Subject: Re: 32 bit dev_t, Revision 2
To: Chris G. Demetriou <cgd@pa.dec.com>
From: Todd Vierling <tv@NetBSD.ORG>
List: tech-kern
Date: 01/11/1998 19:31:49
On Sun, 11 Jan 1998, Chris G. Demetriou wrote:

: > Well, one bit mask at the very least is a good thing: MI versus MD devices. 
: 
: No it's not.  (I was about to say this in another message, too.  8-)
: 
: Why is it important?  What does it accomplish?

Reduces bloat in the devsw tables, if you use separate MI and MD tables.

: between multiple devices of the same ${MACHINE_ARCH} it makes sense to
: have all the same devices -- so you can boot off the same media
: (e.g. CD-ROM, net-boot, etc.)
  [...]
: ${MACHINE_ARCH}s should liteally _share_ a device table (i.e. share
: the source file) and a MAKEDEV script.  The old->new conversion tables
: would have to be in ${MACHINE}-dependent kernel files, but that's no
: problem.

Don't disagree here.  I would have had the, say, m68k MD table be in
sys/arch/m68k/m68k/... that's fine.

: However, between different ${MACHINE_ARCH}s, there are _so_ many other
: problems that need to be solved that getting an extra copy of the
: device nodes for the right arch just isn't very hard, if you're trying
: to do common media.

Hrm?  So are you suggesting that (1) device numbers between different
${MACHINE_ARCH}es should have zero correlation, or that (2) they should
always match even if they don't exist on a different ${MACHINE_ARCH}?  I
thought we were trying to move toward having some commonality in MI device
numbers... that's why I suggested a MI/MD split of two tables.

=====
===== Todd Vierling (Personal tv@pobox.com) =====
== "There's a myth that there is a scarcity of justice to go around, so
== that if we extend justice to 'those people,' it will somehow erode the
== quality of justice everyone else receives."  -- Maria Price