Adding one more FDS record once device deployed over DFU

Question

Hello, 
 
 I am using nRF52840, SDK_16.0.0, SoftDevice S140 V7.0.1 and Segger for flashing the image. I am using ‘ble_app_blinky’. 
 
 Assume I have one FDS record. With this binary, we released devices to field. 
 Later we want to add few more FDS records. We will generate new DFU package with increased FDS records. 
 Using DFU will there be impact in case: 
 
 1) Without changing number of pages FDS_VIRTUAL_PAGES, if I just increase number of records and do DFU will there be any issues. 
 2) How about changing number of pages FDS_VIRTUAL_PAGES. 
 
 Will it cause any problem in re-constructing the FDS records after device reset. 
 
 Thanks & Regards 
 Vishnu Beema

Vidar Berg · Accepted Answer

Hello Vishnu , 
 Later we want to add few more FDS records. We will generate new DFU package with increased FDS records. 
 Assume the records are written at runtime by the new app, and not included in the FW image? The application can store as many records it wants as long as there is free space available. 
 You can increase FDS_VIRTUAL_PAGES, but then you should also make sure to increase the reserved app data region inside the bootloader to ensure it doesn't overwrite FDS pages during DFU. See Memory layout 
 Best regards, 
 Vidar

Vidar Berg · Answer

Hello, 
 1. Sorry, not sure I understand what you mean. FDS will never attempt to overwrite an existing record. FDS documentation for reference: Flash Data Storage 
 2. Yes, it's the NRF_DFU_APP_DATA_AREA_SIZE you need to modify. But note that 1024 is the page size in 4-byte words while NRF_DFU_APP_DATA_AREA_SIZE defines the number of bytes to reserve. 12288 / 4096 = 3 flash pages. 
 3. Yes. 
 4. It should be fine as long as your application handles variable payload lengths for this particular record. 
 Best regards, 
 Vidar

Vidar Berg · Answer

Hi, 
 Yes, you can add new records before and after DFU. 
 Best regards, 
 Vidar

Adding one more FDS record once device deployed over DFU

Top Replies