Firstly the stock DHCP daemon does not support if statements in the configuration, so this bit to keep iPXE from being told to load iPXE (a loop) didn't work
if exists user-class and option user-class = "iPXE" {
filename "http://10.0.0.1/pxelinux.0";
}
else {
filename "undionly.kpxe";
}
To get it to work I had to follow the alternate advice on the chainloading documentation about Breaking the loop with an embedded script.
However, recompiling udnionly.kpxe on OpenBSD 4.9 failed, with the error:
net/fcels.c: In function 'fc_els_prli_detect':
net/fcels.c:1108: internal compiler error: Segmentation fault: 11
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
gmake: *** [bin/fcels.o] Error 1
(this was GCC 4.2.1). FreeBSD 8.2 also has the same version of GCC and comes up with the same error.
I ended up using an Ubuntu 10.04.3 box, which I believe was GCC 4.4.x, and that worked fine.
FreeBSD, OpenBSD, and 2007 Daylight Savings Time
Just a followup to my earlier post on updating FreeBSD to handle the changes in Daylight Savings Time starting in 2007....
There are a couple mentions [1], [2] on the freebsd-stable mailing list that the /etc/localtime file is binary compatible across various versions of FreeBSD.
This means you only have to get one good copy of /etc/localtime for your timezone, either by pulling from a FreeBSD 6.2 or higher machine, or installing the misc/zoneinfo port on one older machine and run tzsetup. Once you have that good version, you can copy it around to your other FreeBSD boxes, regardless of what version they're running.
This seems to also work between FreeBSD and OpenBSD (and perhaps Net and Dragonfly). I had a single OpenBSD 3.7 machine I wanted to update, and it seems to work OK to use a /etc/localtime pulled from a FreeBSD box. On OpenBSD (3.7 at least), /etc/localtime was a symlink to a file in /usr/share/zoneinfo/. I just removed the symlink and made a new one pointing to a new timezone file I stuck somewhere on the disk. Checking for the correct DST dates in OpenBSD seems to be the same as with FreeBSD: