Sun-4/110 NetBSD Diskless NFS Issue

[Samuel Furtaw <samfurtaw%gmail.com@localhost>]

Hi all,

I've been tinkering on-and-off for several months trying to get NetBSD
to run on my Sun-4/110 workstation. I haven't had any success with
SCSI emulators, so I've been working on running the machine diskless.
I have already successfully run SunOS 4.1.4 diskless over the network,
so I translated most of my existing server setup into a "NetBSD"
config.

The issue I'm running into is that, when pulling the kernel over NFS,
the loader times out (with an error=60) when pulling the second chunk
of the kernel. It does actually pull the first 1024 bytes of the
kernel successfully, judging based on a Wireshark capture.

Here is the text output to the terminal:
```
root addr=172.16.0.2 path=/export/netbsd/root
read header failed: Unknown error: code 60
Cannot load netbsd: error=60
```

In order to get it loading at all, I have compiled a kernel without
most other SPARC components in order to fit within RAM - in my
disk-based testing it refused to unpack the kernel if it was larger
than 4MB (I only have 8MB total to work with.)

In the Wireshark capture, what's odd is that the first 1024-byte chunk
of the kernel is pulled successfully, but when requesting the second
chunk (offset 1024), the responses are sent by the server and plainly
visible. The loader still asks for 3 retransmits before finally
quitting.

Oh - and my NFS, TFTP, and RARP are hosted on a NetBSD 9.3 VM; my
DHCP/BOOTP and boot options are handled by OpenWrt.

Would anyone have a clue what could be going on here? I believe I've
ruled out most other factors that could be affecting this.

Thanks,
Samuel