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_CRC_T10DIF if X86_64 81 select ARCH_HAS_CURRENT_STACK_POINTER 82 select ARCH_HAS_DEBUG_VIRTUAL 83 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 84 select ARCH_HAS_DEVMEM_IS_ALLOWED 85 select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN 86 select ARCH_HAS_EARLY_DEBUG if KGDB 87 select ARCH_HAS_ELF_RANDOMIZE 88 select ARCH_HAS_EXECMEM_ROX if X86_64 89 select ARCH_HAS_FAST_MULTIPLIER 90 select ARCH_HAS_FORTIFY_SOURCE 91 select ARCH_HAS_GCOV_PROFILE_ALL 92 select ARCH_HAS_KCOV if X86_64 93 select ARCH_HAS_KERNEL_FPU_SUPPORT 94 select ARCH_HAS_MEM_ENCRYPT 95 select ARCH_HAS_MEMBARRIER_SYNC_CORE 96 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 97 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 98 select ARCH_HAS_PMEM_API if X86_64 99 select ARCH_HAS_PREEMPT_LAZY 100 select ARCH_HAS_PTE_DEVMAP if X86_64 101 select ARCH_HAS_PTE_SPECIAL 102 select ARCH_HAS_HW_PTE_YOUNG 103 select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 104 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 105 select ARCH_HAS_COPY_MC if X86_64 106 select ARCH_HAS_SET_MEMORY 107 select ARCH_HAS_SET_DIRECT_MAP 108 select ARCH_HAS_STRICT_KERNEL_RWX 109 select ARCH_HAS_STRICT_MODULE_RWX 110 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 111 select ARCH_HAS_SYSCALL_WRAPPER 112 select ARCH_HAS_UBSAN 113 select ARCH_HAS_DEBUG_WX 114 select ARCH_HAS_ZONE_DMA_SET if EXPERT 115 select ARCH_HAVE_NMI_SAFE_CMPXCHG 116 select ARCH_HAVE_EXTRA_ELF_NOTES 117 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 118 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 119 select ARCH_MIGHT_HAVE_PC_PARPORT 120 select ARCH_MIGHT_HAVE_PC_SERIO 121 select ARCH_STACKWALK 122 select ARCH_SUPPORTS_ACPI 123 select ARCH_SUPPORTS_ATOMIC_RMW 124 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 125 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 126 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 127 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 128 select ARCH_SUPPORTS_CFI_CLANG if X86_64 129 select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG 130 select ARCH_SUPPORTS_LTO_CLANG 131 select ARCH_SUPPORTS_LTO_CLANG_THIN 132 select ARCH_SUPPORTS_RT 133 select ARCH_SUPPORTS_AUTOFDO_CLANG 134 select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64 135 select ARCH_USE_BUILTIN_BSWAP 136 select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8 137 select ARCH_USE_MEMTEST 138 select ARCH_USE_QUEUED_RWLOCKS 139 select ARCH_USE_QUEUED_SPINLOCKS 140 select ARCH_USE_SYM_ANNOTATIONS 141 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 142 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 143 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 144 select ARCH_WANTS_NO_INSTR 145 select ARCH_WANT_GENERAL_HUGETLB 146 select ARCH_WANT_HUGE_PMD_SHARE 147 select ARCH_WANT_LD_ORPHAN_WARN 148 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 149 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 150 select ARCH_WANTS_THP_SWAP if X86_64 151 select ARCH_HAS_PARANOID_L1D_FLUSH 152 select BUILDTIME_TABLE_SORT 153 select CLKEVT_I8253 154 select CLOCKSOURCE_WATCHDOG 155 # Word-size accesses may read uninitialized data past the trailing \0 156 # in strings and cause false KMSAN reports. 157 select DCACHE_WORD_ACCESS if !KMSAN 158 select DYNAMIC_SIGFRAME 159 select EDAC_ATOMIC_SCRUB 160 select EDAC_SUPPORT 161 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 162 select GENERIC_CLOCKEVENTS_BROADCAST_IDLE if GENERIC_CLOCKEVENTS_BROADCAST 163 select GENERIC_CLOCKEVENTS_MIN_ADJUST 164 select GENERIC_CMOS_UPDATE 165 select GENERIC_CPU_AUTOPROBE 166 select GENERIC_CPU_DEVICES 167 select GENERIC_CPU_VULNERABILITIES 168 select GENERIC_EARLY_IOREMAP 169 select GENERIC_ENTRY 170 select GENERIC_IOMAP 171 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 172 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 173 select GENERIC_IRQ_MIGRATION if SMP 174 select GENERIC_IRQ_PROBE 175 select GENERIC_IRQ_RESERVATION_MODE 176 select GENERIC_IRQ_SHOW 177 select GENERIC_PENDING_IRQ if SMP 178 select GENERIC_PTDUMP 179 select GENERIC_SMP_IDLE_THREAD 180 select GENERIC_TIME_VSYSCALL 181 select GENERIC_GETTIMEOFDAY 182 select GENERIC_VDSO_TIME_NS 183 select GENERIC_VDSO_OVERFLOW_PROTECT 184 select GUP_GET_PXX_LOW_HIGH if X86_PAE 185 select HARDIRQS_SW_RESEND 186 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 187 select HAS_IOPORT 188 select HAVE_ACPI_APEI if ACPI 189 select HAVE_ACPI_APEI_NMI if ACPI 190 select HAVE_ALIGNED_STRUCT_PAGE 191 select HAVE_ARCH_AUDITSYSCALL 192 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 193 select HAVE_ARCH_HUGE_VMALLOC if X86_64 194 select HAVE_ARCH_JUMP_LABEL 195 select HAVE_ARCH_JUMP_LABEL_RELATIVE 196 select HAVE_ARCH_KASAN if X86_64 197 select HAVE_ARCH_KASAN_VMALLOC if X86_64 198 select HAVE_ARCH_KFENCE 199 select HAVE_ARCH_KMSAN if X86_64 200 select HAVE_ARCH_KGDB 201 select HAVE_ARCH_MMAP_RND_BITS if MMU 202 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 203 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 204 select HAVE_ARCH_PREL32_RELOCATIONS 205 select HAVE_ARCH_SECCOMP_FILTER 206 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 207 select HAVE_ARCH_STACKLEAK 208 select HAVE_ARCH_TRACEHOOK 209 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 210 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 211 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 212 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 213 select HAVE_ARCH_VMAP_STACK if X86_64 214 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 215 select HAVE_ARCH_WITHIN_STACK_FRAMES 216 select HAVE_ASM_MODVERSIONS 217 select HAVE_CMPXCHG_DOUBLE 218 select HAVE_CMPXCHG_LOCAL 219 select HAVE_CONTEXT_TRACKING_USER if X86_64 220 select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER 221 select HAVE_C_RECORDMCOUNT 222 select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 223 select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT 224 select HAVE_BUILDTIME_MCOUNT_SORT 225 select HAVE_DEBUG_KMEMLEAK 226 select HAVE_DMA_CONTIGUOUS 227 select HAVE_DYNAMIC_FTRACE 228 select HAVE_DYNAMIC_FTRACE_WITH_REGS 229 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 230 select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64 231 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 232 select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 233 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 234 select HAVE_EBPF_JIT 235 select HAVE_EFFICIENT_UNALIGNED_ACCESS 236 select HAVE_EISA if X86_32 237 select HAVE_EXIT_THREAD 238 select HAVE_GUP_FAST 239 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 240 select HAVE_FTRACE_GRAPH_FUNC if HAVE_FUNCTION_GRAPH_TRACER 241 select HAVE_FTRACE_MCOUNT_RECORD 242 select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER 243 select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 244 select HAVE_FUNCTION_TRACER 245 select HAVE_GCC_PLUGINS 246 select HAVE_HW_BREAKPOINT 247 select HAVE_IOREMAP_PROT 248 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 249 select HAVE_IRQ_TIME_ACCOUNTING 250 select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 251 select HAVE_KERNEL_BZIP2 252 select HAVE_KERNEL_GZIP 253 select HAVE_KERNEL_LZ4 254 select HAVE_KERNEL_LZMA 255 select HAVE_KERNEL_LZO 256 select HAVE_KERNEL_XZ 257 select HAVE_KERNEL_ZSTD 258 select HAVE_KPROBES 259 select HAVE_KPROBES_ON_FTRACE 260 select HAVE_FUNCTION_ERROR_INJECTION 261 select HAVE_KRETPROBES 262 select HAVE_RETHOOK 263 select HAVE_LIVEPATCH if X86_64 264 select HAVE_MIXED_BREAKPOINTS_REGS 265 select HAVE_MOD_ARCH_SPECIFIC 266 select HAVE_MOVE_PMD 267 select HAVE_MOVE_PUD 268 select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 269 select HAVE_NMI 270 select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 271 select HAVE_OBJTOOL if X86_64 272 select HAVE_OPTPROBES 273 select HAVE_PAGE_SIZE_4KB 274 select HAVE_PCSPKR_PLATFORM 275 select HAVE_PERF_EVENTS 276 select HAVE_PERF_EVENTS_NMI 277 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 278 select HAVE_PCI 279 select HAVE_PERF_REGS 280 select HAVE_PERF_USER_STACK_DUMP 281 select MMU_GATHER_RCU_TABLE_FREE 282 select MMU_GATHER_MERGE_VMAS 283 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 284 select HAVE_REGS_AND_STACK_ACCESS_API 285 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 286 select HAVE_FUNCTION_ARG_ACCESS_API 287 select HAVE_SETUP_PER_CPU_AREA 288 select HAVE_SOFTIRQ_ON_OWN_STACK 289 select HAVE_STACKPROTECTOR 290 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 291 select HAVE_STATIC_CALL 292 select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 293 select HAVE_PREEMPT_DYNAMIC_CALL 294 select HAVE_RSEQ 295 select HAVE_RUST if X86_64 296 select HAVE_SYSCALL_TRACEPOINTS 297 select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 298 select HAVE_UNSTABLE_SCHED_CLOCK 299 select HAVE_USER_RETURN_NOTIFIER 300 select HAVE_GENERIC_VDSO 301 select VDSO_GETRANDOM if X86_64 302 select HOTPLUG_PARALLEL if SMP && X86_64 303 select HOTPLUG_SMT if SMP 304 select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 305 select IRQ_FORCED_THREADING 306 select LOCK_MM_AND_FIND_VMA 307 select NEED_PER_CPU_EMBED_FIRST_CHUNK 308 select NEED_PER_CPU_PAGE_FIRST_CHUNK 309 select NEED_SG_DMA_LENGTH 310 select NUMA_MEMBLKS if NUMA 311 select PCI_DOMAINS if PCI 312 select PCI_LOCKLESS_CONFIG if PCI 313 select PERF_EVENTS 314 select RTC_LIB 315 select RTC_MC146818_LIB 316 select SPARSE_IRQ 317 select SYSCTL_EXCEPTION_TRACE 318 select THREAD_INFO_IN_TASK 319 select TRACE_IRQFLAGS_SUPPORT 320 select TRACE_IRQFLAGS_NMI_SUPPORT 321 select USER_STACKTRACE_SUPPORT 322 select HAVE_ARCH_KCSAN if X86_64 323 select PROC_PID_ARCH_STATUS if PROC_FS 324 select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 325 select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 326 select FUNCTION_ALIGNMENT_4B 327 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 328 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 329 select ARCH_SUPPORTS_PT_RECLAIM if X86_64 330 331config INSTRUCTION_DECODER 332 def_bool y 333 depends on KPROBES || PERF_EVENTS || UPROBES 334 335config OUTPUT_FORMAT 336 string 337 default "elf32-i386" if X86_32 338 default "elf64-x86-64" if X86_64 339 340config LOCKDEP_SUPPORT 341 def_bool y 342 343config STACKTRACE_SUPPORT 344 def_bool y 345 346config MMU 347 def_bool y 348 349config ARCH_MMAP_RND_BITS_MIN 350 default 28 if 64BIT 351 default 8 352 353config ARCH_MMAP_RND_BITS_MAX 354 default 32 if 64BIT 355 default 16 356 357config ARCH_MMAP_RND_COMPAT_BITS_MIN 358 default 8 359 360config ARCH_MMAP_RND_COMPAT_BITS_MAX 361 default 16 362 363config SBUS 364 bool 365 366config GENERIC_ISA_DMA 367 def_bool y 368 depends on ISA_DMA_API 369 370config GENERIC_CSUM 371 bool 372 default y if KMSAN || KASAN 373 374config GENERIC_BUG 375 def_bool y 376 depends on BUG 377 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 378 379config GENERIC_BUG_RELATIVE_POINTERS 380 bool 381 382config ARCH_MAY_HAVE_PC_FDC 383 def_bool y 384 depends on ISA_DMA_API 385 386config GENERIC_CALIBRATE_DELAY 387 def_bool y 388 389config ARCH_HAS_CPU_RELAX 390 def_bool y 391 392config ARCH_HIBERNATION_POSSIBLE 393 def_bool y 394 395config ARCH_SUSPEND_POSSIBLE 396 def_bool y 397 398config AUDIT_ARCH 399 def_bool y if X86_64 400 401config KASAN_SHADOW_OFFSET 402 hex 403 depends on KASAN 404 default 0xdffffc0000000000 405 406config HAVE_INTEL_TXT 407 def_bool y 408 depends on INTEL_IOMMU && ACPI 409 410config X86_64_SMP 411 def_bool y 412 depends on X86_64 && SMP 413 414config ARCH_SUPPORTS_UPROBES 415 def_bool y 416 417config FIX_EARLYCON_MEM 418 def_bool y 419 420config DYNAMIC_PHYSICAL_MASK 421 bool 422 423config PGTABLE_LEVELS 424 int 425 default 5 if X86_5LEVEL 426 default 4 if X86_64 427 default 3 if X86_PAE 428 default 2 429 430menu "Processor type and features" 431 432config SMP 433 bool "Symmetric multi-processing support" 434 help 435 This enables support for systems with more than one CPU. If you have 436 a system with only one CPU, say N. If you have a system with more 437 than one CPU, say Y. 438 439 If you say N here, the kernel will run on uni- and multiprocessor 440 machines, but will use only one CPU of a multiprocessor machine. If 441 you say Y here, the kernel will run on many, but not all, 442 uniprocessor machines. On a uniprocessor machine, the kernel 443 will run faster if you say N here. 444 445 Note that if you say Y here and choose architecture "586" or 446 "Pentium" under "Processor family", the kernel will not work on 486 447 architectures. Similarly, multiprocessor kernels for the "PPro" 448 architecture may not work on all Pentium based boards. 449 450 People using multiprocessor machines who say Y here should also say 451 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 452 Management" code will be disabled if you say Y here. 453 454 See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 455 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 456 <http://www.tldp.org/docs.html#howto>. 457 458 If you don't know what to do here, say N. 459 460config X86_X2APIC 461 bool "Support x2apic" 462 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 463 help 464 This enables x2apic support on CPUs that have this feature. 465 466 This allows 32-bit apic IDs (so it can support very large systems), 467 and accesses the local apic via MSRs not via mmio. 468 469 Some Intel systems circa 2022 and later are locked into x2APIC mode 470 and can not fall back to the legacy APIC modes if SGX or TDX are 471 enabled in the BIOS. They will boot with very reduced functionality 472 without enabling this option. 473 474 If you don't know what to do here, say N. 475 476config X86_POSTED_MSI 477 bool "Enable MSI and MSI-x delivery by posted interrupts" 478 depends on X86_64 && IRQ_REMAP 479 help 480 This enables MSIs that are under interrupt remapping to be delivered as 481 posted interrupts to the host kernel. Interrupt throughput can 482 potentially be improved by coalescing CPU notifications during high 483 frequency bursts. 484 485 If you don't know what to do here, say N. 486 487config X86_MPPARSE 488 bool "Enable MPS table" if ACPI 489 default y 490 depends on X86_LOCAL_APIC 491 help 492 For old smp systems that do not have proper acpi support. Newer systems 493 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 494 495config X86_CPU_RESCTRL 496 bool "x86 CPU resource control support" 497 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 498 select KERNFS 499 select PROC_CPU_RESCTRL if PROC_FS 500 help 501 Enable x86 CPU resource control support. 502 503 Provide support for the allocation and monitoring of system resources 504 usage by the CPU. 505 506 Intel calls this Intel Resource Director Technology 507 (Intel(R) RDT). More information about RDT can be found in the 508 Intel x86 Architecture Software Developer Manual. 509 510 AMD calls this AMD Platform Quality of Service (AMD QoS). 511 More information about AMD QoS can be found in the AMD64 Technology 512 Platform Quality of Service Extensions manual. 513 514 Say N if unsure. 515 516config X86_FRED 517 bool "Flexible Return and Event Delivery" 518 depends on X86_64 519 help 520 When enabled, try to use Flexible Return and Event Delivery 521 instead of the legacy SYSCALL/SYSENTER/IDT architecture for 522 ring transitions and exception/interrupt handling if the 523 system supports it. 524 525config X86_EXTENDED_PLATFORM 526 bool "Support for extended (non-PC) x86 platforms" 527 default y 528 help 529 If you disable this option then the kernel will only support 530 standard PC platforms. (which covers the vast majority of 531 systems out there.) 532 533 If you enable this option then you'll be able to select support 534 for the following non-PC x86 platforms, depending on the value of 535 CONFIG_64BIT. 536 537 32-bit platforms (CONFIG_64BIT=n): 538 Goldfish (Android emulator) 539 AMD Elan 540 RDC R-321x SoC 541 SGI 320/540 (Visual Workstation) 542 543 64-bit platforms (CONFIG_64BIT=y): 544 Numascale NumaChip 545 ScaleMP vSMP 546 SGI Ultraviolet 547 Merrifield/Moorefield MID devices 548 549 If you have one of these systems, or if you want to build a 550 generic distribution kernel, say Y here - otherwise say N. 551 552# This is an alphabetically sorted list of 64 bit extended platforms 553# Please maintain the alphabetic order if and when there are additions 554config X86_NUMACHIP 555 bool "Numascale NumaChip" 556 depends on X86_64 557 depends on X86_EXTENDED_PLATFORM 558 depends on NUMA 559 depends on SMP 560 depends on X86_X2APIC 561 depends on PCI_MMCONFIG 562 help 563 Adds support for Numascale NumaChip large-SMP systems. Needed to 564 enable more than ~168 cores. 565 If you don't have one of these, you should say N here. 566 567config X86_VSMP 568 bool "ScaleMP vSMP" 569 select HYPERVISOR_GUEST 570 select PARAVIRT 571 depends on X86_64 && PCI 572 depends on X86_EXTENDED_PLATFORM 573 depends on SMP 574 help 575 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 576 supposed to run on these EM64T-based machines. Only choose this option 577 if you have one of these machines. 578 579config X86_UV 580 bool "SGI Ultraviolet" 581 depends on X86_64 582 depends on X86_EXTENDED_PLATFORM 583 depends on NUMA 584 depends on EFI 585 depends on KEXEC_CORE 586 depends on X86_X2APIC 587 depends on PCI 588 help 589 This option is needed in order to support SGI Ultraviolet systems. 590 If you don't have one of these, you should say N here. 591 592config X86_INTEL_MID 593 bool "Intel Z34xx/Z35xx MID platform support" 594 depends on X86_EXTENDED_PLATFORM 595 depends on X86_PLATFORM_DEVICES 596 depends on PCI 597 depends on X86_64 || (EXPERT && PCI_GOANY) 598 depends on X86_IO_APIC 599 select I2C 600 select DW_APB_TIMER 601 select INTEL_SCU_PCI 602 help 603 Select to build a kernel capable of supporting 64-bit Intel MID 604 (Mobile Internet Device) platform systems which do not have 605 the PCI legacy interfaces. 606 607 The only supported devices are the 22nm Merrified (Z34xx) 608 and Moorefield (Z35xx) SoC used in the Intel Edison board and 609 a small number of Android devices such as the Asus Zenfone 2, 610 Asus FonePad 8 and Dell Venue 7. 611 612 If you are building for a PC class system or non-MID tablet 613 SoCs like Bay Trail (Z36xx/Z37xx), say N here. 614 615 Intel MID platforms are based on an Intel processor and chipset which 616 consume less power than most of the x86 derivatives. 617 618config X86_GOLDFISH 619 bool "Goldfish (Virtual Platform)" 620 depends on X86_EXTENDED_PLATFORM 621 help 622 Enable support for the Goldfish virtual platform used primarily 623 for Android development. Unless you are building for the Android 624 Goldfish emulator say N here. 625 626# Following is an alphabetically sorted list of 32 bit extended platforms 627# Please maintain the alphabetic order if and when there are additions 628 629config X86_INTEL_CE 630 bool "CE4100 TV platform" 631 depends on PCI 632 depends on PCI_GODIRECT 633 depends on X86_IO_APIC 634 depends on X86_32 635 depends on X86_EXTENDED_PLATFORM 636 select X86_REBOOTFIXUPS 637 select OF 638 select OF_EARLY_FLATTREE 639 help 640 Select for the Intel CE media processor (CE4100) SOC. 641 This option compiles in support for the CE4100 SOC for settop 642 boxes and media devices. 643 644config X86_INTEL_QUARK 645 bool "Intel Quark platform support" 646 depends on X86_32 647 depends on X86_EXTENDED_PLATFORM 648 depends on X86_PLATFORM_DEVICES 649 depends on X86_TSC 650 depends on PCI 651 depends on PCI_GOANY 652 depends on X86_IO_APIC 653 select IOSF_MBI 654 select INTEL_IMR 655 select COMMON_CLK 656 help 657 Select to include support for Quark X1000 SoC. 658 Say Y here if you have a Quark based system such as the Arduino 659 compatible Intel Galileo. 660 661config X86_INTEL_LPSS 662 bool "Intel Low Power Subsystem Support" 663 depends on X86 && ACPI && PCI 664 select COMMON_CLK 665 select PINCTRL 666 select IOSF_MBI 667 help 668 Select to build support for Intel Low Power Subsystem such as 669 found on Intel Lynxpoint PCH. Selecting this option enables 670 things like clock tree (common clock framework) and pincontrol 671 which are needed by the LPSS peripheral drivers. 672 673config X86_AMD_PLATFORM_DEVICE 674 bool "AMD ACPI2Platform devices support" 675 depends on ACPI 676 select COMMON_CLK 677 select PINCTRL 678 help 679 Select to interpret AMD specific ACPI device to platform device 680 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 681 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 682 implemented under PINCTRL subsystem. 683 684config IOSF_MBI 685 tristate "Intel SoC IOSF Sideband support for SoC platforms" 686 depends on PCI 687 help 688 This option enables sideband register access support for Intel SoC 689 platforms. On these platforms the IOSF sideband is used in lieu of 690 MSR's for some register accesses, mostly but not limited to thermal 691 and power. Drivers may query the availability of this device to 692 determine if they need the sideband in order to work on these 693 platforms. The sideband is available on the following SoC products. 694 This list is not meant to be exclusive. 695 - BayTrail 696 - Braswell 697 - Quark 698 699 You should say Y if you are running a kernel on one of these SoC's. 700 701config IOSF_MBI_DEBUG 702 bool "Enable IOSF sideband access through debugfs" 703 depends on IOSF_MBI && DEBUG_FS 704 help 705 Select this option to expose the IOSF sideband access registers (MCR, 706 MDR, MCRX) through debugfs to write and read register information from 707 different units on the SoC. This is most useful for obtaining device 708 state information for debug and analysis. As this is a general access 709 mechanism, users of this option would have specific knowledge of the 710 device they want to access. 711 712 If you don't require the option or are in doubt, say N. 713 714config X86_RDC321X 715 bool "RDC R-321x SoC" 716 depends on X86_32 717 depends on X86_EXTENDED_PLATFORM 718 select M486 719 select X86_REBOOTFIXUPS 720 help 721 This option is needed for RDC R-321x system-on-chip, also known 722 as R-8610-(G). 723 If you don't have one of these chips, you should say N here. 724 725config X86_SUPPORTS_MEMORY_FAILURE 726 def_bool y 727 # MCE code calls memory_failure(): 728 depends on X86_MCE 729 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 730 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 731 depends on X86_64 || !SPARSEMEM 732 select ARCH_SUPPORTS_MEMORY_FAILURE 733 734config X86_32_IRIS 735 tristate "Eurobraille/Iris poweroff module" 736 depends on X86_32 737 help 738 The Iris machines from EuroBraille do not have APM or ACPI support 739 to shut themselves down properly. A special I/O sequence is 740 needed to do so, which is what this module does at 741 kernel shutdown. 742 743 This is only for Iris machines from EuroBraille. 744 745 If unused, say N. 746 747config SCHED_OMIT_FRAME_POINTER 748 def_bool y 749 prompt "Single-depth WCHAN output" 750 depends on X86 751 help 752 Calculate simpler /proc/<PID>/wchan values. If this option 753 is disabled then wchan values will recurse back to the 754 caller function. This provides more accurate wchan values, 755 at the expense of slightly more scheduling overhead. 756 757 If in doubt, say "Y". 758 759menuconfig HYPERVISOR_GUEST 760 bool "Linux guest support" 761 help 762 Say Y here to enable options for running Linux under various hyper- 763 visors. This option enables basic hypervisor detection and platform 764 setup. 765 766 If you say N, all options in this submenu will be skipped and 767 disabled, and Linux guest support won't be built in. 768 769if HYPERVISOR_GUEST 770 771config PARAVIRT 772 bool "Enable paravirtualization code" 773 depends on HAVE_STATIC_CALL 774 help 775 This changes the kernel so it can modify itself when it is run 776 under a hypervisor, potentially improving performance significantly 777 over full virtualization. However, when run without a hypervisor 778 the kernel is theoretically slower and slightly larger. 779 780config PARAVIRT_XXL 781 bool 782 783config PARAVIRT_DEBUG 784 bool "paravirt-ops debugging" 785 depends on PARAVIRT && DEBUG_KERNEL 786 help 787 Enable to debug paravirt_ops internals. Specifically, BUG if 788 a paravirt_op is missing when it is called. 789 790config PARAVIRT_SPINLOCKS 791 bool "Paravirtualization layer for spinlocks" 792 depends on PARAVIRT && SMP 793 help 794 Paravirtualized spinlocks allow a pvops backend to replace the 795 spinlock implementation with something virtualization-friendly 796 (for example, block the virtual CPU rather than spinning). 797 798 It has a minimal impact on native kernels and gives a nice performance 799 benefit on paravirtualized KVM / Xen kernels. 800 801 If you are unsure how to answer this question, answer Y. 802 803config X86_HV_CALLBACK_VECTOR 804 def_bool n 805 806source "arch/x86/xen/Kconfig" 807 808config KVM_GUEST 809 bool "KVM Guest support (including kvmclock)" 810 depends on PARAVIRT 811 select PARAVIRT_CLOCK 812 select ARCH_CPUIDLE_HALTPOLL 813 select X86_HV_CALLBACK_VECTOR 814 default y 815 help 816 This option enables various optimizations for running under the KVM 817 hypervisor. It includes a paravirtualized clock, so that instead 818 of relying on a PIT (or probably other) emulation by the 819 underlying device model, the host provides the guest with 820 timing infrastructure such as time of day, and system time 821 822config ARCH_CPUIDLE_HALTPOLL 823 def_bool n 824 prompt "Disable host haltpoll when loading haltpoll driver" 825 help 826 If virtualized under KVM, disable host haltpoll. 827 828config PVH 829 bool "Support for running PVH guests" 830 help 831 This option enables the PVH entry point for guest virtual machines 832 as specified in the x86/HVM direct boot ABI. 833 834config PARAVIRT_TIME_ACCOUNTING 835 bool "Paravirtual steal time accounting" 836 depends on PARAVIRT 837 help 838 Select this option to enable fine granularity task steal time 839 accounting. Time spent executing other tasks in parallel with 840 the current vCPU is discounted from the vCPU power. To account for 841 that, there can be a small performance impact. 842 843 If in doubt, say N here. 844 845config PARAVIRT_CLOCK 846 bool 847 848config JAILHOUSE_GUEST 849 bool "Jailhouse non-root cell support" 850 depends on X86_64 && PCI 851 select X86_PM_TIMER 852 help 853 This option allows to run Linux as guest in a Jailhouse non-root 854 cell. You can leave this option disabled if you only want to start 855 Jailhouse and run Linux afterwards in the root cell. 856 857config ACRN_GUEST 858 bool "ACRN Guest support" 859 depends on X86_64 860 select X86_HV_CALLBACK_VECTOR 861 help 862 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 863 a flexible, lightweight reference open-source hypervisor, built with 864 real-time and safety-criticality in mind. It is built for embedded 865 IOT with small footprint and real-time features. More details can be 866 found in https://projectacrn.org/. 867 868config INTEL_TDX_GUEST 869 bool "Intel TDX (Trust Domain Extensions) - Guest Support" 870 depends on X86_64 && CPU_SUP_INTEL 871 depends on X86_X2APIC 872 depends on EFI_STUB 873 select ARCH_HAS_CC_PLATFORM 874 select X86_MEM_ENCRYPT 875 select X86_MCE 876 select UNACCEPTED_MEMORY 877 help 878 Support running as a guest under Intel TDX. Without this support, 879 the guest kernel can not boot or run under TDX. 880 TDX includes memory encryption and integrity capabilities 881 which protect the confidentiality and integrity of guest 882 memory contents and CPU state. TDX guests are protected from 883 some attacks from the VMM. 884 885endif # HYPERVISOR_GUEST 886 887source "arch/x86/Kconfig.cpu" 888 889config HPET_TIMER 890 def_bool X86_64 891 prompt "HPET Timer Support" if X86_32 892 help 893 Use the IA-PC HPET (High Precision Event Timer) to manage 894 time in preference to the PIT and RTC, if a HPET is 895 present. 896 HPET is the next generation timer replacing legacy 8254s. 897 The HPET provides a stable time base on SMP 898 systems, unlike the TSC, but it is more expensive to access, 899 as it is off-chip. The interface used is documented 900 in the HPET spec, revision 1. 901 902 You can safely choose Y here. However, HPET will only be 903 activated if the platform and the BIOS support this feature. 904 Otherwise the 8254 will be used for timing services. 905 906 Choose N to continue using the legacy 8254 timer. 907 908config HPET_EMULATE_RTC 909 def_bool y 910 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 911 912# Mark as expert because too many people got it wrong. 913# The code disables itself when not needed. 914config DMI 915 default y 916 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 917 bool "Enable DMI scanning" if EXPERT 918 help 919 Enabled scanning of DMI to identify machine quirks. Say Y 920 here unless you have verified that your setup is not 921 affected by entries in the DMI blacklist. Required by PNP 922 BIOS code. 923 924config GART_IOMMU 925 bool "Old AMD GART IOMMU support" 926 select IOMMU_HELPER 927 select SWIOTLB 928 depends on X86_64 && PCI && AMD_NB 929 help 930 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 931 GART based hardware IOMMUs. 932 933 The GART supports full DMA access for devices with 32-bit access 934 limitations, on systems with more than 3 GB. This is usually needed 935 for USB, sound, many IDE/SATA chipsets and some other devices. 936 937 Newer systems typically have a modern AMD IOMMU, supported via 938 the CONFIG_AMD_IOMMU=y config option. 939 940 In normal configurations this driver is only active when needed: 941 there's more than 3 GB of memory and the system contains a 942 32-bit limited device. 943 944 If unsure, say Y. 945 946config BOOT_VESA_SUPPORT 947 bool 948 help 949 If true, at least one selected framebuffer driver can take advantage 950 of VESA video modes set at an early boot stage via the vga= parameter. 951 952config MAXSMP 953 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 954 depends on X86_64 && SMP && DEBUG_KERNEL 955 select CPUMASK_OFFSTACK 956 help 957 Enable maximum number of CPUS and NUMA Nodes for this architecture. 958 If unsure, say N. 959 960# 961# The maximum number of CPUs supported: 962# 963# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 964# and which can be configured interactively in the 965# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 966# 967# The ranges are different on 32-bit and 64-bit kernels, depending on 968# hardware capabilities and scalability features of the kernel. 969# 970# ( If MAXSMP is enabled we just use the highest possible value and disable 971# interactive configuration. ) 972# 973 974config NR_CPUS_RANGE_BEGIN 975 int 976 default NR_CPUS_RANGE_END if MAXSMP 977 default 1 if !SMP 978 default 2 979 980config NR_CPUS_RANGE_END 981 int 982 depends on X86_32 983 default 8 if SMP 984 default 1 if !SMP 985 986config NR_CPUS_RANGE_END 987 int 988 depends on X86_64 989 default 8192 if SMP && CPUMASK_OFFSTACK 990 default 512 if SMP && !CPUMASK_OFFSTACK 991 default 1 if !SMP 992 993config NR_CPUS_DEFAULT 994 int 995 depends on X86_32 996 default 8 if SMP 997 default 1 if !SMP 998 999config NR_CPUS_DEFAULT 1000 int 1001 depends on X86_64 1002 default 8192 if MAXSMP 1003 default 64 if SMP 1004 default 1 if !SMP 1005 1006config NR_CPUS 1007 int "Maximum number of CPUs" if SMP && !MAXSMP 1008 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1009 default NR_CPUS_DEFAULT 1010 help 1011 This allows you to specify the maximum number of CPUs which this 1012 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1013 supported value is 8192, otherwise the maximum value is 512. The 1014 minimum value which makes sense is 2. 1015 1016 This is purely to save memory: each supported CPU adds about 8KB 1017 to the kernel image. 1018 1019config SCHED_CLUSTER 1020 bool "Cluster scheduler support" 1021 depends on SMP 1022 default y 1023 help 1024 Cluster scheduler support improves the CPU scheduler's decision 1025 making when dealing with machines that have clusters of CPUs. 1026 Cluster usually means a couple of CPUs which are placed closely 1027 by sharing mid-level caches, last-level cache tags or internal 1028 busses. 1029 1030config SCHED_SMT 1031 def_bool y if SMP 1032 1033config SCHED_MC 1034 def_bool y 1035 prompt "Multi-core scheduler support" 1036 depends on SMP 1037 help 1038 Multi-core scheduler support improves the CPU scheduler's decision 1039 making when dealing with multi-core CPU chips at a cost of slightly 1040 increased overhead in some places. If unsure say N here. 1041 1042config SCHED_MC_PRIO 1043 bool "CPU core priorities scheduler support" 1044 depends on SCHED_MC 1045 select X86_INTEL_PSTATE if CPU_SUP_INTEL 1046 select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI 1047 select CPU_FREQ 1048 default y 1049 help 1050 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1051 core ordering determined at manufacturing time, which allows 1052 certain cores to reach higher turbo frequencies (when running 1053 single threaded workloads) than others. 1054 1055 Enabling this kernel feature teaches the scheduler about 1056 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1057 scheduler's CPU selection logic accordingly, so that higher 1058 overall system performance can be achieved. 1059 1060 This feature will have no effect on CPUs without this feature. 1061 1062 If unsure say Y here. 1063 1064config UP_LATE_INIT 1065 def_bool y 1066 depends on !SMP && X86_LOCAL_APIC 1067 1068config X86_UP_APIC 1069 bool "Local APIC support on uniprocessors" if !PCI_MSI 1070 default PCI_MSI 1071 depends on X86_32 && !SMP 1072 help 1073 A local APIC (Advanced Programmable Interrupt Controller) is an 1074 integrated interrupt controller in the CPU. If you have a single-CPU 1075 system which has a processor with a local APIC, you can say Y here to 1076 enable and use it. If you say Y here even though your machine doesn't 1077 have a local APIC, then the kernel will still run with no slowdown at 1078 all. The local APIC supports CPU-generated self-interrupts (timer, 1079 performance counters), and the NMI watchdog which detects hard 1080 lockups. 1081 1082config X86_UP_IOAPIC 1083 bool "IO-APIC support on uniprocessors" 1084 depends on X86_UP_APIC 1085 help 1086 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1087 SMP-capable replacement for PC-style interrupt controllers. Most 1088 SMP systems and many recent uniprocessor systems have one. 1089 1090 If you have a single-CPU system with an IO-APIC, you can say Y here 1091 to use it. If you say Y here even though your machine doesn't have 1092 an IO-APIC, then the kernel will still run with no slowdown at all. 1093 1094config X86_LOCAL_APIC 1095 def_bool y 1096 depends on X86_64 || SMP || X86_UP_APIC || PCI_MSI 1097 select IRQ_DOMAIN_HIERARCHY 1098 1099config ACPI_MADT_WAKEUP 1100 def_bool y 1101 depends on X86_64 1102 depends on ACPI 1103 depends on SMP 1104 depends on X86_LOCAL_APIC 1105 1106config X86_IO_APIC 1107 def_bool y 1108 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1109 1110config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1111 bool "Reroute for broken boot IRQs" 1112 depends on X86_IO_APIC 1113 help 1114 This option enables a workaround that fixes a source of 1115 spurious interrupts. This is recommended when threaded 1116 interrupt handling is used on systems where the generation of 1117 superfluous "boot interrupts" cannot be disabled. 1118 1119 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1120 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1121 kernel does during interrupt handling). On chipsets where this 1122 boot IRQ generation cannot be disabled, this workaround keeps 1123 the original IRQ line masked so that only the equivalent "boot 1124 IRQ" is delivered to the CPUs. The workaround also tells the 1125 kernel to set up the IRQ handler on the boot IRQ line. In this 1126 way only one interrupt is delivered to the kernel. Otherwise 1127 the spurious second interrupt may cause the kernel to bring 1128 down (vital) interrupt lines. 1129 1130 Only affects "broken" chipsets. Interrupt sharing may be 1131 increased on these systems. 1132 1133config X86_MCE 1134 bool "Machine Check / overheating reporting" 1135 select GENERIC_ALLOCATOR 1136 default y 1137 help 1138 Machine Check support allows the processor to notify the 1139 kernel if it detects a problem (e.g. overheating, data corruption). 1140 The action the kernel takes depends on the severity of the problem, 1141 ranging from warning messages to halting the machine. 1142 1143config X86_MCELOG_LEGACY 1144 bool "Support for deprecated /dev/mcelog character device" 1145 depends on X86_MCE 1146 help 1147 Enable support for /dev/mcelog which is needed by the old mcelog 1148 userspace logging daemon. Consider switching to the new generation 1149 rasdaemon solution. 1150 1151config X86_MCE_INTEL 1152 def_bool y 1153 prompt "Intel MCE features" 1154 depends on X86_MCE && X86_LOCAL_APIC 1155 help 1156 Additional support for intel specific MCE features such as 1157 the thermal monitor. 1158 1159config X86_MCE_AMD 1160 def_bool y 1161 prompt "AMD MCE features" 1162 depends on X86_MCE && X86_LOCAL_APIC 1163 help 1164 Additional support for AMD specific MCE features such as 1165 the DRAM Error Threshold. 1166 1167config X86_ANCIENT_MCE 1168 bool "Support for old Pentium 5 / WinChip machine checks" 1169 depends on X86_32 && X86_MCE 1170 help 1171 Include support for machine check handling on old Pentium 5 or WinChip 1172 systems. These typically need to be enabled explicitly on the command 1173 line. 1174 1175config X86_MCE_THRESHOLD 1176 depends on X86_MCE_AMD || X86_MCE_INTEL 1177 def_bool y 1178 1179config X86_MCE_INJECT 1180 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1181 tristate "Machine check injector support" 1182 help 1183 Provide support for injecting machine checks for testing purposes. 1184 If you don't know what a machine check is and you don't do kernel 1185 QA it is safe to say n. 1186 1187source "arch/x86/events/Kconfig" 1188 1189config X86_LEGACY_VM86 1190 bool "Legacy VM86 support" 1191 depends on X86_32 1192 help 1193 This option allows user programs to put the CPU into V8086 1194 mode, which is an 80286-era approximation of 16-bit real mode. 1195 1196 Some very old versions of X and/or vbetool require this option 1197 for user mode setting. Similarly, DOSEMU will use it if 1198 available to accelerate real mode DOS programs. However, any 1199 recent version of DOSEMU, X, or vbetool should be fully 1200 functional even without kernel VM86 support, as they will all 1201 fall back to software emulation. Nevertheless, if you are using 1202 a 16-bit DOS program where 16-bit performance matters, vm86 1203 mode might be faster than emulation and you might want to 1204 enable this option. 1205 1206 Note that any app that works on a 64-bit kernel is unlikely to 1207 need this option, as 64-bit kernels don't, and can't, support 1208 V8086 mode. This option is also unrelated to 16-bit protected 1209 mode and is not needed to run most 16-bit programs under Wine. 1210 1211 Enabling this option increases the complexity of the kernel 1212 and slows down exception handling a tiny bit. 1213 1214 If unsure, say N here. 1215 1216config VM86 1217 bool 1218 default X86_LEGACY_VM86 1219 1220config X86_16BIT 1221 bool "Enable support for 16-bit segments" if EXPERT 1222 default y 1223 depends on MODIFY_LDT_SYSCALL 1224 help 1225 This option is required by programs like Wine to run 16-bit 1226 protected mode legacy code on x86 processors. Disabling 1227 this option saves about 300 bytes on i386, or around 6K text 1228 plus 16K runtime memory on x86-64, 1229 1230config X86_ESPFIX32 1231 def_bool y 1232 depends on X86_16BIT && X86_32 1233 1234config X86_ESPFIX64 1235 def_bool y 1236 depends on X86_16BIT && X86_64 1237 1238config X86_VSYSCALL_EMULATION 1239 bool "Enable vsyscall emulation" if EXPERT 1240 default y 1241 depends on X86_64 1242 help 1243 This enables emulation of the legacy vsyscall page. Disabling 1244 it is roughly equivalent to booting with vsyscall=none, except 1245 that it will also disable the helpful warning if a program 1246 tries to use a vsyscall. With this option set to N, offending 1247 programs will just segfault, citing addresses of the form 1248 0xffffffffff600?00. 1249 1250 This option is required by many programs built before 2013, and 1251 care should be used even with newer programs if set to N. 1252 1253 Disabling this option saves about 7K of kernel size and 1254 possibly 4K of additional runtime pagetable memory. 1255 1256config X86_IOPL_IOPERM 1257 bool "IOPERM and IOPL Emulation" 1258 default y 1259 help 1260 This enables the ioperm() and iopl() syscalls which are necessary 1261 for legacy applications. 1262 1263 Legacy IOPL support is an overbroad mechanism which allows user 1264 space aside of accessing all 65536 I/O ports also to disable 1265 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1266 capabilities and permission from potentially active security 1267 modules. 1268 1269 The emulation restricts the functionality of the syscall to 1270 only allowing the full range I/O port access, but prevents the 1271 ability to disable interrupts from user space which would be 1272 granted if the hardware IOPL mechanism would be used. 1273 1274config TOSHIBA 1275 tristate "Toshiba Laptop support" 1276 depends on X86_32 1277 help 1278 This adds a driver to safely access the System Management Mode of 1279 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1280 not work on models with a Phoenix BIOS. The System Management Mode 1281 is used to set the BIOS and power saving options on Toshiba portables. 1282 1283 For information on utilities to make use of this driver see the 1284 Toshiba Linux utilities web site at: 1285 <http://www.buzzard.org.uk/toshiba/>. 1286 1287 Say Y if you intend to run this kernel on a Toshiba portable. 1288 Say N otherwise. 1289 1290config X86_REBOOTFIXUPS 1291 bool "Enable X86 board specific fixups for reboot" 1292 depends on X86_32 1293 help 1294 This enables chipset and/or board specific fixups to be done 1295 in order to get reboot to work correctly. This is only needed on 1296 some combinations of hardware and BIOS. The symptom, for which 1297 this config is intended, is when reboot ends with a stalled/hung 1298 system. 1299 1300 Currently, the only fixup is for the Geode machines using 1301 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1302 1303 Say Y if you want to enable the fixup. Currently, it's safe to 1304 enable this option even if you don't need it. 1305 Say N otherwise. 1306 1307config MICROCODE 1308 def_bool y 1309 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1310 select CRYPTO_LIB_SHA256 if CPU_SUP_AMD 1311 1312config MICROCODE_INITRD32 1313 def_bool y 1314 depends on MICROCODE && X86_32 && BLK_DEV_INITRD 1315 1316config MICROCODE_LATE_LOADING 1317 bool "Late microcode loading (DANGEROUS)" 1318 default n 1319 depends on MICROCODE && SMP 1320 help 1321 Loading microcode late, when the system is up and executing instructions 1322 is a tricky business and should be avoided if possible. Just the sequence 1323 of synchronizing all cores and SMT threads is one fragile dance which does 1324 not guarantee that cores might not softlock after the loading. Therefore, 1325 use this at your own risk. Late loading taints the kernel unless the 1326 microcode header indicates that it is safe for late loading via the 1327 minimal revision check. This minimal revision check can be enforced on 1328 the kernel command line with "microcode.minrev=Y". 1329 1330config MICROCODE_LATE_FORCE_MINREV 1331 bool "Enforce late microcode loading minimal revision check" 1332 default n 1333 depends on MICROCODE_LATE_LOADING 1334 help 1335 To prevent that users load microcode late which modifies already 1336 in use features, newer microcode patches have a minimum revision field 1337 in the microcode header, which tells the kernel which minimum 1338 revision must be active in the CPU to safely load that new microcode 1339 late into the running system. If disabled the check will not 1340 be enforced but the kernel will be tainted when the minimal 1341 revision check fails. 1342 1343 This minimal revision check can also be controlled via the 1344 "microcode.minrev" parameter on the kernel command line. 1345 1346 If unsure say Y. 1347 1348config X86_MSR 1349 tristate "/dev/cpu/*/msr - Model-specific register support" 1350 help 1351 This device gives privileged processes access to the x86 1352 Model-Specific Registers (MSRs). It is a character device with 1353 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1354 MSR accesses are directed to a specific CPU on multi-processor 1355 systems. 1356 1357config X86_CPUID 1358 tristate "/dev/cpu/*/cpuid - CPU information support" 1359 help 1360 This device gives processes access to the x86 CPUID instruction to 1361 be executed on a specific processor. It is a character device 1362 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1363 /dev/cpu/31/cpuid. 1364 1365config HIGHMEM4G 1366 bool "High Memory Support" 1367 depends on X86_32 1368 help 1369 Linux can use up to 4 Gigabytes of physical memory on x86 systems. 1370 However, the address space of 32-bit x86 processors is only 4 1371 Gigabytes large. That means that, if you have a large amount of 1372 physical memory, not all of it can be "permanently mapped" by the 1373 kernel. The physical memory that's not permanently mapped is called 1374 "high memory". 1375 1376 If you are compiling a kernel which will never run on a machine with 1377 more than 1 Gigabyte total physical RAM, answer "off" here (default 1378 choice and suitable for most users). This will result in a "3GB/1GB" 1379 split: 3GB are mapped so that each process sees a 3GB virtual memory 1380 space and the remaining part of the 4GB virtual memory space is used 1381 by the kernel to permanently map as much physical memory as 1382 possible. 1383 1384 If the machine has between 1 and 4 Gigabytes physical RAM, then 1385 answer "Y" here. 1386 1387 If unsure, say N. 1388 1389choice 1390 prompt "Memory split" if EXPERT 1391 default VMSPLIT_3G 1392 depends on X86_32 1393 help 1394 Select the desired split between kernel and user memory. 1395 1396 If the address range available to the kernel is less than the 1397 physical memory installed, the remaining memory will be available 1398 as "high memory". Accessing high memory is a little more costly 1399 than low memory, as it needs to be mapped into the kernel first. 1400 Note that increasing the kernel address space limits the range 1401 available to user programs, making the address space there 1402 tighter. Selecting anything other than the default 3G/1G split 1403 will also likely make your kernel incompatible with binary-only 1404 kernel modules. 1405 1406 If you are not absolutely sure what you are doing, leave this 1407 option alone! 1408 1409 config VMSPLIT_3G 1410 bool "3G/1G user/kernel split" 1411 config VMSPLIT_3G_OPT 1412 depends on !X86_PAE 1413 bool "3G/1G user/kernel split (for full 1G low memory)" 1414 config VMSPLIT_2G 1415 bool "2G/2G user/kernel split" 1416 config VMSPLIT_2G_OPT 1417 depends on !X86_PAE 1418 bool "2G/2G user/kernel split (for full 2G low memory)" 1419 config VMSPLIT_1G 1420 bool "1G/3G user/kernel split" 1421endchoice 1422 1423config PAGE_OFFSET 1424 hex 1425 default 0xB0000000 if VMSPLIT_3G_OPT 1426 default 0x80000000 if VMSPLIT_2G 1427 default 0x78000000 if VMSPLIT_2G_OPT 1428 default 0x40000000 if VMSPLIT_1G 1429 default 0xC0000000 1430 depends on X86_32 1431 1432config HIGHMEM 1433 def_bool HIGHMEM4G 1434 1435config X86_PAE 1436 bool "PAE (Physical Address Extension) Support" 1437 depends on X86_32 && X86_HAVE_PAE 1438 select PHYS_ADDR_T_64BIT 1439 help 1440 PAE is required for NX support, and furthermore enables 1441 larger swapspace support for non-overcommit purposes. It 1442 has the cost of more pagetable lookup overhead, and also 1443 consumes more pagetable space per process. 1444 1445config X86_5LEVEL 1446 bool "Enable 5-level page tables support" 1447 default y 1448 select DYNAMIC_MEMORY_LAYOUT 1449 select SPARSEMEM_VMEMMAP 1450 depends on X86_64 1451 help 1452 5-level paging enables access to larger address space: 1453 up to 128 PiB of virtual address space and 4 PiB of 1454 physical address space. 1455 1456 It will be supported by future Intel CPUs. 1457 1458 A kernel with the option enabled can be booted on machines that 1459 support 4- or 5-level paging. 1460 1461 See Documentation/arch/x86/x86_64/5level-paging.rst for more 1462 information. 1463 1464 Say N if unsure. 1465 1466config X86_DIRECT_GBPAGES 1467 def_bool y 1468 depends on X86_64 1469 help 1470 Certain kernel features effectively disable kernel 1471 linear 1 GB mappings (even if the CPU otherwise 1472 supports them), so don't confuse the user by printing 1473 that we have them enabled. 1474 1475config X86_CPA_STATISTICS 1476 bool "Enable statistic for Change Page Attribute" 1477 depends on DEBUG_FS 1478 help 1479 Expose statistics about the Change Page Attribute mechanism, which 1480 helps to determine the effectiveness of preserving large and huge 1481 page mappings when mapping protections are changed. 1482 1483config X86_MEM_ENCRYPT 1484 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1485 select DYNAMIC_PHYSICAL_MASK 1486 def_bool n 1487 1488config AMD_MEM_ENCRYPT 1489 bool "AMD Secure Memory Encryption (SME) support" 1490 depends on X86_64 && CPU_SUP_AMD 1491 depends on EFI_STUB 1492 select DMA_COHERENT_POOL 1493 select ARCH_USE_MEMREMAP_PROT 1494 select INSTRUCTION_DECODER 1495 select ARCH_HAS_CC_PLATFORM 1496 select X86_MEM_ENCRYPT 1497 select UNACCEPTED_MEMORY 1498 select CRYPTO_LIB_AESGCM 1499 help 1500 Say yes to enable support for the encryption of system memory. 1501 This requires an AMD processor that supports Secure Memory 1502 Encryption (SME). 1503 1504# Common NUMA Features 1505config NUMA 1506 bool "NUMA Memory Allocation and Scheduler Support" 1507 depends on SMP 1508 depends on X86_64 1509 select USE_PERCPU_NUMA_NODE_ID 1510 select OF_NUMA if OF 1511 help 1512 Enable NUMA (Non-Uniform Memory Access) support. 1513 1514 The kernel will try to allocate memory used by a CPU on the 1515 local memory controller of the CPU and add some more 1516 NUMA awareness to the kernel. 1517 1518 For 64-bit this is recommended if the system is Intel Core i7 1519 (or later), AMD Opteron, or EM64T NUMA. 1520 1521 Otherwise, you should say N. 1522 1523config AMD_NUMA 1524 def_bool y 1525 prompt "Old style AMD Opteron NUMA detection" 1526 depends on X86_64 && NUMA && PCI 1527 help 1528 Enable AMD NUMA node topology detection. You should say Y here if 1529 you have a multi processor AMD system. This uses an old method to 1530 read the NUMA configuration directly from the builtin Northbridge 1531 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1532 which also takes priority if both are compiled in. 1533 1534config X86_64_ACPI_NUMA 1535 def_bool y 1536 prompt "ACPI NUMA detection" 1537 depends on X86_64 && NUMA && ACPI && PCI 1538 select ACPI_NUMA 1539 help 1540 Enable ACPI SRAT based node topology detection. 1541 1542config NODES_SHIFT 1543 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1544 range 1 10 1545 default "10" if MAXSMP 1546 default "6" if X86_64 1547 default "3" 1548 depends on NUMA 1549 help 1550 Specify the maximum number of NUMA Nodes available on the target 1551 system. Increases memory reserved to accommodate various tables. 1552 1553config ARCH_FLATMEM_ENABLE 1554 def_bool y 1555 depends on X86_32 && !NUMA 1556 1557config ARCH_SPARSEMEM_ENABLE 1558 def_bool y 1559 depends on X86_64 || NUMA || X86_32 1560 select SPARSEMEM_STATIC if X86_32 1561 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1562 1563config ARCH_SPARSEMEM_DEFAULT 1564 def_bool X86_64 || (NUMA && X86_32) 1565 1566config ARCH_SELECT_MEMORY_MODEL 1567 def_bool y 1568 depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1569 1570config ARCH_MEMORY_PROBE 1571 bool "Enable sysfs memory/probe interface" 1572 depends on MEMORY_HOTPLUG 1573 help 1574 This option enables a sysfs memory/probe interface for testing. 1575 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1576 If you are unsure how to answer this question, answer N. 1577 1578config ARCH_PROC_KCORE_TEXT 1579 def_bool y 1580 depends on X86_64 && PROC_KCORE 1581 1582config ILLEGAL_POINTER_VALUE 1583 hex 1584 default 0 if X86_32 1585 default 0xdead000000000000 if X86_64 1586 1587config X86_PMEM_LEGACY_DEVICE 1588 bool 1589 1590config X86_PMEM_LEGACY 1591 tristate "Support non-standard NVDIMMs and ADR protected memory" 1592 depends on PHYS_ADDR_T_64BIT 1593 depends on BLK_DEV 1594 select X86_PMEM_LEGACY_DEVICE 1595 select NUMA_KEEP_MEMINFO if NUMA 1596 select LIBNVDIMM 1597 help 1598 Treat memory marked using the non-standard e820 type of 12 as used 1599 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1600 The kernel will offer these regions to the 'pmem' driver so 1601 they can be used for persistent storage. 1602 1603 Say Y if unsure. 1604 1605config X86_CHECK_BIOS_CORRUPTION 1606 bool "Check for low memory corruption" 1607 help 1608 Periodically check for memory corruption in low memory, which 1609 is suspected to be caused by BIOS. Even when enabled in the 1610 configuration, it is disabled at runtime. Enable it by 1611 setting "memory_corruption_check=1" on the kernel command 1612 line. By default it scans the low 64k of memory every 60 1613 seconds; see the memory_corruption_check_size and 1614 memory_corruption_check_period parameters in 1615 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1616 1617 When enabled with the default parameters, this option has 1618 almost no overhead, as it reserves a relatively small amount 1619 of memory and scans it infrequently. It both detects corruption 1620 and prevents it from affecting the running system. 1621 1622 It is, however, intended as a diagnostic tool; if repeatable 1623 BIOS-originated corruption always affects the same memory, 1624 you can use memmap= to prevent the kernel from using that 1625 memory. 1626 1627config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1628 bool "Set the default setting of memory_corruption_check" 1629 depends on X86_CHECK_BIOS_CORRUPTION 1630 default y 1631 help 1632 Set whether the default state of memory_corruption_check is 1633 on or off. 1634 1635config MATH_EMULATION 1636 bool 1637 depends on MODIFY_LDT_SYSCALL 1638 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1639 help 1640 Linux can emulate a math coprocessor (used for floating point 1641 operations) if you don't have one. 486DX and Pentium processors have 1642 a math coprocessor built in, 486SX and 386 do not, unless you added 1643 a 487DX or 387, respectively. (The messages during boot time can 1644 give you some hints here ["man dmesg"].) Everyone needs either a 1645 coprocessor or this emulation. 1646 1647 If you don't have a math coprocessor, you need to say Y here; if you 1648 say Y here even though you have a coprocessor, the coprocessor will 1649 be used nevertheless. (This behavior can be changed with the kernel 1650 command line option "no387", which comes handy if your coprocessor 1651 is broken. Try "man bootparam" or see the documentation of your boot 1652 loader (lilo or loadlin) about how to pass options to the kernel at 1653 boot time.) This means that it is a good idea to say Y here if you 1654 intend to use this kernel on different machines. 1655 1656 More information about the internals of the Linux math coprocessor 1657 emulation can be found in <file:arch/x86/math-emu/README>. 1658 1659 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1660 kernel, it won't hurt. 1661 1662config MTRR 1663 def_bool y 1664 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1665 help 1666 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1667 the Memory Type Range Registers (MTRRs) may be used to control 1668 processor access to memory ranges. This is most useful if you have 1669 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1670 allows bus write transfers to be combined into a larger transfer 1671 before bursting over the PCI/AGP bus. This can increase performance 1672 of image write operations 2.5 times or more. Saying Y here creates a 1673 /proc/mtrr file which may be used to manipulate your processor's 1674 MTRRs. Typically the X server should use this. 1675 1676 This code has a reasonably generic interface so that similar 1677 control registers on other processors can be easily supported 1678 as well: 1679 1680 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1681 Registers (ARRs) which provide a similar functionality to MTRRs. For 1682 these, the ARRs are used to emulate the MTRRs. 1683 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1684 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1685 write-combining. All of these processors are supported by this code 1686 and it makes sense to say Y here if you have one of them. 1687 1688 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1689 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1690 can lead to all sorts of problems, so it's good to say Y here. 1691 1692 You can safely say Y even if your machine doesn't have MTRRs, you'll 1693 just add about 9 KB to your kernel. 1694 1695 See <file:Documentation/arch/x86/mtrr.rst> for more information. 1696 1697config MTRR_SANITIZER 1698 def_bool y 1699 prompt "MTRR cleanup support" 1700 depends on MTRR 1701 help 1702 Convert MTRR layout from continuous to discrete, so X drivers can 1703 add writeback entries. 1704 1705 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1706 The largest mtrr entry size for a continuous block can be set with 1707 mtrr_chunk_size. 1708 1709 If unsure, say Y. 1710 1711config MTRR_SANITIZER_ENABLE_DEFAULT 1712 int "MTRR cleanup enable value (0-1)" 1713 range 0 1 1714 default "0" 1715 depends on MTRR_SANITIZER 1716 help 1717 Enable mtrr cleanup default value 1718 1719config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1720 int "MTRR cleanup spare reg num (0-7)" 1721 range 0 7 1722 default "1" 1723 depends on MTRR_SANITIZER 1724 help 1725 mtrr cleanup spare entries default, it can be changed via 1726 mtrr_spare_reg_nr=N on the kernel command line. 1727 1728config X86_PAT 1729 def_bool y 1730 prompt "x86 PAT support" if EXPERT 1731 depends on MTRR 1732 select ARCH_USES_PG_ARCH_2 1733 help 1734 Use PAT attributes to setup page level cache control. 1735 1736 PATs are the modern equivalents of MTRRs and are much more 1737 flexible than MTRRs. 1738 1739 Say N here if you see bootup problems (boot crash, boot hang, 1740 spontaneous reboots) or a non-working video driver. 1741 1742 If unsure, say Y. 1743 1744config X86_UMIP 1745 def_bool y 1746 prompt "User Mode Instruction Prevention" if EXPERT 1747 help 1748 User Mode Instruction Prevention (UMIP) is a security feature in 1749 some x86 processors. If enabled, a general protection fault is 1750 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1751 executed in user mode. These instructions unnecessarily expose 1752 information about the hardware state. 1753 1754 The vast majority of applications do not use these instructions. 1755 For the very few that do, software emulation is provided in 1756 specific cases in protected and virtual-8086 modes. Emulated 1757 results are dummy. 1758 1759config CC_HAS_IBT 1760 # GCC >= 9 and binutils >= 2.29 1761 # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1762 # Clang/LLVM >= 14 1763 # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1764 # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1765 def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1766 (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1767 $(as-instr,endbr64) 1768 1769config X86_CET 1770 def_bool n 1771 help 1772 CET features configured (Shadow stack or IBT) 1773 1774config X86_KERNEL_IBT 1775 prompt "Indirect Branch Tracking" 1776 def_bool y 1777 depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1778 # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1779 depends on !LD_IS_LLD || LLD_VERSION >= 140000 1780 select OBJTOOL 1781 select X86_CET 1782 help 1783 Build the kernel with support for Indirect Branch Tracking, a 1784 hardware support course-grain forward-edge Control Flow Integrity 1785 protection. It enforces that all indirect calls must land on 1786 an ENDBR instruction, as such, the compiler will instrument the 1787 code with them to make this happen. 1788 1789 In addition to building the kernel with IBT, seal all functions that 1790 are not indirect call targets, avoiding them ever becoming one. 1791 1792 This requires LTO like objtool runs and will slow down the build. It 1793 does significantly reduce the number of ENDBR instructions in the 1794 kernel image. 1795 1796config X86_INTEL_MEMORY_PROTECTION_KEYS 1797 prompt "Memory Protection Keys" 1798 def_bool y 1799 # Note: only available in 64-bit mode 1800 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1801 select ARCH_USES_HIGH_VMA_FLAGS 1802 select ARCH_HAS_PKEYS 1803 help 1804 Memory Protection Keys provides a mechanism for enforcing 1805 page-based protections, but without requiring modification of the 1806 page tables when an application changes protection domains. 1807 1808 For details, see Documentation/core-api/protection-keys.rst 1809 1810 If unsure, say y. 1811 1812config ARCH_PKEY_BITS 1813 int 1814 default 4 1815 1816choice 1817 prompt "TSX enable mode" 1818 depends on CPU_SUP_INTEL 1819 default X86_INTEL_TSX_MODE_OFF 1820 help 1821 Intel's TSX (Transactional Synchronization Extensions) feature 1822 allows to optimize locking protocols through lock elision which 1823 can lead to a noticeable performance boost. 1824 1825 On the other hand it has been shown that TSX can be exploited 1826 to form side channel attacks (e.g. TAA) and chances are there 1827 will be more of those attacks discovered in the future. 1828 1829 Therefore TSX is not enabled by default (aka tsx=off). An admin 1830 might override this decision by tsx=on the command line parameter. 1831 Even with TSX enabled, the kernel will attempt to enable the best 1832 possible TAA mitigation setting depending on the microcode available 1833 for the particular machine. 1834 1835 This option allows to set the default tsx mode between tsx=on, =off 1836 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1837 details. 1838 1839 Say off if not sure, auto if TSX is in use but it should be used on safe 1840 platforms or on if TSX is in use and the security aspect of tsx is not 1841 relevant. 1842 1843config X86_INTEL_TSX_MODE_OFF 1844 bool "off" 1845 help 1846 TSX is disabled if possible - equals to tsx=off command line parameter. 1847 1848config X86_INTEL_TSX_MODE_ON 1849 bool "on" 1850 help 1851 TSX is always enabled on TSX capable HW - equals the tsx=on command 1852 line parameter. 1853 1854config X86_INTEL_TSX_MODE_AUTO 1855 bool "auto" 1856 help 1857 TSX is enabled on TSX capable HW that is believed to be safe against 1858 side channel attacks- equals the tsx=auto command line parameter. 1859endchoice 1860 1861config X86_SGX 1862 bool "Software Guard eXtensions (SGX)" 1863 depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC 1864 depends on CRYPTO=y 1865 depends on CRYPTO_SHA256=y 1866 select MMU_NOTIFIER 1867 select NUMA_KEEP_MEMINFO if NUMA 1868 select XARRAY_MULTI 1869 help 1870 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1871 that can be used by applications to set aside private regions of code 1872 and data, referred to as enclaves. An enclave's private memory can 1873 only be accessed by code running within the enclave. Accesses from 1874 outside the enclave, including other enclaves, are disallowed by 1875 hardware. 1876 1877 If unsure, say N. 1878 1879config X86_USER_SHADOW_STACK 1880 bool "X86 userspace shadow stack" 1881 depends on AS_WRUSS 1882 depends on X86_64 1883 select ARCH_USES_HIGH_VMA_FLAGS 1884 select ARCH_HAS_USER_SHADOW_STACK 1885 select X86_CET 1886 help 1887 Shadow stack protection is a hardware feature that detects function 1888 return address corruption. This helps mitigate ROP attacks. 1889 Applications must be enabled to use it, and old userspace does not 1890 get protection "for free". 1891 1892 CPUs supporting shadow stacks were first released in 2020. 1893 1894 See Documentation/arch/x86/shstk.rst for more information. 1895 1896 If unsure, say N. 1897 1898config INTEL_TDX_HOST 1899 bool "Intel Trust Domain Extensions (TDX) host support" 1900 depends on CPU_SUP_INTEL 1901 depends on X86_64 1902 depends on KVM_INTEL 1903 depends on X86_X2APIC 1904 select ARCH_KEEP_MEMBLOCK 1905 depends on CONTIG_ALLOC 1906 depends on !KEXEC_CORE 1907 depends on X86_MCE 1908 help 1909 Intel Trust Domain Extensions (TDX) protects guest VMs from malicious 1910 host and certain physical attacks. This option enables necessary TDX 1911 support in the host kernel to run confidential VMs. 1912 1913 If unsure, say N. 1914 1915config EFI 1916 bool "EFI runtime service support" 1917 depends on ACPI 1918 select UCS2_STRING 1919 select EFI_RUNTIME_WRAPPERS 1920 select ARCH_USE_MEMREMAP_PROT 1921 select EFI_RUNTIME_MAP if KEXEC_CORE 1922 help 1923 This enables the kernel to use EFI runtime services that are 1924 available (such as the EFI variable services). 1925 1926 This option is only useful on systems that have EFI firmware. 1927 In addition, you should use the latest ELILO loader available 1928 at <http://elilo.sourceforge.net> in order to take advantage 1929 of EFI runtime services. However, even with this option, the 1930 resultant kernel should continue to boot on existing non-EFI 1931 platforms. 1932 1933config EFI_STUB 1934 bool "EFI stub support" 1935 depends on EFI 1936 select RELOCATABLE 1937 help 1938 This kernel feature allows a bzImage to be loaded directly 1939 by EFI firmware without the use of a bootloader. 1940 1941 See Documentation/admin-guide/efi-stub.rst for more information. 1942 1943config EFI_HANDOVER_PROTOCOL 1944 bool "EFI handover protocol (DEPRECATED)" 1945 depends on EFI_STUB 1946 default y 1947 help 1948 Select this in order to include support for the deprecated EFI 1949 handover protocol, which defines alternative entry points into the 1950 EFI stub. This is a practice that has no basis in the UEFI 1951 specification, and requires a priori knowledge on the part of the 1952 bootloader about Linux/x86 specific ways of passing the command line 1953 and initrd, and where in memory those assets may be loaded. 1954 1955 If in doubt, say Y. Even though the corresponding support is not 1956 present in upstream GRUB or other bootloaders, most distros build 1957 GRUB with numerous downstream patches applied, and may rely on the 1958 handover protocol as as result. 1959 1960config EFI_MIXED 1961 bool "EFI mixed-mode support" 1962 depends on EFI_STUB && X86_64 1963 help 1964 Enabling this feature allows a 64-bit kernel to be booted 1965 on a 32-bit firmware, provided that your CPU supports 64-bit 1966 mode. 1967 1968 Note that it is not possible to boot a mixed-mode enabled 1969 kernel via the EFI boot stub - a bootloader that supports 1970 the EFI handover protocol must be used. 1971 1972 If unsure, say N. 1973 1974config EFI_RUNTIME_MAP 1975 bool "Export EFI runtime maps to sysfs" if EXPERT 1976 depends on EFI 1977 help 1978 Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. 1979 That memory map is required by the 2nd kernel to set up EFI virtual 1980 mappings after kexec, but can also be used for debugging purposes. 1981 1982 See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. 1983 1984source "kernel/Kconfig.hz" 1985 1986config ARCH_SUPPORTS_KEXEC 1987 def_bool y 1988 1989config ARCH_SUPPORTS_KEXEC_FILE 1990 def_bool X86_64 1991 1992config ARCH_SELECTS_KEXEC_FILE 1993 def_bool y 1994 depends on KEXEC_FILE 1995 select HAVE_IMA_KEXEC if IMA 1996 1997config ARCH_SUPPORTS_KEXEC_PURGATORY 1998 def_bool y 1999 2000config ARCH_SUPPORTS_KEXEC_SIG 2001 def_bool y 2002 2003config ARCH_SUPPORTS_KEXEC_SIG_FORCE 2004 def_bool y 2005 2006config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG 2007 def_bool y 2008 2009config ARCH_SUPPORTS_KEXEC_JUMP 2010 def_bool y 2011 2012config ARCH_SUPPORTS_CRASH_DUMP 2013 def_bool X86_64 || (X86_32 && HIGHMEM) 2014 2015config ARCH_DEFAULT_CRASH_DUMP 2016 def_bool y 2017 2018config ARCH_SUPPORTS_CRASH_HOTPLUG 2019 def_bool y 2020 2021config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 2022 def_bool CRASH_RESERVE 2023 2024config PHYSICAL_START 2025 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2026 default "0x1000000" 2027 help 2028 This gives the physical address where the kernel is loaded. 2029 2030 If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage 2031 will decompress itself to above physical address and run from there. 2032 Otherwise, bzImage will run from the address where it has been loaded 2033 by the boot loader. The only exception is if it is loaded below the 2034 above physical address, in which case it will relocate itself there. 2035 2036 In normal kdump cases one does not have to set/change this option 2037 as now bzImage can be compiled as a completely relocatable image 2038 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2039 address. This option is mainly useful for the folks who don't want 2040 to use a bzImage for capturing the crash dump and want to use a 2041 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2042 to be specifically compiled to run from a specific memory area 2043 (normally a reserved region) and this option comes handy. 2044 2045 So if you are using bzImage for capturing the crash dump, 2046 leave the value here unchanged to 0x1000000 and set 2047 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2048 for capturing the crash dump change this value to start of 2049 the reserved region. In other words, it can be set based on 2050 the "X" value as specified in the "crashkernel=YM@XM" 2051 command line boot parameter passed to the panic-ed 2052 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2053 for more details about crash dumps. 2054 2055 Usage of bzImage for capturing the crash dump is recommended as 2056 one does not have to build two kernels. Same kernel can be used 2057 as production kernel and capture kernel. Above option should have 2058 gone away after relocatable bzImage support is introduced. But it 2059 is present because there are users out there who continue to use 2060 vmlinux for dump capture. This option should go away down the 2061 line. 2062 2063 Don't change this unless you know what you are doing. 2064 2065config RELOCATABLE 2066 bool "Build a relocatable kernel" 2067 default y 2068 help 2069 This builds a kernel image that retains relocation information 2070 so it can be loaded someplace besides the default 1MB. 2071 The relocations tend to make the kernel binary about 10% larger, 2072 but are discarded at runtime. 2073 2074 One use is for the kexec on panic case where the recovery kernel 2075 must live at a different physical address than the primary 2076 kernel. 2077 2078 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2079 it has been loaded at and the compile time physical address 2080 (CONFIG_PHYSICAL_START) is used as the minimum location. 2081 2082config RANDOMIZE_BASE 2083 bool "Randomize the address of the kernel image (KASLR)" 2084 depends on RELOCATABLE 2085 default y 2086 help 2087 In support of Kernel Address Space Layout Randomization (KASLR), 2088 this randomizes the physical address at which the kernel image 2089 is decompressed and the virtual address where the kernel 2090 image is mapped, as a security feature that deters exploit 2091 attempts relying on knowledge of the location of kernel 2092 code internals. 2093 2094 On 64-bit, the kernel physical and virtual addresses are 2095 randomized separately. The physical address will be anywhere 2096 between 16MB and the top of physical memory (up to 64TB). The 2097 virtual address will be randomized from 16MB up to 1GB (9 bits 2098 of entropy). Note that this also reduces the memory space 2099 available to kernel modules from 1.5GB to 1GB. 2100 2101 On 32-bit, the kernel physical and virtual addresses are 2102 randomized together. They will be randomized from 16MB up to 2103 512MB (8 bits of entropy). 2104 2105 Entropy is generated using the RDRAND instruction if it is 2106 supported. If RDTSC is supported, its value is mixed into 2107 the entropy pool as well. If neither RDRAND nor RDTSC are 2108 supported, then entropy is read from the i8254 timer. The 2109 usable entropy is limited by the kernel being built using 2110 2GB addressing, and that PHYSICAL_ALIGN must be at a 2111 minimum of 2MB. As a result, only 10 bits of entropy are 2112 theoretically possible, but the implementations are further 2113 limited due to memory layouts. 2114 2115 If unsure, say Y. 2116 2117# Relocation on x86 needs some additional build support 2118config X86_NEED_RELOCS 2119 def_bool y 2120 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2121 2122config PHYSICAL_ALIGN 2123 hex "Alignment value to which kernel should be aligned" 2124 default "0x200000" 2125 range 0x2000 0x1000000 if X86_32 2126 range 0x200000 0x1000000 if X86_64 2127 help 2128 This value puts the alignment restrictions on physical address 2129 where kernel is loaded and run from. Kernel is compiled for an 2130 address which meets above alignment restriction. 2131 2132 If bootloader loads the kernel at a non-aligned address and 2133 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2134 address aligned to above value and run from there. 2135 2136 If bootloader loads the kernel at a non-aligned address and 2137 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2138 load address and decompress itself to the address it has been 2139 compiled for and run from there. The address for which kernel is 2140 compiled already meets above alignment restrictions. Hence the 2141 end result is that kernel runs from a physical address meeting 2142 above alignment restrictions. 2143 2144 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2145 this value must be a multiple of 0x200000. 2146 2147 Don't change this unless you know what you are doing. 2148 2149config DYNAMIC_MEMORY_LAYOUT 2150 bool 2151 help 2152 This option makes base addresses of vmalloc and vmemmap as well as 2153 __PAGE_OFFSET movable during boot. 2154 2155config RANDOMIZE_MEMORY 2156 bool "Randomize the kernel memory sections" 2157 depends on X86_64 2158 depends on RANDOMIZE_BASE 2159 select DYNAMIC_MEMORY_LAYOUT 2160 default RANDOMIZE_BASE 2161 help 2162 Randomizes the base virtual address of kernel memory sections 2163 (physical memory mapping, vmalloc & vmemmap). This security feature 2164 makes exploits relying on predictable memory locations less reliable. 2165 2166 The order of allocations remains unchanged. Entropy is generated in 2167 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2168 configuration have in average 30,000 different possible virtual 2169 addresses for each memory section. 2170 2171 If unsure, say Y. 2172 2173config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2174 hex "Physical memory mapping padding" if EXPERT 2175 depends on RANDOMIZE_MEMORY 2176 default "0xa" if MEMORY_HOTPLUG 2177 default "0x0" 2178 range 0x1 0x40 if MEMORY_HOTPLUG 2179 range 0x0 0x40 2180 help 2181 Define the padding in terabytes added to the existing physical 2182 memory size during kernel memory randomization. It is useful 2183 for memory hotplug support but reduces the entropy available for 2184 address randomization. 2185 2186 If unsure, leave at the default value. 2187 2188config ADDRESS_MASKING 2189 bool "Linear Address Masking support" 2190 depends on X86_64 2191 depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS 2192 help 2193 Linear Address Masking (LAM) modifies the checking that is applied 2194 to 64-bit linear addresses, allowing software to use of the 2195 untranslated address bits for metadata. 2196 2197 The capability can be used for efficient address sanitizers (ASAN) 2198 implementation and for optimizations in JITs. 2199 2200config HOTPLUG_CPU 2201 def_bool y 2202 depends on SMP 2203 2204config COMPAT_VDSO 2205 def_bool n 2206 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2207 depends on COMPAT_32 2208 help 2209 Certain buggy versions of glibc will crash if they are 2210 presented with a 32-bit vDSO that is not mapped at the address 2211 indicated in its segment table. 2212 2213 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2214 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2215 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2216 the only released version with the bug, but OpenSUSE 9 2217 contains a buggy "glibc 2.3.2". 2218 2219 The symptom of the bug is that everything crashes on startup, saying: 2220 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2221 2222 Saying Y here changes the default value of the vdso32 boot 2223 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2224 This works around the glibc bug but hurts performance. 2225 2226 If unsure, say N: if you are compiling your own kernel, you 2227 are unlikely to be using a buggy version of glibc. 2228 2229choice 2230 prompt "vsyscall table for legacy applications" 2231 depends on X86_64 2232 default LEGACY_VSYSCALL_XONLY 2233 help 2234 Legacy user code that does not know how to find the vDSO expects 2235 to be able to issue three syscalls by calling fixed addresses in 2236 kernel space. Since this location is not randomized with ASLR, 2237 it can be used to assist security vulnerability exploitation. 2238 2239 This setting can be changed at boot time via the kernel command 2240 line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2241 is deprecated and can only be enabled using the kernel command 2242 line. 2243 2244 On a system with recent enough glibc (2.14 or newer) and no 2245 static binaries, you can say None without a performance penalty 2246 to improve security. 2247 2248 If unsure, select "Emulate execution only". 2249 2250 config LEGACY_VSYSCALL_XONLY 2251 bool "Emulate execution only" 2252 help 2253 The kernel traps and emulates calls into the fixed vsyscall 2254 address mapping and does not allow reads. This 2255 configuration is recommended when userspace might use the 2256 legacy vsyscall area but support for legacy binary 2257 instrumentation of legacy code is not needed. It mitigates 2258 certain uses of the vsyscall area as an ASLR-bypassing 2259 buffer. 2260 2261 config LEGACY_VSYSCALL_NONE 2262 bool "None" 2263 help 2264 There will be no vsyscall mapping at all. This will 2265 eliminate any risk of ASLR bypass due to the vsyscall 2266 fixed address mapping. Attempts to use the vsyscalls 2267 will be reported to dmesg, so that either old or 2268 malicious userspace programs can be identified. 2269 2270endchoice 2271 2272config CMDLINE_BOOL 2273 bool "Built-in kernel command line" 2274 help 2275 Allow for specifying boot arguments to the kernel at 2276 build time. On some systems (e.g. embedded ones), it is 2277 necessary or convenient to provide some or all of the 2278 kernel boot arguments with the kernel itself (that is, 2279 to not rely on the boot loader to provide them.) 2280 2281 To compile command line arguments into the kernel, 2282 set this option to 'Y', then fill in the 2283 boot arguments in CONFIG_CMDLINE. 2284 2285 Systems with fully functional boot loaders (i.e. non-embedded) 2286 should leave this option set to 'N'. 2287 2288config CMDLINE 2289 string "Built-in kernel command string" 2290 depends on CMDLINE_BOOL 2291 default "" 2292 help 2293 Enter arguments here that should be compiled into the kernel 2294 image and used at boot time. If the boot loader provides a 2295 command line at boot time, it is appended to this string to 2296 form the full kernel command line, when the system boots. 2297 2298 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2299 change this behavior. 2300 2301 In most cases, the command line (whether built-in or provided 2302 by the boot loader) should specify the device for the root 2303 file system. 2304 2305config CMDLINE_OVERRIDE 2306 bool "Built-in command line overrides boot loader arguments" 2307 depends on CMDLINE_BOOL && CMDLINE != "" 2308 help 2309 Set this option to 'Y' to have the kernel ignore the boot loader 2310 command line, and use ONLY the built-in command line. 2311 2312 This is used to work around broken boot loaders. This should 2313 be set to 'N' under normal conditions. 2314 2315config MODIFY_LDT_SYSCALL 2316 bool "Enable the LDT (local descriptor table)" if EXPERT 2317 default y 2318 help 2319 Linux can allow user programs to install a per-process x86 2320 Local Descriptor Table (LDT) using the modify_ldt(2) system 2321 call. This is required to run 16-bit or segmented code such as 2322 DOSEMU or some Wine programs. It is also used by some very old 2323 threading libraries. 2324 2325 Enabling this feature adds a small amount of overhead to 2326 context switches and increases the low-level kernel attack 2327 surface. Disabling it removes the modify_ldt(2) system call. 2328 2329 Saying 'N' here may make sense for embedded or server kernels. 2330 2331config STRICT_SIGALTSTACK_SIZE 2332 bool "Enforce strict size checking for sigaltstack" 2333 depends on DYNAMIC_SIGFRAME 2334 help 2335 For historical reasons MINSIGSTKSZ is a constant which became 2336 already too small with AVX512 support. Add a mechanism to 2337 enforce strict checking of the sigaltstack size against the 2338 real size of the FPU frame. This option enables the check 2339 by default. It can also be controlled via the kernel command 2340 line option 'strict_sas_size' independent of this config 2341 switch. Enabling it might break existing applications which 2342 allocate a too small sigaltstack but 'work' because they 2343 never get a signal delivered. 2344 2345 Say 'N' unless you want to really enforce this check. 2346 2347config CFI_AUTO_DEFAULT 2348 bool "Attempt to use FineIBT by default at boot time" 2349 depends on FINEIBT 2350 default y 2351 help 2352 Attempt to use FineIBT by default at boot time. If enabled, 2353 this is the same as booting with "cfi=auto". If disabled, 2354 this is the same as booting with "cfi=kcfi". 2355 2356source "kernel/livepatch/Kconfig" 2357 2358config X86_BUS_LOCK_DETECT 2359 bool "Split Lock Detect and Bus Lock Detect support" 2360 depends on CPU_SUP_INTEL || CPU_SUP_AMD 2361 default y 2362 help 2363 Enable Split Lock Detect and Bus Lock Detect functionalities. 2364 See <file:Documentation/arch/x86/buslock.rst> for more information. 2365 2366endmenu 2367 2368config CC_HAS_NAMED_AS 2369 def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null) 2370 depends on CC_IS_GCC 2371 2372# 2373# -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN) 2374# are incompatible with named address spaces with GCC < 13.3 2375# (see GCC PR sanitizer/111736 and also PR sanitizer/115172). 2376# 2377 2378config CC_HAS_NAMED_AS_FIXED_SANITIZERS 2379 def_bool y 2380 depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300 2381 depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200 2382 2383config USE_X86_SEG_SUPPORT 2384 def_bool CC_HAS_NAMED_AS 2385 depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS 2386 2387config CC_HAS_SLS 2388 def_bool $(cc-option,-mharden-sls=all) 2389 2390config CC_HAS_RETURN_THUNK 2391 def_bool $(cc-option,-mfunction-return=thunk-extern) 2392 2393config CC_HAS_ENTRY_PADDING 2394 def_bool $(cc-option,-fpatchable-function-entry=16,16) 2395 2396config CC_HAS_KCFI_ARITY 2397 def_bool $(cc-option,-fsanitize=kcfi -fsanitize-kcfi-arity) 2398 depends on CC_IS_CLANG && !RUST 2399 2400config FUNCTION_PADDING_CFI 2401 int 2402 default 59 if FUNCTION_ALIGNMENT_64B 2403 default 27 if FUNCTION_ALIGNMENT_32B 2404 default 11 if FUNCTION_ALIGNMENT_16B 2405 default 3 if FUNCTION_ALIGNMENT_8B 2406 default 0 2407 2408# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG 2409# except Kconfig can't do arithmetic :/ 2410config FUNCTION_PADDING_BYTES 2411 int 2412 default FUNCTION_PADDING_CFI if CFI_CLANG 2413 default FUNCTION_ALIGNMENT 2414 2415config CALL_PADDING 2416 def_bool n 2417 depends on CC_HAS_ENTRY_PADDING && OBJTOOL 2418 select FUNCTION_ALIGNMENT_16B 2419 2420config FINEIBT 2421 def_bool y 2422 depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE 2423 select CALL_PADDING 2424 2425config FINEIBT_BHI 2426 def_bool y 2427 depends on FINEIBT && CC_HAS_KCFI_ARITY 2428 2429config HAVE_CALL_THUNKS 2430 def_bool y 2431 depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL 2432 2433config CALL_THUNKS 2434 def_bool n 2435 select CALL_PADDING 2436 2437config PREFIX_SYMBOLS 2438 def_bool y 2439 depends on CALL_PADDING && !CFI_CLANG 2440 2441menuconfig CPU_MITIGATIONS 2442 bool "Mitigations for CPU vulnerabilities" 2443 default y 2444 help 2445 Say Y here to enable options which enable mitigations for hardware 2446 vulnerabilities (usually related to speculative execution). 2447 Mitigations can be disabled or restricted to SMT systems at runtime 2448 via the "mitigations" kernel parameter. 2449 2450 If you say N, all mitigations will be disabled. This CANNOT be 2451 overridden at runtime. 2452 2453 Say 'Y', unless you really know what you are doing. 2454 2455if CPU_MITIGATIONS 2456 2457config MITIGATION_PAGE_TABLE_ISOLATION 2458 bool "Remove the kernel mapping in user mode" 2459 default y 2460 depends on (X86_64 || X86_PAE) 2461 help 2462 This feature reduces the number of hardware side channels by 2463 ensuring that the majority of kernel addresses are not mapped 2464 into userspace. 2465 2466 See Documentation/arch/x86/pti.rst for more details. 2467 2468config MITIGATION_RETPOLINE 2469 bool "Avoid speculative indirect branches in kernel" 2470 select OBJTOOL if HAVE_OBJTOOL 2471 default y 2472 help 2473 Compile kernel with the retpoline compiler options to guard against 2474 kernel-to-user data leaks by avoiding speculative indirect 2475 branches. Requires a compiler with -mindirect-branch=thunk-extern 2476 support for full protection. The kernel may run slower. 2477 2478config MITIGATION_RETHUNK 2479 bool "Enable return-thunks" 2480 depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK 2481 select OBJTOOL if HAVE_OBJTOOL 2482 default y if X86_64 2483 help 2484 Compile the kernel with the return-thunks compiler option to guard 2485 against kernel-to-user data leaks by avoiding return speculation. 2486 Requires a compiler with -mfunction-return=thunk-extern 2487 support for full protection. The kernel may run slower. 2488 2489config MITIGATION_UNRET_ENTRY 2490 bool "Enable UNRET on kernel entry" 2491 depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64 2492 default y 2493 help 2494 Compile the kernel with support for the retbleed=unret mitigation. 2495 2496config MITIGATION_CALL_DEPTH_TRACKING 2497 bool "Mitigate RSB underflow with call depth tracking" 2498 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 2499 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 2500 select CALL_THUNKS 2501 default y 2502 help 2503 Compile the kernel with call depth tracking to mitigate the Intel 2504 SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off 2505 by default and needs to be enabled on the kernel command line via the 2506 retbleed=stuff option. For non-affected systems the overhead of this 2507 option is marginal as the call depth tracking is using run-time 2508 generated call thunks in a compiler generated padding area and call 2509 patching. This increases text size by ~5%. For non affected systems 2510 this space is unused. On affected SKL systems this results in a 2511 significant performance gain over the IBRS mitigation. 2512 2513config CALL_THUNKS_DEBUG 2514 bool "Enable call thunks and call depth tracking debugging" 2515 depends on MITIGATION_CALL_DEPTH_TRACKING 2516 select FUNCTION_ALIGNMENT_32B 2517 default n 2518 help 2519 Enable call/ret counters for imbalance detection and build in 2520 a noisy dmesg about callthunks generation and call patching for 2521 trouble shooting. The debug prints need to be enabled on the 2522 kernel command line with 'debug-callthunks'. 2523 Only enable this when you are debugging call thunks as this 2524 creates a noticeable runtime overhead. If unsure say N. 2525 2526config MITIGATION_IBPB_ENTRY 2527 bool "Enable IBPB on kernel entry" 2528 depends on CPU_SUP_AMD && X86_64 2529 default y 2530 help 2531 Compile the kernel with support for the retbleed=ibpb and 2532 spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations. 2533 2534config MITIGATION_IBRS_ENTRY 2535 bool "Enable IBRS on kernel entry" 2536 depends on CPU_SUP_INTEL && X86_64 2537 default y 2538 help 2539 Compile the kernel with support for the spectre_v2=ibrs mitigation. 2540 This mitigates both spectre_v2 and retbleed at great cost to 2541 performance. 2542 2543config MITIGATION_SRSO 2544 bool "Mitigate speculative RAS overflow on AMD" 2545 depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK 2546 default y 2547 help 2548 Enable the SRSO mitigation needed on AMD Zen1-4 machines. 2549 2550config MITIGATION_SLS 2551 bool "Mitigate Straight-Line-Speculation" 2552 depends on CC_HAS_SLS && X86_64 2553 select OBJTOOL if HAVE_OBJTOOL 2554 default n 2555 help 2556 Compile the kernel with straight-line-speculation options to guard 2557 against straight line speculation. The kernel image might be slightly 2558 larger. 2559 2560config MITIGATION_GDS 2561 bool "Mitigate Gather Data Sampling" 2562 depends on CPU_SUP_INTEL 2563 default y 2564 help 2565 Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware 2566 vulnerability which allows unprivileged speculative access to data 2567 which was previously stored in vector registers. The attacker uses gather 2568 instructions to infer the stale vector register data. 2569 2570config MITIGATION_RFDS 2571 bool "RFDS Mitigation" 2572 depends on CPU_SUP_INTEL 2573 default y 2574 help 2575 Enable mitigation for Register File Data Sampling (RFDS) by default. 2576 RFDS is a hardware vulnerability which affects Intel Atom CPUs. It 2577 allows unprivileged speculative access to stale data previously 2578 stored in floating point, vector and integer registers. 2579 See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> 2580 2581config MITIGATION_SPECTRE_BHI 2582 bool "Mitigate Spectre-BHB (Branch History Injection)" 2583 depends on CPU_SUP_INTEL 2584 default y 2585 help 2586 Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks 2587 where the branch history buffer is poisoned to speculatively steer 2588 indirect branches. 2589 See <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2590 2591config MITIGATION_MDS 2592 bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug" 2593 depends on CPU_SUP_INTEL 2594 default y 2595 help 2596 Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is 2597 a hardware vulnerability which allows unprivileged speculative access 2598 to data which is available in various CPU internal buffers. 2599 See also <file:Documentation/admin-guide/hw-vuln/mds.rst> 2600 2601config MITIGATION_TAA 2602 bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug" 2603 depends on CPU_SUP_INTEL 2604 default y 2605 help 2606 Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware 2607 vulnerability that allows unprivileged speculative access to data 2608 which is available in various CPU internal buffers by using 2609 asynchronous aborts within an Intel TSX transactional region. 2610 See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst> 2611 2612config MITIGATION_MMIO_STALE_DATA 2613 bool "Mitigate MMIO Stale Data hardware bug" 2614 depends on CPU_SUP_INTEL 2615 default y 2616 help 2617 Enable mitigation for MMIO Stale Data hardware bugs. Processor MMIO 2618 Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO) 2619 vulnerabilities that can expose data. The vulnerabilities require the 2620 attacker to have access to MMIO. 2621 See also 2622 <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst> 2623 2624config MITIGATION_L1TF 2625 bool "Mitigate L1 Terminal Fault (L1TF) hardware bug" 2626 depends on CPU_SUP_INTEL 2627 default y 2628 help 2629 Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a 2630 hardware vulnerability which allows unprivileged speculative access to data 2631 available in the Level 1 Data Cache. 2632 See <file:Documentation/admin-guide/hw-vuln/l1tf.rst 2633 2634config MITIGATION_RETBLEED 2635 bool "Mitigate RETBleed hardware bug" 2636 depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY 2637 default y 2638 help 2639 Enable mitigation for RETBleed (Arbitrary Speculative Code Execution 2640 with Return Instructions) vulnerability. RETBleed is a speculative 2641 execution attack which takes advantage of microarchitectural behavior 2642 in many modern microprocessors, similar to Spectre v2. An 2643 unprivileged attacker can use these flaws to bypass conventional 2644 memory security restrictions to gain read access to privileged memory 2645 that would otherwise be inaccessible. 2646 2647config MITIGATION_SPECTRE_V1 2648 bool "Mitigate SPECTRE V1 hardware bug" 2649 default y 2650 help 2651 Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a 2652 class of side channel attacks that takes advantage of speculative 2653 execution that bypasses conditional branch instructions used for 2654 memory access bounds check. 2655 See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2656 2657config MITIGATION_SPECTRE_V2 2658 bool "Mitigate SPECTRE V2 hardware bug" 2659 default y 2660 help 2661 Enable mitigation for Spectre V2 (Branch Target Injection). Spectre 2662 V2 is a class of side channel attacks that takes advantage of 2663 indirect branch predictors inside the processor. In Spectre variant 2 2664 attacks, the attacker can steer speculative indirect branches in the 2665 victim to gadget code by poisoning the branch target buffer of a CPU 2666 used for predicting indirect branch addresses. 2667 See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2668 2669config MITIGATION_SRBDS 2670 bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug" 2671 depends on CPU_SUP_INTEL 2672 default y 2673 help 2674 Enable mitigation for Special Register Buffer Data Sampling (SRBDS). 2675 SRBDS is a hardware vulnerability that allows Microarchitectural Data 2676 Sampling (MDS) techniques to infer values returned from special 2677 register accesses. An unprivileged user can extract values returned 2678 from RDRAND and RDSEED executed on another core or sibling thread 2679 using MDS techniques. 2680 See also 2681 <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst> 2682 2683config MITIGATION_SSB 2684 bool "Mitigate Speculative Store Bypass (SSB) hardware bug" 2685 default y 2686 help 2687 Enable mitigation for Speculative Store Bypass (SSB). SSB is a 2688 hardware security vulnerability and its exploitation takes advantage 2689 of speculative execution in a similar way to the Meltdown and Spectre 2690 security vulnerabilities. 2691 2692endif 2693 2694config ARCH_HAS_ADD_PAGES 2695 def_bool y 2696 depends on ARCH_ENABLE_MEMORY_HOTPLUG 2697 2698menu "Power management and ACPI options" 2699 2700config ARCH_HIBERNATION_HEADER 2701 def_bool y 2702 depends on HIBERNATION 2703 2704source "kernel/power/Kconfig" 2705 2706source "drivers/acpi/Kconfig" 2707 2708config X86_APM_BOOT 2709 def_bool y 2710 depends on APM 2711 2712menuconfig APM 2713 tristate "APM (Advanced Power Management) BIOS support" 2714 depends on X86_32 && PM_SLEEP 2715 help 2716 APM is a BIOS specification for saving power using several different 2717 techniques. This is mostly useful for battery powered laptops with 2718 APM compliant BIOSes. If you say Y here, the system time will be 2719 reset after a RESUME operation, the /proc/apm device will provide 2720 battery status information, and user-space programs will receive 2721 notification of APM "events" (e.g. battery status change). 2722 2723 If you select "Y" here, you can disable actual use of the APM 2724 BIOS by passing the "apm=off" option to the kernel at boot time. 2725 2726 Note that the APM support is almost completely disabled for 2727 machines with more than one CPU. 2728 2729 In order to use APM, you will need supporting software. For location 2730 and more information, read <file:Documentation/power/apm-acpi.rst> 2731 and the Battery Powered Linux mini-HOWTO, available from 2732 <http://www.tldp.org/docs.html#howto>. 2733 2734 This driver does not spin down disk drives (see the hdparm(8) 2735 manpage ("man 8 hdparm") for that), and it doesn't turn off 2736 VESA-compliant "green" monitors. 2737 2738 This driver does not support the TI 4000M TravelMate and the ACER 2739 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2740 desktop machines also don't have compliant BIOSes, and this driver 2741 may cause those machines to panic during the boot phase. 2742 2743 Generally, if you don't have a battery in your machine, there isn't 2744 much point in using this driver and you should say N. If you get 2745 random kernel OOPSes or reboots that don't seem to be related to 2746 anything, try disabling/enabling this option (or disabling/enabling 2747 APM in your BIOS). 2748 2749 Some other things you should try when experiencing seemingly random, 2750 "weird" problems: 2751 2752 1) make sure that you have enough swap space and that it is 2753 enabled. 2754 2) pass the "idle=poll" option to the kernel 2755 3) switch on floating point emulation in the kernel and pass 2756 the "no387" option to the kernel 2757 4) pass the "floppy=nodma" option to the kernel 2758 5) pass the "mem=4M" option to the kernel (thereby disabling 2759 all but the first 4 MB of RAM) 2760 6) make sure that the CPU is not over clocked. 2761 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2762 8) disable the cache from your BIOS settings 2763 9) install a fan for the video card or exchange video RAM 2764 10) install a better fan for the CPU 2765 11) exchange RAM chips 2766 12) exchange the motherboard. 2767 2768 To compile this driver as a module, choose M here: the 2769 module will be called apm. 2770 2771if APM 2772 2773config APM_IGNORE_USER_SUSPEND 2774 bool "Ignore USER SUSPEND" 2775 help 2776 This option will ignore USER SUSPEND requests. On machines with a 2777 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2778 series notebooks, it is necessary to say Y because of a BIOS bug. 2779 2780config APM_DO_ENABLE 2781 bool "Enable PM at boot time" 2782 help 2783 Enable APM features at boot time. From page 36 of the APM BIOS 2784 specification: "When disabled, the APM BIOS does not automatically 2785 power manage devices, enter the Standby State, enter the Suspend 2786 State, or take power saving steps in response to CPU Idle calls." 2787 This driver will make CPU Idle calls when Linux is idle (unless this 2788 feature is turned off -- see "Do CPU IDLE calls", below). This 2789 should always save battery power, but more complicated APM features 2790 will be dependent on your BIOS implementation. You may need to turn 2791 this option off if your computer hangs at boot time when using APM 2792 support, or if it beeps continuously instead of suspending. Turn 2793 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2794 T400CDT. This is off by default since most machines do fine without 2795 this feature. 2796 2797config APM_CPU_IDLE 2798 depends on CPU_IDLE 2799 bool "Make CPU Idle calls when idle" 2800 help 2801 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2802 On some machines, this can activate improved power savings, such as 2803 a slowed CPU clock rate, when the machine is idle. These idle calls 2804 are made after the idle loop has run for some length of time (e.g., 2805 333 mS). On some machines, this will cause a hang at boot time or 2806 whenever the CPU becomes idle. (On machines with more than one CPU, 2807 this option does nothing.) 2808 2809config APM_DISPLAY_BLANK 2810 bool "Enable console blanking using APM" 2811 help 2812 Enable console blanking using the APM. Some laptops can use this to 2813 turn off the LCD backlight when the screen blanker of the Linux 2814 virtual console blanks the screen. Note that this is only used by 2815 the virtual console screen blanker, and won't turn off the backlight 2816 when using the X Window system. This also doesn't have anything to 2817 do with your VESA-compliant power-saving monitor. Further, this 2818 option doesn't work for all laptops -- it might not turn off your 2819 backlight at all, or it might print a lot of errors to the console, 2820 especially if you are using gpm. 2821 2822config APM_ALLOW_INTS 2823 bool "Allow interrupts during APM BIOS calls" 2824 help 2825 Normally we disable external interrupts while we are making calls to 2826 the APM BIOS as a measure to lessen the effects of a badly behaving 2827 BIOS implementation. The BIOS should reenable interrupts if it 2828 needs to. Unfortunately, some BIOSes do not -- especially those in 2829 many of the newer IBM Thinkpads. If you experience hangs when you 2830 suspend, try setting this to Y. Otherwise, say N. 2831 2832endif # APM 2833 2834source "drivers/cpufreq/Kconfig" 2835 2836source "drivers/cpuidle/Kconfig" 2837 2838source "drivers/idle/Kconfig" 2839 2840endmenu 2841 2842menu "Bus options (PCI etc.)" 2843 2844choice 2845 prompt "PCI access mode" 2846 depends on X86_32 && PCI 2847 default PCI_GOANY 2848 help 2849 On PCI systems, the BIOS can be used to detect the PCI devices and 2850 determine their configuration. However, some old PCI motherboards 2851 have BIOS bugs and may crash if this is done. Also, some embedded 2852 PCI-based systems don't have any BIOS at all. Linux can also try to 2853 detect the PCI hardware directly without using the BIOS. 2854 2855 With this option, you can specify how Linux should detect the 2856 PCI devices. If you choose "BIOS", the BIOS will be used, 2857 if you choose "Direct", the BIOS won't be used, and if you 2858 choose "MMConfig", then PCI Express MMCONFIG will be used. 2859 If you choose "Any", the kernel will try MMCONFIG, then the 2860 direct access method and falls back to the BIOS if that doesn't 2861 work. If unsure, go with the default, which is "Any". 2862 2863config PCI_GOBIOS 2864 bool "BIOS" 2865 2866config PCI_GOMMCONFIG 2867 bool "MMConfig" 2868 2869config PCI_GODIRECT 2870 bool "Direct" 2871 2872config PCI_GOOLPC 2873 bool "OLPC XO-1" 2874 depends on OLPC 2875 2876config PCI_GOANY 2877 bool "Any" 2878 2879endchoice 2880 2881config PCI_BIOS 2882 def_bool y 2883 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2884 2885# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2886config PCI_DIRECT 2887 def_bool y 2888 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2889 2890config PCI_MMCONFIG 2891 bool "Support mmconfig PCI config space access" if X86_64 2892 default y 2893 depends on PCI && (ACPI || JAILHOUSE_GUEST) 2894 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2895 2896config PCI_OLPC 2897 def_bool y 2898 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2899 2900config PCI_XEN 2901 def_bool y 2902 depends on PCI && XEN 2903 2904config MMCONF_FAM10H 2905 def_bool y 2906 depends on X86_64 && PCI_MMCONFIG && ACPI 2907 2908config PCI_CNB20LE_QUIRK 2909 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2910 depends on PCI 2911 help 2912 Read the PCI windows out of the CNB20LE host bridge. This allows 2913 PCI hotplug to work on systems with the CNB20LE chipset which do 2914 not have ACPI. 2915 2916 There's no public spec for this chipset, and this functionality 2917 is known to be incomplete. 2918 2919 You should say N unless you know you need this. 2920 2921config ISA_BUS 2922 bool "ISA bus support on modern systems" if EXPERT 2923 help 2924 Expose ISA bus device drivers and options available for selection and 2925 configuration. Enable this option if your target machine has an ISA 2926 bus. ISA is an older system, displaced by PCI and newer bus 2927 architectures -- if your target machine is modern, it probably does 2928 not have an ISA bus. 2929 2930 If unsure, say N. 2931 2932# x86_64 have no ISA slots, but can have ISA-style DMA. 2933config ISA_DMA_API 2934 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2935 default y 2936 help 2937 Enables ISA-style DMA support for devices requiring such controllers. 2938 If unsure, say Y. 2939 2940if X86_32 2941 2942config ISA 2943 bool "ISA support" 2944 help 2945 Find out whether you have ISA slots on your motherboard. ISA is the 2946 name of a bus system, i.e. the way the CPU talks to the other stuff 2947 inside your box. Other bus systems are PCI, EISA, MicroChannel 2948 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2949 newer boards don't support it. If you have ISA, say Y, otherwise N. 2950 2951config SCx200 2952 tristate "NatSemi SCx200 support" 2953 help 2954 This provides basic support for National Semiconductor's 2955 (now AMD's) Geode processors. The driver probes for the 2956 PCI-IDs of several on-chip devices, so its a good dependency 2957 for other scx200_* drivers. 2958 2959 If compiled as a module, the driver is named scx200. 2960 2961config SCx200HR_TIMER 2962 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2963 depends on SCx200 2964 default y 2965 help 2966 This driver provides a clocksource built upon the on-chip 2967 27MHz high-resolution timer. Its also a workaround for 2968 NSC Geode SC-1100's buggy TSC, which loses time when the 2969 processor goes idle (as is done by the scheduler). The 2970 other workaround is idle=poll boot option. 2971 2972config OLPC 2973 bool "One Laptop Per Child support" 2974 depends on !X86_PAE 2975 select GPIOLIB 2976 select OF 2977 select OF_PROMTREE 2978 select IRQ_DOMAIN 2979 select OLPC_EC 2980 help 2981 Add support for detecting the unique features of the OLPC 2982 XO hardware. 2983 2984config OLPC_XO1_PM 2985 bool "OLPC XO-1 Power Management" 2986 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2987 help 2988 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2989 2990config OLPC_XO1_RTC 2991 bool "OLPC XO-1 Real Time Clock" 2992 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2993 help 2994 Add support for the XO-1 real time clock, which can be used as a 2995 programmable wakeup source. 2996 2997config OLPC_XO1_SCI 2998 bool "OLPC XO-1 SCI extras" 2999 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 3000 depends on INPUT=y 3001 select POWER_SUPPLY 3002 help 3003 Add support for SCI-based features of the OLPC XO-1 laptop: 3004 - EC-driven system wakeups 3005 - Power button 3006 - Ebook switch 3007 - Lid switch 3008 - AC adapter status updates 3009 - Battery status updates 3010 3011config OLPC_XO15_SCI 3012 bool "OLPC XO-1.5 SCI extras" 3013 depends on OLPC && ACPI 3014 select POWER_SUPPLY 3015 help 3016 Add support for SCI-based features of the OLPC XO-1.5 laptop: 3017 - EC-driven system wakeups 3018 - AC adapter status updates 3019 - Battery status updates 3020 3021config GEODE_COMMON 3022 bool 3023 3024config ALIX 3025 bool "PCEngines ALIX System Support (LED setup)" 3026 select GPIOLIB 3027 select GEODE_COMMON 3028 help 3029 This option enables system support for the PCEngines ALIX. 3030 At present this just sets up LEDs for GPIO control on 3031 ALIX2/3/6 boards. However, other system specific setup should 3032 get added here. 3033 3034 Note: You must still enable the drivers for GPIO and LED support 3035 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 3036 3037 Note: You have to set alix.force=1 for boards with Award BIOS. 3038 3039config NET5501 3040 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 3041 select GPIOLIB 3042 select GEODE_COMMON 3043 help 3044 This option enables system support for the Soekris Engineering net5501. 3045 3046config GEOS 3047 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 3048 select GPIOLIB 3049 select GEODE_COMMON 3050 depends on DMI 3051 help 3052 This option enables system support for the Traverse Technologies GEOS. 3053 3054config TS5500 3055 bool "Technologic Systems TS-5500 platform support" 3056 depends on MELAN 3057 select CHECK_SIGNATURE 3058 select NEW_LEDS 3059 select LEDS_CLASS 3060 help 3061 This option enables system support for the Technologic Systems TS-5500. 3062 3063endif # X86_32 3064 3065config AMD_NB 3066 def_bool y 3067 depends on AMD_NODE 3068 3069config AMD_NODE 3070 def_bool y 3071 depends on CPU_SUP_AMD && PCI 3072 3073endmenu 3074 3075menu "Binary Emulations" 3076 3077config IA32_EMULATION 3078 bool "IA32 Emulation" 3079 depends on X86_64 3080 select ARCH_WANT_OLD_COMPAT_IPC 3081 select BINFMT_ELF 3082 select COMPAT_OLD_SIGACTION 3083 help 3084 Include code to run legacy 32-bit programs under a 3085 64-bit kernel. You should likely turn this on, unless you're 3086 100% sure that you don't have any 32-bit programs left. 3087 3088config IA32_EMULATION_DEFAULT_DISABLED 3089 bool "IA32 emulation disabled by default" 3090 default n 3091 depends on IA32_EMULATION 3092 help 3093 Make IA32 emulation disabled by default. This prevents loading 32-bit 3094 processes and access to 32-bit syscalls. If unsure, leave it to its 3095 default value. 3096 3097config X86_X32_ABI 3098 bool "x32 ABI for 64-bit mode" 3099 depends on X86_64 3100 # llvm-objcopy does not convert x86_64 .note.gnu.property or 3101 # compressed debug sections to x86_x32 properly: 3102 # https://github.com/ClangBuiltLinux/linux/issues/514 3103 # https://github.com/ClangBuiltLinux/linux/issues/1141 3104 depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 3105 help 3106 Include code to run binaries for the x32 native 32-bit ABI 3107 for 64-bit processors. An x32 process gets access to the 3108 full 64-bit register file and wide data path while leaving 3109 pointers at 32 bits for smaller memory footprint. 3110 3111config COMPAT_32 3112 def_bool y 3113 depends on IA32_EMULATION || X86_32 3114 select HAVE_UID16 3115 select OLD_SIGSUSPEND3 3116 3117config COMPAT 3118 def_bool y 3119 depends on IA32_EMULATION || X86_X32_ABI 3120 3121config COMPAT_FOR_U64_ALIGNMENT 3122 def_bool y 3123 depends on COMPAT 3124 3125endmenu 3126 3127config HAVE_ATOMIC_IOMAP 3128 def_bool y 3129 depends on X86_32 3130 3131source "arch/x86/kvm/Kconfig" 3132 3133source "arch/x86/Kconfig.cpufeatures" 3134 3135source "arch/x86/Kconfig.assembler" 3136