# SPDX-License-Identifier: GPL-2.0-only # # For a description of the syntax of this configuration file, # see Documentation/kbuild/kconfig-language.rst. # config 64BIT bool config 32BIT bool config RISCV def_bool y select ACPI_GENERIC_GSI if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ARCH_DMA_DEFAULT_COHERENT select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_BINFMT_FLAT select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEBUG_VM_PGTABLE select ARCH_HAS_DEBUG_WX select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_KCOV select ARCH_HAS_MMIOWB select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SET_DIRECT_MAP if MMU select ARCH_HAS_SET_MEMORY if MMU select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL select ARCH_HAS_SYSCALL_WRAPPER select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_HAS_VDSO_DATA select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT select ARCH_STACKWALK select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_CFI_CLANG select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU select ARCH_SUPPORTS_HUGETLBFS if MMU select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU select ARCH_SUPPORTS_PER_VMA_LOCK if MMU select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK select ARCH_USE_MEMTEST select ARCH_USE_QUEUED_RWLOCKS select ARCH_USES_CFI_TRAPS if CFI_CLANG select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT select ARCH_WANT_HUGE_PMD_SHARE if 64BIT select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU select BUILDTIME_TABLE_SORT if MMU select CLINT_TIMER if !MMU select CLONE_BACKWARDS select COMMON_CLK select CPU_PM if CPU_IDLE || HIBERNATION select EDAC_SUPPORT select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) select GENERIC_ARCH_TOPOLOGY select GENERIC_ATOMIC64 if !64BIT select GENERIC_CLOCKEVENTS_BROADCAST if SMP select GENERIC_EARLY_IOREMAP select GENERIC_ENTRY select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO select GENERIC_IDLE_POLL_SETUP select GENERIC_IOREMAP if MMU select GENERIC_IRQ_IPI if SMP select GENERIC_IRQ_IPI_MUX if SMP select GENERIC_IRQ_MULTI_HANDLER select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL select GENERIC_LIB_DEVMEM_IS_ALLOWED select GENERIC_PCI_IOMAP select GENERIC_PTDUMP if MMU select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL if MMU && 64BIT select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO select HARDIRQS_SW_RESEND select HAS_IOPORT if MMU select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL select HAVE_ARCH_KASAN if MMU && 64BIT select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT select HAVE_ARCH_KFENCE if MMU && 64BIT select HAVE_ARCH_KGDB if !XIP_KERNEL select HAVE_ARCH_KGDB_QXFER_PKT select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD select HAVE_ARCH_VMAP_STACK if MMU && 64BIT select HAVE_ASM_MODVERSIONS select HAVE_CONTEXT_TRACKING_USER select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS if MMU select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION select HAVE_EBPF_JIT if MMU select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_FUNCTION_ERROR_INJECTION select HAVE_GCC_PLUGINS select HAVE_GENERIC_VDSO if MMU && 64BIT select HAVE_IRQ_TIME_ACCOUNTING select HAVE_KPROBES if !XIP_KERNEL select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL select HAVE_KRETPROBES if !XIP_KERNEL # https://github.com/ClangBuiltLinux/linux/issues/1881 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD select HAVE_MOVE_PMD select HAVE_MOVE_PUD select HAVE_PCI select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_POSIX_CPU_TIMERS_TASK_WORK select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RETHOOK if !XIP_KERNEL select HAVE_RSEQ select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA if MODULES select MODULE_SECTIONS if MODULES select OF select OF_EARLY_FLATTREE select OF_IRQ select PCI_DOMAINS_GENERIC if PCI select PCI_MSI if PCI select RISCV_ALTERNATIVE if !XIP_KERNEL select RISCV_INTC select RISCV_TIMER if RISCV_SBI select SIFIVE_PLIC select SPARSE_IRQ select SYSCTL_EXCEPTION_TRACE select THREAD_INFO_IN_TASK select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU select ZONE_DMA32 if 64BIT config CLANG_SUPPORTS_DYNAMIC_FTRACE def_bool CC_IS_CLANG # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e depends on CLANG_VERSION >= 130000 # https://github.com/ClangBuiltLinux/linux/issues/1817 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) config GCC_SUPPORTS_DYNAMIC_FTRACE def_bool CC_IS_GCC depends on $(cc-option,-fpatchable-function-entry=8) config HAVE_SHADOW_CALL_STACK def_bool $(cc-option,-fsanitize=shadow-call-stack) # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 depends on $(ld-option,--no-relax-gp) config ARCH_MMAP_RND_BITS_MIN default 18 if 64BIT default 8 config ARCH_MMAP_RND_COMPAT_BITS_MIN default 8 # max bits determined by the following formula: # VA_BITS - PAGE_SHIFT - 3 config ARCH_MMAP_RND_BITS_MAX default 24 if 64BIT # SV39 based default 17 config ARCH_MMAP_RND_COMPAT_BITS_MAX default 17 # set if we run in machine mode, cleared if we run in supervisor mode config RISCV_M_MODE bool default !MMU # set if we are running in S-mode and can use SBI calls config RISCV_SBI bool depends on !RISCV_M_MODE default y config MMU bool "MMU-based Paged Memory Management Support" default y help Select if you want MMU-based virtualised addressing space support by paged memory management. If unsure, say 'Y'. config PAGE_OFFSET hex default 0xC0000000 if 32BIT && MMU default 0x80000000 if !MMU default 0xff60000000000000 if 64BIT config KASAN_SHADOW_OFFSET hex depends on KASAN_GENERIC default 0xdfffffff00000000 if 64BIT default 0xffffffff if 32BIT config ARCH_FLATMEM_ENABLE def_bool !NUMA config ARCH_SPARSEMEM_ENABLE def_bool y depends on MMU select SPARSEMEM_STATIC if 32BIT && SPARSEMEM select SPARSEMEM_VMEMMAP_ENABLE if 64BIT config ARCH_SELECT_MEMORY_MODEL def_bool ARCH_SPARSEMEM_ENABLE config ARCH_SUPPORTS_UPROBES def_bool y config STACKTRACE_SUPPORT def_bool y config GENERIC_BUG def_bool y depends on BUG select GENERIC_BUG_RELATIVE_POINTERS if 64BIT config GENERIC_BUG_RELATIVE_POINTERS bool config GENERIC_CALIBRATE_DELAY def_bool y config GENERIC_CSUM def_bool y config GENERIC_HWEIGHT def_bool y config FIX_EARLYCON_MEM def_bool MMU config PGTABLE_LEVELS int default 5 if 64BIT default 2 config LOCKDEP_SUPPORT def_bool y config RISCV_DMA_NONCOHERENT bool select ARCH_HAS_DMA_PREP_COHERENT select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB select DMA_DIRECT_REMAP if MMU config RISCV_NONSTANDARD_CACHE_OPS bool depends on RISCV_DMA_NONCOHERENT help This enables function pointer support for non-standard noncoherent systems to handle cache management. config AS_HAS_INSN def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) config AS_HAS_OPTION_ARCH # https://reviews.llvm.org/D123515 def_bool y depends on $(as-instr, .option arch$(comma) +m) depends on !$(as-instr, .option arch$(comma) -i) source "arch/riscv/Kconfig.socs" source "arch/riscv/Kconfig.errata" menu "Platform type" config NONPORTABLE bool "Allow configurations that result in non-portable kernels" help RISC-V kernel binaries are compatible between all known systems whenever possible, but there are some use cases that can only be satisfied by configurations that result in kernel binaries that are not portable between systems. Selecting N does not guarantee kernels will be portable to all known systems. Selecting any of the options guarded by NONPORTABLE will result in kernel binaries that are unlikely to be portable between systems. If unsure, say N. choice prompt "Base ISA" default ARCH_RV64I help This selects the base ISA that this kernel will target and must match the target platform. config ARCH_RV32I bool "RV32I" depends on NONPORTABLE select 32BIT select GENERIC_LIB_ASHLDI3 select GENERIC_LIB_ASHRDI3 select GENERIC_LIB_LSHRDI3 select GENERIC_LIB_UCMPDI2 config ARCH_RV64I bool "RV64I" select 64BIT select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 select SWIOTLB if MMU endchoice # We must be able to map all physical memory into the kernel, but the compiler # is still a bit more efficient when generating code if it's setup in a manner # such that it can only map 2GiB of memory. choice prompt "Kernel Code Model" default CMODEL_MEDLOW if 32BIT default CMODEL_MEDANY if 64BIT config CMODEL_MEDLOW bool "medium low code model" config CMODEL_MEDANY bool "medium any code model" endchoice config MODULE_SECTIONS bool select HAVE_MOD_ARCH_SPECIFIC config SMP bool "Symmetric Multi-Processing" help This enables support for systems with more than one CPU. If you say N here, the kernel will run on single and multiprocessor machines, but will use only one CPU of a multiprocessor machine. If you say Y here, the kernel will run on many, but not all, single processor machines. On a single processor machine, the kernel will run faster if you say N here. If you don't know what to do here, say N. config SCHED_MC bool "Multi-core scheduler support" depends on SMP help Multi-core scheduler support improves the CPU scheduler's decision making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. config NR_CPUS int "Maximum number of CPUs (2-512)" depends on SMP range 2 512 if !RISCV_SBI_V01 range 2 32 if RISCV_SBI_V01 && 32BIT range 2 64 if RISCV_SBI_V01 && 64BIT default "32" if 32BIT default "64" if 64BIT config HOTPLUG_CPU bool "Support for hot-pluggable CPUs" depends on SMP select GENERIC_IRQ_MIGRATION help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu. Say N if you want to disable CPU hotplug. choice prompt "CPU Tuning" default TUNE_GENERIC config TUNE_GENERIC bool "generic" endchoice # Common NUMA Features config NUMA bool "NUMA Memory Allocation and Scheduler Support" depends on SMP && MMU select ARCH_SUPPORTS_NUMA_BALANCING select GENERIC_ARCH_NUMA select NEED_PER_CPU_EMBED_FIRST_CHUNK select OF_NUMA select USE_PERCPU_NUMA_NODE_ID help Enable NUMA (Non-Uniform Memory Access) support. The kernel will try to allocate memory used by a CPU on the local memory of the CPU and add some more NUMA awareness to the kernel. config NODES_SHIFT int "Maximum NUMA Nodes (as a power of 2)" range 1 10 default "2" depends on NUMA help Specify the maximum number of NUMA Nodes available on the target system. Increases memory reserved to accommodate various tables. config RISCV_ALTERNATIVE bool depends on !XIP_KERNEL help This Kconfig allows the kernel to automatically patch the erratum or cpufeature required by the execution platform at run time. The code patching overhead is minimal, as it's only done once at boot and once on each module load. config RISCV_ALTERNATIVE_EARLY bool depends on RISCV_ALTERNATIVE help Allows early patching of the kernel for special errata config RISCV_ISA_C bool "Emit compressed instructions when building Linux" default y help Adds "C" to the ISA subsets that the toolchain is allowed to emit when building Linux, which results in compressed instructions in the Linux binary. If you don't know what to do here, say Y. config RISCV_ISA_SVNAPOT bool "Svnapot extension support for supervisor mode NAPOT pages" depends on 64BIT && MMU depends on RISCV_ALTERNATIVE default y help Allow kernel to detect the Svnapot ISA-extension dynamically at boot time and enable its usage. The Svnapot extension is used to mark contiguous PTEs as a range of contiguous virtual-to-physical translations for a naturally aligned power-of-2 (NAPOT) granularity larger than the base 4KB page size. When HUGETLBFS is also selected this option unconditionally allocates some memory for each NAPOT page size supported by the kernel. When optimizing for low memory consumption and for platforms without the Svnapot extension, it may be better to say N here. If you don't know what to do here, say Y. config RISCV_ISA_SVPBMT bool "Svpbmt extension support for supervisor mode page-based memory types" depends on 64BIT && MMU depends on RISCV_ALTERNATIVE default y help Adds support to dynamically detect the presence of the Svpbmt ISA-extension (Supervisor-mode: page-based memory types) and enable its usage. The memory type for a page contains a combination of attributes that indicate the cacheability, idempotency, and ordering properties for access to that page. The Svpbmt extension is only available on 64-bit cpus. If you don't know what to do here, say Y. config TOOLCHAIN_HAS_V bool default y depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 depends on AS_HAS_OPTION_ARCH config RISCV_ISA_V bool "VECTOR extension support" depends on TOOLCHAIN_HAS_V depends on FPU select DYNAMIC_SIGFRAME default y help Say N here if you want to disable all vector related procedure in the kernel. If you don't know what to do here, say Y. config RISCV_ISA_V_DEFAULT_ENABLE bool "Enable userspace Vector by default" depends on RISCV_ISA_V default y help Say Y here if you want to enable Vector in userspace by default. Otherwise, userspace has to make explicit prctl() call to enable Vector, or enable it via the sysctl interface. If you don't know what to do here, say Y. config TOOLCHAIN_HAS_ZBB bool default y depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 depends on AS_HAS_OPTION_ARCH config RISCV_ISA_ZBB bool "Zbb extension support for bit manipulation instructions" depends on TOOLCHAIN_HAS_ZBB depends on MMU depends on RISCV_ALTERNATIVE default y help Adds support to dynamically detect the presence of the ZBB extension (basic bit manipulation) and enable its usage. The Zbb extension provides instructions to accelerate a number of bit-specific operations (count bit population, sign extending, bitrotation, etc). If you don't know what to do here, say Y. config RISCV_ISA_ZICBOM bool "Zicbom extension support for non-coherent DMA operation" depends on MMU depends on RISCV_ALTERNATIVE default y select RISCV_DMA_NONCOHERENT help Adds support to dynamically detect the presence of the ZICBOM extension (Cache Block Management Operations) and enable its usage. The Zicbom extension can be used to handle for example non-coherent DMA support on devices that need it. If you don't know what to do here, say Y. config RISCV_ISA_ZICBOZ bool "Zicboz extension support for faster zeroing of memory" depends on MMU depends on RISCV_ALTERNATIVE default y help Enable the use of the Zicboz extension (cbo.zero instruction) when available. The Zicboz extension is used for faster zeroing of memory. If you don't know what to do here, say Y. config TOOLCHAIN_HAS_ZIHINTPAUSE bool default y depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI def_bool y # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd depends on AS_IS_GNU && AS_VERSION >= 23600 help Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 20191213 version, which moves some instructions from the I extension to the Zicsr and Zifencei extensions. This requires explicitly specifying Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr and Zifencei are supported in binutils from version 2.36 onwards. To make life easier, and avoid forcing toolchains that default to a newer ISA spec to version 2.2, relax the check to binutils >= 2.36. For clang < 17 or GCC < 11.3.0, for which this is not possible or need special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. config TOOLCHAIN_NEEDS_OLD_ISA_SPEC def_bool y depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) help Certain versions of clang and GCC do not support zicsr and zifencei via -march. This option causes an older ISA spec compatible with these older versions of clang and GCC to be passed to GAS, which has the same result as passing zicsr and zifencei to -march. config FPU bool "FPU support" default y help Say N here if you want to disable all floating-point related procedure in the kernel. If you don't know what to do here, say Y. config IRQ_STACKS bool "Independent irq & softirq stacks" if EXPERT default y select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_SOFTIRQ_ON_OWN_STACK help Add independent irq & softirq stacks for percpu to prevent kernel stack overflows. We may save some memory footprint by disabling IRQ_STACKS. config THREAD_SIZE_ORDER int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT range 0 4 default 1 if 32BIT && !KASAN default 3 if 64BIT && KASAN default 2 help Specify the Pages of thread stack size (from 4KB to 64KB), which also affects irq stack size, which is equal to thread stack size. endmenu # "Platform type" menu "Kernel features" source "kernel/Kconfig.hz" config RISCV_SBI_V01 bool "SBI v0.1 support" depends on RISCV_SBI help This config allows kernel to use SBI v0.1 APIs. This will be deprecated in future once legacy M-mode software are no longer in use. config RISCV_BOOT_SPINWAIT bool "Spinwait booting method" depends on SMP default y if RISCV_SBI_V01 || RISCV_M_MODE help This enables support for booting Linux via spinwait method. In the spinwait method, all cores randomly jump to Linux. One of the cores gets chosen via lottery and all other keep spinning on a percpu variable. This method cannot support CPU hotplug and sparse hartid scheme. It should be only enabled for M-mode Linux or platforms relying on older firmware without SBI HSM extension. All other platforms should rely on ordered booting via SBI HSM extension which gets chosen dynamically at runtime if the firmware supports it. Since spinwait is incompatible with sparse hart IDs, it requires NR_CPUS be large enough to contain the physical hart ID of the first hart to enter Linux. If unsure what to do here, say N. config ARCH_SUPPORTS_KEXEC def_bool MMU config ARCH_SELECTS_KEXEC def_bool y depends on KEXEC select HOTPLUG_CPU if SMP config ARCH_SUPPORTS_KEXEC_FILE def_bool 64BIT && MMU config ARCH_SELECTS_KEXEC_FILE def_bool y depends on KEXEC_FILE select HAVE_IMA_KEXEC if IMA select KEXEC_ELF config ARCH_SUPPORTS_KEXEC_PURGATORY def_bool KEXEC_FILE depends on CRYPTO=y depends on CRYPTO_SHA256=y config ARCH_SUPPORTS_CRASH_DUMP def_bool y config COMPAT bool "Kernel support for 32-bit U-mode" default 64BIT depends on 64BIT && MMU help This option enables support for a 32-bit U-mode running under a 64-bit kernel at S-mode. riscv32-specific components such as system calls, the user helper functions (vdso), signal rt_frame functions and the ptrace interface are handled appropriately by the kernel. If you want to execute 32-bit userspace applications, say Y. config RELOCATABLE bool "Build a relocatable kernel" depends on MMU && 64BIT && !XIP_KERNEL help This builds a kernel as a Position Independent Executable (PIE), which retains all relocation metadata required to relocate the kernel binary at runtime to a different virtual address than the address it was linked at. Since RISCV uses the RELA relocation format, this requires a relocation pass at runtime even if the kernel is loaded at the same address it was linked at. If unsure, say N. config RANDOMIZE_BASE bool "Randomize the address of the kernel image" select RELOCATABLE depends on MMU && 64BIT && !XIP_KERNEL help Randomizes the virtual address at which the kernel image is loaded, as a security feature that deters exploit attempts relying on knowledge of the location of kernel internals. It is the bootloader's job to provide entropy, by passing a random u64 value in /chosen/kaslr-seed at kernel entry. When booting via the UEFI stub, it will invoke the firmware's EFI_RNG_PROTOCOL implementation (if available) to supply entropy to the kernel proper. In addition, it will randomise the physical location of the kernel Image as well. If unsure, say N. endmenu # "Kernel features" menu "Boot options" config CMDLINE string "Built-in kernel command line" help For most platforms, the arguments for the kernel's command line are provided at run-time, during boot. However, there are cases where either no arguments are being provided or the provided arguments are insufficient or even invalid. When that occurs, it is possible to define a built-in command line here and choose how the kernel should use it later on. choice prompt "Built-in command line usage" if CMDLINE != "" default CMDLINE_FALLBACK help Choose how the kernel will handle the provided built-in command line. config CMDLINE_FALLBACK bool "Use bootloader kernel arguments if available" help Use the built-in command line as fallback in case we get nothing during boot. This is the default behaviour. config CMDLINE_EXTEND bool "Extend bootloader kernel arguments" help The command-line arguments provided during boot will be appended to the built-in command line. This is useful in cases where the provided arguments are insufficient and you don't want to or cannot modify them. config CMDLINE_FORCE bool "Always use the default kernel command string" help Always use the built-in command line, even if we get one during boot. This is useful in case you need to override the provided command line on systems where you don't have or want control over it. endchoice config EFI_STUB bool config EFI bool "UEFI runtime support" depends on OF && !XIP_KERNEL depends on MMU default y select ARCH_SUPPORTS_ACPI if 64BIT select EFI_GENERIC_STUB select EFI_PARAMS_FROM_FDT select EFI_RUNTIME_WRAPPERS select EFI_STUB select LIBFDT select RISCV_ISA_C select UCS2_STRING help This option provides support for runtime services provided by UEFI firmware (such as non-volatile variables, realtime clock, and platform reset). A UEFI stub is also provided to allow the kernel to be booted as an EFI application. This is only useful on systems that have UEFI firmware. config CC_HAVE_STACKPROTECTOR_TLS def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) config STACKPROTECTOR_PER_TASK def_bool y depends on !RANDSTRUCT depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS config PHYS_RAM_BASE_FIXED bool "Explicitly specified physical RAM address" depends on NONPORTABLE default n config PHYS_RAM_BASE hex "Platform Physical RAM address" depends on PHYS_RAM_BASE_FIXED default "0x80000000" help This is the physical address of RAM in the system. It has to be explicitly specified to run early relocations of read-write data from flash to RAM. config XIP_KERNEL bool "Kernel Execute-In-Place from ROM" depends on MMU && SPARSEMEM && NONPORTABLE # This prevents XIP from being enabled by all{yes,mod}config, which # fail to build since XIP doesn't support large kernels. depends on !COMPILE_TEST select PHYS_RAM_BASE_FIXED help Execute-In-Place allows the kernel to run from non-volatile storage directly addressable by the CPU, such as NOR flash. This saves RAM space since the text section of the kernel is not loaded from flash to RAM. Read-write sections, such as the data section and stack, are still copied to RAM. The XIP kernel is not compressed since it has to run directly from flash, so it will take more space to store it. The flash address used to link the kernel object files, and for storing it, is configuration dependent. Therefore, if you say Y here, you must know the proper physical address where to store the kernel image depending on your own flash memory usage. Also note that the make target becomes "make xipImage" rather than "make zImage" or "make Image". The final kernel binary to put in ROM memory will be arch/riscv/boot/xipImage. SPARSEMEM is required because the kernel text and rodata that are flash resident are not backed by memmap, then any attempt to get a struct page on those regions will trigger a fault. If unsure, say N. config XIP_PHYS_ADDR hex "XIP Kernel Physical Location" depends on XIP_KERNEL default "0x21000000" help This is the physical address in your flash memory the kernel will be linked for and stored to. This address is dependent on your own flash usage. config RISCV_ISA_FALLBACK bool "Permit falling back to parsing riscv,isa for extension support by default" default y help Parsing the "riscv,isa" devicetree property has been deprecated and replaced by a list of explicitly defined strings. For compatibility with existing platforms, the kernel will fall back to parsing the "riscv,isa" property if the replacements are not found. Selecting N here will result in a kernel that does not use the fallback, unless the commandline "riscv_isa_fallback" parameter is present. Please see the dt-binding, located at Documentation/devicetree/bindings/riscv/extensions.yaml for details on the replacement properties, "riscv,isa-base" and "riscv,isa-extensions". endmenu # "Boot options" config BUILTIN_DTB bool depends on OF && NONPORTABLE default y if XIP_KERNEL config PORTABLE bool default !NONPORTABLE select EFI select MMU select OF menu "Power management options" source "kernel/power/Kconfig" # Hibernation is only possible on systems where the SBI implementation has # marked its reserved memory as not accessible from, or does not run # from the same memory as, Linux config ARCH_HIBERNATION_POSSIBLE def_bool NONPORTABLE config ARCH_HIBERNATION_HEADER def_bool HIBERNATION config ARCH_SUSPEND_POSSIBLE def_bool y endmenu # "Power management options" menu "CPU Power Management" source "drivers/cpuidle/Kconfig" source "drivers/cpufreq/Kconfig" endmenu # "CPU Power Management" source "arch/riscv/kvm/Kconfig" source "drivers/acpi/Kconfig"