This topic shows how to quickly deploy a customized kernel and/or device tree to your target device.

The methods explained in this topic are for manual deployment during the development phase. For production-ready firmware updates see:

After customizing the kernel source code, you may have built just the kernel recipe or a full Digi Embedded Yocto image recipe.

Program single files

If you built only the kernel recipe, you can find the kernel binary and device tree blobs in the tmp/deploy/images/ccmp15-dvk/ folder of your project. You can deploy these single files to your linux_a partition, which is formatted in UBIFS file system.

Update files from the operating system

The linux_a partition is automatically mounted to /mnt/linux, but as a read-only file system.

  1. Remount the linux_a partition with read/write permissions:

    # mount -o remount,rw /mnt/linux_a

  2. Copy the kernel file, device tree blob, or device tree overlay, from the development computer to the target, for example via SSH:

    $ scp tmp/deploy/images/ccmp15-dvk/zImage-ccmp15-dvk.bin root@<ccmp15-IP>:/mnt/linux_a/
$ scp tmp/deploy/images/ccmp15-dvk/your-platform.dtb root@<ccmp15-IP>:/mnt/linux_a/
$ scp tmp/deploy/images/ccmp15-dvk/your-dt-overlay.dtbo root@<ccmp15-IP>:/mnt/linux_a/

  3. Run sync on the target to make sure Linux writes the changes to the file system:

    # sync

  4. Reboot the target to load the new files.

    U-Boot loads:

    • the kernel file pointed to by environment variable zimage

    • the device tree pointed to by variable fdt-file

    • the device tree overlays in variable overlays

    Check if you need to change the values of these U-Boot variables to point to your new files.

Program image files (full partition update)

If you built a full image recipe (dey-image-webkit, for example), Digi Embedded Yocto generates an image file for the linux_a partition, such as dey-image-webkit-wayland-ccmp15-dvk.boot.ubifs.

  1. Place the image file into your TFTP exposed folder. You can alternatively use an external media, such as a USB disk or a microSD card.

  2. Boot the target and press any key to stop the automatic U-Boot boot process.

  3. Run the update command to update the entire linux_a partition, for example via TFTP:

    => update linux_a tftp <image-filename>

See Program images from U-Boot for additional information on updating from U-Boot.