Repeater for the console client

[Marco Gerards]

Hi,

At the moment I am working on a repeater option for the keyboard
driver of the console client.  I will do the same for the mouse driver
I am writing.

Because not everyone is familiar with the console client I will start
with some background information.  The console client is a very small
program that links to libcons and communicates with the console server
using this library.  To make this program useful it can load drivers,
which are simply so-libraries.

Most people use the `vga' and `pc_kbd' drivers.  At the moment I am
writing `pc_mouse'.  To make it possible to start xfree while the
console client is started a repeater will be used.  That is simply a
translator that is started from (for example) the `pc_kbd' driver.
This is required because only one program can open the Mach device.

Some months ago I wrote a patch to add such functionality to
`pc_kbd'.  In order to do this I simply used libtrivfs.  This worked
perfectly.  Now I can start xfree while the console client is active.
Using the repeater like: `-d pc_kbd --repeat=/dev/kbd' a keyboard
translator is set on the /dev/kbd node.

After that I started working on the `pc_mouse' driver.  This will add
xterm like mouse support to the console.  In addition to that I want
to use this to replace the mouse translator that is used in debian.
To do this I have to add a repeater option to this driver like I did
for pc_kbd.

In case you have not guessed already, I encountered a program with
libtrivfs.  It is not possible to use libtrivfs twice from within the
same program (once from pc_kbd and once from pc_mouse).  Is there some
way to make this possible?  I must admit I don't know much about the
dynamic linker, but I could not find anything that could help me from
studying documentation I found.

Two other solutions i can think of are:

1)  Changing libtrivfs.  Perhaps by making a struct in which the
    calback function addresses and global variables are stored.

2) Using netfs to create /dev/console/ (the path is configurable, of
   course) in which translators can be stored.  This requires a change
   to the console client.  In that case the console client sets up the
   /dev/console/ translator and drivers can use some special function
   to set up a translator in that directory.

Any feedback is appreciated.  I really hope other people might have
other ideas to deal with this problem.  Otherwise please tell me if
either solution #1 or solution #2 is acceptable so I can continue
hacking.

Thanks,
Marco