Path: utzoo!utgpu!watserv1!watdragon!tiger!mwandel
From: mwandel@tiger.waterloo.edu (Markus Wandel)
Newsgroups: comp.sys.amiga.tech
Subject: What ever happened to the original autoboot scheme?
Keywords: adddosnode autoboot autodocs
Message-ID: <23078@watdragon.waterloo.edu>
Date: 10 Apr 90 00:42:01 GMT
Sender: daemon@watdragon.waterloo.edu
Distribution: comp
Lines: 33

I've been wondering about this one for a while.

In the 1.2 autodocs, there is a description of a simple, elegant autoboot
scheme for disks.  It involves the AddDOSNode() function, which is documented
like this:

	ok = AddDosNode( bootPri, flags, deviceNode )
	D0               D0       D1     A0

It is explained quite clearly that to enter a bootable disk into the system,
all you have to do is build a device node for it, and enter it into the system
via AddDosNode() before the DOS comes up.  Then the system will attempt to boot
off each bootable device, in order of boot priority, and start up on the one
where it finds the first valid boot block.  It says that to never boot one
should specify -128 as the boot priority.

What a nice scheme!  Too bad it doesn't exist.  What exists instead is a kludge.
One has to manufacture a "Boot Node", point it to an autoconfig-related
structure, which in turn points to some boot code in ROM.  The AddDosNode()
call can apparently not be used.  There are no boot blocks, and the device
with highest boot priority always wins.  Moreover, the floppy disk is not
at boot priority zero after all; (if memory serves) it is always checked first
and a bootable floppy always overrides everything else.  It seems that to
implement the original scheme would have taken less code both on Commodore's
part and on the part of the device driver implementers.

So what happened to the original scheme?  Why did it get abandoned?  Does
someone (out of the two or three people in the world who know) have a comment
on this?

Markus Wandel
mwandel@tiger.waterloo.edu
(519) 884-9547