How to terminate console on serial port (UART)

Related documentation:

• port.serial
• https://dev.openwrt.org/ticket/11243
• http://web.cecs.pdx.edu/~jrb/ui/linux/driver4.txt
• http://www.networksecuritytoolkit.org/nst/docs/user/ch11s02.html

First method (NO need re-build the Kernel):

1. Edit sysctl.conf file on your device:

• /etc/sysctl.conf

Add the new line at the begining of this file:

kernel.printk = 0 4 1 7

2. Edit inittab file on your device:

• /etc/inittab

up to revision r28294

Find line in this file:

ttyS0::askfirst:/bin/ash --loginttyATH0::askfirst:/bin/ash --login

Edit the line by following example:

#ttyS0::askfirst:/bin/ash --login#ttyATH0::askfirst:/bin/ash --login

since revision r36992

Find line in this file:

::askconsole:/bin/ash --login

Edit the line by following example:

#::askconsole:/bin/ash --login

3. Reboot your device.

Note:If you need to use the terminal for RAW data/Modem data, then you need to reconfigure this terminal/dev/tty* via coreutils-stty module.

Second method (need re-build the Kernel):

You can change the Kernel command line:

• target/linux/ar71xx/config-X.XX

where 'X.XX' - the last version of Kernel build.

Find line in this file:

CONFIG_CMDLINE="rootfstype=squashfs,jffs2 noinitrd"

Add the parameter 'console=null':

CONFIG_CMDLINE="rootfstype=squashfs,jffs2 noinitrd console=null"

Then you have to recompile the Kernel with 'make target/linux/{clean,prepare} V=s QUILT=1' and then'make V=99', after this, re-install new firmware on your device.

Forum discussion:

https://forum.openwrt.org/viewtopic.php?id=47723