Impact on Secure Serial DFU if there is change in Flash and Ram address

[beemavishnu]

Hello,

 

I am using nRF52840 S140 v7.0.1 and using ble_app_blinky. I have a query on Secure Serial DFU if there is a change in Flash and Ram address.

 In original example code below are the macros.

 

FLASH_START=0x27000

FLASH_SIZE=0xd9000

RAM_START=0x20002300

RAM_SIZE=0x3dd00

 

After adding our code, we need to modify macro to

 

FLASH_START=0x27000

FLASH_SIZE=0xd1000

RAM_START=0x20002A20

RAM_SIZE=0x3D5E0

 

Because of this will it cause any issue if we do Secure Serial DFU on original binary with latest package with changed FLASH_SIZE and RAM_SIZE macros.

 

Thanks & Regards

Vishnu Beema

[Hung Bui]

Hei Vishnu, 
The RAM modification wouldn't have anything to do with the DFU because the application won't run at the same time as the bootloader. 
Regarding the FLASH modification , so in your application you reduce the Flash size ? Do you have any reason to do so ? 
Changing that wouldn't affect the DFU process neither, but I'm not very certain why you want to change the flash size. 

Note that if you plan to have the bootloader you need to recalculate the maximum flash size to avoid that the application area overlap the bootloader area.