[coreboot] suspend/resume in v3

Marc Jones Marc.Jones at amd.com
Mon Sep 8 18:14:21 CEST 2008

Carl-Daniel Hailfinger wrote:

> Yes, but the problem is that the CAR area can't be saved before enabling
> CAR. That means we have to reserve the memory. Let me summarize the
> current black list:
> - 0x00000-0x9FFFF is low 640 kB. May break bootloaders and 16-bit OS.
> - 0xA0000-0xAFFFF is VGA graphics memory mapped area.
> - 0xB0000-0xB7FFF is ancient monochrome memmapped, but may still be
> decoded by newer VGA cards.
> - 0xB8000-0xBFFFF is VGA text mode memory mapped area.
> - 0xC0000-???? is VGA ROM location.
> - 0xF0000-0xFFFFF is used by SeaBIOS.
> IMO, the first choice would be 0xC4000-0xCFFFF (if VGA ROMs are 16 kB or
> smaller). 0xE0000-0xEFFFF would be the next possibility. If we can
> verify that bootloaders and operating systems can handle a reserved area
> below 0x9FFFF, that might be a viable choice as well.

Late to this discussion but here are my $.02.

Most VBIOS may truncate themselves to be smaller after init but the 
initial image size is 32K or larger these days.

E0000 is the normal location for BIOS expansion. I recommend allocating 
from EFFFF down and leave room at the bottom for more expansion ROMs.


Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com

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