nRF5340 exchange datas between applacation core and net core

[Deang]

Recently I develop products on nRF5340, I plan to make the full BLE stack run in the net-core, and app-core only runs application. It involves data exchenge between net-core and app-core, which may be the most difficult part.

So I have the following questions:

1. Is the scheme effective?

2. How to implement the scheme?

3. Is there the relevant documents description?

3 What is the relevance between openAMP and RPC?

[Vidar Berg]

Hello,

1. Is the scheme effective?

 It should be, but please note that this architecture is currently only supported for development as noted here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_nrf5340.html#bluetooth-low-energy. This means that the feature lacks test coverage, and that there may be missing functionality.

2. How to implement the scheme?

 I would recommend you start with the Host nRF RPC sample: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/rpc_host/README.html#ble-rpc-host

3. Is there the relevant documents description?

 Yes, please see link above.

3 What is the relevance between openAMP and RPC?

 It's openAMP that facilites communication between the cores (https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_nrf5340.html#inter-core-communication). nRF RPC uses openAMP as the transport layer.

Best regards,

Vidar

[Deang]

Hi Vidar,

Thanks for the reply.

Now, it worked that exchanging data between application core and net core via openAMP, and I understood the principle of RPC. But there are some problems I haven't figured out yet.

When using RPC to call remote CPU functions, the memory allocated by NRF_RPC_CBOR_ALLOC is used to cache the encoded command and paramters. If the parameter of the function is a lots of data, it would need to allocate  much memory to accommodate the data. Is there any other way to achieve this? Is it work to copy the data to the shared memory area?

[Vidar Berg]

Hi,

NRF_RPC_CBOR_ALLOC allocates memory from stack and automatically frees it once the data has been passed to the send function (openAMP). Is the stack usage a concern?

Deang said:

Is it work to copy the data to the shared memory area?

Yes, correct.