initrd funciton in grub.conf

[sigix]

[tmr777]

This is a compressed file system that is loaded into a RAM drive by the kernel at boot. After loading , the kernel typically runs the linuxrc script contained in the root of the fs. For the purpose of a typical install with a local hard drive, it serves these purposes:

1. linuxrc provides bash script for recognizing scsi, usb, pcmcia, firewire devices for purpose of booting non-ide root partitions.
2. Determines the root partition, mounts it, and passes control to it using pivot_root, and chroot. (this is how the LIVECD root is determined as well).
3. Displays pretty boot splash.

None of which is needed if your root partition is recognized by the kernel (this is the case with normal ide). Long of the short -- you probably don't need it.

I do think this is a source of confusion in Gentoo's kernel building process. As genkernel stabilizes, I'm sure this will be a readily available option. OTOH, Gentoo may be attempting to standardize the process and needs initrd to provide the level of graphical install and device recognition they desire.

Good luck,

_Terry