xref: /linux/arch/riscv/Kconfig (revision 64f7b77f0bd9271861ed9e410e9856b6b0b21c48)
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_KCOV
36	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
37	select ARCH_HAS_MEMBARRIER_CALLBACKS
38	select ARCH_HAS_MEMBARRIER_SYNC_CORE
39	select ARCH_HAS_MMIOWB
40	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
41	select ARCH_HAS_PMEM_API
42	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
43	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
44	select ARCH_HAS_PTE_SPECIAL
45	select ARCH_HAS_SET_DIRECT_MAP if MMU
46	select ARCH_HAS_SET_MEMORY if MMU
47	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
48	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
49	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
50	select ARCH_HAS_SYSCALL_WRAPPER
51	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
52	select ARCH_HAS_UBSAN
53	select ARCH_HAS_VDSO_DATA
54	select ARCH_KEEP_MEMBLOCK if ACPI
55	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
56	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
57	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
58	select ARCH_STACKWALK
59	select ARCH_SUPPORTS_ATOMIC_RMW
60	select ARCH_SUPPORTS_CFI_CLANG
61	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
62	select ARCH_SUPPORTS_HUGETLBFS if MMU
63	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
64	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
65	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
66	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
67	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
68	select ARCH_SUPPORTS_RT
69	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
70	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
71	select ARCH_USE_MEMTEST
72	select ARCH_USE_QUEUED_RWLOCKS
73	select ARCH_USE_SYM_ANNOTATIONS
74	select ARCH_USES_CFI_TRAPS if CFI_CLANG
75	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
76	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
77	select ARCH_WANT_FRAME_POINTERS
78	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
79	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
80	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
81	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
82	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
83	select ARCH_WANTS_NO_INSTR
84	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
85	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
86	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
87	select BUILDTIME_TABLE_SORT if MMU
88	select CLINT_TIMER if RISCV_M_MODE
89	select CLONE_BACKWARDS
90	select COMMON_CLK
91	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
92	select EDAC_SUPPORT
93	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
94	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
95	select GENERIC_ARCH_TOPOLOGY
96	select GENERIC_ATOMIC64 if !64BIT
97	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
98	select GENERIC_CPU_DEVICES
99	select GENERIC_CPU_VULNERABILITIES
100	select GENERIC_EARLY_IOREMAP
101	select GENERIC_ENTRY
102	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
103	select GENERIC_IDLE_POLL_SETUP
104	select GENERIC_IOREMAP if MMU
105	select GENERIC_IRQ_IPI if SMP
106	select GENERIC_IRQ_IPI_MUX if SMP
107	select GENERIC_IRQ_MULTI_HANDLER
108	select GENERIC_IRQ_SHOW
109	select GENERIC_IRQ_SHOW_LEVEL
110	select GENERIC_LIB_DEVMEM_IS_ALLOWED
111	select GENERIC_PCI_IOMAP
112	select GENERIC_PTDUMP if MMU
113	select GENERIC_SCHED_CLOCK
114	select GENERIC_SMP_IDLE_THREAD
115	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
116	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
117	select HARDIRQS_SW_RESEND
118	select HAS_IOPORT if MMU
119	select HAVE_ALIGNED_STRUCT_PAGE
120	select HAVE_ARCH_AUDITSYSCALL
121	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
122	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
123	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
124	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
125	select HAVE_ARCH_KASAN if MMU && 64BIT
126	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
127	select HAVE_ARCH_KFENCE if MMU && 64BIT
128	select HAVE_ARCH_KGDB if !XIP_KERNEL
129	select HAVE_ARCH_KGDB_QXFER_PKT
130	select HAVE_ARCH_MMAP_RND_BITS if MMU
131	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
132	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
133	select HAVE_ARCH_SECCOMP_FILTER
134	select HAVE_ARCH_STACKLEAK
135	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
136	select HAVE_ARCH_TRACEHOOK
137	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
138	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
139	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
140	select HAVE_ASM_MODVERSIONS
141	select HAVE_CONTEXT_TRACKING_USER
142	select HAVE_DEBUG_KMEMLEAK
143	select HAVE_DMA_CONTIGUOUS if MMU
144	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
145	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
146	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
147	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
148	select HAVE_FUNCTION_GRAPH_TRACER
149	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
150	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
151	select HAVE_EBPF_JIT if MMU
152	select HAVE_GUP_FAST if MMU
153	select HAVE_FUNCTION_ARG_ACCESS_API
154	select HAVE_FUNCTION_ERROR_INJECTION
155	select HAVE_GCC_PLUGINS
156	select HAVE_GENERIC_VDSO if MMU && 64BIT
157	select HAVE_IRQ_TIME_ACCOUNTING
158	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
159	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
160	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
161	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
162	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
163	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
164	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
165	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
166	select HAVE_KPROBES if !XIP_KERNEL
167	select HAVE_KRETPROBES if !XIP_KERNEL
168	# https://github.com/ClangBuiltLinux/linux/issues/1881
169	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
170	select HAVE_MOVE_PMD
171	select HAVE_MOVE_PUD
172	select HAVE_PAGE_SIZE_4KB
173	select HAVE_PCI
174	select HAVE_PERF_EVENTS
175	select HAVE_PERF_REGS
176	select HAVE_PERF_USER_STACK_DUMP
177	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
178	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
179	select HAVE_REGS_AND_STACK_ACCESS_API
180	select HAVE_RETHOOK if !XIP_KERNEL
181	select HAVE_RSEQ
182	select HAVE_RUST if RUSTC_SUPPORTS_RISCV
183	select HAVE_SAMPLE_FTRACE_DIRECT
184	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
185	select HAVE_STACKPROTECTOR
186	select HAVE_SYSCALL_TRACEPOINTS
187	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
188	select IRQ_DOMAIN
189	select IRQ_FORCED_THREADING
190	select KASAN_VMALLOC if KASAN
191	select LOCK_MM_AND_FIND_VMA
192	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
193	select MODULES_USE_ELF_RELA if MODULES
194	select OF
195	select OF_EARLY_FLATTREE
196	select OF_IRQ
197	select PCI_DOMAINS_GENERIC if PCI
198	select PCI_ECAM if (ACPI && PCI)
199	select PCI_MSI if PCI
200	select RISCV_ALTERNATIVE if !XIP_KERNEL
201	select RISCV_APLIC
202	select RISCV_IMSIC
203	select RISCV_INTC
204	select RISCV_TIMER if RISCV_SBI
205	select SIFIVE_PLIC
206	select SPARSE_IRQ
207	select SYSCTL_EXCEPTION_TRACE
208	select THREAD_INFO_IN_TASK
209	select TRACE_IRQFLAGS_SUPPORT
210	select UACCESS_MEMCPY if !MMU
211	select USER_STACKTRACE_SUPPORT
212	select ZONE_DMA32 if 64BIT
213
214config RUSTC_SUPPORTS_RISCV
215	def_bool y
216	depends on 64BIT
217	# Shadow call stack requires rustc version 1.82+ due to use of the
218	# -Zsanitizer=shadow-call-stack flag.
219	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
220
221config CLANG_SUPPORTS_DYNAMIC_FTRACE
222	def_bool CC_IS_CLANG
223	# https://github.com/ClangBuiltLinux/linux/issues/1817
224	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
225
226config GCC_SUPPORTS_DYNAMIC_FTRACE
227	def_bool CC_IS_GCC
228	depends on $(cc-option,-fpatchable-function-entry=8)
229
230config HAVE_SHADOW_CALL_STACK
231	def_bool $(cc-option,-fsanitize=shadow-call-stack)
232	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
233	depends on $(ld-option,--no-relax-gp)
234
235config RISCV_USE_LINKER_RELAXATION
236	def_bool y
237	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
238	depends on !LD_IS_LLD || LLD_VERSION >= 150000
239
240# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
241config ARCH_HAS_BROKEN_DWARF5
242	def_bool y
243	depends on RISCV_USE_LINKER_RELAXATION
244	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
245	depends on AS_IS_LLVM && AS_VERSION < 180000
246	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
247	depends on LD_IS_LLD && LLD_VERSION < 180000
248
249config ARCH_MMAP_RND_BITS_MIN
250	default 18 if 64BIT
251	default 8
252
253config ARCH_MMAP_RND_COMPAT_BITS_MIN
254	default 8
255
256# max bits determined by the following formula:
257#  VA_BITS - PAGE_SHIFT - 3
258config ARCH_MMAP_RND_BITS_MAX
259	default 24 if 64BIT # SV39 based
260	default 17
261
262config ARCH_MMAP_RND_COMPAT_BITS_MAX
263	default 17
264
265# set if we run in machine mode, cleared if we run in supervisor mode
266config RISCV_M_MODE
267	bool "Build a kernel that runs in machine mode"
268	depends on !MMU
269	default y
270	help
271	  Select this option if you want to run the kernel in M-mode,
272	  without the assistance of any other firmware.
273
274# set if we are running in S-mode and can use SBI calls
275config RISCV_SBI
276	bool
277	depends on !RISCV_M_MODE
278	default y
279
280config MMU
281	bool "MMU-based Paged Memory Management Support"
282	default y
283	help
284	  Select if you want MMU-based virtualised addressing space
285	  support by paged memory management. If unsure, say 'Y'.
286
287config PAGE_OFFSET
288	hex
289	default 0x80000000 if !MMU && RISCV_M_MODE
290	default 0x80200000 if !MMU
291	default 0xc0000000 if 32BIT
292	default 0xff60000000000000 if 64BIT
293
294config KASAN_SHADOW_OFFSET
295	hex
296	depends on KASAN_GENERIC
297	default 0xdfffffff00000000 if 64BIT
298	default 0xffffffff if 32BIT
299
300config ARCH_FLATMEM_ENABLE
301	def_bool !NUMA
302
303config ARCH_SPARSEMEM_ENABLE
304	def_bool y
305	depends on MMU
306	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
307	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
308
309config ARCH_SELECT_MEMORY_MODEL
310	def_bool ARCH_SPARSEMEM_ENABLE
311
312config ARCH_SUPPORTS_UPROBES
313	def_bool y
314
315config STACKTRACE_SUPPORT
316	def_bool y
317
318config GENERIC_BUG
319	def_bool y
320	depends on BUG
321	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
322
323config GENERIC_BUG_RELATIVE_POINTERS
324	bool
325
326config GENERIC_CALIBRATE_DELAY
327	def_bool y
328
329config GENERIC_CSUM
330	def_bool y
331
332config GENERIC_HWEIGHT
333	def_bool y
334
335config FIX_EARLYCON_MEM
336	def_bool MMU
337
338config ILLEGAL_POINTER_VALUE
339	hex
340	default 0 if 32BIT
341	default 0xdead000000000000 if 64BIT
342
343config PGTABLE_LEVELS
344	int
345	default 5 if 64BIT
346	default 2
347
348config LOCKDEP_SUPPORT
349	def_bool y
350
351config RISCV_DMA_NONCOHERENT
352	bool
353	select ARCH_HAS_DMA_PREP_COHERENT
354	select ARCH_HAS_SETUP_DMA_OPS
355	select ARCH_HAS_SYNC_DMA_FOR_CPU
356	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
357	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
358
359config RISCV_NONSTANDARD_CACHE_OPS
360	bool
361	help
362	  This enables function pointer support for non-standard noncoherent
363	  systems to handle cache management.
364
365config AS_HAS_INSN
366	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
367
368config AS_HAS_OPTION_ARCH
369	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
370	def_bool y
371	depends on $(as-instr, .option arch$(comma) +m)
372
373source "arch/riscv/Kconfig.socs"
374source "arch/riscv/Kconfig.errata"
375
376menu "Platform type"
377
378config NONPORTABLE
379	bool "Allow configurations that result in non-portable kernels"
380	help
381	  RISC-V kernel binaries are compatible between all known systems
382	  whenever possible, but there are some use cases that can only be
383	  satisfied by configurations that result in kernel binaries that are
384	  not portable between systems.
385
386	  Selecting N does not guarantee kernels will be portable to all known
387	  systems.  Selecting any of the options guarded by NONPORTABLE will
388	  result in kernel binaries that are unlikely to be portable between
389	  systems.
390
391	  If unsure, say N.
392
393choice
394	prompt "Base ISA"
395	default ARCH_RV64I
396	help
397	  This selects the base ISA that this kernel will target and must match
398	  the target platform.
399
400config ARCH_RV32I
401	bool "RV32I"
402	depends on NONPORTABLE
403	select 32BIT
404	select GENERIC_LIB_ASHLDI3
405	select GENERIC_LIB_ASHRDI3
406	select GENERIC_LIB_LSHRDI3
407	select GENERIC_LIB_UCMPDI2
408
409config ARCH_RV64I
410	bool "RV64I"
411	select 64BIT
412	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
413	select SWIOTLB if MMU
414
415endchoice
416
417# We must be able to map all physical memory into the kernel, but the compiler
418# is still a bit more efficient when generating code if it's setup in a manner
419# such that it can only map 2GiB of memory.
420choice
421	prompt "Kernel Code Model"
422	default CMODEL_MEDLOW if 32BIT
423	default CMODEL_MEDANY if 64BIT
424
425	config CMODEL_MEDLOW
426		bool "medium low code model"
427	config CMODEL_MEDANY
428		bool "medium any code model"
429endchoice
430
431config MODULE_SECTIONS
432	bool
433	select HAVE_MOD_ARCH_SPECIFIC
434
435config SMP
436	bool "Symmetric Multi-Processing"
437	help
438	  This enables support for systems with more than one CPU.  If
439	  you say N here, the kernel will run on single and
440	  multiprocessor machines, but will use only one CPU of a
441	  multiprocessor machine. If you say Y here, the kernel will run
442	  on many, but not all, single processor machines. On a single
443	  processor machine, the kernel will run faster if you say N
444	  here.
445
446	  If you don't know what to do here, say N.
447
448config SCHED_MC
449	bool "Multi-core scheduler support"
450	depends on SMP
451	help
452	  Multi-core scheduler support improves the CPU scheduler's decision
453	  making when dealing with multi-core CPU chips at a cost of slightly
454	  increased overhead in some places. If unsure say N here.
455
456config NR_CPUS
457	int "Maximum number of CPUs (2-512)"
458	depends on SMP
459	range 2 512 if !RISCV_SBI_V01
460	range 2 32 if RISCV_SBI_V01 && 32BIT
461	range 2 64 if RISCV_SBI_V01 && 64BIT
462	default "32" if 32BIT
463	default "64" if 64BIT
464
465config HOTPLUG_CPU
466	bool "Support for hot-pluggable CPUs"
467	depends on SMP
468	select GENERIC_IRQ_MIGRATION
469	help
470
471	  Say Y here to experiment with turning CPUs off and on.  CPUs
472	  can be controlled through /sys/devices/system/cpu.
473
474	  Say N if you want to disable CPU hotplug.
475
476choice
477	prompt "CPU Tuning"
478	default TUNE_GENERIC
479
480config TUNE_GENERIC
481	bool "generic"
482
483endchoice
484
485# Common NUMA Features
486config NUMA
487	bool "NUMA Memory Allocation and Scheduler Support"
488	depends on SMP && MMU
489	select ARCH_SUPPORTS_NUMA_BALANCING
490	select GENERIC_ARCH_NUMA
491	select HAVE_SETUP_PER_CPU_AREA
492	select NEED_PER_CPU_EMBED_FIRST_CHUNK
493	select NEED_PER_CPU_PAGE_FIRST_CHUNK
494	select OF_NUMA
495	select USE_PERCPU_NUMA_NODE_ID
496	help
497	  Enable NUMA (Non-Uniform Memory Access) support.
498
499	  The kernel will try to allocate memory used by a CPU on the
500	  local memory of the CPU and add some more NUMA awareness to the kernel.
501
502config NODES_SHIFT
503	int "Maximum NUMA Nodes (as a power of 2)"
504	range 1 10
505	default "2"
506	depends on NUMA
507	help
508	  Specify the maximum number of NUMA Nodes available on the target
509	  system.  Increases memory reserved to accommodate various tables.
510
511choice
512	prompt "RISC-V spinlock type"
513	default RISCV_COMBO_SPINLOCKS
514
515config RISCV_TICKET_SPINLOCKS
516	bool "Using ticket spinlock"
517
518config RISCV_QUEUED_SPINLOCKS
519	bool "Using queued spinlock"
520	depends on SMP && MMU && NONPORTABLE
521	select ARCH_USE_QUEUED_SPINLOCKS
522	help
523	  The queued spinlock implementation requires the forward progress
524	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
525	  LR/SC with Ziccrse provide such guarantee.
526
527	  Select this if and only if Zabha or Ziccrse is available on your
528	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
529	  without one of those extensions.
530
531	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
532	  when supported and otherwise ticket spinlocks.
533
534config RISCV_COMBO_SPINLOCKS
535	bool "Using combo spinlock"
536	depends on SMP && MMU
537	select ARCH_USE_QUEUED_SPINLOCKS
538	help
539	  Embed both queued spinlock and ticket lock so that the spinlock
540	  implementation can be chosen at runtime.
541
542endchoice
543
544config RISCV_ALTERNATIVE
545	bool
546	depends on !XIP_KERNEL
547	help
548	  This Kconfig allows the kernel to automatically patch the
549	  erratum or cpufeature required by the execution platform at run
550	  time. The code patching overhead is minimal, as it's only done
551	  once at boot and once on each module load.
552
553config RISCV_ALTERNATIVE_EARLY
554	bool
555	depends on RISCV_ALTERNATIVE
556	help
557	  Allows early patching of the kernel for special errata
558
559config RISCV_ISA_C
560	bool "Emit compressed instructions when building Linux"
561	default y
562	help
563	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
564	  when building Linux, which results in compressed instructions in the
565	  Linux binary.
566
567	  If you don't know what to do here, say Y.
568
569config RISCV_ISA_SUPM
570	bool "Supm extension for userspace pointer masking"
571	depends on 64BIT
572	default y
573	help
574	  Add support for pointer masking in userspace (Supm) when the
575	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
576
577	  If this option is disabled, userspace will be unable to use
578	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
579
580config RISCV_ISA_SVNAPOT
581	bool "Svnapot extension support for supervisor mode NAPOT pages"
582	depends on 64BIT && MMU
583	depends on RISCV_ALTERNATIVE
584	default y
585	help
586	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
587	  time and enable its usage.
588
589	  The Svnapot extension is used to mark contiguous PTEs as a range
590	  of contiguous virtual-to-physical translations for a naturally
591	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
592	  size. When HUGETLBFS is also selected this option unconditionally
593	  allocates some memory for each NAPOT page size supported by the kernel.
594	  When optimizing for low memory consumption and for platforms without
595	  the Svnapot extension, it may be better to say N here.
596
597	  If you don't know what to do here, say Y.
598
599config RISCV_ISA_SVPBMT
600	bool "Svpbmt extension support for supervisor mode page-based memory types"
601	depends on 64BIT && MMU
602	depends on RISCV_ALTERNATIVE
603	default y
604	help
605	   Adds support to dynamically detect the presence of the Svpbmt
606	   ISA-extension (Supervisor-mode: page-based memory types) and
607	   enable its usage.
608
609	   The memory type for a page contains a combination of attributes
610	   that indicate the cacheability, idempotency, and ordering
611	   properties for access to that page.
612
613	   The Svpbmt extension is only available on 64-bit cpus.
614
615	   If you don't know what to do here, say Y.
616
617config TOOLCHAIN_HAS_V
618	bool
619	default y
620	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
621	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
622	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
623	depends on AS_HAS_OPTION_ARCH
624
625config RISCV_ISA_V
626	bool "VECTOR extension support"
627	depends on TOOLCHAIN_HAS_V
628	depends on FPU
629	select DYNAMIC_SIGFRAME
630	default y
631	help
632	  Say N here if you want to disable all vector related procedure
633	  in the kernel.
634
635	  If you don't know what to do here, say Y.
636
637config RISCV_ISA_V_DEFAULT_ENABLE
638	bool "Enable userspace Vector by default"
639	depends on RISCV_ISA_V
640	default y
641	help
642	  Say Y here if you want to enable Vector in userspace by default.
643	  Otherwise, userspace has to make explicit prctl() call to enable
644	  Vector, or enable it via the sysctl interface.
645
646	  If you don't know what to do here, say Y.
647
648config RISCV_ISA_V_UCOPY_THRESHOLD
649	int "Threshold size for vectorized user copies"
650	depends on RISCV_ISA_V
651	default 768
652	help
653	  Prefer using vectorized copy_to_user()/copy_from_user() when the
654	  workload size exceeds this value.
655
656config RISCV_ISA_V_PREEMPTIVE
657	bool "Run kernel-mode Vector with kernel preemption"
658	depends on PREEMPTION
659	depends on RISCV_ISA_V
660	default y
661	help
662	  Usually, in-kernel SIMD routines are run with preemption disabled.
663	  Functions which envoke long running SIMD thus must yield core's
664	  vector unit to prevent blocking other tasks for too long.
665
666	  This config allows kernel to run SIMD without explicitly disable
667	  preemption. Enabling this config will result in higher memory
668	  consumption due to the allocation of per-task's kernel Vector context.
669
670config RISCV_ISA_ZAWRS
671	bool "Zawrs extension support for more efficient busy waiting"
672	depends on RISCV_ALTERNATIVE
673	default y
674	help
675	  The Zawrs extension defines instructions to be used in polling loops
676	  which allow a hart to enter a low-power state or to trap to the
677	  hypervisor while waiting on a store to a memory location. Enable the
678	  use of these instructions in the kernel when the Zawrs extension is
679	  detected at boot.
680
681config TOOLCHAIN_HAS_ZABHA
682	bool
683	default y
684	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
685	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
686	depends on AS_HAS_OPTION_ARCH
687
688config RISCV_ISA_ZABHA
689	bool "Zabha extension support for atomic byte/halfword operations"
690	depends on TOOLCHAIN_HAS_ZABHA
691	depends on RISCV_ALTERNATIVE
692	default y
693	help
694	  Enable the use of the Zabha ISA-extension to implement kernel
695	  byte/halfword atomic memory operations when it is detected at boot.
696
697	  If you don't know what to do here, say Y.
698
699config TOOLCHAIN_HAS_ZACAS
700	bool
701	default y
702	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
703	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
704	depends on AS_HAS_OPTION_ARCH
705
706config RISCV_ISA_ZACAS
707	bool "Zacas extension support for atomic CAS"
708	depends on TOOLCHAIN_HAS_ZACAS
709	depends on RISCV_ALTERNATIVE
710	default y
711	help
712	  Enable the use of the Zacas ISA-extension to implement kernel atomic
713	  cmpxchg operations when it is detected at boot.
714
715	  If you don't know what to do here, say Y.
716
717config TOOLCHAIN_HAS_ZBB
718	bool
719	default y
720	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
721	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
722	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
723	depends on AS_HAS_OPTION_ARCH
724
725# This symbol indicates that the toolchain supports all v1.0 vector crypto
726# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
727# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
728config TOOLCHAIN_HAS_VECTOR_CRYPTO
729	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
730	depends on AS_HAS_OPTION_ARCH
731
732config RISCV_ISA_ZBA
733	bool "Zba extension support for bit manipulation instructions"
734	default y
735	help
736	   Add support for enabling optimisations in the kernel when the Zba
737	   extension is detected at boot.
738
739	   The Zba extension provides instructions to accelerate the generation
740	   of addresses that index into arrays of basic data types.
741
742	   If you don't know what to do here, say Y.
743
744config RISCV_ISA_ZBB
745	bool "Zbb extension support for bit manipulation instructions"
746	depends on TOOLCHAIN_HAS_ZBB
747	depends on RISCV_ALTERNATIVE
748	default y
749	help
750	   Adds support to dynamically detect the presence of the ZBB
751	   extension (basic bit manipulation) and enable its usage.
752
753	   The Zbb extension provides instructions to accelerate a number
754	   of bit-specific operations (count bit population, sign extending,
755	   bitrotation, etc).
756
757	   If you don't know what to do here, say Y.
758
759config TOOLCHAIN_HAS_ZBC
760	bool
761	default y
762	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
763	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
764	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
765	depends on AS_HAS_OPTION_ARCH
766
767config RISCV_ISA_ZBC
768	bool "Zbc extension support for carry-less multiplication instructions"
769	depends on TOOLCHAIN_HAS_ZBC
770	depends on MMU
771	depends on RISCV_ALTERNATIVE
772	default y
773	help
774	   Adds support to dynamically detect the presence of the Zbc
775	   extension (carry-less multiplication) and enable its usage.
776
777	   The Zbc extension could accelerate CRC (cyclic redundancy check)
778	   calculations.
779
780	   If you don't know what to do here, say Y.
781
782config RISCV_ISA_ZICBOM
783	bool "Zicbom extension support for non-coherent DMA operation"
784	depends on MMU
785	depends on RISCV_ALTERNATIVE
786	default y
787	select RISCV_DMA_NONCOHERENT
788	select DMA_DIRECT_REMAP
789	help
790	   Adds support to dynamically detect the presence of the ZICBOM
791	   extension (Cache Block Management Operations) and enable its
792	   usage.
793
794	   The Zicbom extension can be used to handle for example
795	   non-coherent DMA support on devices that need it.
796
797	   If you don't know what to do here, say Y.
798
799config RISCV_ISA_ZICBOZ
800	bool "Zicboz extension support for faster zeroing of memory"
801	depends on RISCV_ALTERNATIVE
802	default y
803	help
804	   Enable the use of the Zicboz extension (cbo.zero instruction)
805	   when available.
806
807	   The Zicboz extension is used for faster zeroing of memory.
808
809	   If you don't know what to do here, say Y.
810
811config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
812	def_bool y
813	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
814	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
815	depends on AS_IS_GNU && AS_VERSION >= 23600
816	help
817	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
818	  20191213 version, which moves some instructions from the I extension to
819	  the Zicsr and Zifencei extensions. This requires explicitly specifying
820	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
821	  and Zifencei are supported in binutils from version 2.36 onwards.
822	  To make life easier, and avoid forcing toolchains that default to a
823	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
824	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
825	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
826
827config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
828	def_bool y
829	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
830	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
831	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
832	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
833	help
834	  Certain versions of clang and GCC do not support zicsr and zifencei via
835	  -march. This option causes an older ISA spec compatible with these older
836	  versions of clang and GCC to be passed to GAS, which has the same result
837	  as passing zicsr and zifencei to -march.
838
839config FPU
840	bool "FPU support"
841	default y
842	help
843	  Say N here if you want to disable all floating-point related procedure
844	  in the kernel.
845
846	  If you don't know what to do here, say Y.
847
848config IRQ_STACKS
849	bool "Independent irq & softirq stacks" if EXPERT
850	default y
851	select HAVE_IRQ_EXIT_ON_IRQ_STACK
852	select HAVE_SOFTIRQ_ON_OWN_STACK
853	help
854	  Add independent irq & softirq stacks for percpu to prevent kernel stack
855	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
856
857config THREAD_SIZE_ORDER
858	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
859	range 0 4
860	default 1 if 32BIT
861	default 2
862	help
863	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
864	  affects irq stack size, which is equal to thread stack size.
865
866config RISCV_MISALIGNED
867	bool
868	help
869	  Embed support for detecting and emulating misaligned
870	  scalar or vector loads and stores.
871
872config RISCV_SCALAR_MISALIGNED
873	bool
874	select RISCV_MISALIGNED
875	select SYSCTL_ARCH_UNALIGN_ALLOW
876	help
877	  Embed support for emulating misaligned loads and stores.
878
879config RISCV_VECTOR_MISALIGNED
880	bool
881	select RISCV_MISALIGNED
882	depends on RISCV_ISA_V
883	help
884	  Enable detecting support for vector misaligned loads and stores.
885
886choice
887	prompt "Unaligned Accesses Support"
888	default RISCV_PROBE_UNALIGNED_ACCESS
889	help
890	  This determines the level of support for unaligned accesses. This
891	  information is used by the kernel to perform optimizations. It is also
892	  exposed to user space via the hwprobe syscall. The hardware will be
893	  probed at boot by default.
894
895config RISCV_PROBE_UNALIGNED_ACCESS
896	bool "Probe for hardware unaligned access support"
897	select RISCV_SCALAR_MISALIGNED
898	help
899	  During boot, the kernel will run a series of tests to determine the
900	  speed of unaligned accesses. This probing will dynamically determine
901	  the speed of unaligned accesses on the underlying system. If unaligned
902	  memory accesses trap into the kernel as they are not supported by the
903	  system, the kernel will emulate the unaligned accesses to preserve the
904	  UABI.
905
906config RISCV_EMULATED_UNALIGNED_ACCESS
907	bool "Emulate unaligned access where system support is missing"
908	select RISCV_SCALAR_MISALIGNED
909	help
910	  If unaligned memory accesses trap into the kernel as they are not
911	  supported by the system, the kernel will emulate the unaligned
912	  accesses to preserve the UABI. When the underlying system does support
913	  unaligned accesses, the unaligned accesses are assumed to be slow.
914
915config RISCV_SLOW_UNALIGNED_ACCESS
916	bool "Assume the system supports slow unaligned memory accesses"
917	depends on NONPORTABLE
918	help
919	  Assume that the system supports slow unaligned memory accesses. The
920	  kernel and userspace programs may not be able to run at all on systems
921	  that do not support unaligned memory accesses.
922
923config RISCV_EFFICIENT_UNALIGNED_ACCESS
924	bool "Assume the system supports fast unaligned memory accesses"
925	depends on NONPORTABLE
926	select DCACHE_WORD_ACCESS if MMU
927	select HAVE_EFFICIENT_UNALIGNED_ACCESS
928	help
929	  Assume that the system supports fast unaligned memory accesses. When
930	  enabled, this option improves the performance of the kernel on such
931	  systems. However, the kernel and userspace programs will run much more
932	  slowly, or will not be able to run at all, on systems that do not
933	  support efficient unaligned memory accesses.
934
935endchoice
936
937choice
938	prompt "Vector unaligned Accesses Support"
939	depends on RISCV_ISA_V
940	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
941	help
942	  This determines the level of support for vector unaligned accesses. This
943	  information is used by the kernel to perform optimizations. It is also
944	  exposed to user space via the hwprobe syscall. The hardware will be
945	  probed at boot by default.
946
947config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
948	bool "Probe speed of vector unaligned accesses"
949	select RISCV_VECTOR_MISALIGNED
950	depends on RISCV_ISA_V
951	help
952	  During boot, the kernel will run a series of tests to determine the
953	  speed of vector unaligned accesses if they are supported. This probing
954	  will dynamically determine the speed of vector unaligned accesses on
955	  the underlying system if they are supported.
956
957config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
958	bool "Assume the system supports slow vector unaligned memory accesses"
959	depends on NONPORTABLE
960	help
961	  Assume that the system supports slow vector unaligned memory accesses. The
962	  kernel and userspace programs may not be able to run at all on systems
963	  that do not support unaligned memory accesses.
964
965config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
966	bool "Assume the system supports fast vector unaligned memory accesses"
967	depends on NONPORTABLE
968	help
969	  Assume that the system supports fast vector unaligned memory accesses. When
970	  enabled, this option improves the performance of the kernel on such
971	  systems. However, the kernel and userspace programs will run much more
972	  slowly, or will not be able to run at all, on systems that do not
973	  support efficient unaligned memory accesses.
974
975endchoice
976
977source "arch/riscv/Kconfig.vendor"
978
979endmenu # "Platform type"
980
981menu "Kernel features"
982
983source "kernel/Kconfig.hz"
984
985config RISCV_SBI_V01
986	bool "SBI v0.1 support"
987	depends on RISCV_SBI
988	help
989	  This config allows kernel to use SBI v0.1 APIs. This will be
990	  deprecated in future once legacy M-mode software are no longer in use.
991
992config RISCV_BOOT_SPINWAIT
993	bool "Spinwait booting method"
994	depends on SMP
995	default y if RISCV_SBI_V01 || RISCV_M_MODE
996	help
997	  This enables support for booting Linux via spinwait method. In the
998	  spinwait method, all cores randomly jump to Linux. One of the cores
999	  gets chosen via lottery and all other keep spinning on a percpu
1000	  variable. This method cannot support CPU hotplug and sparse hartid
1001	  scheme. It should be only enabled for M-mode Linux or platforms relying
1002	  on older firmware without SBI HSM extension. All other platforms should
1003	  rely on ordered booting via SBI HSM extension which gets chosen
1004	  dynamically at runtime if the firmware supports it.
1005
1006	  Since spinwait is incompatible with sparse hart IDs, it requires
1007	  NR_CPUS be large enough to contain the physical hart ID of the first
1008	  hart to enter Linux.
1009
1010	  If unsure what to do here, say N.
1011
1012config ARCH_SUPPORTS_KEXEC
1013	def_bool y
1014
1015config ARCH_SELECTS_KEXEC
1016	def_bool y
1017	depends on KEXEC
1018	select HOTPLUG_CPU if SMP
1019
1020config ARCH_SUPPORTS_KEXEC_FILE
1021	def_bool 64BIT
1022
1023config ARCH_SELECTS_KEXEC_FILE
1024	def_bool y
1025	depends on KEXEC_FILE
1026	select HAVE_IMA_KEXEC if IMA
1027	select KEXEC_ELF
1028
1029config ARCH_SUPPORTS_KEXEC_PURGATORY
1030	def_bool ARCH_SUPPORTS_KEXEC_FILE
1031
1032config ARCH_SUPPORTS_CRASH_DUMP
1033	def_bool y
1034
1035config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1036	def_bool CRASH_RESERVE
1037
1038config COMPAT
1039	bool "Kernel support for 32-bit U-mode"
1040	default 64BIT
1041	depends on 64BIT && MMU
1042	help
1043	  This option enables support for a 32-bit U-mode running under a 64-bit
1044	  kernel at S-mode. riscv32-specific components such as system calls,
1045	  the user helper functions (vdso), signal rt_frame functions and the
1046	  ptrace interface are handled appropriately by the kernel.
1047
1048	  If you want to execute 32-bit userspace applications, say Y.
1049
1050config PARAVIRT
1051	bool "Enable paravirtualization code"
1052	depends on RISCV_SBI
1053	help
1054	  This changes the kernel so it can modify itself when it is run
1055	  under a hypervisor, potentially improving performance significantly
1056	  over full virtualization.
1057
1058config PARAVIRT_TIME_ACCOUNTING
1059	bool "Paravirtual steal time accounting"
1060	depends on PARAVIRT
1061	help
1062	  Select this option to enable fine granularity task steal time
1063	  accounting. Time spent executing other tasks in parallel with
1064	  the current vCPU is discounted from the vCPU power. To account for
1065	  that, there can be a small performance impact.
1066
1067	  If in doubt, say N here.
1068
1069config RELOCATABLE
1070	bool "Build a relocatable kernel"
1071	depends on MMU && 64BIT && !XIP_KERNEL
1072	select MODULE_SECTIONS if MODULES
1073	help
1074          This builds a kernel as a Position Independent Executable (PIE),
1075          which retains all relocation metadata required to relocate the
1076          kernel binary at runtime to a different virtual address than the
1077          address it was linked at.
1078          Since RISCV uses the RELA relocation format, this requires a
1079          relocation pass at runtime even if the kernel is loaded at the
1080          same address it was linked at.
1081
1082          If unsure, say N.
1083
1084config RANDOMIZE_BASE
1085        bool "Randomize the address of the kernel image"
1086        select RELOCATABLE
1087        depends on MMU && 64BIT && !XIP_KERNEL
1088        help
1089          Randomizes the virtual address at which the kernel image is
1090          loaded, as a security feature that deters exploit attempts
1091          relying on knowledge of the location of kernel internals.
1092
1093          It is the bootloader's job to provide entropy, by passing a
1094          random u64 value in /chosen/kaslr-seed at kernel entry.
1095
1096          When booting via the UEFI stub, it will invoke the firmware's
1097          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1098          to the kernel proper. In addition, it will randomise the physical
1099          location of the kernel Image as well.
1100
1101          If unsure, say N.
1102
1103endmenu # "Kernel features"
1104
1105menu "Boot options"
1106
1107config CMDLINE
1108	string "Built-in kernel command line"
1109	help
1110	  For most platforms, the arguments for the kernel's command line
1111	  are provided at run-time, during boot. However, there are cases
1112	  where either no arguments are being provided or the provided
1113	  arguments are insufficient or even invalid.
1114
1115	  When that occurs, it is possible to define a built-in command
1116	  line here and choose how the kernel should use it later on.
1117
1118choice
1119	prompt "Built-in command line usage"
1120	depends on CMDLINE != ""
1121	default CMDLINE_FALLBACK
1122	help
1123	  Choose how the kernel will handle the provided built-in command
1124	  line.
1125
1126config CMDLINE_FALLBACK
1127	bool "Use bootloader kernel arguments if available"
1128	help
1129	  Use the built-in command line as fallback in case we get nothing
1130	  during boot. This is the default behaviour.
1131
1132config CMDLINE_EXTEND
1133	bool "Extend bootloader kernel arguments"
1134	help
1135	  The command-line arguments provided during boot will be
1136	  appended to the built-in command line. This is useful in
1137	  cases where the provided arguments are insufficient and
1138	  you don't want to or cannot modify them.
1139
1140config CMDLINE_FORCE
1141	bool "Always use the default kernel command string"
1142	help
1143	  Always use the built-in command line, even if we get one during
1144	  boot. This is useful in case you need to override the provided
1145	  command line on systems where you don't have or want control
1146	  over it.
1147
1148endchoice
1149
1150config EFI_STUB
1151	bool
1152
1153config EFI
1154	bool "UEFI runtime support"
1155	depends on OF && !XIP_KERNEL
1156	depends on MMU
1157	default y
1158	select ARCH_SUPPORTS_ACPI if 64BIT
1159	select EFI_GENERIC_STUB
1160	select EFI_PARAMS_FROM_FDT
1161	select EFI_RUNTIME_WRAPPERS
1162	select EFI_STUB
1163	select LIBFDT
1164	select RISCV_ISA_C
1165	select UCS2_STRING
1166	help
1167	  This option provides support for runtime services provided
1168	  by UEFI firmware (such as non-volatile variables, realtime
1169	  clock, and platform reset). A UEFI stub is also provided to
1170	  allow the kernel to be booted as an EFI application. This
1171	  is only useful on systems that have UEFI firmware.
1172
1173config DMI
1174	bool "Enable support for SMBIOS (DMI) tables"
1175	depends on EFI
1176	default y
1177	help
1178	  This enables SMBIOS/DMI feature for systems.
1179
1180	  This option is only useful on systems that have UEFI firmware.
1181	  However, even with this option, the resultant kernel should
1182	  continue to boot on existing non-UEFI platforms.
1183
1184config CC_HAVE_STACKPROTECTOR_TLS
1185	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1186
1187config STACKPROTECTOR_PER_TASK
1188	def_bool y
1189	depends on !RANDSTRUCT
1190	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1191
1192config PHYS_RAM_BASE_FIXED
1193	bool "Explicitly specified physical RAM address"
1194	depends on NONPORTABLE
1195	default n
1196
1197config PHYS_RAM_BASE
1198	hex "Platform Physical RAM address"
1199	depends on PHYS_RAM_BASE_FIXED
1200	default "0x80000000"
1201	help
1202	  This is the physical address of RAM in the system. It has to be
1203	  explicitly specified to run early relocations of read-write data
1204	  from flash to RAM.
1205
1206config XIP_KERNEL
1207	bool "Kernel Execute-In-Place from ROM"
1208	depends on MMU && SPARSEMEM && NONPORTABLE
1209	# This prevents XIP from being enabled by all{yes,mod}config, which
1210	# fail to build since XIP doesn't support large kernels.
1211	depends on !COMPILE_TEST
1212	select PHYS_RAM_BASE_FIXED
1213	help
1214	  Execute-In-Place allows the kernel to run from non-volatile storage
1215	  directly addressable by the CPU, such as NOR flash. This saves RAM
1216	  space since the text section of the kernel is not loaded from flash
1217	  to RAM.  Read-write sections, such as the data section and stack,
1218	  are still copied to RAM.  The XIP kernel is not compressed since
1219	  it has to run directly from flash, so it will take more space to
1220	  store it.  The flash address used to link the kernel object files,
1221	  and for storing it, is configuration dependent. Therefore, if you
1222	  say Y here, you must know the proper physical address where to
1223	  store the kernel image depending on your own flash memory usage.
1224
1225	  Also note that the make target becomes "make xipImage" rather than
1226	  "make zImage" or "make Image".  The final kernel binary to put in
1227	  ROM memory will be arch/riscv/boot/xipImage.
1228
1229	  SPARSEMEM is required because the kernel text and rodata that are
1230	  flash resident are not backed by memmap, then any attempt to get
1231	  a struct page on those regions will trigger a fault.
1232
1233	  If unsure, say N.
1234
1235config XIP_PHYS_ADDR
1236	hex "XIP Kernel Physical Location"
1237	depends on XIP_KERNEL
1238	default "0x21000000"
1239	help
1240	  This is the physical address in your flash memory the kernel will
1241	  be linked for and stored to.  This address is dependent on your
1242	  own flash usage.
1243
1244config RISCV_ISA_FALLBACK
1245	bool "Permit falling back to parsing riscv,isa for extension support by default"
1246	default y
1247	help
1248	  Parsing the "riscv,isa" devicetree property has been deprecated and
1249	  replaced by a list of explicitly defined strings. For compatibility
1250	  with existing platforms, the kernel will fall back to parsing the
1251	  "riscv,isa" property if the replacements are not found.
1252
1253	  Selecting N here will result in a kernel that does not use the
1254	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1255	  present.
1256
1257	  Please see the dt-binding, located at
1258	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1259	  on the replacement properties, "riscv,isa-base" and
1260	  "riscv,isa-extensions".
1261
1262config BUILTIN_DTB
1263	bool "Built-in device tree"
1264	depends on OF && NONPORTABLE
1265	help
1266	  Build a device tree into the Linux image.
1267	  This option should be selected if no bootloader is being used.
1268	  If unsure, say N.
1269
1270
1271config BUILTIN_DTB_SOURCE
1272	string "Built-in device tree source"
1273	depends on BUILTIN_DTB
1274	help
1275	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1276	  for the DTS file that will be used to produce the DTB linked into the
1277	  kernel.
1278
1279endmenu # "Boot options"
1280
1281config PORTABLE
1282	bool
1283	default !NONPORTABLE
1284	select EFI
1285	select MMU
1286	select OF
1287
1288config ARCH_PROC_KCORE_TEXT
1289	def_bool y
1290
1291menu "Power management options"
1292
1293source "kernel/power/Kconfig"
1294
1295config ARCH_HIBERNATION_POSSIBLE
1296	def_bool y
1297
1298config ARCH_HIBERNATION_HEADER
1299	def_bool HIBERNATION
1300
1301config ARCH_SUSPEND_POSSIBLE
1302	def_bool y
1303
1304endmenu # "Power management options"
1305
1306menu "CPU Power Management"
1307
1308source "drivers/cpuidle/Kconfig"
1309
1310source "drivers/cpufreq/Kconfig"
1311
1312endmenu # "CPU Power Management"
1313
1314source "arch/riscv/kvm/Kconfig"
1315
1316source "drivers/acpi/Kconfig"
1317