The following figure describes the firmware structure that integrates the Amazon Sidewalk protocol stack and enables Amazon Sidewalk connectivity for the end device. The Platform Abstraction Layer assures communication between Silicon Labs Gecko SDK and the Amazon Sidewalk protocol stack. The developer creates applications on top of the stack, which Silicon Labs provides as a precompiled library.
The Amazon Sidewalk stack contains the following blocks:
Application Layer Library: Contains API call definitions to be used in application development.
BLE Network Interface: Contains Amazon Sidewalk-specific configuration for the Bluetooth LE (BLE) link layer.
Sub-GHz Network Interface: Contains Amazon Sidewalk-specific configuration for sub-GHz link layer and Semtech drivers.
MAC Layer: Amazon Sidewalk implementation of the MAC layer.
The following software components are used by the stack:
FreeRTOS: Used as a base to run the stack.
PSA crypto: Used for all cryptographic operation.
BLE stack: Used to access the BLE stack.
SPI driver: Used only in sub-GHz-enabled applications, for communication with a third-party sub-GHz radio module.
RAIL: Used to access the radio and high-precision timers.
Amazon Sidewalk extension contains three library files: one for the Sidewalk stack, one for the BLE stack and the last one for the Semtech chip driver. The Silicon Labs Platform Abstraction Layer is available in source in the extension.