Messages in this thread | | | Date | Wed, 15 Jul 2009 19:13:23 -0400 | Subject | Re: Why do we probe option roms at 2K boundaries? | From | Jon Smirl <> |
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On Wed, Jul 15, 2009 at 7:10 PM, Alan Cox<alan@lxorguk.ukuu.org.uk> wrote: >> 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 ;)
Random link from google, slide 21 http://download.microsoft.com/download/9/8/f/98f3fe47-dfc3-4e74-92a3-088782200fe7/TWAR05005_WinHEC05.ppt
PCI 3.0+ allows 512b alignment, but you must first make sure you are on a PCI 3.0+ system.
> >> 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. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
-- Jon Smirl jonsmirl@gmail.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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