| comment "Processor Type" |
| |
| # Select CPU types depending on the architecture selected. This selects |
| # which CPUs we support in the kernel image, and the compiler instruction |
| # optimiser behaviour. |
| |
| # ARM7TDMI |
| config CPU_ARM7TDMI |
| bool |
| depends on !MMU |
| select CPU_32v4T |
| select CPU_ABRT_LV4T |
| select CPU_CACHE_V4 |
| select CPU_PABRT_LEGACY |
| help |
| A 32-bit RISC microprocessor based on the ARM7 processor core |
| which has no memory control unit and cache. |
| |
| Say Y if you want support for the ARM7TDMI processor. |
| Otherwise, say N. |
| |
| # ARM720T |
| config CPU_ARM720T |
| bool |
| select CPU_32v4T |
| select CPU_ABRT_LV4T |
| select CPU_CACHE_V4 |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WT if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WT if MMU |
| help |
| A 32-bit RISC processor with 8kByte Cache, Write Buffer and |
| MMU built around an ARM7TDMI core. |
| |
| Say Y if you want support for the ARM720T processor. |
| Otherwise, say N. |
| |
| # ARM740T |
| config CPU_ARM740T |
| bool |
| depends on !MMU |
| select CPU_32v4T |
| select CPU_ABRT_LV4T |
| select CPU_CACHE_V4 |
| select CPU_CP15_MPU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| help |
| A 32-bit RISC processor with 8KB cache or 4KB variants, |
| write buffer and MPU(Protection Unit) built around |
| an ARM7TDMI core. |
| |
| Say Y if you want support for the ARM740T processor. |
| Otherwise, say N. |
| |
| # ARM9TDMI |
| config CPU_ARM9TDMI |
| bool |
| depends on !MMU |
| select CPU_32v4T |
| select CPU_ABRT_NOMMU |
| select CPU_CACHE_V4 |
| select CPU_PABRT_LEGACY |
| help |
| A 32-bit RISC microprocessor based on the ARM9 processor core |
| which has no memory control unit and cache. |
| |
| Say Y if you want support for the ARM9TDMI processor. |
| Otherwise, say N. |
| |
| # ARM920T |
| config CPU_ARM920T |
| bool |
| select CPU_32v4T |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_V4WT |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM920T is licensed to be produced by numerous vendors, |
| and is used in the Cirrus EP93xx and the Samsung S3C2410. |
| |
| Say Y if you want support for the ARM920T processor. |
| Otherwise, say N. |
| |
| # ARM922T |
| config CPU_ARM922T |
| bool |
| select CPU_32v4T |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_V4WT |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM922T is a version of the ARM920T, but with smaller |
| instruction and data caches. It is used in Altera's |
| Excalibur XA device family and Micrel's KS8695 Centaur. |
| |
| Say Y if you want support for the ARM922T processor. |
| Otherwise, say N. |
| |
| # ARM925T |
| config CPU_ARM925T |
| bool |
| select CPU_32v4T |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_V4WT |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM925T is a mix between the ARM920T and ARM926T, but with |
| different instruction and data caches. It is used in TI's OMAP |
| device family. |
| |
| Say Y if you want support for the ARM925T processor. |
| Otherwise, say N. |
| |
| # ARM926T |
| config CPU_ARM926T |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5TJ |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| This is a variant of the ARM920. It has slightly different |
| instruction sequences for cache and TLB operations. Curiously, |
| there is no documentation on it at the ARM corporate website. |
| |
| Say Y if you want support for the ARM926T processor. |
| Otherwise, say N. |
| |
| # FA526 |
| config CPU_FA526 |
| bool |
| select CPU_32v4 |
| select CPU_ABRT_EV4 |
| select CPU_CACHE_FA |
| select CPU_CACHE_VIVT |
| select CPU_COPY_FA if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_TLB_FA if MMU |
| help |
| The FA526 is a version of the ARMv4 compatible processor with |
| Branch Target Buffer, Unified TLB and cache line size 16. |
| |
| Say Y if you want support for the FA526 processor. |
| Otherwise, say N. |
| |
| # ARM940T |
| config CPU_ARM940T |
| bool |
| depends on !MMU |
| select CPU_32v4T |
| select CPU_ABRT_NOMMU |
| select CPU_CACHE_VIVT |
| select CPU_CP15_MPU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| help |
| ARM940T is a member of the ARM9TDMI family of general- |
| purpose microprocessors with MPU and separate 4KB |
| instruction and 4KB data cases, each with a 4-word line |
| length. |
| |
| Say Y if you want support for the ARM940T processor. |
| Otherwise, say N. |
| |
| # ARM946E-S |
| config CPU_ARM946E |
| bool |
| depends on !MMU |
| select CPU_32v5 |
| select CPU_ABRT_NOMMU |
| select CPU_CACHE_VIVT |
| select CPU_CP15_MPU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| help |
| ARM946E-S is a member of the ARM9E-S family of high- |
| performance, 32-bit system-on-chip processor solutions. |
| The TCM and ARMv5TE 32-bit instruction set is supported. |
| |
| Say Y if you want support for the ARM946E-S processor. |
| Otherwise, say N. |
| |
| # ARM1020 - needs validating |
| config CPU_ARM1020 |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_V4WT |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM1020 is the 32K cached version of the ARM10 processor, |
| with an addition of a floating-point unit. |
| |
| Say Y if you want support for the ARM1020 processor. |
| Otherwise, say N. |
| |
| # ARM1020E - needs validating |
| config CPU_ARM1020E |
| bool |
| depends on n |
| select CPU_32v5 |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_V4WT |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| |
| # ARM1022E |
| config CPU_ARM1022 |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV4T |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU # can probably do better |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM1022E is an implementation of the ARMv5TE architecture |
| based upon the ARM10 integer core with a 16KiB L1 Harvard cache, |
| embedded trace macrocell, and a floating-point unit. |
| |
| Say Y if you want support for the ARM1022E processor. |
| Otherwise, say N. |
| |
| # ARM1026EJ-S |
| config CPU_ARM1026 |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10 |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU # can probably do better |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| help |
| The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture |
| based upon the ARM10 integer core. |
| |
| Say Y if you want support for the ARM1026EJ-S processor. |
| Otherwise, say N. |
| |
| # SA110 |
| config CPU_SA110 |
| bool |
| select CPU_32v3 if ARCH_RPC |
| select CPU_32v4 if !ARCH_RPC |
| select CPU_ABRT_EV4 |
| select CPU_CACHE_V4WB |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_TLB_V4WB if MMU |
| help |
| The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and |
| is available at five speeds ranging from 100 MHz to 233 MHz. |
| More information is available at |
| <http://developer.intel.com/design/strong/sa110.htm>. |
| |
| Say Y if you want support for the SA-110 processor. |
| Otherwise, say N. |
| |
| # SA1100 |
| config CPU_SA1100 |
| bool |
| select CPU_32v4 |
| select CPU_ABRT_EV4 |
| select CPU_CACHE_V4WB |
| select CPU_CACHE_VIVT |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_TLB_V4WB if MMU |
| |
| # XScale |
| config CPU_XSCALE |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5T |
| select CPU_CACHE_VIVT |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| |
| # XScale Core Version 3 |
| config CPU_XSC3 |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5T |
| select CPU_CACHE_VIVT |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| select IO_36 |
| |
| # Marvell PJ1 (Mohawk) |
| config CPU_MOHAWK |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5T |
| select CPU_CACHE_VIVT |
| select CPU_COPY_V4WB if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V4WBI if MMU |
| |
| # Feroceon |
| config CPU_FEROCEON |
| bool |
| select CPU_32v5 |
| select CPU_ABRT_EV5T |
| select CPU_CACHE_VIVT |
| select CPU_COPY_FEROCEON if MMU |
| select CPU_CP15_MMU |
| select CPU_PABRT_LEGACY |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_FEROCEON if MMU |
| |
| config CPU_FEROCEON_OLD_ID |
| bool "Accept early Feroceon cores with an ARM926 ID" |
| depends on CPU_FEROCEON && !CPU_ARM926T |
| default y |
| help |
| This enables the usage of some old Feroceon cores |
| for which the CPU ID is equal to the ARM926 ID. |
| Relevant for Feroceon-1850 and early Feroceon-2850. |
| |
| # Marvell PJ4 |
| config CPU_PJ4 |
| bool |
| select ARM_THUMBEE |
| select CPU_V7 |
| |
| config CPU_PJ4B |
| bool |
| select CPU_V7 |
| |
| # ARMv6 |
| config CPU_V6 |
| bool |
| select CPU_32v6 |
| select CPU_ABRT_EV6 |
| select CPU_CACHE_V6 |
| select CPU_CACHE_VIPT |
| select CPU_COPY_V6 if MMU |
| select CPU_CP15_MMU |
| select CPU_HAS_ASID if MMU |
| select CPU_PABRT_V6 |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V6 if MMU |
| |
| # ARMv6k |
| config CPU_V6K |
| bool |
| select CPU_32v6 |
| select CPU_32v6K |
| select CPU_ABRT_EV6 |
| select CPU_CACHE_V6 |
| select CPU_CACHE_VIPT |
| select CPU_COPY_V6 if MMU |
| select CPU_CP15_MMU |
| select CPU_HAS_ASID if MMU |
| select CPU_PABRT_V6 |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V6 if MMU |
| |
| # ARMv7 |
| config CPU_V7 |
| bool |
| select CPU_32v6K |
| select CPU_32v7 |
| select CPU_ABRT_EV7 |
| select CPU_CACHE_V7 |
| select CPU_CACHE_VIPT |
| select CPU_COPY_V6 if MMU |
| select CPU_CP15_MMU if MMU |
| select CPU_CP15_MPU if !MMU |
| select CPU_HAS_ASID if MMU |
| select CPU_PABRT_V7 |
| select CPU_THUMB_CAPABLE |
| select CPU_TLB_V7 if MMU |
| |
| # ARMv7M |
| config CPU_V7M |
| bool |
| select CPU_32v7M |
| select CPU_ABRT_NOMMU |
| select CPU_CACHE_V7M |
| select CPU_CACHE_NOP |
| select CPU_PABRT_LEGACY |
| select CPU_THUMBONLY |
| |
| config CPU_THUMBONLY |
| bool |
| select CPU_THUMB_CAPABLE |
| # There are no CPUs available with MMU that don't implement an ARM ISA: |
| depends on !MMU |
| help |
| Select this if your CPU doesn't support the 32 bit ARM instructions. |
| |
| config CPU_THUMB_CAPABLE |
| bool |
| help |
| Select this if your CPU can support Thumb mode. |
| |
| # Figure out what processor architecture version we should be using. |
| # This defines the compiler instruction set which depends on the machine type. |
| config CPU_32v3 |
| bool |
| select CPU_USE_DOMAINS if MMU |
| select NEED_KUSER_HELPERS |
| select TLS_REG_EMUL if SMP || !MMU |
| select CPU_NO_EFFICIENT_FFS |
| |
| config CPU_32v4 |
| bool |
| select CPU_USE_DOMAINS if MMU |
| select NEED_KUSER_HELPERS |
| select TLS_REG_EMUL if SMP || !MMU |
| select CPU_NO_EFFICIENT_FFS |
| |
| config CPU_32v4T |
| bool |
| select CPU_USE_DOMAINS if MMU |
| select NEED_KUSER_HELPERS |
| select TLS_REG_EMUL if SMP || !MMU |
| select CPU_NO_EFFICIENT_FFS |
| |
| config CPU_32v5 |
| bool |
| select CPU_USE_DOMAINS if MMU |
| select NEED_KUSER_HELPERS |
| select TLS_REG_EMUL if SMP || !MMU |
| |
| config CPU_32v6 |
| bool |
| select TLS_REG_EMUL if !CPU_32v6K && !MMU |
| |
| config CPU_32v6K |
| bool |
| |
| config CPU_32v7 |
| bool |
| |
| config CPU_32v7M |
| bool |
| |
| # The abort model |
| config CPU_ABRT_NOMMU |
| bool |
| |
| config CPU_ABRT_EV4 |
| bool |
| |
| config CPU_ABRT_EV4T |
| bool |
| |
| config CPU_ABRT_LV4T |
| bool |
| |
| config CPU_ABRT_EV5T |
| bool |
| |
| config CPU_ABRT_EV5TJ |
| bool |
| |
| config CPU_ABRT_EV6 |
| bool |
| |
| config CPU_ABRT_EV7 |
| bool |
| |
| config CPU_PABRT_LEGACY |
| bool |
| |
| config CPU_PABRT_V6 |
| bool |
| |
| config CPU_PABRT_V7 |
| bool |
| |
| # The cache model |
| config CPU_CACHE_V4 |
| bool |
| |
| config CPU_CACHE_V4WT |
| bool |
| |
| config CPU_CACHE_V4WB |
| bool |
| |
| config CPU_CACHE_V6 |
| bool |
| |
| config CPU_CACHE_V7 |
| bool |
| |
| config CPU_CACHE_NOP |
| bool |
| |
| config CPU_CACHE_VIVT |
| bool |
| |
| config CPU_CACHE_VIPT |
| bool |
| |
| config CPU_CACHE_FA |
| bool |
| |
| config CPU_CACHE_V7M |
| bool |
| |
| if MMU |
| # The copy-page model |
| config CPU_COPY_V4WT |
| bool |
| |
| config CPU_COPY_V4WB |
| bool |
| |
| config CPU_COPY_FEROCEON |
| bool |
| |
| config CPU_COPY_FA |
| bool |
| |
| config CPU_COPY_V6 |
| bool |
| |
| # This selects the TLB model |
| config CPU_TLB_V4WT |
| bool |
| help |
| ARM Architecture Version 4 TLB with writethrough cache. |
| |
| config CPU_TLB_V4WB |
| bool |
| help |
| ARM Architecture Version 4 TLB with writeback cache. |
| |
| config CPU_TLB_V4WBI |
| bool |
| help |
| ARM Architecture Version 4 TLB with writeback cache and invalidate |
| instruction cache entry. |
| |
| config CPU_TLB_FEROCEON |
| bool |
| help |
| Feroceon TLB (v4wbi with non-outer-cachable page table walks). |
| |
| config CPU_TLB_FA |
| bool |
| help |
| Faraday ARM FA526 architecture, unified TLB with writeback cache |
| and invalidate instruction cache entry. Branch target buffer is |
| also supported. |
| |
| config CPU_TLB_V6 |
| bool |
| |
| config CPU_TLB_V7 |
| bool |
| |
| config VERIFY_PERMISSION_FAULT |
| bool |
| endif |
| |
| config CPU_HAS_ASID |
| bool |
| help |
| This indicates whether the CPU has the ASID register; used to |
| tag TLB and possibly cache entries. |
| |
| config CPU_CP15 |
| bool |
| help |
| Processor has the CP15 register. |
| |
| config CPU_CP15_MMU |
| bool |
| select CPU_CP15 |
| help |
| Processor has the CP15 register, which has MMU related registers. |
| |
| config CPU_CP15_MPU |
| bool |
| select CPU_CP15 |
| help |
| Processor has the CP15 register, which has MPU related registers. |
| |
| config CPU_USE_DOMAINS |
| bool |
| help |
| This option enables or disables the use of domain switching |
| via the set_fs() function. |
| |
| config CPU_V7M_NUM_IRQ |
| int "Number of external interrupts connected to the NVIC" |
| depends on CPU_V7M |
| default 90 if ARCH_STM32 |
| default 38 if ARCH_EFM32 |
| default 112 if SOC_VF610 |
| default 240 |
| help |
| This option indicates the number of interrupts connected to the NVIC. |
| The value can be larger than the real number of interrupts supported |
| by the system, but must not be lower. |
| The default value is 240, corresponding to the maximum number of |
| interrupts supported by the NVIC on Cortex-M family. |
| |
| If unsure, keep default value. |
| |
| # |
| # CPU supports 36-bit I/O |
| # |
| config IO_36 |
| bool |
| |
| comment "Processor Features" |
| |
| config ARM_LPAE |
| bool "Support for the Large Physical Address Extension" |
| depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \ |
| !CPU_32v4 && !CPU_32v3 |
| help |
| Say Y if you have an ARMv7 processor supporting the LPAE page |
| table format and you would like to access memory beyond the |
| 4GB limit. The resulting kernel image will not run on |
| processors without the LPA extension. |
| |
| If unsure, say N. |
| |
| config ARM_PV_FIXUP |
| def_bool y |
| depends on ARM_LPAE && ARM_PATCH_PHYS_VIRT && ARCH_KEYSTONE |
| |
| config ARCH_PHYS_ADDR_T_64BIT |
| def_bool ARM_LPAE |
| |
| config ARCH_DMA_ADDR_T_64BIT |
| bool |
| |
| config ARM_THUMB |
| bool "Support Thumb user binaries" if !CPU_THUMBONLY |
| depends on CPU_THUMB_CAPABLE |
| default y |
| help |
| Say Y if you want to include kernel support for running user space |
| Thumb binaries. |
| |
| The Thumb instruction set is a compressed form of the standard ARM |
| instruction set resulting in smaller binaries at the expense of |
| slightly less efficient code. |
| |
| If you don't know what this all is, saying Y is a safe choice. |
| |
| config ARM_THUMBEE |
| bool "Enable ThumbEE CPU extension" |
| depends on CPU_V7 |
| help |
| Say Y here if you have a CPU with the ThumbEE extension and code to |
| make use of it. Say N for code that can run on CPUs without ThumbEE. |
| |
| config ARM_VIRT_EXT |
| bool |
| depends on MMU |
| default y if CPU_V7 |
| help |
| Enable the kernel to make use of the ARM Virtualization |
| Extensions to install hypervisors without run-time firmware |
| assistance. |
| |
| A compliant bootloader is required in order to make maximum |
| use of this feature. Refer to Documentation/arm/Booting for |
| details. |
| |
| config SWP_EMULATE |
| bool "Emulate SWP/SWPB instructions" if !SMP |
| depends on CPU_V7 |
| default y if SMP |
| select HAVE_PROC_CPU if PROC_FS |
| help |
| ARMv6 architecture deprecates use of the SWP/SWPB instructions. |
| ARMv7 multiprocessing extensions introduce the ability to disable |
| these instructions, triggering an undefined instruction exception |
| when executed. Say Y here to enable software emulation of these |
| instructions for userspace (not kernel) using LDREX/STREX. |
| Also creates /proc/cpu/swp_emulation for statistics. |
| |
| 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, LDREX/STREX 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 CPU_BIG_ENDIAN |
| bool "Build big-endian kernel" |
| depends on ARCH_SUPPORTS_BIG_ENDIAN |
| help |
| Say Y if you plan on running a kernel in big-endian mode. |
| Note that your board must be properly built and your board |
| port must properly enable any big-endian related features |
| of your chipset/board/processor. |
| |
| config CPU_ENDIAN_BE8 |
| bool |
| depends on CPU_BIG_ENDIAN |
| default CPU_V6 || CPU_V6K || CPU_V7 |
| help |
| Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors. |
| |
| config CPU_ENDIAN_BE32 |
| bool |
| depends on CPU_BIG_ENDIAN |
| default !CPU_ENDIAN_BE8 |
| help |
| Support for the BE-32 (big-endian) mode on pre-ARMv6 processors. |
| |
| config CPU_HIGH_VECTOR |
| depends on !MMU && CPU_CP15 && !CPU_ARM740T |
| bool "Select the High exception vector" |
| help |
| Say Y here to select high exception vector(0xFFFF0000~). |
| The exception vector can vary depending on the platform |
| design in nommu mode. If your platform needs to select |
| high exception vector, say Y. |
| Otherwise or if you are unsure, say N, and the low exception |
| vector (0x00000000~) will be used. |
| |
| config CPU_ICACHE_DISABLE |
| bool "Disable I-Cache (I-bit)" |
| depends on (CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)) || CPU_V7M |
| help |
| Say Y here to disable the processor instruction cache. Unless |
| you have a reason not to or are unsure, say N. |
| |
| config CPU_DCACHE_DISABLE |
| bool "Disable D-Cache (C-bit)" |
| depends on (CPU_CP15 && !SMP) || CPU_V7M |
| help |
| Say Y here to disable the processor data cache. Unless |
| you have a reason not to or are unsure, say N. |
| |
| config CPU_DCACHE_SIZE |
| hex |
| depends on CPU_ARM740T || CPU_ARM946E |
| default 0x00001000 if CPU_ARM740T |
| default 0x00002000 # default size for ARM946E-S |
| help |
| Some cores are synthesizable to have various sized cache. For |
| ARM946E-S case, it can vary from 0KB to 1MB. |
| To support such cache operations, it is efficient to know the size |
| before compile time. |
| If your SoC is configured to have a different size, define the value |
| here with proper conditions. |
| |
| config CPU_DCACHE_WRITETHROUGH |
| bool "Force write through D-cache" |
| depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE |
| default y if CPU_ARM925T |
| help |
| Say Y here to use the data cache in writethrough mode. Unless you |
| specifically require this or are unsure, say N. |
| |
| config CPU_CACHE_ROUND_ROBIN |
| bool "Round robin I and D cache replacement algorithm" |
| depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE) |
| help |
| Say Y here to use the predictable round-robin cache replacement |
| policy. Unless you specifically require this or are unsure, say N. |
| |
| config CPU_BPREDICT_DISABLE |
| bool "Disable branch prediction" |
| depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 || CPU_V7M |
| help |
| Say Y here to disable branch prediction. If unsure, say N. |
| |
| config TLS_REG_EMUL |
| bool |
| select NEED_KUSER_HELPERS |
| help |
| An SMP system using a pre-ARMv6 processor (there are apparently |
| a few prototypes like that in existence) and therefore access to |
| that required register must be emulated. |
| |
| config NEED_KUSER_HELPERS |
| bool |
| |
| config KUSER_HELPERS |
| bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS |
| depends on MMU |
| default y |
| help |
| Warning: disabling this option may break user programs. |
| |
| Provide kuser helpers in the vector page. The kernel provides |
| helper code to userspace in read only form at a fixed location |
| in the high vector page to allow userspace to be independent of |
| the CPU type fitted to the system. This permits binaries to be |
| run on ARMv4 through to ARMv7 without modification. |
| |
| See Documentation/arm/kernel_user_helpers.txt for details. |
| |
| However, the fixed address nature of these helpers can be used |
| by ROP (return orientated programming) authors when creating |
| exploits. |
| |
| If all of the binaries and libraries which run on your platform |
| are built specifically for your platform, and make no use of |
| these helpers, then you can turn this option off to hinder |
| such exploits. However, in that case, if a binary or library |
| relying on those helpers is run, it will receive a SIGILL signal, |
| which will terminate the program. |
| |
| Say N here only if you are absolutely certain that you do not |
| need these helpers; otherwise, the safe option is to say Y. |
| |
| config VDSO |
| bool "Enable VDSO for acceleration of some system calls" |
| depends on AEABI && MMU && CPU_V7 |
| default y if ARM_ARCH_TIMER |
| select GENERIC_TIME_VSYSCALL |
| help |
| Place in the process address space an ELF shared object |
| providing fast implementations of gettimeofday and |
| clock_gettime. Systems that implement the ARM architected |
| timer will receive maximum benefit. |
| |
| You must have glibc 2.22 or later for programs to seamlessly |
| take advantage of this. |
| |
| config DMA_CACHE_RWFO |
| bool "Enable read/write for ownership DMA cache maintenance" |
| depends on CPU_V6K && SMP |
| default y |
| help |
| The Snoop Control Unit on ARM11MPCore does not detect the |
| cache maintenance operations and the dma_{map,unmap}_area() |
| functions may leave stale cache entries on other CPUs. By |
| enabling this option, Read or Write For Ownership in the ARMv6 |
| DMA cache maintenance functions is performed. These LDR/STR |
| instructions change the cache line state to shared or modified |
| so that the cache operation has the desired effect. |
| |
| Note that the workaround is only valid on processors that do |
| not perform speculative loads into the D-cache. For such |
| processors, if cache maintenance operations are not broadcast |
| in hardware, other workarounds are needed (e.g. cache |
| maintenance broadcasting in software via FIQ). |
| |
| config OUTER_CACHE |
| bool |
| |
| config OUTER_CACHE_SYNC |
| bool |
| select ARM_HEAVY_MB |
| help |
| The outer cache has a outer_cache_fns.sync function pointer |
| that can be used to drain the write buffer of the outer cache. |
| |
| config CACHE_FEROCEON_L2 |
| bool "Enable the Feroceon L2 cache controller" |
| depends on ARCH_MV78XX0 || ARCH_MVEBU |
| default y |
| select OUTER_CACHE |
| help |
| This option enables the Feroceon L2 cache controller. |
| |
| config CACHE_FEROCEON_L2_WRITETHROUGH |
| bool "Force Feroceon L2 cache write through" |
| depends on CACHE_FEROCEON_L2 |
| help |
| Say Y here to use the Feroceon L2 cache in writethrough mode. |
| Unless you specifically require this, say N for writeback mode. |
| |
| config MIGHT_HAVE_CACHE_L2X0 |
| bool |
| help |
| This option should be selected by machines which have a L2x0 |
| or PL310 cache controller, but where its use is optional. |
| |
| The only effect of this option is to make CACHE_L2X0 and |
| related options available to the user for configuration. |
| |
| Boards or SoCs which always require the cache controller |
| support to be present should select CACHE_L2X0 directly |
| instead of this option, thus preventing the user from |
| inadvertently configuring a broken kernel. |
| |
| config CACHE_L2X0 |
| bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0 |
| default MIGHT_HAVE_CACHE_L2X0 |
| select OUTER_CACHE |
| select OUTER_CACHE_SYNC |
| help |
| This option enables the L2x0 PrimeCell. |
| |
| config CACHE_L2X0_PMU |
| bool "L2x0 performance monitor support" if CACHE_L2X0 |
| depends on PERF_EVENTS |
| help |
| This option enables support for the performance monitoring features |
| of the L220 and PL310 outer cache controllers. |
| |
| if CACHE_L2X0 |
| |
| config PL310_ERRATA_588369 |
| bool "PL310 errata: Clean & Invalidate maintenance operations do not invalidate clean lines" |
| help |
| The PL310 L2 cache controller implements three types of Clean & |
| Invalidate maintenance operations: by Physical Address |
| (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC). |
| They are architecturally defined to behave as the execution of a |
| clean operation followed immediately by an invalidate operation, |
| both performing to the same memory location. This functionality |
| is not correctly implemented in PL310 prior to r2p0 (fixed in r2p0) |
| as clean lines are not invalidated as a result of these operations. |
| |
| config PL310_ERRATA_727915 |
| bool "PL310 errata: Background Clean & Invalidate by Way operation can cause data corruption" |
| help |
| PL310 implements the Clean & Invalidate by Way L2 cache maintenance |
| operation (offset 0x7FC). This operation runs in background so that |
| PL310 can handle normal accesses while it is in progress. Under very |
| rare circumstances, due to this erratum, write data can be lost when |
| PL310 treats a cacheable write transaction during a Clean & |
| Invalidate by Way operation. Revisions prior to r3p1 are affected by |
| this errata (fixed in r3p1). |
| |
| config PL310_ERRATA_753970 |
| bool "PL310 errata: cache sync operation may be faulty" |
| help |
| This option enables the workaround for the 753970 PL310 (r3p0) erratum. |
| |
| Under some condition the effect of cache sync operation on |
| the store buffer still remains when the operation completes. |
| This means that the store buffer is always asked to drain and |
| this prevents it from merging any further writes. The workaround |
| is to replace the normal offset of cache sync operation (0x730) |
| by another offset targeting an unmapped PL310 register 0x740. |
| This has the same effect as the cache sync operation: store buffer |
| drain and waiting for all buffers empty. |
| |
| config PL310_ERRATA_769419 |
| bool "PL310 errata: no automatic Store Buffer drain" |
| help |
| On revisions of the PL310 prior to r3p2, the Store Buffer does |
| not automatically drain. This can cause normal, non-cacheable |
| writes to be retained when the memory system is idle, leading |
| to suboptimal I/O performance for drivers using coherent DMA. |
| This option adds a write barrier to the cpu_idle loop so that, |
| on systems with an outer cache, the store buffer is drained |
| explicitly. |
| |
| endif |
| |
| config CACHE_TAUROS2 |
| bool "Enable the Tauros2 L2 cache controller" |
| depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4) |
| default y |
| select OUTER_CACHE |
| help |
| This option enables the Tauros2 L2 cache controller (as |
| found on PJ1/PJ4). |
| |
| config CACHE_UNIPHIER |
| bool "Enable the UniPhier outer cache controller" |
| depends on ARCH_UNIPHIER |
| select ARM_L1_CACHE_SHIFT_7 |
| select OUTER_CACHE |
| select OUTER_CACHE_SYNC |
| help |
| This option enables the UniPhier outer cache (system cache) |
| controller. |
| |
| config CACHE_XSC3L2 |
| bool "Enable the L2 cache on XScale3" |
| depends on CPU_XSC3 |
| default y |
| select OUTER_CACHE |
| help |
| This option enables the L2 cache on XScale3. |
| |
| config ARM_L1_CACHE_SHIFT_6 |
| bool |
| default y if CPU_V7 |
| help |
| Setting ARM L1 cache line size to 64 Bytes. |
| |
| config ARM_L1_CACHE_SHIFT_7 |
| bool |
| help |
| Setting ARM L1 cache line size to 128 Bytes. |
| |
| config ARM_L1_CACHE_SHIFT |
| int |
| default 7 if ARM_L1_CACHE_SHIFT_7 |
| default 6 if ARM_L1_CACHE_SHIFT_6 |
| default 5 |
| |
| config ARM_DMA_MEM_BUFFERABLE |
| bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K || CPU_V7M) && !CPU_V7 |
| default y if CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M |
| help |
| Historically, the kernel has used strongly ordered mappings to |
| provide DMA coherent memory. With the advent of ARMv7, mapping |
| memory with differing types results in unpredictable behaviour, |
| so on these CPUs, this option is forced on. |
| |
| Multiple mappings with differing attributes is also unpredictable |
| on ARMv6 CPUs, but since they do not have aggressive speculative |
| prefetch, no harm appears to occur. |
| |
| However, drivers may be missing the necessary barriers for ARMv6, |
| and therefore turning this on may result in unpredictable driver |
| behaviour. Therefore, we offer this as an option. |
| |
| On some of the beefier ARMv7-M machines (with DMA and write |
| buffers) you likely want this enabled, while those that |
| didn't need it until now also won't need it in the future. |
| |
| You are recommended say 'Y' here and debug any affected drivers. |
| |
| config ARM_HEAVY_MB |
| bool |
| |
| config ARCH_SUPPORTS_BIG_ENDIAN |
| bool |
| help |
| This option specifies the architecture can support big endian |
| operation. |
| |
| config DEBUG_ALIGN_RODATA |
| bool "Make rodata strictly non-executable" |
| depends on STRICT_KERNEL_RWX |
| default y |
| help |
| If this is set, rodata will be made explicitly non-executable. This |
| provides protection on the rare chance that attackers might find and |
| use ROP gadgets that exist in the rodata section. This adds an |
| additional section-aligned split of rodata from kernel text so it |
| can be made explicitly non-executable. This padding may waste memory |
| space to gain the additional protection. |