1 # SPDX-License-Identifier: GPL-2.0
5 select ARCH_32BIT_OFF_T
6 select ARCH_CLOCKSOURCE_DATA
7 select ARCH_HAS_BINFMT_FLAT
8 select ARCH_HAS_DEBUG_VIRTUAL if MMU
9 select ARCH_HAS_DEVMEM_IS_ALLOWED
10 select ARCH_HAS_ELF_RANDOMIZE
11 select ARCH_HAS_FORTIFY_SOURCE
12 select ARCH_HAS_KEEPINITRD
14 select ARCH_HAS_MEMBARRIER_SYNC_CORE
15 select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
16 select ARCH_HAS_PHYS_TO_DMA
17 select ARCH_HAS_SETUP_DMA_OPS
18 select ARCH_HAS_SET_MEMORY
19 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
20 select ARCH_HAS_STRICT_MODULE_RWX if MMU
21 select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
22 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
23 select ARCH_HAVE_CUSTOM_GPIO_H
24 select ARCH_HAS_GCOV_PROFILE_ALL
25 select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC
26 select ARCH_MIGHT_HAVE_PC_PARPORT
27 select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
28 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
29 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
30 select ARCH_SUPPORTS_ATOMIC_RMW
31 select ARCH_USE_BUILTIN_BSWAP
32 select ARCH_USE_CMPXCHG_LOCKREF
33 select ARCH_WANT_IPC_PARSE_VERSION
34 select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
35 select BUILDTIME_EXTABLE_SORT if MMU
36 select CLONE_BACKWARDS
37 select CPU_PM if SUSPEND || CPU_IDLE
38 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
39 select DMA_DECLARE_COHERENT
40 select DMA_REMAP if MMU
42 select EDAC_ATOMIC_SCRUB
43 select GENERIC_ALLOCATOR
44 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
45 select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
46 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
47 select GENERIC_CPU_AUTOPROBE
48 select GENERIC_EARLY_IOREMAP
49 select GENERIC_IDLE_POLL_SETUP
50 select GENERIC_IRQ_PROBE
51 select GENERIC_IRQ_SHOW
52 select GENERIC_IRQ_SHOW_LEVEL
53 select GENERIC_PCI_IOMAP
54 select GENERIC_SCHED_CLOCK
55 select GENERIC_SMP_IDLE_THREAD
56 select GENERIC_STRNCPY_FROM_USER
57 select GENERIC_STRNLEN_USER
58 select HANDLE_DOMAIN_IRQ
59 select HARDIRQS_SW_RESEND
60 select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
61 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
62 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
63 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
64 select HAVE_ARCH_MMAP_RND_BITS if MMU
65 select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
66 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
67 select HAVE_ARCH_TRACEHOOK
68 select HAVE_ARM_SMCCC if CPU_V7
69 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
70 select HAVE_CONTEXT_TRACKING
71 select HAVE_C_RECORDMCOUNT
72 select HAVE_DEBUG_KMEMLEAK
73 select HAVE_DMA_CONTIGUOUS if MMU
74 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
75 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
76 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
77 select HAVE_EXIT_THREAD
78 select HAVE_FAST_GUP if ARM_LPAE
79 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
80 select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
81 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
82 select HAVE_GCC_PLUGINS
83 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
84 select HAVE_IDE if PCI || ISA || PCMCIA
85 select HAVE_IRQ_TIME_ACCOUNTING
86 select HAVE_KERNEL_GZIP
87 select HAVE_KERNEL_LZ4
88 select HAVE_KERNEL_LZMA
89 select HAVE_KERNEL_LZO
91 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
92 select HAVE_KRETPROBES if HAVE_KPROBES
93 select HAVE_MOD_ARCH_SPECIFIC
95 select HAVE_OPROFILE if HAVE_PERF_EVENTS
96 select HAVE_OPTPROBES if !THUMB2_KERNEL
97 select HAVE_PERF_EVENTS
99 select HAVE_PERF_USER_STACK_DUMP
100 select HAVE_RCU_TABLE_FREE if SMP && ARM_LPAE
101 select HAVE_REGS_AND_STACK_ACCESS_API
103 select HAVE_STACKPROTECTOR
104 select HAVE_SYSCALL_TRACEPOINTS
106 select HAVE_VIRT_CPU_ACCOUNTING_GEN
107 select IRQ_FORCED_THREADING
108 select MODULES_USE_ELF_REL
109 select NEED_DMA_MAP_STATE
110 select OF_EARLY_FLATTREE if OF
112 select OLD_SIGSUSPEND3
113 select PCI_SYSCALL if PCI
114 select PERF_USE_VMALLOC
117 select SYS_SUPPORTS_APM_EMULATION
118 # Above selects are sorted alphabetically; please add new ones
119 # according to that. Thanks.
121 The ARM series is a line of low-power-consumption RISC chip designs
122 licensed by ARM Ltd and targeted at embedded applications and
123 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
124 manufactured, but legacy ARM-based PC hardware remains popular in
125 Europe. There is an ARM Linux project with a web page at
126 <http://www.arm.linux.org.uk/>.
128 config ARM_HAS_SG_CHAIN
131 config ARM_DMA_USE_IOMMU
133 select ARM_HAS_SG_CHAIN
134 select NEED_SG_DMA_LENGTH
138 config ARM_DMA_IOMMU_ALIGNMENT
139 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
143 DMA mapping framework by default aligns all buffers to the smallest
144 PAGE_SIZE order which is greater than or equal to the requested buffer
145 size. This works well for buffers up to a few hundreds kilobytes, but
146 for larger buffers it just a waste of address space. Drivers which has
147 relatively small addressing window (like 64Mib) might run out of
148 virtual space with just a few allocations.
150 With this parameter you can specify the maximum PAGE_SIZE order for
151 DMA IOMMU buffers. Larger buffers will be aligned only to this
152 specified order. The order is expressed as a power of two multiplied
157 config SYS_SUPPORTS_APM_EMULATION
162 select GENERIC_ALLOCATOR
173 config STACKTRACE_SUPPORT
177 config LOCKDEP_SUPPORT
181 config TRACE_IRQFLAGS_SUPPORT
185 config ARCH_HAS_ILOG2_U32
188 config ARCH_HAS_ILOG2_U64
191 config ARCH_HAS_BANDGAP
194 config FIX_EARLYCON_MEM
197 config GENERIC_HWEIGHT
201 config GENERIC_CALIBRATE_DELAY
205 config ARCH_MAY_HAVE_PC_FDC
211 config ARCH_SUPPORTS_UPROBES
214 config ARCH_HAS_DMA_SET_COHERENT_MASK
217 config GENERIC_ISA_DMA
223 config NEED_RET_TO_USER
229 config ARM_PATCH_PHYS_VIRT
230 bool "Patch physical to virtual translations at runtime" if EMBEDDED
232 depends on !XIP_KERNEL && MMU
234 Patch phys-to-virt and virt-to-phys translation functions at
235 boot and module load time according to the position of the
236 kernel in system memory.
238 This can only be used with non-XIP MMU kernels where the base
239 of physical memory is at a 16MB boundary.
241 Only disable this option if you know that you do not require
242 this feature (eg, building a kernel for a single machine) and
243 you need to shrink the kernel to the minimal size.
245 config NEED_MACH_IO_H
248 Select this when mach/io.h is required to provide special
249 definitions for this platform. The need for mach/io.h should
250 be avoided when possible.
252 config NEED_MACH_MEMORY_H
255 Select this when mach/memory.h is required to provide special
256 definitions for this platform. The need for mach/memory.h should
257 be avoided when possible.
260 hex "Physical address of main memory" if MMU
261 depends on !ARM_PATCH_PHYS_VIRT
262 default DRAM_BASE if !MMU
263 default 0x00000000 if ARCH_EBSA110 || \
269 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
270 default 0x20000000 if ARCH_S5PV210
271 default 0xc0000000 if ARCH_SA1100
273 Please provide the physical address corresponding to the
274 location of main memory in your system.
280 config PGTABLE_LEVELS
282 default 3 if ARM_LPAE
288 bool "MMU-based Paged Memory Management Support"
291 Select if you want MMU-based virtualised addressing space
292 support by paged memory management. If unsure, say 'Y'.
294 config ARCH_MMAP_RND_BITS_MIN
297 config ARCH_MMAP_RND_BITS_MAX
298 default 14 if PAGE_OFFSET=0x40000000
299 default 15 if PAGE_OFFSET=0x80000000
303 # The "ARM system type" choice list is ordered alphabetically by option
304 # text. Please add new entries in the option alphabetic order.
307 prompt "ARM system type"
308 default ARM_SINGLE_ARMV7M if !MMU
309 default ARCH_MULTIPLATFORM if MMU
311 config ARCH_MULTIPLATFORM
312 bool "Allow multiple platforms to be selected"
314 select ARM_HAS_SG_CHAIN
315 select ARM_PATCH_PHYS_VIRT
319 select GENERIC_CLOCKEVENTS
320 select GENERIC_IRQ_MULTI_HANDLER
322 select PCI_DOMAINS_GENERIC if PCI
326 config ARM_SINGLE_ARMV7M
327 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
334 select GENERIC_CLOCKEVENTS
341 select ARCH_USES_GETTIMEOFFSET
344 select NEED_MACH_IO_H
345 select NEED_MACH_MEMORY_H
348 This is an evaluation board for the StrongARM processor available
349 from Digital. It has limited hardware on-board, including an
350 Ethernet interface, two PCMCIA sockets, two serial ports and a
355 select ARCH_SPARSEMEM_ENABLE
357 imply ARM_PATCH_PHYS_VIRT
363 select GENERIC_CLOCKEVENTS
366 This enables support for the Cirrus EP93xx series of CPUs.
368 config ARCH_FOOTBRIDGE
372 select GENERIC_CLOCKEVENTS
374 select NEED_MACH_IO_H if !MMU
375 select NEED_MACH_MEMORY_H
377 Support for systems based on the DC21285 companion chip
378 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
384 select NEED_MACH_MEMORY_H
385 select NEED_RET_TO_USER
391 Support for Intel's IOP13XX (XScale) family of processors.
399 select NEED_RET_TO_USER
403 Support for Intel's 80219 and IOP32X (XScale) family of
412 select NEED_RET_TO_USER
416 Support for Intel's IOP33X (XScale) family of processors.
421 select ARCH_HAS_DMA_SET_COHERENT_MASK
422 select ARCH_SUPPORTS_BIG_ENDIAN
424 select DMABOUNCE if PCI
425 select GENERIC_CLOCKEVENTS
426 select GENERIC_IRQ_MULTI_HANDLER
432 select NEED_MACH_IO_H
433 select USB_EHCI_BIG_ENDIAN_DESC
434 select USB_EHCI_BIG_ENDIAN_MMIO
436 Support for Intel's IXP4XX (XScale) family of processors.
441 select GENERIC_CLOCKEVENTS
442 select GENERIC_IRQ_MULTI_HANDLER
448 select PLAT_ORION_LEGACY
450 select PM_GENERIC_DOMAINS if PM
452 Support for the Marvell Dove SoC 88AP510
455 bool "Micrel/Kendin KS8695"
458 select GENERIC_CLOCKEVENTS
460 select NEED_MACH_MEMORY_H
462 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
463 System-on-Chip devices.
466 bool "Nuvoton W90X900 CPU"
470 select GENERIC_CLOCKEVENTS
473 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
474 At present, the w90x900 has been renamed nuc900, regarding
475 the ARM series product line, you can login the following
476 link address to know more.
478 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
479 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
485 select CLKSRC_LPC32XX
488 select GENERIC_CLOCKEVENTS
489 select GENERIC_IRQ_MULTI_HANDLER
494 Support for the NXP LPC32XX family of processors
497 bool "PXA2xx/PXA3xx-based"
500 select ARM_CPU_SUSPEND if PM
507 select CPU_XSCALE if !CPU_XSC3
508 select GENERIC_CLOCKEVENTS
509 select GENERIC_IRQ_MULTI_HANDLER
517 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
523 select ARCH_MAY_HAVE_PC_FDC
524 select ARCH_SPARSEMEM_ENABLE
525 select ARM_HAS_SG_CHAIN
529 select HAVE_PATA_PLATFORM
531 select NEED_MACH_IO_H
532 select NEED_MACH_MEMORY_H
535 On the Acorn Risc-PC, Linux can support the internal IDE disk and
536 CD-ROM interface, serial and parallel port, and the floppy drive.
541 select ARCH_SPARSEMEM_ENABLE
545 select TIMER_OF if OF
549 select GENERIC_CLOCKEVENTS
550 select GENERIC_IRQ_MULTI_HANDLER
555 select NEED_MACH_MEMORY_H
558 Support for StrongARM 11x0 based boards.
561 bool "Samsung S3C24XX SoCs"
564 select CLKSRC_SAMSUNG_PWM
565 select GENERIC_CLOCKEVENTS
568 select GENERIC_IRQ_MULTI_HANDLER
569 select HAVE_S3C2410_I2C if I2C
570 select HAVE_S3C2410_WATCHDOG if WATCHDOG
571 select HAVE_S3C_RTC if RTC_CLASS
572 select NEED_MACH_IO_H
576 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
577 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
578 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
579 Samsung SMDK2410 development board (and derivatives).
583 select ARCH_HAS_HOLES_MEMORYMODEL
586 select GENERIC_ALLOCATOR
587 select GENERIC_CLOCKEVENTS
588 select GENERIC_IRQ_CHIP
589 select GENERIC_IRQ_MULTI_HANDLER
592 select PM_GENERIC_DOMAINS if PM
593 select PM_GENERIC_DOMAINS_OF if PM && OF
595 select RESET_CONTROLLER
600 Support for TI's DaVinci platform.
605 select ARCH_HAS_HOLES_MEMORYMODEL
609 select GENERIC_CLOCKEVENTS
610 select GENERIC_IRQ_CHIP
611 select GENERIC_IRQ_MULTI_HANDLER
615 select NEED_MACH_IO_H if PCCARD
616 select NEED_MACH_MEMORY_H
619 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
623 menu "Multiple platform selection"
624 depends on ARCH_MULTIPLATFORM
626 comment "CPU Core family selection"
629 bool "ARMv4 based platforms (FA526)"
630 depends on !ARCH_MULTI_V6_V7
631 select ARCH_MULTI_V4_V5
634 config ARCH_MULTI_V4T
635 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
636 depends on !ARCH_MULTI_V6_V7
637 select ARCH_MULTI_V4_V5
638 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
639 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
640 CPU_ARM925T || CPU_ARM940T)
643 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
644 depends on !ARCH_MULTI_V6_V7
645 select ARCH_MULTI_V4_V5
646 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
647 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
648 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
650 config ARCH_MULTI_V4_V5
654 bool "ARMv6 based platforms (ARM11)"
655 select ARCH_MULTI_V6_V7
659 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
661 select ARCH_MULTI_V6_V7
665 config ARCH_MULTI_V6_V7
667 select MIGHT_HAVE_CACHE_L2X0
669 config ARCH_MULTI_CPU_AUTO
670 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
676 bool "Dummy Virtual Machine"
677 depends on ARCH_MULTI_V7
680 select ARM_GIC_V2M if PCI
682 select ARM_GIC_V3_ITS if PCI
684 select HAVE_ARM_ARCH_TIMER
685 select ARCH_SUPPORTS_BIG_ENDIAN
688 # This is sorted alphabetically by mach-* pathname. However, plat-*
689 # Kconfigs may be included either alphabetically (according to the
690 # plat- suffix) or along side the corresponding mach-* source.
692 source "arch/arm/mach-actions/Kconfig"
694 source "arch/arm/mach-alpine/Kconfig"
696 source "arch/arm/mach-artpec/Kconfig"
698 source "arch/arm/mach-asm9260/Kconfig"
700 source "arch/arm/mach-aspeed/Kconfig"
702 source "arch/arm/mach-at91/Kconfig"
704 source "arch/arm/mach-axxia/Kconfig"
706 source "arch/arm/mach-bcm/Kconfig"
708 source "arch/arm/mach-berlin/Kconfig"
710 source "arch/arm/mach-clps711x/Kconfig"
712 source "arch/arm/mach-cns3xxx/Kconfig"
714 source "arch/arm/mach-davinci/Kconfig"
716 source "arch/arm/mach-digicolor/Kconfig"
718 source "arch/arm/mach-dove/Kconfig"
720 source "arch/arm/mach-ep93xx/Kconfig"
722 source "arch/arm/mach-exynos/Kconfig"
723 source "arch/arm/plat-samsung/Kconfig"
725 source "arch/arm/mach-footbridge/Kconfig"
727 source "arch/arm/mach-gemini/Kconfig"
729 source "arch/arm/mach-highbank/Kconfig"
731 source "arch/arm/mach-hisi/Kconfig"
733 source "arch/arm/mach-imx/Kconfig"
735 source "arch/arm/mach-integrator/Kconfig"
737 source "arch/arm/mach-iop13xx/Kconfig"
739 source "arch/arm/mach-iop32x/Kconfig"
741 source "arch/arm/mach-iop33x/Kconfig"
743 source "arch/arm/mach-ixp4xx/Kconfig"
745 source "arch/arm/mach-keystone/Kconfig"
747 source "arch/arm/mach-ks8695/Kconfig"
749 source "arch/arm/mach-mediatek/Kconfig"
751 source "arch/arm/mach-meson/Kconfig"
753 source "arch/arm/mach-milbeaut/Kconfig"
755 source "arch/arm/mach-mmp/Kconfig"
757 source "arch/arm/mach-moxart/Kconfig"
759 source "arch/arm/mach-mv78xx0/Kconfig"
761 source "arch/arm/mach-mvebu/Kconfig"
763 source "arch/arm/mach-mxs/Kconfig"
765 source "arch/arm/mach-nomadik/Kconfig"
767 source "arch/arm/mach-npcm/Kconfig"
769 source "arch/arm/mach-nspire/Kconfig"
771 source "arch/arm/plat-omap/Kconfig"
773 source "arch/arm/mach-omap1/Kconfig"
775 source "arch/arm/mach-omap2/Kconfig"
777 source "arch/arm/mach-orion5x/Kconfig"
779 source "arch/arm/mach-oxnas/Kconfig"
781 source "arch/arm/mach-picoxcell/Kconfig"
783 source "arch/arm/mach-prima2/Kconfig"
785 source "arch/arm/mach-pxa/Kconfig"
786 source "arch/arm/plat-pxa/Kconfig"
788 source "arch/arm/mach-qcom/Kconfig"
790 source "arch/arm/mach-rda/Kconfig"
792 source "arch/arm/mach-realview/Kconfig"
794 source "arch/arm/mach-rockchip/Kconfig"
796 source "arch/arm/mach-s3c24xx/Kconfig"
798 source "arch/arm/mach-s3c64xx/Kconfig"
800 source "arch/arm/mach-s5pv210/Kconfig"
802 source "arch/arm/mach-sa1100/Kconfig"
804 source "arch/arm/mach-shmobile/Kconfig"
806 source "arch/arm/mach-socfpga/Kconfig"
808 source "arch/arm/mach-spear/Kconfig"
810 source "arch/arm/mach-sti/Kconfig"
812 source "arch/arm/mach-stm32/Kconfig"
814 source "arch/arm/mach-sunxi/Kconfig"
816 source "arch/arm/mach-tango/Kconfig"
818 source "arch/arm/mach-tegra/Kconfig"
820 source "arch/arm/mach-u300/Kconfig"
822 source "arch/arm/mach-uniphier/Kconfig"
824 source "arch/arm/mach-ux500/Kconfig"
826 source "arch/arm/mach-versatile/Kconfig"
828 source "arch/arm/mach-vexpress/Kconfig"
829 source "arch/arm/plat-versatile/Kconfig"
831 source "arch/arm/mach-vt8500/Kconfig"
833 source "arch/arm/mach-w90x900/Kconfig"
835 source "arch/arm/mach-zx/Kconfig"
837 source "arch/arm/mach-zynq/Kconfig"
839 # ARMv7-M architecture
841 bool "Energy Micro efm32"
842 depends on ARM_SINGLE_ARMV7M
845 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
849 bool "NXP LPC18xx/LPC43xx"
850 depends on ARM_SINGLE_ARMV7M
851 select ARCH_HAS_RESET_CONTROLLER
853 select CLKSRC_LPC32XX
856 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
857 high performance microcontrollers.
860 bool "ARM MPS2 platform"
861 depends on ARM_SINGLE_ARMV7M
865 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
866 with a range of available cores like Cortex-M3/M4/M7.
868 Please, note that depends which Application Note is used memory map
869 for the platform may vary, so adjustment of RAM base might be needed.
871 # Definitions to make life easier
877 select GENERIC_CLOCKEVENTS
883 select GENERIC_IRQ_CHIP
886 config PLAT_ORION_LEGACY
893 config PLAT_VERSATILE
896 source "arch/arm/mm/Kconfig"
899 bool "Enable iWMMXt support"
900 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
901 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
903 Enable support for iWMMXt context switching at run time if
904 running on a CPU that supports it.
907 source "arch/arm/Kconfig-nommu"
910 config PJ4B_ERRATA_4742
911 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
912 depends on CPU_PJ4B && MACH_ARMADA_370
915 When coming out of either a Wait for Interrupt (WFI) or a Wait for
916 Event (WFE) IDLE states, a specific timing sensitivity exists between
917 the retiring WFI/WFE instructions and the newly issued subsequent
918 instructions. This sensitivity can result in a CPU hang scenario.
920 The software must insert either a Data Synchronization Barrier (DSB)
921 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
924 config ARM_ERRATA_326103
925 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
928 Executing a SWP instruction to read-only memory does not set bit 11
929 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
930 treat the access as a read, preventing a COW from occurring and
931 causing the faulting task to livelock.
933 config ARM_ERRATA_411920
934 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
935 depends on CPU_V6 || CPU_V6K
937 Invalidation of the Instruction Cache operation can
938 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
939 It does not affect the MPCore. This option enables the ARM Ltd.
940 recommended workaround.
942 config ARM_ERRATA_430973
943 bool "ARM errata: Stale prediction on replaced interworking branch"
946 This option enables the workaround for the 430973 Cortex-A8
947 r1p* erratum. If a code sequence containing an ARM/Thumb
948 interworking branch is replaced with another code sequence at the
949 same virtual address, whether due to self-modifying code or virtual
950 to physical address re-mapping, Cortex-A8 does not recover from the
951 stale interworking branch prediction. This results in Cortex-A8
952 executing the new code sequence in the incorrect ARM or Thumb state.
953 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
954 and also flushes the branch target cache at every context switch.
955 Note that setting specific bits in the ACTLR register may not be
956 available in non-secure mode.
958 config ARM_ERRATA_458693
959 bool "ARM errata: Processor deadlock when a false hazard is created"
961 depends on !ARCH_MULTIPLATFORM
963 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
964 erratum. For very specific sequences of memory operations, it is
965 possible for a hazard condition intended for a cache line to instead
966 be incorrectly associated with a different cache line. This false
967 hazard might then cause a processor deadlock. The workaround enables
968 the L1 caching of the NEON accesses and disables the PLD instruction
969 in the ACTLR register. Note that setting specific bits in the ACTLR
970 register may not be available in non-secure mode.
972 config ARM_ERRATA_460075
973 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
975 depends on !ARCH_MULTIPLATFORM
977 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
978 erratum. Any asynchronous access to the L2 cache may encounter a
979 situation in which recent store transactions to the L2 cache are lost
980 and overwritten with stale memory contents from external memory. The
981 workaround disables the write-allocate mode for the L2 cache via the
982 ACTLR register. Note that setting specific bits in the ACTLR register
983 may not be available in non-secure mode.
985 config ARM_ERRATA_742230
986 bool "ARM errata: DMB operation may be faulty"
987 depends on CPU_V7 && SMP
988 depends on !ARCH_MULTIPLATFORM
990 This option enables the workaround for the 742230 Cortex-A9
991 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
992 between two write operations may not ensure the correct visibility
993 ordering of the two writes. This workaround sets a specific bit in
994 the diagnostic register of the Cortex-A9 which causes the DMB
995 instruction to behave as a DSB, ensuring the correct behaviour of
998 config ARM_ERRATA_742231
999 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1000 depends on CPU_V7 && SMP
1001 depends on !ARCH_MULTIPLATFORM
1003 This option enables the workaround for the 742231 Cortex-A9
1004 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1005 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1006 accessing some data located in the same cache line, may get corrupted
1007 data due to bad handling of the address hazard when the line gets
1008 replaced from one of the CPUs at the same time as another CPU is
1009 accessing it. This workaround sets specific bits in the diagnostic
1010 register of the Cortex-A9 which reduces the linefill issuing
1011 capabilities of the processor.
1013 config ARM_ERRATA_643719
1014 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1015 depends on CPU_V7 && SMP
1018 This option enables the workaround for the 643719 Cortex-A9 (prior to
1019 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1020 register returns zero when it should return one. The workaround
1021 corrects this value, ensuring cache maintenance operations which use
1022 it behave as intended and avoiding data corruption.
1024 config ARM_ERRATA_720789
1025 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1028 This option enables the workaround for the 720789 Cortex-A9 (prior to
1029 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1030 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1031 As a consequence of this erratum, some TLB entries which should be
1032 invalidated are not, resulting in an incoherency in the system page
1033 tables. The workaround changes the TLB flushing routines to invalidate
1034 entries regardless of the ASID.
1036 config ARM_ERRATA_743622
1037 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1039 depends on !ARCH_MULTIPLATFORM
1041 This option enables the workaround for the 743622 Cortex-A9
1042 (r2p*) erratum. Under very rare conditions, a faulty
1043 optimisation in the Cortex-A9 Store Buffer may lead to data
1044 corruption. This workaround sets a specific bit in the diagnostic
1045 register of the Cortex-A9 which disables the Store Buffer
1046 optimisation, preventing the defect from occurring. This has no
1047 visible impact on the overall performance or power consumption of the
1050 config ARM_ERRATA_751472
1051 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1053 depends on !ARCH_MULTIPLATFORM
1055 This option enables the workaround for the 751472 Cortex-A9 (prior
1056 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1057 completion of a following broadcasted operation if the second
1058 operation is received by a CPU before the ICIALLUIS has completed,
1059 potentially leading to corrupted entries in the cache or TLB.
1061 config ARM_ERRATA_754322
1062 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1065 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1066 r3p*) erratum. A speculative memory access may cause a page table walk
1067 which starts prior to an ASID switch but completes afterwards. This
1068 can populate the micro-TLB with a stale entry which may be hit with
1069 the new ASID. This workaround places two dsb instructions in the mm
1070 switching code so that no page table walks can cross the ASID switch.
1072 config ARM_ERRATA_754327
1073 bool "ARM errata: no automatic Store Buffer drain"
1074 depends on CPU_V7 && SMP
1076 This option enables the workaround for the 754327 Cortex-A9 (prior to
1077 r2p0) erratum. The Store Buffer does not have any automatic draining
1078 mechanism and therefore a livelock may occur if an external agent
1079 continuously polls a memory location waiting to observe an update.
1080 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1081 written polling loops from denying visibility of updates to memory.
1083 config ARM_ERRATA_364296
1084 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1087 This options enables the workaround for the 364296 ARM1136
1088 r0p2 erratum (possible cache data corruption with
1089 hit-under-miss enabled). It sets the undocumented bit 31 in
1090 the auxiliary control register and the FI bit in the control
1091 register, thus disabling hit-under-miss without putting the
1092 processor into full low interrupt latency mode. ARM11MPCore
1095 config ARM_ERRATA_764369
1096 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1097 depends on CPU_V7 && SMP
1099 This option enables the workaround for erratum 764369
1100 affecting Cortex-A9 MPCore with two or more processors (all
1101 current revisions). Under certain timing circumstances, a data
1102 cache line maintenance operation by MVA targeting an Inner
1103 Shareable memory region may fail to proceed up to either the
1104 Point of Coherency or to the Point of Unification of the
1105 system. This workaround adds a DSB instruction before the
1106 relevant cache maintenance functions and sets a specific bit
1107 in the diagnostic control register of the SCU.
1109 config ARM_ERRATA_775420
1110 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1113 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1114 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1115 operation aborts with MMU exception, it might cause the processor
1116 to deadlock. This workaround puts DSB before executing ISB if
1117 an abort may occur on cache maintenance.
1119 config ARM_ERRATA_798181
1120 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1121 depends on CPU_V7 && SMP
1123 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1124 adequately shooting down all use of the old entries. This
1125 option enables the Linux kernel workaround for this erratum
1126 which sends an IPI to the CPUs that are running the same ASID
1127 as the one being invalidated.
1129 config ARM_ERRATA_773022
1130 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1133 This option enables the workaround for the 773022 Cortex-A15
1134 (up to r0p4) erratum. In certain rare sequences of code, the
1135 loop buffer may deliver incorrect instructions. This
1136 workaround disables the loop buffer to avoid the erratum.
1138 config ARM_ERRATA_818325_852422
1139 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1142 This option enables the workaround for:
1143 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1144 instruction might deadlock. Fixed in r0p1.
1145 - Cortex-A12 852422: Execution of a sequence of instructions might
1146 lead to either a data corruption or a CPU deadlock. Not fixed in
1147 any Cortex-A12 cores yet.
1148 This workaround for all both errata involves setting bit[12] of the
1149 Feature Register. This bit disables an optimisation applied to a
1150 sequence of 2 instructions that use opposing condition codes.
1152 config ARM_ERRATA_821420
1153 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1156 This option enables the workaround for the 821420 Cortex-A12
1157 (all revs) erratum. In very rare timing conditions, a sequence
1158 of VMOV to Core registers instructions, for which the second
1159 one is in the shadow of a branch or abort, can lead to a
1160 deadlock when the VMOV instructions are issued out-of-order.
1162 config ARM_ERRATA_825619
1163 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1166 This option enables the workaround for the 825619 Cortex-A12
1167 (all revs) erratum. Within rare timing constraints, executing a
1168 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1169 and Device/Strongly-Ordered loads and stores might cause deadlock
1171 config ARM_ERRATA_857271
1172 bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1175 This option enables the workaround for the 857271 Cortex-A12
1176 (all revs) erratum. Under very rare timing conditions, the CPU might
1177 hang. The workaround is expected to have a < 1% performance impact.
1179 config ARM_ERRATA_852421
1180 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1183 This option enables the workaround for the 852421 Cortex-A17
1184 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1185 execution of a DMB ST instruction might fail to properly order
1186 stores from GroupA and stores from GroupB.
1188 config ARM_ERRATA_852423
1189 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1192 This option enables the workaround for:
1193 - Cortex-A17 852423: Execution of a sequence of instructions might
1194 lead to either a data corruption or a CPU deadlock. Not fixed in
1195 any Cortex-A17 cores yet.
1196 This is identical to Cortex-A12 erratum 852422. It is a separate
1197 config option from the A12 erratum due to the way errata are checked
1200 config ARM_ERRATA_857272
1201 bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1204 This option enables the workaround for the 857272 Cortex-A17 erratum.
1205 This erratum is not known to be fixed in any A17 revision.
1206 This is identical to Cortex-A12 erratum 857271. It is a separate
1207 config option from the A12 erratum due to the way errata are checked
1212 source "arch/arm/common/Kconfig"
1219 Find out whether you have ISA slots on your motherboard. ISA is the
1220 name of a bus system, i.e. the way the CPU talks to the other stuff
1221 inside your box. Other bus systems are PCI, EISA, MicroChannel
1222 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1223 newer boards don't support it. If you have ISA, say Y, otherwise N.
1225 # Select ISA DMA controller support
1230 # Select ISA DMA interface
1234 config PCI_NANOENGINE
1235 bool "BSE nanoEngine PCI support"
1236 depends on SA1100_NANOENGINE
1238 Enable PCI on the BSE nanoEngine board.
1240 config PCI_HOST_ITE8152
1242 depends on PCI && MACH_ARMCORE
1246 config ARM_ERRATA_814220
1247 bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1250 The v7 ARM states that all cache and branch predictor maintenance
1251 operations that do not specify an address execute, relative to
1252 each other, in program order.
1253 However, because of this erratum, an L2 set/way cache maintenance
1254 operation can overtake an L1 set/way cache maintenance operation.
1255 This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1260 menu "Kernel Features"
1265 This option should be selected by machines which have an SMP-
1268 The only effect of this option is to make the SMP-related
1269 options available to the user for configuration.
1272 bool "Symmetric Multi-Processing"
1273 depends on CPU_V6K || CPU_V7
1274 depends on GENERIC_CLOCKEVENTS
1276 depends on MMU || ARM_MPU
1279 This enables support for systems with more than one CPU. If you have
1280 a system with only one CPU, say N. If you have a system with more
1281 than one CPU, say Y.
1283 If you say N here, the kernel will run on uni- and multiprocessor
1284 machines, but will use only one CPU of a multiprocessor machine. If
1285 you say Y here, the kernel will run on many, but not all,
1286 uniprocessor machines. On a uniprocessor machine, the kernel
1287 will run faster if you say N here.
1289 See also <file:Documentation/x86/i386/IO-APIC.rst>,
1290 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1291 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1293 If you don't know what to do here, say N.
1296 bool "Allow booting SMP kernel on uniprocessor systems"
1297 depends on SMP && !XIP_KERNEL && MMU
1300 SMP kernels contain instructions which fail on non-SMP processors.
1301 Enabling this option allows the kernel to modify itself to make
1302 these instructions safe. Disabling it allows about 1K of space
1305 If you don't know what to do here, say Y.
1307 config ARM_CPU_TOPOLOGY
1308 bool "Support cpu topology definition"
1309 depends on SMP && CPU_V7
1312 Support ARM cpu topology definition. The MPIDR register defines
1313 affinity between processors which is then used to describe the cpu
1314 topology of an ARM System.
1317 bool "Multi-core scheduler support"
1318 depends on ARM_CPU_TOPOLOGY
1320 Multi-core scheduler support improves the CPU scheduler's decision
1321 making when dealing with multi-core CPU chips at a cost of slightly
1322 increased overhead in some places. If unsure say N here.
1325 bool "SMT scheduler support"
1326 depends on ARM_CPU_TOPOLOGY
1328 Improves the CPU scheduler's decision making when dealing with
1329 MultiThreading at a cost of slightly increased overhead in some
1330 places. If unsure say N here.
1335 This option enables support for the ARM snoop control unit
1337 config HAVE_ARM_ARCH_TIMER
1338 bool "Architected timer support"
1340 select ARM_ARCH_TIMER
1341 select GENERIC_CLOCKEVENTS
1343 This option enables support for the ARM architected timer
1348 This options enables support for the ARM timer and watchdog unit
1351 bool "Multi-Cluster Power Management"
1352 depends on CPU_V7 && SMP
1354 This option provides the common power management infrastructure
1355 for (multi-)cluster based systems, such as big.LITTLE based
1358 config MCPM_QUAD_CLUSTER
1362 To avoid wasting resources unnecessarily, MCPM only supports up
1363 to 2 clusters by default.
1364 Platforms with 3 or 4 clusters that use MCPM must select this
1365 option to allow the additional clusters to be managed.
1368 bool "big.LITTLE support (Experimental)"
1369 depends on CPU_V7 && SMP
1372 This option enables support selections for the big.LITTLE
1373 system architecture.
1376 bool "big.LITTLE switcher support"
1377 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1380 The big.LITTLE "switcher" provides the core functionality to
1381 transparently handle transition between a cluster of A15's
1382 and a cluster of A7's in a big.LITTLE system.
1384 config BL_SWITCHER_DUMMY_IF
1385 tristate "Simple big.LITTLE switcher user interface"
1386 depends on BL_SWITCHER && DEBUG_KERNEL
1388 This is a simple and dummy char dev interface to control
1389 the big.LITTLE switcher core code. It is meant for
1390 debugging purposes only.
1393 prompt "Memory split"
1397 Select the desired split between kernel and user memory.
1399 If you are not absolutely sure what you are doing, leave this
1403 bool "3G/1G user/kernel split"
1404 config VMSPLIT_3G_OPT
1405 depends on !ARM_LPAE
1406 bool "3G/1G user/kernel split (for full 1G low memory)"
1408 bool "2G/2G user/kernel split"
1410 bool "1G/3G user/kernel split"
1415 default PHYS_OFFSET if !MMU
1416 default 0x40000000 if VMSPLIT_1G
1417 default 0x80000000 if VMSPLIT_2G
1418 default 0xB0000000 if VMSPLIT_3G_OPT
1422 int "Maximum number of CPUs (2-32)"
1428 bool "Support for hot-pluggable CPUs"
1430 select GENERIC_IRQ_MIGRATION
1432 Say Y here to experiment with turning CPUs off and on. CPUs
1433 can be controlled through /sys/devices/system/cpu.
1436 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1437 depends on HAVE_ARM_SMCCC
1440 Say Y here if you want Linux to communicate with system firmware
1441 implementing the PSCI specification for CPU-centric power
1442 management operations described in ARM document number ARM DEN
1443 0022A ("Power State Coordination Interface System Software on
1446 # The GPIO number here must be sorted by descending number. In case of
1447 # a multiplatform kernel, we just want the highest value required by the
1448 # selected platforms.
1451 default 2048 if ARCH_SOCFPGA
1452 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1454 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1455 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1456 default 416 if ARCH_SUNXI
1457 default 392 if ARCH_U8500
1458 default 352 if ARCH_VT8500
1459 default 288 if ARCH_ROCKCHIP
1460 default 264 if MACH_H4700
1463 Maximum number of GPIOs in the system.
1465 If unsure, leave the default value.
1469 default 200 if ARCH_EBSA110
1470 default 128 if SOC_AT91RM9200
1474 depends on HZ_FIXED = 0
1475 prompt "Timer frequency"
1499 default HZ_FIXED if HZ_FIXED != 0
1500 default 100 if HZ_100
1501 default 200 if HZ_200
1502 default 250 if HZ_250
1503 default 300 if HZ_300
1504 default 500 if HZ_500
1508 def_bool HIGH_RES_TIMERS
1510 config THUMB2_KERNEL
1511 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1512 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1513 default y if CPU_THUMBONLY
1516 By enabling this option, the kernel will be compiled in
1521 config THUMB2_AVOID_R_ARM_THM_JUMP11
1522 bool "Work around buggy Thumb-2 short branch relocations in gas"
1523 depends on THUMB2_KERNEL && MODULES
1526 Various binutils versions can resolve Thumb-2 branches to
1527 locally-defined, preemptible global symbols as short-range "b.n"
1528 branch instructions.
1530 This is a problem, because there's no guarantee the final
1531 destination of the symbol, or any candidate locations for a
1532 trampoline, are within range of the branch. For this reason, the
1533 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1534 relocation in modules at all, and it makes little sense to add
1537 The symptom is that the kernel fails with an "unsupported
1538 relocation" error when loading some modules.
1540 Until fixed tools are available, passing
1541 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1542 code which hits this problem, at the cost of a bit of extra runtime
1543 stack usage in some cases.
1545 The problem is described in more detail at:
1546 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1548 Only Thumb-2 kernels are affected.
1550 Unless you are sure your tools don't have this problem, say Y.
1552 config ARM_PATCH_IDIV
1553 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1554 depends on CPU_32v7 && !XIP_KERNEL
1557 The ARM compiler inserts calls to __aeabi_idiv() and
1558 __aeabi_uidiv() when it needs to perform division on signed
1559 and unsigned integers. Some v7 CPUs have support for the sdiv
1560 and udiv instructions that can be used to implement those
1563 Enabling this option allows the kernel to modify itself to
1564 replace the first two instructions of these library functions
1565 with the sdiv or udiv plus "bx lr" instructions when the CPU
1566 it is running on supports them. Typically this will be faster
1567 and less power intensive than running the original library
1568 code to do integer division.
1571 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && !CPU_V7M && !CPU_V6 && !CPU_V6K
1572 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K
1574 This option allows for the kernel to be compiled using the latest
1575 ARM ABI (aka EABI). This is only useful if you are using a user
1576 space environment that is also compiled with EABI.
1578 Since there are major incompatibilities between the legacy ABI and
1579 EABI, especially with regard to structure member alignment, this
1580 option also changes the kernel syscall calling convention to
1581 disambiguate both ABIs and allow for backward compatibility support
1582 (selected with CONFIG_OABI_COMPAT).
1584 To use this you need GCC version 4.0.0 or later.
1587 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1588 depends on AEABI && !THUMB2_KERNEL
1590 This option preserves the old syscall interface along with the
1591 new (ARM EABI) one. It also provides a compatibility layer to
1592 intercept syscalls that have structure arguments which layout
1593 in memory differs between the legacy ABI and the new ARM EABI
1594 (only for non "thumb" binaries). This option adds a tiny
1595 overhead to all syscalls and produces a slightly larger kernel.
1597 The seccomp filter system will not be available when this is
1598 selected, since there is no way yet to sensibly distinguish
1599 between calling conventions during filtering.
1601 If you know you'll be using only pure EABI user space then you
1602 can say N here. If this option is not selected and you attempt
1603 to execute a legacy ABI binary then the result will be
1604 UNPREDICTABLE (in fact it can be predicted that it won't work
1605 at all). If in doubt say N.
1607 config ARCH_HAS_HOLES_MEMORYMODEL
1610 config ARCH_SPARSEMEM_ENABLE
1613 config ARCH_SPARSEMEM_DEFAULT
1614 def_bool ARCH_SPARSEMEM_ENABLE
1616 config HAVE_ARCH_PFN_VALID
1617 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1620 bool "High Memory Support"
1623 The address space of ARM processors is only 4 Gigabytes large
1624 and it has to accommodate user address space, kernel address
1625 space as well as some memory mapped IO. That means that, if you
1626 have a large amount of physical memory and/or IO, not all of the
1627 memory can be "permanently mapped" by the kernel. The physical
1628 memory that is not permanently mapped is called "high memory".
1630 Depending on the selected kernel/user memory split, minimum
1631 vmalloc space and actual amount of RAM, you may not need this
1632 option which should result in a slightly faster kernel.
1637 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1641 The VM uses one page of physical memory for each page table.
1642 For systems with a lot of processes, this can use a lot of
1643 precious low memory, eventually leading to low memory being
1644 consumed by page tables. Setting this option will allow
1645 user-space 2nd level page tables to reside in high memory.
1647 config CPU_SW_DOMAIN_PAN
1648 bool "Enable use of CPU domains to implement privileged no-access"
1649 depends on MMU && !ARM_LPAE
1652 Increase kernel security by ensuring that normal kernel accesses
1653 are unable to access userspace addresses. This can help prevent
1654 use-after-free bugs becoming an exploitable privilege escalation
1655 by ensuring that magic values (such as LIST_POISON) will always
1656 fault when dereferenced.
1658 CPUs with low-vector mappings use a best-efforts implementation.
1659 Their lower 1MB needs to remain accessible for the vectors, but
1660 the remainder of userspace will become appropriately inaccessible.
1662 config HW_PERF_EVENTS
1666 config SYS_SUPPORTS_HUGETLBFS
1670 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1674 config ARCH_WANT_GENERAL_HUGETLB
1677 config ARM_MODULE_PLTS
1678 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1682 Allocate PLTs when loading modules so that jumps and calls whose
1683 targets are too far away for their relative offsets to be encoded
1684 in the instructions themselves can be bounced via veneers in the
1685 module's PLT. This allows modules to be allocated in the generic
1686 vmalloc area after the dedicated module memory area has been
1687 exhausted. The modules will use slightly more memory, but after
1688 rounding up to page size, the actual memory footprint is usually
1691 Disabling this is usually safe for small single-platform
1692 configurations. If unsure, say y.
1694 config FORCE_MAX_ZONEORDER
1695 int "Maximum zone order"
1696 default "12" if SOC_AM33XX
1697 default "9" if SA1111 || ARCH_EFM32
1700 The kernel memory allocator divides physically contiguous memory
1701 blocks into "zones", where each zone is a power of two number of
1702 pages. This option selects the largest power of two that the kernel
1703 keeps in the memory allocator. If you need to allocate very large
1704 blocks of physically contiguous memory, then you may need to
1705 increase this value.
1707 This config option is actually maximum order plus one. For example,
1708 a value of 11 means that the largest free memory block is 2^10 pages.
1710 config ALIGNMENT_TRAP
1712 depends on CPU_CP15_MMU
1713 default y if !ARCH_EBSA110
1714 select HAVE_PROC_CPU if PROC_FS
1716 ARM processors cannot fetch/store information which is not
1717 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1718 address divisible by 4. On 32-bit ARM processors, these non-aligned
1719 fetch/store instructions will be emulated in software if you say
1720 here, which has a severe performance impact. This is necessary for
1721 correct operation of some network protocols. With an IP-only
1722 configuration it is safe to say N, otherwise say Y.
1724 config UACCESS_WITH_MEMCPY
1725 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1727 default y if CPU_FEROCEON
1729 Implement faster copy_to_user and clear_user methods for CPU
1730 cores where a 8-word STM instruction give significantly higher
1731 memory write throughput than a sequence of individual 32bit stores.
1733 A possible side effect is a slight increase in scheduling latency
1734 between threads sharing the same address space if they invoke
1735 such copy operations with large buffers.
1737 However, if the CPU data cache is using a write-allocate mode,
1738 this option is unlikely to provide any performance gain.
1742 prompt "Enable seccomp to safely compute untrusted bytecode"
1744 This kernel feature is useful for number crunching applications
1745 that may need to compute untrusted bytecode during their
1746 execution. By using pipes or other transports made available to
1747 the process as file descriptors supporting the read/write
1748 syscalls, it's possible to isolate those applications in
1749 their own address space using seccomp. Once seccomp is
1750 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1751 and the task is only allowed to execute a few safe syscalls
1752 defined by each seccomp mode.
1755 bool "Enable paravirtualization code"
1757 This changes the kernel so it can modify itself when it is run
1758 under a hypervisor, potentially improving performance significantly
1759 over full virtualization.
1761 config PARAVIRT_TIME_ACCOUNTING
1762 bool "Paravirtual steal time accounting"
1765 Select this option to enable fine granularity task steal time
1766 accounting. Time spent executing other tasks in parallel with
1767 the current vCPU is discounted from the vCPU power. To account for
1768 that, there can be a small performance impact.
1770 If in doubt, say N here.
1777 bool "Xen guest support on ARM"
1778 depends on ARM && AEABI && OF
1779 depends on CPU_V7 && !CPU_V6
1780 depends on !GENERIC_ATOMIC64
1782 select ARCH_DMA_ADDR_T_64BIT
1788 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1790 config STACKPROTECTOR_PER_TASK
1791 bool "Use a unique stack canary value for each task"
1792 depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1793 select GCC_PLUGIN_ARM_SSP_PER_TASK
1796 Due to the fact that GCC uses an ordinary symbol reference from
1797 which to load the value of the stack canary, this value can only
1798 change at reboot time on SMP systems, and all tasks running in the
1799 kernel's address space are forced to use the same canary value for
1800 the entire duration that the system is up.
1802 Enable this option to switch to a different method that uses a
1803 different canary value for each task.
1810 bool "Flattened Device Tree support"
1814 Include support for flattened device tree machine descriptions.
1817 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1820 This is the traditional way of passing data to the kernel at boot
1821 time. If you are solely relying on the flattened device tree (or
1822 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1823 to remove ATAGS support from your kernel binary. If unsure,
1826 config DEPRECATED_PARAM_STRUCT
1827 bool "Provide old way to pass kernel parameters"
1830 This was deprecated in 2001 and announced to live on for 5 years.
1831 Some old boot loaders still use this way.
1833 # Compressed boot loader in ROM. Yes, we really want to ask about
1834 # TEXT and BSS so we preserve their values in the config files.
1835 config ZBOOT_ROM_TEXT
1836 hex "Compressed ROM boot loader base address"
1839 The physical address at which the ROM-able zImage is to be
1840 placed in the target. Platforms which normally make use of
1841 ROM-able zImage formats normally set this to a suitable
1842 value in their defconfig file.
1844 If ZBOOT_ROM is not enabled, this has no effect.
1846 config ZBOOT_ROM_BSS
1847 hex "Compressed ROM boot loader BSS address"
1850 The base address of an area of read/write memory in the target
1851 for the ROM-able zImage which must be available while the
1852 decompressor is running. It must be large enough to hold the
1853 entire decompressed kernel plus an additional 128 KiB.
1854 Platforms which normally make use of ROM-able zImage formats
1855 normally set this to a suitable value in their defconfig file.
1857 If ZBOOT_ROM is not enabled, this has no effect.
1860 bool "Compressed boot loader in ROM/flash"
1861 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1862 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1864 Say Y here if you intend to execute your compressed kernel image
1865 (zImage) directly from ROM or flash. If unsure, say N.
1867 config ARM_APPENDED_DTB
1868 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1871 With this option, the boot code will look for a device tree binary
1872 (DTB) appended to zImage
1873 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1875 This is meant as a backward compatibility convenience for those
1876 systems with a bootloader that can't be upgraded to accommodate
1877 the documented boot protocol using a device tree.
1879 Beware that there is very little in terms of protection against
1880 this option being confused by leftover garbage in memory that might
1881 look like a DTB header after a reboot if no actual DTB is appended
1882 to zImage. Do not leave this option active in a production kernel
1883 if you don't intend to always append a DTB. Proper passing of the
1884 location into r2 of a bootloader provided DTB is always preferable
1887 config ARM_ATAG_DTB_COMPAT
1888 bool "Supplement the appended DTB with traditional ATAG information"
1889 depends on ARM_APPENDED_DTB
1891 Some old bootloaders can't be updated to a DTB capable one, yet
1892 they provide ATAGs with memory configuration, the ramdisk address,
1893 the kernel cmdline string, etc. Such information is dynamically
1894 provided by the bootloader and can't always be stored in a static
1895 DTB. To allow a device tree enabled kernel to be used with such
1896 bootloaders, this option allows zImage to extract the information
1897 from the ATAG list and store it at run time into the appended DTB.
1900 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1901 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1903 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1904 bool "Use bootloader kernel arguments if available"
1906 Uses the command-line options passed by the boot loader instead of
1907 the device tree bootargs property. If the boot loader doesn't provide
1908 any, the device tree bootargs property will be used.
1910 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1911 bool "Extend with bootloader kernel arguments"
1913 The command-line arguments provided by the boot loader will be
1914 appended to the the device tree bootargs property.
1919 string "Default kernel command string"
1922 On some architectures (EBSA110 and CATS), there is currently no way
1923 for the boot loader to pass arguments to the kernel. For these
1924 architectures, you should supply some command-line options at build
1925 time by entering them here. As a minimum, you should specify the
1926 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1929 prompt "Kernel command line type" if CMDLINE != ""
1930 default CMDLINE_FROM_BOOTLOADER
1933 config CMDLINE_FROM_BOOTLOADER
1934 bool "Use bootloader kernel arguments if available"
1936 Uses the command-line options passed by the boot loader. If
1937 the boot loader doesn't provide any, the default kernel command
1938 string provided in CMDLINE will be used.
1940 config CMDLINE_EXTEND
1941 bool "Extend bootloader kernel arguments"
1943 The command-line arguments provided by the boot loader will be
1944 appended to the default kernel command string.
1946 config CMDLINE_FORCE
1947 bool "Always use the default kernel command string"
1949 Always use the default kernel command string, even if the boot
1950 loader passes other arguments to the kernel.
1951 This is useful if you cannot or don't want to change the
1952 command-line options your boot loader passes to the kernel.
1956 bool "Kernel Execute-In-Place from ROM"
1957 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1959 Execute-In-Place allows the kernel to run from non-volatile storage
1960 directly addressable by the CPU, such as NOR flash. This saves RAM
1961 space since the text section of the kernel is not loaded from flash
1962 to RAM. Read-write sections, such as the data section and stack,
1963 are still copied to RAM. The XIP kernel is not compressed since
1964 it has to run directly from flash, so it will take more space to
1965 store it. The flash address used to link the kernel object files,
1966 and for storing it, is configuration dependent. Therefore, if you
1967 say Y here, you must know the proper physical address where to
1968 store the kernel image depending on your own flash memory usage.
1970 Also note that the make target becomes "make xipImage" rather than
1971 "make zImage" or "make Image". The final kernel binary to put in
1972 ROM memory will be arch/arm/boot/xipImage.
1976 config XIP_PHYS_ADDR
1977 hex "XIP Kernel Physical Location"
1978 depends on XIP_KERNEL
1979 default "0x00080000"
1981 This is the physical address in your flash memory the kernel will
1982 be linked for and stored to. This address is dependent on your
1985 config XIP_DEFLATED_DATA
1986 bool "Store kernel .data section compressed in ROM"
1987 depends on XIP_KERNEL
1990 Before the kernel is actually executed, its .data section has to be
1991 copied to RAM from ROM. This option allows for storing that data
1992 in compressed form and decompressed to RAM rather than merely being
1993 copied, saving some precious ROM space. A possible drawback is a
1994 slightly longer boot delay.
1997 bool "Kexec system call (EXPERIMENTAL)"
1998 depends on (!SMP || PM_SLEEP_SMP)
2002 kexec is a system call that implements the ability to shutdown your
2003 current kernel, and to start another kernel. It is like a reboot
2004 but it is independent of the system firmware. And like a reboot
2005 you can start any kernel with it, not just Linux.
2007 It is an ongoing process to be certain the hardware in a machine
2008 is properly shutdown, so do not be surprised if this code does not
2009 initially work for you.
2012 bool "Export atags in procfs"
2013 depends on ATAGS && KEXEC
2016 Should the atags used to boot the kernel be exported in an "atags"
2017 file in procfs. Useful with kexec.
2020 bool "Build kdump crash kernel (EXPERIMENTAL)"
2022 Generate crash dump after being started by kexec. This should
2023 be normally only set in special crash dump kernels which are
2024 loaded in the main kernel with kexec-tools into a specially
2025 reserved region and then later executed after a crash by
2026 kdump/kexec. The crash dump kernel must be compiled to a
2027 memory address not used by the main kernel
2029 For more details see Documentation/admin-guide/kdump/kdump.rst
2031 config AUTO_ZRELADDR
2032 bool "Auto calculation of the decompressed kernel image address"
2034 ZRELADDR is the physical address where the decompressed kernel
2035 image will be placed. If AUTO_ZRELADDR is selected, the address
2036 will be determined at run-time by masking the current IP with
2037 0xf8000000. This assumes the zImage being placed in the first 128MB
2038 from start of memory.
2044 bool "UEFI runtime support"
2045 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2047 select EFI_PARAMS_FROM_FDT
2050 select EFI_RUNTIME_WRAPPERS
2052 This option provides support for runtime services provided
2053 by UEFI firmware (such as non-volatile variables, realtime
2054 clock, and platform reset). A UEFI stub is also provided to
2055 allow the kernel to be booted as an EFI application. This
2056 is only useful for kernels that may run on systems that have
2060 bool "Enable support for SMBIOS (DMI) tables"
2064 This enables SMBIOS/DMI feature for systems.
2066 This option is only useful on systems that have UEFI firmware.
2067 However, even with this option, the resultant kernel should
2068 continue to boot on existing non-UEFI platforms.
2070 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
2071 i.e., the the practice of identifying the platform via DMI to
2072 decide whether certain workarounds for buggy hardware and/or
2073 firmware need to be enabled. This would require the DMI subsystem
2074 to be enabled much earlier than we do on ARM, which is non-trivial.
2078 menu "CPU Power Management"
2080 source "drivers/cpufreq/Kconfig"
2082 source "drivers/cpuidle/Kconfig"
2086 menu "Floating point emulation"
2088 comment "At least one emulation must be selected"
2091 bool "NWFPE math emulation"
2092 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2094 Say Y to include the NWFPE floating point emulator in the kernel.
2095 This is necessary to run most binaries. Linux does not currently
2096 support floating point hardware so you need to say Y here even if
2097 your machine has an FPA or floating point co-processor podule.
2099 You may say N here if you are going to load the Acorn FPEmulator
2100 early in the bootup.
2103 bool "Support extended precision"
2104 depends on FPE_NWFPE
2106 Say Y to include 80-bit support in the kernel floating-point
2107 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2108 Note that gcc does not generate 80-bit operations by default,
2109 so in most cases this option only enlarges the size of the
2110 floating point emulator without any good reason.
2112 You almost surely want to say N here.
2115 bool "FastFPE math emulation (EXPERIMENTAL)"
2116 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2118 Say Y here to include the FAST floating point emulator in the kernel.
2119 This is an experimental much faster emulator which now also has full
2120 precision for the mantissa. It does not support any exceptions.
2121 It is very simple, and approximately 3-6 times faster than NWFPE.
2123 It should be sufficient for most programs. It may be not suitable
2124 for scientific calculations, but you have to check this for yourself.
2125 If you do not feel you need a faster FP emulation you should better
2129 bool "VFP-format floating point maths"
2130 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2132 Say Y to include VFP support code in the kernel. This is needed
2133 if your hardware includes a VFP unit.
2135 Please see <file:Documentation/arm/vfp/release-notes.rst> for
2136 release notes and additional status information.
2138 Say N if your target does not have VFP hardware.
2146 bool "Advanced SIMD (NEON) Extension support"
2147 depends on VFPv3 && CPU_V7
2149 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2152 config KERNEL_MODE_NEON
2153 bool "Support for NEON in kernel mode"
2154 depends on NEON && AEABI
2156 Say Y to include support for NEON in kernel mode.
2160 menu "Power management options"
2162 source "kernel/power/Kconfig"
2164 config ARCH_SUSPEND_POSSIBLE
2165 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2166 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2169 config ARM_CPU_SUSPEND
2170 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2171 depends on ARCH_SUSPEND_POSSIBLE
2173 config ARCH_HIBERNATION_POSSIBLE
2176 default y if ARCH_SUSPEND_POSSIBLE
2180 source "drivers/firmware/Kconfig"
2183 source "arch/arm/crypto/Kconfig"
2186 source "arch/arm/kvm/Kconfig"