1. Make sure that you have the kernel sources installed. As annoying as this may seem, you will need to recompile the kernel to change this image.
2. Download fblogo, either from http://freakzone.net/gordon/#fblogo or from your distribution's package repository. It is a quite common tool so it should be available as a package.
3. Create or otherwise obtain the image, but be warned that there are some constraints: no more than 224 colors, and 80x80px size so that you do not disturb the messages shown by your distro at boot time. You need not be too restrictive when creating the image: we will use another tool to convert it so that it meets the color-related prerequisites.
4. Save the image as png, and run the following:
pngtopnm logo.png | ppmquant -fs223| pnmtoplainpnm > logo_linux_clut224.ppm cp logo_linux_clut224.ppm /usr/src/linux/drivers/video/logo/
5. Now configure your kernel, making sure that the following options are enabled (they can be found under the Device Drivers, Graphics Support subsection):
- Support for frame buffer devices
- VESA VGA graphics support
- Video mode selection support
- Framebuffer Console support
- Select compiled-in fonts
- VGA 8x16 font
- Bootup logo
- Standard 224-color Linux logo
6. Change your bootloader to use the new kernel. Make sure you also add a VGA argument to it, so that it boots into a graphic mode. For example:
kernel (hd0,0)/vmlinuz root=/dev/hda1 vga=0x318