Framebuffer or standard VGA ?

Stefan Reinauer stepan at
Wed Sep 11 06:04:00 CEST 2002

* Antony Stone <Antony at> [020911 09:26]:
> Forgive my ignorance, but isn't this what the Bios chip on the VGA card 
> itself is for (in the case where you have a physical card plugged into the 
> motherboard, and not an all-in-one integrated motherboard chipset) ?

> I mean, surely that's the reason why, when you turn on a 'standard' PC with a 
> normal graphics card and a normal Bios, you see the starup messages for the 
> graphics card *first*, and *then* you see the Bios logo and config screen....?

the system bios has no way of user notification/interaction before vga
is initialized. When PCI/AGP is initialized, all expansion cards
containing an option rom are initialized by executing their
initialization functions.

> Couldn't LinuxBios simply call the appropriate init code in a graphics card 
> Bios in order to get a text console, and then carry on afterwards in the same 
> way a normal boot loader would ?

There's already code in linuxbios to do something like this. (as well as
a userspace emulation program, which is kind of incomplete)
The problem is that you have to emulate quite some legacy pc bios
functionality to be able to do this. As that's all 16bit code (and
LinuxBIOS is completely 32bit) this is not always trivial.


The x86 isn't all that complex - it just doesn't make a lot of
sense.          -- Mike Johnson, Leader of 80x86 Design at AMD
	                          Microprocessor Report (1994)

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