Subject: Re: wsdisplay, early consoles etc.
To: Bill Studenmund <wrstuden@netbsd.org>
From: Michael Lorenz <macallan@netbsd.org>
List: tech-kern
Date: 11/05/2006 13:36:07
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hello,
On Nov 5, 2006, at 12:32, Bill Studenmund wrote:
> On Sat, Nov 04, 2006 at 01:54:02PM -0500, Michael Lorenz wrote:
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> Hello,
>>
>> On Oct 26, 2006, at 13:36, Michael Lorenz wrote:
>>
>>> Besides that - we should come up with a generic interface to let a
>>> driver find out if it's supposed to become the system console or not.
>>> On OpenFirmware machines that's easy - just check /choosen/stdout -
>>> but it's ugly to have OF-dependencies in drivers that reside in
>>> sys/dev/pci. Maybe we should just have the MD autoconf code attach
>>> properties for:
>>> - - console
>>> - - display mode
>>> - - font
>>> - - whatever I can't think of right now
>>
>> I guess no protest means no objections?
>
> For some reason, I'm having a negative reaction to the use of
> "overwrite".
> And I'm not sure if it's really a problem or not.
During autoconf it's not as far as I can tell.
> I think I like the idea of being able to use a simple console driver
> then
> update to a more sophisiticated one once we know the hardware. And I
> like
> the idea about MI console description.
My main motivation is the problem we'd have with selecting an early
console driver before autoconf runs. We'd need some sort of
mini-autoconf before autoconf so better have some simple catch-all and
let autoconf select the one we'll end up using.
> So let me try this question. Why should the console be updated only
> once?
Good question - mainly because the current wsdisplay_cnattach() has a
KASSERT() that makes sure it's only called exactly once and I'd assume
whoever put it there had a good reason to do so.
I'm not sure what would break if we'd allow moving the console around
at runtime - probably not much.
have fun
Michael
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (Darwin)
iQEVAwUBRU4vF8pnzkX8Yg2nAQLMoQf+NdDVUP99aiCGbU0wBXbnfbQYSykueiXr
rp8dsJRWNlmf7iHvEFsv2FsAdBmGsXIN+RFHJCXs4HqhsdXAfN08/5an5+rHCH92
Qe+xeTwPecnR4m3ZLgkD5844LZ55/xVwiT3gDI1GF5GXPIxyOAlFuPhQqH5ZAS9J
36woyUFPTEm7gBYqW7Fms9Zu58ZwRfHN+5hoZ1ulmcuhwxgt7iR9QQttdB5gWTBK
tKu5juugzfuHENIt0xnA/sQKp7+Dj1UfkHdfu6x4gHEXd7BlumYfpGY3mrXN3DNM
wlNQV2NZauBYvv2ENihviXOwrusfevZk6/wbNdOlnYovfGWBLXtcEg==
=Anij
-----END PGP SIGNATURE-----