Unable to determine your tty name on Debian Wheezy on ARM

Question

while trying to create my Debian Wheezy image for a FriendlyARM mini210s ARM single board computer, I am bumping into this issue.

I have opened a terminal via serial sudo screen /dev/cu.usbserial 115200 and that my current output:

[    3.398751] apple 0003:05AC:0220.0003: input: USB HID v1.11 Device [Apple, Inc Apple Keyboard] on usb-s5p-ehci-1.4.2/input1
INIT: version 2.88 booting
INIT: Entering runlevel: 2
INIT: Id "X1" respawning too fast: disabled for 5 minutes

Debian GNU/Linux 7 FriendlyARM ttySAC0

FriendlyARM login: root      <======= entered root and hit return
Unable to determine your tty name.    <===== THE ISSUE

Debian GNU/Linux 7 FriendlyARM ttySAC0

FriendlyARM login: 

INIT: Id "6" respawning too fast: disabled for 5 minutes
INIT: Id "5" respawning too fast: disabled for 5 minutes
INIT: Id "4" respawning too fast: disabled for 5 minutes
INIT: Id "3" respawning too fast: disabled for 5 minutes
INIT: Id "2" respawning too fast: disabled for 5 minutes
INIT: Id "X1" respawning too fast: disabled for 5 minutes
INIT: Id "5" respawning too fast: disabled for 5 minutes
INIT: Id "2" respawning too fast: disabled for 5 minutes
INIT: Id "6" respawning too fast: disabled for 5 minutes
INIT: Id "4" respawning too fast: disabled for 5 minutes
INIT: Id "3" respawning too fast: disabled for 5 minutes

On the touchscreen, I have a message saying:

"login: PAM Failure, aborting: Critical error - immediate abort"

Can someone help me decrypt what this is tell me?

How I created my rootfs

sudo debootstrap --arch=armel --foreign wheezy rootfs/ http://ftp.us.debian.org/debian

echo "proc /proc proc none 0 0" >> rootfs/etc/fstab
echo "mini210s-anybots"
echo "mini210s-anybots" > rootfs/etc/hostname 
mkdir -p rootfs/usr/share/man/man1/
mknod rootfs/dev/console c 5 1
mknod rootfs/dev/tty1 c 4 1
mknod dev/ttySAC0 c 204 64     <==== the serial port

then I created an image with yaffs2utils and booted on my FriendlyARM (I describe the process here, it's a bit long).

I copied the inittab from a functioning Debian Squeeze image, which contains these lines

T1:2345:respawn:/sbin/getty 115200 ttySAC0      <=== terminal on serial port RS232 
X1:2345:respawn:/bin/login -f root tty1 </dev/tty1 >/dev/tty1 2>&1
2:23:respawn:/sbin/getty 38400 tty2
3:23:respawn:/sbin/getty 38400 tty3
4:23:respawn:/sbin/getty 38400 tty4
5:23:respawn:/sbin/getty 38400 tty5
6:23:respawn:/sbin/getty 38400 tty6

I am most certainly missing a couple of steps.

UPDATE Added missing devices

Apparently I need to configure some devices. I inspired myself from this post

mknod -m 0600 ./rootfs/dev/console  c 5 1
mknod -m 0660 ./rootfs/dev/full     c 1 7
mknod -m 0640 ./rootfs/dev/kmem     c 1 2
mknod -m 0660 ./rootfs/dev/loop0    b 7 0
mknod -m 0640 ./rootfs/dev/mem      c 1 1
mknod -m 0666 ./rootfs/dev/null     c 1 3
mknod -m 0640 ./rootfs/dev/port     c 1 4
mknod -m 0666 ./rootfs/dev/random   c 1 8
mknod -m 0660 ./rootfs/dev/tty      c 5 0
mknod -m 0666 ./rootfs/dev/urandom  c 1 9
mknod -m 0666 ./rootfs/dev/zero     c 1 5

mknod -m 0660 ./rootfs/dev/tty0     c 5 0
mknod -m 0660 ./rootfs/dev/tty1     c 5 1
mknod -m 0660 ./rootfs/dev/tty2     c 5 2
mknod -m 0660 ./rootfs/dev/tty3     c 5 3
mknod -m 0660 ./rootfs/dev/tty4     c 5 4
mknod -m 0660 ./rootfs/dev/tty5     c 5 5

... but still experiencing the issue.

now addding these

mknod -m 0660 ./rootfs/dev/ram0 b 1 0
mknod -m 0660 ./rootfs/dev/ram1 b 1 1
mknod -m 0660 ./rootfs/dev/ram2 b 1 2
mknod -m 0660 ./rootfs/dev/ram3 b 1 3
mknod -m 0660 ./rootfs/dev/ram4 b 1 4
mknod -m 0660 ./rootfs/dev/ram5 b 1 5
mknod -m 0660 ./rootfs/dev/ram6 b 1 6
mknod -m 0660 ./rootfs/dev/ram7 b 1 7
mknod -m 0660 ./rootfs/dev/ram8 b 1 8
mknod -m 0660 ./rootfs/dev/ram9 b 1 9
mknod -m 0660 ./rootfs/dev/ram10 b 1 10
mknod -m 0660 ./rootfs/dev/ram11 b 1 11
mknod -m 0660 ./rootfs/dev/ram12 b 1 12
mknod -m 0660 ./rootfs/dev/ram13 b 1 13
mknod -m 0660 ./rootfs/dev/ram14 b 1 14
mknod -m 0660 ./rootfs/dev/ram15 b 1 15

My new rootfs/dev

root@ubuntu:/home/joel/debian-mini210s/rootfs/dev# ls -al
total 8
drwxr-xr-x  2 root root    4096 Jan 19 17:27 .
drwxr-xr-x 19 root root    4096 Jun 22  2012 ..
crw-r--r--  1 root root   5,  1 Jan 19 14:07 console
crw-rw----  1 root root   1,  7 Jan 19 17:05 full
crw-r-----  1 root root   1,  2 Jan 19 17:05 kmem
brw-rw----  1 root root   7,  0 Jan 19 17:05 loop0
crw-r-----  1 root root   1,  1 Jan 19 17:05 mem
crw-rw-rw-  1 root root   1,  3 Jan 19 17:05 null
crw-r-----  1 root root   1,  4 Jan 19 17:05 port
brw-rw----  1 root root   1,  0 Jan 19 17:27 ram0
brw-rw----  1 root root   1,  1 Jan 19 17:27 ram1
brw-rw----  1 root root   1, 10 Jan 19 17:27 ram10
brw-rw----  1 root root   1, 11 Jan 19 17:27 ram11
brw-rw----  1 root root   1, 12 Jan 19 17:27 ram12
brw-rw----  1 root root   1, 13 Jan 19 17:27 ram13
brw-rw----  1 root root   1, 14 Jan 19 17:27 ram14
brw-rw----  1 root root   1, 15 Jan 19 17:27 ram15
brw-rw----  1 root root   1,  2 Jan 19 17:27 ram2
brw-rw----  1 root root   1,  3 Jan 19 17:27 ram3
brw-rw----  1 root root   1,  4 Jan 19 17:27 ram4
brw-rw----  1 root root   1,  5 Jan 19 17:27 ram5
brw-rw----  1 root root   1,  6 Jan 19 17:27 ram6
brw-rw----  1 root root   1,  7 Jan 19 17:27 ram7
brw-rw----  1 root root   1,  8 Jan 19 17:27 ram8
brw-rw----  1 root root   1,  9 Jan 19 17:27 ram9
crw-rw-rw-  1 root root   1,  8 Jan 19 17:05 random
crw-rw----  1 root root   5,  0 Jan 19 17:05 tty
crw-rw----  1 root root   5,  0 Jan 19 17:07 tty0
crw-r--r--  1 root root   4,  1 Jan 19 14:47 tty1
crw-rw----  1 root root   5,  2 Jan 19 17:07 tty2
crw-rw----  1 root root   5,  3 Jan 19 17:07 tty3
crw-rw----  1 root root   5,  4 Jan 19 17:07 tty4
crw-rw----  1 root root   5,  5 Jan 19 17:07 tty5
crw-r--r--  1 root root 204, 64 Jan 19 14:11 ttySAC0
crw-rw-rw-  1 root root   1,  9 Jan 19 17:05 urandom
crw-rw-rw-  1 root root   1,  5 Jan 19 17:05 zero

but still getting Unable to determine your tty name

UPDATE - added ttySAC0 to /etc/securetty

In vim /etc/pam.d/login Line:

auth [success=ok new_authtok_reqd=ok ignore=ignore user_unknown=bad default=die] pam_securetty.so

this should allo login without password, if device listed. ... but that didn't work out as I expected.

Found on the Internet about this issue

On AskUbuntu

eBook on the issue

Answer 1

I suspect the underlying issue is nothing to do with your tty, but rather that is a consequence of the far more important error message further down, PAM Failure, aborting: Critical error - immediate abort.

This article from the Debian Help site may help. (TL;DR? CR/LF on the end of lines in PAM configuration files is bad.) But without knowing what you've done with the PAM subsystem it can only be a guess.

Answer 2

You're missing several things in /dev. You were initially missing /dev/tty, which the kernel internally reroutes to the calling process's own terminal. The getty and login programs talk to a specific terminal (here /dev/ttySAC0), but after that other programs just want to communicate via whichever terminal they're running on, and they use /dev/tty for that. You've created it, but with the wrong permissions: /dev/tty needs to be accessible by all processes. So does /dev/full, by the way, although it's very rarely used so that probably doesn't break anything in practice.

chmod a+rw /dev/tty

(/dev/console, on the other hand, is correctly reserved to root. /dev/tty refers to the terminal that the process is running on, which can be a software terminal such as xterm, sshd, screen, etc. /dev/console, on the other hand, refers to a console, i.e. a physical terminal; few programs need to interact with the console as such.)

In addition, in order to use terminal emulators such as screen, you need to create /dev/ptmx and to mount /dev/pts.

mknod -m 666 /dev/ptmx c 5 2
mkdir /dev/pts

and put the following line in /etc/fstab or run the equivalent mount command at boot time, with 5 replaced by the group ID for tty (check `/etc/group):

devpts /dev/pts devpts gid=5,mode=620 0 0

That's all I see for now. I haven't tested, it's possible that something else is missing.