Setting DFU_APP_DATA_RESERVED

Question

I am struggling with the correct value to use for DFU_APP_DATA_RESERVED in the bootloader. My application uses the Device Manager and has one block allocated for to pstorage. I know i need to account for my pstorage block but do I need to account for the space used by DeviceManager and the swap block? If so how do I determine the number of blocks reserved by Device Manager? 
 Thanks,
Darren

Vidar Berg · Accepted Answer

The SWAP page must always be accounted for as it's always stored on top of the other pages. However, you only need to preserve the DM page if you wish to preserve the bonding information. 
 
 In case you only want to keep your application data you must make sure to have it allocated above the DM page. That you can control by registering your pstorage instance before initializing the DM module, documentation here . In this case you would have to preserve at least 2 pages depending on the size of your application data. 
 If you want to keep both you need to determine how much is allocated for the DM. This depends on the number of bonds, cccds, etc that is set in the DM config. It's typically one page, but you can check by multiplying ALL_CONTEXT_SIZE with DEVICE_MANAGER_MAX_BONDS.