xref: /linux/arch/riscv/Kconfig (revision 37b33c68b00089a574ebd0a856a5d554eb3001b7)
1# SPDX-License-Identifier: GPL-2.0-only
2#
3# For a description of the syntax of this configuration file,
4# see Documentation/kbuild/kconfig-language.rst.
5#
6
7config 64BIT
8	bool
9
10config 32BIT
11	bool
12
13config RISCV
14	def_bool y
15	select ACPI_GENERIC_GSI if ACPI
16	select ACPI_MCFG if (ACPI && PCI)
17	select ACPI_PPTT if ACPI
18	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
19	select ACPI_SPCR_TABLE if ACPI
20	select ARCH_DMA_DEFAULT_COHERENT
21	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
22	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP
23	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
24	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
25	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
26	select ARCH_HAS_BINFMT_FLAT
27	select ARCH_HAS_CRC32 if RISCV_ISA_ZBC
28	select ARCH_HAS_CURRENT_STACK_POINTER
29	select ARCH_HAS_DEBUG_VIRTUAL if MMU
30	select ARCH_HAS_DEBUG_VM_PGTABLE
31	select ARCH_HAS_DEBUG_WX
32	select ARCH_HAS_FAST_MULTIPLIER
33	select ARCH_HAS_FORTIFY_SOURCE
34	select ARCH_HAS_GCOV_PROFILE_ALL
35	select ARCH_HAS_GIGANTIC_PAGE
36	select ARCH_HAS_HW_PTE_YOUNG
37	select ARCH_HAS_KCOV
38	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
39	select ARCH_HAS_MEMBARRIER_CALLBACKS
40	select ARCH_HAS_MEMBARRIER_SYNC_CORE
41	select ARCH_HAS_MMIOWB
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_PMEM_API
44	select ARCH_HAS_PREEMPT_LAZY
45	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
46	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
47	select ARCH_HAS_PTE_SPECIAL
48	select ARCH_HAS_SET_DIRECT_MAP if MMU
49	select ARCH_HAS_SET_MEMORY if MMU
50	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
51	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
52	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
53	select ARCH_HAS_SYSCALL_WRAPPER
54	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
55	select ARCH_HAS_UBSAN
56	select ARCH_HAS_VDSO_TIME_DATA
57	select ARCH_KEEP_MEMBLOCK if ACPI
58	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
59	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
60	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
61	select ARCH_STACKWALK
62	select ARCH_SUPPORTS_ATOMIC_RMW
63	select ARCH_SUPPORTS_CFI_CLANG
64	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
65	select ARCH_SUPPORTS_HUGETLBFS if MMU
66	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
67	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
68	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
69	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
70	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
71	select ARCH_SUPPORTS_RT
72	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
73	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
74	select ARCH_USE_MEMTEST
75	select ARCH_USE_QUEUED_RWLOCKS
76	select ARCH_USE_SYM_ANNOTATIONS
77	select ARCH_USES_CFI_TRAPS if CFI_CLANG
78	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
79	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
80	select ARCH_WANT_FRAME_POINTERS
81	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
82	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
83	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
84	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
85	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
86	select ARCH_WANTS_NO_INSTR
87	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
88	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
89	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
90	select BUILDTIME_TABLE_SORT if MMU
91	select CLINT_TIMER if RISCV_M_MODE
92	select CLONE_BACKWARDS
93	select COMMON_CLK
94	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
95	select EDAC_SUPPORT
96	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
97	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
98	select GENERIC_ARCH_TOPOLOGY
99	select GENERIC_ATOMIC64 if !64BIT
100	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
101	select GENERIC_CPU_DEVICES
102	select GENERIC_CPU_VULNERABILITIES
103	select GENERIC_EARLY_IOREMAP
104	select GENERIC_ENTRY
105	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
106	select GENERIC_IDLE_POLL_SETUP
107	select GENERIC_IOREMAP if MMU
108	select GENERIC_IRQ_IPI if SMP
109	select GENERIC_IRQ_IPI_MUX if SMP
110	select GENERIC_IRQ_MULTI_HANDLER
111	select GENERIC_IRQ_SHOW
112	select GENERIC_IRQ_SHOW_LEVEL
113	select GENERIC_LIB_DEVMEM_IS_ALLOWED
114	select GENERIC_PCI_IOMAP
115	select GENERIC_PTDUMP if MMU
116	select GENERIC_SCHED_CLOCK
117	select GENERIC_SMP_IDLE_THREAD
118	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
119	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
120	select HARDIRQS_SW_RESEND
121	select HAS_IOPORT if MMU
122	select HAVE_ALIGNED_STRUCT_PAGE
123	select HAVE_ARCH_AUDITSYSCALL
124	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
125	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
126	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
127	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
128	select HAVE_ARCH_KASAN if MMU && 64BIT
129	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
130	select HAVE_ARCH_KFENCE if MMU && 64BIT
131	select HAVE_ARCH_KGDB if !XIP_KERNEL
132	select HAVE_ARCH_KGDB_QXFER_PKT
133	select HAVE_ARCH_MMAP_RND_BITS if MMU
134	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
135	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
136	select HAVE_ARCH_SECCOMP_FILTER
137	select HAVE_ARCH_STACKLEAK
138	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
139	select HAVE_ARCH_TRACEHOOK
140	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
141	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
142	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
143	select HAVE_ASM_MODVERSIONS
144	select HAVE_CONTEXT_TRACKING_USER
145	select HAVE_DEBUG_KMEMLEAK
146	select HAVE_DMA_CONTIGUOUS if MMU
147	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
148	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
149	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
150	select HAVE_FTRACE_GRAPH_FUNC
151	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
152	select HAVE_FUNCTION_GRAPH_TRACER
153	select HAVE_FUNCTION_GRAPH_FREGS
154	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
155	select HAVE_EBPF_JIT if MMU
156	select HAVE_GUP_FAST if MMU
157	select HAVE_FUNCTION_ARG_ACCESS_API
158	select HAVE_FUNCTION_ERROR_INJECTION
159	select HAVE_GCC_PLUGINS
160	select HAVE_GENERIC_VDSO if MMU && 64BIT
161	select HAVE_IRQ_TIME_ACCOUNTING
162	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
163	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
164	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
165	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
166	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
167	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
168	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
169	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
170	select HAVE_KPROBES if !XIP_KERNEL
171	select HAVE_KRETPROBES if !XIP_KERNEL
172	# https://github.com/ClangBuiltLinux/linux/issues/1881
173	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
174	select HAVE_MOVE_PMD
175	select HAVE_MOVE_PUD
176	select HAVE_PAGE_SIZE_4KB
177	select HAVE_PCI
178	select HAVE_PERF_EVENTS
179	select HAVE_PERF_REGS
180	select HAVE_PERF_USER_STACK_DUMP
181	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
182	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
183	select HAVE_REGS_AND_STACK_ACCESS_API
184	select HAVE_RETHOOK if !XIP_KERNEL
185	select HAVE_RSEQ
186	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
187	select HAVE_SAMPLE_FTRACE_DIRECT
188	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
189	select HAVE_STACKPROTECTOR
190	select HAVE_SYSCALL_TRACEPOINTS
191	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
192	select IRQ_DOMAIN
193	select IRQ_FORCED_THREADING
194	select KASAN_VMALLOC if KASAN
195	select LOCK_MM_AND_FIND_VMA
196	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
197	select MODULES_USE_ELF_RELA if MODULES
198	select OF
199	select OF_EARLY_FLATTREE
200	select OF_IRQ
201	select PCI_DOMAINS_GENERIC if PCI
202	select PCI_ECAM if (ACPI && PCI)
203	select PCI_MSI if PCI
204	select RISCV_ALTERNATIVE if !XIP_KERNEL
205	select RISCV_APLIC
206	select RISCV_IMSIC
207	select RISCV_INTC
208	select RISCV_TIMER if RISCV_SBI
209	select SIFIVE_PLIC
210	select SPARSE_IRQ
211	select SYSCTL_EXCEPTION_TRACE
212	select THREAD_INFO_IN_TASK
213	select TRACE_IRQFLAGS_SUPPORT
214	select UACCESS_MEMCPY if !MMU
215	select USER_STACKTRACE_SUPPORT
216	select ZONE_DMA32 if 64BIT
217
218config RUSTC_SUPPORTS_RISCV
219	def_bool y
220	depends on 64BIT
221	# Shadow call stack requires rustc version 1.82+ due to use of the
222	# -Zsanitizer=shadow-call-stack flag.
223	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
224
225config CLANG_SUPPORTS_DYNAMIC_FTRACE
226	def_bool CC_IS_CLANG
227	# https://github.com/ClangBuiltLinux/linux/issues/1817
228	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
229
230config GCC_SUPPORTS_DYNAMIC_FTRACE
231	def_bool CC_IS_GCC
232	depends on $(cc-option,-fpatchable-function-entry=8)
233
234config HAVE_SHADOW_CALL_STACK
235	def_bool $(cc-option,-fsanitize=shadow-call-stack)
236	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
237	depends on $(ld-option,--no-relax-gp)
238
239config RISCV_USE_LINKER_RELAXATION
240	def_bool y
241	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
242	depends on !LD_IS_LLD || LLD_VERSION >= 150000
243
244# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
245config ARCH_HAS_BROKEN_DWARF5
246	def_bool y
247	depends on RISCV_USE_LINKER_RELAXATION
248	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
249	depends on AS_IS_LLVM && AS_VERSION < 180000
250	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
251	depends on LD_IS_LLD && LLD_VERSION < 180000
252
253config ARCH_MMAP_RND_BITS_MIN
254	default 18 if 64BIT
255	default 8
256
257config ARCH_MMAP_RND_COMPAT_BITS_MIN
258	default 8
259
260# max bits determined by the following formula:
261#  VA_BITS - PAGE_SHIFT - 3
262config ARCH_MMAP_RND_BITS_MAX
263	default 24 if 64BIT # SV39 based
264	default 17
265
266config ARCH_MMAP_RND_COMPAT_BITS_MAX
267	default 17
268
269# set if we run in machine mode, cleared if we run in supervisor mode
270config RISCV_M_MODE
271	bool "Build a kernel that runs in machine mode"
272	depends on !MMU
273	default y
274	help
275	  Select this option if you want to run the kernel in M-mode,
276	  without the assistance of any other firmware.
277
278# set if we are running in S-mode and can use SBI calls
279config RISCV_SBI
280	bool
281	depends on !RISCV_M_MODE
282	default y
283
284config MMU
285	bool "MMU-based Paged Memory Management Support"
286	default y
287	help
288	  Select if you want MMU-based virtualised addressing space
289	  support by paged memory management. If unsure, say 'Y'.
290
291config PAGE_OFFSET
292	hex
293	default 0x80000000 if !MMU && RISCV_M_MODE
294	default 0x80200000 if !MMU
295	default 0xc0000000 if 32BIT
296	default 0xff60000000000000 if 64BIT
297
298config KASAN_SHADOW_OFFSET
299	hex
300	depends on KASAN_GENERIC
301	default 0xdfffffff00000000 if 64BIT
302	default 0xffffffff if 32BIT
303
304config ARCH_FLATMEM_ENABLE
305	def_bool !NUMA
306
307config ARCH_SPARSEMEM_ENABLE
308	def_bool y
309	depends on MMU
310	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
311	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
312
313config ARCH_SELECT_MEMORY_MODEL
314	def_bool ARCH_SPARSEMEM_ENABLE
315
316config ARCH_SUPPORTS_UPROBES
317	def_bool y
318
319config STACKTRACE_SUPPORT
320	def_bool y
321
322config GENERIC_BUG
323	def_bool y
324	depends on BUG
325	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
326
327config GENERIC_BUG_RELATIVE_POINTERS
328	bool
329
330config GENERIC_CALIBRATE_DELAY
331	def_bool y
332
333config GENERIC_CSUM
334	def_bool y
335
336config GENERIC_HWEIGHT
337	def_bool y
338
339config FIX_EARLYCON_MEM
340	def_bool MMU
341
342config ILLEGAL_POINTER_VALUE
343	hex
344	default 0 if 32BIT
345	default 0xdead000000000000 if 64BIT
346
347config PGTABLE_LEVELS
348	int
349	default 5 if 64BIT
350	default 2
351
352config LOCKDEP_SUPPORT
353	def_bool y
354
355config RISCV_DMA_NONCOHERENT
356	bool
357	select ARCH_HAS_DMA_PREP_COHERENT
358	select ARCH_HAS_SETUP_DMA_OPS
359	select ARCH_HAS_SYNC_DMA_FOR_CPU
360	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
361	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
362
363config RISCV_NONSTANDARD_CACHE_OPS
364	bool
365	help
366	  This enables function pointer support for non-standard noncoherent
367	  systems to handle cache management.
368
369config AS_HAS_INSN
370	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
371
372config AS_HAS_OPTION_ARCH
373	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
374	def_bool y
375	depends on $(as-instr, .option arch$(comma) +m)
376
377source "arch/riscv/Kconfig.socs"
378source "arch/riscv/Kconfig.errata"
379
380menu "Platform type"
381
382config NONPORTABLE
383	bool "Allow configurations that result in non-portable kernels"
384	help
385	  RISC-V kernel binaries are compatible between all known systems
386	  whenever possible, but there are some use cases that can only be
387	  satisfied by configurations that result in kernel binaries that are
388	  not portable between systems.
389
390	  Selecting N does not guarantee kernels will be portable to all known
391	  systems.  Selecting any of the options guarded by NONPORTABLE will
392	  result in kernel binaries that are unlikely to be portable between
393	  systems.
394
395	  If unsure, say N.
396
397choice
398	prompt "Base ISA"
399	default ARCH_RV64I
400	help
401	  This selects the base ISA that this kernel will target and must match
402	  the target platform.
403
404config ARCH_RV32I
405	bool "RV32I"
406	depends on NONPORTABLE
407	select 32BIT
408	select GENERIC_LIB_ASHLDI3
409	select GENERIC_LIB_ASHRDI3
410	select GENERIC_LIB_LSHRDI3
411	select GENERIC_LIB_UCMPDI2
412
413config ARCH_RV64I
414	bool "RV64I"
415	select 64BIT
416	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
417	select SWIOTLB if MMU
418
419endchoice
420
421# We must be able to map all physical memory into the kernel, but the compiler
422# is still a bit more efficient when generating code if it's setup in a manner
423# such that it can only map 2GiB of memory.
424choice
425	prompt "Kernel Code Model"
426	default CMODEL_MEDLOW if 32BIT
427	default CMODEL_MEDANY if 64BIT
428
429	config CMODEL_MEDLOW
430		bool "medium low code model"
431	config CMODEL_MEDANY
432		bool "medium any code model"
433endchoice
434
435config MODULE_SECTIONS
436	bool
437	select HAVE_MOD_ARCH_SPECIFIC
438
439config SMP
440	bool "Symmetric Multi-Processing"
441	help
442	  This enables support for systems with more than one CPU.  If
443	  you say N here, the kernel will run on single and
444	  multiprocessor machines, but will use only one CPU of a
445	  multiprocessor machine. If you say Y here, the kernel will run
446	  on many, but not all, single processor machines. On a single
447	  processor machine, the kernel will run faster if you say N
448	  here.
449
450	  If you don't know what to do here, say N.
451
452config SCHED_MC
453	bool "Multi-core scheduler support"
454	depends on SMP
455	help
456	  Multi-core scheduler support improves the CPU scheduler's decision
457	  making when dealing with multi-core CPU chips at a cost of slightly
458	  increased overhead in some places. If unsure say N here.
459
460config NR_CPUS
461	int "Maximum number of CPUs (2-512)"
462	depends on SMP
463	range 2 512 if !RISCV_SBI_V01
464	range 2 32 if RISCV_SBI_V01 && 32BIT
465	range 2 64 if RISCV_SBI_V01 && 64BIT
466	default "32" if 32BIT
467	default "64" if 64BIT
468
469config HOTPLUG_CPU
470	bool "Support for hot-pluggable CPUs"
471	depends on SMP
472	select GENERIC_IRQ_MIGRATION
473	help
474
475	  Say Y here to experiment with turning CPUs off and on.  CPUs
476	  can be controlled through /sys/devices/system/cpu.
477
478	  Say N if you want to disable CPU hotplug.
479
480choice
481	prompt "CPU Tuning"
482	default TUNE_GENERIC
483
484config TUNE_GENERIC
485	bool "generic"
486
487endchoice
488
489# Common NUMA Features
490config NUMA
491	bool "NUMA Memory Allocation and Scheduler Support"
492	depends on SMP && MMU
493	select ARCH_SUPPORTS_NUMA_BALANCING
494	select GENERIC_ARCH_NUMA
495	select HAVE_SETUP_PER_CPU_AREA
496	select NEED_PER_CPU_EMBED_FIRST_CHUNK
497	select NEED_PER_CPU_PAGE_FIRST_CHUNK
498	select OF_NUMA
499	select USE_PERCPU_NUMA_NODE_ID
500	help
501	  Enable NUMA (Non-Uniform Memory Access) support.
502
503	  The kernel will try to allocate memory used by a CPU on the
504	  local memory of the CPU and add some more NUMA awareness to the kernel.
505
506config NODES_SHIFT
507	int "Maximum NUMA Nodes (as a power of 2)"
508	range 1 10
509	default "2"
510	depends on NUMA
511	help
512	  Specify the maximum number of NUMA Nodes available on the target
513	  system.  Increases memory reserved to accommodate various tables.
514
515choice
516	prompt "RISC-V spinlock type"
517	default RISCV_COMBO_SPINLOCKS
518
519config RISCV_TICKET_SPINLOCKS
520	bool "Using ticket spinlock"
521
522config RISCV_QUEUED_SPINLOCKS
523	bool "Using queued spinlock"
524	depends on SMP && MMU && NONPORTABLE
525	select ARCH_USE_QUEUED_SPINLOCKS
526	help
527	  The queued spinlock implementation requires the forward progress
528	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
529	  LR/SC with Ziccrse provide such guarantee.
530
531	  Select this if and only if Zabha or Ziccrse is available on your
532	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
533	  without one of those extensions.
534
535	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
536	  when supported and otherwise ticket spinlocks.
537
538config RISCV_COMBO_SPINLOCKS
539	bool "Using combo spinlock"
540	depends on SMP && MMU
541	select ARCH_USE_QUEUED_SPINLOCKS
542	help
543	  Embed both queued spinlock and ticket lock so that the spinlock
544	  implementation can be chosen at runtime.
545
546endchoice
547
548config RISCV_ALTERNATIVE
549	bool
550	depends on !XIP_KERNEL
551	help
552	  This Kconfig allows the kernel to automatically patch the
553	  erratum or cpufeature required by the execution platform at run
554	  time. The code patching overhead is minimal, as it's only done
555	  once at boot and once on each module load.
556
557config RISCV_ALTERNATIVE_EARLY
558	bool
559	depends on RISCV_ALTERNATIVE
560	help
561	  Allows early patching of the kernel for special errata
562
563config RISCV_ISA_C
564	bool "Emit compressed instructions when building Linux"
565	default y
566	help
567	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
568	  when building Linux, which results in compressed instructions in the
569	  Linux binary.
570
571	  If you don't know what to do here, say Y.
572
573config RISCV_ISA_SUPM
574	bool "Supm extension for userspace pointer masking"
575	depends on 64BIT
576	default y
577	help
578	  Add support for pointer masking in userspace (Supm) when the
579	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
580
581	  If this option is disabled, userspace will be unable to use
582	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
583
584config RISCV_ISA_SVNAPOT
585	bool "Svnapot extension support for supervisor mode NAPOT pages"
586	depends on 64BIT && MMU
587	depends on RISCV_ALTERNATIVE
588	default y
589	help
590	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
591	  time and enable its usage.
592
593	  The Svnapot extension is used to mark contiguous PTEs as a range
594	  of contiguous virtual-to-physical translations for a naturally
595	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
596	  size. When HUGETLBFS is also selected this option unconditionally
597	  allocates some memory for each NAPOT page size supported by the kernel.
598	  When optimizing for low memory consumption and for platforms without
599	  the Svnapot extension, it may be better to say N here.
600
601	  If you don't know what to do here, say Y.
602
603config RISCV_ISA_SVPBMT
604	bool "Svpbmt extension support for supervisor mode page-based memory types"
605	depends on 64BIT && MMU
606	depends on RISCV_ALTERNATIVE
607	default y
608	help
609	   Adds support to dynamically detect the presence of the Svpbmt
610	   ISA-extension (Supervisor-mode: page-based memory types) and
611	   enable its usage.
612
613	   The memory type for a page contains a combination of attributes
614	   that indicate the cacheability, idempotency, and ordering
615	   properties for access to that page.
616
617	   The Svpbmt extension is only available on 64-bit cpus.
618
619	   If you don't know what to do here, say Y.
620
621config TOOLCHAIN_HAS_V
622	bool
623	default y
624	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
625	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
626	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
627	depends on AS_HAS_OPTION_ARCH
628
629config RISCV_ISA_V
630	bool "VECTOR extension support"
631	depends on TOOLCHAIN_HAS_V
632	depends on FPU
633	select DYNAMIC_SIGFRAME
634	default y
635	help
636	  Say N here if you want to disable all vector related procedure
637	  in the kernel.
638
639	  If you don't know what to do here, say Y.
640
641config RISCV_ISA_V_DEFAULT_ENABLE
642	bool "Enable userspace Vector by default"
643	depends on RISCV_ISA_V
644	default y
645	help
646	  Say Y here if you want to enable Vector in userspace by default.
647	  Otherwise, userspace has to make explicit prctl() call to enable
648	  Vector, or enable it via the sysctl interface.
649
650	  If you don't know what to do here, say Y.
651
652config RISCV_ISA_V_UCOPY_THRESHOLD
653	int "Threshold size for vectorized user copies"
654	depends on RISCV_ISA_V
655	default 768
656	help
657	  Prefer using vectorized copy_to_user()/copy_from_user() when the
658	  workload size exceeds this value.
659
660config RISCV_ISA_V_PREEMPTIVE
661	bool "Run kernel-mode Vector with kernel preemption"
662	depends on PREEMPTION
663	depends on RISCV_ISA_V
664	default y
665	help
666	  Usually, in-kernel SIMD routines are run with preemption disabled.
667	  Functions which envoke long running SIMD thus must yield core's
668	  vector unit to prevent blocking other tasks for too long.
669
670	  This config allows kernel to run SIMD without explicitly disable
671	  preemption. Enabling this config will result in higher memory
672	  consumption due to the allocation of per-task's kernel Vector context.
673
674config RISCV_ISA_ZAWRS
675	bool "Zawrs extension support for more efficient busy waiting"
676	depends on RISCV_ALTERNATIVE
677	default y
678	help
679	  The Zawrs extension defines instructions to be used in polling loops
680	  which allow a hart to enter a low-power state or to trap to the
681	  hypervisor while waiting on a store to a memory location. Enable the
682	  use of these instructions in the kernel when the Zawrs extension is
683	  detected at boot.
684
685config TOOLCHAIN_HAS_ZABHA
686	bool
687	default y
688	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
689	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
690	depends on AS_HAS_OPTION_ARCH
691
692config RISCV_ISA_ZABHA
693	bool "Zabha extension support for atomic byte/halfword operations"
694	depends on TOOLCHAIN_HAS_ZABHA
695	depends on RISCV_ALTERNATIVE
696	default y
697	help
698	  Enable the use of the Zabha ISA-extension to implement kernel
699	  byte/halfword atomic memory operations when it is detected at boot.
700
701	  If you don't know what to do here, say Y.
702
703config TOOLCHAIN_HAS_ZACAS
704	bool
705	default y
706	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
707	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
708	depends on AS_HAS_OPTION_ARCH
709
710config RISCV_ISA_ZACAS
711	bool "Zacas extension support for atomic CAS"
712	depends on TOOLCHAIN_HAS_ZACAS
713	depends on RISCV_ALTERNATIVE
714	default y
715	help
716	  Enable the use of the Zacas ISA-extension to implement kernel atomic
717	  cmpxchg operations when it is detected at boot.
718
719	  If you don't know what to do here, say Y.
720
721config TOOLCHAIN_HAS_ZBB
722	bool
723	default y
724	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
725	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
726	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
727	depends on AS_HAS_OPTION_ARCH
728
729# This symbol indicates that the toolchain supports all v1.0 vector crypto
730# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
731# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
732config TOOLCHAIN_HAS_VECTOR_CRYPTO
733	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
734	depends on AS_HAS_OPTION_ARCH
735
736config RISCV_ISA_ZBA
737	bool "Zba extension support for bit manipulation instructions"
738	default y
739	help
740	   Add support for enabling optimisations in the kernel when the Zba
741	   extension is detected at boot.
742
743	   The Zba extension provides instructions to accelerate the generation
744	   of addresses that index into arrays of basic data types.
745
746	   If you don't know what to do here, say Y.
747
748config RISCV_ISA_ZBB
749	bool "Zbb extension support for bit manipulation instructions"
750	depends on TOOLCHAIN_HAS_ZBB
751	depends on RISCV_ALTERNATIVE
752	default y
753	help
754	   Adds support to dynamically detect the presence of the ZBB
755	   extension (basic bit manipulation) and enable its usage.
756
757	   The Zbb extension provides instructions to accelerate a number
758	   of bit-specific operations (count bit population, sign extending,
759	   bitrotation, etc).
760
761	   If you don't know what to do here, say Y.
762
763config TOOLCHAIN_HAS_ZBC
764	bool
765	default y
766	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
767	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
768	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
769	depends on AS_HAS_OPTION_ARCH
770
771config RISCV_ISA_ZBC
772	bool "Zbc extension support for carry-less multiplication instructions"
773	depends on TOOLCHAIN_HAS_ZBC
774	depends on MMU
775	depends on RISCV_ALTERNATIVE
776	default y
777	help
778	   Adds support to dynamically detect the presence of the Zbc
779	   extension (carry-less multiplication) and enable its usage.
780
781	   The Zbc extension could accelerate CRC (cyclic redundancy check)
782	   calculations.
783
784	   If you don't know what to do here, say Y.
785
786config RISCV_ISA_ZICBOM
787	bool "Zicbom extension support for non-coherent DMA operation"
788	depends on MMU
789	depends on RISCV_ALTERNATIVE
790	default y
791	select RISCV_DMA_NONCOHERENT
792	select DMA_DIRECT_REMAP
793	help
794	   Adds support to dynamically detect the presence of the ZICBOM
795	   extension (Cache Block Management Operations) and enable its
796	   usage.
797
798	   The Zicbom extension can be used to handle for example
799	   non-coherent DMA support on devices that need it.
800
801	   If you don't know what to do here, say Y.
802
803config RISCV_ISA_ZICBOZ
804	bool "Zicboz extension support for faster zeroing of memory"
805	depends on RISCV_ALTERNATIVE
806	default y
807	help
808	   Enable the use of the Zicboz extension (cbo.zero instruction)
809	   when available.
810
811	   The Zicboz extension is used for faster zeroing of memory.
812
813	   If you don't know what to do here, say Y.
814
815config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
816	def_bool y
817	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
818	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
819	depends on AS_IS_GNU && AS_VERSION >= 23600
820	help
821	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
822	  20191213 version, which moves some instructions from the I extension to
823	  the Zicsr and Zifencei extensions. This requires explicitly specifying
824	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
825	  and Zifencei are supported in binutils from version 2.36 onwards.
826	  To make life easier, and avoid forcing toolchains that default to a
827	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
828	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
829	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
830
831config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
832	def_bool y
833	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
834	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
835	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
836	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
837	help
838	  Certain versions of clang and GCC do not support zicsr and zifencei via
839	  -march. This option causes an older ISA spec compatible with these older
840	  versions of clang and GCC to be passed to GAS, which has the same result
841	  as passing zicsr and zifencei to -march.
842
843config FPU
844	bool "FPU support"
845	default y
846	help
847	  Say N here if you want to disable all floating-point related procedure
848	  in the kernel.
849
850	  If you don't know what to do here, say Y.
851
852config IRQ_STACKS
853	bool "Independent irq & softirq stacks" if EXPERT
854	default y
855	select HAVE_IRQ_EXIT_ON_IRQ_STACK
856	select HAVE_SOFTIRQ_ON_OWN_STACK
857	help
858	  Add independent irq & softirq stacks for percpu to prevent kernel stack
859	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
860
861config THREAD_SIZE_ORDER
862	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
863	range 0 4
864	default 1 if 32BIT
865	default 2
866	help
867	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
868	  affects irq stack size, which is equal to thread stack size.
869
870config RISCV_MISALIGNED
871	bool
872	help
873	  Embed support for detecting and emulating misaligned
874	  scalar or vector loads and stores.
875
876config RISCV_SCALAR_MISALIGNED
877	bool
878	select RISCV_MISALIGNED
879	select SYSCTL_ARCH_UNALIGN_ALLOW
880	help
881	  Embed support for emulating misaligned loads and stores.
882
883config RISCV_VECTOR_MISALIGNED
884	bool
885	select RISCV_MISALIGNED
886	depends on RISCV_ISA_V
887	help
888	  Enable detecting support for vector misaligned loads and stores.
889
890choice
891	prompt "Unaligned Accesses Support"
892	default RISCV_PROBE_UNALIGNED_ACCESS
893	help
894	  This determines the level of support for unaligned accesses. This
895	  information is used by the kernel to perform optimizations. It is also
896	  exposed to user space via the hwprobe syscall. The hardware will be
897	  probed at boot by default.
898
899config RISCV_PROBE_UNALIGNED_ACCESS
900	bool "Probe for hardware unaligned access support"
901	select RISCV_SCALAR_MISALIGNED
902	help
903	  During boot, the kernel will run a series of tests to determine the
904	  speed of unaligned accesses. This probing will dynamically determine
905	  the speed of unaligned accesses on the underlying system. If unaligned
906	  memory accesses trap into the kernel as they are not supported by the
907	  system, the kernel will emulate the unaligned accesses to preserve the
908	  UABI.
909
910config RISCV_EMULATED_UNALIGNED_ACCESS
911	bool "Emulate unaligned access where system support is missing"
912	select RISCV_SCALAR_MISALIGNED
913	help
914	  If unaligned memory accesses trap into the kernel as they are not
915	  supported by the system, the kernel will emulate the unaligned
916	  accesses to preserve the UABI. When the underlying system does support
917	  unaligned accesses, the unaligned accesses are assumed to be slow.
918
919config RISCV_SLOW_UNALIGNED_ACCESS
920	bool "Assume the system supports slow unaligned memory accesses"
921	depends on NONPORTABLE
922	help
923	  Assume that the system supports slow unaligned memory accesses. The
924	  kernel and userspace programs may not be able to run at all on systems
925	  that do not support unaligned memory accesses.
926
927config RISCV_EFFICIENT_UNALIGNED_ACCESS
928	bool "Assume the system supports fast unaligned memory accesses"
929	depends on NONPORTABLE
930	select DCACHE_WORD_ACCESS if MMU
931	select HAVE_EFFICIENT_UNALIGNED_ACCESS
932	help
933	  Assume that the system supports fast unaligned memory accesses. When
934	  enabled, this option improves the performance of the kernel on such
935	  systems. However, the kernel and userspace programs will run much more
936	  slowly, or will not be able to run at all, on systems that do not
937	  support efficient unaligned memory accesses.
938
939endchoice
940
941choice
942	prompt "Vector unaligned Accesses Support"
943	depends on RISCV_ISA_V
944	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
945	help
946	  This determines the level of support for vector unaligned accesses. This
947	  information is used by the kernel to perform optimizations. It is also
948	  exposed to user space via the hwprobe syscall. The hardware will be
949	  probed at boot by default.
950
951config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
952	bool "Probe speed of vector unaligned accesses"
953	select RISCV_VECTOR_MISALIGNED
954	depends on RISCV_ISA_V
955	help
956	  During boot, the kernel will run a series of tests to determine the
957	  speed of vector unaligned accesses if they are supported. This probing
958	  will dynamically determine the speed of vector unaligned accesses on
959	  the underlying system if they are supported.
960
961config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
962	bool "Assume the system supports slow vector unaligned memory accesses"
963	depends on NONPORTABLE
964	help
965	  Assume that the system supports slow vector unaligned memory accesses. The
966	  kernel and userspace programs may not be able to run at all on systems
967	  that do not support unaligned memory accesses.
968
969config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
970	bool "Assume the system supports fast vector unaligned memory accesses"
971	depends on NONPORTABLE
972	help
973	  Assume that the system supports fast vector unaligned memory accesses. When
974	  enabled, this option improves the performance of the kernel on such
975	  systems. However, the kernel and userspace programs will run much more
976	  slowly, or will not be able to run at all, on systems that do not
977	  support efficient unaligned memory accesses.
978
979endchoice
980
981source "arch/riscv/Kconfig.vendor"
982
983endmenu # "Platform type"
984
985menu "Kernel features"
986
987source "kernel/Kconfig.hz"
988
989config RISCV_SBI_V01
990	bool "SBI v0.1 support"
991	depends on RISCV_SBI
992	help
993	  This config allows kernel to use SBI v0.1 APIs. This will be
994	  deprecated in future once legacy M-mode software are no longer in use.
995
996config RISCV_BOOT_SPINWAIT
997	bool "Spinwait booting method"
998	depends on SMP
999	default y if RISCV_SBI_V01 || RISCV_M_MODE
1000	help
1001	  This enables support for booting Linux via spinwait method. In the
1002	  spinwait method, all cores randomly jump to Linux. One of the cores
1003	  gets chosen via lottery and all other keep spinning on a percpu
1004	  variable. This method cannot support CPU hotplug and sparse hartid
1005	  scheme. It should be only enabled for M-mode Linux or platforms relying
1006	  on older firmware without SBI HSM extension. All other platforms should
1007	  rely on ordered booting via SBI HSM extension which gets chosen
1008	  dynamically at runtime if the firmware supports it.
1009
1010	  Since spinwait is incompatible with sparse hart IDs, it requires
1011	  NR_CPUS be large enough to contain the physical hart ID of the first
1012	  hart to enter Linux.
1013
1014	  If unsure what to do here, say N.
1015
1016config ARCH_SUPPORTS_KEXEC
1017	def_bool y
1018
1019config ARCH_SELECTS_KEXEC
1020	def_bool y
1021	depends on KEXEC
1022	select HOTPLUG_CPU if SMP
1023
1024config ARCH_SUPPORTS_KEXEC_FILE
1025	def_bool 64BIT
1026
1027config ARCH_SELECTS_KEXEC_FILE
1028	def_bool y
1029	depends on KEXEC_FILE
1030	select HAVE_IMA_KEXEC if IMA
1031	select KEXEC_ELF
1032
1033config ARCH_SUPPORTS_KEXEC_PURGATORY
1034	def_bool ARCH_SUPPORTS_KEXEC_FILE
1035
1036config ARCH_SUPPORTS_CRASH_DUMP
1037	def_bool y
1038
1039config ARCH_DEFAULT_CRASH_DUMP
1040	def_bool y
1041
1042config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1043	def_bool CRASH_RESERVE
1044
1045config COMPAT
1046	bool "Kernel support for 32-bit U-mode"
1047	default 64BIT
1048	depends on 64BIT && MMU
1049	help
1050	  This option enables support for a 32-bit U-mode running under a 64-bit
1051	  kernel at S-mode. riscv32-specific components such as system calls,
1052	  the user helper functions (vdso), signal rt_frame functions and the
1053	  ptrace interface are handled appropriately by the kernel.
1054
1055	  If you want to execute 32-bit userspace applications, say Y.
1056
1057config PARAVIRT
1058	bool "Enable paravirtualization code"
1059	depends on RISCV_SBI
1060	help
1061	  This changes the kernel so it can modify itself when it is run
1062	  under a hypervisor, potentially improving performance significantly
1063	  over full virtualization.
1064
1065config PARAVIRT_TIME_ACCOUNTING
1066	bool "Paravirtual steal time accounting"
1067	depends on PARAVIRT
1068	help
1069	  Select this option to enable fine granularity task steal time
1070	  accounting. Time spent executing other tasks in parallel with
1071	  the current vCPU is discounted from the vCPU power. To account for
1072	  that, there can be a small performance impact.
1073
1074	  If in doubt, say N here.
1075
1076config RELOCATABLE
1077	bool "Build a relocatable kernel"
1078	depends on MMU && 64BIT && !XIP_KERNEL
1079	select MODULE_SECTIONS if MODULES
1080	help
1081          This builds a kernel as a Position Independent Executable (PIE),
1082          which retains all relocation metadata required to relocate the
1083          kernel binary at runtime to a different virtual address than the
1084          address it was linked at.
1085          Since RISCV uses the RELA relocation format, this requires a
1086          relocation pass at runtime even if the kernel is loaded at the
1087          same address it was linked at.
1088
1089          If unsure, say N.
1090
1091config RANDOMIZE_BASE
1092        bool "Randomize the address of the kernel image"
1093        select RELOCATABLE
1094        depends on MMU && 64BIT && !XIP_KERNEL
1095        help
1096          Randomizes the virtual address at which the kernel image is
1097          loaded, as a security feature that deters exploit attempts
1098          relying on knowledge of the location of kernel internals.
1099
1100          It is the bootloader's job to provide entropy, by passing a
1101          random u64 value in /chosen/kaslr-seed at kernel entry.
1102
1103          When booting via the UEFI stub, it will invoke the firmware's
1104          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1105          to the kernel proper. In addition, it will randomise the physical
1106          location of the kernel Image as well.
1107
1108          If unsure, say N.
1109
1110endmenu # "Kernel features"
1111
1112menu "Boot options"
1113
1114config CMDLINE
1115	string "Built-in kernel command line"
1116	help
1117	  For most platforms, the arguments for the kernel's command line
1118	  are provided at run-time, during boot. However, there are cases
1119	  where either no arguments are being provided or the provided
1120	  arguments are insufficient or even invalid.
1121
1122	  When that occurs, it is possible to define a built-in command
1123	  line here and choose how the kernel should use it later on.
1124
1125choice
1126	prompt "Built-in command line usage"
1127	depends on CMDLINE != ""
1128	default CMDLINE_FALLBACK
1129	help
1130	  Choose how the kernel will handle the provided built-in command
1131	  line.
1132
1133config CMDLINE_FALLBACK
1134	bool "Use bootloader kernel arguments if available"
1135	help
1136	  Use the built-in command line as fallback in case we get nothing
1137	  during boot. This is the default behaviour.
1138
1139config CMDLINE_EXTEND
1140	bool "Extend bootloader kernel arguments"
1141	help
1142	  The command-line arguments provided during boot will be
1143	  appended to the built-in command line. This is useful in
1144	  cases where the provided arguments are insufficient and
1145	  you don't want to or cannot modify them.
1146
1147config CMDLINE_FORCE
1148	bool "Always use the default kernel command string"
1149	help
1150	  Always use the built-in command line, even if we get one during
1151	  boot. This is useful in case you need to override the provided
1152	  command line on systems where you don't have or want control
1153	  over it.
1154
1155endchoice
1156
1157config EFI_STUB
1158	bool
1159
1160config EFI
1161	bool "UEFI runtime support"
1162	depends on OF && !XIP_KERNEL
1163	depends on MMU
1164	default y
1165	select ARCH_SUPPORTS_ACPI if 64BIT
1166	select EFI_GENERIC_STUB
1167	select EFI_PARAMS_FROM_FDT
1168	select EFI_RUNTIME_WRAPPERS
1169	select EFI_STUB
1170	select LIBFDT
1171	select RISCV_ISA_C
1172	select UCS2_STRING
1173	help
1174	  This option provides support for runtime services provided
1175	  by UEFI firmware (such as non-volatile variables, realtime
1176	  clock, and platform reset). A UEFI stub is also provided to
1177	  allow the kernel to be booted as an EFI application. This
1178	  is only useful on systems that have UEFI firmware.
1179
1180config DMI
1181	bool "Enable support for SMBIOS (DMI) tables"
1182	depends on EFI
1183	default y
1184	help
1185	  This enables SMBIOS/DMI feature for systems.
1186
1187	  This option is only useful on systems that have UEFI firmware.
1188	  However, even with this option, the resultant kernel should
1189	  continue to boot on existing non-UEFI platforms.
1190
1191config CC_HAVE_STACKPROTECTOR_TLS
1192	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1193
1194config STACKPROTECTOR_PER_TASK
1195	def_bool y
1196	depends on !RANDSTRUCT
1197	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1198
1199config PHYS_RAM_BASE_FIXED
1200	bool "Explicitly specified physical RAM address"
1201	depends on NONPORTABLE
1202	default n
1203
1204config PHYS_RAM_BASE
1205	hex "Platform Physical RAM address"
1206	depends on PHYS_RAM_BASE_FIXED
1207	default "0x80000000"
1208	help
1209	  This is the physical address of RAM in the system. It has to be
1210	  explicitly specified to run early relocations of read-write data
1211	  from flash to RAM.
1212
1213config XIP_KERNEL
1214	bool "Kernel Execute-In-Place from ROM"
1215	depends on MMU && SPARSEMEM && NONPORTABLE
1216	# This prevents XIP from being enabled by all{yes,mod}config, which
1217	# fail to build since XIP doesn't support large kernels.
1218	depends on !COMPILE_TEST
1219	select PHYS_RAM_BASE_FIXED
1220	help
1221	  Execute-In-Place allows the kernel to run from non-volatile storage
1222	  directly addressable by the CPU, such as NOR flash. This saves RAM
1223	  space since the text section of the kernel is not loaded from flash
1224	  to RAM.  Read-write sections, such as the data section and stack,
1225	  are still copied to RAM.  The XIP kernel is not compressed since
1226	  it has to run directly from flash, so it will take more space to
1227	  store it.  The flash address used to link the kernel object files,
1228	  and for storing it, is configuration dependent. Therefore, if you
1229	  say Y here, you must know the proper physical address where to
1230	  store the kernel image depending on your own flash memory usage.
1231
1232	  Also note that the make target becomes "make xipImage" rather than
1233	  "make zImage" or "make Image".  The final kernel binary to put in
1234	  ROM memory will be arch/riscv/boot/xipImage.
1235
1236	  SPARSEMEM is required because the kernel text and rodata that are
1237	  flash resident are not backed by memmap, then any attempt to get
1238	  a struct page on those regions will trigger a fault.
1239
1240	  If unsure, say N.
1241
1242config XIP_PHYS_ADDR
1243	hex "XIP Kernel Physical Location"
1244	depends on XIP_KERNEL
1245	default "0x21000000"
1246	help
1247	  This is the physical address in your flash memory the kernel will
1248	  be linked for and stored to.  This address is dependent on your
1249	  own flash usage.
1250
1251config RISCV_ISA_FALLBACK
1252	bool "Permit falling back to parsing riscv,isa for extension support by default"
1253	default y
1254	help
1255	  Parsing the "riscv,isa" devicetree property has been deprecated and
1256	  replaced by a list of explicitly defined strings. For compatibility
1257	  with existing platforms, the kernel will fall back to parsing the
1258	  "riscv,isa" property if the replacements are not found.
1259
1260	  Selecting N here will result in a kernel that does not use the
1261	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1262	  present.
1263
1264	  Please see the dt-binding, located at
1265	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1266	  on the replacement properties, "riscv,isa-base" and
1267	  "riscv,isa-extensions".
1268
1269config BUILTIN_DTB
1270	bool "Built-in device tree"
1271	depends on OF && NONPORTABLE
1272	help
1273	  Build a device tree into the Linux image.
1274	  This option should be selected if no bootloader is being used.
1275	  If unsure, say N.
1276
1277
1278config BUILTIN_DTB_SOURCE
1279	string "Built-in device tree source"
1280	depends on BUILTIN_DTB
1281	help
1282	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1283	  for the DTS file that will be used to produce the DTB linked into the
1284	  kernel.
1285
1286endmenu # "Boot options"
1287
1288config PORTABLE
1289	bool
1290	default !NONPORTABLE
1291	select EFI
1292	select MMU
1293	select OF
1294
1295config ARCH_PROC_KCORE_TEXT
1296	def_bool y
1297
1298menu "Power management options"
1299
1300source "kernel/power/Kconfig"
1301
1302config ARCH_HIBERNATION_POSSIBLE
1303	def_bool y
1304
1305config ARCH_HIBERNATION_HEADER
1306	def_bool HIBERNATION
1307
1308config ARCH_SUSPEND_POSSIBLE
1309	def_bool y
1310
1311endmenu # "Power management options"
1312
1313menu "CPU Power Management"
1314
1315source "drivers/cpuidle/Kconfig"
1316
1317source "drivers/cpufreq/Kconfig"
1318
1319endmenu # "CPU Power Management"
1320
1321source "arch/riscv/kvm/Kconfig"
1322
1323source "drivers/acpi/Kconfig"
1324