hello, I have the same player than you and I didn't manage to make it working. I don't have any firmware. Sorry !
The only thing I found is the real size of the player : 16 Gb !!
And 1 Byte = 8 bits, so the real capacitie is 2 Go !!! and not 8 Go !
You can find the doc of the nand flash memory following this link :
Hynix Semic nand flash
good luck !