NRF52832 RAM Integrity Check with Bootloader and Soft Device

[Greg Nowak]

I'm working on a medical device that is using the NRF52832 chipset for communication.  One of the tests that I'm required to perform on startup is a RAM check. 

On the other processors in my system I have "free reign" over memory in the bootloader to perform said RAM integrity check.  

My question is:

Has anyone written a RAM integrity check for the NRF52832?  

How are the RAM regions effected by having a soft device enabled in the system?  

Is there any way to check the RAM that the soft device is using without messing up the soft device execution?  

Generally speaking these tests are performed in the bootloader prior to launching the application.  I'm using a bootloader and I'd like to add my code to the startup sequence prior to launching the application.  

[Kenneth]

Hi,

You have full access (only 8bytes reserved) to the entire RAM before the softdevice is enabled run-time (after softdevice enabled then the softdevice will allocate/reserve much of the RAM for it's usage):
https://www.nordicsemi.com/DocLib/Content/SoftDevice_Spec/s132/latest/SDS/s1xx/mem_usage/mem_resource_reqs 

I am not aware of any RAM integrity check routine in specific, but it should be possible to write and read zeros/ones to the entire RAM and readback as you see fit in the beginning of the bootloader (before the softdevice is enabled run time). The 8 first bytes should have a fixed value before softdevice is enabled, so you can also readback and check that these values are correct in the bootloader.

Best regards,
Kenneth