Tim Pushor wrote:
Hi all,
I am planning on purchasing a crystalfontz LCD panel to be able to have a rudimentary interface with the system without having a keyboard/monitor/shell.
I'm not sure whether to go the serial or USB route. What I want to do is to be able to display status as the system is coming up, then have a user level application accept input from the panel and display various statistics, then when the system is brought down, for the panel to notify the user that it is safe to turn off the machine.
For the startup and shutdown I would need to hack stuff into the kernel. I have done a fair bit of C programming over the years, but never worked in the kernel. So I have 2 real questions:
Would it be easier to control the USB or Serial panel from the Kernel?
And - does anyone have any recommendations as to where I could even start looking in the kernel to do what I want?
Thanks, Tim
(Please CC: me as I am not subscribed to this list - Thanks!)
Greetings!
I'd guess that the serial version would be the way to go, since FreeBSD has builtin support for displaying to serial console (typically used for headless systems, allowing admins to use a serial communications program like HyperTerminal under Windows for out- and input). This is, of course, assuming that the LCD panel interfaces like a serial terminal. If it does, you've got about half the job done, as FreeBSD will happily print bootup and shutdown information out-of-the-box.
Further, if it announces touches to the screen as regular keypresses, you're even luckier. All that really would remain for you to do was to write the UI (as I don't think a ready-made solution exists for what you want. I may be wrong, though). If this is to be a GUI (on top of X, that is), you'd have to find out if X will display to serial terminal. If it doesn't, I'm sure any idea you can come up with is just as good/better than mine. ;-)
Worst case scenario; the LCD screen interfaces like a toaster. My best bet would be to do a kernel module. More info on how to do those can be found here:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/index.html
I encourage others to elaborate (and correct me, of course) as they see fit. Not having done much actual work on FreeBSD myself, what I propose here is what my programmer's mind sees as probable based on what documentation and experimenting I have seen and done.
Hope this helps! :-) -Henrik W Lund _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
