The assembler used to compile chip32 virtual machine binaries is the official bass assembler.
The "architectures/chip32.vm.arch" architecture file has been provided to assemble the chip32 instructions using bass.
The development branch of bass v19 is used & the source code can be found here:
https://github.com/ARM9/bass/tree/devel
Place the bass executable for your OS in a directory along with the "architectures" folder in the same directory.
bass [source_in]
or
bass [source_in] -o [file_out]
Compile to single executable on GCC using make.
cd bass
make