ROM Data Compression

This game uses JCALG1 (Thanks Wisk & Alex O). The library and more information can be also found on Jeremy Collake's GitHub, the original library is written by Jeremy Collake. Quite some time ago.

This is based on previous research done by various members on the RomHacking Forum. My research tells me that rom_start does a DMA copy of a block of code from the ROM into IWRAM to facilitate on-the-fly decompression. You can look at game specific pages for how this works per-asset or review the IDA Database for the particular game for a coded example. The code gets copied to 0x03000000, I have called it jcalg1_dasm.

If you want specific information about compressed assets, refer to the Game's Page for it, as information per game may be different, or caveats might noted.