[coreboot] MPTable can not be high-memory on Linux

Kevin O'Connor kevin at koconnor.net
Sun Feb 22 23:32:26 CET 2009


On Sun, Feb 22, 2009 at 01:33:35PM -0800, Yinghai Lu wrote:
[...]
> >>>  BIOS-e820: 0000000000090000 - 0000000000100000 (reserved)
> >>>  BIOS-e820: 0000000000100000 - 000000003f7f0000 (usable)
> >>>  BIOS-e820: 000000003f7f0000 - 0000000040000000 (reserved)
[...]
> >>> found SMP MP-table at [c00f9fc0] 000f9fc0
[...]
> 
> that should work for a long time.
> 
> 0xf9fc0 < 1M is quite < max_low_pfn, so wonder why bootmem could panic.

On this machine the mptable "floating" structure is at 0xf9fc0.  It
points to the rest of the table which is in the 0x3f7f0000 area.

Note, that this is on a Coreboot+SeaBIOS machine - so we can change
the bios.  However, the mptable spec does allow for part of the table
to be high memory.

-Kevin




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