On Fri, Mar 02, 2007 at 05:22:57PM +0100, Uwe Hermann wrote:
On Fri, Mar 02, 2007 at 04:09:28PM +0100, Luc Verhaegen wrote:
This motherboards BIOS is supposed to have a "CrashFree" BIOS, and i have a hard time finding out what that actually is supposed to do. I have a hard time looking through the marketing, and some bits have already fallen off the web.
I think we should have a section in the FAQ/wiki about all these CrashFree, Virtual DualBIOS and whatnot features...
Each one should be tested by somebody who owns the respective hardware, and then we document which of those really work if you brick the board by flashing a non-working LinuxBIOS image (and which don't).
If we can, we should also gather some information about how extactly they work internally (software-only, hardware-based, two chips, splitting one chip in two (virtual) halves etc.).
This will be very useful for lots of people, I presume...
Uwe.
Hrm.
First of all, let me assert that i have absolutely no clue about flashroms, so i might be talking pure rubbish here. But let me line up some facts, and what i think might be going on here.
Facts: * The part itself is an SST39SF020A, a well known 256kB part. * flashrom is reading: id1 0x25, id2 0x1e with probe_jedec at 256kB. * Asus provides a 256kB (exactly) BIOS Image for this board, so it will be filling this rom completely.
So, i see two options: * Asus crashfree doesn't protect against a bad flash, but did manage to change the IDs returned (is this even possible?). * The board has a tiny bit of seperate flash itself, the bios in there gets loaded first from the top of address space, which later on loads and runs the BIOS in the SST39SF020A. This would mean that the SST39SF020A lives somewhere else, and its id can be found, probably at some 512 or so boundary not too far away from the 256kB mark.
Is there anything wrong in those hypotheses? Am i missing something?
Anyway, testing options:
* make flashrom probe_jedec at 256kB, and subsequent 4k boundaries until 0xFF, 0xFF is returned. If it stops at 260kB, then there's no seperate BIOS.
* hotplug a rom (when i get them -- don't go through willem.org unless you're a pensioner) in at one point and see whether flashrom then is able to identify that one.
* try to directly read out the rom coming out of the board using a willem programmer.
Does any of this make sense?
Luc Verhaegen.