Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2config ARM
3 bool
4 default y
5 select ARCH_32BIT_OFF_T
6 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND
7 select ARCH_HAS_BINFMT_FLAT
8 select ARCH_HAS_CURRENT_STACK_POINTER
9 select ARCH_HAS_DEBUG_VIRTUAL if MMU
10 select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
11 select ARCH_HAS_ELF_RANDOMIZE
12 select ARCH_HAS_FORTIFY_SOURCE
13 select ARCH_HAS_KEEPINITRD
14 select ARCH_HAS_KCOV
15 select ARCH_HAS_MEMBARRIER_SYNC_CORE
16 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
17 select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
18 select ARCH_HAS_SETUP_DMA_OPS
19 select ARCH_HAS_SET_MEMORY
20 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
21 select ARCH_HAS_STRICT_MODULE_RWX if MMU
22 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
23 select ARCH_HAS_SYNC_DMA_FOR_CPU
24 select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
25 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
26 select ARCH_HAVE_CUSTOM_GPIO_H
27 select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
28 select ARCH_HAS_GCOV_PROFILE_ALL
29 select ARCH_KEEP_MEMBLOCK
30 select ARCH_MIGHT_HAVE_PC_PARPORT
31 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
32 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
33 select ARCH_SUPPORTS_ATOMIC_RMW
34 select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
35 select ARCH_USE_BUILTIN_BSWAP
36 select ARCH_USE_CMPXCHG_LOCKREF
37 select ARCH_USE_MEMTEST
38 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
39 select ARCH_WANT_GENERAL_HUGETLB
40 select ARCH_WANT_IPC_PARSE_VERSION
41 select ARCH_WANT_LD_ORPHAN_WARN
42 select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
43 select BUILDTIME_TABLE_SORT if MMU
44 select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE)
45 select CLONE_BACKWARDS
46 select CPU_PM if SUSPEND || CPU_IDLE
47 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select DMA_DECLARE_COHERENT
49 select DMA_GLOBAL_POOL if !MMU
50 select DMA_OPS
51 select DMA_NONCOHERENT_MMAP if MMU
52 select EDAC_SUPPORT
53 select EDAC_ATOMIC_SCRUB
54 select GENERIC_ALLOCATOR
55 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
56 select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
57 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
58 select GENERIC_IRQ_IPI if SMP
59 select GENERIC_CPU_AUTOPROBE
60 select GENERIC_EARLY_IOREMAP
61 select GENERIC_IDLE_POLL_SETUP
62 select GENERIC_IRQ_MULTI_HANDLER
63 select GENERIC_IRQ_PROBE
64 select GENERIC_IRQ_SHOW
65 select GENERIC_IRQ_SHOW_LEVEL
66 select GENERIC_LIB_DEVMEM_IS_ALLOWED
67 select GENERIC_PCI_IOMAP
68 select GENERIC_SCHED_CLOCK
69 select GENERIC_SMP_IDLE_THREAD
70 select HARDIRQS_SW_RESEND
71 select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
72 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
73 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
74 select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
75 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
76 select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
77 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
78 select HAVE_ARCH_MMAP_RND_BITS if MMU
79 select HAVE_ARCH_PFN_VALID
80 select HAVE_ARCH_SECCOMP
81 select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
82 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
83 select HAVE_ARCH_TRACEHOOK
84 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
85 select HAVE_ARM_SMCCC if CPU_V7
86 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
87 select HAVE_CONTEXT_TRACKING_USER
88 select HAVE_C_RECORDMCOUNT
89 select HAVE_BUILDTIME_MCOUNT_SORT
90 select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
91 select HAVE_DMA_CONTIGUOUS if MMU
92 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
93 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
94 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
95 select HAVE_EXIT_THREAD
96 select HAVE_FAST_GUP if ARM_LPAE
97 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
98 select HAVE_FUNCTION_GRAPH_TRACER
99 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
100 select HAVE_GCC_PLUGINS
101 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
102 select HAVE_IRQ_TIME_ACCOUNTING
103 select HAVE_KERNEL_GZIP
104 select HAVE_KERNEL_LZ4
105 select HAVE_KERNEL_LZMA
106 select HAVE_KERNEL_LZO
107 select HAVE_KERNEL_XZ
108 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
109 select HAVE_KRETPROBES if HAVE_KPROBES
110 select HAVE_MOD_ARCH_SPECIFIC
111 select HAVE_NMI
112 select HAVE_OPTPROBES if !THUMB2_KERNEL
113 select HAVE_PCI if MMU
114 select HAVE_PERF_EVENTS
115 select HAVE_PERF_REGS
116 select HAVE_PERF_USER_STACK_DUMP
117 select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
118 select HAVE_REGS_AND_STACK_ACCESS_API
119 select HAVE_RSEQ
120 select HAVE_STACKPROTECTOR
121 select HAVE_SYSCALL_TRACEPOINTS
122 select HAVE_UID16
123 select HAVE_VIRT_CPU_ACCOUNTING_GEN
124 select IRQ_FORCED_THREADING
125 select MODULES_USE_ELF_REL
126 select NEED_DMA_MAP_STATE
127 select OF_EARLY_FLATTREE if OF
128 select OLD_SIGACTION
129 select OLD_SIGSUSPEND3
130 select PCI_DOMAINS_GENERIC if PCI
131 select PCI_SYSCALL if PCI
132 select PERF_USE_VMALLOC
133 select RTC_LIB
134 select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
135 select SYS_SUPPORTS_APM_EMULATION
136 select THREAD_INFO_IN_TASK
137 select TIMER_OF if OF
138 select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
139 select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
140 select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
141 # Above selects are sorted alphabetically; please add new ones
142 # according to that. Thanks.
143 help
144 The ARM series is a line of low-power-consumption RISC chip designs
145 licensed by ARM Ltd and targeted at embedded applications and
146 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
147 manufactured, but legacy ARM-based PC hardware remains popular in
148 Europe. There is an ARM Linux project with a web page at
149 <http://www.arm.linux.org.uk/>.
150
151config ARM_HAS_GROUP_RELOCS
152 def_bool y
153 depends on !LD_IS_LLD || LLD_VERSION >= 140000
154 depends on !COMPILE_TEST
155 help
156 Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
157 relocations, which have been around for a long time, but were not
158 supported in LLD until version 14. The combined range is -/+ 256 MiB,
159 which is usually sufficient, but not for allyesconfig, so we disable
160 this feature when doing compile testing.
161
162config ARM_DMA_USE_IOMMU
163 bool
164 select NEED_SG_DMA_LENGTH
165
166if ARM_DMA_USE_IOMMU
167
168config ARM_DMA_IOMMU_ALIGNMENT
169 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
170 range 4 9
171 default 8
172 help
173 DMA mapping framework by default aligns all buffers to the smallest
174 PAGE_SIZE order which is greater than or equal to the requested buffer
175 size. This works well for buffers up to a few hundreds kilobytes, but
176 for larger buffers it just a waste of address space. Drivers which has
177 relatively small addressing window (like 64Mib) might run out of
178 virtual space with just a few allocations.
179
180 With this parameter you can specify the maximum PAGE_SIZE order for
181 DMA IOMMU buffers. Larger buffers will be aligned only to this
182 specified order. The order is expressed as a power of two multiplied
183 by the PAGE_SIZE.
184
185endif
186
187config SYS_SUPPORTS_APM_EMULATION
188 bool
189
190config HAVE_TCM
191 bool
192 select GENERIC_ALLOCATOR
193
194config HAVE_PROC_CPU
195 bool
196
197config NO_IOPORT_MAP
198 bool
199
200config SBUS
201 bool
202
203config STACKTRACE_SUPPORT
204 bool
205 default y
206
207config LOCKDEP_SUPPORT
208 bool
209 default y
210
211config ARCH_HAS_ILOG2_U32
212 bool
213
214config ARCH_HAS_ILOG2_U64
215 bool
216
217config ARCH_HAS_BANDGAP
218 bool
219
220config FIX_EARLYCON_MEM
221 def_bool y if MMU
222
223config GENERIC_HWEIGHT
224 bool
225 default y
226
227config GENERIC_CALIBRATE_DELAY
228 bool
229 default y
230
231config ARCH_MAY_HAVE_PC_FDC
232 bool
233
234config ARCH_SUPPORTS_UPROBES
235 def_bool y
236
237config GENERIC_ISA_DMA
238 bool
239
240config FIQ
241 bool
242
243config ARCH_MTD_XIP
244 bool
245
246config ARM_PATCH_PHYS_VIRT
247 bool "Patch physical to virtual translations at runtime" if EMBEDDED
248 default y
249 depends on MMU
250 help
251 Patch phys-to-virt and virt-to-phys translation functions at
252 boot and module load time according to the position of the
253 kernel in system memory.
254
255 This can only be used with non-XIP MMU kernels where the base
256 of physical memory is at a 2 MiB boundary.
257
258 Only disable this option if you know that you do not require
259 this feature (eg, building a kernel for a single machine) and
260 you need to shrink the kernel to the minimal size.
261
262config NEED_MACH_IO_H
263 bool
264 help
265 Select this when mach/io.h is required to provide special
266 definitions for this platform. The need for mach/io.h should
267 be avoided when possible.
268
269config NEED_MACH_MEMORY_H
270 bool
271 help
272 Select this when mach/memory.h is required to provide special
273 definitions for this platform. The need for mach/memory.h should
274 be avoided when possible.
275
276config PHYS_OFFSET
277 hex "Physical address of main memory" if MMU
278 depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
279 default DRAM_BASE if !MMU
280 default 0x00000000 if ARCH_FOOTBRIDGE
281 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
282 default 0x30000000 if ARCH_S3C24XX
283 default 0xa0000000 if ARCH_IOP32X || ARCH_PXA
284 default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
285 default 0
286 help
287 Please provide the physical address corresponding to the
288 location of main memory in your system.
289
290config GENERIC_BUG
291 def_bool y
292 depends on BUG
293
294config PGTABLE_LEVELS
295 int
296 default 3 if ARM_LPAE
297 default 2
298
299menu "System Type"
300
301config MMU
302 bool "MMU-based Paged Memory Management Support"
303 default y
304 help
305 Select if you want MMU-based virtualised addressing space
306 support by paged memory management. If unsure, say 'Y'.
307
308config ARM_SINGLE_ARMV7M
309 def_bool !MMU
310 select ARM_NVIC
311 select CPU_V7M
312 select NO_IOPORT_MAP
313
314config ARCH_MMAP_RND_BITS_MIN
315 default 8
316
317config ARCH_MMAP_RND_BITS_MAX
318 default 14 if PAGE_OFFSET=0x40000000
319 default 15 if PAGE_OFFSET=0x80000000
320 default 16
321
322config ARCH_MULTIPLATFORM
323 bool "Require kernel to be portable to multiple machines" if EXPERT
324 depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
325 default y
326 help
327 In general, all Arm machines can be supported in a single
328 kernel image, covering either Armv4/v5 or Armv6/v7.
329
330 However, some configuration options require hardcoding machine
331 specific physical addresses or enable errata workarounds that may
332 break other machines.
333
334 Selecting N here allows using those options, including
335 DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
336
337menu "Platform selection"
338 depends on MMU
339
340comment "CPU Core family selection"
341
342config ARCH_MULTI_V4
343 bool "ARMv4 based platforms (FA526, StrongARM)"
344 depends on !ARCH_MULTI_V6_V7
345 select ARCH_MULTI_V4_V5
346 select CPU_FA526 if !(CPU_SA110 || CPU_SA1100)
347
348config ARCH_MULTI_V4T
349 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
350 depends on !ARCH_MULTI_V6_V7
351 select ARCH_MULTI_V4_V5
352 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
353 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
354 CPU_ARM925T || CPU_ARM940T)
355
356config ARCH_MULTI_V5
357 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
358 depends on !ARCH_MULTI_V6_V7
359 select ARCH_MULTI_V4_V5
360 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
361 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
362 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
363
364config ARCH_MULTI_V4_V5
365 bool
366
367config ARCH_MULTI_V6
368 bool "ARMv6 based platforms (ARM11)"
369 select ARCH_MULTI_V6_V7
370 select CPU_V6K
371
372config ARCH_MULTI_V7
373 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
374 default y
375 select ARCH_MULTI_V6_V7
376 select CPU_V7
377 select HAVE_SMP
378
379config ARCH_MULTI_V6_V7
380 bool
381 select MIGHT_HAVE_CACHE_L2X0
382
383config ARCH_MULTI_CPU_AUTO
384 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
385 select ARCH_MULTI_V5
386
387endmenu
388
389config ARCH_VIRT
390 bool "Dummy Virtual Machine"
391 depends on ARCH_MULTI_V7
392 select ARM_AMBA
393 select ARM_GIC
394 select ARM_GIC_V2M if PCI
395 select ARM_GIC_V3
396 select ARM_GIC_V3_ITS if PCI
397 select ARM_PSCI
398 select HAVE_ARM_ARCH_TIMER
399
400config ARCH_AIROHA
401 bool "Airoha SoC Support"
402 depends on ARCH_MULTI_V7
403 select ARM_AMBA
404 select ARM_GIC
405 select ARM_GIC_V3
406 select ARM_PSCI
407 select HAVE_ARM_ARCH_TIMER
408 help
409 Support for Airoha EN7523 SoCs
410
411#
412# This is sorted alphabetically by mach-* pathname. However, plat-*
413# Kconfigs may be included either alphabetically (according to the
414# plat- suffix) or along side the corresponding mach-* source.
415#
416source "arch/arm/mach-actions/Kconfig"
417
418source "arch/arm/mach-alpine/Kconfig"
419
420source "arch/arm/mach-artpec/Kconfig"
421
422source "arch/arm/mach-asm9260/Kconfig"
423
424source "arch/arm/mach-aspeed/Kconfig"
425
426source "arch/arm/mach-at91/Kconfig"
427
428source "arch/arm/mach-axxia/Kconfig"
429
430source "arch/arm/mach-bcm/Kconfig"
431
432source "arch/arm/mach-berlin/Kconfig"
433
434source "arch/arm/mach-clps711x/Kconfig"
435
436source "arch/arm/mach-cns3xxx/Kconfig"
437
438source "arch/arm/mach-davinci/Kconfig"
439
440source "arch/arm/mach-digicolor/Kconfig"
441
442source "arch/arm/mach-dove/Kconfig"
443
444source "arch/arm/mach-ep93xx/Kconfig"
445
446source "arch/arm/mach-exynos/Kconfig"
447
448source "arch/arm/mach-footbridge/Kconfig"
449
450source "arch/arm/mach-gemini/Kconfig"
451
452source "arch/arm/mach-highbank/Kconfig"
453
454source "arch/arm/mach-hisi/Kconfig"
455
456source "arch/arm/mach-hpe/Kconfig"
457
458source "arch/arm/mach-imx/Kconfig"
459
460source "arch/arm/mach-iop32x/Kconfig"
461
462source "arch/arm/mach-ixp4xx/Kconfig"
463
464source "arch/arm/mach-keystone/Kconfig"
465
466source "arch/arm/mach-lpc32xx/Kconfig"
467
468source "arch/arm/mach-mediatek/Kconfig"
469
470source "arch/arm/mach-meson/Kconfig"
471
472source "arch/arm/mach-milbeaut/Kconfig"
473
474source "arch/arm/mach-mmp/Kconfig"
475
476source "arch/arm/mach-moxart/Kconfig"
477
478source "arch/arm/mach-mstar/Kconfig"
479
480source "arch/arm/mach-mv78xx0/Kconfig"
481
482source "arch/arm/mach-mvebu/Kconfig"
483
484source "arch/arm/mach-mxs/Kconfig"
485
486source "arch/arm/mach-nomadik/Kconfig"
487
488source "arch/arm/mach-npcm/Kconfig"
489
490source "arch/arm/mach-nspire/Kconfig"
491
492source "arch/arm/mach-omap1/Kconfig"
493
494source "arch/arm/mach-omap2/Kconfig"
495
496source "arch/arm/mach-orion5x/Kconfig"
497
498source "arch/arm/mach-oxnas/Kconfig"
499
500source "arch/arm/mach-pxa/Kconfig"
501
502source "arch/arm/mach-qcom/Kconfig"
503
504source "arch/arm/mach-rda/Kconfig"
505
506source "arch/arm/mach-realtek/Kconfig"
507
508source "arch/arm/mach-rpc/Kconfig"
509
510source "arch/arm/mach-rockchip/Kconfig"
511
512source "arch/arm/mach-s3c/Kconfig"
513
514source "arch/arm/mach-s5pv210/Kconfig"
515
516source "arch/arm/mach-sa1100/Kconfig"
517
518source "arch/arm/mach-shmobile/Kconfig"
519
520source "arch/arm/mach-socfpga/Kconfig"
521
522source "arch/arm/mach-spear/Kconfig"
523
524source "arch/arm/mach-sti/Kconfig"
525
526source "arch/arm/mach-stm32/Kconfig"
527
528source "arch/arm/mach-sunplus/Kconfig"
529
530source "arch/arm/mach-sunxi/Kconfig"
531
532source "arch/arm/mach-tegra/Kconfig"
533
534source "arch/arm/mach-uniphier/Kconfig"
535
536source "arch/arm/mach-ux500/Kconfig"
537
538source "arch/arm/mach-versatile/Kconfig"
539
540source "arch/arm/mach-vt8500/Kconfig"
541
542source "arch/arm/mach-zynq/Kconfig"
543
544# ARMv7-M architecture
545config ARCH_LPC18XX
546 bool "NXP LPC18xx/LPC43xx"
547 depends on ARM_SINGLE_ARMV7M
548 select ARCH_HAS_RESET_CONTROLLER
549 select ARM_AMBA
550 select CLKSRC_LPC32XX
551 select PINCTRL
552 help
553 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
554 high performance microcontrollers.
555
556config ARCH_MPS2
557 bool "ARM MPS2 platform"
558 depends on ARM_SINGLE_ARMV7M
559 select ARM_AMBA
560 select CLKSRC_MPS2
561 help
562 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
563 with a range of available cores like Cortex-M3/M4/M7.
564
565 Please, note that depends which Application Note is used memory map
566 for the platform may vary, so adjustment of RAM base might be needed.
567
568# Definitions to make life easier
569config ARCH_ACORN
570 bool
571
572config PLAT_ORION
573 bool
574 select CLKSRC_MMIO
575 select GENERIC_IRQ_CHIP
576 select IRQ_DOMAIN
577
578config PLAT_ORION_LEGACY
579 bool
580 select PLAT_ORION
581
582config PLAT_VERSATILE
583 bool
584
585source "arch/arm/mm/Kconfig"
586
587config IWMMXT
588 bool "Enable iWMMXt support"
589 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
590 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
591 help
592 Enable support for iWMMXt context switching at run time if
593 running on a CPU that supports it.
594
595if !MMU
596source "arch/arm/Kconfig-nommu"
597endif
598
599config PJ4B_ERRATA_4742
600 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
601 depends on CPU_PJ4B && MACH_ARMADA_370
602 default y
603 help
604 When coming out of either a Wait for Interrupt (WFI) or a Wait for
605 Event (WFE) IDLE states, a specific timing sensitivity exists between
606 the retiring WFI/WFE instructions and the newly issued subsequent
607 instructions. This sensitivity can result in a CPU hang scenario.
608 Workaround:
609 The software must insert either a Data Synchronization Barrier (DSB)
610 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
611 instruction
612
613config ARM_ERRATA_326103
614 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
615 depends on CPU_V6
616 help
617 Executing a SWP instruction to read-only memory does not set bit 11
618 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
619 treat the access as a read, preventing a COW from occurring and
620 causing the faulting task to livelock.
621
622config ARM_ERRATA_411920
623 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
624 depends on CPU_V6 || CPU_V6K
625 help
626 Invalidation of the Instruction Cache operation can
627 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
628 It does not affect the MPCore. This option enables the ARM Ltd.
629 recommended workaround.
630
631config ARM_ERRATA_430973
632 bool "ARM errata: Stale prediction on replaced interworking branch"
633 depends on CPU_V7
634 help
635 This option enables the workaround for the 430973 Cortex-A8
636 r1p* erratum. If a code sequence containing an ARM/Thumb
637 interworking branch is replaced with another code sequence at the
638 same virtual address, whether due to self-modifying code or virtual
639 to physical address re-mapping, Cortex-A8 does not recover from the
640 stale interworking branch prediction. This results in Cortex-A8
641 executing the new code sequence in the incorrect ARM or Thumb state.
642 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
643 and also flushes the branch target cache at every context switch.
644 Note that setting specific bits in the ACTLR register may not be
645 available in non-secure mode.
646
647config ARM_ERRATA_458693
648 bool "ARM errata: Processor deadlock when a false hazard is created"
649 depends on CPU_V7
650 depends on !ARCH_MULTIPLATFORM
651 help
652 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
653 erratum. For very specific sequences of memory operations, it is
654 possible for a hazard condition intended for a cache line to instead
655 be incorrectly associated with a different cache line. This false
656 hazard might then cause a processor deadlock. The workaround enables
657 the L1 caching of the NEON accesses and disables the PLD instruction
658 in the ACTLR register. Note that setting specific bits in the ACTLR
659 register may not be available in non-secure mode.
660
661config ARM_ERRATA_460075
662 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
663 depends on CPU_V7
664 depends on !ARCH_MULTIPLATFORM
665 help
666 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
667 erratum. Any asynchronous access to the L2 cache may encounter a
668 situation in which recent store transactions to the L2 cache are lost
669 and overwritten with stale memory contents from external memory. The
670 workaround disables the write-allocate mode for the L2 cache via the
671 ACTLR register. Note that setting specific bits in the ACTLR register
672 may not be available in non-secure mode.
673
674config ARM_ERRATA_742230
675 bool "ARM errata: DMB operation may be faulty"
676 depends on CPU_V7 && SMP
677 depends on !ARCH_MULTIPLATFORM
678 help
679 This option enables the workaround for the 742230 Cortex-A9
680 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
681 between two write operations may not ensure the correct visibility
682 ordering of the two writes. This workaround sets a specific bit in
683 the diagnostic register of the Cortex-A9 which causes the DMB
684 instruction to behave as a DSB, ensuring the correct behaviour of
685 the two writes.
686
687config ARM_ERRATA_742231
688 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
689 depends on CPU_V7 && SMP
690 depends on !ARCH_MULTIPLATFORM
691 help
692 This option enables the workaround for the 742231 Cortex-A9
693 (r2p0..r2p2) erratum. Under certain conditions, specific to the
694 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
695 accessing some data located in the same cache line, may get corrupted
696 data due to bad handling of the address hazard when the line gets
697 replaced from one of the CPUs at the same time as another CPU is
698 accessing it. This workaround sets specific bits in the diagnostic
699 register of the Cortex-A9 which reduces the linefill issuing
700 capabilities of the processor.
701
702config ARM_ERRATA_643719
703 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
704 depends on CPU_V7 && SMP
705 default y
706 help
707 This option enables the workaround for the 643719 Cortex-A9 (prior to
708 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
709 register returns zero when it should return one. The workaround
710 corrects this value, ensuring cache maintenance operations which use
711 it behave as intended and avoiding data corruption.
712
713config ARM_ERRATA_720789
714 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
715 depends on CPU_V7
716 help
717 This option enables the workaround for the 720789 Cortex-A9 (prior to
718 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
719 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
720 As a consequence of this erratum, some TLB entries which should be
721 invalidated are not, resulting in an incoherency in the system page
722 tables. The workaround changes the TLB flushing routines to invalidate
723 entries regardless of the ASID.
724
725config ARM_ERRATA_743622
726 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
727 depends on CPU_V7
728 depends on !ARCH_MULTIPLATFORM
729 help
730 This option enables the workaround for the 743622 Cortex-A9
731 (r2p*) erratum. Under very rare conditions, a faulty
732 optimisation in the Cortex-A9 Store Buffer may lead to data
733 corruption. This workaround sets a specific bit in the diagnostic
734 register of the Cortex-A9 which disables the Store Buffer
735 optimisation, preventing the defect from occurring. This has no
736 visible impact on the overall performance or power consumption of the
737 processor.
738
739config ARM_ERRATA_751472
740 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
741 depends on CPU_V7
742 depends on !ARCH_MULTIPLATFORM
743 help
744 This option enables the workaround for the 751472 Cortex-A9 (prior
745 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
746 completion of a following broadcasted operation if the second
747 operation is received by a CPU before the ICIALLUIS has completed,
748 potentially leading to corrupted entries in the cache or TLB.
749
750config ARM_ERRATA_754322
751 bool "ARM errata: possible faulty MMU translations following an ASID switch"
752 depends on CPU_V7
753 help
754 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
755 r3p*) erratum. A speculative memory access may cause a page table walk
756 which starts prior to an ASID switch but completes afterwards. This
757 can populate the micro-TLB with a stale entry which may be hit with
758 the new ASID. This workaround places two dsb instructions in the mm
759 switching code so that no page table walks can cross the ASID switch.
760
761config ARM_ERRATA_754327
762 bool "ARM errata: no automatic Store Buffer drain"
763 depends on CPU_V7 && SMP
764 help
765 This option enables the workaround for the 754327 Cortex-A9 (prior to
766 r2p0) erratum. The Store Buffer does not have any automatic draining
767 mechanism and therefore a livelock may occur if an external agent
768 continuously polls a memory location waiting to observe an update.
769 This workaround defines cpu_relax() as smp_mb(), preventing correctly
770 written polling loops from denying visibility of updates to memory.
771
772config ARM_ERRATA_364296
773 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
774 depends on CPU_V6
775 help
776 This options enables the workaround for the 364296 ARM1136
777 r0p2 erratum (possible cache data corruption with
778 hit-under-miss enabled). It sets the undocumented bit 31 in
779 the auxiliary control register and the FI bit in the control
780 register, thus disabling hit-under-miss without putting the
781 processor into full low interrupt latency mode. ARM11MPCore
782 is not affected.
783
784config ARM_ERRATA_764369
785 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
786 depends on CPU_V7 && SMP
787 help
788 This option enables the workaround for erratum 764369
789 affecting Cortex-A9 MPCore with two or more processors (all
790 current revisions). Under certain timing circumstances, a data
791 cache line maintenance operation by MVA targeting an Inner
792 Shareable memory region may fail to proceed up to either the
793 Point of Coherency or to the Point of Unification of the
794 system. This workaround adds a DSB instruction before the
795 relevant cache maintenance functions and sets a specific bit
796 in the diagnostic control register of the SCU.
797
798config ARM_ERRATA_764319
799 bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
800 depends on CPU_V7
801 help
802 This option enables the workaround for the 764319 Cortex A-9 erratum.
803 CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
804 unexpected Undefined Instruction exception when the DBGSWENABLE
805 external pin is set to 0, even when the CP14 accesses are performed
806 from a privileged mode. This work around catches the exception in a
807 way the kernel does not stop execution.
808
809config ARM_ERRATA_775420
810 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
811 depends on CPU_V7
812 help
813 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
814 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
815 operation aborts with MMU exception, it might cause the processor
816 to deadlock. This workaround puts DSB before executing ISB if
817 an abort may occur on cache maintenance.
818
819config ARM_ERRATA_798181
820 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
821 depends on CPU_V7 && SMP
822 help
823 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
824 adequately shooting down all use of the old entries. This
825 option enables the Linux kernel workaround for this erratum
826 which sends an IPI to the CPUs that are running the same ASID
827 as the one being invalidated.
828
829config ARM_ERRATA_773022
830 bool "ARM errata: incorrect instructions may be executed from loop buffer"
831 depends on CPU_V7
832 help
833 This option enables the workaround for the 773022 Cortex-A15
834 (up to r0p4) erratum. In certain rare sequences of code, the
835 loop buffer may deliver incorrect instructions. This
836 workaround disables the loop buffer to avoid the erratum.
837
838config ARM_ERRATA_818325_852422
839 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
840 depends on CPU_V7
841 help
842 This option enables the workaround for:
843 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
844 instruction might deadlock. Fixed in r0p1.
845 - Cortex-A12 852422: Execution of a sequence of instructions might
846 lead to either a data corruption or a CPU deadlock. Not fixed in
847 any Cortex-A12 cores yet.
848 This workaround for all both errata involves setting bit[12] of the
849 Feature Register. This bit disables an optimisation applied to a
850 sequence of 2 instructions that use opposing condition codes.
851
852config ARM_ERRATA_821420
853 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
854 depends on CPU_V7
855 help
856 This option enables the workaround for the 821420 Cortex-A12
857 (all revs) erratum. In very rare timing conditions, a sequence
858 of VMOV to Core registers instructions, for which the second
859 one is in the shadow of a branch or abort, can lead to a
860 deadlock when the VMOV instructions are issued out-of-order.
861
862config ARM_ERRATA_825619
863 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
864 depends on CPU_V7
865 help
866 This option enables the workaround for the 825619 Cortex-A12
867 (all revs) erratum. Within rare timing constraints, executing a
868 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
869 and Device/Strongly-Ordered loads and stores might cause deadlock
870
871config ARM_ERRATA_857271
872 bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
873 depends on CPU_V7
874 help
875 This option enables the workaround for the 857271 Cortex-A12
876 (all revs) erratum. Under very rare timing conditions, the CPU might
877 hang. The workaround is expected to have a < 1% performance impact.
878
879config ARM_ERRATA_852421
880 bool "ARM errata: A17: DMB ST might fail to create order between stores"
881 depends on CPU_V7
882 help
883 This option enables the workaround for the 852421 Cortex-A17
884 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
885 execution of a DMB ST instruction might fail to properly order
886 stores from GroupA and stores from GroupB.
887
888config ARM_ERRATA_852423
889 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
890 depends on CPU_V7
891 help
892 This option enables the workaround for:
893 - Cortex-A17 852423: Execution of a sequence of instructions might
894 lead to either a data corruption or a CPU deadlock. Not fixed in
895 any Cortex-A17 cores yet.
896 This is identical to Cortex-A12 erratum 852422. It is a separate
897 config option from the A12 erratum due to the way errata are checked
898 for and handled.
899
900config ARM_ERRATA_857272
901 bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
902 depends on CPU_V7
903 help
904 This option enables the workaround for the 857272 Cortex-A17 erratum.
905 This erratum is not known to be fixed in any A17 revision.
906 This is identical to Cortex-A12 erratum 857271. It is a separate
907 config option from the A12 erratum due to the way errata are checked
908 for and handled.
909
910endmenu
911
912source "arch/arm/common/Kconfig"
913
914menu "Bus support"
915
916config ISA
917 bool
918 help
919 Find out whether you have ISA slots on your motherboard. ISA is the
920 name of a bus system, i.e. the way the CPU talks to the other stuff
921 inside your box. Other bus systems are PCI, EISA, MicroChannel
922 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
923 newer boards don't support it. If you have ISA, say Y, otherwise N.
924
925# Select ISA DMA interface
926config ISA_DMA_API
927 bool
928
929config PCI_NANOENGINE
930 bool "BSE nanoEngine PCI support"
931 depends on SA1100_NANOENGINE
932 help
933 Enable PCI on the BSE nanoEngine board.
934
935config ARM_ERRATA_814220
936 bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
937 depends on CPU_V7
938 help
939 The v7 ARM states that all cache and branch predictor maintenance
940 operations that do not specify an address execute, relative to
941 each other, in program order.
942 However, because of this erratum, an L2 set/way cache maintenance
943 operation can overtake an L1 set/way cache maintenance operation.
944 This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
945 r0p4, r0p5.
946
947endmenu
948
949menu "Kernel Features"
950
951config HAVE_SMP
952 bool
953 help
954 This option should be selected by machines which have an SMP-
955 capable CPU.
956
957 The only effect of this option is to make the SMP-related
958 options available to the user for configuration.
959
960config SMP
961 bool "Symmetric Multi-Processing"
962 depends on CPU_V6K || CPU_V7
963 depends on HAVE_SMP
964 depends on MMU || ARM_MPU
965 select IRQ_WORK
966 help
967 This enables support for systems with more than one CPU. If you have
968 a system with only one CPU, say N. If you have a system with more
969 than one CPU, say Y.
970
971 If you say N here, the kernel will run on uni- and multiprocessor
972 machines, but will use only one CPU of a multiprocessor machine. If
973 you say Y here, the kernel will run on many, but not all,
974 uniprocessor machines. On a uniprocessor machine, the kernel
975 will run faster if you say N here.
976
977 See also <file:Documentation/x86/i386/IO-APIC.rst>,
978 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
979 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
980
981 If you don't know what to do here, say N.
982
983config SMP_ON_UP
984 bool "Allow booting SMP kernel on uniprocessor systems"
985 depends on SMP && MMU
986 default y
987 help
988 SMP kernels contain instructions which fail on non-SMP processors.
989 Enabling this option allows the kernel to modify itself to make
990 these instructions safe. Disabling it allows about 1K of space
991 savings.
992
993 If you don't know what to do here, say Y.
994
995
996config CURRENT_POINTER_IN_TPIDRURO
997 def_bool y
998 depends on CPU_32v6K && !CPU_V6
999
1000config IRQSTACKS
1001 def_bool y
1002 select HAVE_IRQ_EXIT_ON_IRQ_STACK
1003 select HAVE_SOFTIRQ_ON_OWN_STACK
1004
1005config ARM_CPU_TOPOLOGY
1006 bool "Support cpu topology definition"
1007 depends on SMP && CPU_V7
1008 default y
1009 help
1010 Support ARM cpu topology definition. The MPIDR register defines
1011 affinity between processors which is then used to describe the cpu
1012 topology of an ARM System.
1013
1014config SCHED_MC
1015 bool "Multi-core scheduler support"
1016 depends on ARM_CPU_TOPOLOGY
1017 help
1018 Multi-core scheduler support improves the CPU scheduler's decision
1019 making when dealing with multi-core CPU chips at a cost of slightly
1020 increased overhead in some places. If unsure say N here.
1021
1022config SCHED_SMT
1023 bool "SMT scheduler support"
1024 depends on ARM_CPU_TOPOLOGY
1025 help
1026 Improves the CPU scheduler's decision making when dealing with
1027 MultiThreading at a cost of slightly increased overhead in some
1028 places. If unsure say N here.
1029
1030config HAVE_ARM_SCU
1031 bool
1032 help
1033 This option enables support for the ARM snoop control unit
1034
1035config HAVE_ARM_ARCH_TIMER
1036 bool "Architected timer support"
1037 depends on CPU_V7
1038 select ARM_ARCH_TIMER
1039 help
1040 This option enables support for the ARM architected timer
1041
1042config HAVE_ARM_TWD
1043 bool
1044 help
1045 This options enables support for the ARM timer and watchdog unit
1046
1047config MCPM
1048 bool "Multi-Cluster Power Management"
1049 depends on CPU_V7 && SMP
1050 help
1051 This option provides the common power management infrastructure
1052 for (multi-)cluster based systems, such as big.LITTLE based
1053 systems.
1054
1055config MCPM_QUAD_CLUSTER
1056 bool
1057 depends on MCPM
1058 help
1059 To avoid wasting resources unnecessarily, MCPM only supports up
1060 to 2 clusters by default.
1061 Platforms with 3 or 4 clusters that use MCPM must select this
1062 option to allow the additional clusters to be managed.
1063
1064config BIG_LITTLE
1065 bool "big.LITTLE support (Experimental)"
1066 depends on CPU_V7 && SMP
1067 select MCPM
1068 help
1069 This option enables support selections for the big.LITTLE
1070 system architecture.
1071
1072config BL_SWITCHER
1073 bool "big.LITTLE switcher support"
1074 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1075 select CPU_PM
1076 help
1077 The big.LITTLE "switcher" provides the core functionality to
1078 transparently handle transition between a cluster of A15's
1079 and a cluster of A7's in a big.LITTLE system.
1080
1081config BL_SWITCHER_DUMMY_IF
1082 tristate "Simple big.LITTLE switcher user interface"
1083 depends on BL_SWITCHER && DEBUG_KERNEL
1084 help
1085 This is a simple and dummy char dev interface to control
1086 the big.LITTLE switcher core code. It is meant for
1087 debugging purposes only.
1088
1089choice
1090 prompt "Memory split"
1091 depends on MMU
1092 default VMSPLIT_3G
1093 help
1094 Select the desired split between kernel and user memory.
1095
1096 If you are not absolutely sure what you are doing, leave this
1097 option alone!
1098
1099 config VMSPLIT_3G
1100 bool "3G/1G user/kernel split"
1101 config VMSPLIT_3G_OPT
1102 depends on !ARM_LPAE
1103 bool "3G/1G user/kernel split (for full 1G low memory)"
1104 config VMSPLIT_2G
1105 bool "2G/2G user/kernel split"
1106 config VMSPLIT_1G
1107 bool "1G/3G user/kernel split"
1108endchoice
1109
1110config PAGE_OFFSET
1111 hex
1112 default PHYS_OFFSET if !MMU
1113 default 0x40000000 if VMSPLIT_1G
1114 default 0x80000000 if VMSPLIT_2G
1115 default 0xB0000000 if VMSPLIT_3G_OPT
1116 default 0xC0000000
1117
1118config KASAN_SHADOW_OFFSET
1119 hex
1120 depends on KASAN
1121 default 0x1f000000 if PAGE_OFFSET=0x40000000
1122 default 0x5f000000 if PAGE_OFFSET=0x80000000
1123 default 0x9f000000 if PAGE_OFFSET=0xC0000000
1124 default 0x8f000000 if PAGE_OFFSET=0xB0000000
1125 default 0xffffffff
1126
1127config NR_CPUS
1128 int "Maximum number of CPUs (2-32)"
1129 range 2 16 if DEBUG_KMAP_LOCAL
1130 range 2 32 if !DEBUG_KMAP_LOCAL
1131 depends on SMP
1132 default "4"
1133 help
1134 The maximum number of CPUs that the kernel can support.
1135 Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1136 debugging is enabled, which uses half of the per-CPU fixmap
1137 slots as guard regions.
1138
1139config HOTPLUG_CPU
1140 bool "Support for hot-pluggable CPUs"
1141 depends on SMP
1142 select GENERIC_IRQ_MIGRATION
1143 help
1144 Say Y here to experiment with turning CPUs off and on. CPUs
1145 can be controlled through /sys/devices/system/cpu.
1146
1147config ARM_PSCI
1148 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1149 depends on HAVE_ARM_SMCCC
1150 select ARM_PSCI_FW
1151 help
1152 Say Y here if you want Linux to communicate with system firmware
1153 implementing the PSCI specification for CPU-centric power
1154 management operations described in ARM document number ARM DEN
1155 0022A ("Power State Coordination Interface System Software on
1156 ARM processors").
1157
1158# The GPIO number here must be sorted by descending number. In case of
1159# a multiplatform kernel, we just want the highest value required by the
1160# selected platforms.
1161config ARCH_NR_GPIO
1162 int
1163 default 2048 if ARCH_INTEL_SOCFPGA
1164 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1165 ARCH_ZYNQ || ARCH_ASPEED
1166 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1167 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1168 default 416 if ARCH_SUNXI
1169 default 392 if ARCH_U8500
1170 default 352 if ARCH_VT8500
1171 default 288 if ARCH_ROCKCHIP
1172 default 264 if MACH_H4700
1173 default 0
1174 help
1175 Maximum number of GPIOs in the system.
1176
1177 If unsure, leave the default value.
1178
1179config HZ_FIXED
1180 int
1181 default 128 if SOC_AT91RM9200
1182 default 0
1183
1184choice
1185 depends on HZ_FIXED = 0
1186 prompt "Timer frequency"
1187
1188config HZ_100
1189 bool "100 Hz"
1190
1191config HZ_200
1192 bool "200 Hz"
1193
1194config HZ_250
1195 bool "250 Hz"
1196
1197config HZ_300
1198 bool "300 Hz"
1199
1200config HZ_500
1201 bool "500 Hz"
1202
1203config HZ_1000
1204 bool "1000 Hz"
1205
1206endchoice
1207
1208config HZ
1209 int
1210 default HZ_FIXED if HZ_FIXED != 0
1211 default 100 if HZ_100
1212 default 200 if HZ_200
1213 default 250 if HZ_250
1214 default 300 if HZ_300
1215 default 500 if HZ_500
1216 default 1000
1217
1218config SCHED_HRTICK
1219 def_bool HIGH_RES_TIMERS
1220
1221config THUMB2_KERNEL
1222 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1223 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1224 default y if CPU_THUMBONLY
1225 select ARM_UNWIND
1226 help
1227 By enabling this option, the kernel will be compiled in
1228 Thumb-2 mode.
1229
1230 If unsure, say N.
1231
1232config ARM_PATCH_IDIV
1233 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1234 depends on CPU_32v7
1235 default y
1236 help
1237 The ARM compiler inserts calls to __aeabi_idiv() and
1238 __aeabi_uidiv() when it needs to perform division on signed
1239 and unsigned integers. Some v7 CPUs have support for the sdiv
1240 and udiv instructions that can be used to implement those
1241 functions.
1242
1243 Enabling this option allows the kernel to modify itself to
1244 replace the first two instructions of these library functions
1245 with the sdiv or udiv plus "bx lr" instructions when the CPU
1246 it is running on supports them. Typically this will be faster
1247 and less power intensive than running the original library
1248 code to do integer division.
1249
1250config AEABI
1251 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1252 !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1253 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1254 help
1255 This option allows for the kernel to be compiled using the latest
1256 ARM ABI (aka EABI). This is only useful if you are using a user
1257 space environment that is also compiled with EABI.
1258
1259 Since there are major incompatibilities between the legacy ABI and
1260 EABI, especially with regard to structure member alignment, this
1261 option also changes the kernel syscall calling convention to
1262 disambiguate both ABIs and allow for backward compatibility support
1263 (selected with CONFIG_OABI_COMPAT).
1264
1265 To use this you need GCC version 4.0.0 or later.
1266
1267config OABI_COMPAT
1268 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1269 depends on AEABI && !THUMB2_KERNEL
1270 help
1271 This option preserves the old syscall interface along with the
1272 new (ARM EABI) one. It also provides a compatibility layer to
1273 intercept syscalls that have structure arguments which layout
1274 in memory differs between the legacy ABI and the new ARM EABI
1275 (only for non "thumb" binaries). This option adds a tiny
1276 overhead to all syscalls and produces a slightly larger kernel.
1277
1278 The seccomp filter system will not be available when this is
1279 selected, since there is no way yet to sensibly distinguish
1280 between calling conventions during filtering.
1281
1282 If you know you'll be using only pure EABI user space then you
1283 can say N here. If this option is not selected and you attempt
1284 to execute a legacy ABI binary then the result will be
1285 UNPREDICTABLE (in fact it can be predicted that it won't work
1286 at all). If in doubt say N.
1287
1288config ARCH_SELECT_MEMORY_MODEL
1289 def_bool y
1290
1291config ARCH_FLATMEM_ENABLE
1292 def_bool !(ARCH_RPC || ARCH_SA1100)
1293
1294config ARCH_SPARSEMEM_ENABLE
1295 def_bool !ARCH_FOOTBRIDGE
1296 select SPARSEMEM_STATIC if SPARSEMEM
1297
1298config HIGHMEM
1299 bool "High Memory Support"
1300 depends on MMU
1301 select KMAP_LOCAL
1302 select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1303 help
1304 The address space of ARM processors is only 4 Gigabytes large
1305 and it has to accommodate user address space, kernel address
1306 space as well as some memory mapped IO. That means that, if you
1307 have a large amount of physical memory and/or IO, not all of the
1308 memory can be "permanently mapped" by the kernel. The physical
1309 memory that is not permanently mapped is called "high memory".
1310
1311 Depending on the selected kernel/user memory split, minimum
1312 vmalloc space and actual amount of RAM, you may not need this
1313 option which should result in a slightly faster kernel.
1314
1315 If unsure, say n.
1316
1317config HIGHPTE
1318 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1319 depends on HIGHMEM
1320 default y
1321 help
1322 The VM uses one page of physical memory for each page table.
1323 For systems with a lot of processes, this can use a lot of
1324 precious low memory, eventually leading to low memory being
1325 consumed by page tables. Setting this option will allow
1326 user-space 2nd level page tables to reside in high memory.
1327
1328config CPU_SW_DOMAIN_PAN
1329 bool "Enable use of CPU domains to implement privileged no-access"
1330 depends on MMU && !ARM_LPAE
1331 default y
1332 help
1333 Increase kernel security by ensuring that normal kernel accesses
1334 are unable to access userspace addresses. This can help prevent
1335 use-after-free bugs becoming an exploitable privilege escalation
1336 by ensuring that magic values (such as LIST_POISON) will always
1337 fault when dereferenced.
1338
1339 CPUs with low-vector mappings use a best-efforts implementation.
1340 Their lower 1MB needs to remain accessible for the vectors, but
1341 the remainder of userspace will become appropriately inaccessible.
1342
1343config HW_PERF_EVENTS
1344 def_bool y
1345 depends on ARM_PMU
1346
1347config ARM_MODULE_PLTS
1348 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1349 depends on MODULES
1350 select KASAN_VMALLOC if KASAN
1351 default y
1352 help
1353 Allocate PLTs when loading modules so that jumps and calls whose
1354 targets are too far away for their relative offsets to be encoded
1355 in the instructions themselves can be bounced via veneers in the
1356 module's PLT. This allows modules to be allocated in the generic
1357 vmalloc area after the dedicated module memory area has been
1358 exhausted. The modules will use slightly more memory, but after
1359 rounding up to page size, the actual memory footprint is usually
1360 the same.
1361
1362 Disabling this is usually safe for small single-platform
1363 configurations. If unsure, say y.
1364
1365config ARCH_FORCE_MAX_ORDER
1366 int "Maximum zone order"
1367 default "12" if SOC_AM33XX
1368 default "9" if SA1111
1369 default "11"
1370 help
1371 The kernel memory allocator divides physically contiguous memory
1372 blocks into "zones", where each zone is a power of two number of
1373 pages. This option selects the largest power of two that the kernel
1374 keeps in the memory allocator. If you need to allocate very large
1375 blocks of physically contiguous memory, then you may need to
1376 increase this value.
1377
1378 This config option is actually maximum order plus one. For example,
1379 a value of 11 means that the largest free memory block is 2^10 pages.
1380
1381config ALIGNMENT_TRAP
1382 def_bool CPU_CP15_MMU
1383 select HAVE_PROC_CPU if PROC_FS
1384 help
1385 ARM processors cannot fetch/store information which is not
1386 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1387 address divisible by 4. On 32-bit ARM processors, these non-aligned
1388 fetch/store instructions will be emulated in software if you say
1389 here, which has a severe performance impact. This is necessary for
1390 correct operation of some network protocols. With an IP-only
1391 configuration it is safe to say N, otherwise say Y.
1392
1393config UACCESS_WITH_MEMCPY
1394 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1395 depends on MMU
1396 default y if CPU_FEROCEON
1397 help
1398 Implement faster copy_to_user and clear_user methods for CPU
1399 cores where a 8-word STM instruction give significantly higher
1400 memory write throughput than a sequence of individual 32bit stores.
1401
1402 A possible side effect is a slight increase in scheduling latency
1403 between threads sharing the same address space if they invoke
1404 such copy operations with large buffers.
1405
1406 However, if the CPU data cache is using a write-allocate mode,
1407 this option is unlikely to provide any performance gain.
1408
1409config PARAVIRT
1410 bool "Enable paravirtualization code"
1411 help
1412 This changes the kernel so it can modify itself when it is run
1413 under a hypervisor, potentially improving performance significantly
1414 over full virtualization.
1415
1416config PARAVIRT_TIME_ACCOUNTING
1417 bool "Paravirtual steal time accounting"
1418 select PARAVIRT
1419 help
1420 Select this option to enable fine granularity task steal time
1421 accounting. Time spent executing other tasks in parallel with
1422 the current vCPU is discounted from the vCPU power. To account for
1423 that, there can be a small performance impact.
1424
1425 If in doubt, say N here.
1426
1427config XEN_DOM0
1428 def_bool y
1429 depends on XEN
1430
1431config XEN
1432 bool "Xen guest support on ARM"
1433 depends on ARM && AEABI && OF
1434 depends on CPU_V7 && !CPU_V6
1435 depends on !GENERIC_ATOMIC64
1436 depends on MMU
1437 select ARCH_DMA_ADDR_T_64BIT
1438 select ARM_PSCI
1439 select SWIOTLB
1440 select SWIOTLB_XEN
1441 select PARAVIRT
1442 help
1443 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1444
1445config CC_HAVE_STACKPROTECTOR_TLS
1446 def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
1447
1448config STACKPROTECTOR_PER_TASK
1449 bool "Use a unique stack canary value for each task"
1450 depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
1451 depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
1452 select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
1453 default y
1454 help
1455 Due to the fact that GCC uses an ordinary symbol reference from
1456 which to load the value of the stack canary, this value can only
1457 change at reboot time on SMP systems, and all tasks running in the
1458 kernel's address space are forced to use the same canary value for
1459 the entire duration that the system is up.
1460
1461 Enable this option to switch to a different method that uses a
1462 different canary value for each task.
1463
1464endmenu
1465
1466menu "Boot options"
1467
1468config USE_OF
1469 bool "Flattened Device Tree support"
1470 select IRQ_DOMAIN
1471 select OF
1472 help
1473 Include support for flattened device tree machine descriptions.
1474
1475config ATAGS
1476 bool "Support for the traditional ATAGS boot data passing"
1477 default y
1478 help
1479 This is the traditional way of passing data to the kernel at boot
1480 time. If you are solely relying on the flattened device tree (or
1481 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1482 to remove ATAGS support from your kernel binary.
1483
1484config UNUSED_BOARD_FILES
1485 bool "Board support for machines without known users"
1486 depends on ATAGS
1487 help
1488 Most ATAGS based board files are completely unused and are
1489 scheduled for removal in early 2023, and left out of kernels
1490 by default now. If you are using a board file that is marked
1491 as unused, turn on this option to build support into the kernel.
1492
1493 To keep support for your individual board from being removed,
1494 send a reply to the email discussion at
1495 https://lore.kernel.org/all/CAK8P3a0Z9vGEQbVRBo84bSyPFM-LF+hs5w8ZA51g2Z+NsdtDQA@mail.gmail.com/
1496
1497config DEPRECATED_PARAM_STRUCT
1498 bool "Provide old way to pass kernel parameters"
1499 depends on ATAGS
1500 help
1501 This was deprecated in 2001 and announced to live on for 5 years.
1502 Some old boot loaders still use this way.
1503
1504# Compressed boot loader in ROM. Yes, we really want to ask about
1505# TEXT and BSS so we preserve their values in the config files.
1506config ZBOOT_ROM_TEXT
1507 hex "Compressed ROM boot loader base address"
1508 default 0x0
1509 help
1510 The physical address at which the ROM-able zImage is to be
1511 placed in the target. Platforms which normally make use of
1512 ROM-able zImage formats normally set this to a suitable
1513 value in their defconfig file.
1514
1515 If ZBOOT_ROM is not enabled, this has no effect.
1516
1517config ZBOOT_ROM_BSS
1518 hex "Compressed ROM boot loader BSS address"
1519 default 0x0
1520 help
1521 The base address of an area of read/write memory in the target
1522 for the ROM-able zImage which must be available while the
1523 decompressor is running. It must be large enough to hold the
1524 entire decompressed kernel plus an additional 128 KiB.
1525 Platforms which normally make use of ROM-able zImage formats
1526 normally set this to a suitable value in their defconfig file.
1527
1528 If ZBOOT_ROM is not enabled, this has no effect.
1529
1530config ZBOOT_ROM
1531 bool "Compressed boot loader in ROM/flash"
1532 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1533 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1534 help
1535 Say Y here if you intend to execute your compressed kernel image
1536 (zImage) directly from ROM or flash. If unsure, say N.
1537
1538config ARM_APPENDED_DTB
1539 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1540 depends on OF
1541 help
1542 With this option, the boot code will look for a device tree binary
1543 (DTB) appended to zImage
1544 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1545
1546 This is meant as a backward compatibility convenience for those
1547 systems with a bootloader that can't be upgraded to accommodate
1548 the documented boot protocol using a device tree.
1549
1550 Beware that there is very little in terms of protection against
1551 this option being confused by leftover garbage in memory that might
1552 look like a DTB header after a reboot if no actual DTB is appended
1553 to zImage. Do not leave this option active in a production kernel
1554 if you don't intend to always append a DTB. Proper passing of the
1555 location into r2 of a bootloader provided DTB is always preferable
1556 to this option.
1557
1558config ARM_ATAG_DTB_COMPAT
1559 bool "Supplement the appended DTB with traditional ATAG information"
1560 depends on ARM_APPENDED_DTB
1561 help
1562 Some old bootloaders can't be updated to a DTB capable one, yet
1563 they provide ATAGs with memory configuration, the ramdisk address,
1564 the kernel cmdline string, etc. Such information is dynamically
1565 provided by the bootloader and can't always be stored in a static
1566 DTB. To allow a device tree enabled kernel to be used with such
1567 bootloaders, this option allows zImage to extract the information
1568 from the ATAG list and store it at run time into the appended DTB.
1569
1570choice
1571 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1572 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1573
1574config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1575 bool "Use bootloader kernel arguments if available"
1576 help
1577 Uses the command-line options passed by the boot loader instead of
1578 the device tree bootargs property. If the boot loader doesn't provide
1579 any, the device tree bootargs property will be used.
1580
1581config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1582 bool "Extend with bootloader kernel arguments"
1583 help
1584 The command-line arguments provided by the boot loader will be
1585 appended to the the device tree bootargs property.
1586
1587endchoice
1588
1589config CMDLINE
1590 string "Default kernel command string"
1591 default ""
1592 help
1593 On some architectures (e.g. CATS), there is currently no way
1594 for the boot loader to pass arguments to the kernel. For these
1595 architectures, you should supply some command-line options at build
1596 time by entering them here. As a minimum, you should specify the
1597 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1598
1599choice
1600 prompt "Kernel command line type" if CMDLINE != ""
1601 default CMDLINE_FROM_BOOTLOADER
1602
1603config CMDLINE_FROM_BOOTLOADER
1604 bool "Use bootloader kernel arguments if available"
1605 help
1606 Uses the command-line options passed by the boot loader. If
1607 the boot loader doesn't provide any, the default kernel command
1608 string provided in CMDLINE will be used.
1609
1610config CMDLINE_EXTEND
1611 bool "Extend bootloader kernel arguments"
1612 help
1613 The command-line arguments provided by the boot loader will be
1614 appended to the default kernel command string.
1615
1616config CMDLINE_FORCE
1617 bool "Always use the default kernel command string"
1618 help
1619 Always use the default kernel command string, even if the boot
1620 loader passes other arguments to the kernel.
1621 This is useful if you cannot or don't want to change the
1622 command-line options your boot loader passes to the kernel.
1623endchoice
1624
1625config XIP_KERNEL
1626 bool "Kernel Execute-In-Place from ROM"
1627 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1628 depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
1629 help
1630 Execute-In-Place allows the kernel to run from non-volatile storage
1631 directly addressable by the CPU, such as NOR flash. This saves RAM
1632 space since the text section of the kernel is not loaded from flash
1633 to RAM. Read-write sections, such as the data section and stack,
1634 are still copied to RAM. The XIP kernel is not compressed since
1635 it has to run directly from flash, so it will take more space to
1636 store it. The flash address used to link the kernel object files,
1637 and for storing it, is configuration dependent. Therefore, if you
1638 say Y here, you must know the proper physical address where to
1639 store the kernel image depending on your own flash memory usage.
1640
1641 Also note that the make target becomes "make xipImage" rather than
1642 "make zImage" or "make Image". The final kernel binary to put in
1643 ROM memory will be arch/arm/boot/xipImage.
1644
1645 If unsure, say N.
1646
1647config XIP_PHYS_ADDR
1648 hex "XIP Kernel Physical Location"
1649 depends on XIP_KERNEL
1650 default "0x00080000"
1651 help
1652 This is the physical address in your flash memory the kernel will
1653 be linked for and stored to. This address is dependent on your
1654 own flash usage.
1655
1656config XIP_DEFLATED_DATA
1657 bool "Store kernel .data section compressed in ROM"
1658 depends on XIP_KERNEL
1659 select ZLIB_INFLATE
1660 help
1661 Before the kernel is actually executed, its .data section has to be
1662 copied to RAM from ROM. This option allows for storing that data
1663 in compressed form and decompressed to RAM rather than merely being
1664 copied, saving some precious ROM space. A possible drawback is a
1665 slightly longer boot delay.
1666
1667config KEXEC
1668 bool "Kexec system call (EXPERIMENTAL)"
1669 depends on (!SMP || PM_SLEEP_SMP)
1670 depends on MMU
1671 select KEXEC_CORE
1672 help
1673 kexec is a system call that implements the ability to shutdown your
1674 current kernel, and to start another kernel. It is like a reboot
1675 but it is independent of the system firmware. And like a reboot
1676 you can start any kernel with it, not just Linux.
1677
1678 It is an ongoing process to be certain the hardware in a machine
1679 is properly shutdown, so do not be surprised if this code does not
1680 initially work for you.
1681
1682config ATAGS_PROC
1683 bool "Export atags in procfs"
1684 depends on ATAGS && KEXEC
1685 default y
1686 help
1687 Should the atags used to boot the kernel be exported in an "atags"
1688 file in procfs. Useful with kexec.
1689
1690config CRASH_DUMP
1691 bool "Build kdump crash kernel (EXPERIMENTAL)"
1692 help
1693 Generate crash dump after being started by kexec. This should
1694 be normally only set in special crash dump kernels which are
1695 loaded in the main kernel with kexec-tools into a specially
1696 reserved region and then later executed after a crash by
1697 kdump/kexec. The crash dump kernel must be compiled to a
1698 memory address not used by the main kernel
1699
1700 For more details see Documentation/admin-guide/kdump/kdump.rst
1701
1702config AUTO_ZRELADDR
1703 bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
1704 default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
1705 help
1706 ZRELADDR is the physical address where the decompressed kernel
1707 image will be placed. If AUTO_ZRELADDR is selected, the address
1708 will be determined at run-time, either by masking the current IP
1709 with 0xf8000000, or, if invalid, from the DTB passed in r2.
1710 This assumes the zImage being placed in the first 128MB from
1711 start of memory.
1712
1713config EFI_STUB
1714 bool
1715
1716config EFI
1717 bool "UEFI runtime support"
1718 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1719 select UCS2_STRING
1720 select EFI_PARAMS_FROM_FDT
1721 select EFI_STUB
1722 select EFI_GENERIC_STUB
1723 select EFI_RUNTIME_WRAPPERS
1724 help
1725 This option provides support for runtime services provided
1726 by UEFI firmware (such as non-volatile variables, realtime
1727 clock, and platform reset). A UEFI stub is also provided to
1728 allow the kernel to be booted as an EFI application. This
1729 is only useful for kernels that may run on systems that have
1730 UEFI firmware.
1731
1732config DMI
1733 bool "Enable support for SMBIOS (DMI) tables"
1734 depends on EFI
1735 default y
1736 help
1737 This enables SMBIOS/DMI feature for systems.
1738
1739 This option is only useful on systems that have UEFI firmware.
1740 However, even with this option, the resultant kernel should
1741 continue to boot on existing non-UEFI platforms.
1742
1743 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1744 i.e., the the practice of identifying the platform via DMI to
1745 decide whether certain workarounds for buggy hardware and/or
1746 firmware need to be enabled. This would require the DMI subsystem
1747 to be enabled much earlier than we do on ARM, which is non-trivial.
1748
1749endmenu
1750
1751menu "CPU Power Management"
1752
1753source "drivers/cpufreq/Kconfig"
1754
1755source "drivers/cpuidle/Kconfig"
1756
1757endmenu
1758
1759menu "Floating point emulation"
1760
1761comment "At least one emulation must be selected"
1762
1763config FPE_NWFPE
1764 bool "NWFPE math emulation"
1765 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1766 help
1767 Say Y to include the NWFPE floating point emulator in the kernel.
1768 This is necessary to run most binaries. Linux does not currently
1769 support floating point hardware so you need to say Y here even if
1770 your machine has an FPA or floating point co-processor podule.
1771
1772 You may say N here if you are going to load the Acorn FPEmulator
1773 early in the bootup.
1774
1775config FPE_NWFPE_XP
1776 bool "Support extended precision"
1777 depends on FPE_NWFPE
1778 help
1779 Say Y to include 80-bit support in the kernel floating-point
1780 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1781 Note that gcc does not generate 80-bit operations by default,
1782 so in most cases this option only enlarges the size of the
1783 floating point emulator without any good reason.
1784
1785 You almost surely want to say N here.
1786
1787config FPE_FASTFPE
1788 bool "FastFPE math emulation (EXPERIMENTAL)"
1789 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1790 help
1791 Say Y here to include the FAST floating point emulator in the kernel.
1792 This is an experimental much faster emulator which now also has full
1793 precision for the mantissa. It does not support any exceptions.
1794 It is very simple, and approximately 3-6 times faster than NWFPE.
1795
1796 It should be sufficient for most programs. It may be not suitable
1797 for scientific calculations, but you have to check this for yourself.
1798 If you do not feel you need a faster FP emulation you should better
1799 choose NWFPE.
1800
1801config VFP
1802 bool "VFP-format floating point maths"
1803 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1804 help
1805 Say Y to include VFP support code in the kernel. This is needed
1806 if your hardware includes a VFP unit.
1807
1808 Please see <file:Documentation/arm/vfp/release-notes.rst> for
1809 release notes and additional status information.
1810
1811 Say N if your target does not have VFP hardware.
1812
1813config VFPv3
1814 bool
1815 depends on VFP
1816 default y if CPU_V7
1817
1818config NEON
1819 bool "Advanced SIMD (NEON) Extension support"
1820 depends on VFPv3 && CPU_V7
1821 help
1822 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1823 Extension.
1824
1825config KERNEL_MODE_NEON
1826 bool "Support for NEON in kernel mode"
1827 depends on NEON && AEABI
1828 help
1829 Say Y to include support for NEON in kernel mode.
1830
1831endmenu
1832
1833menu "Power management options"
1834
1835source "kernel/power/Kconfig"
1836
1837config ARCH_SUSPEND_POSSIBLE
1838 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1839 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1840 def_bool y
1841
1842config ARM_CPU_SUSPEND
1843 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1844 depends on ARCH_SUSPEND_POSSIBLE
1845
1846config ARCH_HIBERNATION_POSSIBLE
1847 bool
1848 depends on MMU
1849 default y if ARCH_SUSPEND_POSSIBLE
1850
1851endmenu
1852
1853source "arch/arm/Kconfig.assembler"