tests: on_target: Update README.md

Adding instructions to run test locally.

Signed-off-by: Giacomo Dematteis <[email protected]>

tests/on_target/README.md

@@ -1,22 +1,33 @@
 # OOB on target test
 
-Test docker image: ghcr.io/dematteisgiacomo/ubuntu-jlink-nrfutil:latest
+## Run test locally
 
-Base ubuntu image with jlink and nrfutil device installed (see Dockerfile)
-
-pytest is used
-
-## Test description
-
-To be added.
-
-## Run test docker image locally
+### Setup docker
 ```shell
+docker pull ghcr.io/hello-nrfcloud/firmware:v2.0.0-preview31
+cd <path_to_oob_dir>
+cp <path_to_hex>/merged.hex thingy91x-oob/tests/on_target/artifacts/
 docker run --rm -it \
   --privileged \
   -v /dev:/dev:rw \
   -v /run/udev:/run/udev \
-  ghcr.io/hello-nrfcloud/firmware:latest
+  -v <abspath_to_oob_dir>:/work/thingy91x-oob \
+  ghcr.io/hello-nrfcloud/firmware:v2.0.0-preview31 \
+  /bin/bash
+```
+
+### Verify nrfutil/jlink works
+```shell
+nrfutil -V
+nrfutil device list
+```
+
+### Run test
+```shell
+cd thingy91x-oob/tests/on_target
+pip install -r requirements.txt --break-system-packages
+export SEGGER=<your_segger>
+pytest -s -v -m dut1 tests --firmware-hex artifacts/merged.hex
 ```
 
 ## Test docker image version control