Disabling serial console to allow serial port to be used.

[gcams]

I have a fairly unusual setup, in that I want to use my Zeroshell ALIX box to pull info from the serial device using a bash script (I have the Alix 1D with VGA console and therefore don’t need a serial console). I note that inittab spawns a serial console which is preventing me from using the serial port for other purposes.

Is it possible to disable this somehow? I have tried modifying the inittab file, but as it’s pulled from the cdrom image, it get’s re-written on reboot. Is there a way to make this a permanent change?

Any advise or help most gratefully appreciated!

[imported_fulvio]

To disable the serial console after the boot you have to comment the line

7:2345:respawn:/sbin/agetty -i -n -l /root/kerbynet.cgi/scripts/localman 38400 ttyS0

in the file /etc/inittab

and execute the command

init q

to re-examine it.

Regards
Fulvio

[gcams]

Thanks fulvio, that’s a big help! Much appreciated!!

[Larry Baker]

Fulvio,

It looks to me like the solution you have given here does not survive a reboot. Is there a procedure to make this change permanent? (I tried to edit a copy of /etc/inittab in /Database/etc/inittab, but that did not work.)

Larry Baker

[Larry Baker]

Fulvio,

It looks to me like the solution you have given here does not survive a reboot. Is there a procedure to make this change permanent? (I tried to edit a copy of /etc/inittab in /Database/etc/inittab, but that did not work.)

Larry Baker

[ppalias]

Hi Larry,
for every change in ZS to be made effective after reboot you have to install it in “System” -> “Setup” -> “Startup/Cron” -> “PreBoot”.
In that field write the command

cp /Database/etc/inittab /etc/inittab

[Larry Baker]

In the SYSTEM > Setup page, select the Startup/Cron tab.

Select the Post Boot script from the pull-down menu

Edit the Post Boot script:

>>> SNIP <<<
# Startup Script

# Disable the COM1 serial port console

[ -f /etc/inittab.original ] || cp /etc/inittab{,.original}
/etc/inittab
sed /agetty.*localman.*ttyS0$/s/^/#/
telinit q

>>> SNIP <<<

Select Status: Enabled

Select Save

Reboot.

[Larry Baker]

My posts seem to be getting garbled. The line starting with </etc should be

/etc/inittab

[Larry Baker]

This is very frustrating. For some reason, the line will not post correctly. The script redirects the sed command’s stdin to /etc/inittab.original and stdout to /etc/inittab.

[ppalias]

Use the “Code” tags to display the shell code properly. However I think the solution to just copy the inittab in the preboot is more simple.

[Larry Baker]

Thank you for the suggestion to use the Code tags. I did not expect the posting to get mangled (the Preview was correct).

I wrote the code to make a copy of the original inittab and used sed the way I did so that the code would work with any version of ZeroShell that might be released. If inittab changes, I expect this code will still work.

[tls]

The code did not exactly work for me, so I make it a little cleaner, thus building on your idea:

[ -f /etc/inittab.original ] || cp /etc/inittab{,.original}

sed -i 's/(^.*ttyS0.*$)/#1/' /etc/inittab

telinit q

Many thanks for posting the initial issue – I had the same problem, wanted to ttyS0 to hook into my edge switch on the serial line so I could always get to my systems.

–tls

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