arch/riscv/Kconfig

   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
   7 config 64BIT
   8         bool
   9
  10 config 32BIT
  11         bool
  12
  13 config RISCV
  14         def_bool y
  15         # even on 32-bit, physical (and DMA) addresses are > 32-bits
  16         select PHYS_ADDR_T_64BIT
  17         select OF
  18         select OF_EARLY_FLATTREE
  19         select OF_IRQ
  20         select ARCH_WANT_FRAME_POINTERS
  21         select CLONE_BACKWARDS
  22         select COMMON_CLK
  23         select GENERIC_CLOCKEVENTS
  24         select GENERIC_CPU_DEVICES
  25         select GENERIC_IRQ_SHOW
  26         select GENERIC_PCI_IOMAP
  27         select GENERIC_SCHED_CLOCK
  28         select GENERIC_STRNCPY_FROM_USER
  29         select GENERIC_STRNLEN_USER
  30         select GENERIC_SMP_IDLE_THREAD
  31         select GENERIC_ATOMIC64 if !64BIT
  32         select HAVE_ARCH_AUDITSYSCALL
  33         select HAVE_MEMBLOCK_NODE_MAP
  34         select HAVE_DMA_CONTIGUOUS
  35         select HAVE_FUTEX_CMPXCHG if FUTEX
  36         select HAVE_PERF_EVENTS
  37         select HAVE_SYSCALL_TRACEPOINTS
  38         select IRQ_DOMAIN
  39         select SPARSE_IRQ
  40         select SYSCTL_EXCEPTION_TRACE
  41         select HAVE_ARCH_TRACEHOOK
  42         select HAVE_PCI
  43         select MODULES_USE_ELF_RELA if MODULES
  44         select MODULE_SECTIONS if MODULES
  45         select THREAD_INFO_IN_TASK
  46         select PCI_DOMAINS_GENERIC if PCI
  47         select PCI_MSI if PCI
  48         select RISCV_TIMER
  49         select GENERIC_IRQ_MULTI_HANDLER
  50         select ARCH_HAS_PTE_SPECIAL
  51         select ARCH_HAS_MMIOWB
  52         select HAVE_EBPF_JIT if 64BIT
  53
  54 config MMU
  55         def_bool y
  56
  57 config ZONE_DMA32
  58         bool
  59         default y if 64BIT
  60
  61 config PAGE_OFFSET
  62         hex
  63         default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
  64         default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
  65         default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
  66
  67 config STACKTRACE_SUPPORT
  68         def_bool y
  69
  70 config TRACE_IRQFLAGS_SUPPORT
  71         def_bool y
  72
  73 config GENERIC_BUG
  74         def_bool y
  75         depends on BUG
  76         select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
  77
  78 config GENERIC_BUG_RELATIVE_POINTERS
  79         bool
  80
  81 config GENERIC_CALIBRATE_DELAY
  82         def_bool y
  83
  84 config GENERIC_CSUM
  85         def_bool y
  86
  87 config GENERIC_HWEIGHT
  88         def_bool y
  89
  90 config FIX_EARLYCON_MEM
  91         def_bool y
  92
  93 config PGTABLE_LEVELS
  94         int
  95         default 3 if 64BIT
  96         default 2
  97
  98 menu "Platform type"
  99
 100 choice
 101         prompt "Base ISA"
 102         default ARCH_RV64I
 103         help
 104           This selects the base ISA that this kernel will target and must match
 105           the target platform.
 106
 107 config ARCH_RV32I
 108         bool "RV32I"
 109         select 32BIT
 110         select GENERIC_LIB_ASHLDI3
 111         select GENERIC_LIB_ASHRDI3
 112         select GENERIC_LIB_LSHRDI3
 113         select GENERIC_LIB_UCMPDI2
 114
 115 config ARCH_RV64I
 116         bool "RV64I"
 117         select 64BIT
 118         select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
 119         select HAVE_FUNCTION_TRACER
 120         select HAVE_FUNCTION_GRAPH_TRACER
 121         select HAVE_FTRACE_MCOUNT_RECORD
 122         select HAVE_DYNAMIC_FTRACE
 123         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 124         select SWIOTLB
 125
 126 endchoice
 127
 128 # We must be able to map all physical memory into the kernel, but the compiler
 129 # is still a bit more efficient when generating code if it's setup in a manner
 130 # such that it can only map 2GiB of memory.
 131 choice
 132         prompt "Kernel Code Model"
 133         default CMODEL_MEDLOW if 32BIT
 134         default CMODEL_MEDANY if 64BIT
 135
 136         config CMODEL_MEDLOW
 137                 bool "medium low code model"
 138         config CMODEL_MEDANY
 139                 bool "medium any code model"
 140 endchoice
 141
 142 config MODULE_SECTIONS
 143         bool
 144         select HAVE_MOD_ARCH_SPECIFIC
 145
 146 choice
 147         prompt "Maximum Physical Memory"
 148         default MAXPHYSMEM_2GB if 32BIT
 149         default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
 150         default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
 151
 152         config MAXPHYSMEM_2GB
 153                 bool "2GiB"
 154         config MAXPHYSMEM_128GB
 155                 depends on 64BIT && CMODEL_MEDANY
 156                 bool "128GiB"
 157 endchoice
 158
 159
 160 config SMP
 161         bool "Symmetric Multi-Processing"
 162         help
 163           This enables support for systems with more than one CPU.  If
 164           you say N here, the kernel will run on single and
 165           multiprocessor machines, but will use only one CPU of a
 166           multiprocessor machine. If you say Y here, the kernel will run
 167           on many, but not all, single processor machines. On a single
 168           processor machine, the kernel will run faster if you say N
 169           here.
 170
 171           If you don't know what to do here, say N.
 172
 173 config NR_CPUS
 174         int "Maximum number of CPUs (2-32)"
 175         range 2 32
 176         depends on SMP
 177         default "8"
 178
 179 choice
 180         prompt "CPU Tuning"
 181         default TUNE_GENERIC
 182
 183 config TUNE_GENERIC
 184         bool "generic"
 185
 186 endchoice
 187
 188 config RISCV_ISA_C
 189         bool "Emit compressed instructions when building Linux"
 190         default y
 191         help
 192            Adds "C" to the ISA subsets that the toolchain is allowed to emit
 193            when building Linux, which results in compressed instructions in the
 194            Linux binary.
 195
 196            If you don't know what to do here, say Y.
 197
 198 menu "supported PMU type"
 199         depends on PERF_EVENTS
 200
 201 config RISCV_BASE_PMU
 202         bool "Base Performance Monitoring Unit"
 203         def_bool y
 204         help
 205           A base PMU that serves as a reference implementation and has limited
 206           feature of perf.  It can run on any RISC-V machines so serves as the
 207           fallback, but this option can also be disable to reduce kernel size.
 208
 209 endmenu
 210
 211 config FPU
 212         bool "FPU support"
 213         default y
 214         help
 215           Say N here if you want to disable all floating-point related procedure
 216           in the kernel.
 217
 218           If you don't know what to do here, say Y.
 219
 220 endmenu
 221
 222 menu "Kernel features"
 223
 224 source "kernel/Kconfig.hz"
 225
 226 endmenu
 227
 228 menu "Boot options"
 229
 230 config CMDLINE
 231         string "Built-in kernel command line"
 232         help
 233           For most platforms, the arguments for the kernel's command line
 234           are provided at run-time, during boot. However, there are cases
 235           where either no arguments are being provided or the provided
 236           arguments are insufficient or even invalid.
 237
 238           When that occurs, it is possible to define a built-in command
 239           line here and choose how the kernel should use it later on.
 240
 241 choice
 242         prompt "Built-in command line usage" if CMDLINE != ""
 243         default CMDLINE_FALLBACK
 244         help
 245           Choose how the kernel will handle the provided built-in command
 246           line.
 247
 248 config CMDLINE_FALLBACK
 249         bool "Use bootloader kernel arguments if available"
 250         help
 251           Use the built-in command line as fallback in case we get nothing
 252           during boot. This is the default behaviour.
 253
 254 config CMDLINE_EXTEND
 255         bool "Extend bootloader kernel arguments"
 256         help
 257           The command-line arguments provided during boot will be
 258           appended to the built-in command line. This is useful in
 259           cases where the provided arguments are insufficient and
 260           you don't want to or cannot modify them.
 261
 262
 263 config CMDLINE_FORCE
 264         bool "Always use the default kernel command string"
 265         help
 266           Always use the built-in command line, even if we get one during
 267           boot. This is useful in case you need to override the provided
 268           command line on systems where you don't have or want control
 269           over it.
 270
 271 endchoice
 272
 273 endmenu
 274
 275 menu "Power management options"
 276
 277 source "kernel/power/Kconfig"
 278
 279 endmenu