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 select ARCH_HAS_ELFCORE_COMPAT 36 select ZONE_DMA32 37 38config FORCE_DYNAMIC_FTRACE 39 def_bool y 40 depends on X86_32 41 depends on FUNCTION_TRACER 42 select DYNAMIC_FTRACE 43 help 44 We keep the static function tracing (!DYNAMIC_FTRACE) around 45 in order to test the non static function tracing in the 46 generic code, as other architectures still use it. But we 47 only need to keep it around for x86_64. No need to keep it 48 for x86_32. For x86_32, force DYNAMIC_FTRACE. 49# 50# Arch settings 51# 52# ( Note that options that are marked 'if X86_64' could in principle be 53# ported to 32-bit as well. ) 54# 55config X86 56 def_bool y 57 # 58 # Note: keep this list sorted alphabetically 59 # 60 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 61 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 62 select ARCH_32BIT_OFF_T if X86_32 63 select ARCH_CLOCKSOURCE_INIT 64 select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 65 select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM) 66 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 67 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 68 select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 69 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 70 select ARCH_HAS_CACHE_LINE_SIZE 71 select ARCH_HAS_DEBUG_VIRTUAL 72 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 73 select ARCH_HAS_DEVMEM_IS_ALLOWED 74 select ARCH_HAS_EARLY_DEBUG if KGDB 75 select ARCH_HAS_ELF_RANDOMIZE 76 select ARCH_HAS_FAST_MULTIPLIER 77 select ARCH_HAS_FILTER_PGPROT 78 select ARCH_HAS_FORTIFY_SOURCE 79 select ARCH_HAS_GCOV_PROFILE_ALL 80 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 81 select ARCH_HAS_MEM_ENCRYPT 82 select ARCH_HAS_MEMBARRIER_SYNC_CORE 83 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 84 select ARCH_HAS_PMEM_API if X86_64 85 select ARCH_HAS_PTE_DEVMAP if X86_64 86 select ARCH_HAS_PTE_SPECIAL 87 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 88 select ARCH_HAS_COPY_MC if X86_64 89 select ARCH_HAS_SET_MEMORY 90 select ARCH_HAS_SET_DIRECT_MAP 91 select ARCH_HAS_STRICT_KERNEL_RWX 92 select ARCH_HAS_STRICT_MODULE_RWX 93 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 94 select ARCH_HAS_SYSCALL_WRAPPER 95 select ARCH_HAS_UBSAN_SANITIZE_ALL 96 select ARCH_HAS_DEBUG_WX 97 select ARCH_HAS_ZONE_DMA_SET if EXPERT 98 select ARCH_HAVE_NMI_SAFE_CMPXCHG 99 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 100 select ARCH_MIGHT_HAVE_PC_PARPORT 101 select ARCH_MIGHT_HAVE_PC_SERIO 102 select ARCH_STACKWALK 103 select ARCH_SUPPORTS_ACPI 104 select ARCH_SUPPORTS_ATOMIC_RMW 105 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 106 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 107 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 108 select ARCH_SUPPORTS_LTO_CLANG 109 select ARCH_SUPPORTS_LTO_CLANG_THIN 110 select ARCH_USE_BUILTIN_BSWAP 111 select ARCH_USE_MEMTEST 112 select ARCH_USE_QUEUED_RWLOCKS 113 select ARCH_USE_QUEUED_SPINLOCKS 114 select ARCH_USE_SYM_ANNOTATIONS 115 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 116 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 117 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 118 select ARCH_WANTS_NO_INSTR 119 select ARCH_WANT_HUGE_PMD_SHARE 120 select ARCH_WANT_LD_ORPHAN_WARN 121 select ARCH_WANTS_THP_SWAP if X86_64 122 select BUILDTIME_TABLE_SORT 123 select CLKEVT_I8253 124 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 125 select CLOCKSOURCE_WATCHDOG 126 select DCACHE_WORD_ACCESS 127 select EDAC_ATOMIC_SCRUB 128 select EDAC_SUPPORT 129 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 130 select GENERIC_CLOCKEVENTS_MIN_ADJUST 131 select GENERIC_CMOS_UPDATE 132 select GENERIC_CPU_AUTOPROBE 133 select GENERIC_CPU_VULNERABILITIES 134 select GENERIC_EARLY_IOREMAP 135 select GENERIC_ENTRY 136 select GENERIC_FIND_FIRST_BIT 137 select GENERIC_IOMAP 138 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 139 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 140 select GENERIC_IRQ_MIGRATION if SMP 141 select GENERIC_IRQ_PROBE 142 select GENERIC_IRQ_RESERVATION_MODE 143 select GENERIC_IRQ_SHOW 144 select GENERIC_PENDING_IRQ if SMP 145 select GENERIC_PTDUMP 146 select GENERIC_SMP_IDLE_THREAD 147 select GENERIC_STRNCPY_FROM_USER 148 select GENERIC_STRNLEN_USER 149 select GENERIC_TIME_VSYSCALL 150 select GENERIC_GETTIMEOFDAY 151 select GENERIC_VDSO_TIME_NS 152 select GUP_GET_PTE_LOW_HIGH if X86_PAE 153 select HARDIRQS_SW_RESEND 154 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 155 select HAVE_ACPI_APEI if ACPI 156 select HAVE_ACPI_APEI_NMI if ACPI 157 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 158 select HAVE_ARCH_AUDITSYSCALL 159 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 160 select HAVE_ARCH_JUMP_LABEL 161 select HAVE_ARCH_JUMP_LABEL_RELATIVE 162 select HAVE_ARCH_KASAN if X86_64 163 select HAVE_ARCH_KASAN_VMALLOC if X86_64 164 select HAVE_ARCH_KFENCE 165 select HAVE_ARCH_KGDB 166 select HAVE_ARCH_MMAP_RND_BITS if MMU 167 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 168 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 169 select HAVE_ARCH_PREL32_RELOCATIONS 170 select HAVE_ARCH_SECCOMP_FILTER 171 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 172 select HAVE_ARCH_STACKLEAK 173 select HAVE_ARCH_TRACEHOOK 174 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 175 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 176 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 177 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 178 select HAVE_ARCH_VMAP_STACK if X86_64 179 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 180 select HAVE_ARCH_WITHIN_STACK_FRAMES 181 select HAVE_ASM_MODVERSIONS 182 select HAVE_CMPXCHG_DOUBLE 183 select HAVE_CMPXCHG_LOCAL 184 select HAVE_CONTEXT_TRACKING if X86_64 185 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 186 select HAVE_C_RECORDMCOUNT 187 select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION 188 select HAVE_DEBUG_KMEMLEAK 189 select HAVE_DMA_CONTIGUOUS 190 select HAVE_DYNAMIC_FTRACE 191 select HAVE_DYNAMIC_FTRACE_WITH_REGS 192 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 193 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 194 select HAVE_EBPF_JIT 195 select HAVE_EFFICIENT_UNALIGNED_ACCESS 196 select HAVE_EISA 197 select HAVE_EXIT_THREAD 198 select HAVE_FAST_GUP 199 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 200 select HAVE_FTRACE_MCOUNT_RECORD 201 select HAVE_FUNCTION_GRAPH_TRACER 202 select HAVE_FUNCTION_TRACER 203 select HAVE_GCC_PLUGINS 204 select HAVE_HW_BREAKPOINT 205 select HAVE_IDE 206 select HAVE_IOREMAP_PROT 207 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 208 select HAVE_IRQ_TIME_ACCOUNTING 209 select HAVE_KERNEL_BZIP2 210 select HAVE_KERNEL_GZIP 211 select HAVE_KERNEL_LZ4 212 select HAVE_KERNEL_LZMA 213 select HAVE_KERNEL_LZO 214 select HAVE_KERNEL_XZ 215 select HAVE_KERNEL_ZSTD 216 select HAVE_KPROBES 217 select HAVE_KPROBES_ON_FTRACE 218 select HAVE_FUNCTION_ERROR_INJECTION 219 select HAVE_KRETPROBES 220 select HAVE_KVM 221 select HAVE_LIVEPATCH if X86_64 222 select HAVE_MIXED_BREAKPOINTS_REGS 223 select HAVE_MOD_ARCH_SPECIFIC 224 select HAVE_MOVE_PMD 225 select HAVE_MOVE_PUD 226 select HAVE_NMI 227 select HAVE_OPTPROBES 228 select HAVE_PCSPKR_PLATFORM 229 select HAVE_PERF_EVENTS 230 select HAVE_PERF_EVENTS_NMI 231 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 232 select HAVE_PCI 233 select HAVE_PERF_REGS 234 select HAVE_PERF_USER_STACK_DUMP 235 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 236 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 237 select HAVE_REGS_AND_STACK_ACCESS_API 238 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 239 select HAVE_FUNCTION_ARG_ACCESS_API 240 select HAVE_SOFTIRQ_ON_OWN_STACK 241 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 242 select HAVE_STACK_VALIDATION if X86_64 243 select HAVE_STATIC_CALL 244 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 245 select HAVE_PREEMPT_DYNAMIC 246 select HAVE_RSEQ 247 select HAVE_SYSCALL_TRACEPOINTS 248 select HAVE_UNSTABLE_SCHED_CLOCK 249 select HAVE_USER_RETURN_NOTIFIER 250 select HAVE_GENERIC_VDSO 251 select HOTPLUG_SMT if SMP 252 select IRQ_FORCED_THREADING 253 select NEED_SG_DMA_LENGTH 254 select PCI_DOMAINS if PCI 255 select PCI_LOCKLESS_CONFIG if PCI 256 select PERF_EVENTS 257 select RTC_LIB 258 select RTC_MC146818_LIB 259 select SPARSE_IRQ 260 select SRCU 261 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 262 select SYSCTL_EXCEPTION_TRACE 263 select THREAD_INFO_IN_TASK 264 select USER_STACKTRACE_SUPPORT 265 select VIRT_TO_BUS 266 select HAVE_ARCH_KCSAN if X86_64 267 select X86_FEATURE_NAMES if PROC_FS 268 select PROC_PID_ARCH_STATUS if PROC_FS 269 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 270 271config INSTRUCTION_DECODER 272 def_bool y 273 depends on KPROBES || PERF_EVENTS || UPROBES 274 275config OUTPUT_FORMAT 276 string 277 default "elf32-i386" if X86_32 278 default "elf64-x86-64" if X86_64 279 280config LOCKDEP_SUPPORT 281 def_bool y 282 283config STACKTRACE_SUPPORT 284 def_bool y 285 286config MMU 287 def_bool y 288 289config ARCH_MMAP_RND_BITS_MIN 290 default 28 if 64BIT 291 default 8 292 293config ARCH_MMAP_RND_BITS_MAX 294 default 32 if 64BIT 295 default 16 296 297config ARCH_MMAP_RND_COMPAT_BITS_MIN 298 default 8 299 300config ARCH_MMAP_RND_COMPAT_BITS_MAX 301 default 16 302 303config SBUS 304 bool 305 306config GENERIC_ISA_DMA 307 def_bool y 308 depends on ISA_DMA_API 309 310config GENERIC_BUG 311 def_bool y 312 depends on BUG 313 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 314 315config GENERIC_BUG_RELATIVE_POINTERS 316 bool 317 318config ARCH_MAY_HAVE_PC_FDC 319 def_bool y 320 depends on ISA_DMA_API 321 322config GENERIC_CALIBRATE_DELAY 323 def_bool y 324 325config ARCH_HAS_CPU_RELAX 326 def_bool y 327 328config ARCH_HAS_FILTER_PGPROT 329 def_bool y 330 331config HAVE_SETUP_PER_CPU_AREA 332 def_bool y 333 334config NEED_PER_CPU_EMBED_FIRST_CHUNK 335 def_bool y 336 337config NEED_PER_CPU_PAGE_FIRST_CHUNK 338 def_bool y 339 340config ARCH_HIBERNATION_POSSIBLE 341 def_bool y 342 343config ARCH_SUSPEND_POSSIBLE 344 def_bool y 345 346config ARCH_WANT_GENERAL_HUGETLB 347 def_bool y 348 349config AUDIT_ARCH 350 def_bool y if X86_64 351 352config KASAN_SHADOW_OFFSET 353 hex 354 depends on KASAN 355 default 0xdffffc0000000000 356 357config HAVE_INTEL_TXT 358 def_bool y 359 depends on INTEL_IOMMU && ACPI 360 361config X86_32_SMP 362 def_bool y 363 depends on X86_32 && SMP 364 365config X86_64_SMP 366 def_bool y 367 depends on X86_64 && SMP 368 369config ARCH_SUPPORTS_UPROBES 370 def_bool y 371 372config FIX_EARLYCON_MEM 373 def_bool y 374 375config DYNAMIC_PHYSICAL_MASK 376 bool 377 378config PGTABLE_LEVELS 379 int 380 default 5 if X86_5LEVEL 381 default 4 if X86_64 382 default 3 if X86_PAE 383 default 2 384 385config CC_HAS_SANE_STACKPROTECTOR 386 bool 387 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 388 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 389 help 390 We have to make sure stack protector is unconditionally disabled if 391 the compiler produces broken code or if it does not let us control 392 the segment on 32-bit kernels. 393 394menu "Processor type and features" 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 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 KEXEC_CORE 568 depends on X86_X2APIC 569 depends on PCI 570 help 571 This option is needed in order to support SGI Ultraviolet systems. 572 If you don't have one of these, you should say N here. 573 574# Following is an alphabetically sorted list of 32 bit extended platforms 575# Please maintain the alphabetic order if and when there are additions 576 577config X86_GOLDFISH 578 bool "Goldfish (Virtual Platform)" 579 depends on X86_EXTENDED_PLATFORM 580 help 581 Enable support for the Goldfish virtual platform used primarily 582 for Android development. Unless you are building for the Android 583 Goldfish emulator say N here. 584 585config X86_INTEL_CE 586 bool "CE4100 TV platform" 587 depends on PCI 588 depends on PCI_GODIRECT 589 depends on X86_IO_APIC 590 depends on X86_32 591 depends on X86_EXTENDED_PLATFORM 592 select X86_REBOOTFIXUPS 593 select OF 594 select OF_EARLY_FLATTREE 595 help 596 Select for the Intel CE media processor (CE4100) SOC. 597 This option compiles in support for the CE4100 SOC for settop 598 boxes and media devices. 599 600config X86_INTEL_MID 601 bool "Intel MID platform support" 602 depends on X86_EXTENDED_PLATFORM 603 depends on X86_PLATFORM_DEVICES 604 depends on PCI 605 depends on X86_64 || (PCI_GOANY && X86_32) 606 depends on X86_IO_APIC 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 depends on HAVE_STATIC_CALL 775 help 776 This changes the kernel so it can modify itself when it is run 777 under a hypervisor, potentially improving performance significantly 778 over full virtualization. However, when run without a hypervisor 779 the kernel is theoretically slower and slightly larger. 780 781config PARAVIRT_XXL 782 bool 783 784config PARAVIRT_DEBUG 785 bool "paravirt-ops debugging" 786 depends on PARAVIRT && DEBUG_KERNEL 787 help 788 Enable to debug paravirt_ops internals. Specifically, BUG if 789 a paravirt_op is missing when it is called. 790 791config PARAVIRT_SPINLOCKS 792 bool "Paravirtualization layer for spinlocks" 793 depends on PARAVIRT && SMP 794 help 795 Paravirtualized spinlocks allow a pvops backend to replace the 796 spinlock implementation with something virtualization-friendly 797 (for example, block the virtual CPU rather than spinning). 798 799 It has a minimal impact on native kernels and gives a nice performance 800 benefit on paravirtualized KVM / Xen kernels. 801 802 If you are unsure how to answer this question, answer Y. 803 804config X86_HV_CALLBACK_VECTOR 805 def_bool n 806 807source "arch/x86/xen/Kconfig" 808 809config KVM_GUEST 810 bool "KVM Guest support (including kvmclock)" 811 depends on PARAVIRT 812 select PARAVIRT_CLOCK 813 select ARCH_CPUIDLE_HALTPOLL 814 select X86_HV_CALLBACK_VECTOR 815 default y 816 help 817 This option enables various optimizations for running under the KVM 818 hypervisor. It includes a paravirtualized clock, so that instead 819 of relying on a PIT (or probably other) emulation by the 820 underlying device model, the host provides the guest with 821 timing infrastructure such as time of day, and system time 822 823config ARCH_CPUIDLE_HALTPOLL 824 def_bool n 825 prompt "Disable host haltpoll when loading haltpoll driver" 826 help 827 If virtualized under KVM, disable host haltpoll. 828 829config PVH 830 bool "Support for running PVH guests" 831 help 832 This option enables the PVH entry point for guest virtual machines 833 as specified in the x86/HVM direct boot ABI. 834 835config PARAVIRT_TIME_ACCOUNTING 836 bool "Paravirtual steal time accounting" 837 depends on PARAVIRT 838 help 839 Select this option to enable fine granularity task steal time 840 accounting. Time spent executing other tasks in parallel with 841 the current vCPU is discounted from the vCPU power. To account for 842 that, there can be a small performance impact. 843 844 If in doubt, say N here. 845 846config PARAVIRT_CLOCK 847 bool 848 849config JAILHOUSE_GUEST 850 bool "Jailhouse non-root cell support" 851 depends on X86_64 && PCI 852 select X86_PM_TIMER 853 help 854 This option allows to run Linux as guest in a Jailhouse non-root 855 cell. You can leave this option disabled if you only want to start 856 Jailhouse and run Linux afterwards in the root cell. 857 858config ACRN_GUEST 859 bool "ACRN Guest support" 860 depends on X86_64 861 select X86_HV_CALLBACK_VECTOR 862 help 863 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 864 a flexible, lightweight reference open-source hypervisor, built with 865 real-time and safety-criticality in mind. It is built for embedded 866 IOT with small footprint and real-time features. More details can be 867 found in https://projectacrn.org/. 868 869endif #HYPERVISOR_GUEST 870 871source "arch/x86/Kconfig.cpu" 872 873config HPET_TIMER 874 def_bool X86_64 875 prompt "HPET Timer Support" if X86_32 876 help 877 Use the IA-PC HPET (High Precision Event Timer) to manage 878 time in preference to the PIT and RTC, if a HPET is 879 present. 880 HPET is the next generation timer replacing legacy 8254s. 881 The HPET provides a stable time base on SMP 882 systems, unlike the TSC, but it is more expensive to access, 883 as it is off-chip. The interface used is documented 884 in the HPET spec, revision 1. 885 886 You can safely choose Y here. However, HPET will only be 887 activated if the platform and the BIOS support this feature. 888 Otherwise the 8254 will be used for timing services. 889 890 Choose N to continue using the legacy 8254 timer. 891 892config HPET_EMULATE_RTC 893 def_bool y 894 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 895 896# Mark as expert because too many people got it wrong. 897# The code disables itself when not needed. 898config DMI 899 default y 900 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 901 bool "Enable DMI scanning" if EXPERT 902 help 903 Enabled scanning of DMI to identify machine quirks. Say Y 904 here unless you have verified that your setup is not 905 affected by entries in the DMI blacklist. Required by PNP 906 BIOS code. 907 908config GART_IOMMU 909 bool "Old AMD GART IOMMU support" 910 select DMA_OPS 911 select IOMMU_HELPER 912 select SWIOTLB 913 depends on X86_64 && PCI && AMD_NB 914 help 915 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 916 GART based hardware IOMMUs. 917 918 The GART supports full DMA access for devices with 32-bit access 919 limitations, on systems with more than 3 GB. This is usually needed 920 for USB, sound, many IDE/SATA chipsets and some other devices. 921 922 Newer systems typically have a modern AMD IOMMU, supported via 923 the CONFIG_AMD_IOMMU=y config option. 924 925 In normal configurations this driver is only active when needed: 926 there's more than 3 GB of memory and the system contains a 927 32-bit limited device. 928 929 If unsure, say Y. 930 931config MAXSMP 932 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 933 depends on X86_64 && SMP && DEBUG_KERNEL 934 select CPUMASK_OFFSTACK 935 help 936 Enable maximum number of CPUS and NUMA Nodes for this architecture. 937 If unsure, say N. 938 939# 940# The maximum number of CPUs supported: 941# 942# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 943# and which can be configured interactively in the 944# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 945# 946# The ranges are different on 32-bit and 64-bit kernels, depending on 947# hardware capabilities and scalability features of the kernel. 948# 949# ( If MAXSMP is enabled we just use the highest possible value and disable 950# interactive configuration. ) 951# 952 953config NR_CPUS_RANGE_BEGIN 954 int 955 default NR_CPUS_RANGE_END if MAXSMP 956 default 1 if !SMP 957 default 2 958 959config NR_CPUS_RANGE_END 960 int 961 depends on X86_32 962 default 64 if SMP && X86_BIGSMP 963 default 8 if SMP && !X86_BIGSMP 964 default 1 if !SMP 965 966config NR_CPUS_RANGE_END 967 int 968 depends on X86_64 969 default 8192 if SMP && CPUMASK_OFFSTACK 970 default 512 if SMP && !CPUMASK_OFFSTACK 971 default 1 if !SMP 972 973config NR_CPUS_DEFAULT 974 int 975 depends on X86_32 976 default 32 if X86_BIGSMP 977 default 8 if SMP 978 default 1 if !SMP 979 980config NR_CPUS_DEFAULT 981 int 982 depends on X86_64 983 default 8192 if MAXSMP 984 default 64 if SMP 985 default 1 if !SMP 986 987config NR_CPUS 988 int "Maximum number of CPUs" if SMP && !MAXSMP 989 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 990 default NR_CPUS_DEFAULT 991 help 992 This allows you to specify the maximum number of CPUs which this 993 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 994 supported value is 8192, otherwise the maximum value is 512. The 995 minimum value which makes sense is 2. 996 997 This is purely to save memory: each supported CPU adds about 8KB 998 to the kernel image. 999 1000config SCHED_SMT 1001 def_bool y if SMP 1002 1003config SCHED_MC 1004 def_bool y 1005 prompt "Multi-core scheduler support" 1006 depends on SMP 1007 help 1008 Multi-core scheduler support improves the CPU scheduler's decision 1009 making when dealing with multi-core CPU chips at a cost of slightly 1010 increased overhead in some places. If unsure say N here. 1011 1012config SCHED_MC_PRIO 1013 bool "CPU core priorities scheduler support" 1014 depends on SCHED_MC && CPU_SUP_INTEL 1015 select X86_INTEL_PSTATE 1016 select CPU_FREQ 1017 default y 1018 help 1019 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1020 core ordering determined at manufacturing time, which allows 1021 certain cores to reach higher turbo frequencies (when running 1022 single threaded workloads) than others. 1023 1024 Enabling this kernel feature teaches the scheduler about 1025 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1026 scheduler's CPU selection logic accordingly, so that higher 1027 overall system performance can be achieved. 1028 1029 This feature will have no effect on CPUs without this feature. 1030 1031 If unsure say Y here. 1032 1033config UP_LATE_INIT 1034 def_bool y 1035 depends on !SMP && X86_LOCAL_APIC 1036 1037config X86_UP_APIC 1038 bool "Local APIC support on uniprocessors" if !PCI_MSI 1039 default PCI_MSI 1040 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1041 help 1042 A local APIC (Advanced Programmable Interrupt Controller) is an 1043 integrated interrupt controller in the CPU. If you have a single-CPU 1044 system which has a processor with a local APIC, you can say Y here to 1045 enable and use it. If you say Y here even though your machine doesn't 1046 have a local APIC, then the kernel will still run with no slowdown at 1047 all. The local APIC supports CPU-generated self-interrupts (timer, 1048 performance counters), and the NMI watchdog which detects hard 1049 lockups. 1050 1051config X86_UP_IOAPIC 1052 bool "IO-APIC support on uniprocessors" 1053 depends on X86_UP_APIC 1054 help 1055 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1056 SMP-capable replacement for PC-style interrupt controllers. Most 1057 SMP systems and many recent uniprocessor systems have one. 1058 1059 If you have a single-CPU system with an IO-APIC, you can say Y here 1060 to use it. If you say Y here even though your machine doesn't have 1061 an IO-APIC, then the kernel will still run with no slowdown at all. 1062 1063config X86_LOCAL_APIC 1064 def_bool y 1065 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1066 select IRQ_DOMAIN_HIERARCHY 1067 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1068 1069config X86_IO_APIC 1070 def_bool y 1071 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1072 1073config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1074 bool "Reroute for broken boot IRQs" 1075 depends on X86_IO_APIC 1076 help 1077 This option enables a workaround that fixes a source of 1078 spurious interrupts. This is recommended when threaded 1079 interrupt handling is used on systems where the generation of 1080 superfluous "boot interrupts" cannot be disabled. 1081 1082 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1083 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1084 kernel does during interrupt handling). On chipsets where this 1085 boot IRQ generation cannot be disabled, this workaround keeps 1086 the original IRQ line masked so that only the equivalent "boot 1087 IRQ" is delivered to the CPUs. The workaround also tells the 1088 kernel to set up the IRQ handler on the boot IRQ line. In this 1089 way only one interrupt is delivered to the kernel. Otherwise 1090 the spurious second interrupt may cause the kernel to bring 1091 down (vital) interrupt lines. 1092 1093 Only affects "broken" chipsets. Interrupt sharing may be 1094 increased on these systems. 1095 1096config X86_MCE 1097 bool "Machine Check / overheating reporting" 1098 select GENERIC_ALLOCATOR 1099 default y 1100 help 1101 Machine Check support allows the processor to notify the 1102 kernel if it detects a problem (e.g. overheating, data corruption). 1103 The action the kernel takes depends on the severity of the problem, 1104 ranging from warning messages to halting the machine. 1105 1106config X86_MCELOG_LEGACY 1107 bool "Support for deprecated /dev/mcelog character device" 1108 depends on X86_MCE 1109 help 1110 Enable support for /dev/mcelog which is needed by the old mcelog 1111 userspace logging daemon. Consider switching to the new generation 1112 rasdaemon solution. 1113 1114config X86_MCE_INTEL 1115 def_bool y 1116 prompt "Intel MCE features" 1117 depends on X86_MCE && X86_LOCAL_APIC 1118 help 1119 Additional support for intel specific MCE features such as 1120 the thermal monitor. 1121 1122config X86_MCE_AMD 1123 def_bool y 1124 prompt "AMD MCE features" 1125 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1126 help 1127 Additional support for AMD specific MCE features such as 1128 the DRAM Error Threshold. 1129 1130config X86_ANCIENT_MCE 1131 bool "Support for old Pentium 5 / WinChip machine checks" 1132 depends on X86_32 && X86_MCE 1133 help 1134 Include support for machine check handling on old Pentium 5 or WinChip 1135 systems. These typically need to be enabled explicitly on the command 1136 line. 1137 1138config X86_MCE_THRESHOLD 1139 depends on X86_MCE_AMD || X86_MCE_INTEL 1140 def_bool y 1141 1142config X86_MCE_INJECT 1143 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1144 tristate "Machine check injector support" 1145 help 1146 Provide support for injecting machine checks for testing purposes. 1147 If you don't know what a machine check is and you don't do kernel 1148 QA it is safe to say n. 1149 1150source "arch/x86/events/Kconfig" 1151 1152config X86_LEGACY_VM86 1153 bool "Legacy VM86 support" 1154 depends on X86_32 1155 help 1156 This option allows user programs to put the CPU into V8086 1157 mode, which is an 80286-era approximation of 16-bit real mode. 1158 1159 Some very old versions of X and/or vbetool require this option 1160 for user mode setting. Similarly, DOSEMU will use it if 1161 available to accelerate real mode DOS programs. However, any 1162 recent version of DOSEMU, X, or vbetool should be fully 1163 functional even without kernel VM86 support, as they will all 1164 fall back to software emulation. Nevertheless, if you are using 1165 a 16-bit DOS program where 16-bit performance matters, vm86 1166 mode might be faster than emulation and you might want to 1167 enable this option. 1168 1169 Note that any app that works on a 64-bit kernel is unlikely to 1170 need this option, as 64-bit kernels don't, and can't, support 1171 V8086 mode. This option is also unrelated to 16-bit protected 1172 mode and is not needed to run most 16-bit programs under Wine. 1173 1174 Enabling this option increases the complexity of the kernel 1175 and slows down exception handling a tiny bit. 1176 1177 If unsure, say N here. 1178 1179config VM86 1180 bool 1181 default X86_LEGACY_VM86 1182 1183config X86_16BIT 1184 bool "Enable support for 16-bit segments" if EXPERT 1185 default y 1186 depends on MODIFY_LDT_SYSCALL 1187 help 1188 This option is required by programs like Wine to run 16-bit 1189 protected mode legacy code on x86 processors. Disabling 1190 this option saves about 300 bytes on i386, or around 6K text 1191 plus 16K runtime memory on x86-64, 1192 1193config X86_ESPFIX32 1194 def_bool y 1195 depends on X86_16BIT && X86_32 1196 1197config X86_ESPFIX64 1198 def_bool y 1199 depends on X86_16BIT && X86_64 1200 1201config X86_VSYSCALL_EMULATION 1202 bool "Enable vsyscall emulation" if EXPERT 1203 default y 1204 depends on X86_64 1205 help 1206 This enables emulation of the legacy vsyscall page. Disabling 1207 it is roughly equivalent to booting with vsyscall=none, except 1208 that it will also disable the helpful warning if a program 1209 tries to use a vsyscall. With this option set to N, offending 1210 programs will just segfault, citing addresses of the form 1211 0xffffffffff600?00. 1212 1213 This option is required by many programs built before 2013, and 1214 care should be used even with newer programs if set to N. 1215 1216 Disabling this option saves about 7K of kernel size and 1217 possibly 4K of additional runtime pagetable memory. 1218 1219config X86_IOPL_IOPERM 1220 bool "IOPERM and IOPL Emulation" 1221 default y 1222 help 1223 This enables the ioperm() and iopl() syscalls which are necessary 1224 for legacy applications. 1225 1226 Legacy IOPL support is an overbroad mechanism which allows user 1227 space aside of accessing all 65536 I/O ports also to disable 1228 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1229 capabilities and permission from potentially active security 1230 modules. 1231 1232 The emulation restricts the functionality of the syscall to 1233 only allowing the full range I/O port access, but prevents the 1234 ability to disable interrupts from user space which would be 1235 granted if the hardware IOPL mechanism would be used. 1236 1237config TOSHIBA 1238 tristate "Toshiba Laptop support" 1239 depends on X86_32 1240 help 1241 This adds a driver to safely access the System Management Mode of 1242 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1243 not work on models with a Phoenix BIOS. The System Management Mode 1244 is used to set the BIOS and power saving options on Toshiba portables. 1245 1246 For information on utilities to make use of this driver see the 1247 Toshiba Linux utilities web site at: 1248 <http://www.buzzard.org.uk/toshiba/>. 1249 1250 Say Y if you intend to run this kernel on a Toshiba portable. 1251 Say N otherwise. 1252 1253config I8K 1254 tristate "Dell i8k legacy laptop support" 1255 select HWMON 1256 select SENSORS_DELL_SMM 1257 help 1258 This option enables legacy /proc/i8k userspace interface in hwmon 1259 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1260 temperature and allows controlling fan speeds of Dell laptops via 1261 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1262 it reports also power and hotkey status. For fan speed control is 1263 needed userspace package i8kutils. 1264 1265 Say Y if you intend to run this kernel on old Dell laptops or want to 1266 use userspace package i8kutils. 1267 Say N otherwise. 1268 1269config X86_REBOOTFIXUPS 1270 bool "Enable X86 board specific fixups for reboot" 1271 depends on X86_32 1272 help 1273 This enables chipset and/or board specific fixups to be done 1274 in order to get reboot to work correctly. This is only needed on 1275 some combinations of hardware and BIOS. The symptom, for which 1276 this config is intended, is when reboot ends with a stalled/hung 1277 system. 1278 1279 Currently, the only fixup is for the Geode machines using 1280 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1281 1282 Say Y if you want to enable the fixup. Currently, it's safe to 1283 enable this option even if you don't need it. 1284 Say N otherwise. 1285 1286config MICROCODE 1287 bool "CPU microcode loading support" 1288 default y 1289 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1290 help 1291 If you say Y here, you will be able to update the microcode on 1292 Intel and AMD processors. The Intel support is for the IA32 family, 1293 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1294 AMD support is for families 0x10 and later. You will obviously need 1295 the actual microcode binary data itself which is not shipped with 1296 the Linux kernel. 1297 1298 The preferred method to load microcode from a detached initrd is described 1299 in Documentation/x86/microcode.rst. For that you need to enable 1300 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1301 initrd for microcode blobs. 1302 1303 In addition, you can build the microcode into the kernel. For that you 1304 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1305 config option. 1306 1307config MICROCODE_INTEL 1308 bool "Intel microcode loading support" 1309 depends on MICROCODE 1310 default MICROCODE 1311 help 1312 This options enables microcode patch loading support for Intel 1313 processors. 1314 1315 For the current Intel microcode data package go to 1316 <https://downloadcenter.intel.com> and search for 1317 'Linux Processor Microcode Data File'. 1318 1319config MICROCODE_AMD 1320 bool "AMD microcode loading support" 1321 depends on MICROCODE 1322 help 1323 If you select this option, microcode patch loading support for AMD 1324 processors will be enabled. 1325 1326config MICROCODE_OLD_INTERFACE 1327 bool "Ancient loading interface (DEPRECATED)" 1328 default n 1329 depends on MICROCODE 1330 help 1331 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1332 which was used by userspace tools like iucode_tool and microcode.ctl. 1333 It is inadequate because it runs too late to be able to properly 1334 load microcode on a machine and it needs special tools. Instead, you 1335 should've switched to the early loading method with the initrd or 1336 builtin microcode by now: Documentation/x86/microcode.rst 1337 1338config X86_MSR 1339 tristate "/dev/cpu/*/msr - Model-specific register support" 1340 help 1341 This device gives privileged processes access to the x86 1342 Model-Specific Registers (MSRs). It is a character device with 1343 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1344 MSR accesses are directed to a specific CPU on multi-processor 1345 systems. 1346 1347config X86_CPUID 1348 tristate "/dev/cpu/*/cpuid - CPU information support" 1349 help 1350 This device gives processes access to the x86 CPUID instruction to 1351 be executed on a specific processor. It is a character device 1352 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1353 /dev/cpu/31/cpuid. 1354 1355choice 1356 prompt "High Memory Support" 1357 default HIGHMEM4G 1358 depends on X86_32 1359 1360config NOHIGHMEM 1361 bool "off" 1362 help 1363 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1364 However, the address space of 32-bit x86 processors is only 4 1365 Gigabytes large. That means that, if you have a large amount of 1366 physical memory, not all of it can be "permanently mapped" by the 1367 kernel. The physical memory that's not permanently mapped is called 1368 "high memory". 1369 1370 If you are compiling a kernel which will never run on a machine with 1371 more than 1 Gigabyte total physical RAM, answer "off" here (default 1372 choice and suitable for most users). This will result in a "3GB/1GB" 1373 split: 3GB are mapped so that each process sees a 3GB virtual memory 1374 space and the remaining part of the 4GB virtual memory space is used 1375 by the kernel to permanently map as much physical memory as 1376 possible. 1377 1378 If the machine has between 1 and 4 Gigabytes physical RAM, then 1379 answer "4GB" here. 1380 1381 If more than 4 Gigabytes is used then answer "64GB" here. This 1382 selection turns Intel PAE (Physical Address Extension) mode on. 1383 PAE implements 3-level paging on IA32 processors. PAE is fully 1384 supported by Linux, PAE mode is implemented on all recent Intel 1385 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1386 then the kernel will not boot on CPUs that don't support PAE! 1387 1388 The actual amount of total physical memory will either be 1389 auto detected or can be forced by using a kernel command line option 1390 such as "mem=256M". (Try "man bootparam" or see the documentation of 1391 your boot loader (lilo or loadlin) about how to pass options to the 1392 kernel at boot time.) 1393 1394 If unsure, say "off". 1395 1396config HIGHMEM4G 1397 bool "4GB" 1398 help 1399 Select this if you have a 32-bit processor and between 1 and 4 1400 gigabytes of physical RAM. 1401 1402config HIGHMEM64G 1403 bool "64GB" 1404 depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1405 select X86_PAE 1406 help 1407 Select this if you have a 32-bit processor and more than 4 1408 gigabytes of physical RAM. 1409 1410endchoice 1411 1412choice 1413 prompt "Memory split" if EXPERT 1414 default VMSPLIT_3G 1415 depends on X86_32 1416 help 1417 Select the desired split between kernel and user memory. 1418 1419 If the address range available to the kernel is less than the 1420 physical memory installed, the remaining memory will be available 1421 as "high memory". Accessing high memory is a little more costly 1422 than low memory, as it needs to be mapped into the kernel first. 1423 Note that increasing the kernel address space limits the range 1424 available to user programs, making the address space there 1425 tighter. Selecting anything other than the default 3G/1G split 1426 will also likely make your kernel incompatible with binary-only 1427 kernel modules. 1428 1429 If you are not absolutely sure what you are doing, leave this 1430 option alone! 1431 1432 config VMSPLIT_3G 1433 bool "3G/1G user/kernel split" 1434 config VMSPLIT_3G_OPT 1435 depends on !X86_PAE 1436 bool "3G/1G user/kernel split (for full 1G low memory)" 1437 config VMSPLIT_2G 1438 bool "2G/2G user/kernel split" 1439 config VMSPLIT_2G_OPT 1440 depends on !X86_PAE 1441 bool "2G/2G user/kernel split (for full 2G low memory)" 1442 config VMSPLIT_1G 1443 bool "1G/3G user/kernel split" 1444endchoice 1445 1446config PAGE_OFFSET 1447 hex 1448 default 0xB0000000 if VMSPLIT_3G_OPT 1449 default 0x80000000 if VMSPLIT_2G 1450 default 0x78000000 if VMSPLIT_2G_OPT 1451 default 0x40000000 if VMSPLIT_1G 1452 default 0xC0000000 1453 depends on X86_32 1454 1455config HIGHMEM 1456 def_bool y 1457 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1458 1459config X86_PAE 1460 bool "PAE (Physical Address Extension) Support" 1461 depends on X86_32 && !HIGHMEM4G 1462 select PHYS_ADDR_T_64BIT 1463 select SWIOTLB 1464 help 1465 PAE is required for NX support, and furthermore enables 1466 larger swapspace support for non-overcommit purposes. It 1467 has the cost of more pagetable lookup overhead, and also 1468 consumes more pagetable space per process. 1469 1470config X86_5LEVEL 1471 bool "Enable 5-level page tables support" 1472 default y 1473 select DYNAMIC_MEMORY_LAYOUT 1474 select SPARSEMEM_VMEMMAP 1475 depends on X86_64 1476 help 1477 5-level paging enables access to larger address space: 1478 upto 128 PiB of virtual address space and 4 PiB of 1479 physical address space. 1480 1481 It will be supported by future Intel CPUs. 1482 1483 A kernel with the option enabled can be booted on machines that 1484 support 4- or 5-level paging. 1485 1486 See Documentation/x86/x86_64/5level-paging.rst for more 1487 information. 1488 1489 Say N if unsure. 1490 1491config X86_DIRECT_GBPAGES 1492 def_bool y 1493 depends on X86_64 1494 help 1495 Certain kernel features effectively disable kernel 1496 linear 1 GB mappings (even if the CPU otherwise 1497 supports them), so don't confuse the user by printing 1498 that we have them enabled. 1499 1500config X86_CPA_STATISTICS 1501 bool "Enable statistic for Change Page Attribute" 1502 depends on DEBUG_FS 1503 help 1504 Expose statistics about the Change Page Attribute mechanism, which 1505 helps to determine the effectiveness of preserving large and huge 1506 page mappings when mapping protections are changed. 1507 1508config AMD_MEM_ENCRYPT 1509 bool "AMD Secure Memory Encryption (SME) support" 1510 depends on X86_64 && CPU_SUP_AMD 1511 select DMA_COHERENT_POOL 1512 select DYNAMIC_PHYSICAL_MASK 1513 select ARCH_USE_MEMREMAP_PROT 1514 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1515 select INSTRUCTION_DECODER 1516 select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 1517 help 1518 Say yes to enable support for the encryption of system memory. 1519 This requires an AMD processor that supports Secure Memory 1520 Encryption (SME). 1521 1522config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1523 bool "Activate AMD Secure Memory Encryption (SME) by default" 1524 default y 1525 depends on AMD_MEM_ENCRYPT 1526 help 1527 Say yes to have system memory encrypted by default if running on 1528 an AMD processor that supports Secure Memory Encryption (SME). 1529 1530 If set to Y, then the encryption of system memory can be 1531 deactivated with the mem_encrypt=off command line option. 1532 1533 If set to N, then the encryption of system memory can be 1534 activated with the mem_encrypt=on command line option. 1535 1536# Common NUMA Features 1537config NUMA 1538 bool "NUMA Memory Allocation and Scheduler Support" 1539 depends on SMP 1540 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1541 default y if X86_BIGSMP 1542 help 1543 Enable NUMA (Non-Uniform Memory Access) support. 1544 1545 The kernel will try to allocate memory used by a CPU on the 1546 local memory controller of the CPU and add some more 1547 NUMA awareness to the kernel. 1548 1549 For 64-bit this is recommended if the system is Intel Core i7 1550 (or later), AMD Opteron, or EM64T NUMA. 1551 1552 For 32-bit this is only needed if you boot a 32-bit 1553 kernel on a 64-bit NUMA platform. 1554 1555 Otherwise, you should say N. 1556 1557config AMD_NUMA 1558 def_bool y 1559 prompt "Old style AMD Opteron NUMA detection" 1560 depends on X86_64 && NUMA && PCI 1561 help 1562 Enable AMD NUMA node topology detection. You should say Y here if 1563 you have a multi processor AMD system. This uses an old method to 1564 read the NUMA configuration directly from the builtin Northbridge 1565 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1566 which also takes priority if both are compiled in. 1567 1568config X86_64_ACPI_NUMA 1569 def_bool y 1570 prompt "ACPI NUMA detection" 1571 depends on X86_64 && NUMA && ACPI && PCI 1572 select ACPI_NUMA 1573 help 1574 Enable ACPI SRAT based node topology detection. 1575 1576config NUMA_EMU 1577 bool "NUMA emulation" 1578 depends on NUMA 1579 help 1580 Enable NUMA emulation. A flat machine will be split 1581 into virtual nodes when booted with "numa=fake=N", where N is the 1582 number of nodes. This is only useful for debugging. 1583 1584config NODES_SHIFT 1585 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1586 range 1 10 1587 default "10" if MAXSMP 1588 default "6" if X86_64 1589 default "3" 1590 depends on NUMA 1591 help 1592 Specify the maximum number of NUMA Nodes available on the target 1593 system. Increases memory reserved to accommodate various tables. 1594 1595config ARCH_FLATMEM_ENABLE 1596 def_bool y 1597 depends on X86_32 && !NUMA 1598 1599config ARCH_SPARSEMEM_ENABLE 1600 def_bool y 1601 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1602 select SPARSEMEM_STATIC if X86_32 1603 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1604 1605config ARCH_SPARSEMEM_DEFAULT 1606 def_bool X86_64 || (NUMA && X86_32) 1607 1608config ARCH_SELECT_MEMORY_MODEL 1609 def_bool y 1610 depends on ARCH_SPARSEMEM_ENABLE 1611 1612config ARCH_MEMORY_PROBE 1613 bool "Enable sysfs memory/probe interface" 1614 depends on X86_64 && MEMORY_HOTPLUG 1615 help 1616 This option enables a sysfs memory/probe interface for testing. 1617 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1618 If you are unsure how to answer this question, answer N. 1619 1620config ARCH_PROC_KCORE_TEXT 1621 def_bool y 1622 depends on X86_64 && PROC_KCORE 1623 1624config ILLEGAL_POINTER_VALUE 1625 hex 1626 default 0 if X86_32 1627 default 0xdead000000000000 if X86_64 1628 1629config X86_PMEM_LEGACY_DEVICE 1630 bool 1631 1632config X86_PMEM_LEGACY 1633 tristate "Support non-standard NVDIMMs and ADR protected memory" 1634 depends on PHYS_ADDR_T_64BIT 1635 depends on BLK_DEV 1636 select X86_PMEM_LEGACY_DEVICE 1637 select NUMA_KEEP_MEMINFO if NUMA 1638 select LIBNVDIMM 1639 help 1640 Treat memory marked using the non-standard e820 type of 12 as used 1641 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1642 The kernel will offer these regions to the 'pmem' driver so 1643 they can be used for persistent storage. 1644 1645 Say Y if unsure. 1646 1647config HIGHPTE 1648 bool "Allocate 3rd-level pagetables from highmem" 1649 depends on HIGHMEM 1650 help 1651 The VM uses one page table entry for each page of physical memory. 1652 For systems with a lot of RAM, this can be wasteful of precious 1653 low memory. Setting this option will put user-space page table 1654 entries in high memory. 1655 1656config X86_CHECK_BIOS_CORRUPTION 1657 bool "Check for low memory corruption" 1658 help 1659 Periodically check for memory corruption in low memory, which 1660 is suspected to be caused by BIOS. Even when enabled in the 1661 configuration, it is disabled at runtime. Enable it by 1662 setting "memory_corruption_check=1" on the kernel command 1663 line. By default it scans the low 64k of memory every 60 1664 seconds; see the memory_corruption_check_size and 1665 memory_corruption_check_period parameters in 1666 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1667 1668 When enabled with the default parameters, this option has 1669 almost no overhead, as it reserves a relatively small amount 1670 of memory and scans it infrequently. It both detects corruption 1671 and prevents it from affecting the running system. 1672 1673 It is, however, intended as a diagnostic tool; if repeatable 1674 BIOS-originated corruption always affects the same memory, 1675 you can use memmap= to prevent the kernel from using that 1676 memory. 1677 1678config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1679 bool "Set the default setting of memory_corruption_check" 1680 depends on X86_CHECK_BIOS_CORRUPTION 1681 default y 1682 help 1683 Set whether the default state of memory_corruption_check is 1684 on or off. 1685 1686config MATH_EMULATION 1687 bool 1688 depends on MODIFY_LDT_SYSCALL 1689 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1690 help 1691 Linux can emulate a math coprocessor (used for floating point 1692 operations) if you don't have one. 486DX and Pentium processors have 1693 a math coprocessor built in, 486SX and 386 do not, unless you added 1694 a 487DX or 387, respectively. (The messages during boot time can 1695 give you some hints here ["man dmesg"].) Everyone needs either a 1696 coprocessor or this emulation. 1697 1698 If you don't have a math coprocessor, you need to say Y here; if you 1699 say Y here even though you have a coprocessor, the coprocessor will 1700 be used nevertheless. (This behavior can be changed with the kernel 1701 command line option "no387", which comes handy if your coprocessor 1702 is broken. Try "man bootparam" or see the documentation of your boot 1703 loader (lilo or loadlin) about how to pass options to the kernel at 1704 boot time.) This means that it is a good idea to say Y here if you 1705 intend to use this kernel on different machines. 1706 1707 More information about the internals of the Linux math coprocessor 1708 emulation can be found in <file:arch/x86/math-emu/README>. 1709 1710 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1711 kernel, it won't hurt. 1712 1713config MTRR 1714 def_bool y 1715 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1716 help 1717 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1718 the Memory Type Range Registers (MTRRs) may be used to control 1719 processor access to memory ranges. This is most useful if you have 1720 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1721 allows bus write transfers to be combined into a larger transfer 1722 before bursting over the PCI/AGP bus. This can increase performance 1723 of image write operations 2.5 times or more. Saying Y here creates a 1724 /proc/mtrr file which may be used to manipulate your processor's 1725 MTRRs. Typically the X server should use this. 1726 1727 This code has a reasonably generic interface so that similar 1728 control registers on other processors can be easily supported 1729 as well: 1730 1731 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1732 Registers (ARRs) which provide a similar functionality to MTRRs. For 1733 these, the ARRs are used to emulate the MTRRs. 1734 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1735 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1736 write-combining. All of these processors are supported by this code 1737 and it makes sense to say Y here if you have one of them. 1738 1739 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1740 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1741 can lead to all sorts of problems, so it's good to say Y here. 1742 1743 You can safely say Y even if your machine doesn't have MTRRs, you'll 1744 just add about 9 KB to your kernel. 1745 1746 See <file:Documentation/x86/mtrr.rst> for more information. 1747 1748config MTRR_SANITIZER 1749 def_bool y 1750 prompt "MTRR cleanup support" 1751 depends on MTRR 1752 help 1753 Convert MTRR layout from continuous to discrete, so X drivers can 1754 add writeback entries. 1755 1756 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1757 The largest mtrr entry size for a continuous block can be set with 1758 mtrr_chunk_size. 1759 1760 If unsure, say Y. 1761 1762config MTRR_SANITIZER_ENABLE_DEFAULT 1763 int "MTRR cleanup enable value (0-1)" 1764 range 0 1 1765 default "0" 1766 depends on MTRR_SANITIZER 1767 help 1768 Enable mtrr cleanup default value 1769 1770config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1771 int "MTRR cleanup spare reg num (0-7)" 1772 range 0 7 1773 default "1" 1774 depends on MTRR_SANITIZER 1775 help 1776 mtrr cleanup spare entries default, it can be changed via 1777 mtrr_spare_reg_nr=N on the kernel command line. 1778 1779config X86_PAT 1780 def_bool y 1781 prompt "x86 PAT support" if EXPERT 1782 depends on MTRR 1783 help 1784 Use PAT attributes to setup page level cache control. 1785 1786 PATs are the modern equivalents of MTRRs and are much more 1787 flexible than MTRRs. 1788 1789 Say N here if you see bootup problems (boot crash, boot hang, 1790 spontaneous reboots) or a non-working video driver. 1791 1792 If unsure, say Y. 1793 1794config ARCH_USES_PG_UNCACHED 1795 def_bool y 1796 depends on X86_PAT 1797 1798config ARCH_RANDOM 1799 def_bool y 1800 prompt "x86 architectural random number generator" if EXPERT 1801 help 1802 Enable the x86 architectural RDRAND instruction 1803 (Intel Bull Mountain technology) to generate random numbers. 1804 If supported, this is a high bandwidth, cryptographically 1805 secure hardware random number generator. 1806 1807config X86_SMAP 1808 def_bool y 1809 prompt "Supervisor Mode Access Prevention" if EXPERT 1810 help 1811 Supervisor Mode Access Prevention (SMAP) is a security 1812 feature in newer Intel processors. There is a small 1813 performance cost if this enabled and turned on; there is 1814 also a small increase in the kernel size if this is enabled. 1815 1816 If unsure, say Y. 1817 1818config X86_UMIP 1819 def_bool y 1820 prompt "User Mode Instruction Prevention" if EXPERT 1821 help 1822 User Mode Instruction Prevention (UMIP) is a security feature in 1823 some x86 processors. If enabled, a general protection fault is 1824 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1825 executed in user mode. These instructions unnecessarily expose 1826 information about the hardware state. 1827 1828 The vast majority of applications do not use these instructions. 1829 For the very few that do, software emulation is provided in 1830 specific cases in protected and virtual-8086 modes. Emulated 1831 results are dummy. 1832 1833config X86_INTEL_MEMORY_PROTECTION_KEYS 1834 prompt "Memory Protection Keys" 1835 def_bool y 1836 # Note: only available in 64-bit mode 1837 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1838 select ARCH_USES_HIGH_VMA_FLAGS 1839 select ARCH_HAS_PKEYS 1840 help 1841 Memory Protection Keys provides a mechanism for enforcing 1842 page-based protections, but without requiring modification of the 1843 page tables when an application changes protection domains. 1844 1845 For details, see Documentation/core-api/protection-keys.rst 1846 1847 If unsure, say y. 1848 1849choice 1850 prompt "TSX enable mode" 1851 depends on CPU_SUP_INTEL 1852 default X86_INTEL_TSX_MODE_OFF 1853 help 1854 Intel's TSX (Transactional Synchronization Extensions) feature 1855 allows to optimize locking protocols through lock elision which 1856 can lead to a noticeable performance boost. 1857 1858 On the other hand it has been shown that TSX can be exploited 1859 to form side channel attacks (e.g. TAA) and chances are there 1860 will be more of those attacks discovered in the future. 1861 1862 Therefore TSX is not enabled by default (aka tsx=off). An admin 1863 might override this decision by tsx=on the command line parameter. 1864 Even with TSX enabled, the kernel will attempt to enable the best 1865 possible TAA mitigation setting depending on the microcode available 1866 for the particular machine. 1867 1868 This option allows to set the default tsx mode between tsx=on, =off 1869 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1870 details. 1871 1872 Say off if not sure, auto if TSX is in use but it should be used on safe 1873 platforms or on if TSX is in use and the security aspect of tsx is not 1874 relevant. 1875 1876config X86_INTEL_TSX_MODE_OFF 1877 bool "off" 1878 help 1879 TSX is disabled if possible - equals to tsx=off command line parameter. 1880 1881config X86_INTEL_TSX_MODE_ON 1882 bool "on" 1883 help 1884 TSX is always enabled on TSX capable HW - equals the tsx=on command 1885 line parameter. 1886 1887config X86_INTEL_TSX_MODE_AUTO 1888 bool "auto" 1889 help 1890 TSX is enabled on TSX capable HW that is believed to be safe against 1891 side channel attacks- equals the tsx=auto command line parameter. 1892endchoice 1893 1894config X86_SGX 1895 bool "Software Guard eXtensions (SGX)" 1896 depends on X86_64 && CPU_SUP_INTEL 1897 depends on CRYPTO=y 1898 depends on CRYPTO_SHA256=y 1899 select SRCU 1900 select MMU_NOTIFIER 1901 select NUMA_KEEP_MEMINFO if NUMA 1902 help 1903 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1904 that can be used by applications to set aside private regions of code 1905 and data, referred to as enclaves. An enclave's private memory can 1906 only be accessed by code running within the enclave. Accesses from 1907 outside the enclave, including other enclaves, are disallowed by 1908 hardware. 1909 1910 If unsure, say N. 1911 1912config EFI 1913 bool "EFI runtime service support" 1914 depends on ACPI 1915 select UCS2_STRING 1916 select EFI_RUNTIME_WRAPPERS 1917 help 1918 This enables the kernel to use EFI runtime services that are 1919 available (such as the EFI variable services). 1920 1921 This option is only useful on systems that have EFI firmware. 1922 In addition, you should use the latest ELILO loader available 1923 at <http://elilo.sourceforge.net> in order to take advantage 1924 of EFI runtime services. However, even with this option, the 1925 resultant kernel should continue to boot on existing non-EFI 1926 platforms. 1927 1928config EFI_STUB 1929 bool "EFI stub support" 1930 depends on EFI && !X86_USE_3DNOW 1931 depends on $(cc-option,-mabi=ms) || X86_32 1932 select RELOCATABLE 1933 help 1934 This kernel feature allows a bzImage to be loaded directly 1935 by EFI firmware without the use of a bootloader. 1936 1937 See Documentation/admin-guide/efi-stub.rst for more information. 1938 1939config EFI_MIXED 1940 bool "EFI mixed-mode support" 1941 depends on EFI_STUB && X86_64 1942 help 1943 Enabling this feature allows a 64-bit kernel to be booted 1944 on a 32-bit firmware, provided that your CPU supports 64-bit 1945 mode. 1946 1947 Note that it is not possible to boot a mixed-mode enabled 1948 kernel via the EFI boot stub - a bootloader that supports 1949 the EFI handover protocol must be used. 1950 1951 If unsure, say N. 1952 1953source "kernel/Kconfig.hz" 1954 1955config KEXEC 1956 bool "kexec system call" 1957 select KEXEC_CORE 1958 help 1959 kexec is a system call that implements the ability to shutdown your 1960 current kernel, and to start another kernel. It is like a reboot 1961 but it is independent of the system firmware. And like a reboot 1962 you can start any kernel with it, not just Linux. 1963 1964 The name comes from the similarity to the exec system call. 1965 1966 It is an ongoing process to be certain the hardware in a machine 1967 is properly shutdown, so do not be surprised if this code does not 1968 initially work for you. As of this writing the exact hardware 1969 interface is strongly in flux, so no good recommendation can be 1970 made. 1971 1972config KEXEC_FILE 1973 bool "kexec file based system call" 1974 select KEXEC_CORE 1975 select BUILD_BIN2C 1976 depends on X86_64 1977 depends on CRYPTO=y 1978 depends on CRYPTO_SHA256=y 1979 help 1980 This is new version of kexec system call. This system call is 1981 file based and takes file descriptors as system call argument 1982 for kernel and initramfs as opposed to list of segments as 1983 accepted by previous system call. 1984 1985config ARCH_HAS_KEXEC_PURGATORY 1986 def_bool KEXEC_FILE 1987 1988config KEXEC_SIG 1989 bool "Verify kernel signature during kexec_file_load() syscall" 1990 depends on KEXEC_FILE 1991 help 1992 1993 This option makes the kexec_file_load() syscall check for a valid 1994 signature of the kernel image. The image can still be loaded without 1995 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 1996 there's a signature that we can check, then it must be valid. 1997 1998 In addition to this option, you need to enable signature 1999 verification for the corresponding kernel image type being 2000 loaded in order for this to work. 2001 2002config KEXEC_SIG_FORCE 2003 bool "Require a valid signature in kexec_file_load() syscall" 2004 depends on KEXEC_SIG 2005 help 2006 This option makes kernel signature verification mandatory for 2007 the kexec_file_load() syscall. 2008 2009config KEXEC_BZIMAGE_VERIFY_SIG 2010 bool "Enable bzImage signature verification support" 2011 depends on KEXEC_SIG 2012 depends on SIGNED_PE_FILE_VERIFICATION 2013 select SYSTEM_TRUSTED_KEYRING 2014 help 2015 Enable bzImage signature verification support. 2016 2017config CRASH_DUMP 2018 bool "kernel crash dumps" 2019 depends on X86_64 || (X86_32 && HIGHMEM) 2020 help 2021 Generate crash dump after being started by kexec. 2022 This should be normally only set in special crash dump kernels 2023 which are loaded in the main kernel with kexec-tools into 2024 a specially reserved region and then later executed after 2025 a crash by kdump/kexec. The crash dump kernel must be compiled 2026 to a memory address not used by the main kernel or BIOS using 2027 PHYSICAL_START, or it must be built as a relocatable image 2028 (CONFIG_RELOCATABLE=y). 2029 For more details see Documentation/admin-guide/kdump/kdump.rst 2030 2031config KEXEC_JUMP 2032 bool "kexec jump" 2033 depends on KEXEC && HIBERNATION 2034 help 2035 Jump between original kernel and kexeced kernel and invoke 2036 code in physical address mode via KEXEC 2037 2038config PHYSICAL_START 2039 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2040 default "0x1000000" 2041 help 2042 This gives the physical address where the kernel is loaded. 2043 2044 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2045 bzImage will decompress itself to above physical address and 2046 run from there. Otherwise, bzImage will run from the address where 2047 it has been loaded by the boot loader and will ignore above physical 2048 address. 2049 2050 In normal kdump cases one does not have to set/change this option 2051 as now bzImage can be compiled as a completely relocatable image 2052 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2053 address. This option is mainly useful for the folks who don't want 2054 to use a bzImage for capturing the crash dump and want to use a 2055 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2056 to be specifically compiled to run from a specific memory area 2057 (normally a reserved region) and this option comes handy. 2058 2059 So if you are using bzImage for capturing the crash dump, 2060 leave the value here unchanged to 0x1000000 and set 2061 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2062 for capturing the crash dump change this value to start of 2063 the reserved region. In other words, it can be set based on 2064 the "X" value as specified in the "crashkernel=YM@XM" 2065 command line boot parameter passed to the panic-ed 2066 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2067 for more details about crash dumps. 2068 2069 Usage of bzImage for capturing the crash dump is recommended as 2070 one does not have to build two kernels. Same kernel can be used 2071 as production kernel and capture kernel. Above option should have 2072 gone away after relocatable bzImage support is introduced. But it 2073 is present because there are users out there who continue to use 2074 vmlinux for dump capture. This option should go away down the 2075 line. 2076 2077 Don't change this unless you know what you are doing. 2078 2079config RELOCATABLE 2080 bool "Build a relocatable kernel" 2081 default y 2082 help 2083 This builds a kernel image that retains relocation information 2084 so it can be loaded someplace besides the default 1MB. 2085 The relocations tend to make the kernel binary about 10% larger, 2086 but are discarded at runtime. 2087 2088 One use is for the kexec on panic case where the recovery kernel 2089 must live at a different physical address than the primary 2090 kernel. 2091 2092 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2093 it has been loaded at and the compile time physical address 2094 (CONFIG_PHYSICAL_START) is used as the minimum location. 2095 2096config RANDOMIZE_BASE 2097 bool "Randomize the address of the kernel image (KASLR)" 2098 depends on RELOCATABLE 2099 default y 2100 help 2101 In support of Kernel Address Space Layout Randomization (KASLR), 2102 this randomizes the physical address at which the kernel image 2103 is decompressed and the virtual address where the kernel 2104 image is mapped, as a security feature that deters exploit 2105 attempts relying on knowledge of the location of kernel 2106 code internals. 2107 2108 On 64-bit, the kernel physical and virtual addresses are 2109 randomized separately. The physical address will be anywhere 2110 between 16MB and the top of physical memory (up to 64TB). The 2111 virtual address will be randomized from 16MB up to 1GB (9 bits 2112 of entropy). Note that this also reduces the memory space 2113 available to kernel modules from 1.5GB to 1GB. 2114 2115 On 32-bit, the kernel physical and virtual addresses are 2116 randomized together. They will be randomized from 16MB up to 2117 512MB (8 bits of entropy). 2118 2119 Entropy is generated using the RDRAND instruction if it is 2120 supported. If RDTSC is supported, its value is mixed into 2121 the entropy pool as well. If neither RDRAND nor RDTSC are 2122 supported, then entropy is read from the i8254 timer. The 2123 usable entropy is limited by the kernel being built using 2124 2GB addressing, and that PHYSICAL_ALIGN must be at a 2125 minimum of 2MB. As a result, only 10 bits of entropy are 2126 theoretically possible, but the implementations are further 2127 limited due to memory layouts. 2128 2129 If unsure, say Y. 2130 2131# Relocation on x86 needs some additional build support 2132config X86_NEED_RELOCS 2133 def_bool y 2134 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2135 2136config PHYSICAL_ALIGN 2137 hex "Alignment value to which kernel should be aligned" 2138 default "0x200000" 2139 range 0x2000 0x1000000 if X86_32 2140 range 0x200000 0x1000000 if X86_64 2141 help 2142 This value puts the alignment restrictions on physical address 2143 where kernel is loaded and run from. Kernel is compiled for an 2144 address which meets above alignment restriction. 2145 2146 If bootloader loads the kernel at a non-aligned address and 2147 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2148 address aligned to above value and run from there. 2149 2150 If bootloader loads the kernel at a non-aligned address and 2151 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2152 load address and decompress itself to the address it has been 2153 compiled for and run from there. The address for which kernel is 2154 compiled already meets above alignment restrictions. Hence the 2155 end result is that kernel runs from a physical address meeting 2156 above alignment restrictions. 2157 2158 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2159 this value must be a multiple of 0x200000. 2160 2161 Don't change this unless you know what you are doing. 2162 2163config DYNAMIC_MEMORY_LAYOUT 2164 bool 2165 help 2166 This option makes base addresses of vmalloc and vmemmap as well as 2167 __PAGE_OFFSET movable during boot. 2168 2169config RANDOMIZE_MEMORY 2170 bool "Randomize the kernel memory sections" 2171 depends on X86_64 2172 depends on RANDOMIZE_BASE 2173 select DYNAMIC_MEMORY_LAYOUT 2174 default RANDOMIZE_BASE 2175 help 2176 Randomizes the base virtual address of kernel memory sections 2177 (physical memory mapping, vmalloc & vmemmap). This security feature 2178 makes exploits relying on predictable memory locations less reliable. 2179 2180 The order of allocations remains unchanged. Entropy is generated in 2181 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2182 configuration have in average 30,000 different possible virtual 2183 addresses for each memory section. 2184 2185 If unsure, say Y. 2186 2187config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2188 hex "Physical memory mapping padding" if EXPERT 2189 depends on RANDOMIZE_MEMORY 2190 default "0xa" if MEMORY_HOTPLUG 2191 default "0x0" 2192 range 0x1 0x40 if MEMORY_HOTPLUG 2193 range 0x0 0x40 2194 help 2195 Define the padding in terabytes added to the existing physical 2196 memory size during kernel memory randomization. It is useful 2197 for memory hotplug support but reduces the entropy available for 2198 address randomization. 2199 2200 If unsure, leave at the default value. 2201 2202config HOTPLUG_CPU 2203 def_bool y 2204 depends on SMP 2205 2206config BOOTPARAM_HOTPLUG_CPU0 2207 bool "Set default setting of cpu0_hotpluggable" 2208 depends on HOTPLUG_CPU 2209 help 2210 Set whether default state of cpu0_hotpluggable is on or off. 2211 2212 Say Y here to enable CPU0 hotplug by default. If this switch 2213 is turned on, there is no need to give cpu0_hotplug kernel 2214 parameter and the CPU0 hotplug feature is enabled by default. 2215 2216 Please note: there are two known CPU0 dependencies if you want 2217 to enable the CPU0 hotplug feature either by this switch or by 2218 cpu0_hotplug kernel parameter. 2219 2220 First, resume from hibernate or suspend always starts from CPU0. 2221 So hibernate and suspend are prevented if CPU0 is offline. 2222 2223 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2224 offline if any interrupt can not migrate out of CPU0. There may 2225 be other CPU0 dependencies. 2226 2227 Please make sure the dependencies are under your control before 2228 you enable this feature. 2229 2230 Say N if you don't want to enable CPU0 hotplug feature by default. 2231 You still can enable the CPU0 hotplug feature at boot by kernel 2232 parameter cpu0_hotplug. 2233 2234config DEBUG_HOTPLUG_CPU0 2235 def_bool n 2236 prompt "Debug CPU0 hotplug" 2237 depends on HOTPLUG_CPU 2238 help 2239 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2240 soon as possible and boots up userspace with CPU0 offlined. User 2241 can online CPU0 back after boot time. 2242 2243 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2244 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2245 compilation or giving cpu0_hotplug kernel parameter at boot. 2246 2247 If unsure, say N. 2248 2249config COMPAT_VDSO 2250 def_bool n 2251 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2252 depends on COMPAT_32 2253 help 2254 Certain buggy versions of glibc will crash if they are 2255 presented with a 32-bit vDSO that is not mapped at the address 2256 indicated in its segment table. 2257 2258 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2259 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2260 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2261 the only released version with the bug, but OpenSUSE 9 2262 contains a buggy "glibc 2.3.2". 2263 2264 The symptom of the bug is that everything crashes on startup, saying: 2265 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2266 2267 Saying Y here changes the default value of the vdso32 boot 2268 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2269 This works around the glibc bug but hurts performance. 2270 2271 If unsure, say N: if you are compiling your own kernel, you 2272 are unlikely to be using a buggy version of glibc. 2273 2274choice 2275 prompt "vsyscall table for legacy applications" 2276 depends on X86_64 2277 default LEGACY_VSYSCALL_XONLY 2278 help 2279 Legacy user code that does not know how to find the vDSO expects 2280 to be able to issue three syscalls by calling fixed addresses in 2281 kernel space. Since this location is not randomized with ASLR, 2282 it can be used to assist security vulnerability exploitation. 2283 2284 This setting can be changed at boot time via the kernel command 2285 line parameter vsyscall=[emulate|xonly|none]. 2286 2287 On a system with recent enough glibc (2.14 or newer) and no 2288 static binaries, you can say None without a performance penalty 2289 to improve security. 2290 2291 If unsure, select "Emulate execution only". 2292 2293 config LEGACY_VSYSCALL_EMULATE 2294 bool "Full emulation" 2295 help 2296 The kernel traps and emulates calls into the fixed vsyscall 2297 address mapping. This makes the mapping non-executable, but 2298 it still contains readable known contents, which could be 2299 used in certain rare security vulnerability exploits. This 2300 configuration is recommended when using legacy userspace 2301 that still uses vsyscalls along with legacy binary 2302 instrumentation tools that require code to be readable. 2303 2304 An example of this type of legacy userspace is running 2305 Pin on an old binary that still uses vsyscalls. 2306 2307 config LEGACY_VSYSCALL_XONLY 2308 bool "Emulate execution only" 2309 help 2310 The kernel traps and emulates calls into the fixed vsyscall 2311 address mapping and does not allow reads. This 2312 configuration is recommended when userspace might use the 2313 legacy vsyscall area but support for legacy binary 2314 instrumentation of legacy code is not needed. It mitigates 2315 certain uses of the vsyscall area as an ASLR-bypassing 2316 buffer. 2317 2318 config LEGACY_VSYSCALL_NONE 2319 bool "None" 2320 help 2321 There will be no vsyscall mapping at all. This will 2322 eliminate any risk of ASLR bypass due to the vsyscall 2323 fixed address mapping. Attempts to use the vsyscalls 2324 will be reported to dmesg, so that either old or 2325 malicious userspace programs can be identified. 2326 2327endchoice 2328 2329config CMDLINE_BOOL 2330 bool "Built-in kernel command line" 2331 help 2332 Allow for specifying boot arguments to the kernel at 2333 build time. On some systems (e.g. embedded ones), it is 2334 necessary or convenient to provide some or all of the 2335 kernel boot arguments with the kernel itself (that is, 2336 to not rely on the boot loader to provide them.) 2337 2338 To compile command line arguments into the kernel, 2339 set this option to 'Y', then fill in the 2340 boot arguments in CONFIG_CMDLINE. 2341 2342 Systems with fully functional boot loaders (i.e. non-embedded) 2343 should leave this option set to 'N'. 2344 2345config CMDLINE 2346 string "Built-in kernel command string" 2347 depends on CMDLINE_BOOL 2348 default "" 2349 help 2350 Enter arguments here that should be compiled into the kernel 2351 image and used at boot time. If the boot loader provides a 2352 command line at boot time, it is appended to this string to 2353 form the full kernel command line, when the system boots. 2354 2355 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2356 change this behavior. 2357 2358 In most cases, the command line (whether built-in or provided 2359 by the boot loader) should specify the device for the root 2360 file system. 2361 2362config CMDLINE_OVERRIDE 2363 bool "Built-in command line overrides boot loader arguments" 2364 depends on CMDLINE_BOOL && CMDLINE != "" 2365 help 2366 Set this option to 'Y' to have the kernel ignore the boot loader 2367 command line, and use ONLY the built-in command line. 2368 2369 This is used to work around broken boot loaders. This should 2370 be set to 'N' under normal conditions. 2371 2372config MODIFY_LDT_SYSCALL 2373 bool "Enable the LDT (local descriptor table)" if EXPERT 2374 default y 2375 help 2376 Linux can allow user programs to install a per-process x86 2377 Local Descriptor Table (LDT) using the modify_ldt(2) system 2378 call. This is required to run 16-bit or segmented code such as 2379 DOSEMU or some Wine programs. It is also used by some very old 2380 threading libraries. 2381 2382 Enabling this feature adds a small amount of overhead to 2383 context switches and increases the low-level kernel attack 2384 surface. Disabling it removes the modify_ldt(2) system call. 2385 2386 Saying 'N' here may make sense for embedded or server kernels. 2387 2388source "kernel/livepatch/Kconfig" 2389 2390endmenu 2391 2392config ARCH_HAS_ADD_PAGES 2393 def_bool y 2394 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2395 2396config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2397 def_bool y 2398 2399config USE_PERCPU_NUMA_NODE_ID 2400 def_bool y 2401 depends on NUMA 2402 2403menu "Power management and ACPI options" 2404 2405config ARCH_HIBERNATION_HEADER 2406 def_bool y 2407 depends on HIBERNATION 2408 2409source "kernel/power/Kconfig" 2410 2411source "drivers/acpi/Kconfig" 2412 2413config X86_APM_BOOT 2414 def_bool y 2415 depends on APM 2416 2417menuconfig APM 2418 tristate "APM (Advanced Power Management) BIOS support" 2419 depends on X86_32 && PM_SLEEP 2420 help 2421 APM is a BIOS specification for saving power using several different 2422 techniques. This is mostly useful for battery powered laptops with 2423 APM compliant BIOSes. If you say Y here, the system time will be 2424 reset after a RESUME operation, the /proc/apm device will provide 2425 battery status information, and user-space programs will receive 2426 notification of APM "events" (e.g. battery status change). 2427 2428 If you select "Y" here, you can disable actual use of the APM 2429 BIOS by passing the "apm=off" option to the kernel at boot time. 2430 2431 Note that the APM support is almost completely disabled for 2432 machines with more than one CPU. 2433 2434 In order to use APM, you will need supporting software. For location 2435 and more information, read <file:Documentation/power/apm-acpi.rst> 2436 and the Battery Powered Linux mini-HOWTO, available from 2437 <http://www.tldp.org/docs.html#howto>. 2438 2439 This driver does not spin down disk drives (see the hdparm(8) 2440 manpage ("man 8 hdparm") for that), and it doesn't turn off 2441 VESA-compliant "green" monitors. 2442 2443 This driver does not support the TI 4000M TravelMate and the ACER 2444 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2445 desktop machines also don't have compliant BIOSes, and this driver 2446 may cause those machines to panic during the boot phase. 2447 2448 Generally, if you don't have a battery in your machine, there isn't 2449 much point in using this driver and you should say N. If you get 2450 random kernel OOPSes or reboots that don't seem to be related to 2451 anything, try disabling/enabling this option (or disabling/enabling 2452 APM in your BIOS). 2453 2454 Some other things you should try when experiencing seemingly random, 2455 "weird" problems: 2456 2457 1) make sure that you have enough swap space and that it is 2458 enabled. 2459 2) pass the "no-hlt" option to the kernel 2460 3) switch on floating point emulation in the kernel and pass 2461 the "no387" option to the kernel 2462 4) pass the "floppy=nodma" option to the kernel 2463 5) pass the "mem=4M" option to the kernel (thereby disabling 2464 all but the first 4 MB of RAM) 2465 6) make sure that the CPU is not over clocked. 2466 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2467 8) disable the cache from your BIOS settings 2468 9) install a fan for the video card or exchange video RAM 2469 10) install a better fan for the CPU 2470 11) exchange RAM chips 2471 12) exchange the motherboard. 2472 2473 To compile this driver as a module, choose M here: the 2474 module will be called apm. 2475 2476if APM 2477 2478config APM_IGNORE_USER_SUSPEND 2479 bool "Ignore USER SUSPEND" 2480 help 2481 This option will ignore USER SUSPEND requests. On machines with a 2482 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2483 series notebooks, it is necessary to say Y because of a BIOS bug. 2484 2485config APM_DO_ENABLE 2486 bool "Enable PM at boot time" 2487 help 2488 Enable APM features at boot time. From page 36 of the APM BIOS 2489 specification: "When disabled, the APM BIOS does not automatically 2490 power manage devices, enter the Standby State, enter the Suspend 2491 State, or take power saving steps in response to CPU Idle calls." 2492 This driver will make CPU Idle calls when Linux is idle (unless this 2493 feature is turned off -- see "Do CPU IDLE calls", below). This 2494 should always save battery power, but more complicated APM features 2495 will be dependent on your BIOS implementation. You may need to turn 2496 this option off if your computer hangs at boot time when using APM 2497 support, or if it beeps continuously instead of suspending. Turn 2498 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2499 T400CDT. This is off by default since most machines do fine without 2500 this feature. 2501 2502config APM_CPU_IDLE 2503 depends on CPU_IDLE 2504 bool "Make CPU Idle calls when idle" 2505 help 2506 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2507 On some machines, this can activate improved power savings, such as 2508 a slowed CPU clock rate, when the machine is idle. These idle calls 2509 are made after the idle loop has run for some length of time (e.g., 2510 333 mS). On some machines, this will cause a hang at boot time or 2511 whenever the CPU becomes idle. (On machines with more than one CPU, 2512 this option does nothing.) 2513 2514config APM_DISPLAY_BLANK 2515 bool "Enable console blanking using APM" 2516 help 2517 Enable console blanking using the APM. Some laptops can use this to 2518 turn off the LCD backlight when the screen blanker of the Linux 2519 virtual console blanks the screen. Note that this is only used by 2520 the virtual console screen blanker, and won't turn off the backlight 2521 when using the X Window system. This also doesn't have anything to 2522 do with your VESA-compliant power-saving monitor. Further, this 2523 option doesn't work for all laptops -- it might not turn off your 2524 backlight at all, or it might print a lot of errors to the console, 2525 especially if you are using gpm. 2526 2527config APM_ALLOW_INTS 2528 bool "Allow interrupts during APM BIOS calls" 2529 help 2530 Normally we disable external interrupts while we are making calls to 2531 the APM BIOS as a measure to lessen the effects of a badly behaving 2532 BIOS implementation. The BIOS should reenable interrupts if it 2533 needs to. Unfortunately, some BIOSes do not -- especially those in 2534 many of the newer IBM Thinkpads. If you experience hangs when you 2535 suspend, try setting this to Y. Otherwise, say N. 2536 2537endif # APM 2538 2539source "drivers/cpufreq/Kconfig" 2540 2541source "drivers/cpuidle/Kconfig" 2542 2543source "drivers/idle/Kconfig" 2544 2545endmenu 2546 2547 2548menu "Bus options (PCI etc.)" 2549 2550choice 2551 prompt "PCI access mode" 2552 depends on X86_32 && PCI 2553 default PCI_GOANY 2554 help 2555 On PCI systems, the BIOS can be used to detect the PCI devices and 2556 determine their configuration. However, some old PCI motherboards 2557 have BIOS bugs and may crash if this is done. Also, some embedded 2558 PCI-based systems don't have any BIOS at all. Linux can also try to 2559 detect the PCI hardware directly without using the BIOS. 2560 2561 With this option, you can specify how Linux should detect the 2562 PCI devices. If you choose "BIOS", the BIOS will be used, 2563 if you choose "Direct", the BIOS won't be used, and if you 2564 choose "MMConfig", then PCI Express MMCONFIG will be used. 2565 If you choose "Any", the kernel will try MMCONFIG, then the 2566 direct access method and falls back to the BIOS if that doesn't 2567 work. If unsure, go with the default, which is "Any". 2568 2569config PCI_GOBIOS 2570 bool "BIOS" 2571 2572config PCI_GOMMCONFIG 2573 bool "MMConfig" 2574 2575config PCI_GODIRECT 2576 bool "Direct" 2577 2578config PCI_GOOLPC 2579 bool "OLPC XO-1" 2580 depends on OLPC 2581 2582config PCI_GOANY 2583 bool "Any" 2584 2585endchoice 2586 2587config PCI_BIOS 2588 def_bool y 2589 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2590 2591# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2592config PCI_DIRECT 2593 def_bool y 2594 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2595 2596config PCI_MMCONFIG 2597 bool "Support mmconfig PCI config space access" if X86_64 2598 default y 2599 depends on PCI && (ACPI || JAILHOUSE_GUEST) 2600 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2601 2602config PCI_OLPC 2603 def_bool y 2604 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2605 2606config PCI_XEN 2607 def_bool y 2608 depends on PCI && XEN 2609 select SWIOTLB_XEN 2610 2611config MMCONF_FAM10H 2612 def_bool y 2613 depends on X86_64 && PCI_MMCONFIG && ACPI 2614 2615config PCI_CNB20LE_QUIRK 2616 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2617 depends on PCI 2618 help 2619 Read the PCI windows out of the CNB20LE host bridge. This allows 2620 PCI hotplug to work on systems with the CNB20LE chipset which do 2621 not have ACPI. 2622 2623 There's no public spec for this chipset, and this functionality 2624 is known to be incomplete. 2625 2626 You should say N unless you know you need this. 2627 2628config ISA_BUS 2629 bool "ISA bus support on modern systems" if EXPERT 2630 help 2631 Expose ISA bus device drivers and options available for selection and 2632 configuration. Enable this option if your target machine has an ISA 2633 bus. ISA is an older system, displaced by PCI and newer bus 2634 architectures -- if your target machine is modern, it probably does 2635 not have an ISA bus. 2636 2637 If unsure, say N. 2638 2639# x86_64 have no ISA slots, but can have ISA-style DMA. 2640config ISA_DMA_API 2641 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2642 default y 2643 help 2644 Enables ISA-style DMA support for devices requiring such controllers. 2645 If unsure, say Y. 2646 2647if X86_32 2648 2649config ISA 2650 bool "ISA support" 2651 help 2652 Find out whether you have ISA slots on your motherboard. ISA is the 2653 name of a bus system, i.e. the way the CPU talks to the other stuff 2654 inside your box. Other bus systems are PCI, EISA, MicroChannel 2655 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2656 newer boards don't support it. If you have ISA, say Y, otherwise N. 2657 2658config SCx200 2659 tristate "NatSemi SCx200 support" 2660 help 2661 This provides basic support for National Semiconductor's 2662 (now AMD's) Geode processors. The driver probes for the 2663 PCI-IDs of several on-chip devices, so its a good dependency 2664 for other scx200_* drivers. 2665 2666 If compiled as a module, the driver is named scx200. 2667 2668config SCx200HR_TIMER 2669 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2670 depends on SCx200 2671 default y 2672 help 2673 This driver provides a clocksource built upon the on-chip 2674 27MHz high-resolution timer. Its also a workaround for 2675 NSC Geode SC-1100's buggy TSC, which loses time when the 2676 processor goes idle (as is done by the scheduler). The 2677 other workaround is idle=poll boot option. 2678 2679config OLPC 2680 bool "One Laptop Per Child support" 2681 depends on !X86_PAE 2682 select GPIOLIB 2683 select OF 2684 select OF_PROMTREE 2685 select IRQ_DOMAIN 2686 select OLPC_EC 2687 help 2688 Add support for detecting the unique features of the OLPC 2689 XO hardware. 2690 2691config OLPC_XO1_PM 2692 bool "OLPC XO-1 Power Management" 2693 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2694 help 2695 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2696 2697config OLPC_XO1_RTC 2698 bool "OLPC XO-1 Real Time Clock" 2699 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2700 help 2701 Add support for the XO-1 real time clock, which can be used as a 2702 programmable wakeup source. 2703 2704config OLPC_XO1_SCI 2705 bool "OLPC XO-1 SCI extras" 2706 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2707 depends on INPUT=y 2708 select POWER_SUPPLY 2709 help 2710 Add support for SCI-based features of the OLPC XO-1 laptop: 2711 - EC-driven system wakeups 2712 - Power button 2713 - Ebook switch 2714 - Lid switch 2715 - AC adapter status updates 2716 - Battery status updates 2717 2718config OLPC_XO15_SCI 2719 bool "OLPC XO-1.5 SCI extras" 2720 depends on OLPC && ACPI 2721 select POWER_SUPPLY 2722 help 2723 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2724 - EC-driven system wakeups 2725 - AC adapter status updates 2726 - Battery status updates 2727 2728config ALIX 2729 bool "PCEngines ALIX System Support (LED setup)" 2730 select GPIOLIB 2731 help 2732 This option enables system support for the PCEngines ALIX. 2733 At present this just sets up LEDs for GPIO control on 2734 ALIX2/3/6 boards. However, other system specific setup should 2735 get added here. 2736 2737 Note: You must still enable the drivers for GPIO and LED support 2738 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2739 2740 Note: You have to set alix.force=1 for boards with Award BIOS. 2741 2742config NET5501 2743 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2744 select GPIOLIB 2745 help 2746 This option enables system support for the Soekris Engineering net5501. 2747 2748config GEOS 2749 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2750 select GPIOLIB 2751 depends on DMI 2752 help 2753 This option enables system support for the Traverse Technologies GEOS. 2754 2755config TS5500 2756 bool "Technologic Systems TS-5500 platform support" 2757 depends on MELAN 2758 select CHECK_SIGNATURE 2759 select NEW_LEDS 2760 select LEDS_CLASS 2761 help 2762 This option enables system support for the Technologic Systems TS-5500. 2763 2764endif # X86_32 2765 2766config AMD_NB 2767 def_bool y 2768 depends on CPU_SUP_AMD && PCI 2769 2770endmenu 2771 2772 2773menu "Binary Emulations" 2774 2775config IA32_EMULATION 2776 bool "IA32 Emulation" 2777 depends on X86_64 2778 select ARCH_WANT_OLD_COMPAT_IPC 2779 select BINFMT_ELF 2780 select COMPAT_OLD_SIGACTION 2781 help 2782 Include code to run legacy 32-bit programs under a 2783 64-bit kernel. You should likely turn this on, unless you're 2784 100% sure that you don't have any 32-bit programs left. 2785 2786config IA32_AOUT 2787 tristate "IA32 a.out support" 2788 depends on IA32_EMULATION 2789 depends on BROKEN 2790 help 2791 Support old a.out binaries in the 32bit emulation. 2792 2793config X86_X32 2794 bool "x32 ABI for 64-bit mode" 2795 depends on X86_64 2796 help 2797 Include code to run binaries for the x32 native 32-bit ABI 2798 for 64-bit processors. An x32 process gets access to the 2799 full 64-bit register file and wide data path while leaving 2800 pointers at 32 bits for smaller memory footprint. 2801 2802 You will need a recent binutils (2.22 or later) with 2803 elf32_x86_64 support enabled to compile a kernel with this 2804 option set. 2805 2806config COMPAT_32 2807 def_bool y 2808 depends on IA32_EMULATION || X86_32 2809 select HAVE_UID16 2810 select OLD_SIGSUSPEND3 2811 2812config COMPAT 2813 def_bool y 2814 depends on IA32_EMULATION || X86_X32 2815 2816if COMPAT 2817config COMPAT_FOR_U64_ALIGNMENT 2818 def_bool y 2819 2820config SYSVIPC_COMPAT 2821 def_bool y 2822 depends on SYSVIPC 2823endif 2824 2825endmenu 2826 2827 2828config HAVE_ATOMIC_IOMAP 2829 def_bool y 2830 depends on X86_32 2831 2832source "drivers/firmware/Kconfig" 2833 2834source "arch/x86/kvm/Kconfig" 2835 2836source "arch/x86/Kconfig.assembler" 2837