DFU lock utility

The DFU lock utility provides a synchronization mechanism for accessing the DFU non-volatile memory. It is needed for application configurations that support more than one DFU transport.

The DFU lock utility provides a basic synchronization API for all declared DFU owners. Each DFU owner can be declared using the dfu_lock_owner structure. The dfu_lock_claim() function is used to claim ownership over the DFU non-volatile memory. This function returns an error if the lock has already been taken by another DFU owner. The dfu_lock_release() function is used by the current owner to release the DFU non-volatile memory when it is no longer used. This function returns an error on the release attempt that is not triggered by the current owner. The dfu_lock_owner.owner_changed callback is used to indicate the change in ownership. The previous owner can use this callback for tracking the DFU non-volatile memory status and the need to erase it before subsequent DFU attempts.

Note

The nRF Desktop DFU transports must voluntarily take lock before accessing the non-volatile memory and release it after they stop using it. The DFU lock utility does not provide any protection against the DFU transport module that writes to the non-volatile memory without taking a lock.

Configuration

Use the CONFIG_DESKTOP_DFU_LOCK option to enable the utility.

Currently, the DFU lock utility is automatically used if you enable both supported DFU transports in your application:

• CONFIG_DESKTOP_CONFIG_CHANNEL_DFU_ENABLE

• CONFIG_DESKTOP_DFU_MCUMGR_ENABLE

You can adjust the logging level of this utility by changing the CONFIG_DESKTOP_DFU_LOCK_LOG_LEVEL Kconfig option.

Implementation details

The DFU lock utility uses the Mutexes for synchronizing updates to its internal state.

API documentation

Header file: applications/nrf_desktop/src/util/dfu_lock.h

Source files: applications/nrf_desktop/src/util/dfu_lock.c

DFU Lock API