xref: /openbmc/linux/arch/arm/Kconfig (revision e481ff3f)
1# SPDX-License-Identifier: GPL-2.0
2config ARM
3	bool
4	default y
5	select ARCH_32BIT_OFF_T
6	select ARCH_HAS_BINFMT_FLAT
7	select ARCH_HAS_DEBUG_VIRTUAL if MMU
8	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
9	select ARCH_HAS_ELF_RANDOMIZE
10	select ARCH_HAS_FORTIFY_SOURCE
11	select ARCH_HAS_KEEPINITRD
12	select ARCH_HAS_KCOV
13	select ARCH_HAS_MEMBARRIER_SYNC_CORE
14	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
15	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
16	select ARCH_HAS_PHYS_TO_DMA
17	select ARCH_HAS_SETUP_DMA_OPS
18	select ARCH_HAS_SET_MEMORY
19	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
20	select ARCH_HAS_STRICT_MODULE_RWX if MMU
21	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB
22	select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
23	select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
24	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
25	select ARCH_HAVE_CUSTOM_GPIO_H
26	select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
27	select ARCH_HAS_GCOV_PROFILE_ALL
28	select ARCH_KEEP_MEMBLOCK
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_SUPPORTS_HUGETLBFS if ARM_LPAE
35	select ARCH_USE_BUILTIN_BSWAP
36	select ARCH_USE_CMPXCHG_LOCKREF
37	select ARCH_USE_MEMTEST
38	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
39	select ARCH_WANT_IPC_PARSE_VERSION
40	select ARCH_WANT_LD_ORPHAN_WARN
41	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
42	select BUILDTIME_TABLE_SORT if MMU
43	select CLONE_BACKWARDS
44	select CPU_PM if SUSPEND || CPU_IDLE
45	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
46	select DMA_DECLARE_COHERENT
47	select DMA_OPS
48	select DMA_REMAP if MMU
49	select EDAC_SUPPORT
50	select EDAC_ATOMIC_SCRUB
51	select GENERIC_ALLOCATOR
52	select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
53	select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
54	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
55	select GENERIC_IRQ_IPI if SMP
56	select GENERIC_CPU_AUTOPROBE
57	select GENERIC_EARLY_IOREMAP
58	select GENERIC_IDLE_POLL_SETUP
59	select GENERIC_IRQ_PROBE
60	select GENERIC_IRQ_SHOW
61	select GENERIC_IRQ_SHOW_LEVEL
62	select GENERIC_LIB_DEVMEM_IS_ALLOWED
63	select GENERIC_PCI_IOMAP
64	select GENERIC_SCHED_CLOCK
65	select GENERIC_SMP_IDLE_THREAD
66	select GENERIC_STRNCPY_FROM_USER
67	select GENERIC_STRNLEN_USER
68	select HANDLE_DOMAIN_IRQ
69	select HARDIRQS_SW_RESEND
70	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
71	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
72	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
73	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
74	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
75	select HAVE_ARCH_MMAP_RND_BITS if MMU
76	select HAVE_ARCH_PFN_VALID
77	select HAVE_ARCH_SECCOMP
78	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
79	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
80	select HAVE_ARCH_TRACEHOOK
81	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
82	select HAVE_ARM_SMCCC if CPU_V7
83	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
84	select HAVE_CONTEXT_TRACKING
85	select HAVE_C_RECORDMCOUNT
86	select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
87	select HAVE_DMA_CONTIGUOUS if MMU
88	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
89	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
90	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
91	select HAVE_EXIT_THREAD
92	select HAVE_FAST_GUP if ARM_LPAE
93	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
94	select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
95	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
96	select HAVE_GCC_PLUGINS
97	select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
98	select HAVE_IDE if PCI || ISA || PCMCIA
99	select HAVE_IRQ_TIME_ACCOUNTING
100	select HAVE_KERNEL_GZIP
101	select HAVE_KERNEL_LZ4
102	select HAVE_KERNEL_LZMA
103	select HAVE_KERNEL_LZO
104	select HAVE_KERNEL_XZ
105	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
106	select HAVE_KRETPROBES if HAVE_KPROBES
107	select HAVE_MOD_ARCH_SPECIFIC
108	select HAVE_NMI
109	select HAVE_OPTPROBES if !THUMB2_KERNEL
110	select HAVE_PERF_EVENTS
111	select HAVE_PERF_REGS
112	select HAVE_PERF_USER_STACK_DUMP
113	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
114	select HAVE_REGS_AND_STACK_ACCESS_API
115	select HAVE_RSEQ
116	select HAVE_STACKPROTECTOR
117	select HAVE_SYSCALL_TRACEPOINTS
118	select HAVE_UID16
119	select HAVE_VIRT_CPU_ACCOUNTING_GEN
120	select IRQ_FORCED_THREADING
121	select MODULES_USE_ELF_REL
122	select NEED_DMA_MAP_STATE
123	select OF_EARLY_FLATTREE if OF
124	select OLD_SIGACTION
125	select OLD_SIGSUSPEND3
126	select PCI_SYSCALL if PCI
127	select PERF_USE_VMALLOC
128	select RTC_LIB
129	select SET_FS
130	select SYS_SUPPORTS_APM_EMULATION
131	# Above selects are sorted alphabetically; please add new ones
132	# according to that.  Thanks.
133	help
134	  The ARM series is a line of low-power-consumption RISC chip designs
135	  licensed by ARM Ltd and targeted at embedded applications and
136	  handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
137	  manufactured, but legacy ARM-based PC hardware remains popular in
138	  Europe.  There is an ARM Linux project with a web page at
139	  <http://www.arm.linux.org.uk/>.
140
141config ARM_HAS_SG_CHAIN
142	bool
143
144config ARM_DMA_USE_IOMMU
145	bool
146	select ARM_HAS_SG_CHAIN
147	select NEED_SG_DMA_LENGTH
148
149if ARM_DMA_USE_IOMMU
150
151config ARM_DMA_IOMMU_ALIGNMENT
152	int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
153	range 4 9
154	default 8
155	help
156	  DMA mapping framework by default aligns all buffers to the smallest
157	  PAGE_SIZE order which is greater than or equal to the requested buffer
158	  size. This works well for buffers up to a few hundreds kilobytes, but
159	  for larger buffers it just a waste of address space. Drivers which has
160	  relatively small addressing window (like 64Mib) might run out of
161	  virtual space with just a few allocations.
162
163	  With this parameter you can specify the maximum PAGE_SIZE order for
164	  DMA IOMMU buffers. Larger buffers will be aligned only to this
165	  specified order. The order is expressed as a power of two multiplied
166	  by the PAGE_SIZE.
167
168endif
169
170config SYS_SUPPORTS_APM_EMULATION
171	bool
172
173config HAVE_TCM
174	bool
175	select GENERIC_ALLOCATOR
176
177config HAVE_PROC_CPU
178	bool
179
180config NO_IOPORT_MAP
181	bool
182
183config SBUS
184	bool
185
186config STACKTRACE_SUPPORT
187	bool
188	default y
189
190config LOCKDEP_SUPPORT
191	bool
192	default y
193
194config TRACE_IRQFLAGS_SUPPORT
195	bool
196	default !CPU_V7M
197
198config ARCH_HAS_ILOG2_U32
199	bool
200
201config ARCH_HAS_ILOG2_U64
202	bool
203
204config ARCH_HAS_BANDGAP
205	bool
206
207config FIX_EARLYCON_MEM
208	def_bool y if MMU
209
210config GENERIC_HWEIGHT
211	bool
212	default y
213
214config GENERIC_CALIBRATE_DELAY
215	bool
216	default y
217
218config ARCH_MAY_HAVE_PC_FDC
219	bool
220
221config ARCH_SUPPORTS_UPROBES
222	def_bool y
223
224config ARCH_HAS_DMA_SET_COHERENT_MASK
225	bool
226
227config GENERIC_ISA_DMA
228	bool
229
230config FIQ
231	bool
232
233config NEED_RET_TO_USER
234	bool
235
236config ARCH_MTD_XIP
237	bool
238
239config ARM_PATCH_PHYS_VIRT
240	bool "Patch physical to virtual translations at runtime" if EMBEDDED
241	default y
242	depends on !XIP_KERNEL && MMU
243	help
244	  Patch phys-to-virt and virt-to-phys translation functions at
245	  boot and module load time according to the position of the
246	  kernel in system memory.
247
248	  This can only be used with non-XIP MMU kernels where the base
249	  of physical memory is at a 2 MiB boundary.
250
251	  Only disable this option if you know that you do not require
252	  this feature (eg, building a kernel for a single machine) and
253	  you need to shrink the kernel to the minimal size.
254
255config NEED_MACH_IO_H
256	bool
257	help
258	  Select this when mach/io.h is required to provide special
259	  definitions for this platform.  The need for mach/io.h should
260	  be avoided when possible.
261
262config NEED_MACH_MEMORY_H
263	bool
264	help
265	  Select this when mach/memory.h is required to provide special
266	  definitions for this platform.  The need for mach/memory.h should
267	  be avoided when possible.
268
269config PHYS_OFFSET
270	hex "Physical address of main memory" if MMU
271	depends on !ARM_PATCH_PHYS_VIRT
272	default DRAM_BASE if !MMU
273	default 0x00000000 if ARCH_FOOTBRIDGE
274	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
275	default 0x20000000 if ARCH_S5PV210
276	default 0xc0000000 if ARCH_SA1100
277	help
278	  Please provide the physical address corresponding to the
279	  location of main memory in your system.
280
281config GENERIC_BUG
282	def_bool y
283	depends on BUG
284
285config PGTABLE_LEVELS
286	int
287	default 3 if ARM_LPAE
288	default 2
289
290menu "System Type"
291
292config MMU
293	bool "MMU-based Paged Memory Management Support"
294	default y
295	help
296	  Select if you want MMU-based virtualised addressing space
297	  support by paged memory management. If unsure, say 'Y'.
298
299config ARCH_MMAP_RND_BITS_MIN
300	default 8
301
302config ARCH_MMAP_RND_BITS_MAX
303	default 14 if PAGE_OFFSET=0x40000000
304	default 15 if PAGE_OFFSET=0x80000000
305	default 16
306
307#
308# The "ARM system type" choice list is ordered alphabetically by option
309# text.  Please add new entries in the option alphabetic order.
310#
311choice
312	prompt "ARM system type"
313	default ARM_SINGLE_ARMV7M if !MMU
314	default ARCH_MULTIPLATFORM if MMU
315
316config ARCH_MULTIPLATFORM
317	bool "Allow multiple platforms to be selected"
318	depends on MMU
319	select ARCH_FLATMEM_ENABLE
320	select ARCH_SPARSEMEM_ENABLE
321	select ARCH_SELECT_MEMORY_MODEL
322	select ARM_HAS_SG_CHAIN
323	select ARM_PATCH_PHYS_VIRT
324	select AUTO_ZRELADDR
325	select TIMER_OF
326	select COMMON_CLK
327	select GENERIC_IRQ_MULTI_HANDLER
328	select HAVE_PCI
329	select PCI_DOMAINS_GENERIC if PCI
330	select SPARSE_IRQ
331	select USE_OF
332
333config ARM_SINGLE_ARMV7M
334	bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
335	depends on !MMU
336	select ARM_NVIC
337	select AUTO_ZRELADDR
338	select TIMER_OF
339	select COMMON_CLK
340	select CPU_V7M
341	select NO_IOPORT_MAP
342	select SPARSE_IRQ
343	select USE_OF
344
345config ARCH_EP93XX
346	bool "EP93xx-based"
347	select ARCH_SPARSEMEM_ENABLE
348	select ARM_AMBA
349	imply ARM_PATCH_PHYS_VIRT
350	select ARM_VIC
351	select GENERIC_IRQ_MULTI_HANDLER
352	select AUTO_ZRELADDR
353	select CLKSRC_MMIO
354	select CPU_ARM920T
355	select GPIOLIB
356	select HAVE_LEGACY_CLK
357	help
358	  This enables support for the Cirrus EP93xx series of CPUs.
359
360config ARCH_FOOTBRIDGE
361	bool "FootBridge"
362	select CPU_SA110
363	select FOOTBRIDGE
364	select HAVE_IDE
365	select NEED_MACH_IO_H if !MMU
366	select NEED_MACH_MEMORY_H
367	help
368	  Support for systems based on the DC21285 companion chip
369	  ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
370
371config ARCH_IOP32X
372	bool "IOP32x-based"
373	depends on MMU
374	select CPU_XSCALE
375	select GPIO_IOP
376	select GPIOLIB
377	select NEED_RET_TO_USER
378	select FORCE_PCI
379	select PLAT_IOP
380	help
381	  Support for Intel's 80219 and IOP32X (XScale) family of
382	  processors.
383
384config ARCH_IXP4XX
385	bool "IXP4xx-based"
386	depends on MMU
387	select ARCH_HAS_DMA_SET_COHERENT_MASK
388	select ARCH_SUPPORTS_BIG_ENDIAN
389	select CPU_XSCALE
390	select DMABOUNCE if PCI
391	select GENERIC_IRQ_MULTI_HANDLER
392	select GPIO_IXP4XX
393	select GPIOLIB
394	select HAVE_PCI
395	select IXP4XX_IRQ
396	select IXP4XX_TIMER
397	# With the new PCI driver this is not needed
398	select NEED_MACH_IO_H if PCI_IXP4XX_LEGACY
399	select USB_EHCI_BIG_ENDIAN_DESC
400	select USB_EHCI_BIG_ENDIAN_MMIO
401	help
402	  Support for Intel's IXP4XX (XScale) family of processors.
403
404config ARCH_DOVE
405	bool "Marvell Dove"
406	select CPU_PJ4
407	select GENERIC_IRQ_MULTI_HANDLER
408	select GPIOLIB
409	select HAVE_PCI
410	select MVEBU_MBUS
411	select PINCTRL
412	select PINCTRL_DOVE
413	select PLAT_ORION_LEGACY
414	select SPARSE_IRQ
415	select PM_GENERIC_DOMAINS if PM
416	help
417	  Support for the Marvell Dove SoC 88AP510
418
419config ARCH_PXA
420	bool "PXA2xx/PXA3xx-based"
421	depends on MMU
422	select ARCH_MTD_XIP
423	select ARM_CPU_SUSPEND if PM
424	select AUTO_ZRELADDR
425	select COMMON_CLK
426	select CLKSRC_PXA
427	select CLKSRC_MMIO
428	select TIMER_OF
429	select CPU_XSCALE if !CPU_XSC3
430	select GENERIC_IRQ_MULTI_HANDLER
431	select GPIO_PXA
432	select GPIOLIB
433	select HAVE_IDE
434	select IRQ_DOMAIN
435	select PLAT_PXA
436	select SPARSE_IRQ
437	help
438	  Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
439
440config ARCH_RPC
441	bool "RiscPC"
442	depends on MMU
443	select ARCH_ACORN
444	select ARCH_MAY_HAVE_PC_FDC
445	select ARCH_SPARSEMEM_ENABLE
446	select ARM_HAS_SG_CHAIN
447	select CPU_SA110
448	select FIQ
449	select HAVE_IDE
450	select HAVE_PATA_PLATFORM
451	select ISA_DMA_API
452	select LEGACY_TIMER_TICK
453	select NEED_MACH_IO_H
454	select NEED_MACH_MEMORY_H
455	select NO_IOPORT_MAP
456	help
457	  On the Acorn Risc-PC, Linux can support the internal IDE disk and
458	  CD-ROM interface, serial and parallel port, and the floppy drive.
459
460config ARCH_SA1100
461	bool "SA1100-based"
462	select ARCH_MTD_XIP
463	select ARCH_SPARSEMEM_ENABLE
464	select CLKSRC_MMIO
465	select CLKSRC_PXA
466	select TIMER_OF if OF
467	select COMMON_CLK
468	select CPU_FREQ
469	select CPU_SA1100
470	select GENERIC_IRQ_MULTI_HANDLER
471	select GPIOLIB
472	select HAVE_IDE
473	select IRQ_DOMAIN
474	select ISA
475	select NEED_MACH_MEMORY_H
476	select SPARSE_IRQ
477	help
478	  Support for StrongARM 11x0 based boards.
479
480config ARCH_S3C24XX
481	bool "Samsung S3C24XX SoCs"
482	select ATAGS
483	select CLKSRC_SAMSUNG_PWM
484	select GPIO_SAMSUNG
485	select GPIOLIB
486	select GENERIC_IRQ_MULTI_HANDLER
487	select HAVE_S3C2410_I2C if I2C
488	select HAVE_S3C_RTC if RTC_CLASS
489	select NEED_MACH_IO_H
490	select S3C2410_WATCHDOG
491	select SAMSUNG_ATAGS
492	select USE_OF
493	select WATCHDOG
494	help
495	  Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
496	  and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
497	  (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
498	  Samsung SMDK2410 development board (and derivatives).
499
500config ARCH_OMAP1
501	bool "TI OMAP1"
502	depends on MMU
503	select ARCH_OMAP
504	select CLKSRC_MMIO
505	select GENERIC_IRQ_CHIP
506	select GENERIC_IRQ_MULTI_HANDLER
507	select GPIOLIB
508	select HAVE_IDE
509	select HAVE_LEGACY_CLK
510	select IRQ_DOMAIN
511	select NEED_MACH_IO_H if PCCARD
512	select NEED_MACH_MEMORY_H
513	select SPARSE_IRQ
514	help
515	  Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
516
517endchoice
518
519menu "Multiple platform selection"
520	depends on ARCH_MULTIPLATFORM
521
522comment "CPU Core family selection"
523
524config ARCH_MULTI_V4
525	bool "ARMv4 based platforms (FA526)"
526	depends on !ARCH_MULTI_V6_V7
527	select ARCH_MULTI_V4_V5
528	select CPU_FA526
529
530config ARCH_MULTI_V4T
531	bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
532	depends on !ARCH_MULTI_V6_V7
533	select ARCH_MULTI_V4_V5
534	select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
535		CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
536		CPU_ARM925T || CPU_ARM940T)
537
538config ARCH_MULTI_V5
539	bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
540	depends on !ARCH_MULTI_V6_V7
541	select ARCH_MULTI_V4_V5
542	select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
543		CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
544		CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
545
546config ARCH_MULTI_V4_V5
547	bool
548
549config ARCH_MULTI_V6
550	bool "ARMv6 based platforms (ARM11)"
551	select ARCH_MULTI_V6_V7
552	select CPU_V6K
553
554config ARCH_MULTI_V7
555	bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
556	default y
557	select ARCH_MULTI_V6_V7
558	select CPU_V7
559	select HAVE_SMP
560
561config ARCH_MULTI_V6_V7
562	bool
563	select MIGHT_HAVE_CACHE_L2X0
564
565config ARCH_MULTI_CPU_AUTO
566	def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
567	select ARCH_MULTI_V5
568
569endmenu
570
571config ARCH_VIRT
572	bool "Dummy Virtual Machine"
573	depends on ARCH_MULTI_V7
574	select ARM_AMBA
575	select ARM_GIC
576	select ARM_GIC_V2M if PCI
577	select ARM_GIC_V3
578	select ARM_GIC_V3_ITS if PCI
579	select ARM_PSCI
580	select HAVE_ARM_ARCH_TIMER
581	select ARCH_SUPPORTS_BIG_ENDIAN
582
583#
584# This is sorted alphabetically by mach-* pathname.  However, plat-*
585# Kconfigs may be included either alphabetically (according to the
586# plat- suffix) or along side the corresponding mach-* source.
587#
588source "arch/arm/mach-actions/Kconfig"
589
590source "arch/arm/mach-alpine/Kconfig"
591
592source "arch/arm/mach-artpec/Kconfig"
593
594source "arch/arm/mach-asm9260/Kconfig"
595
596source "arch/arm/mach-aspeed/Kconfig"
597
598source "arch/arm/mach-at91/Kconfig"
599
600source "arch/arm/mach-axxia/Kconfig"
601
602source "arch/arm/mach-bcm/Kconfig"
603
604source "arch/arm/mach-berlin/Kconfig"
605
606source "arch/arm/mach-clps711x/Kconfig"
607
608source "arch/arm/mach-cns3xxx/Kconfig"
609
610source "arch/arm/mach-davinci/Kconfig"
611
612source "arch/arm/mach-digicolor/Kconfig"
613
614source "arch/arm/mach-dove/Kconfig"
615
616source "arch/arm/mach-ep93xx/Kconfig"
617
618source "arch/arm/mach-exynos/Kconfig"
619
620source "arch/arm/mach-footbridge/Kconfig"
621
622source "arch/arm/mach-gemini/Kconfig"
623
624source "arch/arm/mach-highbank/Kconfig"
625
626source "arch/arm/mach-hisi/Kconfig"
627
628source "arch/arm/mach-imx/Kconfig"
629
630source "arch/arm/mach-integrator/Kconfig"
631
632source "arch/arm/mach-iop32x/Kconfig"
633
634source "arch/arm/mach-ixp4xx/Kconfig"
635
636source "arch/arm/mach-keystone/Kconfig"
637
638source "arch/arm/mach-lpc32xx/Kconfig"
639
640source "arch/arm/mach-mediatek/Kconfig"
641
642source "arch/arm/mach-meson/Kconfig"
643
644source "arch/arm/mach-milbeaut/Kconfig"
645
646source "arch/arm/mach-mmp/Kconfig"
647
648source "arch/arm/mach-moxart/Kconfig"
649
650source "arch/arm/mach-mstar/Kconfig"
651
652source "arch/arm/mach-mv78xx0/Kconfig"
653
654source "arch/arm/mach-mvebu/Kconfig"
655
656source "arch/arm/mach-mxs/Kconfig"
657
658source "arch/arm/mach-nomadik/Kconfig"
659
660source "arch/arm/mach-npcm/Kconfig"
661
662source "arch/arm/mach-nspire/Kconfig"
663
664source "arch/arm/plat-omap/Kconfig"
665
666source "arch/arm/mach-omap1/Kconfig"
667
668source "arch/arm/mach-omap2/Kconfig"
669
670source "arch/arm/mach-orion5x/Kconfig"
671
672source "arch/arm/mach-oxnas/Kconfig"
673
674source "arch/arm/mach-pxa/Kconfig"
675source "arch/arm/plat-pxa/Kconfig"
676
677source "arch/arm/mach-qcom/Kconfig"
678
679source "arch/arm/mach-rda/Kconfig"
680
681source "arch/arm/mach-realtek/Kconfig"
682
683source "arch/arm/mach-realview/Kconfig"
684
685source "arch/arm/mach-rockchip/Kconfig"
686
687source "arch/arm/mach-s3c/Kconfig"
688
689source "arch/arm/mach-s5pv210/Kconfig"
690
691source "arch/arm/mach-sa1100/Kconfig"
692
693source "arch/arm/mach-shmobile/Kconfig"
694
695source "arch/arm/mach-socfpga/Kconfig"
696
697source "arch/arm/mach-spear/Kconfig"
698
699source "arch/arm/mach-sti/Kconfig"
700
701source "arch/arm/mach-stm32/Kconfig"
702
703source "arch/arm/mach-sunxi/Kconfig"
704
705source "arch/arm/mach-tegra/Kconfig"
706
707source "arch/arm/mach-uniphier/Kconfig"
708
709source "arch/arm/mach-ux500/Kconfig"
710
711source "arch/arm/mach-versatile/Kconfig"
712
713source "arch/arm/mach-vexpress/Kconfig"
714
715source "arch/arm/mach-vt8500/Kconfig"
716
717source "arch/arm/mach-zynq/Kconfig"
718
719# ARMv7-M architecture
720config ARCH_LPC18XX
721	bool "NXP LPC18xx/LPC43xx"
722	depends on ARM_SINGLE_ARMV7M
723	select ARCH_HAS_RESET_CONTROLLER
724	select ARM_AMBA
725	select CLKSRC_LPC32XX
726	select PINCTRL
727	help
728	  Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
729	  high performance microcontrollers.
730
731config ARCH_MPS2
732	bool "ARM MPS2 platform"
733	depends on ARM_SINGLE_ARMV7M
734	select ARM_AMBA
735	select CLKSRC_MPS2
736	help
737	  Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
738	  with a range of available cores like Cortex-M3/M4/M7.
739
740	  Please, note that depends which Application Note is used memory map
741	  for the platform may vary, so adjustment of RAM base might be needed.
742
743# Definitions to make life easier
744config ARCH_ACORN
745	bool
746
747config PLAT_IOP
748	bool
749
750config PLAT_ORION
751	bool
752	select CLKSRC_MMIO
753	select COMMON_CLK
754	select GENERIC_IRQ_CHIP
755	select IRQ_DOMAIN
756
757config PLAT_ORION_LEGACY
758	bool
759	select PLAT_ORION
760
761config PLAT_PXA
762	bool
763
764config PLAT_VERSATILE
765	bool
766
767source "arch/arm/mm/Kconfig"
768
769config IWMMXT
770	bool "Enable iWMMXt support"
771	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
772	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
773	help
774	  Enable support for iWMMXt context switching at run time if
775	  running on a CPU that supports it.
776
777if !MMU
778source "arch/arm/Kconfig-nommu"
779endif
780
781config PJ4B_ERRATA_4742
782	bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
783	depends on CPU_PJ4B && MACH_ARMADA_370
784	default y
785	help
786	  When coming out of either a Wait for Interrupt (WFI) or a Wait for
787	  Event (WFE) IDLE states, a specific timing sensitivity exists between
788	  the retiring WFI/WFE instructions and the newly issued subsequent
789	  instructions.  This sensitivity can result in a CPU hang scenario.
790	  Workaround:
791	  The software must insert either a Data Synchronization Barrier (DSB)
792	  or Data Memory Barrier (DMB) command immediately after the WFI/WFE
793	  instruction
794
795config ARM_ERRATA_326103
796	bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
797	depends on CPU_V6
798	help
799	  Executing a SWP instruction to read-only memory does not set bit 11
800	  of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
801	  treat the access as a read, preventing a COW from occurring and
802	  causing the faulting task to livelock.
803
804config ARM_ERRATA_411920
805	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
806	depends on CPU_V6 || CPU_V6K
807	help
808	  Invalidation of the Instruction Cache operation can
809	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
810	  It does not affect the MPCore. This option enables the ARM Ltd.
811	  recommended workaround.
812
813config ARM_ERRATA_430973
814	bool "ARM errata: Stale prediction on replaced interworking branch"
815	depends on CPU_V7
816	help
817	  This option enables the workaround for the 430973 Cortex-A8
818	  r1p* erratum. If a code sequence containing an ARM/Thumb
819	  interworking branch is replaced with another code sequence at the
820	  same virtual address, whether due to self-modifying code or virtual
821	  to physical address re-mapping, Cortex-A8 does not recover from the
822	  stale interworking branch prediction. This results in Cortex-A8
823	  executing the new code sequence in the incorrect ARM or Thumb state.
824	  The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
825	  and also flushes the branch target cache at every context switch.
826	  Note that setting specific bits in the ACTLR register may not be
827	  available in non-secure mode.
828
829config ARM_ERRATA_458693
830	bool "ARM errata: Processor deadlock when a false hazard is created"
831	depends on CPU_V7
832	depends on !ARCH_MULTIPLATFORM
833	help
834	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
835	  erratum. For very specific sequences of memory operations, it is
836	  possible for a hazard condition intended for a cache line to instead
837	  be incorrectly associated with a different cache line. This false
838	  hazard might then cause a processor deadlock. The workaround enables
839	  the L1 caching of the NEON accesses and disables the PLD instruction
840	  in the ACTLR register. Note that setting specific bits in the ACTLR
841	  register may not be available in non-secure mode.
842
843config ARM_ERRATA_460075
844	bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
845	depends on CPU_V7
846	depends on !ARCH_MULTIPLATFORM
847	help
848	  This option enables the workaround for the 460075 Cortex-A8 (r2p0)
849	  erratum. Any asynchronous access to the L2 cache may encounter a
850	  situation in which recent store transactions to the L2 cache are lost
851	  and overwritten with stale memory contents from external memory. The
852	  workaround disables the write-allocate mode for the L2 cache via the
853	  ACTLR register. Note that setting specific bits in the ACTLR register
854	  may not be available in non-secure mode.
855
856config ARM_ERRATA_742230
857	bool "ARM errata: DMB operation may be faulty"
858	depends on CPU_V7 && SMP
859	depends on !ARCH_MULTIPLATFORM
860	help
861	  This option enables the workaround for the 742230 Cortex-A9
862	  (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
863	  between two write operations may not ensure the correct visibility
864	  ordering of the two writes. This workaround sets a specific bit in
865	  the diagnostic register of the Cortex-A9 which causes the DMB
866	  instruction to behave as a DSB, ensuring the correct behaviour of
867	  the two writes.
868
869config ARM_ERRATA_742231
870	bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
871	depends on CPU_V7 && SMP
872	depends on !ARCH_MULTIPLATFORM
873	help
874	  This option enables the workaround for the 742231 Cortex-A9
875	  (r2p0..r2p2) erratum. Under certain conditions, specific to the
876	  Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
877	  accessing some data located in the same cache line, may get corrupted
878	  data due to bad handling of the address hazard when the line gets
879	  replaced from one of the CPUs at the same time as another CPU is
880	  accessing it. This workaround sets specific bits in the diagnostic
881	  register of the Cortex-A9 which reduces the linefill issuing
882	  capabilities of the processor.
883
884config ARM_ERRATA_643719
885	bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
886	depends on CPU_V7 && SMP
887	default y
888	help
889	  This option enables the workaround for the 643719 Cortex-A9 (prior to
890	  r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
891	  register returns zero when it should return one. The workaround
892	  corrects this value, ensuring cache maintenance operations which use
893	  it behave as intended and avoiding data corruption.
894
895config ARM_ERRATA_720789
896	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
897	depends on CPU_V7
898	help
899	  This option enables the workaround for the 720789 Cortex-A9 (prior to
900	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
901	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
902	  As a consequence of this erratum, some TLB entries which should be
903	  invalidated are not, resulting in an incoherency in the system page
904	  tables. The workaround changes the TLB flushing routines to invalidate
905	  entries regardless of the ASID.
906
907config ARM_ERRATA_743622
908	bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
909	depends on CPU_V7
910	depends on !ARCH_MULTIPLATFORM
911	help
912	  This option enables the workaround for the 743622 Cortex-A9
913	  (r2p*) erratum. Under very rare conditions, a faulty
914	  optimisation in the Cortex-A9 Store Buffer may lead to data
915	  corruption. This workaround sets a specific bit in the diagnostic
916	  register of the Cortex-A9 which disables the Store Buffer
917	  optimisation, preventing the defect from occurring. This has no
918	  visible impact on the overall performance or power consumption of the
919	  processor.
920
921config ARM_ERRATA_751472
922	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
923	depends on CPU_V7
924	depends on !ARCH_MULTIPLATFORM
925	help
926	  This option enables the workaround for the 751472 Cortex-A9 (prior
927	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
928	  completion of a following broadcasted operation if the second
929	  operation is received by a CPU before the ICIALLUIS has completed,
930	  potentially leading to corrupted entries in the cache or TLB.
931
932config ARM_ERRATA_754322
933	bool "ARM errata: possible faulty MMU translations following an ASID switch"
934	depends on CPU_V7
935	help
936	  This option enables the workaround for the 754322 Cortex-A9 (r2p*,
937	  r3p*) erratum. A speculative memory access may cause a page table walk
938	  which starts prior to an ASID switch but completes afterwards. This
939	  can populate the micro-TLB with a stale entry which may be hit with
940	  the new ASID. This workaround places two dsb instructions in the mm
941	  switching code so that no page table walks can cross the ASID switch.
942
943config ARM_ERRATA_754327
944	bool "ARM errata: no automatic Store Buffer drain"
945	depends on CPU_V7 && SMP
946	help
947	  This option enables the workaround for the 754327 Cortex-A9 (prior to
948	  r2p0) erratum. The Store Buffer does not have any automatic draining
949	  mechanism and therefore a livelock may occur if an external agent
950	  continuously polls a memory location waiting to observe an update.
951	  This workaround defines cpu_relax() as smp_mb(), preventing correctly
952	  written polling loops from denying visibility of updates to memory.
953
954config ARM_ERRATA_364296
955	bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
956	depends on CPU_V6
957	help
958	  This options enables the workaround for the 364296 ARM1136
959	  r0p2 erratum (possible cache data corruption with
960	  hit-under-miss enabled). It sets the undocumented bit 31 in
961	  the auxiliary control register and the FI bit in the control
962	  register, thus disabling hit-under-miss without putting the
963	  processor into full low interrupt latency mode. ARM11MPCore
964	  is not affected.
965
966config ARM_ERRATA_764369
967	bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
968	depends on CPU_V7 && SMP
969	help
970	  This option enables the workaround for erratum 764369
971	  affecting Cortex-A9 MPCore with two or more processors (all
972	  current revisions). Under certain timing circumstances, a data
973	  cache line maintenance operation by MVA targeting an Inner
974	  Shareable memory region may fail to proceed up to either the
975	  Point of Coherency or to the Point of Unification of the
976	  system. This workaround adds a DSB instruction before the
977	  relevant cache maintenance functions and sets a specific bit
978	  in the diagnostic control register of the SCU.
979
980config ARM_ERRATA_775420
981       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
982       depends on CPU_V7
983       help
984	 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
985	 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
986	 operation aborts with MMU exception, it might cause the processor
987	 to deadlock. This workaround puts DSB before executing ISB if
988	 an abort may occur on cache maintenance.
989
990config ARM_ERRATA_798181
991	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
992	depends on CPU_V7 && SMP
993	help
994	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
995	  adequately shooting down all use of the old entries. This
996	  option enables the Linux kernel workaround for this erratum
997	  which sends an IPI to the CPUs that are running the same ASID
998	  as the one being invalidated.
999
1000config ARM_ERRATA_773022
1001	bool "ARM errata: incorrect instructions may be executed from loop buffer"
1002	depends on CPU_V7
1003	help
1004	  This option enables the workaround for the 773022 Cortex-A15
1005	  (up to r0p4) erratum. In certain rare sequences of code, the
1006	  loop buffer may deliver incorrect instructions. This
1007	  workaround disables the loop buffer to avoid the erratum.
1008
1009config ARM_ERRATA_818325_852422
1010	bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1011	depends on CPU_V7
1012	help
1013	  This option enables the workaround for:
1014	  - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1015	    instruction might deadlock.  Fixed in r0p1.
1016	  - Cortex-A12 852422: Execution of a sequence of instructions might
1017	    lead to either a data corruption or a CPU deadlock.  Not fixed in
1018	    any Cortex-A12 cores yet.
1019	  This workaround for all both errata involves setting bit[12] of the
1020	  Feature Register. This bit disables an optimisation applied to a
1021	  sequence of 2 instructions that use opposing condition codes.
1022
1023config ARM_ERRATA_821420
1024	bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1025	depends on CPU_V7
1026	help
1027	  This option enables the workaround for the 821420 Cortex-A12
1028	  (all revs) erratum. In very rare timing conditions, a sequence
1029	  of VMOV to Core registers instructions, for which the second
1030	  one is in the shadow of a branch or abort, can lead to a
1031	  deadlock when the VMOV instructions are issued out-of-order.
1032
1033config ARM_ERRATA_825619
1034	bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1035	depends on CPU_V7
1036	help
1037	  This option enables the workaround for the 825619 Cortex-A12
1038	  (all revs) erratum. Within rare timing constraints, executing a
1039	  DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1040	  and Device/Strongly-Ordered loads and stores might cause deadlock
1041
1042config ARM_ERRATA_857271
1043	bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1044	depends on CPU_V7
1045	help
1046	  This option enables the workaround for the 857271 Cortex-A12
1047	  (all revs) erratum. Under very rare timing conditions, the CPU might
1048	  hang. The workaround is expected to have a < 1% performance impact.
1049
1050config ARM_ERRATA_852421
1051	bool "ARM errata: A17: DMB ST might fail to create order between stores"
1052	depends on CPU_V7
1053	help
1054	  This option enables the workaround for the 852421 Cortex-A17
1055	  (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1056	  execution of a DMB ST instruction might fail to properly order
1057	  stores from GroupA and stores from GroupB.
1058
1059config ARM_ERRATA_852423
1060	bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1061	depends on CPU_V7
1062	help
1063	  This option enables the workaround for:
1064	  - Cortex-A17 852423: Execution of a sequence of instructions might
1065	    lead to either a data corruption or a CPU deadlock.  Not fixed in
1066	    any Cortex-A17 cores yet.
1067	  This is identical to Cortex-A12 erratum 852422.  It is a separate
1068	  config option from the A12 erratum due to the way errata are checked
1069	  for and handled.
1070
1071config ARM_ERRATA_857272
1072	bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1073	depends on CPU_V7
1074	help
1075	  This option enables the workaround for the 857272 Cortex-A17 erratum.
1076	  This erratum is not known to be fixed in any A17 revision.
1077	  This is identical to Cortex-A12 erratum 857271.  It is a separate
1078	  config option from the A12 erratum due to the way errata are checked
1079	  for and handled.
1080
1081endmenu
1082
1083source "arch/arm/common/Kconfig"
1084
1085menu "Bus support"
1086
1087config ISA
1088	bool
1089	help
1090	  Find out whether you have ISA slots on your motherboard.  ISA is the
1091	  name of a bus system, i.e. the way the CPU talks to the other stuff
1092	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
1093	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1094	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
1095
1096# Select ISA DMA controller support
1097config ISA_DMA
1098	bool
1099	select ISA_DMA_API
1100
1101# Select ISA DMA interface
1102config ISA_DMA_API
1103	bool
1104
1105config PCI_NANOENGINE
1106	bool "BSE nanoEngine PCI support"
1107	depends on SA1100_NANOENGINE
1108	help
1109	  Enable PCI on the BSE nanoEngine board.
1110
1111config ARM_ERRATA_814220
1112	bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1113	depends on CPU_V7
1114	help
1115	  The v7 ARM states that all cache and branch predictor maintenance
1116	  operations that do not specify an address execute, relative to
1117	  each other, in program order.
1118	  However, because of this erratum, an L2 set/way cache maintenance
1119	  operation can overtake an L1 set/way cache maintenance operation.
1120	  This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1121	  r0p4, r0p5.
1122
1123endmenu
1124
1125menu "Kernel Features"
1126
1127config HAVE_SMP
1128	bool
1129	help
1130	  This option should be selected by machines which have an SMP-
1131	  capable CPU.
1132
1133	  The only effect of this option is to make the SMP-related
1134	  options available to the user for configuration.
1135
1136config SMP
1137	bool "Symmetric Multi-Processing"
1138	depends on CPU_V6K || CPU_V7
1139	depends on HAVE_SMP
1140	depends on MMU || ARM_MPU
1141	select IRQ_WORK
1142	help
1143	  This enables support for systems with more than one CPU. If you have
1144	  a system with only one CPU, say N. If you have a system with more
1145	  than one CPU, say Y.
1146
1147	  If you say N here, the kernel will run on uni- and multiprocessor
1148	  machines, but will use only one CPU of a multiprocessor machine. If
1149	  you say Y here, the kernel will run on many, but not all,
1150	  uniprocessor machines. On a uniprocessor machine, the kernel
1151	  will run faster if you say N here.
1152
1153	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
1154	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1155	  <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1156
1157	  If you don't know what to do here, say N.
1158
1159config SMP_ON_UP
1160	bool "Allow booting SMP kernel on uniprocessor systems"
1161	depends on SMP && !XIP_KERNEL && MMU
1162	default y
1163	help
1164	  SMP kernels contain instructions which fail on non-SMP processors.
1165	  Enabling this option allows the kernel to modify itself to make
1166	  these instructions safe.  Disabling it allows about 1K of space
1167	  savings.
1168
1169	  If you don't know what to do here, say Y.
1170
1171config ARM_CPU_TOPOLOGY
1172	bool "Support cpu topology definition"
1173	depends on SMP && CPU_V7
1174	default y
1175	help
1176	  Support ARM cpu topology definition. The MPIDR register defines
1177	  affinity between processors which is then used to describe the cpu
1178	  topology of an ARM System.
1179
1180config SCHED_MC
1181	bool "Multi-core scheduler support"
1182	depends on ARM_CPU_TOPOLOGY
1183	help
1184	  Multi-core scheduler support improves the CPU scheduler's decision
1185	  making when dealing with multi-core CPU chips at a cost of slightly
1186	  increased overhead in some places. If unsure say N here.
1187
1188config SCHED_SMT
1189	bool "SMT scheduler support"
1190	depends on ARM_CPU_TOPOLOGY
1191	help
1192	  Improves the CPU scheduler's decision making when dealing with
1193	  MultiThreading at a cost of slightly increased overhead in some
1194	  places. If unsure say N here.
1195
1196config HAVE_ARM_SCU
1197	bool
1198	help
1199	  This option enables support for the ARM snoop control unit
1200
1201config HAVE_ARM_ARCH_TIMER
1202	bool "Architected timer support"
1203	depends on CPU_V7
1204	select ARM_ARCH_TIMER
1205	help
1206	  This option enables support for the ARM architected timer
1207
1208config HAVE_ARM_TWD
1209	bool
1210	help
1211	  This options enables support for the ARM timer and watchdog unit
1212
1213config MCPM
1214	bool "Multi-Cluster Power Management"
1215	depends on CPU_V7 && SMP
1216	help
1217	  This option provides the common power management infrastructure
1218	  for (multi-)cluster based systems, such as big.LITTLE based
1219	  systems.
1220
1221config MCPM_QUAD_CLUSTER
1222	bool
1223	depends on MCPM
1224	help
1225	  To avoid wasting resources unnecessarily, MCPM only supports up
1226	  to 2 clusters by default.
1227	  Platforms with 3 or 4 clusters that use MCPM must select this
1228	  option to allow the additional clusters to be managed.
1229
1230config BIG_LITTLE
1231	bool "big.LITTLE support (Experimental)"
1232	depends on CPU_V7 && SMP
1233	select MCPM
1234	help
1235	  This option enables support selections for the big.LITTLE
1236	  system architecture.
1237
1238config BL_SWITCHER
1239	bool "big.LITTLE switcher support"
1240	depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1241	select CPU_PM
1242	help
1243	  The big.LITTLE "switcher" provides the core functionality to
1244	  transparently handle transition between a cluster of A15's
1245	  and a cluster of A7's in a big.LITTLE system.
1246
1247config BL_SWITCHER_DUMMY_IF
1248	tristate "Simple big.LITTLE switcher user interface"
1249	depends on BL_SWITCHER && DEBUG_KERNEL
1250	help
1251	  This is a simple and dummy char dev interface to control
1252	  the big.LITTLE switcher core code.  It is meant for
1253	  debugging purposes only.
1254
1255choice
1256	prompt "Memory split"
1257	depends on MMU
1258	default VMSPLIT_3G
1259	help
1260	  Select the desired split between kernel and user memory.
1261
1262	  If you are not absolutely sure what you are doing, leave this
1263	  option alone!
1264
1265	config VMSPLIT_3G
1266		bool "3G/1G user/kernel split"
1267	config VMSPLIT_3G_OPT
1268		depends on !ARM_LPAE
1269		bool "3G/1G user/kernel split (for full 1G low memory)"
1270	config VMSPLIT_2G
1271		bool "2G/2G user/kernel split"
1272	config VMSPLIT_1G
1273		bool "1G/3G user/kernel split"
1274endchoice
1275
1276config PAGE_OFFSET
1277	hex
1278	default PHYS_OFFSET if !MMU
1279	default 0x40000000 if VMSPLIT_1G
1280	default 0x80000000 if VMSPLIT_2G
1281	default 0xB0000000 if VMSPLIT_3G_OPT
1282	default 0xC0000000
1283
1284config KASAN_SHADOW_OFFSET
1285	hex
1286	depends on KASAN
1287	default 0x1f000000 if PAGE_OFFSET=0x40000000
1288	default 0x5f000000 if PAGE_OFFSET=0x80000000
1289	default 0x9f000000 if PAGE_OFFSET=0xC0000000
1290	default 0x8f000000 if PAGE_OFFSET=0xB0000000
1291	default 0xffffffff
1292
1293config NR_CPUS
1294	int "Maximum number of CPUs (2-32)"
1295	range 2 16 if DEBUG_KMAP_LOCAL
1296	range 2 32 if !DEBUG_KMAP_LOCAL
1297	depends on SMP
1298	default "4"
1299	help
1300	  The maximum number of CPUs that the kernel can support.
1301	  Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1302	  debugging is enabled, which uses half of the per-CPU fixmap
1303	  slots as guard regions.
1304
1305config HOTPLUG_CPU
1306	bool "Support for hot-pluggable CPUs"
1307	depends on SMP
1308	select GENERIC_IRQ_MIGRATION
1309	help
1310	  Say Y here to experiment with turning CPUs off and on.  CPUs
1311	  can be controlled through /sys/devices/system/cpu.
1312
1313config ARM_PSCI
1314	bool "Support for the ARM Power State Coordination Interface (PSCI)"
1315	depends on HAVE_ARM_SMCCC
1316	select ARM_PSCI_FW
1317	help
1318	  Say Y here if you want Linux to communicate with system firmware
1319	  implementing the PSCI specification for CPU-centric power
1320	  management operations described in ARM document number ARM DEN
1321	  0022A ("Power State Coordination Interface System Software on
1322	  ARM processors").
1323
1324# The GPIO number here must be sorted by descending number. In case of
1325# a multiplatform kernel, we just want the highest value required by the
1326# selected platforms.
1327config ARCH_NR_GPIO
1328	int
1329	default 2048 if ARCH_INTEL_SOCFPGA
1330	default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1331		ARCH_ZYNQ || ARCH_ASPEED
1332	default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1333		SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1334	default 416 if ARCH_SUNXI
1335	default 392 if ARCH_U8500
1336	default 352 if ARCH_VT8500
1337	default 288 if ARCH_ROCKCHIP
1338	default 264 if MACH_H4700
1339	default 0
1340	help
1341	  Maximum number of GPIOs in the system.
1342
1343	  If unsure, leave the default value.
1344
1345config HZ_FIXED
1346	int
1347	default 128 if SOC_AT91RM9200
1348	default 0
1349
1350choice
1351	depends on HZ_FIXED = 0
1352	prompt "Timer frequency"
1353
1354config HZ_100
1355	bool "100 Hz"
1356
1357config HZ_200
1358	bool "200 Hz"
1359
1360config HZ_250
1361	bool "250 Hz"
1362
1363config HZ_300
1364	bool "300 Hz"
1365
1366config HZ_500
1367	bool "500 Hz"
1368
1369config HZ_1000
1370	bool "1000 Hz"
1371
1372endchoice
1373
1374config HZ
1375	int
1376	default HZ_FIXED if HZ_FIXED != 0
1377	default 100 if HZ_100
1378	default 200 if HZ_200
1379	default 250 if HZ_250
1380	default 300 if HZ_300
1381	default 500 if HZ_500
1382	default 1000
1383
1384config SCHED_HRTICK
1385	def_bool HIGH_RES_TIMERS
1386
1387config THUMB2_KERNEL
1388	bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1389	depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1390	default y if CPU_THUMBONLY
1391	select ARM_UNWIND
1392	help
1393	  By enabling this option, the kernel will be compiled in
1394	  Thumb-2 mode.
1395
1396	  If unsure, say N.
1397
1398config ARM_PATCH_IDIV
1399	bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1400	depends on CPU_32v7 && !XIP_KERNEL
1401	default y
1402	help
1403	  The ARM compiler inserts calls to __aeabi_idiv() and
1404	  __aeabi_uidiv() when it needs to perform division on signed
1405	  and unsigned integers. Some v7 CPUs have support for the sdiv
1406	  and udiv instructions that can be used to implement those
1407	  functions.
1408
1409	  Enabling this option allows the kernel to modify itself to
1410	  replace the first two instructions of these library functions
1411	  with the sdiv or udiv plus "bx lr" instructions when the CPU
1412	  it is running on supports them. Typically this will be faster
1413	  and less power intensive than running the original library
1414	  code to do integer division.
1415
1416config AEABI
1417	bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1418		!CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1419	default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1420	help
1421	  This option allows for the kernel to be compiled using the latest
1422	  ARM ABI (aka EABI).  This is only useful if you are using a user
1423	  space environment that is also compiled with EABI.
1424
1425	  Since there are major incompatibilities between the legacy ABI and
1426	  EABI, especially with regard to structure member alignment, this
1427	  option also changes the kernel syscall calling convention to
1428	  disambiguate both ABIs and allow for backward compatibility support
1429	  (selected with CONFIG_OABI_COMPAT).
1430
1431	  To use this you need GCC version 4.0.0 or later.
1432
1433config OABI_COMPAT
1434	bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1435	depends on AEABI && !THUMB2_KERNEL
1436	help
1437	  This option preserves the old syscall interface along with the
1438	  new (ARM EABI) one. It also provides a compatibility layer to
1439	  intercept syscalls that have structure arguments which layout
1440	  in memory differs between the legacy ABI and the new ARM EABI
1441	  (only for non "thumb" binaries). This option adds a tiny
1442	  overhead to all syscalls and produces a slightly larger kernel.
1443
1444	  The seccomp filter system will not be available when this is
1445	  selected, since there is no way yet to sensibly distinguish
1446	  between calling conventions during filtering.
1447
1448	  If you know you'll be using only pure EABI user space then you
1449	  can say N here. If this option is not selected and you attempt
1450	  to execute a legacy ABI binary then the result will be
1451	  UNPREDICTABLE (in fact it can be predicted that it won't work
1452	  at all). If in doubt say N.
1453
1454config ARCH_SELECT_MEMORY_MODEL
1455	bool
1456
1457config ARCH_FLATMEM_ENABLE
1458	bool
1459
1460config ARCH_SPARSEMEM_ENABLE
1461	bool
1462	select SPARSEMEM_STATIC if SPARSEMEM
1463
1464config HIGHMEM
1465	bool "High Memory Support"
1466	depends on MMU
1467	select KMAP_LOCAL
1468	help
1469	  The address space of ARM processors is only 4 Gigabytes large
1470	  and it has to accommodate user address space, kernel address
1471	  space as well as some memory mapped IO. That means that, if you
1472	  have a large amount of physical memory and/or IO, not all of the
1473	  memory can be "permanently mapped" by the kernel. The physical
1474	  memory that is not permanently mapped is called "high memory".
1475
1476	  Depending on the selected kernel/user memory split, minimum
1477	  vmalloc space and actual amount of RAM, you may not need this
1478	  option which should result in a slightly faster kernel.
1479
1480	  If unsure, say n.
1481
1482config HIGHPTE
1483	bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1484	depends on HIGHMEM
1485	default y
1486	help
1487	  The VM uses one page of physical memory for each page table.
1488	  For systems with a lot of processes, this can use a lot of
1489	  precious low memory, eventually leading to low memory being
1490	  consumed by page tables.  Setting this option will allow
1491	  user-space 2nd level page tables to reside in high memory.
1492
1493config CPU_SW_DOMAIN_PAN
1494	bool "Enable use of CPU domains to implement privileged no-access"
1495	depends on MMU && !ARM_LPAE
1496	default y
1497	help
1498	  Increase kernel security by ensuring that normal kernel accesses
1499	  are unable to access userspace addresses.  This can help prevent
1500	  use-after-free bugs becoming an exploitable privilege escalation
1501	  by ensuring that magic values (such as LIST_POISON) will always
1502	  fault when dereferenced.
1503
1504	  CPUs with low-vector mappings use a best-efforts implementation.
1505	  Their lower 1MB needs to remain accessible for the vectors, but
1506	  the remainder of userspace will become appropriately inaccessible.
1507
1508config HW_PERF_EVENTS
1509	def_bool y
1510	depends on ARM_PMU
1511
1512config ARCH_WANT_GENERAL_HUGETLB
1513	def_bool y
1514
1515config ARM_MODULE_PLTS
1516	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1517	depends on MODULES
1518	default y
1519	help
1520	  Allocate PLTs when loading modules so that jumps and calls whose
1521	  targets are too far away for their relative offsets to be encoded
1522	  in the instructions themselves can be bounced via veneers in the
1523	  module's PLT. This allows modules to be allocated in the generic
1524	  vmalloc area after the dedicated module memory area has been
1525	  exhausted. The modules will use slightly more memory, but after
1526	  rounding up to page size, the actual memory footprint is usually
1527	  the same.
1528
1529	  Disabling this is usually safe for small single-platform
1530	  configurations. If unsure, say y.
1531
1532config FORCE_MAX_ZONEORDER
1533	int "Maximum zone order"
1534	default "12" if SOC_AM33XX
1535	default "9" if SA1111
1536	default "11"
1537	help
1538	  The kernel memory allocator divides physically contiguous memory
1539	  blocks into "zones", where each zone is a power of two number of
1540	  pages.  This option selects the largest power of two that the kernel
1541	  keeps in the memory allocator.  If you need to allocate very large
1542	  blocks of physically contiguous memory, then you may need to
1543	  increase this value.
1544
1545	  This config option is actually maximum order plus one. For example,
1546	  a value of 11 means that the largest free memory block is 2^10 pages.
1547
1548config ALIGNMENT_TRAP
1549	def_bool CPU_CP15_MMU
1550	select HAVE_PROC_CPU if PROC_FS
1551	help
1552	  ARM processors cannot fetch/store information which is not
1553	  naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1554	  address divisible by 4. On 32-bit ARM processors, these non-aligned
1555	  fetch/store instructions will be emulated in software if you say
1556	  here, which has a severe performance impact. This is necessary for
1557	  correct operation of some network protocols. With an IP-only
1558	  configuration it is safe to say N, otherwise say Y.
1559
1560config UACCESS_WITH_MEMCPY
1561	bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1562	depends on MMU
1563	default y if CPU_FEROCEON
1564	help
1565	  Implement faster copy_to_user and clear_user methods for CPU
1566	  cores where a 8-word STM instruction give significantly higher
1567	  memory write throughput than a sequence of individual 32bit stores.
1568
1569	  A possible side effect is a slight increase in scheduling latency
1570	  between threads sharing the same address space if they invoke
1571	  such copy operations with large buffers.
1572
1573	  However, if the CPU data cache is using a write-allocate mode,
1574	  this option is unlikely to provide any performance gain.
1575
1576config PARAVIRT
1577	bool "Enable paravirtualization code"
1578	help
1579	  This changes the kernel so it can modify itself when it is run
1580	  under a hypervisor, potentially improving performance significantly
1581	  over full virtualization.
1582
1583config PARAVIRT_TIME_ACCOUNTING
1584	bool "Paravirtual steal time accounting"
1585	select PARAVIRT
1586	help
1587	  Select this option to enable fine granularity task steal time
1588	  accounting. Time spent executing other tasks in parallel with
1589	  the current vCPU is discounted from the vCPU power. To account for
1590	  that, there can be a small performance impact.
1591
1592	  If in doubt, say N here.
1593
1594config XEN_DOM0
1595	def_bool y
1596	depends on XEN
1597
1598config XEN
1599	bool "Xen guest support on ARM"
1600	depends on ARM && AEABI && OF
1601	depends on CPU_V7 && !CPU_V6
1602	depends on !GENERIC_ATOMIC64
1603	depends on MMU
1604	select ARCH_DMA_ADDR_T_64BIT
1605	select ARM_PSCI
1606	select SWIOTLB
1607	select SWIOTLB_XEN
1608	select PARAVIRT
1609	help
1610	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1611
1612config STACKPROTECTOR_PER_TASK
1613	bool "Use a unique stack canary value for each task"
1614	depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1615	select GCC_PLUGIN_ARM_SSP_PER_TASK
1616	default y
1617	help
1618	  Due to the fact that GCC uses an ordinary symbol reference from
1619	  which to load the value of the stack canary, this value can only
1620	  change at reboot time on SMP systems, and all tasks running in the
1621	  kernel's address space are forced to use the same canary value for
1622	  the entire duration that the system is up.
1623
1624	  Enable this option to switch to a different method that uses a
1625	  different canary value for each task.
1626
1627endmenu
1628
1629menu "Boot options"
1630
1631config USE_OF
1632	bool "Flattened Device Tree support"
1633	select IRQ_DOMAIN
1634	select OF
1635	help
1636	  Include support for flattened device tree machine descriptions.
1637
1638config ATAGS
1639	bool "Support for the traditional ATAGS boot data passing" if USE_OF
1640	default y
1641	help
1642	  This is the traditional way of passing data to the kernel at boot
1643	  time. If you are solely relying on the flattened device tree (or
1644	  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1645	  to remove ATAGS support from your kernel binary.  If unsure,
1646	  leave this to y.
1647
1648config DEPRECATED_PARAM_STRUCT
1649	bool "Provide old way to pass kernel parameters"
1650	depends on ATAGS
1651	help
1652	  This was deprecated in 2001 and announced to live on for 5 years.
1653	  Some old boot loaders still use this way.
1654
1655# Compressed boot loader in ROM.  Yes, we really want to ask about
1656# TEXT and BSS so we preserve their values in the config files.
1657config ZBOOT_ROM_TEXT
1658	hex "Compressed ROM boot loader base address"
1659	default 0x0
1660	help
1661	  The physical address at which the ROM-able zImage is to be
1662	  placed in the target.  Platforms which normally make use of
1663	  ROM-able zImage formats normally set this to a suitable
1664	  value in their defconfig file.
1665
1666	  If ZBOOT_ROM is not enabled, this has no effect.
1667
1668config ZBOOT_ROM_BSS
1669	hex "Compressed ROM boot loader BSS address"
1670	default 0x0
1671	help
1672	  The base address of an area of read/write memory in the target
1673	  for the ROM-able zImage which must be available while the
1674	  decompressor is running. It must be large enough to hold the
1675	  entire decompressed kernel plus an additional 128 KiB.
1676	  Platforms which normally make use of ROM-able zImage formats
1677	  normally set this to a suitable value in their defconfig file.
1678
1679	  If ZBOOT_ROM is not enabled, this has no effect.
1680
1681config ZBOOT_ROM
1682	bool "Compressed boot loader in ROM/flash"
1683	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1684	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1685	help
1686	  Say Y here if you intend to execute your compressed kernel image
1687	  (zImage) directly from ROM or flash.  If unsure, say N.
1688
1689config ARM_APPENDED_DTB
1690	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1691	depends on OF
1692	help
1693	  With this option, the boot code will look for a device tree binary
1694	  (DTB) appended to zImage
1695	  (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1696
1697	  This is meant as a backward compatibility convenience for those
1698	  systems with a bootloader that can't be upgraded to accommodate
1699	  the documented boot protocol using a device tree.
1700
1701	  Beware that there is very little in terms of protection against
1702	  this option being confused by leftover garbage in memory that might
1703	  look like a DTB header after a reboot if no actual DTB is appended
1704	  to zImage.  Do not leave this option active in a production kernel
1705	  if you don't intend to always append a DTB.  Proper passing of the
1706	  location into r2 of a bootloader provided DTB is always preferable
1707	  to this option.
1708
1709config ARM_ATAG_DTB_COMPAT
1710	bool "Supplement the appended DTB with traditional ATAG information"
1711	depends on ARM_APPENDED_DTB
1712	help
1713	  Some old bootloaders can't be updated to a DTB capable one, yet
1714	  they provide ATAGs with memory configuration, the ramdisk address,
1715	  the kernel cmdline string, etc.  Such information is dynamically
1716	  provided by the bootloader and can't always be stored in a static
1717	  DTB.  To allow a device tree enabled kernel to be used with such
1718	  bootloaders, this option allows zImage to extract the information
1719	  from the ATAG list and store it at run time into the appended DTB.
1720
1721choice
1722	prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1723	default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1724
1725config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1726	bool "Use bootloader kernel arguments if available"
1727	help
1728	  Uses the command-line options passed by the boot loader instead of
1729	  the device tree bootargs property. If the boot loader doesn't provide
1730	  any, the device tree bootargs property will be used.
1731
1732config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1733	bool "Extend with bootloader kernel arguments"
1734	help
1735	  The command-line arguments provided by the boot loader will be
1736	  appended to the the device tree bootargs property.
1737
1738endchoice
1739
1740config CMDLINE
1741	string "Default kernel command string"
1742	default ""
1743	help
1744	  On some architectures (e.g. CATS), there is currently no way
1745	  for the boot loader to pass arguments to the kernel. For these
1746	  architectures, you should supply some command-line options at build
1747	  time by entering them here. As a minimum, you should specify the
1748	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
1749
1750choice
1751	prompt "Kernel command line type" if CMDLINE != ""
1752	default CMDLINE_FROM_BOOTLOADER
1753	depends on ATAGS
1754
1755config CMDLINE_FROM_BOOTLOADER
1756	bool "Use bootloader kernel arguments if available"
1757	help
1758	  Uses the command-line options passed by the boot loader. If
1759	  the boot loader doesn't provide any, the default kernel command
1760	  string provided in CMDLINE will be used.
1761
1762config CMDLINE_EXTEND
1763	bool "Extend bootloader kernel arguments"
1764	help
1765	  The command-line arguments provided by the boot loader will be
1766	  appended to the default kernel command string.
1767
1768config CMDLINE_FORCE
1769	bool "Always use the default kernel command string"
1770	help
1771	  Always use the default kernel command string, even if the boot
1772	  loader passes other arguments to the kernel.
1773	  This is useful if you cannot or don't want to change the
1774	  command-line options your boot loader passes to the kernel.
1775endchoice
1776
1777config XIP_KERNEL
1778	bool "Kernel Execute-In-Place from ROM"
1779	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1780	help
1781	  Execute-In-Place allows the kernel to run from non-volatile storage
1782	  directly addressable by the CPU, such as NOR flash. This saves RAM
1783	  space since the text section of the kernel is not loaded from flash
1784	  to RAM.  Read-write sections, such as the data section and stack,
1785	  are still copied to RAM.  The XIP kernel is not compressed since
1786	  it has to run directly from flash, so it will take more space to
1787	  store it.  The flash address used to link the kernel object files,
1788	  and for storing it, is configuration dependent. Therefore, if you
1789	  say Y here, you must know the proper physical address where to
1790	  store the kernel image depending on your own flash memory usage.
1791
1792	  Also note that the make target becomes "make xipImage" rather than
1793	  "make zImage" or "make Image".  The final kernel binary to put in
1794	  ROM memory will be arch/arm/boot/xipImage.
1795
1796	  If unsure, say N.
1797
1798config XIP_PHYS_ADDR
1799	hex "XIP Kernel Physical Location"
1800	depends on XIP_KERNEL
1801	default "0x00080000"
1802	help
1803	  This is the physical address in your flash memory the kernel will
1804	  be linked for and stored to.  This address is dependent on your
1805	  own flash usage.
1806
1807config XIP_DEFLATED_DATA
1808	bool "Store kernel .data section compressed in ROM"
1809	depends on XIP_KERNEL
1810	select ZLIB_INFLATE
1811	help
1812	  Before the kernel is actually executed, its .data section has to be
1813	  copied to RAM from ROM. This option allows for storing that data
1814	  in compressed form and decompressed to RAM rather than merely being
1815	  copied, saving some precious ROM space. A possible drawback is a
1816	  slightly longer boot delay.
1817
1818config KEXEC
1819	bool "Kexec system call (EXPERIMENTAL)"
1820	depends on (!SMP || PM_SLEEP_SMP)
1821	depends on MMU
1822	select KEXEC_CORE
1823	help
1824	  kexec is a system call that implements the ability to shutdown your
1825	  current kernel, and to start another kernel.  It is like a reboot
1826	  but it is independent of the system firmware.   And like a reboot
1827	  you can start any kernel with it, not just Linux.
1828
1829	  It is an ongoing process to be certain the hardware in a machine
1830	  is properly shutdown, so do not be surprised if this code does not
1831	  initially work for you.
1832
1833config ATAGS_PROC
1834	bool "Export atags in procfs"
1835	depends on ATAGS && KEXEC
1836	default y
1837	help
1838	  Should the atags used to boot the kernel be exported in an "atags"
1839	  file in procfs. Useful with kexec.
1840
1841config CRASH_DUMP
1842	bool "Build kdump crash kernel (EXPERIMENTAL)"
1843	help
1844	  Generate crash dump after being started by kexec. This should
1845	  be normally only set in special crash dump kernels which are
1846	  loaded in the main kernel with kexec-tools into a specially
1847	  reserved region and then later executed after a crash by
1848	  kdump/kexec. The crash dump kernel must be compiled to a
1849	  memory address not used by the main kernel
1850
1851	  For more details see Documentation/admin-guide/kdump/kdump.rst
1852
1853config AUTO_ZRELADDR
1854	bool "Auto calculation of the decompressed kernel image address"
1855	help
1856	  ZRELADDR is the physical address where the decompressed kernel
1857	  image will be placed. If AUTO_ZRELADDR is selected, the address
1858	  will be determined at run-time, either by masking the current IP
1859	  with 0xf8000000, or, if invalid, from the DTB passed in r2.
1860	  This assumes the zImage being placed in the first 128MB from
1861	  start of memory.
1862
1863config EFI_STUB
1864	bool
1865
1866config EFI
1867	bool "UEFI runtime support"
1868	depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1869	select UCS2_STRING
1870	select EFI_PARAMS_FROM_FDT
1871	select EFI_STUB
1872	select EFI_GENERIC_STUB
1873	select EFI_RUNTIME_WRAPPERS
1874	help
1875	  This option provides support for runtime services provided
1876	  by UEFI firmware (such as non-volatile variables, realtime
1877	  clock, and platform reset). A UEFI stub is also provided to
1878	  allow the kernel to be booted as an EFI application. This
1879	  is only useful for kernels that may run on systems that have
1880	  UEFI firmware.
1881
1882config DMI
1883	bool "Enable support for SMBIOS (DMI) tables"
1884	depends on EFI
1885	default y
1886	help
1887	  This enables SMBIOS/DMI feature for systems.
1888
1889	  This option is only useful on systems that have UEFI firmware.
1890	  However, even with this option, the resultant kernel should
1891	  continue to boot on existing non-UEFI platforms.
1892
1893	  NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1894	  i.e., the the practice of identifying the platform via DMI to
1895	  decide whether certain workarounds for buggy hardware and/or
1896	  firmware need to be enabled. This would require the DMI subsystem
1897	  to be enabled much earlier than we do on ARM, which is non-trivial.
1898
1899endmenu
1900
1901menu "CPU Power Management"
1902
1903source "drivers/cpufreq/Kconfig"
1904
1905source "drivers/cpuidle/Kconfig"
1906
1907endmenu
1908
1909menu "Floating point emulation"
1910
1911comment "At least one emulation must be selected"
1912
1913config FPE_NWFPE
1914	bool "NWFPE math emulation"
1915	depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1916	help
1917	  Say Y to include the NWFPE floating point emulator in the kernel.
1918	  This is necessary to run most binaries. Linux does not currently
1919	  support floating point hardware so you need to say Y here even if
1920	  your machine has an FPA or floating point co-processor podule.
1921
1922	  You may say N here if you are going to load the Acorn FPEmulator
1923	  early in the bootup.
1924
1925config FPE_NWFPE_XP
1926	bool "Support extended precision"
1927	depends on FPE_NWFPE
1928	help
1929	  Say Y to include 80-bit support in the kernel floating-point
1930	  emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1931	  Note that gcc does not generate 80-bit operations by default,
1932	  so in most cases this option only enlarges the size of the
1933	  floating point emulator without any good reason.
1934
1935	  You almost surely want to say N here.
1936
1937config FPE_FASTFPE
1938	bool "FastFPE math emulation (EXPERIMENTAL)"
1939	depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1940	help
1941	  Say Y here to include the FAST floating point emulator in the kernel.
1942	  This is an experimental much faster emulator which now also has full
1943	  precision for the mantissa.  It does not support any exceptions.
1944	  It is very simple, and approximately 3-6 times faster than NWFPE.
1945
1946	  It should be sufficient for most programs.  It may be not suitable
1947	  for scientific calculations, but you have to check this for yourself.
1948	  If you do not feel you need a faster FP emulation you should better
1949	  choose NWFPE.
1950
1951config VFP
1952	bool "VFP-format floating point maths"
1953	depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1954	help
1955	  Say Y to include VFP support code in the kernel. This is needed
1956	  if your hardware includes a VFP unit.
1957
1958	  Please see <file:Documentation/arm/vfp/release-notes.rst> for
1959	  release notes and additional status information.
1960
1961	  Say N if your target does not have VFP hardware.
1962
1963config VFPv3
1964	bool
1965	depends on VFP
1966	default y if CPU_V7
1967
1968config NEON
1969	bool "Advanced SIMD (NEON) Extension support"
1970	depends on VFPv3 && CPU_V7
1971	help
1972	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1973	  Extension.
1974
1975config KERNEL_MODE_NEON
1976	bool "Support for NEON in kernel mode"
1977	depends on NEON && AEABI
1978	help
1979	  Say Y to include support for NEON in kernel mode.
1980
1981endmenu
1982
1983menu "Power management options"
1984
1985source "kernel/power/Kconfig"
1986
1987config ARCH_SUSPEND_POSSIBLE
1988	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1989		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1990	def_bool y
1991
1992config ARM_CPU_SUSPEND
1993	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1994	depends on ARCH_SUSPEND_POSSIBLE
1995
1996config ARCH_HIBERNATION_POSSIBLE
1997	bool
1998	depends on MMU
1999	default y if ARCH_SUSPEND_POSSIBLE
2000
2001endmenu
2002
2003source "drivers/firmware/Kconfig"
2004
2005if CRYPTO
2006source "arch/arm/crypto/Kconfig"
2007endif
2008
2009source "arch/arm/Kconfig.assembler"
2010