Shell script to build plain elf gcc toolchains for various architectures

./doit -f -a "i386 x86_64 aarch64"

This will download sources to and build 3 toolchains, for i386, x86_64 and aarch64. The resulting output will be located in

<arch>-elf-<version>-<hostos>-<host arch>/

For example: aarch64-elf-7.1.0-Linux-x86_64/

Run ./doit with -h for help.