Messages in this thread | | | Date | Fri, 10 Jul 2009 16:44:56 +0200 | From | Alexey Fisher <> | Subject | Re: Intel BIOS - Corrupted low memory at ffff880000004200 |
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Thomas Gleixner schrieb: > On Fri, 10 Jul 2009, Alexey Fisher wrote: >> Ingo Molnar schrieb: >>> * Matthew Garrett <mjg59@srcf.ucam.org> wrote: >>> >>>> On Mon, Jul 06, 2009 at 06:24:47PM +0200, Alexey Fisher wrote: >>>>> Hallo Ingo, Richard. >>>>> >>>>> I'm getting "Corrupted low memory" trace with my Intel DG45ID board >>>>> after resume. This board has different dmi-bios-vendor... so probably it >>>>> will be nice to have it in your patch. >>>> I'm beginning to think that we should be doing this on all hardware, >>>> perhaps with a kernel option to disable it for embedded devices that >>>> really need that 64K. The low-memory corruption issue seems to be very >>>> widespread. >>> The problem is that the BIOS corrupted memory that it also marked as >>> 'usable' in its E820 map it gave to the kernel. If that memory is not >>> usable, it should not have been marked as such. Also, some of the reports >>> showed corruption beyond this range so the workaround is not universal. >>> >>> So i'd really like to know what is happening there, instead of just zapping >>> support for 64K of RAM on the majority of Linux systems. >>> >>> We might end up doing the same thing in the end (i.e. disable that 64k of >>> RAM) - but it should be an informed decision, not a wild stab in the dark. >>> >>> Ingo >> If i make memory dump like "dd if=/dev/mem of=memdump.dd bs=64k count=1" >> before and after suspend. Will it help you find out whats happening. > > The corrupted low memory printks contain the modifications. Can you > post them please ? > > Thanks, > > tglx
I dumped all between 0000000 - 00ffff0 and there is changes at: 0004200 -> this know one 003c000 - 003fff0 -> this was empty and now it looks like VBIOS 00d18a0 -> i don't know
cat /proc/iomem 00000000-0000ffff : reserved 00010000-0009e7ff : System RAM 0009e800-0009ffff : reserved 000e0000-000fffff : reserved 00100000-bd90dfff : System RAM 01000000-014b1f1b : Kernel code 014b1f1c-0171265f : Kernel data 01794000-01842c07 : Kernel bss .....
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