MY PSP 2.0 Downgrade or hacking

[FF10Freak]

Hi guys, now that nobody knows if the downgrader ( WAB ) will ever be released i started to do sumthing myself. I got my PSP on 2.0 FW ( i updated caus i was noob i didnt know anything about homebrews XD )

What i did was:

I took the normal 1.5 update and unpacked it with "pbp-unpacker" than i got the "param.sfo" the "data.psp" the "data.psar" and that "ICON0.png" ( which is rather unimportant ). What i first did was to change the "param.sfo" ... i opened it in the ".sfo-editor" of that "pbp-unpacker" and changed all written "1.50" in "2.10". That was my Idea ... a "1.50" Update which is covered as "2.10" caus a lower firmware wont work ( it says its lower in the first place and doesnt even start ). I tried it out but didnt even hope of anything. Didnt work ... the psp-video showed up and than ... "corrupted data-error" when i pressed circle there was written "PSP Update ver 2.10" or sumthing ... but than nothing more happened and i got to press the powerbutton like 6 secs to switch off and reboot.

But than i surfed the web a bit and came to think that the "data.psp" is some kind of signiture of sony-products ... and i managed to download the 2.00 fw i allready have on my psp ... i took the "data.psp" from 2.00 and the changed 1.5 "param.sfo" and the "data.psar" from 1.5 packed it as EBOOT.PBP and started it on my psp. Like before the Video came ... then blackscreen like before and than "Corrupted data-error" like before but when i press circle theres written "PSP Update ver" ( no number ) and a "start-button" but i cant do anything caus the psp just goes back to the mainmenu ( i dont have to press powerbutton 6 secs and reboot ).

Is that a small progress? Or just sumthing another person has allready done?

Mh dont know ... but if somebody of you guys know how to edit the "data.psp" or the "data.psar" tell me. Maybe they must fit to the ver "2.10" i created.

I hope my english wasnt to bad and you guys understood what i meant .

[alexh]

No progress.. the whole point is that the signature / encryption will have the CRC/HASH details of the files.... Change anything and you'll need a new signature file.

The generation of the signature files is the tricky (impossible?) bit.

Going in through the front line doesn't (to me) look like a possiblity. I would guess that a future downgrader will use a technique similar to the X-box technique... of overflows within savegame files.

[nickjaco]

good try though i updated and i just took it back after droping it a couple of time and then they replaced it for a nice shint new version1.50 psp "GAME"rules