This is a port of Linux kernel for the RISC-V instruction set architecture. Development is currently based on the 3.14 longterm branch.

1. Fetch upstream sources and overlay the riscv architecture-specific subtree:

    $ curl https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.14.29.tar.xz | tar -xJ
    $ cd linux-3.14.29
    $ git init
    $ git remote add origin https://github.com/riscv/riscv-linux.git
    $ git fetch
    $ git checkout -f -t origin/master
   

2. Populate ./.config with the default symbol values:

    $ make ARCH=riscv defconfig
   

3. Optionally edit the configuration via an ncurses interface:

    $ make ARCH=riscv menuconfig
   

4. Build the uncompressed kernel image:

    $ make ARCH=riscv -j vmlinux
   

5. Boot the kernel in the functional simulator, optionally specifying a raw disk image for the root filesystem:

    $ spike +disk=path/to/root.img vmlinux
   

The riscv-gcc repository includes a copy of the kernel header files. If the userspace API has changed, export the updated headers to the riscv-gcc source directory:

$ make ARCH=riscv headers_check
$ make ARCH=riscv INSTALL_HDR_PATH=path/to/riscv-gcc/linux-headers headers_install

Rebuild riscv-gcc with the linux target:

$ make INSTALL_DIR=path/to/install linux