Flash usage

RE: Flash usage

Hung Bui — Wed, 23 Jan 2019 10:01:56 GMT

Hi Radu,

When you updating the softdevice and application, you need to update the softdevice first and then the application. What happens is that the new application may not work with the old softdevice so you can't verify that it works or not. The suggested process should be: softdevice -> bootloader -> application.

RE: Flash usage

qweqwe12 — Tue, 22 Jan 2019 16:22:50 GMT

Thank you for the reply.

I think I understand now. For this application to function proprely, it also needs to use the binary softdevice and the total combined is what I had in my first post.

Concerning DFU over the air, would I be able to update the application first in the swap bank, do the update and make sure it works, then update softdevices if there is ever a change to it also? I'm asking because this way it would require a smaller swap bank than updating everything at once (softdevice + app.)

Thanks

RE: Flash usage

Hung Bui — Tue, 22 Jan 2019 15:04:50 GMT

Hi Radu,

What you see in the flash/ram usage when compiling is including the softdevice. If you compile using cmake you would see the actual size of the application.

In Project Common setting -> Linker-> Section Placement Macros you can find FLASH_START = 0x26000. This is the start address of the application. If you take the total size minus the start address of the application you will have the size of the application. Same applied for RAM. Please make sure you compile with Release version, not Debug one.

When doing DFU over the air, the bootloader will store the new image in the swap bank when keeping the application running. The full image will be store in the swap area.

It's possible to do single bank update with our bootloader. But then the application will be erased before the image being received, interrupting the normal operation of the network.