Firmware,Flash and Hardware Intro

On this page, I will attempt to explain the basics of the Flash and Firmware of the PSP console.

The Flash And Firmware

Firmwares

Okay, many people are confused by the different PSP Firmwares, and why they lack the abilities that others have. This should clear up any questions you have!

What is a Firmware?

The Firmware, or system software, is the heart of the PSP. It is the PSP's Operating system, similar to Windows or Linux on a PC.

Why do we need it?

Without it, the Hardware would have nothing to boot and operate!

Why do Sony release new Firmwares? 

There are two main reasons why Sony, the creators and developers of the PSP, Release new Firmware revisions. The first, is too add new features and functionality to the software. This is clearly demonstrated by the addition of the Web Browser, "Location Free" capabilities,  RSS and Flash functionality; The list goes on. Later, Sony have introduced Camera and GPS features, for the recently released hardware.

The other reason is Homebrew. Sony are strongly opposed to Piracy. And, with the availability of ISO's, Flash Modifications, and Firmware emulators, this means that Sony has to release Firmware updates to block custom code altogether. A 1st Generation Firmware version (v1.00 to v2.00) has the ability to use these applications. A 2nd Generation Firmware has partial homebrew support, but does not support ISO's etc. 3rd generation firmwares (2.81-present) have no homebrew support. Newer Firmwares almost always have security fixes, which block homebrew. These are described as "Security Updates", or "Fixed holes that could allow intentional damage to the system", Or something similar.

Because of this blockade, Hackers are forced to delve deep into the files, libraries, and features of newer updates, and attempt to find "holes" or "exploits" that could allow custom code to be executed.

I have a newer Firmware, Can I run homebrew?

Over v2.80, homebrew is blocked in all firmwares. This needs an Exploit, to allow custom code to run.

I have a newer firmware, can I revert to an older version?

That requires another Exploit. A special one, at that. It has to allow VSH or Kernel mode, allowing us to access the Restricted sector of the Flash, "Flash0". Replacing a file called "index.dat" with an older version should allow a "downgrade" or "Downdate" to a previous firmware. This was achieved with Firmware version v2.00 using the "MPH downgrader", where an exploit in the librarys for loading "TIFF" images was used to replace the "index.dat". A 1.50 update file was then used to revert to the older firmware.
There was a breakthrough in Firmwares 2.50 and 2.60 via GTA. This allows for Kernel Mode via the eloader, thus a downgrader has been coded. Also, a second TIFF exploit was discovered, so all firmwares have at least partial homebrew support (Excluding v2.81), and firmwares up to v2.71 have kernel mode capabilities. Please read the "Downgrading" guide for further information in reverting to an older firmware revision. 

My PSP recently won't turn on, since I used a Flash accessing application. What is wrong?

You may have a "Bricked" PSP. If a PSP is "Bricked", it is rendered permanently unusable. It's Firmware has been insufficently written, or corrupted. The only means of restoration is to return console under Warranty to Sony, and will inevitably result it the newest Firmware version being flashed to the PSP.

One way to return it to it's original state is the "Mod-chip". It allows for dual-booting of different firmwares. Google "Undiluted Platinum" for more information. 

Another way is to use the "Custom Firmware" recovery mode. This allows you to save your bricked PSP from a bad Gameboot or Bootsound. Note that it cannot save you from a bad PRX or complete firmware mock-up.

What's the hype about TA-082 and TA-086 motherboards?

Well, these motherboards cannot be downgraded below firmware version 2.50.  The hardware checks for a signiature, and with 1.00-2.01, this isn't valid. 0okm recently found a way to downgrade a TA-082 motherboard, but someone tried to hack his gmail account, so he stopped! You can check to see if you have a TA-082 here: [LINK].

Not much is know about TA-086, but 0okm is looking into it.

The Flash

The Flash is divided into two sectors, FLASH1 and FLASH0. The Actual NAND chip is around 32mb. See below.

Flash1

Flash1, the configuration section of the Firmware, is modifiable, even from "User Mode". It contains your system password, Internet and Wi-fi configuration(s). This is the ONLY part of the flash that is legal to distribute freely. Little system modification can be achieved through this sector, but things like custom fonts being loaded from the memory stick is cool.

Flash1 is well known to be completly safe. And, as far as we know, you cannot Brick your PSP through modifying this sector. If something goes wrong, you will get a Blue screen, similar to the error screen of Windows, that instructs you to press [O] to restore Flash1 to its original state.
It is also the only sector that is not read-only.

Flash0

This sector is the 'Daddy' of Flash1, and contains the actual Firmware of the console, which it cannot function without. This sector is read-only, meaning that even if you do manage to run un-signed code, you cannot modify it without VSH or Kernel mode. This feature, to be fair, is essential to the PSP, because if you load a program, which intentionally attacks the Flash (only one in existance), it protects it. It also contains encryption as an extra layer of defence.

However, full control over the features and GUI of the system lie here, so it is in high demand that it is unlocked, to allow GUI modifications, adding new features, and possibly, at some point in the future, a completely custom firmware.

If any part of this sector of the flash becomes damaged, then you will be left with a brick. This can happen via the old fake downgrader trojan, by improper or incomplete modification, or a failed update.

It is illegal to distribute any part of this sector,  as it is the property of Sony, and prohibited by law. Distributing the packed update EBOOT file is fine, but you can't distribute them when they've been dumped from the EBOOT.

The PSP's Hardware:

UMD Drive

What is the UMD drive?

The UMD drive is the slot on the back of the PSP where you insert a UMD disk. It cannot write to a disk, it can only read. The PSP's name for the drive is "DISK0".

Can I write files to a disk via the drive?

As I just said, the drive is incapable of writing to a disk. You can rip the files and modify the game, and emulate it, but you can't write to the disk.

Memory Stick

What is a "Memory Stick"?

A memory stick is the small flat storage device that slides into the slot on the right-hand-side of the PSP system. The sizes range from 32MB all the way up to 8GB*. 

It is the only storage device that you can have full red/write control over without the need for an exploit, hardware or even any code.

The PSP's name for the device is 'MS0', or 'FATMS0'. 

The PSP uses the tiny "Pro Duo" version of the memory stick. 

*Only PSP firmwares above v2.81 allow for use of memory sticks over the size of 4GB. 

Where can I get a cheap one?

I live in the UK, and I use Picstop. You could always try Ebay, but the ones there are often counterfeit. If you're in the US or elsewhere,  Outpost is a good place. Of course, you could always to a search on Froogle!