1 # SPDX-License-Identifier: GPL-2.0-only
3 # For a description of the syntax of this configuration file,
4 # see Documentation/kbuild/kconfig-language.rst.
15 select ACPI_GENERIC_GSI if ACPI
16 select ACPI_MCFG if (ACPI && PCI)
17 select ACPI_PPTT if ACPI
18 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
19 select ACPI_SPCR_TABLE if ACPI
20 select ARCH_DMA_DEFAULT_COHERENT
21 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
22 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP
23 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
24 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
25 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
26 select ARCH_HAS_BINFMT_FLAT
27 select ARCH_HAS_CRC32 if RISCV_ISA_ZBC
28 select ARCH_HAS_CRC64 if 64BIT && RISCV_ISA_ZBC
29 select ARCH_HAS_CRC_T10DIF if RISCV_ISA_ZBC
30 select ARCH_HAS_CURRENT_STACK_POINTER
31 select ARCH_HAS_DEBUG_VIRTUAL if MMU
32 select ARCH_HAS_DEBUG_VM_PGTABLE
33 select ARCH_HAS_DEBUG_WX
34 select ARCH_HAS_FAST_MULTIPLIER
35 select ARCH_HAS_FORTIFY_SOURCE
36 select ARCH_HAS_GCOV_PROFILE_ALL
37 select ARCH_HAS_GIGANTIC_PAGE
38 select ARCH_HAS_HW_PTE_YOUNG
40 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
41 select ARCH_HAS_MEMBARRIER_CALLBACKS
42 select ARCH_HAS_MEMBARRIER_SYNC_CORE
43 select ARCH_HAS_MMIOWB
44 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
45 select ARCH_HAS_PMEM_API
46 select ARCH_HAS_PREEMPT_LAZY
47 select ARCH_HAS_PREPARE_SYNC_CORE_CMD
48 select ARCH_HAS_PTDUMP if MMU
49 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
50 select ARCH_HAS_PTE_SPECIAL
51 select ARCH_HAS_SET_DIRECT_MAP if MMU
52 select ARCH_HAS_SET_MEMORY if MMU
53 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
54 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
55 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
56 select ARCH_HAS_SYSCALL_WRAPPER
57 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
59 select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE
60 select ARCH_KEEP_MEMBLOCK if ACPI
61 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU
62 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
63 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
65 select ARCH_SUPPORTS_ATOMIC_RMW
66 # clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2
67 select ARCH_SUPPORTS_CFI_CLANG if CLANG_VERSION >= 170000
68 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
69 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
70 select ARCH_SUPPORTS_HUGETLBFS if MMU
71 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
72 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
73 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
74 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU
75 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
76 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
77 select ARCH_SUPPORTS_RT
78 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
79 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
80 select ARCH_USE_MEMTEST
81 select ARCH_USE_QUEUED_RWLOCKS
82 select ARCH_USE_SYM_ANNOTATIONS
83 select ARCH_USES_CFI_TRAPS if CFI_CLANG
84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
85 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
86 select ARCH_WANT_FRAME_POINTERS
87 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
88 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
89 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
90 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
91 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
92 select ARCH_WANTS_NO_INSTR
93 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
94 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
95 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
96 select BUILDTIME_TABLE_SORT if MMU
97 select CLINT_TIMER if RISCV_M_MODE
98 select CLONE_BACKWARDS
100 select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB
101 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
103 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
104 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
105 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
106 select GENERIC_ARCH_TOPOLOGY
107 select GENERIC_ATOMIC64 if !64BIT
108 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
109 select GENERIC_CPU_DEVICES
110 select GENERIC_CPU_VULNERABILITIES
111 select GENERIC_EARLY_IOREMAP
113 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
114 select GENERIC_IDLE_POLL_SETUP
115 select GENERIC_IOREMAP if MMU
116 select GENERIC_IRQ_IPI if SMP
117 select GENERIC_IRQ_IPI_MUX if SMP
118 select GENERIC_IRQ_MULTI_HANDLER
119 select GENERIC_IRQ_SHOW
120 select GENERIC_IRQ_SHOW_LEVEL
121 select GENERIC_LIB_DEVMEM_IS_ALLOWED
122 select GENERIC_PENDING_IRQ if SMP
123 select GENERIC_PCI_IOMAP
124 select GENERIC_SCHED_CLOCK
125 select GENERIC_SMP_IDLE_THREAD
126 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
127 select GENERIC_VDSO_DATA_STORE if MMU
128 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
129 select HARDIRQS_SW_RESEND
130 select HAS_IOPORT if MMU
131 select HAVE_ALIGNED_STRUCT_PAGE
132 select HAVE_ARCH_AUDITSYSCALL
133 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
134 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
135 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
136 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
137 select HAVE_ARCH_KASAN if MMU && 64BIT
138 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
139 select HAVE_ARCH_KFENCE if MMU && 64BIT
140 select HAVE_ARCH_KGDB if !XIP_KERNEL
141 select HAVE_ARCH_KGDB_QXFER_PKT
142 select HAVE_ARCH_MMAP_RND_BITS if MMU
143 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
144 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
145 select HAVE_ARCH_SECCOMP_FILTER
146 select HAVE_ARCH_STACKLEAK
147 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
148 select HAVE_ARCH_TRACEHOOK
149 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
150 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU
151 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
152 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
153 select HAVE_ASM_MODVERSIONS
154 select HAVE_CONTEXT_TRACKING_USER
155 select HAVE_DEBUG_KMEMLEAK
156 select HAVE_DMA_CONTIGUOUS if MMU
157 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
158 select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C
159 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
160 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG)
161 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
162 select HAVE_FTRACE_GRAPH_FUNC
163 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
164 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
165 select HAVE_FUNCTION_GRAPH_FREGS
166 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
167 select HAVE_EBPF_JIT if MMU
168 select HAVE_GUP_FAST if MMU
169 select HAVE_FUNCTION_ARG_ACCESS_API
170 select HAVE_FUNCTION_ERROR_INJECTION
171 select HAVE_GCC_PLUGINS
172 select HAVE_GENERIC_VDSO if MMU && 64BIT
173 select HAVE_IRQ_TIME_ACCOUNTING
174 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
175 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
176 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
177 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
178 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
179 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
180 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
181 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
182 select HAVE_KPROBES if !XIP_KERNEL
183 select HAVE_KRETPROBES if !XIP_KERNEL
184 # https://github.com/ClangBuiltLinux/linux/issues/1881
185 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
188 select HAVE_PAGE_SIZE_4KB
190 select HAVE_PERF_EVENTS
191 select HAVE_PERF_REGS
192 select HAVE_PERF_USER_STACK_DUMP
193 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
194 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
195 select HAVE_REGS_AND_STACK_ACCESS_API
196 select HAVE_RETHOOK if !XIP_KERNEL
198 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
199 select HAVE_SAMPLE_FTRACE_DIRECT
200 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
201 select HAVE_STACKPROTECTOR
202 select HAVE_SYSCALL_TRACEPOINTS
203 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
205 select IRQ_FORCED_THREADING
206 select KASAN_VMALLOC if KASAN
207 select LOCK_MM_AND_FIND_VMA
208 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
209 select MODULES_USE_ELF_RELA if MODULES
211 select OF_EARLY_FLATTREE
213 select PCI_DOMAINS_GENERIC if PCI
214 select PCI_ECAM if (ACPI && PCI)
215 select PCI_MSI if PCI
216 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
217 select RISCV_ALTERNATIVE if !XIP_KERNEL
221 select RISCV_TIMER if RISCV_SBI
224 select SYSCTL_EXCEPTION_TRACE
225 select THREAD_INFO_IN_TASK
226 select TRACE_IRQFLAGS_SUPPORT
227 select UACCESS_MEMCPY if !MMU
228 select VDSO_GETRANDOM if HAVE_GENERIC_VDSO
229 select USER_STACKTRACE_SUPPORT
230 select ZONE_DMA32 if 64BIT
232 config RUSTC_SUPPORTS_RISCV
235 # Shadow call stack requires rustc version 1.82+ due to use of the
236 # -Zsanitizer=shadow-call-stack flag.
237 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
239 config CLANG_SUPPORTS_DYNAMIC_FTRACE
241 # https://github.com/ClangBuiltLinux/linux/issues/1817
242 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
244 config GCC_SUPPORTS_DYNAMIC_FTRACE
246 depends on $(cc-option,-fpatchable-function-entry=8)
247 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C
249 config HAVE_SHADOW_CALL_STACK
250 def_bool $(cc-option,-fsanitize=shadow-call-stack)
251 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
252 depends on $(ld-option,--no-relax-gp)
254 config RISCV_USE_LINKER_RELAXATION
256 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
257 depends on !LD_IS_LLD || LLD_VERSION >= 150000
259 # https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
260 config ARCH_HAS_BROKEN_DWARF5
262 depends on RISCV_USE_LINKER_RELAXATION
263 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
264 depends on AS_IS_LLVM && AS_VERSION < 180000
265 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
266 depends on LD_IS_LLD && LLD_VERSION < 180000
268 config ARCH_MMAP_RND_BITS_MIN
272 config ARCH_MMAP_RND_COMPAT_BITS_MIN
275 # max bits determined by the following formula:
276 # VA_BITS - PAGE_SHIFT - 3
277 config ARCH_MMAP_RND_BITS_MAX
278 default 24 if 64BIT # SV39 based
281 config ARCH_MMAP_RND_COMPAT_BITS_MAX
284 # set if we run in machine mode, cleared if we run in supervisor mode
286 bool "Build a kernel that runs in machine mode"
290 Select this option if you want to run the kernel in M-mode,
291 without the assistance of any other firmware.
293 # set if we are running in S-mode and can use SBI calls
296 depends on !RISCV_M_MODE
300 bool "MMU-based Paged Memory Management Support"
303 Select if you want MMU-based virtualised addressing space
304 support by paged memory management. If unsure, say 'Y'.
306 config KASAN_SHADOW_OFFSET
308 depends on KASAN_GENERIC
309 default 0xdfffffff00000000 if 64BIT
310 default 0xffffffff if 32BIT
312 config ARCH_FLATMEM_ENABLE
315 config ARCH_SPARSEMEM_ENABLE
318 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
319 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
321 config ARCH_SELECT_MEMORY_MODEL
322 def_bool ARCH_SPARSEMEM_ENABLE
324 config ARCH_SUPPORTS_UPROBES
327 config STACKTRACE_SUPPORT
333 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
335 config GENERIC_BUG_RELATIVE_POINTERS
338 config GENERIC_CALIBRATE_DELAY
344 config GENERIC_HWEIGHT
347 config FIX_EARLYCON_MEM
350 config ILLEGAL_POINTER_VALUE
353 default 0xdead000000000000 if 64BIT
355 config PGTABLE_LEVELS
360 config LOCKDEP_SUPPORT
363 config RISCV_DMA_NONCOHERENT
365 select ARCH_HAS_DMA_PREP_COHERENT
366 select ARCH_HAS_SETUP_DMA_OPS
367 select ARCH_HAS_SYNC_DMA_FOR_CPU
368 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
369 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
371 config RISCV_NONSTANDARD_CACHE_OPS
374 This enables function pointer support for non-standard noncoherent
375 systems to handle cache management.
378 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
380 config AS_HAS_OPTION_ARCH
381 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
383 depends on $(as-instr, .option arch$(comma) +m)
385 source "arch/riscv/Kconfig.socs"
386 source "arch/riscv/Kconfig.errata"
391 bool "Allow configurations that result in non-portable kernels"
393 RISC-V kernel binaries are compatible between all known systems
394 whenever possible, but there are some use cases that can only be
395 satisfied by configurations that result in kernel binaries that are
396 not portable between systems.
398 Selecting N does not guarantee kernels will be portable to all known
399 systems. Selecting any of the options guarded by NONPORTABLE will
400 result in kernel binaries that are unlikely to be portable between
409 This selects the base ISA that this kernel will target and must match
414 depends on NONPORTABLE
416 select GENERIC_LIB_ASHLDI3
417 select GENERIC_LIB_ASHRDI3
418 select GENERIC_LIB_LSHRDI3
419 select GENERIC_LIB_UCMPDI2
424 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
425 select SWIOTLB if MMU
429 # We must be able to map all physical memory into the kernel, but the compiler
430 # is still a bit more efficient when generating code if it's setup in a manner
431 # such that it can only map 2GiB of memory.
433 prompt "Kernel Code Model"
434 default CMODEL_MEDLOW if 32BIT
435 default CMODEL_MEDANY if 64BIT
438 bool "medium low code model"
440 bool "medium any code model"
443 config MODULE_SECTIONS
445 select HAVE_MOD_ARCH_SPECIFIC
448 bool "Symmetric Multi-Processing"
450 This enables support for systems with more than one CPU. If
451 you say N here, the kernel will run on single and
452 multiprocessor machines, but will use only one CPU of a
453 multiprocessor machine. If you say Y here, the kernel will run
454 on many, but not all, single processor machines. On a single
455 processor machine, the kernel will run faster if you say N
458 If you don't know what to do here, say N.
461 bool "Multi-core scheduler support"
464 Multi-core scheduler support improves the CPU scheduler's decision
465 making when dealing with multi-core CPU chips at a cost of slightly
466 increased overhead in some places. If unsure say N here.
469 int "Maximum number of CPUs (2-512)"
471 range 2 512 if !RISCV_SBI_V01
472 range 2 32 if RISCV_SBI_V01 && 32BIT
473 range 2 64 if RISCV_SBI_V01 && 64BIT
474 default "32" if 32BIT
475 default "64" if 64BIT
478 bool "Support for hot-pluggable CPUs"
480 select GENERIC_IRQ_MIGRATION
483 Say Y here to experiment with turning CPUs off and on. CPUs
484 can be controlled through /sys/devices/system/cpu.
486 Say N if you want to disable CPU hotplug.
497 # Common NUMA Features
499 bool "NUMA Memory Allocation and Scheduler Support"
500 depends on SMP && MMU
501 select ARCH_SUPPORTS_NUMA_BALANCING
502 select GENERIC_ARCH_NUMA
503 select HAVE_SETUP_PER_CPU_AREA
504 select NEED_PER_CPU_EMBED_FIRST_CHUNK
505 select NEED_PER_CPU_PAGE_FIRST_CHUNK
507 select USE_PERCPU_NUMA_NODE_ID
509 Enable NUMA (Non-Uniform Memory Access) support.
511 The kernel will try to allocate memory used by a CPU on the
512 local memory of the CPU and add some more NUMA awareness to the kernel.
515 int "Maximum NUMA Nodes (as a power of 2)"
520 Specify the maximum number of NUMA Nodes available on the target
521 system. Increases memory reserved to accommodate various tables.
524 prompt "RISC-V spinlock type"
525 default RISCV_COMBO_SPINLOCKS
527 config RISCV_TICKET_SPINLOCKS
528 bool "Using ticket spinlock"
530 config RISCV_QUEUED_SPINLOCKS
531 bool "Using queued spinlock"
532 depends on SMP && MMU && NONPORTABLE
533 select ARCH_USE_QUEUED_SPINLOCKS
535 The queued spinlock implementation requires the forward progress
536 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
537 LR/SC with Ziccrse provide such guarantee.
539 Select this if and only if Zabha or Ziccrse is available on your
540 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
541 without one of those extensions.
543 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
544 when supported and otherwise ticket spinlocks.
546 config RISCV_COMBO_SPINLOCKS
547 bool "Using combo spinlock"
548 depends on SMP && MMU
549 select ARCH_USE_QUEUED_SPINLOCKS
551 Embed both queued spinlock and ticket lock so that the spinlock
552 implementation can be chosen at runtime.
556 config RISCV_ALTERNATIVE
558 depends on !XIP_KERNEL
560 This Kconfig allows the kernel to automatically patch the
561 erratum or cpufeature required by the execution platform at run
562 time. The code patching overhead is minimal, as it's only done
563 once at boot and once on each module load.
565 config RISCV_ALTERNATIVE_EARLY
567 depends on RISCV_ALTERNATIVE
569 Allows early patching of the kernel for special errata
572 bool "Emit compressed instructions when building Linux"
575 Adds "C" to the ISA subsets that the toolchain is allowed to emit
576 when building Linux, which results in compressed instructions in the
577 Linux binary. This option produces a kernel that will not run on
578 systems that do not support compressed instructions.
580 If you don't know what to do here, say Y.
582 config RISCV_ISA_SUPM
583 bool "Supm extension for userspace pointer masking"
587 Add support for pointer masking in userspace (Supm) when the
588 underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
590 If this option is disabled, userspace will be unable to use
591 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
593 config RISCV_ISA_SVNAPOT
594 bool "Svnapot extension support for supervisor mode NAPOT pages"
595 depends on 64BIT && MMU
596 depends on RISCV_ALTERNATIVE
599 Enable support for the Svnapot ISA-extension when it is detected
602 The Svnapot extension is used to mark contiguous PTEs as a range
603 of contiguous virtual-to-physical translations for a naturally
604 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
605 size. When HUGETLBFS is also selected this option unconditionally
606 allocates some memory for each NAPOT page size supported by the kernel.
607 When optimizing for low memory consumption and for platforms without
608 the Svnapot extension, it may be better to say N here.
610 If you don't know what to do here, say Y.
612 config RISCV_ISA_SVPBMT
613 bool "Svpbmt extension support for supervisor mode page-based memory types"
614 depends on 64BIT && MMU
615 depends on RISCV_ALTERNATIVE
618 Add support for the Svpbmt ISA-extension (Supervisor-mode:
619 page-based memory types) in the kernel when it is detected at boot.
621 The memory type for a page contains a combination of attributes
622 that indicate the cacheability, idempotency, and ordering
623 properties for access to that page.
625 The Svpbmt extension is only available on 64-bit cpus.
627 If you don't know what to do here, say Y.
629 config TOOLCHAIN_HAS_V
632 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
633 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
634 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
635 depends on AS_HAS_OPTION_ARCH
638 bool "Vector extension support"
639 depends on TOOLCHAIN_HAS_V
641 select DYNAMIC_SIGFRAME
644 Add support for the Vector extension when it is detected at boot.
645 When this option is disabled, neither the kernel nor userspace may
646 use vector procedures.
648 If you don't know what to do here, say Y.
650 config RISCV_ISA_V_DEFAULT_ENABLE
651 bool "Enable userspace Vector by default"
652 depends on RISCV_ISA_V
655 Say Y here if you want to enable Vector in userspace by default.
656 Otherwise, userspace has to make explicit prctl() call to enable
657 Vector, or enable it via the sysctl interface.
659 If you don't know what to do here, say Y.
661 config RISCV_ISA_V_UCOPY_THRESHOLD
662 int "Threshold size for vectorized user copies"
663 depends on RISCV_ISA_V
666 Prefer using vectorized copy_to_user()/copy_from_user() when the
667 workload size exceeds this value.
669 config RISCV_ISA_V_PREEMPTIVE
670 bool "Run kernel-mode Vector with kernel preemption"
671 depends on PREEMPTION
672 depends on RISCV_ISA_V
675 Usually, in-kernel SIMD routines are run with preemption disabled.
676 Functions which invoke long running SIMD thus must yield the core's
677 vector unit to prevent blocking other tasks for too long.
679 This config allows the kernel to run SIMD without explicitly disabling
680 preemption. Enabling this config will result in higher memory consumption
681 due to the allocation of per-task's kernel Vector context.
683 config RISCV_ISA_ZAWRS
684 bool "Zawrs extension support for more efficient busy waiting"
685 depends on RISCV_ALTERNATIVE
688 The Zawrs extension defines instructions to be used in polling loops
689 which allow a hart to enter a low-power state or to trap to the
690 hypervisor while waiting on a store to a memory location. Enable the
691 use of these instructions in the kernel when the Zawrs extension is
694 config TOOLCHAIN_HAS_ZABHA
697 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
698 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
699 depends on AS_HAS_OPTION_ARCH
701 config RISCV_ISA_ZABHA
702 bool "Zabha extension support for atomic byte/halfword operations"
703 depends on TOOLCHAIN_HAS_ZABHA
704 depends on RISCV_ALTERNATIVE
707 Enable the use of the Zabha ISA-extension to implement kernel
708 byte/halfword atomic memory operations when it is detected at boot.
710 If you don't know what to do here, say Y.
712 config TOOLCHAIN_HAS_ZACAS
715 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
716 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
717 depends on AS_HAS_OPTION_ARCH
719 config RISCV_ISA_ZACAS
720 bool "Zacas extension support for atomic CAS"
721 depends on TOOLCHAIN_HAS_ZACAS
722 depends on RISCV_ALTERNATIVE
725 Enable the use of the Zacas ISA-extension to implement kernel atomic
726 cmpxchg operations when it is detected at boot.
728 If you don't know what to do here, say Y.
730 config TOOLCHAIN_HAS_ZBB
733 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
734 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
735 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
736 depends on AS_HAS_OPTION_ARCH
738 # This symbol indicates that the toolchain supports all v1.0 vector crypto
739 # extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once.
740 # binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb.
741 config TOOLCHAIN_HAS_VECTOR_CRYPTO
742 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
743 depends on AS_HAS_OPTION_ARCH
745 config TOOLCHAIN_HAS_ZBA
748 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
749 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
750 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
751 depends on AS_HAS_OPTION_ARCH
754 bool "Zba extension support for bit manipulation instructions"
757 Add support for enabling optimisations in the kernel when the Zba
758 extension is detected at boot.
760 The Zba extension provides instructions to accelerate the generation
761 of addresses that index into arrays of basic data types.
763 If you don't know what to do here, say Y.
766 bool "Zbb extension support for bit manipulation instructions"
767 depends on RISCV_ALTERNATIVE
770 Add support for enabling optimisations in the kernel when the
771 Zbb extension is detected at boot. Some optimisations may
772 additionally depend on toolchain support for Zbb.
774 The Zbb extension provides instructions to accelerate a number
775 of bit-specific operations (count bit population, sign extending,
778 If you don't know what to do here, say Y.
780 config TOOLCHAIN_HAS_ZBC
783 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
784 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
785 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
786 depends on AS_HAS_OPTION_ARCH
789 bool "Zbc extension support for carry-less multiplication instructions"
790 depends on TOOLCHAIN_HAS_ZBC
792 depends on RISCV_ALTERNATIVE
795 Adds support to dynamically detect the presence of the Zbc
796 extension (carry-less multiplication) and enable its usage.
798 The Zbc extension could accelerate CRC (cyclic redundancy check)
801 If you don't know what to do here, say Y.
803 config TOOLCHAIN_HAS_ZBKB
806 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
807 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
808 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
809 depends on AS_HAS_OPTION_ARCH
811 config RISCV_ISA_ZBKB
812 bool "Zbkb extension support for bit manipulation instructions"
813 depends on TOOLCHAIN_HAS_ZBKB
814 depends on RISCV_ALTERNATIVE
817 Adds support to dynamically detect the presence of the ZBKB
818 extension (bit manipulation for cryptography) and enable its usage.
820 The Zbkb extension provides instructions to accelerate a number
821 of common cryptography operations (pack, zip, etc).
823 If you don't know what to do here, say Y.
825 config RISCV_ISA_ZICBOM
826 bool "Zicbom extension support for non-coherent DMA operation"
828 depends on RISCV_ALTERNATIVE
830 select RISCV_DMA_NONCOHERENT
831 select DMA_DIRECT_REMAP
833 Add support for the Zicbom extension (Cache Block Management
834 Operations) and enable its use in the kernel when it is detected
837 The Zicbom extension can be used to handle for example
838 non-coherent DMA support on devices that need it.
840 If you don't know what to do here, say Y.
842 config RISCV_ISA_ZICBOZ
843 bool "Zicboz extension support for faster zeroing of memory"
844 depends on RISCV_ALTERNATIVE
847 Enable the use of the Zicboz extension (cbo.zero instruction)
848 in the kernel when it is detected at boot.
850 The Zicboz extension is used for faster zeroing of memory.
852 If you don't know what to do here, say Y.
854 config RISCV_ISA_ZICBOP
855 bool "Zicbop extension support for cache block prefetch"
857 depends on RISCV_ALTERNATIVE
860 Adds support to dynamically detect the presence of the ZICBOP
861 extension (Cache Block Prefetch Operations) and enable its
864 The Zicbop extension can be used to prefetch cache blocks for
867 If you don't know what to do here, say Y.
869 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
871 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
872 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
873 depends on AS_IS_GNU && AS_VERSION >= 23600
875 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
876 20191213 version, which moves some instructions from the I extension to
877 the Zicsr and Zifencei extensions. This requires explicitly specifying
878 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
879 and Zifencei are supported in binutils from version 2.36 onwards.
880 To make life easier, and avoid forcing toolchains that default to a
881 newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
882 For clang < 17 or GCC < 11.3.0, for which this is not possible or need
883 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
885 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
887 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
888 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
889 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
890 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
892 Certain versions of clang and GCC do not support zicsr and zifencei via
893 -march. This option causes an older ISA spec compatible with these older
894 versions of clang and GCC to be passed to GAS, which has the same result
895 as passing zicsr and zifencei to -march.
901 Add support for floating point operations when an FPU is detected at
902 boot. When this option is disabled, neither the kernel nor userspace
903 may use the floating point unit.
905 If you don't know what to do here, say Y.
908 bool "Independent irq & softirq stacks" if EXPERT
910 select HAVE_IRQ_EXIT_ON_IRQ_STACK
911 select HAVE_SOFTIRQ_ON_OWN_STACK
913 Add independent irq & softirq stacks for percpu to prevent kernel stack
914 overflows. We may save some memory footprint by disabling IRQ_STACKS.
916 config THREAD_SIZE_ORDER
917 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
922 Specify the Pages of thread stack size (from 4KB to 64KB), which also
923 affects irq stack size, which is equal to thread stack size.
925 config RISCV_MISALIGNED
928 Embed support for detecting and emulating misaligned
929 scalar or vector loads and stores.
931 config RISCV_SCALAR_MISALIGNED
933 select RISCV_MISALIGNED
934 select SYSCTL_ARCH_UNALIGN_ALLOW
936 Embed support for emulating misaligned loads and stores.
938 config RISCV_VECTOR_MISALIGNED
940 select RISCV_MISALIGNED
941 depends on RISCV_ISA_V
943 Enable detecting support for vector misaligned loads and stores.
946 prompt "Unaligned Accesses Support"
947 default RISCV_PROBE_UNALIGNED_ACCESS
949 This determines the level of support for unaligned accesses. This
950 information is used by the kernel to perform optimizations. It is also
951 exposed to user space via the hwprobe syscall. The hardware will be
952 probed at boot by default.
954 config RISCV_PROBE_UNALIGNED_ACCESS
955 bool "Probe for hardware unaligned access support"
956 select RISCV_SCALAR_MISALIGNED
958 During boot, the kernel will run a series of tests to determine the
959 speed of unaligned accesses. This probing will dynamically determine
960 the speed of unaligned accesses on the underlying system. If unaligned
961 memory accesses trap into the kernel as they are not supported by the
962 system, the kernel will emulate the unaligned accesses to preserve the
965 config RISCV_EMULATED_UNALIGNED_ACCESS
966 bool "Emulate unaligned access where system support is missing"
967 select RISCV_SCALAR_MISALIGNED
969 If unaligned memory accesses trap into the kernel as they are not
970 supported by the system, the kernel will emulate the unaligned
971 accesses to preserve the UABI. When the underlying system does support
972 unaligned accesses, the unaligned accesses are assumed to be slow.
974 config RISCV_SLOW_UNALIGNED_ACCESS
975 bool "Assume the system supports slow unaligned memory accesses"
976 depends on NONPORTABLE
978 Assume that the system supports slow unaligned memory accesses. The
979 kernel and userspace programs may not be able to run at all on systems
980 that do not support unaligned memory accesses.
982 config RISCV_EFFICIENT_UNALIGNED_ACCESS
983 bool "Assume the system supports fast unaligned memory accesses"
984 depends on NONPORTABLE
985 select DCACHE_WORD_ACCESS if MMU
986 select HAVE_EFFICIENT_UNALIGNED_ACCESS
988 Assume that the system supports fast unaligned memory accesses. When
989 enabled, this option improves the performance of the kernel on such
990 systems. However, the kernel and userspace programs will run much more
991 slowly, or will not be able to run at all, on systems that do not
992 support efficient unaligned memory accesses.
997 prompt "Vector unaligned Accesses Support"
998 depends on RISCV_ISA_V
999 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1001 This determines the level of support for vector unaligned accesses. This
1002 information is used by the kernel to perform optimizations. It is also
1003 exposed to user space via the hwprobe syscall. The hardware will be
1004 probed at boot by default.
1006 config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1007 bool "Probe speed of vector unaligned accesses"
1008 select RISCV_VECTOR_MISALIGNED
1009 depends on RISCV_ISA_V
1011 During boot, the kernel will run a series of tests to determine the
1012 speed of vector unaligned accesses if they are supported. This probing
1013 will dynamically determine the speed of vector unaligned accesses on
1014 the underlying system if they are supported.
1016 config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
1017 bool "Assume the system supports slow vector unaligned memory accesses"
1018 depends on NONPORTABLE
1020 Assume that the system supports slow vector unaligned memory accesses. The
1021 kernel and userspace programs may not be able to run at all on systems
1022 that do not support unaligned memory accesses.
1024 config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
1025 bool "Assume the system supports fast vector unaligned memory accesses"
1026 depends on NONPORTABLE
1028 Assume that the system supports fast vector unaligned memory accesses. When
1029 enabled, this option improves the performance of the kernel on such
1030 systems. However, the kernel and userspace programs will run much more
1031 slowly, or will not be able to run at all, on systems that do not
1032 support efficient unaligned memory accesses.
1036 source "arch/riscv/Kconfig.vendor"
1038 endmenu # "Platform type"
1040 menu "Kernel features"
1042 source "kernel/Kconfig.hz"
1044 config RISCV_SBI_V01
1045 bool "SBI v0.1 support"
1046 depends on RISCV_SBI
1048 This config allows kernel to use SBI v0.1 APIs. This will be
1049 deprecated in future once legacy M-mode software are no longer in use.
1051 config RISCV_BOOT_SPINWAIT
1052 bool "Spinwait booting method"
1054 default y if RISCV_SBI_V01 || RISCV_M_MODE
1056 This enables support for booting Linux via spinwait method. In the
1057 spinwait method, all cores randomly jump to Linux. One of the cores
1058 gets chosen via lottery and all other keep spinning on a percpu
1059 variable. This method cannot support CPU hotplug and sparse hartid
1060 scheme. It should be only enabled for M-mode Linux or platforms relying
1061 on older firmware without SBI HSM extension. All other platforms should
1062 rely on ordered booting via SBI HSM extension which gets chosen
1063 dynamically at runtime if the firmware supports it.
1065 Since spinwait is incompatible with sparse hart IDs, it requires
1066 NR_CPUS be large enough to contain the physical hart ID of the first
1067 hart to enter Linux.
1069 If unsure what to do here, say N.
1071 config ARCH_SUPPORTS_KEXEC
1074 config ARCH_SELECTS_KEXEC
1077 select HOTPLUG_CPU if SMP
1079 config ARCH_SUPPORTS_KEXEC_FILE
1082 config ARCH_SELECTS_KEXEC_FILE
1084 depends on KEXEC_FILE
1085 select HAVE_IMA_KEXEC if IMA
1088 config ARCH_SUPPORTS_KEXEC_PURGATORY
1089 def_bool ARCH_SUPPORTS_KEXEC_FILE
1091 config ARCH_SUPPORTS_CRASH_DUMP
1094 config ARCH_DEFAULT_CRASH_DUMP
1097 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1098 def_bool CRASH_RESERVE
1101 bool "Kernel support for 32-bit U-mode"
1103 depends on 64BIT && MMU
1105 This option enables support for a 32-bit U-mode running under a 64-bit
1106 kernel at S-mode. riscv32-specific components such as system calls,
1107 the user helper functions (vdso), signal rt_frame functions and the
1108 ptrace interface are handled appropriately by the kernel.
1110 If you want to execute 32-bit userspace applications, say Y.
1113 bool "Enable paravirtualization code"
1114 depends on RISCV_SBI
1116 This changes the kernel so it can modify itself when it is run
1117 under a hypervisor, potentially improving performance significantly
1118 over full virtualization.
1120 config PARAVIRT_TIME_ACCOUNTING
1121 bool "Paravirtual steal time accounting"
1124 Select this option to enable fine granularity task steal time
1125 accounting. Time spent executing other tasks in parallel with
1126 the current vCPU is discounted from the vCPU power. To account for
1127 that, there can be a small performance impact.
1129 If in doubt, say N here.
1132 bool "Build a relocatable kernel"
1133 depends on !XIP_KERNEL
1134 select MODULE_SECTIONS if MODULES
1135 select ARCH_VMLINUX_NEEDS_RELOCS
1137 This builds a kernel as a Position Independent Executable (PIE),
1138 which retains all relocation metadata required to relocate the
1139 kernel binary at runtime to a different virtual address than the
1140 address it was linked at.
1141 Since RISCV uses the RELA relocation format, this requires a
1142 relocation pass at runtime even if the kernel is loaded at the
1143 same address it was linked at.
1147 config RANDOMIZE_BASE
1148 bool "Randomize the address of the kernel image"
1150 depends on MMU && 64BIT && !XIP_KERNEL
1152 Randomizes the virtual address at which the kernel image is
1153 loaded, as a security feature that deters exploit attempts
1154 relying on knowledge of the location of kernel internals.
1156 It is the bootloader's job to provide entropy, by passing a
1157 random u64 value in /chosen/kaslr-seed at kernel entry.
1159 When booting via the UEFI stub, it will invoke the firmware's
1160 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1161 to the kernel proper. In addition, it will randomise the physical
1162 location of the kernel Image as well.
1166 endmenu # "Kernel features"
1171 string "Built-in kernel command line"
1173 For most platforms, the arguments for the kernel's command line
1174 are provided at run-time, during boot. However, there are cases
1175 where either no arguments are being provided or the provided
1176 arguments are insufficient or even invalid.
1178 When that occurs, it is possible to define a built-in command
1179 line here and choose how the kernel should use it later on.
1182 prompt "Built-in command line usage"
1183 depends on CMDLINE != ""
1184 default CMDLINE_FALLBACK
1186 Choose how the kernel will handle the provided built-in command
1189 config CMDLINE_FALLBACK
1190 bool "Use bootloader kernel arguments if available"
1192 Use the built-in command line as fallback in case we get nothing
1193 during boot. This is the default behaviour.
1195 config CMDLINE_EXTEND
1196 bool "Extend bootloader kernel arguments"
1198 The built-in command line will be appended to the command-
1199 line arguments provided during boot. This is useful in
1200 cases where the provided arguments are insufficient and
1201 you don't want to or cannot modify them.
1203 config CMDLINE_FORCE
1204 bool "Always use the default kernel command string"
1206 Always use the built-in command line, even if we get one during
1207 boot. This is useful in case you need to override the provided
1208 command line on systems where you don't have or want control
1217 bool "UEFI runtime support"
1218 depends on OF && !XIP_KERNEL
1221 select ARCH_SUPPORTS_ACPI if 64BIT
1222 select EFI_GENERIC_STUB
1223 select EFI_PARAMS_FROM_FDT
1224 select EFI_RUNTIME_WRAPPERS
1230 This option provides support for runtime services provided
1231 by UEFI firmware (such as non-volatile variables, realtime
1232 clock, and platform reset). A UEFI stub is also provided to
1233 allow the kernel to be booted as an EFI application. This
1234 is only useful on systems that have UEFI firmware.
1237 bool "Enable support for SMBIOS (DMI) tables"
1241 This enables SMBIOS/DMI feature for systems.
1243 This option is only useful on systems that have UEFI firmware.
1244 However, even with this option, the resultant kernel should
1245 continue to boot on existing non-UEFI platforms.
1247 config CC_HAVE_STACKPROTECTOR_TLS
1248 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1250 config STACKPROTECTOR_PER_TASK
1252 depends on !RANDSTRUCT
1253 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1255 config PHYS_RAM_BASE_FIXED
1256 bool "Explicitly specified physical RAM address"
1257 depends on NONPORTABLE
1260 config PHYS_RAM_BASE
1261 hex "Platform Physical RAM address"
1262 depends on PHYS_RAM_BASE_FIXED
1263 default "0x80000000"
1265 This is the physical address of RAM in the system. It has to be
1266 explicitly specified to run early relocations of read-write data
1270 bool "Kernel Execute-In-Place from ROM"
1271 depends on MMU && SPARSEMEM && NONPORTABLE
1272 # This prevents XIP from being enabled by all{yes,mod}config, which
1273 # fail to build since XIP doesn't support large kernels.
1274 depends on !COMPILE_TEST
1275 select PHYS_RAM_BASE_FIXED
1277 Execute-In-Place allows the kernel to run from non-volatile storage
1278 directly addressable by the CPU, such as NOR flash. This saves RAM
1279 space since the text section of the kernel is not loaded from flash
1280 to RAM. Read-write sections, such as the data section and stack,
1281 are still copied to RAM. The XIP kernel is not compressed since
1282 it has to run directly from flash, so it will take more space to
1283 store it. The flash address used to link the kernel object files,
1284 and for storing it, is configuration dependent. Therefore, if you
1285 say Y here, you must know the proper physical address where to
1286 store the kernel image depending on your own flash memory usage.
1288 Also note that the make target becomes "make xipImage" rather than
1289 "make zImage" or "make Image". The final kernel binary to put in
1290 ROM memory will be arch/riscv/boot/xipImage.
1292 SPARSEMEM is required because the kernel text and rodata that are
1293 flash resident are not backed by memmap, then any attempt to get
1294 a struct page on those regions will trigger a fault.
1298 config XIP_PHYS_ADDR
1299 hex "XIP Kernel Physical Location"
1300 depends on XIP_KERNEL
1301 default "0x21000000"
1303 This is the physical address in your flash memory the kernel will
1304 be linked for and stored to. This address is dependent on your
1307 config RISCV_ISA_FALLBACK
1308 bool "Permit falling back to parsing riscv,isa for extension support by default"
1311 Parsing the "riscv,isa" devicetree property has been deprecated and
1312 replaced by a list of explicitly defined strings. For compatibility
1313 with existing platforms, the kernel will fall back to parsing the
1314 "riscv,isa" property if the replacements are not found.
1316 Selecting N here will result in a kernel that does not use the
1317 fallback, unless the commandline "riscv_isa_fallback" parameter is
1320 Please see the dt-binding, located at
1321 Documentation/devicetree/bindings/riscv/extensions.yaml for details
1322 on the replacement properties, "riscv,isa-base" and
1323 "riscv,isa-extensions".
1326 bool "Built-in device tree"
1327 depends on OF && NONPORTABLE
1328 select GENERIC_BUILTIN_DTB
1330 Build a device tree into the Linux image.
1331 This option should be selected if no bootloader is being used.
1335 config BUILTIN_DTB_NAME
1336 string "Built-in device tree source"
1337 depends on BUILTIN_DTB
1339 DTS file path (without suffix, relative to arch/riscv/boot/dts)
1340 for the DTS file that will be used to produce the DTB linked into the
1343 endmenu # "Boot options"
1347 default !NONPORTABLE
1352 config ARCH_PROC_KCORE_TEXT
1355 menu "Power management options"
1357 source "kernel/power/Kconfig"
1359 config ARCH_HIBERNATION_POSSIBLE
1362 config ARCH_HIBERNATION_HEADER
1363 def_bool HIBERNATION
1365 config ARCH_SUSPEND_POSSIBLE
1368 endmenu # "Power management options"
1370 menu "CPU Power Management"
1372 source "drivers/cpuidle/Kconfig"
1374 source "drivers/cpufreq/Kconfig"
1376 endmenu # "CPU Power Management"
1378 source "arch/riscv/kvm/Kconfig"
1380 source "drivers/acpi/Kconfig"