Bootloader support


This section describes the support level of the two bootloaders that Mender supports, GRUB and U-Boot.

By default, Mender uses GRUB to boot, and this is the recommended bootloader to use, even on platforms that ordinarily use U-Boot. However, U-Boot can be used in cases where using GRUB is not possible or unsuccessful.

On platforms using Raw flash (UBI), it is only possible to use U-Boot.

The main technical reason for using GRUB rather than U-Boot is that GRUB requires no patching to work with Mender, whereas U-Boot does. For most users this will be the path of least resistance.

Please see the sub sections for GRUB and U-Boot for more details.


Below is a table listing the bootloader support using various device types. All versions of the Mender client software, as well as the rootfs-image update modules, will work with either of the two bootloaders.

Feature Supported
GRUB integration for ARM systems Yes, default
GRUB integration for Flash/UBI devices No
GRUB integration for x86/UEFI systems Yes, default
GRUB integration for x86/BIOS systems Yes
U-Boot integration for ARM systems Yes
U-Boot integration for Flash/UBI devices Yes

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