iPXE NetBooting Ubuntu 14.04.3 LTS

[brownmit]

I'm having a really hard time getting iPXE to work with linux. I've been doing PXE for a long time and have had no problems getting that to work with linux. I love the features of iPXE though and I'm trying to convert my entire PXE environment to iPXE. Rather than burn ROMs etc, I've just set up my DHCP server to pass the undionly.kpxe loader, so technically i'm chaining from PXE to iPXE.

One of the things I put into my configuration was a hook to chain back over to my old PXE configuration so I can boot things in transition. My unbuntu live cd environment is working great there. Here's my stanza in PXE, whic owrks perfectly.

LABEL Ubuntu14043-64
MENU LABEL ^1 - Ubuntu 14.04.3 Desktop (Live,64-bit)
KERNEL /linsetup/ubuntu/14043dx64/casper/vmlinuz.efi
APPEND boot=casper netboot=nfs nfsroot=192.168.15.25:/pxe/linsetup/ubuntu/14043dx64 initrd=/linsetup/ubuntu/14043dx64/casper/initrd.lz ipv6.disable=1 hostname=ubuntu64

Now, here's my corresponding iPXE setup:

set ns 192.168.15.25
set np /pxe/linsetup/ubuntu/14043dx64
set args boot=casper netboot=nfs nfsroot=${ns}:${np} ipv6.disable=1 hostname=ubuntu64
initrd nfs://${ns}:${np}/casper/initrd.lz || goto doError
kernel nfs://${ns}:${np}/casper/vmlinuz.efi ${args} || goto doError
boot

This does not work. It loads the vmlinuz.efi and initrd.lz just fine; during debugging I inserted "imgstat" and "prompt key" before the boot so I could check that the parameters were correct. Boot starts and a few seconds later I get a kernel panic VFS: Unable to mount root fs on unknown block(0,0)

I have read literally dozens of articles all around the web on this, including the app note (http://ipxe.org/appnote/ubuntu_live) and it seems that I'm doing everything right.

I've fiddled with the boot params quite a bit and found:

1. Adding root=/dev/nfs doesn't help, and shouldn't be required in this version of ubuntu
2. adding ip=dhcp does seem to get a bit further - it at least seems to attempt to load the network before the kernel panic
3. adding "ro" doesn't help.
4. adding -- to the end of the arguments doesn't help.
   

Anyone got any working examples with 14.04.x and a current build of ipxe? I actually started this with a 14.04.1 CD and updated to 14.04.3 hoping that would fix it but no luck.

Thanks in advance!