Re: GUI Work

["Vesa Jääskeläinen" <chaac@nic.fi>]

John S. wrote:
> I'm trying to get myself started in all of this, but I have a ton of
> questions.  You'll have to forgive me if they are obvious, but this is
> my first time looking at the grub source.
> 
> Also I have never written code this low-level (on a PC) before.  My most
> relevant experience would probably be writing some ms-dos games, which
> is similar but I'm assuming theres a ton of differences.  So please
> forgive me if I don't know all of the concepts yet.

You don't actually have to care too much about low-level details. What
is required is to write "high-level" GUI using low-level systems provided.

> So here are the questions:
> 
> How much of the video API has been written?

Bitmap support is missing from CVS, but otherwise most of the
functionality should work. There might be some changes, but I have to
think more on some issues raised on this list.

> What exactly does the file vbe.c do?  I'm assuming it implements a VESA
> BIOS Extension interface that we can use when writing the API
> functions.  Please correct me if I'm wrong.  Also how much work is
> required on this set of code?

vbe.c implements VESA Bios Extension 2.0+ driver for GRUB Video
Subsystem. You are not supposed to use this driver directly. Use Video
API instead. It abstracts used video driver, so we can use same GUI code
on all supported platforms.

> If the API has already been started which file is it in?  if it has not,
> which file should be created for it? how about /video/i386/pc/api.c ?

See video/video.c.

There is also term/videoterm.c and commands/videotest.c that exercises
Video API.

Thanks,
Vesa Jääskeläinen