bsnes/docs/install/general.md

Installing the GBA BIOS

For most of the systems higan emulates, the console itself contains (almost) no actual software, so emulating the system does not require infringing the copyright of the hardware manufacturer. However, the Game Boy Advance is different: every device contains a standard library of software routines for common functions games require, often called a "BIOS" by analogy with the Basic Input/Output System used in IBM PC compatibles. Although the GBA BIOS is required in order to emulate GBA games, it cannot be distributed with higan for the same legal reasons that commercial games cannot be distributed with higan, so you'll need to obtain a copy of the BIOS for yourself.

If you have a real GBA and a flash-cart, the Internet contains many tools that will extract the BIOS image so it can be copied to your desktop computer. The correct GBA BIOS file is exactly 16384 bytes long, and has the SHA256 hash fd2547724b505f487e6dcb29ec2ecff3af35a841a77ab2e85fd87350abd36570.

Once you have the correct BIOS file:

1. rename it to bios.rom
   • if you're using Windows, turn off "hide extensions for known file types" so you don't wind up with a file called bios.rom.dat or whatever the file's original extension was.
2. Copy the file into higan's Game Boy Advance.sys folder, alongside the manifest.bml file that is already there.
   • In Windows, find Game Boy Advance.sys in the same folder as higan.exe
   • In Linux, find Game Boy Advance.sys in ~/.local/share/higan/

Note: If you upgrade this version of higan to a newer version, make sure the bios.rom file winds up in the Game Boy Advance.sys folder of the new version.