| title | taxonomy | ||
|---|---|---|---|
Bootloader support |
|
This section describes the support level of the two bootloaders that Mender supports, GRUB and U-Boot. It is assumed that Yocto is the build system used to build the device images.
Below is a table listing the bootloader support using various device types and Yocto Project releases. All versions of the Mender client software will work with either of the two bootloaders.
| Feature \ Yocto Project version | Older than 2.4 (rocko) | 2.4 (rocko) | 2.5 (sumo) | 2.6 (thud) and later |
|---|---|---|---|---|
| GRUB integration for ARM systems | No | No | Yes | Yes, default |
| GRUB integration for Flash/UBI devices | No | No | No | No |
| GRUB integration for x86/UEFI systems | No | Yes, default | Yes, default | Yes, default |
| GRUB integration for x86/BIOS systems | No | No | Yes | Yes |
| U-Boot integration for ARM systems | Yes, default | Yes, default | Yes, default | Yes |
| U-Boot integration for Flash/UBI devices | Partial1 | Partial1 | Yes | Yes |
1 Flash/UBI support is possible in the rocko branch and older, but it is a lot of manual work and not streamlined, which is why the support is marked as partial. We recommend moving to a more recent branch if possible.
If you are just starting out, we recommend trying GRUB integration first, if possible. We recommend moving to U-Boot integration only if integration with GRUB is not possible or unsuccessful.
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.