kernel space to user space /bin/sh startup

kernel space to user space /bin/sh startup

[Tom Strader]

I am trying to boot linux on a PXA270 and I think I almost have it but
the shell seems to not be outputting to the terminal.  The kernel boots,
mounts the root file system, opens ttyS0 and proceeds to call
run_init_process("/bin/sh") however I see no login prompt or shell
appear.  I am using ptxdist to build the kernel and jffs2 image.  After
run_init_process("/bin/sh") is run I can type on the console and
characters are echoed back to the screen, but still no other output.  Is
it possible that the output is being directed to somewhere which is not
correct?  

My /etc/inittab is as follows: 
#############################################################
# 
# /etc/inittab
#
# $Id: inittab 1681 2004-09-01 18:12:49Z  $
#
console::sysinit:/etc/init.d/rcS
console::respawn:/sbin/getty -L 115200 /dev/ttyS0 vt100
# Stuff to do before rebooting
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
#############################################################

My /etc/init.d/rcS is as follows:
#############################################################
#!/bin/sh
#
# /etc/init.d/rcS
#
# $Id: rcS 2054 2004-11-25 10:57:09Z mkl $
#
echo -n "mounting filesystems..."
mount -a 2>/dev/null
echo "done."
# modprobe ppp_async
# loadkmap < /etc/boottime.kmap
# set hostname 
test -e /etc/hostname && hostname -F /etc/hostname
echo -n "creating Network-Device lo..."
ifconfig lo up 127.0.0.1
echo "done."
echo "running rc.d services..."
run-parts -a start /etc/rc.d
#############################################################

This is the final output I see.
VFS: Mounted root (jffs2 filesystem).
Freeing init memory: 76K
opening ttyS0...uart_open(0) called

Now I can type on the console and characters are echoed back, pressing
ctrl-c echoes: "uart_flush_buffer(0) called" so the code is still
running, but I am not sure where I am or why I see no login prompt or
shell command line.
I never see the "mounting filesystems..." echoed to the screen, but the
code does not stall and no errors are reported by the kernel.  Any help
during the transition from init/main.c in kernel space to user space
would be appreciated, so I could debug this further.
I have looked around and have not seen a solution for my problem, most
likely due to the fact that I am not entirely sure what the problem is.


Thanks in advance for your time,
Tom Strader

Re: kernel space to user space /bin/sh startup

[Jan Engelhardt]

On Apr 10 2007 11:22, Tom Strader wrote:

>console::sysinit:/etc/init.d/rcS
>console::respawn:/sbin/getty -L 115200 /dev/ttyS0 vt100

>Now I can type on the console and characters are echoed back, pressing
>ctrl-c echoes: "uart_flush_buffer(0) called" so the code is still
>running, but I am not sure where I am or why I see no login prompt or
>shell command line.
>I never see the "mounting filesystems..." echoed to the screen, but the
>code does not stall and no errors are reported by the kernel.  Any help
>during the transition from init/main.c in kernel space to user space
>would be appreciated, so I could debug this further.
>I have looked around and have not seen a solution for my problem, most
>likely due to the fact that I am not entirely sure what the problem is.

Perhaps your terminal program is set to 9600 bps?



Jan
-- 

RE: kernel space to user space /bin/sh startup

[Tom Strader]

Nope.  Terminal is set correctly, the kernel is outputting messages, the
command line arguments sent to the kernel have 115200 set.  What would
happen if the getty was not started correctly?  Would the echoes in rcS
still appear?  I feel like it may be related to the getty and userspace
prints due to the fact the kernel is still printing and responding to
commands.
Tom

-----Original Message-----
From: Jan Engelhardt [mailto:jengelh@linux01.gwdg.de] 
Sent: Wednesday, April 11, 2007 8:48 AM
To: Tom Strader
Cc: linux-kernel@vger.kernel.org
Subject: Re: kernel space to user space /bin/sh startup


On Apr 10 2007 11:22, Tom Strader wrote:

>console::sysinit:/etc/init.d/rcS
>console::respawn:/sbin/getty -L 115200 /dev/ttyS0 vt100

>Now I can type on the console and characters are echoed back, pressing
>ctrl-c echoes: "uart_flush_buffer(0) called" so the code is still
>running, but I am not sure where I am or why I see no login prompt or
>shell command line.
>I never see the "mounting filesystems..." echoed to the screen, but the
>code does not stall and no errors are reported by the kernel.  Any help
>during the transition from init/main.c in kernel space to user space
>would be appreciated, so I could debug this further.
>I have looked around and have not seen a solution for my problem, most
>likely due to the fact that I am not entirely sure what the problem is.

Perhaps your terminal program is set to 9600 bps?



Jan
-- 

RE: kernel space to user space /bin/sh startup

[Jan Engelhardt]

On Apr 11 2007 08:57, Tom Strader wrote:
>
>Nope.  Terminal is set correctly, the kernel is outputting messages, the
>command line arguments sent to the kernel have 115200 set.  What would
>happen if the getty was not started correctly?

I'd say you have no login prompt then after rcS finished.
Thanks for NOT top posting.

>  Would the echoes in rcS
>still appear?  I feel like it may be related to the getty and userspace
>prints due to the fact the kernel is still printing and responding to
>commands.
>Tom
>
>-----Original Message-----
>From: Jan Engelhardt [mailto:jengelh@linux01.gwdg.de] 
>Sent: Wednesday, April 11, 2007 8:48 AM
>To: Tom Strader
>Cc: linux-kernel@vger.kernel.org
>Subject: Re: kernel space to user space /bin/sh startup
>
>
>On Apr 10 2007 11:22, Tom Strader wrote:
>
>>console::sysinit:/etc/init.d/rcS
>>console::respawn:/sbin/getty -L 115200 /dev/ttyS0 vt100
>
>>Now I can type on the console and characters are echoed back, pressing
>>ctrl-c echoes: "uart_flush_buffer(0) called" so the code is still
>>running, but I am not sure where I am or why I see no login prompt or
>>shell command line.
>>I never see the "mounting filesystems..." echoed to the screen, but the
>>code does not stall and no errors are reported by the kernel.  Any help
>>during the transition from init/main.c in kernel space to user space
>>would be appreciated, so I could debug this further.
>>I have looked around and have not seen a solution for my problem, most
>>likely due to the fact that I am not entirely sure what the problem is.
>
>Perhaps your terminal program is set to 9600 bps?
>
>
>
>Jan
>-- 
>
>
>

Jan
--