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_SUPPORTS_PER_VMA_LOCK 31 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 32 select HAVE_ARCH_SOFT_DIRTY 33 select MODULES_USE_ELF_RELA 34 select NEED_DMA_MAP_STATE 35 select SWIOTLB 36 select ARCH_HAS_ELFCORE_COMPAT 37 select ZONE_DMA32 38 select EXECMEM if DYNAMIC_FTRACE 39 40config FORCE_DYNAMIC_FTRACE 41 def_bool y 42 depends on X86_32 43 depends on FUNCTION_TRACER 44 select DYNAMIC_FTRACE 45 help 46 We keep the static function tracing (!DYNAMIC_FTRACE) around 47 in order to test the non static function tracing in the 48 generic code, as other architectures still use it. But we 49 only need to keep it around for x86_64. No need to keep it 50 for x86_32. For x86_32, force DYNAMIC_FTRACE. 51# 52# Arch settings 53# 54# ( Note that options that are marked 'if X86_64' could in principle be 55# ported to 32-bit as well. ) 56# 57config X86 58 def_bool y 59 # 60 # Note: keep this list sorted alphabetically 61 # 62 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 63 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 64 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 65 select ARCH_32BIT_OFF_T if X86_32 66 select ARCH_CLOCKSOURCE_INIT 67 select ARCH_CONFIGURES_CPU_MITIGATIONS 68 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 69 select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 70 select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 71 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 72 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 73 select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 74 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 75 select ARCH_HAS_CACHE_LINE_SIZE 76 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 77 select ARCH_HAS_CPU_FINALIZE_INIT 78 select ARCH_HAS_CPU_PASID if IOMMU_SVA 79 select ARCH_HAS_CRC32 80 select ARCH_HAS_CRC64 if X86_64 81 select ARCH_HAS_CRC_T10DIF 82 select ARCH_HAS_CURRENT_STACK_POINTER 83 select ARCH_HAS_DEBUG_VIRTUAL 84 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 85 select ARCH_HAS_DEVMEM_IS_ALLOWED 86 select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN 87 select ARCH_HAS_EARLY_DEBUG if KGDB 88 select ARCH_HAS_ELF_RANDOMIZE 89 select ARCH_HAS_EXECMEM_ROX if X86_64 90 select ARCH_HAS_FAST_MULTIPLIER 91 select ARCH_HAS_FORTIFY_SOURCE 92 select ARCH_HAS_GCOV_PROFILE_ALL 93 select ARCH_HAS_KCOV if X86_64 94 select ARCH_HAS_KERNEL_FPU_SUPPORT 95 select ARCH_HAS_MEM_ENCRYPT 96 select ARCH_HAS_MEMBARRIER_SYNC_CORE 97 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 98 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 99 select ARCH_HAS_PMEM_API if X86_64 100 select ARCH_HAS_PREEMPT_LAZY 101 select ARCH_HAS_PTE_DEVMAP if X86_64 102 select ARCH_HAS_PTE_SPECIAL 103 select ARCH_HAS_HW_PTE_YOUNG 104 select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 105 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 106 select ARCH_HAS_COPY_MC if X86_64 107 select ARCH_HAS_SET_MEMORY 108 select ARCH_HAS_SET_DIRECT_MAP 109 select ARCH_HAS_STRICT_KERNEL_RWX 110 select ARCH_HAS_STRICT_MODULE_RWX 111 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 112 select ARCH_HAS_SYSCALL_WRAPPER 113 select ARCH_HAS_UBSAN 114 select ARCH_HAS_DEBUG_WX 115 select ARCH_HAS_ZONE_DMA_SET if EXPERT 116 select ARCH_HAVE_NMI_SAFE_CMPXCHG 117 select ARCH_HAVE_EXTRA_ELF_NOTES 118 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 119 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 120 select ARCH_MIGHT_HAVE_PC_PARPORT 121 select ARCH_MIGHT_HAVE_PC_SERIO 122 select ARCH_STACKWALK 123 select ARCH_SUPPORTS_ACPI 124 select ARCH_SUPPORTS_ATOMIC_RMW 125 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 126 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 127 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 128 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 129 select ARCH_SUPPORTS_CFI_CLANG if X86_64 130 select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG 131 select ARCH_SUPPORTS_LTO_CLANG 132 select ARCH_SUPPORTS_LTO_CLANG_THIN 133 select ARCH_SUPPORTS_RT 134 select ARCH_SUPPORTS_AUTOFDO_CLANG 135 select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64 136 select ARCH_USE_BUILTIN_BSWAP 137 select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8 138 select ARCH_USE_MEMTEST 139 select ARCH_USE_QUEUED_RWLOCKS 140 select ARCH_USE_QUEUED_SPINLOCKS 141 select ARCH_USE_SYM_ANNOTATIONS 142 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 143 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 144 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 145 select ARCH_WANTS_NO_INSTR 146 select ARCH_WANT_GENERAL_HUGETLB 147 select ARCH_WANT_HUGE_PMD_SHARE 148 select ARCH_WANT_LD_ORPHAN_WARN 149 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 150 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 151 select ARCH_WANTS_THP_SWAP if X86_64 152 select ARCH_HAS_PARANOID_L1D_FLUSH 153 select BUILDTIME_TABLE_SORT 154 select CLKEVT_I8253 155 select CLOCKSOURCE_WATCHDOG 156 # Word-size accesses may read uninitialized data past the trailing \0 157 # in strings and cause false KMSAN reports. 158 select DCACHE_WORD_ACCESS if !KMSAN 159 select DYNAMIC_SIGFRAME 160 select EDAC_ATOMIC_SCRUB 161 select EDAC_SUPPORT 162 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 163 select GENERIC_CLOCKEVENTS_BROADCAST_IDLE if GENERIC_CLOCKEVENTS_BROADCAST 164 select GENERIC_CLOCKEVENTS_MIN_ADJUST 165 select GENERIC_CMOS_UPDATE 166 select GENERIC_CPU_AUTOPROBE 167 select GENERIC_CPU_DEVICES 168 select GENERIC_CPU_VULNERABILITIES 169 select GENERIC_EARLY_IOREMAP 170 select GENERIC_ENTRY 171 select GENERIC_IOMAP 172 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 173 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 174 select GENERIC_IRQ_MIGRATION if SMP 175 select GENERIC_IRQ_PROBE 176 select GENERIC_IRQ_RESERVATION_MODE 177 select GENERIC_IRQ_SHOW 178 select GENERIC_PENDING_IRQ if SMP 179 select GENERIC_PTDUMP 180 select GENERIC_SMP_IDLE_THREAD 181 select GENERIC_TIME_VSYSCALL 182 select GENERIC_GETTIMEOFDAY 183 select GENERIC_VDSO_DATA_STORE 184 select GENERIC_VDSO_TIME_NS 185 select GENERIC_VDSO_OVERFLOW_PROTECT 186 select GUP_GET_PXX_LOW_HIGH if X86_PAE 187 select HARDIRQS_SW_RESEND 188 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 189 select HAS_IOPORT 190 select HAVE_ACPI_APEI if ACPI 191 select HAVE_ACPI_APEI_NMI if ACPI 192 select HAVE_ALIGNED_STRUCT_PAGE 193 select HAVE_ARCH_AUDITSYSCALL 194 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 195 select HAVE_ARCH_HUGE_VMALLOC if X86_64 196 select HAVE_ARCH_JUMP_LABEL 197 select HAVE_ARCH_JUMP_LABEL_RELATIVE 198 select HAVE_ARCH_KASAN if X86_64 199 select HAVE_ARCH_KASAN_VMALLOC if X86_64 200 select HAVE_ARCH_KFENCE 201 select HAVE_ARCH_KMSAN if X86_64 202 select HAVE_ARCH_KGDB 203 select HAVE_ARCH_MMAP_RND_BITS if MMU 204 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 205 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 206 select HAVE_ARCH_PREL32_RELOCATIONS 207 select HAVE_ARCH_SECCOMP_FILTER 208 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 209 select HAVE_ARCH_STACKLEAK 210 select HAVE_ARCH_TRACEHOOK 211 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 212 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 213 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 214 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 215 select HAVE_ARCH_VMAP_STACK if X86_64 216 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 217 select HAVE_ARCH_WITHIN_STACK_FRAMES 218 select HAVE_ASM_MODVERSIONS 219 select HAVE_CMPXCHG_DOUBLE 220 select HAVE_CMPXCHG_LOCAL 221 select HAVE_CONTEXT_TRACKING_USER if X86_64 222 select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER 223 select HAVE_C_RECORDMCOUNT 224 select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 225 select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT 226 select HAVE_BUILDTIME_MCOUNT_SORT 227 select HAVE_DEBUG_KMEMLEAK 228 select HAVE_DMA_CONTIGUOUS 229 select HAVE_DYNAMIC_FTRACE 230 select HAVE_DYNAMIC_FTRACE_WITH_REGS 231 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 232 select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64 233 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 234 select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 235 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 236 select HAVE_EBPF_JIT 237 select HAVE_EFFICIENT_UNALIGNED_ACCESS 238 select HAVE_EISA if X86_32 239 select HAVE_EXIT_THREAD 240 select HAVE_GUP_FAST 241 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 242 select HAVE_FTRACE_GRAPH_FUNC if HAVE_FUNCTION_GRAPH_TRACER 243 select HAVE_FTRACE_MCOUNT_RECORD 244 select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER 245 select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 246 select HAVE_FUNCTION_TRACER 247 select HAVE_GCC_PLUGINS 248 select HAVE_HW_BREAKPOINT 249 select HAVE_IOREMAP_PROT 250 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 251 select HAVE_IRQ_TIME_ACCOUNTING 252 select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 253 select HAVE_KERNEL_BZIP2 254 select HAVE_KERNEL_GZIP 255 select HAVE_KERNEL_LZ4 256 select HAVE_KERNEL_LZMA 257 select HAVE_KERNEL_LZO 258 select HAVE_KERNEL_XZ 259 select HAVE_KERNEL_ZSTD 260 select HAVE_KPROBES 261 select HAVE_KPROBES_ON_FTRACE 262 select HAVE_FUNCTION_ERROR_INJECTION 263 select HAVE_KRETPROBES 264 select HAVE_RETHOOK 265 select HAVE_LIVEPATCH if X86_64 266 select HAVE_MIXED_BREAKPOINTS_REGS 267 select HAVE_MOD_ARCH_SPECIFIC 268 select HAVE_MOVE_PMD 269 select HAVE_MOVE_PUD 270 select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 271 select HAVE_NMI 272 select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 273 select HAVE_OBJTOOL if X86_64 274 select HAVE_OPTPROBES 275 select HAVE_PAGE_SIZE_4KB 276 select HAVE_PCSPKR_PLATFORM 277 select HAVE_PERF_EVENTS 278 select HAVE_PERF_EVENTS_NMI 279 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 280 select HAVE_PCI 281 select HAVE_PERF_REGS 282 select HAVE_PERF_USER_STACK_DUMP 283 select MMU_GATHER_RCU_TABLE_FREE 284 select MMU_GATHER_MERGE_VMAS 285 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 286 select HAVE_REGS_AND_STACK_ACCESS_API 287 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 288 select HAVE_FUNCTION_ARG_ACCESS_API 289 select HAVE_SETUP_PER_CPU_AREA 290 select HAVE_SOFTIRQ_ON_OWN_STACK 291 select HAVE_STACKPROTECTOR 292 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 293 select HAVE_STATIC_CALL 294 select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 295 select HAVE_PREEMPT_DYNAMIC_CALL 296 select HAVE_RSEQ 297 select HAVE_RUST if X86_64 298 select HAVE_SYSCALL_TRACEPOINTS 299 select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 300 select HAVE_UNSTABLE_SCHED_CLOCK 301 select HAVE_USER_RETURN_NOTIFIER 302 select HAVE_GENERIC_VDSO 303 select VDSO_GETRANDOM if X86_64 304 select HOTPLUG_PARALLEL if SMP && X86_64 305 select HOTPLUG_SMT if SMP 306 select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 307 select IRQ_FORCED_THREADING 308 select LOCK_MM_AND_FIND_VMA 309 select NEED_PER_CPU_EMBED_FIRST_CHUNK 310 select NEED_PER_CPU_PAGE_FIRST_CHUNK 311 select NEED_SG_DMA_LENGTH 312 select NUMA_MEMBLKS if NUMA 313 select PCI_DOMAINS if PCI 314 select PCI_LOCKLESS_CONFIG if PCI 315 select PERF_EVENTS 316 select RTC_LIB 317 select RTC_MC146818_LIB 318 select SPARSE_IRQ 319 select SYSCTL_EXCEPTION_TRACE 320 select THREAD_INFO_IN_TASK 321 select TRACE_IRQFLAGS_SUPPORT 322 select TRACE_IRQFLAGS_NMI_SUPPORT 323 select USER_STACKTRACE_SUPPORT 324 select HAVE_ARCH_KCSAN if X86_64 325 select PROC_PID_ARCH_STATUS if PROC_FS 326 select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 327 select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 328 select FUNCTION_ALIGNMENT_4B 329 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 330 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 331 select ARCH_SUPPORTS_PT_RECLAIM if X86_64 332 333config INSTRUCTION_DECODER 334 def_bool y 335 depends on KPROBES || PERF_EVENTS || UPROBES 336 337config OUTPUT_FORMAT 338 string 339 default "elf32-i386" if X86_32 340 default "elf64-x86-64" if X86_64 341 342config LOCKDEP_SUPPORT 343 def_bool y 344 345config STACKTRACE_SUPPORT 346 def_bool y 347 348config MMU 349 def_bool y 350 351config ARCH_MMAP_RND_BITS_MIN 352 default 28 if 64BIT 353 default 8 354 355config ARCH_MMAP_RND_BITS_MAX 356 default 32 if 64BIT 357 default 16 358 359config ARCH_MMAP_RND_COMPAT_BITS_MIN 360 default 8 361 362config ARCH_MMAP_RND_COMPAT_BITS_MAX 363 default 16 364 365config SBUS 366 bool 367 368config GENERIC_ISA_DMA 369 def_bool y 370 depends on ISA_DMA_API 371 372config GENERIC_CSUM 373 bool 374 default y if KMSAN || KASAN 375 376config GENERIC_BUG 377 def_bool y 378 depends on BUG 379 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 380 381config GENERIC_BUG_RELATIVE_POINTERS 382 bool 383 384config ARCH_MAY_HAVE_PC_FDC 385 def_bool y 386 depends on ISA_DMA_API 387 388config GENERIC_CALIBRATE_DELAY 389 def_bool y 390 391config ARCH_HAS_CPU_RELAX 392 def_bool y 393 394config ARCH_HIBERNATION_POSSIBLE 395 def_bool y 396 397config ARCH_SUSPEND_POSSIBLE 398 def_bool y 399 400config AUDIT_ARCH 401 def_bool y if X86_64 402 403config KASAN_SHADOW_OFFSET 404 hex 405 depends on KASAN 406 default 0xdffffc0000000000 407 408config HAVE_INTEL_TXT 409 def_bool y 410 depends on INTEL_IOMMU && ACPI 411 412config X86_64_SMP 413 def_bool y 414 depends on X86_64 && SMP 415 416config ARCH_SUPPORTS_UPROBES 417 def_bool y 418 419config FIX_EARLYCON_MEM 420 def_bool y 421 422config DYNAMIC_PHYSICAL_MASK 423 bool 424 425config PGTABLE_LEVELS 426 int 427 default 5 if X86_5LEVEL 428 default 4 if X86_64 429 default 3 if X86_PAE 430 default 2 431 432menu "Processor type and features" 433 434config SMP 435 bool "Symmetric multi-processing support" 436 help 437 This enables support for systems with more than one CPU. If you have 438 a system with only one CPU, say N. If you have a system with more 439 than one CPU, say Y. 440 441 If you say N here, the kernel will run on uni- and multiprocessor 442 machines, but will use only one CPU of a multiprocessor machine. If 443 you say Y here, the kernel will run on many, but not all, 444 uniprocessor machines. On a uniprocessor machine, the kernel 445 will run faster if you say N here. 446 447 Note that if you say Y here and choose architecture "586" or 448 "Pentium" under "Processor family", the kernel will not work on 486 449 architectures. Similarly, multiprocessor kernels for the "PPro" 450 architecture may not work on all Pentium based boards. 451 452 People using multiprocessor machines who say Y here should also say 453 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 454 Management" code will be disabled if you say Y here. 455 456 See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 457 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 458 <http://www.tldp.org/docs.html#howto>. 459 460 If you don't know what to do here, say N. 461 462config X86_X2APIC 463 bool "Support x2apic" 464 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 465 help 466 This enables x2apic support on CPUs that have this feature. 467 468 This allows 32-bit apic IDs (so it can support very large systems), 469 and accesses the local apic via MSRs not via mmio. 470 471 Some Intel systems circa 2022 and later are locked into x2APIC mode 472 and can not fall back to the legacy APIC modes if SGX or TDX are 473 enabled in the BIOS. They will boot with very reduced functionality 474 without enabling this option. 475 476 If you don't know what to do here, say N. 477 478config X86_POSTED_MSI 479 bool "Enable MSI and MSI-x delivery by posted interrupts" 480 depends on X86_64 && IRQ_REMAP 481 help 482 This enables MSIs that are under interrupt remapping to be delivered as 483 posted interrupts to the host kernel. Interrupt throughput can 484 potentially be improved by coalescing CPU notifications during high 485 frequency bursts. 486 487 If you don't know what to do here, say N. 488 489config X86_MPPARSE 490 bool "Enable MPS table" if ACPI 491 default y 492 depends on X86_LOCAL_APIC 493 help 494 For old smp systems that do not have proper acpi support. Newer systems 495 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 496 497config X86_CPU_RESCTRL 498 bool "x86 CPU resource control support" 499 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 500 select KERNFS 501 select PROC_CPU_RESCTRL if PROC_FS 502 select RESCTRL_FS_PSEUDO_LOCK 503 help 504 Enable x86 CPU resource control support. 505 506 Provide support for the allocation and monitoring of system resources 507 usage by the CPU. 508 509 Intel calls this Intel Resource Director Technology 510 (Intel(R) RDT). More information about RDT can be found in the 511 Intel x86 Architecture Software Developer Manual. 512 513 AMD calls this AMD Platform Quality of Service (AMD QoS). 514 More information about AMD QoS can be found in the AMD64 Technology 515 Platform Quality of Service Extensions manual. 516 517 Say N if unsure. 518 519config RESCTRL_FS_PSEUDO_LOCK 520 bool 521 help 522 Software mechanism to pin data in a cache portion using 523 micro-architecture specific knowledge. 524 525config X86_FRED 526 bool "Flexible Return and Event Delivery" 527 depends on X86_64 528 help 529 When enabled, try to use Flexible Return and Event Delivery 530 instead of the legacy SYSCALL/SYSENTER/IDT architecture for 531 ring transitions and exception/interrupt handling if the 532 system supports it. 533 534config X86_EXTENDED_PLATFORM 535 bool "Support for extended (non-PC) x86 platforms" 536 default y 537 help 538 If you disable this option then the kernel will only support 539 standard PC platforms. (which covers the vast majority of 540 systems out there.) 541 542 If you enable this option then you'll be able to select support 543 for the following non-PC x86 platforms, depending on the value of 544 CONFIG_64BIT. 545 546 32-bit platforms (CONFIG_64BIT=n): 547 Goldfish (Android emulator) 548 AMD Elan 549 RDC R-321x SoC 550 SGI 320/540 (Visual Workstation) 551 552 64-bit platforms (CONFIG_64BIT=y): 553 Numascale NumaChip 554 ScaleMP vSMP 555 SGI Ultraviolet 556 Merrifield/Moorefield MID devices 557 558 If you have one of these systems, or if you want to build a 559 generic distribution kernel, say Y here - otherwise say N. 560 561# This is an alphabetically sorted list of 64 bit extended platforms 562# Please maintain the alphabetic order if and when there are additions 563config X86_NUMACHIP 564 bool "Numascale NumaChip" 565 depends on X86_64 566 depends on X86_EXTENDED_PLATFORM 567 depends on NUMA 568 depends on SMP 569 depends on X86_X2APIC 570 depends on PCI_MMCONFIG 571 help 572 Adds support for Numascale NumaChip large-SMP systems. Needed to 573 enable more than ~168 cores. 574 If you don't have one of these, you should say N here. 575 576config X86_VSMP 577 bool "ScaleMP vSMP" 578 select HYPERVISOR_GUEST 579 select PARAVIRT 580 depends on X86_64 && PCI 581 depends on X86_EXTENDED_PLATFORM 582 depends on SMP 583 help 584 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 585 supposed to run on these EM64T-based machines. Only choose this option 586 if you have one of these machines. 587 588config X86_UV 589 bool "SGI Ultraviolet" 590 depends on X86_64 591 depends on X86_EXTENDED_PLATFORM 592 depends on NUMA 593 depends on EFI 594 depends on KEXEC_CORE 595 depends on X86_X2APIC 596 depends on PCI 597 help 598 This option is needed in order to support SGI Ultraviolet systems. 599 If you don't have one of these, you should say N here. 600 601config X86_INTEL_MID 602 bool "Intel Z34xx/Z35xx MID platform support" 603 depends on X86_EXTENDED_PLATFORM 604 depends on X86_PLATFORM_DEVICES 605 depends on PCI 606 depends on X86_64 || (EXPERT && PCI_GOANY) 607 depends on X86_IO_APIC 608 select I2C 609 select DW_APB_TIMER 610 select INTEL_SCU_PCI 611 help 612 Select to build a kernel capable of supporting 64-bit Intel MID 613 (Mobile Internet Device) platform systems which do not have 614 the PCI legacy interfaces. 615 616 The only supported devices are the 22nm Merrified (Z34xx) 617 and Moorefield (Z35xx) SoC used in the Intel Edison board and 618 a small number of Android devices such as the Asus Zenfone 2, 619 Asus FonePad 8 and Dell Venue 7. 620 621 If you are building for a PC class system or non-MID tablet 622 SoCs like Bay Trail (Z36xx/Z37xx), say N here. 623 624 Intel MID platforms are based on an Intel processor and chipset which 625 consume less power than most of the x86 derivatives. 626 627config X86_GOLDFISH 628 bool "Goldfish (Virtual Platform)" 629 depends on X86_EXTENDED_PLATFORM 630 help 631 Enable support for the Goldfish virtual platform used primarily 632 for Android development. Unless you are building for the Android 633 Goldfish emulator say N here. 634 635# Following is an alphabetically sorted list of 32 bit extended platforms 636# Please maintain the alphabetic order if and when there are additions 637 638config X86_INTEL_CE 639 bool "CE4100 TV platform" 640 depends on PCI 641 depends on PCI_GODIRECT 642 depends on X86_IO_APIC 643 depends on X86_32 644 depends on X86_EXTENDED_PLATFORM 645 select X86_REBOOTFIXUPS 646 select OF 647 select OF_EARLY_FLATTREE 648 help 649 Select for the Intel CE media processor (CE4100) SOC. 650 This option compiles in support for the CE4100 SOC for settop 651 boxes and media devices. 652 653config X86_INTEL_QUARK 654 bool "Intel Quark platform support" 655 depends on X86_32 656 depends on X86_EXTENDED_PLATFORM 657 depends on X86_PLATFORM_DEVICES 658 depends on X86_TSC 659 depends on PCI 660 depends on PCI_GOANY 661 depends on X86_IO_APIC 662 select IOSF_MBI 663 select INTEL_IMR 664 select COMMON_CLK 665 help 666 Select to include support for Quark X1000 SoC. 667 Say Y here if you have a Quark based system such as the Arduino 668 compatible Intel Galileo. 669 670config X86_INTEL_LPSS 671 bool "Intel Low Power Subsystem Support" 672 depends on X86 && ACPI && PCI 673 select COMMON_CLK 674 select PINCTRL 675 select IOSF_MBI 676 help 677 Select to build support for Intel Low Power Subsystem such as 678 found on Intel Lynxpoint PCH. Selecting this option enables 679 things like clock tree (common clock framework) and pincontrol 680 which are needed by the LPSS peripheral drivers. 681 682config X86_AMD_PLATFORM_DEVICE 683 bool "AMD ACPI2Platform devices support" 684 depends on ACPI 685 select COMMON_CLK 686 select PINCTRL 687 help 688 Select to interpret AMD specific ACPI device to platform device 689 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 690 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 691 implemented under PINCTRL subsystem. 692 693config IOSF_MBI 694 tristate "Intel SoC IOSF Sideband support for SoC platforms" 695 depends on PCI 696 help 697 This option enables sideband register access support for Intel SoC 698 platforms. On these platforms the IOSF sideband is used in lieu of 699 MSR's for some register accesses, mostly but not limited to thermal 700 and power. Drivers may query the availability of this device to 701 determine if they need the sideband in order to work on these 702 platforms. The sideband is available on the following SoC products. 703 This list is not meant to be exclusive. 704 - BayTrail 705 - Braswell 706 - Quark 707 708 You should say Y if you are running a kernel on one of these SoC's. 709 710config IOSF_MBI_DEBUG 711 bool "Enable IOSF sideband access through debugfs" 712 depends on IOSF_MBI && DEBUG_FS 713 help 714 Select this option to expose the IOSF sideband access registers (MCR, 715 MDR, MCRX) through debugfs to write and read register information from 716 different units on the SoC. This is most useful for obtaining device 717 state information for debug and analysis. As this is a general access 718 mechanism, users of this option would have specific knowledge of the 719 device they want to access. 720 721 If you don't require the option or are in doubt, say N. 722 723config X86_RDC321X 724 bool "RDC R-321x SoC" 725 depends on X86_32 726 depends on X86_EXTENDED_PLATFORM 727 select M486 728 select X86_REBOOTFIXUPS 729 help 730 This option is needed for RDC R-321x system-on-chip, also known 731 as R-8610-(G). 732 If you don't have one of these chips, you should say N here. 733 734config X86_SUPPORTS_MEMORY_FAILURE 735 def_bool y 736 # MCE code calls memory_failure(): 737 depends on X86_MCE 738 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 739 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 740 depends on X86_64 || !SPARSEMEM 741 select ARCH_SUPPORTS_MEMORY_FAILURE 742 743config X86_32_IRIS 744 tristate "Eurobraille/Iris poweroff module" 745 depends on X86_32 746 help 747 The Iris machines from EuroBraille do not have APM or ACPI support 748 to shut themselves down properly. A special I/O sequence is 749 needed to do so, which is what this module does at 750 kernel shutdown. 751 752 This is only for Iris machines from EuroBraille. 753 754 If unused, say N. 755 756config SCHED_OMIT_FRAME_POINTER 757 def_bool y 758 prompt "Single-depth WCHAN output" 759 depends on X86 760 help 761 Calculate simpler /proc/<PID>/wchan values. If this option 762 is disabled then wchan values will recurse back to the 763 caller function. This provides more accurate wchan values, 764 at the expense of slightly more scheduling overhead. 765 766 If in doubt, say "Y". 767 768menuconfig HYPERVISOR_GUEST 769 bool "Linux guest support" 770 help 771 Say Y here to enable options for running Linux under various hyper- 772 visors. This option enables basic hypervisor detection and platform 773 setup. 774 775 If you say N, all options in this submenu will be skipped and 776 disabled, and Linux guest support won't be built in. 777 778if HYPERVISOR_GUEST 779 780config PARAVIRT 781 bool "Enable paravirtualization code" 782 depends on HAVE_STATIC_CALL 783 help 784 This changes the kernel so it can modify itself when it is run 785 under a hypervisor, potentially improving performance significantly 786 over full virtualization. However, when run without a hypervisor 787 the kernel is theoretically slower and slightly larger. 788 789config PARAVIRT_XXL 790 bool 791 792config PARAVIRT_DEBUG 793 bool "paravirt-ops debugging" 794 depends on PARAVIRT && DEBUG_KERNEL 795 help 796 Enable to debug paravirt_ops internals. Specifically, BUG if 797 a paravirt_op is missing when it is called. 798 799config PARAVIRT_SPINLOCKS 800 bool "Paravirtualization layer for spinlocks" 801 depends on PARAVIRT && SMP 802 help 803 Paravirtualized spinlocks allow a pvops backend to replace the 804 spinlock implementation with something virtualization-friendly 805 (for example, block the virtual CPU rather than spinning). 806 807 It has a minimal impact on native kernels and gives a nice performance 808 benefit on paravirtualized KVM / Xen kernels. 809 810 If you are unsure how to answer this question, answer Y. 811 812config X86_HV_CALLBACK_VECTOR 813 def_bool n 814 815source "arch/x86/xen/Kconfig" 816 817config KVM_GUEST 818 bool "KVM Guest support (including kvmclock)" 819 depends on PARAVIRT 820 select PARAVIRT_CLOCK 821 select ARCH_CPUIDLE_HALTPOLL 822 select X86_HV_CALLBACK_VECTOR 823 default y 824 help 825 This option enables various optimizations for running under the KVM 826 hypervisor. It includes a paravirtualized clock, so that instead 827 of relying on a PIT (or probably other) emulation by the 828 underlying device model, the host provides the guest with 829 timing infrastructure such as time of day, and system time 830 831config ARCH_CPUIDLE_HALTPOLL 832 def_bool n 833 prompt "Disable host haltpoll when loading haltpoll driver" 834 help 835 If virtualized under KVM, disable host haltpoll. 836 837config PVH 838 bool "Support for running PVH guests" 839 help 840 This option enables the PVH entry point for guest virtual machines 841 as specified in the x86/HVM direct boot ABI. 842 843config PARAVIRT_TIME_ACCOUNTING 844 bool "Paravirtual steal time accounting" 845 depends on PARAVIRT 846 help 847 Select this option to enable fine granularity task steal time 848 accounting. Time spent executing other tasks in parallel with 849 the current vCPU is discounted from the vCPU power. To account for 850 that, there can be a small performance impact. 851 852 If in doubt, say N here. 853 854config PARAVIRT_CLOCK 855 bool 856 857config JAILHOUSE_GUEST 858 bool "Jailhouse non-root cell support" 859 depends on X86_64 && PCI 860 select X86_PM_TIMER 861 help 862 This option allows to run Linux as guest in a Jailhouse non-root 863 cell. You can leave this option disabled if you only want to start 864 Jailhouse and run Linux afterwards in the root cell. 865 866config ACRN_GUEST 867 bool "ACRN Guest support" 868 depends on X86_64 869 select X86_HV_CALLBACK_VECTOR 870 help 871 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 872 a flexible, lightweight reference open-source hypervisor, built with 873 real-time and safety-criticality in mind. It is built for embedded 874 IOT with small footprint and real-time features. More details can be 875 found in https://projectacrn.org/. 876 877config INTEL_TDX_GUEST 878 bool "Intel TDX (Trust Domain Extensions) - Guest Support" 879 depends on X86_64 && CPU_SUP_INTEL 880 depends on X86_X2APIC 881 depends on EFI_STUB 882 select ARCH_HAS_CC_PLATFORM 883 select X86_MEM_ENCRYPT 884 select X86_MCE 885 select UNACCEPTED_MEMORY 886 help 887 Support running as a guest under Intel TDX. Without this support, 888 the guest kernel can not boot or run under TDX. 889 TDX includes memory encryption and integrity capabilities 890 which protect the confidentiality and integrity of guest 891 memory contents and CPU state. TDX guests are protected from 892 some attacks from the VMM. 893 894endif # HYPERVISOR_GUEST 895 896source "arch/x86/Kconfig.cpu" 897 898config HPET_TIMER 899 def_bool X86_64 900 prompt "HPET Timer Support" if X86_32 901 help 902 Use the IA-PC HPET (High Precision Event Timer) to manage 903 time in preference to the PIT and RTC, if a HPET is 904 present. 905 HPET is the next generation timer replacing legacy 8254s. 906 The HPET provides a stable time base on SMP 907 systems, unlike the TSC, but it is more expensive to access, 908 as it is off-chip. The interface used is documented 909 in the HPET spec, revision 1. 910 911 You can safely choose Y here. However, HPET will only be 912 activated if the platform and the BIOS support this feature. 913 Otherwise the 8254 will be used for timing services. 914 915 Choose N to continue using the legacy 8254 timer. 916 917config HPET_EMULATE_RTC 918 def_bool y 919 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 920 921# Mark as expert because too many people got it wrong. 922# The code disables itself when not needed. 923config DMI 924 default y 925 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 926 bool "Enable DMI scanning" if EXPERT 927 help 928 Enabled scanning of DMI to identify machine quirks. Say Y 929 here unless you have verified that your setup is not 930 affected by entries in the DMI blacklist. Required by PNP 931 BIOS code. 932 933config GART_IOMMU 934 bool "Old AMD GART IOMMU support" 935 select IOMMU_HELPER 936 select SWIOTLB 937 depends on X86_64 && PCI && AMD_NB 938 help 939 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 940 GART based hardware IOMMUs. 941 942 The GART supports full DMA access for devices with 32-bit access 943 limitations, on systems with more than 3 GB. This is usually needed 944 for USB, sound, many IDE/SATA chipsets and some other devices. 945 946 Newer systems typically have a modern AMD IOMMU, supported via 947 the CONFIG_AMD_IOMMU=y config option. 948 949 In normal configurations this driver is only active when needed: 950 there's more than 3 GB of memory and the system contains a 951 32-bit limited device. 952 953 If unsure, say Y. 954 955config BOOT_VESA_SUPPORT 956 bool 957 help 958 If true, at least one selected framebuffer driver can take advantage 959 of VESA video modes set at an early boot stage via the vga= parameter. 960 961config MAXSMP 962 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 963 depends on X86_64 && SMP && DEBUG_KERNEL 964 select CPUMASK_OFFSTACK 965 help 966 Enable maximum number of CPUS and NUMA Nodes for this architecture. 967 If unsure, say N. 968 969# 970# The maximum number of CPUs supported: 971# 972# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 973# and which can be configured interactively in the 974# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 975# 976# The ranges are different on 32-bit and 64-bit kernels, depending on 977# hardware capabilities and scalability features of the kernel. 978# 979# ( If MAXSMP is enabled we just use the highest possible value and disable 980# interactive configuration. ) 981# 982 983config NR_CPUS_RANGE_BEGIN 984 int 985 default NR_CPUS_RANGE_END if MAXSMP 986 default 1 if !SMP 987 default 2 988 989config NR_CPUS_RANGE_END 990 int 991 depends on X86_32 992 default 8 if SMP 993 default 1 if !SMP 994 995config NR_CPUS_RANGE_END 996 int 997 depends on X86_64 998 default 8192 if SMP && CPUMASK_OFFSTACK 999 default 512 if SMP && !CPUMASK_OFFSTACK 1000 default 1 if !SMP 1001 1002config NR_CPUS_DEFAULT 1003 int 1004 depends on X86_32 1005 default 8 if SMP 1006 default 1 if !SMP 1007 1008config NR_CPUS_DEFAULT 1009 int 1010 depends on X86_64 1011 default 8192 if MAXSMP 1012 default 64 if SMP 1013 default 1 if !SMP 1014 1015config NR_CPUS 1016 int "Maximum number of CPUs" if SMP && !MAXSMP 1017 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1018 default NR_CPUS_DEFAULT 1019 help 1020 This allows you to specify the maximum number of CPUs which this 1021 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1022 supported value is 8192, otherwise the maximum value is 512. The 1023 minimum value which makes sense is 2. 1024 1025 This is purely to save memory: each supported CPU adds about 8KB 1026 to the kernel image. 1027 1028config SCHED_CLUSTER 1029 bool "Cluster scheduler support" 1030 depends on SMP 1031 default y 1032 help 1033 Cluster scheduler support improves the CPU scheduler's decision 1034 making when dealing with machines that have clusters of CPUs. 1035 Cluster usually means a couple of CPUs which are placed closely 1036 by sharing mid-level caches, last-level cache tags or internal 1037 busses. 1038 1039config SCHED_SMT 1040 def_bool y if SMP 1041 1042config SCHED_MC 1043 def_bool y 1044 prompt "Multi-core scheduler support" 1045 depends on SMP 1046 help 1047 Multi-core scheduler support improves the CPU scheduler's decision 1048 making when dealing with multi-core CPU chips at a cost of slightly 1049 increased overhead in some places. If unsure say N here. 1050 1051config SCHED_MC_PRIO 1052 bool "CPU core priorities scheduler support" 1053 depends on SCHED_MC 1054 select X86_INTEL_PSTATE if CPU_SUP_INTEL 1055 select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI 1056 select CPU_FREQ 1057 default y 1058 help 1059 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1060 core ordering determined at manufacturing time, which allows 1061 certain cores to reach higher turbo frequencies (when running 1062 single threaded workloads) than others. 1063 1064 Enabling this kernel feature teaches the scheduler about 1065 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1066 scheduler's CPU selection logic accordingly, so that higher 1067 overall system performance can be achieved. 1068 1069 This feature will have no effect on CPUs without this feature. 1070 1071 If unsure say Y here. 1072 1073config UP_LATE_INIT 1074 def_bool y 1075 depends on !SMP && X86_LOCAL_APIC 1076 1077config X86_UP_APIC 1078 bool "Local APIC support on uniprocessors" if !PCI_MSI 1079 default PCI_MSI 1080 depends on X86_32 && !SMP 1081 help 1082 A local APIC (Advanced Programmable Interrupt Controller) is an 1083 integrated interrupt controller in the CPU. If you have a single-CPU 1084 system which has a processor with a local APIC, you can say Y here to 1085 enable and use it. If you say Y here even though your machine doesn't 1086 have a local APIC, then the kernel will still run with no slowdown at 1087 all. The local APIC supports CPU-generated self-interrupts (timer, 1088 performance counters), and the NMI watchdog which detects hard 1089 lockups. 1090 1091config X86_UP_IOAPIC 1092 bool "IO-APIC support on uniprocessors" 1093 depends on X86_UP_APIC 1094 help 1095 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1096 SMP-capable replacement for PC-style interrupt controllers. Most 1097 SMP systems and many recent uniprocessor systems have one. 1098 1099 If you have a single-CPU system with an IO-APIC, you can say Y here 1100 to use it. If you say Y here even though your machine doesn't have 1101 an IO-APIC, then the kernel will still run with no slowdown at all. 1102 1103config X86_LOCAL_APIC 1104 def_bool y 1105 depends on X86_64 || SMP || X86_UP_APIC || PCI_MSI 1106 select IRQ_DOMAIN_HIERARCHY 1107 1108config ACPI_MADT_WAKEUP 1109 def_bool y 1110 depends on X86_64 1111 depends on ACPI 1112 depends on SMP 1113 depends on X86_LOCAL_APIC 1114 1115config X86_IO_APIC 1116 def_bool y 1117 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1118 1119config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1120 bool "Reroute for broken boot IRQs" 1121 depends on X86_IO_APIC 1122 help 1123 This option enables a workaround that fixes a source of 1124 spurious interrupts. This is recommended when threaded 1125 interrupt handling is used on systems where the generation of 1126 superfluous "boot interrupts" cannot be disabled. 1127 1128 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1129 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1130 kernel does during interrupt handling). On chipsets where this 1131 boot IRQ generation cannot be disabled, this workaround keeps 1132 the original IRQ line masked so that only the equivalent "boot 1133 IRQ" is delivered to the CPUs. The workaround also tells the 1134 kernel to set up the IRQ handler on the boot IRQ line. In this 1135 way only one interrupt is delivered to the kernel. Otherwise 1136 the spurious second interrupt may cause the kernel to bring 1137 down (vital) interrupt lines. 1138 1139 Only affects "broken" chipsets. Interrupt sharing may be 1140 increased on these systems. 1141 1142config X86_MCE 1143 bool "Machine Check / overheating reporting" 1144 select GENERIC_ALLOCATOR 1145 default y 1146 help 1147 Machine Check support allows the processor to notify the 1148 kernel if it detects a problem (e.g. overheating, data corruption). 1149 The action the kernel takes depends on the severity of the problem, 1150 ranging from warning messages to halting the machine. 1151 1152config X86_MCELOG_LEGACY 1153 bool "Support for deprecated /dev/mcelog character device" 1154 depends on X86_MCE 1155 help 1156 Enable support for /dev/mcelog which is needed by the old mcelog 1157 userspace logging daemon. Consider switching to the new generation 1158 rasdaemon solution. 1159 1160config X86_MCE_INTEL 1161 def_bool y 1162 prompt "Intel MCE features" 1163 depends on X86_MCE && X86_LOCAL_APIC 1164 help 1165 Additional support for intel specific MCE features such as 1166 the thermal monitor. 1167 1168config X86_MCE_AMD 1169 def_bool y 1170 prompt "AMD MCE features" 1171 depends on X86_MCE && X86_LOCAL_APIC 1172 help 1173 Additional support for AMD specific MCE features such as 1174 the DRAM Error Threshold. 1175 1176config X86_ANCIENT_MCE 1177 bool "Support for old Pentium 5 / WinChip machine checks" 1178 depends on X86_32 && X86_MCE 1179 help 1180 Include support for machine check handling on old Pentium 5 or WinChip 1181 systems. These typically need to be enabled explicitly on the command 1182 line. 1183 1184config X86_MCE_THRESHOLD 1185 depends on X86_MCE_AMD || X86_MCE_INTEL 1186 def_bool y 1187 1188config X86_MCE_INJECT 1189 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1190 tristate "Machine check injector support" 1191 help 1192 Provide support for injecting machine checks for testing purposes. 1193 If you don't know what a machine check is and you don't do kernel 1194 QA it is safe to say n. 1195 1196source "arch/x86/events/Kconfig" 1197 1198config X86_LEGACY_VM86 1199 bool "Legacy VM86 support" 1200 depends on X86_32 1201 help 1202 This option allows user programs to put the CPU into V8086 1203 mode, which is an 80286-era approximation of 16-bit real mode. 1204 1205 Some very old versions of X and/or vbetool require this option 1206 for user mode setting. Similarly, DOSEMU will use it if 1207 available to accelerate real mode DOS programs. However, any 1208 recent version of DOSEMU, X, or vbetool should be fully 1209 functional even without kernel VM86 support, as they will all 1210 fall back to software emulation. Nevertheless, if you are using 1211 a 16-bit DOS program where 16-bit performance matters, vm86 1212 mode might be faster than emulation and you might want to 1213 enable this option. 1214 1215 Note that any app that works on a 64-bit kernel is unlikely to 1216 need this option, as 64-bit kernels don't, and can't, support 1217 V8086 mode. This option is also unrelated to 16-bit protected 1218 mode and is not needed to run most 16-bit programs under Wine. 1219 1220 Enabling this option increases the complexity of the kernel 1221 and slows down exception handling a tiny bit. 1222 1223 If unsure, say N here. 1224 1225config VM86 1226 bool 1227 default X86_LEGACY_VM86 1228 1229config X86_16BIT 1230 bool "Enable support for 16-bit segments" if EXPERT 1231 default y 1232 depends on MODIFY_LDT_SYSCALL 1233 help 1234 This option is required by programs like Wine to run 16-bit 1235 protected mode legacy code on x86 processors. Disabling 1236 this option saves about 300 bytes on i386, or around 6K text 1237 plus 16K runtime memory on x86-64, 1238 1239config X86_ESPFIX32 1240 def_bool y 1241 depends on X86_16BIT && X86_32 1242 1243config X86_ESPFIX64 1244 def_bool y 1245 depends on X86_16BIT && X86_64 1246 1247config X86_VSYSCALL_EMULATION 1248 bool "Enable vsyscall emulation" if EXPERT 1249 default y 1250 depends on X86_64 1251 help 1252 This enables emulation of the legacy vsyscall page. Disabling 1253 it is roughly equivalent to booting with vsyscall=none, except 1254 that it will also disable the helpful warning if a program 1255 tries to use a vsyscall. With this option set to N, offending 1256 programs will just segfault, citing addresses of the form 1257 0xffffffffff600?00. 1258 1259 This option is required by many programs built before 2013, and 1260 care should be used even with newer programs if set to N. 1261 1262 Disabling this option saves about 7K of kernel size and 1263 possibly 4K of additional runtime pagetable memory. 1264 1265config X86_IOPL_IOPERM 1266 bool "IOPERM and IOPL Emulation" 1267 default y 1268 help 1269 This enables the ioperm() and iopl() syscalls which are necessary 1270 for legacy applications. 1271 1272 Legacy IOPL support is an overbroad mechanism which allows user 1273 space aside of accessing all 65536 I/O ports also to disable 1274 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1275 capabilities and permission from potentially active security 1276 modules. 1277 1278 The emulation restricts the functionality of the syscall to 1279 only allowing the full range I/O port access, but prevents the 1280 ability to disable interrupts from user space which would be 1281 granted if the hardware IOPL mechanism would be used. 1282 1283config TOSHIBA 1284 tristate "Toshiba Laptop support" 1285 depends on X86_32 1286 help 1287 This adds a driver to safely access the System Management Mode of 1288 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1289 not work on models with a Phoenix BIOS. The System Management Mode 1290 is used to set the BIOS and power saving options on Toshiba portables. 1291 1292 For information on utilities to make use of this driver see the 1293 Toshiba Linux utilities web site at: 1294 <http://www.buzzard.org.uk/toshiba/>. 1295 1296 Say Y if you intend to run this kernel on a Toshiba portable. 1297 Say N otherwise. 1298 1299config X86_REBOOTFIXUPS 1300 bool "Enable X86 board specific fixups for reboot" 1301 depends on X86_32 1302 help 1303 This enables chipset and/or board specific fixups to be done 1304 in order to get reboot to work correctly. This is only needed on 1305 some combinations of hardware and BIOS. The symptom, for which 1306 this config is intended, is when reboot ends with a stalled/hung 1307 system. 1308 1309 Currently, the only fixup is for the Geode machines using 1310 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1311 1312 Say Y if you want to enable the fixup. Currently, it's safe to 1313 enable this option even if you don't need it. 1314 Say N otherwise. 1315 1316config MICROCODE 1317 def_bool y 1318 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1319 select CRYPTO_LIB_SHA256 if CPU_SUP_AMD 1320 1321config MICROCODE_INITRD32 1322 def_bool y 1323 depends on MICROCODE && X86_32 && BLK_DEV_INITRD 1324 1325config MICROCODE_LATE_LOADING 1326 bool "Late microcode loading (DANGEROUS)" 1327 default n 1328 depends on MICROCODE && SMP 1329 help 1330 Loading microcode late, when the system is up and executing instructions 1331 is a tricky business and should be avoided if possible. Just the sequence 1332 of synchronizing all cores and SMT threads is one fragile dance which does 1333 not guarantee that cores might not softlock after the loading. Therefore, 1334 use this at your own risk. Late loading taints the kernel unless the 1335 microcode header indicates that it is safe for late loading via the 1336 minimal revision check. This minimal revision check can be enforced on 1337 the kernel command line with "microcode.minrev=Y". 1338 1339config MICROCODE_LATE_FORCE_MINREV 1340 bool "Enforce late microcode loading minimal revision check" 1341 default n 1342 depends on MICROCODE_LATE_LOADING 1343 help 1344 To prevent that users load microcode late which modifies already 1345 in use features, newer microcode patches have a minimum revision field 1346 in the microcode header, which tells the kernel which minimum 1347 revision must be active in the CPU to safely load that new microcode 1348 late into the running system. If disabled the check will not 1349 be enforced but the kernel will be tainted when the minimal 1350 revision check fails. 1351 1352 This minimal revision check can also be controlled via the 1353 "microcode.minrev" parameter on the kernel command line. 1354 1355 If unsure say Y. 1356 1357config X86_MSR 1358 tristate "/dev/cpu/*/msr - Model-specific register support" 1359 help 1360 This device gives privileged processes access to the x86 1361 Model-Specific Registers (MSRs). It is a character device with 1362 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1363 MSR accesses are directed to a specific CPU on multi-processor 1364 systems. 1365 1366config X86_CPUID 1367 tristate "/dev/cpu/*/cpuid - CPU information support" 1368 help 1369 This device gives processes access to the x86 CPUID instruction to 1370 be executed on a specific processor. It is a character device 1371 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1372 /dev/cpu/31/cpuid. 1373 1374config HIGHMEM4G 1375 bool "High Memory Support" 1376 depends on X86_32 1377 help 1378 Linux can use up to 4 Gigabytes of physical memory on x86 systems. 1379 However, the address space of 32-bit x86 processors is only 4 1380 Gigabytes large. That means that, if you have a large amount of 1381 physical memory, not all of it can be "permanently mapped" by the 1382 kernel. The physical memory that's not permanently mapped is called 1383 "high memory". 1384 1385 If you are compiling a kernel which will never run on a machine with 1386 more than 1 Gigabyte total physical RAM, answer "off" here (default 1387 choice and suitable for most users). This will result in a "3GB/1GB" 1388 split: 3GB are mapped so that each process sees a 3GB virtual memory 1389 space and the remaining part of the 4GB virtual memory space is used 1390 by the kernel to permanently map as much physical memory as 1391 possible. 1392 1393 If the machine has between 1 and 4 Gigabytes physical RAM, then 1394 answer "Y" here. 1395 1396 If unsure, say N. 1397 1398choice 1399 prompt "Memory split" if EXPERT 1400 default VMSPLIT_3G 1401 depends on X86_32 1402 help 1403 Select the desired split between kernel and user memory. 1404 1405 If the address range available to the kernel is less than the 1406 physical memory installed, the remaining memory will be available 1407 as "high memory". Accessing high memory is a little more costly 1408 than low memory, as it needs to be mapped into the kernel first. 1409 Note that increasing the kernel address space limits the range 1410 available to user programs, making the address space there 1411 tighter. Selecting anything other than the default 3G/1G split 1412 will also likely make your kernel incompatible with binary-only 1413 kernel modules. 1414 1415 If you are not absolutely sure what you are doing, leave this 1416 option alone! 1417 1418 config VMSPLIT_3G 1419 bool "3G/1G user/kernel split" 1420 config VMSPLIT_3G_OPT 1421 depends on !X86_PAE 1422 bool "3G/1G user/kernel split (for full 1G low memory)" 1423 config VMSPLIT_2G 1424 bool "2G/2G user/kernel split" 1425 config VMSPLIT_2G_OPT 1426 depends on !X86_PAE 1427 bool "2G/2G user/kernel split (for full 2G low memory)" 1428 config VMSPLIT_1G 1429 bool "1G/3G user/kernel split" 1430endchoice 1431 1432config PAGE_OFFSET 1433 hex 1434 default 0xB0000000 if VMSPLIT_3G_OPT 1435 default 0x80000000 if VMSPLIT_2G 1436 default 0x78000000 if VMSPLIT_2G_OPT 1437 default 0x40000000 if VMSPLIT_1G 1438 default 0xC0000000 1439 depends on X86_32 1440 1441config HIGHMEM 1442 def_bool HIGHMEM4G 1443 1444config X86_PAE 1445 bool "PAE (Physical Address Extension) Support" 1446 depends on X86_32 && X86_HAVE_PAE 1447 select PHYS_ADDR_T_64BIT 1448 help 1449 PAE is required for NX support, and furthermore enables 1450 larger swapspace support for non-overcommit purposes. It 1451 has the cost of more pagetable lookup overhead, and also 1452 consumes more pagetable space per process. 1453 1454config X86_5LEVEL 1455 bool "Enable 5-level page tables support" 1456 default y 1457 select DYNAMIC_MEMORY_LAYOUT 1458 select SPARSEMEM_VMEMMAP 1459 depends on X86_64 1460 help 1461 5-level paging enables access to larger address space: 1462 up to 128 PiB of virtual address space and 4 PiB of 1463 physical address space. 1464 1465 It will be supported by future Intel CPUs. 1466 1467 A kernel with the option enabled can be booted on machines that 1468 support 4- or 5-level paging. 1469 1470 See Documentation/arch/x86/x86_64/5level-paging.rst for more 1471 information. 1472 1473 Say N if unsure. 1474 1475config X86_DIRECT_GBPAGES 1476 def_bool y 1477 depends on X86_64 1478 help 1479 Certain kernel features effectively disable kernel 1480 linear 1 GB mappings (even if the CPU otherwise 1481 supports them), so don't confuse the user by printing 1482 that we have them enabled. 1483 1484config X86_CPA_STATISTICS 1485 bool "Enable statistic for Change Page Attribute" 1486 depends on DEBUG_FS 1487 help 1488 Expose statistics about the Change Page Attribute mechanism, which 1489 helps to determine the effectiveness of preserving large and huge 1490 page mappings when mapping protections are changed. 1491 1492config X86_MEM_ENCRYPT 1493 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1494 select DYNAMIC_PHYSICAL_MASK 1495 def_bool n 1496 1497config AMD_MEM_ENCRYPT 1498 bool "AMD Secure Memory Encryption (SME) support" 1499 depends on X86_64 && CPU_SUP_AMD 1500 depends on EFI_STUB 1501 select DMA_COHERENT_POOL 1502 select ARCH_USE_MEMREMAP_PROT 1503 select INSTRUCTION_DECODER 1504 select ARCH_HAS_CC_PLATFORM 1505 select X86_MEM_ENCRYPT 1506 select UNACCEPTED_MEMORY 1507 select CRYPTO_LIB_AESGCM 1508 help 1509 Say yes to enable support for the encryption of system memory. 1510 This requires an AMD processor that supports Secure Memory 1511 Encryption (SME). 1512 1513# Common NUMA Features 1514config NUMA 1515 bool "NUMA Memory Allocation and Scheduler Support" 1516 depends on SMP 1517 depends on X86_64 1518 select USE_PERCPU_NUMA_NODE_ID 1519 select OF_NUMA if OF 1520 help 1521 Enable NUMA (Non-Uniform Memory Access) support. 1522 1523 The kernel will try to allocate memory used by a CPU on the 1524 local memory controller of the CPU and add some more 1525 NUMA awareness to the kernel. 1526 1527 For 64-bit this is recommended if the system is Intel Core i7 1528 (or later), AMD Opteron, or EM64T NUMA. 1529 1530 Otherwise, you should say N. 1531 1532config AMD_NUMA 1533 def_bool y 1534 prompt "Old style AMD Opteron NUMA detection" 1535 depends on X86_64 && NUMA && PCI 1536 help 1537 Enable AMD NUMA node topology detection. You should say Y here if 1538 you have a multi processor AMD system. This uses an old method to 1539 read the NUMA configuration directly from the builtin Northbridge 1540 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1541 which also takes priority if both are compiled in. 1542 1543config X86_64_ACPI_NUMA 1544 def_bool y 1545 prompt "ACPI NUMA detection" 1546 depends on X86_64 && NUMA && ACPI && PCI 1547 select ACPI_NUMA 1548 help 1549 Enable ACPI SRAT based node topology detection. 1550 1551config NODES_SHIFT 1552 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1553 range 1 10 1554 default "10" if MAXSMP 1555 default "6" if X86_64 1556 default "3" 1557 depends on NUMA 1558 help 1559 Specify the maximum number of NUMA Nodes available on the target 1560 system. Increases memory reserved to accommodate various tables. 1561 1562config ARCH_FLATMEM_ENABLE 1563 def_bool y 1564 depends on X86_32 && !NUMA 1565 1566config ARCH_SPARSEMEM_ENABLE 1567 def_bool y 1568 depends on X86_64 || NUMA || X86_32 1569 select SPARSEMEM_STATIC if X86_32 1570 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1571 1572config ARCH_SPARSEMEM_DEFAULT 1573 def_bool X86_64 || (NUMA && X86_32) 1574 1575config ARCH_SELECT_MEMORY_MODEL 1576 def_bool y 1577 depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1578 1579config ARCH_MEMORY_PROBE 1580 bool "Enable sysfs memory/probe interface" 1581 depends on MEMORY_HOTPLUG 1582 help 1583 This option enables a sysfs memory/probe interface for testing. 1584 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1585 If you are unsure how to answer this question, answer N. 1586 1587config ARCH_PROC_KCORE_TEXT 1588 def_bool y 1589 depends on X86_64 && PROC_KCORE 1590 1591config ILLEGAL_POINTER_VALUE 1592 hex 1593 default 0 if X86_32 1594 default 0xdead000000000000 if X86_64 1595 1596config X86_PMEM_LEGACY_DEVICE 1597 bool 1598 1599config X86_PMEM_LEGACY 1600 tristate "Support non-standard NVDIMMs and ADR protected memory" 1601 depends on PHYS_ADDR_T_64BIT 1602 depends on BLK_DEV 1603 select X86_PMEM_LEGACY_DEVICE 1604 select NUMA_KEEP_MEMINFO if NUMA 1605 select LIBNVDIMM 1606 help 1607 Treat memory marked using the non-standard e820 type of 12 as used 1608 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1609 The kernel will offer these regions to the 'pmem' driver so 1610 they can be used for persistent storage. 1611 1612 Say Y if unsure. 1613 1614config X86_CHECK_BIOS_CORRUPTION 1615 bool "Check for low memory corruption" 1616 help 1617 Periodically check for memory corruption in low memory, which 1618 is suspected to be caused by BIOS. Even when enabled in the 1619 configuration, it is disabled at runtime. Enable it by 1620 setting "memory_corruption_check=1" on the kernel command 1621 line. By default it scans the low 64k of memory every 60 1622 seconds; see the memory_corruption_check_size and 1623 memory_corruption_check_period parameters in 1624 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1625 1626 When enabled with the default parameters, this option has 1627 almost no overhead, as it reserves a relatively small amount 1628 of memory and scans it infrequently. It both detects corruption 1629 and prevents it from affecting the running system. 1630 1631 It is, however, intended as a diagnostic tool; if repeatable 1632 BIOS-originated corruption always affects the same memory, 1633 you can use memmap= to prevent the kernel from using that 1634 memory. 1635 1636config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1637 bool "Set the default setting of memory_corruption_check" 1638 depends on X86_CHECK_BIOS_CORRUPTION 1639 default y 1640 help 1641 Set whether the default state of memory_corruption_check is 1642 on or off. 1643 1644config MATH_EMULATION 1645 bool 1646 depends on MODIFY_LDT_SYSCALL 1647 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1648 help 1649 Linux can emulate a math coprocessor (used for floating point 1650 operations) if you don't have one. 486DX and Pentium processors have 1651 a math coprocessor built in, 486SX and 386 do not, unless you added 1652 a 487DX or 387, respectively. (The messages during boot time can 1653 give you some hints here ["man dmesg"].) Everyone needs either a 1654 coprocessor or this emulation. 1655 1656 If you don't have a math coprocessor, you need to say Y here; if you 1657 say Y here even though you have a coprocessor, the coprocessor will 1658 be used nevertheless. (This behavior can be changed with the kernel 1659 command line option "no387", which comes handy if your coprocessor 1660 is broken. Try "man bootparam" or see the documentation of your boot 1661 loader (lilo or loadlin) about how to pass options to the kernel at 1662 boot time.) This means that it is a good idea to say Y here if you 1663 intend to use this kernel on different machines. 1664 1665 More information about the internals of the Linux math coprocessor 1666 emulation can be found in <file:arch/x86/math-emu/README>. 1667 1668 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1669 kernel, it won't hurt. 1670 1671config MTRR 1672 def_bool y 1673 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1674 help 1675 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1676 the Memory Type Range Registers (MTRRs) may be used to control 1677 processor access to memory ranges. This is most useful if you have 1678 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1679 allows bus write transfers to be combined into a larger transfer 1680 before bursting over the PCI/AGP bus. This can increase performance 1681 of image write operations 2.5 times or more. Saying Y here creates a 1682 /proc/mtrr file which may be used to manipulate your processor's 1683 MTRRs. Typically the X server should use this. 1684 1685 This code has a reasonably generic interface so that similar 1686 control registers on other processors can be easily supported 1687 as well: 1688 1689 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1690 Registers (ARRs) which provide a similar functionality to MTRRs. For 1691 these, the ARRs are used to emulate the MTRRs. 1692 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1693 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1694 write-combining. All of these processors are supported by this code 1695 and it makes sense to say Y here if you have one of them. 1696 1697 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1698 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1699 can lead to all sorts of problems, so it's good to say Y here. 1700 1701 You can safely say Y even if your machine doesn't have MTRRs, you'll 1702 just add about 9 KB to your kernel. 1703 1704 See <file:Documentation/arch/x86/mtrr.rst> for more information. 1705 1706config MTRR_SANITIZER 1707 def_bool y 1708 prompt "MTRR cleanup support" 1709 depends on MTRR 1710 help 1711 Convert MTRR layout from continuous to discrete, so X drivers can 1712 add writeback entries. 1713 1714 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1715 The largest mtrr entry size for a continuous block can be set with 1716 mtrr_chunk_size. 1717 1718 If unsure, say Y. 1719 1720config MTRR_SANITIZER_ENABLE_DEFAULT 1721 int "MTRR cleanup enable value (0-1)" 1722 range 0 1 1723 default "0" 1724 depends on MTRR_SANITIZER 1725 help 1726 Enable mtrr cleanup default value 1727 1728config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1729 int "MTRR cleanup spare reg num (0-7)" 1730 range 0 7 1731 default "1" 1732 depends on MTRR_SANITIZER 1733 help 1734 mtrr cleanup spare entries default, it can be changed via 1735 mtrr_spare_reg_nr=N on the kernel command line. 1736 1737config X86_PAT 1738 def_bool y 1739 prompt "x86 PAT support" if EXPERT 1740 depends on MTRR 1741 select ARCH_USES_PG_ARCH_2 1742 help 1743 Use PAT attributes to setup page level cache control. 1744 1745 PATs are the modern equivalents of MTRRs and are much more 1746 flexible than MTRRs. 1747 1748 Say N here if you see bootup problems (boot crash, boot hang, 1749 spontaneous reboots) or a non-working video driver. 1750 1751 If unsure, say Y. 1752 1753config X86_UMIP 1754 def_bool y 1755 prompt "User Mode Instruction Prevention" if EXPERT 1756 help 1757 User Mode Instruction Prevention (UMIP) is a security feature in 1758 some x86 processors. If enabled, a general protection fault is 1759 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1760 executed in user mode. These instructions unnecessarily expose 1761 information about the hardware state. 1762 1763 The vast majority of applications do not use these instructions. 1764 For the very few that do, software emulation is provided in 1765 specific cases in protected and virtual-8086 modes. Emulated 1766 results are dummy. 1767 1768config CC_HAS_IBT 1769 # GCC >= 9 and binutils >= 2.29 1770 # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1771 # Clang/LLVM >= 14 1772 # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1773 # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1774 def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1775 (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1776 $(as-instr,endbr64) 1777 1778config X86_CET 1779 def_bool n 1780 help 1781 CET features configured (Shadow stack or IBT) 1782 1783config X86_KERNEL_IBT 1784 prompt "Indirect Branch Tracking" 1785 def_bool y 1786 depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1787 # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1788 depends on !LD_IS_LLD || LLD_VERSION >= 140000 1789 select OBJTOOL 1790 select X86_CET 1791 help 1792 Build the kernel with support for Indirect Branch Tracking, a 1793 hardware support course-grain forward-edge Control Flow Integrity 1794 protection. It enforces that all indirect calls must land on 1795 an ENDBR instruction, as such, the compiler will instrument the 1796 code with them to make this happen. 1797 1798 In addition to building the kernel with IBT, seal all functions that 1799 are not indirect call targets, avoiding them ever becoming one. 1800 1801 This requires LTO like objtool runs and will slow down the build. It 1802 does significantly reduce the number of ENDBR instructions in the 1803 kernel image. 1804 1805config X86_INTEL_MEMORY_PROTECTION_KEYS 1806 prompt "Memory Protection Keys" 1807 def_bool y 1808 # Note: only available in 64-bit mode 1809 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1810 select ARCH_USES_HIGH_VMA_FLAGS 1811 select ARCH_HAS_PKEYS 1812 help 1813 Memory Protection Keys provides a mechanism for enforcing 1814 page-based protections, but without requiring modification of the 1815 page tables when an application changes protection domains. 1816 1817 For details, see Documentation/core-api/protection-keys.rst 1818 1819 If unsure, say y. 1820 1821config ARCH_PKEY_BITS 1822 int 1823 default 4 1824 1825choice 1826 prompt "TSX enable mode" 1827 depends on CPU_SUP_INTEL 1828 default X86_INTEL_TSX_MODE_OFF 1829 help 1830 Intel's TSX (Transactional Synchronization Extensions) feature 1831 allows to optimize locking protocols through lock elision which 1832 can lead to a noticeable performance boost. 1833 1834 On the other hand it has been shown that TSX can be exploited 1835 to form side channel attacks (e.g. TAA) and chances are there 1836 will be more of those attacks discovered in the future. 1837 1838 Therefore TSX is not enabled by default (aka tsx=off). An admin 1839 might override this decision by tsx=on the command line parameter. 1840 Even with TSX enabled, the kernel will attempt to enable the best 1841 possible TAA mitigation setting depending on the microcode available 1842 for the particular machine. 1843 1844 This option allows to set the default tsx mode between tsx=on, =off 1845 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1846 details. 1847 1848 Say off if not sure, auto if TSX is in use but it should be used on safe 1849 platforms or on if TSX is in use and the security aspect of tsx is not 1850 relevant. 1851 1852config X86_INTEL_TSX_MODE_OFF 1853 bool "off" 1854 help 1855 TSX is disabled if possible - equals to tsx=off command line parameter. 1856 1857config X86_INTEL_TSX_MODE_ON 1858 bool "on" 1859 help 1860 TSX is always enabled on TSX capable HW - equals the tsx=on command 1861 line parameter. 1862 1863config X86_INTEL_TSX_MODE_AUTO 1864 bool "auto" 1865 help 1866 TSX is enabled on TSX capable HW that is believed to be safe against 1867 side channel attacks- equals the tsx=auto command line parameter. 1868endchoice 1869 1870config X86_SGX 1871 bool "Software Guard eXtensions (SGX)" 1872 depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC 1873 depends on CRYPTO=y 1874 depends on CRYPTO_SHA256=y 1875 select MMU_NOTIFIER 1876 select NUMA_KEEP_MEMINFO if NUMA 1877 select XARRAY_MULTI 1878 help 1879 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1880 that can be used by applications to set aside private regions of code 1881 and data, referred to as enclaves. An enclave's private memory can 1882 only be accessed by code running within the enclave. Accesses from 1883 outside the enclave, including other enclaves, are disallowed by 1884 hardware. 1885 1886 If unsure, say N. 1887 1888config X86_USER_SHADOW_STACK 1889 bool "X86 userspace shadow stack" 1890 depends on AS_WRUSS 1891 depends on X86_64 1892 select ARCH_USES_HIGH_VMA_FLAGS 1893 select ARCH_HAS_USER_SHADOW_STACK 1894 select X86_CET 1895 help 1896 Shadow stack protection is a hardware feature that detects function 1897 return address corruption. This helps mitigate ROP attacks. 1898 Applications must be enabled to use it, and old userspace does not 1899 get protection "for free". 1900 1901 CPUs supporting shadow stacks were first released in 2020. 1902 1903 See Documentation/arch/x86/shstk.rst for more information. 1904 1905 If unsure, say N. 1906 1907config INTEL_TDX_HOST 1908 bool "Intel Trust Domain Extensions (TDX) host support" 1909 depends on CPU_SUP_INTEL 1910 depends on X86_64 1911 depends on KVM_INTEL 1912 depends on X86_X2APIC 1913 select ARCH_KEEP_MEMBLOCK 1914 depends on CONTIG_ALLOC 1915 depends on !KEXEC_CORE 1916 depends on X86_MCE 1917 help 1918 Intel Trust Domain Extensions (TDX) protects guest VMs from malicious 1919 host and certain physical attacks. This option enables necessary TDX 1920 support in the host kernel to run confidential VMs. 1921 1922 If unsure, say N. 1923 1924config EFI 1925 bool "EFI runtime service support" 1926 depends on ACPI 1927 select UCS2_STRING 1928 select EFI_RUNTIME_WRAPPERS 1929 select ARCH_USE_MEMREMAP_PROT 1930 select EFI_RUNTIME_MAP if KEXEC_CORE 1931 help 1932 This enables the kernel to use EFI runtime services that are 1933 available (such as the EFI variable services). 1934 1935 This option is only useful on systems that have EFI firmware. 1936 In addition, you should use the latest ELILO loader available 1937 at <http://elilo.sourceforge.net> in order to take advantage 1938 of EFI runtime services. However, even with this option, the 1939 resultant kernel should continue to boot on existing non-EFI 1940 platforms. 1941 1942config EFI_STUB 1943 bool "EFI stub support" 1944 depends on EFI 1945 select RELOCATABLE 1946 help 1947 This kernel feature allows a bzImage to be loaded directly 1948 by EFI firmware without the use of a bootloader. 1949 1950 See Documentation/admin-guide/efi-stub.rst for more information. 1951 1952config EFI_HANDOVER_PROTOCOL 1953 bool "EFI handover protocol (DEPRECATED)" 1954 depends on EFI_STUB 1955 default y 1956 help 1957 Select this in order to include support for the deprecated EFI 1958 handover protocol, which defines alternative entry points into the 1959 EFI stub. This is a practice that has no basis in the UEFI 1960 specification, and requires a priori knowledge on the part of the 1961 bootloader about Linux/x86 specific ways of passing the command line 1962 and initrd, and where in memory those assets may be loaded. 1963 1964 If in doubt, say Y. Even though the corresponding support is not 1965 present in upstream GRUB or other bootloaders, most distros build 1966 GRUB with numerous downstream patches applied, and may rely on the 1967 handover protocol as as result. 1968 1969config EFI_MIXED 1970 bool "EFI mixed-mode support" 1971 depends on EFI_STUB && X86_64 1972 help 1973 Enabling this feature allows a 64-bit kernel to be booted 1974 on a 32-bit firmware, provided that your CPU supports 64-bit 1975 mode. 1976 1977 Note that it is not possible to boot a mixed-mode enabled 1978 kernel via the EFI boot stub - a bootloader that supports 1979 the EFI handover protocol must be used. 1980 1981 If unsure, say N. 1982 1983config EFI_RUNTIME_MAP 1984 bool "Export EFI runtime maps to sysfs" if EXPERT 1985 depends on EFI 1986 help 1987 Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. 1988 That memory map is required by the 2nd kernel to set up EFI virtual 1989 mappings after kexec, but can also be used for debugging purposes. 1990 1991 See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. 1992 1993source "kernel/Kconfig.hz" 1994 1995config ARCH_SUPPORTS_KEXEC 1996 def_bool y 1997 1998config ARCH_SUPPORTS_KEXEC_FILE 1999 def_bool X86_64 2000 2001config ARCH_SELECTS_KEXEC_FILE 2002 def_bool y 2003 depends on KEXEC_FILE 2004 select HAVE_IMA_KEXEC if IMA 2005 2006config ARCH_SUPPORTS_KEXEC_PURGATORY 2007 def_bool y 2008 2009config ARCH_SUPPORTS_KEXEC_SIG 2010 def_bool y 2011 2012config ARCH_SUPPORTS_KEXEC_SIG_FORCE 2013 def_bool y 2014 2015config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG 2016 def_bool y 2017 2018config ARCH_SUPPORTS_KEXEC_JUMP 2019 def_bool y 2020 2021config ARCH_SUPPORTS_CRASH_DUMP 2022 def_bool X86_64 || (X86_32 && HIGHMEM) 2023 2024config ARCH_DEFAULT_CRASH_DUMP 2025 def_bool y 2026 2027config ARCH_SUPPORTS_CRASH_HOTPLUG 2028 def_bool y 2029 2030config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 2031 def_bool CRASH_RESERVE 2032 2033config PHYSICAL_START 2034 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2035 default "0x1000000" 2036 help 2037 This gives the physical address where the kernel is loaded. 2038 2039 If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage 2040 will decompress itself to above physical address and run from there. 2041 Otherwise, bzImage will run from the address where it has been loaded 2042 by the boot loader. The only exception is if it is loaded below the 2043 above physical address, in which case it will relocate itself there. 2044 2045 In normal kdump cases one does not have to set/change this option 2046 as now bzImage can be compiled as a completely relocatable image 2047 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2048 address. This option is mainly useful for the folks who don't want 2049 to use a bzImage for capturing the crash dump and want to use a 2050 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2051 to be specifically compiled to run from a specific memory area 2052 (normally a reserved region) and this option comes handy. 2053 2054 So if you are using bzImage for capturing the crash dump, 2055 leave the value here unchanged to 0x1000000 and set 2056 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2057 for capturing the crash dump change this value to start of 2058 the reserved region. In other words, it can be set based on 2059 the "X" value as specified in the "crashkernel=YM@XM" 2060 command line boot parameter passed to the panic-ed 2061 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2062 for more details about crash dumps. 2063 2064 Usage of bzImage for capturing the crash dump is recommended as 2065 one does not have to build two kernels. Same kernel can be used 2066 as production kernel and capture kernel. Above option should have 2067 gone away after relocatable bzImage support is introduced. But it 2068 is present because there are users out there who continue to use 2069 vmlinux for dump capture. This option should go away down the 2070 line. 2071 2072 Don't change this unless you know what you are doing. 2073 2074config RELOCATABLE 2075 bool "Build a relocatable kernel" 2076 default y 2077 help 2078 This builds a kernel image that retains relocation information 2079 so it can be loaded someplace besides the default 1MB. 2080 The relocations tend to make the kernel binary about 10% larger, 2081 but are discarded at runtime. 2082 2083 One use is for the kexec on panic case where the recovery kernel 2084 must live at a different physical address than the primary 2085 kernel. 2086 2087 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2088 it has been loaded at and the compile time physical address 2089 (CONFIG_PHYSICAL_START) is used as the minimum location. 2090 2091config RANDOMIZE_BASE 2092 bool "Randomize the address of the kernel image (KASLR)" 2093 depends on RELOCATABLE 2094 default y 2095 help 2096 In support of Kernel Address Space Layout Randomization (KASLR), 2097 this randomizes the physical address at which the kernel image 2098 is decompressed and the virtual address where the kernel 2099 image is mapped, as a security feature that deters exploit 2100 attempts relying on knowledge of the location of kernel 2101 code internals. 2102 2103 On 64-bit, the kernel physical and virtual addresses are 2104 randomized separately. The physical address will be anywhere 2105 between 16MB and the top of physical memory (up to 64TB). The 2106 virtual address will be randomized from 16MB up to 1GB (9 bits 2107 of entropy). Note that this also reduces the memory space 2108 available to kernel modules from 1.5GB to 1GB. 2109 2110 On 32-bit, the kernel physical and virtual addresses are 2111 randomized together. They will be randomized from 16MB up to 2112 512MB (8 bits of entropy). 2113 2114 Entropy is generated using the RDRAND instruction if it is 2115 supported. If RDTSC is supported, its value is mixed into 2116 the entropy pool as well. If neither RDRAND nor RDTSC are 2117 supported, then entropy is read from the i8254 timer. The 2118 usable entropy is limited by the kernel being built using 2119 2GB addressing, and that PHYSICAL_ALIGN must be at a 2120 minimum of 2MB. As a result, only 10 bits of entropy are 2121 theoretically possible, but the implementations are further 2122 limited due to memory layouts. 2123 2124 If unsure, say Y. 2125 2126# Relocation on x86 needs some additional build support 2127config X86_NEED_RELOCS 2128 def_bool y 2129 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2130 2131config PHYSICAL_ALIGN 2132 hex "Alignment value to which kernel should be aligned" 2133 default "0x200000" 2134 range 0x2000 0x1000000 if X86_32 2135 range 0x200000 0x1000000 if X86_64 2136 help 2137 This value puts the alignment restrictions on physical address 2138 where kernel is loaded and run from. Kernel is compiled for an 2139 address which meets above alignment restriction. 2140 2141 If bootloader loads the kernel at a non-aligned address and 2142 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2143 address aligned to above value and run from there. 2144 2145 If bootloader loads the kernel at a non-aligned address and 2146 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2147 load address and decompress itself to the address it has been 2148 compiled for and run from there. The address for which kernel is 2149 compiled already meets above alignment restrictions. Hence the 2150 end result is that kernel runs from a physical address meeting 2151 above alignment restrictions. 2152 2153 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2154 this value must be a multiple of 0x200000. 2155 2156 Don't change this unless you know what you are doing. 2157 2158config DYNAMIC_MEMORY_LAYOUT 2159 bool 2160 help 2161 This option makes base addresses of vmalloc and vmemmap as well as 2162 __PAGE_OFFSET movable during boot. 2163 2164config RANDOMIZE_MEMORY 2165 bool "Randomize the kernel memory sections" 2166 depends on X86_64 2167 depends on RANDOMIZE_BASE 2168 select DYNAMIC_MEMORY_LAYOUT 2169 default RANDOMIZE_BASE 2170 help 2171 Randomizes the base virtual address of kernel memory sections 2172 (physical memory mapping, vmalloc & vmemmap). This security feature 2173 makes exploits relying on predictable memory locations less reliable. 2174 2175 The order of allocations remains unchanged. Entropy is generated in 2176 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2177 configuration have in average 30,000 different possible virtual 2178 addresses for each memory section. 2179 2180 If unsure, say Y. 2181 2182config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2183 hex "Physical memory mapping padding" if EXPERT 2184 depends on RANDOMIZE_MEMORY 2185 default "0xa" if MEMORY_HOTPLUG 2186 default "0x0" 2187 range 0x1 0x40 if MEMORY_HOTPLUG 2188 range 0x0 0x40 2189 help 2190 Define the padding in terabytes added to the existing physical 2191 memory size during kernel memory randomization. It is useful 2192 for memory hotplug support but reduces the entropy available for 2193 address randomization. 2194 2195 If unsure, leave at the default value. 2196 2197config ADDRESS_MASKING 2198 bool "Linear Address Masking support" 2199 depends on X86_64 2200 depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS 2201 help 2202 Linear Address Masking (LAM) modifies the checking that is applied 2203 to 64-bit linear addresses, allowing software to use of the 2204 untranslated address bits for metadata. 2205 2206 The capability can be used for efficient address sanitizers (ASAN) 2207 implementation and for optimizations in JITs. 2208 2209config HOTPLUG_CPU 2210 def_bool y 2211 depends on SMP 2212 2213config COMPAT_VDSO 2214 def_bool n 2215 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2216 depends on COMPAT_32 2217 help 2218 Certain buggy versions of glibc will crash if they are 2219 presented with a 32-bit vDSO that is not mapped at the address 2220 indicated in its segment table. 2221 2222 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2223 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2224 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2225 the only released version with the bug, but OpenSUSE 9 2226 contains a buggy "glibc 2.3.2". 2227 2228 The symptom of the bug is that everything crashes on startup, saying: 2229 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2230 2231 Saying Y here changes the default value of the vdso32 boot 2232 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2233 This works around the glibc bug but hurts performance. 2234 2235 If unsure, say N: if you are compiling your own kernel, you 2236 are unlikely to be using a buggy version of glibc. 2237 2238choice 2239 prompt "vsyscall table for legacy applications" 2240 depends on X86_64 2241 default LEGACY_VSYSCALL_XONLY 2242 help 2243 Legacy user code that does not know how to find the vDSO expects 2244 to be able to issue three syscalls by calling fixed addresses in 2245 kernel space. Since this location is not randomized with ASLR, 2246 it can be used to assist security vulnerability exploitation. 2247 2248 This setting can be changed at boot time via the kernel command 2249 line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2250 is deprecated and can only be enabled using the kernel command 2251 line. 2252 2253 On a system with recent enough glibc (2.14 or newer) and no 2254 static binaries, you can say None without a performance penalty 2255 to improve security. 2256 2257 If unsure, select "Emulate execution only". 2258 2259 config LEGACY_VSYSCALL_XONLY 2260 bool "Emulate execution only" 2261 help 2262 The kernel traps and emulates calls into the fixed vsyscall 2263 address mapping and does not allow reads. This 2264 configuration is recommended when userspace might use the 2265 legacy vsyscall area but support for legacy binary 2266 instrumentation of legacy code is not needed. It mitigates 2267 certain uses of the vsyscall area as an ASLR-bypassing 2268 buffer. 2269 2270 config LEGACY_VSYSCALL_NONE 2271 bool "None" 2272 help 2273 There will be no vsyscall mapping at all. This will 2274 eliminate any risk of ASLR bypass due to the vsyscall 2275 fixed address mapping. Attempts to use the vsyscalls 2276 will be reported to dmesg, so that either old or 2277 malicious userspace programs can be identified. 2278 2279endchoice 2280 2281config CMDLINE_BOOL 2282 bool "Built-in kernel command line" 2283 help 2284 Allow for specifying boot arguments to the kernel at 2285 build time. On some systems (e.g. embedded ones), it is 2286 necessary or convenient to provide some or all of the 2287 kernel boot arguments with the kernel itself (that is, 2288 to not rely on the boot loader to provide them.) 2289 2290 To compile command line arguments into the kernel, 2291 set this option to 'Y', then fill in the 2292 boot arguments in CONFIG_CMDLINE. 2293 2294 Systems with fully functional boot loaders (i.e. non-embedded) 2295 should leave this option set to 'N'. 2296 2297config CMDLINE 2298 string "Built-in kernel command string" 2299 depends on CMDLINE_BOOL 2300 default "" 2301 help 2302 Enter arguments here that should be compiled into the kernel 2303 image and used at boot time. If the boot loader provides a 2304 command line at boot time, it is appended to this string to 2305 form the full kernel command line, when the system boots. 2306 2307 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2308 change this behavior. 2309 2310 In most cases, the command line (whether built-in or provided 2311 by the boot loader) should specify the device for the root 2312 file system. 2313 2314config CMDLINE_OVERRIDE 2315 bool "Built-in command line overrides boot loader arguments" 2316 depends on CMDLINE_BOOL && CMDLINE != "" 2317 help 2318 Set this option to 'Y' to have the kernel ignore the boot loader 2319 command line, and use ONLY the built-in command line. 2320 2321 This is used to work around broken boot loaders. This should 2322 be set to 'N' under normal conditions. 2323 2324config MODIFY_LDT_SYSCALL 2325 bool "Enable the LDT (local descriptor table)" if EXPERT 2326 default y 2327 help 2328 Linux can allow user programs to install a per-process x86 2329 Local Descriptor Table (LDT) using the modify_ldt(2) system 2330 call. This is required to run 16-bit or segmented code such as 2331 DOSEMU or some Wine programs. It is also used by some very old 2332 threading libraries. 2333 2334 Enabling this feature adds a small amount of overhead to 2335 context switches and increases the low-level kernel attack 2336 surface. Disabling it removes the modify_ldt(2) system call. 2337 2338 Saying 'N' here may make sense for embedded or server kernels. 2339 2340config STRICT_SIGALTSTACK_SIZE 2341 bool "Enforce strict size checking for sigaltstack" 2342 depends on DYNAMIC_SIGFRAME 2343 help 2344 For historical reasons MINSIGSTKSZ is a constant which became 2345 already too small with AVX512 support. Add a mechanism to 2346 enforce strict checking of the sigaltstack size against the 2347 real size of the FPU frame. This option enables the check 2348 by default. It can also be controlled via the kernel command 2349 line option 'strict_sas_size' independent of this config 2350 switch. Enabling it might break existing applications which 2351 allocate a too small sigaltstack but 'work' because they 2352 never get a signal delivered. 2353 2354 Say 'N' unless you want to really enforce this check. 2355 2356config CFI_AUTO_DEFAULT 2357 bool "Attempt to use FineIBT by default at boot time" 2358 depends on FINEIBT 2359 default y 2360 help 2361 Attempt to use FineIBT by default at boot time. If enabled, 2362 this is the same as booting with "cfi=auto". If disabled, 2363 this is the same as booting with "cfi=kcfi". 2364 2365source "kernel/livepatch/Kconfig" 2366 2367config X86_BUS_LOCK_DETECT 2368 bool "Split Lock Detect and Bus Lock Detect support" 2369 depends on CPU_SUP_INTEL || CPU_SUP_AMD 2370 default y 2371 help 2372 Enable Split Lock Detect and Bus Lock Detect functionalities. 2373 See <file:Documentation/arch/x86/buslock.rst> for more information. 2374 2375endmenu 2376 2377config CC_HAS_NAMED_AS 2378 def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null) 2379 depends on CC_IS_GCC 2380 2381# 2382# -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN) 2383# are incompatible with named address spaces with GCC < 13.3 2384# (see GCC PR sanitizer/111736 and also PR sanitizer/115172). 2385# 2386 2387config CC_HAS_NAMED_AS_FIXED_SANITIZERS 2388 def_bool y 2389 depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300 2390 depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200 2391 2392config USE_X86_SEG_SUPPORT 2393 def_bool CC_HAS_NAMED_AS 2394 depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS 2395 2396config CC_HAS_SLS 2397 def_bool $(cc-option,-mharden-sls=all) 2398 2399config CC_HAS_RETURN_THUNK 2400 def_bool $(cc-option,-mfunction-return=thunk-extern) 2401 2402config CC_HAS_ENTRY_PADDING 2403 def_bool $(cc-option,-fpatchable-function-entry=16,16) 2404 2405config CC_HAS_KCFI_ARITY 2406 def_bool $(cc-option,-fsanitize=kcfi -fsanitize-kcfi-arity) 2407 depends on CC_IS_CLANG && !RUST 2408 2409config FUNCTION_PADDING_CFI 2410 int 2411 default 59 if FUNCTION_ALIGNMENT_64B 2412 default 27 if FUNCTION_ALIGNMENT_32B 2413 default 11 if FUNCTION_ALIGNMENT_16B 2414 default 3 if FUNCTION_ALIGNMENT_8B 2415 default 0 2416 2417# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG 2418# except Kconfig can't do arithmetic :/ 2419config FUNCTION_PADDING_BYTES 2420 int 2421 default FUNCTION_PADDING_CFI if CFI_CLANG 2422 default FUNCTION_ALIGNMENT 2423 2424config CALL_PADDING 2425 def_bool n 2426 depends on CC_HAS_ENTRY_PADDING && OBJTOOL 2427 select FUNCTION_ALIGNMENT_16B 2428 2429config FINEIBT 2430 def_bool y 2431 depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE 2432 select CALL_PADDING 2433 2434config FINEIBT_BHI 2435 def_bool y 2436 depends on FINEIBT && CC_HAS_KCFI_ARITY 2437 2438config HAVE_CALL_THUNKS 2439 def_bool y 2440 depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL 2441 2442config CALL_THUNKS 2443 def_bool n 2444 select CALL_PADDING 2445 2446config PREFIX_SYMBOLS 2447 def_bool y 2448 depends on CALL_PADDING && !CFI_CLANG 2449 2450menuconfig CPU_MITIGATIONS 2451 bool "Mitigations for CPU vulnerabilities" 2452 default y 2453 help 2454 Say Y here to enable options which enable mitigations for hardware 2455 vulnerabilities (usually related to speculative execution). 2456 Mitigations can be disabled or restricted to SMT systems at runtime 2457 via the "mitigations" kernel parameter. 2458 2459 If you say N, all mitigations will be disabled. This CANNOT be 2460 overridden at runtime. 2461 2462 Say 'Y', unless you really know what you are doing. 2463 2464if CPU_MITIGATIONS 2465 2466config MITIGATION_PAGE_TABLE_ISOLATION 2467 bool "Remove the kernel mapping in user mode" 2468 default y 2469 depends on (X86_64 || X86_PAE) 2470 help 2471 This feature reduces the number of hardware side channels by 2472 ensuring that the majority of kernel addresses are not mapped 2473 into userspace. 2474 2475 See Documentation/arch/x86/pti.rst for more details. 2476 2477config MITIGATION_RETPOLINE 2478 bool "Avoid speculative indirect branches in kernel" 2479 select OBJTOOL if HAVE_OBJTOOL 2480 default y 2481 help 2482 Compile kernel with the retpoline compiler options to guard against 2483 kernel-to-user data leaks by avoiding speculative indirect 2484 branches. Requires a compiler with -mindirect-branch=thunk-extern 2485 support for full protection. The kernel may run slower. 2486 2487config MITIGATION_RETHUNK 2488 bool "Enable return-thunks" 2489 depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK 2490 select OBJTOOL if HAVE_OBJTOOL 2491 default y if X86_64 2492 help 2493 Compile the kernel with the return-thunks compiler option to guard 2494 against kernel-to-user data leaks by avoiding return speculation. 2495 Requires a compiler with -mfunction-return=thunk-extern 2496 support for full protection. The kernel may run slower. 2497 2498config MITIGATION_UNRET_ENTRY 2499 bool "Enable UNRET on kernel entry" 2500 depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64 2501 default y 2502 help 2503 Compile the kernel with support for the retbleed=unret mitigation. 2504 2505config MITIGATION_CALL_DEPTH_TRACKING 2506 bool "Mitigate RSB underflow with call depth tracking" 2507 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 2508 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 2509 select CALL_THUNKS 2510 default y 2511 help 2512 Compile the kernel with call depth tracking to mitigate the Intel 2513 SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off 2514 by default and needs to be enabled on the kernel command line via the 2515 retbleed=stuff option. For non-affected systems the overhead of this 2516 option is marginal as the call depth tracking is using run-time 2517 generated call thunks in a compiler generated padding area and call 2518 patching. This increases text size by ~5%. For non affected systems 2519 this space is unused. On affected SKL systems this results in a 2520 significant performance gain over the IBRS mitigation. 2521 2522config CALL_THUNKS_DEBUG 2523 bool "Enable call thunks and call depth tracking debugging" 2524 depends on MITIGATION_CALL_DEPTH_TRACKING 2525 select FUNCTION_ALIGNMENT_32B 2526 default n 2527 help 2528 Enable call/ret counters for imbalance detection and build in 2529 a noisy dmesg about callthunks generation and call patching for 2530 trouble shooting. The debug prints need to be enabled on the 2531 kernel command line with 'debug-callthunks'. 2532 Only enable this when you are debugging call thunks as this 2533 creates a noticeable runtime overhead. If unsure say N. 2534 2535config MITIGATION_IBPB_ENTRY 2536 bool "Enable IBPB on kernel entry" 2537 depends on CPU_SUP_AMD && X86_64 2538 default y 2539 help 2540 Compile the kernel with support for the retbleed=ibpb and 2541 spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations. 2542 2543config MITIGATION_IBRS_ENTRY 2544 bool "Enable IBRS on kernel entry" 2545 depends on CPU_SUP_INTEL && X86_64 2546 default y 2547 help 2548 Compile the kernel with support for the spectre_v2=ibrs mitigation. 2549 This mitigates both spectre_v2 and retbleed at great cost to 2550 performance. 2551 2552config MITIGATION_SRSO 2553 bool "Mitigate speculative RAS overflow on AMD" 2554 depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK 2555 default y 2556 help 2557 Enable the SRSO mitigation needed on AMD Zen1-4 machines. 2558 2559config MITIGATION_SLS 2560 bool "Mitigate Straight-Line-Speculation" 2561 depends on CC_HAS_SLS && X86_64 2562 select OBJTOOL if HAVE_OBJTOOL 2563 default n 2564 help 2565 Compile the kernel with straight-line-speculation options to guard 2566 against straight line speculation. The kernel image might be slightly 2567 larger. 2568 2569config MITIGATION_GDS 2570 bool "Mitigate Gather Data Sampling" 2571 depends on CPU_SUP_INTEL 2572 default y 2573 help 2574 Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware 2575 vulnerability which allows unprivileged speculative access to data 2576 which was previously stored in vector registers. The attacker uses gather 2577 instructions to infer the stale vector register data. 2578 2579config MITIGATION_RFDS 2580 bool "RFDS Mitigation" 2581 depends on CPU_SUP_INTEL 2582 default y 2583 help 2584 Enable mitigation for Register File Data Sampling (RFDS) by default. 2585 RFDS is a hardware vulnerability which affects Intel Atom CPUs. It 2586 allows unprivileged speculative access to stale data previously 2587 stored in floating point, vector and integer registers. 2588 See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> 2589 2590config MITIGATION_SPECTRE_BHI 2591 bool "Mitigate Spectre-BHB (Branch History Injection)" 2592 depends on CPU_SUP_INTEL 2593 default y 2594 help 2595 Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks 2596 where the branch history buffer is poisoned to speculatively steer 2597 indirect branches. 2598 See <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2599 2600config MITIGATION_MDS 2601 bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug" 2602 depends on CPU_SUP_INTEL 2603 default y 2604 help 2605 Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is 2606 a hardware vulnerability which allows unprivileged speculative access 2607 to data which is available in various CPU internal buffers. 2608 See also <file:Documentation/admin-guide/hw-vuln/mds.rst> 2609 2610config MITIGATION_TAA 2611 bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug" 2612 depends on CPU_SUP_INTEL 2613 default y 2614 help 2615 Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware 2616 vulnerability that allows unprivileged speculative access to data 2617 which is available in various CPU internal buffers by using 2618 asynchronous aborts within an Intel TSX transactional region. 2619 See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst> 2620 2621config MITIGATION_MMIO_STALE_DATA 2622 bool "Mitigate MMIO Stale Data hardware bug" 2623 depends on CPU_SUP_INTEL 2624 default y 2625 help 2626 Enable mitigation for MMIO Stale Data hardware bugs. Processor MMIO 2627 Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO) 2628 vulnerabilities that can expose data. The vulnerabilities require the 2629 attacker to have access to MMIO. 2630 See also 2631 <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst> 2632 2633config MITIGATION_L1TF 2634 bool "Mitigate L1 Terminal Fault (L1TF) hardware bug" 2635 depends on CPU_SUP_INTEL 2636 default y 2637 help 2638 Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a 2639 hardware vulnerability which allows unprivileged speculative access to data 2640 available in the Level 1 Data Cache. 2641 See <file:Documentation/admin-guide/hw-vuln/l1tf.rst 2642 2643config MITIGATION_RETBLEED 2644 bool "Mitigate RETBleed hardware bug" 2645 depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY 2646 default y 2647 help 2648 Enable mitigation for RETBleed (Arbitrary Speculative Code Execution 2649 with Return Instructions) vulnerability. RETBleed is a speculative 2650 execution attack which takes advantage of microarchitectural behavior 2651 in many modern microprocessors, similar to Spectre v2. An 2652 unprivileged attacker can use these flaws to bypass conventional 2653 memory security restrictions to gain read access to privileged memory 2654 that would otherwise be inaccessible. 2655 2656config MITIGATION_SPECTRE_V1 2657 bool "Mitigate SPECTRE V1 hardware bug" 2658 default y 2659 help 2660 Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a 2661 class of side channel attacks that takes advantage of speculative 2662 execution that bypasses conditional branch instructions used for 2663 memory access bounds check. 2664 See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2665 2666config MITIGATION_SPECTRE_V2 2667 bool "Mitigate SPECTRE V2 hardware bug" 2668 default y 2669 help 2670 Enable mitigation for Spectre V2 (Branch Target Injection). Spectre 2671 V2 is a class of side channel attacks that takes advantage of 2672 indirect branch predictors inside the processor. In Spectre variant 2 2673 attacks, the attacker can steer speculative indirect branches in the 2674 victim to gadget code by poisoning the branch target buffer of a CPU 2675 used for predicting indirect branch addresses. 2676 See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2677 2678config MITIGATION_SRBDS 2679 bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug" 2680 depends on CPU_SUP_INTEL 2681 default y 2682 help 2683 Enable mitigation for Special Register Buffer Data Sampling (SRBDS). 2684 SRBDS is a hardware vulnerability that allows Microarchitectural Data 2685 Sampling (MDS) techniques to infer values returned from special 2686 register accesses. An unprivileged user can extract values returned 2687 from RDRAND and RDSEED executed on another core or sibling thread 2688 using MDS techniques. 2689 See also 2690 <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst> 2691 2692config MITIGATION_SSB 2693 bool "Mitigate Speculative Store Bypass (SSB) hardware bug" 2694 default y 2695 help 2696 Enable mitigation for Speculative Store Bypass (SSB). SSB is a 2697 hardware security vulnerability and its exploitation takes advantage 2698 of speculative execution in a similar way to the Meltdown and Spectre 2699 security vulnerabilities. 2700 2701endif 2702 2703config ARCH_HAS_ADD_PAGES 2704 def_bool y 2705 depends on ARCH_ENABLE_MEMORY_HOTPLUG 2706 2707menu "Power management and ACPI options" 2708 2709config ARCH_HIBERNATION_HEADER 2710 def_bool y 2711 depends on HIBERNATION 2712 2713source "kernel/power/Kconfig" 2714 2715source "drivers/acpi/Kconfig" 2716 2717config X86_APM_BOOT 2718 def_bool y 2719 depends on APM 2720 2721menuconfig APM 2722 tristate "APM (Advanced Power Management) BIOS support" 2723 depends on X86_32 && PM_SLEEP 2724 help 2725 APM is a BIOS specification for saving power using several different 2726 techniques. This is mostly useful for battery powered laptops with 2727 APM compliant BIOSes. If you say Y here, the system time will be 2728 reset after a RESUME operation, the /proc/apm device will provide 2729 battery status information, and user-space programs will receive 2730 notification of APM "events" (e.g. battery status change). 2731 2732 If you select "Y" here, you can disable actual use of the APM 2733 BIOS by passing the "apm=off" option to the kernel at boot time. 2734 2735 Note that the APM support is almost completely disabled for 2736 machines with more than one CPU. 2737 2738 In order to use APM, you will need supporting software. For location 2739 and more information, read <file:Documentation/power/apm-acpi.rst> 2740 and the Battery Powered Linux mini-HOWTO, available from 2741 <http://www.tldp.org/docs.html#howto>. 2742 2743 This driver does not spin down disk drives (see the hdparm(8) 2744 manpage ("man 8 hdparm") for that), and it doesn't turn off 2745 VESA-compliant "green" monitors. 2746 2747 This driver does not support the TI 4000M TravelMate and the ACER 2748 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2749 desktop machines also don't have compliant BIOSes, and this driver 2750 may cause those machines to panic during the boot phase. 2751 2752 Generally, if you don't have a battery in your machine, there isn't 2753 much point in using this driver and you should say N. If you get 2754 random kernel OOPSes or reboots that don't seem to be related to 2755 anything, try disabling/enabling this option (or disabling/enabling 2756 APM in your BIOS). 2757 2758 Some other things you should try when experiencing seemingly random, 2759 "weird" problems: 2760 2761 1) make sure that you have enough swap space and that it is 2762 enabled. 2763 2) pass the "idle=poll" option to the kernel 2764 3) switch on floating point emulation in the kernel and pass 2765 the "no387" option to the kernel 2766 4) pass the "floppy=nodma" option to the kernel 2767 5) pass the "mem=4M" option to the kernel (thereby disabling 2768 all but the first 4 MB of RAM) 2769 6) make sure that the CPU is not over clocked. 2770 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2771 8) disable the cache from your BIOS settings 2772 9) install a fan for the video card or exchange video RAM 2773 10) install a better fan for the CPU 2774 11) exchange RAM chips 2775 12) exchange the motherboard. 2776 2777 To compile this driver as a module, choose M here: the 2778 module will be called apm. 2779 2780if APM 2781 2782config APM_IGNORE_USER_SUSPEND 2783 bool "Ignore USER SUSPEND" 2784 help 2785 This option will ignore USER SUSPEND requests. On machines with a 2786 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2787 series notebooks, it is necessary to say Y because of a BIOS bug. 2788 2789config APM_DO_ENABLE 2790 bool "Enable PM at boot time" 2791 help 2792 Enable APM features at boot time. From page 36 of the APM BIOS 2793 specification: "When disabled, the APM BIOS does not automatically 2794 power manage devices, enter the Standby State, enter the Suspend 2795 State, or take power saving steps in response to CPU Idle calls." 2796 This driver will make CPU Idle calls when Linux is idle (unless this 2797 feature is turned off -- see "Do CPU IDLE calls", below). This 2798 should always save battery power, but more complicated APM features 2799 will be dependent on your BIOS implementation. You may need to turn 2800 this option off if your computer hangs at boot time when using APM 2801 support, or if it beeps continuously instead of suspending. Turn 2802 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2803 T400CDT. This is off by default since most machines do fine without 2804 this feature. 2805 2806config APM_CPU_IDLE 2807 depends on CPU_IDLE 2808 bool "Make CPU Idle calls when idle" 2809 help 2810 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2811 On some machines, this can activate improved power savings, such as 2812 a slowed CPU clock rate, when the machine is idle. These idle calls 2813 are made after the idle loop has run for some length of time (e.g., 2814 333 mS). On some machines, this will cause a hang at boot time or 2815 whenever the CPU becomes idle. (On machines with more than one CPU, 2816 this option does nothing.) 2817 2818config APM_DISPLAY_BLANK 2819 bool "Enable console blanking using APM" 2820 help 2821 Enable console blanking using the APM. Some laptops can use this to 2822 turn off the LCD backlight when the screen blanker of the Linux 2823 virtual console blanks the screen. Note that this is only used by 2824 the virtual console screen blanker, and won't turn off the backlight 2825 when using the X Window system. This also doesn't have anything to 2826 do with your VESA-compliant power-saving monitor. Further, this 2827 option doesn't work for all laptops -- it might not turn off your 2828 backlight at all, or it might print a lot of errors to the console, 2829 especially if you are using gpm. 2830 2831config APM_ALLOW_INTS 2832 bool "Allow interrupts during APM BIOS calls" 2833 help 2834 Normally we disable external interrupts while we are making calls to 2835 the APM BIOS as a measure to lessen the effects of a badly behaving 2836 BIOS implementation. The BIOS should reenable interrupts if it 2837 needs to. Unfortunately, some BIOSes do not -- especially those in 2838 many of the newer IBM Thinkpads. If you experience hangs when you 2839 suspend, try setting this to Y. Otherwise, say N. 2840 2841endif # APM 2842 2843source "drivers/cpufreq/Kconfig" 2844 2845source "drivers/cpuidle/Kconfig" 2846 2847source "drivers/idle/Kconfig" 2848 2849endmenu 2850 2851menu "Bus options (PCI etc.)" 2852 2853choice 2854 prompt "PCI access mode" 2855 depends on X86_32 && PCI 2856 default PCI_GOANY 2857 help 2858 On PCI systems, the BIOS can be used to detect the PCI devices and 2859 determine their configuration. However, some old PCI motherboards 2860 have BIOS bugs and may crash if this is done. Also, some embedded 2861 PCI-based systems don't have any BIOS at all. Linux can also try to 2862 detect the PCI hardware directly without using the BIOS. 2863 2864 With this option, you can specify how Linux should detect the 2865 PCI devices. If you choose "BIOS", the BIOS will be used, 2866 if you choose "Direct", the BIOS won't be used, and if you 2867 choose "MMConfig", then PCI Express MMCONFIG will be used. 2868 If you choose "Any", the kernel will try MMCONFIG, then the 2869 direct access method and falls back to the BIOS if that doesn't 2870 work. If unsure, go with the default, which is "Any". 2871 2872config PCI_GOBIOS 2873 bool "BIOS" 2874 2875config PCI_GOMMCONFIG 2876 bool "MMConfig" 2877 2878config PCI_GODIRECT 2879 bool "Direct" 2880 2881config PCI_GOOLPC 2882 bool "OLPC XO-1" 2883 depends on OLPC 2884 2885config PCI_GOANY 2886 bool "Any" 2887 2888endchoice 2889 2890config PCI_BIOS 2891 def_bool y 2892 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2893 2894# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2895config PCI_DIRECT 2896 def_bool y 2897 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2898 2899config PCI_MMCONFIG 2900 bool "Support mmconfig PCI config space access" if X86_64 2901 default y 2902 depends on PCI && (ACPI || JAILHOUSE_GUEST) 2903 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2904 2905config PCI_OLPC 2906 def_bool y 2907 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2908 2909config PCI_XEN 2910 def_bool y 2911 depends on PCI && XEN 2912 2913config MMCONF_FAM10H 2914 def_bool y 2915 depends on X86_64 && PCI_MMCONFIG && ACPI 2916 2917config PCI_CNB20LE_QUIRK 2918 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2919 depends on PCI 2920 help 2921 Read the PCI windows out of the CNB20LE host bridge. This allows 2922 PCI hotplug to work on systems with the CNB20LE chipset which do 2923 not have ACPI. 2924 2925 There's no public spec for this chipset, and this functionality 2926 is known to be incomplete. 2927 2928 You should say N unless you know you need this. 2929 2930config ISA_BUS 2931 bool "ISA bus support on modern systems" if EXPERT 2932 help 2933 Expose ISA bus device drivers and options available for selection and 2934 configuration. Enable this option if your target machine has an ISA 2935 bus. ISA is an older system, displaced by PCI and newer bus 2936 architectures -- if your target machine is modern, it probably does 2937 not have an ISA bus. 2938 2939 If unsure, say N. 2940 2941# x86_64 have no ISA slots, but can have ISA-style DMA. 2942config ISA_DMA_API 2943 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2944 default y 2945 help 2946 Enables ISA-style DMA support for devices requiring such controllers. 2947 If unsure, say Y. 2948 2949if X86_32 2950 2951config ISA 2952 bool "ISA support" 2953 help 2954 Find out whether you have ISA slots on your motherboard. ISA is the 2955 name of a bus system, i.e. the way the CPU talks to the other stuff 2956 inside your box. Other bus systems are PCI, EISA, MicroChannel 2957 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2958 newer boards don't support it. If you have ISA, say Y, otherwise N. 2959 2960config SCx200 2961 tristate "NatSemi SCx200 support" 2962 help 2963 This provides basic support for National Semiconductor's 2964 (now AMD's) Geode processors. The driver probes for the 2965 PCI-IDs of several on-chip devices, so its a good dependency 2966 for other scx200_* drivers. 2967 2968 If compiled as a module, the driver is named scx200. 2969 2970config SCx200HR_TIMER 2971 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2972 depends on SCx200 2973 default y 2974 help 2975 This driver provides a clocksource built upon the on-chip 2976 27MHz high-resolution timer. Its also a workaround for 2977 NSC Geode SC-1100's buggy TSC, which loses time when the 2978 processor goes idle (as is done by the scheduler). The 2979 other workaround is idle=poll boot option. 2980 2981config OLPC 2982 bool "One Laptop Per Child support" 2983 depends on !X86_PAE 2984 select GPIOLIB 2985 select OF 2986 select OF_PROMTREE 2987 select IRQ_DOMAIN 2988 select OLPC_EC 2989 help 2990 Add support for detecting the unique features of the OLPC 2991 XO hardware. 2992 2993config OLPC_XO1_PM 2994 bool "OLPC XO-1 Power Management" 2995 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2996 help 2997 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2998 2999config OLPC_XO1_RTC 3000 bool "OLPC XO-1 Real Time Clock" 3001 depends on OLPC_XO1_PM && RTC_DRV_CMOS 3002 help 3003 Add support for the XO-1 real time clock, which can be used as a 3004 programmable wakeup source. 3005 3006config OLPC_XO1_SCI 3007 bool "OLPC XO-1 SCI extras" 3008 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 3009 depends on INPUT=y 3010 select POWER_SUPPLY 3011 help 3012 Add support for SCI-based features of the OLPC XO-1 laptop: 3013 - EC-driven system wakeups 3014 - Power button 3015 - Ebook switch 3016 - Lid switch 3017 - AC adapter status updates 3018 - Battery status updates 3019 3020config OLPC_XO15_SCI 3021 bool "OLPC XO-1.5 SCI extras" 3022 depends on OLPC && ACPI 3023 select POWER_SUPPLY 3024 help 3025 Add support for SCI-based features of the OLPC XO-1.5 laptop: 3026 - EC-driven system wakeups 3027 - AC adapter status updates 3028 - Battery status updates 3029 3030config GEODE_COMMON 3031 bool 3032 3033config ALIX 3034 bool "PCEngines ALIX System Support (LED setup)" 3035 select GPIOLIB 3036 select GEODE_COMMON 3037 help 3038 This option enables system support for the PCEngines ALIX. 3039 At present this just sets up LEDs for GPIO control on 3040 ALIX2/3/6 boards. However, other system specific setup should 3041 get added here. 3042 3043 Note: You must still enable the drivers for GPIO and LED support 3044 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 3045 3046 Note: You have to set alix.force=1 for boards with Award BIOS. 3047 3048config NET5501 3049 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 3050 select GPIOLIB 3051 select GEODE_COMMON 3052 help 3053 This option enables system support for the Soekris Engineering net5501. 3054 3055config GEOS 3056 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 3057 select GPIOLIB 3058 select GEODE_COMMON 3059 depends on DMI 3060 help 3061 This option enables system support for the Traverse Technologies GEOS. 3062 3063config TS5500 3064 bool "Technologic Systems TS-5500 platform support" 3065 depends on MELAN 3066 select CHECK_SIGNATURE 3067 select NEW_LEDS 3068 select LEDS_CLASS 3069 help 3070 This option enables system support for the Technologic Systems TS-5500. 3071 3072endif # X86_32 3073 3074config AMD_NB 3075 def_bool y 3076 depends on AMD_NODE 3077 3078config AMD_NODE 3079 def_bool y 3080 depends on CPU_SUP_AMD && PCI 3081 3082endmenu 3083 3084menu "Binary Emulations" 3085 3086config IA32_EMULATION 3087 bool "IA32 Emulation" 3088 depends on X86_64 3089 select ARCH_WANT_OLD_COMPAT_IPC 3090 select BINFMT_ELF 3091 select COMPAT_OLD_SIGACTION 3092 help 3093 Include code to run legacy 32-bit programs under a 3094 64-bit kernel. You should likely turn this on, unless you're 3095 100% sure that you don't have any 32-bit programs left. 3096 3097config IA32_EMULATION_DEFAULT_DISABLED 3098 bool "IA32 emulation disabled by default" 3099 default n 3100 depends on IA32_EMULATION 3101 help 3102 Make IA32 emulation disabled by default. This prevents loading 32-bit 3103 processes and access to 32-bit syscalls. If unsure, leave it to its 3104 default value. 3105 3106config X86_X32_ABI 3107 bool "x32 ABI for 64-bit mode" 3108 depends on X86_64 3109 # llvm-objcopy does not convert x86_64 .note.gnu.property or 3110 # compressed debug sections to x86_x32 properly: 3111 # https://github.com/ClangBuiltLinux/linux/issues/514 3112 # https://github.com/ClangBuiltLinux/linux/issues/1141 3113 depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 3114 help 3115 Include code to run binaries for the x32 native 32-bit ABI 3116 for 64-bit processors. An x32 process gets access to the 3117 full 64-bit register file and wide data path while leaving 3118 pointers at 32 bits for smaller memory footprint. 3119 3120config COMPAT_32 3121 def_bool y 3122 depends on IA32_EMULATION || X86_32 3123 select HAVE_UID16 3124 select OLD_SIGSUSPEND3 3125 3126config COMPAT 3127 def_bool y 3128 depends on IA32_EMULATION || X86_X32_ABI 3129 3130config COMPAT_FOR_U64_ALIGNMENT 3131 def_bool y 3132 depends on COMPAT 3133 3134endmenu 3135 3136config HAVE_ATOMIC_IOMAP 3137 def_bool y 3138 depends on X86_32 3139 3140source "arch/x86/kvm/Kconfig" 3141 3142source "arch/x86/Kconfig.cpufeatures" 3143 3144source "arch/x86/Kconfig.assembler" 3145