On 10/01/2010 08:55 PM, Piscium wrote: > On 1 October 2010 17:44, BandiPat <magicpag...@earthlink.net> wrote: > > >> I don't think it's the monitor's resolution that you should be concerned >> with, but your graphics cards framebuffer. Since the graphics card's engine >> hasn't been fully activated yet, you are relegated to the framebuffer only >> to display images. Normally this will be 1280x1024 or smaller. >> > Well, 1920X1080 displays well with png with a file of 3.2 Mbytes. > > >> Have you tried a 1280x1024 size jpeg for your background image? >> > Following your suggestion I hacked grub.cfg to display 1280x1024. Then > I got two other images of this resolution, one png, one jpeg. The png > displayed well, the jpeg didn't. > > At this point I thought that no jpeg could be displayed. To test this > hypothesis I started Gimp and created a basic jpeg, with some > scribbles with a red brush on a white background. The file was > obviously much smaller than the others I had tested, only 78 Kbytes. > This file displayed well. > > The conclusion appears to be that the jpeg module in grub2 is very > fussy about the files that it displays. Note there was nothing special > about the files I wanted to display. The "green_mountains" was taken > from a blog, and the two 1280x1024 images were taken from the Gnome > Art website. > It's not really "nothing particular". With pictures taken by my camera it works fine. > There is a file grub-core/video/readers/jpeg.c. It has plenty of debug > statements like: > "grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails"); > > Is there some easy way to read the text of these messages? (I have no > JTAG and my hardware does not support virtualization). > > They aren't debug messages but error messages which are shown if you call background_image manually. Bluepill extensions are useless for debugging GRUB and sticking to the simplest qemu is the best option. Qemu works on any hardware. > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel > >
-- Regards Vladimir 'φ-coder/phcoder' Serbinenko _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
