Hi ChipRocker,
so the firmware you build ends up as an .RKW file and if you copy it to the System folder it does not get executed? What exactly does happen? In my first attempts to write my own code I modified a firmware internal filename ("HOLDON.BIN") to get some feedback. The firmware will write to/create this file when the player is turned off. You could compare the disassembly of your built against the original firmware maybe using
Code:
arm-elf-objdump -D -m arm -b binary BASE.RKW | cat > BASE.asm
arm-elf-objdump -D -m arm -b binary NEW_BASE.RKW | cat > NEW_BASE.asm
diff BASE.asm NEW_BASE.asm
Another issue maybe that the crc32 codes (for header and/or code) of your new BASE.RKW are incorrect this would prevent the loader from executing it but I think it will load the backup version from "SYSTEM00" folder instead. Compatible crc32 generation code can be found in that rkwpatch.c thats available from the link I did mention earlier.
Wait, did you check whether you have an 16bit or 18bit interfaced lcd? Locate that transform function thats called from within mcu_writereg and then its a matter of 0xFC00 or 0x3F00 iirc.
Regards