@nick I got around it temporarily by using a super simple malloc implementation that didn't have free(). That probably would work good enough for the stuff I was doing since the main purpose of malloc is just to set up some buffers for audio playback. I don't think it uses malloc except to set those up, so if playback never frees then that would work.

GBA has two RAM locations: work ram (ewram) and fast ram (iwram) so you need two separate allocators somehow. Also interrupt functions need to be in iwram so during build you have to copy those functions and then somehow make sure your malloc doesn't overwrite them.

this is ALL just to get a common sound library to work lol