How does the commercial roms start?

Actarus · Post by **Actarus** » Mon Jun 30, 2008 5:26 pm

Hi all

Im working on my emulator and Im loading a commercial rom. In the file ISO I found 2 binary file BOOT.BIN and EBOOT.BIN. What are they?
Waht my emulator must load?

Thanks all for answers.

adrahil · Post by **adrahil** » Mon Jun 30, 2008 6:26 pm

EBOOT.BIN is what the PSP starts. It is decrypted first with KIRK, then launched.

BOOT.BIN is a devkit version of the game. It may be older, contain different code, use a different environment, or, in the worst case, be nulled out. (At some point Sony had started nulling out the BOOT.BINs of several games, around 3.0 FW if i recall correctly, but quite a few games I have bought since still have it)

If you want to do emulation, you will have to decrypt the EBOOT.BIN on a PSP, and then run it as a usermode PRX on your emulator. Using the BOOT.BIN is generally not a good idea, for the reasons mentionned above.

Actarus · Post by **Actarus** » Mon Jun 30, 2008 11:04 pm

decrypt? how?

adrahil · Post by **adrahil** » Mon Jun 30, 2008 11:48 pm

With the PSP cryptography engine, the inner workings of which are not known, apart from the almost certainty that the algorithm used is a combination of AES, SHA1 and CBC.

jean · Post by **jean** » Tue Jul 01, 2008 1:08 am

just my two cents: how about a small client-server application embedded in emulator that pass encrypted data to PSP over USB connection and gets back it decrypted? first time emulator should use a real PSP to do the job this way, while subsequent ones it could rely on cached data, allowing even to treat PSP as a sort of UMD drive....if i correctly understand this has to be done for each file containing executable code, not just eboot....however the amount of data to pass forth and back is small relatively to that of media related data.
Warning of the "piracy-detected" alarm certainly sounding in someone's mind here around....until today PSP emulation was seen as a way to easily debug homebrews without having to swap files or even turning on PSP. Workaround of signed data could be seen as an attempt to promote piracy.
(Final note: i do not share this last point...if i buy something then i'm free to use it any way i want: let me use my PSP games on my dishwasher if i've fun doing it)

hlide · Post by **hlide** » Tue Jul 01, 2008 1:34 am

I was wondering if such a tool already exists. I'm interested since I'll need it for a future PSP emulator. It shouldn't be a problem if you need a PSP to do so : extracting and uncrypting binaries from a game. If someone wants to run his/her (bought) game on a PC, he/she would simply need to run this tool on his/her PSP and retrieve the extracted binaries and data for his/her PSP emulator.

The question is : does this tool already exist ?

hlide · Post by **hlide** » Tue Jul 01, 2008 1:44 am

BTW, I'm curious to know which language you use to code SAM.

jean · Post by **jean** » Tue Jul 01, 2008 1:44 am

yep....don't remember the name but it exist: i was just suggesting to integrate it in the emulator itself to avoid bothering to move files around

moonlight · Post by **moonlight** » Tue Jul 01, 2008 1:58 am

i think jasonuk prxdecrypter decrypts eboot.bin

jas0nuk · Post by **jas0nuk** » Tue Jul 01, 2008 2:27 am

As moonlight said, my "PRXdecrypter" tool will decrypt EBOOT.BIN (and a bunch of other filetypes you'll never be interested in)

Here's the latest binary, since all the current public releases have an annoying bug:
http://www.sendspace.com/file/p5x2nj

Create "enc" folder on the root of your memory stick, put your EBOOT.BIN in there, run the app, follow instructions, and the file will be replaced with a decrypted version.

Actarus · Post by **Actarus** » Tue Jul 01, 2008 2:52 am

OMG what it happens? How can i decrypt the eboot.bin in my emulator?
Where is the source code. OMG again I cant understand.

* * * EDIT * _ * i can release the source code of my emulator if you want.

hlide · Post by **hlide** » Tue Jul 01, 2008 2:56 am

thx jas0nuk

Pirata Nervo · Post by **Pirata Nervo** » Tue Jul 01, 2008 3:01 am

@Actarus, then you are not ready to create a emulator

jas0nuk · Post by **jas0nuk** » Tue Jul 01, 2008 3:12 am

Actarus, it has already been explained -_-
The PSP decrypts binaries using KIRK which appears to be quite a complicated mask rom. I doubt it will ever be emulated, so you'll have to decrypt EBOOT.BIN files on a PSP before you try and run them in an emualtor.

Actarus · Post by **Actarus** » Tue Jul 01, 2008 4:30 am

cool :( i must

whistler · Post by **whistler** » Tue Jul 01, 2008 6:10 am

Pirata Nervo wrote:@Actarus, then you are not ready to create a emulator

what you going on about? he's done a good job so far

http://actarus.runhost.net/

hlide · Post by **hlide** » Tue Jul 01, 2008 6:18 am

Actarus wrote:* * * EDIT * _ * i can release the source code of my emulator if you want.

sure ^_^, i'm very curious about your own approacha bout PSP emulation.

so far, there are 4 (incomplete) PSP emulators :

potemkin from ector (C++)
pspplayer from noxa (C#)
pspemulator from soywiz (D)

and yours still unknown to me. :)

Pirata Nervo · Post by **Pirata Nervo** » Tue Jul 01, 2008 6:24 am

@whistler, I meant an emulator which decrypts the EBOOT.BIN because he does not understand how it is decrypted and it has already been explained.
I believe he has made a good job but going into UMD emulation is even more hard

Actarus · Post by **Actarus** » Tue Jul 01, 2008 2:36 pm

yes umd emulation is very hard. I must have 2 pc for debug, now i must purchase.

cloudhunter · Post by **cloudhunter** » Tue Jul 01, 2008 6:25 pm

Can't you debug without a second PC? :/ Seems a bit senseless.

Cloudy

jean · Post by **jean** » Tue Jul 01, 2008 7:25 pm

i think jasonuk prxdecrypter decrypts eboot.bin

Create "enc" folder on the root of your memory stick,...

Don't think i explained that well...
I remember i saw jas0nuk's decrypter, but i also remember of someone else's app (probably using same core code) sending data forth and back over USB for decryption without having to bother moving files around...
So i meant to embed "client code" in PC-side emulator while a "decryption service" is running on PSP...the whole process is done on the fly and noone can shout "to the pirate!".

PS: it would be very nice to see a good emulator, but the fact is (similarly when we speak of project Utopia) PSP hardware is _NOT_ well known at the moment...let's take VME for instance...it seems a sort of embedded FPGA but no one has succeded in investigating it afaik....Hope someone can deny me.