questions about your project

[<ph...@ip...>]

Hopefully this will go through w/o subscribing.  I am already
subscribed to way too many mailing lists as it is, and I don't
want to add another, unless this is something I am genuinely
interested in.  I couldn't exactly tell what the scope of the
project was from the web page (though certain things are clearly
covered, others not covered may be considered to be in scope but
just not an issue right now).

Please copy me directly on any replies.  Maybe the answers will
encourage my interest to join.

1.

I have written a kernel patch which allows a process which has
a virtual console open in read mode to call an ioctl() on it to
inject a small string of characters into the keyboard input as
if they had been typed on the keyboard.  It only accepts the
string if it won't overflow the buffer.  I personally have a
few uses for this, and even though I have not fully studied it
for security concerns and best practices, I've already put it
into use on my systems.  It comes with a small C program which
lets scripts inject data, including converting \ and ^ notation
(in the sample program, not the ioctl).  Although a number of
people have suggested I use pty's to do the things I needed this
for, I consider a pty and the program that has to stay keeping
the pty side open as being overhead I don't want, considering
that I only inject data rather infrequently.

Is this an area which would be considered to be part of the
virtual console redevelopment effort?


2.

I've been interested in frame buffer consoles, but I have found
that for many uses, they remain to slow.  Further, some of the
ways they were is causing difficulty with how I use them.

In particular, I find myself frustrated with the lack of distinct
console abstraction with frame buffers.  There is technically
just one frame buffer, with limited access.  What I really would
like to see is frame buffering where each virtual console has its
entire screen cached (and yes, I understand this can be as much
as 4 megabyte or more per console) so that when switching consoles,
the original contents are always re-presented, and the processes
owning that console can make changes while I'm "away" and I can
see the results of those changes when I switch back.

I'd also like to see one other feature, which could help address
the space requirement for fully cached frame buffers, as well as
the slowness issues I see.  This would be to have each virtual
console individually define what mode they are in, be that frame
buffer, or text mode.  That way I could choose to have 2 consoles
in frame buffer mode with 4 megs each, and 50 consoles with no
more than 16K each (based on my SVGATextMode extended size of
120x58).

I've never found out if X Windows _must_, or simply _may_, use its
frame buffer driver when Linux is booted up in frame buffer console
mode, since I didn't stay with frame buffers long enough to try it.
If it _must_, I'd sure like to see it changed to _may_ (with the
obvious other choice of accessing the raw video device as it does
without frame buffers).

Would this project be addressing issues like these?


3.

Also, an idea I had a couple years ago, which I never followed up on
with anyone, might be applicable here.  The idea was to have a screen
saver device.  This device would work much like a virtual console
(and in the case of frame buffers, should work like that, too).  But
what it would be used for is to be the replacement content for when
the screen saver timer pops.  It would initially have a blank content
but a program could place content there to be seen in place of blank
content when the timer pops.  There would also need to be a means for
the program which has it open to know (without polling) when that
screen is being displayed, and when it is not.  One thought is to
call an ioctl() to enable signals USR1 and USR2 as indications.
A program like Seti@Home could use that to start working only when
its display is brought up by the screen saver.  Many other things
could be possible.


Anyway, I'm just sort of checking to see if there is any mesh between
my interests, and what this project is working on.  I'd like to find
out more.

-- 
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| Phil Howard - KA9WGN |   Dallas   | http://linuxhomepage.com/ |
| phi...@ip... | Texas, USA | http://phil.ipal.org/     |
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