i386/100831: sio ignores BIOS information about serial ports - bounty offered

[Jo Rhett]

The following reply was made to PR i386/100831; it has been noted by GNATS.

From: Jo Rhett <jrhett at svcolo.com>
To: Bruce Evans <bde at zeta.org.au>
Cc: freebsd-gnats-submit at FreeBSD.org, freebsd-i386 at FreeBSD.org
Subject: Re: i386/100831: sio ignores BIOS information about serial ports - bounty offered
Date: Mon, 31 Jul 2006 08:30:53 -0700

 On Mon, Jul 31, 2006 at 07:55:42PM +1000, Bruce Evans wrote:
 > On Tue, 25 Jul 2006, Jo Rhett wrote:
 > >>Description:
 > >For our motherboard, "Serial A" in hardwired on the board with a 9-pin 
 > >connector.  "Serial B" is a normal serial connector that can be wired 
 > >anywhere.  Rackable uses this connector to connect to their out-of-band 
 > >management interface.
 > >
 > >So in the BIOS configuration, we assign COM1 = "Serial B" and COM2 = 
 > >"Serial A".  This works perfectly for the POST console redirection and 
 > >FreeBSD boot process.
 
 > I think you just need to swap the ports in /boot/device.hints?
 
 device.hints contains what you expect.  0x3f8 should be sio0, but its not.
 This is apparently ignored.
 
 > initialization uses the apparently-higher-level resource access functions
 > it is actually just using the hints, so the hints had better be correct
 > -- they are more than hints.
  
 Sure, but they aren't working.  That's the nature of this beast/bug.
 
 > I don't know exactly what happens with ACPI.  Ideally, ACPI should set
 > the resource values to match the BIOS, and this might involve ignoring
 > most hints and this changing the values from their defaults, but for
 > consoles any changes in the values would be wrong and might result in
 > the high-level console (/dev/console) being attached to a different
 > device than the low-level console (the one used for kernel printfs).
 
 Exactly what I'm worried about.
 
 -- 
 Jo Rhett
 senior geek
 SVcolo : Silicon Valley Colocation