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_DEVMEM_IS_ALLOWED
9 select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
10 select ARCH_HAS_ELF_RANDOMIZE
11 select ARCH_HAS_FORTIFY_SOURCE
12 select ARCH_HAS_KEEPINITRD
13 select ARCH_HAS_KCOV
14 select ARCH_HAS_MEMBARRIER_SYNC_CORE
15 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
16 select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
17 select ARCH_HAS_PHYS_TO_DMA
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 if SWIOTLB
23 select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
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_HAS_GCOV_PROFILE_ALL
28 select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC
29 select ARCH_MIGHT_HAVE_PC_PARPORT
30 select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
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_USE_BUILTIN_BSWAP
35 select ARCH_USE_CMPXCHG_LOCKREF
36 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
37 select ARCH_WANT_IPC_PARSE_VERSION
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_CPU_AUTOPROBE
53 select GENERIC_EARLY_IOREMAP
54 select GENERIC_IDLE_POLL_SETUP
55 select GENERIC_IRQ_PROBE
56 select GENERIC_IRQ_SHOW
57 select GENERIC_IRQ_SHOW_LEVEL
58 select GENERIC_PCI_IOMAP
59 select GENERIC_SCHED_CLOCK
60 select GENERIC_SMP_IDLE_THREAD
61 select GENERIC_STRNCPY_FROM_USER
62 select GENERIC_STRNLEN_USER
63 select HANDLE_DOMAIN_IRQ
64 select HARDIRQS_SW_RESEND
65 select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
66 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
67 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
68 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
69 select HAVE_ARCH_MMAP_RND_BITS if MMU
70 select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
71 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
72 select HAVE_ARCH_TRACEHOOK
73 select HAVE_ARM_SMCCC if CPU_V7
74 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
75 select HAVE_CONTEXT_TRACKING
76 select HAVE_C_RECORDMCOUNT
77 select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
78 select HAVE_DMA_CONTIGUOUS if MMU
79 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
80 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
81 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
82 select HAVE_EXIT_THREAD
83 select HAVE_FAST_GUP if ARM_LPAE
84 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
85 select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
86 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && (CC_IS_GCC || CLANG_VERSION >= 100000)
87 select HAVE_GCC_PLUGINS
88 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
89 select HAVE_IDE if PCI || ISA || PCMCIA
90 select HAVE_IRQ_TIME_ACCOUNTING
91 select HAVE_KERNEL_GZIP
92 select HAVE_KERNEL_LZ4
93 select HAVE_KERNEL_LZMA
94 select HAVE_KERNEL_LZO
95 select HAVE_KERNEL_XZ
96 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
97 select HAVE_KRETPROBES if HAVE_KPROBES
98 select HAVE_MOD_ARCH_SPECIFIC
99 select HAVE_NMI
100 select HAVE_OPROFILE if HAVE_PERF_EVENTS
101 select HAVE_OPTPROBES if !THUMB2_KERNEL
102 select HAVE_PERF_EVENTS
103 select HAVE_PERF_REGS
104 select HAVE_PERF_USER_STACK_DUMP
105 select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
106 select HAVE_REGS_AND_STACK_ACCESS_API
107 select HAVE_RSEQ
108 select HAVE_STACKPROTECTOR
109 select HAVE_SYSCALL_TRACEPOINTS
110 select HAVE_UID16
111 select HAVE_VIRT_CPU_ACCOUNTING_GEN
112 select IRQ_FORCED_THREADING
113 select MODULES_USE_ELF_REL
114 select NEED_DMA_MAP_STATE
115 select OF_EARLY_FLATTREE if OF
116 select OLD_SIGACTION
117 select OLD_SIGSUSPEND3
118 select PCI_SYSCALL if PCI
119 select PERF_USE_VMALLOC
120 select RTC_LIB
121 select SYS_SUPPORTS_APM_EMULATION
122 # Above selects are sorted alphabetically; please add new ones
123 # according to that. Thanks.
124 help
125 The ARM series is a line of low-power-consumption RISC chip designs
126 licensed by ARM Ltd and targeted at embedded applications and
127 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
128 manufactured, but legacy ARM-based PC hardware remains popular in
129 Europe. There is an ARM Linux project with a web page at
130 <http://www.arm.linux.org.uk/>.
131
132config ARM_HAS_SG_CHAIN
133 bool
134
135config ARM_DMA_USE_IOMMU
136 bool
137 select ARM_HAS_SG_CHAIN
138 select NEED_SG_DMA_LENGTH
139
140if ARM_DMA_USE_IOMMU
141
142config ARM_DMA_IOMMU_ALIGNMENT
143 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
144 range 4 9
145 default 8
146 help
147 DMA mapping framework by default aligns all buffers to the smallest
148 PAGE_SIZE order which is greater than or equal to the requested buffer
149 size. This works well for buffers up to a few hundreds kilobytes, but
150 for larger buffers it just a waste of address space. Drivers which has
151 relatively small addressing window (like 64Mib) might run out of
152 virtual space with just a few allocations.
153
154 With this parameter you can specify the maximum PAGE_SIZE order for
155 DMA IOMMU buffers. Larger buffers will be aligned only to this
156 specified order. The order is expressed as a power of two multiplied
157 by the PAGE_SIZE.
158
159endif
160
161config SYS_SUPPORTS_APM_EMULATION
162 bool
163
164config HAVE_TCM
165 bool
166 select GENERIC_ALLOCATOR
167
168config HAVE_PROC_CPU
169 bool
170
171config NO_IOPORT_MAP
172 bool
173
174config SBUS
175 bool
176
177config STACKTRACE_SUPPORT
178 bool
179 default y
180
181config LOCKDEP_SUPPORT
182 bool
183 default y
184
185config TRACE_IRQFLAGS_SUPPORT
186 bool
187 default !CPU_V7M
188
189config ARCH_HAS_ILOG2_U32
190 bool
191
192config ARCH_HAS_ILOG2_U64
193 bool
194
195config ARCH_HAS_BANDGAP
196 bool
197
198config FIX_EARLYCON_MEM
199 def_bool y if MMU
200
201config GENERIC_HWEIGHT
202 bool
203 default y
204
205config GENERIC_CALIBRATE_DELAY
206 bool
207 default y
208
209config ARCH_MAY_HAVE_PC_FDC
210 bool
211
212config ZONE_DMA
213 bool
214
215config ARCH_SUPPORTS_UPROBES
216 def_bool y
217
218config ARCH_HAS_DMA_SET_COHERENT_MASK
219 bool
220
221config GENERIC_ISA_DMA
222 bool
223
224config FIQ
225 bool
226
227config NEED_RET_TO_USER
228 bool
229
230config ARCH_MTD_XIP
231 bool
232
233config ARM_PATCH_PHYS_VIRT
234 bool "Patch physical to virtual translations at runtime" if EMBEDDED
235 default y
236 depends on !XIP_KERNEL && MMU
237 help
238 Patch phys-to-virt and virt-to-phys translation functions at
239 boot and module load time according to the position of the
240 kernel in system memory.
241
242 This can only be used with non-XIP MMU kernels where the base
243 of physical memory is at a 16MB boundary.
244
245 Only disable this option if you know that you do not require
246 this feature (eg, building a kernel for a single machine) and
247 you need to shrink the kernel to the minimal size.
248
249config NEED_MACH_IO_H
250 bool
251 help
252 Select this when mach/io.h is required to provide special
253 definitions for this platform. The need for mach/io.h should
254 be avoided when possible.
255
256config NEED_MACH_MEMORY_H
257 bool
258 help
259 Select this when mach/memory.h is required to provide special
260 definitions for this platform. The need for mach/memory.h should
261 be avoided when possible.
262
263config PHYS_OFFSET
264 hex "Physical address of main memory" if MMU
265 depends on !ARM_PATCH_PHYS_VIRT
266 default DRAM_BASE if !MMU
267 default 0x00000000 if ARCH_EBSA110 || \
268 ARCH_FOOTBRIDGE || \
269 ARCH_INTEGRATOR || \
270 ARCH_REALVIEW
271 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
272 default 0x20000000 if ARCH_S5PV210
273 default 0xc0000000 if ARCH_SA1100
274 help
275 Please provide the physical address corresponding to the
276 location of main memory in your system.
277
278config GENERIC_BUG
279 def_bool y
280 depends on BUG
281
282config PGTABLE_LEVELS
283 int
284 default 3 if ARM_LPAE
285 default 2
286
287menu "System Type"
288
289config MMU
290 bool "MMU-based Paged Memory Management Support"
291 default y
292 help
293 Select if you want MMU-based virtualised addressing space
294 support by paged memory management. If unsure, say 'Y'.
295
296config ARCH_MMAP_RND_BITS_MIN
297 default 8
298
299config ARCH_MMAP_RND_BITS_MAX
300 default 14 if PAGE_OFFSET=0x40000000
301 default 15 if PAGE_OFFSET=0x80000000
302 default 16
303
304#
305# The "ARM system type" choice list is ordered alphabetically by option
306# text. Please add new entries in the option alphabetic order.
307#
308choice
309 prompt "ARM system type"
310 default ARM_SINGLE_ARMV7M if !MMU
311 default ARCH_MULTIPLATFORM if MMU
312
313config ARCH_MULTIPLATFORM
314 bool "Allow multiple platforms to be selected"
315 depends on MMU
316 select ARCH_FLATMEM_ENABLE
317 select ARCH_SPARSEMEM_ENABLE
318 select ARCH_SELECT_MEMORY_MODEL
319 select ARM_HAS_SG_CHAIN
320 select ARM_PATCH_PHYS_VIRT
321 select AUTO_ZRELADDR
322 select TIMER_OF
323 select COMMON_CLK
324 select GENERIC_CLOCKEVENTS
325 select GENERIC_IRQ_MULTI_HANDLER
326 select HAVE_PCI
327 select PCI_DOMAINS_GENERIC if PCI
328 select SPARSE_IRQ
329 select USE_OF
330
331config ARM_SINGLE_ARMV7M
332 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
333 depends on !MMU
334 select ARM_NVIC
335 select AUTO_ZRELADDR
336 select TIMER_OF
337 select COMMON_CLK
338 select CPU_V7M
339 select GENERIC_CLOCKEVENTS
340 select NO_IOPORT_MAP
341 select SPARSE_IRQ
342 select USE_OF
343
344config ARCH_EBSA110
345 bool "EBSA-110"
346 select ARCH_USES_GETTIMEOFFSET
347 select CPU_SA110
348 select ISA
349 select NEED_MACH_IO_H
350 select NEED_MACH_MEMORY_H
351 select NO_IOPORT_MAP
352 help
353 This is an evaluation board for the StrongARM processor available
354 from Digital. It has limited hardware on-board, including an
355 Ethernet interface, two PCMCIA sockets, two serial ports and a
356 parallel port.
357
358config ARCH_EP93XX
359 bool "EP93xx-based"
360 select ARCH_SPARSEMEM_ENABLE
361 select ARM_AMBA
362 imply ARM_PATCH_PHYS_VIRT
363 select ARM_VIC
364 select AUTO_ZRELADDR
365 select CLKDEV_LOOKUP
366 select CLKSRC_MMIO
367 select CPU_ARM920T
368 select GENERIC_CLOCKEVENTS
369 select GPIOLIB
370 select HAVE_LEGACY_CLK
371 help
372 This enables support for the Cirrus EP93xx series of CPUs.
373
374config ARCH_FOOTBRIDGE
375 bool "FootBridge"
376 select CPU_SA110
377 select FOOTBRIDGE
378 select GENERIC_CLOCKEVENTS
379 select HAVE_IDE
380 select NEED_MACH_IO_H if !MMU
381 select NEED_MACH_MEMORY_H
382 help
383 Support for systems based on the DC21285 companion chip
384 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
385
386config ARCH_IOP32X
387 bool "IOP32x-based"
388 depends on MMU
389 select CPU_XSCALE
390 select GPIO_IOP
391 select GPIOLIB
392 select NEED_RET_TO_USER
393 select FORCE_PCI
394 select PLAT_IOP
395 help
396 Support for Intel's 80219 and IOP32X (XScale) family of
397 processors.
398
399config ARCH_IXP4XX
400 bool "IXP4xx-based"
401 depends on MMU
402 select ARCH_HAS_DMA_SET_COHERENT_MASK
403 select ARCH_SUPPORTS_BIG_ENDIAN
404 select CPU_XSCALE
405 select DMABOUNCE if PCI
406 select GENERIC_CLOCKEVENTS
407 select GENERIC_IRQ_MULTI_HANDLER
408 select GPIO_IXP4XX
409 select GPIOLIB
410 select HAVE_PCI
411 select IXP4XX_IRQ
412 select IXP4XX_TIMER
413 select NEED_MACH_IO_H
414 select USB_EHCI_BIG_ENDIAN_DESC
415 select USB_EHCI_BIG_ENDIAN_MMIO
416 help
417 Support for Intel's IXP4XX (XScale) family of processors.
418
419config ARCH_DOVE
420 bool "Marvell Dove"
421 select CPU_PJ4
422 select GENERIC_CLOCKEVENTS
423 select GENERIC_IRQ_MULTI_HANDLER
424 select GPIOLIB
425 select HAVE_PCI
426 select MVEBU_MBUS
427 select PINCTRL
428 select PINCTRL_DOVE
429 select PLAT_ORION_LEGACY
430 select SPARSE_IRQ
431 select PM_GENERIC_DOMAINS if PM
432 help
433 Support for the Marvell Dove SoC 88AP510
434
435config ARCH_PXA
436 bool "PXA2xx/PXA3xx-based"
437 depends on MMU
438 select ARCH_MTD_XIP
439 select ARM_CPU_SUSPEND if PM
440 select AUTO_ZRELADDR
441 select COMMON_CLK
442 select CLKSRC_PXA
443 select CLKSRC_MMIO
444 select TIMER_OF
445 select CPU_XSCALE if !CPU_XSC3
446 select GENERIC_CLOCKEVENTS
447 select GENERIC_IRQ_MULTI_HANDLER
448 select GPIO_PXA
449 select GPIOLIB
450 select HAVE_IDE
451 select IRQ_DOMAIN
452 select PLAT_PXA
453 select SPARSE_IRQ
454 help
455 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
456
457config ARCH_RPC
458 bool "RiscPC"
459 depends on MMU
460 select ARCH_ACORN
461 select ARCH_MAY_HAVE_PC_FDC
462 select ARCH_SPARSEMEM_ENABLE
463 select ARM_HAS_SG_CHAIN
464 select CPU_SA110
465 select FIQ
466 select HAVE_IDE
467 select HAVE_PATA_PLATFORM
468 select ISA_DMA_API
469 select NEED_MACH_IO_H
470 select NEED_MACH_MEMORY_H
471 select NO_IOPORT_MAP
472 help
473 On the Acorn Risc-PC, Linux can support the internal IDE disk and
474 CD-ROM interface, serial and parallel port, and the floppy drive.
475
476config ARCH_SA1100
477 bool "SA1100-based"
478 select ARCH_MTD_XIP
479 select ARCH_SPARSEMEM_ENABLE
480 select CLKSRC_MMIO
481 select CLKSRC_PXA
482 select TIMER_OF if OF
483 select COMMON_CLK
484 select CPU_FREQ
485 select CPU_SA1100
486 select GENERIC_CLOCKEVENTS
487 select GENERIC_IRQ_MULTI_HANDLER
488 select GPIOLIB
489 select HAVE_IDE
490 select IRQ_DOMAIN
491 select ISA
492 select NEED_MACH_MEMORY_H
493 select SPARSE_IRQ
494 help
495 Support for StrongARM 11x0 based boards.
496
497config ARCH_S3C24XX
498 bool "Samsung S3C24XX SoCs"
499 select ATAGS
500 select CLKSRC_SAMSUNG_PWM
501 select GENERIC_CLOCKEVENTS
502 select GPIO_SAMSUNG
503 select GPIOLIB
504 select GENERIC_IRQ_MULTI_HANDLER
505 select HAVE_S3C2410_I2C if I2C
506 select HAVE_S3C2410_WATCHDOG if WATCHDOG
507 select HAVE_S3C_RTC if RTC_CLASS
508 select NEED_MACH_IO_H
509 select SAMSUNG_ATAGS
510 select USE_OF
511 help
512 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
513 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
514 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
515 Samsung SMDK2410 development board (and derivatives).
516
517config ARCH_OMAP1
518 bool "TI OMAP1"
519 depends on MMU
520 select ARCH_HAS_HOLES_MEMORYMODEL
521 select ARCH_OMAP
522 select CLKDEV_LOOKUP
523 select CLKSRC_MMIO
524 select GENERIC_CLOCKEVENTS
525 select GENERIC_IRQ_CHIP
526 select GENERIC_IRQ_MULTI_HANDLER
527 select GPIOLIB
528 select HAVE_IDE
529 select HAVE_LEGACY_CLK
530 select IRQ_DOMAIN
531 select NEED_MACH_IO_H if PCCARD
532 select NEED_MACH_MEMORY_H
533 select SPARSE_IRQ
534 help
535 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
536
537endchoice
538
539menu "Multiple platform selection"
540 depends on ARCH_MULTIPLATFORM
541
542comment "CPU Core family selection"
543
544config ARCH_MULTI_V4
545 bool "ARMv4 based platforms (FA526)"
546 depends on !ARCH_MULTI_V6_V7
547 select ARCH_MULTI_V4_V5
548 select CPU_FA526
549
550config ARCH_MULTI_V4T
551 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
552 depends on !ARCH_MULTI_V6_V7
553 select ARCH_MULTI_V4_V5
554 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
555 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
556 CPU_ARM925T || CPU_ARM940T)
557
558config ARCH_MULTI_V5
559 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
560 depends on !ARCH_MULTI_V6_V7
561 select ARCH_MULTI_V4_V5
562 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
563 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
564 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
565
566config ARCH_MULTI_V4_V5
567 bool
568
569config ARCH_MULTI_V6
570 bool "ARMv6 based platforms (ARM11)"
571 select ARCH_MULTI_V6_V7
572 select CPU_V6K
573
574config ARCH_MULTI_V7
575 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
576 default y
577 select ARCH_MULTI_V6_V7
578 select CPU_V7
579 select HAVE_SMP
580
581config ARCH_MULTI_V6_V7
582 bool
583 select MIGHT_HAVE_CACHE_L2X0
584
585config ARCH_MULTI_CPU_AUTO
586 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
587 select ARCH_MULTI_V5
588
589endmenu
590
591config ARCH_VIRT
592 bool "Dummy Virtual Machine"
593 depends on ARCH_MULTI_V7
594 select ARM_AMBA
595 select ARM_GIC
596 select ARM_GIC_V2M if PCI
597 select ARM_GIC_V3
598 select ARM_GIC_V3_ITS if PCI
599 select ARM_PSCI
600 select HAVE_ARM_ARCH_TIMER
601 select ARCH_SUPPORTS_BIG_ENDIAN
602
603#
604# This is sorted alphabetically by mach-* pathname. However, plat-*
605# Kconfigs may be included either alphabetically (according to the
606# plat- suffix) or along side the corresponding mach-* source.
607#
608source "arch/arm/mach-actions/Kconfig"
609
610source "arch/arm/mach-alpine/Kconfig"
611
612source "arch/arm/mach-artpec/Kconfig"
613
614source "arch/arm/mach-asm9260/Kconfig"
615
616source "arch/arm/mach-aspeed/Kconfig"
617
618source "arch/arm/mach-at91/Kconfig"
619
620source "arch/arm/mach-axxia/Kconfig"
621
622source "arch/arm/mach-bcm/Kconfig"
623
624source "arch/arm/mach-berlin/Kconfig"
625
626source "arch/arm/mach-clps711x/Kconfig"
627
628source "arch/arm/mach-cns3xxx/Kconfig"
629
630source "arch/arm/mach-davinci/Kconfig"
631
632source "arch/arm/mach-digicolor/Kconfig"
633
634source "arch/arm/mach-dove/Kconfig"
635
636source "arch/arm/mach-ep93xx/Kconfig"
637
638source "arch/arm/mach-exynos/Kconfig"
639source "arch/arm/plat-samsung/Kconfig"
640
641source "arch/arm/mach-footbridge/Kconfig"
642
643source "arch/arm/mach-gemini/Kconfig"
644
645source "arch/arm/mach-highbank/Kconfig"
646
647source "arch/arm/mach-hisi/Kconfig"
648
649source "arch/arm/mach-imx/Kconfig"
650
651source "arch/arm/mach-integrator/Kconfig"
652
653source "arch/arm/mach-iop32x/Kconfig"
654
655source "arch/arm/mach-ixp4xx/Kconfig"
656
657source "arch/arm/mach-keystone/Kconfig"
658
659source "arch/arm/mach-lpc32xx/Kconfig"
660
661source "arch/arm/mach-mediatek/Kconfig"
662
663source "arch/arm/mach-meson/Kconfig"
664
665source "arch/arm/mach-milbeaut/Kconfig"
666
667source "arch/arm/mach-mmp/Kconfig"
668
669source "arch/arm/mach-moxart/Kconfig"
670
671source "arch/arm/mach-mstar/Kconfig"
672
673source "arch/arm/mach-mv78xx0/Kconfig"
674
675source "arch/arm/mach-mvebu/Kconfig"
676
677source "arch/arm/mach-mxs/Kconfig"
678
679source "arch/arm/mach-nomadik/Kconfig"
680
681source "arch/arm/mach-npcm/Kconfig"
682
683source "arch/arm/mach-nspire/Kconfig"
684
685source "arch/arm/plat-omap/Kconfig"
686
687source "arch/arm/mach-omap1/Kconfig"
688
689source "arch/arm/mach-omap2/Kconfig"
690
691source "arch/arm/mach-orion5x/Kconfig"
692
693source "arch/arm/mach-oxnas/Kconfig"
694
695source "arch/arm/mach-picoxcell/Kconfig"
696
697source "arch/arm/mach-prima2/Kconfig"
698
699source "arch/arm/mach-pxa/Kconfig"
700source "arch/arm/plat-pxa/Kconfig"
701
702source "arch/arm/mach-qcom/Kconfig"
703
704source "arch/arm/mach-rda/Kconfig"
705
706source "arch/arm/mach-realtek/Kconfig"
707
708source "arch/arm/mach-realview/Kconfig"
709
710source "arch/arm/mach-rockchip/Kconfig"
711
712source "arch/arm/mach-s3c24xx/Kconfig"
713
714source "arch/arm/mach-s3c64xx/Kconfig"
715
716source "arch/arm/mach-s5pv210/Kconfig"
717
718source "arch/arm/mach-sa1100/Kconfig"
719
720source "arch/arm/mach-shmobile/Kconfig"
721
722source "arch/arm/mach-socfpga/Kconfig"
723
724source "arch/arm/mach-spear/Kconfig"
725
726source "arch/arm/mach-sti/Kconfig"
727
728source "arch/arm/mach-stm32/Kconfig"
729
730source "arch/arm/mach-sunxi/Kconfig"
731
732source "arch/arm/mach-tango/Kconfig"
733
734source "arch/arm/mach-tegra/Kconfig"
735
736source "arch/arm/mach-u300/Kconfig"
737
738source "arch/arm/mach-uniphier/Kconfig"
739
740source "arch/arm/mach-ux500/Kconfig"
741
742source "arch/arm/mach-versatile/Kconfig"
743
744source "arch/arm/mach-vexpress/Kconfig"
745
746source "arch/arm/mach-vt8500/Kconfig"
747
748source "arch/arm/mach-zx/Kconfig"
749
750source "arch/arm/mach-zynq/Kconfig"
751
752# ARMv7-M architecture
753config ARCH_EFM32
754 bool "Energy Micro efm32"
755 depends on ARM_SINGLE_ARMV7M
756 select GPIOLIB
757 help
758 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
759 processors.
760
761config ARCH_LPC18XX
762 bool "NXP LPC18xx/LPC43xx"
763 depends on ARM_SINGLE_ARMV7M
764 select ARCH_HAS_RESET_CONTROLLER
765 select ARM_AMBA
766 select CLKSRC_LPC32XX
767 select PINCTRL
768 help
769 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
770 high performance microcontrollers.
771
772config ARCH_MPS2
773 bool "ARM MPS2 platform"
774 depends on ARM_SINGLE_ARMV7M
775 select ARM_AMBA
776 select CLKSRC_MPS2
777 help
778 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
779 with a range of available cores like Cortex-M3/M4/M7.
780
781 Please, note that depends which Application Note is used memory map
782 for the platform may vary, so adjustment of RAM base might be needed.
783
784# Definitions to make life easier
785config ARCH_ACORN
786 bool
787
788config PLAT_IOP
789 bool
790 select GENERIC_CLOCKEVENTS
791
792config PLAT_ORION
793 bool
794 select CLKSRC_MMIO
795 select COMMON_CLK
796 select GENERIC_IRQ_CHIP
797 select IRQ_DOMAIN
798
799config PLAT_ORION_LEGACY
800 bool
801 select PLAT_ORION
802
803config PLAT_PXA
804 bool
805
806config PLAT_VERSATILE
807 bool
808
809source "arch/arm/mm/Kconfig"
810
811config IWMMXT
812 bool "Enable iWMMXt support"
813 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
814 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
815 help
816 Enable support for iWMMXt context switching at run time if
817 running on a CPU that supports it.
818
819if !MMU
820source "arch/arm/Kconfig-nommu"
821endif
822
823config PJ4B_ERRATA_4742
824 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
825 depends on CPU_PJ4B && MACH_ARMADA_370
826 default y
827 help
828 When coming out of either a Wait for Interrupt (WFI) or a Wait for
829 Event (WFE) IDLE states, a specific timing sensitivity exists between
830 the retiring WFI/WFE instructions and the newly issued subsequent
831 instructions. This sensitivity can result in a CPU hang scenario.
832 Workaround:
833 The software must insert either a Data Synchronization Barrier (DSB)
834 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
835 instruction
836
837config ARM_ERRATA_326103
838 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
839 depends on CPU_V6
840 help
841 Executing a SWP instruction to read-only memory does not set bit 11
842 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
843 treat the access as a read, preventing a COW from occurring and
844 causing the faulting task to livelock.
845
846config ARM_ERRATA_411920
847 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
848 depends on CPU_V6 || CPU_V6K
849 help
850 Invalidation of the Instruction Cache operation can
851 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
852 It does not affect the MPCore. This option enables the ARM Ltd.
853 recommended workaround.
854
855config ARM_ERRATA_430973
856 bool "ARM errata: Stale prediction on replaced interworking branch"
857 depends on CPU_V7
858 help
859 This option enables the workaround for the 430973 Cortex-A8
860 r1p* erratum. If a code sequence containing an ARM/Thumb
861 interworking branch is replaced with another code sequence at the
862 same virtual address, whether due to self-modifying code or virtual
863 to physical address re-mapping, Cortex-A8 does not recover from the
864 stale interworking branch prediction. This results in Cortex-A8
865 executing the new code sequence in the incorrect ARM or Thumb state.
866 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
867 and also flushes the branch target cache at every context switch.
868 Note that setting specific bits in the ACTLR register may not be
869 available in non-secure mode.
870
871config ARM_ERRATA_458693
872 bool "ARM errata: Processor deadlock when a false hazard is created"
873 depends on CPU_V7
874 depends on !ARCH_MULTIPLATFORM
875 help
876 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
877 erratum. For very specific sequences of memory operations, it is
878 possible for a hazard condition intended for a cache line to instead
879 be incorrectly associated with a different cache line. This false
880 hazard might then cause a processor deadlock. The workaround enables
881 the L1 caching of the NEON accesses and disables the PLD instruction
882 in the ACTLR register. Note that setting specific bits in the ACTLR
883 register may not be available in non-secure mode.
884
885config ARM_ERRATA_460075
886 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
887 depends on CPU_V7
888 depends on !ARCH_MULTIPLATFORM
889 help
890 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
891 erratum. Any asynchronous access to the L2 cache may encounter a
892 situation in which recent store transactions to the L2 cache are lost
893 and overwritten with stale memory contents from external memory. The
894 workaround disables the write-allocate mode for the L2 cache via the
895 ACTLR register. Note that setting specific bits in the ACTLR register
896 may not be available in non-secure mode.
897
898config ARM_ERRATA_742230
899 bool "ARM errata: DMB operation may be faulty"
900 depends on CPU_V7 && SMP
901 depends on !ARCH_MULTIPLATFORM
902 help
903 This option enables the workaround for the 742230 Cortex-A9
904 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
905 between two write operations may not ensure the correct visibility
906 ordering of the two writes. This workaround sets a specific bit in
907 the diagnostic register of the Cortex-A9 which causes the DMB
908 instruction to behave as a DSB, ensuring the correct behaviour of
909 the two writes.
910
911config ARM_ERRATA_742231
912 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
913 depends on CPU_V7 && SMP
914 depends on !ARCH_MULTIPLATFORM
915 help
916 This option enables the workaround for the 742231 Cortex-A9
917 (r2p0..r2p2) erratum. Under certain conditions, specific to the
918 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
919 accessing some data located in the same cache line, may get corrupted
920 data due to bad handling of the address hazard when the line gets
921 replaced from one of the CPUs at the same time as another CPU is
922 accessing it. This workaround sets specific bits in the diagnostic
923 register of the Cortex-A9 which reduces the linefill issuing
924 capabilities of the processor.
925
926config ARM_ERRATA_643719
927 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
928 depends on CPU_V7 && SMP
929 default y
930 help
931 This option enables the workaround for the 643719 Cortex-A9 (prior to
932 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
933 register returns zero when it should return one. The workaround
934 corrects this value, ensuring cache maintenance operations which use
935 it behave as intended and avoiding data corruption.
936
937config ARM_ERRATA_720789
938 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
939 depends on CPU_V7
940 help
941 This option enables the workaround for the 720789 Cortex-A9 (prior to
942 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
943 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
944 As a consequence of this erratum, some TLB entries which should be
945 invalidated are not, resulting in an incoherency in the system page
946 tables. The workaround changes the TLB flushing routines to invalidate
947 entries regardless of the ASID.
948
949config ARM_ERRATA_743622
950 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
951 depends on CPU_V7
952 depends on !ARCH_MULTIPLATFORM
953 help
954 This option enables the workaround for the 743622 Cortex-A9
955 (r2p*) erratum. Under very rare conditions, a faulty
956 optimisation in the Cortex-A9 Store Buffer may lead to data
957 corruption. This workaround sets a specific bit in the diagnostic
958 register of the Cortex-A9 which disables the Store Buffer
959 optimisation, preventing the defect from occurring. This has no
960 visible impact on the overall performance or power consumption of the
961 processor.
962
963config ARM_ERRATA_751472
964 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
965 depends on CPU_V7
966 depends on !ARCH_MULTIPLATFORM
967 help
968 This option enables the workaround for the 751472 Cortex-A9 (prior
969 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
970 completion of a following broadcasted operation if the second
971 operation is received by a CPU before the ICIALLUIS has completed,
972 potentially leading to corrupted entries in the cache or TLB.
973
974config ARM_ERRATA_754322
975 bool "ARM errata: possible faulty MMU translations following an ASID switch"
976 depends on CPU_V7
977 help
978 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
979 r3p*) erratum. A speculative memory access may cause a page table walk
980 which starts prior to an ASID switch but completes afterwards. This
981 can populate the micro-TLB with a stale entry which may be hit with
982 the new ASID. This workaround places two dsb instructions in the mm
983 switching code so that no page table walks can cross the ASID switch.
984
985config ARM_ERRATA_754327
986 bool "ARM errata: no automatic Store Buffer drain"
987 depends on CPU_V7 && SMP
988 help
989 This option enables the workaround for the 754327 Cortex-A9 (prior to
990 r2p0) erratum. The Store Buffer does not have any automatic draining
991 mechanism and therefore a livelock may occur if an external agent
992 continuously polls a memory location waiting to observe an update.
993 This workaround defines cpu_relax() as smp_mb(), preventing correctly
994 written polling loops from denying visibility of updates to memory.
995
996config ARM_ERRATA_364296
997 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
998 depends on CPU_V6
999 help
1000 This options enables the workaround for the 364296 ARM1136
1001 r0p2 erratum (possible cache data corruption with
1002 hit-under-miss enabled). It sets the undocumented bit 31 in
1003 the auxiliary control register and the FI bit in the control
1004 register, thus disabling hit-under-miss without putting the
1005 processor into full low interrupt latency mode. ARM11MPCore
1006 is not affected.
1007
1008config ARM_ERRATA_764369
1009 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1010 depends on CPU_V7 && SMP
1011 help
1012 This option enables the workaround for erratum 764369
1013 affecting Cortex-A9 MPCore with two or more processors (all
1014 current revisions). Under certain timing circumstances, a data
1015 cache line maintenance operation by MVA targeting an Inner
1016 Shareable memory region may fail to proceed up to either the
1017 Point of Coherency or to the Point of Unification of the
1018 system. This workaround adds a DSB instruction before the
1019 relevant cache maintenance functions and sets a specific bit
1020 in the diagnostic control register of the SCU.
1021
1022config ARM_ERRATA_775420
1023 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1024 depends on CPU_V7
1025 help
1026 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1027 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
1028 operation aborts with MMU exception, it might cause the processor
1029 to deadlock. This workaround puts DSB before executing ISB if
1030 an abort may occur on cache maintenance.
1031
1032config ARM_ERRATA_798181
1033 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1034 depends on CPU_V7 && SMP
1035 help
1036 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1037 adequately shooting down all use of the old entries. This
1038 option enables the Linux kernel workaround for this erratum
1039 which sends an IPI to the CPUs that are running the same ASID
1040 as the one being invalidated.
1041
1042config ARM_ERRATA_773022
1043 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1044 depends on CPU_V7
1045 help
1046 This option enables the workaround for the 773022 Cortex-A15
1047 (up to r0p4) erratum. In certain rare sequences of code, the
1048 loop buffer may deliver incorrect instructions. This
1049 workaround disables the loop buffer to avoid the erratum.
1050
1051config ARM_ERRATA_818325_852422
1052 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1053 depends on CPU_V7
1054 help
1055 This option enables the workaround for:
1056 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1057 instruction might deadlock. Fixed in r0p1.
1058 - Cortex-A12 852422: Execution of a sequence of instructions might
1059 lead to either a data corruption or a CPU deadlock. Not fixed in
1060 any Cortex-A12 cores yet.
1061 This workaround for all both errata involves setting bit[12] of the
1062 Feature Register. This bit disables an optimisation applied to a
1063 sequence of 2 instructions that use opposing condition codes.
1064
1065config ARM_ERRATA_821420
1066 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1067 depends on CPU_V7
1068 help
1069 This option enables the workaround for the 821420 Cortex-A12
1070 (all revs) erratum. In very rare timing conditions, a sequence
1071 of VMOV to Core registers instructions, for which the second
1072 one is in the shadow of a branch or abort, can lead to a
1073 deadlock when the VMOV instructions are issued out-of-order.
1074
1075config ARM_ERRATA_825619
1076 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1077 depends on CPU_V7
1078 help
1079 This option enables the workaround for the 825619 Cortex-A12
1080 (all revs) erratum. Within rare timing constraints, executing a
1081 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1082 and Device/Strongly-Ordered loads and stores might cause deadlock
1083
1084config ARM_ERRATA_857271
1085 bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1086 depends on CPU_V7
1087 help
1088 This option enables the workaround for the 857271 Cortex-A12
1089 (all revs) erratum. Under very rare timing conditions, the CPU might
1090 hang. The workaround is expected to have a < 1% performance impact.
1091
1092config ARM_ERRATA_852421
1093 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1094 depends on CPU_V7
1095 help
1096 This option enables the workaround for the 852421 Cortex-A17
1097 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1098 execution of a DMB ST instruction might fail to properly order
1099 stores from GroupA and stores from GroupB.
1100
1101config ARM_ERRATA_852423
1102 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1103 depends on CPU_V7
1104 help
1105 This option enables the workaround for:
1106 - Cortex-A17 852423: Execution of a sequence of instructions might
1107 lead to either a data corruption or a CPU deadlock. Not fixed in
1108 any Cortex-A17 cores yet.
1109 This is identical to Cortex-A12 erratum 852422. It is a separate
1110 config option from the A12 erratum due to the way errata are checked
1111 for and handled.
1112
1113config ARM_ERRATA_857272
1114 bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1115 depends on CPU_V7
1116 help
1117 This option enables the workaround for the 857272 Cortex-A17 erratum.
1118 This erratum is not known to be fixed in any A17 revision.
1119 This is identical to Cortex-A12 erratum 857271. It is a separate
1120 config option from the A12 erratum due to the way errata are checked
1121 for and handled.
1122
1123endmenu
1124
1125source "arch/arm/common/Kconfig"
1126
1127menu "Bus support"
1128
1129config ISA
1130 bool
1131 help
1132 Find out whether you have ISA slots on your motherboard. ISA is the
1133 name of a bus system, i.e. the way the CPU talks to the other stuff
1134 inside your box. Other bus systems are PCI, EISA, MicroChannel
1135 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1136 newer boards don't support it. If you have ISA, say Y, otherwise N.
1137
1138# Select ISA DMA controller support
1139config ISA_DMA
1140 bool
1141 select ISA_DMA_API
1142
1143# Select ISA DMA interface
1144config ISA_DMA_API
1145 bool
1146
1147config PCI_NANOENGINE
1148 bool "BSE nanoEngine PCI support"
1149 depends on SA1100_NANOENGINE
1150 help
1151 Enable PCI on the BSE nanoEngine board.
1152
1153config ARM_ERRATA_814220
1154 bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1155 depends on CPU_V7
1156 help
1157 The v7 ARM states that all cache and branch predictor maintenance
1158 operations that do not specify an address execute, relative to
1159 each other, in program order.
1160 However, because of this erratum, an L2 set/way cache maintenance
1161 operation can overtake an L1 set/way cache maintenance operation.
1162 This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1163 r0p4, r0p5.
1164
1165endmenu
1166
1167menu "Kernel Features"
1168
1169config HAVE_SMP
1170 bool
1171 help
1172 This option should be selected by machines which have an SMP-
1173 capable CPU.
1174
1175 The only effect of this option is to make the SMP-related
1176 options available to the user for configuration.
1177
1178config SMP
1179 bool "Symmetric Multi-Processing"
1180 depends on CPU_V6K || CPU_V7
1181 depends on GENERIC_CLOCKEVENTS
1182 depends on HAVE_SMP
1183 depends on MMU || ARM_MPU
1184 select IRQ_WORK
1185 help
1186 This enables support for systems with more than one CPU. If you have
1187 a system with only one CPU, say N. If you have a system with more
1188 than one CPU, say Y.
1189
1190 If you say N here, the kernel will run on uni- and multiprocessor
1191 machines, but will use only one CPU of a multiprocessor machine. If
1192 you say Y here, the kernel will run on many, but not all,
1193 uniprocessor machines. On a uniprocessor machine, the kernel
1194 will run faster if you say N here.
1195
1196 See also <file:Documentation/x86/i386/IO-APIC.rst>,
1197 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1198 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1199
1200 If you don't know what to do here, say N.
1201
1202config SMP_ON_UP
1203 bool "Allow booting SMP kernel on uniprocessor systems"
1204 depends on SMP && !XIP_KERNEL && MMU
1205 default y
1206 help
1207 SMP kernels contain instructions which fail on non-SMP processors.
1208 Enabling this option allows the kernel to modify itself to make
1209 these instructions safe. Disabling it allows about 1K of space
1210 savings.
1211
1212 If you don't know what to do here, say Y.
1213
1214config ARM_CPU_TOPOLOGY
1215 bool "Support cpu topology definition"
1216 depends on SMP && CPU_V7
1217 default y
1218 help
1219 Support ARM cpu topology definition. The MPIDR register defines
1220 affinity between processors which is then used to describe the cpu
1221 topology of an ARM System.
1222
1223config SCHED_MC
1224 bool "Multi-core scheduler support"
1225 depends on ARM_CPU_TOPOLOGY
1226 help
1227 Multi-core scheduler support improves the CPU scheduler's decision
1228 making when dealing with multi-core CPU chips at a cost of slightly
1229 increased overhead in some places. If unsure say N here.
1230
1231config SCHED_SMT
1232 bool "SMT scheduler support"
1233 depends on ARM_CPU_TOPOLOGY
1234 help
1235 Improves the CPU scheduler's decision making when dealing with
1236 MultiThreading at a cost of slightly increased overhead in some
1237 places. If unsure say N here.
1238
1239config HAVE_ARM_SCU
1240 bool
1241 help
1242 This option enables support for the ARM snoop control unit
1243
1244config HAVE_ARM_ARCH_TIMER
1245 bool "Architected timer support"
1246 depends on CPU_V7
1247 select ARM_ARCH_TIMER
1248 help
1249 This option enables support for the ARM architected timer
1250
1251config HAVE_ARM_TWD
1252 bool
1253 help
1254 This options enables support for the ARM timer and watchdog unit
1255
1256config MCPM
1257 bool "Multi-Cluster Power Management"
1258 depends on CPU_V7 && SMP
1259 help
1260 This option provides the common power management infrastructure
1261 for (multi-)cluster based systems, such as big.LITTLE based
1262 systems.
1263
1264config MCPM_QUAD_CLUSTER
1265 bool
1266 depends on MCPM
1267 help
1268 To avoid wasting resources unnecessarily, MCPM only supports up
1269 to 2 clusters by default.
1270 Platforms with 3 or 4 clusters that use MCPM must select this
1271 option to allow the additional clusters to be managed.
1272
1273config BIG_LITTLE
1274 bool "big.LITTLE support (Experimental)"
1275 depends on CPU_V7 && SMP
1276 select MCPM
1277 help
1278 This option enables support selections for the big.LITTLE
1279 system architecture.
1280
1281config BL_SWITCHER
1282 bool "big.LITTLE switcher support"
1283 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1284 select CPU_PM
1285 help
1286 The big.LITTLE "switcher" provides the core functionality to
1287 transparently handle transition between a cluster of A15's
1288 and a cluster of A7's in a big.LITTLE system.
1289
1290config BL_SWITCHER_DUMMY_IF
1291 tristate "Simple big.LITTLE switcher user interface"
1292 depends on BL_SWITCHER && DEBUG_KERNEL
1293 help
1294 This is a simple and dummy char dev interface to control
1295 the big.LITTLE switcher core code. It is meant for
1296 debugging purposes only.
1297
1298choice
1299 prompt "Memory split"
1300 depends on MMU
1301 default VMSPLIT_3G
1302 help
1303 Select the desired split between kernel and user memory.
1304
1305 If you are not absolutely sure what you are doing, leave this
1306 option alone!
1307
1308 config VMSPLIT_3G
1309 bool "3G/1G user/kernel split"
1310 config VMSPLIT_3G_OPT
1311 depends on !ARM_LPAE
1312 bool "3G/1G user/kernel split (for full 1G low memory)"
1313 config VMSPLIT_2G
1314 bool "2G/2G user/kernel split"
1315 config VMSPLIT_1G
1316 bool "1G/3G user/kernel split"
1317endchoice
1318
1319config PAGE_OFFSET
1320 hex
1321 default PHYS_OFFSET if !MMU
1322 default 0x40000000 if VMSPLIT_1G
1323 default 0x80000000 if VMSPLIT_2G
1324 default 0xB0000000 if VMSPLIT_3G_OPT
1325 default 0xC0000000
1326
1327config NR_CPUS
1328 int "Maximum number of CPUs (2-32)"
1329 range 2 32
1330 depends on SMP
1331 default "4"
1332
1333config HOTPLUG_CPU
1334 bool "Support for hot-pluggable CPUs"
1335 depends on SMP
1336 select GENERIC_IRQ_MIGRATION
1337 help
1338 Say Y here to experiment with turning CPUs off and on. CPUs
1339 can be controlled through /sys/devices/system/cpu.
1340
1341config ARM_PSCI
1342 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1343 depends on HAVE_ARM_SMCCC
1344 select ARM_PSCI_FW
1345 help
1346 Say Y here if you want Linux to communicate with system firmware
1347 implementing the PSCI specification for CPU-centric power
1348 management operations described in ARM document number ARM DEN
1349 0022A ("Power State Coordination Interface System Software on
1350 ARM processors").
1351
1352# The GPIO number here must be sorted by descending number. In case of
1353# a multiplatform kernel, we just want the highest value required by the
1354# selected platforms.
1355config ARCH_NR_GPIO
1356 int
1357 default 2048 if ARCH_SOCFPGA
1358 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1359 ARCH_ZYNQ || ARCH_ASPEED
1360 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1361 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1362 default 416 if ARCH_SUNXI
1363 default 392 if ARCH_U8500
1364 default 352 if ARCH_VT8500
1365 default 288 if ARCH_ROCKCHIP
1366 default 264 if MACH_H4700
1367 default 0
1368 help
1369 Maximum number of GPIOs in the system.
1370
1371 If unsure, leave the default value.
1372
1373config HZ_FIXED
1374 int
1375 default 200 if ARCH_EBSA110
1376 default 128 if SOC_AT91RM9200
1377 default 0
1378
1379choice
1380 depends on HZ_FIXED = 0
1381 prompt "Timer frequency"
1382
1383config HZ_100
1384 bool "100 Hz"
1385
1386config HZ_200
1387 bool "200 Hz"
1388
1389config HZ_250
1390 bool "250 Hz"
1391
1392config HZ_300
1393 bool "300 Hz"
1394
1395config HZ_500
1396 bool "500 Hz"
1397
1398config HZ_1000
1399 bool "1000 Hz"
1400
1401endchoice
1402
1403config HZ
1404 int
1405 default HZ_FIXED if HZ_FIXED != 0
1406 default 100 if HZ_100
1407 default 200 if HZ_200
1408 default 250 if HZ_250
1409 default 300 if HZ_300
1410 default 500 if HZ_500
1411 default 1000
1412
1413config SCHED_HRTICK
1414 def_bool HIGH_RES_TIMERS
1415
1416config THUMB2_KERNEL
1417 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1418 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1419 default y if CPU_THUMBONLY
1420 select ARM_UNWIND
1421 help
1422 By enabling this option, the kernel will be compiled in
1423 Thumb-2 mode.
1424
1425 If unsure, say N.
1426
1427config ARM_PATCH_IDIV
1428 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1429 depends on CPU_32v7 && !XIP_KERNEL
1430 default y
1431 help
1432 The ARM compiler inserts calls to __aeabi_idiv() and
1433 __aeabi_uidiv() when it needs to perform division on signed
1434 and unsigned integers. Some v7 CPUs have support for the sdiv
1435 and udiv instructions that can be used to implement those
1436 functions.
1437
1438 Enabling this option allows the kernel to modify itself to
1439 replace the first two instructions of these library functions
1440 with the sdiv or udiv plus "bx lr" instructions when the CPU
1441 it is running on supports them. Typically this will be faster
1442 and less power intensive than running the original library
1443 code to do integer division.
1444
1445config AEABI
1446 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1447 !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1448 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1449 help
1450 This option allows for the kernel to be compiled using the latest
1451 ARM ABI (aka EABI). This is only useful if you are using a user
1452 space environment that is also compiled with EABI.
1453
1454 Since there are major incompatibilities between the legacy ABI and
1455 EABI, especially with regard to structure member alignment, this
1456 option also changes the kernel syscall calling convention to
1457 disambiguate both ABIs and allow for backward compatibility support
1458 (selected with CONFIG_OABI_COMPAT).
1459
1460 To use this you need GCC version 4.0.0 or later.
1461
1462config OABI_COMPAT
1463 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1464 depends on AEABI && !THUMB2_KERNEL
1465 help
1466 This option preserves the old syscall interface along with the
1467 new (ARM EABI) one. It also provides a compatibility layer to
1468 intercept syscalls that have structure arguments which layout
1469 in memory differs between the legacy ABI and the new ARM EABI
1470 (only for non "thumb" binaries). This option adds a tiny
1471 overhead to all syscalls and produces a slightly larger kernel.
1472
1473 The seccomp filter system will not be available when this is
1474 selected, since there is no way yet to sensibly distinguish
1475 between calling conventions during filtering.
1476
1477 If you know you'll be using only pure EABI user space then you
1478 can say N here. If this option is not selected and you attempt
1479 to execute a legacy ABI binary then the result will be
1480 UNPREDICTABLE (in fact it can be predicted that it won't work
1481 at all). If in doubt say N.
1482
1483config ARCH_HAS_HOLES_MEMORYMODEL
1484 bool
1485
1486config ARCH_SELECT_MEMORY_MODEL
1487 bool
1488
1489config ARCH_FLATMEM_ENABLE
1490 bool
1491
1492config ARCH_SPARSEMEM_ENABLE
1493 bool
1494 select SPARSEMEM_STATIC if SPARSEMEM
1495
1496config HAVE_ARCH_PFN_VALID
1497 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1498
1499config HIGHMEM
1500 bool "High Memory Support"
1501 depends on MMU
1502 help
1503 The address space of ARM processors is only 4 Gigabytes large
1504 and it has to accommodate user address space, kernel address
1505 space as well as some memory mapped IO. That means that, if you
1506 have a large amount of physical memory and/or IO, not all of the
1507 memory can be "permanently mapped" by the kernel. The physical
1508 memory that is not permanently mapped is called "high memory".
1509
1510 Depending on the selected kernel/user memory split, minimum
1511 vmalloc space and actual amount of RAM, you may not need this
1512 option which should result in a slightly faster kernel.
1513
1514 If unsure, say n.
1515
1516config HIGHPTE
1517 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1518 depends on HIGHMEM
1519 default y
1520 help
1521 The VM uses one page of physical memory for each page table.
1522 For systems with a lot of processes, this can use a lot of
1523 precious low memory, eventually leading to low memory being
1524 consumed by page tables. Setting this option will allow
1525 user-space 2nd level page tables to reside in high memory.
1526
1527config CPU_SW_DOMAIN_PAN
1528 bool "Enable use of CPU domains to implement privileged no-access"
1529 depends on MMU && !ARM_LPAE
1530 default y
1531 help
1532 Increase kernel security by ensuring that normal kernel accesses
1533 are unable to access userspace addresses. This can help prevent
1534 use-after-free bugs becoming an exploitable privilege escalation
1535 by ensuring that magic values (such as LIST_POISON) will always
1536 fault when dereferenced.
1537
1538 CPUs with low-vector mappings use a best-efforts implementation.
1539 Their lower 1MB needs to remain accessible for the vectors, but
1540 the remainder of userspace will become appropriately inaccessible.
1541
1542config HW_PERF_EVENTS
1543 def_bool y
1544 depends on ARM_PMU
1545
1546config SYS_SUPPORTS_HUGETLBFS
1547 def_bool y
1548 depends on ARM_LPAE
1549
1550config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1551 def_bool y
1552 depends on ARM_LPAE
1553
1554config ARCH_WANT_GENERAL_HUGETLB
1555 def_bool y
1556
1557config ARM_MODULE_PLTS
1558 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1559 depends on MODULES
1560 default y
1561 help
1562 Allocate PLTs when loading modules so that jumps and calls whose
1563 targets are too far away for their relative offsets to be encoded
1564 in the instructions themselves can be bounced via veneers in the
1565 module's PLT. This allows modules to be allocated in the generic
1566 vmalloc area after the dedicated module memory area has been
1567 exhausted. The modules will use slightly more memory, but after
1568 rounding up to page size, the actual memory footprint is usually
1569 the same.
1570
1571 Disabling this is usually safe for small single-platform
1572 configurations. If unsure, say y.
1573
1574config FORCE_MAX_ZONEORDER
1575 int "Maximum zone order"
1576 default "12" if SOC_AM33XX
1577 default "9" if SA1111 || ARCH_EFM32
1578 default "11"
1579 help
1580 The kernel memory allocator divides physically contiguous memory
1581 blocks into "zones", where each zone is a power of two number of
1582 pages. This option selects the largest power of two that the kernel
1583 keeps in the memory allocator. If you need to allocate very large
1584 blocks of physically contiguous memory, then you may need to
1585 increase this value.
1586
1587 This config option is actually maximum order plus one. For example,
1588 a value of 11 means that the largest free memory block is 2^10 pages.
1589
1590config ALIGNMENT_TRAP
1591 bool
1592 depends on CPU_CP15_MMU
1593 default y if !ARCH_EBSA110
1594 select HAVE_PROC_CPU if PROC_FS
1595 help
1596 ARM processors cannot fetch/store information which is not
1597 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1598 address divisible by 4. On 32-bit ARM processors, these non-aligned
1599 fetch/store instructions will be emulated in software if you say
1600 here, which has a severe performance impact. This is necessary for
1601 correct operation of some network protocols. With an IP-only
1602 configuration it is safe to say N, otherwise say Y.
1603
1604config UACCESS_WITH_MEMCPY
1605 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1606 depends on MMU
1607 default y if CPU_FEROCEON
1608 help
1609 Implement faster copy_to_user and clear_user methods for CPU
1610 cores where a 8-word STM instruction give significantly higher
1611 memory write throughput than a sequence of individual 32bit stores.
1612
1613 A possible side effect is a slight increase in scheduling latency
1614 between threads sharing the same address space if they invoke
1615 such copy operations with large buffers.
1616
1617 However, if the CPU data cache is using a write-allocate mode,
1618 this option is unlikely to provide any performance gain.
1619
1620config SECCOMP
1621 bool
1622 prompt "Enable seccomp to safely compute untrusted bytecode"
1623 help
1624 This kernel feature is useful for number crunching applications
1625 that may need to compute untrusted bytecode during their
1626 execution. By using pipes or other transports made available to
1627 the process as file descriptors supporting the read/write
1628 syscalls, it's possible to isolate those applications in
1629 their own address space using seccomp. Once seccomp is
1630 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1631 and the task is only allowed to execute a few safe syscalls
1632 defined by each seccomp mode.
1633
1634config PARAVIRT
1635 bool "Enable paravirtualization code"
1636 help
1637 This changes the kernel so it can modify itself when it is run
1638 under a hypervisor, potentially improving performance significantly
1639 over full virtualization.
1640
1641config PARAVIRT_TIME_ACCOUNTING
1642 bool "Paravirtual steal time accounting"
1643 select PARAVIRT
1644 help
1645 Select this option to enable fine granularity task steal time
1646 accounting. Time spent executing other tasks in parallel with
1647 the current vCPU is discounted from the vCPU power. To account for
1648 that, there can be a small performance impact.
1649
1650 If in doubt, say N here.
1651
1652config XEN_DOM0
1653 def_bool y
1654 depends on XEN
1655
1656config XEN
1657 bool "Xen guest support on ARM"
1658 depends on ARM && AEABI && OF
1659 depends on CPU_V7 && !CPU_V6
1660 depends on !GENERIC_ATOMIC64
1661 depends on MMU
1662 select ARCH_DMA_ADDR_T_64BIT
1663 select ARM_PSCI
1664 select SWIOTLB
1665 select SWIOTLB_XEN
1666 select PARAVIRT
1667 help
1668 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1669
1670config STACKPROTECTOR_PER_TASK
1671 bool "Use a unique stack canary value for each task"
1672 depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1673 select GCC_PLUGIN_ARM_SSP_PER_TASK
1674 default y
1675 help
1676 Due to the fact that GCC uses an ordinary symbol reference from
1677 which to load the value of the stack canary, this value can only
1678 change at reboot time on SMP systems, and all tasks running in the
1679 kernel's address space are forced to use the same canary value for
1680 the entire duration that the system is up.
1681
1682 Enable this option to switch to a different method that uses a
1683 different canary value for each task.
1684
1685endmenu
1686
1687menu "Boot options"
1688
1689config USE_OF
1690 bool "Flattened Device Tree support"
1691 select IRQ_DOMAIN
1692 select OF
1693 help
1694 Include support for flattened device tree machine descriptions.
1695
1696config ATAGS
1697 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1698 default y
1699 help
1700 This is the traditional way of passing data to the kernel at boot
1701 time. If you are solely relying on the flattened device tree (or
1702 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1703 to remove ATAGS support from your kernel binary. If unsure,
1704 leave this to y.
1705
1706config DEPRECATED_PARAM_STRUCT
1707 bool "Provide old way to pass kernel parameters"
1708 depends on ATAGS
1709 help
1710 This was deprecated in 2001 and announced to live on for 5 years.
1711 Some old boot loaders still use this way.
1712
1713# Compressed boot loader in ROM. Yes, we really want to ask about
1714# TEXT and BSS so we preserve their values in the config files.
1715config ZBOOT_ROM_TEXT
1716 hex "Compressed ROM boot loader base address"
1717 default 0x0
1718 help
1719 The physical address at which the ROM-able zImage is to be
1720 placed in the target. Platforms which normally make use of
1721 ROM-able zImage formats normally set this to a suitable
1722 value in their defconfig file.
1723
1724 If ZBOOT_ROM is not enabled, this has no effect.
1725
1726config ZBOOT_ROM_BSS
1727 hex "Compressed ROM boot loader BSS address"
1728 default 0x0
1729 help
1730 The base address of an area of read/write memory in the target
1731 for the ROM-able zImage which must be available while the
1732 decompressor is running. It must be large enough to hold the
1733 entire decompressed kernel plus an additional 128 KiB.
1734 Platforms which normally make use of ROM-able zImage formats
1735 normally set this to a suitable value in their defconfig file.
1736
1737 If ZBOOT_ROM is not enabled, this has no effect.
1738
1739config ZBOOT_ROM
1740 bool "Compressed boot loader in ROM/flash"
1741 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1742 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1743 help
1744 Say Y here if you intend to execute your compressed kernel image
1745 (zImage) directly from ROM or flash. If unsure, say N.
1746
1747config ARM_APPENDED_DTB
1748 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1749 depends on OF
1750 help
1751 With this option, the boot code will look for a device tree binary
1752 (DTB) appended to zImage
1753 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1754
1755 This is meant as a backward compatibility convenience for those
1756 systems with a bootloader that can't be upgraded to accommodate
1757 the documented boot protocol using a device tree.
1758
1759 Beware that there is very little in terms of protection against
1760 this option being confused by leftover garbage in memory that might
1761 look like a DTB header after a reboot if no actual DTB is appended
1762 to zImage. Do not leave this option active in a production kernel
1763 if you don't intend to always append a DTB. Proper passing of the
1764 location into r2 of a bootloader provided DTB is always preferable
1765 to this option.
1766
1767config ARM_ATAG_DTB_COMPAT
1768 bool "Supplement the appended DTB with traditional ATAG information"
1769 depends on ARM_APPENDED_DTB
1770 help
1771 Some old bootloaders can't be updated to a DTB capable one, yet
1772 they provide ATAGs with memory configuration, the ramdisk address,
1773 the kernel cmdline string, etc. Such information is dynamically
1774 provided by the bootloader and can't always be stored in a static
1775 DTB. To allow a device tree enabled kernel to be used with such
1776 bootloaders, this option allows zImage to extract the information
1777 from the ATAG list and store it at run time into the appended DTB.
1778
1779choice
1780 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1781 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1782
1783config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1784 bool "Use bootloader kernel arguments if available"
1785 help
1786 Uses the command-line options passed by the boot loader instead of
1787 the device tree bootargs property. If the boot loader doesn't provide
1788 any, the device tree bootargs property will be used.
1789
1790config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1791 bool "Extend with bootloader kernel arguments"
1792 help
1793 The command-line arguments provided by the boot loader will be
1794 appended to the the device tree bootargs property.
1795
1796endchoice
1797
1798config CMDLINE
1799 string "Default kernel command string"
1800 default ""
1801 help
1802 On some architectures (EBSA110 and CATS), there is currently no way
1803 for the boot loader to pass arguments to the kernel. For these
1804 architectures, you should supply some command-line options at build
1805 time by entering them here. As a minimum, you should specify the
1806 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1807
1808choice
1809 prompt "Kernel command line type" if CMDLINE != ""
1810 default CMDLINE_FROM_BOOTLOADER
1811 depends on ATAGS
1812
1813config CMDLINE_FROM_BOOTLOADER
1814 bool "Use bootloader kernel arguments if available"
1815 help
1816 Uses the command-line options passed by the boot loader. If
1817 the boot loader doesn't provide any, the default kernel command
1818 string provided in CMDLINE will be used.
1819
1820config CMDLINE_EXTEND
1821 bool "Extend bootloader kernel arguments"
1822 help
1823 The command-line arguments provided by the boot loader will be
1824 appended to the default kernel command string.
1825
1826config CMDLINE_FORCE
1827 bool "Always use the default kernel command string"
1828 help
1829 Always use the default kernel command string, even if the boot
1830 loader passes other arguments to the kernel.
1831 This is useful if you cannot or don't want to change the
1832 command-line options your boot loader passes to the kernel.
1833endchoice
1834
1835config XIP_KERNEL
1836 bool "Kernel Execute-In-Place from ROM"
1837 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1838 help
1839 Execute-In-Place allows the kernel to run from non-volatile storage
1840 directly addressable by the CPU, such as NOR flash. This saves RAM
1841 space since the text section of the kernel is not loaded from flash
1842 to RAM. Read-write sections, such as the data section and stack,
1843 are still copied to RAM. The XIP kernel is not compressed since
1844 it has to run directly from flash, so it will take more space to
1845 store it. The flash address used to link the kernel object files,
1846 and for storing it, is configuration dependent. Therefore, if you
1847 say Y here, you must know the proper physical address where to
1848 store the kernel image depending on your own flash memory usage.
1849
1850 Also note that the make target becomes "make xipImage" rather than
1851 "make zImage" or "make Image". The final kernel binary to put in
1852 ROM memory will be arch/arm/boot/xipImage.
1853
1854 If unsure, say N.
1855
1856config XIP_PHYS_ADDR
1857 hex "XIP Kernel Physical Location"
1858 depends on XIP_KERNEL
1859 default "0x00080000"
1860 help
1861 This is the physical address in your flash memory the kernel will
1862 be linked for and stored to. This address is dependent on your
1863 own flash usage.
1864
1865config XIP_DEFLATED_DATA
1866 bool "Store kernel .data section compressed in ROM"
1867 depends on XIP_KERNEL
1868 select ZLIB_INFLATE
1869 help
1870 Before the kernel is actually executed, its .data section has to be
1871 copied to RAM from ROM. This option allows for storing that data
1872 in compressed form and decompressed to RAM rather than merely being
1873 copied, saving some precious ROM space. A possible drawback is a
1874 slightly longer boot delay.
1875
1876config KEXEC
1877 bool "Kexec system call (EXPERIMENTAL)"
1878 depends on (!SMP || PM_SLEEP_SMP)
1879 depends on MMU
1880 select KEXEC_CORE
1881 help
1882 kexec is a system call that implements the ability to shutdown your
1883 current kernel, and to start another kernel. It is like a reboot
1884 but it is independent of the system firmware. And like a reboot
1885 you can start any kernel with it, not just Linux.
1886
1887 It is an ongoing process to be certain the hardware in a machine
1888 is properly shutdown, so do not be surprised if this code does not
1889 initially work for you.
1890
1891config ATAGS_PROC
1892 bool "Export atags in procfs"
1893 depends on ATAGS && KEXEC
1894 default y
1895 help
1896 Should the atags used to boot the kernel be exported in an "atags"
1897 file in procfs. Useful with kexec.
1898
1899config CRASH_DUMP
1900 bool "Build kdump crash kernel (EXPERIMENTAL)"
1901 help
1902 Generate crash dump after being started by kexec. This should
1903 be normally only set in special crash dump kernels which are
1904 loaded in the main kernel with kexec-tools into a specially
1905 reserved region and then later executed after a crash by
1906 kdump/kexec. The crash dump kernel must be compiled to a
1907 memory address not used by the main kernel
1908
1909 For more details see Documentation/admin-guide/kdump/kdump.rst
1910
1911config AUTO_ZRELADDR
1912 bool "Auto calculation of the decompressed kernel image address"
1913 help
1914 ZRELADDR is the physical address where the decompressed kernel
1915 image will be placed. If AUTO_ZRELADDR is selected, the address
1916 will be determined at run-time by masking the current IP with
1917 0xf8000000. This assumes the zImage being placed in the first 128MB
1918 from start of memory.
1919
1920config EFI_STUB
1921 bool
1922
1923config EFI
1924 bool "UEFI runtime support"
1925 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1926 select UCS2_STRING
1927 select EFI_PARAMS_FROM_FDT
1928 select EFI_STUB
1929 select EFI_GENERIC_STUB
1930 select EFI_RUNTIME_WRAPPERS
1931 help
1932 This option provides support for runtime services provided
1933 by UEFI firmware (such as non-volatile variables, realtime
1934 clock, and platform reset). A UEFI stub is also provided to
1935 allow the kernel to be booted as an EFI application. This
1936 is only useful for kernels that may run on systems that have
1937 UEFI firmware.
1938
1939config DMI
1940 bool "Enable support for SMBIOS (DMI) tables"
1941 depends on EFI
1942 default y
1943 help
1944 This enables SMBIOS/DMI feature for systems.
1945
1946 This option is only useful on systems that have UEFI firmware.
1947 However, even with this option, the resultant kernel should
1948 continue to boot on existing non-UEFI platforms.
1949
1950 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1951 i.e., the the practice of identifying the platform via DMI to
1952 decide whether certain workarounds for buggy hardware and/or
1953 firmware need to be enabled. This would require the DMI subsystem
1954 to be enabled much earlier than we do on ARM, which is non-trivial.
1955
1956endmenu
1957
1958menu "CPU Power Management"
1959
1960source "drivers/cpufreq/Kconfig"
1961
1962source "drivers/cpuidle/Kconfig"
1963
1964endmenu
1965
1966menu "Floating point emulation"
1967
1968comment "At least one emulation must be selected"
1969
1970config FPE_NWFPE
1971 bool "NWFPE math emulation"
1972 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1973 help
1974 Say Y to include the NWFPE floating point emulator in the kernel.
1975 This is necessary to run most binaries. Linux does not currently
1976 support floating point hardware so you need to say Y here even if
1977 your machine has an FPA or floating point co-processor podule.
1978
1979 You may say N here if you are going to load the Acorn FPEmulator
1980 early in the bootup.
1981
1982config FPE_NWFPE_XP
1983 bool "Support extended precision"
1984 depends on FPE_NWFPE
1985 help
1986 Say Y to include 80-bit support in the kernel floating-point
1987 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1988 Note that gcc does not generate 80-bit operations by default,
1989 so in most cases this option only enlarges the size of the
1990 floating point emulator without any good reason.
1991
1992 You almost surely want to say N here.
1993
1994config FPE_FASTFPE
1995 bool "FastFPE math emulation (EXPERIMENTAL)"
1996 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1997 help
1998 Say Y here to include the FAST floating point emulator in the kernel.
1999 This is an experimental much faster emulator which now also has full
2000 precision for the mantissa. It does not support any exceptions.
2001 It is very simple, and approximately 3-6 times faster than NWFPE.
2002
2003 It should be sufficient for most programs. It may be not suitable
2004 for scientific calculations, but you have to check this for yourself.
2005 If you do not feel you need a faster FP emulation you should better
2006 choose NWFPE.
2007
2008config VFP
2009 bool "VFP-format floating point maths"
2010 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2011 help
2012 Say Y to include VFP support code in the kernel. This is needed
2013 if your hardware includes a VFP unit.
2014
2015 Please see <file:Documentation/arm/vfp/release-notes.rst> for
2016 release notes and additional status information.
2017
2018 Say N if your target does not have VFP hardware.
2019
2020config VFPv3
2021 bool
2022 depends on VFP
2023 default y if CPU_V7
2024
2025config NEON
2026 bool "Advanced SIMD (NEON) Extension support"
2027 depends on VFPv3 && CPU_V7
2028 help
2029 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2030 Extension.
2031
2032config KERNEL_MODE_NEON
2033 bool "Support for NEON in kernel mode"
2034 depends on NEON && AEABI
2035 help
2036 Say Y to include support for NEON in kernel mode.
2037
2038endmenu
2039
2040menu "Power management options"
2041
2042source "kernel/power/Kconfig"
2043
2044config ARCH_SUSPEND_POSSIBLE
2045 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2046 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2047 def_bool y
2048
2049config ARM_CPU_SUSPEND
2050 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2051 depends on ARCH_SUSPEND_POSSIBLE
2052
2053config ARCH_HIBERNATION_POSSIBLE
2054 bool
2055 depends on MMU
2056 default y if ARCH_SUSPEND_POSSIBLE
2057
2058endmenu
2059
2060source "drivers/firmware/Kconfig"
2061
2062if CRYPTO
2063source "arch/arm/crypto/Kconfig"
2064endif
2065
2066source "arch/arm/Kconfig.assembler"