Hi, Valdis, Yes, I understand shell is a user program. I just added some uart print to see what's happening. (while trying to open a shell on LCD using USB keyboard..) When I see it n fbcon_scroll function(one of console switch functions which connect to bit blit functions)(in drivers/video/console/fbcon.c) while some printks are scrolled up on the LCD, the vc_data is using tty null (vc->port.tty->name is null) then at some point changes to tty1. This is even when I set "console=tty0 " in the boot argument. When I set "console=tty1 ", it's the same. This is when I remvoed /etc/inittab file so that defulat inittab is put in place by busybox... I understand busybox init starts shells on tty2,tty3,and tty4. So the output is using tty1. In input side, when I use print (to uart) on kbd_keycoad function(drivers/tty/vt/keyboard.c), and press any key, I can see the vc->port.tty->name is tty1. (vc is of type vc_data). So the input is connected to tty1 (same as output). But I don't see any change on the LCD at that state (as I press the keyboard). Any idea? any suggestion will be appreciated. I don't know how to assign tty and how to make the fbconsole(or vc on it) to appear on the LCD so to speak. regards, Chan
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org<mailto:Kernelnewbies@kernelnewbies.org> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ________________________________ From : "valdis.kletni...@vt.edu" <valdis.kletni...@vt.edu> Sent : 2014-03-12 21:14:49 ( +09:00 ) To : Kim Chan <c...@etri.re.kr> Cc : Kernel <bu.ker...@gmail.com>, kernelnewbies@kernelnewbies.org <kernelnewbies@kernelnewbies.org> Subject : Re: Does register_chrdev function make device file under /dev ? On Tue, 11 Mar 2014 08:01:26 -0000, Kim Chan said: > To my understanding, device file is needed when a user program wants to > access the device and we don't need to generate the device file for us to use > the device in kernel. Is my understanding correct? Right. You don't need to generate the device file because you shouldn't be accessing the device in a file-like manner from inside the kernel. > I am trying to open a shell on my LCD (is it going to be tty2 That's userspace, not kernel access.
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