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_HAS_BINFMT_FLAT
7 select ARCH_HAS_DEBUG_VIRTUAL if MMU
8 select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
9 select ARCH_HAS_ELF_RANDOMIZE
10 select ARCH_HAS_FORTIFY_SOURCE
11 select ARCH_HAS_KEEPINITRD
12 select ARCH_HAS_KCOV
13 select ARCH_HAS_MEMBARRIER_SYNC_CORE
14 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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_SYNC_DMA_FOR_DEVICE if SWIOTLB
22 select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
23 select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
24 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
25 select ARCH_HAVE_CUSTOM_GPIO_H
26 select ARCH_HAS_GCOV_PROFILE_ALL
27 select ARCH_KEEP_MEMBLOCK
28 select ARCH_MIGHT_HAVE_PC_PARPORT
29 select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
30 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
31 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
32 select ARCH_SUPPORTS_ATOMIC_RMW
33 select ARCH_USE_BUILTIN_BSWAP
34 select ARCH_USE_CMPXCHG_LOCKREF
35 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
36 select ARCH_WANT_IPC_PARSE_VERSION
37 select ARCH_WANT_LD_ORPHAN_WARN
38 select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
39 select BUILDTIME_TABLE_SORT if MMU
40 select CLONE_BACKWARDS
41 select CPU_PM if SUSPEND || CPU_IDLE
42 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
43 select DMA_DECLARE_COHERENT
44 select DMA_OPS
45 select DMA_REMAP if MMU
46 select EDAC_SUPPORT
47 select EDAC_ATOMIC_SCRUB
48 select GENERIC_ALLOCATOR
49 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
50 select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
51 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
52 select GENERIC_IRQ_IPI if SMP
53 select GENERIC_CPU_AUTOPROBE
54 select GENERIC_EARLY_IOREMAP
55 select GENERIC_IDLE_POLL_SETUP
56 select GENERIC_IRQ_PROBE
57 select GENERIC_IRQ_SHOW
58 select GENERIC_IRQ_SHOW_LEVEL
59 select GENERIC_LIB_DEVMEM_IS_ALLOWED
60 select GENERIC_PCI_IOMAP
61 select GENERIC_SCHED_CLOCK
62 select GENERIC_SMP_IDLE_THREAD
63 select GENERIC_STRNCPY_FROM_USER
64 select GENERIC_STRNLEN_USER
65 select HANDLE_DOMAIN_IRQ
66 select HARDIRQS_SW_RESEND
67 select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
68 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
69 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
70 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
71 select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
72 select HAVE_ARCH_MMAP_RND_BITS if MMU
73 select HAVE_ARCH_PFN_VALID
74 select HAVE_ARCH_SECCOMP
75 select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
76 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
77 select HAVE_ARCH_TRACEHOOK
78 select HAVE_ARM_SMCCC if CPU_V7
79 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
80 select HAVE_CONTEXT_TRACKING
81 select HAVE_C_RECORDMCOUNT
82 select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
83 select HAVE_DMA_CONTIGUOUS if MMU
84 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
85 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
86 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
87 select HAVE_EXIT_THREAD
88 select HAVE_FAST_GUP if ARM_LPAE
89 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
90 select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
91 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
92 select HAVE_GCC_PLUGINS
93 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
94 select HAVE_IDE if PCI || ISA || PCMCIA
95 select HAVE_IRQ_TIME_ACCOUNTING
96 select HAVE_KERNEL_GZIP
97 select HAVE_KERNEL_LZ4
98 select HAVE_KERNEL_LZMA
99 select HAVE_KERNEL_LZO
100 select HAVE_KERNEL_XZ
101 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
102 select HAVE_KRETPROBES if HAVE_KPROBES
103 select HAVE_MOD_ARCH_SPECIFIC
104 select HAVE_NMI
105 select HAVE_OPROFILE if HAVE_PERF_EVENTS
106 select HAVE_OPTPROBES if !THUMB2_KERNEL
107 select HAVE_PERF_EVENTS
108 select HAVE_PERF_REGS
109 select HAVE_PERF_USER_STACK_DUMP
110 select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
111 select HAVE_REGS_AND_STACK_ACCESS_API
112 select HAVE_RSEQ
113 select HAVE_STACKPROTECTOR
114 select HAVE_SYSCALL_TRACEPOINTS
115 select HAVE_UID16
116 select HAVE_VIRT_CPU_ACCOUNTING_GEN
117 select IRQ_FORCED_THREADING
118 select MODULES_USE_ELF_REL
119 select NEED_DMA_MAP_STATE
120 select OF_EARLY_FLATTREE if OF
121 select OLD_SIGACTION
122 select OLD_SIGSUSPEND3
123 select PCI_SYSCALL if PCI
124 select PERF_USE_VMALLOC
125 select RTC_LIB
126 select SET_FS
127 select SYS_SUPPORTS_APM_EMULATION
128 # Above selects are sorted alphabetically; please add new ones
129 # according to that. Thanks.
130 help
131 The ARM series is a line of low-power-consumption RISC chip designs
132 licensed by ARM Ltd and targeted at embedded applications and
133 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
134 manufactured, but legacy ARM-based PC hardware remains popular in
135 Europe. There is an ARM Linux project with a web page at
136 <http://www.arm.linux.org.uk/>.
137
138config ARM_HAS_SG_CHAIN
139 bool
140
141config ARM_DMA_USE_IOMMU
142 bool
143 select ARM_HAS_SG_CHAIN
144 select NEED_SG_DMA_LENGTH
145
146if ARM_DMA_USE_IOMMU
147
148config ARM_DMA_IOMMU_ALIGNMENT
149 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
150 range 4 9
151 default 8
152 help
153 DMA mapping framework by default aligns all buffers to the smallest
154 PAGE_SIZE order which is greater than or equal to the requested buffer
155 size. This works well for buffers up to a few hundreds kilobytes, but
156 for larger buffers it just a waste of address space. Drivers which has
157 relatively small addressing window (like 64Mib) might run out of
158 virtual space with just a few allocations.
159
160 With this parameter you can specify the maximum PAGE_SIZE order for
161 DMA IOMMU buffers. Larger buffers will be aligned only to this
162 specified order. The order is expressed as a power of two multiplied
163 by the PAGE_SIZE.
164
165endif
166
167config SYS_SUPPORTS_APM_EMULATION
168 bool
169
170config HAVE_TCM
171 bool
172 select GENERIC_ALLOCATOR
173
174config HAVE_PROC_CPU
175 bool
176
177config NO_IOPORT_MAP
178 bool
179
180config SBUS
181 bool
182
183config STACKTRACE_SUPPORT
184 bool
185 default y
186
187config LOCKDEP_SUPPORT
188 bool
189 default y
190
191config TRACE_IRQFLAGS_SUPPORT
192 bool
193 default !CPU_V7M
194
195config ARCH_HAS_ILOG2_U32
196 bool
197
198config ARCH_HAS_ILOG2_U64
199 bool
200
201config ARCH_HAS_BANDGAP
202 bool
203
204config FIX_EARLYCON_MEM
205 def_bool y if MMU
206
207config GENERIC_HWEIGHT
208 bool
209 default y
210
211config GENERIC_CALIBRATE_DELAY
212 bool
213 default y
214
215config ARCH_MAY_HAVE_PC_FDC
216 bool
217
218config ZONE_DMA
219 bool
220
221config ARCH_SUPPORTS_UPROBES
222 def_bool y
223
224config ARCH_HAS_DMA_SET_COHERENT_MASK
225 bool
226
227config GENERIC_ISA_DMA
228 bool
229
230config FIQ
231 bool
232
233config NEED_RET_TO_USER
234 bool
235
236config ARCH_MTD_XIP
237 bool
238
239config ARM_PATCH_PHYS_VIRT
240 bool "Patch physical to virtual translations at runtime" if EMBEDDED
241 default y
242 depends on !XIP_KERNEL && MMU
243 help
244 Patch phys-to-virt and virt-to-phys translation functions at
245 boot and module load time according to the position of the
246 kernel in system memory.
247
248 This can only be used with non-XIP MMU kernels where the base
249 of physical memory is at a 2 MiB boundary.
250
251 Only disable this option if you know that you do not require
252 this feature (eg, building a kernel for a single machine) and
253 you need to shrink the kernel to the minimal size.
254
255config NEED_MACH_IO_H
256 bool
257 help
258 Select this when mach/io.h is required to provide special
259 definitions for this platform. The need for mach/io.h should
260 be avoided when possible.
261
262config NEED_MACH_MEMORY_H
263 bool
264 help
265 Select this when mach/memory.h is required to provide special
266 definitions for this platform. The need for mach/memory.h should
267 be avoided when possible.
268
269config PHYS_OFFSET
270 hex "Physical address of main memory" if MMU
271 depends on !ARM_PATCH_PHYS_VIRT
272 default DRAM_BASE if !MMU
273 default 0x00000000 if ARCH_FOOTBRIDGE
274 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
275 default 0x20000000 if ARCH_S5PV210
276 default 0xc0000000 if ARCH_SA1100
277 help
278 Please provide the physical address corresponding to the
279 location of main memory in your system.
280
281config GENERIC_BUG
282 def_bool y
283 depends on BUG
284
285config PGTABLE_LEVELS
286 int
287 default 3 if ARM_LPAE
288 default 2
289
290menu "System Type"
291
292config MMU
293 bool "MMU-based Paged Memory Management Support"
294 default y
295 help
296 Select if you want MMU-based virtualised addressing space
297 support by paged memory management. If unsure, say 'Y'.
298
299config ARCH_MMAP_RND_BITS_MIN
300 default 8
301
302config ARCH_MMAP_RND_BITS_MAX
303 default 14 if PAGE_OFFSET=0x40000000
304 default 15 if PAGE_OFFSET=0x80000000
305 default 16
306
307#
308# The "ARM system type" choice list is ordered alphabetically by option
309# text. Please add new entries in the option alphabetic order.
310#
311choice
312 prompt "ARM system type"
313 default ARM_SINGLE_ARMV7M if !MMU
314 default ARCH_MULTIPLATFORM if MMU
315
316config ARCH_MULTIPLATFORM
317 bool "Allow multiple platforms to be selected"
318 depends on MMU
319 select ARCH_FLATMEM_ENABLE
320 select ARCH_SPARSEMEM_ENABLE
321 select ARCH_SELECT_MEMORY_MODEL
322 select ARM_HAS_SG_CHAIN
323 select ARM_PATCH_PHYS_VIRT
324 select AUTO_ZRELADDR
325 select TIMER_OF
326 select COMMON_CLK
327 select GENERIC_IRQ_MULTI_HANDLER
328 select HAVE_PCI
329 select PCI_DOMAINS_GENERIC if PCI
330 select SPARSE_IRQ
331 select USE_OF
332
333config ARM_SINGLE_ARMV7M
334 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
335 depends on !MMU
336 select ARM_NVIC
337 select AUTO_ZRELADDR
338 select TIMER_OF
339 select COMMON_CLK
340 select CPU_V7M
341 select NO_IOPORT_MAP
342 select SPARSE_IRQ
343 select USE_OF
344
345config ARCH_EP93XX
346 bool "EP93xx-based"
347 select ARCH_SPARSEMEM_ENABLE
348 select ARM_AMBA
349 imply ARM_PATCH_PHYS_VIRT
350 select ARM_VIC
351 select AUTO_ZRELADDR
352 select CLKDEV_LOOKUP
353 select CLKSRC_MMIO
354 select CPU_ARM920T
355 select GPIOLIB
356 select HAVE_LEGACY_CLK
357 help
358 This enables support for the Cirrus EP93xx series of CPUs.
359
360config ARCH_FOOTBRIDGE
361 bool "FootBridge"
362 select CPU_SA110
363 select FOOTBRIDGE
364 select HAVE_IDE
365 select NEED_MACH_IO_H if !MMU
366 select NEED_MACH_MEMORY_H
367 help
368 Support for systems based on the DC21285 companion chip
369 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
370
371config ARCH_IOP32X
372 bool "IOP32x-based"
373 depends on MMU
374 select CPU_XSCALE
375 select GPIO_IOP
376 select GPIOLIB
377 select NEED_RET_TO_USER
378 select FORCE_PCI
379 select PLAT_IOP
380 help
381 Support for Intel's 80219 and IOP32X (XScale) family of
382 processors.
383
384config ARCH_IXP4XX
385 bool "IXP4xx-based"
386 depends on MMU
387 select ARCH_HAS_DMA_SET_COHERENT_MASK
388 select ARCH_SUPPORTS_BIG_ENDIAN
389 select CPU_XSCALE
390 select DMABOUNCE if PCI
391 select GENERIC_IRQ_MULTI_HANDLER
392 select GPIO_IXP4XX
393 select GPIOLIB
394 select HAVE_PCI
395 select IXP4XX_IRQ
396 select IXP4XX_TIMER
397 select NEED_MACH_IO_H
398 select USB_EHCI_BIG_ENDIAN_DESC
399 select USB_EHCI_BIG_ENDIAN_MMIO
400 help
401 Support for Intel's IXP4XX (XScale) family of processors.
402
403config ARCH_DOVE
404 bool "Marvell Dove"
405 select CPU_PJ4
406 select GENERIC_IRQ_MULTI_HANDLER
407 select GPIOLIB
408 select HAVE_PCI
409 select MVEBU_MBUS
410 select PINCTRL
411 select PINCTRL_DOVE
412 select PLAT_ORION_LEGACY
413 select SPARSE_IRQ
414 select PM_GENERIC_DOMAINS if PM
415 help
416 Support for the Marvell Dove SoC 88AP510
417
418config ARCH_PXA
419 bool "PXA2xx/PXA3xx-based"
420 depends on MMU
421 select ARCH_MTD_XIP
422 select ARM_CPU_SUSPEND if PM
423 select AUTO_ZRELADDR
424 select COMMON_CLK
425 select CLKSRC_PXA
426 select CLKSRC_MMIO
427 select TIMER_OF
428 select CPU_XSCALE if !CPU_XSC3
429 select GENERIC_IRQ_MULTI_HANDLER
430 select GPIO_PXA
431 select GPIOLIB
432 select HAVE_IDE
433 select IRQ_DOMAIN
434 select PLAT_PXA
435 select SPARSE_IRQ
436 help
437 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
438
439config ARCH_RPC
440 bool "RiscPC"
441 depends on MMU
442 select ARCH_ACORN
443 select ARCH_MAY_HAVE_PC_FDC
444 select ARCH_SPARSEMEM_ENABLE
445 select ARM_HAS_SG_CHAIN
446 select CPU_SA110
447 select FIQ
448 select HAVE_IDE
449 select HAVE_PATA_PLATFORM
450 select ISA_DMA_API
451 select LEGACY_TIMER_TICK
452 select NEED_MACH_IO_H
453 select NEED_MACH_MEMORY_H
454 select NO_IOPORT_MAP
455 help
456 On the Acorn Risc-PC, Linux can support the internal IDE disk and
457 CD-ROM interface, serial and parallel port, and the floppy drive.
458
459config ARCH_SA1100
460 bool "SA1100-based"
461 select ARCH_MTD_XIP
462 select ARCH_SPARSEMEM_ENABLE
463 select CLKSRC_MMIO
464 select CLKSRC_PXA
465 select TIMER_OF if OF
466 select COMMON_CLK
467 select CPU_FREQ
468 select CPU_SA1100
469 select GENERIC_IRQ_MULTI_HANDLER
470 select GPIOLIB
471 select HAVE_IDE
472 select IRQ_DOMAIN
473 select ISA
474 select NEED_MACH_MEMORY_H
475 select SPARSE_IRQ
476 help
477 Support for StrongARM 11x0 based boards.
478
479config ARCH_S3C24XX
480 bool "Samsung S3C24XX SoCs"
481 select ATAGS
482 select CLKSRC_SAMSUNG_PWM
483 select GPIO_SAMSUNG
484 select GPIOLIB
485 select GENERIC_IRQ_MULTI_HANDLER
486 select HAVE_S3C2410_I2C if I2C
487 select HAVE_S3C_RTC if RTC_CLASS
488 select NEED_MACH_IO_H
489 select S3C2410_WATCHDOG
490 select SAMSUNG_ATAGS
491 select USE_OF
492 select WATCHDOG
493 help
494 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
495 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
496 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
497 Samsung SMDK2410 development board (and derivatives).
498
499config ARCH_OMAP1
500 bool "TI OMAP1"
501 depends on MMU
502 select ARCH_OMAP
503 select CLKDEV_LOOKUP
504 select CLKSRC_MMIO
505 select GENERIC_IRQ_CHIP
506 select GENERIC_IRQ_MULTI_HANDLER
507 select GPIOLIB
508 select HAVE_IDE
509 select HAVE_LEGACY_CLK
510 select IRQ_DOMAIN
511 select NEED_MACH_IO_H if PCCARD
512 select NEED_MACH_MEMORY_H
513 select SPARSE_IRQ
514 help
515 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
516
517endchoice
518
519menu "Multiple platform selection"
520 depends on ARCH_MULTIPLATFORM
521
522comment "CPU Core family selection"
523
524config ARCH_MULTI_V4
525 bool "ARMv4 based platforms (FA526)"
526 depends on !ARCH_MULTI_V6_V7
527 select ARCH_MULTI_V4_V5
528 select CPU_FA526
529
530config ARCH_MULTI_V4T
531 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
532 depends on !ARCH_MULTI_V6_V7
533 select ARCH_MULTI_V4_V5
534 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
535 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
536 CPU_ARM925T || CPU_ARM940T)
537
538config ARCH_MULTI_V5
539 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
540 depends on !ARCH_MULTI_V6_V7
541 select ARCH_MULTI_V4_V5
542 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
543 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
544 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
545
546config ARCH_MULTI_V4_V5
547 bool
548
549config ARCH_MULTI_V6
550 bool "ARMv6 based platforms (ARM11)"
551 select ARCH_MULTI_V6_V7
552 select CPU_V6K
553
554config ARCH_MULTI_V7
555 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
556 default y
557 select ARCH_MULTI_V6_V7
558 select CPU_V7
559 select HAVE_SMP
560
561config ARCH_MULTI_V6_V7
562 bool
563 select MIGHT_HAVE_CACHE_L2X0
564
565config ARCH_MULTI_CPU_AUTO
566 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
567 select ARCH_MULTI_V5
568
569endmenu
570
571config ARCH_VIRT
572 bool "Dummy Virtual Machine"
573 depends on ARCH_MULTI_V7
574 select ARM_AMBA
575 select ARM_GIC
576 select ARM_GIC_V2M if PCI
577 select ARM_GIC_V3
578 select ARM_GIC_V3_ITS if PCI
579 select ARM_PSCI
580 select HAVE_ARM_ARCH_TIMER
581 select ARCH_SUPPORTS_BIG_ENDIAN
582
583#
584# This is sorted alphabetically by mach-* pathname. However, plat-*
585# Kconfigs may be included either alphabetically (according to the
586# plat- suffix) or along side the corresponding mach-* source.
587#
588source "arch/arm/mach-actions/Kconfig"
589
590source "arch/arm/mach-alpine/Kconfig"
591
592source "arch/arm/mach-artpec/Kconfig"
593
594source "arch/arm/mach-asm9260/Kconfig"
595
596source "arch/arm/mach-aspeed/Kconfig"
597
598source "arch/arm/mach-at91/Kconfig"
599
600source "arch/arm/mach-axxia/Kconfig"
601
602source "arch/arm/mach-bcm/Kconfig"
603
604source "arch/arm/mach-berlin/Kconfig"
605
606source "arch/arm/mach-clps711x/Kconfig"
607
608source "arch/arm/mach-cns3xxx/Kconfig"
609
610source "arch/arm/mach-davinci/Kconfig"
611
612source "arch/arm/mach-digicolor/Kconfig"
613
614source "arch/arm/mach-dove/Kconfig"
615
616source "arch/arm/mach-ep93xx/Kconfig"
617
618source "arch/arm/mach-exynos/Kconfig"
619
620source "arch/arm/mach-footbridge/Kconfig"
621
622source "arch/arm/mach-gemini/Kconfig"
623
624source "arch/arm/mach-highbank/Kconfig"
625
626source "arch/arm/mach-hisi/Kconfig"
627
628source "arch/arm/mach-imx/Kconfig"
629
630source "arch/arm/mach-integrator/Kconfig"
631
632source "arch/arm/mach-iop32x/Kconfig"
633
634source "arch/arm/mach-ixp4xx/Kconfig"
635
636source "arch/arm/mach-keystone/Kconfig"
637
638source "arch/arm/mach-lpc32xx/Kconfig"
639
640source "arch/arm/mach-mediatek/Kconfig"
641
642source "arch/arm/mach-meson/Kconfig"
643
644source "arch/arm/mach-milbeaut/Kconfig"
645
646source "arch/arm/mach-mmp/Kconfig"
647
648source "arch/arm/mach-moxart/Kconfig"
649
650source "arch/arm/mach-mstar/Kconfig"
651
652source "arch/arm/mach-mv78xx0/Kconfig"
653
654source "arch/arm/mach-mvebu/Kconfig"
655
656source "arch/arm/mach-mxs/Kconfig"
657
658source "arch/arm/mach-nomadik/Kconfig"
659
660source "arch/arm/mach-npcm/Kconfig"
661
662source "arch/arm/mach-nspire/Kconfig"
663
664source "arch/arm/plat-omap/Kconfig"
665
666source "arch/arm/mach-omap1/Kconfig"
667
668source "arch/arm/mach-omap2/Kconfig"
669
670source "arch/arm/mach-orion5x/Kconfig"
671
672source "arch/arm/mach-oxnas/Kconfig"
673
674source "arch/arm/mach-picoxcell/Kconfig"
675
676source "arch/arm/mach-prima2/Kconfig"
677
678source "arch/arm/mach-pxa/Kconfig"
679source "arch/arm/plat-pxa/Kconfig"
680
681source "arch/arm/mach-qcom/Kconfig"
682
683source "arch/arm/mach-rda/Kconfig"
684
685source "arch/arm/mach-realtek/Kconfig"
686
687source "arch/arm/mach-realview/Kconfig"
688
689source "arch/arm/mach-rockchip/Kconfig"
690
691source "arch/arm/mach-s3c/Kconfig"
692
693source "arch/arm/mach-s5pv210/Kconfig"
694
695source "arch/arm/mach-sa1100/Kconfig"
696
697source "arch/arm/mach-shmobile/Kconfig"
698
699source "arch/arm/mach-socfpga/Kconfig"
700
701source "arch/arm/mach-spear/Kconfig"
702
703source "arch/arm/mach-sti/Kconfig"
704
705source "arch/arm/mach-stm32/Kconfig"
706
707source "arch/arm/mach-sunxi/Kconfig"
708
709source "arch/arm/mach-tango/Kconfig"
710
711source "arch/arm/mach-tegra/Kconfig"
712
713source "arch/arm/mach-u300/Kconfig"
714
715source "arch/arm/mach-uniphier/Kconfig"
716
717source "arch/arm/mach-ux500/Kconfig"
718
719source "arch/arm/mach-versatile/Kconfig"
720
721source "arch/arm/mach-vexpress/Kconfig"
722
723source "arch/arm/mach-vt8500/Kconfig"
724
725source "arch/arm/mach-zx/Kconfig"
726
727source "arch/arm/mach-zynq/Kconfig"
728
729# ARMv7-M architecture
730config ARCH_EFM32
731 bool "Energy Micro efm32"
732 depends on ARM_SINGLE_ARMV7M
733 select GPIOLIB
734 help
735 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
736 processors.
737
738config ARCH_LPC18XX
739 bool "NXP LPC18xx/LPC43xx"
740 depends on ARM_SINGLE_ARMV7M
741 select ARCH_HAS_RESET_CONTROLLER
742 select ARM_AMBA
743 select CLKSRC_LPC32XX
744 select PINCTRL
745 help
746 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
747 high performance microcontrollers.
748
749config ARCH_MPS2
750 bool "ARM MPS2 platform"
751 depends on ARM_SINGLE_ARMV7M
752 select ARM_AMBA
753 select CLKSRC_MPS2
754 help
755 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
756 with a range of available cores like Cortex-M3/M4/M7.
757
758 Please, note that depends which Application Note is used memory map
759 for the platform may vary, so adjustment of RAM base might be needed.
760
761# Definitions to make life easier
762config ARCH_ACORN
763 bool
764
765config PLAT_IOP
766 bool
767
768config PLAT_ORION
769 bool
770 select CLKSRC_MMIO
771 select COMMON_CLK
772 select GENERIC_IRQ_CHIP
773 select IRQ_DOMAIN
774
775config PLAT_ORION_LEGACY
776 bool
777 select PLAT_ORION
778
779config PLAT_PXA
780 bool
781
782config PLAT_VERSATILE
783 bool
784
785source "arch/arm/mm/Kconfig"
786
787config IWMMXT
788 bool "Enable iWMMXt support"
789 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
790 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
791 help
792 Enable support for iWMMXt context switching at run time if
793 running on a CPU that supports it.
794
795if !MMU
796source "arch/arm/Kconfig-nommu"
797endif
798
799config PJ4B_ERRATA_4742
800 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
801 depends on CPU_PJ4B && MACH_ARMADA_370
802 default y
803 help
804 When coming out of either a Wait for Interrupt (WFI) or a Wait for
805 Event (WFE) IDLE states, a specific timing sensitivity exists between
806 the retiring WFI/WFE instructions and the newly issued subsequent
807 instructions. This sensitivity can result in a CPU hang scenario.
808 Workaround:
809 The software must insert either a Data Synchronization Barrier (DSB)
810 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
811 instruction
812
813config ARM_ERRATA_326103
814 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
815 depends on CPU_V6
816 help
817 Executing a SWP instruction to read-only memory does not set bit 11
818 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
819 treat the access as a read, preventing a COW from occurring and
820 causing the faulting task to livelock.
821
822config ARM_ERRATA_411920
823 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
824 depends on CPU_V6 || CPU_V6K
825 help
826 Invalidation of the Instruction Cache operation can
827 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
828 It does not affect the MPCore. This option enables the ARM Ltd.
829 recommended workaround.
830
831config ARM_ERRATA_430973
832 bool "ARM errata: Stale prediction on replaced interworking branch"
833 depends on CPU_V7
834 help
835 This option enables the workaround for the 430973 Cortex-A8
836 r1p* erratum. If a code sequence containing an ARM/Thumb
837 interworking branch is replaced with another code sequence at the
838 same virtual address, whether due to self-modifying code or virtual
839 to physical address re-mapping, Cortex-A8 does not recover from the
840 stale interworking branch prediction. This results in Cortex-A8
841 executing the new code sequence in the incorrect ARM or Thumb state.
842 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
843 and also flushes the branch target cache at every context switch.
844 Note that setting specific bits in the ACTLR register may not be
845 available in non-secure mode.
846
847config ARM_ERRATA_458693
848 bool "ARM errata: Processor deadlock when a false hazard is created"
849 depends on CPU_V7
850 depends on !ARCH_MULTIPLATFORM
851 help
852 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
853 erratum. For very specific sequences of memory operations, it is
854 possible for a hazard condition intended for a cache line to instead
855 be incorrectly associated with a different cache line. This false
856 hazard might then cause a processor deadlock. The workaround enables
857 the L1 caching of the NEON accesses and disables the PLD instruction
858 in the ACTLR register. Note that setting specific bits in the ACTLR
859 register may not be available in non-secure mode.
860
861config ARM_ERRATA_460075
862 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
863 depends on CPU_V7
864 depends on !ARCH_MULTIPLATFORM
865 help
866 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
867 erratum. Any asynchronous access to the L2 cache may encounter a
868 situation in which recent store transactions to the L2 cache are lost
869 and overwritten with stale memory contents from external memory. The
870 workaround disables the write-allocate mode for the L2 cache via the
871 ACTLR register. Note that setting specific bits in the ACTLR register
872 may not be available in non-secure mode.
873
874config ARM_ERRATA_742230
875 bool "ARM errata: DMB operation may be faulty"
876 depends on CPU_V7 && SMP
877 depends on !ARCH_MULTIPLATFORM
878 help
879 This option enables the workaround for the 742230 Cortex-A9
880 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
881 between two write operations may not ensure the correct visibility
882 ordering of the two writes. This workaround sets a specific bit in
883 the diagnostic register of the Cortex-A9 which causes the DMB
884 instruction to behave as a DSB, ensuring the correct behaviour of
885 the two writes.
886
887config ARM_ERRATA_742231
888 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
889 depends on CPU_V7 && SMP
890 depends on !ARCH_MULTIPLATFORM
891 help
892 This option enables the workaround for the 742231 Cortex-A9
893 (r2p0..r2p2) erratum. Under certain conditions, specific to the
894 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
895 accessing some data located in the same cache line, may get corrupted
896 data due to bad handling of the address hazard when the line gets
897 replaced from one of the CPUs at the same time as another CPU is
898 accessing it. This workaround sets specific bits in the diagnostic
899 register of the Cortex-A9 which reduces the linefill issuing
900 capabilities of the processor.
901
902config ARM_ERRATA_643719
903 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
904 depends on CPU_V7 && SMP
905 default y
906 help
907 This option enables the workaround for the 643719 Cortex-A9 (prior to
908 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
909 register returns zero when it should return one. The workaround
910 corrects this value, ensuring cache maintenance operations which use
911 it behave as intended and avoiding data corruption.
912
913config ARM_ERRATA_720789
914 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
915 depends on CPU_V7
916 help
917 This option enables the workaround for the 720789 Cortex-A9 (prior to
918 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
919 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
920 As a consequence of this erratum, some TLB entries which should be
921 invalidated are not, resulting in an incoherency in the system page
922 tables. The workaround changes the TLB flushing routines to invalidate
923 entries regardless of the ASID.
924
925config ARM_ERRATA_743622
926 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
927 depends on CPU_V7
928 depends on !ARCH_MULTIPLATFORM
929 help
930 This option enables the workaround for the 743622 Cortex-A9
931 (r2p*) erratum. Under very rare conditions, a faulty
932 optimisation in the Cortex-A9 Store Buffer may lead to data
933 corruption. This workaround sets a specific bit in the diagnostic
934 register of the Cortex-A9 which disables the Store Buffer
935 optimisation, preventing the defect from occurring. This has no
936 visible impact on the overall performance or power consumption of the
937 processor.
938
939config ARM_ERRATA_751472
940 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
941 depends on CPU_V7
942 depends on !ARCH_MULTIPLATFORM
943 help
944 This option enables the workaround for the 751472 Cortex-A9 (prior
945 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
946 completion of a following broadcasted operation if the second
947 operation is received by a CPU before the ICIALLUIS has completed,
948 potentially leading to corrupted entries in the cache or TLB.
949
950config ARM_ERRATA_754322
951 bool "ARM errata: possible faulty MMU translations following an ASID switch"
952 depends on CPU_V7
953 help
954 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
955 r3p*) erratum. A speculative memory access may cause a page table walk
956 which starts prior to an ASID switch but completes afterwards. This
957 can populate the micro-TLB with a stale entry which may be hit with
958 the new ASID. This workaround places two dsb instructions in the mm
959 switching code so that no page table walks can cross the ASID switch.
960
961config ARM_ERRATA_754327
962 bool "ARM errata: no automatic Store Buffer drain"
963 depends on CPU_V7 && SMP
964 help
965 This option enables the workaround for the 754327 Cortex-A9 (prior to
966 r2p0) erratum. The Store Buffer does not have any automatic draining
967 mechanism and therefore a livelock may occur if an external agent
968 continuously polls a memory location waiting to observe an update.
969 This workaround defines cpu_relax() as smp_mb(), preventing correctly
970 written polling loops from denying visibility of updates to memory.
971
972config ARM_ERRATA_364296
973 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
974 depends on CPU_V6
975 help
976 This options enables the workaround for the 364296 ARM1136
977 r0p2 erratum (possible cache data corruption with
978 hit-under-miss enabled). It sets the undocumented bit 31 in
979 the auxiliary control register and the FI bit in the control
980 register, thus disabling hit-under-miss without putting the
981 processor into full low interrupt latency mode. ARM11MPCore
982 is not affected.
983
984config ARM_ERRATA_764369
985 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
986 depends on CPU_V7 && SMP
987 help
988 This option enables the workaround for erratum 764369
989 affecting Cortex-A9 MPCore with two or more processors (all
990 current revisions). Under certain timing circumstances, a data
991 cache line maintenance operation by MVA targeting an Inner
992 Shareable memory region may fail to proceed up to either the
993 Point of Coherency or to the Point of Unification of the
994 system. This workaround adds a DSB instruction before the
995 relevant cache maintenance functions and sets a specific bit
996 in the diagnostic control register of the SCU.
997
998config ARM_ERRATA_775420
999 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1000 depends on CPU_V7
1001 help
1002 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1003 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
1004 operation aborts with MMU exception, it might cause the processor
1005 to deadlock. This workaround puts DSB before executing ISB if
1006 an abort may occur on cache maintenance.
1007
1008config ARM_ERRATA_798181
1009 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1010 depends on CPU_V7 && SMP
1011 help
1012 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1013 adequately shooting down all use of the old entries. This
1014 option enables the Linux kernel workaround for this erratum
1015 which sends an IPI to the CPUs that are running the same ASID
1016 as the one being invalidated.
1017
1018config ARM_ERRATA_773022
1019 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1020 depends on CPU_V7
1021 help
1022 This option enables the workaround for the 773022 Cortex-A15
1023 (up to r0p4) erratum. In certain rare sequences of code, the
1024 loop buffer may deliver incorrect instructions. This
1025 workaround disables the loop buffer to avoid the erratum.
1026
1027config ARM_ERRATA_818325_852422
1028 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1029 depends on CPU_V7
1030 help
1031 This option enables the workaround for:
1032 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1033 instruction might deadlock. Fixed in r0p1.
1034 - Cortex-A12 852422: Execution of a sequence of instructions might
1035 lead to either a data corruption or a CPU deadlock. Not fixed in
1036 any Cortex-A12 cores yet.
1037 This workaround for all both errata involves setting bit[12] of the
1038 Feature Register. This bit disables an optimisation applied to a
1039 sequence of 2 instructions that use opposing condition codes.
1040
1041config ARM_ERRATA_821420
1042 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1043 depends on CPU_V7
1044 help
1045 This option enables the workaround for the 821420 Cortex-A12
1046 (all revs) erratum. In very rare timing conditions, a sequence
1047 of VMOV to Core registers instructions, for which the second
1048 one is in the shadow of a branch or abort, can lead to a
1049 deadlock when the VMOV instructions are issued out-of-order.
1050
1051config ARM_ERRATA_825619
1052 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1053 depends on CPU_V7
1054 help
1055 This option enables the workaround for the 825619 Cortex-A12
1056 (all revs) erratum. Within rare timing constraints, executing a
1057 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1058 and Device/Strongly-Ordered loads and stores might cause deadlock
1059
1060config ARM_ERRATA_857271
1061 bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1062 depends on CPU_V7
1063 help
1064 This option enables the workaround for the 857271 Cortex-A12
1065 (all revs) erratum. Under very rare timing conditions, the CPU might
1066 hang. The workaround is expected to have a < 1% performance impact.
1067
1068config ARM_ERRATA_852421
1069 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1070 depends on CPU_V7
1071 help
1072 This option enables the workaround for the 852421 Cortex-A17
1073 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1074 execution of a DMB ST instruction might fail to properly order
1075 stores from GroupA and stores from GroupB.
1076
1077config ARM_ERRATA_852423
1078 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1079 depends on CPU_V7
1080 help
1081 This option enables the workaround for:
1082 - Cortex-A17 852423: Execution of a sequence of instructions might
1083 lead to either a data corruption or a CPU deadlock. Not fixed in
1084 any Cortex-A17 cores yet.
1085 This is identical to Cortex-A12 erratum 852422. It is a separate
1086 config option from the A12 erratum due to the way errata are checked
1087 for and handled.
1088
1089config ARM_ERRATA_857272
1090 bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1091 depends on CPU_V7
1092 help
1093 This option enables the workaround for the 857272 Cortex-A17 erratum.
1094 This erratum is not known to be fixed in any A17 revision.
1095 This is identical to Cortex-A12 erratum 857271. It is a separate
1096 config option from the A12 erratum due to the way errata are checked
1097 for and handled.
1098
1099endmenu
1100
1101source "arch/arm/common/Kconfig"
1102
1103menu "Bus support"
1104
1105config ISA
1106 bool
1107 help
1108 Find out whether you have ISA slots on your motherboard. ISA is the
1109 name of a bus system, i.e. the way the CPU talks to the other stuff
1110 inside your box. Other bus systems are PCI, EISA, MicroChannel
1111 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1112 newer boards don't support it. If you have ISA, say Y, otherwise N.
1113
1114# Select ISA DMA controller support
1115config ISA_DMA
1116 bool
1117 select ISA_DMA_API
1118
1119# Select ISA DMA interface
1120config ISA_DMA_API
1121 bool
1122
1123config PCI_NANOENGINE
1124 bool "BSE nanoEngine PCI support"
1125 depends on SA1100_NANOENGINE
1126 help
1127 Enable PCI on the BSE nanoEngine board.
1128
1129config ARM_ERRATA_814220
1130 bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1131 depends on CPU_V7
1132 help
1133 The v7 ARM states that all cache and branch predictor maintenance
1134 operations that do not specify an address execute, relative to
1135 each other, in program order.
1136 However, because of this erratum, an L2 set/way cache maintenance
1137 operation can overtake an L1 set/way cache maintenance operation.
1138 This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1139 r0p4, r0p5.
1140
1141endmenu
1142
1143menu "Kernel Features"
1144
1145config HAVE_SMP
1146 bool
1147 help
1148 This option should be selected by machines which have an SMP-
1149 capable CPU.
1150
1151 The only effect of this option is to make the SMP-related
1152 options available to the user for configuration.
1153
1154config SMP
1155 bool "Symmetric Multi-Processing"
1156 depends on CPU_V6K || CPU_V7
1157 depends on HAVE_SMP
1158 depends on MMU || ARM_MPU
1159 select IRQ_WORK
1160 help
1161 This enables support for systems with more than one CPU. If you have
1162 a system with only one CPU, say N. If you have a system with more
1163 than one CPU, say Y.
1164
1165 If you say N here, the kernel will run on uni- and multiprocessor
1166 machines, but will use only one CPU of a multiprocessor machine. If
1167 you say Y here, the kernel will run on many, but not all,
1168 uniprocessor machines. On a uniprocessor machine, the kernel
1169 will run faster if you say N here.
1170
1171 See also <file:Documentation/x86/i386/IO-APIC.rst>,
1172 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1173 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1174
1175 If you don't know what to do here, say N.
1176
1177config SMP_ON_UP
1178 bool "Allow booting SMP kernel on uniprocessor systems"
1179 depends on SMP && !XIP_KERNEL && MMU
1180 default y
1181 help
1182 SMP kernels contain instructions which fail on non-SMP processors.
1183 Enabling this option allows the kernel to modify itself to make
1184 these instructions safe. Disabling it allows about 1K of space
1185 savings.
1186
1187 If you don't know what to do here, say Y.
1188
1189config ARM_CPU_TOPOLOGY
1190 bool "Support cpu topology definition"
1191 depends on SMP && CPU_V7
1192 default y
1193 help
1194 Support ARM cpu topology definition. The MPIDR register defines
1195 affinity between processors which is then used to describe the cpu
1196 topology of an ARM System.
1197
1198config SCHED_MC
1199 bool "Multi-core scheduler support"
1200 depends on ARM_CPU_TOPOLOGY
1201 help
1202 Multi-core scheduler support improves the CPU scheduler's decision
1203 making when dealing with multi-core CPU chips at a cost of slightly
1204 increased overhead in some places. If unsure say N here.
1205
1206config SCHED_SMT
1207 bool "SMT scheduler support"
1208 depends on ARM_CPU_TOPOLOGY
1209 help
1210 Improves the CPU scheduler's decision making when dealing with
1211 MultiThreading at a cost of slightly increased overhead in some
1212 places. If unsure say N here.
1213
1214config HAVE_ARM_SCU
1215 bool
1216 help
1217 This option enables support for the ARM snoop control unit
1218
1219config HAVE_ARM_ARCH_TIMER
1220 bool "Architected timer support"
1221 depends on CPU_V7
1222 select ARM_ARCH_TIMER
1223 help
1224 This option enables support for the ARM architected timer
1225
1226config HAVE_ARM_TWD
1227 bool
1228 help
1229 This options enables support for the ARM timer and watchdog unit
1230
1231config MCPM
1232 bool "Multi-Cluster Power Management"
1233 depends on CPU_V7 && SMP
1234 help
1235 This option provides the common power management infrastructure
1236 for (multi-)cluster based systems, such as big.LITTLE based
1237 systems.
1238
1239config MCPM_QUAD_CLUSTER
1240 bool
1241 depends on MCPM
1242 help
1243 To avoid wasting resources unnecessarily, MCPM only supports up
1244 to 2 clusters by default.
1245 Platforms with 3 or 4 clusters that use MCPM must select this
1246 option to allow the additional clusters to be managed.
1247
1248config BIG_LITTLE
1249 bool "big.LITTLE support (Experimental)"
1250 depends on CPU_V7 && SMP
1251 select MCPM
1252 help
1253 This option enables support selections for the big.LITTLE
1254 system architecture.
1255
1256config BL_SWITCHER
1257 bool "big.LITTLE switcher support"
1258 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1259 select CPU_PM
1260 help
1261 The big.LITTLE "switcher" provides the core functionality to
1262 transparently handle transition between a cluster of A15's
1263 and a cluster of A7's in a big.LITTLE system.
1264
1265config BL_SWITCHER_DUMMY_IF
1266 tristate "Simple big.LITTLE switcher user interface"
1267 depends on BL_SWITCHER && DEBUG_KERNEL
1268 help
1269 This is a simple and dummy char dev interface to control
1270 the big.LITTLE switcher core code. It is meant for
1271 debugging purposes only.
1272
1273choice
1274 prompt "Memory split"
1275 depends on MMU
1276 default VMSPLIT_3G
1277 help
1278 Select the desired split between kernel and user memory.
1279
1280 If you are not absolutely sure what you are doing, leave this
1281 option alone!
1282
1283 config VMSPLIT_3G
1284 bool "3G/1G user/kernel split"
1285 config VMSPLIT_3G_OPT
1286 depends on !ARM_LPAE
1287 bool "3G/1G user/kernel split (for full 1G low memory)"
1288 config VMSPLIT_2G
1289 bool "2G/2G user/kernel split"
1290 config VMSPLIT_1G
1291 bool "1G/3G user/kernel split"
1292endchoice
1293
1294config PAGE_OFFSET
1295 hex
1296 default PHYS_OFFSET if !MMU
1297 default 0x40000000 if VMSPLIT_1G
1298 default 0x80000000 if VMSPLIT_2G
1299 default 0xB0000000 if VMSPLIT_3G_OPT
1300 default 0xC0000000
1301
1302config KASAN_SHADOW_OFFSET
1303 hex
1304 depends on KASAN
1305 default 0x1f000000 if PAGE_OFFSET=0x40000000
1306 default 0x5f000000 if PAGE_OFFSET=0x80000000
1307 default 0x9f000000 if PAGE_OFFSET=0xC0000000
1308 default 0x8f000000 if PAGE_OFFSET=0xB0000000
1309 default 0xffffffff
1310
1311config NR_CPUS
1312 int "Maximum number of CPUs (2-32)"
1313 range 2 32
1314 depends on SMP
1315 default "4"
1316
1317config HOTPLUG_CPU
1318 bool "Support for hot-pluggable CPUs"
1319 depends on SMP
1320 select GENERIC_IRQ_MIGRATION
1321 help
1322 Say Y here to experiment with turning CPUs off and on. CPUs
1323 can be controlled through /sys/devices/system/cpu.
1324
1325config ARM_PSCI
1326 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1327 depends on HAVE_ARM_SMCCC
1328 select ARM_PSCI_FW
1329 help
1330 Say Y here if you want Linux to communicate with system firmware
1331 implementing the PSCI specification for CPU-centric power
1332 management operations described in ARM document number ARM DEN
1333 0022A ("Power State Coordination Interface System Software on
1334 ARM processors").
1335
1336# The GPIO number here must be sorted by descending number. In case of
1337# a multiplatform kernel, we just want the highest value required by the
1338# selected platforms.
1339config ARCH_NR_GPIO
1340 int
1341 default 2048 if ARCH_SOCFPGA
1342 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1343 ARCH_ZYNQ || ARCH_ASPEED
1344 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1345 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1346 default 416 if ARCH_SUNXI
1347 default 392 if ARCH_U8500
1348 default 352 if ARCH_VT8500
1349 default 288 if ARCH_ROCKCHIP
1350 default 264 if MACH_H4700
1351 default 0
1352 help
1353 Maximum number of GPIOs in the system.
1354
1355 If unsure, leave the default value.
1356
1357config HZ_FIXED
1358 int
1359 default 128 if SOC_AT91RM9200
1360 default 0
1361
1362choice
1363 depends on HZ_FIXED = 0
1364 prompt "Timer frequency"
1365
1366config HZ_100
1367 bool "100 Hz"
1368
1369config HZ_200
1370 bool "200 Hz"
1371
1372config HZ_250
1373 bool "250 Hz"
1374
1375config HZ_300
1376 bool "300 Hz"
1377
1378config HZ_500
1379 bool "500 Hz"
1380
1381config HZ_1000
1382 bool "1000 Hz"
1383
1384endchoice
1385
1386config HZ
1387 int
1388 default HZ_FIXED if HZ_FIXED != 0
1389 default 100 if HZ_100
1390 default 200 if HZ_200
1391 default 250 if HZ_250
1392 default 300 if HZ_300
1393 default 500 if HZ_500
1394 default 1000
1395
1396config SCHED_HRTICK
1397 def_bool HIGH_RES_TIMERS
1398
1399config THUMB2_KERNEL
1400 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1401 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1402 default y if CPU_THUMBONLY
1403 select ARM_UNWIND
1404 help
1405 By enabling this option, the kernel will be compiled in
1406 Thumb-2 mode.
1407
1408 If unsure, say N.
1409
1410config ARM_PATCH_IDIV
1411 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1412 depends on CPU_32v7 && !XIP_KERNEL
1413 default y
1414 help
1415 The ARM compiler inserts calls to __aeabi_idiv() and
1416 __aeabi_uidiv() when it needs to perform division on signed
1417 and unsigned integers. Some v7 CPUs have support for the sdiv
1418 and udiv instructions that can be used to implement those
1419 functions.
1420
1421 Enabling this option allows the kernel to modify itself to
1422 replace the first two instructions of these library functions
1423 with the sdiv or udiv plus "bx lr" instructions when the CPU
1424 it is running on supports them. Typically this will be faster
1425 and less power intensive than running the original library
1426 code to do integer division.
1427
1428config AEABI
1429 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1430 !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1431 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1432 help
1433 This option allows for the kernel to be compiled using the latest
1434 ARM ABI (aka EABI). This is only useful if you are using a user
1435 space environment that is also compiled with EABI.
1436
1437 Since there are major incompatibilities between the legacy ABI and
1438 EABI, especially with regard to structure member alignment, this
1439 option also changes the kernel syscall calling convention to
1440 disambiguate both ABIs and allow for backward compatibility support
1441 (selected with CONFIG_OABI_COMPAT).
1442
1443 To use this you need GCC version 4.0.0 or later.
1444
1445config OABI_COMPAT
1446 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1447 depends on AEABI && !THUMB2_KERNEL
1448 help
1449 This option preserves the old syscall interface along with the
1450 new (ARM EABI) one. It also provides a compatibility layer to
1451 intercept syscalls that have structure arguments which layout
1452 in memory differs between the legacy ABI and the new ARM EABI
1453 (only for non "thumb" binaries). This option adds a tiny
1454 overhead to all syscalls and produces a slightly larger kernel.
1455
1456 The seccomp filter system will not be available when this is
1457 selected, since there is no way yet to sensibly distinguish
1458 between calling conventions during filtering.
1459
1460 If you know you'll be using only pure EABI user space then you
1461 can say N here. If this option is not selected and you attempt
1462 to execute a legacy ABI binary then the result will be
1463 UNPREDICTABLE (in fact it can be predicted that it won't work
1464 at all). If in doubt say N.
1465
1466config ARCH_SELECT_MEMORY_MODEL
1467 bool
1468
1469config ARCH_FLATMEM_ENABLE
1470 bool
1471
1472config ARCH_SPARSEMEM_ENABLE
1473 bool
1474 select SPARSEMEM_STATIC if SPARSEMEM
1475
1476config HIGHMEM
1477 bool "High Memory Support"
1478 depends on MMU
1479 select KMAP_LOCAL
1480 help
1481 The address space of ARM processors is only 4 Gigabytes large
1482 and it has to accommodate user address space, kernel address
1483 space as well as some memory mapped IO. That means that, if you
1484 have a large amount of physical memory and/or IO, not all of the
1485 memory can be "permanently mapped" by the kernel. The physical
1486 memory that is not permanently mapped is called "high memory".
1487
1488 Depending on the selected kernel/user memory split, minimum
1489 vmalloc space and actual amount of RAM, you may not need this
1490 option which should result in a slightly faster kernel.
1491
1492 If unsure, say n.
1493
1494config HIGHPTE
1495 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1496 depends on HIGHMEM
1497 default y
1498 help
1499 The VM uses one page of physical memory for each page table.
1500 For systems with a lot of processes, this can use a lot of
1501 precious low memory, eventually leading to low memory being
1502 consumed by page tables. Setting this option will allow
1503 user-space 2nd level page tables to reside in high memory.
1504
1505config CPU_SW_DOMAIN_PAN
1506 bool "Enable use of CPU domains to implement privileged no-access"
1507 depends on MMU && !ARM_LPAE
1508 default y
1509 help
1510 Increase kernel security by ensuring that normal kernel accesses
1511 are unable to access userspace addresses. This can help prevent
1512 use-after-free bugs becoming an exploitable privilege escalation
1513 by ensuring that magic values (such as LIST_POISON) will always
1514 fault when dereferenced.
1515
1516 CPUs with low-vector mappings use a best-efforts implementation.
1517 Their lower 1MB needs to remain accessible for the vectors, but
1518 the remainder of userspace will become appropriately inaccessible.
1519
1520config HW_PERF_EVENTS
1521 def_bool y
1522 depends on ARM_PMU
1523
1524config SYS_SUPPORTS_HUGETLBFS
1525 def_bool y
1526 depends on ARM_LPAE
1527
1528config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1529 def_bool y
1530 depends on ARM_LPAE
1531
1532config ARCH_WANT_GENERAL_HUGETLB
1533 def_bool y
1534
1535config ARM_MODULE_PLTS
1536 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1537 depends on MODULES
1538 default y
1539 help
1540 Allocate PLTs when loading modules so that jumps and calls whose
1541 targets are too far away for their relative offsets to be encoded
1542 in the instructions themselves can be bounced via veneers in the
1543 module's PLT. This allows modules to be allocated in the generic
1544 vmalloc area after the dedicated module memory area has been
1545 exhausted. The modules will use slightly more memory, but after
1546 rounding up to page size, the actual memory footprint is usually
1547 the same.
1548
1549 Disabling this is usually safe for small single-platform
1550 configurations. If unsure, say y.
1551
1552config FORCE_MAX_ZONEORDER
1553 int "Maximum zone order"
1554 default "12" if SOC_AM33XX
1555 default "9" if SA1111 || ARCH_EFM32
1556 default "11"
1557 help
1558 The kernel memory allocator divides physically contiguous memory
1559 blocks into "zones", where each zone is a power of two number of
1560 pages. This option selects the largest power of two that the kernel
1561 keeps in the memory allocator. If you need to allocate very large
1562 blocks of physically contiguous memory, then you may need to
1563 increase this value.
1564
1565 This config option is actually maximum order plus one. For example,
1566 a value of 11 means that the largest free memory block is 2^10 pages.
1567
1568config ALIGNMENT_TRAP
1569 def_bool CPU_CP15_MMU
1570 select HAVE_PROC_CPU if PROC_FS
1571 help
1572 ARM processors cannot fetch/store information which is not
1573 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1574 address divisible by 4. On 32-bit ARM processors, these non-aligned
1575 fetch/store instructions will be emulated in software if you say
1576 here, which has a severe performance impact. This is necessary for
1577 correct operation of some network protocols. With an IP-only
1578 configuration it is safe to say N, otherwise say Y.
1579
1580config UACCESS_WITH_MEMCPY
1581 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1582 depends on MMU
1583 default y if CPU_FEROCEON
1584 help
1585 Implement faster copy_to_user and clear_user methods for CPU
1586 cores where a 8-word STM instruction give significantly higher
1587 memory write throughput than a sequence of individual 32bit stores.
1588
1589 A possible side effect is a slight increase in scheduling latency
1590 between threads sharing the same address space if they invoke
1591 such copy operations with large buffers.
1592
1593 However, if the CPU data cache is using a write-allocate mode,
1594 this option is unlikely to provide any performance gain.
1595
1596config PARAVIRT
1597 bool "Enable paravirtualization code"
1598 help
1599 This changes the kernel so it can modify itself when it is run
1600 under a hypervisor, potentially improving performance significantly
1601 over full virtualization.
1602
1603config PARAVIRT_TIME_ACCOUNTING
1604 bool "Paravirtual steal time accounting"
1605 select PARAVIRT
1606 help
1607 Select this option to enable fine granularity task steal time
1608 accounting. Time spent executing other tasks in parallel with
1609 the current vCPU is discounted from the vCPU power. To account for
1610 that, there can be a small performance impact.
1611
1612 If in doubt, say N here.
1613
1614config XEN_DOM0
1615 def_bool y
1616 depends on XEN
1617
1618config XEN
1619 bool "Xen guest support on ARM"
1620 depends on ARM && AEABI && OF
1621 depends on CPU_V7 && !CPU_V6
1622 depends on !GENERIC_ATOMIC64
1623 depends on MMU
1624 select ARCH_DMA_ADDR_T_64BIT
1625 select ARM_PSCI
1626 select SWIOTLB
1627 select SWIOTLB_XEN
1628 select PARAVIRT
1629 help
1630 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1631
1632config STACKPROTECTOR_PER_TASK
1633 bool "Use a unique stack canary value for each task"
1634 depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1635 select GCC_PLUGIN_ARM_SSP_PER_TASK
1636 default y
1637 help
1638 Due to the fact that GCC uses an ordinary symbol reference from
1639 which to load the value of the stack canary, this value can only
1640 change at reboot time on SMP systems, and all tasks running in the
1641 kernel's address space are forced to use the same canary value for
1642 the entire duration that the system is up.
1643
1644 Enable this option to switch to a different method that uses a
1645 different canary value for each task.
1646
1647endmenu
1648
1649menu "Boot options"
1650
1651config USE_OF
1652 bool "Flattened Device Tree support"
1653 select IRQ_DOMAIN
1654 select OF
1655 help
1656 Include support for flattened device tree machine descriptions.
1657
1658config ATAGS
1659 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1660 default y
1661 help
1662 This is the traditional way of passing data to the kernel at boot
1663 time. If you are solely relying on the flattened device tree (or
1664 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1665 to remove ATAGS support from your kernel binary. If unsure,
1666 leave this to y.
1667
1668config DEPRECATED_PARAM_STRUCT
1669 bool "Provide old way to pass kernel parameters"
1670 depends on ATAGS
1671 help
1672 This was deprecated in 2001 and announced to live on for 5 years.
1673 Some old boot loaders still use this way.
1674
1675# Compressed boot loader in ROM. Yes, we really want to ask about
1676# TEXT and BSS so we preserve their values in the config files.
1677config ZBOOT_ROM_TEXT
1678 hex "Compressed ROM boot loader base address"
1679 default 0x0
1680 help
1681 The physical address at which the ROM-able zImage is to be
1682 placed in the target. Platforms which normally make use of
1683 ROM-able zImage formats normally set this to a suitable
1684 value in their defconfig file.
1685
1686 If ZBOOT_ROM is not enabled, this has no effect.
1687
1688config ZBOOT_ROM_BSS
1689 hex "Compressed ROM boot loader BSS address"
1690 default 0x0
1691 help
1692 The base address of an area of read/write memory in the target
1693 for the ROM-able zImage which must be available while the
1694 decompressor is running. It must be large enough to hold the
1695 entire decompressed kernel plus an additional 128 KiB.
1696 Platforms which normally make use of ROM-able zImage formats
1697 normally set this to a suitable value in their defconfig file.
1698
1699 If ZBOOT_ROM is not enabled, this has no effect.
1700
1701config ZBOOT_ROM
1702 bool "Compressed boot loader in ROM/flash"
1703 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1704 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1705 help
1706 Say Y here if you intend to execute your compressed kernel image
1707 (zImage) directly from ROM or flash. If unsure, say N.
1708
1709config ARM_APPENDED_DTB
1710 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1711 depends on OF
1712 help
1713 With this option, the boot code will look for a device tree binary
1714 (DTB) appended to zImage
1715 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1716
1717 This is meant as a backward compatibility convenience for those
1718 systems with a bootloader that can't be upgraded to accommodate
1719 the documented boot protocol using a device tree.
1720
1721 Beware that there is very little in terms of protection against
1722 this option being confused by leftover garbage in memory that might
1723 look like a DTB header after a reboot if no actual DTB is appended
1724 to zImage. Do not leave this option active in a production kernel
1725 if you don't intend to always append a DTB. Proper passing of the
1726 location into r2 of a bootloader provided DTB is always preferable
1727 to this option.
1728
1729config ARM_ATAG_DTB_COMPAT
1730 bool "Supplement the appended DTB with traditional ATAG information"
1731 depends on ARM_APPENDED_DTB
1732 help
1733 Some old bootloaders can't be updated to a DTB capable one, yet
1734 they provide ATAGs with memory configuration, the ramdisk address,
1735 the kernel cmdline string, etc. Such information is dynamically
1736 provided by the bootloader and can't always be stored in a static
1737 DTB. To allow a device tree enabled kernel to be used with such
1738 bootloaders, this option allows zImage to extract the information
1739 from the ATAG list and store it at run time into the appended DTB.
1740
1741choice
1742 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1743 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1744
1745config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1746 bool "Use bootloader kernel arguments if available"
1747 help
1748 Uses the command-line options passed by the boot loader instead of
1749 the device tree bootargs property. If the boot loader doesn't provide
1750 any, the device tree bootargs property will be used.
1751
1752config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1753 bool "Extend with bootloader kernel arguments"
1754 help
1755 The command-line arguments provided by the boot loader will be
1756 appended to the the device tree bootargs property.
1757
1758endchoice
1759
1760config CMDLINE
1761 string "Default kernel command string"
1762 default ""
1763 help
1764 On some architectures (e.g. CATS), there is currently no way
1765 for the boot loader to pass arguments to the kernel. For these
1766 architectures, you should supply some command-line options at build
1767 time by entering them here. As a minimum, you should specify the
1768 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1769
1770choice
1771 prompt "Kernel command line type" if CMDLINE != ""
1772 default CMDLINE_FROM_BOOTLOADER
1773 depends on ATAGS
1774
1775config CMDLINE_FROM_BOOTLOADER
1776 bool "Use bootloader kernel arguments if available"
1777 help
1778 Uses the command-line options passed by the boot loader. If
1779 the boot loader doesn't provide any, the default kernel command
1780 string provided in CMDLINE will be used.
1781
1782config CMDLINE_EXTEND
1783 bool "Extend bootloader kernel arguments"
1784 help
1785 The command-line arguments provided by the boot loader will be
1786 appended to the default kernel command string.
1787
1788config CMDLINE_FORCE
1789 bool "Always use the default kernel command string"
1790 help
1791 Always use the default kernel command string, even if the boot
1792 loader passes other arguments to the kernel.
1793 This is useful if you cannot or don't want to change the
1794 command-line options your boot loader passes to the kernel.
1795endchoice
1796
1797config XIP_KERNEL
1798 bool "Kernel Execute-In-Place from ROM"
1799 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1800 help
1801 Execute-In-Place allows the kernel to run from non-volatile storage
1802 directly addressable by the CPU, such as NOR flash. This saves RAM
1803 space since the text section of the kernel is not loaded from flash
1804 to RAM. Read-write sections, such as the data section and stack,
1805 are still copied to RAM. The XIP kernel is not compressed since
1806 it has to run directly from flash, so it will take more space to
1807 store it. The flash address used to link the kernel object files,
1808 and for storing it, is configuration dependent. Therefore, if you
1809 say Y here, you must know the proper physical address where to
1810 store the kernel image depending on your own flash memory usage.
1811
1812 Also note that the make target becomes "make xipImage" rather than
1813 "make zImage" or "make Image". The final kernel binary to put in
1814 ROM memory will be arch/arm/boot/xipImage.
1815
1816 If unsure, say N.
1817
1818config XIP_PHYS_ADDR
1819 hex "XIP Kernel Physical Location"
1820 depends on XIP_KERNEL
1821 default "0x00080000"
1822 help
1823 This is the physical address in your flash memory the kernel will
1824 be linked for and stored to. This address is dependent on your
1825 own flash usage.
1826
1827config XIP_DEFLATED_DATA
1828 bool "Store kernel .data section compressed in ROM"
1829 depends on XIP_KERNEL
1830 select ZLIB_INFLATE
1831 help
1832 Before the kernel is actually executed, its .data section has to be
1833 copied to RAM from ROM. This option allows for storing that data
1834 in compressed form and decompressed to RAM rather than merely being
1835 copied, saving some precious ROM space. A possible drawback is a
1836 slightly longer boot delay.
1837
1838config KEXEC
1839 bool "Kexec system call (EXPERIMENTAL)"
1840 depends on (!SMP || PM_SLEEP_SMP)
1841 depends on MMU
1842 select KEXEC_CORE
1843 help
1844 kexec is a system call that implements the ability to shutdown your
1845 current kernel, and to start another kernel. It is like a reboot
1846 but it is independent of the system firmware. And like a reboot
1847 you can start any kernel with it, not just Linux.
1848
1849 It is an ongoing process to be certain the hardware in a machine
1850 is properly shutdown, so do not be surprised if this code does not
1851 initially work for you.
1852
1853config ATAGS_PROC
1854 bool "Export atags in procfs"
1855 depends on ATAGS && KEXEC
1856 default y
1857 help
1858 Should the atags used to boot the kernel be exported in an "atags"
1859 file in procfs. Useful with kexec.
1860
1861config CRASH_DUMP
1862 bool "Build kdump crash kernel (EXPERIMENTAL)"
1863 help
1864 Generate crash dump after being started by kexec. This should
1865 be normally only set in special crash dump kernels which are
1866 loaded in the main kernel with kexec-tools into a specially
1867 reserved region and then later executed after a crash by
1868 kdump/kexec. The crash dump kernel must be compiled to a
1869 memory address not used by the main kernel
1870
1871 For more details see Documentation/admin-guide/kdump/kdump.rst
1872
1873config AUTO_ZRELADDR
1874 bool "Auto calculation of the decompressed kernel image address"
1875 help
1876 ZRELADDR is the physical address where the decompressed kernel
1877 image will be placed. If AUTO_ZRELADDR is selected, the address
1878 will be determined at run-time by masking the current IP with
1879 0xf8000000. This assumes the zImage being placed in the first 128MB
1880 from start of memory.
1881
1882config EFI_STUB
1883 bool
1884
1885config EFI
1886 bool "UEFI runtime support"
1887 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1888 select UCS2_STRING
1889 select EFI_PARAMS_FROM_FDT
1890 select EFI_STUB
1891 select EFI_GENERIC_STUB
1892 select EFI_RUNTIME_WRAPPERS
1893 help
1894 This option provides support for runtime services provided
1895 by UEFI firmware (such as non-volatile variables, realtime
1896 clock, and platform reset). A UEFI stub is also provided to
1897 allow the kernel to be booted as an EFI application. This
1898 is only useful for kernels that may run on systems that have
1899 UEFI firmware.
1900
1901config DMI
1902 bool "Enable support for SMBIOS (DMI) tables"
1903 depends on EFI
1904 default y
1905 help
1906 This enables SMBIOS/DMI feature for systems.
1907
1908 This option is only useful on systems that have UEFI firmware.
1909 However, even with this option, the resultant kernel should
1910 continue to boot on existing non-UEFI platforms.
1911
1912 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1913 i.e., the the practice of identifying the platform via DMI to
1914 decide whether certain workarounds for buggy hardware and/or
1915 firmware need to be enabled. This would require the DMI subsystem
1916 to be enabled much earlier than we do on ARM, which is non-trivial.
1917
1918endmenu
1919
1920menu "CPU Power Management"
1921
1922source "drivers/cpufreq/Kconfig"
1923
1924source "drivers/cpuidle/Kconfig"
1925
1926endmenu
1927
1928menu "Floating point emulation"
1929
1930comment "At least one emulation must be selected"
1931
1932config FPE_NWFPE
1933 bool "NWFPE math emulation"
1934 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1935 help
1936 Say Y to include the NWFPE floating point emulator in the kernel.
1937 This is necessary to run most binaries. Linux does not currently
1938 support floating point hardware so you need to say Y here even if
1939 your machine has an FPA or floating point co-processor podule.
1940
1941 You may say N here if you are going to load the Acorn FPEmulator
1942 early in the bootup.
1943
1944config FPE_NWFPE_XP
1945 bool "Support extended precision"
1946 depends on FPE_NWFPE
1947 help
1948 Say Y to include 80-bit support in the kernel floating-point
1949 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1950 Note that gcc does not generate 80-bit operations by default,
1951 so in most cases this option only enlarges the size of the
1952 floating point emulator without any good reason.
1953
1954 You almost surely want to say N here.
1955
1956config FPE_FASTFPE
1957 bool "FastFPE math emulation (EXPERIMENTAL)"
1958 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1959 help
1960 Say Y here to include the FAST floating point emulator in the kernel.
1961 This is an experimental much faster emulator which now also has full
1962 precision for the mantissa. It does not support any exceptions.
1963 It is very simple, and approximately 3-6 times faster than NWFPE.
1964
1965 It should be sufficient for most programs. It may be not suitable
1966 for scientific calculations, but you have to check this for yourself.
1967 If you do not feel you need a faster FP emulation you should better
1968 choose NWFPE.
1969
1970config VFP
1971 bool "VFP-format floating point maths"
1972 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1973 help
1974 Say Y to include VFP support code in the kernel. This is needed
1975 if your hardware includes a VFP unit.
1976
1977 Please see <file:Documentation/arm/vfp/release-notes.rst> for
1978 release notes and additional status information.
1979
1980 Say N if your target does not have VFP hardware.
1981
1982config VFPv3
1983 bool
1984 depends on VFP
1985 default y if CPU_V7
1986
1987config NEON
1988 bool "Advanced SIMD (NEON) Extension support"
1989 depends on VFPv3 && CPU_V7
1990 help
1991 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1992 Extension.
1993
1994config KERNEL_MODE_NEON
1995 bool "Support for NEON in kernel mode"
1996 depends on NEON && AEABI
1997 help
1998 Say Y to include support for NEON in kernel mode.
1999
2000endmenu
2001
2002menu "Power management options"
2003
2004source "kernel/power/Kconfig"
2005
2006config ARCH_SUSPEND_POSSIBLE
2007 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2008 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2009 def_bool y
2010
2011config ARM_CPU_SUSPEND
2012 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2013 depends on ARCH_SUSPEND_POSSIBLE
2014
2015config ARCH_HIBERNATION_POSSIBLE
2016 bool
2017 depends on MMU
2018 default y if ARCH_SUSPEND_POSSIBLE
2019
2020endmenu
2021
2022source "drivers/firmware/Kconfig"
2023
2024if CRYPTO
2025source "arch/arm/crypto/Kconfig"
2026endif
2027
2028source "arch/arm/Kconfig.assembler"