Bootloaders and DFU

Depending on the device, you need to use different bootloader and DFU solutions:

• For the nRF54H Series, use Software Updates for Internet of Things (SUIT). The SUIT procedure is the only supported bootloader and Device Firmware Update (DFU) procedure for this device.

• For the remaining Nordic Semiconductor devices, use MCUboot and nRF Secure Immutable Bootloader (NSIB).

See the following diagram and table for further comparison.

MCUboot, SUIT, and nRF Secure Immutable Bootloader architecture comparison

Characteristic	MCUboot	SUIT	nRF Secure Immutable Bootloader
Primary function	Bootloader and DFU	Flexible, script-based DFU system	Secure Immutable Bootloader
Customization	Built by users; partitions customized with Kconfig options and DTS. Kconfig and DTS configurable with multi-image builds or sysbuild. Becomes static post-compilation.	SDFW provided by Nordic, delivered in binary form. Customizable with manifests and configuration.	Limited; focused on initial boot security.
Slot management	Symmetrical primary and secondary slot style. Primary slot is where the system is executed from (by default). Secondary slot is the destination for the DFU (by default).	Single DFU partition; components act as slots. The DFU partition size can be located anywhere in the nonvolatile memory, accessible in the application core. Information about the location of the DFU is not hardcoded in the SDFW and can be changed between updates.	Not applicable for firmware updates.
Slot characteristics	Equal primary and secondary slot sizes lead to high memory overhead.	Single DFU partition with customizable component sizes.	Highly efficient due to immutable design.
Slot definition	Static definition; challenging to change post-deployment.	Technical possibility to change component definitions between updates.	Fixed and immutable; no post-deployment changes.
Invocation process	Limited customization through metadata.	Flexible customization within the manifest (metadata).	Authenticated firmware execution; no update mechanism post-boot.
Flash memory layout	Specific allocations for primary and secondary slots.	Single DFU partition with flexible component slots.	OTP regions for provisioned data; specific layout for boot and application partitions.

To learn more, refer to the following documentation pages:

Subpages:

• MCUboot and NSIB
  • Quick start guide
  • Enabling a bootloader chain using sysbuild
  • Enabling a bootloader chain using child and parent images (deprecated)
  • Secure bootloader chain
  • Partitioning device memory
  • Image versions
  • Customizing the bootloader
  • Signature keys
  • Downgrade protection
• Using QSPI XIP split image
  • Requirements
  • Network core image updates
  • Create the Partition Manager static files
  • Create a linker file
  • Set additional Kconfig options
  • Configure sysbuild
  • Relocate code to QSPI flash
  • Set QSPI flash initialization priority
  • Programming with the QSPI XIP split image
  • Firmware updates
  • File descriptions
• Command-line tool
  • Configuring the transport
  • Saving the connection configuration
  • General options
  • List of commands
  • Image management
  • Statistics management
  • Filesystem management
• MCUboot image compression
  • Sample
  • Required setup
• Sysbuild-assigned image IDs
  • MCUboot-only images
  • Getting image IDs in an application
  • Image numbers
  • MCUboot update package version