Pi Zero W rotate terminal

Question

I'm using a CLI only interface with the pi zero W, and wanted to use an older monitor, which doesn't have the ability to rotate the screen itself. Since it's command line only the "$DISPLAY" variable is empty, so setting display_rotate= {0,1,2,3} in /boot/config.txt does nothing.

I was wondering if there are alternatives to this, or if I'm better off using windows WLS to go headless

Answer 1

Did you try
display_hdmi_rotate=2
?
put it in config.txt

Answer 2

Although I haven't tried it, this should work, since CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y is in the default kernel config, at least for the 64-bit 5.10.52 I checked.¹ Another clue would be the existence of /sys/class/graphics/fbcon/rotate and rotate_all, which is how the rotation can be changed -- eg. from sudo bash (because sudo does not apply to a normal redirect)

echo 1 > /sys/class/graphics/fbcon/rotate_all 

Should do a quarter clockwise rotation (valid values are 0, 1, 2, 3). The difference between rotate and rotate_all is that each virtual console (there are 6 accessible by default) has its own framebuffer, and the former only rotates the current one (which should be fine, but if you want to automate this at boot you should have it apply to all).

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1. To do that, from a writable directory:

    sudo modprobe configs
    cp /proc/config.gz .
    gunzip config.gz
    grep FRAMEBUFFER_CONSOLE config
   

   You should get something like:

    CONFIG_FRAMEBUFFER_CONSOLE=y
    CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
    CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y
    # CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER is not set