during fedora boot, what picks up the initrd.img from /boot?

[Tom Horsley]

>   i'm sure i'm going to regret asking this only seconds after i hit
> ENTER, but at what point during the boot process does the kernel's
> corresponding /boot/initrd.img file kick in and get used?

When it says "RedHat Nash" near the beginning of the boot then
goes away for a half hour (OK, maybe not that long :-) it is
processing the init script from the initrd.img file (nash is
the name for the shell-like program that interprets the script).