Forums GAMERGEN

Sony, being as sneaky as they are decided to do a rather interesting move. As researched by Coyotebean, Sony started enforcing using a public key method of verifying KIRK data and removing the ability to load the old types of data. As they did this, firmware 6.30+ cannot decrypt the updater and the PRX inside and therefore cannot use the index.dat spoofing to downgrade.

This application does the simple job of rebooting into the updater with a PRX that allows the updater to decrypt. A PRX that uses the pspdecrypt source and index.dat spoofing, nothing fancy.

So, I’ll stop blabering, here is the Readme:

6.35/6.31 -> 6.20 Downgrader By Davee

[What does it do?]
Allows users who are incontent with their firmware to downgrade to 6.20 using the Sony Updater.

[How do I use it?]
Copy the "PSP" folder to your PSP. The downgrader is "signed" and can be launched from OFW XMB. You need to copy the 6.20 update to PSP/GAME/UPDATE/EBOOT.PBP and for PSPgo it must be the eflash it is placed on. After setup run the downgrader and follow the onscreen instructions.

[What does it technically do?]
It uses the utility/power exploit to gain kernel access and reboots into the updater with a special PRX running. This PRX uses the pspdecrypt functionality to decrypt the updater PRX when needed. This allows the updater to boot in the newer firmwares.

[I'm a dev, sup?]
The source is in the SRC folder... if you even read this. Use the source for referencing, updating, snipping etc, remember where you got it from. Also, there is a HBL Sukkiri version, see the "Makefile" for info on the various modes, etc

[Credits]
bbtgp - legend. Continued updates to psardumper (pspdecrypt) and the signing application "prxEncrypter".
coyotebean - legend. Coninuted updates to psardumper (pspdecrypt) and large influence and research regarding cryptographics.
kgsws - legend. First application signed and method released.
Silverspring - legend. Lots and lots of info on KIRK where we'd still be in the dark without.
Bubbletune - BTCNF injection code and bits and bobs here ;D

[READ]
You run the application at your OWN risk. I am not help accountable if you PSP -mot censuré- up.
If you’re too lazy to read it then basically, you copy over the PSP folder to your PSP and put the 6.20 update to “PSP/GAME/UPDATE/EBOOT.PBP”.

Easy.