More details on the Eden support

Peter Stuge stuge-linuxbios at
Fri Nov 1 18:53:01 CET 2002

On Fri, Nov 01, 2002 at 02:12:28PM -0500, GNUOrder wrote:
> > The main point of my question, though, was if anyone was aware of another
> > way to program the flash short of unsoldering it.  I wasn't aware of any,
> > and maybe it seemed like a silly question, but if the mobo mfrs would start
> > using the LPC interface flash, and put a header on the mobo to access it,
> > you could program it from a PC-LPT interface with a specially wired cable
> > (plus a few R's and D's).  This has been done on the Xbox and the software
> > is available on the net.  
> LinuxBIOS and kernel on the xbox?  Where do I get a copy.  I may have to pick 
> up a used xbox.  I dont think we would get the kind of help with porting 
> linuxbios to that than we have other platforms.  :)

The Xbox BIOS is actually somewhat documented on
And there's the $55k (I believe) reward for making an open source Xbox BIOS.
Might compensate for the lack of documentation?  :)

Anyway, it's fairly easy to get hold of an "alternative" Xbox BIOS that
allows you to run any software you want on your Xbox, not just stuff signed
by MS.  This other BIOS image can be put either into the TSOP40 memory
soldered to the Xbox mainboard, or in a LPC memory that is connected to the
LPC bus in the Xbox.  You also need to pull down a signal on the mainboard
to ground to make it boot from the LPC bus instead of the legacy ROM bus.

I do believe that most flash memory chips are reprogrammable using the JEDEC
commands, documented in any compliant flash memory data sheet.  That does
however involve writing to the chip and that's usually where the problem is,
write-enable signals aren't always wired to the flash memory chips on
mainboards and when they are they're connected to some GPIO port on the
chipset.  In some cases the memory controller also needs to be set to allow
ROM writes, by flipping the right bit in the chipset PCI config space,
otherwise it'll just block any write requests to the relevant address

For the LPC programmer and friends, check out


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