Subject: Heads up - setroot changes
To: NetBSD port-arm32 <port-arm32@NetBSD.ORG>
From: Mark Brinicombe <amb@physig.ph.kcl.ac.uk>
List: port-arm32
Date: 02/03/1997 04:01:15
Hi,
  Ok those of your tracking NetBSD-current will be aware of the new setrot
changes that have been made in the last few days.

For everyone else there has been some new MI code added to support
wildcarding of the root device and the root filesystem type. This MI code
is used by all ports to provide consistancy etc.

There are a number of side effects of this change that will affect
NetBSD/arm32 users. Some of these are due to the nature of our boot
proceedure. I don't think any of the other ports have a WIMP based GUI
bootloader which is something we get as we are booting from a WIMP
environment.

1. The swap device is now assumed to be the b partition on the root device
unless a kernel is built specially specifing swap elsewhere. This means
that if you have swap somewhere other than where the install script places
it you will have problems with the kernels I put online. Also the swap
field in the bootloader is now ignored so you cannot use it to specify
multiple swap devices for the generic kernels I put online. mutliple swap
can be support with custom kernels and the sequential swap option I
believe.
NOTE: This 'limitation' should be short lived as very soon specify swap
devices will be completely removed from the kernel and will be
completely determined for user land via the fstab etc.

2. New kernels will not support installations. A separate installation
kernels will be required. This is because if the kernel has a memory disc
configured along with hooks to support setting up a root fs the kernel
will always boot from the memorydisc. If the boot fails you can specific
anotherroot fs etc.
This means that new install kernels will be required so that the install
root image can be installed in the memory disk.
(A side effect is I need to rewrite the way the memory disk gets loaded)

New kernels will be appearing very shortly.

A consequence of point 2 is that I am looking to produce some kernels with
a built in miniroot. This will mean that the kernel size will be larger
but that the kernel will already have a root filesystem builting thus
eliminating the need for a separate root floppy.
One concern will be the size. As things stand I should be able to fit a
compressed kernel with miniroot on a 1.44MB floppy for xfer purposed but
that will be getting tight.

Cheers,
				Mark