[OpenBIOS] success on l440gx+ ram

Wallace I. Kroeker WallaceKroeker at smarttech.com
Wed Feb 16 07:33:17 CET 2000


The trick is to setup the VGA BIOS.  One of the links off the OpenBIOS site
has a list of Interrupts and Ports.  You need to look at kicking the VGA
BIOS via Interrupt 11h (I think that is the correct one).  There was a
complete section that described the VGA BIOS.  

I will put the code up here a little later today (I am out of the office and
the code right now).  You need to set the mode (07 is MDA mode) and then get
it to load one of the VGA BIOS character tables and then activate that
character set.
I put this code into the boot16/start.asm right after the MDA and CDA init
code.  The basic form is:
	;; set up register (I think AX was used) for init
	int 11h
	
	;; set up for character set load
	int 11h
...

Now the only other trick is that the MDA address range is different than the
typical VGA so you need to change this in firmware/init/VGA.h  .

Also, call video_init in firmware/init/main.c (or is it console.c? ...).
The MDA is 0 and VGA is 4 (I set up some defines).

So now you should get the OpenBIOS logo to print out.

Sorry for not giving you the code snippets but I will get them to you later.

> -----Original Message-----
> From:	Ronald G. Minnich [SMTP:rminnich at lanl.gov]
> Sent:	Tuesday, February 15, 2000 7:18 PM
> To:	openbios at elvis.informatik.uni-freiburg.de
> Subject:	[OpenBIOS] success on l440gx+ ram
> 
> I forgot to put a 0x17 in reg 0x76 after the mode set command. Sheesh. 
> 
> dram is now working fine. I am actually in protected mode in the 32-bit
> openbios startup, getting ready to gunzip linux and jump to it. 
> 
> Now the trick is to figure out why I have no display :-)
> 
> All I want for now is a vga-compatible thing, very limited in scope. So I
> want the absolute minimum hardware only. Any hints would be welcome. 
> 
> ron
> 
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