PDA ramblings...

Matt Rogers matt at matt.rogers.name
Thu Feb 6 18:23:51 PST 2003


On Thursday 06 February 2003 08:11 pm, you wrote:
> Well, I've spent two hours when I should have been sleeping tonight to
> reverse engineer more of the bootloader...
>
> I have a partial map of the call structure of the bootloader, and where
> its data is (attached below for the curious).
>

hehe, i'm curious :)

> I know where all the code and data is up to 0x71c8, which is about half
> of the total amount of code in the bootloader.
>
> hopefully most of the rest will be data, but I doubt it.
>

Here's hoping!

> I have identified what code I can, except that I got tired, so much is
> labeled 'code' and 'data'. Eventually, all of the code will be traced so
> I can see the call sequence.
>
> I can identify a lot of the code by the locations in memory that it
> accesses, as I have a document with the memory map of a PXA250
> microporcessor. this will make identifying MMU, CF, SD, IR, and other IO
> code easy, although it wont help me see WHAT the code is up to...
>

Ok, I think i know what SD and IR stand for. Enlighten those of us who don't 
know what MMU or CF stand for. (We're not worthy!!!!! :) )

> Tomorrow, I will see if I can finish at least the map, and hopefully the
> call-tree as well.
>

I wish I had that much time on my hands. Stupid school stuff :(

> All I can say is... THANK GOD that 3/4 of the 256KB is image data! this
> is a LONG slow plod.

Image data? what kind of image data? (hehe, i'm thinking logos and stupid shit 
like that, even though that's probably not at all what it is)

>
> Im going to be pda-less for a couple of days, since it needs to return
> to toshiba for minor repairs (audio recording 'clicks' and the wireless
> switch is broken, bah!). when I get it back, hopefully I will have some
> code to try on it ;-)

Only a couple of days? Now that's what I call service! Nice! (Let's hope it 
doesn't turn into weeks)

> Oh, and I have found a local company that will do SMT rework of mBGA
> chips... Im going to buy a PXA255 (faster CPU, basically a PXA250
> without the bugs in its cache) and get it fitted. I will then have the
> fastest XScale PDA in the world (and the difference is NOT small - over
> 4X the memory bandwidth!) ;-)

faster is good :)

> I am getting the 'extended temperature' version of the chip too, on the
> grounds that it will be a 'tougher' sample, and might withstand
> overclocking... I wonder if I can get the PDA to run at 600MHz... that
> would be TOTALLY cool. (I think that may cause all the other timings
> (serial, CF, etc.) to run 33% fast also though, so that may not be a
> good idea...).
>
That would be cool.  :)  


> Well, My head is fscked now, and I still have to clean the kitchen,
> before bed. night night...
[snip of bootloader map]

Interesting.  Makes me want to brush up on my assembly again. (and to think 
that my assembly class (the only time i've actually programmed in assembly) 
was only two years ago). 

Matt 
-- 
Unsubscribe: send email to listar at linuxfromscratch.org
and put 'unsubscribe lfs-chat' in the subject header of the message



More information about the lfs-chat mailing list