1# SPDX-License-Identifier: GPL-2.0-only 2# 3# For a description of the syntax of this configuration file, 4# see Documentation/kbuild/kconfig-language.rst. 5# 6 7config 64BIT 8 bool 9 10config 32BIT 11 bool 12 13config RISCV 14 def_bool y 15 select OF 16 select OF_EARLY_FLATTREE 17 select OF_IRQ 18 select ARCH_HAS_BINFMT_FLAT 19 select ARCH_HAS_DEBUG_WX 20 select ARCH_WANT_FRAME_POINTERS 21 select CLONE_BACKWARDS 22 select COMMON_CLK 23 select GENERIC_CLOCKEVENTS 24 select GENERIC_IRQ_SHOW 25 select GENERIC_PCI_IOMAP 26 select GENERIC_SCHED_CLOCK 27 select GENERIC_STRNCPY_FROM_USER if MMU 28 select GENERIC_STRNLEN_USER if MMU 29 select GENERIC_SMP_IDLE_THREAD 30 select GENERIC_ATOMIC64 if !64BIT 31 select GENERIC_IOREMAP 32 select GENERIC_PTDUMP if MMU 33 select HAVE_ARCH_AUDITSYSCALL 34 select HAVE_ARCH_SECCOMP_FILTER 35 select HAVE_ASM_MODVERSIONS 36 select HAVE_DMA_CONTIGUOUS if MMU 37 select HAVE_FUTEX_CMPXCHG if FUTEX 38 select HAVE_PERF_EVENTS 39 select HAVE_PERF_REGS 40 select HAVE_PERF_USER_STACK_DUMP 41 select HAVE_SYSCALL_TRACEPOINTS 42 select IRQ_DOMAIN 43 select SPARSE_IRQ 44 select SYSCTL_EXCEPTION_TRACE 45 select HAVE_ARCH_TRACEHOOK 46 select HAVE_PCI 47 select MODULES_USE_ELF_RELA if MODULES 48 select MODULE_SECTIONS if MODULES 49 select THREAD_INFO_IN_TASK 50 select PCI_DOMAINS_GENERIC if PCI 51 select PCI_MSI if PCI 52 select RISCV_TIMER 53 select GENERIC_IRQ_MULTI_HANDLER 54 select GENERIC_ARCH_TOPOLOGY if SMP 55 select ARCH_HAS_PTE_SPECIAL 56 select ARCH_HAS_MMIOWB 57 select ARCH_HAS_DEBUG_VIRTUAL if MMU 58 select HAVE_EBPF_JIT if MMU 59 select EDAC_SUPPORT 60 select ARCH_HAS_GIGANTIC_PAGE 61 select ARCH_HAS_SET_DIRECT_MAP 62 select ARCH_HAS_SET_MEMORY 63 select ARCH_HAS_STRICT_KERNEL_RWX if MMU 64 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 65 select SPARSEMEM_STATIC if 32BIT 66 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 67 select HAVE_ARCH_MMAP_RND_BITS if MMU 68 select ARCH_HAS_GCOV_PROFILE_ALL 69 select HAVE_COPY_THREAD_TLS 70 select HAVE_ARCH_KASAN if MMU && 64BIT 71 select HAVE_ARCH_KGDB 72 select HAVE_ARCH_KGDB_QXFER_PKT 73 74config ARCH_MMAP_RND_BITS_MIN 75 default 18 if 64BIT 76 default 8 77 78# max bits determined by the following formula: 79# VA_BITS - PAGE_SHIFT - 3 80config ARCH_MMAP_RND_BITS_MAX 81 default 24 if 64BIT # SV39 based 82 default 17 83 84# set if we run in machine mode, cleared if we run in supervisor mode 85config RISCV_M_MODE 86 bool 87 default !MMU 88 89# set if we are running in S-mode and can use SBI calls 90config RISCV_SBI 91 bool 92 depends on !RISCV_M_MODE 93 default y 94 95config MMU 96 bool "MMU-based Paged Memory Management Support" 97 default y 98 help 99 Select if you want MMU-based virtualised addressing space 100 support by paged memory management. If unsure, say 'Y'. 101 102config ZONE_DMA32 103 bool 104 default y if 64BIT 105 106config VA_BITS 107 int 108 default 32 if 32BIT 109 default 39 if 64BIT 110 111config PA_BITS 112 int 113 default 34 if 32BIT 114 default 56 if 64BIT 115 116config PAGE_OFFSET 117 hex 118 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB 119 default 0x80000000 if 64BIT && !MMU 120 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB 121 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB 122 123config ARCH_FLATMEM_ENABLE 124 def_bool y 125 126config ARCH_SPARSEMEM_ENABLE 127 def_bool y 128 depends on MMU 129 select SPARSEMEM_VMEMMAP_ENABLE 130 131config ARCH_SELECT_MEMORY_MODEL 132 def_bool ARCH_SPARSEMEM_ENABLE 133 134config ARCH_WANT_GENERAL_HUGETLB 135 def_bool y 136 137config ARCH_SUPPORTS_DEBUG_PAGEALLOC 138 def_bool y 139 140config SYS_SUPPORTS_HUGETLBFS 141 depends on MMU 142 def_bool y 143 144config STACKTRACE_SUPPORT 145 def_bool y 146 147config TRACE_IRQFLAGS_SUPPORT 148 def_bool y 149 150config GENERIC_BUG 151 def_bool y 152 depends on BUG 153 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 154 155config GENERIC_BUG_RELATIVE_POINTERS 156 bool 157 158config GENERIC_CALIBRATE_DELAY 159 def_bool y 160 161config GENERIC_CSUM 162 def_bool y 163 164config GENERIC_HWEIGHT 165 def_bool y 166 167config FIX_EARLYCON_MEM 168 def_bool MMU 169 170config PGTABLE_LEVELS 171 int 172 default 3 if 64BIT 173 default 2 174 175source "arch/riscv/Kconfig.socs" 176 177menu "Platform type" 178 179choice 180 prompt "Base ISA" 181 default ARCH_RV64I 182 help 183 This selects the base ISA that this kernel will target and must match 184 the target platform. 185 186config ARCH_RV32I 187 bool "RV32I" 188 select 32BIT 189 select GENERIC_LIB_ASHLDI3 190 select GENERIC_LIB_ASHRDI3 191 select GENERIC_LIB_LSHRDI3 192 select GENERIC_LIB_UCMPDI2 193 select MMU 194 195config ARCH_RV64I 196 bool "RV64I" 197 select 64BIT 198 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000 199 select HAVE_FUNCTION_TRACER 200 select HAVE_FUNCTION_GRAPH_TRACER 201 select HAVE_FTRACE_MCOUNT_RECORD 202 select HAVE_DYNAMIC_FTRACE if MMU 203 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 204 select SWIOTLB if MMU 205 206endchoice 207 208# We must be able to map all physical memory into the kernel, but the compiler 209# is still a bit more efficient when generating code if it's setup in a manner 210# such that it can only map 2GiB of memory. 211choice 212 prompt "Kernel Code Model" 213 default CMODEL_MEDLOW if 32BIT 214 default CMODEL_MEDANY if 64BIT 215 216 config CMODEL_MEDLOW 217 bool "medium low code model" 218 config CMODEL_MEDANY 219 bool "medium any code model" 220endchoice 221 222config MODULE_SECTIONS 223 bool 224 select HAVE_MOD_ARCH_SPECIFIC 225 226choice 227 prompt "Maximum Physical Memory" 228 default MAXPHYSMEM_2GB if 32BIT 229 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW 230 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY 231 232 config MAXPHYSMEM_2GB 233 bool "2GiB" 234 config MAXPHYSMEM_128GB 235 depends on 64BIT && CMODEL_MEDANY 236 bool "128GiB" 237endchoice 238 239 240config SMP 241 bool "Symmetric Multi-Processing" 242 help 243 This enables support for systems with more than one CPU. If 244 you say N here, the kernel will run on single and 245 multiprocessor machines, but will use only one CPU of a 246 multiprocessor machine. If you say Y here, the kernel will run 247 on many, but not all, single processor machines. On a single 248 processor machine, the kernel will run faster if you say N 249 here. 250 251 If you don't know what to do here, say N. 252 253config NR_CPUS 254 int "Maximum number of CPUs (2-32)" 255 range 2 32 256 depends on SMP 257 default "8" 258 259config HOTPLUG_CPU 260 bool "Support for hot-pluggable CPUs" 261 depends on SMP 262 select GENERIC_IRQ_MIGRATION 263 help 264 265 Say Y here to experiment with turning CPUs off and on. CPUs 266 can be controlled through /sys/devices/system/cpu. 267 268 Say N if you want to disable CPU hotplug. 269 270choice 271 prompt "CPU Tuning" 272 default TUNE_GENERIC 273 274config TUNE_GENERIC 275 bool "generic" 276 277endchoice 278 279config RISCV_ISA_C 280 bool "Emit compressed instructions when building Linux" 281 default y 282 help 283 Adds "C" to the ISA subsets that the toolchain is allowed to emit 284 when building Linux, which results in compressed instructions in the 285 Linux binary. 286 287 If you don't know what to do here, say Y. 288 289menu "supported PMU type" 290 depends on PERF_EVENTS 291 292config RISCV_BASE_PMU 293 bool "Base Performance Monitoring Unit" 294 def_bool y 295 help 296 A base PMU that serves as a reference implementation and has limited 297 feature of perf. It can run on any RISC-V machines so serves as the 298 fallback, but this option can also be disable to reduce kernel size. 299 300endmenu 301 302config FPU 303 bool "FPU support" 304 default y 305 help 306 Say N here if you want to disable all floating-point related procedure 307 in the kernel. 308 309 If you don't know what to do here, say Y. 310 311endmenu 312 313menu "Kernel features" 314 315source "kernel/Kconfig.hz" 316 317config SECCOMP 318 bool "Enable seccomp to safely compute untrusted bytecode" 319 help 320 This kernel feature is useful for number crunching applications 321 that may need to compute untrusted bytecode during their 322 execution. By using pipes or other transports made available to 323 the process as file descriptors supporting the read/write 324 syscalls, it's possible to isolate those applications in 325 their own address space using seccomp. Once seccomp is 326 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 327 and the task is only allowed to execute a few safe syscalls 328 defined by each seccomp mode. 329 330config RISCV_SBI_V01 331 bool "SBI v0.1 support" 332 default y 333 depends on RISCV_SBI 334 help 335 This config allows kernel to use SBI v0.1 APIs. This will be 336 deprecated in future once legacy M-mode software are no longer in use. 337endmenu 338 339menu "Boot options" 340 341config CMDLINE 342 string "Built-in kernel command line" 343 help 344 For most platforms, the arguments for the kernel's command line 345 are provided at run-time, during boot. However, there are cases 346 where either no arguments are being provided or the provided 347 arguments are insufficient or even invalid. 348 349 When that occurs, it is possible to define a built-in command 350 line here and choose how the kernel should use it later on. 351 352choice 353 prompt "Built-in command line usage" if CMDLINE != "" 354 default CMDLINE_FALLBACK 355 help 356 Choose how the kernel will handle the provided built-in command 357 line. 358 359config CMDLINE_FALLBACK 360 bool "Use bootloader kernel arguments if available" 361 help 362 Use the built-in command line as fallback in case we get nothing 363 during boot. This is the default behaviour. 364 365config CMDLINE_EXTEND 366 bool "Extend bootloader kernel arguments" 367 help 368 The command-line arguments provided during boot will be 369 appended to the built-in command line. This is useful in 370 cases where the provided arguments are insufficient and 371 you don't want to or cannot modify them. 372 373 374config CMDLINE_FORCE 375 bool "Always use the default kernel command string" 376 help 377 Always use the built-in command line, even if we get one during 378 boot. This is useful in case you need to override the provided 379 command line on systems where you don't have or want control 380 over it. 381 382endchoice 383 384endmenu 385 386config BUILTIN_DTB 387 def_bool n 388 depends on RISCV_M_MODE 389 depends on OF 390 391menu "Power management options" 392 393source "kernel/power/Kconfig" 394 395endmenu 396