This project provides a set of Makefiles and support scripts
for building RISC-V toolchains. Quick usage guide:
./configure --prefix=/opt/riscv rv64-gnu rv64-musl
make
make DESTDIR=path/to/somewhere install
make hello
make run-hello # requires qemu-riscv in $PATH
This is a partial alternative to https://github.com/riscv/riscv-gnu-toolchain
The toolchain is built with a single set of tools (ld, as, gcc etc)
and several independent sysroots, one per target. Each target gets properly
prefixed commands (riscv64-unknown-gnu-ld, riscv64-unknown-gnu-gcc etc)
pairing the tools with the right sysroot for the target.
Any subset of supported configurations can be built.
The build process is interruptable: hit ctrl-c, repeat the same make command,
and it should continue from about the point where it was interrupted.
DESTDIR is properly supported. Nothing is written to $prefix until
make install. Having another toolchain installed in $prefix should not
affect the build.
The toolchain is fully usable in-place without installation:
staging/bin/riscv64-unknown-linux-gnu-gcc -o hello hello.c
qemu-riscv64 -L staging/riscv64-unknown-linux-gnu ./hello
Expected use cases:
* Building 64/32 glibc toolchain without soft-float/no-atomic options
(pretty common case yet poorly supported by riscv-gnu-toolchain).
* Libc experiments with reasonably fast iterations
(musl builds, getting that -fPIC into a particular glibc config).
* Packaging resulting toolchains with common package managers.
See NOTES on how and why this works. And please keep in mind the approach
taken here is quite unusual for gcc toolchains, and may require tweaks
to work in some cases.
Some configurations are not fully supported yet. Non-patched libstdc++
fails to build on RV32 (see patches/), newlib sysroots are built without
libstdc++, bare-metal target is incomplete, musl is incomplete upstream.
This may change later.
Note the toolchain will be built from whatever sources happen to be checked
out in riscv-gcc and riscv-binutils-gdb. In case specific branches are needed,
like priv-1.9.x for instance, prepare the sources before starting the build,
or rebuild/restage/reinstall affected components.