[U-Boot-Users] [RFC] Splash image

[Joey Oravec <joravec@drewtech.com>]

"Rodolfo Giometti" <giometti@enneenne.com> wrote in message 
news:20070718083012.GE4836 at enneenne.com...
> I'm planning to review the splash image support and in order to do that
> my next steps should be:
>
> 1) Remove the logo support.

As long as it's modular, I agreed because the two functions are nearly 
identical. It's important to add/remove code to keep the size down. Probably 
should test for a pointer to a compressed (gzip) image, uncompress, then 
call the bmp_display.

> 2) Rewrite the lcd_display_bitmap() in order to be more portable
> across several BPP values.

Keep it modular; have a bitmap_display(addr, x, y) robust to bpp that is 
called from an lcd_display_splash_screen(). Account for 24-bit LCDs and 
files. The bit-per-pixel data structure was a poor-fit with 24-bit, and I 
didn't even try to support colormapped files on a truecolor display. Great 
idea because it might save a ton of flash to display an 8bpp image on a 
24bpp display.

3. If there's an overall flash savings, it would be nice to support GIF, 
PNG, or some other format smaller than a BMP. How complex is the parsing, 
and would it be a net savings on flash?

4. Account for text overlay on splash screen. There are callbacks for bootup 
progress, and it's nice to lcd_printf() the status to some rectangle on the 
screen. Even better if it scrolls or clears nicely.

5. Document and improve the videolfb ATAG. I hardcode my framebuffer to the 
end of RAM, don't tell linux to use that memory, and pass the info to linux. 
The display still flickers until you remove the re-initialization, but at 
least Linux won't move and therefore clobber the contents of the 
framebuffer.

-joey