sl0pboy.git/tools/mk_sl0pboy_bios.py, branch mastersl0pboy - a Game Boy Color emulator (companion to the gbos OS)https://git.sl0p.foo/sl0pboy.git/atom/tools/mk_sl0pboy_bios.py?h=master2026-07-18T20:45:06Ztools: mk_sl0pboy_bios.py - fork the CGB boot ROM's GAME BOY -> SL0PBOY2026-07-18T20:45:06Zgbc devgbc@localhost2026-07-18T20:45:06Zurn:sha1:79c8551c0599ea087502ae59bbe72d1ae8bbabf1
The stock CGB boot ROM draws its GAME BOY wordmark from a 192-byte blob
at $0607 (routine $03F0 copies it to VRAM tiles $08-$37: 48 tiles, 4
bytes each, every byte a row doubled vertically). This re-encodes that
blob with a bold-italic SL0PBOY bitmap of the same size and patches it
in place over a local bios/gbc_bios.bin -> bios/sl0pboy_bios.bin. No
code moves; the cart's own Nintendo logo ($104) is untouched so the
integrity check still passes and the boot hands off normally.
bios/ stays gitignored (copyrighted boot ROM); run this to produce the
fork locally. Verified end to end: logo drop + color + chime -> gbos.