Missing console on RasPi3 7” Touchscreen

[udoschneider]

Initial discussion on Elixir Forum: https://elixirforum.com/t/missing-console-on-raspi3-7-touchscreen/66393

Environment

• Elixir version (elixir -v):

Erlang/OTP 27 [erts-15.1.1] [source] [64-bit] [smp:24:24] [ds:24:24:10] [async-threads:1] [jit:ns]
Elixir 1.17.3 (compiled with Erlang/OTP 27)

• Nerves environment: (mix nerves.env --info)

|nerves| Environment Package List

  No packages found
|nerves| Loadpaths Start

|nerves| Precompile Start

|nerves| Precompile End


Nerves environment
  MIX_TARGET:   host
  MIX_ENV:      dev

NERVES_SYSTEM is unset
NERVES_TOOLCHAIN is unset
|nerves| Environment Variable List
  target:     host
  toolchain:  unset
  system:     unset
  app:        .

|nerves| Loadpaths End

• Additional information about your host, target hardware or environment that
  may help
  Target is rpi3 with Touchcreen

Current behavior

The Raspi 7" Touchscreen stopped working with commit e0c8981.

Expected behavior

Linux/Nerves console on screen

[udoschneider]

A quick check with the vc4-kms-dsi-7inch overlay added and

display_auto_detect=1
dtoverlay=vc4-kms-dsi-7inch

in config.txt didn’t yield any success.

Also, adding all the dtbos from https://github.com/raspberrypi/rpi-firmware/tree/master/overlays to the system did not work. My understanding of display_auto_detect is that if the appropriate DTO is available, then it should be working. My current assumption is that a module is missing. I will compare lsmod from Raspbian to Nerves next.