diskless booting and t134

[Daniel Feenberg]

I am trying to do diskless booting, and find it requires much esoteric
knowledge. Right now I am trying to make the /conf/${class}/ function
provided in FreeBSD 6.0 work. It is briefly documented in the
"diskless" manpage, but with no examples. I have  had  success with
/conf/${ip}/ but not with ${class}.

I have

option t134-cookie code 134=text

at the beginning of my dhcpd.conf file, and

option t134-cookie "client"

with the other parameters for the diskless client. dhcp accepts this
and goes into background. The dhcpd server is on a FreeBSD 5.2.1
system, but since any slight variation on these commands is diagnosed,
I have the impression that the dhcp server is ok with these settings.

I have added at  /disklessroot/conf/client/etc/rc.local  an
identifiable file, yet when I boot the diskless client and look at
/etc/rc.local on it, it is clearly not the file from conf/client/etc
but the one in conf/default/etc/

I have tried using /disklessroot/conf/123.123.123.123/etc/rc.local
(where actual ip address is obfusticated) and that file is correctly
picked up. So the /conf system is functioning.

I can't tell what might be wrong, but if I look in /etc/rc.initdiskless
it does echo the value of ${class}, which in my case is blank rather
than the expected "client". If I run "kenv" or "sysctl -a" and search
the output for this variable, I don't see anything with "134",
"cookie", or "client". My thought is that maybe the "t134" feature
isn't supported in the 6.0 release kernel. I couldn't find out anything
about it, other than seeing it referred to in a couple of messages as
"kern.bootp_cookie". Anyone familiar with this function?

I am using an unmodified 6.0 #0 kernel, with the default options. It
does serve to generate a system that boots and functions (except
where programs write to read-only filesystems.

Thanks

Daniel Feenberg
feenberg isat nber dotte org