On Tue, 12 Mar 2013 16:59:26 +0000 (GMT) Bertho Grandpied <[email protected]> wrote:
> > Some time ago, "Andrew Goodbody" noted : > >> I'm pretty sure that the detection of FWH devices requires > >> writing to the address space used and you cannot do that as > >> you cannot set the BIOS WE bit in the chipset. So unless you > >> can get around the SMI protection of that bit then there is > >> no way to detect the chip in use. Even if you did detect it, > >> you still could not program it. > > And I responded : > > I'll check whether the BIOS also has locked access to SMRAM > > - usually it wasn't done at the time. If the SMRAM is > > accessible from outside SMM, it would be straightforward to > > bypass the protection (just replace an RSM instruction as > > the SMI "handler" ;-) > > Which was done successfully a mompent ago... BIOS was not locking the SMM > settings on this Intel board fortunately, so replacing a plain RSM > instruction at the SMI origin (A000:8000) took just a couple minutes' > hacking, then for sure Flashrom was able to detect the FWH, to dump and also > to update the flash image successfully :=) Nice one, congratulations :) Maybe this could be transformed to a patch for flashrom... I would like to see your code (if any) in any case, can you publish it please? > This complete circumvention of the (idiotic) BIOS 'protection' has achieved > my original purpose - be able to modify the BIOS ad libitum. I did not have > to search for the specific GPIO or similar method which the official BIOS > patchers use. Because there is none... just the SMM protection (I guess). -- Kind regards/Mit freundlichen Grüßen, Stefan Tauner _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
