nRF52832 Bootloader at end of Flash memory

[beemavishnu]

Hello,

In below link, I am bit confused between “With bootloader” and “Without bootloader”. What for this bootloader.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.3.0%2Flib_fstorage.html

 

But as per SoftDevice Memory usage, I am seeing only “Master Boot Record”.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.3.0%2Flib_fstorage.html

 

I want to write data records into Flash. To be safe side I am trying to understand what for “Bootloader” at end of Flash, so that I don’t what to corrupt. Also I loaded “ble_app_blinky” (ble_peripheral) and in Memory layout I am not seeing any Bootloader at end of Flash.

Thanks & Regards

Vishnu Beema

[Sigurd]

Hi,

Using a bootloader is optional, if you don't use one, the FDS/fstorage will storage the data records at the end of flash. If you use a bootloader, fstorage/fds will store the data below the bootloader area. Ths fds detects if there is booloader present or not in a internal function called flash_bounds_set(), so you don't need to manually configure that.

[beemavishnu]

Hi,

In my code I am using both "Flash Storage" and "Flash Data Storage".

1) Assume there is no boot loader, but as part of nrf_fstorage_init(), in 'fstorage' we give start & end address of Flash. Whether this will reserve flash between Start & End.

2) Assume start & end in fstorage as 96th page start address and 128th page End address. Later if I initialize fds_init() whether data records are stored below 96th page or it will overlap fds records with fstorage.

Thanks & Regards

Vishnu Beema

[Sigurd]

1) 

beemavishnu said:

Whether this will reserve flash between Start & End.

That is where in flash that instance of fstorage will store data. BUT, fstorage makes no effort to ensure that different instances operate on non-overlapping flash memory regions. It is up to the users to ensure that their usage of the module does not disrupt others'.

beemavishnu said:

2) Assume start & end in fstorage as 96th page start address and 128th page End address. Later if I initialize fds_init() whether data records are stored below 96th page or it will overlap fds records with fstorage

Yes, you will get overlap. The fstorage instance that fds uses as backend will not be aware of the other fstorage instance.(FDS will by default use the 3 last pages(FDS_VIRTUAL_PAGES) in this case.)

[beemavishnu]

Thank you for your inputs.

Yes, its getting overlapped. I tested and I am getting FDS_ERR_NO_SPACE_IN_FLASH error.