1config ARM64 2 def_bool y 3 select ACPI_CCA_REQUIRED if ACPI 4 select ACPI_GENERIC_GSI if ACPI 5 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 6 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 7 select ARCH_HAS_ELF_RANDOMIZE 8 select ARCH_HAS_GCOV_PROFILE_ALL 9 select ARCH_HAS_SG_CHAIN 10 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 11 select ARCH_USE_CMPXCHG_LOCKREF 12 select ARCH_SUPPORTS_ATOMIC_RMW 13 select ARCH_WANT_OPTIONAL_GPIOLIB 14 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 15 select ARCH_WANT_FRAME_POINTERS 16 select ARM_AMBA 17 select ARM_ARCH_TIMER 18 select ARM_GIC 19 select AUDIT_ARCH_COMPAT_GENERIC 20 select ARM_GIC_V2M if PCI_MSI 21 select ARM_GIC_V3 22 select ARM_GIC_V3_ITS if PCI_MSI 23 select ARM_PSCI_FW 24 select BUILDTIME_EXTABLE_SORT 25 select CLONE_BACKWARDS 26 select COMMON_CLK 27 select CPU_PM if (SUSPEND || CPU_IDLE) 28 select DCACHE_WORD_ACCESS 29 select EDAC_SUPPORT 30 select FRAME_POINTER 31 select GENERIC_ALLOCATOR 32 select GENERIC_CLOCKEVENTS 33 select GENERIC_CLOCKEVENTS_BROADCAST 34 select GENERIC_CPU_AUTOPROBE 35 select GENERIC_EARLY_IOREMAP 36 select GENERIC_IDLE_POLL_SETUP 37 select GENERIC_IRQ_PROBE 38 select GENERIC_IRQ_SHOW 39 select GENERIC_IRQ_SHOW_LEVEL 40 select GENERIC_PCI_IOMAP 41 select GENERIC_SCHED_CLOCK 42 select GENERIC_SMP_IDLE_THREAD 43 select GENERIC_STRNCPY_FROM_USER 44 select GENERIC_STRNLEN_USER 45 select GENERIC_TIME_VSYSCALL 46 select HANDLE_DOMAIN_IRQ 47 select HARDIRQS_SW_RESEND 48 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 49 select HAVE_ARCH_AUDITSYSCALL 50 select HAVE_ARCH_BITREVERSE 51 select HAVE_ARCH_JUMP_LABEL 52 select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 53 select HAVE_ARCH_KGDB 54 select HAVE_ARCH_SECCOMP_FILTER 55 select HAVE_ARCH_TRACEHOOK 56 select HAVE_BPF_JIT 57 select HAVE_C_RECORDMCOUNT 58 select HAVE_CC_STACKPROTECTOR 59 select HAVE_CMPXCHG_DOUBLE 60 select HAVE_CMPXCHG_LOCAL 61 select HAVE_DEBUG_BUGVERBOSE 62 select HAVE_DEBUG_KMEMLEAK 63 select HAVE_DMA_API_DEBUG 64 select HAVE_DMA_ATTRS 65 select HAVE_DMA_CONTIGUOUS 66 select HAVE_DYNAMIC_FTRACE 67 select HAVE_EFFICIENT_UNALIGNED_ACCESS 68 select HAVE_FTRACE_MCOUNT_RECORD 69 select HAVE_FUNCTION_TRACER 70 select HAVE_FUNCTION_GRAPH_TRACER 71 select HAVE_GENERIC_DMA_COHERENT 72 select HAVE_HW_BREAKPOINT if PERF_EVENTS 73 select HAVE_MEMBLOCK 74 select HAVE_PATA_PLATFORM 75 select HAVE_PERF_EVENTS 76 select HAVE_PERF_REGS 77 select HAVE_PERF_USER_STACK_DUMP 78 select HAVE_RCU_TABLE_FREE 79 select HAVE_SYSCALL_TRACEPOINTS 80 select IOMMU_DMA if IOMMU_SUPPORT 81 select IRQ_DOMAIN 82 select IRQ_FORCED_THREADING 83 select MODULES_USE_ELF_RELA 84 select NO_BOOTMEM 85 select OF 86 select OF_EARLY_FLATTREE 87 select OF_RESERVED_MEM 88 select PERF_USE_VMALLOC 89 select POWER_RESET 90 select POWER_SUPPLY 91 select RTC_LIB 92 select SPARSE_IRQ 93 select SYSCTL_EXCEPTION_TRACE 94 select HAVE_CONTEXT_TRACKING 95 help 96 ARM 64-bit (AArch64) Linux support. 97 98config 64BIT 99 def_bool y 100 101config ARCH_PHYS_ADDR_T_64BIT 102 def_bool y 103 104config MMU 105 def_bool y 106 107config NO_IOPORT_MAP 108 def_bool y if !PCI 109 110config STACKTRACE_SUPPORT 111 def_bool y 112 113config ILLEGAL_POINTER_VALUE 114 hex 115 default 0xdead000000000000 116 117config LOCKDEP_SUPPORT 118 def_bool y 119 120config TRACE_IRQFLAGS_SUPPORT 121 def_bool y 122 123config RWSEM_XCHGADD_ALGORITHM 124 def_bool y 125 126config GENERIC_BUG 127 def_bool y 128 depends on BUG 129 130config GENERIC_BUG_RELATIVE_POINTERS 131 def_bool y 132 depends on GENERIC_BUG 133 134config GENERIC_HWEIGHT 135 def_bool y 136 137config GENERIC_CSUM 138 def_bool y 139 140config GENERIC_CALIBRATE_DELAY 141 def_bool y 142 143config ZONE_DMA 144 def_bool y 145 146config HAVE_GENERIC_RCU_GUP 147 def_bool y 148 149config ARCH_DMA_ADDR_T_64BIT 150 def_bool y 151 152config NEED_DMA_MAP_STATE 153 def_bool y 154 155config NEED_SG_DMA_LENGTH 156 def_bool y 157 158config SMP 159 def_bool y 160 161config SWIOTLB 162 def_bool y 163 164config IOMMU_HELPER 165 def_bool SWIOTLB 166 167config KERNEL_MODE_NEON 168 def_bool y 169 170config FIX_EARLYCON_MEM 171 def_bool y 172 173config PGTABLE_LEVELS 174 int 175 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 176 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 177 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 178 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 179 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 180 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 181 182source "init/Kconfig" 183 184source "kernel/Kconfig.freezer" 185 186source "arch/arm64/Kconfig.platforms" 187 188menu "Bus support" 189 190config PCI 191 bool "PCI support" 192 help 193 This feature enables support for PCI bus system. If you say Y 194 here, the kernel will include drivers and infrastructure code 195 to support PCI bus devices. 196 197config PCI_DOMAINS 198 def_bool PCI 199 200config PCI_DOMAINS_GENERIC 201 def_bool PCI 202 203config PCI_SYSCALL 204 def_bool PCI 205 206source "drivers/pci/Kconfig" 207source "drivers/pci/pcie/Kconfig" 208source "drivers/pci/hotplug/Kconfig" 209 210endmenu 211 212menu "Kernel Features" 213 214menu "ARM errata workarounds via the alternatives framework" 215 216config ARM64_ERRATUM_826319 217 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 218 default y 219 help 220 This option adds an alternative code sequence to work around ARM 221 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 222 AXI master interface and an L2 cache. 223 224 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 225 and is unable to accept a certain write via this interface, it will 226 not progress on read data presented on the read data channel and the 227 system can deadlock. 228 229 The workaround promotes data cache clean instructions to 230 data cache clean-and-invalidate. 231 Please note that this does not necessarily enable the workaround, 232 as it depends on the alternative framework, which will only patch 233 the kernel if an affected CPU is detected. 234 235 If unsure, say Y. 236 237config ARM64_ERRATUM_827319 238 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 239 default y 240 help 241 This option adds an alternative code sequence to work around ARM 242 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 243 master interface and an L2 cache. 244 245 Under certain conditions this erratum can cause a clean line eviction 246 to occur at the same time as another transaction to the same address 247 on the AMBA 5 CHI interface, which can cause data corruption if the 248 interconnect reorders the two transactions. 249 250 The workaround promotes data cache clean instructions to 251 data cache clean-and-invalidate. 252 Please note that this does not necessarily enable the workaround, 253 as it depends on the alternative framework, which will only patch 254 the kernel if an affected CPU is detected. 255 256 If unsure, say Y. 257 258config ARM64_ERRATUM_824069 259 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 260 default y 261 help 262 This option adds an alternative code sequence to work around ARM 263 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 264 to a coherent interconnect. 265 266 If a Cortex-A53 processor is executing a store or prefetch for 267 write instruction at the same time as a processor in another 268 cluster is executing a cache maintenance operation to the same 269 address, then this erratum might cause a clean cache line to be 270 incorrectly marked as dirty. 271 272 The workaround promotes data cache clean instructions to 273 data cache clean-and-invalidate. 274 Please note that this option does not necessarily enable the 275 workaround, as it depends on the alternative framework, which will 276 only patch the kernel if an affected CPU is detected. 277 278 If unsure, say Y. 279 280config ARM64_ERRATUM_819472 281 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 282 default y 283 help 284 This option adds an alternative code sequence to work around ARM 285 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 286 present when it is connected to a coherent interconnect. 287 288 If the processor is executing a load and store exclusive sequence at 289 the same time as a processor in another cluster is executing a cache 290 maintenance operation to the same address, then this erratum might 291 cause data corruption. 292 293 The workaround promotes data cache clean instructions to 294 data cache clean-and-invalidate. 295 Please note that this does not necessarily enable the workaround, 296 as it depends on the alternative framework, which will only patch 297 the kernel if an affected CPU is detected. 298 299 If unsure, say Y. 300 301config ARM64_ERRATUM_832075 302 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 303 default y 304 help 305 This option adds an alternative code sequence to work around ARM 306 erratum 832075 on Cortex-A57 parts up to r1p2. 307 308 Affected Cortex-A57 parts might deadlock when exclusive load/store 309 instructions to Write-Back memory are mixed with Device loads. 310 311 The workaround is to promote device loads to use Load-Acquire 312 semantics. 313 Please note that this does not necessarily enable the workaround, 314 as it depends on the alternative framework, which will only patch 315 the kernel if an affected CPU is detected. 316 317 If unsure, say Y. 318 319config ARM64_ERRATUM_834220 320 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 321 depends on KVM 322 default y 323 help 324 This option adds an alternative code sequence to work around ARM 325 erratum 834220 on Cortex-A57 parts up to r1p2. 326 327 Affected Cortex-A57 parts might report a Stage 2 translation 328 fault as the result of a Stage 1 fault for load crossing a 329 page boundary when there is a permission or device memory 330 alignment fault at Stage 1 and a translation fault at Stage 2. 331 332 The workaround is to verify that the Stage 1 translation 333 doesn't generate a fault before handling the Stage 2 fault. 334 Please note that this does not necessarily enable the workaround, 335 as it depends on the alternative framework, which will only patch 336 the kernel if an affected CPU is detected. 337 338 If unsure, say Y. 339 340config ARM64_ERRATUM_845719 341 bool "Cortex-A53: 845719: a load might read incorrect data" 342 depends on COMPAT 343 default y 344 help 345 This option adds an alternative code sequence to work around ARM 346 erratum 845719 on Cortex-A53 parts up to r0p4. 347 348 When running a compat (AArch32) userspace on an affected Cortex-A53 349 part, a load at EL0 from a virtual address that matches the bottom 32 350 bits of the virtual address used by a recent load at (AArch64) EL1 351 might return incorrect data. 352 353 The workaround is to write the contextidr_el1 register on exception 354 return to a 32-bit task. 355 Please note that this does not necessarily enable the workaround, 356 as it depends on the alternative framework, which will only patch 357 the kernel if an affected CPU is detected. 358 359 If unsure, say Y. 360 361config ARM64_ERRATUM_843419 362 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 363 depends on MODULES 364 default y 365 help 366 This option builds kernel modules using the large memory model in 367 order to avoid the use of the ADRP instruction, which can cause 368 a subsequent memory access to use an incorrect address on Cortex-A53 369 parts up to r0p4. 370 371 Note that the kernel itself must be linked with a version of ld 372 which fixes potentially affected ADRP instructions through the 373 use of veneers. 374 375 If unsure, say Y. 376 377config CAVIUM_ERRATUM_22375 378 bool "Cavium erratum 22375, 24313" 379 default y 380 help 381 Enable workaround for erratum 22375, 24313. 382 383 This implements two gicv3-its errata workarounds for ThunderX. Both 384 with small impact affecting only ITS table allocation. 385 386 erratum 22375: only alloc 8MB table size 387 erratum 24313: ignore memory access type 388 389 The fixes are in ITS initialization and basically ignore memory access 390 type and table size provided by the TYPER and BASER registers. 391 392 If unsure, say Y. 393 394config CAVIUM_ERRATUM_23154 395 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 396 default y 397 help 398 The gicv3 of ThunderX requires a modified version for 399 reading the IAR status to ensure data synchronization 400 (access to icc_iar1_el1 is not sync'ed before and after). 401 402 If unsure, say Y. 403 404endmenu 405 406 407choice 408 prompt "Page size" 409 default ARM64_4K_PAGES 410 help 411 Page size (translation granule) configuration. 412 413config ARM64_4K_PAGES 414 bool "4KB" 415 help 416 This feature enables 4KB pages support. 417 418config ARM64_16K_PAGES 419 bool "16KB" 420 help 421 The system will use 16KB pages support. AArch32 emulation 422 requires applications compiled with 16K (or a multiple of 16K) 423 aligned segments. 424 425config ARM64_64K_PAGES 426 bool "64KB" 427 help 428 This feature enables 64KB pages support (4KB by default) 429 allowing only two levels of page tables and faster TLB 430 look-up. AArch32 emulation requires applications compiled 431 with 64K aligned segments. 432 433endchoice 434 435choice 436 prompt "Virtual address space size" 437 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 438 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 439 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 440 help 441 Allows choosing one of multiple possible virtual address 442 space sizes. The level of translation table is determined by 443 a combination of page size and virtual address space size. 444 445config ARM64_VA_BITS_36 446 bool "36-bit" if EXPERT 447 depends on ARM64_16K_PAGES 448 449config ARM64_VA_BITS_39 450 bool "39-bit" 451 depends on ARM64_4K_PAGES 452 453config ARM64_VA_BITS_42 454 bool "42-bit" 455 depends on ARM64_64K_PAGES 456 457config ARM64_VA_BITS_47 458 bool "47-bit" 459 depends on ARM64_16K_PAGES 460 461config ARM64_VA_BITS_48 462 bool "48-bit" 463 464endchoice 465 466config ARM64_VA_BITS 467 int 468 default 36 if ARM64_VA_BITS_36 469 default 39 if ARM64_VA_BITS_39 470 default 42 if ARM64_VA_BITS_42 471 default 47 if ARM64_VA_BITS_47 472 default 48 if ARM64_VA_BITS_48 473 474config CPU_BIG_ENDIAN 475 bool "Build big-endian kernel" 476 help 477 Say Y if you plan on running a kernel in big-endian mode. 478 479config SCHED_MC 480 bool "Multi-core scheduler support" 481 help 482 Multi-core scheduler support improves the CPU scheduler's decision 483 making when dealing with multi-core CPU chips at a cost of slightly 484 increased overhead in some places. If unsure say N here. 485 486config SCHED_SMT 487 bool "SMT scheduler support" 488 help 489 Improves the CPU scheduler's decision making when dealing with 490 MultiThreading at a cost of slightly increased overhead in some 491 places. If unsure say N here. 492 493config NR_CPUS 494 int "Maximum number of CPUs (2-4096)" 495 range 2 4096 496 # These have to remain sorted largest to smallest 497 default "64" 498 499config HOTPLUG_CPU 500 bool "Support for hot-pluggable CPUs" 501 select GENERIC_IRQ_MIGRATION 502 help 503 Say Y here to experiment with turning CPUs off and on. CPUs 504 can be controlled through /sys/devices/system/cpu. 505 506source kernel/Kconfig.preempt 507source kernel/Kconfig.hz 508 509config ARCH_HAS_HOLES_MEMORYMODEL 510 def_bool y if SPARSEMEM 511 512config ARCH_SPARSEMEM_ENABLE 513 def_bool y 514 select SPARSEMEM_VMEMMAP_ENABLE 515 516config ARCH_SPARSEMEM_DEFAULT 517 def_bool ARCH_SPARSEMEM_ENABLE 518 519config ARCH_SELECT_MEMORY_MODEL 520 def_bool ARCH_SPARSEMEM_ENABLE 521 522config HAVE_ARCH_PFN_VALID 523 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM 524 525config HW_PERF_EVENTS 526 def_bool y 527 depends on ARM_PMU 528 529config SYS_SUPPORTS_HUGETLBFS 530 def_bool y 531 532config ARCH_WANT_GENERAL_HUGETLB 533 def_bool y 534 535config ARCH_WANT_HUGE_PMD_SHARE 536 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 537 538config HAVE_ARCH_TRANSPARENT_HUGEPAGE 539 def_bool y 540 541config ARCH_HAS_CACHE_LINE_SIZE 542 def_bool y 543 544source "mm/Kconfig" 545 546config SECCOMP 547 bool "Enable seccomp to safely compute untrusted bytecode" 548 ---help--- 549 This kernel feature is useful for number crunching applications 550 that may need to compute untrusted bytecode during their 551 execution. By using pipes or other transports made available to 552 the process as file descriptors supporting the read/write 553 syscalls, it's possible to isolate those applications in 554 their own address space using seccomp. Once seccomp is 555 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 556 and the task is only allowed to execute a few safe syscalls 557 defined by each seccomp mode. 558 559config XEN_DOM0 560 def_bool y 561 depends on XEN 562 563config XEN 564 bool "Xen guest support on ARM64" 565 depends on ARM64 && OF 566 select SWIOTLB_XEN 567 help 568 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 569 570config FORCE_MAX_ZONEORDER 571 int 572 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 573 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 574 default "11" 575 help 576 The kernel memory allocator divides physically contiguous memory 577 blocks into "zones", where each zone is a power of two number of 578 pages. This option selects the largest power of two that the kernel 579 keeps in the memory allocator. If you need to allocate very large 580 blocks of physically contiguous memory, then you may need to 581 increase this value. 582 583 This config option is actually maximum order plus one. For example, 584 a value of 11 means that the largest free memory block is 2^10 pages. 585 586 We make sure that we can allocate upto a HugePage size for each configuration. 587 Hence we have : 588 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 589 590 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 591 4M allocations matching the default size used by generic code. 592 593menuconfig ARMV8_DEPRECATED 594 bool "Emulate deprecated/obsolete ARMv8 instructions" 595 depends on COMPAT 596 help 597 Legacy software support may require certain instructions 598 that have been deprecated or obsoleted in the architecture. 599 600 Enable this config to enable selective emulation of these 601 features. 602 603 If unsure, say Y 604 605if ARMV8_DEPRECATED 606 607config SWP_EMULATION 608 bool "Emulate SWP/SWPB instructions" 609 help 610 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 611 they are always undefined. Say Y here to enable software 612 emulation of these instructions for userspace using LDXR/STXR. 613 614 In some older versions of glibc [<=2.8] SWP is used during futex 615 trylock() operations with the assumption that the code will not 616 be preempted. This invalid assumption may be more likely to fail 617 with SWP emulation enabled, leading to deadlock of the user 618 application. 619 620 NOTE: when accessing uncached shared regions, LDXR/STXR rely 621 on an external transaction monitoring block called a global 622 monitor to maintain update atomicity. If your system does not 623 implement a global monitor, this option can cause programs that 624 perform SWP operations to uncached memory to deadlock. 625 626 If unsure, say Y 627 628config CP15_BARRIER_EMULATION 629 bool "Emulate CP15 Barrier instructions" 630 help 631 The CP15 barrier instructions - CP15ISB, CP15DSB, and 632 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 633 strongly recommended to use the ISB, DSB, and DMB 634 instructions instead. 635 636 Say Y here to enable software emulation of these 637 instructions for AArch32 userspace code. When this option is 638 enabled, CP15 barrier usage is traced which can help 639 identify software that needs updating. 640 641 If unsure, say Y 642 643config SETEND_EMULATION 644 bool "Emulate SETEND instruction" 645 help 646 The SETEND instruction alters the data-endianness of the 647 AArch32 EL0, and is deprecated in ARMv8. 648 649 Say Y here to enable software emulation of the instruction 650 for AArch32 userspace code. 651 652 Note: All the cpus on the system must have mixed endian support at EL0 653 for this feature to be enabled. If a new CPU - which doesn't support mixed 654 endian - is hotplugged in after this feature has been enabled, there could 655 be unexpected results in the applications. 656 657 If unsure, say Y 658endif 659 660menu "ARMv8.1 architectural features" 661 662config ARM64_HW_AFDBM 663 bool "Support for hardware updates of the Access and Dirty page flags" 664 default y 665 help 666 The ARMv8.1 architecture extensions introduce support for 667 hardware updates of the access and dirty information in page 668 table entries. When enabled in TCR_EL1 (HA and HD bits) on 669 capable processors, accesses to pages with PTE_AF cleared will 670 set this bit instead of raising an access flag fault. 671 Similarly, writes to read-only pages with the DBM bit set will 672 clear the read-only bit (AP[2]) instead of raising a 673 permission fault. 674 675 Kernels built with this configuration option enabled continue 676 to work on pre-ARMv8.1 hardware and the performance impact is 677 minimal. If unsure, say Y. 678 679config ARM64_PAN 680 bool "Enable support for Privileged Access Never (PAN)" 681 default y 682 help 683 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 684 prevents the kernel or hypervisor from accessing user-space (EL0) 685 memory directly. 686 687 Choosing this option will cause any unprotected (not using 688 copy_to_user et al) memory access to fail with a permission fault. 689 690 The feature is detected at runtime, and will remain as a 'nop' 691 instruction if the cpu does not implement the feature. 692 693config ARM64_LSE_ATOMICS 694 bool "Atomic instructions" 695 help 696 As part of the Large System Extensions, ARMv8.1 introduces new 697 atomic instructions that are designed specifically to scale in 698 very large systems. 699 700 Say Y here to make use of these instructions for the in-kernel 701 atomic routines. This incurs a small overhead on CPUs that do 702 not support these instructions and requires the kernel to be 703 built with binutils >= 2.25. 704 705endmenu 706 707endmenu 708 709menu "Boot options" 710 711config CMDLINE 712 string "Default kernel command string" 713 default "" 714 help 715 Provide a set of default command-line options at build time by 716 entering them here. As a minimum, you should specify the the 717 root device (e.g. root=/dev/nfs). 718 719config CMDLINE_FORCE 720 bool "Always use the default kernel command string" 721 help 722 Always use the default kernel command string, even if the boot 723 loader passes other arguments to the kernel. 724 This is useful if you cannot or don't want to change the 725 command-line options your boot loader passes to the kernel. 726 727config EFI_STUB 728 bool 729 730config EFI 731 bool "UEFI runtime support" 732 depends on OF && !CPU_BIG_ENDIAN 733 select LIBFDT 734 select UCS2_STRING 735 select EFI_PARAMS_FROM_FDT 736 select EFI_RUNTIME_WRAPPERS 737 select EFI_STUB 738 select EFI_ARMSTUB 739 default y 740 help 741 This option provides support for runtime services provided 742 by UEFI firmware (such as non-volatile variables, realtime 743 clock, and platform reset). A UEFI stub is also provided to 744 allow the kernel to be booted as an EFI application. This 745 is only useful on systems that have UEFI firmware. 746 747config DMI 748 bool "Enable support for SMBIOS (DMI) tables" 749 depends on EFI 750 default y 751 help 752 This enables SMBIOS/DMI feature for systems. 753 754 This option is only useful on systems that have UEFI firmware. 755 However, even with this option, the resultant kernel should 756 continue to boot on existing non-UEFI platforms. 757 758endmenu 759 760menu "Userspace binary formats" 761 762source "fs/Kconfig.binfmt" 763 764config COMPAT 765 bool "Kernel support for 32-bit EL0" 766 depends on ARM64_4K_PAGES || EXPERT 767 select COMPAT_BINFMT_ELF 768 select HAVE_UID16 769 select OLD_SIGSUSPEND3 770 select COMPAT_OLD_SIGACTION 771 help 772 This option enables support for a 32-bit EL0 running under a 64-bit 773 kernel at EL1. AArch32-specific components such as system calls, 774 the user helper functions, VFP support and the ptrace interface are 775 handled appropriately by the kernel. 776 777 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 778 that you will only be able to execute AArch32 binaries that were compiled 779 with page size aligned segments. 780 781 If you want to execute 32-bit userspace applications, say Y. 782 783config SYSVIPC_COMPAT 784 def_bool y 785 depends on COMPAT && SYSVIPC 786 787endmenu 788 789menu "Power management options" 790 791source "kernel/power/Kconfig" 792 793config ARCH_SUSPEND_POSSIBLE 794 def_bool y 795 796endmenu 797 798menu "CPU Power Management" 799 800source "drivers/cpuidle/Kconfig" 801 802source "drivers/cpufreq/Kconfig" 803 804endmenu 805 806source "net/Kconfig" 807 808source "drivers/Kconfig" 809 810source "drivers/firmware/Kconfig" 811 812source "drivers/acpi/Kconfig" 813 814source "fs/Kconfig" 815 816source "arch/arm64/kvm/Kconfig" 817 818source "arch/arm64/Kconfig.debug" 819 820source "security/Kconfig" 821 822source "crypto/Kconfig" 823if CRYPTO 824source "arch/arm64/crypto/Kconfig" 825endif 826 827source "lib/Kconfig" 828