fbprobe

Documentation

Overview

fbprobe draws straight to the Echo Show 5's framebuffer: a background, color bars and large text, rotated for the landscape orientation the device is used in. It is the first step of the TECHO5 display layer — proving that the kernel framebuffer reaches the panel without Android.

It is also the only thing that can write to the screen in the rescue environment, where the daemon may not be running at all, so it can be given something to say instead of the test image.

fbprobe                 # paint the test image and pan it onto the panel
fbprobe -fill 1c1511    # solid color only
fbprobe -info           # print the framebuffer geometry and exit
fbprobe -dump shot.png  # write what the panel is showing now to a PNG
fbprobe -title RESCUE -lines "first line|second line" -hold 1000h
fbprobe -watch -watch-for 30s   # how often the panel's page changes, reading only
fbprobe -bench 300             # pan as fast as the driver takes it, timing fill and pan