How large is the size peer manager uses?

[Haruki Kawakami]

I'm trying to determine DFU_APP_DATA_RESERVED and FDS_VIRTUAL_PAGES. According to this Q&A, DFU_APP_DATA_RESERVED must be the same FDS_VIRTUAL_PAGES, if FDS_VIRTUAL_PAGE_SIZE is 1024.

My application uses 11 pages, so 11+the size peer manager uses must be FDS_VIRTUAL_PAGES( and DFU_APP_DATA_RESERVED). Is this right?

However, I cannot find how large size peer manager uses is.

Would you tell me the size?

[Petter Myhre]

Where did you get "if FDS_VIRTUAL_PAGE_SIZE is 1024" from?

Do you want to reserve your complete application? Don't you just wanted to reserve the part of flash that FDS uses?

You should find the value of FDS_VIRTUAL_PAGES in your application, you can search for it, but usually it is found in sd_config.h, and unmodified the value is 3. Then DFU_APP_DATA_RESERVED should be set to 3.

[Haruki Kawakami]

I can define 1024 or 2048 for FDS_VIRTUAL_PAGE_SIZE, right? I choose 1024, and this is the same as CODE_PAGE_SIZE in nrf_dfu_types.h.

I want to preserve complete application data on DFU. And I know 11 pages are used for my application data, but it is not clear how much pages peer manager uses. I want to preserve both my application data and peer database.

So please tell me how much pages peer manager uses.

[Petter Myhre]

Yes, correct.

I see. You are storing your application data in flash, but you are not using FDS to do it. If you are using the 11 pages below FDS. And you haven't modified FDS_VIRTUAL_PAGES (3) or FDS_VIRTUAL_PAGE_SIZE (1024) you should set DFU_APP_DATA_RESERVED to 14.

Please be aware that this only works if you application data is stored in the 11 pages below the flash area FDS is typically using.

[Haruki Kawakami]

I'm using FDS to store my application data.

But still DFU_APP_DATA_RESERVED and FDS_VIRTUAL_PAGES should be 14?

[Petter Myhre]

Ok.

FDS_VIRTUAL_PAGES should be whatever you set it to. I can't tell you how many flash pages you need to store you application data in addition to other data (the Peer Manager uses FDS to store bond information for example). Please be aware that this is a file system, it is not 11 pages for application and 2 pages for Peer Manager, they share 13 pages of flash (if FDS_VIRTUAL_PAGES is set to 14 (one page is swap page)).

DFU_APP_DATA_RESERVED should be set equal to FDS_VIRTUAL_PAGES yes.