[yocto] How to disable a linux virtual terminal...

[Greer, Charles (ext)]

Hi all,

Would anyone know how to disable the virtual terminals in linux?  I am using Yocto, Morty version on an i.MX6 processor.  Even though our base distribution is Yocto, unfortunately we have diverged from building it with recipes, so this is more of a straight linux question than Yocto...

To give some detail as to my problem:  It is for an embedded device that has an HDMI port - when I attach a terminal to the HDMI port it shows the Linux Penguin logo, a getty service and blanks out after 600 seconds.  I just want to use the hdmi port as an output with nothing displayed on the output and I want it to stay on all the time.

I have found that the hdmi port maps to /dev/tty1 - when I type:  echo "asdfasdf" > /dev/tty1 I see the characters output to the monitor.

Here are a few things I have tried to no avail - a lot of these are not needed if I can figure out how to disable it as a virtual terminal...


*         I figured out how to disable the getty service but a cursor still blinks.   I don't even want a cursor to show



*         I have tried to disable the display of the penguins  by disabling the LOGO in the kernel config parameters:
#CONFIG_LOGO=y
#CONFIG_LOGO_LINUX_MONO=y
#CONFIG_LOGO_LINUX_VGA16=y
#CONFIG_LOGO_LINUX_CLUT224=y

To no avail.  The logo still shows ::( .


*         The fact that it blanks after 600 seconds is console blanking - I can see it set to 600 in the file:  /sys/module/kernel/parameters/consoleblank.  When I issue the command:  echo -e '\033[9;0]'>/dev/tty1

It sets the console blanking to 0 and wakes the terminal.  Being able to wake the console up is limited success but I would like to disable the virtual terminal altogether...


*         I tried commenting out these virtual terminal defines in the config file to no avail:
#CONFIG_VT=y
#CONFIG_VT_CONSOLE=y
#CONFIG_VT_CONSOLE_SLEEP=y
#CONFIG_HW_CONSOLE=y
#CONFIG_VT_HW_CONSOLE_BINDING=y


Everything I have read suggests that /dev/tty1 is a virtual terminal or console.  From what I read about the VT option, disabling the CONFIG_VT should do it:

VT - Virtual terminal

Say yes here to get support for terminal devices with display and keyboard devices. These are called "virtual" because you can run several virtual terminals (also called virtual consoles) on one physical terminal.

You need at least one virtual terminal device in order to make use of your keyboard and monitor. Therefore, only people configuring an embedded system would want to say no here in order to save some memory; the only way to log into such a system is then via a serial or network connection.

Virtual terminals are useful because, for example, one virtual terminal can display system messages and warnings, another one can be used for a text-mode user session, and a third could run an X session, all in parallel. Switching between virtual terminals is done with certain key combinations, usually Alt-function key.

If you are unsure, say yes, or else you won't be able to do much with your Linux system.
But for some reason it doesn't do anything!


*         I found this thread;  https://askubuntu.com/questions/357039/how-do-i-disable-virtual-consoles-tty1-6.  But it is not much help since my distribution does not have any of the directories in the solutions offered in this thread.  For instance I do not have a /etc/events.d nor do I have a /etc/default/console-setup file nor do I have a /etc/init directory...   I imagine the reason for this is that my distribution uses systemd and the solutions are SysV based init maybe?

Disabling the logo or console blanking would not be necessary if I could just figure out how to disable that port as a terminal...

So does anyone have pointers or things I could try?  I am relatively new (returning after 10 years - I worked with DNX 10 years ago v2.6 and it seems everything I knew about init is fairly obsolete lol) to linux so I am sure I am missing a lot...
Thanks,

-          Chuck

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