• Enterprise Platform Development
  • Pre-Requisites
  • Links
    • STM32L4
    • STM32F7
• Repository Structure
• Project Structure
  • L0 Lowlevel
  • L1 Third Party device dependent
  • L2 Drivers
  • L2 Board
  • L3 Functional third party library
  • L4 Modules
  • L5 Application
• Roadmap
  • Understanding your ARM Toolchain
  • Cross Compilation with Buildsystems
  • ARM Linker Script
  • Platform
  • RTOS
  • Languages
  • Debugging
  • Unit-Test
  • Mocking
  • Third Party Modules
  • Tool Integration

Enterprise Platform Development

• Developing an Enterprise-level Embedded software stack from scratch by identifying and integrating required components
• Flexibility and control over every part of Firmware development i.e from the Linker script level to the firmware application design.
• Use modern build systems (CMake and Meson) to make a IDE independent development environment to reduce cost of development and maintenance.
• Integrate tooling such as static analysis, clang-format, unit testing, mocking and debugging to improve the quality of code.

Download this PDF for a diagrammatic explanation.

Pre-Requisites

• arm-none-eabi-* GNU Toolchain
• CMake/Meson
• Ninja
• STM32CubeProgrammer
• OpenOCD
• VSCode Plugins
  • CMake
  • Cortex-Debug
  • C/C++

Links

STM32L4

• STM32 Website for B-L475E-IOT01A
• STM32L475_x examples use the B-L475E-IOT01A board

STM32F7

• STM32 Website for NUCLEO-F746ZG
• STM32F7ZG examples use the NUCLEO-F746ZG board

Repository Structure

• Baremetal
  • Low level Linker script and learning
  • Integrate critical external components to a project
• doc
  • Component datasheeets
  • Board schematics and microcontroller datasheets
• STM32_HAL
  • STM32 HAL based examples for various microcontrollers
• Template
  • Projects built after Minimal_CMSIS in Baremetal
  • Actual application level code with various levels of tooling support
  • Takes each core part of an embedded system and creates a project around it
• third_party
  • Third Party software ZIP files used in Template projects
• tools
  • Tools used by the project, pre-installed in your system
  • Links or ZIP files

Project Structure

Create a folder structure that would need minimal change when porting between different architectures and microcontrollers

To port our project to a different controller we would need to update these folders

• l0_lowlevel
• l1_third_party_device_specific
• l2_drivers

To port our project to a different board we would need to update these folders

• l2_board_specific
• l5_application

Platform independent code

• l3_functional_third_party
• l4_module (Design drivers that use the platform agnostic l2_drivers)

+-- l0_lowlevel
| +-- arm_cmsis
| +-- linker_script
| +-- device
| +-- toolchain_specific_syscalls
+-- l1_third_party_device_specific
| +-- RTOS
| +-- External_Libraries_device_specific
+-- l2_drivers
| +-- gpio_device_specific
| +-- uart_device_specific
+-- l2_board_specific
| +-- peripheral_initialization
+-- l3_functional_third_party
| +-- ring_buffer
+-- l4_module
| +-- sensors/actuators
| +-- technology
| +-- protocol
+-- l5_application
| +-- application_logic
| +-- main.c

L0 Lowlevel

• ARM CMSIS 5 has different compiler and architecture specific changes
• ARM CMSIS 5 Linker script is dependent on architecture of microcontroller
• Device Header is dependent of the Microcontroller Manufacturer
• Device Startup is dependent on ARM Architecture and Microcontroller Manufacturer

L1 Third Party device dependent

• Certain Third Party software changes its behaviour based on the architecture and device
• For example: FreeRTOS needs to be configured differently according to different microcontroller family and architectures

L2 Drivers

• Basic drivers for GPIO, Interrupt Handing
• Basic protocol for UART, SPI, I2C
• These are microcontroller and architecture dependent

L2 Board

• For internal board_specific initialization
• Syscalls based externed functions

L3 Functional third party library

• Functional Third Party code integrated into the project
• For example: Ring Buffer, JSON Library

L4 Modules

Writing code for various hardwares i.e

• Communication
• Sensors
• Actuators

L5 Application

• Application Logic for the project
• main.c resides on the top level

Roadmap

Understanding your ARM Toolchain

• arm-none-eabi-*
• clang for ARM

Cross Compilation with Buildsystems

• CMake
• Meson
• Bazel
• Premake
• Scons

ARM Linker Script

• Custom Linker Script
• Custom Startup
• Integrate CMSIS Linker Script
• Integrated CMSIS Startup

Platform

• CMSIS_5
• STM32 HAL

RTOS

• Amazon FreeRTOS
• Microsoft ThreadX

Languages

• C
  • Baremetal
  • Basic Driver
  • RTOS
  • Unit Testing
  • Design
  • Tooling
• C++
  • Baremetal
  • Basic Driver
  • RTOS
  • Unit Testing
  • Design
  • Tooling
• Rust
  • Baremetal
  • Basic Driver
  • RTOS
  • Unit Testing
  • Design
  • Tooling

Debugging

• openOCD
• arm-none-eabi-gdb
• Semihosting

Unit-Test

• Unity
• CppUTest
• Google Tests
• Catch

Mocking

• Fake Function Framework (FFF)
• CMock
• CppUMock
• Google Mock

Third Party Modules

• Ring Buffer
• JSON Parser

Tool Integration

• Clang Format
• Static Analysis
• Code Coverage
• Continuous Integration
• Documentation Generator