After downloading one of the Mender demo images or Building a Mender Yocto Project image for the first time, you need to write the storage image to the flash of the device.
sdimg generator, which is part of meta-mender, generates disk images with exactly four partitions: one boot, two rootfs and one data partition. It is intended as a reference implementation for testing and simple production use. For more advanced use cases, please refer to your board's tools for generating disk images and flashing storage, such as
You need an image file to flash to the entire storage of the
meta-mender-core creates these files with a
suffix, so they are easy to recognize. This file contains
all the partitions of the given storage device, as
described in Partition layout.
In this initial provisioning you will flash and overwrite everything on the given device storage.
There are several methods to flash storage, and the simplest
case is if your device uses a SD card. Currently, this is the approach
we assume you take here, but the same
.sdimg file can be used
to flash any block device. See
Flash memory types
for a clarification of what is meant by block device in this context.
Be careful! If you point to the wrong
<DEVICE> when executing the command below, you risk overwriting your workstation's local or connected storage devices.
Assuming you are in the same directory as your
.sdimg, you can write the sdimg to the SD card using the following command:
sudo dd if=<PATH-TO-IMAGE>.sdimg of=<DEVICE> bs=1M && sudo sync
This may take a few minutes, depending on the size of the image.