| config ARM64 |
| def_bool y |
| select ACPI_CCA_REQUIRED if ACPI |
| select ACPI_GENERIC_GSI if ACPI |
| select ACPI_REDUCED_HARDWARE_ONLY if ACPI |
| select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE |
| select ARCH_HAS_ELF_RANDOMIZE |
| select ARCH_HAS_GCOV_PROFILE_ALL |
| select ARCH_HAS_SG_CHAIN |
| select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST |
| select ARCH_USE_CMPXCHG_LOCKREF |
| select ARCH_SUPPORTS_ATOMIC_RMW |
| select ARCH_WANT_OPTIONAL_GPIOLIB |
| select ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
| select ARCH_WANT_FRAME_POINTERS |
| select ARM_AMBA |
| select ARM_ARCH_TIMER |
| select ARM_GIC |
| select AUDIT_ARCH_COMPAT_GENERIC |
| select ARM_GIC_V2M if PCI_MSI |
| select ARM_GIC_V3 |
| select ARM_GIC_V3_ITS if PCI_MSI |
| select ARM_PSCI_FW |
| select BUILDTIME_EXTABLE_SORT |
| select CLONE_BACKWARDS |
| select COMMON_CLK |
| select CPU_PM if (SUSPEND || CPU_IDLE) |
| select DCACHE_WORD_ACCESS |
| select EDAC_SUPPORT |
| select FRAME_POINTER |
| select GENERIC_ALLOCATOR |
| select GENERIC_CLOCKEVENTS |
| select GENERIC_CLOCKEVENTS_BROADCAST |
| select GENERIC_CPU_AUTOPROBE |
| select GENERIC_EARLY_IOREMAP |
| select GENERIC_IDLE_POLL_SETUP |
| select GENERIC_IRQ_PROBE |
| select GENERIC_IRQ_SHOW |
| select GENERIC_IRQ_SHOW_LEVEL |
| select GENERIC_PCI_IOMAP |
| select GENERIC_SCHED_CLOCK |
| select GENERIC_SMP_IDLE_THREAD |
| select GENERIC_STRNCPY_FROM_USER |
| select GENERIC_STRNLEN_USER |
| select GENERIC_TIME_VSYSCALL |
| select HANDLE_DOMAIN_IRQ |
| select HARDIRQS_SW_RESEND |
| select HAVE_ALIGNED_STRUCT_PAGE if SLUB |
| select HAVE_ARCH_AUDITSYSCALL |
| select HAVE_ARCH_BITREVERSE |
| select HAVE_ARCH_JUMP_LABEL |
| select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48) |
| select HAVE_ARCH_KGDB |
| select HAVE_ARCH_SECCOMP_FILTER |
| select HAVE_ARCH_TRACEHOOK |
| select HAVE_BPF_JIT |
| select HAVE_C_RECORDMCOUNT |
| select HAVE_CC_STACKPROTECTOR |
| select HAVE_CMPXCHG_DOUBLE |
| select HAVE_CMPXCHG_LOCAL |
| select HAVE_DEBUG_BUGVERBOSE |
| select HAVE_DEBUG_KMEMLEAK |
| select HAVE_DMA_API_DEBUG |
| select HAVE_DMA_ATTRS |
| select HAVE_DMA_CONTIGUOUS |
| select HAVE_DYNAMIC_FTRACE |
| select HAVE_EFFICIENT_UNALIGNED_ACCESS |
| select HAVE_FTRACE_MCOUNT_RECORD |
| select HAVE_FUNCTION_TRACER |
| select HAVE_FUNCTION_GRAPH_TRACER |
| select HAVE_GENERIC_DMA_COHERENT |
| select HAVE_HW_BREAKPOINT if PERF_EVENTS |
| select HAVE_MEMBLOCK |
| select HAVE_PATA_PLATFORM |
| select HAVE_PERF_EVENTS |
| select HAVE_PERF_REGS |
| select HAVE_PERF_USER_STACK_DUMP |
| select HAVE_RCU_TABLE_FREE |
| select HAVE_SYSCALL_TRACEPOINTS |
| select IOMMU_DMA if IOMMU_SUPPORT |
| select IRQ_DOMAIN |
| select IRQ_FORCED_THREADING |
| select MODULES_USE_ELF_RELA |
| select NO_BOOTMEM |
| select OF |
| select OF_EARLY_FLATTREE |
| select OF_RESERVED_MEM |
| select PERF_USE_VMALLOC |
| select POWER_RESET |
| select POWER_SUPPLY |
| select RTC_LIB |
| select SPARSE_IRQ |
| select SYSCTL_EXCEPTION_TRACE |
| select HAVE_CONTEXT_TRACKING |
| help |
| ARM 64-bit (AArch64) Linux support. |
| |
| config 64BIT |
| def_bool y |
| |
| config ARCH_PHYS_ADDR_T_64BIT |
| def_bool y |
| |
| config MMU |
| def_bool y |
| |
| config NO_IOPORT_MAP |
| def_bool y if !PCI |
| |
| config STACKTRACE_SUPPORT |
| def_bool y |
| |
| config ILLEGAL_POINTER_VALUE |
| hex |
| default 0xdead000000000000 |
| |
| config LOCKDEP_SUPPORT |
| def_bool y |
| |
| config TRACE_IRQFLAGS_SUPPORT |
| def_bool y |
| |
| config RWSEM_XCHGADD_ALGORITHM |
| def_bool y |
| |
| config GENERIC_BUG |
| def_bool y |
| depends on BUG |
| |
| config GENERIC_BUG_RELATIVE_POINTERS |
| def_bool y |
| depends on GENERIC_BUG |
| |
| config GENERIC_HWEIGHT |
| def_bool y |
| |
| config GENERIC_CSUM |
| def_bool y |
| |
| config GENERIC_CALIBRATE_DELAY |
| def_bool y |
| |
| config ZONE_DMA |
| def_bool y |
| |
| config HAVE_GENERIC_RCU_GUP |
| def_bool y |
| |
| config ARCH_DMA_ADDR_T_64BIT |
| def_bool y |
| |
| config NEED_DMA_MAP_STATE |
| def_bool y |
| |
| config NEED_SG_DMA_LENGTH |
| def_bool y |
| |
| config SMP |
| def_bool y |
| |
| config SWIOTLB |
| def_bool y |
| |
| config IOMMU_HELPER |
| def_bool SWIOTLB |
| |
| config KERNEL_MODE_NEON |
| def_bool y |
| |
| config FIX_EARLYCON_MEM |
| def_bool y |
| |
| config PGTABLE_LEVELS |
| int |
| default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 |
| default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 |
| default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 |
| default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 |
| default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 |
| default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 |
| |
| source "init/Kconfig" |
| |
| source "kernel/Kconfig.freezer" |
| |
| source "arch/arm64/Kconfig.platforms" |
| |
| menu "Bus support" |
| |
| config PCI |
| bool "PCI support" |
| help |
| This feature enables support for PCI bus system. If you say Y |
| here, the kernel will include drivers and infrastructure code |
| to support PCI bus devices. |
| |
| config PCI_DOMAINS |
| def_bool PCI |
| |
| config PCI_DOMAINS_GENERIC |
| def_bool PCI |
| |
| config PCI_SYSCALL |
| def_bool PCI |
| |
| source "drivers/pci/Kconfig" |
| source "drivers/pci/pcie/Kconfig" |
| source "drivers/pci/hotplug/Kconfig" |
| |
| endmenu |
| |
| menu "Kernel Features" |
| |
| menu "ARM errata workarounds via the alternatives framework" |
| |
| config ARM64_ERRATUM_826319 |
| bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or |
| AXI master interface and an L2 cache. |
| |
| If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors |
| and is unable to accept a certain write via this interface, it will |
| not progress on read data presented on the read data channel and the |
| system can deadlock. |
| |
| The workaround promotes data cache clean instructions to |
| data cache clean-and-invalidate. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_827319 |
| bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI |
| master interface and an L2 cache. |
| |
| Under certain conditions this erratum can cause a clean line eviction |
| to occur at the same time as another transaction to the same address |
| on the AMBA 5 CHI interface, which can cause data corruption if the |
| interconnect reorders the two transactions. |
| |
| The workaround promotes data cache clean instructions to |
| data cache clean-and-invalidate. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_824069 |
| bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected |
| to a coherent interconnect. |
| |
| If a Cortex-A53 processor is executing a store or prefetch for |
| write instruction at the same time as a processor in another |
| cluster is executing a cache maintenance operation to the same |
| address, then this erratum might cause a clean cache line to be |
| incorrectly marked as dirty. |
| |
| The workaround promotes data cache clean instructions to |
| data cache clean-and-invalidate. |
| Please note that this option does not necessarily enable the |
| workaround, as it depends on the alternative framework, which will |
| only patch the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_819472 |
| bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache |
| present when it is connected to a coherent interconnect. |
| |
| If the processor is executing a load and store exclusive sequence at |
| the same time as a processor in another cluster is executing a cache |
| maintenance operation to the same address, then this erratum might |
| cause data corruption. |
| |
| The workaround promotes data cache clean instructions to |
| data cache clean-and-invalidate. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_832075 |
| bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 832075 on Cortex-A57 parts up to r1p2. |
| |
| Affected Cortex-A57 parts might deadlock when exclusive load/store |
| instructions to Write-Back memory are mixed with Device loads. |
| |
| The workaround is to promote device loads to use Load-Acquire |
| semantics. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_834220 |
| bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" |
| depends on KVM |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 834220 on Cortex-A57 parts up to r1p2. |
| |
| Affected Cortex-A57 parts might report a Stage 2 translation |
| fault as the result of a Stage 1 fault for load crossing a |
| page boundary when there is a permission or device memory |
| alignment fault at Stage 1 and a translation fault at Stage 2. |
| |
| The workaround is to verify that the Stage 1 translation |
| doesn't generate a fault before handling the Stage 2 fault. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_845719 |
| bool "Cortex-A53: 845719: a load might read incorrect data" |
| depends on COMPAT |
| default y |
| help |
| This option adds an alternative code sequence to work around ARM |
| erratum 845719 on Cortex-A53 parts up to r0p4. |
| |
| When running a compat (AArch32) userspace on an affected Cortex-A53 |
| part, a load at EL0 from a virtual address that matches the bottom 32 |
| bits of the virtual address used by a recent load at (AArch64) EL1 |
| might return incorrect data. |
| |
| The workaround is to write the contextidr_el1 register on exception |
| return to a 32-bit task. |
| Please note that this does not necessarily enable the workaround, |
| as it depends on the alternative framework, which will only patch |
| the kernel if an affected CPU is detected. |
| |
| If unsure, say Y. |
| |
| config ARM64_ERRATUM_843419 |
| bool "Cortex-A53: 843419: A load or store might access an incorrect address" |
| depends on MODULES |
| default y |
| help |
| This option builds kernel modules using the large memory model in |
| order to avoid the use of the ADRP instruction, which can cause |
| a subsequent memory access to use an incorrect address on Cortex-A53 |
| parts up to r0p4. |
| |
| Note that the kernel itself must be linked with a version of ld |
| which fixes potentially affected ADRP instructions through the |
| use of veneers. |
| |
| If unsure, say Y. |
| |
| config CAVIUM_ERRATUM_22375 |
| bool "Cavium erratum 22375, 24313" |
| default y |
| help |
| Enable workaround for erratum 22375, 24313. |
| |
| This implements two gicv3-its errata workarounds for ThunderX. Both |
| with small impact affecting only ITS table allocation. |
| |
| erratum 22375: only alloc 8MB table size |
| erratum 24313: ignore memory access type |
| |
| The fixes are in ITS initialization and basically ignore memory access |
| type and table size provided by the TYPER and BASER registers. |
| |
| If unsure, say Y. |
| |
| config CAVIUM_ERRATUM_23154 |
| bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" |
| default y |
| help |
| The gicv3 of ThunderX requires a modified version for |
| reading the IAR status to ensure data synchronization |
| (access to icc_iar1_el1 is not sync'ed before and after). |
| |
| If unsure, say Y. |
| |
| endmenu |
| |
| |
| choice |
| prompt "Page size" |
| default ARM64_4K_PAGES |
| help |
| Page size (translation granule) configuration. |
| |
| config ARM64_4K_PAGES |
| bool "4KB" |
| help |
| This feature enables 4KB pages support. |
| |
| config ARM64_16K_PAGES |
| bool "16KB" |
| help |
| The system will use 16KB pages support. AArch32 emulation |
| requires applications compiled with 16K (or a multiple of 16K) |
| aligned segments. |
| |
| config ARM64_64K_PAGES |
| bool "64KB" |
| help |
| This feature enables 64KB pages support (4KB by default) |
| allowing only two levels of page tables and faster TLB |
| look-up. AArch32 emulation requires applications compiled |
| with 64K aligned segments. |
| |
| endchoice |
| |
| choice |
| prompt "Virtual address space size" |
| default ARM64_VA_BITS_39 if ARM64_4K_PAGES |
| default ARM64_VA_BITS_47 if ARM64_16K_PAGES |
| default ARM64_VA_BITS_42 if ARM64_64K_PAGES |
| help |
| Allows choosing one of multiple possible virtual address |
| space sizes. The level of translation table is determined by |
| a combination of page size and virtual address space size. |
| |
| config ARM64_VA_BITS_36 |
| bool "36-bit" if EXPERT |
| depends on ARM64_16K_PAGES |
| |
| config ARM64_VA_BITS_39 |
| bool "39-bit" |
| depends on ARM64_4K_PAGES |
| |
| config ARM64_VA_BITS_42 |
| bool "42-bit" |
| depends on ARM64_64K_PAGES |
| |
| config ARM64_VA_BITS_47 |
| bool "47-bit" |
| depends on ARM64_16K_PAGES |
| |
| config ARM64_VA_BITS_48 |
| bool "48-bit" |
| |
| endchoice |
| |
| config ARM64_VA_BITS |
| int |
| default 36 if ARM64_VA_BITS_36 |
| default 39 if ARM64_VA_BITS_39 |
| default 42 if ARM64_VA_BITS_42 |
| default 47 if ARM64_VA_BITS_47 |
| default 48 if ARM64_VA_BITS_48 |
| |
| config CPU_BIG_ENDIAN |
| bool "Build big-endian kernel" |
| help |
| Say Y if you plan on running a kernel in big-endian mode. |
| |
| config SCHED_MC |
| bool "Multi-core scheduler support" |
| help |
| Multi-core scheduler support improves the CPU scheduler's decision |
| making when dealing with multi-core CPU chips at a cost of slightly |
| increased overhead in some places. If unsure say N here. |
| |
| config SCHED_SMT |
| bool "SMT scheduler support" |
| help |
| Improves the CPU scheduler's decision making when dealing with |
| MultiThreading at a cost of slightly increased overhead in some |
| places. If unsure say N here. |
| |
| config NR_CPUS |
| int "Maximum number of CPUs (2-4096)" |
| range 2 4096 |
| # These have to remain sorted largest to smallest |
| default "64" |
| |
| config HOTPLUG_CPU |
| bool "Support for hot-pluggable CPUs" |
| select GENERIC_IRQ_MIGRATION |
| help |
| Say Y here to experiment with turning CPUs off and on. CPUs |
| can be controlled through /sys/devices/system/cpu. |
| |
| source kernel/Kconfig.preempt |
| source kernel/Kconfig.hz |
| |
| config ARCH_HAS_HOLES_MEMORYMODEL |
| def_bool y if SPARSEMEM |
| |
| config ARCH_SPARSEMEM_ENABLE |
| def_bool y |
| select SPARSEMEM_VMEMMAP_ENABLE |
| |
| config ARCH_SPARSEMEM_DEFAULT |
| def_bool ARCH_SPARSEMEM_ENABLE |
| |
| config ARCH_SELECT_MEMORY_MODEL |
| def_bool ARCH_SPARSEMEM_ENABLE |
| |
| config HAVE_ARCH_PFN_VALID |
| def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM |
| |
| config HW_PERF_EVENTS |
| def_bool y |
| depends on ARM_PMU |
| |
| config SYS_SUPPORTS_HUGETLBFS |
| def_bool y |
| |
| config ARCH_WANT_GENERAL_HUGETLB |
| def_bool y |
| |
| config ARCH_WANT_HUGE_PMD_SHARE |
| def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) |
| |
| config HAVE_ARCH_TRANSPARENT_HUGEPAGE |
| def_bool y |
| |
| config ARCH_HAS_CACHE_LINE_SIZE |
| def_bool y |
| |
| source "mm/Kconfig" |
| |
| config SECCOMP |
| bool "Enable seccomp to safely compute untrusted bytecode" |
| ---help--- |
| This kernel feature is useful for number crunching applications |
| that may need to compute untrusted bytecode during their |
| execution. By using pipes or other transports made available to |
| the process as file descriptors supporting the read/write |
| syscalls, it's possible to isolate those applications in |
| their own address space using seccomp. Once seccomp is |
| enabled via prctl(PR_SET_SECCOMP), it cannot be disabled |
| and the task is only allowed to execute a few safe syscalls |
| defined by each seccomp mode. |
| |
| config XEN_DOM0 |
| def_bool y |
| depends on XEN |
| |
| config XEN |
| bool "Xen guest support on ARM64" |
| depends on ARM64 && OF |
| select SWIOTLB_XEN |
| help |
| Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. |
| |
| config FORCE_MAX_ZONEORDER |
| int |
| default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) |
| default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) |
| default "11" |
| help |
| The kernel memory allocator divides physically contiguous memory |
| blocks into "zones", where each zone is a power of two number of |
| pages. This option selects the largest power of two that the kernel |
| keeps in the memory allocator. If you need to allocate very large |
| blocks of physically contiguous memory, then you may need to |
| increase this value. |
| |
| This config option is actually maximum order plus one. For example, |
| a value of 11 means that the largest free memory block is 2^10 pages. |
| |
| We make sure that we can allocate upto a HugePage size for each configuration. |
| Hence we have : |
| MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 |
| |
| However for 4K, we choose a higher default value, 11 as opposed to 10, giving us |
| 4M allocations matching the default size used by generic code. |
| |
| menuconfig ARMV8_DEPRECATED |
| bool "Emulate deprecated/obsolete ARMv8 instructions" |
| depends on COMPAT |
| help |
| Legacy software support may require certain instructions |
| that have been deprecated or obsoleted in the architecture. |
| |
| Enable this config to enable selective emulation of these |
| features. |
| |
| If unsure, say Y |
| |
| if ARMV8_DEPRECATED |
| |
| config SWP_EMULATION |
| bool "Emulate SWP/SWPB instructions" |
| help |
| ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that |
| they are always undefined. Say Y here to enable software |
| emulation of these instructions for userspace using LDXR/STXR. |
| |
| In some older versions of glibc [<=2.8] SWP is used during futex |
| trylock() operations with the assumption that the code will not |
| be preempted. This invalid assumption may be more likely to fail |
| with SWP emulation enabled, leading to deadlock of the user |
| application. |
| |
| NOTE: when accessing uncached shared regions, LDXR/STXR rely |
| on an external transaction monitoring block called a global |
| monitor to maintain update atomicity. If your system does not |
| implement a global monitor, this option can cause programs that |
| perform SWP operations to uncached memory to deadlock. |
| |
| If unsure, say Y |
| |
| config CP15_BARRIER_EMULATION |
| bool "Emulate CP15 Barrier instructions" |
| help |
| The CP15 barrier instructions - CP15ISB, CP15DSB, and |
| CP15DMB - are deprecated in ARMv8 (and ARMv7). It is |
| strongly recommended to use the ISB, DSB, and DMB |
| instructions instead. |
| |
| Say Y here to enable software emulation of these |
| instructions for AArch32 userspace code. When this option is |
| enabled, CP15 barrier usage is traced which can help |
| identify software that needs updating. |
| |
| If unsure, say Y |
| |
| config SETEND_EMULATION |
| bool "Emulate SETEND instruction" |
| help |
| The SETEND instruction alters the data-endianness of the |
| AArch32 EL0, and is deprecated in ARMv8. |
| |
| Say Y here to enable software emulation of the instruction |
| for AArch32 userspace code. |
| |
| Note: All the cpus on the system must have mixed endian support at EL0 |
| for this feature to be enabled. If a new CPU - which doesn't support mixed |
| endian - is hotplugged in after this feature has been enabled, there could |
| be unexpected results in the applications. |
| |
| If unsure, say Y |
| endif |
| |
| menu "ARMv8.1 architectural features" |
| |
| config ARM64_HW_AFDBM |
| bool "Support for hardware updates of the Access and Dirty page flags" |
| default y |
| help |
| The ARMv8.1 architecture extensions introduce support for |
| hardware updates of the access and dirty information in page |
| table entries. When enabled in TCR_EL1 (HA and HD bits) on |
| capable processors, accesses to pages with PTE_AF cleared will |
| set this bit instead of raising an access flag fault. |
| Similarly, writes to read-only pages with the DBM bit set will |
| clear the read-only bit (AP[2]) instead of raising a |
| permission fault. |
| |
| Kernels built with this configuration option enabled continue |
| to work on pre-ARMv8.1 hardware and the performance impact is |
| minimal. If unsure, say Y. |
| |
| config ARM64_PAN |
| bool "Enable support for Privileged Access Never (PAN)" |
| default y |
| help |
| Privileged Access Never (PAN; part of the ARMv8.1 Extensions) |
| prevents the kernel or hypervisor from accessing user-space (EL0) |
| memory directly. |
| |
| Choosing this option will cause any unprotected (not using |
| copy_to_user et al) memory access to fail with a permission fault. |
| |
| The feature is detected at runtime, and will remain as a 'nop' |
| instruction if the cpu does not implement the feature. |
| |
| config ARM64_LSE_ATOMICS |
| bool "Atomic instructions" |
| help |
| As part of the Large System Extensions, ARMv8.1 introduces new |
| atomic instructions that are designed specifically to scale in |
| very large systems. |
| |
| Say Y here to make use of these instructions for the in-kernel |
| atomic routines. This incurs a small overhead on CPUs that do |
| not support these instructions and requires the kernel to be |
| built with binutils >= 2.25. |
| |
| endmenu |
| |
| endmenu |
| |
| menu "Boot options" |
| |
| config CMDLINE |
| string "Default kernel command string" |
| default "" |
| help |
| Provide a set of default command-line options at build time by |
| entering them here. As a minimum, you should specify the the |
| root device (e.g. root=/dev/nfs). |
| |
| config CMDLINE_FORCE |
| bool "Always use the default kernel command string" |
| help |
| Always use the default kernel command string, even if the boot |
| loader passes other arguments to the kernel. |
| This is useful if you cannot or don't want to change the |
| command-line options your boot loader passes to the kernel. |
| |
| config EFI_STUB |
| bool |
| |
| config EFI |
| bool "UEFI runtime support" |
| depends on OF && !CPU_BIG_ENDIAN |
| select LIBFDT |
| select UCS2_STRING |
| select EFI_PARAMS_FROM_FDT |
| select EFI_RUNTIME_WRAPPERS |
| select EFI_STUB |
| select EFI_ARMSTUB |
| default y |
| help |
| This option provides support for runtime services provided |
| by UEFI firmware (such as non-volatile variables, realtime |
| clock, and platform reset). A UEFI stub is also provided to |
| allow the kernel to be booted as an EFI application. This |
| is only useful on systems that have UEFI firmware. |
| |
| config DMI |
| bool "Enable support for SMBIOS (DMI) tables" |
| depends on EFI |
| default y |
| help |
| This enables SMBIOS/DMI feature for systems. |
| |
| This option is only useful on systems that have UEFI firmware. |
| However, even with this option, the resultant kernel should |
| continue to boot on existing non-UEFI platforms. |
| |
| endmenu |
| |
| menu "Userspace binary formats" |
| |
| source "fs/Kconfig.binfmt" |
| |
| config COMPAT |
| bool "Kernel support for 32-bit EL0" |
| depends on ARM64_4K_PAGES || EXPERT |
| select COMPAT_BINFMT_ELF |
| select HAVE_UID16 |
| select OLD_SIGSUSPEND3 |
| select COMPAT_OLD_SIGACTION |
| help |
| This option enables support for a 32-bit EL0 running under a 64-bit |
| kernel at EL1. AArch32-specific components such as system calls, |
| the user helper functions, VFP support and the ptrace interface are |
| handled appropriately by the kernel. |
| |
| If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware |
| that you will only be able to execute AArch32 binaries that were compiled |
| with page size aligned segments. |
| |
| If you want to execute 32-bit userspace applications, say Y. |
| |
| config SYSVIPC_COMPAT |
| def_bool y |
| depends on COMPAT && SYSVIPC |
| |
| endmenu |
| |
| menu "Power management options" |
| |
| source "kernel/power/Kconfig" |
| |
| config ARCH_SUSPEND_POSSIBLE |
| def_bool y |
| |
| endmenu |
| |
| menu "CPU Power Management" |
| |
| source "drivers/cpuidle/Kconfig" |
| |
| source "drivers/cpufreq/Kconfig" |
| |
| endmenu |
| |
| source "net/Kconfig" |
| |
| source "drivers/Kconfig" |
| |
| source "drivers/firmware/Kconfig" |
| |
| source "drivers/acpi/Kconfig" |
| |
| source "fs/Kconfig" |
| |
| source "arch/arm64/kvm/Kconfig" |
| |
| source "arch/arm64/Kconfig.debug" |
| |
| source "security/Kconfig" |
| |
| source "crypto/Kconfig" |
| if CRYPTO |
| source "arch/arm64/crypto/Kconfig" |
| endif |
| |
| source "lib/Kconfig" |