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[mirror_ubuntu-hirsute-kernel.git] / arch / arm / Kconfig
1 # SPDX-License-Identifier: GPL-2.0
2 config 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 ARCH_WANT_LD_ORPHAN_WARN
39 select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
40 select BUILDTIME_TABLE_SORT if MMU
41 select CLONE_BACKWARDS
42 select CPU_PM if SUSPEND || CPU_IDLE
43 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
44 select DMA_DECLARE_COHERENT
45 select DMA_OPS
46 select DMA_REMAP if MMU
47 select EDAC_SUPPORT
48 select EDAC_ATOMIC_SCRUB
49 select GENERIC_ALLOCATOR
50 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
51 select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
52 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
53 select GENERIC_IRQ_IPI if SMP
54 select GENERIC_CPU_AUTOPROBE
55 select GENERIC_EARLY_IOREMAP
56 select GENERIC_IDLE_POLL_SETUP
57 select GENERIC_IRQ_PROBE
58 select GENERIC_IRQ_SHOW
59 select GENERIC_IRQ_SHOW_LEVEL
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_MMAP_RND_BITS if MMU
72 select HAVE_ARCH_SECCOMP
73 select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
74 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
75 select HAVE_ARCH_TRACEHOOK
76 select HAVE_ARM_SMCCC if CPU_V7
77 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
78 select HAVE_CONTEXT_TRACKING
79 select HAVE_C_RECORDMCOUNT
80 select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
81 select HAVE_DMA_CONTIGUOUS if MMU
82 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
83 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
84 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
85 select HAVE_EXIT_THREAD
86 select HAVE_FAST_GUP if ARM_LPAE
87 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
88 select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
89 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
90 select HAVE_GCC_PLUGINS
91 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
92 select HAVE_IDE if PCI || ISA || PCMCIA
93 select HAVE_IRQ_TIME_ACCOUNTING
94 select HAVE_KERNEL_GZIP
95 select HAVE_KERNEL_LZ4
96 select HAVE_KERNEL_LZMA
97 select HAVE_KERNEL_LZO
98 select HAVE_KERNEL_XZ
99 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
100 select HAVE_KRETPROBES if HAVE_KPROBES
101 select HAVE_MOD_ARCH_SPECIFIC
102 select HAVE_NMI
103 select HAVE_OPROFILE if HAVE_PERF_EVENTS
104 select HAVE_OPTPROBES if !THUMB2_KERNEL
105 select HAVE_PERF_EVENTS
106 select HAVE_PERF_REGS
107 select HAVE_PERF_USER_STACK_DUMP
108 select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
109 select HAVE_REGS_AND_STACK_ACCESS_API
110 select HAVE_RSEQ
111 select HAVE_STACKPROTECTOR
112 select HAVE_SYSCALL_TRACEPOINTS
113 select HAVE_UID16
114 select HAVE_VIRT_CPU_ACCOUNTING_GEN
115 select IRQ_FORCED_THREADING
116 select MODULES_USE_ELF_REL
117 select NEED_DMA_MAP_STATE
118 select OF_EARLY_FLATTREE if OF
119 select OLD_SIGACTION
120 select OLD_SIGSUSPEND3
121 select PCI_SYSCALL if PCI
122 select PERF_USE_VMALLOC
123 select RTC_LIB
124 select SET_FS
125 select SYS_SUPPORTS_APM_EMULATION
126 # Above selects are sorted alphabetically; please add new ones
127 # according to that. Thanks.
128 help
129 The ARM series is a line of low-power-consumption RISC chip designs
130 licensed by ARM Ltd and targeted at embedded applications and
131 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
132 manufactured, but legacy ARM-based PC hardware remains popular in
133 Europe. There is an ARM Linux project with a web page at
134 <http://www.arm.linux.org.uk/>.
135
136 config ARM_HAS_SG_CHAIN
137 bool
138
139 config ARM_DMA_USE_IOMMU
140 bool
141 select ARM_HAS_SG_CHAIN
142 select NEED_SG_DMA_LENGTH
143
144 if ARM_DMA_USE_IOMMU
145
146 config ARM_DMA_IOMMU_ALIGNMENT
147 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
148 range 4 9
149 default 8
150 help
151 DMA mapping framework by default aligns all buffers to the smallest
152 PAGE_SIZE order which is greater than or equal to the requested buffer
153 size. This works well for buffers up to a few hundreds kilobytes, but
154 for larger buffers it just a waste of address space. Drivers which has
155 relatively small addressing window (like 64Mib) might run out of
156 virtual space with just a few allocations.
157
158 With this parameter you can specify the maximum PAGE_SIZE order for
159 DMA IOMMU buffers. Larger buffers will be aligned only to this
160 specified order. The order is expressed as a power of two multiplied
161 by the PAGE_SIZE.
162
163 endif
164
165 config SYS_SUPPORTS_APM_EMULATION
166 bool
167
168 config HAVE_TCM
169 bool
170 select GENERIC_ALLOCATOR
171
172 config HAVE_PROC_CPU
173 bool
174
175 config NO_IOPORT_MAP
176 bool
177
178 config SBUS
179 bool
180
181 config STACKTRACE_SUPPORT
182 bool
183 default y
184
185 config LOCKDEP_SUPPORT
186 bool
187 default y
188
189 config TRACE_IRQFLAGS_SUPPORT
190 bool
191 default !CPU_V7M
192
193 config ARCH_HAS_ILOG2_U32
194 bool
195
196 config ARCH_HAS_ILOG2_U64
197 bool
198
199 config ARCH_HAS_BANDGAP
200 bool
201
202 config FIX_EARLYCON_MEM
203 def_bool y if MMU
204
205 config GENERIC_HWEIGHT
206 bool
207 default y
208
209 config GENERIC_CALIBRATE_DELAY
210 bool
211 default y
212
213 config ARCH_MAY_HAVE_PC_FDC
214 bool
215
216 config ZONE_DMA
217 bool
218
219 config ARCH_SUPPORTS_UPROBES
220 def_bool y
221
222 config ARCH_HAS_DMA_SET_COHERENT_MASK
223 bool
224
225 config GENERIC_ISA_DMA
226 bool
227
228 config FIQ
229 bool
230
231 config NEED_RET_TO_USER
232 bool
233
234 config ARCH_MTD_XIP
235 bool
236
237 config ARM_PATCH_PHYS_VIRT
238 bool "Patch physical to virtual translations at runtime" if EMBEDDED
239 default y
240 depends on !XIP_KERNEL && MMU
241 help
242 Patch phys-to-virt and virt-to-phys translation functions at
243 boot and module load time according to the position of the
244 kernel in system memory.
245
246 This can only be used with non-XIP MMU kernels where the base
247 of physical memory is at a 16MB boundary.
248
249 Only disable this option if you know that you do not require
250 this feature (eg, building a kernel for a single machine) and
251 you need to shrink the kernel to the minimal size.
252
253 config NEED_MACH_IO_H
254 bool
255 help
256 Select this when mach/io.h is required to provide special
257 definitions for this platform. The need for mach/io.h should
258 be avoided when possible.
259
260 config NEED_MACH_MEMORY_H
261 bool
262 help
263 Select this when mach/memory.h is required to provide special
264 definitions for this platform. The need for mach/memory.h should
265 be avoided when possible.
266
267 config PHYS_OFFSET
268 hex "Physical address of main memory" if MMU
269 depends on !ARM_PATCH_PHYS_VIRT
270 default DRAM_BASE if !MMU
271 default 0x00000000 if ARCH_EBSA110 || \
272 ARCH_FOOTBRIDGE
273 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
274 default 0x20000000 if ARCH_S5PV210
275 default 0xc0000000 if ARCH_SA1100
276 help
277 Please provide the physical address corresponding to the
278 location of main memory in your system.
279
280 config GENERIC_BUG
281 def_bool y
282 depends on BUG
283
284 config PGTABLE_LEVELS
285 int
286 default 3 if ARM_LPAE
287 default 2
288
289 menu "System Type"
290
291 config MMU
292 bool "MMU-based Paged Memory Management Support"
293 default y
294 help
295 Select if you want MMU-based virtualised addressing space
296 support by paged memory management. If unsure, say 'Y'.
297
298 config ARCH_MMAP_RND_BITS_MIN
299 default 8
300
301 config ARCH_MMAP_RND_BITS_MAX
302 default 14 if PAGE_OFFSET=0x40000000
303 default 15 if PAGE_OFFSET=0x80000000
304 default 16
305
306 #
307 # The "ARM system type" choice list is ordered alphabetically by option
308 # text. Please add new entries in the option alphabetic order.
309 #
310 choice
311 prompt "ARM system type"
312 default ARM_SINGLE_ARMV7M if !MMU
313 default ARCH_MULTIPLATFORM if MMU
314
315 config ARCH_MULTIPLATFORM
316 bool "Allow multiple platforms to be selected"
317 depends on MMU
318 select ARCH_FLATMEM_ENABLE
319 select ARCH_SPARSEMEM_ENABLE
320 select ARCH_SELECT_MEMORY_MODEL
321 select ARM_HAS_SG_CHAIN
322 select ARM_PATCH_PHYS_VIRT
323 select AUTO_ZRELADDR
324 select TIMER_OF
325 select COMMON_CLK
326 select GENERIC_CLOCKEVENTS
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
333 config 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 GENERIC_CLOCKEVENTS
342 select NO_IOPORT_MAP
343 select SPARSE_IRQ
344 select USE_OF
345
346 config ARCH_EBSA110
347 bool "EBSA-110"
348 select ARCH_USES_GETTIMEOFFSET
349 select CPU_SA110
350 select ISA
351 select NEED_MACH_IO_H
352 select NEED_MACH_MEMORY_H
353 select NO_IOPORT_MAP
354 help
355 This is an evaluation board for the StrongARM processor available
356 from Digital. It has limited hardware on-board, including an
357 Ethernet interface, two PCMCIA sockets, two serial ports and a
358 parallel port.
359
360 config ARCH_EP93XX
361 bool "EP93xx-based"
362 select ARCH_SPARSEMEM_ENABLE
363 select ARM_AMBA
364 imply ARM_PATCH_PHYS_VIRT
365 select ARM_VIC
366 select AUTO_ZRELADDR
367 select CLKDEV_LOOKUP
368 select CLKSRC_MMIO
369 select CPU_ARM920T
370 select GENERIC_CLOCKEVENTS
371 select GPIOLIB
372 select HAVE_LEGACY_CLK
373 help
374 This enables support for the Cirrus EP93xx series of CPUs.
375
376 config ARCH_FOOTBRIDGE
377 bool "FootBridge"
378 select CPU_SA110
379 select FOOTBRIDGE
380 select GENERIC_CLOCKEVENTS
381 select HAVE_IDE
382 select NEED_MACH_IO_H if !MMU
383 select NEED_MACH_MEMORY_H
384 help
385 Support for systems based on the DC21285 companion chip
386 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
387
388 config ARCH_IOP32X
389 bool "IOP32x-based"
390 depends on MMU
391 select CPU_XSCALE
392 select GPIO_IOP
393 select GPIOLIB
394 select NEED_RET_TO_USER
395 select FORCE_PCI
396 select PLAT_IOP
397 help
398 Support for Intel's 80219 and IOP32X (XScale) family of
399 processors.
400
401 config ARCH_IXP4XX
402 bool "IXP4xx-based"
403 depends on MMU
404 select ARCH_HAS_DMA_SET_COHERENT_MASK
405 select ARCH_SUPPORTS_BIG_ENDIAN
406 select CPU_XSCALE
407 select DMABOUNCE if PCI
408 select GENERIC_CLOCKEVENTS
409 select GENERIC_IRQ_MULTI_HANDLER
410 select GPIO_IXP4XX
411 select GPIOLIB
412 select HAVE_PCI
413 select IXP4XX_IRQ
414 select IXP4XX_TIMER
415 select NEED_MACH_IO_H
416 select USB_EHCI_BIG_ENDIAN_DESC
417 select USB_EHCI_BIG_ENDIAN_MMIO
418 help
419 Support for Intel's IXP4XX (XScale) family of processors.
420
421 config ARCH_DOVE
422 bool "Marvell Dove"
423 select CPU_PJ4
424 select GENERIC_CLOCKEVENTS
425 select GENERIC_IRQ_MULTI_HANDLER
426 select GPIOLIB
427 select HAVE_PCI
428 select MVEBU_MBUS
429 select PINCTRL
430 select PINCTRL_DOVE
431 select PLAT_ORION_LEGACY
432 select SPARSE_IRQ
433 select PM_GENERIC_DOMAINS if PM
434 help
435 Support for the Marvell Dove SoC 88AP510
436
437 config ARCH_PXA
438 bool "PXA2xx/PXA3xx-based"
439 depends on MMU
440 select ARCH_MTD_XIP
441 select ARM_CPU_SUSPEND if PM
442 select AUTO_ZRELADDR
443 select COMMON_CLK
444 select CLKSRC_PXA
445 select CLKSRC_MMIO
446 select TIMER_OF
447 select CPU_XSCALE if !CPU_XSC3
448 select GENERIC_CLOCKEVENTS
449 select GENERIC_IRQ_MULTI_HANDLER
450 select GPIO_PXA
451 select GPIOLIB
452 select HAVE_IDE
453 select IRQ_DOMAIN
454 select PLAT_PXA
455 select SPARSE_IRQ
456 help
457 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
458
459 config ARCH_RPC
460 bool "RiscPC"
461 depends on MMU
462 select ARCH_ACORN
463 select ARCH_MAY_HAVE_PC_FDC
464 select ARCH_SPARSEMEM_ENABLE
465 select ARM_HAS_SG_CHAIN
466 select CPU_SA110
467 select FIQ
468 select HAVE_IDE
469 select HAVE_PATA_PLATFORM
470 select ISA_DMA_API
471 select NEED_MACH_IO_H
472 select NEED_MACH_MEMORY_H
473 select NO_IOPORT_MAP
474 help
475 On the Acorn Risc-PC, Linux can support the internal IDE disk and
476 CD-ROM interface, serial and parallel port, and the floppy drive.
477
478 config ARCH_SA1100
479 bool "SA1100-based"
480 select ARCH_MTD_XIP
481 select ARCH_SPARSEMEM_ENABLE
482 select CLKSRC_MMIO
483 select CLKSRC_PXA
484 select TIMER_OF if OF
485 select COMMON_CLK
486 select CPU_FREQ
487 select CPU_SA1100
488 select GENERIC_CLOCKEVENTS
489 select GENERIC_IRQ_MULTI_HANDLER
490 select GPIOLIB
491 select HAVE_IDE
492 select IRQ_DOMAIN
493 select ISA
494 select NEED_MACH_MEMORY_H
495 select SPARSE_IRQ
496 help
497 Support for StrongARM 11x0 based boards.
498
499 config ARCH_S3C24XX
500 bool "Samsung S3C24XX SoCs"
501 select ATAGS
502 select CLKSRC_SAMSUNG_PWM
503 select GENERIC_CLOCKEVENTS
504 select GPIO_SAMSUNG
505 select GPIOLIB
506 select GENERIC_IRQ_MULTI_HANDLER
507 select HAVE_S3C2410_I2C if I2C
508 select HAVE_S3C_RTC if RTC_CLASS
509 select NEED_MACH_IO_H
510 select S3C2410_WATCHDOG
511 select SAMSUNG_ATAGS
512 select USE_OF
513 select WATCHDOG
514 help
515 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
516 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
517 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
518 Samsung SMDK2410 development board (and derivatives).
519
520 config ARCH_OMAP1
521 bool "TI OMAP1"
522 depends on MMU
523 select ARCH_HAS_HOLES_MEMORYMODEL
524 select ARCH_OMAP
525 select CLKDEV_LOOKUP
526 select CLKSRC_MMIO
527 select GENERIC_CLOCKEVENTS
528 select GENERIC_IRQ_CHIP
529 select GENERIC_IRQ_MULTI_HANDLER
530 select GPIOLIB
531 select HAVE_IDE
532 select HAVE_LEGACY_CLK
533 select IRQ_DOMAIN
534 select NEED_MACH_IO_H if PCCARD
535 select NEED_MACH_MEMORY_H
536 select SPARSE_IRQ
537 help
538 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
539
540 endchoice
541
542 menu "Multiple platform selection"
543 depends on ARCH_MULTIPLATFORM
544
545 comment "CPU Core family selection"
546
547 config ARCH_MULTI_V4
548 bool "ARMv4 based platforms (FA526)"
549 depends on !ARCH_MULTI_V6_V7
550 select ARCH_MULTI_V4_V5
551 select CPU_FA526
552
553 config ARCH_MULTI_V4T
554 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
555 depends on !ARCH_MULTI_V6_V7
556 select ARCH_MULTI_V4_V5
557 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
558 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
559 CPU_ARM925T || CPU_ARM940T)
560
561 config ARCH_MULTI_V5
562 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
563 depends on !ARCH_MULTI_V6_V7
564 select ARCH_MULTI_V4_V5
565 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
566 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
567 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
568
569 config ARCH_MULTI_V4_V5
570 bool
571
572 config ARCH_MULTI_V6
573 bool "ARMv6 based platforms (ARM11)"
574 select ARCH_MULTI_V6_V7
575 select CPU_V6K
576
577 config ARCH_MULTI_V7
578 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
579 default y
580 select ARCH_MULTI_V6_V7
581 select CPU_V7
582 select HAVE_SMP
583
584 config ARCH_MULTI_V6_V7
585 bool
586 select MIGHT_HAVE_CACHE_L2X0
587
588 config ARCH_MULTI_CPU_AUTO
589 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
590 select ARCH_MULTI_V5
591
592 endmenu
593
594 config ARCH_VIRT
595 bool "Dummy Virtual Machine"
596 depends on ARCH_MULTI_V7
597 select ARM_AMBA
598 select ARM_GIC
599 select ARM_GIC_V2M if PCI
600 select ARM_GIC_V3
601 select ARM_GIC_V3_ITS if PCI
602 select ARM_PSCI
603 select HAVE_ARM_ARCH_TIMER
604 select ARCH_SUPPORTS_BIG_ENDIAN
605
606 #
607 # This is sorted alphabetically by mach-* pathname. However, plat-*
608 # Kconfigs may be included either alphabetically (according to the
609 # plat- suffix) or along side the corresponding mach-* source.
610 #
611 source "arch/arm/mach-actions/Kconfig"
612
613 source "arch/arm/mach-alpine/Kconfig"
614
615 source "arch/arm/mach-artpec/Kconfig"
616
617 source "arch/arm/mach-asm9260/Kconfig"
618
619 source "arch/arm/mach-aspeed/Kconfig"
620
621 source "arch/arm/mach-at91/Kconfig"
622
623 source "arch/arm/mach-axxia/Kconfig"
624
625 source "arch/arm/mach-bcm/Kconfig"
626
627 source "arch/arm/mach-berlin/Kconfig"
628
629 source "arch/arm/mach-clps711x/Kconfig"
630
631 source "arch/arm/mach-cns3xxx/Kconfig"
632
633 source "arch/arm/mach-davinci/Kconfig"
634
635 source "arch/arm/mach-digicolor/Kconfig"
636
637 source "arch/arm/mach-dove/Kconfig"
638
639 source "arch/arm/mach-ep93xx/Kconfig"
640
641 source "arch/arm/mach-exynos/Kconfig"
642
643 source "arch/arm/mach-footbridge/Kconfig"
644
645 source "arch/arm/mach-gemini/Kconfig"
646
647 source "arch/arm/mach-highbank/Kconfig"
648
649 source "arch/arm/mach-hisi/Kconfig"
650
651 source "arch/arm/mach-imx/Kconfig"
652
653 source "arch/arm/mach-integrator/Kconfig"
654
655 source "arch/arm/mach-iop32x/Kconfig"
656
657 source "arch/arm/mach-ixp4xx/Kconfig"
658
659 source "arch/arm/mach-keystone/Kconfig"
660
661 source "arch/arm/mach-lpc32xx/Kconfig"
662
663 source "arch/arm/mach-mediatek/Kconfig"
664
665 source "arch/arm/mach-meson/Kconfig"
666
667 source "arch/arm/mach-milbeaut/Kconfig"
668
669 source "arch/arm/mach-mmp/Kconfig"
670
671 source "arch/arm/mach-moxart/Kconfig"
672
673 source "arch/arm/mach-mstar/Kconfig"
674
675 source "arch/arm/mach-mv78xx0/Kconfig"
676
677 source "arch/arm/mach-mvebu/Kconfig"
678
679 source "arch/arm/mach-mxs/Kconfig"
680
681 source "arch/arm/mach-nomadik/Kconfig"
682
683 source "arch/arm/mach-npcm/Kconfig"
684
685 source "arch/arm/mach-nspire/Kconfig"
686
687 source "arch/arm/plat-omap/Kconfig"
688
689 source "arch/arm/mach-omap1/Kconfig"
690
691 source "arch/arm/mach-omap2/Kconfig"
692
693 source "arch/arm/mach-orion5x/Kconfig"
694
695 source "arch/arm/mach-oxnas/Kconfig"
696
697 source "arch/arm/mach-picoxcell/Kconfig"
698
699 source "arch/arm/mach-prima2/Kconfig"
700
701 source "arch/arm/mach-pxa/Kconfig"
702 source "arch/arm/plat-pxa/Kconfig"
703
704 source "arch/arm/mach-qcom/Kconfig"
705
706 source "arch/arm/mach-rda/Kconfig"
707
708 source "arch/arm/mach-realtek/Kconfig"
709
710 source "arch/arm/mach-realview/Kconfig"
711
712 source "arch/arm/mach-rockchip/Kconfig"
713
714 source "arch/arm/mach-s3c/Kconfig"
715
716 source "arch/arm/mach-s5pv210/Kconfig"
717
718 source "arch/arm/mach-sa1100/Kconfig"
719
720 source "arch/arm/mach-shmobile/Kconfig"
721
722 source "arch/arm/mach-socfpga/Kconfig"
723
724 source "arch/arm/mach-spear/Kconfig"
725
726 source "arch/arm/mach-sti/Kconfig"
727
728 source "arch/arm/mach-stm32/Kconfig"
729
730 source "arch/arm/mach-sunxi/Kconfig"
731
732 source "arch/arm/mach-tango/Kconfig"
733
734 source "arch/arm/mach-tegra/Kconfig"
735
736 source "arch/arm/mach-u300/Kconfig"
737
738 source "arch/arm/mach-uniphier/Kconfig"
739
740 source "arch/arm/mach-ux500/Kconfig"
741
742 source "arch/arm/mach-versatile/Kconfig"
743
744 source "arch/arm/mach-vexpress/Kconfig"
745
746 source "arch/arm/mach-vt8500/Kconfig"
747
748 source "arch/arm/mach-zx/Kconfig"
749
750 source "arch/arm/mach-zynq/Kconfig"
751
752 # ARMv7-M architecture
753 config 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
761 config 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
772 config 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
785 config ARCH_ACORN
786 bool
787
788 config PLAT_IOP
789 bool
790 select GENERIC_CLOCKEVENTS
791
792 config PLAT_ORION
793 bool
794 select CLKSRC_MMIO
795 select COMMON_CLK
796 select GENERIC_IRQ_CHIP
797 select IRQ_DOMAIN
798
799 config PLAT_ORION_LEGACY
800 bool
801 select PLAT_ORION
802
803 config PLAT_PXA
804 bool
805
806 config PLAT_VERSATILE
807 bool
808
809 source "arch/arm/mm/Kconfig"
810
811 config 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
819 if !MMU
820 source "arch/arm/Kconfig-nommu"
821 endif
822
823 config 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
837 config 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
846 config 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
855 config 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
871 config 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
885 config 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
898 config 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
911 config 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
926 config 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
937 config 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
949 config 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
963 config 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
974 config 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
985 config 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
996 config 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
1008 config 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
1022 config 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
1032 config 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
1042 config 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
1051 config 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
1065 config 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
1075 config 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
1084 config 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
1092 config 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
1101 config 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
1113 config 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
1123 endmenu
1124
1125 source "arch/arm/common/Kconfig"
1126
1127 menu "Bus support"
1128
1129 config 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
1139 config ISA_DMA
1140 bool
1141 select ISA_DMA_API
1142
1143 # Select ISA DMA interface
1144 config ISA_DMA_API
1145 bool
1146
1147 config PCI_NANOENGINE
1148 bool "BSE nanoEngine PCI support"
1149 depends on SA1100_NANOENGINE
1150 help
1151 Enable PCI on the BSE nanoEngine board.
1152
1153 config 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
1165 endmenu
1166
1167 menu "Kernel Features"
1168
1169 config 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
1178 config 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
1202 config 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
1214 config 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
1223 config 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
1231 config 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
1239 config HAVE_ARM_SCU
1240 bool
1241 help
1242 This option enables support for the ARM snoop control unit
1243
1244 config 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
1251 config HAVE_ARM_TWD
1252 bool
1253 help
1254 This options enables support for the ARM timer and watchdog unit
1255
1256 config 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
1264 config 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
1273 config 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
1281 config 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
1290 config 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
1298 choice
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"
1317 endchoice
1318
1319 config 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
1327 config NR_CPUS
1328 int "Maximum number of CPUs (2-32)"
1329 range 2 32
1330 depends on SMP
1331 default "4"
1332
1333 config 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
1341 config 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.
1355 config 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
1373 config HZ_FIXED
1374 int
1375 default 200 if ARCH_EBSA110
1376 default 128 if SOC_AT91RM9200
1377 default 0
1378
1379 choice
1380 depends on HZ_FIXED = 0
1381 prompt "Timer frequency"
1382
1383 config HZ_100
1384 bool "100 Hz"
1385
1386 config HZ_200
1387 bool "200 Hz"
1388
1389 config HZ_250
1390 bool "250 Hz"
1391
1392 config HZ_300
1393 bool "300 Hz"
1394
1395 config HZ_500
1396 bool "500 Hz"
1397
1398 config HZ_1000
1399 bool "1000 Hz"
1400
1401 endchoice
1402
1403 config 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
1413 config SCHED_HRTICK
1414 def_bool HIGH_RES_TIMERS
1415
1416 config 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
1427 config 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
1445 config 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
1462 config 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
1483 config ARCH_HAS_HOLES_MEMORYMODEL
1484 bool
1485
1486 config ARCH_SELECT_MEMORY_MODEL
1487 bool
1488
1489 config ARCH_FLATMEM_ENABLE
1490 bool
1491
1492 config ARCH_SPARSEMEM_ENABLE
1493 bool
1494 select SPARSEMEM_STATIC if SPARSEMEM
1495
1496 config HAVE_ARCH_PFN_VALID
1497 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1498
1499 config HIGHMEM
1500 bool "High Memory Support"
1501 depends on MMU
1502 select KMAP_LOCAL
1503 help
1504 The address space of ARM processors is only 4 Gigabytes large
1505 and it has to accommodate user address space, kernel address
1506 space as well as some memory mapped IO. That means that, if you
1507 have a large amount of physical memory and/or IO, not all of the
1508 memory can be "permanently mapped" by the kernel. The physical
1509 memory that is not permanently mapped is called "high memory".
1510
1511 Depending on the selected kernel/user memory split, minimum
1512 vmalloc space and actual amount of RAM, you may not need this
1513 option which should result in a slightly faster kernel.
1514
1515 If unsure, say n.
1516
1517 config HIGHPTE
1518 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1519 depends on HIGHMEM
1520 default y
1521 help
1522 The VM uses one page of physical memory for each page table.
1523 For systems with a lot of processes, this can use a lot of
1524 precious low memory, eventually leading to low memory being
1525 consumed by page tables. Setting this option will allow
1526 user-space 2nd level page tables to reside in high memory.
1527
1528 config CPU_SW_DOMAIN_PAN
1529 bool "Enable use of CPU domains to implement privileged no-access"
1530 depends on MMU && !ARM_LPAE
1531 default y
1532 help
1533 Increase kernel security by ensuring that normal kernel accesses
1534 are unable to access userspace addresses. This can help prevent
1535 use-after-free bugs becoming an exploitable privilege escalation
1536 by ensuring that magic values (such as LIST_POISON) will always
1537 fault when dereferenced.
1538
1539 CPUs with low-vector mappings use a best-efforts implementation.
1540 Their lower 1MB needs to remain accessible for the vectors, but
1541 the remainder of userspace will become appropriately inaccessible.
1542
1543 config HW_PERF_EVENTS
1544 def_bool y
1545 depends on ARM_PMU
1546
1547 config SYS_SUPPORTS_HUGETLBFS
1548 def_bool y
1549 depends on ARM_LPAE
1550
1551 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1552 def_bool y
1553 depends on ARM_LPAE
1554
1555 config ARCH_WANT_GENERAL_HUGETLB
1556 def_bool y
1557
1558 config ARM_MODULE_PLTS
1559 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1560 depends on MODULES
1561 default y
1562 help
1563 Allocate PLTs when loading modules so that jumps and calls whose
1564 targets are too far away for their relative offsets to be encoded
1565 in the instructions themselves can be bounced via veneers in the
1566 module's PLT. This allows modules to be allocated in the generic
1567 vmalloc area after the dedicated module memory area has been
1568 exhausted. The modules will use slightly more memory, but after
1569 rounding up to page size, the actual memory footprint is usually
1570 the same.
1571
1572 Disabling this is usually safe for small single-platform
1573 configurations. If unsure, say y.
1574
1575 config FORCE_MAX_ZONEORDER
1576 int "Maximum zone order"
1577 default "12" if SOC_AM33XX
1578 default "9" if SA1111 || ARCH_EFM32
1579 default "11"
1580 help
1581 The kernel memory allocator divides physically contiguous memory
1582 blocks into "zones", where each zone is a power of two number of
1583 pages. This option selects the largest power of two that the kernel
1584 keeps in the memory allocator. If you need to allocate very large
1585 blocks of physically contiguous memory, then you may need to
1586 increase this value.
1587
1588 This config option is actually maximum order plus one. For example,
1589 a value of 11 means that the largest free memory block is 2^10 pages.
1590
1591 config ALIGNMENT_TRAP
1592 bool
1593 depends on CPU_CP15_MMU
1594 default y if !ARCH_EBSA110
1595 select HAVE_PROC_CPU if PROC_FS
1596 help
1597 ARM processors cannot fetch/store information which is not
1598 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1599 address divisible by 4. On 32-bit ARM processors, these non-aligned
1600 fetch/store instructions will be emulated in software if you say
1601 here, which has a severe performance impact. This is necessary for
1602 correct operation of some network protocols. With an IP-only
1603 configuration it is safe to say N, otherwise say Y.
1604
1605 config UACCESS_WITH_MEMCPY
1606 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1607 depends on MMU
1608 default y if CPU_FEROCEON
1609 help
1610 Implement faster copy_to_user and clear_user methods for CPU
1611 cores where a 8-word STM instruction give significantly higher
1612 memory write throughput than a sequence of individual 32bit stores.
1613
1614 A possible side effect is a slight increase in scheduling latency
1615 between threads sharing the same address space if they invoke
1616 such copy operations with large buffers.
1617
1618 However, if the CPU data cache is using a write-allocate mode,
1619 this option is unlikely to provide any performance gain.
1620
1621 config PARAVIRT
1622 bool "Enable paravirtualization code"
1623 help
1624 This changes the kernel so it can modify itself when it is run
1625 under a hypervisor, potentially improving performance significantly
1626 over full virtualization.
1627
1628 config PARAVIRT_TIME_ACCOUNTING
1629 bool "Paravirtual steal time accounting"
1630 select PARAVIRT
1631 help
1632 Select this option to enable fine granularity task steal time
1633 accounting. Time spent executing other tasks in parallel with
1634 the current vCPU is discounted from the vCPU power. To account for
1635 that, there can be a small performance impact.
1636
1637 If in doubt, say N here.
1638
1639 config XEN_DOM0
1640 def_bool y
1641 depends on XEN
1642
1643 config XEN
1644 bool "Xen guest support on ARM"
1645 depends on ARM && AEABI && OF
1646 depends on CPU_V7 && !CPU_V6
1647 depends on !GENERIC_ATOMIC64
1648 depends on MMU
1649 select ARCH_DMA_ADDR_T_64BIT
1650 select ARM_PSCI
1651 select SWIOTLB
1652 select SWIOTLB_XEN
1653 select PARAVIRT
1654 help
1655 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1656
1657 config STACKPROTECTOR_PER_TASK
1658 bool "Use a unique stack canary value for each task"
1659 depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1660 select GCC_PLUGIN_ARM_SSP_PER_TASK
1661 default y
1662 help
1663 Due to the fact that GCC uses an ordinary symbol reference from
1664 which to load the value of the stack canary, this value can only
1665 change at reboot time on SMP systems, and all tasks running in the
1666 kernel's address space are forced to use the same canary value for
1667 the entire duration that the system is up.
1668
1669 Enable this option to switch to a different method that uses a
1670 different canary value for each task.
1671
1672 endmenu
1673
1674 menu "Boot options"
1675
1676 config USE_OF
1677 bool "Flattened Device Tree support"
1678 select IRQ_DOMAIN
1679 select OF
1680 help
1681 Include support for flattened device tree machine descriptions.
1682
1683 config ATAGS
1684 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1685 default y
1686 help
1687 This is the traditional way of passing data to the kernel at boot
1688 time. If you are solely relying on the flattened device tree (or
1689 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1690 to remove ATAGS support from your kernel binary. If unsure,
1691 leave this to y.
1692
1693 config DEPRECATED_PARAM_STRUCT
1694 bool "Provide old way to pass kernel parameters"
1695 depends on ATAGS
1696 help
1697 This was deprecated in 2001 and announced to live on for 5 years.
1698 Some old boot loaders still use this way.
1699
1700 # Compressed boot loader in ROM. Yes, we really want to ask about
1701 # TEXT and BSS so we preserve their values in the config files.
1702 config ZBOOT_ROM_TEXT
1703 hex "Compressed ROM boot loader base address"
1704 default 0x0
1705 help
1706 The physical address at which the ROM-able zImage is to be
1707 placed in the target. Platforms which normally make use of
1708 ROM-able zImage formats normally set this to a suitable
1709 value in their defconfig file.
1710
1711 If ZBOOT_ROM is not enabled, this has no effect.
1712
1713 config ZBOOT_ROM_BSS
1714 hex "Compressed ROM boot loader BSS address"
1715 default 0x0
1716 help
1717 The base address of an area of read/write memory in the target
1718 for the ROM-able zImage which must be available while the
1719 decompressor is running. It must be large enough to hold the
1720 entire decompressed kernel plus an additional 128 KiB.
1721 Platforms which normally make use of ROM-able zImage formats
1722 normally set this to a suitable value in their defconfig file.
1723
1724 If ZBOOT_ROM is not enabled, this has no effect.
1725
1726 config ZBOOT_ROM
1727 bool "Compressed boot loader in ROM/flash"
1728 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1729 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1730 help
1731 Say Y here if you intend to execute your compressed kernel image
1732 (zImage) directly from ROM or flash. If unsure, say N.
1733
1734 config ARM_APPENDED_DTB
1735 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1736 depends on OF
1737 help
1738 With this option, the boot code will look for a device tree binary
1739 (DTB) appended to zImage
1740 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1741
1742 This is meant as a backward compatibility convenience for those
1743 systems with a bootloader that can't be upgraded to accommodate
1744 the documented boot protocol using a device tree.
1745
1746 Beware that there is very little in terms of protection against
1747 this option being confused by leftover garbage in memory that might
1748 look like a DTB header after a reboot if no actual DTB is appended
1749 to zImage. Do not leave this option active in a production kernel
1750 if you don't intend to always append a DTB. Proper passing of the
1751 location into r2 of a bootloader provided DTB is always preferable
1752 to this option.
1753
1754 config ARM_ATAG_DTB_COMPAT
1755 bool "Supplement the appended DTB with traditional ATAG information"
1756 depends on ARM_APPENDED_DTB
1757 help
1758 Some old bootloaders can't be updated to a DTB capable one, yet
1759 they provide ATAGs with memory configuration, the ramdisk address,
1760 the kernel cmdline string, etc. Such information is dynamically
1761 provided by the bootloader and can't always be stored in a static
1762 DTB. To allow a device tree enabled kernel to be used with such
1763 bootloaders, this option allows zImage to extract the information
1764 from the ATAG list and store it at run time into the appended DTB.
1765
1766 choice
1767 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1768 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1769
1770 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1771 bool "Use bootloader kernel arguments if available"
1772 help
1773 Uses the command-line options passed by the boot loader instead of
1774 the device tree bootargs property. If the boot loader doesn't provide
1775 any, the device tree bootargs property will be used.
1776
1777 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1778 bool "Extend with bootloader kernel arguments"
1779 help
1780 The command-line arguments provided by the boot loader will be
1781 appended to the the device tree bootargs property.
1782
1783 endchoice
1784
1785 config CMDLINE
1786 string "Default kernel command string"
1787 default ""
1788 help
1789 On some architectures (EBSA110 and CATS), there is currently no way
1790 for the boot loader to pass arguments to the kernel. For these
1791 architectures, you should supply some command-line options at build
1792 time by entering them here. As a minimum, you should specify the
1793 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1794
1795 choice
1796 prompt "Kernel command line type" if CMDLINE != ""
1797 default CMDLINE_FROM_BOOTLOADER
1798 depends on ATAGS
1799
1800 config CMDLINE_FROM_BOOTLOADER
1801 bool "Use bootloader kernel arguments if available"
1802 help
1803 Uses the command-line options passed by the boot loader. If
1804 the boot loader doesn't provide any, the default kernel command
1805 string provided in CMDLINE will be used.
1806
1807 config CMDLINE_EXTEND
1808 bool "Extend bootloader kernel arguments"
1809 help
1810 The command-line arguments provided by the boot loader will be
1811 appended to the default kernel command string.
1812
1813 config CMDLINE_FORCE
1814 bool "Always use the default kernel command string"
1815 help
1816 Always use the default kernel command string, even if the boot
1817 loader passes other arguments to the kernel.
1818 This is useful if you cannot or don't want to change the
1819 command-line options your boot loader passes to the kernel.
1820 endchoice
1821
1822 config XIP_KERNEL
1823 bool "Kernel Execute-In-Place from ROM"
1824 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1825 help
1826 Execute-In-Place allows the kernel to run from non-volatile storage
1827 directly addressable by the CPU, such as NOR flash. This saves RAM
1828 space since the text section of the kernel is not loaded from flash
1829 to RAM. Read-write sections, such as the data section and stack,
1830 are still copied to RAM. The XIP kernel is not compressed since
1831 it has to run directly from flash, so it will take more space to
1832 store it. The flash address used to link the kernel object files,
1833 and for storing it, is configuration dependent. Therefore, if you
1834 say Y here, you must know the proper physical address where to
1835 store the kernel image depending on your own flash memory usage.
1836
1837 Also note that the make target becomes "make xipImage" rather than
1838 "make zImage" or "make Image". The final kernel binary to put in
1839 ROM memory will be arch/arm/boot/xipImage.
1840
1841 If unsure, say N.
1842
1843 config XIP_PHYS_ADDR
1844 hex "XIP Kernel Physical Location"
1845 depends on XIP_KERNEL
1846 default "0x00080000"
1847 help
1848 This is the physical address in your flash memory the kernel will
1849 be linked for and stored to. This address is dependent on your
1850 own flash usage.
1851
1852 config XIP_DEFLATED_DATA
1853 bool "Store kernel .data section compressed in ROM"
1854 depends on XIP_KERNEL
1855 select ZLIB_INFLATE
1856 help
1857 Before the kernel is actually executed, its .data section has to be
1858 copied to RAM from ROM. This option allows for storing that data
1859 in compressed form and decompressed to RAM rather than merely being
1860 copied, saving some precious ROM space. A possible drawback is a
1861 slightly longer boot delay.
1862
1863 config KEXEC
1864 bool "Kexec system call (EXPERIMENTAL)"
1865 depends on (!SMP || PM_SLEEP_SMP)
1866 depends on MMU
1867 select KEXEC_CORE
1868 help
1869 kexec is a system call that implements the ability to shutdown your
1870 current kernel, and to start another kernel. It is like a reboot
1871 but it is independent of the system firmware. And like a reboot
1872 you can start any kernel with it, not just Linux.
1873
1874 It is an ongoing process to be certain the hardware in a machine
1875 is properly shutdown, so do not be surprised if this code does not
1876 initially work for you.
1877
1878 config ATAGS_PROC
1879 bool "Export atags in procfs"
1880 depends on ATAGS && KEXEC
1881 default y
1882 help
1883 Should the atags used to boot the kernel be exported in an "atags"
1884 file in procfs. Useful with kexec.
1885
1886 config CRASH_DUMP
1887 bool "Build kdump crash kernel (EXPERIMENTAL)"
1888 help
1889 Generate crash dump after being started by kexec. This should
1890 be normally only set in special crash dump kernels which are
1891 loaded in the main kernel with kexec-tools into a specially
1892 reserved region and then later executed after a crash by
1893 kdump/kexec. The crash dump kernel must be compiled to a
1894 memory address not used by the main kernel
1895
1896 For more details see Documentation/admin-guide/kdump/kdump.rst
1897
1898 config AUTO_ZRELADDR
1899 bool "Auto calculation of the decompressed kernel image address"
1900 help
1901 ZRELADDR is the physical address where the decompressed kernel
1902 image will be placed. If AUTO_ZRELADDR is selected, the address
1903 will be determined at run-time by masking the current IP with
1904 0xf8000000. This assumes the zImage being placed in the first 128MB
1905 from start of memory.
1906
1907 config EFI_STUB
1908 bool
1909
1910 config EFI
1911 bool "UEFI runtime support"
1912 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1913 select UCS2_STRING
1914 select EFI_PARAMS_FROM_FDT
1915 select EFI_STUB
1916 select EFI_GENERIC_STUB
1917 select EFI_RUNTIME_WRAPPERS
1918 help
1919 This option provides support for runtime services provided
1920 by UEFI firmware (such as non-volatile variables, realtime
1921 clock, and platform reset). A UEFI stub is also provided to
1922 allow the kernel to be booted as an EFI application. This
1923 is only useful for kernels that may run on systems that have
1924 UEFI firmware.
1925
1926 config DMI
1927 bool "Enable support for SMBIOS (DMI) tables"
1928 depends on EFI
1929 default y
1930 help
1931 This enables SMBIOS/DMI feature for systems.
1932
1933 This option is only useful on systems that have UEFI firmware.
1934 However, even with this option, the resultant kernel should
1935 continue to boot on existing non-UEFI platforms.
1936
1937 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1938 i.e., the the practice of identifying the platform via DMI to
1939 decide whether certain workarounds for buggy hardware and/or
1940 firmware need to be enabled. This would require the DMI subsystem
1941 to be enabled much earlier than we do on ARM, which is non-trivial.
1942
1943 endmenu
1944
1945 menu "CPU Power Management"
1946
1947 source "drivers/cpufreq/Kconfig"
1948
1949 source "drivers/cpuidle/Kconfig"
1950
1951 endmenu
1952
1953 menu "Floating point emulation"
1954
1955 comment "At least one emulation must be selected"
1956
1957 config FPE_NWFPE
1958 bool "NWFPE math emulation"
1959 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1960 help
1961 Say Y to include the NWFPE floating point emulator in the kernel.
1962 This is necessary to run most binaries. Linux does not currently
1963 support floating point hardware so you need to say Y here even if
1964 your machine has an FPA or floating point co-processor podule.
1965
1966 You may say N here if you are going to load the Acorn FPEmulator
1967 early in the bootup.
1968
1969 config FPE_NWFPE_XP
1970 bool "Support extended precision"
1971 depends on FPE_NWFPE
1972 help
1973 Say Y to include 80-bit support in the kernel floating-point
1974 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1975 Note that gcc does not generate 80-bit operations by default,
1976 so in most cases this option only enlarges the size of the
1977 floating point emulator without any good reason.
1978
1979 You almost surely want to say N here.
1980
1981 config FPE_FASTFPE
1982 bool "FastFPE math emulation (EXPERIMENTAL)"
1983 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1984 help
1985 Say Y here to include the FAST floating point emulator in the kernel.
1986 This is an experimental much faster emulator which now also has full
1987 precision for the mantissa. It does not support any exceptions.
1988 It is very simple, and approximately 3-6 times faster than NWFPE.
1989
1990 It should be sufficient for most programs. It may be not suitable
1991 for scientific calculations, but you have to check this for yourself.
1992 If you do not feel you need a faster FP emulation you should better
1993 choose NWFPE.
1994
1995 config VFP
1996 bool "VFP-format floating point maths"
1997 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1998 help
1999 Say Y to include VFP support code in the kernel. This is needed
2000 if your hardware includes a VFP unit.
2001
2002 Please see <file:Documentation/arm/vfp/release-notes.rst> for
2003 release notes and additional status information.
2004
2005 Say N if your target does not have VFP hardware.
2006
2007 config VFPv3
2008 bool
2009 depends on VFP
2010 default y if CPU_V7
2011
2012 config NEON
2013 bool "Advanced SIMD (NEON) Extension support"
2014 depends on VFPv3 && CPU_V7
2015 help
2016 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2017 Extension.
2018
2019 config KERNEL_MODE_NEON
2020 bool "Support for NEON in kernel mode"
2021 depends on NEON && AEABI
2022 help
2023 Say Y to include support for NEON in kernel mode.
2024
2025 endmenu
2026
2027 menu "Power management options"
2028
2029 source "kernel/power/Kconfig"
2030
2031 config ARCH_SUSPEND_POSSIBLE
2032 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2033 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2034 def_bool y
2035
2036 config ARM_CPU_SUSPEND
2037 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2038 depends on ARCH_SUSPEND_POSSIBLE
2039
2040 config ARCH_HIBERNATION_POSSIBLE
2041 bool
2042 depends on MMU
2043 default y if ARCH_SUSPEND_POSSIBLE
2044
2045 endmenu
2046
2047 source "drivers/firmware/Kconfig"
2048
2049 if CRYPTO
2050 source "arch/arm/crypto/Kconfig"
2051 endif
2052
2053 source "arch/arm/Kconfig.assembler"