Although it is possible to compile and install Mender independently, we have optimized the installation experience for those who build their Linux images using Yocto Project.
Mender's meta layer, meta-mender, has several branches that map to given releases of the Yocto Project. However, note that Mender is tested and maintained against the latest release branch of the Yocto Project only. Older branches for the Yocto Project are still kept in meta-mender, but they might not work seamlessly as they are not continuously tested by Mender. We appreciate community contributions to help maintain older branches!
Mender has no official support for other build systems. However, by following the right steps, it is possible to adapt other build systems to Mender's needs. Please see this blog post for an example (note that some of Mender's needs may have changed since the blog post was made).
The client binaries, which are written in Go, are around 7 MiB in size.
Our physical reference device, the BeagleBone Black, comes with a 1 GHz ARM Cortex-A8 processor, with 512 MiB of RAM. Mender also has a virtual QEMU-based reference device using the
vexpress-qemu machine type. We use both these devices in our continuous integration process so they are well supported.
To support atomic rootfs rollback, Mender integrates with the bootloader of the device. Currently Mender supports U-Boot.
As Mender relies on the
CONFIG_BOOTCOUNT_ENV feature of U-Boot, which was introduced in October 2013, Mender currently recommends U-Boot v2014.07 or newer. If you have an older version of U-Boot, it is possible to apply some extra patches to make this work. Please see the section about U-Boot versions without BOOTLIMIT support for more information.
Besides any special configuration to support the device, U-Boot needs to be compiled and used with the following features:
Support for modifying U-Boot variables from user space is also required so that fw_printenv/fw_setenv utilities (from u-boot-fw-utils) are available in user space. These utilities can be compiled from U-Boot sources and are part of U-Boot.
Please see Integrating with U-Boot for more information.
While Mender itself does not have any specific kernel requirements beyond what a normal Linux kernel provides, it relies on systemd, which does have one such requirement: The
CONFIG_FHANDLE feature must be enabled in the kernel. The symptom if this feature is unavailable is that systemd hangs during boot looking for device files.
Please see Partition layout.
Certificate verification requires the device clock to be running correctly at all times. Make sure to either have a reliable clock or use network time synchronization. Please see certificate troubleshooting for more information about the symptoms of this issue.