Talking Point: Non Existant PSP Downgrader... ?

The highly respected MaxConsole user known as 'Mr A' has let us know his thoughts on the rumoured WAB PSP downgrader and what it will take to actually make a firmware downgrader for the PSP . The editorial contains a few minor insults but most importantly 'Mr A' backs himself up with technical information as we have all come to expect from him. Let's just get straight that this is HIS view and not written by MaxConsole staff!

Recently we have all been exposed to a large amount of hype and rumors relating to attempts to downgrade PSP's firmware for the purpose of using homebrew software. Two groups in particular, WAB and PSP-DEV have been claiming that they have a downgrader working but as yet all we have seen from either of these groups are a bunch of faked videos - no actual information or anything else which might suggest that they actually do have something working.

I have quite a bit of experience with reverse engineering etc and have personally examined the PSP firmware upgrade procedure by decrypting the updater executable and accompanying data file so I know how it all works. If either WAB or PSP-DEV had the skills to do this then they would probably never have claimed that they could downgrade the firmware since they would know exactly what is involved and that its not possible through software alone. I will try to explain how this all works without getting too technical..

As you know, the PSP upgrades come in the form of EBOOT.PBP archive files. The archives contain the encrypted upgrade executable (DATA.PSP), the encrypted data file (DATA.PSAR) and some other information such as the firmware version which is contained in the PARAM.SFO file. The PARAM.SFO file has been the focus of many downgrade attempts, but all these attempts have been in vain. While the PSP OS does indeed use this file to get the firmware version which will be upgraded to, even if you can bypass this first check and actually get a updater running (say 1.50 updater on 1.52 system) you will still not be able to downgrade.

This is because there is yet another check inside the update executable. The version information for the firmware which will be updated to is stored alongwith the rest of the upgrade data in the DATA.PSAR file. Once you start the upgrade the version information from the DATA.PSAR file is compared with the version of the firmware your PSP is currently running. If your PSP is running a more recent version than is contained in the DATA.PSAR file then you will receive an error.
Currently it is not possible for us to encrypt our own DATA.PSAR files or executable files. So we cannot simply edit the version information in the PSAR and we cannot simply patch out the check in the updater executable. I bet now some of you are thinking why dont you just change the firmware on your PSP so its reported as 1.00, then the upgrade will work!. In order to change the firmware version you will need to be able to execute unsigned code, if this was possible then a downgrade might not even be needed at all.

I dont see a working downgrade method appearing any time soon, especially with everybody going about it the wrong way! WAB dont seem to know what they are doing and they probably think that since you guys dont know either they can feed you crap. I just hope after reading this you are a bit more educated on the subject and now the lies they feed wont stick or continue giving people false hope for something which will most probably never come (at least not from these kids ala WAB).

And for those of you who have never heard of Mr A before, he was the first developer to correctly identify the changes of the v2.0 firmware and why it will be HARD to crack. Even IGN picked up on what he said, time will tell if he is right on this one too!

Oh and we hate having to say this time and time again, but unfortunately other websites forget basic ethics, so...if you wish to use any part of this article or refer to it then we expect MaxConsole to be clearly creditied.


source !!

i wish this isn't true but i'm afraid that he's right

Here's a forum article from Maxconsole regarding the possibility that a software-based firmware downgrader not even being possible:




And here's Yoshihiros typically cryptic response complete with signature profanity & leet-speak.




(Article too big to post on main newspage)

Once more, the possibility of the downgrader could still go either way.

I still say a downgrader isn't the answer in the long run... the games will start using AVC at some point and what then?
have 2 PSPs? I guess it's an option, but I think in the end someone will hack 2.0.

I agree, It won't be long at all before games become dependant on 2.0. It is possible that one of the loaders could incorporate the 2.0 libraries and still function, but no doubt they'll look for a way around it. I'd imagine if anything does, GTA will be the first game to try and do it as market saturation will be HUGE. I'd expect an exploit for 2.0 to be far more preferable than a downgrade, that way we retain the ability to play AVCs which are SO much better than normal MP4s, the web-browser is quite handy, plus all the various other little extras.

Then there's like likelihood that Sony will release another firmware before the end of the year. (Maybe?).

Yeah, i always wondered how they would do it, i mean changing the param.sfo has been done before and well.. yeah *shrug*, cant really think what else they'd do

apperintley officaly certified repair centers have a devise for reflashing a flash failed psp from what I here its just some sort of cable that somehow connects somewhere inside the psp somehow sureley "we" can get ahold of one of those and software 4 it and revirse engineer,
although I have not seen one such a device in some form or another must exsist sence its the second most common problem with the psp

btw, if you guys didnt noticed merged 2 topics on the same thing anyways..


Actually... i think thats quite possible.

I dont think many people would be that willing to open their psps and connect some cables though. You'd be able to downgrade your psp if you even got the cable working. You'd just need to make some slight modifications to the psp itself possible but yeah.

why not? everyboady installs modchips in there PS2's its no differint and dose not involve sodering so everyboady could handle it assumeing what outhers have said is true

the trailer video for GTA sure had that blurry MP4 look to me... here's hoping that it doesn't require 2.0 software or codecs

...I've lost my faith that a downgrader will EVER be released... Or the fact that i will ever play snes games everywhere...the reason why i bought my psp...

I agree - short of a chip, don't think we are going to get our machines running homebrew

I reckon modifying Version 2 is the way to go, but it looks like a long way off as everybody seems to be concerntrating on Downgrading !!??

I wouldn't lose faith... back in the spring all us 1.50ers were depressed that those with 1.0 Japan PSPs could have all sorts of fun while we couldn't.

Oh how the worm has turned.

If I was a 2.0er I'd be hoping that GTA:LCS uses AVC video so that we all have to upgrade and the hacking teams will get serious about 2.0 loaders.

of course... that would suck so boo to that

I may be niave but why doesnt someone just beging working on a Modchip for the Psp instead of going thru the firmware? and if not that then why not build a small device that is for this purpose alone, which doesnt require the firmware?

I.e say a small addon that runs its own formware if u like which with the aid of say a chip or special UMD bypasses the sony firmware and loads its own first?

It would be somewhat hard to fit in the psp itself i'd imagine and hasnt team executioner bin' working on one along with the other-memory usage device?