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Video mode code / eCos demo


Hi,

This one's a bit obscure, but I noticed it by comparing with the grub
code:

  /* Now trip to the graphics mode.  */
  if (set_vbe_mode (mode_number | (1 << 14)) != 0x004F)

That 1 << 14 (0x4000) lets you use the 'linear framebuffer mode',
which is pretty important if you want to avoid that other, awful thing
where you have to continually select the frame you want to work in.

Once again, I'm not sure if this should just be mentioned in the docs
(or maybe even just the .cdl), or if it would be convenient to add in
a bit of code to actually set the bit.

        "If you wish to access the screen as a linear framebuffer, be
        sure to logical or the mode you select with 0x4000."

BTW, I finally got my eCos demonstration hacked together:

wget http://www.dedasys.com/image.bin
cp image.bin /dev/fd0
# or dd or whatever to write it to the disk, raw
reboot from floppy

The images I selected(*) ought to be refreshing to look at if it's as
hot where you are as it is here in Italy!

It's still a bit buggy, but it boots and runs on the three pc's I
have, and I like it as a demo, because with something like Linux, you
simply could not pack in the same number of images (even if this demo
only fills the disk halfway, adding more images is pretty easy).

Maybe adding a web server in another thread, to serve up the same
images over the web, would be neat, but I'm afraid I've spent enough
time on this myself for now.

Anyway, thanks for all the help!

Ciao,
-- 
David N. Welton
   Consulting: http://www.dedasys.com/
     Personal: http://www.dedasys.com/davidw/
Free Software: http://www.dedasys.com/freesoftware/
   Apache Tcl: http://tcl.apache.org/

(*) All mine, except the grand canyon one by my partner Ilenia.
They're all on my web site, for that matter.

-- 
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