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Supressing console output with "quiet" option or console=NULL or console=/dev/null NOT working...

Posted on 2008-10-21
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Last Modified: 2013-12-16
I have an embedded target on which I do not want console output to appear on-screen at boot time, nor do I want console data streaming out the serial port.

During development and test I would like a console on the screen or the serial port. I want to control this by changing my "console" parameter on the kernel command line I pass from my bootloader.

Some years ago I did this by setting console=NULL or console=/dev/null (I can't remember exactly). This suppressed all console output on a production unit.

For engineering use I would interrupt the bootloader and specify a "console=tty" (screen) or "console=tty0,115200" (serial port) option and get the console output as desired for engineering use.

For the 2.6.24 kernel I've tried a "quiet" option, but this is not working. I'm getting text on my LCD.

The only method that eliminates ALL output to my LCD is when I specify a "console=ttyPSC0,115200" (a serial port). This then routes all the console output to the port, but I don't want it there either!

Can anyone help me to understand why console=/dev/null is not working, or why the "quiet" option is not working? Thanks!
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Question by:mike_timmons
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Mysidia earned 2000 total points
ID: 22793437
Try
loglevel=4
(To log messages  only  levels 4 and lower numbered [more severe] messages via kprint)

Take action to suppress output from init scripts   that normally send output to the console, also.



and/or   boot the kernel with console directed to an unused local tty

console=tty2


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