Subject: Re: cac/ld problems
To: Chris Ross <cross+netbsd@distal.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: current-users
Date: 06/21/2004 14:05:28
On Mon, Jun 21, 2004 at 01:57:09PM -0400, Chris Ross wrote:
> Thor Lancelot Simon wrote:
> >Perhaps not, but it's been this way for well over 10 years, and all of
> >386BSD's other descendents have the exact same "feature".
> 
>   I beg to differ.  BSD/OS has never thought anything like that.
> Partition 'c' is the whole disk, and 'd' is never presumed to be
> anything other than what you tell it.

BSD/OS isn't a descendent of 386BSD, though many of the machine-dependent
parts had the same original author.

>   And while my familiarity with FreeBSD is limited, I don't have
> any recollection of doing any such thing on this machine when
> I installed FreeBSD 5.2.1.

FreeBSD retooled their entire disksubr some time ago; until then it worked
basically just like ours.

>   So, saying "it's been this way for well over 10 years" seems
> a little pre-mature.  Can someone check to see when the partions

No, I assure you, I am painfully aware of the relevant history, as
odd as that history may seem to you.

> beyond 'h' were added to NetBSD?  I'd guess any presumtion about
> 'd' wasn't made until after that...

That's wrong, too.

What you're seeing is a dubious attempt to account for the presence of
both the BSD disklabel and the BIOS MBR: in theory, the BSD system just
isn't ever supposed to use 'd', because the entire portion of the disk
that "belongs to it" is described by the 'c' partition, as always.

Unfortunately, it's not that simple.  We have native tools for installing
bootblocks, adjusting the partition table, and so forth, and those really
_do_ need to deal with areas of the disk outside the part "owned" by our
kernel; thus the necessity to use a partition to actually name the whole
logical disk presented by the controller.

And that partition is 'd', and has been for, as I said, more than 10
years now.  Is it strange?  Yes.  Bogus?  Quite possibly.  But it's
also how we've always done it, not some recent change, as you posit.

Thor