There is a race condition somewhere between kernel output and normal
output when you use a serial console. This is a long standing bug, and
I vaguely remember seeing an analysis of the race here quite some time ago.

The symptoms are: as soon as the init process starts, the console hangs
completely.

I can reproduce this about 4 out of 5 times I reboot a machine running
-current, with ISDN4BSD added (which outputs a lot of information at pseudo-
device attach time) and using a serial console at 19200 bps.

As soon as I comment out the printf's in I4B the boot always succeeds.

I would spent some work on fixing this, but don't have any idea where
to start looking. Any hints?


Martin