xref: /linux/arch/riscv/Kconfig (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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_CURRENT_STACK_POINTER
28	select ARCH_HAS_DEBUG_VIRTUAL if MMU
29	select ARCH_HAS_DEBUG_VM_PGTABLE
30	select ARCH_HAS_DEBUG_WX
31	select ARCH_HAS_FAST_MULTIPLIER
32	select ARCH_HAS_FORTIFY_SOURCE
33	select ARCH_HAS_GCOV_PROFILE_ALL
34	select ARCH_HAS_GIGANTIC_PAGE
35	select ARCH_HAS_HW_PTE_YOUNG
36	select ARCH_HAS_KCOV
37	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
38	select ARCH_HAS_MEMBARRIER_CALLBACKS
39	select ARCH_HAS_MEMBARRIER_SYNC_CORE
40	select ARCH_HAS_MMIOWB
41	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
42	select ARCH_HAS_PMEM_API
43	select ARCH_HAS_PREEMPT_LAZY
44	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
45	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_SET_DIRECT_MAP if MMU
48	select ARCH_HAS_SET_MEMORY if MMU
49	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
50	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
51	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
52	select ARCH_HAS_SYSCALL_WRAPPER
53	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
54	select ARCH_HAS_UBSAN
55	select ARCH_HAS_VDSO_TIME_DATA
56	select ARCH_KEEP_MEMBLOCK if ACPI
57	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
58	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
59	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
60	select ARCH_STACKWALK
61	select ARCH_SUPPORTS_ATOMIC_RMW
62	select ARCH_SUPPORTS_CFI_CLANG
63	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
64	select ARCH_SUPPORTS_HUGETLBFS if MMU
65	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
66	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
67	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
68	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
69	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
70	select ARCH_SUPPORTS_RT
71	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
72	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
73	select ARCH_USE_MEMTEST
74	select ARCH_USE_QUEUED_RWLOCKS
75	select ARCH_USE_SYM_ANNOTATIONS
76	select ARCH_USES_CFI_TRAPS if CFI_CLANG
77	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
78	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
79	select ARCH_WANT_FRAME_POINTERS
80	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
81	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
82	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
83	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
84	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
85	select ARCH_WANTS_NO_INSTR
86	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
87	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
88	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
89	select BUILDTIME_TABLE_SORT if MMU
90	select CLINT_TIMER if RISCV_M_MODE
91	select CLONE_BACKWARDS
92	select COMMON_CLK
93	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
94	select EDAC_SUPPORT
95	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
96	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
97	select GENERIC_ARCH_TOPOLOGY
98	select GENERIC_ATOMIC64 if !64BIT
99	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
100	select GENERIC_CPU_DEVICES
101	select GENERIC_CPU_VULNERABILITIES
102	select GENERIC_EARLY_IOREMAP
103	select GENERIC_ENTRY
104	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
105	select GENERIC_IDLE_POLL_SETUP
106	select GENERIC_IOREMAP if MMU
107	select GENERIC_IRQ_IPI if SMP
108	select GENERIC_IRQ_IPI_MUX if SMP
109	select GENERIC_IRQ_MULTI_HANDLER
110	select GENERIC_IRQ_SHOW
111	select GENERIC_IRQ_SHOW_LEVEL
112	select GENERIC_LIB_DEVMEM_IS_ALLOWED
113	select GENERIC_PCI_IOMAP
114	select GENERIC_PTDUMP if MMU
115	select GENERIC_SCHED_CLOCK
116	select GENERIC_SMP_IDLE_THREAD
117	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
118	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
119	select HARDIRQS_SW_RESEND
120	select HAS_IOPORT if MMU
121	select HAVE_ALIGNED_STRUCT_PAGE
122	select HAVE_ARCH_AUDITSYSCALL
123	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
124	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
125	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
126	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
127	select HAVE_ARCH_KASAN if MMU && 64BIT
128	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
129	select HAVE_ARCH_KFENCE if MMU && 64BIT
130	select HAVE_ARCH_KGDB if !XIP_KERNEL
131	select HAVE_ARCH_KGDB_QXFER_PKT
132	select HAVE_ARCH_MMAP_RND_BITS if MMU
133	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
134	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
135	select HAVE_ARCH_SECCOMP_FILTER
136	select HAVE_ARCH_STACKLEAK
137	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
138	select HAVE_ARCH_TRACEHOOK
139	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
140	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
141	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
142	select HAVE_ASM_MODVERSIONS
143	select HAVE_CONTEXT_TRACKING_USER
144	select HAVE_DEBUG_KMEMLEAK
145	select HAVE_DMA_CONTIGUOUS if MMU
146	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
147	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
148	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
149	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
150	select HAVE_FUNCTION_GRAPH_TRACER
151	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
152	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
153	select HAVE_EBPF_JIT if MMU
154	select HAVE_GUP_FAST if MMU
155	select HAVE_FUNCTION_ARG_ACCESS_API
156	select HAVE_FUNCTION_ERROR_INJECTION
157	select HAVE_GCC_PLUGINS
158	select HAVE_GENERIC_VDSO if MMU && 64BIT
159	select HAVE_IRQ_TIME_ACCOUNTING
160	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
161	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
162	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
163	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
164	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
165	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
166	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
167	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
168	select HAVE_KPROBES if !XIP_KERNEL
169	select HAVE_KRETPROBES if !XIP_KERNEL
170	# https://github.com/ClangBuiltLinux/linux/issues/1881
171	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
172	select HAVE_MOVE_PMD
173	select HAVE_MOVE_PUD
174	select HAVE_PAGE_SIZE_4KB
175	select HAVE_PCI
176	select HAVE_PERF_EVENTS
177	select HAVE_PERF_REGS
178	select HAVE_PERF_USER_STACK_DUMP
179	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
180	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
181	select HAVE_REGS_AND_STACK_ACCESS_API
182	select HAVE_RETHOOK if !XIP_KERNEL
183	select HAVE_RSEQ
184	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
185	select HAVE_SAMPLE_FTRACE_DIRECT
186	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
187	select HAVE_STACKPROTECTOR
188	select HAVE_SYSCALL_TRACEPOINTS
189	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
190	select IRQ_DOMAIN
191	select IRQ_FORCED_THREADING
192	select KASAN_VMALLOC if KASAN
193	select LOCK_MM_AND_FIND_VMA
194	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
195	select MODULES_USE_ELF_RELA if MODULES
196	select OF
197	select OF_EARLY_FLATTREE
198	select OF_IRQ
199	select PCI_DOMAINS_GENERIC if PCI
200	select PCI_ECAM if (ACPI && PCI)
201	select PCI_MSI if PCI
202	select RISCV_ALTERNATIVE if !XIP_KERNEL
203	select RISCV_APLIC
204	select RISCV_IMSIC
205	select RISCV_INTC
206	select RISCV_TIMER if RISCV_SBI
207	select SIFIVE_PLIC
208	select SPARSE_IRQ
209	select SYSCTL_EXCEPTION_TRACE
210	select THREAD_INFO_IN_TASK
211	select TRACE_IRQFLAGS_SUPPORT
212	select UACCESS_MEMCPY if !MMU
213	select USER_STACKTRACE_SUPPORT
214	select ZONE_DMA32 if 64BIT
215
216config RUSTC_SUPPORTS_RISCV
217	def_bool y
218	depends on 64BIT
219	# Shadow call stack requires rustc version 1.82+ due to use of the
220	# -Zsanitizer=shadow-call-stack flag.
221	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
222
223config CLANG_SUPPORTS_DYNAMIC_FTRACE
224	def_bool CC_IS_CLANG
225	# https://github.com/ClangBuiltLinux/linux/issues/1817
226	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
227
228config GCC_SUPPORTS_DYNAMIC_FTRACE
229	def_bool CC_IS_GCC
230	depends on $(cc-option,-fpatchable-function-entry=8)
231
232config HAVE_SHADOW_CALL_STACK
233	def_bool $(cc-option,-fsanitize=shadow-call-stack)
234	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
235	depends on $(ld-option,--no-relax-gp)
236
237config RISCV_USE_LINKER_RELAXATION
238	def_bool y
239	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
240	depends on !LD_IS_LLD || LLD_VERSION >= 150000
241
242# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
243config ARCH_HAS_BROKEN_DWARF5
244	def_bool y
245	depends on RISCV_USE_LINKER_RELAXATION
246	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
247	depends on AS_IS_LLVM && AS_VERSION < 180000
248	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
249	depends on LD_IS_LLD && LLD_VERSION < 180000
250
251config ARCH_MMAP_RND_BITS_MIN
252	default 18 if 64BIT
253	default 8
254
255config ARCH_MMAP_RND_COMPAT_BITS_MIN
256	default 8
257
258# max bits determined by the following formula:
259#  VA_BITS - PAGE_SHIFT - 3
260config ARCH_MMAP_RND_BITS_MAX
261	default 24 if 64BIT # SV39 based
262	default 17
263
264config ARCH_MMAP_RND_COMPAT_BITS_MAX
265	default 17
266
267# set if we run in machine mode, cleared if we run in supervisor mode
268config RISCV_M_MODE
269	bool "Build a kernel that runs in machine mode"
270	depends on !MMU
271	default y
272	help
273	  Select this option if you want to run the kernel in M-mode,
274	  without the assistance of any other firmware.
275
276# set if we are running in S-mode and can use SBI calls
277config RISCV_SBI
278	bool
279	depends on !RISCV_M_MODE
280	default y
281
282config MMU
283	bool "MMU-based Paged Memory Management Support"
284	default y
285	help
286	  Select if you want MMU-based virtualised addressing space
287	  support by paged memory management. If unsure, say 'Y'.
288
289config PAGE_OFFSET
290	hex
291	default 0x80000000 if !MMU && RISCV_M_MODE
292	default 0x80200000 if !MMU
293	default 0xc0000000 if 32BIT
294	default 0xff60000000000000 if 64BIT
295
296config KASAN_SHADOW_OFFSET
297	hex
298	depends on KASAN_GENERIC
299	default 0xdfffffff00000000 if 64BIT
300	default 0xffffffff if 32BIT
301
302config ARCH_FLATMEM_ENABLE
303	def_bool !NUMA
304
305config ARCH_SPARSEMEM_ENABLE
306	def_bool y
307	depends on MMU
308	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
309	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
310
311config ARCH_SELECT_MEMORY_MODEL
312	def_bool ARCH_SPARSEMEM_ENABLE
313
314config ARCH_SUPPORTS_UPROBES
315	def_bool y
316
317config STACKTRACE_SUPPORT
318	def_bool y
319
320config GENERIC_BUG
321	def_bool y
322	depends on BUG
323	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
324
325config GENERIC_BUG_RELATIVE_POINTERS
326	bool
327
328config GENERIC_CALIBRATE_DELAY
329	def_bool y
330
331config GENERIC_CSUM
332	def_bool y
333
334config GENERIC_HWEIGHT
335	def_bool y
336
337config FIX_EARLYCON_MEM
338	def_bool MMU
339
340config ILLEGAL_POINTER_VALUE
341	hex
342	default 0 if 32BIT
343	default 0xdead000000000000 if 64BIT
344
345config PGTABLE_LEVELS
346	int
347	default 5 if 64BIT
348	default 2
349
350config LOCKDEP_SUPPORT
351	def_bool y
352
353config RISCV_DMA_NONCOHERENT
354	bool
355	select ARCH_HAS_DMA_PREP_COHERENT
356	select ARCH_HAS_SETUP_DMA_OPS
357	select ARCH_HAS_SYNC_DMA_FOR_CPU
358	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
359	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
360
361config RISCV_NONSTANDARD_CACHE_OPS
362	bool
363	help
364	  This enables function pointer support for non-standard noncoherent
365	  systems to handle cache management.
366
367config AS_HAS_INSN
368	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
369
370config AS_HAS_OPTION_ARCH
371	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
372	def_bool y
373	depends on $(as-instr, .option arch$(comma) +m)
374
375source "arch/riscv/Kconfig.socs"
376source "arch/riscv/Kconfig.errata"
377
378menu "Platform type"
379
380config NONPORTABLE
381	bool "Allow configurations that result in non-portable kernels"
382	help
383	  RISC-V kernel binaries are compatible between all known systems
384	  whenever possible, but there are some use cases that can only be
385	  satisfied by configurations that result in kernel binaries that are
386	  not portable between systems.
387
388	  Selecting N does not guarantee kernels will be portable to all known
389	  systems.  Selecting any of the options guarded by NONPORTABLE will
390	  result in kernel binaries that are unlikely to be portable between
391	  systems.
392
393	  If unsure, say N.
394
395choice
396	prompt "Base ISA"
397	default ARCH_RV64I
398	help
399	  This selects the base ISA that this kernel will target and must match
400	  the target platform.
401
402config ARCH_RV32I
403	bool "RV32I"
404	depends on NONPORTABLE
405	select 32BIT
406	select GENERIC_LIB_ASHLDI3
407	select GENERIC_LIB_ASHRDI3
408	select GENERIC_LIB_LSHRDI3
409	select GENERIC_LIB_UCMPDI2
410
411config ARCH_RV64I
412	bool "RV64I"
413	select 64BIT
414	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
415	select SWIOTLB if MMU
416
417endchoice
418
419# We must be able to map all physical memory into the kernel, but the compiler
420# is still a bit more efficient when generating code if it's setup in a manner
421# such that it can only map 2GiB of memory.
422choice
423	prompt "Kernel Code Model"
424	default CMODEL_MEDLOW if 32BIT
425	default CMODEL_MEDANY if 64BIT
426
427	config CMODEL_MEDLOW
428		bool "medium low code model"
429	config CMODEL_MEDANY
430		bool "medium any code model"
431endchoice
432
433config MODULE_SECTIONS
434	bool
435	select HAVE_MOD_ARCH_SPECIFIC
436
437config SMP
438	bool "Symmetric Multi-Processing"
439	help
440	  This enables support for systems with more than one CPU.  If
441	  you say N here, the kernel will run on single and
442	  multiprocessor machines, but will use only one CPU of a
443	  multiprocessor machine. If you say Y here, the kernel will run
444	  on many, but not all, single processor machines. On a single
445	  processor machine, the kernel will run faster if you say N
446	  here.
447
448	  If you don't know what to do here, say N.
449
450config SCHED_MC
451	bool "Multi-core scheduler support"
452	depends on SMP
453	help
454	  Multi-core scheduler support improves the CPU scheduler's decision
455	  making when dealing with multi-core CPU chips at a cost of slightly
456	  increased overhead in some places. If unsure say N here.
457
458config NR_CPUS
459	int "Maximum number of CPUs (2-512)"
460	depends on SMP
461	range 2 512 if !RISCV_SBI_V01
462	range 2 32 if RISCV_SBI_V01 && 32BIT
463	range 2 64 if RISCV_SBI_V01 && 64BIT
464	default "32" if 32BIT
465	default "64" if 64BIT
466
467config HOTPLUG_CPU
468	bool "Support for hot-pluggable CPUs"
469	depends on SMP
470	select GENERIC_IRQ_MIGRATION
471	help
472
473	  Say Y here to experiment with turning CPUs off and on.  CPUs
474	  can be controlled through /sys/devices/system/cpu.
475
476	  Say N if you want to disable CPU hotplug.
477
478choice
479	prompt "CPU Tuning"
480	default TUNE_GENERIC
481
482config TUNE_GENERIC
483	bool "generic"
484
485endchoice
486
487# Common NUMA Features
488config NUMA
489	bool "NUMA Memory Allocation and Scheduler Support"
490	depends on SMP && MMU
491	select ARCH_SUPPORTS_NUMA_BALANCING
492	select GENERIC_ARCH_NUMA
493	select HAVE_SETUP_PER_CPU_AREA
494	select NEED_PER_CPU_EMBED_FIRST_CHUNK
495	select NEED_PER_CPU_PAGE_FIRST_CHUNK
496	select OF_NUMA
497	select USE_PERCPU_NUMA_NODE_ID
498	help
499	  Enable NUMA (Non-Uniform Memory Access) support.
500
501	  The kernel will try to allocate memory used by a CPU on the
502	  local memory of the CPU and add some more NUMA awareness to the kernel.
503
504config NODES_SHIFT
505	int "Maximum NUMA Nodes (as a power of 2)"
506	range 1 10
507	default "2"
508	depends on NUMA
509	help
510	  Specify the maximum number of NUMA Nodes available on the target
511	  system.  Increases memory reserved to accommodate various tables.
512
513choice
514	prompt "RISC-V spinlock type"
515	default RISCV_COMBO_SPINLOCKS
516
517config RISCV_TICKET_SPINLOCKS
518	bool "Using ticket spinlock"
519
520config RISCV_QUEUED_SPINLOCKS
521	bool "Using queued spinlock"
522	depends on SMP && MMU && NONPORTABLE
523	select ARCH_USE_QUEUED_SPINLOCKS
524	help
525	  The queued spinlock implementation requires the forward progress
526	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
527	  LR/SC with Ziccrse provide such guarantee.
528
529	  Select this if and only if Zabha or Ziccrse is available on your
530	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
531	  without one of those extensions.
532
533	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
534	  when supported and otherwise ticket spinlocks.
535
536config RISCV_COMBO_SPINLOCKS
537	bool "Using combo spinlock"
538	depends on SMP && MMU
539	select ARCH_USE_QUEUED_SPINLOCKS
540	help
541	  Embed both queued spinlock and ticket lock so that the spinlock
542	  implementation can be chosen at runtime.
543
544endchoice
545
546config RISCV_ALTERNATIVE
547	bool
548	depends on !XIP_KERNEL
549	help
550	  This Kconfig allows the kernel to automatically patch the
551	  erratum or cpufeature required by the execution platform at run
552	  time. The code patching overhead is minimal, as it's only done
553	  once at boot and once on each module load.
554
555config RISCV_ALTERNATIVE_EARLY
556	bool
557	depends on RISCV_ALTERNATIVE
558	help
559	  Allows early patching of the kernel for special errata
560
561config RISCV_ISA_C
562	bool "Emit compressed instructions when building Linux"
563	default y
564	help
565	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
566	  when building Linux, which results in compressed instructions in the
567	  Linux binary.
568
569	  If you don't know what to do here, say Y.
570
571config RISCV_ISA_SUPM
572	bool "Supm extension for userspace pointer masking"
573	depends on 64BIT
574	default y
575	help
576	  Add support for pointer masking in userspace (Supm) when the
577	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
578
579	  If this option is disabled, userspace will be unable to use
580	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
581
582config RISCV_ISA_SVNAPOT
583	bool "Svnapot extension support for supervisor mode NAPOT pages"
584	depends on 64BIT && MMU
585	depends on RISCV_ALTERNATIVE
586	default y
587	help
588	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
589	  time and enable its usage.
590
591	  The Svnapot extension is used to mark contiguous PTEs as a range
592	  of contiguous virtual-to-physical translations for a naturally
593	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
594	  size. When HUGETLBFS is also selected this option unconditionally
595	  allocates some memory for each NAPOT page size supported by the kernel.
596	  When optimizing for low memory consumption and for platforms without
597	  the Svnapot extension, it may be better to say N here.
598
599	  If you don't know what to do here, say Y.
600
601config RISCV_ISA_SVPBMT
602	bool "Svpbmt extension support for supervisor mode page-based memory types"
603	depends on 64BIT && MMU
604	depends on RISCV_ALTERNATIVE
605	default y
606	help
607	   Adds support to dynamically detect the presence of the Svpbmt
608	   ISA-extension (Supervisor-mode: page-based memory types) and
609	   enable its usage.
610
611	   The memory type for a page contains a combination of attributes
612	   that indicate the cacheability, idempotency, and ordering
613	   properties for access to that page.
614
615	   The Svpbmt extension is only available on 64-bit cpus.
616
617	   If you don't know what to do here, say Y.
618
619config TOOLCHAIN_HAS_V
620	bool
621	default y
622	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
623	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
624	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
625	depends on AS_HAS_OPTION_ARCH
626
627config RISCV_ISA_V
628	bool "VECTOR extension support"
629	depends on TOOLCHAIN_HAS_V
630	depends on FPU
631	select DYNAMIC_SIGFRAME
632	default y
633	help
634	  Say N here if you want to disable all vector related procedure
635	  in the kernel.
636
637	  If you don't know what to do here, say Y.
638
639config RISCV_ISA_V_DEFAULT_ENABLE
640	bool "Enable userspace Vector by default"
641	depends on RISCV_ISA_V
642	default y
643	help
644	  Say Y here if you want to enable Vector in userspace by default.
645	  Otherwise, userspace has to make explicit prctl() call to enable
646	  Vector, or enable it via the sysctl interface.
647
648	  If you don't know what to do here, say Y.
649
650config RISCV_ISA_V_UCOPY_THRESHOLD
651	int "Threshold size for vectorized user copies"
652	depends on RISCV_ISA_V
653	default 768
654	help
655	  Prefer using vectorized copy_to_user()/copy_from_user() when the
656	  workload size exceeds this value.
657
658config RISCV_ISA_V_PREEMPTIVE
659	bool "Run kernel-mode Vector with kernel preemption"
660	depends on PREEMPTION
661	depends on RISCV_ISA_V
662	default y
663	help
664	  Usually, in-kernel SIMD routines are run with preemption disabled.
665	  Functions which envoke long running SIMD thus must yield core's
666	  vector unit to prevent blocking other tasks for too long.
667
668	  This config allows kernel to run SIMD without explicitly disable
669	  preemption. Enabling this config will result in higher memory
670	  consumption due to the allocation of per-task's kernel Vector context.
671
672config RISCV_ISA_ZAWRS
673	bool "Zawrs extension support for more efficient busy waiting"
674	depends on RISCV_ALTERNATIVE
675	default y
676	help
677	  The Zawrs extension defines instructions to be used in polling loops
678	  which allow a hart to enter a low-power state or to trap to the
679	  hypervisor while waiting on a store to a memory location. Enable the
680	  use of these instructions in the kernel when the Zawrs extension is
681	  detected at boot.
682
683config TOOLCHAIN_HAS_ZABHA
684	bool
685	default y
686	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
687	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
688	depends on AS_HAS_OPTION_ARCH
689
690config RISCV_ISA_ZABHA
691	bool "Zabha extension support for atomic byte/halfword operations"
692	depends on TOOLCHAIN_HAS_ZABHA
693	depends on RISCV_ALTERNATIVE
694	default y
695	help
696	  Enable the use of the Zabha ISA-extension to implement kernel
697	  byte/halfword atomic memory operations when it is detected at boot.
698
699	  If you don't know what to do here, say Y.
700
701config TOOLCHAIN_HAS_ZACAS
702	bool
703	default y
704	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
705	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
706	depends on AS_HAS_OPTION_ARCH
707
708config RISCV_ISA_ZACAS
709	bool "Zacas extension support for atomic CAS"
710	depends on TOOLCHAIN_HAS_ZACAS
711	depends on RISCV_ALTERNATIVE
712	default y
713	help
714	  Enable the use of the Zacas ISA-extension to implement kernel atomic
715	  cmpxchg operations when it is detected at boot.
716
717	  If you don't know what to do here, say Y.
718
719config TOOLCHAIN_HAS_ZBB
720	bool
721	default y
722	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
723	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
724	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
725	depends on AS_HAS_OPTION_ARCH
726
727# This symbol indicates that the toolchain supports all v1.0 vector crypto
728# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
729# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
730config TOOLCHAIN_HAS_VECTOR_CRYPTO
731	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
732	depends on AS_HAS_OPTION_ARCH
733
734config RISCV_ISA_ZBA
735	bool "Zba extension support for bit manipulation instructions"
736	default y
737	help
738	   Add support for enabling optimisations in the kernel when the Zba
739	   extension is detected at boot.
740
741	   The Zba extension provides instructions to accelerate the generation
742	   of addresses that index into arrays of basic data types.
743
744	   If you don't know what to do here, say Y.
745
746config RISCV_ISA_ZBB
747	bool "Zbb extension support for bit manipulation instructions"
748	depends on TOOLCHAIN_HAS_ZBB
749	depends on RISCV_ALTERNATIVE
750	default y
751	help
752	   Adds support to dynamically detect the presence of the ZBB
753	   extension (basic bit manipulation) and enable its usage.
754
755	   The Zbb extension provides instructions to accelerate a number
756	   of bit-specific operations (count bit population, sign extending,
757	   bitrotation, etc).
758
759	   If you don't know what to do here, say Y.
760
761config TOOLCHAIN_HAS_ZBC
762	bool
763	default y
764	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
765	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
766	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
767	depends on AS_HAS_OPTION_ARCH
768
769config RISCV_ISA_ZBC
770	bool "Zbc extension support for carry-less multiplication instructions"
771	depends on TOOLCHAIN_HAS_ZBC
772	depends on MMU
773	depends on RISCV_ALTERNATIVE
774	default y
775	help
776	   Adds support to dynamically detect the presence of the Zbc
777	   extension (carry-less multiplication) and enable its usage.
778
779	   The Zbc extension could accelerate CRC (cyclic redundancy check)
780	   calculations.
781
782	   If you don't know what to do here, say Y.
783
784config RISCV_ISA_ZICBOM
785	bool "Zicbom extension support for non-coherent DMA operation"
786	depends on MMU
787	depends on RISCV_ALTERNATIVE
788	default y
789	select RISCV_DMA_NONCOHERENT
790	select DMA_DIRECT_REMAP
791	help
792	   Adds support to dynamically detect the presence of the ZICBOM
793	   extension (Cache Block Management Operations) and enable its
794	   usage.
795
796	   The Zicbom extension can be used to handle for example
797	   non-coherent DMA support on devices that need it.
798
799	   If you don't know what to do here, say Y.
800
801config RISCV_ISA_ZICBOZ
802	bool "Zicboz extension support for faster zeroing of memory"
803	depends on RISCV_ALTERNATIVE
804	default y
805	help
806	   Enable the use of the Zicboz extension (cbo.zero instruction)
807	   when available.
808
809	   The Zicboz extension is used for faster zeroing of memory.
810
811	   If you don't know what to do here, say Y.
812
813config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
814	def_bool y
815	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
816	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
817	depends on AS_IS_GNU && AS_VERSION >= 23600
818	help
819	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
820	  20191213 version, which moves some instructions from the I extension to
821	  the Zicsr and Zifencei extensions. This requires explicitly specifying
822	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
823	  and Zifencei are supported in binutils from version 2.36 onwards.
824	  To make life easier, and avoid forcing toolchains that default to a
825	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
826	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
827	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
828
829config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
830	def_bool y
831	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
832	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
833	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
834	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
835	help
836	  Certain versions of clang and GCC do not support zicsr and zifencei via
837	  -march. This option causes an older ISA spec compatible with these older
838	  versions of clang and GCC to be passed to GAS, which has the same result
839	  as passing zicsr and zifencei to -march.
840
841config FPU
842	bool "FPU support"
843	default y
844	help
845	  Say N here if you want to disable all floating-point related procedure
846	  in the kernel.
847
848	  If you don't know what to do here, say Y.
849
850config IRQ_STACKS
851	bool "Independent irq & softirq stacks" if EXPERT
852	default y
853	select HAVE_IRQ_EXIT_ON_IRQ_STACK
854	select HAVE_SOFTIRQ_ON_OWN_STACK
855	help
856	  Add independent irq & softirq stacks for percpu to prevent kernel stack
857	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
858
859config THREAD_SIZE_ORDER
860	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
861	range 0 4
862	default 1 if 32BIT
863	default 2
864	help
865	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
866	  affects irq stack size, which is equal to thread stack size.
867
868config RISCV_MISALIGNED
869	bool
870	help
871	  Embed support for detecting and emulating misaligned
872	  scalar or vector loads and stores.
873
874config RISCV_SCALAR_MISALIGNED
875	bool
876	select RISCV_MISALIGNED
877	select SYSCTL_ARCH_UNALIGN_ALLOW
878	help
879	  Embed support for emulating misaligned loads and stores.
880
881config RISCV_VECTOR_MISALIGNED
882	bool
883	select RISCV_MISALIGNED
884	depends on RISCV_ISA_V
885	help
886	  Enable detecting support for vector misaligned loads and stores.
887
888choice
889	prompt "Unaligned Accesses Support"
890	default RISCV_PROBE_UNALIGNED_ACCESS
891	help
892	  This determines the level of support for unaligned accesses. This
893	  information is used by the kernel to perform optimizations. It is also
894	  exposed to user space via the hwprobe syscall. The hardware will be
895	  probed at boot by default.
896
897config RISCV_PROBE_UNALIGNED_ACCESS
898	bool "Probe for hardware unaligned access support"
899	select RISCV_SCALAR_MISALIGNED
900	help
901	  During boot, the kernel will run a series of tests to determine the
902	  speed of unaligned accesses. This probing will dynamically determine
903	  the speed of unaligned accesses on the underlying system. If unaligned
904	  memory accesses trap into the kernel as they are not supported by the
905	  system, the kernel will emulate the unaligned accesses to preserve the
906	  UABI.
907
908config RISCV_EMULATED_UNALIGNED_ACCESS
909	bool "Emulate unaligned access where system support is missing"
910	select RISCV_SCALAR_MISALIGNED
911	help
912	  If unaligned memory accesses trap into the kernel as they are not
913	  supported by the system, the kernel will emulate the unaligned
914	  accesses to preserve the UABI. When the underlying system does support
915	  unaligned accesses, the unaligned accesses are assumed to be slow.
916
917config RISCV_SLOW_UNALIGNED_ACCESS
918	bool "Assume the system supports slow unaligned memory accesses"
919	depends on NONPORTABLE
920	help
921	  Assume that the system supports slow unaligned memory accesses. The
922	  kernel and userspace programs may not be able to run at all on systems
923	  that do not support unaligned memory accesses.
924
925config RISCV_EFFICIENT_UNALIGNED_ACCESS
926	bool "Assume the system supports fast unaligned memory accesses"
927	depends on NONPORTABLE
928	select DCACHE_WORD_ACCESS if MMU
929	select HAVE_EFFICIENT_UNALIGNED_ACCESS
930	help
931	  Assume that the system supports fast unaligned memory accesses. When
932	  enabled, this option improves the performance of the kernel on such
933	  systems. However, the kernel and userspace programs will run much more
934	  slowly, or will not be able to run at all, on systems that do not
935	  support efficient unaligned memory accesses.
936
937endchoice
938
939choice
940	prompt "Vector unaligned Accesses Support"
941	depends on RISCV_ISA_V
942	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
943	help
944	  This determines the level of support for vector unaligned accesses. This
945	  information is used by the kernel to perform optimizations. It is also
946	  exposed to user space via the hwprobe syscall. The hardware will be
947	  probed at boot by default.
948
949config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
950	bool "Probe speed of vector unaligned accesses"
951	select RISCV_VECTOR_MISALIGNED
952	depends on RISCV_ISA_V
953	help
954	  During boot, the kernel will run a series of tests to determine the
955	  speed of vector unaligned accesses if they are supported. This probing
956	  will dynamically determine the speed of vector unaligned accesses on
957	  the underlying system if they are supported.
958
959config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
960	bool "Assume the system supports slow vector unaligned memory accesses"
961	depends on NONPORTABLE
962	help
963	  Assume that the system supports slow vector unaligned memory accesses. The
964	  kernel and userspace programs may not be able to run at all on systems
965	  that do not support unaligned memory accesses.
966
967config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
968	bool "Assume the system supports fast vector unaligned memory accesses"
969	depends on NONPORTABLE
970	help
971	  Assume that the system supports fast vector unaligned memory accesses. When
972	  enabled, this option improves the performance of the kernel on such
973	  systems. However, the kernel and userspace programs will run much more
974	  slowly, or will not be able to run at all, on systems that do not
975	  support efficient unaligned memory accesses.
976
977endchoice
978
979source "arch/riscv/Kconfig.vendor"
980
981endmenu # "Platform type"
982
983menu "Kernel features"
984
985source "kernel/Kconfig.hz"
986
987config RISCV_SBI_V01
988	bool "SBI v0.1 support"
989	depends on RISCV_SBI
990	help
991	  This config allows kernel to use SBI v0.1 APIs. This will be
992	  deprecated in future once legacy M-mode software are no longer in use.
993
994config RISCV_BOOT_SPINWAIT
995	bool "Spinwait booting method"
996	depends on SMP
997	default y if RISCV_SBI_V01 || RISCV_M_MODE
998	help
999	  This enables support for booting Linux via spinwait method. In the
1000	  spinwait method, all cores randomly jump to Linux. One of the cores
1001	  gets chosen via lottery and all other keep spinning on a percpu
1002	  variable. This method cannot support CPU hotplug and sparse hartid
1003	  scheme. It should be only enabled for M-mode Linux or platforms relying
1004	  on older firmware without SBI HSM extension. All other platforms should
1005	  rely on ordered booting via SBI HSM extension which gets chosen
1006	  dynamically at runtime if the firmware supports it.
1007
1008	  Since spinwait is incompatible with sparse hart IDs, it requires
1009	  NR_CPUS be large enough to contain the physical hart ID of the first
1010	  hart to enter Linux.
1011
1012	  If unsure what to do here, say N.
1013
1014config ARCH_SUPPORTS_KEXEC
1015	def_bool y
1016
1017config ARCH_SELECTS_KEXEC
1018	def_bool y
1019	depends on KEXEC
1020	select HOTPLUG_CPU if SMP
1021
1022config ARCH_SUPPORTS_KEXEC_FILE
1023	def_bool 64BIT
1024
1025config ARCH_SELECTS_KEXEC_FILE
1026	def_bool y
1027	depends on KEXEC_FILE
1028	select HAVE_IMA_KEXEC if IMA
1029	select KEXEC_ELF
1030
1031config ARCH_SUPPORTS_KEXEC_PURGATORY
1032	def_bool ARCH_SUPPORTS_KEXEC_FILE
1033
1034config ARCH_SUPPORTS_CRASH_DUMP
1035	def_bool y
1036
1037config ARCH_DEFAULT_CRASH_DUMP
1038	def_bool y
1039
1040config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1041	def_bool CRASH_RESERVE
1042
1043config COMPAT
1044	bool "Kernel support for 32-bit U-mode"
1045	default 64BIT
1046	depends on 64BIT && MMU
1047	help
1048	  This option enables support for a 32-bit U-mode running under a 64-bit
1049	  kernel at S-mode. riscv32-specific components such as system calls,
1050	  the user helper functions (vdso), signal rt_frame functions and the
1051	  ptrace interface are handled appropriately by the kernel.
1052
1053	  If you want to execute 32-bit userspace applications, say Y.
1054
1055config PARAVIRT
1056	bool "Enable paravirtualization code"
1057	depends on RISCV_SBI
1058	help
1059	  This changes the kernel so it can modify itself when it is run
1060	  under a hypervisor, potentially improving performance significantly
1061	  over full virtualization.
1062
1063config PARAVIRT_TIME_ACCOUNTING
1064	bool "Paravirtual steal time accounting"
1065	depends on PARAVIRT
1066	help
1067	  Select this option to enable fine granularity task steal time
1068	  accounting. Time spent executing other tasks in parallel with
1069	  the current vCPU is discounted from the vCPU power. To account for
1070	  that, there can be a small performance impact.
1071
1072	  If in doubt, say N here.
1073
1074config RELOCATABLE
1075	bool "Build a relocatable kernel"
1076	depends on MMU && 64BIT && !XIP_KERNEL
1077	select MODULE_SECTIONS if MODULES
1078	help
1079          This builds a kernel as a Position Independent Executable (PIE),
1080          which retains all relocation metadata required to relocate the
1081          kernel binary at runtime to a different virtual address than the
1082          address it was linked at.
1083          Since RISCV uses the RELA relocation format, this requires a
1084          relocation pass at runtime even if the kernel is loaded at the
1085          same address it was linked at.
1086
1087          If unsure, say N.
1088
1089config RANDOMIZE_BASE
1090        bool "Randomize the address of the kernel image"
1091        select RELOCATABLE
1092        depends on MMU && 64BIT && !XIP_KERNEL
1093        help
1094          Randomizes the virtual address at which the kernel image is
1095          loaded, as a security feature that deters exploit attempts
1096          relying on knowledge of the location of kernel internals.
1097
1098          It is the bootloader's job to provide entropy, by passing a
1099          random u64 value in /chosen/kaslr-seed at kernel entry.
1100
1101          When booting via the UEFI stub, it will invoke the firmware's
1102          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1103          to the kernel proper. In addition, it will randomise the physical
1104          location of the kernel Image as well.
1105
1106          If unsure, say N.
1107
1108endmenu # "Kernel features"
1109
1110menu "Boot options"
1111
1112config CMDLINE
1113	string "Built-in kernel command line"
1114	help
1115	  For most platforms, the arguments for the kernel's command line
1116	  are provided at run-time, during boot. However, there are cases
1117	  where either no arguments are being provided or the provided
1118	  arguments are insufficient or even invalid.
1119
1120	  When that occurs, it is possible to define a built-in command
1121	  line here and choose how the kernel should use it later on.
1122
1123choice
1124	prompt "Built-in command line usage"
1125	depends on CMDLINE != ""
1126	default CMDLINE_FALLBACK
1127	help
1128	  Choose how the kernel will handle the provided built-in command
1129	  line.
1130
1131config CMDLINE_FALLBACK
1132	bool "Use bootloader kernel arguments if available"
1133	help
1134	  Use the built-in command line as fallback in case we get nothing
1135	  during boot. This is the default behaviour.
1136
1137config CMDLINE_EXTEND
1138	bool "Extend bootloader kernel arguments"
1139	help
1140	  The command-line arguments provided during boot will be
1141	  appended to the built-in command line. This is useful in
1142	  cases where the provided arguments are insufficient and
1143	  you don't want to or cannot modify them.
1144
1145config CMDLINE_FORCE
1146	bool "Always use the default kernel command string"
1147	help
1148	  Always use the built-in command line, even if we get one during
1149	  boot. This is useful in case you need to override the provided
1150	  command line on systems where you don't have or want control
1151	  over it.
1152
1153endchoice
1154
1155config EFI_STUB
1156	bool
1157
1158config EFI
1159	bool "UEFI runtime support"
1160	depends on OF && !XIP_KERNEL
1161	depends on MMU
1162	default y
1163	select ARCH_SUPPORTS_ACPI if 64BIT
1164	select EFI_GENERIC_STUB
1165	select EFI_PARAMS_FROM_FDT
1166	select EFI_RUNTIME_WRAPPERS
1167	select EFI_STUB
1168	select LIBFDT
1169	select RISCV_ISA_C
1170	select UCS2_STRING
1171	help
1172	  This option provides support for runtime services provided
1173	  by UEFI firmware (such as non-volatile variables, realtime
1174	  clock, and platform reset). A UEFI stub is also provided to
1175	  allow the kernel to be booted as an EFI application. This
1176	  is only useful on systems that have UEFI firmware.
1177
1178config DMI
1179	bool "Enable support for SMBIOS (DMI) tables"
1180	depends on EFI
1181	default y
1182	help
1183	  This enables SMBIOS/DMI feature for systems.
1184
1185	  This option is only useful on systems that have UEFI firmware.
1186	  However, even with this option, the resultant kernel should
1187	  continue to boot on existing non-UEFI platforms.
1188
1189config CC_HAVE_STACKPROTECTOR_TLS
1190	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1191
1192config STACKPROTECTOR_PER_TASK
1193	def_bool y
1194	depends on !RANDSTRUCT
1195	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1196
1197config PHYS_RAM_BASE_FIXED
1198	bool "Explicitly specified physical RAM address"
1199	depends on NONPORTABLE
1200	default n
1201
1202config PHYS_RAM_BASE
1203	hex "Platform Physical RAM address"
1204	depends on PHYS_RAM_BASE_FIXED
1205	default "0x80000000"
1206	help
1207	  This is the physical address of RAM in the system. It has to be
1208	  explicitly specified to run early relocations of read-write data
1209	  from flash to RAM.
1210
1211config XIP_KERNEL
1212	bool "Kernel Execute-In-Place from ROM"
1213	depends on MMU && SPARSEMEM && NONPORTABLE
1214	# This prevents XIP from being enabled by all{yes,mod}config, which
1215	# fail to build since XIP doesn't support large kernels.
1216	depends on !COMPILE_TEST
1217	select PHYS_RAM_BASE_FIXED
1218	help
1219	  Execute-In-Place allows the kernel to run from non-volatile storage
1220	  directly addressable by the CPU, such as NOR flash. This saves RAM
1221	  space since the text section of the kernel is not loaded from flash
1222	  to RAM.  Read-write sections, such as the data section and stack,
1223	  are still copied to RAM.  The XIP kernel is not compressed since
1224	  it has to run directly from flash, so it will take more space to
1225	  store it.  The flash address used to link the kernel object files,
1226	  and for storing it, is configuration dependent. Therefore, if you
1227	  say Y here, you must know the proper physical address where to
1228	  store the kernel image depending on your own flash memory usage.
1229
1230	  Also note that the make target becomes "make xipImage" rather than
1231	  "make zImage" or "make Image".  The final kernel binary to put in
1232	  ROM memory will be arch/riscv/boot/xipImage.
1233
1234	  SPARSEMEM is required because the kernel text and rodata that are
1235	  flash resident are not backed by memmap, then any attempt to get
1236	  a struct page on those regions will trigger a fault.
1237
1238	  If unsure, say N.
1239
1240config XIP_PHYS_ADDR
1241	hex "XIP Kernel Physical Location"
1242	depends on XIP_KERNEL
1243	default "0x21000000"
1244	help
1245	  This is the physical address in your flash memory the kernel will
1246	  be linked for and stored to.  This address is dependent on your
1247	  own flash usage.
1248
1249config RISCV_ISA_FALLBACK
1250	bool "Permit falling back to parsing riscv,isa for extension support by default"
1251	default y
1252	help
1253	  Parsing the "riscv,isa" devicetree property has been deprecated and
1254	  replaced by a list of explicitly defined strings. For compatibility
1255	  with existing platforms, the kernel will fall back to parsing the
1256	  "riscv,isa" property if the replacements are not found.
1257
1258	  Selecting N here will result in a kernel that does not use the
1259	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1260	  present.
1261
1262	  Please see the dt-binding, located at
1263	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1264	  on the replacement properties, "riscv,isa-base" and
1265	  "riscv,isa-extensions".
1266
1267config BUILTIN_DTB
1268	bool "Built-in device tree"
1269	depends on OF && NONPORTABLE
1270	help
1271	  Build a device tree into the Linux image.
1272	  This option should be selected if no bootloader is being used.
1273	  If unsure, say N.
1274
1275
1276config BUILTIN_DTB_SOURCE
1277	string "Built-in device tree source"
1278	depends on BUILTIN_DTB
1279	help
1280	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1281	  for the DTS file that will be used to produce the DTB linked into the
1282	  kernel.
1283
1284endmenu # "Boot options"
1285
1286config PORTABLE
1287	bool
1288	default !NONPORTABLE
1289	select EFI
1290	select MMU
1291	select OF
1292
1293config ARCH_PROC_KCORE_TEXT
1294	def_bool y
1295
1296menu "Power management options"
1297
1298source "kernel/power/Kconfig"
1299
1300config ARCH_HIBERNATION_POSSIBLE
1301	def_bool y
1302
1303config ARCH_HIBERNATION_HEADER
1304	def_bool HIBERNATION
1305
1306config ARCH_SUSPEND_POSSIBLE
1307	def_bool y
1308
1309endmenu # "Power management options"
1310
1311menu "CPU Power Management"
1312
1313source "drivers/cpuidle/Kconfig"
1314
1315source "drivers/cpufreq/Kconfig"
1316
1317endmenu # "CPU Power Management"
1318
1319source "arch/riscv/kvm/Kconfig"
1320
1321source "drivers/acpi/Kconfig"
1322