riscv uclinux

Download sources

$ git clone https://github.com/chmmn/riscv-uclinux.git
$ cd riscv-uclinux
$ make -f toolchain.mk sources

Build GNU toolchain

Edit toolchain.mk:

PREFIX=/opt/riscv-nommu
TARGET=riscv32-unknown-linux-gnu
ARCH=rv32ima
ABI=ilp32

or

PREFIX=/opt/riscv-nommu
TARGET=riscv64-unknown-linux-gnu
ARCH=rv64imafdc
ABI=lp64d

Build toolchain:

$ for i in binutils gcc1 headers uclibc-ng gcc2 elf2flt;do make -f toolchain.mk ${i}_config; make -f toolchain.mk ${i}_build; make -f toolchain.mk ${i}_install; done

Run gcc:

$ /opt/riscv-nommu/bin/riscv32-unknown-linux-gnu-g++ -v

or

$ /opt/riscv-nommu/bin/riscv64-unknown-linux-gnu-g++ -v

Build flat binary.

$ riscv32-unknown-linux-gnu-gcc -c -fPIC -O2 main.c -o main.o
$ riscv32-unknown-linux-gnu-gcc -Wl,-elf2flt=-r main.o -o main

Prebuilt busybox root cpio file

32bit

wget https://www.whatfun.me/riscv/rootfs/rootfs32.cpio.gz

64bit

wget https://www.whatfun.me/riscv/rootfs/rootfs64.cpio.gz

Prebuilt vmlinux

32bit

$ wget https://www.whatfun.me/riscv/vmlinux32.bz2
$ bunzip2 vmlinux32.bz2

run it

$ spike --isa=rv32ima -m0x80000000:0x60000000 vmlinux

or

# qemu-system-riscv32 -kernel vmlinux -nographic

64bit

$ wget https://www.whatfun.me/riscv/vmlinux64.bz2
$ bunzip2 vmlinux64.bz2

run it

$ spike --isa=rv64imafdc vmlinux

or

# qemu-system-riscv64 -kernel vmlinux -nographic