The NetBSD bootstrap code can't boot a filesystem that's been
converted from an Ultrix with "fsck -c 1". One has to do "fsck -c 2".

On a Ultrix filesystem converted with fsck -c 1, the values in the
superblock for fs->fs_qbmask and fs->fs_qfmask aren't useful -- I'd
guess they're probably zero.  This has the nasty effect of making the
variable |block_size| in ufs.c:buf_read_file() end up as zero, which
results in an infinite loop.

I fixed this by converting a root partition with fsck -c 2.
With that change, and some slight hacking on the bootstrap code
to make it fit in 15 blocks, I can boot a native netbsd a.out kernel.
Wheee.

What's a good distribution format for all this? E-mailing source patches?
Putting a disk image of a miniroot up for anonymous FTP??