Running with VGA

YhLu YhLu at tyan.com
Thu Jan 13 18:44:00 CET 2005


The problem is no body touch that range. Even init_ecc_memory will skip the
first 1M range.

YH
-----Original Message-----
From: Li-Ta Lo [mailto:ollie at lanl.gov] 
Sent: Thursday, January 13, 2005 7:50 PM
To: YhLu
Cc: Sagiv Yefet; LinuxBIOS
Subject: RE: Running with VGA

On Thu, 2005-01-13 at 19:50, YhLu wrote:
> It seems after if after cpu init do the onboard vga init, it will work.
> 
> The CPU init only do the init ECC and clear that after 1M. ... Werid! And
it
> is not wiped out after power off.
> 
> 

I read your log file again. The font buffer address (0xA0000 - 0xBFFFF)
is controlled by MTRR. The MTRR can direct access of this region to
the main memory or to IO cards. Because the VGA card is inited before
CPU, the MTRRs are not inited correctly. When BIOS loads font data,
it loads it into main memory not the DRAM on the card (actually also
on the mainboard).

Ollie




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