Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 21 Mar 1999 05:22:13 +0900
From:      "Daniel C. Sobral" <dcs@newsguy.com>
To:        Mike Smith <mike@smith.net.au>
Cc:        =?iso-8859-1?Q?S=F8ren?= Schmidt <sos@freebsd.dk>, current@FreeBSD.ORG
Subject:   Re: How to add a new bootdevice to the new boot code ???
Message-ID:  <36F40375.624C03D0@newsguy.com>
References:  <199903201944.LAA12569@dingo.cdrom.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Mike Smith wrote:
> 
> > The major number passed to the kernel is a product of a lot of
> > guesswork, because the loader has simply not enough information. I
> > have added a bit of code to my version of loader so you can use the
> > variable root_device_major_number to override the major number to be
> > passed to the kernel. I'm inclined to commit it, but I expect strong
> > objections from Mike, who wants the right thing done before we go
> > too far with these hacks.
> 
> Correct.

On both accounts, I suppose... :-)

> However Justin's random number comment speaks back to a technique I was
> working on earlier, where such a number would be secreted in the
> disklabel of the disk to be booted.  This number would have to be
> generated in a fairly unique fashion (I planned to use the TOD to try
> to keep it from wrapping), and it'd then be passed in in the
> environment or as an argument to the kernel.

How would that work with netboot or booting from foreign fs, such as
FAT?

If we restrict ourselves to disklabel-carrying fs, an alternative
would be writing the date&time plus a semi-random number (such as
time down to ms) on the disklabel of the disk selected, and passing
this number to the kernel.

[reads what you said again]

Unless, of course, that's precisely what you are talking about...
:-) I'm not sure if you are talking about a pre-generated label, or
one written at boot time. It all rests on the meaning of TOD
(tentatively translated as Time Of Day... :).

> However, there's another technique which would work quite well, and one
> I'm actually moderately enamoured of (modulo it's ability to confuse
> the heck out of people).
> 
> Use the "last mounted on" field to find and mount filesystems.

Again, same objections... :-)

--
Daniel C. Sobral			(8-DCS)
dcs@newsguy.com
dcs@freebsd.org

	"What happened?"
	"It moved, sir!"


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?36F40375.624C03D0>