platform

Introduction

These directories provide the implementation of the porting layer on supported SDKs/MCUs from various vendors. The platform/common directory contains anything that is common across platforms e.g. the platform/common/runner source code which allows any or all of the examples/tests to be run.

Also provided is a static_size "platform", which includes stubs for the porting layer and dummy configuration files in order that all of the ubxlib platform independent code can be measured for [static] flash/RAM size.

Supported MCUs

The MCUs supported by the platforms are as follows:

• Espressif ESP-IDF: ESP32.
• ST Microelectronics' STM32Cube IDE: STM32F4 and STM32U5.
• zephyr: we test NRF52/NRF53, STM32, NXP and also Linux/Posix for development purposes, but any MCU that is supported by Zephyr may work transparently.
• not really an MCU but windows is supported for development/test purposes.
• Linux: not an MCU but native Linux is supported.

In addition to the above, support is included for building certain frameworks as a ubxlib library under PlatformIO.

The following platform is DEPRECATED and will be REMOVED at release 1.5, likely mid 2024:

• Nordic nRF5 SDK on NRF52: please use zephyr instead.

Structure

Each platform sub-directory includes the following items:

• src: the .c files that implement the porting layer for the platform.
• app: the entry point, main(): configure the platform, start the RTOS and then run the chosen examples/tests in an RTOS task.
• u_cfg_os_platform_specific.h: task priorities and stack sizes for the platform, built into this code.
• mcu/<mcu>: build files and configuration files for the MCUs supported on the platform.
  • cfg: configuration defining which MCU pin is connected to which module pin both for normal operation and for testing, stack sizes, task priorities, etc. At least the following header files will be found for each platform:
    • u_cfg_app_platform_specific.h: information that is passed into the APIs from an application, e.g. defining what pin is connected to what.
    • u_cfg_test_platform_specific.h: as u_cfg_app_platform_specific.h but this time values to be used by the test application.
    • u_cfg_hw_platform_specific.h: HW definitions required by the platform and built into this code, e.g. which MCU HW blocks are used internally by the API
  • runner: build metadata that will build all of the unit tests and examples for the given MCU.