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Re: [Xen-devel] [Patch] Expand shadow memory area for using option ROM

Keir Fraser wrote
On 26/12/2008 04:46, "Akio Takebe" <takebe_akio@xxxxxxxxxxxxxx> wrote:

This patch is:
- replace e820 table from 0xe0000 to 0xeb000.
- expand shadowr from 0xc0000-0xdffff to 0xc0000-0xe8fff.
- fix scan size of VGA BIOS.

after this patch, BIOS map is below.
 BIOS map:
  c0000-c8fff: VGA BIOS
  c9000-d57ff: Etherboot ROM
  d5800-e0fff: PCI Option ROMs
  e9000-e919c: SMBIOS tables
  f0000-fffff: Main BIOS


1. Why does the VGA BIOS 'scan size' need to be fixed? What's wrong with
scanning only up to 0xc8000 for it, and letting option ROMs continue to
reside from 0xc8000? Indeed, won't the VGABIOS always be at 0xc0000, so we
could actually only probe that address for it, and let option ROMs load as
low as 0xc0800?

Because the current VGA BIOS uses 0xc0000-0xc8fff from the following log.
I want just to avoid the unnecessary scanning.

(XEN) HVM1: BIOS map:
(XEN) HVM1:  c0000-c8fff: VGA BIOS
(XEN) HVM1:  c9000-d57ff: Etherboot ROM
(XEN) HVM1:  e9000-e919c: SMBIOS tables
(XEN) HVM1:  f0000-fffff: Main BIOS

I think rombios works fine if we drop the part of the patch.

2. It'd be nice to give E820_PHYSICAL_ADDRESS a definition in config.h and
then use that instead of hardcoding the address throughout rombios.c.

I'll try it.

Best Regards,

Akio Takebe

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