RISC-V GNU Compiler Toolchain
This is the RISC-V C and C++ cross-compiler. It supports two build modes: a generic ELF/Newlib toolchain and a more sophisticated Linux-ELF/glibc toolchain.
Prerequisites
Several standard packages are needed to build the toolchain. On Ubuntu, executing the following command should suffice:
$ sudo apt-get install autoconf automake autotools-dev curl libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc
On Fedora/CentOS/RHEL OS, executing the following command should suffice:
$ sudo yum install autoconf automake libmpc-devel mpfr-devel gmp-devel gawk bison flex texinfo patchutils gcc gcc-c++
On OS X, you can use Homebrew to install the dependencies:
$ brew install gawk gnu-sed gmp mpfr libmpc isl
To build the glibc (Linux) on OS X, you will need to build within a case-sensitive file system. The simplest approach is to create and mount a new disk image with a case sensitive format. Make sure that the mount point does not contain spaces. This is not necessary to build newlib or gcc itself on OS X.
This process will start by downloading about 200 MiB of upstream sources, then will patch, build, and install the toolchain. If a local cache of the upstream sources exists in $(DISTDIR), it will be used; the default location is /var/cache/distfiles. Your computer will need about 8 GiB of disk space to complete the process.
Installation (Newlib)
To build the Newlib cross-compiler, pick an install path. If you choose,
say, /opt/riscv, then add /opt/riscv/bin to your PATH now. Then, simply
run the following command:
./configure --prefix=/opt/riscv
make
You should now be able to use riscv-gcc and its cousins.
Installation (Linux)
To build the Linux cross-compiler, pick an install path. If you choose,
say, /opt/riscv, then add /opt/riscv/bin to your PATH now. Then, simply
run the following command:
./configure --prefix=/opt/riscv
make linux
Installation (Linux multilib)
To build the Linux cross-compiler with support for both 32-bit and 64-bit, run the following commands:
./configure --prefix=/opt/riscv --enable-multilib
make linux
The multilib compiler will have the prefix riscv-unknown-linux-gnu-, rather than the usual prefix (riscv32-... or riscv64-...).
Advanced Options
There are a number of additional options that may be passed to configure. See './configure --help' for more details.