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 ARCH_CLOCKSOURCE_INIT
16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18 select ARCH_HAS_BINFMT_FLAT
19 select ARCH_HAS_CURRENT_STACK_POINTER
20 select ARCH_HAS_DEBUG_VM_PGTABLE
21 select ARCH_HAS_DEBUG_VIRTUAL if MMU
22 select ARCH_HAS_DEBUG_WX
23 select ARCH_HAS_FORTIFY_SOURCE
24 select ARCH_HAS_GCOV_PROFILE_ALL
25 select ARCH_HAS_GIGANTIC_PAGE
27 select ARCH_HAS_MMIOWB
28 select ARCH_HAS_PTE_SPECIAL
29 select ARCH_HAS_SET_DIRECT_MAP if MMU
30 select ARCH_HAS_SET_MEMORY if MMU
31 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
32 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
33 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34 select ARCH_HAS_UBSAN_SANITIZE_ALL
35 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
36 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
38 select ARCH_SUPPORTS_ATOMIC_RMW
39 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
40 select ARCH_SUPPORTS_HUGETLBFS if MMU
41 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
42 select ARCH_USE_MEMTEST
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
45 select ARCH_WANT_FRAME_POINTERS
46 select ARCH_WANT_GENERAL_HUGETLB
47 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
48 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
49 select BUILDTIME_TABLE_SORT if MMU
50 select CLONE_BACKWARDS
51 select CLINT_TIMER if !MMU
53 select CPU_PM if CPU_IDLE
55 select GENERIC_ARCH_TOPOLOGY if SMP
56 select GENERIC_ATOMIC64 if !64BIT
57 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
58 select GENERIC_EARLY_IOREMAP
59 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
60 select GENERIC_IDLE_POLL_SETUP
61 select GENERIC_IOREMAP if MMU
62 select GENERIC_IRQ_MULTI_HANDLER
63 select GENERIC_IRQ_SHOW
64 select GENERIC_IRQ_SHOW_LEVEL
65 select GENERIC_LIB_DEVMEM_IS_ALLOWED
66 select GENERIC_PCI_IOMAP
67 select GENERIC_PTDUMP if MMU
68 select GENERIC_SCHED_CLOCK
69 select GENERIC_SMP_IDLE_THREAD
70 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
71 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
72 select HAVE_ARCH_AUDITSYSCALL
73 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
74 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
75 select HAVE_ARCH_KASAN if MMU && 64BIT
76 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
77 select HAVE_ARCH_KFENCE if MMU && 64BIT
78 select HAVE_ARCH_KGDB if !XIP_KERNEL
79 select HAVE_ARCH_KGDB_QXFER_PKT
80 select HAVE_ARCH_MMAP_RND_BITS if MMU
81 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
82 select HAVE_ARCH_SECCOMP_FILTER
83 select HAVE_ARCH_TRACEHOOK
84 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
85 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
86 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
87 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
88 select HAVE_ASM_MODVERSIONS
89 select HAVE_CONTEXT_TRACKING_USER
90 select HAVE_DEBUG_KMEMLEAK
91 select HAVE_DMA_CONTIGUOUS if MMU
92 select HAVE_EBPF_JIT if MMU
93 select HAVE_FUNCTION_ERROR_INJECTION
94 select HAVE_GCC_PLUGINS
95 select HAVE_GENERIC_VDSO if MMU && 64BIT
96 select HAVE_IRQ_TIME_ACCOUNTING
97 select HAVE_KPROBES if !XIP_KERNEL
98 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
99 select HAVE_KRETPROBES if !XIP_KERNEL
103 select HAVE_PERF_EVENTS
104 select HAVE_PERF_REGS
105 select HAVE_PERF_USER_STACK_DUMP
106 select HAVE_REGS_AND_STACK_ACCESS_API
107 select HAVE_FUNCTION_ARG_ACCESS_API
108 select HAVE_STACKPROTECTOR
109 select HAVE_SYSCALL_TRACEPOINTS
112 select IRQ_FORCED_THREADING
113 select MODULES_USE_ELF_RELA if MODULES
114 select MODULE_SECTIONS if MODULES
116 select OF_DMA_DEFAULT_COHERENT
117 select OF_EARLY_FLATTREE
119 select PCI_DOMAINS_GENERIC if PCI
120 select PCI_MSI if PCI
122 select RISCV_TIMER if RISCV_SBI
124 select SYSCTL_EXCEPTION_TRACE
125 select THREAD_INFO_IN_TASK
126 select TRACE_IRQFLAGS_SUPPORT
127 select UACCESS_MEMCPY if !MMU
128 select ZONE_DMA32 if 64BIT
130 config ARCH_MMAP_RND_BITS_MIN
134 config ARCH_MMAP_RND_COMPAT_BITS_MIN
137 # max bits determined by the following formula:
138 # VA_BITS - PAGE_SHIFT - 3
139 config ARCH_MMAP_RND_BITS_MAX
140 default 24 if 64BIT # SV39 based
143 config ARCH_MMAP_RND_COMPAT_BITS_MAX
146 # set if we run in machine mode, cleared if we run in supervisor mode
151 # set if we are running in S-mode and can use SBI calls
154 depends on !RISCV_M_MODE
158 bool "MMU-based Paged Memory Management Support"
161 Select if you want MMU-based virtualised addressing space
162 support by paged memory management. If unsure, say 'Y'.
166 default 0xC0000000 if 32BIT
167 default 0x80000000 if 64BIT && !MMU
168 default 0xff60000000000000 if 64BIT
170 config KASAN_SHADOW_OFFSET
172 depends on KASAN_GENERIC
173 default 0xdfffffff00000000 if 64BIT
174 default 0xffffffff if 32BIT
176 config ARCH_FLATMEM_ENABLE
179 config ARCH_SPARSEMEM_ENABLE
182 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
183 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
185 config ARCH_SELECT_MEMORY_MODEL
186 def_bool ARCH_SPARSEMEM_ENABLE
188 config ARCH_SUPPORTS_UPROBES
191 config STACKTRACE_SUPPORT
197 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
199 config GENERIC_BUG_RELATIVE_POINTERS
202 config GENERIC_CALIBRATE_DELAY
208 config GENERIC_HWEIGHT
211 config FIX_EARLYCON_MEM
214 config PGTABLE_LEVELS
219 config LOCKDEP_SUPPORT
222 config RISCV_DMA_NONCOHERENT
224 select ARCH_HAS_DMA_PREP_COHERENT
225 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
226 select ARCH_HAS_SYNC_DMA_FOR_CPU
227 select ARCH_HAS_SETUP_DMA_OPS
228 select DMA_DIRECT_REMAP
230 source "arch/riscv/Kconfig.socs"
231 source "arch/riscv/Kconfig.erratas"
236 bool "Allow configurations that result in non-portable kernels"
238 RISC-V kernel binaries are compatible between all known systems
239 whenever possible, but there are some use cases that can only be
240 satisfied by configurations that result in kernel binaries that are
241 not portable between systems.
243 Selecting N does not guarantee kernels will be portable to all known
244 systems. Selecting any of the options guarded by NONPORTABLE will
245 result in kernel binaries that are unlikely to be portable between
254 This selects the base ISA that this kernel will target and must match
259 depends on NONPORTABLE
261 select GENERIC_LIB_ASHLDI3
262 select GENERIC_LIB_ASHRDI3
263 select GENERIC_LIB_LSHRDI3
264 select GENERIC_LIB_UCMPDI2
270 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
271 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
272 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
273 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
274 select HAVE_FUNCTION_GRAPH_TRACER
275 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
276 select SWIOTLB if MMU
280 # We must be able to map all physical memory into the kernel, but the compiler
281 # is still a bit more efficient when generating code if it's setup in a manner
282 # such that it can only map 2GiB of memory.
284 prompt "Kernel Code Model"
285 default CMODEL_MEDLOW if 32BIT
286 default CMODEL_MEDANY if 64BIT
289 bool "medium low code model"
291 bool "medium any code model"
294 config MODULE_SECTIONS
296 select HAVE_MOD_ARCH_SPECIFIC
299 bool "Symmetric Multi-Processing"
301 This enables support for systems with more than one CPU. If
302 you say N here, the kernel will run on single and
303 multiprocessor machines, but will use only one CPU of a
304 multiprocessor machine. If you say Y here, the kernel will run
305 on many, but not all, single processor machines. On a single
306 processor machine, the kernel will run faster if you say N
309 If you don't know what to do here, say N.
312 int "Maximum number of CPUs (2-32)"
318 bool "Support for hot-pluggable CPUs"
320 select GENERIC_IRQ_MIGRATION
323 Say Y here to experiment with turning CPUs off and on. CPUs
324 can be controlled through /sys/devices/system/cpu.
326 Say N if you want to disable CPU hotplug.
337 # Common NUMA Features
339 bool "NUMA Memory Allocation and Scheduler Support"
340 depends on SMP && MMU
341 select GENERIC_ARCH_NUMA
343 select ARCH_SUPPORTS_NUMA_BALANCING
344 select USE_PERCPU_NUMA_NODE_ID
345 select NEED_PER_CPU_EMBED_FIRST_CHUNK
347 Enable NUMA (Non-Uniform Memory Access) support.
349 The kernel will try to allocate memory used by a CPU on the
350 local memory of the CPU and add some more NUMA awareness to the kernel.
353 int "Maximum NUMA Nodes (as a power of 2)"
358 Specify the maximum number of NUMA Nodes available on the target
359 system. Increases memory reserved to accommodate various tables.
361 config RISCV_ALTERNATIVE
363 depends on !XIP_KERNEL
365 This Kconfig allows the kernel to automatically patch the
366 errata required by the execution platform at run time. The
367 code patching is performed once in the boot stages. It means
368 that the overhead from this mechanism is just taken once.
370 config RISCV_ALTERNATIVE_EARLY
372 depends on RISCV_ALTERNATIVE
374 Allows early patching of the kernel for special errata
377 bool "Emit compressed instructions when building Linux"
380 Adds "C" to the ISA subsets that the toolchain is allowed to emit
381 when building Linux, which results in compressed instructions in the
384 If you don't know what to do here, say Y.
386 config RISCV_ISA_SVPBMT
387 bool "SVPBMT extension support"
388 depends on 64BIT && MMU
389 select RISCV_ALTERNATIVE
392 Adds support to dynamically detect the presence of the SVPBMT
393 ISA-extension (Supervisor-mode: page-based memory types) and
396 The memory type for a page contains a combination of attributes
397 that indicate the cacheability, idempotency, and ordering
398 properties for access to that page.
400 The SVPBMT extension is only available on 64Bit cpus.
402 If you don't know what to do here, say Y.
406 default y if 64BIT && $(cc-option,-mabi=lp64 -march=rv64ima_zicbom)
407 default y if 32BIT && $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom)
409 config RISCV_ISA_ZICBOM
410 bool "Zicbom extension support for non-coherent DMA operation"
411 depends on CC_HAS_ZICBOM
412 depends on !XIP_KERNEL && MMU
413 select RISCV_DMA_NONCOHERENT
414 select RISCV_ALTERNATIVE
417 Adds support to dynamically detect the presence of the ZICBOM
418 extension (Cache Block Management Operations) and enable its
421 The Zicbom extension can be used to handle for example
422 non-coherent DMA support on devices that need it.
424 If you don't know what to do here, say Y.
430 Say N here if you want to disable all floating-point related procedure
433 If you don't know what to do here, say Y.
435 endmenu # "Platform type"
437 menu "Kernel features"
439 source "kernel/Kconfig.hz"
442 bool "SBI v0.1 support"
445 This config allows kernel to use SBI v0.1 APIs. This will be
446 deprecated in future once legacy M-mode software are no longer in use.
448 config RISCV_BOOT_SPINWAIT
449 bool "Spinwait booting method"
451 default y if RISCV_SBI_V01 || RISCV_M_MODE
453 This enables support for booting Linux via spinwait method. In the
454 spinwait method, all cores randomly jump to Linux. One of the cores
455 gets chosen via lottery and all other keep spinning on a percpu
456 variable. This method cannot support CPU hotplug and sparse hartid
457 scheme. It should be only enabled for M-mode Linux or platforms relying
458 on older firmware without SBI HSM extension. All other platforms should
459 rely on ordered booting via SBI HSM extension which gets chosen
460 dynamically at runtime if the firmware supports it.
462 Since spinwait is incompatible with sparse hart IDs, it requires
463 NR_CPUS be large enough to contain the physical hart ID of the first
466 If unsure what to do here, say N.
469 bool "Kexec system call"
471 select HOTPLUG_CPU if SMP
474 kexec is a system call that implements the ability to shutdown your
475 current kernel, and to start another kernel. It is like a reboot
476 but it is independent of the system firmware. And like a reboot
477 you can start any kernel with it, not just Linux.
479 The name comes from the similarity to the exec system call.
482 bool "kexec file based systmem call"
485 select HAVE_IMA_KEXEC if IMA
488 This is new version of kexec system call. This system call is
489 file based and takes file descriptors as system call argument
490 for kernel and initramfs as opposed to list of segments as
491 accepted by previous system call.
493 If you don't know what to do here, say Y.
495 config ARCH_HAS_KEXEC_PURGATORY
498 depends on CRYPTO_SHA256=y
501 bool "Build kdump crash kernel"
503 Generate crash dump after being started by kexec. This should
504 be normally only set in special crash dump kernels which are
505 loaded in the main kernel with kexec-tools into a specially
506 reserved region and then later executed after a crash by
509 For more details see Documentation/admin-guide/kdump/kdump.rst
512 bool "Kernel support for 32-bit U-mode"
514 depends on 64BIT && MMU
516 This option enables support for a 32-bit U-mode running under a 64-bit
517 kernel at S-mode. riscv32-specific components such as system calls,
518 the user helper functions (vdso), signal rt_frame functions and the
519 ptrace interface are handled appropriately by the kernel.
521 If you want to execute 32-bit userspace applications, say Y.
523 endmenu # "Kernel features"
528 string "Built-in kernel command line"
530 For most platforms, the arguments for the kernel's command line
531 are provided at run-time, during boot. However, there are cases
532 where either no arguments are being provided or the provided
533 arguments are insufficient or even invalid.
535 When that occurs, it is possible to define a built-in command
536 line here and choose how the kernel should use it later on.
539 prompt "Built-in command line usage" if CMDLINE != ""
540 default CMDLINE_FALLBACK
542 Choose how the kernel will handle the provided built-in command
545 config CMDLINE_FALLBACK
546 bool "Use bootloader kernel arguments if available"
548 Use the built-in command line as fallback in case we get nothing
549 during boot. This is the default behaviour.
551 config CMDLINE_EXTEND
552 bool "Extend bootloader kernel arguments"
554 The command-line arguments provided during boot will be
555 appended to the built-in command line. This is useful in
556 cases where the provided arguments are insufficient and
557 you don't want to or cannot modify them.
560 bool "Always use the default kernel command string"
562 Always use the built-in command line, even if we get one during
563 boot. This is useful in case you need to override the provided
564 command line on systems where you don't have or want control
573 bool "UEFI runtime support"
574 depends on OF && !XIP_KERNEL
577 select EFI_PARAMS_FROM_FDT
579 select EFI_GENERIC_STUB
580 select EFI_RUNTIME_WRAPPERS
585 This option provides support for runtime services provided
586 by UEFI firmware (such as non-volatile variables, realtime
587 clock, and platform reset). A UEFI stub is also provided to
588 allow the kernel to be booted as an EFI application. This
589 is only useful on systems that have UEFI firmware.
591 config CC_HAVE_STACKPROTECTOR_TLS
592 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
594 config STACKPROTECTOR_PER_TASK
596 depends on !RANDSTRUCT
597 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
599 config PHYS_RAM_BASE_FIXED
600 bool "Explicitly specified physical RAM address"
601 depends on NONPORTABLE
605 hex "Platform Physical RAM address"
606 depends on PHYS_RAM_BASE_FIXED
609 This is the physical address of RAM in the system. It has to be
610 explicitly specified to run early relocations of read-write data
614 bool "Kernel Execute-In-Place from ROM"
615 depends on MMU && SPARSEMEM && NONPORTABLE
616 # This prevents XIP from being enabled by all{yes,mod}config, which
617 # fail to build since XIP doesn't support large kernels.
618 depends on !COMPILE_TEST
619 select PHYS_RAM_BASE_FIXED
621 Execute-In-Place allows the kernel to run from non-volatile storage
622 directly addressable by the CPU, such as NOR flash. This saves RAM
623 space since the text section of the kernel is not loaded from flash
624 to RAM. Read-write sections, such as the data section and stack,
625 are still copied to RAM. The XIP kernel is not compressed since
626 it has to run directly from flash, so it will take more space to
627 store it. The flash address used to link the kernel object files,
628 and for storing it, is configuration dependent. Therefore, if you
629 say Y here, you must know the proper physical address where to
630 store the kernel image depending on your own flash memory usage.
632 Also note that the make target becomes "make xipImage" rather than
633 "make zImage" or "make Image". The final kernel binary to put in
634 ROM memory will be arch/riscv/boot/xipImage.
636 SPARSEMEM is required because the kernel text and rodata that are
637 flash resident are not backed by memmap, then any attempt to get
638 a struct page on those regions will trigger a fault.
643 hex "XIP Kernel Physical Location"
644 depends on XIP_KERNEL
647 This is the physical address in your flash memory the kernel will
648 be linked for and stored to. This address is dependent on your
651 endmenu # "Boot options"
655 depends on OF && NONPORTABLE
656 default y if XIP_KERNEL
665 menu "Power management options"
667 source "kernel/power/Kconfig"
669 endmenu # "Power management options"
671 menu "CPU Power Management"
673 source "drivers/cpuidle/Kconfig"
675 endmenu # "CPU Power Management"
677 source "arch/riscv/kvm/Kconfig"