This set of tools builds gcc+glibc cross-toolchains.
It worked in 2020, but hasn't been maintained since.
You may be able to make it work with some tweaks.

Build machine requirements:

- GNU make 4.0+
- gcc 6.2+
- binutils 2.25+
- gawk 3.1.2+
- bison 2.7+
- sed 3.02+
- python 3.4+