This repository implements an entirely manually-written, pure bare metal Blinky Project for the STM32H7A3ZIT6Q (NUCLEO-144-H7A3).
Features include:
- CPU, power, chip, clock and PLL initialization,
- D/I cache and FPU initialization,
- timebase derived from SysTick,
- blinky LED show on three bits,
- implementation in C11/C++20 with absolute minimal use of assembly.
This project also includes a straightforward sample C++ class implementation and instantiation. This is used to exhibit a mixed-language C/C++ application.
A clear and easy-to-understand build system based on GNUmake completes this fun and educational project.
This repository provides keen insight on starting up a bare metal ARM(R) Cortex(R)-M7 controller.
The application boots from memory address and stack location in the first two entries of the interrupt vector table. Subsequent initialization brings the CPU up to full speed at 280 MHz with the appropriate number of flash-access wait states.
Following low-level chip initialization, the program jumps to
the main() subroutine. Here the data and instruction caches
are initialized to produce full CPU performance capabilities
of the microcontroller.
The blinky LED show utilizes three LED ports to count in binary in a visual fashion. The SysTick interrupt is enabled to provide the timebase for the blinky LED show, with the LED toggling action in the interrupt handler.
Build on *nix* is easy using an installed gcc-arm-none-eabi
cd Blinky_Nucleo_H7A3
bash Rebuild.shThe build results including ELF-file, HEX-mask, MAP-file
and assembly list file are created in the Outputdirectory.
If gcc-arm-none-eabi is not installed, it can easily
be installed with
sudo apt install gcc-arm-none-eabiCI runs on pushes and pull-requests with a simple
build and result verification on ubuntu-latest
using GutHub Actions.