I've reuploaded the files from the Baidu drive here if anyone is having trouble downloading them:
http://www.solidfiles.com/v/vZ23YrzV2GQZPIndeed, they don't seem to work on emulators. This makes me wonder if there's some special code in the GBA emulators for these things that makes them work, but I somehow doubt it. I stopped trying to get the firmware files from my console a while back, but I might start again.
EDIT: Googling this time found me
this thread where people are sharing firmware files for what looks to be the same console (or type of consoles). There appear to be instructions on how to put the thing into "ADFU mode", after which I could possibly read the firmware off the handheld, but Google translate gives me incomprehensible output so I can't quite understand what's going on.