I’m afraid the display driver does not have have an option to mirror the image. Anyway I expect there’s something wrong with the overall setup:
- The Colibri iMX6 will always output pixels from top-left to bottom-right (well, there’s a rotation option, but let’s ignore that for now, it cannot mirror the image).
- The display datasheet does not mention anything about mirroring
- I remember I saw displays which had two signals on the connector that could be strapped to mirror the image horizontally and/or vertically. Your display does not mention such a signal.
- I once had a display on my desk (also with no mirroring configuration pins) which mirrored the image horizontally sometimes, even if I didn’t change any configuration.
What I suspect:
I assume the display controller on the display still has the option of mirroring the image, even though this option is not routed to the connector.
Under particular conditions this mirroring can be unwantedly triggered. Possible reasons could be a bad solder joint on the display, EMI overruling a high-impedance pull resistor, or maybe the power-up cycle timings.
Maybe the display supplier can give you more hints, or if you can identify the display controller on the display, you might be able to find this datasheet for more information.