1 Download
There is a well maintained git repository with a RISC-V cross-gcc. It has been updated from gcc 9 to gcc 10 in the days just before 2020-06-11. Download the current
toolchain from git:
git clone --recursive https://github.com/riscv/riscv-gnu-toolchain
Cloning into 'riscv-gnu-toolchain'... remote: Enumerating objects: 1, done. remote: Counting objects: 100% (1/1), done. remote: Total 7704 (delta 0), reused 0 (delta 0), pack-reused 7703 Receiving objects: 100% (7704/7704), 4.72 MiB | 1.07 MiB/s, done. Resolving deltas: 100% (3903/3903), done. Submodule 'qemu' (https://git.qemu.org/git/qemu.git) registered for path 'qemu' Submodule 'riscv-binutils' (https://github.com/riscv/riscv-binutils-gdb.git) registered for path 'riscv-binutils' Submodule 'riscv-dejagnu' (https://github.com/riscv/riscv-dejagnu.git) registered for path 'riscv-dejagnu' Submodule 'riscv-gcc' (https://github.com/riscv/riscv-gcc.git) registered for path 'riscv-gcc' Submodule 'riscv-gdb' (https://github.com/riscv/riscv-binutils-gdb.git) registered for path 'riscv-gdb' Submodule 'riscv-glibc' (https://github.com/riscv/riscv-glibc.git) registered for path 'riscv-glibc' Submodule 'riscv-newlib' (https://github.com/riscv/riscv-newlib.git) registered for path 'riscv-newlib' Cloning into '/home/h/riscv/riscv-gnu-toolchain/qemu'... ⋮
git downloads 3.26 GB over a 12 Mbit/s DSL line within an hour.
2 Compile the Toolchain
I prefer to compile the toolchain in a dedicated directory. For that I create build, enter the working directory, and configure the compilation from there. The
prefix-parameter sets the installation directory. The architecture is rv32imac because the GD32VF103 is a 32-bit MCU with a 32 GPR (General Purpose
Register) file, integer multiply/divide, atomics, and compressed (16bit) ISA set.
cd riscv-gnu-toolchain/ mkdir build cd build ../configure --prefix=/opt/riscv --with-arch=rv32imac --with-abi=ilp32
checking for gcc... /usr/local/gcc-9.2/bin/gcc-9.2 checking whether the C compiler works... yes ⋮ configure: creating ./config.status config.status: creating Makefile config.status: creating scripts/wrapper/awk/awk config.status: creating scripts/wrapper/sed/sed
To install the toolchain type
make
An hour later the cross-compiler is installed at /opt/riscv/bin/riscv32-unknown-elf-gcc.
3 Next Steps
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| GNU Toolchain Provided |
The left branch (gcc and sim via elf) of the system is complete. To test it, we must provide input to gcc. This will be done in the next
blog.
