Messages in this thread | | | Date | Thu, 16 Jul 2009 00:10:16 +0100 | From | Alan Cox <> | Subject | Re: Why do we probe option roms at 2K boundaries? |
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> interrogating a data structure stored in option-rom memory. My initial > implementation involved blindly scanning from c0000 to f0000 in 512 byte > increments. Neil and others pointed out that this may not be a safe
It isn't safe. If you hit certain ISA devices your system will drop dead. OTOH I doubt anyone has an intel matrix raid controller and a WD80x3 on the same box ;)
> Recently Hans has been working to get Fedora up and running on a recent > Intel software RAID platform and noticed that the option-rom is no > longer visible with the 2K aligned scan. I.e. he needed to make the > following changes to the mdadm probe_roms() routine:
Option ROMs should be 2K aligned. Is your data structure part of a ROM or an actual ROM header ?
> Is this safe? Should the kernel be updated as well? I am assuming that > you were the one that originally introduced the 2K aligned scan with > this commit from the historical git:
Actually I don't think that was me, don't remember it anyway.
The man to bug at the moment on ROM magic is probably H Peter Anvin however.
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