Messages in this thread | | | Date | Tue, 29 Apr 1997 14:12:46 +0200 (MET DST) | From | Geert Uytterhoeven <> | Subject | Re: New /dev/console and /dev/tty0 |
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On 29 Apr 1997, Kohtala Marko wrote: >Geert Uytterhoeven <Geert.Uytterhoeven@cs.kuleuven.ac.be> writes: > >> In summary, while we created an `automatic' /dev/console, we lost the ability >> to access the current virtual console (formerly /dev/tty0), or am I missing >> something?? > >When I wrote the change, my thought was that /dev/console would >continue to work as before (it already was automatic) when there are >the virtual terminal devices. However, I failed to bring this thought >into the code.
I think you've got a bit confused by devices.t{ex,xt}. This document (incorrectly) states that c 4 0 should be /dev/console, while it was supposed to be /dev/tty0. If you read the statement about the console at the end, this becomes clear (and I did ask H. Peter Anvin).
>The concept of console is a bit vague here and in the source. In my >view console is the device for managing the machine and where kernel >messages go and from which you can get the single user shell >prompt. Video and keyboard and the virtual terminal devices using them
100% agreed. This is what I understand by `console' too.
>are just one fancy device driver among the serial ports and other >terminal devices. Their only association with console is that they >could be used as a console, just like most other terminal >devices. /dev/console should not be relied for giving any virtual >terminal. It can be relied to find the console.
Yep, that's what /dev/tty0 served for.
>This is simple logic (albeit new with the introduction of alternate >console devices): if it is true that > > virtual terminal is a console > >it does NOT follow that > > console is a virtual terminal
100% agreed.
>Now, when we have no /dev/tty[1-9]* devices, I thought that best is to >have /dev/console go automatically to any existing console device. The >c 4 0 is pairs nicely with c 5 0, which is the tty of the current >process, so I thought I keep using that. > >The only problem that I see is that programs rely on the old notion of >console to find foreground virtual terminals. This can be alleviated
They always were incorrect, since they had to use /dev/tty0 instead of /dev/console.
>by giving /dev/tty[1-9]* priority over serial consoles, so that they >are /dev/console when both vt and serial consoles are used. Some >people might not want that, but they are minority and still not worse >off than before the serial console change.
Hmmm... That's not what I want. I want to have the console messages and the single user shell (and the kernel monitor when I hit BREAK, or on panic :-) on /dev/ttyS0, while I do use /dev/tty[1-9]* for normal business.
The only clean solution I see is to allocate a new major/minor pair for /dev/console, and keep on using /dev/tty0 for the current VT (and for gpm, X, loadkeys, clock (on m68k), etc...).
Greetings,
Geert
-- Geert Uytterhoeven Geert.Uytterhoeven@cs.kuleuven.ac.be Wavelets, Linux/m68k on Amiga http://www.cs.kuleuven.ac.be/~geert/ Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium
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