RISC-V: Build Infrastructure
This patch contains all the build infrastructure that actually enables
the RISC-V port. This includes Makefiles, linker scripts, and Kconfig
files. It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
new file mode 100644
index 0000000..2c6adf1
--- /dev/null
+++ b/arch/riscv/Kconfig
@@ -0,0 +1,310 @@
+#
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.txt.
+#
+
+config RISCV
+ def_bool y
+ select OF
+ select OF_EARLY_FLATTREE
+ select OF_IRQ
+ select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+ select ARCH_WANT_FRAME_POINTERS
+ select CLONE_BACKWARDS
+ select COMMON_CLK
+ select GENERIC_CLOCKEVENTS
+ select GENERIC_CPU_DEVICES
+ select GENERIC_IRQ_SHOW
+ select GENERIC_PCI_IOMAP
+ select GENERIC_STRNCPY_FROM_USER
+ select GENERIC_STRNLEN_USER
+ select GENERIC_SMP_IDLE_THREAD
+ select GENERIC_ATOMIC64 if !64BIT || !RISCV_ISA_A
+ select ARCH_WANT_OPTIONAL_GPIOLIB
+ select HAVE_MEMBLOCK
+ select HAVE_DMA_API_DEBUG
+ select HAVE_DMA_CONTIGUOUS
+ select HAVE_GENERIC_DMA_COHERENT
+ select IRQ_DOMAIN
+ select NO_BOOTMEM
+ select RISCV_ISA_A if SMP
+ select SPARSE_IRQ
+ select SYSCTL_EXCEPTION_TRACE
+ select HAVE_ARCH_TRACEHOOK
+ select MODULES_USE_ELF_RELA if MODULES
+ select THREAD_INFO_IN_TASK
+ select RISCV_IRQ_INTC
+ select RISCV_TIMER
+
+config MMU
+ def_bool y
+
+# even on 32-bit, physical (and DMA) addresses are > 32-bits
+config ARCH_PHYS_ADDR_T_64BIT
+ def_bool y
+
+config ARCH_DMA_ADDR_T_64BIT
+ def_bool y
+
+config PAGE_OFFSET
+ hex
+ default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
+ default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
+ default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
+
+config STACKTRACE_SUPPORT
+ def_bool y
+
+config RWSEM_GENERIC_SPINLOCK
+ 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 PGTABLE_LEVELS
+ int
+ default 3 if 64BIT
+ default 2
+
+config HAVE_KPROBES
+ def_bool n
+
+config DMA_NOOP_OPS
+ def_bool y
+
+menu "Platform type"
+
+choice
+ prompt "Base ISA"
+ default ARCH_RV64I
+ help
+ This selects the base ISA that this kernel will traget and must match
+ the target platform.
+
+config ARCH_RV32I
+ bool "RV32I"
+ select CPU_SUPPORTS_32BIT_KERNEL
+ select 32BIT
+ select GENERIC_ASHLDI3
+ select GENERIC_ASHRDI3
+ select GENERIC_LSHRDI3
+
+config ARCH_RV64I
+ bool "RV64I"
+ select CPU_SUPPORTS_64BIT_KERNEL
+ select 64BIT
+
+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
+
+choice
+ prompt "Maximum Physical Memory"
+ default MAXPHYSMEM_2GB if 32BIT
+ default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
+ default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
+
+ config MAXPHYSMEM_2GB
+ bool "2GiB"
+ config MAXPHYSMEM_128GB
+ depends on 64BIT && CMODEL_MEDANY
+ bool "128GiB"
+endchoice
+
+
+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 NR_CPUS
+ int "Maximum number of CPUs (2-32)"
+ range 2 32
+ depends on SMP
+ default "8"
+
+config CPU_SUPPORTS_32BIT_KERNEL
+ bool
+config CPU_SUPPORTS_64BIT_KERNEL
+ bool
+
+choice
+ prompt "CPU Tuning"
+ default TUNE_GENERIC
+
+config TUNE_GENERIC
+ bool "generic"
+
+endchoice
+
+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_A
+ def_bool y
+
+endmenu
+
+menu "Kernel type"
+
+choice
+ prompt "Kernel code model"
+ default 64BIT
+
+config 32BIT
+ bool "32-bit kernel"
+ depends on CPU_SUPPORTS_32BIT_KERNEL
+ help
+ Select this option to build a 32-bit kernel.
+
+config 64BIT
+ bool "64-bit kernel"
+ depends on CPU_SUPPORTS_64BIT_KERNEL
+ help
+ Select this option to build a 64-bit kernel.
+
+endchoice
+
+source "mm/Kconfig"
+
+source "kernel/Kconfig.preempt"
+
+source "kernel/Kconfig.hz"
+
+endmenu
+
+menu "Bus support"
+
+config PCI
+ bool "PCI support"
+ select PCI_MSI
+ help
+ This feature enables support for PCI bus system. If you say Y
+ here, the kernel will include drivers and infrastructure code
+ to support PCI bus devices.
+
+ If you don't know what to do here, say Y.
+
+config PCI_DOMAINS
+ def_bool PCI
+
+config PCI_DOMAINS_GENERIC
+ def_bool PCI
+
+source "drivers/pci/Kconfig"
+
+endmenu
+
+source "init/Kconfig"
+
+source "kernel/Kconfig.freezer"
+
+menu "Executable file formats"
+
+source "fs/Kconfig.binfmt"
+
+endmenu
+
+menu "Power management options"
+
+source kernel/power/Kconfig
+
+endmenu
+
+source "net/Kconfig"
+
+source "drivers/Kconfig"
+
+source "fs/Kconfig"
+
+menu "Kernel hacking"
+
+config CMDLINE_BOOL
+ bool "Built-in kernel command line"
+ help
+ For most platforms, it is firmware or second stage bootloader
+ that by default specifies the kernel command line options.
+ However, it might be necessary or advantageous to either override
+ the default kernel command line or add a few extra options to it.
+ For such cases, this option allows hardcoding command line options
+ directly into the kernel.
+
+ For that, choose 'Y' here and fill in the extra boot parameters
+ in CONFIG_CMDLINE.
+
+ The built-in options will be concatenated to the default command
+ line if CMDLINE_OVERRIDE is set to 'N'. Otherwise, the default
+ command line will be ignored and replaced by the built-in string.
+
+config CMDLINE
+ string "Built-in kernel command string"
+ depends on CMDLINE_BOOL
+ default ""
+ help
+ Supply command-line options at build time by entering them here.
+
+config CMDLINE_OVERRIDE
+ bool "Built-in command line overrides bootloader arguments"
+ depends on CMDLINE_BOOL
+ help
+ Set this option to 'Y' to have the kernel ignore the bootloader
+ or firmware command line. Instead, the built-in command line
+ will be used exclusively.
+
+ If you don't know what to do here, say N.
+
+config EARLY_PRINTK
+ def_bool y
+
+source "lib/Kconfig.debug"
+
+config CMDLINE_BOOL
+ bool
+endmenu
+
+source "security/Kconfig"
+
+source "crypto/Kconfig"
+
+source "lib/Kconfig"