sagatr
August 24th, 2005, 20:41
The following idea is a possible solution on how to downgrade your firmware to version 1.5. You will need the following files and program to perform this downgrade :
1. Version 1.5 EBOOT.PBP
2. pbp-unpacker-0.94
If you install pbp unpacker and open EBOOT.PBP you will notice it contains 4 files. The file we need to modify is PARAM.SFO. If you open the PARAM.SFO files you will see 14 lines of code.
Line 5 is: TITLE PSP Update ver 1.50
Line 14 is: UPDATER_VER 1.50
If you modify the above lines to:
Line 5 is: TITLE PSP Update ver 2.10
Line 14 is: UPDATER_VER 2.10
and save the file PARAM.SFO. Finally you need to create a new EBOOT.PBP using the modfied PARAM.SFO.
You can now use this new EBOOT.PBP and downgrade your PSP the same way as you update. You should no longer get the error "Your PSP does not require an update" as it will think you are updating the PSP to version 2.10.
I have not tested this. I will do so as soon as i get hold of a UK PSP on the first of September which will come with verion 2.0 firmware.
1. Version 1.5 EBOOT.PBP
2. pbp-unpacker-0.94
If you install pbp unpacker and open EBOOT.PBP you will notice it contains 4 files. The file we need to modify is PARAM.SFO. If you open the PARAM.SFO files you will see 14 lines of code.
Line 5 is: TITLE PSP Update ver 1.50
Line 14 is: UPDATER_VER 1.50
If you modify the above lines to:
Line 5 is: TITLE PSP Update ver 2.10
Line 14 is: UPDATER_VER 2.10
and save the file PARAM.SFO. Finally you need to create a new EBOOT.PBP using the modfied PARAM.SFO.
You can now use this new EBOOT.PBP and downgrade your PSP the same way as you update. You should no longer get the error "Your PSP does not require an update" as it will think you are updating the PSP to version 2.10.
I have not tested this. I will do so as soon as i get hold of a UK PSP on the first of September which will come with verion 2.0 firmware.