[OLPC-devel] Re: AMD Geode GX framebuffer: support OLPC

[ollie]

On Tue, 2006-08-15 at 10:15 -0600, Ronald G Minnich wrote:
> ollie wrote:
> 
> > I haven't looked at the very early init of Linux kernel for a long
> > time. IIRC, we can just boot the vmlinux ELF image with LinuxBIOS/FILO
> > The ELF image does not contain the arch/i386/boot stuff at all. Is
> > there any reason we have to load something like bzImage?
> > 
> 
> I think the issue is that VGA parameters have to be set. See below. How 
> do we want to do this?
> 

Why do we have to do that? These parameters were never set for any of
the previous LinuxBIOS platforms with VGA support. Does the GX2 
framebuffer driver require it?

The code in arch/i386/boot is for old fashion bootloaders like LILO/GRUB
and to make Linux kernel a boot floppy disk. On LinuxBIOS platforms 
with Etherboot or FILO, they are not even in the image.

Ollie
 
> ron
> 
> 
> 
> >>>#ifdef CONFIG_VIDEO_SELECT
> >>>        movw    %fs:(0x01fa), %ax               # User selected video mode
> >>>        cmpw    $ASK_VGA, %ax                   # Bring up the menu
> >>>        jz      vid2
> >>>
> >>>        call    mode_set                        # Set the mode
> >>>        jc      vid1
> >>>
> >>>        leaw    badmdt, %si                     # Invalid mode ID
> >>>        call    prtstr
> >>>vid2:   call    mode_menu
> >>>vid1:
> >>>#ifdef CONFIG_VIDEO_RETAIN
> >>>        call    restore_screen                  # Restore screen contents
> >>>#endif /* CONFIG_VIDEO_RETAIN */
> >>>        call    store_edid
> >>>#endif /* CONFIG_VIDEO_SELECT */