This is a disassembly of Pokémon Crystal.
It uses the following ROM as a base:
Pokemon - Crystal Version (UE) (V1.0) [C][!].gbc
To assemble, first install RGBDS and put it in your path.
The version of RGBDS needed is rgbds-linux:
Then copy the Pokémon ROM to this directory as "baserom.gbc".
Then run "make" in your shell.
This will output a file named "pokecrystal.gbc".
See also the disassembly of Pokémon Red: