config ARM bool default y select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT if MMU select CLONE_BACKWARDS select CPU_PM if (SUSPEND || CPU_IDLE) select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS select EDAC_SUPPORT select EDAC_ATOMIC_SCRUB select GENERIC_ALLOCATOR select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) select GENERIC_CLOCKEVENTS_BROADCAST if SMP 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 HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT select HAVE_CC_STACKPROTECTOR select HAVE_CONTEXT_TRACKING select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_API_DEBUG select HAVE_DMA_ATTRS select HAVE_DMA_CONTIGUOUS if MMU select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL) select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL) select HAVE_FUNCTION_TRACER if (!XIP_KERNEL) select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)) select HAVE_IDE if PCI || ISA || PCMCIA select HAVE_IRQ_TIME_ACCOUNTING select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZ4 select HAVE_KERNEL_LZMA select HAVE_KERNEL_LZO select HAVE_KERNEL_XZ select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M select HAVE_KRETPROBES if (HAVE_KPROBES) select HAVE_MEMBLOCK select HAVE_MOD_ARCH_SPECIFIC select HAVE_OPROFILE if (HAVE_PERF_EVENTS) select HAVE_OPTPROBES if !THUMB2_KERNEL select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE) select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 select HAVE_VIRT_CPU_ACCOUNTING_GEN select IRQ_FORCED_THREADING select MODULES_USE_ELF_REL select NO_BOOTMEM select OLD_SIGACTION select OLD_SIGSUSPEND3 select PERF_USE_VMALLOC select RTC_LIB select SYS_SUPPORTS_APM_EMULATION # Above selects are sorted alphabetically; please add new ones # according to that. Thanks. help The ARM series is a line of low-power-consumption RISC chip designs licensed by ARM Ltd and targeted at embedded applications and handhelds such as the Compaq IPAQ. ARM-based PCs are no longer manufactured, but legacy ARM-based PC hardware remains popular in Europe. There is an ARM Linux project with a web page at . config ARM_HAS_SG_CHAIN select ARCH_HAS_SG_CHAIN bool config NEED_SG_DMA_LENGTH bool config ARM_DMA_USE_IOMMU bool select ARM_HAS_SG_CHAIN select NEED_SG_DMA_LENGTH if ARM_DMA_USE_IOMMU config ARM_DMA_IOMMU_ALIGNMENT int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers" range 4 9 default 8 help DMA mapping framework by default aligns all buffers to the smallest PAGE_SIZE order which is greater than or equal to the requested buffer size. This works well for buffers up to a few hundreds kilobytes, but for larger buffers it just a waste of address space. Drivers which has relatively small addressing window (like 64Mib) might run out of virtual space with just a few allocations. With this parameter you can specify the maximum PAGE_SIZE order for DMA IOMMU buffers. Larger buffers will be aligned only to this specified order. The order is expressed as a power of two multiplied by the PAGE_SIZE. endif config MIGHT_HAVE_PCI bool config SYS_SUPPORTS_APM_EMULATION bool config HAVE_TCM bool select GENERIC_ALLOCATOR config HAVE_PROC_CPU bool config NO_IOPORT_MAP bool config EISA bool ---help--- The Extended Industry Standard Architecture (EISA) bus was developed as an open alternative to the IBM MicroChannel bus. The EISA bus provided some of the features of the IBM MicroChannel bus while maintaining backward compatibility with cards made for the older ISA bus. The EISA bus saw limited use between 1988 and 1995 when it was made obsolete by the PCI bus. Say Y here if you are building a kernel for an EISA-based machine. Otherwise, say N. config SBUS bool config STACKTRACE_SUPPORT bool default y config HAVE_LATENCYTOP_SUPPORT bool depends on !SMP default y config LOCKDEP_SUPPORT bool default y config TRACE_IRQFLAGS_SUPPORT bool default !CPU_V7M config RWSEM_XCHGADD_ALGORITHM bool default y config ARCH_HAS_ILOG2_U32 bool config ARCH_HAS_ILOG2_U64 bool config ARCH_HAS_BANDGAP bool config FIX_EARLYCON_MEM def_bool y if MMU config GENERIC_HWEIGHT bool default y config GENERIC_CALIBRATE_DELAY bool default y config ARCH_MAY_HAVE_PC_FDC bool config ZONE_DMA bool config NEED_DMA_MAP_STATE def_bool y config ARCH_SUPPORTS_UPROBES def_bool y config ARCH_HAS_DMA_SET_COHERENT_MASK bool config GENERIC_ISA_DMA bool config FIQ bool config NEED_RET_TO_USER bool config ARCH_MTD_XIP bool config VECTORS_BASE hex default 0xffff0000 if MMU || CPU_HIGH_VECTOR default DRAM_BASE if REMAP_VECTORS_TO_RAM default 0x00000000 help The base address of exception vectors. This must be two pages in size. config ARM_PATCH_PHYS_VIRT bool "Patch physical to virtual translations at runtime" if EMBEDDED default y depends on !XIP_KERNEL && MMU depends on !ARCH_REALVIEW || !SPARSEMEM help Patch phys-to-virt and virt-to-phys translation functions at boot and module load time according to the position of the kernel in system memory. This can only be used with non-XIP MMU kernels where the base of physical memory is at a 16MB boundary. Only disable this option if you know that you do not require this feature (eg, building a kernel for a single machine) and you need to shrink the kernel to the minimal size. config NEED_MACH_IO_H bool help Select this when mach/io.h is required to provide special definitions for this platform. The need for mach/io.h should be avoided when possible. config NEED_MACH_MEMORY_H bool help Select this when mach/memory.h is required to provide special definitions for this platform. The need for mach/memory.h should be avoided when possible. config PHYS_OFFSET hex "Physical address of main memory" if MMU depends on !ARM_PATCH_PHYS_VIRT default DRAM_BASE if !MMU default 0x00000000 if ARCH_EBSA110 || \ ARCH_FOOTBRIDGE || \ ARCH_INTEGRATOR || \ ARCH_IOP13XX || \ ARCH_KS8695 || \ (ARCH_REALVIEW && !REALVIEW_HIGH_PHYS_OFFSET) default 0x10000000 if ARCH_OMAP1 || ARCH_RPC default 0x20000000 if ARCH_S5PV210 default 0x70000000 if REALVIEW_HIGH_PHYS_OFFSET default 0xc0000000 if ARCH_SA1100 help Please provide the physical address corresponding to the location of main memory in your system. config GENERIC_BUG def_bool y depends on BUG config PGTABLE_LEVELS int default 3 if ARM_LPAE default 2 source "init/Kconfig" source "kernel/Kconfig.freezer" menu "System Type" config MMU bool "MMU-based Paged Memory Management Support" default y help Select if you want MMU-based virtualised addressing space support by paged memory management. If unsure, say 'Y'. # # The "ARM system type" choice list is ordered alphabetically by option # text. Please add new entries in the option alphabetic order. # choice prompt "ARM system type" default ARCH_VERSATILE if !MMU default ARCH_MULTIPLATFORM if MMU config ARCH_MULTIPLATFORM bool "Allow multiple platforms to be selected" depends on MMU select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_HAS_SG_CHAIN select ARM_PATCH_PHYS_VIRT select AUTO_ZRELADDR select CLKSRC_OF select COMMON_CLK select GENERIC_CLOCKEVENTS select MIGHT_HAVE_PCI select MULTI_IRQ_HANDLER select SPARSE_IRQ select USE_OF config ARM_SINGLE_ARMV7M bool "ARMv7-M based platforms (Cortex-M0/M3/M4)" depends on !MMU select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_NVIC select AUTO_ZRELADDR select CLKSRC_OF select COMMON_CLK select CPU_V7M select GENERIC_CLOCKEVENTS select NO_IOPORT_MAP select SPARSE_IRQ select USE_OF config ARCH_REALVIEW bool "ARM Ltd. RealView family" select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_AMBA select ARM_TIMER_SP804 select COMMON_CLK select COMMON_CLK_VERSATILE select GENERIC_CLOCKEVENTS select GPIO_PL061 if GPIOLIB select ICST select NEED_MACH_MEMORY_H select PLAT_VERSATILE select PLAT_VERSATILE_SCHED_CLOCK help This enables support for ARM Ltd RealView boards. config ARCH_VERSATILE bool "ARM Ltd. Versatile family" select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_AMBA select ARM_TIMER_SP804 select ARM_VIC select CLKDEV_LOOKUP select GENERIC_CLOCKEVENTS select HAVE_MACH_CLKDEV select ICST select PLAT_VERSATILE select PLAT_VERSATILE_CLOCK select PLAT_VERSATILE_SCHED_CLOCK select VERSATILE_FPGA_IRQ help This enables support for ARM Ltd Versatile board. config ARCH_CLPS711X bool "Cirrus Logic CLPS711x/EP721x/EP731x-based" select ARCH_REQUIRE_GPIOLIB select AUTO_ZRELADDR select CLKSRC_MMIO select COMMON_CLK select CPU_ARM720T select GENERIC_CLOCKEVENTS select MFD_SYSCON select SOC_BUS help Support for Cirrus Logic 711x/721x/731x based boards. config ARCH_GEMINI bool "Cortina Systems Gemini" select ARCH_REQUIRE_GPIOLIB select CLKSRC_MMIO select CPU_FA526 select GENERIC_CLOCKEVENTS help Support for the Cortina Systems Gemini family SoCs config ARCH_EBSA110 bool "EBSA-110" select ARCH_USES_GETTIMEOFFSET select CPU_SA110 select ISA select NEED_MACH_IO_H select NEED_MACH_MEMORY_H select NO_IOPORT_MAP help This is an evaluation board for the StrongARM processor available from Digital. It has limited hardware on-board, including an Ethernet interface, two PCMCIA sockets, two serial ports and a parallel port. config ARCH_EP93XX bool "EP93xx-based" select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_REQUIRE_GPIOLIB select ARM_AMBA select ARM_PATCH_PHYS_VIRT select ARM_VIC select AUTO_ZRELADDR select CLKDEV_LOOKUP select CLKSRC_MMIO select CPU_ARM920T select GENERIC_CLOCKEVENTS help This enables support for the Cirrus EP93xx series of CPUs. config ARCH_FOOTBRIDGE bool "FootBridge" select CPU_SA110 select FOOTBRIDGE select GENERIC_CLOCKEVENTS select HAVE_IDE select NEED_MACH_IO_H if !MMU select NEED_MACH_MEMORY_H help Support for systems based on the DC21285 companion chip ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder. config ARCH_NETX bool "Hilscher NetX based" select ARM_VIC select CLKSRC_MMIO select CPU_ARM926T select GENERIC_CLOCKEVENTS help This enables support for systems based on the Hilscher NetX Soc config ARCH_IOP13XX bool "IOP13xx-based" depends on MMU select CPU_XSC3 select NEED_MACH_MEMORY_H select NEED_RET_TO_USER select PCI select PLAT_IOP select VMSPLIT_1G select SPARSE_IRQ help Support for Intel's IOP13XX (XScale) family of processors. config ARCH_IOP32X bool "IOP32x-based" depends on MMU select ARCH_REQUIRE_GPIOLIB select CPU_XSCALE select GPIO_IOP select NEED_RET_TO_USER select PCI select PLAT_IOP help Support for Intel's 80219 and IOP32X (XScale) family of processors. config ARCH_IOP33X bool "IOP33x-based" depends on MMU select ARCH_REQUIRE_GPIOLIB select CPU_XSCALE select GPIO_IOP select NEED_RET_TO_USER select PCI select PLAT_IOP help Support for Intel's IOP33X (XScale) family of processors. config ARCH_IXP4XX bool "IXP4xx-based" depends on MMU select ARCH_HAS_DMA_SET_COHERENT_MASK select ARCH_REQUIRE_GPIOLIB select ARCH_SUPPORTS_BIG_ENDIAN select CLKSRC_MMIO select CPU_XSCALE select DMABOUNCE if PCI select GENERIC_CLOCKEVENTS select MIGHT_HAVE_PCI select NEED_MACH_IO_H select USB_EHCI_BIG_ENDIAN_DESC select USB_EHCI_BIG_ENDIAN_MMIO help Support for Intel's IXP4XX (XScale) family of processors. config ARCH_DOVE bool "Marvell Dove" select ARCH_REQUIRE_GPIOLIB select CPU_PJ4 select GENERIC_CLOCKEVENTS select MIGHT_HAVE_PCI select MVEBU_MBUS select PINCTRL select PINCTRL_DOVE select PLAT_ORION_LEGACY help Support for the Marvell Dove SoC 88AP510 config ARCH_MV78XX0 bool "Marvell MV78xx0" select ARCH_REQUIRE_GPIOLIB select CPU_FEROCEON select GENERIC_CLOCKEVENTS select MVEBU_MBUS select PCI select PLAT_ORION_LEGACY help Support for the following Marvell MV78xx0 series SoCs: MV781x0, MV782x0. config ARCH_ORION5X bool "Marvell Orion" depends on MMU select ARCH_REQUIRE_GPIOLIB select CPU_FEROCEON select GENERIC_CLOCKEVENTS select MVEBU_MBUS select PCI select PLAT_ORION_LEGACY select MULTI_IRQ_HANDLER help Support for the following Marvell Orion 5x series SoCs: Orion-1 (5181), Orion-VoIP (5181L), Orion-NAS (5182), Orion-2 (5281), Orion-1-90 (6183). config ARCH_MMP bool "Marvell PXA168/910/MMP2" depends on MMU select ARCH_REQUIRE_GPIOLIB select CLKDEV_LOOKUP select GENERIC_ALLOCATOR select GENERIC_CLOCKEVENTS select GPIO_PXA select IRQ_DOMAIN select MULTI_IRQ_HANDLER select PINCTRL select PLAT_PXA select SPARSE_IRQ help Support for Marvell's PXA168/PXA910(MMP) and MMP2 processor line. config ARCH_KS8695 bool "Micrel/Kendin KS8695" select ARCH_REQUIRE_GPIOLIB select CLKSRC_MMIO select CPU_ARM922T select GENERIC_CLOCKEVENTS select NEED_MACH_MEMORY_H help Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based System-on-Chip devices. config ARCH_W90X900 bool "Nuvoton W90X900 CPU" select ARCH_REQUIRE_GPIOLIB select CLKDEV_LOOKUP select CLKSRC_MMIO select CPU_ARM926T select GENERIC_CLOCKEVENTS help Support for Nuvoton (Winbond logic dept.) ARM9 processor, At present, the w90x900 has been renamed nuc900, regarding the ARM series product line, you can login the following link address to know more. config ARCH_LPC32XX bool "NXP LPC32XX" select ARCH_REQUIRE_GPIOLIB select ARM_AMBA select CLKDEV_LOOKUP select CLKSRC_MMIO select CPU_ARM926T select GENERIC_CLOCKEVENTS select HAVE_IDE select USE_OF help Support for the NXP LPC32XX family of processors config ARCH_PXA bool "PXA2xx/PXA3xx-based" depends on MMU select ARCH_MTD_XIP select ARCH_REQUIRE_GPIOLIB select ARM_CPU_SUSPEND if PM select AUTO_ZRELADDR select COMMON_CLK select CLKDEV_LOOKUP select CLKSRC_MMIO select CLKSRC_OF select GENERIC_CLOCKEVENTS select GPIO_PXA select HAVE_IDE select IRQ_DOMAIN select MULTI_IRQ_HANDLER select PLAT_PXA select SPARSE_IRQ help Support for Intel/Marvell's PXA2xx/PXA3xx processor line. config ARCH_SHMOBILE_LEGACY bool "Renesas ARM SoCs (non-multiplatform)" select ARCH_SHMOBILE select ARM_PATCH_PHYS_VIRT if MMU select CLKDEV_LOOKUP select CPU_V7 select GENERIC_CLOCKEVENTS select HAVE_ARM_SCU if SMP select HAVE_ARM_TWD if SMP select HAVE_SMP select MIGHT_HAVE_CACHE_L2X0 select MULTI_IRQ_HANDLER select NO_IOPORT_MAP select PINCTRL select PM_GENERIC_DOMAINS if PM select SH_CLK_CPG select SPARSE_IRQ help Support for Renesas ARM SoC platforms using a non-multiplatform kernel. This includes the SH-Mobile, R-Mobile, EMMA-Mobile, R-Car and RZ families. config ARCH_RPC bool "RiscPC" depends on MMU select ARCH_ACORN select ARCH_MAY_HAVE_PC_FDC select ARCH_SPARSEMEM_ENABLE select ARCH_USES_GETTIMEOFFSET select CPU_SA110 select FIQ select HAVE_IDE select HAVE_PATA_PLATFORM select ISA_DMA_API select NEED_MACH_IO_H select NEED_MACH_MEMORY_H select NO_IOPORT_MAP select VIRT_TO_BUS help On the Acorn Risc-PC, Linux can support the internal IDE disk and CD-ROM interface, serial and parallel port, and the floppy drive. config ARCH_SA1100 bool "SA1100-based" select ARCH_MTD_XIP select ARCH_REQUIRE_GPIOLIB select ARCH_SPARSEMEM_ENABLE select CLKDEV_LOOKUP select CLKSRC_MMIO select CPU_FREQ select CPU_SA1100 select GENERIC_CLOCKEVENTS select HAVE_IDE select IRQ_DOMAIN select ISA select MULTI_IRQ_HANDLER select NEED_MACH_MEMORY_H select SPARSE_IRQ help Support for StrongARM 11x0 based boards. config ARCH_S3C24XX bool "Samsung S3C24XX SoCs" select ARCH_REQUIRE_GPIOLIB select ATAGS select CLKDEV_LOOKUP select CLKSRC_SAMSUNG_PWM select GENERIC_CLOCKEVENTS select GPIO_SAMSUNG select HAVE_S3C2410_I2C if I2C select HAVE_S3C2410_WATCHDOG if WATCHDOG select HAVE_S3C_RTC if RTC_CLASS select MULTI_IRQ_HANDLER select NEED_MACH_IO_H select SAMSUNG_ATAGS help Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST (), the IPAQ 1940 or the Samsung SMDK2410 development board (and derivatives). config ARCH_S3C64XX bool "Samsung S3C64XX" select ARCH_REQUIRE_GPIOLIB select ARM_AMBA select ARM_VIC select ATAGS select CLKDEV_LOOKUP select CLKSRC_SAMSUNG_PWM select COMMON_CLK_SAMSUNG select CPU_V6K select GENERIC_CLOCKEVENTS select GPIO_SAMSUNG select HAVE_S3C2410_I2C if I2C select HAVE_S3C2410_WATCHDOG if WATCHDOG select HAVE_TCM select NO_IOPORT_MAP select PLAT_SAMSUNG select PM_GENERIC_DOMAINS if PM select S3C_DEV_NAND select S3C_GPIO_TRACK select SAMSUNG_ATAGS select SAMSUNG_WAKEMASK select SAMSUNG_WDT_RESET help Samsung S3C64XX series based systems config ARCH_DAVINCI bool "TI DaVinci" select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_REQUIRE_GPIOLIB select CLKDEV_LOOKUP select GENERIC_ALLOCATOR select GENERIC_CLOCKEVENTS select GENERIC_IRQ_CHIP select HAVE_IDE select TI_PRIV_EDMA select USE_OF select ZONE_DMA help Support for TI's DaVinci platform. config ARCH_OMAP1 bool "TI OMAP1" depends on MMU select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_OMAP select ARCH_REQUIRE_GPIOLIB select CLKDEV_LOOKUP select CLKSRC_MMIO select GENERIC_CLOCKEVENTS select GENERIC_IRQ_CHIP select HAVE_IDE select IRQ_DOMAIN select MULTI_IRQ_HANDLER select NEED_MACH_IO_H if PCCARD select NEED_MACH_MEMORY_H select SPARSE_IRQ help Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx) endchoice menu "Multiple platform selection" depends on ARCH_MULTIPLATFORM comment "CPU Core family selection" config ARCH_MULTI_V4 bool "ARMv4 based platforms (FA526)" depends on !ARCH_MULTI_V6_V7 select ARCH_MULTI_V4_V5 select CPU_FA526 config ARCH_MULTI_V4T bool "ARMv4T based platforms (ARM720T, ARM920T, ...)" depends on !ARCH_MULTI_V6_V7 select ARCH_MULTI_V4_V5 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \ CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \ CPU_ARM925T || CPU_ARM940T) config ARCH_MULTI_V5 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)" depends on !ARCH_MULTI_V6_V7 select ARCH_MULTI_V4_V5 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \ CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \ CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON) config ARCH_MULTI_V4_V5 bool config ARCH_MULTI_V6 bool "ARMv6 based platforms (ARM11)" select ARCH_MULTI_V6_V7 select CPU_V6K config ARCH_MULTI_V7 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)" default y select ARCH_MULTI_V6_V7 select CPU_V7 select HAVE_SMP config ARCH_MULTI_V6_V7 bool select MIGHT_HAVE_CACHE_L2X0 config ARCH_MULTI_CPU_AUTO def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7) select ARCH_MULTI_V5 endmenu config ARCH_VIRT bool "Dummy Virtual Machine" if ARCH_MULTI_V7 select ARM_AMBA select ARM_GIC select ARM_GIC_V3 select ARM_PSCI select HAVE_ARM_ARCH_TIMER # # This is sorted alphabetically by mach-* pathname. However, plat-* # Kconfigs may be included either alphabetically (according to the # plat- suffix) or along side the corresponding mach-* source. # source "arch/arm/mach-mvebu/Kconfig" source "arch/arm/mach-alpine/Kconfig" source "arch/arm/mach-asm9260/Kconfig" source "arch/arm/mach-at91/Kconfig" source "arch/arm/mach-axxia/Kconfig" source "arch/arm/mach-bcm/Kconfig" source "arch/arm/mach-berlin/Kconfig" source "arch/arm/mach-clps711x/Kconfig" source "arch/arm/mach-cns3xxx/Kconfig" source "arch/arm/mach-davinci/Kconfig" source "arch/arm/mach-digicolor/Kconfig" source "arch/arm/mach-dove/Kconfig" source "arch/arm/mach-ep93xx/Kconfig" source "arch/arm/mach-footbridge/Kconfig" source "arch/arm/mach-gemini/Kconfig" source "arch/arm/mach-highbank/Kconfig" source "arch/arm/mach-hisi/Kconfig" source "arch/arm/mach-integrator/Kconfig" source "arch/arm/mach-iop32x/Kconfig" source "arch/arm/mach-iop33x/Kconfig" source "arch/arm/mach-iop13xx/Kconfig" source "arch/arm/mach-ixp4xx/Kconfig" source "arch/arm/mach-keystone/Kconfig" source "arch/arm/mach-ks8695/Kconfig" source "arch/arm/mach-meson/Kconfig" source "arch/arm/mach-moxart/Kconfig" source "arch/arm/mach-mv78xx0/Kconfig" source "arch/arm/mach-imx/Kconfig" source "arch/arm/mach-mediatek/Kconfig" source "arch/arm/mach-mxs/Kconfig" source "arch/arm/mach-netx/Kconfig" source "arch/arm/mach-nomadik/Kconfig" source "arch/arm/mach-nspire/Kconfig" source "arch/arm/plat-omap/Kconfig" source "arch/arm/mach-omap1/Kconfig" source "arch/arm/mach-omap2/Kconfig" source "arch/arm/mach-orion5x/Kconfig" source "arch/arm/mach-picoxcell/Kconfig" source "arch/arm/mach-pxa/Kconfig" source "arch/arm/plat-pxa/Kconfig" source "arch/arm/mach-mmp/Kconfig" source "arch/arm/mach-qcom/Kconfig" source "arch/arm/mach-realview/Kconfig" source "arch/arm/mach-rockchip/Kconfig" source "arch/arm/mach-sa1100/Kconfig" source "arch/arm/mach-socfpga/Kconfig" source "arch/arm/mach-spear/Kconfig" source "arch/arm/mach-sti/Kconfig" source "arch/arm/mach-s3c24xx/Kconfig" source "arch/arm/mach-s3c64xx/Kconfig" source "arch/arm/mach-s5pv210/Kconfig" source "arch/arm/mach-exynos/Kconfig" source "arch/arm/plat-samsung/Kconfig" source "arch/arm/mach-shmobile/Kconfig" source "arch/arm/mach-sunxi/Kconfig" source "arch/arm/mach-prima2/Kconfig" source "arch/arm/mach-tegra/Kconfig" source "arch/arm/mach-u300/Kconfig" source "arch/arm/mach-uniphier/Kconfig" source "arch/arm/mach-ux500/Kconfig" source "arch/arm/mach-versatile/Kconfig" source "arch/arm/mach-vexpress/Kconfig" source "arch/arm/plat-versatile/Kconfig" source "arch/arm/mach-vt8500/Kconfig" source "arch/arm/mach-w90x900/Kconfig" source "arch/arm/mach-zx/Kconfig" source "arch/arm/mach-zynq/Kconfig" # ARMv7-M architecture config ARCH_EFM32 bool "Energy Micro efm32" depends on ARM_SINGLE_ARMV7M select ARCH_REQUIRE_GPIOLIB help Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko processors. config ARCH_LPC18XX bool "NXP LPC18xx/LPC43xx" depends on ARM_SINGLE_ARMV7M select ARCH_HAS_RESET_CONTROLLER select ARM_AMBA select CLKSRC_LPC32XX select PINCTRL help Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4 high performance microcontrollers. config ARCH_STM32 bool "STMicrolectronics STM32" depends on ARM_SINGLE_ARMV7M select ARCH_HAS_RESET_CONTROLLER select ARMV7M_SYSTICK select CLKSRC_STM32 select RESET_CONTROLLER help Support for STMicroelectronics STM32 processors. # Definitions to make life easier config ARCH_ACORN bool config PLAT_IOP bool select GENERIC_CLOCKEVENTS config PLAT_ORION bool select CLKSRC_MMIO select COMMON_CLK select GENERIC_IRQ_CHIP select IRQ_DOMAIN config PLAT_ORION_LEGACY bool select PLAT_ORION config PLAT_PXA bool config PLAT_VERSATILE bool source "arch/arm/firmware/Kconfig" source arch/arm/mm/Kconfig config IWMMXT bool "Enable iWMMXt support" depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B help Enable support for iWMMXt context switching at run time if running on a CPU that supports it. config MULTI_IRQ_HANDLER bool help Allow each machine to specify it's own IRQ handler at run time. if !MMU source "arch/arm/Kconfig-nommu" endif config PJ4B_ERRATA_4742 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation" depends on CPU_PJ4B && MACH_ARMADA_370 default y help When coming out of either a Wait for Interrupt (WFI) or a Wait for Event (WFE) IDLE states, a specific timing sensitivity exists between the retiring WFI/WFE instructions and the newly issued subsequent instructions. This sensitivity can result in a CPU hang scenario. Workaround: The software must insert either a Data Synchronization Barrier (DSB) or Data Memory Barrier (DMB) command immediately after the WFI/WFE instruction config ARM_ERRATA_326103 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory" depends on CPU_V6 help Executing a SWP instruction to read-only memory does not set bit 11 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to treat the access as a read, preventing a COW from occurring and causing the faulting task to livelock. config ARM_ERRATA_411920 bool "ARM errata: Invalidation of the Instruction Cache operation can fail" depends on CPU_V6 || CPU_V6K help Invalidation of the Instruction Cache operation can fail. This erratum is present in 1136 (before r1p4), 1156 and 1176. It does not affect the MPCore. This option enables the ARM Ltd. recommended workaround. config ARM_ERRATA_430973 bool "ARM errata: Stale prediction on replaced interworking branch" depends on CPU_V7 help This option enables the workaround for the 430973 Cortex-A8 r1p* erratum. If a code sequence containing an ARM/Thumb interworking branch is replaced with another code sequence at the same virtual address, whether due to self-modifying code or virtual to physical address re-mapping, Cortex-A8 does not recover from the stale interworking branch prediction. This results in Cortex-A8 executing the new code sequence in the incorrect ARM or Thumb state. The workaround enables the BTB/BTAC operations by setting ACTLR.IBE and also flushes the branch target cache at every context switch. Note that setting specific bits in the ACTLR register may not be available in non-secure mode. config ARM_ERRATA_458693 bool "ARM errata: Processor deadlock when a false hazard is created" depends on CPU_V7 depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 458693 Cortex-A8 (r2p0) erratum. For very specific sequences of memory operations, it is possible for a hazard condition intended for a cache line to instead be incorrectly associated with a different cache line. This false hazard might then cause a processor deadlock. The workaround enables the L1 caching of the NEON accesses and disables the PLD instruction in the ACTLR register. Note that setting specific bits in the ACTLR register may not be available in non-secure mode. config ARM_ERRATA_460075 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data" depends on CPU_V7 depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 460075 Cortex-A8 (r2p0) erratum. Any asynchronous access to the L2 cache may encounter a situation in which recent store transactions to the L2 cache are lost and overwritten with stale memory contents from external memory. The workaround disables the write-allocate mode for the L2 cache via the ACTLR register. Note that setting specific bits in the ACTLR register may not be available in non-secure mode. config ARM_ERRATA_742230 bool "ARM errata: DMB operation may be faulty" depends on CPU_V7 && SMP depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 742230 Cortex-A9 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction between two write operations may not ensure the correct visibility ordering of the two writes. This workaround sets a specific bit in the diagnostic register of the Cortex-A9 which causes the DMB instruction to behave as a DSB, ensuring the correct behaviour of the two writes. config ARM_ERRATA_742231 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption" depends on CPU_V7 && SMP depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 742231 Cortex-A9 (r2p0..r2p2) erratum. Under certain conditions, specific to the Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode, accessing some data located in the same cache line, may get corrupted data due to bad handling of the address hazard when the line gets replaced from one of the CPUs at the same time as another CPU is accessing it. This workaround sets specific bits in the diagnostic register of the Cortex-A9 which reduces the linefill issuing capabilities of the processor. config ARM_ERRATA_643719 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect" depends on CPU_V7 && SMP default y help This option enables the workaround for the 643719 Cortex-A9 (prior to r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR register returns zero when it should return one. The workaround corrects this value, ensuring cache maintenance operations which use it behave as intended and avoiding data corruption. config ARM_ERRATA_720789 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID" depends on CPU_V7 help This option enables the workaround for the 720789 Cortex-A9 (prior to r2p0) erratum. A faulty ASID can be sent to the other CPUs for the broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS. As a consequence of this erratum, some TLB entries which should be invalidated are not, resulting in an incoherency in the system page tables. The workaround changes the TLB flushing routines to invalidate entries regardless of the ASID. config ARM_ERRATA_743622 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption" depends on CPU_V7 depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 743622 Cortex-A9 (r2p*) erratum. Under very rare conditions, a faulty optimisation in the Cortex-A9 Store Buffer may lead to data corruption. This workaround sets a specific bit in the diagnostic register of the Cortex-A9 which disables the Store Buffer optimisation, preventing the defect from occurring. This has no visible impact on the overall performance or power consumption of the processor. config ARM_ERRATA_751472 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation" depends on CPU_V7 depends on !ARCH_MULTIPLATFORM help This option enables the workaround for the 751472 Cortex-A9 (prior to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the completion of a following broadcasted operation if the second operation is received by a CPU before the ICIALLUIS has completed, potentially leading to corrupted entries in the cache or TLB. config ARM_ERRATA_754322 bool "ARM errata: possible faulty MMU translations following an ASID switch" depends on CPU_V7 help This option enables the workaround for the 754322 Cortex-A9 (r2p*, r3p*) erratum. A speculative memory access may cause a page table walk which starts prior to an ASID switch but completes afterwards. This can populate the micro-TLB with a stale entry which may be hit with the new ASID. This workaround places two dsb instructions in the mm switching code so that no page table walks can cross the ASID switch. config ARM_ERRATA_754327 bool "ARM errata: no automatic Store Buffer drain" depends on CPU_V7 && SMP help This option enables the workaround for the 754327 Cortex-A9 (prior to r2p0) erratum. The Store Buffer does not have any automatic draining mechanism and therefore a livelock may occur if an external agent continuously polls a memory location waiting to observe an update. This workaround defines cpu_relax() as smp_mb(), preventing correctly written polling loops from denying visibility of updates to memory. config ARM_ERRATA_364296 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled" depends on CPU_V6 help This options enables the workaround for the 364296 ARM1136 r0p2 erratum (possible cache data corruption with hit-under-miss enabled). It sets the undocumented bit 31 in the auxiliary control register and the FI bit in the control register, thus disabling hit-under-miss without putting the processor into full low interrupt latency mode. ARM11MPCore is not affected. config ARM_ERRATA_764369 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed" depends on CPU_V7 && SMP help This option enables the workaround for erratum 764369 affecting Cortex-A9 MPCore with two or more processors (all current revisions). Under certain timing circumstances, a data cache line maintenance operation by MVA targeting an Inner Shareable memory region may fail to proceed up to either the Point of Coherency or to the Point of Unification of the system. This workaround adds a DSB instruction before the relevant cache maintenance functions and sets a specific bit in the diagnostic control register of the SCU. config ARM_ERRATA_775420 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock" depends on CPU_V7 help This option enables the workaround for the 775420 Cortex-A9 (r2p2, r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance operation aborts with MMU exception, it might cause the processor to deadlock. This workaround puts DSB before executing ISB if an abort may occur on cache maintenance. config ARM_ERRATA_798181 bool "ARM errata: TLBI/DSB failure on Cortex-A15" depends on CPU_V7 && SMP help On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not adequately shooting down all use of the old entries. This option enables the Linux kernel workaround for this erratum which sends an IPI to the CPUs that are running the same ASID as the one being invalidated. config ARM_ERRATA_773022 bool "ARM errata: incorrect instructions may be executed from loop buffer" depends on CPU_V7 help This option enables the workaround for the 773022 Cortex-A15 (up to r0p4) erratum. In certain rare sequences of code, the loop buffer may deliver incorrect instructions. This workaround disables the loop buffer to avoid the erratum. endmenu source "arch/arm/common/Kconfig" menu "Bus support" config ISA bool help Find out whether you have ISA slots on your motherboard. ISA is the name of a bus system, i.e. the way the CPU talks to the other stuff inside your box. Other bus systems are PCI, EISA, MicroChannel (MCA) or VESA. ISA is an older system, now being displaced by PCI; newer boards don't support it. If you have ISA, say Y, otherwise N. # Select ISA DMA controller support config ISA_DMA bool select ISA_DMA_API # Select ISA DMA interface config ISA_DMA_API bool config PCI bool "PCI support" if MIGHT_HAVE_PCI help Find out whether you have a PCI motherboard. PCI is the name of a bus system, i.e. the way the CPU talks to the other stuff inside your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or VESA. If you have PCI, say Y, otherwise N. config PCI_DOMAINS bool depends on PCI config PCI_DOMAINS_GENERIC def_bool PCI_DOMAINS config PCI_NANOENGINE bool "BSE nanoEngine PCI support" depends on SA1100_NANOENGINE help Enable PCI on the BSE nanoEngine board. config PCI_SYSCALL def_bool PCI config PCI_HOST_ITE8152 bool depends on PCI && MACH_ARMCORE default y select DMABOUNCE source "drivers/pci/Kconfig" source "drivers/pci/pcie/Kconfig" source "drivers/pcmcia/Kconfig" endmenu menu "Kernel Features" config HAVE_SMP bool help This option should be selected by machines which have an SMP- capable CPU. The only effect of this option is to make the SMP-related options available to the user for configuration. config SMP bool "Symmetric Multi-Processing" depends on CPU_V6K || CPU_V7 depends on GENERIC_CLOCKEVENTS depends on HAVE_SMP depends on MMU || ARM_MPU select IRQ_WORK help This enables support for systems with more than one CPU. If you have a system with only one CPU, say N. If you have a system with more than one CPU, say Y. If you say N here, the kernel will run on uni- and multiprocessor machines, but will use only one CPU of a multiprocessor machine. If you say Y here, the kernel will run on many, but not all, uniprocessor machines. On a uniprocessor machine, the kernel will run faster if you say N here. See also , and the SMP-HOWTO available at . If you don't know what to do here, say N. config SMP_ON_UP bool "Allow booting SMP kernel on uniprocessor systems" depends on SMP && !XIP_KERNEL && MMU default y help SMP kernels contain instructions which fail on non-SMP processors. Enabling this option allows the kernel to modify itself to make these instructions safe. Disabling it allows about 1K of space savings. If you don't know what to do here, say Y. config ARM_CPU_TOPOLOGY bool "Support cpu topology definition" depends on SMP && CPU_V7 default y help Support ARM cpu topology definition. The MPIDR register defines affinity between processors which is then used to describe the cpu topology of an ARM System. config SCHED_MC bool "Multi-core scheduler support" depends on ARM_CPU_TOPOLOGY 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" depends on ARM_CPU_TOPOLOGY 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 HAVE_ARM_SCU bool help This option enables support for the ARM system coherency unit config HAVE_ARM_ARCH_TIMER bool "Architected timer support" depends on CPU_V7 select ARM_ARCH_TIMER select GENERIC_CLOCKEVENTS help This option enables support for the ARM architected timer config HAVE_ARM_TWD bool select CLKSRC_OF if OF help This options enables support for the ARM timer and watchdog unit config MCPM bool "Multi-Cluster Power Management" depends on CPU_V7 && SMP help This option provides the common power management infrastructure for (multi-)cluster based systems, such as big.LITTLE based systems. config MCPM_QUAD_CLUSTER bool depends on MCPM help To avoid wasting resources unnecessarily, MCPM only supports up to 2 clusters by default. Platforms with 3 or 4 clusters that use MCPM must select this option to allow the additional clusters to be managed. config BIG_LITTLE bool "big.LITTLE support (Experimental)" depends on CPU_V7 && SMP select MCPM help This option enables support selections for the big.LITTLE system architecture. config BL_SWITCHER bool "big.LITTLE switcher support" depends on BIG_LITTLE && MCPM && HOTPLUG_CPU select ARM_CPU_SUSPEND select CPU_PM help The big.LITTLE "switcher" provides the core functionality to transparently handle transition between a cluster of A15's and a cluster of A7's in a big.LITTLE system. config BL_SWITCHER_DUMMY_IF tristate "Simple big.LITTLE switcher user interface" depends on BL_SWITCHER && DEBUG_KERNEL help This is a simple and dummy char dev interface to control the big.LITTLE switcher core code. It is meant for debugging purposes only. choice prompt "Memory split" depends on MMU default VMSPLIT_3G help Select the desired split between kernel and user memory. If you are not absolutely sure what you are doing, leave this option alone! config VMSPLIT_3G bool "3G/1G user/kernel split" config VMSPLIT_3G_OPT bool "3G/1G user/kernel split (for full 1G low memory)" config VMSPLIT_2G bool "2G/2G user/kernel split" config VMSPLIT_1G bool "1G/3G user/kernel split" endchoice config PAGE_OFFSET hex default PHYS_OFFSET if !MMU default 0x40000000 if VMSPLIT_1G default 0x80000000 if VMSPLIT_2G default 0xB0000000 if VMSPLIT_3G_OPT default 0xC0000000 config NR_CPUS int "Maximum number of CPUs (2-32)" range 2 32 depends on SMP default "4" config HOTPLUG_CPU bool "Support for hot-pluggable CPUs" depends on SMP help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu. config ARM_PSCI bool "Support for the ARM Power State Coordination Interface (PSCI)" depends on CPU_V7 select ARM_PSCI_FW help Say Y here if you want Linux to communicate with system firmware implementing the PSCI specification for CPU-centric power management operations described in ARM document number ARM DEN 0022A ("Power State Coordination Interface System Software on ARM processors"). # The GPIO number here must be sorted by descending number. In case of # a multiplatform kernel, we just want the highest value required by the # selected platforms. config ARCH_NR_GPIO int default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \ ARCH_ZYNQ default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \ SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210 default 416 if ARCH_SUNXI default 392 if ARCH_U8500 default 352 if ARCH_VT8500 default 288 if ARCH_ROCKCHIP default 264 if MACH_H4700 default 0 help Maximum number of GPIOs in the system. If unsure, leave the default value. source kernel/Kconfig.preempt config HZ_FIXED int default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \ ARCH_S5PV210 || ARCH_EXYNOS4 default 128 if SOC_AT91RM9200 default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE_LEGACY default 0 choice depends on HZ_FIXED = 0 prompt "Timer frequency" config HZ_100 bool "100 Hz" config HZ_200 bool "200 Hz" config HZ_250 bool "250 Hz" config HZ_300 bool "300 Hz" config HZ_500 bool "500 Hz" config HZ_1000 bool "1000 Hz" endchoice config HZ int default HZ_FIXED if HZ_FIXED != 0 default 100 if HZ_100 default 200 if HZ_200 default 250 if HZ_250 default 300 if HZ_300 default 500 if HZ_500 default 1000 config SCHED_HRTICK def_bool HIGH_RES_TIMERS config THUMB2_KERNEL bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K default y if CPU_THUMBONLY select AEABI select ARM_ASM_UNIFIED select ARM_UNWIND help By enabling this option, the kernel will be compiled in Thumb-2 mode. A compiler/assembler that understand the unified ARM-Thumb syntax is needed. If unsure, say N. config THUMB2_AVOID_R_ARM_THM_JUMP11 bool "Work around buggy Thumb-2 short branch relocations in gas" depends on THUMB2_KERNEL && MODULES default y help Various binutils versions can resolve Thumb-2 branches to locally-defined, preemptible global symbols as short-range "b.n" branch instructions. This is a problem, because there's no guarantee the final destination of the symbol, or any candidate locations for a trampoline, are within range of the branch. For this reason, the kernel does not support fixing up the R_ARM_THM_JUMP11 (102) relocation in modules at all, and it makes little sense to add support. The symptom is that the kernel fails with an "unsupported relocation" error when loading some modules. Until fixed tools are available, passing -fno-optimize-sibling-calls to gcc should prevent gcc generating code which hits this problem, at the cost of a bit of extra runtime stack usage in some cases. The problem is described in more detail at: https://bugs.launchpad.net/binutils-linaro/+bug/725126 Only Thumb-2 kernels are affected. Unless you are sure your tools don't have this problem, say Y. config ARM_ASM_UNIFIED bool config AEABI bool "Use the ARM EABI to compile the kernel" help This option allows for the kernel to be compiled using the latest ARM ABI (aka EABI). This is only useful if you are using a user space environment that is also compiled with EABI. Since there are major incompatibilities between the legacy ABI and EABI, especially with regard to structure member alignment, this option also changes the kernel syscall calling convention to disambiguate both ABIs and allow for backward compatibility support (selected with CONFIG_OABI_COMPAT). To use this you need GCC version 4.0.0 or later. config OABI_COMPAT bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)" depends on AEABI && !THUMB2_KERNEL help This option preserves the old syscall interface along with the new (ARM EABI) one. It also provides a compatibility layer to intercept syscalls that have structure arguments which layout in memory differs between the legacy ABI and the new ARM EABI (only for non "thumb" binaries). This option adds a tiny overhead to all syscalls and produces a slightly larger kernel. The seccomp filter system will not be available when this is selected, since there is no way yet to sensibly distinguish between calling conventions during filtering. If you know you'll be using only pure EABI user space then you can say N here. If this option is not selected and you attempt to execute a legacy ABI binary then the result will be UNPREDICTABLE (in fact it can be predicted that it won't work at all). If in doubt say N. config ARCH_HAS_HOLES_MEMORYMODEL bool config ARCH_SPARSEMEM_ENABLE bool 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 HAVE_GENERIC_RCU_GUP def_bool y depends on ARM_LPAE config HIGHMEM bool "High Memory Support" depends on MMU help The address space of ARM processors is only 4 Gigabytes large and it has to accommodate user address space, kernel address space as well as some memory mapped IO. That means that, if you have a large amount of physical memory and/or IO, not all of the memory can be "permanently mapped" by the kernel. The physical memory that is not permanently mapped is called "high memory". Depending on the selected kernel/user memory split, minimum vmalloc space and actual amount of RAM, you may not need this option which should result in a slightly faster kernel. If unsure, say n. config HIGHPTE bool "Allocate 2nd-level pagetables from highmem" if EXPERT depends on HIGHMEM default y help The VM uses one page of physical memory for each page table. For systems with a lot of processes, this can use a lot of precious low memory, eventually leading to low memory being consumed by page tables. Setting this option will allow user-space 2nd level page tables to reside in high memory. config CPU_SW_DOMAIN_PAN bool "Enable use of CPU domains to implement privileged no-access" depends on MMU && !ARM_LPAE default y help Increase kernel security by ensuring that normal kernel accesses are unable to access userspace addresses. This can help prevent use-after-free bugs becoming an exploitable privilege escalation by ensuring that magic values (such as LIST_POISON) will always fault when dereferenced. CPUs with low-vector mappings use a best-efforts implementation. Their lower 1MB needs to remain accessible for the vectors, but the remainder of userspace will become appropriately inaccessible. config HW_PERF_EVENTS def_bool y depends on ARM_PMU config SYS_SUPPORTS_HUGETLBFS def_bool y depends on ARM_LPAE config HAVE_ARCH_TRANSPARENT_HUGEPAGE def_bool y depends on ARM_LPAE config ARCH_WANT_GENERAL_HUGETLB def_bool y config ARM_MODULE_PLTS bool "Use PLTs to allow module memory to spill over into vmalloc area" depends on MODULES help Allocate PLTs when loading modules so that jumps and calls whose targets are too far away for their relative offsets to be encoded in the instructions themselves can be bounced via veneers in the module's PLT. This allows modules to be allocated in the generic vmalloc area after the dedicated module memory area has been exhausted. The modules will use slightly more memory, but after rounding up to page size, the actual memory footprint is usually the same. Say y if you are getting out of memory errors while loading modules source "mm/Kconfig" config FORCE_MAX_ZONEORDER int "Maximum zone order" if ARCH_SHMOBILE_LEGACY range 11 64 if ARCH_SHMOBILE_LEGACY default "12" if SOC_AM33XX default "9" if SA1111 || ARCH_EFM32 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. config ALIGNMENT_TRAP bool depends on CPU_CP15_MMU default y if !ARCH_EBSA110 select HAVE_PROC_CPU if PROC_FS help ARM processors cannot fetch/store information which is not naturally aligned on the bus, i.e., a 4 byte fetch must start at an address divisible by 4. On 32-bit ARM processors, these non-aligned fetch/store instructions will be emulated in software if you say here, which has a severe performance impact. This is necessary for correct operation of some network protocols. With an IP-only configuration it is safe to say N, otherwise say Y. config UACCESS_WITH_MEMCPY bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()" depends on MMU default y if CPU_FEROCEON help Implement faster copy_to_user and clear_user methods for CPU cores where a 8-word STM instruction give significantly higher memory write throughput than a sequence of individual 32bit stores. A possible side effect is a slight increase in scheduling latency between threads sharing the same address space if they invoke such copy operations with large buffers. However, if the CPU data cache is using a write-allocate mode, this option is unlikely to provide any performance gain. config SECCOMP bool prompt "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 SWIOTLB def_bool y config IOMMU_HELPER def_bool SWIOTLB config XEN_DOM0 def_bool y depends on XEN config XEN bool "Xen guest support on ARM" depends on ARM && AEABI && OF depends on CPU_V7 && !CPU_V6 depends on !GENERIC_ATOMIC64 depends on MMU select ARCH_DMA_ADDR_T_64BIT select ARM_PSCI select SWIOTLB_XEN help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. endmenu menu "Boot options" config USE_OF bool "Flattened Device Tree support" select IRQ_DOMAIN select OF select OF_EARLY_FLATTREE select OF_RESERVED_MEM help Include support for flattened device tree machine descriptions. config ATAGS bool "Support for the traditional ATAGS boot data passing" if USE_OF default y help This is the traditional way of passing data to the kernel at boot time. If you are solely relying on the flattened device tree (or the ARM_ATAG_DTB_COMPAT option) then you may unselect this option to remove ATAGS support from your kernel binary. If unsure, leave this to y. config DEPRECATED_PARAM_STRUCT bool "Provide old way to pass kernel parameters" depends on ATAGS help This was deprecated in 2001 and announced to live on for 5 years. Some old boot loaders still use this way. # Compressed boot loader in ROM. Yes, we really want to ask about # TEXT and BSS so we preserve their values in the config files. config ZBOOT_ROM_TEXT hex "Compressed ROM boot loader base address" default "0" help The physical address at which the ROM-able zImage is to be placed in the target. Platforms which normally make use of ROM-able zImage formats normally set this to a suitable value in their defconfig file. If ZBOOT_ROM is not enabled, this has no effect. config ZBOOT_ROM_BSS hex "Compressed ROM boot loader BSS address" default "0" help The base address of an area of read/write memory in the target for the ROM-able zImage which must be available while the decompressor is running. It must be large enough to hold the entire decompressed kernel plus an additional 128 KiB. Platforms which normally make use of ROM-able zImage formats normally set this to a suitable value in their defconfig file. If ZBOOT_ROM is not enabled, this has no effect. config ZBOOT_ROM bool "Compressed boot loader in ROM/flash" depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR help Say Y here if you intend to execute your compressed kernel image (zImage) directly from ROM or flash. If unsure, say N. config ARM_APPENDED_DTB bool "Use appended device tree blob to zImage (EXPERIMENTAL)" depends on OF help With this option, the boot code will look for a device tree binary (DTB) appended to zImage (e.g. cat zImage .dtb > zImage_w_dtb). This is meant as a backward compatibility convenience for those systems with a bootloader that can't be upgraded to accommodate the documented boot protocol using a device tree. Beware that there is very little in terms of protection against this option being confused by leftover garbage in memory that might look like a DTB header after a reboot if no actual DTB is appended to zImage. Do not leave this option active in a production kernel if you don't intend to always append a DTB. Proper passing of the location into r2 of a bootloader provided DTB is always preferable to this option. config ARM_ATAG_DTB_COMPAT bool "Supplement the appended DTB with traditional ATAG information" depends on ARM_APPENDED_DTB help Some old bootloaders can't be updated to a DTB capable one, yet they provide ATAGs with memory configuration, the ramdisk address, the kernel cmdline string, etc. Such information is dynamically provided by the bootloader and can't always be stored in a static DTB. To allow a device tree enabled kernel to be used with such bootloaders, this option allows zImage to extract the information from the ATAG list and store it at run time into the appended DTB. choice prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER bool "Use bootloader kernel arguments if available" help Uses the command-line options passed by the boot loader instead of the device tree bootargs property. If the boot loader doesn't provide any, the device tree bootargs property will be used. config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND bool "Extend with bootloader kernel arguments" help The command-line arguments provided by the boot loader will be appended to the the device tree bootargs property. endchoice config CMDLINE string "Default kernel command string" default "" help On some architectures (EBSA110 and CATS), there is currently no way for the boot loader to pass arguments to the kernel. For these architectures, you should supply some command-line options at build time by entering them here. As a minimum, you should specify the memory size and the root device (e.g., mem=64M root=/dev/nfs). choice prompt "Kernel command line type" if CMDLINE != "" default CMDLINE_FROM_BOOTLOADER depends on ATAGS config CMDLINE_FROM_BOOTLOADER bool "Use bootloader kernel arguments if available" help Uses the command-line options passed by the boot loader. If the boot loader doesn't provide any, the default kernel command string provided in CMDLINE will be used. config CMDLINE_EXTEND bool "Extend bootloader kernel arguments" help The command-line arguments provided by the boot loader will be appended to the default kernel command string. 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. endchoice config XIP_KERNEL bool "Kernel Execute-In-Place from ROM" depends on !ARM_LPAE && !ARCH_MULTIPLATFORM help Execute-In-Place allows the kernel to run from non-volatile storage directly addressable by the CPU, such as NOR flash. This saves RAM space since the text section of the kernel is not loaded from flash to RAM. Read-write sections, such as the data section and stack, are still copied to RAM. The XIP kernel is not compressed since it has to run directly from flash, so it will take more space to store it. The flash address used to link the kernel object files, and for storing it, is configuration dependent. Therefore, if you say Y here, you must know the proper physical address where to store the kernel image depending on your own flash memory usage. Also note that the make target becomes "make xipImage" rather than "make zImage" or "make Image". The final kernel binary to put in ROM memory will be arch/arm/boot/xipImage. If unsure, say N. config XIP_PHYS_ADDR hex "XIP Kernel Physical Location" depends on XIP_KERNEL default "0x00080000" help This is the physical address in your flash memory the kernel will be linked for and stored to. This address is dependent on your own flash usage. config KEXEC bool "Kexec system call (EXPERIMENTAL)" depends on (!SMP || PM_SLEEP_SMP) depends on !CPU_V7M select KEXEC_CORE help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot but it is independent of the system firmware. And like a reboot you can start any kernel with it, not just Linux. It is an ongoing process to be certain the hardware in a machine is properly shutdown, so do not be surprised if this code does not initially work for you. config ATAGS_PROC bool "Export atags in procfs" depends on ATAGS && KEXEC default y help Should the atags used to boot the kernel be exported in an "atags" file in procfs. Useful with kexec. config CRASH_DUMP bool "Build kdump crash kernel (EXPERIMENTAL)" help Generate crash dump after being started by kexec. This should be normally only set in special crash dump kernels which are loaded in the main kernel with kexec-tools into a specially reserved region and then later executed after a crash by kdump/kexec. The crash dump kernel must be compiled to a memory address not used by the main kernel For more details see Documentation/kdump/kdump.txt config AUTO_ZRELADDR bool "Auto calculation of the decompressed kernel image address" help ZRELADDR is the physical address where the decompressed kernel image will be placed. If AUTO_ZRELADDR is selected, the address will be determined at run-time by masking the current IP with 0xf8000000. This assumes the zImage being placed in the first 128MB from start of memory. endmenu menu "CPU Power Management" source "drivers/cpufreq/Kconfig" source "drivers/cpuidle/Kconfig" endmenu menu "Floating point emulation" comment "At least one emulation must be selected" config FPE_NWFPE bool "NWFPE math emulation" depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL ---help--- Say Y to include the NWFPE floating point emulator in the kernel. This is necessary to run most binaries. Linux does not currently support floating point hardware so you need to say Y here even if your machine has an FPA or floating point co-processor podule. You may say N here if you are going to load the Acorn FPEmulator early in the bootup. config FPE_NWFPE_XP bool "Support extended precision" depends on FPE_NWFPE help Say Y to include 80-bit support in the kernel floating-point emulator. Otherwise, only 32 and 64-bit support is compiled in. Note that gcc does not generate 80-bit operations by default, so in most cases this option only enlarges the size of the floating point emulator without any good reason. You almost surely want to say N here. config FPE_FASTFPE bool "FastFPE math emulation (EXPERIMENTAL)" depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 ---help--- Say Y here to include the FAST floating point emulator in the kernel. This is an experimental much faster emulator which now also has full precision for the mantissa. It does not support any exceptions. It is very simple, and approximately 3-6 times faster than NWFPE. It should be sufficient for most programs. It may be not suitable for scientific calculations, but you have to check this for yourself. If you do not feel you need a faster FP emulation you should better choose NWFPE. config VFP bool "VFP-format floating point maths" depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON help Say Y to include VFP support code in the kernel. This is needed if your hardware includes a VFP unit. Please see for release notes and additional status information. Say N if your target does not have VFP hardware. config VFPv3 bool depends on VFP default y if CPU_V7 config NEON bool "Advanced SIMD (NEON) Extension support" depends on VFPv3 && CPU_V7 help Say Y to include support code for NEON, the ARMv7 Advanced SIMD Extension. config KERNEL_MODE_NEON bool "Support for NEON in kernel mode" depends on NEON && AEABI help Say Y to include support for NEON in kernel mode. endmenu menu "Userspace binary formats" source "fs/Kconfig.binfmt" endmenu menu "Power management options" source "kernel/power/Kconfig" config ARCH_SUSPEND_POSSIBLE depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \ CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK def_bool y config ARM_CPU_SUSPEND def_bool PM_SLEEP config ARCH_HIBERNATION_POSSIBLE bool depends on MMU default y if ARCH_SUSPEND_POSSIBLE endmenu source "net/Kconfig" source "drivers/Kconfig" source "drivers/firmware/Kconfig" source "fs/Kconfig" source "arch/arm/Kconfig.debug" source "security/Kconfig" source "crypto/Kconfig" if CRYPTO source "arch/arm/crypto/Kconfig" endif source "lib/Kconfig" source "arch/arm/kvm/Kconfig"