Bug#620041: About the new option --setup-dir of setupcon

[Anton Zinoviev <anton@lml.bas.bg>]

In the new version of console-setup (1.72) setupcon has a new option 
--setup-dir (for now it is undocumented).  If you want to configure the 
console (both the font, the encoding and the keyboard) during the initrd 
phase, this can be achieved easily in the following way.  Suppose 
/tmp/initrd/ has the files of the future initrd image.  Then run the 
following command:

   setupcon --setup-dir /tmp/initrd

This will create an extremely simple script /tmp/initrd/bin/setupcon 
that you can use in order to configure the console.  Additionaly, in 
/tmp/initrd/etc/console-setup/ the files required for the configuration 
will be copied.

Notice that among these files, there will be device files for tty1-tty6. 
The configuration script of Ubuntu for the console uses mknod to create 
such device files.  The current method of console-setup is simpler to 
implement (because the code is shared between Linux and kFreeBSD), it 
will not be, however, difficult to change initrd/bin/setupcon to use 
mknod and to remove the device files from the initrd image.  Please 
tell, if you want this change.

Lastly, setupcon will create a file /tmp/initrd/morefiles.  This file 
doesn't have to be included in the initrd image.  Instead it lists the 
utilities that must be included in the initrd image.  Depending on 
whether kbd or console-tools is installed this will be

/bin/kbd_mode
/bin/setfont
/usr/bin/loadkeys (notice that this is a symlink to /bin/loadkeys)

or

/usr/bin/kbd_mode
/usr/bin/consolechars
/bin/loadkeys

One advantage of the early console configuration is that there will be 
no need to change the font during the execution of the boot scripts, the 
screen will not flicker and the full history will be preserved on the 
console. In order achieve this the boot scripts of console-setup have to 
know that the console has been already configured by initrd.  Please, 
advice how this can be achieved.  I suppose the following is one 
possible method:

1. initrd creates an empty file /tmp/console-is-configured

2. the boot scripts of console-setup do not configure the console if 
they see such a file.

3. They, however, remove this file (so these scripts can be used 
normally after the system boots and /tmp is not poluted with unnecessary 
file).

Anton Zinoviev