I just built a fresh -current kernel for my dreamcast, and it appears
to be mangling packets, and has other problems. :)
It prints several things as zero when it shouldn't during autoconfig.
Things like "total memory", "available memory", buffers, the resolution
of the pvr, etc are zero.

It boots and attempts to DHCP, but the packets on the wire are mangled.
I can provide the tcpdump output if that would help.

I am using the same toolchain I used to generate my last known working
kernel. (February 1)  Since then I've moved and haven't been able to 
mess with the dreamcast until today.  I'll try checking out different
dates from the repository and try to figure out when it broke.

-Andrew