[Guide/FAQ] Flash0 inside and out

[Archaemic]

So you want to edit your flash0? Well, that's kinda risky, but here's what you should know.

Accessing flash0 There are quite a few ways to access flash0. The best way to do it, however, is to use either the recovery menu or the vshmenu. In recovery, go to Advanced and select Toggle USB (flash0), and make sure to have a memory card inserted and a USB cable plugged in. The other way to do this is to open the vshmenu and change the USB device setting to Flash 0 instead of Memory Stick and then go to USB mode. You should now have access to flash0. However, you should read the rest of this guide before modifying any files. The recovery mode method is better because the files won't be in use when you perform operations on the files.

What's where? Obviously, first thing you should know about flash0 is what's where. There are 5 base folders in the root of flash0, data, dic, font, kd and vsh, and, if you have the 1.50 kernel installed, either kn or km, depending on whether you're on 2.71 SE through 3.52 M33 or 3.71 M33. If you can only see dic, font and vsh, see the FAQ. The folders contain the follow: data contains certificates used with various things. You should never touch this folder. dic contains dictionaries used with the Asian fonts. You can delete the contents of this folder if you don't use the Asian language options. However, some games still use the Asian fonts even if you're using English. font contains the fonts. You can dummy some files here (see the FAQ), and you can also replace the fonts with other fonts. Doing this is beyond the scope of this guide, but some themes may come with ltnX.pgf files. Those go here. kd contains the core of the firmware. Do not touch this folder. kn/km contains the core of the other firmware in the hybrid set. On 2.71-3.52, this contains just that, but on 3.71, it contains 1.50. Do not touch this folder vsh contains binaries associated with the XMB. Theme files ending with .rco go inside the vsh/resource folder and files ending with .prx and .bin go in the vsh/module folder. Do NOT put them in the vsh/nodule folder or vsh/podule folder. The nodule/podule folder is where the 1.50 kernel vsh files are located.

Warnings Always make a backup of your flash0 files before you start messing with them Do not restore a full backup of flash0 files. Just restore the files you were messing with individually Do not flash kd files from another PSP if your firmware is newer than 2.80. This will result in a brick because these files are encrypted in such a way that they only work on one PSP. Do not format flash0. This is the firmware! Without it, how do you expect the PSP to run? Do not edit the files in kd unless you have a Pandora's Battery ready -- you'll be needing it. Do not delete any files ever, except for the contents of the dic folder, which are mostly safe to delete.

FAQ Q: I can't see all of the folders. Is something wrong? A: No, the folders are just hidden. To reveal them, go to Tools > Folder Options > View and make sure that Hidden Files are being shown an system files are not being hidden. Windows will give you a warning, but it will reveal the hidden folders. To permanently make them visible, enter the folder in the command line and enter attrib -S -H /S /D Q: My flash0 is full! What can I delete? A: First off, you can delete the entire contents of the dic folder if you're not using any of the Asian languages or games which don't use the Asian fonts. This folder contains extra stuff that's only used with those languages and won't be missed if you're just using English. If that's STILL not enough space, you can "dummy" fonts. That is, you can delete the gb3s1518.bwfon and jpn0.pgf files in the font folder so long as you replace them with copies of the ltn0.pgf file. You should now have enough flash space. Q: Which files in vsh/resource do what? A: See this guide Q: I messed with flash and now my PSP won't boot! What should I do? A: If you can still access recovery mode (holding R when you start the PSP), you can reflash the firmware by putting the installer in PSP/GAME/RECOVERY, and if that doesn't work, you can use the Pandora's Battery. Q: This program tells me to flash a file to one of the folders that this guide said not to touch. Is this a bricker? A: Probably not. Just make sure that the program is explicitly for the firmware you are on and that you flash the files to the right place.

Credits Guide written by Archaemic. Ideas for stuff to add: -SC-Lakitu, Greyone, headlesslizard, JumpR, mohaas05 Correcting my assumptions: MaTiAz

Last updated January 15, 2008
If it's been several months since this guide has been updated, it might be out of date. Beware!

This guide is still very much a work in progress, so feel free to contribute. Also, if there's already a guide like this that I missed, feel free to do whatever to this thread.

[-SC-Lakitu]

You should add a couple things:

-You shouldn't flash files that aren't made for your firmware unless you are absolutely sure it will work ok.

-Never, ever format the flash0.

[Greyone]

Originally Posted by Archaemic

[*]dic contains dictionaries used with the Asian fonts. You can delete the contents of this folder if you don't use the Asian language options.

You should add that some games use the Asian fonts even if it's in english

(mhf for example)

[Bubbletune]

What about the new 'km' folder in 3.71 M33, which holds the 1.50 kernel add-on (if you install it)?

[headlesslizard]

DOnt flash to kn? Isnt that where the old vsh.prx hack was done? Hmmmm, and what about module? Though module seems to be safe flashing the new remoteplay functions, work great.

[Archaemic]

Originally Posted by JumpR

What about the new 'km' folder in 3.71 M33, which holds the 1.50 kernel add-on (if you install it)?

I was not aware of this folder, as I don't have 3.71 M33.

Anyway, guide updated.

[chux_chux]

nice

[terryxq]

Hi

I can not find "kn", 3.71 M33-2, phat PSP-1000

[-SC-Lakitu]

Originally Posted by terryxq

Hi

I can not find "kn", 3.71 M33-2, phat PSP-1000

Then you probably have the flash0:/km folder replacing it like I do.

[terryxq]

Originally Posted by -SC-Lakitu

Then you probably have the flash0:/km folder replacing it like I do.

... I think it maybe I don't have 1.5 addon, so there are neither kn nor km ...

[demonchild]

Great guide. This will be very useful for newbies just coming onto custom firmware..

[mohaas05]

this should also be updated for 3.71 because vsh/nodule no longer exists and flash0:/km and vsh/podule have been added. I believe that podule is used for the 1.5 kernel.

[Archaemic]

I'll upgrade my second PSP to 3.71 later (I guess) and update the guide then.

[Archaemic]

More updates concerning the 1.50 kernel and what's where.

Maybe I should extend this guide to flash1 and/or NAND overall?

[mohaas05]

i guess. the NAND contains flash0, flash1, flash2, flash3 (and possibly a flash4 and flash5 due to references found in 3.71), the IDstorage, and IPL.

[Archaemic]

Actually, it does NOT contain a flash4 nor flash5, despite references to these partitions in the firmware. I suppose it might have been some planned partition on the Slim that never actually happened, but it's definitely not on the Fat.

[PSPLinkFan]

Great guide, I would definitely recommend that you (or someone else if they want to) make a nand guide or a reference of what nand is because there are so many threads asking questions about nand and this should reduce the number of threads.

[vodkkaa]

can I have some confirmation on the size of the Slims NAND. I know that it has 64MB of RAM but does it also have 66MB of flash space or is it still at 33MB.

[mohaas05]

Originally Posted by vodkkaa

can I have some confirmation on the size of the Slims NAND. I know that it has 64MB of RAM but does it also have 66MB of flash space or is it still at 33MB.

the slim has 66mb of flash0 space.

[Archaemic]

Wrong, the Slim has 66MB of NAND space, most of which is allocated to flash0, but definitely not all of it.

[mohaas05]

Originally Posted by Archaemic

Wrong, the Slim has 66MB of NAND space, most of which is allocated to flash0, but definitely not all of it.

well considering flash1, flash2, flash3 are all about 1mb. Im sure IDstorage and IPL are even less so I'd say the slim has about 62-64mb of flash space.

[MaTiAz]

Just thought I'd mention one thing...

The /kd/ folder in pre-3.71 M33 firmwares contains the 1.50 kernel, but on 3.71 M33 it contains the 3.71 kernel and /km/ contains the 1.50 kernel. /kn/ on 2.71 SE and later (except for 3.71 M33 of course) contains the second kernel (2.71 or 3.x).

[Archaemic]

Huh, really? I'll fix that right now.

[chux_chux]

Originally Posted by -SC-Lakitu

You should add a couple things:

-You shouldn't flash files that aren't made for your firmware unless you are absolutely sure it will work ok.

-Never, ever format the flash0.

Unless you make a back up! Then u can do what ever

[mohaas05]

Originally Posted by chux_chux

Unless you make a back up! Then u can do what ever

its still not a good idea because you'll never know if say, you develop a bad block after making the backup. then u cant use it.

[headlesslizard]

WHy cant you use it? If you develop a bad block afterwards? Im confused. I thought a nand dump could repair stuff like that.

[Archaemic]

If the block has actually physically gone bad, reads/writes on that block will be unreliable or impossible. It's impossible to repair with software.

[md2]

so with a fat psp, what should the size of the flash0 be, optimally..?

i assume that when you have the flash0 toggled via usb, you can select all the directories, and then check the properties - this should give you the size of the flash0, and its "size on disk."

[psp2468]

good guide!

[mohaas05]

Originally Posted by md2

so with a fat psp, what should the size of the flash0 be, optimally..?

i assume that when you have the flash0 toggled via usb, you can select all the directories, and then check the properties - this should give you the size of the flash0, and its "size on disk."

flash0 is 32mb i think.