Board memory layouts

This page documents the RRAM (flash) and SRAM partition layouts for supported bm_* board configurations. Use the three-level tabs (DK → SoC → SoftDevice) to view layouts for each combination. Each diagram shows the partitions from low address (bottom) to high address (top), with hex addresses on the left and sizes on the right.

The diagrams are auto-generated from the board devicetree sources by doc/_scripts/gen_memory_layouts.py. Re-run that script when the devicetree files change:

python doc/_scripts/gen_memory_layouts.py

Partition descriptions 

The diagrams use descriptive names. The table below maps each to the devicetree partition label and describes its role.

RRAM partitions 

Partition (diagram)	DTS label	Description
MCUboot	`boot`	MCUboot bootloader image. Present only in MCUboot configurations.
Storage: Peer Manager	`peer_manager`	Persistent storage for Bluetooth bonding and peer data.
Storage: User data	`storage0`	General-purpose non-volatile storage using BM ZMS.
Application	`slot0`	Main application firmware image.
Firmware Loader	`slot1`	Firmware loader / secondary slot for DFU. Present only in MCUboot configurations.
SoftDevice	`softdevice`	Nordic SoftDevice Bluetooth LE stack binary.
Metadata	`metadata`	MCUboot metadata region. Present only in MCUboot configurations.

SRAM partitions 

Partition (diagram)	DTS label	Description
KMU reserved	—	128 bytes reserved by the Key Management Unit at the start of SRAM (synthetic region, no partition label in DTS).
SoftDevice RAM	`softdevice_ram`	Allocated RAM for the SoftDevice. Consists of SoftDevice static RAM with a size depending on the SoftDevice variant (S115 vs S145) and SoftDevice Dynamic RAM with a size depending on the number of connections and required buffer sizes.
Application RAM	`app_ram`	RAM available for the application.
Retained RAM	`RetainedMem`	Retained memory region for MCUboot settings persistence across resets. Present only in MCUboot configurations.