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 ARCH_HAS_UBSAN_SANITIZE_ALL
20 select AUDIT_ARCH_COMPAT_GENERIC
21 select ARM_GIC_V2M if PCI_MSI
23 select ARM_GIC_V3_ITS if PCI_MSI
25 select BUILDTIME_EXTABLE_SORT
26 select CLONE_BACKWARDS
28 select CPU_PM if (SUSPEND || CPU_IDLE)
29 select DCACHE_WORD_ACCESS
32 select GENERIC_ALLOCATOR
33 select GENERIC_CLOCKEVENTS
34 select GENERIC_CLOCKEVENTS_BROADCAST
35 select GENERIC_CPU_AUTOPROBE
36 select GENERIC_EARLY_IOREMAP
37 select GENERIC_IDLE_POLL_SETUP
38 select GENERIC_IRQ_PROBE
39 select GENERIC_IRQ_SHOW
40 select GENERIC_IRQ_SHOW_LEVEL
41 select GENERIC_PCI_IOMAP
42 select GENERIC_SCHED_CLOCK
43 select GENERIC_SMP_IDLE_THREAD
44 select GENERIC_STRNCPY_FROM_USER
45 select GENERIC_STRNLEN_USER
46 select GENERIC_TIME_VSYSCALL
47 select HANDLE_DOMAIN_IRQ
48 select HARDIRQS_SW_RESEND
49 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
50 select HAVE_ARCH_AUDITSYSCALL
51 select HAVE_ARCH_BITREVERSE
52 select HAVE_ARCH_HARDENED_USERCOPY
53 select HAVE_ARCH_HUGE_VMAP
54 select HAVE_ARCH_JUMP_LABEL
55 select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
57 select HAVE_ARCH_MMAP_RND_BITS
58 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
59 select HAVE_ARCH_SECCOMP_FILTER
60 select HAVE_ARCH_TRACEHOOK
62 select HAVE_C_RECORDMCOUNT
63 select HAVE_CC_STACKPROTECTOR
64 select HAVE_CMPXCHG_DOUBLE
65 select HAVE_CMPXCHG_LOCAL
66 select HAVE_DEBUG_BUGVERBOSE
67 select HAVE_DEBUG_KMEMLEAK
68 select HAVE_DMA_API_DEBUG
70 select HAVE_DMA_CONTIGUOUS
71 select HAVE_DYNAMIC_FTRACE
72 select HAVE_EFFICIENT_UNALIGNED_ACCESS
73 select HAVE_FTRACE_MCOUNT_RECORD
74 select HAVE_FUNCTION_TRACER
75 select HAVE_FUNCTION_GRAPH_TRACER
76 select HAVE_GENERIC_DMA_COHERENT
77 select HAVE_HW_BREAKPOINT if PERF_EVENTS
78 select HAVE_IRQ_TIME_ACCOUNTING
80 select HAVE_PATA_PLATFORM
81 select HAVE_PERF_EVENTS
83 select HAVE_PERF_USER_STACK_DUMP
84 select HAVE_RCU_TABLE_FREE
85 select HAVE_SYSCALL_TRACEPOINTS
86 select IOMMU_DMA if IOMMU_SUPPORT
88 select IRQ_FORCED_THREADING
89 select MODULES_USE_ELF_RELA
92 select OF_EARLY_FLATTREE
93 select OF_RESERVED_MEM
94 select PERF_USE_VMALLOC
99 select SYSCTL_EXCEPTION_TRACE
100 select HAVE_CONTEXT_TRACKING
102 ARM 64-bit (AArch64) Linux support.
107 config ARCH_PHYS_ADDR_T_64BIT
113 config ARCH_MMAP_RND_BITS_MIN
114 default 14 if ARM64_64K_PAGES
115 default 16 if ARM64_16K_PAGES
118 # max bits determined by the following formula:
119 # VA_BITS - PAGE_SHIFT - 3
120 config ARCH_MMAP_RND_BITS_MAX
121 default 19 if ARM64_VA_BITS=36
122 default 24 if ARM64_VA_BITS=39
123 default 27 if ARM64_VA_BITS=42
124 default 30 if ARM64_VA_BITS=47
125 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
126 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
127 default 33 if ARM64_VA_BITS=48
128 default 14 if ARM64_64K_PAGES
129 default 16 if ARM64_16K_PAGES
132 config ARCH_MMAP_RND_COMPAT_BITS_MIN
133 default 7 if ARM64_64K_PAGES
134 default 9 if ARM64_16K_PAGES
137 config ARCH_MMAP_RND_COMPAT_BITS_MAX
143 config ILLEGAL_POINTER_VALUE
145 default 0xdead000000000000
147 config STACKTRACE_SUPPORT
150 config ILLEGAL_POINTER_VALUE
152 default 0xdead000000000000
154 config LOCKDEP_SUPPORT
157 config TRACE_IRQFLAGS_SUPPORT
160 config RWSEM_XCHGADD_ALGORITHM
167 config GENERIC_BUG_RELATIVE_POINTERS
169 depends on GENERIC_BUG
171 config GENERIC_HWEIGHT
177 config GENERIC_CALIBRATE_DELAY
183 config HAVE_GENERIC_RCU_GUP
186 config ARCH_DMA_ADDR_T_64BIT
189 config NEED_DMA_MAP_STATE
192 config NEED_SG_DMA_LENGTH
204 config KERNEL_MODE_NEON
207 config FIX_EARLYCON_MEM
210 config PGTABLE_LEVELS
212 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
213 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
214 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
215 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
216 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
217 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
219 source "init/Kconfig"
221 source "kernel/Kconfig.freezer"
223 source "arch/arm64/Kconfig.platforms"
230 This feature enables support for PCI bus system. If you say Y
231 here, the kernel will include drivers and infrastructure code
232 to support PCI bus devices.
237 config PCI_DOMAINS_GENERIC
243 source "drivers/pci/Kconfig"
244 source "drivers/pci/pcie/Kconfig"
245 source "drivers/pci/hotplug/Kconfig"
249 menu "Kernel Features"
251 menu "ARM errata workarounds via the alternatives framework"
253 config ARM64_ERRATUM_826319
254 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
257 This option adds an alternative code sequence to work around ARM
258 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
259 AXI master interface and an L2 cache.
261 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
262 and is unable to accept a certain write via this interface, it will
263 not progress on read data presented on the read data channel and the
266 The workaround promotes data cache clean instructions to
267 data cache clean-and-invalidate.
268 Please note that this does not necessarily enable the workaround,
269 as it depends on the alternative framework, which will only patch
270 the kernel if an affected CPU is detected.
274 config ARM64_ERRATUM_827319
275 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
278 This option adds an alternative code sequence to work around ARM
279 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
280 master interface and an L2 cache.
282 Under certain conditions this erratum can cause a clean line eviction
283 to occur at the same time as another transaction to the same address
284 on the AMBA 5 CHI interface, which can cause data corruption if the
285 interconnect reorders the two transactions.
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.
295 config ARM64_ERRATUM_824069
296 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
299 This option adds an alternative code sequence to work around ARM
300 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
301 to a coherent interconnect.
303 If a Cortex-A53 processor is executing a store or prefetch for
304 write instruction at the same time as a processor in another
305 cluster is executing a cache maintenance operation to the same
306 address, then this erratum might cause a clean cache line to be
307 incorrectly marked as dirty.
309 The workaround promotes data cache clean instructions to
310 data cache clean-and-invalidate.
311 Please note that this option does not necessarily enable the
312 workaround, as it depends on the alternative framework, which will
313 only patch the kernel if an affected CPU is detected.
317 config ARM64_ERRATUM_819472
318 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
321 This option adds an alternative code sequence to work around ARM
322 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
323 present when it is connected to a coherent interconnect.
325 If the processor is executing a load and store exclusive sequence at
326 the same time as a processor in another cluster is executing a cache
327 maintenance operation to the same address, then this erratum might
328 cause data corruption.
330 The workaround promotes data cache clean instructions to
331 data cache clean-and-invalidate.
332 Please note that this does not necessarily enable the workaround,
333 as it depends on the alternative framework, which will only patch
334 the kernel if an affected CPU is detected.
338 config ARM64_ERRATUM_832075
339 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
342 This option adds an alternative code sequence to work around ARM
343 erratum 832075 on Cortex-A57 parts up to r1p2.
345 Affected Cortex-A57 parts might deadlock when exclusive load/store
346 instructions to Write-Back memory are mixed with Device loads.
348 The workaround is to promote device loads to use Load-Acquire
350 Please note that this does not necessarily enable the workaround,
351 as it depends on the alternative framework, which will only patch
352 the kernel if an affected CPU is detected.
356 config ARM64_ERRATUM_834220
357 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
361 This option adds an alternative code sequence to work around ARM
362 erratum 834220 on Cortex-A57 parts up to r1p2.
364 Affected Cortex-A57 parts might report a Stage 2 translation
365 fault as the result of a Stage 1 fault for load crossing a
366 page boundary when there is a permission or device memory
367 alignment fault at Stage 1 and a translation fault at Stage 2.
369 The workaround is to verify that the Stage 1 translation
370 doesn't generate a fault before handling the Stage 2 fault.
371 Please note that this does not necessarily enable the workaround,
372 as it depends on the alternative framework, which will only patch
373 the kernel if an affected CPU is detected.
377 config ARM64_ERRATUM_845719
378 bool "Cortex-A53: 845719: a load might read incorrect data"
382 This option adds an alternative code sequence to work around ARM
383 erratum 845719 on Cortex-A53 parts up to r0p4.
385 When running a compat (AArch32) userspace on an affected Cortex-A53
386 part, a load at EL0 from a virtual address that matches the bottom 32
387 bits of the virtual address used by a recent load at (AArch64) EL1
388 might return incorrect data.
390 The workaround is to write the contextidr_el1 register on exception
391 return to a 32-bit task.
392 Please note that this does not necessarily enable the workaround,
393 as it depends on the alternative framework, which will only patch
394 the kernel if an affected CPU is detected.
398 config ARM64_ERRATUM_843419
399 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
402 select ARM64_MODULE_CMODEL_LARGE
404 This option builds kernel modules using the large memory model in
405 order to avoid the use of the ADRP instruction, which can cause
406 a subsequent memory access to use an incorrect address on Cortex-A53
409 Note that the kernel itself must be linked with a version of ld
410 which fixes potentially affected ADRP instructions through the
415 config CAVIUM_ERRATUM_22375
416 bool "Cavium erratum 22375, 24313"
419 Enable workaround for erratum 22375, 24313.
421 This implements two gicv3-its errata workarounds for ThunderX. Both
422 with small impact affecting only ITS table allocation.
424 erratum 22375: only alloc 8MB table size
425 erratum 24313: ignore memory access type
427 The fixes are in ITS initialization and basically ignore memory access
428 type and table size provided by the TYPER and BASER registers.
432 config CAVIUM_ERRATUM_23154
433 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
436 The gicv3 of ThunderX requires a modified version for
437 reading the IAR status to ensure data synchronization
438 (access to icc_iar1_el1 is not sync'ed before and after).
442 config CAVIUM_ERRATUM_27456
443 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
446 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
447 instructions may cause the icache to become corrupted if it
448 contains data for a non-current ASID. The fix is to
449 invalidate the icache when changing the mm context.
458 default ARM64_4K_PAGES
460 Page size (translation granule) configuration.
462 config ARM64_4K_PAGES
465 This feature enables 4KB pages support.
467 config ARM64_16K_PAGES
470 The system will use 16KB pages support. AArch32 emulation
471 requires applications compiled with 16K (or a multiple of 16K)
474 config ARM64_64K_PAGES
477 This feature enables 64KB pages support (4KB by default)
478 allowing only two levels of page tables and faster TLB
479 look-up. AArch32 emulation requires applications compiled
480 with 64K aligned segments.
485 prompt "Virtual address space size"
486 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
487 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
488 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
490 Allows choosing one of multiple possible virtual address
491 space sizes. The level of translation table is determined by
492 a combination of page size and virtual address space size.
494 config ARM64_VA_BITS_36
495 bool "36-bit" if EXPERT
496 depends on ARM64_16K_PAGES
498 config ARM64_VA_BITS_39
500 depends on ARM64_4K_PAGES
502 config ARM64_VA_BITS_42
504 depends on ARM64_64K_PAGES
506 config ARM64_VA_BITS_47
508 depends on ARM64_16K_PAGES
510 config ARM64_VA_BITS_48
517 default 36 if ARM64_VA_BITS_36
518 default 39 if ARM64_VA_BITS_39
519 default 42 if ARM64_VA_BITS_42
520 default 47 if ARM64_VA_BITS_47
521 default 48 if ARM64_VA_BITS_48
523 config CPU_BIG_ENDIAN
524 bool "Build big-endian kernel"
526 Say Y if you plan on running a kernel in big-endian mode.
529 bool "Multi-core scheduler support"
531 Multi-core scheduler support improves the CPU scheduler's decision
532 making when dealing with multi-core CPU chips at a cost of slightly
533 increased overhead in some places. If unsure say N here.
536 bool "SMT scheduler support"
538 Improves the CPU scheduler's decision making when dealing with
539 MultiThreading at a cost of slightly increased overhead in some
540 places. If unsure say N here.
543 int "Maximum number of CPUs (2-4096)"
545 # These have to remain sorted largest to smallest
549 bool "Support for hot-pluggable CPUs"
550 select GENERIC_IRQ_MIGRATION
552 Say Y here to experiment with turning CPUs off and on. CPUs
553 can be controlled through /sys/devices/system/cpu.
555 source kernel/Kconfig.preempt
556 source kernel/Kconfig.hz
558 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
561 config ARCH_HAS_HOLES_MEMORYMODEL
562 def_bool y if SPARSEMEM
564 config ARCH_SPARSEMEM_ENABLE
566 select SPARSEMEM_VMEMMAP_ENABLE
568 config ARCH_SPARSEMEM_DEFAULT
569 def_bool ARCH_SPARSEMEM_ENABLE
571 config ARCH_SELECT_MEMORY_MODEL
572 def_bool ARCH_SPARSEMEM_ENABLE
574 config HAVE_ARCH_PFN_VALID
575 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
577 config HW_PERF_EVENTS
581 config SYS_SUPPORTS_HUGETLBFS
584 config ARCH_WANT_HUGE_PMD_SHARE
585 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
587 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
590 config ARCH_HAS_CACHE_LINE_SIZE
596 bool "Enable seccomp to safely compute untrusted bytecode"
598 This kernel feature is useful for number crunching applications
599 that may need to compute untrusted bytecode during their
600 execution. By using pipes or other transports made available to
601 the process as file descriptors supporting the read/write
602 syscalls, it's possible to isolate those applications in
603 their own address space using seccomp. Once seccomp is
604 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
605 and the task is only allowed to execute a few safe syscalls
606 defined by each seccomp mode.
613 bool "Xen guest support on ARM64"
614 depends on ARM64 && OF
617 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
619 config FORCE_MAX_ZONEORDER
621 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
622 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
625 The kernel memory allocator divides physically contiguous memory
626 blocks into "zones", where each zone is a power of two number of
627 pages. This option selects the largest power of two that the kernel
628 keeps in the memory allocator. If you need to allocate very large
629 blocks of physically contiguous memory, then you may need to
632 This config option is actually maximum order plus one. For example,
633 a value of 11 means that the largest free memory block is 2^10 pages.
635 We make sure that we can allocate upto a HugePage size for each configuration.
637 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
639 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
640 4M allocations matching the default size used by generic code.
642 menuconfig ARMV8_DEPRECATED
643 bool "Emulate deprecated/obsolete ARMv8 instructions"
646 Legacy software support may require certain instructions
647 that have been deprecated or obsoleted in the architecture.
649 Enable this config to enable selective emulation of these
657 bool "Emulate SWP/SWPB instructions"
659 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
660 they are always undefined. Say Y here to enable software
661 emulation of these instructions for userspace using LDXR/STXR.
663 In some older versions of glibc [<=2.8] SWP is used during futex
664 trylock() operations with the assumption that the code will not
665 be preempted. This invalid assumption may be more likely to fail
666 with SWP emulation enabled, leading to deadlock of the user
669 NOTE: when accessing uncached shared regions, LDXR/STXR rely
670 on an external transaction monitoring block called a global
671 monitor to maintain update atomicity. If your system does not
672 implement a global monitor, this option can cause programs that
673 perform SWP operations to uncached memory to deadlock.
677 config CP15_BARRIER_EMULATION
678 bool "Emulate CP15 Barrier instructions"
680 The CP15 barrier instructions - CP15ISB, CP15DSB, and
681 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
682 strongly recommended to use the ISB, DSB, and DMB
683 instructions instead.
685 Say Y here to enable software emulation of these
686 instructions for AArch32 userspace code. When this option is
687 enabled, CP15 barrier usage is traced which can help
688 identify software that needs updating.
692 config SETEND_EMULATION
693 bool "Emulate SETEND instruction"
695 The SETEND instruction alters the data-endianness of the
696 AArch32 EL0, and is deprecated in ARMv8.
698 Say Y here to enable software emulation of the instruction
699 for AArch32 userspace code.
701 Note: All the cpus on the system must have mixed endian support at EL0
702 for this feature to be enabled. If a new CPU - which doesn't support mixed
703 endian - is hotplugged in after this feature has been enabled, there could
704 be unexpected results in the applications.
709 menu "ARMv8.1 architectural features"
711 config ARM64_HW_AFDBM
712 bool "Support for hardware updates of the Access and Dirty page flags"
715 The ARMv8.1 architecture extensions introduce support for
716 hardware updates of the access and dirty information in page
717 table entries. When enabled in TCR_EL1 (HA and HD bits) on
718 capable processors, accesses to pages with PTE_AF cleared will
719 set this bit instead of raising an access flag fault.
720 Similarly, writes to read-only pages with the DBM bit set will
721 clear the read-only bit (AP[2]) instead of raising a
724 Kernels built with this configuration option enabled continue
725 to work on pre-ARMv8.1 hardware and the performance impact is
726 minimal. If unsure, say Y.
729 bool "Enable support for Privileged Access Never (PAN)"
732 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
733 prevents the kernel or hypervisor from accessing user-space (EL0)
736 Choosing this option will cause any unprotected (not using
737 copy_to_user et al) memory access to fail with a permission fault.
739 The feature is detected at runtime, and will remain as a 'nop'
740 instruction if the cpu does not implement the feature.
742 config ARM64_LSE_ATOMICS
743 bool "Atomic instructions"
745 As part of the Large System Extensions, ARMv8.1 introduces new
746 atomic instructions that are designed specifically to scale in
749 Say Y here to make use of these instructions for the in-kernel
750 atomic routines. This incurs a small overhead on CPUs that do
751 not support these instructions and requires the kernel to be
752 built with binutils >= 2.25.
757 bool "Enable support for User Access Override (UAO)"
760 User Access Override (UAO; part of the ARMv8.2 Extensions)
761 causes the 'unprivileged' variant of the load/store instructions to
762 be overriden to be privileged.
764 This option changes get_user() and friends to use the 'unprivileged'
765 variant of the load/store instructions. This ensures that user-space
766 really did have access to the supplied memory. When addr_limit is
767 set to kernel memory the UAO bit will be set, allowing privileged
768 access to kernel memory.
770 Choosing this option will cause copy_to_user() et al to use user-space
773 The feature is detected at runtime, the kernel will use the
774 regular load/store instructions if the cpu does not implement the
777 config ARM64_MODULE_CMODEL_LARGE
780 config ARM64_MODULE_PLTS
782 select ARM64_MODULE_CMODEL_LARGE
783 select HAVE_MOD_ARCH_SPECIFIC
788 This builds the kernel as a Position Independent Executable (PIE),
789 which retains all relocation metadata required to relocate the
790 kernel binary at runtime to a different virtual address than the
791 address it was linked at.
792 Since AArch64 uses the RELA relocation format, this requires a
793 relocation pass at runtime even if the kernel is loaded at the
794 same address it was linked at.
796 config RANDOMIZE_BASE
797 bool "Randomize the address of the kernel image"
798 select ARM64_MODULE_PLTS if MODULES
801 Randomizes the virtual address at which the kernel image is
802 loaded, as a security feature that deters exploit attempts
803 relying on knowledge of the location of kernel internals.
805 It is the bootloader's job to provide entropy, by passing a
806 random u64 value in /chosen/kaslr-seed at kernel entry.
808 When booting via the UEFI stub, it will invoke the firmware's
809 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
810 to the kernel proper. In addition, it will randomise the physical
811 location of the kernel Image as well.
815 config RANDOMIZE_MODULE_REGION_FULL
816 bool "Randomize the module region independently from the core kernel"
817 depends on RANDOMIZE_BASE && !DYNAMIC_FTRACE
820 Randomizes the location of the module region without considering the
821 location of the core kernel. This way, it is impossible for modules
822 to leak information about the location of core kernel data structures
823 but it does imply that function calls between modules and the core
824 kernel will need to be resolved via veneers in the module PLT.
826 When this option is not set, the module region will be randomized over
827 a limited range that contains the [_stext, _etext] interval of the
828 core kernel, so branch relocations are always in range.
834 config ARM64_ACPI_PARKING_PROTOCOL
835 bool "Enable support for the ARM64 ACPI parking protocol"
838 Enable support for the ARM64 ACPI parking protocol. If disabled
839 the kernel will not allow booting through the ARM64 ACPI parking
840 protocol even if the corresponding data is present in the ACPI
844 string "Default kernel command string"
847 Provide a set of default command-line options at build time by
848 entering them here. As a minimum, you should specify the the
849 root device (e.g. root=/dev/nfs).
852 prompt "Kernel command line type" if CMDLINE != ""
853 default CMDLINE_FROM_BOOTLOADER
855 config CMDLINE_FROM_BOOTLOADER
856 bool "Use bootloader kernel arguments if available"
858 Uses the command-line options passed by the boot loader. If
859 the boot loader doesn't provide any, the default kernel command
860 string provided in CMDLINE will be used.
862 config CMDLINE_EXTEND
863 bool "Extend bootloader kernel arguments"
865 The command-line arguments provided by the boot loader will be
866 appended to the default kernel command string.
869 bool "Always use the default kernel command string"
871 Always use the default kernel command string, even if the boot
872 loader passes other arguments to the kernel.
873 This is useful if you cannot or don't want to change the
874 command-line options your boot loader passes to the kernel.
881 bool "UEFI runtime support"
882 depends on OF && !CPU_BIG_ENDIAN
885 select EFI_PARAMS_FROM_FDT
886 select EFI_RUNTIME_WRAPPERS
891 This option provides support for runtime services provided
892 by UEFI firmware (such as non-volatile variables, realtime
893 clock, and platform reset). A UEFI stub is also provided to
894 allow the kernel to be booted as an EFI application. This
895 is only useful on systems that have UEFI firmware.
898 bool "Enable support for SMBIOS (DMI) tables"
902 This enables SMBIOS/DMI feature for systems.
904 This option is only useful on systems that have UEFI firmware.
905 However, even with this option, the resultant kernel should
906 continue to boot on existing non-UEFI platforms.
908 config BUILD_ARM64_APPENDED_DTB_IMAGE
909 bool "Build a concatenated Image.gz/dtb by default"
912 Enabling this option will cause a concatenated Image.gz and list of
913 DTBs to be built by default (instead of a standalone Image.gz.)
914 The image will built in arch/arm64/boot/Image.gz-dtb
916 config BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES
917 string "Default dtb names"
918 depends on BUILD_ARM64_APPENDED_DTB_IMAGE
920 Space separated list of names of dtbs to append when
921 building a concatenated Image.gz-dtb.
925 menu "Userspace binary formats"
927 source "fs/Kconfig.binfmt"
930 bool "Kernel support for 32-bit EL0"
931 depends on ARM64_4K_PAGES || EXPERT
932 select COMPAT_BINFMT_ELF
934 select OLD_SIGSUSPEND3
935 select COMPAT_OLD_SIGACTION
937 This option enables support for a 32-bit EL0 running under a 64-bit
938 kernel at EL1. AArch32-specific components such as system calls,
939 the user helper functions, VFP support and the ptrace interface are
940 handled appropriately by the kernel.
942 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
943 that you will only be able to execute AArch32 binaries that were compiled
944 with page size aligned segments.
946 If you want to execute 32-bit userspace applications, say Y.
948 config SYSVIPC_COMPAT
950 depends on COMPAT && SYSVIPC
954 menu "Power management options"
956 source "kernel/power/Kconfig"
958 config ARCH_SUSPEND_POSSIBLE
963 menu "CPU Power Management"
965 source "drivers/cpuidle/Kconfig"
967 source "drivers/cpufreq/Kconfig"
973 source "drivers/Kconfig"
975 source "drivers/firmware/Kconfig"
977 source "drivers/acpi/Kconfig"
981 source "arch/arm64/kvm/Kconfig"
983 source "arch/arm64/Kconfig.debug"
985 source "security/Kconfig"
987 source "crypto/Kconfig"
989 source "arch/arm64/crypto/Kconfig"