Ok. I now used a stock Firered, your files (picture,raw,pal),inserted them where you did (everything with UnLz GBA and fix pointers),inserted the original routine at 0x800050 ( also tried the
mov r0, #0x1
mov r2, #0x0
mov r3, #0x0
str r0, [SP]
mov r0, r2
ldr r4, gpu_tilemap_config_and_commit...