In order to improve the system's appearance while booting, a splash screen system has been added. Creating and customising splash screens is fairly straightforward once the kernel has been patched. The Heber supplied kernel already has the relevant patches applied.
The splash screen driver uses the framebuffer device to render 16 bit images directly to the frame buffer. Rather than compile the desired image into the kernel itself the image is added to an initial boot ram disk. As the system boots, the boot loader (Lilo) copies the kernel image and the initial RAM disk into memory. Once the system starts to boot the kernel can then use this ram disk to access any extra data it needs in this case the graphics needed for the screen. The system has two graphics images a silent image used for this initial boot and a second image used as a background after the kernel has finished booting. The system also allows for animations to be overlayed on top of the splash screens.
Each splash screen layout is controlled by one or more configuration files these are text files describing the layout and operation of the splash screen.
The background bitmaps are 1024x768 JPEG files. Any animations should be in MNG format.
For further information on boot splash, refer to www.bootsplash.org.
To implement a splash screen on a system booting from Compact Flash, (assuming the use of a patched kernel):
#splash -s -f pathToConfigurationFile > /your compact flash path /boot/initrd.splash
This command creates/overwrites a suitable RAM disk image with the JPEGs and the animation commands. If several configurations or there is a need to put other data in the ram disk then the splash screen can be appended using:
#splash -s -f pathToConfigurationFile >> /your compact flash path /boot/initrd
The next stage is to change the boot loaded script so it will create the ram disk and append kernel command line parameters needed. (This assumes the use of Lilo as a boot loader).
To create the RAM disk at boot time add the lines:
initrd=/boot/initrd/splash
It is a good idea to set the VGA to the correct mode. In this case 1024x768 by 16bits. vga=791
The kernel needs a couple off command line parameters. These should be added using the append instruction:
append ="vga=791 splash=silent"
The vga=791 entry tells the frame buffer driver to use VESA mode 791 that is 1024x768x16 bit.
The splash=silent turns on the graphics boot display.
Now move to what will be the root of the Compact Flash drive, once it has booted, and run Lilo to create the boot entries:
lilo -r /media/sda1 -C etc/target.lilo.conf
Unmount the Compact Flash drive and it should be ready for testing.