maybe these links are usefull :
pmp player developing
HOW TO RECOVER/EDIT/BACKUP FIRMWARE OF PMP PLAYER SUNPLUS SPMP3050A
sunplus pmp modding
Btw. can u help me? My firmware backup is corrupted of this player ( see pic) , can u you send me yours?
Internal specs :
chip1:
sunplus
spmp3052a-hl171
0822
M184722
chip2:
hynix kor
hy27ut088g2a
tpcb 825h
m8xjsm204