Messages in this thread |  | | | Subject | Re: New /dev/console and /dev/tty0 | | From | Kohtala Marko <> | | Date | 29 Apr 1997 14:23:25 +0300 |
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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.
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 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.
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
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 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.
-- --- Marko Kohtala - Marko.Kohtala@ntc.nokia.com, Marko.Kohtala@hut.fi
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