xref: /openbmc/linux/arch/arm/Kconfig (revision 46eeaa11bdd1bc9e077bdf741d32ca7235d263c6)
1 # SPDX-License-Identifier: GPL-2.0
2 config ARM
3 	bool
4 	default y
5 	select ARCH_32BIT_OFF_T
6 	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND
7 	select ARCH_HAS_BINFMT_FLAT
8 	select ARCH_HAS_CPU_FINALIZE_INIT if MMU
9 	select ARCH_HAS_CURRENT_STACK_POINTER
10 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
11 	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
12 	select ARCH_HAS_ELF_RANDOMIZE
13 	select ARCH_HAS_FORTIFY_SOURCE
14 	select ARCH_HAS_KEEPINITRD
15 	select ARCH_HAS_KCOV
16 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
17 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
18 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
19 	select ARCH_HAS_SETUP_DMA_OPS
20 	select ARCH_HAS_SET_MEMORY
21 	select ARCH_STACKWALK
22 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
23 	select ARCH_HAS_STRICT_MODULE_RWX if MMU
24 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
25 	select ARCH_HAS_SYNC_DMA_FOR_CPU
26 	select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
27 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
28 	select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
29 	select ARCH_HAS_GCOV_PROFILE_ALL
30 	select ARCH_KEEP_MEMBLOCK
31 	select ARCH_HAS_UBSAN_SANITIZE_ALL
32 	select ARCH_MIGHT_HAVE_PC_PARPORT
33 	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
34 	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
35 	select ARCH_SUPPORTS_ATOMIC_RMW
36 	select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
37 	select ARCH_USE_BUILTIN_BSWAP
38 	select ARCH_USE_CMPXCHG_LOCKREF
39 	select ARCH_USE_MEMTEST
40 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
41 	select ARCH_WANT_GENERAL_HUGETLB
42 	select ARCH_WANT_IPC_PARSE_VERSION
43 	select ARCH_WANT_LD_ORPHAN_WARN
44 	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
45 	select BUILDTIME_TABLE_SORT if MMU
46 	select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE)
47 	select CLONE_BACKWARDS
48 	select CPU_PM if SUSPEND || CPU_IDLE
49 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
50 	select DMA_DECLARE_COHERENT
51 	select DMA_GLOBAL_POOL if !MMU
52 	select DMA_OPS
53 	select DMA_NONCOHERENT_MMAP if MMU
54 	select EDAC_SUPPORT
55 	select EDAC_ATOMIC_SCRUB
56 	select GENERIC_ALLOCATOR
57 	select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
58 	select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
59 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
60 	select GENERIC_IRQ_IPI if SMP
61 	select GENERIC_CPU_AUTOPROBE
62 	select GENERIC_EARLY_IOREMAP
63 	select GENERIC_IDLE_POLL_SETUP
64 	select GENERIC_IRQ_MULTI_HANDLER
65 	select GENERIC_IRQ_PROBE
66 	select GENERIC_IRQ_SHOW
67 	select GENERIC_IRQ_SHOW_LEVEL
68 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
69 	select GENERIC_PCI_IOMAP
70 	select GENERIC_SCHED_CLOCK
71 	select GENERIC_SMP_IDLE_THREAD
72 	select HARDIRQS_SW_RESEND
73 	select HAS_IOPORT
74 	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
75 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
76 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
77 	select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
78 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
79 	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
80 	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
81 	select HAVE_ARCH_MMAP_RND_BITS if MMU
82 	select HAVE_ARCH_PFN_VALID
83 	select HAVE_ARCH_SECCOMP
84 	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
85 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
86 	select HAVE_ARCH_TRACEHOOK
87 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
88 	select HAVE_ARM_SMCCC if CPU_V7
89 	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
90 	select HAVE_CONTEXT_TRACKING_USER
91 	select HAVE_C_RECORDMCOUNT
92 	select HAVE_BUILDTIME_MCOUNT_SORT
93 	select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
94 	select HAVE_DMA_CONTIGUOUS if MMU
95 	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
96 	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
97 	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
98 	select HAVE_EXIT_THREAD
99 	select HAVE_FAST_GUP if ARM_LPAE
100 	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
101 	select HAVE_FUNCTION_ERROR_INJECTION
102 	select HAVE_FUNCTION_GRAPH_TRACER
103 	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
104 	select HAVE_GCC_PLUGINS
105 	select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
106 	select HAVE_IRQ_TIME_ACCOUNTING
107 	select HAVE_KERNEL_GZIP
108 	select HAVE_KERNEL_LZ4
109 	select HAVE_KERNEL_LZMA
110 	select HAVE_KERNEL_LZO
111 	select HAVE_KERNEL_XZ
112 	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
113 	select HAVE_KRETPROBES if HAVE_KPROBES
114 	select HAVE_MOD_ARCH_SPECIFIC
115 	select HAVE_NMI
116 	select HAVE_OPTPROBES if !THUMB2_KERNEL
117 	select HAVE_PCI if MMU
118 	select HAVE_PERF_EVENTS
119 	select HAVE_PERF_REGS
120 	select HAVE_PERF_USER_STACK_DUMP
121 	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
122 	select HAVE_REGS_AND_STACK_ACCESS_API
123 	select HAVE_RSEQ
124 	select HAVE_STACKPROTECTOR
125 	select HAVE_SYSCALL_TRACEPOINTS
126 	select HAVE_UID16
127 	select HAVE_VIRT_CPU_ACCOUNTING_GEN
128 	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
129 	select IRQ_FORCED_THREADING
130 	select LOCK_MM_AND_FIND_VMA
131 	select MODULES_USE_ELF_REL
132 	select NEED_DMA_MAP_STATE
133 	select OF_EARLY_FLATTREE if OF
134 	select OLD_SIGACTION
135 	select OLD_SIGSUSPEND3
136 	select PCI_DOMAINS_GENERIC if PCI
137 	select PCI_SYSCALL if PCI
138 	select PERF_USE_VMALLOC
139 	select RTC_LIB
140 	select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
141 	select SYS_SUPPORTS_APM_EMULATION
142 	select THREAD_INFO_IN_TASK
143 	select TIMER_OF if OF
144 	select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
145 	select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
146 	select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
147 	# Above selects are sorted alphabetically; please add new ones
148 	# according to that.  Thanks.
149 	help
150 	  The ARM series is a line of low-power-consumption RISC chip designs
151 	  licensed by ARM Ltd and targeted at embedded applications and
152 	  handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
153 	  manufactured, but legacy ARM-based PC hardware remains popular in
154 	  Europe.  There is an ARM Linux project with a web page at
155 	  <http://www.arm.linux.org.uk/>.
156 
157 config ARM_HAS_GROUP_RELOCS
158 	def_bool y
159 	depends on !LD_IS_LLD || LLD_VERSION >= 140000
160 	depends on !COMPILE_TEST
161 	help
162 	  Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
163 	  relocations, which have been around for a long time, but were not
164 	  supported in LLD until version 14. The combined range is -/+ 256 MiB,
165 	  which is usually sufficient, but not for allyesconfig, so we disable
166 	  this feature when doing compile testing.
167 
168 config ARM_DMA_USE_IOMMU
169 	bool
170 	select NEED_SG_DMA_LENGTH
171 
172 if ARM_DMA_USE_IOMMU
173 
174 config ARM_DMA_IOMMU_ALIGNMENT
175 	int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
176 	range 4 9
177 	default 8
178 	help
179 	  DMA mapping framework by default aligns all buffers to the smallest
180 	  PAGE_SIZE order which is greater than or equal to the requested buffer
181 	  size. This works well for buffers up to a few hundreds kilobytes, but
182 	  for larger buffers it just a waste of address space. Drivers which has
183 	  relatively small addressing window (like 64Mib) might run out of
184 	  virtual space with just a few allocations.
185 
186 	  With this parameter you can specify the maximum PAGE_SIZE order for
187 	  DMA IOMMU buffers. Larger buffers will be aligned only to this
188 	  specified order. The order is expressed as a power of two multiplied
189 	  by the PAGE_SIZE.
190 
191 endif
192 
193 config SYS_SUPPORTS_APM_EMULATION
194 	bool
195 
196 config HAVE_TCM
197 	bool
198 	select GENERIC_ALLOCATOR
199 
200 config HAVE_PROC_CPU
201 	bool
202 
203 config NO_IOPORT_MAP
204 	bool
205 
206 config SBUS
207 	bool
208 
209 config STACKTRACE_SUPPORT
210 	bool
211 	default y
212 
213 config LOCKDEP_SUPPORT
214 	bool
215 	default y
216 
217 config ARCH_HAS_ILOG2_U32
218 	bool
219 
220 config ARCH_HAS_ILOG2_U64
221 	bool
222 
223 config ARCH_HAS_BANDGAP
224 	bool
225 
226 config FIX_EARLYCON_MEM
227 	def_bool y if MMU
228 
229 config GENERIC_HWEIGHT
230 	bool
231 	default y
232 
233 config GENERIC_CALIBRATE_DELAY
234 	bool
235 	default y
236 
237 config ARCH_MAY_HAVE_PC_FDC
238 	bool
239 
240 config ARCH_SUPPORTS_UPROBES
241 	def_bool y
242 
243 config GENERIC_ISA_DMA
244 	bool
245 
246 config FIQ
247 	bool
248 
249 config ARCH_MTD_XIP
250 	bool
251 
252 config ARM_PATCH_PHYS_VIRT
253 	bool "Patch physical to virtual translations at runtime" if !ARCH_MULTIPLATFORM
254 	default y
255 	depends on MMU
256 	help
257 	  Patch phys-to-virt and virt-to-phys translation functions at
258 	  boot and module load time according to the position of the
259 	  kernel in system memory.
260 
261 	  This can only be used with non-XIP MMU kernels where the base
262 	  of physical memory is at a 2 MiB boundary.
263 
264 	  Only disable this option if you know that you do not require
265 	  this feature (eg, building a kernel for a single machine) and
266 	  you need to shrink the kernel to the minimal size.
267 
268 config NEED_MACH_IO_H
269 	bool
270 	help
271 	  Select this when mach/io.h is required to provide special
272 	  definitions for this platform.  The need for mach/io.h should
273 	  be avoided when possible.
274 
275 config NEED_MACH_MEMORY_H
276 	bool
277 	help
278 	  Select this when mach/memory.h is required to provide special
279 	  definitions for this platform.  The need for mach/memory.h should
280 	  be avoided when possible.
281 
282 config PHYS_OFFSET
283 	hex "Physical address of main memory" if MMU
284 	depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
285 	default DRAM_BASE if !MMU
286 	default 0x00000000 if ARCH_FOOTBRIDGE
287 	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
288 	default 0xa0000000 if ARCH_PXA
289 	default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
290 	default 0
291 	help
292 	  Please provide the physical address corresponding to the
293 	  location of main memory in your system.
294 
295 config GENERIC_BUG
296 	def_bool y
297 	depends on BUG
298 
299 config PGTABLE_LEVELS
300 	int
301 	default 3 if ARM_LPAE
302 	default 2
303 
304 menu "System Type"
305 
306 config MMU
307 	bool "MMU-based Paged Memory Management Support"
308 	default y
309 	help
310 	  Select if you want MMU-based virtualised addressing space
311 	  support by paged memory management. If unsure, say 'Y'.
312 
313 config ARM_SINGLE_ARMV7M
314 	def_bool !MMU
315 	select ARM_NVIC
316 	select CPU_V7M
317 	select NO_IOPORT_MAP
318 
319 config ARCH_MMAP_RND_BITS_MIN
320 	default 8
321 
322 config ARCH_MMAP_RND_BITS_MAX
323 	default 14 if PAGE_OFFSET=0x40000000
324 	default 15 if PAGE_OFFSET=0x80000000
325 	default 16
326 
327 config ARCH_MULTIPLATFORM
328 	bool "Require kernel to be portable to multiple machines" if EXPERT
329 	depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
330 	default y
331 	help
332 	  In general, all Arm machines can be supported in a single
333 	  kernel image, covering either Armv4/v5 or Armv6/v7.
334 
335 	  However, some configuration options require hardcoding machine
336 	  specific physical addresses or enable errata workarounds that may
337 	  break other machines.
338 
339 	  Selecting N here allows using those options, including
340 	  DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
341 
342 menu "Platform selection"
343 	depends on MMU
344 
345 comment "CPU Core family selection"
346 
347 config ARCH_MULTI_V4
348 	bool "ARMv4 based platforms (FA526, StrongARM)"
349 	depends on !ARCH_MULTI_V6_V7
350 	# https://github.com/llvm/llvm-project/issues/50764
351 	depends on !LD_IS_LLD || LLD_VERSION >= 160000
352 	select ARCH_MULTI_V4_V5
353 	select CPU_FA526 if !(CPU_SA110 || CPU_SA1100)
354 
355 config ARCH_MULTI_V4T
356 	bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
357 	depends on !ARCH_MULTI_V6_V7
358 	# https://github.com/llvm/llvm-project/issues/50764
359 	depends on !LD_IS_LLD || LLD_VERSION >= 160000
360 	select ARCH_MULTI_V4_V5
361 	select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
362 		CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
363 		CPU_ARM925T || CPU_ARM940T)
364 
365 config ARCH_MULTI_V5
366 	bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
367 	depends on !ARCH_MULTI_V6_V7
368 	select ARCH_MULTI_V4_V5
369 	select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
370 		CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
371 		CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
372 
373 config ARCH_MULTI_V4_V5
374 	bool
375 
376 config ARCH_MULTI_V6
377 	bool "ARMv6 based platforms (ARM11)"
378 	select ARCH_MULTI_V6_V7
379 	select CPU_V6K
380 
381 config ARCH_MULTI_V7
382 	bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
383 	default y
384 	select ARCH_MULTI_V6_V7
385 	select CPU_V7
386 	select HAVE_SMP
387 
388 config ARCH_MULTI_V6_V7
389 	bool
390 	select MIGHT_HAVE_CACHE_L2X0
391 
392 config ARCH_MULTI_CPU_AUTO
393 	def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
394 	select ARCH_MULTI_V5
395 
396 endmenu
397 
398 config ARCH_VIRT
399 	bool "Dummy Virtual Machine"
400 	depends on ARCH_MULTI_V7
401 	select ARM_AMBA
402 	select ARM_GIC
403 	select ARM_GIC_V2M if PCI
404 	select ARM_GIC_V3
405 	select ARM_GIC_V3_ITS if PCI
406 	select ARM_PSCI
407 	select HAVE_ARM_ARCH_TIMER
408 
409 config ARCH_AIROHA
410 	bool "Airoha SoC Support"
411 	depends on ARCH_MULTI_V7
412 	select ARM_AMBA
413 	select ARM_GIC
414 	select ARM_GIC_V3
415 	select ARM_PSCI
416 	select HAVE_ARM_ARCH_TIMER
417 	help
418 	  Support for Airoha EN7523 SoCs
419 
420 #
421 # This is sorted alphabetically by mach-* pathname.  However, plat-*
422 # Kconfigs may be included either alphabetically (according to the
423 # plat- suffix) or along side the corresponding mach-* source.
424 #
425 source "arch/arm/mach-actions/Kconfig"
426 
427 source "arch/arm/mach-alpine/Kconfig"
428 
429 source "arch/arm/mach-artpec/Kconfig"
430 
431 source "arch/arm/mach-asm9260/Kconfig"
432 
433 source "arch/arm/mach-aspeed/Kconfig"
434 
435 source "arch/arm/mach-at91/Kconfig"
436 
437 source "arch/arm/mach-axxia/Kconfig"
438 
439 source "arch/arm/mach-bcm/Kconfig"
440 
441 source "arch/arm/mach-berlin/Kconfig"
442 
443 source "arch/arm/mach-clps711x/Kconfig"
444 
445 source "arch/arm/mach-davinci/Kconfig"
446 
447 source "arch/arm/mach-digicolor/Kconfig"
448 
449 source "arch/arm/mach-dove/Kconfig"
450 
451 source "arch/arm/mach-ep93xx/Kconfig"
452 
453 source "arch/arm/mach-exynos/Kconfig"
454 
455 source "arch/arm/mach-footbridge/Kconfig"
456 
457 source "arch/arm/mach-gemini/Kconfig"
458 
459 source "arch/arm/mach-highbank/Kconfig"
460 
461 source "arch/arm/mach-hisi/Kconfig"
462 
463 source "arch/arm/mach-hpe/Kconfig"
464 
465 source "arch/arm/mach-imx/Kconfig"
466 
467 source "arch/arm/mach-ixp4xx/Kconfig"
468 
469 source "arch/arm/mach-keystone/Kconfig"
470 
471 source "arch/arm/mach-lpc32xx/Kconfig"
472 
473 source "arch/arm/mach-mediatek/Kconfig"
474 
475 source "arch/arm/mach-meson/Kconfig"
476 
477 source "arch/arm/mach-milbeaut/Kconfig"
478 
479 source "arch/arm/mach-mmp/Kconfig"
480 
481 source "arch/arm/mach-moxart/Kconfig"
482 
483 source "arch/arm/mach-mstar/Kconfig"
484 
485 source "arch/arm/mach-mv78xx0/Kconfig"
486 
487 source "arch/arm/mach-mvebu/Kconfig"
488 
489 source "arch/arm/mach-mxs/Kconfig"
490 
491 source "arch/arm/mach-nomadik/Kconfig"
492 
493 source "arch/arm/mach-npcm/Kconfig"
494 
495 source "arch/arm/mach-nspire/Kconfig"
496 
497 source "arch/arm/mach-omap1/Kconfig"
498 
499 source "arch/arm/mach-omap2/Kconfig"
500 
501 source "arch/arm/mach-orion5x/Kconfig"
502 
503 source "arch/arm/mach-pxa/Kconfig"
504 
505 source "arch/arm/mach-qcom/Kconfig"
506 
507 source "arch/arm/mach-rda/Kconfig"
508 
509 source "arch/arm/mach-realtek/Kconfig"
510 
511 source "arch/arm/mach-rpc/Kconfig"
512 
513 source "arch/arm/mach-rockchip/Kconfig"
514 
515 source "arch/arm/mach-s3c/Kconfig"
516 
517 source "arch/arm/mach-s5pv210/Kconfig"
518 
519 source "arch/arm/mach-sa1100/Kconfig"
520 
521 source "arch/arm/mach-shmobile/Kconfig"
522 
523 source "arch/arm/mach-socfpga/Kconfig"
524 
525 source "arch/arm/mach-spear/Kconfig"
526 
527 source "arch/arm/mach-sti/Kconfig"
528 
529 source "arch/arm/mach-stm32/Kconfig"
530 
531 source "arch/arm/mach-sunplus/Kconfig"
532 
533 source "arch/arm/mach-sunxi/Kconfig"
534 
535 source "arch/arm/mach-tegra/Kconfig"
536 
537 source "arch/arm/mach-uniphier/Kconfig"
538 
539 source "arch/arm/mach-ux500/Kconfig"
540 
541 source "arch/arm/mach-versatile/Kconfig"
542 
543 source "arch/arm/mach-vt8500/Kconfig"
544 
545 source "arch/arm/mach-zynq/Kconfig"
546 
547 # ARMv7-M architecture
548 config ARCH_LPC18XX
549 	bool "NXP LPC18xx/LPC43xx"
550 	depends on ARM_SINGLE_ARMV7M
551 	select ARCH_HAS_RESET_CONTROLLER
552 	select ARM_AMBA
553 	select CLKSRC_LPC32XX
554 	select PINCTRL
555 	help
556 	  Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
557 	  high performance microcontrollers.
558 
559 config ARCH_MPS2
560 	bool "ARM MPS2 platform"
561 	depends on ARM_SINGLE_ARMV7M
562 	select ARM_AMBA
563 	select CLKSRC_MPS2
564 	help
565 	  Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
566 	  with a range of available cores like Cortex-M3/M4/M7.
567 
568 	  Please, note that depends which Application Note is used memory map
569 	  for the platform may vary, so adjustment of RAM base might be needed.
570 
571 # Definitions to make life easier
572 config ARCH_ACORN
573 	bool
574 
575 config PLAT_ORION
576 	bool
577 	select CLKSRC_MMIO
578 	select GENERIC_IRQ_CHIP
579 	select IRQ_DOMAIN
580 
581 config PLAT_ORION_LEGACY
582 	bool
583 	select PLAT_ORION
584 
585 config PLAT_VERSATILE
586 	bool
587 
588 source "arch/arm/mm/Kconfig"
589 
590 config IWMMXT
591 	bool "Enable iWMMXt support"
592 	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
593 	default y if PXA27x || PXA3xx || ARCH_MMP
594 	help
595 	  Enable support for iWMMXt context switching at run time if
596 	  running on a CPU that supports it.
597 
598 if !MMU
599 source "arch/arm/Kconfig-nommu"
600 endif
601 
602 config PJ4B_ERRATA_4742
603 	bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
604 	depends on CPU_PJ4B && MACH_ARMADA_370
605 	default y
606 	help
607 	  When coming out of either a Wait for Interrupt (WFI) or a Wait for
608 	  Event (WFE) IDLE states, a specific timing sensitivity exists between
609 	  the retiring WFI/WFE instructions and the newly issued subsequent
610 	  instructions.  This sensitivity can result in a CPU hang scenario.
611 	  Workaround:
612 	  The software must insert either a Data Synchronization Barrier (DSB)
613 	  or Data Memory Barrier (DMB) command immediately after the WFI/WFE
614 	  instruction
615 
616 config ARM_ERRATA_326103
617 	bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
618 	depends on CPU_V6
619 	help
620 	  Executing a SWP instruction to read-only memory does not set bit 11
621 	  of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
622 	  treat the access as a read, preventing a COW from occurring and
623 	  causing the faulting task to livelock.
624 
625 config ARM_ERRATA_411920
626 	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
627 	depends on CPU_V6 || CPU_V6K
628 	help
629 	  Invalidation of the Instruction Cache operation can
630 	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
631 	  It does not affect the MPCore. This option enables the ARM Ltd.
632 	  recommended workaround.
633 
634 config ARM_ERRATA_430973
635 	bool "ARM errata: Stale prediction on replaced interworking branch"
636 	depends on CPU_V7
637 	help
638 	  This option enables the workaround for the 430973 Cortex-A8
639 	  r1p* erratum. If a code sequence containing an ARM/Thumb
640 	  interworking branch is replaced with another code sequence at the
641 	  same virtual address, whether due to self-modifying code or virtual
642 	  to physical address re-mapping, Cortex-A8 does not recover from the
643 	  stale interworking branch prediction. This results in Cortex-A8
644 	  executing the new code sequence in the incorrect ARM or Thumb state.
645 	  The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
646 	  and also flushes the branch target cache at every context switch.
647 	  Note that setting specific bits in the ACTLR register may not be
648 	  available in non-secure mode.
649 
650 config ARM_ERRATA_458693
651 	bool "ARM errata: Processor deadlock when a false hazard is created"
652 	depends on CPU_V7
653 	depends on !ARCH_MULTIPLATFORM
654 	help
655 	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
656 	  erratum. For very specific sequences of memory operations, it is
657 	  possible for a hazard condition intended for a cache line to instead
658 	  be incorrectly associated with a different cache line. This false
659 	  hazard might then cause a processor deadlock. The workaround enables
660 	  the L1 caching of the NEON accesses and disables the PLD instruction
661 	  in the ACTLR register. Note that setting specific bits in the ACTLR
662 	  register may not be available in non-secure mode and thus is not
663 	  available on a multiplatform kernel. This should be applied by the
664 	  bootloader instead.
665 
666 config ARM_ERRATA_460075
667 	bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
668 	depends on CPU_V7
669 	depends on !ARCH_MULTIPLATFORM
670 	help
671 	  This option enables the workaround for the 460075 Cortex-A8 (r2p0)
672 	  erratum. Any asynchronous access to the L2 cache may encounter a
673 	  situation in which recent store transactions to the L2 cache are lost
674 	  and overwritten with stale memory contents from external memory. The
675 	  workaround disables the write-allocate mode for the L2 cache via the
676 	  ACTLR register. Note that setting specific bits in the ACTLR register
677 	  may not be available in non-secure mode and thus is not available on
678 	  a multiplatform kernel. This should be applied by the bootloader
679 	  instead.
680 
681 config ARM_ERRATA_742230
682 	bool "ARM errata: DMB operation may be faulty"
683 	depends on CPU_V7 && SMP
684 	depends on !ARCH_MULTIPLATFORM
685 	help
686 	  This option enables the workaround for the 742230 Cortex-A9
687 	  (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
688 	  between two write operations may not ensure the correct visibility
689 	  ordering of the two writes. This workaround sets a specific bit in
690 	  the diagnostic register of the Cortex-A9 which causes the DMB
691 	  instruction to behave as a DSB, ensuring the correct behaviour of
692 	  the two writes. Note that setting specific bits in the diagnostics
693 	  register may not be available in non-secure mode and thus is not
694 	  available on a multiplatform kernel. This should be applied by the
695 	  bootloader instead.
696 
697 config ARM_ERRATA_742231
698 	bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
699 	depends on CPU_V7 && SMP
700 	depends on !ARCH_MULTIPLATFORM
701 	help
702 	  This option enables the workaround for the 742231 Cortex-A9
703 	  (r2p0..r2p2) erratum. Under certain conditions, specific to the
704 	  Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
705 	  accessing some data located in the same cache line, may get corrupted
706 	  data due to bad handling of the address hazard when the line gets
707 	  replaced from one of the CPUs at the same time as another CPU is
708 	  accessing it. This workaround sets specific bits in the diagnostic
709 	  register of the Cortex-A9 which reduces the linefill issuing
710 	  capabilities of the processor. Note that setting specific bits in the
711 	  diagnostics register may not be available in non-secure mode and thus
712 	  is not available on a multiplatform kernel. This should be applied by
713 	  the bootloader instead.
714 
715 config ARM_ERRATA_643719
716 	bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
717 	depends on CPU_V7 && SMP
718 	default y
719 	help
720 	  This option enables the workaround for the 643719 Cortex-A9 (prior to
721 	  r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
722 	  register returns zero when it should return one. The workaround
723 	  corrects this value, ensuring cache maintenance operations which use
724 	  it behave as intended and avoiding data corruption.
725 
726 config ARM_ERRATA_720789
727 	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
728 	depends on CPU_V7
729 	help
730 	  This option enables the workaround for the 720789 Cortex-A9 (prior to
731 	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
732 	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
733 	  As a consequence of this erratum, some TLB entries which should be
734 	  invalidated are not, resulting in an incoherency in the system page
735 	  tables. The workaround changes the TLB flushing routines to invalidate
736 	  entries regardless of the ASID.
737 
738 config ARM_ERRATA_743622
739 	bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
740 	depends on CPU_V7
741 	depends on !ARCH_MULTIPLATFORM
742 	help
743 	  This option enables the workaround for the 743622 Cortex-A9
744 	  (r2p*) erratum. Under very rare conditions, a faulty
745 	  optimisation in the Cortex-A9 Store Buffer may lead to data
746 	  corruption. This workaround sets a specific bit in the diagnostic
747 	  register of the Cortex-A9 which disables the Store Buffer
748 	  optimisation, preventing the defect from occurring. This has no
749 	  visible impact on the overall performance or power consumption of the
750 	  processor. Note that setting specific bits in the diagnostics register
751 	  may not be available in non-secure mode and thus is not available on a
752 	  multiplatform kernel. This should be applied by the bootloader instead.
753 
754 config ARM_ERRATA_751472
755 	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
756 	depends on CPU_V7
757 	depends on !ARCH_MULTIPLATFORM
758 	help
759 	  This option enables the workaround for the 751472 Cortex-A9 (prior
760 	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
761 	  completion of a following broadcasted operation if the second
762 	  operation is received by a CPU before the ICIALLUIS has completed,
763 	  potentially leading to corrupted entries in the cache or TLB.
764 	  Note that setting specific bits in the diagnostics register may
765 	  not be available in non-secure mode and thus is not available on
766 	  a multiplatform kernel. This should be applied by the bootloader
767 	  instead.
768 
769 config ARM_ERRATA_754322
770 	bool "ARM errata: possible faulty MMU translations following an ASID switch"
771 	depends on CPU_V7
772 	help
773 	  This option enables the workaround for the 754322 Cortex-A9 (r2p*,
774 	  r3p*) erratum. A speculative memory access may cause a page table walk
775 	  which starts prior to an ASID switch but completes afterwards. This
776 	  can populate the micro-TLB with a stale entry which may be hit with
777 	  the new ASID. This workaround places two dsb instructions in the mm
778 	  switching code so that no page table walks can cross the ASID switch.
779 
780 config ARM_ERRATA_754327
781 	bool "ARM errata: no automatic Store Buffer drain"
782 	depends on CPU_V7 && SMP
783 	help
784 	  This option enables the workaround for the 754327 Cortex-A9 (prior to
785 	  r2p0) erratum. The Store Buffer does not have any automatic draining
786 	  mechanism and therefore a livelock may occur if an external agent
787 	  continuously polls a memory location waiting to observe an update.
788 	  This workaround defines cpu_relax() as smp_mb(), preventing correctly
789 	  written polling loops from denying visibility of updates to memory.
790 
791 config ARM_ERRATA_364296
792 	bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
793 	depends on CPU_V6
794 	help
795 	  This options enables the workaround for the 364296 ARM1136
796 	  r0p2 erratum (possible cache data corruption with
797 	  hit-under-miss enabled). It sets the undocumented bit 31 in
798 	  the auxiliary control register and the FI bit in the control
799 	  register, thus disabling hit-under-miss without putting the
800 	  processor into full low interrupt latency mode. ARM11MPCore
801 	  is not affected.
802 
803 config ARM_ERRATA_764369
804 	bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
805 	depends on CPU_V7 && SMP
806 	help
807 	  This option enables the workaround for erratum 764369
808 	  affecting Cortex-A9 MPCore with two or more processors (all
809 	  current revisions). Under certain timing circumstances, a data
810 	  cache line maintenance operation by MVA targeting an Inner
811 	  Shareable memory region may fail to proceed up to either the
812 	  Point of Coherency or to the Point of Unification of the
813 	  system. This workaround adds a DSB instruction before the
814 	  relevant cache maintenance functions and sets a specific bit
815 	  in the diagnostic control register of the SCU.
816 
817 config ARM_ERRATA_764319
818 	bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
819 	depends on CPU_V7
820 	help
821 	  This option enables the workaround for the 764319 Cortex A-9 erratum.
822 	  CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
823 	  unexpected Undefined Instruction exception when the DBGSWENABLE
824 	  external pin is set to 0, even when the CP14 accesses are performed
825 	  from a privileged mode. This work around catches the exception in a
826 	  way the kernel does not stop execution.
827 
828 config ARM_ERRATA_775420
829        bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
830        depends on CPU_V7
831        help
832 	 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
833 	 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
834 	 operation aborts with MMU exception, it might cause the processor
835 	 to deadlock. This workaround puts DSB before executing ISB if
836 	 an abort may occur on cache maintenance.
837 
838 config ARM_ERRATA_798181
839 	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
840 	depends on CPU_V7 && SMP
841 	help
842 	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
843 	  adequately shooting down all use of the old entries. This
844 	  option enables the Linux kernel workaround for this erratum
845 	  which sends an IPI to the CPUs that are running the same ASID
846 	  as the one being invalidated.
847 
848 config ARM_ERRATA_773022
849 	bool "ARM errata: incorrect instructions may be executed from loop buffer"
850 	depends on CPU_V7
851 	help
852 	  This option enables the workaround for the 773022 Cortex-A15
853 	  (up to r0p4) erratum. In certain rare sequences of code, the
854 	  loop buffer may deliver incorrect instructions. This
855 	  workaround disables the loop buffer to avoid the erratum.
856 
857 config ARM_ERRATA_818325_852422
858 	bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
859 	depends on CPU_V7
860 	help
861 	  This option enables the workaround for:
862 	  - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
863 	    instruction might deadlock.  Fixed in r0p1.
864 	  - Cortex-A12 852422: Execution of a sequence of instructions might
865 	    lead to either a data corruption or a CPU deadlock.  Not fixed in
866 	    any Cortex-A12 cores yet.
867 	  This workaround for all both errata involves setting bit[12] of the
868 	  Feature Register. This bit disables an optimisation applied to a
869 	  sequence of 2 instructions that use opposing condition codes.
870 
871 config ARM_ERRATA_821420
872 	bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
873 	depends on CPU_V7
874 	help
875 	  This option enables the workaround for the 821420 Cortex-A12
876 	  (all revs) erratum. In very rare timing conditions, a sequence
877 	  of VMOV to Core registers instructions, for which the second
878 	  one is in the shadow of a branch or abort, can lead to a
879 	  deadlock when the VMOV instructions are issued out-of-order.
880 
881 config ARM_ERRATA_825619
882 	bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
883 	depends on CPU_V7
884 	help
885 	  This option enables the workaround for the 825619 Cortex-A12
886 	  (all revs) erratum. Within rare timing constraints, executing a
887 	  DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
888 	  and Device/Strongly-Ordered loads and stores might cause deadlock
889 
890 config ARM_ERRATA_857271
891 	bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
892 	depends on CPU_V7
893 	help
894 	  This option enables the workaround for the 857271 Cortex-A12
895 	  (all revs) erratum. Under very rare timing conditions, the CPU might
896 	  hang. The workaround is expected to have a < 1% performance impact.
897 
898 config ARM_ERRATA_852421
899 	bool "ARM errata: A17: DMB ST might fail to create order between stores"
900 	depends on CPU_V7
901 	help
902 	  This option enables the workaround for the 852421 Cortex-A17
903 	  (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
904 	  execution of a DMB ST instruction might fail to properly order
905 	  stores from GroupA and stores from GroupB.
906 
907 config ARM_ERRATA_852423
908 	bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
909 	depends on CPU_V7
910 	help
911 	  This option enables the workaround for:
912 	  - Cortex-A17 852423: Execution of a sequence of instructions might
913 	    lead to either a data corruption or a CPU deadlock.  Not fixed in
914 	    any Cortex-A17 cores yet.
915 	  This is identical to Cortex-A12 erratum 852422.  It is a separate
916 	  config option from the A12 erratum due to the way errata are checked
917 	  for and handled.
918 
919 config ARM_ERRATA_857272
920 	bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
921 	depends on CPU_V7
922 	help
923 	  This option enables the workaround for the 857272 Cortex-A17 erratum.
924 	  This erratum is not known to be fixed in any A17 revision.
925 	  This is identical to Cortex-A12 erratum 857271.  It is a separate
926 	  config option from the A12 erratum due to the way errata are checked
927 	  for and handled.
928 
929 endmenu
930 
931 source "arch/arm/common/Kconfig"
932 
933 menu "Bus support"
934 
935 config ISA
936 	bool
937 	help
938 	  Find out whether you have ISA slots on your motherboard.  ISA is the
939 	  name of a bus system, i.e. the way the CPU talks to the other stuff
940 	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
941 	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
942 	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
943 
944 # Select ISA DMA interface
945 config ISA_DMA_API
946 	bool
947 
948 config ARM_ERRATA_814220
949 	bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
950 	depends on CPU_V7
951 	help
952 	  The v7 ARM states that all cache and branch predictor maintenance
953 	  operations that do not specify an address execute, relative to
954 	  each other, in program order.
955 	  However, because of this erratum, an L2 set/way cache maintenance
956 	  operation can overtake an L1 set/way cache maintenance operation.
957 	  This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
958 	  r0p4, r0p5.
959 
960 endmenu
961 
962 menu "Kernel Features"
963 
964 config HAVE_SMP
965 	bool
966 	help
967 	  This option should be selected by machines which have an SMP-
968 	  capable CPU.
969 
970 	  The only effect of this option is to make the SMP-related
971 	  options available to the user for configuration.
972 
973 config SMP
974 	bool "Symmetric Multi-Processing"
975 	depends on CPU_V6K || CPU_V7
976 	depends on HAVE_SMP
977 	depends on MMU || ARM_MPU
978 	select IRQ_WORK
979 	help
980 	  This enables support for systems with more than one CPU. If you have
981 	  a system with only one CPU, say N. If you have a system with more
982 	  than one CPU, say Y.
983 
984 	  If you say N here, the kernel will run on uni- and multiprocessor
985 	  machines, but will use only one CPU of a multiprocessor machine. If
986 	  you say Y here, the kernel will run on many, but not all,
987 	  uniprocessor machines. On a uniprocessor machine, the kernel
988 	  will run faster if you say N here.
989 
990 	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
991 	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
992 	  <http://tldp.org/HOWTO/SMP-HOWTO.html>.
993 
994 	  If you don't know what to do here, say N.
995 
996 config SMP_ON_UP
997 	bool "Allow booting SMP kernel on uniprocessor systems"
998 	depends on SMP && MMU
999 	default y
1000 	help
1001 	  SMP kernels contain instructions which fail on non-SMP processors.
1002 	  Enabling this option allows the kernel to modify itself to make
1003 	  these instructions safe.  Disabling it allows about 1K of space
1004 	  savings.
1005 
1006 	  If you don't know what to do here, say Y.
1007 
1008 
1009 config CURRENT_POINTER_IN_TPIDRURO
1010 	def_bool y
1011 	depends on CPU_32v6K && !CPU_V6
1012 
1013 config IRQSTACKS
1014 	def_bool y
1015 	select HAVE_IRQ_EXIT_ON_IRQ_STACK
1016 	select HAVE_SOFTIRQ_ON_OWN_STACK
1017 
1018 config ARM_CPU_TOPOLOGY
1019 	bool "Support cpu topology definition"
1020 	depends on SMP && CPU_V7
1021 	default y
1022 	help
1023 	  Support ARM cpu topology definition. The MPIDR register defines
1024 	  affinity between processors which is then used to describe the cpu
1025 	  topology of an ARM System.
1026 
1027 config SCHED_MC
1028 	bool "Multi-core scheduler support"
1029 	depends on ARM_CPU_TOPOLOGY
1030 	help
1031 	  Multi-core scheduler support improves the CPU scheduler's decision
1032 	  making when dealing with multi-core CPU chips at a cost of slightly
1033 	  increased overhead in some places. If unsure say N here.
1034 
1035 config SCHED_SMT
1036 	bool "SMT scheduler support"
1037 	depends on ARM_CPU_TOPOLOGY
1038 	help
1039 	  Improves the CPU scheduler's decision making when dealing with
1040 	  MultiThreading at a cost of slightly increased overhead in some
1041 	  places. If unsure say N here.
1042 
1043 config HAVE_ARM_SCU
1044 	bool
1045 	help
1046 	  This option enables support for the ARM snoop control unit
1047 
1048 config HAVE_ARM_ARCH_TIMER
1049 	bool "Architected timer support"
1050 	depends on CPU_V7
1051 	select ARM_ARCH_TIMER
1052 	help
1053 	  This option enables support for the ARM architected timer
1054 
1055 config HAVE_ARM_TWD
1056 	bool
1057 	help
1058 	  This options enables support for the ARM timer and watchdog unit
1059 
1060 config MCPM
1061 	bool "Multi-Cluster Power Management"
1062 	depends on CPU_V7 && SMP
1063 	help
1064 	  This option provides the common power management infrastructure
1065 	  for (multi-)cluster based systems, such as big.LITTLE based
1066 	  systems.
1067 
1068 config MCPM_QUAD_CLUSTER
1069 	bool
1070 	depends on MCPM
1071 	help
1072 	  To avoid wasting resources unnecessarily, MCPM only supports up
1073 	  to 2 clusters by default.
1074 	  Platforms with 3 or 4 clusters that use MCPM must select this
1075 	  option to allow the additional clusters to be managed.
1076 
1077 config BIG_LITTLE
1078 	bool "big.LITTLE support (Experimental)"
1079 	depends on CPU_V7 && SMP
1080 	select MCPM
1081 	help
1082 	  This option enables support selections for the big.LITTLE
1083 	  system architecture.
1084 
1085 config BL_SWITCHER
1086 	bool "big.LITTLE switcher support"
1087 	depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1088 	select CPU_PM
1089 	help
1090 	  The big.LITTLE "switcher" provides the core functionality to
1091 	  transparently handle transition between a cluster of A15's
1092 	  and a cluster of A7's in a big.LITTLE system.
1093 
1094 config BL_SWITCHER_DUMMY_IF
1095 	tristate "Simple big.LITTLE switcher user interface"
1096 	depends on BL_SWITCHER && DEBUG_KERNEL
1097 	help
1098 	  This is a simple and dummy char dev interface to control
1099 	  the big.LITTLE switcher core code.  It is meant for
1100 	  debugging purposes only.
1101 
1102 choice
1103 	prompt "Memory split"
1104 	depends on MMU
1105 	default VMSPLIT_3G
1106 	help
1107 	  Select the desired split between kernel and user memory.
1108 
1109 	  If you are not absolutely sure what you are doing, leave this
1110 	  option alone!
1111 
1112 	config VMSPLIT_3G
1113 		bool "3G/1G user/kernel split"
1114 	config VMSPLIT_3G_OPT
1115 		depends on !ARM_LPAE
1116 		bool "3G/1G user/kernel split (for full 1G low memory)"
1117 	config VMSPLIT_2G
1118 		bool "2G/2G user/kernel split"
1119 	config VMSPLIT_1G
1120 		bool "1G/3G user/kernel split"
1121 endchoice
1122 
1123 config PAGE_OFFSET
1124 	hex
1125 	default PHYS_OFFSET if !MMU
1126 	default 0x40000000 if VMSPLIT_1G
1127 	default 0x80000000 if VMSPLIT_2G
1128 	default 0xB0000000 if VMSPLIT_3G_OPT
1129 	default 0xC0000000
1130 
1131 config KASAN_SHADOW_OFFSET
1132 	hex
1133 	depends on KASAN
1134 	default 0x1f000000 if PAGE_OFFSET=0x40000000
1135 	default 0x5f000000 if PAGE_OFFSET=0x80000000
1136 	default 0x9f000000 if PAGE_OFFSET=0xC0000000
1137 	default 0x8f000000 if PAGE_OFFSET=0xB0000000
1138 	default 0xffffffff
1139 
1140 config NR_CPUS
1141 	int "Maximum number of CPUs (2-32)"
1142 	range 2 16 if DEBUG_KMAP_LOCAL
1143 	range 2 32 if !DEBUG_KMAP_LOCAL
1144 	depends on SMP
1145 	default "4"
1146 	help
1147 	  The maximum number of CPUs that the kernel can support.
1148 	  Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1149 	  debugging is enabled, which uses half of the per-CPU fixmap
1150 	  slots as guard regions.
1151 
1152 config HOTPLUG_CPU
1153 	bool "Support for hot-pluggable CPUs"
1154 	depends on SMP
1155 	select GENERIC_IRQ_MIGRATION
1156 	help
1157 	  Say Y here to experiment with turning CPUs off and on.  CPUs
1158 	  can be controlled through /sys/devices/system/cpu.
1159 
1160 config ARM_PSCI
1161 	bool "Support for the ARM Power State Coordination Interface (PSCI)"
1162 	depends on HAVE_ARM_SMCCC
1163 	select ARM_PSCI_FW
1164 	help
1165 	  Say Y here if you want Linux to communicate with system firmware
1166 	  implementing the PSCI specification for CPU-centric power
1167 	  management operations described in ARM document number ARM DEN
1168 	  0022A ("Power State Coordination Interface System Software on
1169 	  ARM processors").
1170 
1171 config HZ_FIXED
1172 	int
1173 	default 128 if SOC_AT91RM9200
1174 	default 0
1175 
1176 choice
1177 	depends on HZ_FIXED = 0
1178 	prompt "Timer frequency"
1179 
1180 config HZ_100
1181 	bool "100 Hz"
1182 
1183 config HZ_200
1184 	bool "200 Hz"
1185 
1186 config HZ_250
1187 	bool "250 Hz"
1188 
1189 config HZ_300
1190 	bool "300 Hz"
1191 
1192 config HZ_500
1193 	bool "500 Hz"
1194 
1195 config HZ_1000
1196 	bool "1000 Hz"
1197 
1198 endchoice
1199 
1200 config HZ
1201 	int
1202 	default HZ_FIXED if HZ_FIXED != 0
1203 	default 100 if HZ_100
1204 	default 200 if HZ_200
1205 	default 250 if HZ_250
1206 	default 300 if HZ_300
1207 	default 500 if HZ_500
1208 	default 1000
1209 
1210 config SCHED_HRTICK
1211 	def_bool HIGH_RES_TIMERS
1212 
1213 config THUMB2_KERNEL
1214 	bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1215 	depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1216 	default y if CPU_THUMBONLY
1217 	select ARM_UNWIND
1218 	help
1219 	  By enabling this option, the kernel will be compiled in
1220 	  Thumb-2 mode.
1221 
1222 	  If unsure, say N.
1223 
1224 config ARM_PATCH_IDIV
1225 	bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1226 	depends on CPU_32v7
1227 	default y
1228 	help
1229 	  The ARM compiler inserts calls to __aeabi_idiv() and
1230 	  __aeabi_uidiv() when it needs to perform division on signed
1231 	  and unsigned integers. Some v7 CPUs have support for the sdiv
1232 	  and udiv instructions that can be used to implement those
1233 	  functions.
1234 
1235 	  Enabling this option allows the kernel to modify itself to
1236 	  replace the first two instructions of these library functions
1237 	  with the sdiv or udiv plus "bx lr" instructions when the CPU
1238 	  it is running on supports them. Typically this will be faster
1239 	  and less power intensive than running the original library
1240 	  code to do integer division.
1241 
1242 config AEABI
1243 	bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1244 		!CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1245 	default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1246 	help
1247 	  This option allows for the kernel to be compiled using the latest
1248 	  ARM ABI (aka EABI).  This is only useful if you are using a user
1249 	  space environment that is also compiled with EABI.
1250 
1251 	  Since there are major incompatibilities between the legacy ABI and
1252 	  EABI, especially with regard to structure member alignment, this
1253 	  option also changes the kernel syscall calling convention to
1254 	  disambiguate both ABIs and allow for backward compatibility support
1255 	  (selected with CONFIG_OABI_COMPAT).
1256 
1257 	  To use this you need GCC version 4.0.0 or later.
1258 
1259 config OABI_COMPAT
1260 	bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1261 	depends on AEABI && !THUMB2_KERNEL
1262 	help
1263 	  This option preserves the old syscall interface along with the
1264 	  new (ARM EABI) one. It also provides a compatibility layer to
1265 	  intercept syscalls that have structure arguments which layout
1266 	  in memory differs between the legacy ABI and the new ARM EABI
1267 	  (only for non "thumb" binaries). This option adds a tiny
1268 	  overhead to all syscalls and produces a slightly larger kernel.
1269 
1270 	  The seccomp filter system will not be available when this is
1271 	  selected, since there is no way yet to sensibly distinguish
1272 	  between calling conventions during filtering.
1273 
1274 	  If you know you'll be using only pure EABI user space then you
1275 	  can say N here. If this option is not selected and you attempt
1276 	  to execute a legacy ABI binary then the result will be
1277 	  UNPREDICTABLE (in fact it can be predicted that it won't work
1278 	  at all). If in doubt say N.
1279 
1280 config ARCH_SELECT_MEMORY_MODEL
1281 	def_bool y
1282 
1283 config ARCH_FLATMEM_ENABLE
1284 	def_bool !(ARCH_RPC || ARCH_SA1100)
1285 
1286 config ARCH_SPARSEMEM_ENABLE
1287 	def_bool !ARCH_FOOTBRIDGE
1288 	select SPARSEMEM_STATIC if SPARSEMEM
1289 
1290 config HIGHMEM
1291 	bool "High Memory Support"
1292 	depends on MMU
1293 	select KMAP_LOCAL
1294 	select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1295 	help
1296 	  The address space of ARM processors is only 4 Gigabytes large
1297 	  and it has to accommodate user address space, kernel address
1298 	  space as well as some memory mapped IO. That means that, if you
1299 	  have a large amount of physical memory and/or IO, not all of the
1300 	  memory can be "permanently mapped" by the kernel. The physical
1301 	  memory that is not permanently mapped is called "high memory".
1302 
1303 	  Depending on the selected kernel/user memory split, minimum
1304 	  vmalloc space and actual amount of RAM, you may not need this
1305 	  option which should result in a slightly faster kernel.
1306 
1307 	  If unsure, say n.
1308 
1309 config HIGHPTE
1310 	bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1311 	depends on HIGHMEM
1312 	default y
1313 	help
1314 	  The VM uses one page of physical memory for each page table.
1315 	  For systems with a lot of processes, this can use a lot of
1316 	  precious low memory, eventually leading to low memory being
1317 	  consumed by page tables.  Setting this option will allow
1318 	  user-space 2nd level page tables to reside in high memory.
1319 
1320 config CPU_SW_DOMAIN_PAN
1321 	bool "Enable use of CPU domains to implement privileged no-access"
1322 	depends on MMU && !ARM_LPAE
1323 	default y
1324 	help
1325 	  Increase kernel security by ensuring that normal kernel accesses
1326 	  are unable to access userspace addresses.  This can help prevent
1327 	  use-after-free bugs becoming an exploitable privilege escalation
1328 	  by ensuring that magic values (such as LIST_POISON) will always
1329 	  fault when dereferenced.
1330 
1331 	  CPUs with low-vector mappings use a best-efforts implementation.
1332 	  Their lower 1MB needs to remain accessible for the vectors, but
1333 	  the remainder of userspace will become appropriately inaccessible.
1334 
1335 config HW_PERF_EVENTS
1336 	def_bool y
1337 	depends on ARM_PMU
1338 
1339 config ARM_MODULE_PLTS
1340 	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1341 	depends on MODULES
1342 	select KASAN_VMALLOC if KASAN
1343 	default y
1344 	help
1345 	  Allocate PLTs when loading modules so that jumps and calls whose
1346 	  targets are too far away for their relative offsets to be encoded
1347 	  in the instructions themselves can be bounced via veneers in the
1348 	  module's PLT. This allows modules to be allocated in the generic
1349 	  vmalloc area after the dedicated module memory area has been
1350 	  exhausted. The modules will use slightly more memory, but after
1351 	  rounding up to page size, the actual memory footprint is usually
1352 	  the same.
1353 
1354 	  Disabling this is usually safe for small single-platform
1355 	  configurations. If unsure, say y.
1356 
1357 config ARCH_FORCE_MAX_ORDER
1358 	int "Order of maximal physically contiguous allocations"
1359 	default "11" if SOC_AM33XX
1360 	default "8" if SA1111
1361 	default "10"
1362 	help
1363 	  The kernel page allocator limits the size of maximal physically
1364 	  contiguous allocations. The limit is called MAX_ORDER and it
1365 	  defines the maximal power of two of number of pages that can be
1366 	  allocated as a single contiguous block. This option allows
1367 	  overriding the default setting when ability to allocate very
1368 	  large blocks of physically contiguous memory is required.
1369 
1370 	  Don't change if unsure.
1371 
1372 config ALIGNMENT_TRAP
1373 	def_bool CPU_CP15_MMU
1374 	select HAVE_PROC_CPU if PROC_FS
1375 	help
1376 	  ARM processors cannot fetch/store information which is not
1377 	  naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1378 	  address divisible by 4. On 32-bit ARM processors, these non-aligned
1379 	  fetch/store instructions will be emulated in software if you say
1380 	  here, which has a severe performance impact. This is necessary for
1381 	  correct operation of some network protocols. With an IP-only
1382 	  configuration it is safe to say N, otherwise say Y.
1383 
1384 config UACCESS_WITH_MEMCPY
1385 	bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1386 	depends on MMU
1387 	default y if CPU_FEROCEON
1388 	help
1389 	  Implement faster copy_to_user and clear_user methods for CPU
1390 	  cores where a 8-word STM instruction give significantly higher
1391 	  memory write throughput than a sequence of individual 32bit stores.
1392 
1393 	  A possible side effect is a slight increase in scheduling latency
1394 	  between threads sharing the same address space if they invoke
1395 	  such copy operations with large buffers.
1396 
1397 	  However, if the CPU data cache is using a write-allocate mode,
1398 	  this option is unlikely to provide any performance gain.
1399 
1400 config PARAVIRT
1401 	bool "Enable paravirtualization code"
1402 	help
1403 	  This changes the kernel so it can modify itself when it is run
1404 	  under a hypervisor, potentially improving performance significantly
1405 	  over full virtualization.
1406 
1407 config PARAVIRT_TIME_ACCOUNTING
1408 	bool "Paravirtual steal time accounting"
1409 	select PARAVIRT
1410 	help
1411 	  Select this option to enable fine granularity task steal time
1412 	  accounting. Time spent executing other tasks in parallel with
1413 	  the current vCPU is discounted from the vCPU power. To account for
1414 	  that, there can be a small performance impact.
1415 
1416 	  If in doubt, say N here.
1417 
1418 config XEN_DOM0
1419 	def_bool y
1420 	depends on XEN
1421 
1422 config XEN
1423 	bool "Xen guest support on ARM"
1424 	depends on ARM && AEABI && OF
1425 	depends on CPU_V7 && !CPU_V6
1426 	depends on !GENERIC_ATOMIC64
1427 	depends on MMU
1428 	select ARCH_DMA_ADDR_T_64BIT
1429 	select ARM_PSCI
1430 	select SWIOTLB
1431 	select SWIOTLB_XEN
1432 	select PARAVIRT
1433 	help
1434 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1435 
1436 config CC_HAVE_STACKPROTECTOR_TLS
1437 	def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
1438 
1439 config STACKPROTECTOR_PER_TASK
1440 	bool "Use a unique stack canary value for each task"
1441 	depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
1442 	depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
1443 	select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
1444 	default y
1445 	help
1446 	  Due to the fact that GCC uses an ordinary symbol reference from
1447 	  which to load the value of the stack canary, this value can only
1448 	  change at reboot time on SMP systems, and all tasks running in the
1449 	  kernel's address space are forced to use the same canary value for
1450 	  the entire duration that the system is up.
1451 
1452 	  Enable this option to switch to a different method that uses a
1453 	  different canary value for each task.
1454 
1455 endmenu
1456 
1457 menu "Boot options"
1458 
1459 config USE_OF
1460 	bool "Flattened Device Tree support"
1461 	select IRQ_DOMAIN
1462 	select OF
1463 	help
1464 	  Include support for flattened device tree machine descriptions.
1465 
1466 config ARCH_WANT_FLAT_DTB_INSTALL
1467 	def_bool y
1468 
1469 config ATAGS
1470 	bool "Support for the traditional ATAGS boot data passing"
1471 	default y
1472 	help
1473 	  This is the traditional way of passing data to the kernel at boot
1474 	  time. If you are solely relying on the flattened device tree (or
1475 	  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1476 	  to remove ATAGS support from your kernel binary.
1477 
1478 config DEPRECATED_PARAM_STRUCT
1479 	bool "Provide old way to pass kernel parameters"
1480 	depends on ATAGS
1481 	help
1482 	  This was deprecated in 2001 and announced to live on for 5 years.
1483 	  Some old boot loaders still use this way.
1484 
1485 # Compressed boot loader in ROM.  Yes, we really want to ask about
1486 # TEXT and BSS so we preserve their values in the config files.
1487 config ZBOOT_ROM_TEXT
1488 	hex "Compressed ROM boot loader base address"
1489 	default 0x0
1490 	help
1491 	  The physical address at which the ROM-able zImage is to be
1492 	  placed in the target.  Platforms which normally make use of
1493 	  ROM-able zImage formats normally set this to a suitable
1494 	  value in their defconfig file.
1495 
1496 	  If ZBOOT_ROM is not enabled, this has no effect.
1497 
1498 config ZBOOT_ROM_BSS
1499 	hex "Compressed ROM boot loader BSS address"
1500 	default 0x0
1501 	help
1502 	  The base address of an area of read/write memory in the target
1503 	  for the ROM-able zImage which must be available while the
1504 	  decompressor is running. It must be large enough to hold the
1505 	  entire decompressed kernel plus an additional 128 KiB.
1506 	  Platforms which normally make use of ROM-able zImage formats
1507 	  normally set this to a suitable value in their defconfig file.
1508 
1509 	  If ZBOOT_ROM is not enabled, this has no effect.
1510 
1511 config ZBOOT_ROM
1512 	bool "Compressed boot loader in ROM/flash"
1513 	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1514 	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1515 	help
1516 	  Say Y here if you intend to execute your compressed kernel image
1517 	  (zImage) directly from ROM or flash.  If unsure, say N.
1518 
1519 config ARM_APPENDED_DTB
1520 	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1521 	depends on OF
1522 	help
1523 	  With this option, the boot code will look for a device tree binary
1524 	  (DTB) appended to zImage
1525 	  (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1526 
1527 	  This is meant as a backward compatibility convenience for those
1528 	  systems with a bootloader that can't be upgraded to accommodate
1529 	  the documented boot protocol using a device tree.
1530 
1531 	  Beware that there is very little in terms of protection against
1532 	  this option being confused by leftover garbage in memory that might
1533 	  look like a DTB header after a reboot if no actual DTB is appended
1534 	  to zImage.  Do not leave this option active in a production kernel
1535 	  if you don't intend to always append a DTB.  Proper passing of the
1536 	  location into r2 of a bootloader provided DTB is always preferable
1537 	  to this option.
1538 
1539 config ARM_ATAG_DTB_COMPAT
1540 	bool "Supplement the appended DTB with traditional ATAG information"
1541 	depends on ARM_APPENDED_DTB
1542 	help
1543 	  Some old bootloaders can't be updated to a DTB capable one, yet
1544 	  they provide ATAGs with memory configuration, the ramdisk address,
1545 	  the kernel cmdline string, etc.  Such information is dynamically
1546 	  provided by the bootloader and can't always be stored in a static
1547 	  DTB.  To allow a device tree enabled kernel to be used with such
1548 	  bootloaders, this option allows zImage to extract the information
1549 	  from the ATAG list and store it at run time into the appended DTB.
1550 
1551 choice
1552 	prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1553 	default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1554 
1555 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1556 	bool "Use bootloader kernel arguments if available"
1557 	help
1558 	  Uses the command-line options passed by the boot loader instead of
1559 	  the device tree bootargs property. If the boot loader doesn't provide
1560 	  any, the device tree bootargs property will be used.
1561 
1562 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1563 	bool "Extend with bootloader kernel arguments"
1564 	help
1565 	  The command-line arguments provided by the boot loader will be
1566 	  appended to the the device tree bootargs property.
1567 
1568 endchoice
1569 
1570 config CMDLINE
1571 	string "Default kernel command string"
1572 	default ""
1573 	help
1574 	  On some architectures (e.g. CATS), there is currently no way
1575 	  for the boot loader to pass arguments to the kernel. For these
1576 	  architectures, you should supply some command-line options at build
1577 	  time by entering them here. As a minimum, you should specify the
1578 	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
1579 
1580 choice
1581 	prompt "Kernel command line type" if CMDLINE != ""
1582 	default CMDLINE_FROM_BOOTLOADER
1583 
1584 config CMDLINE_FROM_BOOTLOADER
1585 	bool "Use bootloader kernel arguments if available"
1586 	help
1587 	  Uses the command-line options passed by the boot loader. If
1588 	  the boot loader doesn't provide any, the default kernel command
1589 	  string provided in CMDLINE will be used.
1590 
1591 config CMDLINE_EXTEND
1592 	bool "Extend bootloader kernel arguments"
1593 	help
1594 	  The command-line arguments provided by the boot loader will be
1595 	  appended to the default kernel command string.
1596 
1597 config CMDLINE_FORCE
1598 	bool "Always use the default kernel command string"
1599 	help
1600 	  Always use the default kernel command string, even if the boot
1601 	  loader passes other arguments to the kernel.
1602 	  This is useful if you cannot or don't want to change the
1603 	  command-line options your boot loader passes to the kernel.
1604 endchoice
1605 
1606 config XIP_KERNEL
1607 	bool "Kernel Execute-In-Place from ROM"
1608 	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1609 	depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
1610 	help
1611 	  Execute-In-Place allows the kernel to run from non-volatile storage
1612 	  directly addressable by the CPU, such as NOR flash. This saves RAM
1613 	  space since the text section of the kernel is not loaded from flash
1614 	  to RAM.  Read-write sections, such as the data section and stack,
1615 	  are still copied to RAM.  The XIP kernel is not compressed since
1616 	  it has to run directly from flash, so it will take more space to
1617 	  store it.  The flash address used to link the kernel object files,
1618 	  and for storing it, is configuration dependent. Therefore, if you
1619 	  say Y here, you must know the proper physical address where to
1620 	  store the kernel image depending on your own flash memory usage.
1621 
1622 	  Also note that the make target becomes "make xipImage" rather than
1623 	  "make zImage" or "make Image".  The final kernel binary to put in
1624 	  ROM memory will be arch/arm/boot/xipImage.
1625 
1626 	  If unsure, say N.
1627 
1628 config XIP_PHYS_ADDR
1629 	hex "XIP Kernel Physical Location"
1630 	depends on XIP_KERNEL
1631 	default "0x00080000"
1632 	help
1633 	  This is the physical address in your flash memory the kernel will
1634 	  be linked for and stored to.  This address is dependent on your
1635 	  own flash usage.
1636 
1637 config XIP_DEFLATED_DATA
1638 	bool "Store kernel .data section compressed in ROM"
1639 	depends on XIP_KERNEL
1640 	select ZLIB_INFLATE
1641 	help
1642 	  Before the kernel is actually executed, its .data section has to be
1643 	  copied to RAM from ROM. This option allows for storing that data
1644 	  in compressed form and decompressed to RAM rather than merely being
1645 	  copied, saving some precious ROM space. A possible drawback is a
1646 	  slightly longer boot delay.
1647 
1648 config ARCH_SUPPORTS_KEXEC
1649 	def_bool (!SMP || PM_SLEEP_SMP) && MMU
1650 
1651 config ATAGS_PROC
1652 	bool "Export atags in procfs"
1653 	depends on ATAGS && KEXEC
1654 	default y
1655 	help
1656 	  Should the atags used to boot the kernel be exported in an "atags"
1657 	  file in procfs. Useful with kexec.
1658 
1659 config ARCH_SUPPORTS_CRASH_DUMP
1660 	def_bool y
1661 
1662 config AUTO_ZRELADDR
1663 	bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
1664 	default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
1665 	help
1666 	  ZRELADDR is the physical address where the decompressed kernel
1667 	  image will be placed. If AUTO_ZRELADDR is selected, the address
1668 	  will be determined at run-time, either by masking the current IP
1669 	  with 0xf8000000, or, if invalid, from the DTB passed in r2.
1670 	  This assumes the zImage being placed in the first 128MB from
1671 	  start of memory.
1672 
1673 config EFI_STUB
1674 	bool
1675 
1676 config EFI
1677 	bool "UEFI runtime support"
1678 	depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1679 	select UCS2_STRING
1680 	select EFI_PARAMS_FROM_FDT
1681 	select EFI_STUB
1682 	select EFI_GENERIC_STUB
1683 	select EFI_RUNTIME_WRAPPERS
1684 	help
1685 	  This option provides support for runtime services provided
1686 	  by UEFI firmware (such as non-volatile variables, realtime
1687 	  clock, and platform reset). A UEFI stub is also provided to
1688 	  allow the kernel to be booted as an EFI application. This
1689 	  is only useful for kernels that may run on systems that have
1690 	  UEFI firmware.
1691 
1692 config DMI
1693 	bool "Enable support for SMBIOS (DMI) tables"
1694 	depends on EFI
1695 	default y
1696 	help
1697 	  This enables SMBIOS/DMI feature for systems.
1698 
1699 	  This option is only useful on systems that have UEFI firmware.
1700 	  However, even with this option, the resultant kernel should
1701 	  continue to boot on existing non-UEFI platforms.
1702 
1703 	  NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1704 	  i.e., the the practice of identifying the platform via DMI to
1705 	  decide whether certain workarounds for buggy hardware and/or
1706 	  firmware need to be enabled. This would require the DMI subsystem
1707 	  to be enabled much earlier than we do on ARM, which is non-trivial.
1708 
1709 endmenu
1710 
1711 menu "CPU Power Management"
1712 
1713 source "drivers/cpufreq/Kconfig"
1714 
1715 source "drivers/cpuidle/Kconfig"
1716 
1717 endmenu
1718 
1719 menu "Floating point emulation"
1720 
1721 comment "At least one emulation must be selected"
1722 
1723 config FPE_NWFPE
1724 	bool "NWFPE math emulation"
1725 	depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1726 	help
1727 	  Say Y to include the NWFPE floating point emulator in the kernel.
1728 	  This is necessary to run most binaries. Linux does not currently
1729 	  support floating point hardware so you need to say Y here even if
1730 	  your machine has an FPA or floating point co-processor podule.
1731 
1732 	  You may say N here if you are going to load the Acorn FPEmulator
1733 	  early in the bootup.
1734 
1735 config FPE_NWFPE_XP
1736 	bool "Support extended precision"
1737 	depends on FPE_NWFPE
1738 	help
1739 	  Say Y to include 80-bit support in the kernel floating-point
1740 	  emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1741 	  Note that gcc does not generate 80-bit operations by default,
1742 	  so in most cases this option only enlarges the size of the
1743 	  floating point emulator without any good reason.
1744 
1745 	  You almost surely want to say N here.
1746 
1747 config FPE_FASTFPE
1748 	bool "FastFPE math emulation (EXPERIMENTAL)"
1749 	depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1750 	help
1751 	  Say Y here to include the FAST floating point emulator in the kernel.
1752 	  This is an experimental much faster emulator which now also has full
1753 	  precision for the mantissa.  It does not support any exceptions.
1754 	  It is very simple, and approximately 3-6 times faster than NWFPE.
1755 
1756 	  It should be sufficient for most programs.  It may be not suitable
1757 	  for scientific calculations, but you have to check this for yourself.
1758 	  If you do not feel you need a faster FP emulation you should better
1759 	  choose NWFPE.
1760 
1761 config VFP
1762 	bool "VFP-format floating point maths"
1763 	depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1764 	help
1765 	  Say Y to include VFP support code in the kernel. This is needed
1766 	  if your hardware includes a VFP unit.
1767 
1768 	  Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
1769 	  release notes and additional status information.
1770 
1771 	  Say N if your target does not have VFP hardware.
1772 
1773 config VFPv3
1774 	bool
1775 	depends on VFP
1776 	default y if CPU_V7
1777 
1778 config NEON
1779 	bool "Advanced SIMD (NEON) Extension support"
1780 	depends on VFPv3 && CPU_V7
1781 	help
1782 	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1783 	  Extension.
1784 
1785 config KERNEL_MODE_NEON
1786 	bool "Support for NEON in kernel mode"
1787 	depends on NEON && AEABI
1788 	help
1789 	  Say Y to include support for NEON in kernel mode.
1790 
1791 endmenu
1792 
1793 menu "Power management options"
1794 
1795 source "kernel/power/Kconfig"
1796 
1797 config ARCH_SUSPEND_POSSIBLE
1798 	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1799 		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1800 	def_bool y
1801 
1802 config ARM_CPU_SUSPEND
1803 	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1804 	depends on ARCH_SUSPEND_POSSIBLE
1805 
1806 config ARCH_HIBERNATION_POSSIBLE
1807 	bool
1808 	depends on MMU
1809 	default y if ARCH_SUSPEND_POSSIBLE
1810 
1811 endmenu
1812 
1813 source "arch/arm/Kconfig.assembler"
1814