C cross compiler toolchain targeting M68K and Z80 microprocessors (Neo Geo/Mega Drive/Master System) should compile under Linux and Windows (With MSYS2/WSL) Mac was not been tested, but should work with the necessary dependencies.
The makefile download software latest versions from their respective mirrors by default. To use a different version, change the $(LINK...) variables.
Dependencies
Ubuntu
apt-get install make texinfo bison flex unzip gcc g++ curl python expat diffutils libgmp-dev libmpfr-dev mpc libmpc-dev libisl-dev libc++-dev libboost-all-dev
Windows (MSYS2 MinGW terminal)
pacman -S make texinfo bison flex unzip mingw-w64-x86_64-gcc mingw-w64-x86_64-curl mingw-w64-x86_64-python mingw-w64-x86_64-expat mingw-w64-x86_64-diffutils mingw-w64-x86_64-gmp mingw-w64-x86_64-mpfr mingw-w64-x86_64-mpc mingw-w64-x86_64-isl mingw-w64-x86_64-libc++ mingw-w64-x86_64-boost
NeoGeo and Mega Drive compiler toolchain
make install_gcc-newlib_m68k && make install_sdcc_z80
The Master System only needs SDCC
make install_sdcc_z80
To set the environment variables
source set_environment_variables.sh
To set the environment variables permanently
# Add environment variables to ~/.bash_profile
source set_environment_variables_permanently.sh
Windows extra information - Using the Toolchain outside of MSYS2 MinGW terminal
You may want to use this Toolchain outside of MSYS2 MinGW terminal on Windows, for use in IDE's, in order to do that, copy any needed libraries to the Toolchain /bin folder. ldd command can help you with that. Only files inside /mingw64/bin/ are needed.
Usage example:
ldd ./m68k-elf-gcc