1 # SPDX-License-Identifier: GPL-2.0
5 select ARCH_CLOCKSOURCE_DATA
6 select ARCH_DISCARD_MEMBLOCK if !HAVE_ARCH_PFN_VALID && !KEXEC
7 select ARCH_HAS_DEBUG_VIRTUAL if MMU
8 select ARCH_HAS_DEVMEM_IS_ALLOWED
9 select ARCH_HAS_ELF_RANDOMIZE
10 select ARCH_HAS_FORTIFY_SOURCE
12 select ARCH_HAS_MEMBARRIER_SYNC_CORE
13 select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
14 select ARCH_HAS_PHYS_TO_DMA
15 select ARCH_HAS_SET_MEMORY
16 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
17 select ARCH_HAS_STRICT_MODULE_RWX if MMU
18 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
19 select ARCH_HAVE_CUSTOM_GPIO_H
20 select ARCH_HAS_GCOV_PROFILE_ALL
21 select ARCH_MIGHT_HAVE_PC_PARPORT
22 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
23 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
24 select ARCH_SUPPORTS_ATOMIC_RMW
25 select ARCH_USE_BUILTIN_BSWAP
26 select ARCH_USE_CMPXCHG_LOCKREF
27 select ARCH_WANT_IPC_PARSE_VERSION
28 select BUILDTIME_EXTABLE_SORT if MMU
29 select CLONE_BACKWARDS
30 select CPU_PM if (SUSPEND || CPU_IDLE)
31 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
32 select DMA_DIRECT_OPS if !MMU
34 select EDAC_ATOMIC_SCRUB
35 select GENERIC_ALLOCATOR
36 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
37 select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
38 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
39 select GENERIC_CPU_AUTOPROBE
40 select GENERIC_EARLY_IOREMAP
41 select GENERIC_IDLE_POLL_SETUP
42 select GENERIC_IRQ_PROBE
43 select GENERIC_IRQ_SHOW
44 select GENERIC_IRQ_SHOW_LEVEL
45 select GENERIC_PCI_IOMAP
46 select GENERIC_SCHED_CLOCK
47 select GENERIC_SMP_IDLE_THREAD
48 select GENERIC_STRNCPY_FROM_USER
49 select GENERIC_STRNLEN_USER
50 select HANDLE_DOMAIN_IRQ
51 select HARDIRQS_SW_RESEND
52 select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
53 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
54 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
55 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
56 select HAVE_ARCH_MMAP_RND_BITS if MMU
57 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
58 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
59 select HAVE_ARCH_TRACEHOOK
60 select HAVE_ARM_SMCCC if CPU_V7
61 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
62 select HAVE_CONTEXT_TRACKING
63 select HAVE_C_RECORDMCOUNT
64 select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
65 select HAVE_DMA_CONTIGUOUS if MMU
66 select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
67 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
68 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
69 select HAVE_EXIT_THREAD
70 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
71 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL && !CC_IS_CLANG)
72 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
73 select HAVE_FUTEX_CMPXCHG if FUTEX
74 select HAVE_GCC_PLUGINS
75 select HAVE_GENERIC_DMA_COHERENT
76 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
77 select HAVE_IDE if PCI || ISA || PCMCIA
78 select HAVE_IRQ_TIME_ACCOUNTING
79 select HAVE_KERNEL_GZIP
80 select HAVE_KERNEL_LZ4
81 select HAVE_KERNEL_LZMA
82 select HAVE_KERNEL_LZO
84 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
85 select HAVE_KRETPROBES if (HAVE_KPROBES)
87 select HAVE_MOD_ARCH_SPECIFIC
89 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
90 select HAVE_OPTPROBES if !THUMB2_KERNEL
91 select HAVE_PERF_EVENTS
93 select HAVE_PERF_USER_STACK_DUMP
94 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
95 select HAVE_REGS_AND_STACK_ACCESS_API
97 select HAVE_STACKPROTECTOR
98 select HAVE_SYSCALL_TRACEPOINTS
100 select HAVE_VIRT_CPU_ACCOUNTING_GEN
101 select IRQ_FORCED_THREADING
102 select MODULES_USE_ELF_REL
103 select NEED_DMA_MAP_STATE
105 select OF_EARLY_FLATTREE if OF
106 select OF_RESERVED_MEM if OF
108 select OLD_SIGSUSPEND3
109 select PERF_USE_VMALLOC
112 select SYS_SUPPORTS_APM_EMULATION
113 # Above selects are sorted alphabetically; please add new ones
114 # according to that. Thanks.
116 The ARM series is a line of low-power-consumption RISC chip designs
117 licensed by ARM Ltd and targeted at embedded applications and
118 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
119 manufactured, but legacy ARM-based PC hardware remains popular in
120 Europe. There is an ARM Linux project with a web page at
121 <http://www.arm.linux.org.uk/>.
123 config ARM_HAS_SG_CHAIN
124 select ARCH_HAS_SG_CHAIN
127 config ARM_DMA_USE_IOMMU
129 select ARM_HAS_SG_CHAIN
130 select NEED_SG_DMA_LENGTH
134 config ARM_DMA_IOMMU_ALIGNMENT
135 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
139 DMA mapping framework by default aligns all buffers to the smallest
140 PAGE_SIZE order which is greater than or equal to the requested buffer
141 size. This works well for buffers up to a few hundreds kilobytes, but
142 for larger buffers it just a waste of address space. Drivers which has
143 relatively small addressing window (like 64Mib) might run out of
144 virtual space with just a few allocations.
146 With this parameter you can specify the maximum PAGE_SIZE order for
147 DMA IOMMU buffers. Larger buffers will be aligned only to this
148 specified order. The order is expressed as a power of two multiplied
153 config MIGHT_HAVE_PCI
156 config SYS_SUPPORTS_APM_EMULATION
161 select GENERIC_ALLOCATOR
172 The Extended Industry Standard Architecture (EISA) bus was
173 developed as an open alternative to the IBM MicroChannel bus.
175 The EISA bus provided some of the features of the IBM MicroChannel
176 bus while maintaining backward compatibility with cards made for
177 the older ISA bus. The EISA bus saw limited use between 1988 and
178 1995 when it was made obsolete by the PCI bus.
180 Say Y here if you are building a kernel for an EISA-based machine.
187 config STACKTRACE_SUPPORT
191 config LOCKDEP_SUPPORT
195 config TRACE_IRQFLAGS_SUPPORT
199 config RWSEM_XCHGADD_ALGORITHM
203 config ARCH_HAS_ILOG2_U32
206 config ARCH_HAS_ILOG2_U64
209 config ARCH_HAS_BANDGAP
212 config FIX_EARLYCON_MEM
215 config GENERIC_HWEIGHT
219 config GENERIC_CALIBRATE_DELAY
223 config ARCH_MAY_HAVE_PC_FDC
229 config ARCH_SUPPORTS_UPROBES
232 config ARCH_HAS_DMA_SET_COHERENT_MASK
235 config GENERIC_ISA_DMA
241 config NEED_RET_TO_USER
247 config ARM_PATCH_PHYS_VIRT
248 bool "Patch physical to virtual translations at runtime" if EMBEDDED
250 depends on !XIP_KERNEL && MMU
252 Patch phys-to-virt and virt-to-phys translation functions at
253 boot and module load time according to the position of the
254 kernel in system memory.
256 This can only be used with non-XIP MMU kernels where the base
257 of physical memory is at a 16MB boundary.
259 Only disable this option if you know that you do not require
260 this feature (eg, building a kernel for a single machine) and
261 you need to shrink the kernel to the minimal size.
263 config NEED_MACH_IO_H
266 Select this when mach/io.h is required to provide special
267 definitions for this platform. The need for mach/io.h should
268 be avoided when possible.
270 config NEED_MACH_MEMORY_H
273 Select this when mach/memory.h is required to provide special
274 definitions for this platform. The need for mach/memory.h should
275 be avoided when possible.
278 hex "Physical address of main memory" if MMU
279 depends on !ARM_PATCH_PHYS_VIRT
280 default DRAM_BASE if !MMU
281 default 0x00000000 if ARCH_EBSA110 || \
287 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
288 default 0x20000000 if ARCH_S5PV210
289 default 0xc0000000 if ARCH_SA1100
291 Please provide the physical address corresponding to the
292 location of main memory in your system.
298 config PGTABLE_LEVELS
300 default 3 if ARM_LPAE
306 bool "MMU-based Paged Memory Management Support"
309 Select if you want MMU-based virtualised addressing space
310 support by paged memory management. If unsure, say 'Y'.
312 config ARCH_MMAP_RND_BITS_MIN
315 config ARCH_MMAP_RND_BITS_MAX
316 default 14 if PAGE_OFFSET=0x40000000
317 default 15 if PAGE_OFFSET=0x80000000
321 # The "ARM system type" choice list is ordered alphabetically by option
322 # text. Please add new entries in the option alphabetic order.
325 prompt "ARM system type"
326 default ARM_SINGLE_ARMV7M if !MMU
327 default ARCH_MULTIPLATFORM if MMU
329 config ARCH_MULTIPLATFORM
330 bool "Allow multiple platforms to be selected"
332 select ARM_HAS_SG_CHAIN
333 select ARM_PATCH_PHYS_VIRT
337 select GENERIC_CLOCKEVENTS
338 select GENERIC_IRQ_MULTI_HANDLER
339 select MIGHT_HAVE_PCI
340 select PCI_DOMAINS if PCI
344 config ARM_SINGLE_ARMV7M
345 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
352 select GENERIC_CLOCKEVENTS
359 select ARCH_USES_GETTIMEOFFSET
362 select NEED_MACH_IO_H
363 select NEED_MACH_MEMORY_H
366 This is an evaluation board for the StrongARM processor available
367 from Digital. It has limited hardware on-board, including an
368 Ethernet interface, two PCMCIA sockets, two serial ports and a
373 select ARCH_SPARSEMEM_ENABLE
375 imply ARM_PATCH_PHYS_VIRT
381 select GENERIC_CLOCKEVENTS
384 This enables support for the Cirrus EP93xx series of CPUs.
386 config ARCH_FOOTBRIDGE
390 select GENERIC_CLOCKEVENTS
392 select NEED_MACH_IO_H if !MMU
393 select NEED_MACH_MEMORY_H
395 Support for systems based on the DC21285 companion chip
396 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
399 bool "Hilscher NetX based"
403 select GENERIC_CLOCKEVENTS
405 This enables support for systems based on the Hilscher NetX Soc
411 select NEED_MACH_MEMORY_H
412 select NEED_RET_TO_USER
418 Support for Intel's IOP13XX (XScale) family of processors.
426 select NEED_RET_TO_USER
430 Support for Intel's 80219 and IOP32X (XScale) family of
439 select NEED_RET_TO_USER
443 Support for Intel's IOP33X (XScale) family of processors.
448 select ARCH_HAS_DMA_SET_COHERENT_MASK
449 select ARCH_SUPPORTS_BIG_ENDIAN
452 select DMABOUNCE if PCI
453 select GENERIC_CLOCKEVENTS
455 select MIGHT_HAVE_PCI
456 select NEED_MACH_IO_H
457 select USB_EHCI_BIG_ENDIAN_DESC
458 select USB_EHCI_BIG_ENDIAN_MMIO
460 Support for Intel's IXP4XX (XScale) family of processors.
465 select GENERIC_CLOCKEVENTS
466 select GENERIC_IRQ_MULTI_HANDLER
468 select MIGHT_HAVE_PCI
472 select PLAT_ORION_LEGACY
474 select PM_GENERIC_DOMAINS if PM
476 Support for the Marvell Dove SoC 88AP510
479 bool "Micrel/Kendin KS8695"
482 select GENERIC_CLOCKEVENTS
484 select NEED_MACH_MEMORY_H
486 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
487 System-on-Chip devices.
490 bool "Nuvoton W90X900 CPU"
494 select GENERIC_CLOCKEVENTS
497 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
498 At present, the w90x900 has been renamed nuc900, regarding
499 the ARM series product line, you can login the following
500 link address to know more.
502 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
503 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
509 select CLKSRC_LPC32XX
512 select GENERIC_CLOCKEVENTS
513 select GENERIC_IRQ_MULTI_HANDLER
518 Support for the NXP LPC32XX family of processors
521 bool "PXA2xx/PXA3xx-based"
524 select ARM_CPU_SUSPEND if PM
531 select CPU_XSCALE if !CPU_XSC3
532 select GENERIC_CLOCKEVENTS
533 select GENERIC_IRQ_MULTI_HANDLER
541 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
547 select ARCH_MAY_HAVE_PC_FDC
548 select ARCH_SPARSEMEM_ENABLE
549 select ARCH_USES_GETTIMEOFFSET
553 select HAVE_PATA_PLATFORM
555 select NEED_MACH_IO_H
556 select NEED_MACH_MEMORY_H
559 On the Acorn Risc-PC, Linux can support the internal IDE disk and
560 CD-ROM interface, serial and parallel port, and the floppy drive.
565 select ARCH_SPARSEMEM_ENABLE
569 select TIMER_OF if OF
572 select GENERIC_CLOCKEVENTS
573 select GENERIC_IRQ_MULTI_HANDLER
578 select NEED_MACH_MEMORY_H
581 Support for StrongARM 11x0 based boards.
584 bool "Samsung S3C24XX SoCs"
587 select CLKSRC_SAMSUNG_PWM
588 select GENERIC_CLOCKEVENTS
591 select GENERIC_IRQ_MULTI_HANDLER
592 select HAVE_S3C2410_I2C if I2C
593 select HAVE_S3C2410_WATCHDOG if WATCHDOG
594 select HAVE_S3C_RTC if RTC_CLASS
595 select NEED_MACH_IO_H
596 select S3C2410_WATCHDOG
601 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
602 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
603 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
604 Samsung SMDK2410 development board (and derivatives).
608 select ARCH_HAS_HOLES_MEMORYMODEL
611 select GENERIC_ALLOCATOR
612 select GENERIC_CLOCKEVENTS
613 select GENERIC_IRQ_CHIP
616 select PM_GENERIC_DOMAINS if PM
617 select PM_GENERIC_DOMAINS_OF if PM && OF
619 select RESET_CONTROLLER
623 Support for TI's DaVinci platform.
628 select ARCH_HAS_HOLES_MEMORYMODEL
632 select GENERIC_CLOCKEVENTS
633 select GENERIC_IRQ_CHIP
634 select GENERIC_IRQ_MULTI_HANDLER
638 select NEED_MACH_IO_H if PCCARD
639 select NEED_MACH_MEMORY_H
642 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
646 menu "Multiple platform selection"
647 depends on ARCH_MULTIPLATFORM
649 comment "CPU Core family selection"
652 bool "ARMv4 based platforms (FA526)"
653 depends on !ARCH_MULTI_V6_V7
654 select ARCH_MULTI_V4_V5
657 config ARCH_MULTI_V4T
658 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
659 depends on !ARCH_MULTI_V6_V7
660 select ARCH_MULTI_V4_V5
661 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
662 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
663 CPU_ARM925T || CPU_ARM940T)
666 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
667 depends on !ARCH_MULTI_V6_V7
668 select ARCH_MULTI_V4_V5
669 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
670 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
671 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
673 config ARCH_MULTI_V4_V5
677 bool "ARMv6 based platforms (ARM11)"
678 select ARCH_MULTI_V6_V7
682 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
684 select ARCH_MULTI_V6_V7
688 config ARCH_MULTI_V6_V7
690 select MIGHT_HAVE_CACHE_L2X0
692 config ARCH_MULTI_CPU_AUTO
693 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
699 bool "Dummy Virtual Machine"
700 depends on ARCH_MULTI_V7
703 select ARM_GIC_V2M if PCI
705 select ARM_GIC_V3_ITS if PCI
707 select HAVE_ARM_ARCH_TIMER
710 # This is sorted alphabetically by mach-* pathname. However, plat-*
711 # Kconfigs may be included either alphabetically (according to the
712 # plat- suffix) or along side the corresponding mach-* source.
714 source "arch/arm/mach-actions/Kconfig"
716 source "arch/arm/mach-alpine/Kconfig"
718 source "arch/arm/mach-artpec/Kconfig"
720 source "arch/arm/mach-asm9260/Kconfig"
722 source "arch/arm/mach-aspeed/Kconfig"
724 source "arch/arm/mach-at91/Kconfig"
726 source "arch/arm/mach-axxia/Kconfig"
728 source "arch/arm/mach-bcm/Kconfig"
730 source "arch/arm/mach-berlin/Kconfig"
732 source "arch/arm/mach-clps711x/Kconfig"
734 source "arch/arm/mach-cns3xxx/Kconfig"
736 source "arch/arm/mach-davinci/Kconfig"
738 source "arch/arm/mach-digicolor/Kconfig"
740 source "arch/arm/mach-dove/Kconfig"
742 source "arch/arm/mach-ep93xx/Kconfig"
744 source "arch/arm/mach-exynos/Kconfig"
745 source "arch/arm/plat-samsung/Kconfig"
747 source "arch/arm/mach-footbridge/Kconfig"
749 source "arch/arm/mach-gemini/Kconfig"
751 source "arch/arm/mach-highbank/Kconfig"
753 source "arch/arm/mach-hisi/Kconfig"
755 source "arch/arm/mach-imx/Kconfig"
757 source "arch/arm/mach-integrator/Kconfig"
759 source "arch/arm/mach-iop13xx/Kconfig"
761 source "arch/arm/mach-iop32x/Kconfig"
763 source "arch/arm/mach-iop33x/Kconfig"
765 source "arch/arm/mach-ixp4xx/Kconfig"
767 source "arch/arm/mach-keystone/Kconfig"
769 source "arch/arm/mach-ks8695/Kconfig"
771 source "arch/arm/mach-mediatek/Kconfig"
773 source "arch/arm/mach-meson/Kconfig"
775 source "arch/arm/mach-mmp/Kconfig"
777 source "arch/arm/mach-moxart/Kconfig"
779 source "arch/arm/mach-mv78xx0/Kconfig"
781 source "arch/arm/mach-mvebu/Kconfig"
783 source "arch/arm/mach-mxs/Kconfig"
785 source "arch/arm/mach-netx/Kconfig"
787 source "arch/arm/mach-nomadik/Kconfig"
789 source "arch/arm/mach-npcm/Kconfig"
791 source "arch/arm/mach-nspire/Kconfig"
793 source "arch/arm/plat-omap/Kconfig"
795 source "arch/arm/mach-omap1/Kconfig"
797 source "arch/arm/mach-omap2/Kconfig"
799 source "arch/arm/mach-orion5x/Kconfig"
801 source "arch/arm/mach-oxnas/Kconfig"
803 source "arch/arm/mach-picoxcell/Kconfig"
805 source "arch/arm/mach-prima2/Kconfig"
807 source "arch/arm/mach-pxa/Kconfig"
808 source "arch/arm/plat-pxa/Kconfig"
810 source "arch/arm/mach-qcom/Kconfig"
812 source "arch/arm/mach-realview/Kconfig"
814 source "arch/arm/mach-rockchip/Kconfig"
816 source "arch/arm/mach-s3c24xx/Kconfig"
818 source "arch/arm/mach-s3c64xx/Kconfig"
820 source "arch/arm/mach-s5pv210/Kconfig"
822 source "arch/arm/mach-sa1100/Kconfig"
824 source "arch/arm/mach-shmobile/Kconfig"
826 source "arch/arm/mach-socfpga/Kconfig"
828 source "arch/arm/mach-spear/Kconfig"
830 source "arch/arm/mach-sti/Kconfig"
832 source "arch/arm/mach-stm32/Kconfig"
834 source "arch/arm/mach-sunxi/Kconfig"
836 source "arch/arm/mach-tango/Kconfig"
838 source "arch/arm/mach-tegra/Kconfig"
840 source "arch/arm/mach-u300/Kconfig"
842 source "arch/arm/mach-uniphier/Kconfig"
844 source "arch/arm/mach-ux500/Kconfig"
846 source "arch/arm/mach-versatile/Kconfig"
848 source "arch/arm/mach-vexpress/Kconfig"
849 source "arch/arm/plat-versatile/Kconfig"
851 source "arch/arm/mach-vt8500/Kconfig"
853 source "arch/arm/mach-w90x900/Kconfig"
855 source "arch/arm/mach-zx/Kconfig"
857 source "arch/arm/mach-zynq/Kconfig"
859 # ARMv7-M architecture
861 bool "Energy Micro efm32"
862 depends on ARM_SINGLE_ARMV7M
865 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
869 bool "NXP LPC18xx/LPC43xx"
870 depends on ARM_SINGLE_ARMV7M
871 select ARCH_HAS_RESET_CONTROLLER
873 select CLKSRC_LPC32XX
876 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
877 high performance microcontrollers.
880 bool "ARM MPS2 platform"
881 depends on ARM_SINGLE_ARMV7M
885 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
886 with a range of available cores like Cortex-M3/M4/M7.
888 Please, note that depends which Application Note is used memory map
889 for the platform may vary, so adjustment of RAM base might be needed.
891 # Definitions to make life easier
897 select GENERIC_CLOCKEVENTS
903 select GENERIC_IRQ_CHIP
906 config PLAT_ORION_LEGACY
913 config PLAT_VERSATILE
916 source "arch/arm/firmware/Kconfig"
918 source arch/arm/mm/Kconfig
921 bool "Enable iWMMXt support"
922 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
923 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
925 Enable support for iWMMXt context switching at run time if
926 running on a CPU that supports it.
929 source "arch/arm/Kconfig-nommu"
932 config PJ4B_ERRATA_4742
933 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
934 depends on CPU_PJ4B && MACH_ARMADA_370
937 When coming out of either a Wait for Interrupt (WFI) or a Wait for
938 Event (WFE) IDLE states, a specific timing sensitivity exists between
939 the retiring WFI/WFE instructions and the newly issued subsequent
940 instructions. This sensitivity can result in a CPU hang scenario.
942 The software must insert either a Data Synchronization Barrier (DSB)
943 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
946 config ARM_ERRATA_326103
947 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
950 Executing a SWP instruction to read-only memory does not set bit 11
951 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
952 treat the access as a read, preventing a COW from occurring and
953 causing the faulting task to livelock.
955 config ARM_ERRATA_411920
956 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
957 depends on CPU_V6 || CPU_V6K
959 Invalidation of the Instruction Cache operation can
960 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
961 It does not affect the MPCore. This option enables the ARM Ltd.
962 recommended workaround.
964 config ARM_ERRATA_430973
965 bool "ARM errata: Stale prediction on replaced interworking branch"
968 This option enables the workaround for the 430973 Cortex-A8
969 r1p* erratum. If a code sequence containing an ARM/Thumb
970 interworking branch is replaced with another code sequence at the
971 same virtual address, whether due to self-modifying code or virtual
972 to physical address re-mapping, Cortex-A8 does not recover from the
973 stale interworking branch prediction. This results in Cortex-A8
974 executing the new code sequence in the incorrect ARM or Thumb state.
975 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
976 and also flushes the branch target cache at every context switch.
977 Note that setting specific bits in the ACTLR register may not be
978 available in non-secure mode.
980 config ARM_ERRATA_458693
981 bool "ARM errata: Processor deadlock when a false hazard is created"
983 depends on !ARCH_MULTIPLATFORM
985 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
986 erratum. For very specific sequences of memory operations, it is
987 possible for a hazard condition intended for a cache line to instead
988 be incorrectly associated with a different cache line. This false
989 hazard might then cause a processor deadlock. The workaround enables
990 the L1 caching of the NEON accesses and disables the PLD instruction
991 in the ACTLR register. Note that setting specific bits in the ACTLR
992 register may not be available in non-secure mode.
994 config ARM_ERRATA_460075
995 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
997 depends on !ARCH_MULTIPLATFORM
999 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1000 erratum. Any asynchronous access to the L2 cache may encounter a
1001 situation in which recent store transactions to the L2 cache are lost
1002 and overwritten with stale memory contents from external memory. The
1003 workaround disables the write-allocate mode for the L2 cache via the
1004 ACTLR register. Note that setting specific bits in the ACTLR register
1005 may not be available in non-secure mode.
1007 config ARM_ERRATA_742230
1008 bool "ARM errata: DMB operation may be faulty"
1009 depends on CPU_V7 && SMP
1010 depends on !ARCH_MULTIPLATFORM
1012 This option enables the workaround for the 742230 Cortex-A9
1013 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1014 between two write operations may not ensure the correct visibility
1015 ordering of the two writes. This workaround sets a specific bit in
1016 the diagnostic register of the Cortex-A9 which causes the DMB
1017 instruction to behave as a DSB, ensuring the correct behaviour of
1020 config ARM_ERRATA_742231
1021 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1022 depends on CPU_V7 && SMP
1023 depends on !ARCH_MULTIPLATFORM
1025 This option enables the workaround for the 742231 Cortex-A9
1026 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1027 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1028 accessing some data located in the same cache line, may get corrupted
1029 data due to bad handling of the address hazard when the line gets
1030 replaced from one of the CPUs at the same time as another CPU is
1031 accessing it. This workaround sets specific bits in the diagnostic
1032 register of the Cortex-A9 which reduces the linefill issuing
1033 capabilities of the processor.
1035 config ARM_ERRATA_643719
1036 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1037 depends on CPU_V7 && SMP
1040 This option enables the workaround for the 643719 Cortex-A9 (prior to
1041 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1042 register returns zero when it should return one. The workaround
1043 corrects this value, ensuring cache maintenance operations which use
1044 it behave as intended and avoiding data corruption.
1046 config ARM_ERRATA_720789
1047 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1050 This option enables the workaround for the 720789 Cortex-A9 (prior to
1051 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1052 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1053 As a consequence of this erratum, some TLB entries which should be
1054 invalidated are not, resulting in an incoherency in the system page
1055 tables. The workaround changes the TLB flushing routines to invalidate
1056 entries regardless of the ASID.
1058 config ARM_ERRATA_743622
1059 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1061 depends on !ARCH_MULTIPLATFORM
1063 This option enables the workaround for the 743622 Cortex-A9
1064 (r2p*) erratum. Under very rare conditions, a faulty
1065 optimisation in the Cortex-A9 Store Buffer may lead to data
1066 corruption. This workaround sets a specific bit in the diagnostic
1067 register of the Cortex-A9 which disables the Store Buffer
1068 optimisation, preventing the defect from occurring. This has no
1069 visible impact on the overall performance or power consumption of the
1072 config ARM_ERRATA_751472
1073 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1075 depends on !ARCH_MULTIPLATFORM
1077 This option enables the workaround for the 751472 Cortex-A9 (prior
1078 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1079 completion of a following broadcasted operation if the second
1080 operation is received by a CPU before the ICIALLUIS has completed,
1081 potentially leading to corrupted entries in the cache or TLB.
1083 config ARM_ERRATA_754322
1084 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1087 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1088 r3p*) erratum. A speculative memory access may cause a page table walk
1089 which starts prior to an ASID switch but completes afterwards. This
1090 can populate the micro-TLB with a stale entry which may be hit with
1091 the new ASID. This workaround places two dsb instructions in the mm
1092 switching code so that no page table walks can cross the ASID switch.
1094 config ARM_ERRATA_754327
1095 bool "ARM errata: no automatic Store Buffer drain"
1096 depends on CPU_V7 && SMP
1098 This option enables the workaround for the 754327 Cortex-A9 (prior to
1099 r2p0) erratum. The Store Buffer does not have any automatic draining
1100 mechanism and therefore a livelock may occur if an external agent
1101 continuously polls a memory location waiting to observe an update.
1102 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1103 written polling loops from denying visibility of updates to memory.
1105 config ARM_ERRATA_364296
1106 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1109 This options enables the workaround for the 364296 ARM1136
1110 r0p2 erratum (possible cache data corruption with
1111 hit-under-miss enabled). It sets the undocumented bit 31 in
1112 the auxiliary control register and the FI bit in the control
1113 register, thus disabling hit-under-miss without putting the
1114 processor into full low interrupt latency mode. ARM11MPCore
1117 config ARM_ERRATA_764369
1118 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1119 depends on CPU_V7 && SMP
1121 This option enables the workaround for erratum 764369
1122 affecting Cortex-A9 MPCore with two or more processors (all
1123 current revisions). Under certain timing circumstances, a data
1124 cache line maintenance operation by MVA targeting an Inner
1125 Shareable memory region may fail to proceed up to either the
1126 Point of Coherency or to the Point of Unification of the
1127 system. This workaround adds a DSB instruction before the
1128 relevant cache maintenance functions and sets a specific bit
1129 in the diagnostic control register of the SCU.
1131 config ARM_ERRATA_775420
1132 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1135 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1136 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1137 operation aborts with MMU exception, it might cause the processor
1138 to deadlock. This workaround puts DSB before executing ISB if
1139 an abort may occur on cache maintenance.
1141 config ARM_ERRATA_798181
1142 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1143 depends on CPU_V7 && SMP
1145 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1146 adequately shooting down all use of the old entries. This
1147 option enables the Linux kernel workaround for this erratum
1148 which sends an IPI to the CPUs that are running the same ASID
1149 as the one being invalidated.
1151 config ARM_ERRATA_773022
1152 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1155 This option enables the workaround for the 773022 Cortex-A15
1156 (up to r0p4) erratum. In certain rare sequences of code, the
1157 loop buffer may deliver incorrect instructions. This
1158 workaround disables the loop buffer to avoid the erratum.
1160 config ARM_ERRATA_818325_852422
1161 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1164 This option enables the workaround for:
1165 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1166 instruction might deadlock. Fixed in r0p1.
1167 - Cortex-A12 852422: Execution of a sequence of instructions might
1168 lead to either a data corruption or a CPU deadlock. Not fixed in
1169 any Cortex-A12 cores yet.
1170 This workaround for all both errata involves setting bit[12] of the
1171 Feature Register. This bit disables an optimisation applied to a
1172 sequence of 2 instructions that use opposing condition codes.
1174 config ARM_ERRATA_821420
1175 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1178 This option enables the workaround for the 821420 Cortex-A12
1179 (all revs) erratum. In very rare timing conditions, a sequence
1180 of VMOV to Core registers instructions, for which the second
1181 one is in the shadow of a branch or abort, can lead to a
1182 deadlock when the VMOV instructions are issued out-of-order.
1184 config ARM_ERRATA_825619
1185 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1188 This option enables the workaround for the 825619 Cortex-A12
1189 (all revs) erratum. Within rare timing constraints, executing a
1190 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1191 and Device/Strongly-Ordered loads and stores might cause deadlock
1193 config ARM_ERRATA_852421
1194 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1197 This option enables the workaround for the 852421 Cortex-A17
1198 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1199 execution of a DMB ST instruction might fail to properly order
1200 stores from GroupA and stores from GroupB.
1202 config ARM_ERRATA_852423
1203 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1206 This option enables the workaround for:
1207 - Cortex-A17 852423: Execution of a sequence of instructions might
1208 lead to either a data corruption or a CPU deadlock. Not fixed in
1209 any Cortex-A17 cores yet.
1210 This is identical to Cortex-A12 erratum 852422. It is a separate
1211 config option from the A12 erratum due to the way errata are checked
1216 source "arch/arm/common/Kconfig"
1223 Find out whether you have ISA slots on your motherboard. ISA is the
1224 name of a bus system, i.e. the way the CPU talks to the other stuff
1225 inside your box. Other bus systems are PCI, EISA, MicroChannel
1226 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1227 newer boards don't support it. If you have ISA, say Y, otherwise N.
1229 # Select ISA DMA controller support
1234 # Select ISA DMA interface
1239 bool "PCI support" if MIGHT_HAVE_PCI
1241 Find out whether you have a PCI motherboard. PCI is the name of a
1242 bus system, i.e. the way the CPU talks to the other stuff inside
1243 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1244 VESA. If you have PCI, say Y, otherwise N.
1247 bool "Support for multiple PCI domains"
1250 Enable PCI domains kernel management. Say Y if your machine
1251 has a PCI bus hierarchy that requires more than one PCI
1252 domain (aka segment) to be correctly managed. Say N otherwise.
1254 If you don't know what to do here, say N.
1256 config PCI_DOMAINS_GENERIC
1257 def_bool PCI_DOMAINS
1259 config PCI_NANOENGINE
1260 bool "BSE nanoEngine PCI support"
1261 depends on SA1100_NANOENGINE
1263 Enable PCI on the BSE nanoEngine board.
1268 config PCI_HOST_ITE8152
1270 depends on PCI && MACH_ARMCORE
1274 source "drivers/pci/Kconfig"
1276 source "drivers/pcmcia/Kconfig"
1280 menu "Kernel Features"
1285 This option should be selected by machines which have an SMP-
1288 The only effect of this option is to make the SMP-related
1289 options available to the user for configuration.
1292 bool "Symmetric Multi-Processing"
1293 depends on CPU_V6K || CPU_V7
1294 depends on GENERIC_CLOCKEVENTS
1296 depends on MMU || ARM_MPU
1299 This enables support for systems with more than one CPU. If you have
1300 a system with only one CPU, say N. If you have a system with more
1301 than one CPU, say Y.
1303 If you say N here, the kernel will run on uni- and multiprocessor
1304 machines, but will use only one CPU of a multiprocessor machine. If
1305 you say Y here, the kernel will run on many, but not all,
1306 uniprocessor machines. On a uniprocessor machine, the kernel
1307 will run faster if you say N here.
1309 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1310 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
1311 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1313 If you don't know what to do here, say N.
1316 bool "Allow booting SMP kernel on uniprocessor systems"
1317 depends on SMP && !XIP_KERNEL && MMU
1320 SMP kernels contain instructions which fail on non-SMP processors.
1321 Enabling this option allows the kernel to modify itself to make
1322 these instructions safe. Disabling it allows about 1K of space
1325 If you don't know what to do here, say Y.
1327 config ARM_CPU_TOPOLOGY
1328 bool "Support cpu topology definition"
1329 depends on SMP && CPU_V7
1332 Support ARM cpu topology definition. The MPIDR register defines
1333 affinity between processors which is then used to describe the cpu
1334 topology of an ARM System.
1337 bool "Multi-core scheduler support"
1338 depends on ARM_CPU_TOPOLOGY
1340 Multi-core scheduler support improves the CPU scheduler's decision
1341 making when dealing with multi-core CPU chips at a cost of slightly
1342 increased overhead in some places. If unsure say N here.
1345 bool "SMT scheduler support"
1346 depends on ARM_CPU_TOPOLOGY
1348 Improves the CPU scheduler's decision making when dealing with
1349 MultiThreading at a cost of slightly increased overhead in some
1350 places. If unsure say N here.
1355 This option enables support for the ARM system coherency unit
1357 config HAVE_ARM_ARCH_TIMER
1358 bool "Architected timer support"
1360 select ARM_ARCH_TIMER
1361 select GENERIC_CLOCKEVENTS
1363 This option enables support for the ARM architected timer
1367 select TIMER_OF if OF
1369 This options enables support for the ARM timer and watchdog unit
1372 bool "Multi-Cluster Power Management"
1373 depends on CPU_V7 && SMP
1375 This option provides the common power management infrastructure
1376 for (multi-)cluster based systems, such as big.LITTLE based
1379 config MCPM_QUAD_CLUSTER
1383 To avoid wasting resources unnecessarily, MCPM only supports up
1384 to 2 clusters by default.
1385 Platforms with 3 or 4 clusters that use MCPM must select this
1386 option to allow the additional clusters to be managed.
1389 bool "big.LITTLE support (Experimental)"
1390 depends on CPU_V7 && SMP
1393 This option enables support selections for the big.LITTLE
1394 system architecture.
1397 bool "big.LITTLE switcher support"
1398 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1401 The big.LITTLE "switcher" provides the core functionality to
1402 transparently handle transition between a cluster of A15's
1403 and a cluster of A7's in a big.LITTLE system.
1405 config BL_SWITCHER_DUMMY_IF
1406 tristate "Simple big.LITTLE switcher user interface"
1407 depends on BL_SWITCHER && DEBUG_KERNEL
1409 This is a simple and dummy char dev interface to control
1410 the big.LITTLE switcher core code. It is meant for
1411 debugging purposes only.
1414 prompt "Memory split"
1418 Select the desired split between kernel and user memory.
1420 If you are not absolutely sure what you are doing, leave this
1424 bool "3G/1G user/kernel split"
1425 config VMSPLIT_3G_OPT
1426 depends on !ARM_LPAE
1427 bool "3G/1G user/kernel split (for full 1G low memory)"
1429 bool "2G/2G user/kernel split"
1431 bool "1G/3G user/kernel split"
1436 default PHYS_OFFSET if !MMU
1437 default 0x40000000 if VMSPLIT_1G
1438 default 0x80000000 if VMSPLIT_2G
1439 default 0xB0000000 if VMSPLIT_3G_OPT
1443 int "Maximum number of CPUs (2-32)"
1449 bool "Support for hot-pluggable CPUs"
1451 select GENERIC_IRQ_MIGRATION
1453 Say Y here to experiment with turning CPUs off and on. CPUs
1454 can be controlled through /sys/devices/system/cpu.
1457 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1458 depends on HAVE_ARM_SMCCC
1461 Say Y here if you want Linux to communicate with system firmware
1462 implementing the PSCI specification for CPU-centric power
1463 management operations described in ARM document number ARM DEN
1464 0022A ("Power State Coordination Interface System Software on
1467 # The GPIO number here must be sorted by descending number. In case of
1468 # a multiplatform kernel, we just want the highest value required by the
1469 # selected platforms.
1472 default 2048 if ARCH_SOCFPGA
1473 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1475 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1476 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1477 default 416 if ARCH_SUNXI
1478 default 392 if ARCH_U8500
1479 default 352 if ARCH_VT8500
1480 default 288 if ARCH_ROCKCHIP
1481 default 264 if MACH_H4700
1484 Maximum number of GPIOs in the system.
1486 If unsure, leave the default value.
1490 default 200 if ARCH_EBSA110
1491 default 128 if SOC_AT91RM9200
1495 depends on HZ_FIXED = 0
1496 prompt "Timer frequency"
1520 default HZ_FIXED if HZ_FIXED != 0
1521 default 100 if HZ_100
1522 default 200 if HZ_200
1523 default 250 if HZ_250
1524 default 300 if HZ_300
1525 default 500 if HZ_500
1529 def_bool HIGH_RES_TIMERS
1531 config THUMB2_KERNEL
1532 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1533 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1534 default y if CPU_THUMBONLY
1537 By enabling this option, the kernel will be compiled in
1542 config THUMB2_AVOID_R_ARM_THM_JUMP11
1543 bool "Work around buggy Thumb-2 short branch relocations in gas"
1544 depends on THUMB2_KERNEL && MODULES
1547 Various binutils versions can resolve Thumb-2 branches to
1548 locally-defined, preemptible global symbols as short-range "b.n"
1549 branch instructions.
1551 This is a problem, because there's no guarantee the final
1552 destination of the symbol, or any candidate locations for a
1553 trampoline, are within range of the branch. For this reason, the
1554 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1555 relocation in modules at all, and it makes little sense to add
1558 The symptom is that the kernel fails with an "unsupported
1559 relocation" error when loading some modules.
1561 Until fixed tools are available, passing
1562 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1563 code which hits this problem, at the cost of a bit of extra runtime
1564 stack usage in some cases.
1566 The problem is described in more detail at:
1567 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1569 Only Thumb-2 kernels are affected.
1571 Unless you are sure your tools don't have this problem, say Y.
1573 config ARM_PATCH_IDIV
1574 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1575 depends on CPU_32v7 && !XIP_KERNEL
1578 The ARM compiler inserts calls to __aeabi_idiv() and
1579 __aeabi_uidiv() when it needs to perform division on signed
1580 and unsigned integers. Some v7 CPUs have support for the sdiv
1581 and udiv instructions that can be used to implement those
1584 Enabling this option allows the kernel to modify itself to
1585 replace the first two instructions of these library functions
1586 with the sdiv or udiv plus "bx lr" instructions when the CPU
1587 it is running on supports them. Typically this will be faster
1588 and less power intensive than running the original library
1589 code to do integer division.
1592 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1593 !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1594 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1596 This option allows for the kernel to be compiled using the latest
1597 ARM ABI (aka EABI). This is only useful if you are using a user
1598 space environment that is also compiled with EABI.
1600 Since there are major incompatibilities between the legacy ABI and
1601 EABI, especially with regard to structure member alignment, this
1602 option also changes the kernel syscall calling convention to
1603 disambiguate both ABIs and allow for backward compatibility support
1604 (selected with CONFIG_OABI_COMPAT).
1606 To use this you need GCC version 4.0.0 or later.
1609 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1610 depends on AEABI && !THUMB2_KERNEL
1612 This option preserves the old syscall interface along with the
1613 new (ARM EABI) one. It also provides a compatibility layer to
1614 intercept syscalls that have structure arguments which layout
1615 in memory differs between the legacy ABI and the new ARM EABI
1616 (only for non "thumb" binaries). This option adds a tiny
1617 overhead to all syscalls and produces a slightly larger kernel.
1619 The seccomp filter system will not be available when this is
1620 selected, since there is no way yet to sensibly distinguish
1621 between calling conventions during filtering.
1623 If you know you'll be using only pure EABI user space then you
1624 can say N here. If this option is not selected and you attempt
1625 to execute a legacy ABI binary then the result will be
1626 UNPREDICTABLE (in fact it can be predicted that it won't work
1627 at all). If in doubt say N.
1629 config ARCH_HAS_HOLES_MEMORYMODEL
1632 config ARCH_SPARSEMEM_ENABLE
1635 config ARCH_SPARSEMEM_DEFAULT
1636 def_bool ARCH_SPARSEMEM_ENABLE
1638 config ARCH_SELECT_MEMORY_MODEL
1639 def_bool ARCH_SPARSEMEM_ENABLE
1641 config HAVE_ARCH_PFN_VALID
1642 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1644 config HAVE_GENERIC_GUP
1649 bool "High Memory Support"
1652 The address space of ARM processors is only 4 Gigabytes large
1653 and it has to accommodate user address space, kernel address
1654 space as well as some memory mapped IO. That means that, if you
1655 have a large amount of physical memory and/or IO, not all of the
1656 memory can be "permanently mapped" by the kernel. The physical
1657 memory that is not permanently mapped is called "high memory".
1659 Depending on the selected kernel/user memory split, minimum
1660 vmalloc space and actual amount of RAM, you may not need this
1661 option which should result in a slightly faster kernel.
1666 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1670 The VM uses one page of physical memory for each page table.
1671 For systems with a lot of processes, this can use a lot of
1672 precious low memory, eventually leading to low memory being
1673 consumed by page tables. Setting this option will allow
1674 user-space 2nd level page tables to reside in high memory.
1676 config CPU_SW_DOMAIN_PAN
1677 bool "Enable use of CPU domains to implement privileged no-access"
1678 depends on MMU && !ARM_LPAE
1681 Increase kernel security by ensuring that normal kernel accesses
1682 are unable to access userspace addresses. This can help prevent
1683 use-after-free bugs becoming an exploitable privilege escalation
1684 by ensuring that magic values (such as LIST_POISON) will always
1685 fault when dereferenced.
1687 CPUs with low-vector mappings use a best-efforts implementation.
1688 Their lower 1MB needs to remain accessible for the vectors, but
1689 the remainder of userspace will become appropriately inaccessible.
1691 config HW_PERF_EVENTS
1695 config SYS_SUPPORTS_HUGETLBFS
1699 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1703 config ARCH_WANT_GENERAL_HUGETLB
1706 config ARM_MODULE_PLTS
1707 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1711 Allocate PLTs when loading modules so that jumps and calls whose
1712 targets are too far away for their relative offsets to be encoded
1713 in the instructions themselves can be bounced via veneers in the
1714 module's PLT. This allows modules to be allocated in the generic
1715 vmalloc area after the dedicated module memory area has been
1716 exhausted. The modules will use slightly more memory, but after
1717 rounding up to page size, the actual memory footprint is usually
1720 Disabling this is usually safe for small single-platform
1721 configurations. If unsure, say y.
1723 config FORCE_MAX_ZONEORDER
1724 int "Maximum zone order"
1725 default "12" if SOC_AM33XX
1726 default "9" if SA1111 || ARCH_EFM32
1729 The kernel memory allocator divides physically contiguous memory
1730 blocks into "zones", where each zone is a power of two number of
1731 pages. This option selects the largest power of two that the kernel
1732 keeps in the memory allocator. If you need to allocate very large
1733 blocks of physically contiguous memory, then you may need to
1734 increase this value.
1736 This config option is actually maximum order plus one. For example,
1737 a value of 11 means that the largest free memory block is 2^10 pages.
1739 config ALIGNMENT_TRAP
1741 depends on CPU_CP15_MMU
1742 default y if !ARCH_EBSA110
1743 select HAVE_PROC_CPU if PROC_FS
1745 ARM processors cannot fetch/store information which is not
1746 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1747 address divisible by 4. On 32-bit ARM processors, these non-aligned
1748 fetch/store instructions will be emulated in software if you say
1749 here, which has a severe performance impact. This is necessary for
1750 correct operation of some network protocols. With an IP-only
1751 configuration it is safe to say N, otherwise say Y.
1753 config UACCESS_WITH_MEMCPY
1754 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1756 default y if CPU_FEROCEON
1758 Implement faster copy_to_user and clear_user methods for CPU
1759 cores where a 8-word STM instruction give significantly higher
1760 memory write throughput than a sequence of individual 32bit stores.
1762 A possible side effect is a slight increase in scheduling latency
1763 between threads sharing the same address space if they invoke
1764 such copy operations with large buffers.
1766 However, if the CPU data cache is using a write-allocate mode,
1767 this option is unlikely to provide any performance gain.
1771 prompt "Enable seccomp to safely compute untrusted bytecode"
1773 This kernel feature is useful for number crunching applications
1774 that may need to compute untrusted bytecode during their
1775 execution. By using pipes or other transports made available to
1776 the process as file descriptors supporting the read/write
1777 syscalls, it's possible to isolate those applications in
1778 their own address space using seccomp. Once seccomp is
1779 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1780 and the task is only allowed to execute a few safe syscalls
1781 defined by each seccomp mode.
1784 bool "Enable paravirtualization code"
1786 This changes the kernel so it can modify itself when it is run
1787 under a hypervisor, potentially improving performance significantly
1788 over full virtualization.
1790 config PARAVIRT_TIME_ACCOUNTING
1791 bool "Paravirtual steal time accounting"
1795 Select this option to enable fine granularity task steal time
1796 accounting. Time spent executing other tasks in parallel with
1797 the current vCPU is discounted from the vCPU power. To account for
1798 that, there can be a small performance impact.
1800 If in doubt, say N here.
1807 bool "Xen guest support on ARM"
1808 depends on ARM && AEABI && OF
1809 depends on CPU_V7 && !CPU_V6
1810 depends on !GENERIC_ATOMIC64
1812 select ARCH_DMA_ADDR_T_64BIT
1818 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1825 bool "Flattened Device Tree support"
1829 Include support for flattened device tree machine descriptions.
1832 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1835 This is the traditional way of passing data to the kernel at boot
1836 time. If you are solely relying on the flattened device tree (or
1837 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1838 to remove ATAGS support from your kernel binary. If unsure,
1841 config DEPRECATED_PARAM_STRUCT
1842 bool "Provide old way to pass kernel parameters"
1845 This was deprecated in 2001 and announced to live on for 5 years.
1846 Some old boot loaders still use this way.
1848 # Compressed boot loader in ROM. Yes, we really want to ask about
1849 # TEXT and BSS so we preserve their values in the config files.
1850 config ZBOOT_ROM_TEXT
1851 hex "Compressed ROM boot loader base address"
1854 The physical address at which the ROM-able zImage is to be
1855 placed in the target. Platforms which normally make use of
1856 ROM-able zImage formats normally set this to a suitable
1857 value in their defconfig file.
1859 If ZBOOT_ROM is not enabled, this has no effect.
1861 config ZBOOT_ROM_BSS
1862 hex "Compressed ROM boot loader BSS address"
1865 The base address of an area of read/write memory in the target
1866 for the ROM-able zImage which must be available while the
1867 decompressor is running. It must be large enough to hold the
1868 entire decompressed kernel plus an additional 128 KiB.
1869 Platforms which normally make use of ROM-able zImage formats
1870 normally set this to a suitable value in their defconfig file.
1872 If ZBOOT_ROM is not enabled, this has no effect.
1875 bool "Compressed boot loader in ROM/flash"
1876 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1877 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1879 Say Y here if you intend to execute your compressed kernel image
1880 (zImage) directly from ROM or flash. If unsure, say N.
1882 config ARM_APPENDED_DTB
1883 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1886 With this option, the boot code will look for a device tree binary
1887 (DTB) appended to zImage
1888 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1890 This is meant as a backward compatibility convenience for those
1891 systems with a bootloader that can't be upgraded to accommodate
1892 the documented boot protocol using a device tree.
1894 Beware that there is very little in terms of protection against
1895 this option being confused by leftover garbage in memory that might
1896 look like a DTB header after a reboot if no actual DTB is appended
1897 to zImage. Do not leave this option active in a production kernel
1898 if you don't intend to always append a DTB. Proper passing of the
1899 location into r2 of a bootloader provided DTB is always preferable
1902 config ARM_ATAG_DTB_COMPAT
1903 bool "Supplement the appended DTB with traditional ATAG information"
1904 depends on ARM_APPENDED_DTB
1906 Some old bootloaders can't be updated to a DTB capable one, yet
1907 they provide ATAGs with memory configuration, the ramdisk address,
1908 the kernel cmdline string, etc. Such information is dynamically
1909 provided by the bootloader and can't always be stored in a static
1910 DTB. To allow a device tree enabled kernel to be used with such
1911 bootloaders, this option allows zImage to extract the information
1912 from the ATAG list and store it at run time into the appended DTB.
1915 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1916 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1918 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1919 bool "Use bootloader kernel arguments if available"
1921 Uses the command-line options passed by the boot loader instead of
1922 the device tree bootargs property. If the boot loader doesn't provide
1923 any, the device tree bootargs property will be used.
1925 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1926 bool "Extend with bootloader kernel arguments"
1928 The command-line arguments provided by the boot loader will be
1929 appended to the the device tree bootargs property.
1934 string "Default kernel command string"
1937 On some architectures (EBSA110 and CATS), there is currently no way
1938 for the boot loader to pass arguments to the kernel. For these
1939 architectures, you should supply some command-line options at build
1940 time by entering them here. As a minimum, you should specify the
1941 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1944 prompt "Kernel command line type" if CMDLINE != ""
1945 default CMDLINE_FROM_BOOTLOADER
1947 config CMDLINE_FROM_BOOTLOADER
1948 bool "Use bootloader kernel arguments if available"
1950 Uses the command-line options passed by the boot loader. If
1951 the boot loader doesn't provide any, the default kernel command
1952 string provided in CMDLINE will be used.
1954 config CMDLINE_EXTEND
1955 bool "Extend bootloader kernel arguments"
1957 The command-line arguments provided by the boot loader will be
1958 appended to the default kernel command string.
1960 config CMDLINE_FORCE
1961 bool "Always use the default kernel command string"
1963 Always use the default kernel command string, even if the boot
1964 loader passes other arguments to the kernel.
1965 This is useful if you cannot or don't want to change the
1966 command-line options your boot loader passes to the kernel.
1970 bool "Kernel Execute-In-Place from ROM"
1971 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1973 Execute-In-Place allows the kernel to run from non-volatile storage
1974 directly addressable by the CPU, such as NOR flash. This saves RAM
1975 space since the text section of the kernel is not loaded from flash
1976 to RAM. Read-write sections, such as the data section and stack,
1977 are still copied to RAM. The XIP kernel is not compressed since
1978 it has to run directly from flash, so it will take more space to
1979 store it. The flash address used to link the kernel object files,
1980 and for storing it, is configuration dependent. Therefore, if you
1981 say Y here, you must know the proper physical address where to
1982 store the kernel image depending on your own flash memory usage.
1984 Also note that the make target becomes "make xipImage" rather than
1985 "make zImage" or "make Image". The final kernel binary to put in
1986 ROM memory will be arch/arm/boot/xipImage.
1990 config XIP_PHYS_ADDR
1991 hex "XIP Kernel Physical Location"
1992 depends on XIP_KERNEL
1993 default "0x00080000"
1995 This is the physical address in your flash memory the kernel will
1996 be linked for and stored to. This address is dependent on your
1999 config XIP_DEFLATED_DATA
2000 bool "Store kernel .data section compressed in ROM"
2001 depends on XIP_KERNEL
2004 Before the kernel is actually executed, its .data section has to be
2005 copied to RAM from ROM. This option allows for storing that data
2006 in compressed form and decompressed to RAM rather than merely being
2007 copied, saving some precious ROM space. A possible drawback is a
2008 slightly longer boot delay.
2011 bool "Kexec system call (EXPERIMENTAL)"
2012 depends on (!SMP || PM_SLEEP_SMP)
2016 kexec is a system call that implements the ability to shutdown your
2017 current kernel, and to start another kernel. It is like a reboot
2018 but it is independent of the system firmware. And like a reboot
2019 you can start any kernel with it, not just Linux.
2021 It is an ongoing process to be certain the hardware in a machine
2022 is properly shutdown, so do not be surprised if this code does not
2023 initially work for you.
2026 bool "Export atags in procfs"
2027 depends on ATAGS && KEXEC
2030 Should the atags used to boot the kernel be exported in an "atags"
2031 file in procfs. Useful with kexec.
2034 bool "Build kdump crash kernel (EXPERIMENTAL)"
2036 Generate crash dump after being started by kexec. This should
2037 be normally only set in special crash dump kernels which are
2038 loaded in the main kernel with kexec-tools into a specially
2039 reserved region and then later executed after a crash by
2040 kdump/kexec. The crash dump kernel must be compiled to a
2041 memory address not used by the main kernel
2043 For more details see Documentation/kdump/kdump.txt
2045 config AUTO_ZRELADDR
2046 bool "Auto calculation of the decompressed kernel image address"
2048 ZRELADDR is the physical address where the decompressed kernel
2049 image will be placed. If AUTO_ZRELADDR is selected, the address
2050 will be determined at run-time by masking the current IP with
2051 0xf8000000. This assumes the zImage being placed in the first 128MB
2052 from start of memory.
2058 bool "UEFI runtime support"
2059 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2061 select EFI_PARAMS_FROM_FDT
2064 select EFI_RUNTIME_WRAPPERS
2066 This option provides support for runtime services provided
2067 by UEFI firmware (such as non-volatile variables, realtime
2068 clock, and platform reset). A UEFI stub is also provided to
2069 allow the kernel to be booted as an EFI application. This
2070 is only useful for kernels that may run on systems that have
2074 bool "Enable support for SMBIOS (DMI) tables"
2078 This enables SMBIOS/DMI feature for systems.
2080 This option is only useful on systems that have UEFI firmware.
2081 However, even with this option, the resultant kernel should
2082 continue to boot on existing non-UEFI platforms.
2084 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
2085 i.e., the the practice of identifying the platform via DMI to
2086 decide whether certain workarounds for buggy hardware and/or
2087 firmware need to be enabled. This would require the DMI subsystem
2088 to be enabled much earlier than we do on ARM, which is non-trivial.
2092 menu "CPU Power Management"
2094 source "drivers/cpufreq/Kconfig"
2096 source "drivers/cpuidle/Kconfig"
2100 menu "Floating point emulation"
2102 comment "At least one emulation must be selected"
2105 bool "NWFPE math emulation"
2106 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2108 Say Y to include the NWFPE floating point emulator in the kernel.
2109 This is necessary to run most binaries. Linux does not currently
2110 support floating point hardware so you need to say Y here even if
2111 your machine has an FPA or floating point co-processor podule.
2113 You may say N here if you are going to load the Acorn FPEmulator
2114 early in the bootup.
2117 bool "Support extended precision"
2118 depends on FPE_NWFPE
2120 Say Y to include 80-bit support in the kernel floating-point
2121 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2122 Note that gcc does not generate 80-bit operations by default,
2123 so in most cases this option only enlarges the size of the
2124 floating point emulator without any good reason.
2126 You almost surely want to say N here.
2129 bool "FastFPE math emulation (EXPERIMENTAL)"
2130 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2132 Say Y here to include the FAST floating point emulator in the kernel.
2133 This is an experimental much faster emulator which now also has full
2134 precision for the mantissa. It does not support any exceptions.
2135 It is very simple, and approximately 3-6 times faster than NWFPE.
2137 It should be sufficient for most programs. It may be not suitable
2138 for scientific calculations, but you have to check this for yourself.
2139 If you do not feel you need a faster FP emulation you should better
2143 bool "VFP-format floating point maths"
2144 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2146 Say Y to include VFP support code in the kernel. This is needed
2147 if your hardware includes a VFP unit.
2149 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2150 release notes and additional status information.
2152 Say N if your target does not have VFP hardware.
2160 bool "Advanced SIMD (NEON) Extension support"
2161 depends on VFPv3 && CPU_V7
2163 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2166 config KERNEL_MODE_NEON
2167 bool "Support for NEON in kernel mode"
2168 depends on NEON && AEABI
2170 Say Y to include support for NEON in kernel mode.
2174 menu "Power management options"
2176 source "kernel/power/Kconfig"
2178 config ARCH_SUSPEND_POSSIBLE
2179 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2180 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2183 config ARM_CPU_SUSPEND
2184 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2185 depends on ARCH_SUSPEND_POSSIBLE
2187 config ARCH_HIBERNATION_POSSIBLE
2190 default y if ARCH_SUSPEND_POSSIBLE
2194 source "drivers/firmware/Kconfig"
2197 source "arch/arm/crypto/Kconfig"
2200 source "arch/arm/kvm/Kconfig"