Runtime chosen image sample application

This sample demonstrates how to use a non flash storage to retrieve the image being booted. It was tested on a FRDM K64F. Both slots are used to store two different images. The image to be booted is selected based on a button press.

Build

Build mcuboot. First, ensure ZEPHYR_SDK_INSTALL_DIR is defined. From the sample directory, run the following commands:

  source <path-to-zephyr>/zephyr-env.sh

  west build -p -b frdm_k64f ../../../boot/zephyr/ -- \
      -DEXTRA_ZEPHYR_MODULES=$PWD/hooks -DEXTRA_CONF_FILE="$PWD/sample.conf"

  west build -t flash

Then, build the sample application to be loaded. We need to build it twice, one for each slot. From the sample app directory (mcuboot/samples/non-flash-source/zephyr/app), run:

  west build -p -b frdm_k64f .
  west flash

Then change the overlay file to use the second slot. For instance, open boards/frdm_k64f.overlay and change the line:

  zephyr,code-partition = &slot0_partition;

to:

    zephyr,code-partition = &slot1_partition;

And build and flash again:

  west build -b frdm_k64f .
  west flash

Run

Open a serial terminal to see the output and reset the board. It shall boot the image on slot0 by default. By keeping the SW2 button pressed during reset, the bootloader will boot the one on slot1.