SVC Number

[BricoFlo]

Hello, 

i'm trying to understand how nrf52 and softdevice work to use it in the future, i'm working on STM32 and i have my own RTOS, i try to appropriate the platform by porting my rtos on nrf52.

I didn't find any documentation on how should i retrieve the SVC number when called by soft device : when SVC is called on cortex core i know that SVC number can be obtained by reading the instruction but with the softdevice as this is redirected i don't know how i can obtain that number.

[Vidar Berg]

Hello,

All SVC numbers that the application uses to interface with the Softdevice are handled inside the Softdevice. The Softdevice uses a separate SW interrupts to notify the application of various Softdevice events.

This is explained in more detail in the "Supervisor call interface" chapter of the SDK documentation and the "Application programming interface" section in the SDS.

I would suggest taking a look at the Heart Rate Application with FreeRTOS example from the nRF5 SDK to maybe get an overview of what's required to use the Softdevice with an RTOS.

[BricoFlo]

I already read the Supervisor Call interface chapter of the SDK but for numbers not intercepted by Softdevice and redirected to my SVC handler, how can i get the SVC Number if available ? 

[Vidar Berg]

It will be forwarded to the SVC_Handler in your application If the number was not in the Softdevice's SVC range.

[BricoFlo]

by a function parameter ? meaning that i have one parameter used for this, so not usable as other M4 ?

[Vidar Berg]

The app gets notified of the SVC through an interrupt regardless if the Softdevice is present or not. The difference is the SVC interrupt gets routed through the Softdevice first.