arch/arm64/Kconfig

   1 config 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 GENERIC_ALLOCATOR
  31         select GENERIC_CLOCKEVENTS
  32         select GENERIC_CLOCKEVENTS_BROADCAST
  33         select GENERIC_CPU_AUTOPROBE
  34         select GENERIC_EARLY_IOREMAP
  35         select GENERIC_IRQ_PROBE
  36         select GENERIC_IRQ_SHOW
  37         select GENERIC_IRQ_SHOW_LEVEL
  38         select GENERIC_PCI_IOMAP
  39         select GENERIC_SCHED_CLOCK
  40         select GENERIC_SMP_IDLE_THREAD
  41         select GENERIC_STRNCPY_FROM_USER
  42         select GENERIC_STRNLEN_USER
  43         select GENERIC_TIME_VSYSCALL
  44         select HANDLE_DOMAIN_IRQ
  45         select HARDIRQS_SW_RESEND
  46         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
  47         select HAVE_ARCH_AUDITSYSCALL
  48         select HAVE_ARCH_BITREVERSE
  49         select HAVE_ARCH_JUMP_LABEL
  50         select HAVE_ARCH_KGDB
  51         select HAVE_ARCH_SECCOMP_FILTER
  52         select HAVE_ARCH_TRACEHOOK
  53         select HAVE_BPF_JIT
  54         select HAVE_C_RECORDMCOUNT
  55         select HAVE_CC_STACKPROTECTOR
  56         select HAVE_CMPXCHG_DOUBLE
  57         select HAVE_CMPXCHG_LOCAL
  58         select HAVE_DEBUG_BUGVERBOSE
  59         select HAVE_DEBUG_KMEMLEAK
  60         select HAVE_DMA_API_DEBUG
  61         select HAVE_DMA_ATTRS
  62         select HAVE_DMA_CONTIGUOUS
  63         select HAVE_DYNAMIC_FTRACE
  64         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  65         select HAVE_FTRACE_MCOUNT_RECORD
  66         select HAVE_FUNCTION_TRACER
  67         select HAVE_FUNCTION_GRAPH_TRACER
  68         select HAVE_GENERIC_DMA_COHERENT
  69         select HAVE_HW_BREAKPOINT if PERF_EVENTS
  70         select HAVE_MEMBLOCK
  71         select HAVE_PATA_PLATFORM
  72         select HAVE_PERF_EVENTS
  73         select HAVE_PERF_REGS
  74         select HAVE_PERF_USER_STACK_DUMP
  75         select HAVE_RCU_TABLE_FREE
  76         select HAVE_SYSCALL_TRACEPOINTS
  77         select IRQ_DOMAIN
  78         select IRQ_FORCED_THREADING
  79         select MODULES_USE_ELF_RELA
  80         select NO_BOOTMEM
  81         select OF
  82         select OF_EARLY_FLATTREE
  83         select OF_RESERVED_MEM
  84         select PERF_USE_VMALLOC
  85         select POWER_RESET
  86         select POWER_SUPPLY
  87         select RTC_LIB
  88         select SPARSE_IRQ
  89         select SYSCTL_EXCEPTION_TRACE
  90         select HAVE_CONTEXT_TRACKING
  91         help
  92           ARM 64-bit (AArch64) Linux support.
  93
  94 config 64BIT
  95         def_bool y
  96
  97 config ARCH_PHYS_ADDR_T_64BIT
  98         def_bool y
  99
 100 config MMU
 101         def_bool y
 102
 103 config NO_IOPORT_MAP
 104         def_bool y if !PCI
 105
 106 config STACKTRACE_SUPPORT
 107         def_bool y
 108
 109 config ILLEGAL_POINTER_VALUE
 110         hex
 111         default 0xdead000000000000
 112
 113 config LOCKDEP_SUPPORT
 114         def_bool y
 115
 116 config TRACE_IRQFLAGS_SUPPORT
 117         def_bool y
 118
 119 config RWSEM_XCHGADD_ALGORITHM
 120         def_bool y
 121
 122 config GENERIC_BUG
 123         def_bool y
 124         depends on BUG
 125
 126 config GENERIC_BUG_RELATIVE_POINTERS
 127         def_bool y
 128         depends on GENERIC_BUG
 129
 130 config GENERIC_HWEIGHT
 131         def_bool y
 132
 133 config GENERIC_CSUM
 134         def_bool y
 135
 136 config GENERIC_CALIBRATE_DELAY
 137         def_bool y
 138
 139 config ZONE_DMA
 140         def_bool y
 141
 142 config HAVE_GENERIC_RCU_GUP
 143         def_bool y
 144
 145 config ARCH_DMA_ADDR_T_64BIT
 146         def_bool y
 147
 148 config NEED_DMA_MAP_STATE
 149         def_bool y
 150
 151 config NEED_SG_DMA_LENGTH
 152         def_bool y
 153
 154 config SMP
 155         def_bool y
 156
 157 config SWIOTLB
 158         def_bool y
 159
 160 config IOMMU_HELPER
 161         def_bool SWIOTLB
 162
 163 config KERNEL_MODE_NEON
 164         def_bool y
 165
 166 config FIX_EARLYCON_MEM
 167         def_bool y
 168
 169 config PGTABLE_LEVELS
 170         int
 171         default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
 172         default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
 173         default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
 174         default 4 if ARM64_4K_PAGES && ARM64_VA_BITS_48
 175
 176 source "init/Kconfig"
 177
 178 source "kernel/Kconfig.freezer"
 179
 180 source "arch/arm64/Kconfig.platforms"
 181
 182 menu "Bus support"
 183
 184 config PCI
 185         bool "PCI support"
 186         help
 187           This feature enables support for PCI bus system. If you say Y
 188           here, the kernel will include drivers and infrastructure code
 189           to support PCI bus devices.
 190
 191 config PCI_DOMAINS
 192         def_bool PCI
 193
 194 config PCI_DOMAINS_GENERIC
 195         def_bool PCI
 196
 197 config PCI_SYSCALL
 198         def_bool PCI
 199
 200 source "drivers/pci/Kconfig"
 201 source "drivers/pci/pcie/Kconfig"
 202 source "drivers/pci/hotplug/Kconfig"
 203
 204 endmenu
 205
 206 menu "Kernel Features"
 207
 208 menu "ARM errata workarounds via the alternatives framework"
 209
 210 config ARM64_ERRATUM_826319
 211         bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
 212         default y
 213         help
 214           This option adds an alternative code sequence to work around ARM
 215           erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
 216           AXI master interface and an L2 cache.
 217
 218           If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
 219           and is unable to accept a certain write via this interface, it will
 220           not progress on read data presented on the read data channel and the
 221           system can deadlock.
 222
 223           The workaround promotes data cache clean instructions to
 224           data cache clean-and-invalidate.
 225           Please note that this does not necessarily enable the workaround,
 226           as it depends on the alternative framework, which will only patch
 227           the kernel if an affected CPU is detected.
 228
 229           If unsure, say Y.
 230
 231 config ARM64_ERRATUM_827319
 232         bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
 233         default y
 234         help
 235           This option adds an alternative code sequence to work around ARM
 236           erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
 237           master interface and an L2 cache.
 238
 239           Under certain conditions this erratum can cause a clean line eviction
 240           to occur at the same time as another transaction to the same address
 241           on the AMBA 5 CHI interface, which can cause data corruption if the
 242           interconnect reorders the two transactions.
 243
 244           The workaround promotes data cache clean instructions to
 245           data cache clean-and-invalidate.
 246           Please note that this does not necessarily enable the workaround,
 247           as it depends on the alternative framework, which will only patch
 248           the kernel if an affected CPU is detected.
 249
 250           If unsure, say Y.
 251
 252 config ARM64_ERRATUM_824069
 253         bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
 254         default y
 255         help
 256           This option adds an alternative code sequence to work around ARM
 257           erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
 258           to a coherent interconnect.
 259
 260           If a Cortex-A53 processor is executing a store or prefetch for
 261           write instruction at the same time as a processor in another
 262           cluster is executing a cache maintenance operation to the same
 263           address, then this erratum might cause a clean cache line to be
 264           incorrectly marked as dirty.
 265
 266           The workaround promotes data cache clean instructions to
 267           data cache clean-and-invalidate.
 268           Please note that this option does not necessarily enable the
 269           workaround, as it depends on the alternative framework, which will
 270           only patch the kernel if an affected CPU is detected.
 271
 272           If unsure, say Y.
 273
 274 config ARM64_ERRATUM_819472
 275         bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
 276         default y
 277         help
 278           This option adds an alternative code sequence to work around ARM
 279           erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
 280           present when it is connected to a coherent interconnect.
 281
 282           If the processor is executing a load and store exclusive sequence at
 283           the same time as a processor in another cluster is executing a cache
 284           maintenance operation to the same address, then this erratum might
 285           cause data corruption.
 286
 287           The workaround promotes data cache clean instructions to
 288           data cache clean-and-invalidate.
 289           Please note that this does not necessarily enable the workaround,
 290           as it depends on the alternative framework, which will only patch
 291           the kernel if an affected CPU is detected.
 292
 293           If unsure, say Y.
 294
 295 config ARM64_ERRATUM_832075
 296         bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
 297         default y
 298         help
 299           This option adds an alternative code sequence to work around ARM
 300           erratum 832075 on Cortex-A57 parts up to r1p2.
 301
 302           Affected Cortex-A57 parts might deadlock when exclusive load/store
 303           instructions to Write-Back memory are mixed with Device loads.
 304
 305           The workaround is to promote device loads to use Load-Acquire
 306           semantics.
 307           Please note that this does not necessarily enable the workaround,
 308           as it depends on the alternative framework, which will only patch
 309           the kernel if an affected CPU is detected.
 310
 311           If unsure, say Y.
 312
 313 config ARM64_ERRATUM_845719
 314         bool "Cortex-A53: 845719: a load might read incorrect data"
 315         depends on COMPAT
 316         default y
 317         help
 318           This option adds an alternative code sequence to work around ARM
 319           erratum 845719 on Cortex-A53 parts up to r0p4.
 320
 321           When running a compat (AArch32) userspace on an affected Cortex-A53
 322           part, a load at EL0 from a virtual address that matches the bottom 32
 323           bits of the virtual address used by a recent load at (AArch64) EL1
 324           might return incorrect data.
 325
 326           The workaround is to write the contextidr_el1 register on exception
 327           return to a 32-bit task.
 328           Please note that this does not necessarily enable the workaround,
 329           as it depends on the alternative framework, which will only patch
 330           the kernel if an affected CPU is detected.
 331
 332           If unsure, say Y.
 333
 334 endmenu
 335
 336
 337 choice
 338         prompt "Page size"
 339         default ARM64_4K_PAGES
 340         help
 341           Page size (translation granule) configuration.
 342
 343 config ARM64_4K_PAGES
 344         bool "4KB"
 345         help
 346           This feature enables 4KB pages support.
 347
 348 config ARM64_64K_PAGES
 349         bool "64KB"
 350         help
 351           This feature enables 64KB pages support (4KB by default)
 352           allowing only two levels of page tables and faster TLB
 353           look-up. AArch32 emulation is not available when this feature
 354           is enabled.
 355
 356 endchoice
 357
 358 choice
 359         prompt "Virtual address space size"
 360         default ARM64_VA_BITS_39 if ARM64_4K_PAGES
 361         default ARM64_VA_BITS_42 if ARM64_64K_PAGES
 362         help
 363           Allows choosing one of multiple possible virtual address
 364           space sizes. The level of translation table is determined by
 365           a combination of page size and virtual address space size.
 366
 367 config ARM64_VA_BITS_39
 368         bool "39-bit"
 369         depends on ARM64_4K_PAGES
 370
 371 config ARM64_VA_BITS_42
 372         bool "42-bit"
 373         depends on ARM64_64K_PAGES
 374
 375 config ARM64_VA_BITS_48
 376         bool "48-bit"
 377
 378 endchoice
 379
 380 config ARM64_VA_BITS
 381         int
 382         default 39 if ARM64_VA_BITS_39
 383         default 42 if ARM64_VA_BITS_42
 384         default 48 if ARM64_VA_BITS_48
 385
 386 config CPU_BIG_ENDIAN
 387        bool "Build big-endian kernel"
 388        help
 389          Say Y if you plan on running a kernel in big-endian mode.
 390
 391 config SCHED_MC
 392         bool "Multi-core scheduler support"
 393         help
 394           Multi-core scheduler support improves the CPU scheduler's decision
 395           making when dealing with multi-core CPU chips at a cost of slightly
 396           increased overhead in some places. If unsure say N here.
 397
 398 config SCHED_SMT
 399         bool "SMT scheduler support"
 400         help
 401           Improves the CPU scheduler's decision making when dealing with
 402           MultiThreading at a cost of slightly increased overhead in some
 403           places. If unsure say N here.
 404
 405 config NR_CPUS
 406         int "Maximum number of CPUs (2-4096)"
 407         range 2 4096
 408         # These have to remain sorted largest to smallest
 409         default "64"
 410
 411 config HOTPLUG_CPU
 412         bool "Support for hot-pluggable CPUs"
 413         help
 414           Say Y here to experiment with turning CPUs off and on.  CPUs
 415           can be controlled through /sys/devices/system/cpu.
 416
 417 source kernel/Kconfig.preempt
 418
 419 config HZ
 420         int
 421         default 100
 422
 423 config ARCH_HAS_HOLES_MEMORYMODEL
 424         def_bool y if SPARSEMEM
 425
 426 config ARCH_SPARSEMEM_ENABLE
 427         def_bool y
 428         select SPARSEMEM_VMEMMAP_ENABLE
 429
 430 config ARCH_SPARSEMEM_DEFAULT
 431         def_bool ARCH_SPARSEMEM_ENABLE
 432
 433 config ARCH_SELECT_MEMORY_MODEL
 434         def_bool ARCH_SPARSEMEM_ENABLE
 435
 436 config HAVE_ARCH_PFN_VALID
 437         def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
 438
 439 config HW_PERF_EVENTS
 440         bool "Enable hardware performance counter support for perf events"
 441         depends on PERF_EVENTS
 442         default y
 443         help
 444           Enable hardware performance counter support for perf events. If
 445           disabled, perf events will use software events only.
 446
 447 config SYS_SUPPORTS_HUGETLBFS
 448         def_bool y
 449
 450 config ARCH_WANT_GENERAL_HUGETLB
 451         def_bool y
 452
 453 config ARCH_WANT_HUGE_PMD_SHARE
 454         def_bool y if !ARM64_64K_PAGES
 455
 456 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
 457         def_bool y
 458
 459 config ARCH_HAS_CACHE_LINE_SIZE
 460         def_bool y
 461
 462 source "mm/Kconfig"
 463
 464 config SECCOMP
 465         bool "Enable seccomp to safely compute untrusted bytecode"
 466         ---help---
 467           This kernel feature is useful for number crunching applications
 468           that may need to compute untrusted bytecode during their
 469           execution. By using pipes or other transports made available to
 470           the process as file descriptors supporting the read/write
 471           syscalls, it's possible to isolate those applications in
 472           their own address space using seccomp. Once seccomp is
 473           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
 474           and the task is only allowed to execute a few safe syscalls
 475           defined by each seccomp mode.
 476
 477 config XEN_DOM0
 478         def_bool y
 479         depends on XEN
 480
 481 config XEN
 482         bool "Xen guest support on ARM64"
 483         depends on ARM64 && OF
 484         select SWIOTLB_XEN
 485         help
 486           Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
 487
 488 config FORCE_MAX_ZONEORDER
 489         int
 490         default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
 491         default "11"
 492
 493 menuconfig ARMV8_DEPRECATED
 494         bool "Emulate deprecated/obsolete ARMv8 instructions"
 495         depends on COMPAT
 496         help
 497           Legacy software support may require certain instructions
 498           that have been deprecated or obsoleted in the architecture.
 499
 500           Enable this config to enable selective emulation of these
 501           features.
 502
 503           If unsure, say Y
 504
 505 if ARMV8_DEPRECATED
 506
 507 config SWP_EMULATION
 508         bool "Emulate SWP/SWPB instructions"
 509         help
 510           ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
 511           they are always undefined. Say Y here to enable software
 512           emulation of these instructions for userspace using LDXR/STXR.
 513
 514           In some older versions of glibc [<=2.8] SWP is used during futex
 515           trylock() operations with the assumption that the code will not
 516           be preempted. This invalid assumption may be more likely to fail
 517           with SWP emulation enabled, leading to deadlock of the user
 518           application.
 519
 520           NOTE: when accessing uncached shared regions, LDXR/STXR rely
 521           on an external transaction monitoring block called a global
 522           monitor to maintain update atomicity. If your system does not
 523           implement a global monitor, this option can cause programs that
 524           perform SWP operations to uncached memory to deadlock.
 525
 526           If unsure, say Y
 527
 528 config CP15_BARRIER_EMULATION
 529         bool "Emulate CP15 Barrier instructions"
 530         help
 531           The CP15 barrier instructions - CP15ISB, CP15DSB, and
 532           CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
 533           strongly recommended to use the ISB, DSB, and DMB
 534           instructions instead.
 535
 536           Say Y here to enable software emulation of these
 537           instructions for AArch32 userspace code. When this option is
 538           enabled, CP15 barrier usage is traced which can help
 539           identify software that needs updating.
 540
 541           If unsure, say Y
 542
 543 config SETEND_EMULATION
 544         bool "Emulate SETEND instruction"
 545         help
 546           The SETEND instruction alters the data-endianness of the
 547           AArch32 EL0, and is deprecated in ARMv8.
 548
 549           Say Y here to enable software emulation of the instruction
 550           for AArch32 userspace code.
 551
 552           Note: All the cpus on the system must have mixed endian support at EL0
 553           for this feature to be enabled. If a new CPU - which doesn't support mixed
 554           endian - is hotplugged in after this feature has been enabled, there could
 555           be unexpected results in the applications.
 556
 557           If unsure, say Y
 558 endif
 559
 560 menu "ARMv8.1 architectural features"
 561
 562 config ARM64_HW_AFDBM
 563         bool "Support for hardware updates of the Access and Dirty page flags"
 564         default y
 565         help
 566           The ARMv8.1 architecture extensions introduce support for
 567           hardware updates of the access and dirty information in page
 568           table entries. When enabled in TCR_EL1 (HA and HD bits) on
 569           capable processors, accesses to pages with PTE_AF cleared will
 570           set this bit instead of raising an access flag fault.
 571           Similarly, writes to read-only pages with the DBM bit set will
 572           clear the read-only bit (AP[2]) instead of raising a
 573           permission fault.
 574
 575           Kernels built with this configuration option enabled continue
 576           to work on pre-ARMv8.1 hardware and the performance impact is
 577           minimal. If unsure, say Y.
 578
 579 config ARM64_PAN
 580         bool "Enable support for Privileged Access Never (PAN)"
 581         default y
 582         help
 583          Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
 584          prevents the kernel or hypervisor from accessing user-space (EL0)
 585          memory directly.
 586
 587          Choosing this option will cause any unprotected (not using
 588          copy_to_user et al) memory access to fail with a permission fault.
 589
 590          The feature is detected at runtime, and will remain as a 'nop'
 591          instruction if the cpu does not implement the feature.
 592
 593 config ARM64_LSE_ATOMICS
 594         bool "Atomic instructions"
 595         help
 596           As part of the Large System Extensions, ARMv8.1 introduces new
 597           atomic instructions that are designed specifically to scale in
 598           very large systems.
 599
 600           Say Y here to make use of these instructions for the in-kernel
 601           atomic routines. This incurs a small overhead on CPUs that do
 602           not support these instructions and requires the kernel to be
 603           built with binutils >= 2.25.
 604
 605 endmenu
 606
 607 endmenu
 608
 609 menu "Boot options"
 610
 611 config CMDLINE
 612         string "Default kernel command string"
 613         default ""
 614         help
 615           Provide a set of default command-line options at build time by
 616           entering them here. As a minimum, you should specify the the
 617           root device (e.g. root=/dev/nfs).
 618
 619 config CMDLINE_FORCE
 620         bool "Always use the default kernel command string"
 621         help
 622           Always use the default kernel command string, even if the boot
 623           loader passes other arguments to the kernel.
 624           This is useful if you cannot or don't want to change the
 625           command-line options your boot loader passes to the kernel.
 626
 627 config EFI_STUB
 628         bool
 629
 630 config EFI
 631         bool "UEFI runtime support"
 632         depends on OF && !CPU_BIG_ENDIAN
 633         select LIBFDT
 634         select UCS2_STRING
 635         select EFI_PARAMS_FROM_FDT
 636         select EFI_RUNTIME_WRAPPERS
 637         select EFI_STUB
 638         select EFI_ARMSTUB
 639         default y
 640         help
 641           This option provides support for runtime services provided
 642           by UEFI firmware (such as non-volatile variables, realtime
 643           clock, and platform reset). A UEFI stub is also provided to
 644           allow the kernel to be booted as an EFI application. This
 645           is only useful on systems that have UEFI firmware.
 646
 647 config DMI
 648         bool "Enable support for SMBIOS (DMI) tables"
 649         depends on EFI
 650         default y
 651         help
 652           This enables SMBIOS/DMI feature for systems.
 653
 654           This option is only useful on systems that have UEFI firmware.
 655           However, even with this option, the resultant kernel should
 656           continue to boot on existing non-UEFI platforms.
 657
 658 endmenu
 659
 660 menu "Userspace binary formats"
 661
 662 source "fs/Kconfig.binfmt"
 663
 664 config COMPAT
 665         bool "Kernel support for 32-bit EL0"
 666         depends on !ARM64_64K_PAGES || EXPERT
 667         select COMPAT_BINFMT_ELF
 668         select HAVE_UID16
 669         select OLD_SIGSUSPEND3
 670         select COMPAT_OLD_SIGACTION
 671         help
 672           This option enables support for a 32-bit EL0 running under a 64-bit
 673           kernel at EL1. AArch32-specific components such as system calls,
 674           the user helper functions, VFP support and the ptrace interface are
 675           handled appropriately by the kernel.
 676
 677           If you also enabled CONFIG_ARM64_64K_PAGES, please be aware that you
 678           will only be able to execute AArch32 binaries that were compiled with
 679           64k aligned segments.
 680
 681           If you want to execute 32-bit userspace applications, say Y.
 682
 683 config SYSVIPC_COMPAT
 684         def_bool y
 685         depends on COMPAT && SYSVIPC
 686
 687 endmenu
 688
 689 menu "Power management options"
 690
 691 source "kernel/power/Kconfig"
 692
 693 config ARCH_SUSPEND_POSSIBLE
 694         def_bool y
 695
 696 endmenu
 697
 698 menu "CPU Power Management"
 699
 700 source "drivers/cpuidle/Kconfig"
 701
 702 source "drivers/cpufreq/Kconfig"
 703
 704 endmenu
 705
 706 source "net/Kconfig"
 707
 708 source "drivers/Kconfig"
 709
 710 source "drivers/firmware/Kconfig"
 711
 712 source "drivers/acpi/Kconfig"
 713
 714 source "fs/Kconfig"
 715
 716 source "arch/arm64/kvm/Kconfig"
 717
 718 source "arch/arm64/Kconfig.debug"
 719
 720 source "security/Kconfig"
 721
 722 source "crypto/Kconfig"
 723 if CRYPTO
 724 source "arch/arm64/crypto/Kconfig"
 725 endif
 726
 727 source "lib/Kconfig"