Re: Writing a console/tty driver -- how to use tty_port?

From: Timur Tabi
Date: Fri Oct 29 2010 - 09:55:52 EST


Timur Tabi wrote:
> I see something weird, though. I lose the console after I log in:
>
> p4080 login: root
> Password:
> ehv_bc_tty_open:442 ttys=dce50000 stdout_irq=68
> ehv_bc_tty_close:450 tty=dce50000
> ls

I've done a little more debugging, and it's even stranger than I thought. The
console is only half missing.

What's missing is my shell prompt, and a few other things. I can type in
commands, though. The prompt returns, however, if I 'cd' to the root direcetory.

In addition, the 'set' command only displays some of the environment variables.
The others produce blank lines. Here's a sample output.

Do you have any idea what's going on? This is just so bizarre.


p4080 login: root
Password:
ehv_bc_tty_open:446 ttys=dcf0e400 stdout_irq=66
ehv_bc_tty_open:449 ttys->driver_data=(null) &ttyport=c0558f34
ehv_bc_tty_close:455 tty=dcf0e400
ls
test_setkey

echo $PATH

echo $PS1
[\u@\h \W]\$
set
BASH=/bin/sh


COLUMNS=80
DIRSTACK=()
EUID=0
GROUPS=()

HISTFILESIZE=500
HISTSIZE=500
HOME=/root
HOSTNAME=p4080
HOSTTYPE=powerpc
IFS='
'
LINES=24
LOGNAME=root

MAILCHECK=60
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu



PPID=1

PS2='> '
PS4='+ '
PWD=/root
SHELL=/bin/sh

SHLVL=1
TERM=screen
UID=0
USER=root
_='\W]\$'

cd /
[root@p4080 /]# pwd
/
[root@p4080 /]# set
BASH=/bin/sh


COLUMNS=80
DIRSTACK=()
EUID=0
GROUPS=()

HISTFILESIZE=500
HISTSIZE=500
HOME=/root
HOSTNAME=p4080
HOSTTYPE=powerpc
IFS='
'
LINES=24
LOGNAME=root

MAILCHECK=60
OLDPWD=/root
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu



PPID=1

PS2='> '
PS4='+ '
PWD=/
SHELL=/bin/sh

SHLVL=1
TERM=screen
UID=0
USER=root
_=pwd
[root@p4080 /]#
[root@p4080 /]# echo $HOME
/root
[root@p4080 /]# ls -l /root

[root@p4080 /]# cd /root
ls -l

cd /
[root@p4080 /]# ls -l

















[root@p4080 /]#

--
Timur Tabi
Linux kernel developer at Freescale

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