kernel load failure

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

I have 2 laptops with identical cases if not identical internals. One is
my everyday -current/amd64 laptop. I have been trying to netboot the
other one which keeps failing to load the kernel over nfs, at the stage
where the twiddle is still printing the first number. (I think there are
normally 3.)

pxeboot_bin and the kernels are all a few day old -current/amd64.
I tried GENERIC, GENERIC with DEBUG (no extra printing), a compressed
GENERIC, and the kernel from the working laptop. Repeating the
netboot, the load would always stop at the same place for that
kernel. (Different places for different kernels, so not "network
transferred given number of bytes".) Compressed and corresponding
uncompressed kernels stop at the same place. I also tried a
GENERIC/i386 kernel (in case of "can't cope with instruction XXX"),
and the same happened.

On a whim, I tried

  FreeBSD-11.0-CURRENT-amd64-20150716-r285616-bootonly.iso.xz

which successfully netbooted.

Any suggestions on what might be going on?

Cheers,

Patrick