XDA2i Guide to cooking the Extended ROM

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I finally found a method for backing up and modifying the Extended ROM on an XDA2i device.

http://en.pdamobiz.com/en/forum/foru...p?TID=373&PN=1

Unfortunately, although this method is able to do most of what I want, some of the cab files do not self-extract successfully during the reset process.

Graham. -- Issue resolved. No spaces allowed in Cab file name --

Before you ask, yes the cab files do self-extract successfully if tried manually (i.e. outside of the reset process).

If anyone has any ideas why some cab files work and others do not, please let me know.

I played with the information in the article yesterday.. Some information in the article is incorrect. They state the ext. rom is 24 MB but when following the steps on the website this is incorrect !

Sure, extra drive reports a 24 MB drive but the what's backuped to the SD card doesn't include the whole 24 MB the ext. rom supposedly has !

What I'm typing below is more guess work than knowledge.
"d2s 80000000 3BF0000" probably means "dump to SD card" for a total length of 80000000 hex starting at 3BF0000 hex.

80000000 hex is 2147483648 in decimal. These aren't the amount in bytes that are copied.. I to honest it I have no real idea in what it are but when dividing it by 1024^2/100 you get 20,48. The / 100 is something I made up since that gives me about the amount in MBs I can put in the ext. ROM without having corrupted files. I don't want to experiment with larger values since I haven't studied the tools that are used in the article enough yet.

In short, be sure not to put more than say 20 MB in the ext. ROM and most likely your problems are solved. I personally put an executable sprite backup file in the ext ROM, packaged it in a way it will be copied to storage and run from there. It's the most effective way I could think of to fill an extended ROM. Simply with a fully installed but clean backup of the pocket pc.

Anyhow, that's it for now.

I considered it being a problem with size and reduced the amount of data in the Extended ROM by a huge amount (deleted several of the cab files that I did not need).
This reduced it down to around 13Mb for what it's worth.

All of the files installed to the ROM ok, but when the process which reads the Config.txt file reached the parts regarding two of the cabs I wanted to install, the files failed to self-extract without giving any feedback.

Several other cab files I wanted to install worked fine.

What all this means is that the problem (probably) lies somewhere other than the size of the Extended ROM.

Thanks for the post sparcle and if you find out anything more please let me know.

If anyone else can help here, please feel free to contribute.

Graham.

As above guide:

CE Rom size is 2700000 (hex)
Total backup size is 3BF0000 (hex)

So extended rom size is 3BF0000-2700000 = 14F0000 (hex) or 21,954,560 (dec)

So extended rom size shall not be over than 21,954,560 in total space.

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But itsme's document

http://wiki.xda-developers.com/index...neRomStructure

82700000-83f00000 extended rom

So backup range shall be 3F00000. (size = 66060288 (dec) which you can not use 64mb card, you have to use 128mb card to backup)

So sorry, I'll ask my friend ruchonburi to recheck again.

Just a quick note on the sizes you gave above:

83,f00,000 - 82,700,000 = 1,800,000 (hex)
= 25,165,824 (dec) (24Mb) for the extended rom.

83,f00,000 - 80,000,000
= 3,f00,000 (hex) = 63Mb for the whole rom

The document given at the site uses:
80,000,000 to 83,bf0,000 which may miss some of the extended ROM, which may explain my problem.

I will try using the numbers from wiki and see if it works.

Cheers,
Graham.

I tried using d2s 80000000 3f00000 to create the SD Card backup initially and I still had the same problem with some CAB files extracting successfully and some not.

Graham.

Looks like the issue may lie with spaces in the CAB filenames.

If it is I will kick myself for not realising it sooner and then post here to let you know.

Graham.

Ouch, ouch, ouch....

I've finished kicking myself.
The problem was indeed the space in the cab filename.

On the plus side it means that the process works fine.

Graham.

i just want to ask......by cooking Ext Rom....how much free space that can be use after that???? does it effect any upgrade in the future????

The Extended ROM is an area that you cannot normally write to and is not considered part of the memory (as far as I am aware) under Settings/Memory.

By cooking the ROM you can alter what applications get installed when the device is hard reset. The installed applications will take up their normal memory allocation so in that respect it will reduce the amount of memory available to further applications.

It is possible to increase the amount of memory available by cooking the ROM as there may be elements of the Extended ROM that came with the device that you do not actually want installed. This is done either by removing the relevant cab file completely or by removing the relevant entry from the Config.txt file (both should be done, but one or the other will have the same effect).

Hope this helps,
Graham.