How to configure a small HDMI screen for the Raspberry Pi using Buildroot customization scripts.
This article is part of a series written to keep track of the attempts to create small Linux systems for embedded applications. The principal tool used for the purpose is Buildroot and the target hardware are the cheap and pretty common Raspberry Pi and Raspberry Pi 2 boards. The ultimate goal is to identify a set of tools and methods that are architecture-agnostic and modular enough to be a potential candidate for the development of industrial applications (control and HMI) on generic hardware.
This note in particular describes the necessary steps taken to set up a WaveShare 5in HDMI LCD (B) display on the Raspberry Pi 2 (wiki). See also the previous article if you want to configure the WaveShare 3.5in LCD (A).
Configure the display
In the boot partition of the SD card image add the following lines to the config.txt file:
hdmi_cvt 800 480 60 6 0 0 0
Device Tree Overlay
see how to apply device tree overlay related to the fbtft https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays
the page contains reference to few overlays for know display, WaveShare ones among them
overlays have to be placed in the boot partition in