Bug#550429: kfreebsd-7: add BOOTP kernel options for NFS Root support

[Robert Millan <rmh@debian.org>]

2011/6/17 Vagrant Cascadian <vagrant@freegeek.org>:
> reopen 550429
> reassign 550429 kfreebsd-8
> thanks
>
> as far as i know, this is still an outstanding issue for the newer versions of
> kfreebsd.

This problem could be solved by removing all network drivers
from kernel.

If network drivers are only built as modules, then BOOTP and
BOOTP_NFSROOT can be enabled (in my tests with recent
kernels, BOOTP_COMPAT and BOOTP_NFSV3 are not necessary
anymore).

Then disk-based boot proceeds as follows:

1: GRUB loads kernel from disk
2: kernel boots and, having no network drivers, proceeds
    with mounting a disk filesystem as root.
3: kernel starts init, which loads network modules from either:
   a) Hardcoded list in /etc/modutils
   b) Starts devd, which auto-detects hardware and loads appropiate
   modules (the beginning of this is in #630614).

And network-based boot proceeds as follows:

1: GRUB loads kernel via TFTP
2: GRUB loads either:
    a) a specific network module for this computer
    b) all network modules
3: kernel boots via DHCP/NFS

-- 
Robert Millan