how to set the RAM start sddress of app and bootloader

[piepie]

I am working on OTA DFU about nRF52810. My refernece project are ble_app_uart\pca10040\s132 and bootloader_secure_ble\pca10040 I find that the RAM start address between are different. This is the start RAM address of APP:

This is the start RAM address of bootloader:

I am confusing why they are different? Is there anything I ignored? I am using SDK_14.0.0. How should I set the RAM start sddress of APP and bootloader? thx.

[Hung Bui]

@stayhungry: You may want to reduce the size of the bootloader by using our legacy bootloader instead of using the secured one. Of course, you will lose the signing feature of the bootloader. But the legacy one is only about 12kB.

In addition, you can do single bank update (automatically selected in the bootloader, if the image size is larger than max dual bank limit) instead of dual bank.

This mean you can have about 36kB for the application. And can update 36kB new image.

[Stayhungry]

Thanks，Hung Bui.

Where can I find the legacy bootloader information?

If I use single bank update, it means that the risk of damage to the firmware in the DFU process is considered?

How to calculate the APP space is 36KB? 192 (flash size) - 140 (softdevice) - 12 (legacy bootloader) - 4 (bootloader setting) = 36KB?

[Hung Bui]

Hi,

Legacy bootloader is the bootloader we supported from SDK v6 until SDK v11. It won't be compatible with your current application+softdevice if you are using newer SDK.

But you can port it to the latest SDK. I don't see any big issue porting that example to newer SDK (and newer Softdevice).

Yes, I simply calculate application size as what you wrote. It could be smaller if you want to reserver application data.

[Stayhungry]

Thank you very much, your help is very useful.