU Idle calls when idle" 2566 help 2567 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2568 On some machines, this can activate improved power savings, such as 2569 a slowed CPU clock rate, when the machine is idle. These idle calls 2570 are made after the idle loop has run for some length of time (e.g., 2571 333 mS). On some machines, this will cause a hang at boot time or 2572 whenever the CPU becomes idle. (On machines with more than one CPU, 2573 this option does nothing.) 2574 2575config APM_DISPLAY_BLANK 2576 bool "Enable console blanking using APM" 2577 help 2578 Enable console blanking using the APM. Some laptops can use this to 2579 turn off the LCD backlight when the screen blanker of the Linux 2580 virtual console blanks the screen. Note that this is only used by 2581 the virtual console screen blanker, and won't turn off the backlight 2582 when using the X Window system. This also doesn't have anything to 2583 do with your VESA-compliant power-saving monitor. Further, this 2584 option doesn't work for all laptops -- it might not turn off your 2585 backlight at all, or it might print a lot of errors to the console, 2586 especially if you are using gpm. 2587 2588config APM_ALLOW_INTS 2589 bool "Allow interrupts during APM BIOS calls" 2590 help 2591 Normally we disable external interrupts while we are making calls to 2592 the APM BIOS as a measure to lessen the effects of a badly behaving 2593 BIOS implementation. The BIOS should reenable interrupts if it 2594 needs to. Unfortunately, some BIOSes do not -- especially those in 2595 many of the newer IBM Thinkpads. If you experience hangs when you 2596 suspend, try setting this to Y. Otherwise, say N. 2597 2598endif # APM 2599 2600source "drivers/cpufreq/Kconfig" 2601 2602source "drivers/cpuidle/Kconfig" 2603 2604source "drivers/idle/Kconfig" 2605 2606endmenu 2607 2608 2609menu "Bus options (PCI etc.)" 2610 2611choice 2612 prompt "PCI access mode" 2613 depends on X86_32 && PCI 2614 default PCI_GOANY 2615 help 2616 On PCI systems, the BIOS can be used to detect the PCI devices and 2617 determine their configuration. However, some old PCI motherboards 2618 have BIOS bugs and may crash if this is done. Also, some embedded 2619 PCI-based systems don't have any BIOS at all. Linux can also try to 2620 detect the PCI hardware directly without using the BIOS. 2621 2622 With this option, you can specify how Linux should detect the 2623 PCI devices. If you choose "BIOS", the BIOS will be used, 2624 if you choose "Direct", the BIOS won't be used, and if you 2625 choose "MMConfig", then PCI Express MMCONFIG will be used. 2626 If you choose "Any", the kernel will try MMCONFIG, then the 2627 direct access method and falls back to the BIOS if that doesn't 2628 work. If unsure, go with the default, which is "Any". 2629 2630config PCI_GOBIOS 2631 bool "BIOS" 2632 2633config PCI_GOMMCONFIG 2634 bool "MMConfig" 2635 2636config PCI_GODIRECT 2637 bool "Direct" 2638 2639config PCI_GOOLPC 2640 bool "OLPC XO-1" 2641 depends on OLPC 2642 2643config PCI_GOANY 2644 bool "Any" 2645 2646endchoice 2647 2648config PCI_BIOS 2649 def_bool y 2650 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2651 2652# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2653config PCI_DIRECT 2654 def_bool y 2655 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2656 2657config PCI_MMCONFIG 2658 bool "Support mmconfig PCI config space access" if X86_64 2659 default y 2660 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2661 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2662 2663config PCI_OLPC 2664 def_bool y 2665 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2666 2667config PCI_XEN 2668 def_bool y 2669 depends on PCI && XEN 2670 select SWIOTLB_XEN 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 2689config ISA_BUS 2690 bool "ISA bus support on modern systems" if EXPERT 2691 help 2692 Expose ISA bus device drivers and options available for selection and 2693 configuration. Enable this option if your target machine has an ISA 2694 bus. ISA is an older system, displaced by PCI and newer bus 2695 architectures -- if your target machine is modern, it probably does 2696 not have an ISA bus. 2697 2698 If unsure, say N. 2699 2700# x86_64 have no ISA slots, but can have ISA-style DMA. 2701config ISA_DMA_API 2702 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2703 default y 2704 help 2705 Enables ISA-style DMA support for devices requiring such controllers. 2706 If unsure, say Y. 2707 2708if X86_32 2709 2710config ISA 2711 bool "ISA support" 2712 help 2713 Find out whether you have ISA slots on your motherboard. ISA is the 2714 name of a bus system, i.e. the way the CPU talks to the other stuff 2715 inside your box. Other bus systems are PCI, EISA, MicroChannel 2716 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2717 newer boards don't support it. If you have ISA, say Y, otherwise N. 2718 2719config SCx200 2720 tristate "NatSemi SCx200 support" 2721 help 2722 This provides basic support for National Semiconductor's 2723 (now AMD's) Geode processors. The driver probes for the 2724 PCI-IDs of several on-chip devices, so its a good dependency 2725 for other scx200_* drivers. 2726 2727 If compiled as a module, the driver is named scx200. 2728 2729config SCx200HR_TIMER 2730 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2731 depends on SCx200 2732 default y 2733 help 2734 This driver provides a clocksource built upon the on-chip 2735 27MHz high-resolution timer. Its also a workaround for 2736 NSC Geode SC-1100's buggy TSC, which loses time when the 2737 processor goes idle (as is done by the scheduler). The 2738 other workaround is idle=poll boot option. 2739 2740config OLPC 2741 bool "One Laptop Per Child support" 2742 depends on !X86_PAE 2743 select GPIOLIB 2744 select OF 2745 select OF_PROMTREE 2746 select IRQ_DOMAIN 2747 select OLPC_EC 2748 help 2749 Add support for detecting the unique features of the OLPC 2750 XO hardware. 2751 2752config OLPC_XO1_PM 2753 bool "OLPC XO-1 Power Management" 2754 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2755 help 2756 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2757 2758config OLPC_XO1_RTC 2759 bool "OLPC XO-1 Real Time Clock" 2760 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2761 help 2762 Add support for the XO-1 real time clock, which can be used as a 2763 programmable wakeup source. 2764 2765config OLPC_XO1_SCI 2766 bool "OLPC XO-1 SCI extras" 2767 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2768 depends on INPUT=y 2769 select POWER_SUPPLY 2770 help 2771 Add support for SCI-based features of the OLPC XO-1 laptop: 2772 - EC-driven system wakeups 2773 - Power button 2774 - Ebook switch 2775 - Lid switch 2776 - AC adapter status updates 2777 - Battery status updates 2778 2779config OLPC_XO15_SCI 2780 bool "OLPC XO-1.5 SCI extras" 2781 depends on OLPC && ACPI 2782 select POWER_SUPPLY 2783 help 2784 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2785 - EC-driven system wakeups 2786 - AC adapter status updates 2787 - Battery status updates 2788 2789config ALIX 2790 bool "PCEngines ALIX System Support (LED setup)" 2791 select GPIOLIB 2792 help 2793 This option enables system support for the PCEngines ALIX. 2794 At present this just sets up LEDs for GPIO control on 2795 ALIX2/3/6 boards. However, other system specific setup should 2796 get added here. 2797 2798 Note: You must still enable the drivers for GPIO and LED support 2799 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2800 2801 Note: You have to set alix.force=1 for boards with Award BIOS. 2802 2803config NET5501 2804 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2805 select GPIOLIB 2806 help 2807 This option enables system support for the Soekris Engineering net5501. 2808 2809config GEOS 2810 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2811 select GPIOLIB 2812 depends on DMI 2813 help 2814 This option enables system support for the Traverse Technologies GEOS. 2815 2816config TS5500 2817 bool "Technologic Systems TS-5500 platform support" 2818 depends on MELAN 2819 select CHECK_SIGNATURE 2820 select NEW_LEDS 2821 select LEDS_CLASS 2822 help 2823 This option enables system support for the Technologic Systems TS-5500. 2824 2825endif # X86_32 2826 2827config AMD_NB 2828 def_bool y 2829 depends on CPU_SUP_AMD && PCI 2830 2831config X86_SYSFB 2832 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2833 help 2834 Firmwares often provide initial graphics framebuffers so the BIOS, 2835 bootloader or kernel can show basic video-output during boot for 2836 user-guidance and debugging. Historically, x86 used the VESA BIOS 2837 Extensions and EFI-framebuffers for this, which are mostly limited 2838 to x86. 2839 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2840 framebuffers so the new generic system-framebuffer drivers can be 2841 used on x86. If the framebuffer is not compatible with the generic 2842 modes, it is advertised as fallback platform framebuffer so legacy 2843 drivers like efifb, vesafb and uvesafb can pick it up. 2844 If this option is not selected, all system framebuffers are always 2845 marked as fallback platform framebuffers as usual. 2846 2847 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2848 not be able to pick up generic system framebuffers if this option 2849 is selected. You are highly encouraged to enable simplefb as 2850 replacement if you select this option. simplefb can correctly deal 2851 with generic system framebuffers. But you should still keep vesafb 2852 and others enabled as fallback if a system framebuffer is 2853 incompatible with simplefb. 2854 2855 If unsure, say Y. 2856 2857endmenu 2858 2859 2860menu "Binary Emulations" 2861 2862config IA32_EMULATION 2863 bool "IA32 Emulation" 2864 depends on X86_64 2865 select ARCH_WANT_OLD_COMPAT_IPC 2866 select BINFMT_ELF 2867 select COMPAT_BINFMT_ELF 2868 select COMPAT_OLD_SIGACTION 2869 help 2870 Include code to run legacy 32-bit programs under a 2871 64-bit kernel. You should likely turn this on, unless you're 2872 100% sure that you don't have any 32-bit programs left. 2873 2874config IA32_AOUT 2875 tristate "IA32 a.out support" 2876 depends on IA32_EMULATION 2877 depends on BROKEN 2878 help 2879 Support old a.out binaries in the 32bit emulation. 2880 2881config X86_X32 2882 bool "x32 ABI for 64-bit mode" 2883 depends on X86_64 2884 help 2885 Include code to run binaries for the x32 native 32-bit ABI 2886 for 64-bit processors. An x32 process gets access to the 2887 full 64-bit register file and wide data path while leaving 2888 pointers at 32 bits for smaller memory footprint. 2889 2890 You will need a recent binutils (2.22 or later) with 2891 elf32_x86_64 support enabled to compile a kernel with this 2892 option set. 2893 2894config COMPAT_32 2895 def_bool y 2896 depends on IA32_EMULATION || X86_32 2897 select HAVE_UID16 2898 select OLD_SIGSUSPEND3 2899 2900config COMPAT 2901 def_bool y 2902 depends on IA32_EMULATION || X86_X32 2903 2904if COMPAT 2905config COMPAT_FOR_U64_ALIGNMENT 2906 def_bool y 2907 2908config SYSVIPC_COMPAT 2909 def_bool y 2910 depends on SYSVIPC 2911endif 2912 2913endmenu 2914 2915 2916config HAVE_ATOMIC_IOMAP 2917 def_bool y 2918 depends on X86_32 2919 2920source "drivers/firmware/Kconfig" 2921 2922source "arch/x86/kvm/Kconfig" 2923 2924source "arch/x86/Kconfig.assembler" 2925