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_DMA_DEFAULT_COHERENT
16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
19 select ARCH_HAS_BINFMT_FLAT
20 select ARCH_HAS_CURRENT_STACK_POINTER
21 select ARCH_HAS_DEBUG_VIRTUAL if MMU
22 select ARCH_HAS_DEBUG_VM_PGTABLE
23 select ARCH_HAS_DEBUG_WX
24 select ARCH_HAS_FORTIFY_SOURCE
25 select ARCH_HAS_GCOV_PROFILE_ALL
26 select ARCH_HAS_GIGANTIC_PAGE
28 select ARCH_HAS_MMIOWB
29 select ARCH_HAS_PMEM_API
30 select ARCH_HAS_PTE_SPECIAL
31 select ARCH_HAS_SET_DIRECT_MAP if MMU
32 select ARCH_HAS_SET_MEMORY if MMU
33 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
34 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
35 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
36 select ARCH_HAS_UBSAN_SANITIZE_ALL
37 select ARCH_HAS_VDSO_DATA
38 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
39 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
41 select ARCH_SUPPORTS_ATOMIC_RMW
42 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
43 select ARCH_SUPPORTS_HUGETLBFS if MMU
44 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
45 select ARCH_USE_MEMTEST
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
48 select ARCH_WANT_FRAME_POINTERS
49 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
50 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
51 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
52 select ARCH_WANT_OPTIMIZE_VMEMMAP
53 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
54 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
55 select BUILDTIME_TABLE_SORT if MMU
56 select CLINT_TIMER if !MMU
57 select CLONE_BACKWARDS
59 select CPU_PM if CPU_IDLE || HIBERNATION
61 select GENERIC_ARCH_TOPOLOGY
62 select GENERIC_ATOMIC64 if !64BIT
63 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
64 select GENERIC_EARLY_IOREMAP
66 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
67 select GENERIC_IDLE_POLL_SETUP
68 select GENERIC_IOREMAP if MMU
69 select GENERIC_IRQ_IPI if SMP
70 select GENERIC_IRQ_IPI_MUX if SMP
71 select GENERIC_IRQ_MULTI_HANDLER
72 select GENERIC_IRQ_SHOW
73 select GENERIC_IRQ_SHOW_LEVEL
74 select GENERIC_LIB_DEVMEM_IS_ALLOWED
75 select GENERIC_PCI_IOMAP
76 select GENERIC_PTDUMP if MMU
77 select GENERIC_SCHED_CLOCK
78 select GENERIC_SMP_IDLE_THREAD
79 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
80 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
81 select HARDIRQS_SW_RESEND
82 select HAS_IOPORT if MMU
83 select HAVE_ARCH_AUDITSYSCALL
84 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
85 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
86 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
87 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
88 select HAVE_ARCH_KASAN if MMU && 64BIT
89 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
90 select HAVE_ARCH_KFENCE if MMU && 64BIT
91 select HAVE_ARCH_KGDB if !XIP_KERNEL
92 select HAVE_ARCH_KGDB_QXFER_PKT
93 select HAVE_ARCH_MMAP_RND_BITS if MMU
94 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
95 select HAVE_ARCH_SECCOMP_FILTER
96 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
97 select HAVE_ARCH_TRACEHOOK
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
99 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
100 select HAVE_ASM_MODVERSIONS
101 select HAVE_CONTEXT_TRACKING_USER
102 select HAVE_DEBUG_KMEMLEAK
103 select HAVE_DMA_CONTIGUOUS if MMU
104 select HAVE_EBPF_JIT if MMU
105 select HAVE_FUNCTION_ARG_ACCESS_API
106 select HAVE_FUNCTION_ERROR_INJECTION
107 select HAVE_GCC_PLUGINS
108 select HAVE_GENERIC_VDSO if MMU && 64BIT
109 select HAVE_IRQ_TIME_ACCOUNTING
110 select HAVE_KPROBES if !XIP_KERNEL
111 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
112 select HAVE_KRETPROBES if !XIP_KERNEL
113 select HAVE_RETHOOK if !XIP_KERNEL
117 select HAVE_PERF_EVENTS
118 select HAVE_PERF_REGS
119 select HAVE_PERF_USER_STACK_DUMP
120 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
121 select HAVE_REGS_AND_STACK_ACCESS_API
123 select HAVE_STACKPROTECTOR
124 select HAVE_SYSCALL_TRACEPOINTS
126 select IRQ_FORCED_THREADING
127 select KASAN_VMALLOC if KASAN
128 select MODULES_USE_ELF_RELA if MODULES
129 select MODULE_SECTIONS if MODULES
131 select OF_EARLY_FLATTREE
133 select PCI_DOMAINS_GENERIC if PCI
134 select PCI_MSI if PCI
135 select RISCV_ALTERNATIVE if !XIP_KERNEL
137 select RISCV_TIMER if RISCV_SBI
140 select SYSCTL_EXCEPTION_TRACE
141 select THREAD_INFO_IN_TASK
142 select TRACE_IRQFLAGS_SUPPORT
143 select UACCESS_MEMCPY if !MMU
144 select ZONE_DMA32 if 64BIT
145 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
146 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
147 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
148 select HAVE_FUNCTION_GRAPH_TRACER
149 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
151 config CLANG_SUPPORTS_DYNAMIC_FTRACE
153 # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
154 depends on CLANG_VERSION >= 130000
155 # https://github.com/ClangBuiltLinux/linux/issues/1817
156 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
158 config GCC_SUPPORTS_DYNAMIC_FTRACE
160 depends on $(cc-option,-fpatchable-function-entry=8)
162 config ARCH_MMAP_RND_BITS_MIN
166 config ARCH_MMAP_RND_COMPAT_BITS_MIN
169 # max bits determined by the following formula:
170 # VA_BITS - PAGE_SHIFT - 3
171 config ARCH_MMAP_RND_BITS_MAX
172 default 24 if 64BIT # SV39 based
175 config ARCH_MMAP_RND_COMPAT_BITS_MAX
178 # set if we run in machine mode, cleared if we run in supervisor mode
183 # set if we are running in S-mode and can use SBI calls
186 depends on !RISCV_M_MODE
190 bool "MMU-based Paged Memory Management Support"
193 Select if you want MMU-based virtualised addressing space
194 support by paged memory management. If unsure, say 'Y'.
198 default 0xC0000000 if 32BIT && MMU
199 default 0x80000000 if !MMU
200 default 0xff60000000000000 if 64BIT
202 config KASAN_SHADOW_OFFSET
204 depends on KASAN_GENERIC
205 default 0xdfffffff00000000 if 64BIT
206 default 0xffffffff if 32BIT
208 config ARCH_FLATMEM_ENABLE
211 config ARCH_SPARSEMEM_ENABLE
214 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
215 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
217 config ARCH_SELECT_MEMORY_MODEL
218 def_bool ARCH_SPARSEMEM_ENABLE
220 config ARCH_SUPPORTS_UPROBES
223 config STACKTRACE_SUPPORT
229 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
231 config GENERIC_BUG_RELATIVE_POINTERS
234 config GENERIC_CALIBRATE_DELAY
240 config GENERIC_HWEIGHT
243 config FIX_EARLYCON_MEM
246 config PGTABLE_LEVELS
251 config LOCKDEP_SUPPORT
254 config RISCV_DMA_NONCOHERENT
256 select ARCH_HAS_DMA_PREP_COHERENT
257 select ARCH_HAS_SETUP_DMA_OPS
258 select ARCH_HAS_SYNC_DMA_FOR_CPU
259 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
260 select DMA_DIRECT_REMAP
263 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
265 source "arch/riscv/Kconfig.socs"
266 source "arch/riscv/Kconfig.errata"
271 bool "Allow configurations that result in non-portable kernels"
273 RISC-V kernel binaries are compatible between all known systems
274 whenever possible, but there are some use cases that can only be
275 satisfied by configurations that result in kernel binaries that are
276 not portable between systems.
278 Selecting N does not guarantee kernels will be portable to all known
279 systems. Selecting any of the options guarded by NONPORTABLE will
280 result in kernel binaries that are unlikely to be portable between
289 This selects the base ISA that this kernel will target and must match
294 depends on NONPORTABLE
296 select GENERIC_LIB_ASHLDI3
297 select GENERIC_LIB_ASHRDI3
298 select GENERIC_LIB_LSHRDI3
299 select GENERIC_LIB_UCMPDI2
304 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
305 select SWIOTLB if MMU
309 # We must be able to map all physical memory into the kernel, but the compiler
310 # is still a bit more efficient when generating code if it's setup in a manner
311 # such that it can only map 2GiB of memory.
313 prompt "Kernel Code Model"
314 default CMODEL_MEDLOW if 32BIT
315 default CMODEL_MEDANY if 64BIT
318 bool "medium low code model"
320 bool "medium any code model"
323 config MODULE_SECTIONS
325 select HAVE_MOD_ARCH_SPECIFIC
328 bool "Symmetric Multi-Processing"
330 This enables support for systems with more than one CPU. If
331 you say N here, the kernel will run on single and
332 multiprocessor machines, but will use only one CPU of a
333 multiprocessor machine. If you say Y here, the kernel will run
334 on many, but not all, single processor machines. On a single
335 processor machine, the kernel will run faster if you say N
338 If you don't know what to do here, say N.
341 bool "Multi-core scheduler support"
344 Multi-core scheduler support improves the CPU scheduler's decision
345 making when dealing with multi-core CPU chips at a cost of slightly
346 increased overhead in some places. If unsure say N here.
349 int "Maximum number of CPUs (2-512)"
351 range 2 512 if !RISCV_SBI_V01
352 range 2 32 if RISCV_SBI_V01 && 32BIT
353 range 2 64 if RISCV_SBI_V01 && 64BIT
354 default "32" if 32BIT
355 default "64" if 64BIT
358 bool "Support for hot-pluggable CPUs"
360 select GENERIC_IRQ_MIGRATION
363 Say Y here to experiment with turning CPUs off and on. CPUs
364 can be controlled through /sys/devices/system/cpu.
366 Say N if you want to disable CPU hotplug.
377 # Common NUMA Features
379 bool "NUMA Memory Allocation and Scheduler Support"
380 depends on SMP && MMU
381 select ARCH_SUPPORTS_NUMA_BALANCING
382 select GENERIC_ARCH_NUMA
383 select NEED_PER_CPU_EMBED_FIRST_CHUNK
385 select USE_PERCPU_NUMA_NODE_ID
387 Enable NUMA (Non-Uniform Memory Access) support.
389 The kernel will try to allocate memory used by a CPU on the
390 local memory of the CPU and add some more NUMA awareness to the kernel.
393 int "Maximum NUMA Nodes (as a power of 2)"
398 Specify the maximum number of NUMA Nodes available on the target
399 system. Increases memory reserved to accommodate various tables.
401 config RISCV_ALTERNATIVE
403 depends on !XIP_KERNEL
405 This Kconfig allows the kernel to automatically patch the
406 erratum or cpufeature required by the execution platform at run
407 time. The code patching overhead is minimal, as it's only done
408 once at boot and once on each module load.
410 config RISCV_ALTERNATIVE_EARLY
412 depends on RISCV_ALTERNATIVE
414 Allows early patching of the kernel for special errata
417 bool "Emit compressed instructions when building Linux"
420 Adds "C" to the ISA subsets that the toolchain is allowed to emit
421 when building Linux, which results in compressed instructions in the
424 If you don't know what to do here, say Y.
426 config RISCV_ISA_SVNAPOT
427 bool "Svnapot extension support for supervisor mode NAPOT pages"
428 depends on 64BIT && MMU
429 depends on RISCV_ALTERNATIVE
432 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
433 time and enable its usage.
435 The Svnapot extension is used to mark contiguous PTEs as a range
436 of contiguous virtual-to-physical translations for a naturally
437 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
438 size. When HUGETLBFS is also selected this option unconditionally
439 allocates some memory for each NAPOT page size supported by the kernel.
440 When optimizing for low memory consumption and for platforms without
441 the Svnapot extension, it may be better to say N here.
443 If you don't know what to do here, say Y.
445 config RISCV_ISA_SVPBMT
446 bool "Svpbmt extension support for supervisor mode page-based memory types"
447 depends on 64BIT && MMU
448 depends on RISCV_ALTERNATIVE
451 Adds support to dynamically detect the presence of the Svpbmt
452 ISA-extension (Supervisor-mode: page-based memory types) and
455 The memory type for a page contains a combination of attributes
456 that indicate the cacheability, idempotency, and ordering
457 properties for access to that page.
459 The Svpbmt extension is only available on 64-bit cpus.
461 If you don't know what to do here, say Y.
463 config TOOLCHAIN_HAS_ZBB
466 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
467 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
468 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
472 bool "Zbb extension support for bit manipulation instructions"
473 depends on TOOLCHAIN_HAS_ZBB
475 depends on RISCV_ALTERNATIVE
478 Adds support to dynamically detect the presence of the ZBB
479 extension (basic bit manipulation) and enable its usage.
481 The Zbb extension provides instructions to accelerate a number
482 of bit-specific operations (count bit population, sign extending,
485 If you don't know what to do here, say Y.
487 config RISCV_ISA_ZICBOM
488 bool "Zicbom extension support for non-coherent DMA operation"
490 depends on RISCV_ALTERNATIVE
492 select RISCV_DMA_NONCOHERENT
494 Adds support to dynamically detect the presence of the ZICBOM
495 extension (Cache Block Management Operations) and enable its
498 The Zicbom extension can be used to handle for example
499 non-coherent DMA support on devices that need it.
501 If you don't know what to do here, say Y.
503 config RISCV_ISA_ZICBOZ
504 bool "Zicboz extension support for faster zeroing of memory"
506 depends on RISCV_ALTERNATIVE
509 Enable the use of the Zicboz extension (cbo.zero instruction)
512 The Zicboz extension is used for faster zeroing of memory.
514 If you don't know what to do here, say Y.
516 config TOOLCHAIN_HAS_ZIHINTPAUSE
519 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
520 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
521 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
523 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
525 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
526 depends on AS_IS_GNU && AS_VERSION >= 23800
528 Newer binutils versions default to ISA spec version 20191213 which
529 moves some instructions from the I extension to the Zicsr and Zifencei
532 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
534 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
535 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
536 depends on CC_IS_CLANG && CLANG_VERSION < 170000
538 Certain versions of clang do not support zicsr and zifencei via -march
539 but newer versions of binutils require it for the reasons noted in the
540 help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This
541 option causes an older ISA spec compatible with these older versions
542 of clang to be passed to GAS, which has the same result as passing zicsr
543 and zifencei to -march.
549 Say N here if you want to disable all floating-point related procedure
552 If you don't know what to do here, say Y.
554 endmenu # "Platform type"
556 menu "Kernel features"
558 source "kernel/Kconfig.hz"
561 bool "SBI v0.1 support"
564 This config allows kernel to use SBI v0.1 APIs. This will be
565 deprecated in future once legacy M-mode software are no longer in use.
567 config RISCV_BOOT_SPINWAIT
568 bool "Spinwait booting method"
570 default y if RISCV_SBI_V01 || RISCV_M_MODE
572 This enables support for booting Linux via spinwait method. In the
573 spinwait method, all cores randomly jump to Linux. One of the cores
574 gets chosen via lottery and all other keep spinning on a percpu
575 variable. This method cannot support CPU hotplug and sparse hartid
576 scheme. It should be only enabled for M-mode Linux or platforms relying
577 on older firmware without SBI HSM extension. All other platforms should
578 rely on ordered booting via SBI HSM extension which gets chosen
579 dynamically at runtime if the firmware supports it.
581 Since spinwait is incompatible with sparse hart IDs, it requires
582 NR_CPUS be large enough to contain the physical hart ID of the first
585 If unsure what to do here, say N.
588 bool "Kexec system call"
590 select HOTPLUG_CPU if SMP
593 kexec is a system call that implements the ability to shutdown your
594 current kernel, and to start another kernel. It is like a reboot
595 but it is independent of the system firmware. And like a reboot
596 you can start any kernel with it, not just Linux.
598 The name comes from the similarity to the exec system call.
601 bool "kexec file based systmem call"
602 depends on 64BIT && MMU
603 select HAVE_IMA_KEXEC if IMA
607 This is new version of kexec system call. This system call is
608 file based and takes file descriptors as system call argument
609 for kernel and initramfs as opposed to list of segments as
610 accepted by previous system call.
612 If you don't know what to do here, say Y.
614 config ARCH_HAS_KEXEC_PURGATORY
617 depends on CRYPTO_SHA256=y
620 bool "Build kdump crash kernel"
622 Generate crash dump after being started by kexec. This should
623 be normally only set in special crash dump kernels which are
624 loaded in the main kernel with kexec-tools into a specially
625 reserved region and then later executed after a crash by
628 For more details see Documentation/admin-guide/kdump/kdump.rst
631 bool "Kernel support for 32-bit U-mode"
633 depends on 64BIT && MMU
635 This option enables support for a 32-bit U-mode running under a 64-bit
636 kernel at S-mode. riscv32-specific components such as system calls,
637 the user helper functions (vdso), signal rt_frame functions and the
638 ptrace interface are handled appropriately by the kernel.
640 If you want to execute 32-bit userspace applications, say Y.
643 bool "Build a relocatable kernel"
644 depends on MMU && 64BIT && !XIP_KERNEL
646 This builds a kernel as a Position Independent Executable (PIE),
647 which retains all relocation metadata required to relocate the
648 kernel binary at runtime to a different virtual address than the
649 address it was linked at.
650 Since RISCV uses the RELA relocation format, this requires a
651 relocation pass at runtime even if the kernel is loaded at the
652 same address it was linked at.
656 endmenu # "Kernel features"
661 string "Built-in kernel command line"
663 For most platforms, the arguments for the kernel's command line
664 are provided at run-time, during boot. However, there are cases
665 where either no arguments are being provided or the provided
666 arguments are insufficient or even invalid.
668 When that occurs, it is possible to define a built-in command
669 line here and choose how the kernel should use it later on.
672 prompt "Built-in command line usage" if CMDLINE != ""
673 default CMDLINE_FALLBACK
675 Choose how the kernel will handle the provided built-in command
678 config CMDLINE_FALLBACK
679 bool "Use bootloader kernel arguments if available"
681 Use the built-in command line as fallback in case we get nothing
682 during boot. This is the default behaviour.
684 config CMDLINE_EXTEND
685 bool "Extend bootloader kernel arguments"
687 The command-line arguments provided during boot will be
688 appended to the built-in command line. This is useful in
689 cases where the provided arguments are insufficient and
690 you don't want to or cannot modify them.
693 bool "Always use the default kernel command string"
695 Always use the built-in command line, even if we get one during
696 boot. This is useful in case you need to override the provided
697 command line on systems where you don't have or want control
706 bool "UEFI runtime support"
707 depends on OF && !XIP_KERNEL
710 select EFI_GENERIC_STUB
711 select EFI_PARAMS_FROM_FDT
712 select EFI_RUNTIME_WRAPPERS
718 This option provides support for runtime services provided
719 by UEFI firmware (such as non-volatile variables, realtime
720 clock, and platform reset). A UEFI stub is also provided to
721 allow the kernel to be booted as an EFI application. This
722 is only useful on systems that have UEFI firmware.
724 config CC_HAVE_STACKPROTECTOR_TLS
725 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
727 config STACKPROTECTOR_PER_TASK
729 depends on !RANDSTRUCT
730 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
732 config PHYS_RAM_BASE_FIXED
733 bool "Explicitly specified physical RAM address"
734 depends on NONPORTABLE
738 hex "Platform Physical RAM address"
739 depends on PHYS_RAM_BASE_FIXED
742 This is the physical address of RAM in the system. It has to be
743 explicitly specified to run early relocations of read-write data
747 bool "Kernel Execute-In-Place from ROM"
748 depends on MMU && SPARSEMEM && NONPORTABLE
749 # This prevents XIP from being enabled by all{yes,mod}config, which
750 # fail to build since XIP doesn't support large kernels.
751 depends on !COMPILE_TEST
752 select PHYS_RAM_BASE_FIXED
754 Execute-In-Place allows the kernel to run from non-volatile storage
755 directly addressable by the CPU, such as NOR flash. This saves RAM
756 space since the text section of the kernel is not loaded from flash
757 to RAM. Read-write sections, such as the data section and stack,
758 are still copied to RAM. The XIP kernel is not compressed since
759 it has to run directly from flash, so it will take more space to
760 store it. The flash address used to link the kernel object files,
761 and for storing it, is configuration dependent. Therefore, if you
762 say Y here, you must know the proper physical address where to
763 store the kernel image depending on your own flash memory usage.
765 Also note that the make target becomes "make xipImage" rather than
766 "make zImage" or "make Image". The final kernel binary to put in
767 ROM memory will be arch/riscv/boot/xipImage.
769 SPARSEMEM is required because the kernel text and rodata that are
770 flash resident are not backed by memmap, then any attempt to get
771 a struct page on those regions will trigger a fault.
776 hex "XIP Kernel Physical Location"
777 depends on XIP_KERNEL
780 This is the physical address in your flash memory the kernel will
781 be linked for and stored to. This address is dependent on your
784 endmenu # "Boot options"
788 depends on OF && NONPORTABLE
789 default y if XIP_KERNEL
798 menu "Power management options"
800 source "kernel/power/Kconfig"
802 config ARCH_HIBERNATION_POSSIBLE
805 config ARCH_HIBERNATION_HEADER
808 endmenu # "Power management options"
810 menu "CPU Power Management"
812 source "drivers/cpuidle/Kconfig"
814 source "drivers/cpufreq/Kconfig"
816 endmenu # "CPU Power Management"
818 source "arch/riscv/kvm/Kconfig"