[CentOS] rebuilding anaconda for centos 4.0

Hi all:

I'm trying to rebuild the anaconda installer for Centos 4.0 (i386) to add some 
RPMs and do some other things, and I've run into a problem.  I've done lots of 
anaconda rebuilds for Tao Linux 1.0, and I'm bringing those bits forward into 
Centos 4.0.  The all-knowing web hasn't turned up anything useful.  It looks 
like the PXE-loaded kernel unpacked and mounted the initrd OK, but then things 
went awry (quickly).  Anyone seen this on a PXE boot of an anaconda build?

<snip>
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem).
VFS: Cannot open root device "<NULL>" or unknown-block(3,2)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,2)

Help or pointers to applicable docs very welcome.

--
Dave Thompson  ( thomas(at)cs(dot)wisc(dot)edu )

Associate Researcher                  Department of Computer Science
University of Wisconsin-Madison       http://www.cs.wisc.edu/(twiddle)thomas
1210 West Dayton Street
Madison, WI 53706-1685
--