Ah a common problem when compiling a new kernel for a fresh start. Used to happen to me too on Red Hat based distros
1. What for is initrd.img?
Initial ramdisk file is a binary file consists of a small kernel modules that you want to load before switching into your real root partition (ramdisk here as it runs on ur RAM). Red Hat always do this with for their filesystems (biasly referring to ext3 most of the time). So you will need 2 load kernel module (ext3) before VFS can use it mount that partition.
What for is bootspalsh. Can initrd.img be replace with bootsplash somehow?
Bootsplash is a new toy in your linux where when you boot your linux, you dont see those kernel log messages showing hardware detection but a nice splash screen with cool pictures and progress bar.
Bootsplash project tis here. I used to re-compile the kernel to support bootsplash on slackware.
--> http://bootsplash.org/Welcome_to_the_graphical_world_of_Linux
Why Command “make dep” answered that this is not necessary?
Depends on which kernel version you compile. And when u run it.
1. I presume u r compiling a kernel 2.6.x
2. If not you have just recompiled and ran once "make dep". So if you do so again without any change to existing binaries, you will get this message.
