1. Embedded Linux logo Display principleEmbedded Linux is directly based on the framebuffer. Direct display of a PPM format image. It kernel/drivers/video/fbcon.c in the Fbcon_show_logo () to complete, the maximum color support 224 colors and less common 255 colors. The default logo file is drivers/video/logo/logo_linux_clut224.ppm.
2. Production processBecause the Linux logo format needs to be displayed in PPM format. This format is a format that uses ASCII to describe image data. In general, only a handful of software can recognize this format. "Linux commune www.LinuxIDC.com" So assuming you have a good logo image (jpg or PNG format, preferably the latter), then there are two ways to create the logo ppm format. First of all, you have to ensure that the size of your logo can not exceed your screen size, the first production can choose a smaller point. Like the default logo only 80*80. Can be displayed in various situations.
2.1 Using the NETPBM package for conversionRHEL5 has installed these tools. It comes with netpbm-10.35-6.fc6, assuming you have PNG data as follows:
pngtopnm huisen-logo-linux.png > HUISEN-LOGO-LINUX.PNM#转换png成pnm格式
pnmquant 224 huisen-logo-linux.pnm > HUISEN-LOGO-LINUX224.PNM#转换像素数为224
PNMTOPLAINPNM HUISEN-LOGO-LINUX224.PNM > logo_linux_clut224.ppm
#转换二进制的pnm格式为文本的ppm格式.
CP logo_m32r_clut224.ppm linux-2.6.28.6/drivers/video/logo/logo_linux_clut224.ppm
rm-f linux-2.6.28.6/drivers/video/logo/logo_linux_clut224.c
Embedded Linux modified Start logo
