[syslinux] isolinux 2.0 boot graphic display issue

[H. Peter Anvin]

Daniel Robbins wrote:
> 
> If it were simply some kind of bug regarding setting color registers,
> then the colors would be wrong but the graphic would still be visible,
> or at least the text would appear in the same place. Right now it looks
> like it is somehow skipping the graphic display process entirely.
> 

Are you in text or graphics mode?  (You can most easily tell by whether 
or not the cursor is flashing.)

> VGA is a pretty basic thing -- both these cards should be able to
> display 640x480x16 colors bug-free with no problem. These are modern
> cards. Other programs can obviously use the 6480x480x16 color mode with
> no problem. It is likely an issue with the isolinux program itself.

VGA is a highly complex, and most importantly *obsolete* thing.  Modern 
cards are going to be increasingly likely to have problems, if recent 
history is any indication ("does it pass WHQL?  Ship it then!")

> If you point me to the code that initializes the graphics mode, I can
> forward this issue to a friend of mine who is an expert in VGA and VESA
> programming and see what he can do. That way, you won't have to waste
> your time looking into this cosmetic bug. Just give me a few pointers of
> what to look at.

That would be nice.  The code is all in the file "graphics.inc"; the 
mode is set in the function "vgasetmode".

	-hpa