Re: request for assistance: accessing ttys from kernel space

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

> Currently, speakup is using direct hardware access to communicate with
> serial ports.  Doing so, however, has limitations since we are hard
> coding port addresses and IRQ numbers.  For example, we have a user

I pointed this out several years ago

> What I would like to discuss is how we can access ttys from kernel
> space.  If we could do this, it would definitely make things much easier
> for us in speakup.

Basically - use a line discipline, that lets you sit on top of a tty and
interact with the hardware

> We need to be able to access the ttys as early as possible in the boot
> sequence.  Any help, suggestions, or guidance you could give us would be
> greatly appreciated.

We may need to make some special provision for that aspect - we already
do so for the early serial console support. The ldisc is the start point
then there may be some bits that need to be extended around it.

A bigger problem is going to be the fact non USB serial is vanishing bit
by bit. We do have a USB console but it's truely crazy stuff and
extending it scares me 8)