Subject: Re: Multiple values for locators
To: Gordon W. Ross <firstname.lastname@example.org>
From: Charles M. Hannum <email@example.com>
Date: 03/25/1997 17:50:56
firstname.lastname@example.org (Gordon W. Ross) writes:
> > From: email@example.com (Charles M. Hannum)
> > Date: 25 Mar 1997 17:26:36 -0500
> > I have a severe need to express multiple values for a locator for
> > indirect devices. e.g. I need to be able to do:
> > sb0 at isa? port 0x220 irq 1 drq 1,5
> > gus0 at isa? port 0x300 irq 1 drq 5,7
> > Right now, where this is done at all, it's typically done via some
> > hack involving the `flags' field.
> Would it be easier to use a "mask" instead? i.e.:
> sb0 at isa? port 0x220 irq 1 drqs 0x22 # 1,5
> gus0 at isa? port 0x300 irq 1 drqs 0xA0 # 5,7
1) That implies some representation issues which simply aren't
correct. e.g. Technically, wdc should be described as:
wdc0 at isa? port 0x1f0,0x3f6 irq 14
and I'm certainly not going to introduce a bitmap for the `port'
2) The previous examples do *not* say `select one of these values';
they say `use these two values'. The ordering may be very important,
since the values may be used for quite different purposes.