Toolchain setup

Install Homebrew package manager (for MAC)

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install OpenOCD for ST-Link Debugging

brew install openocd

Install ARM Embedded Toolchain

# not sure about the brew tap, but it works.
brew tap PX4/homebrew-px4
brew update
brew install gcc-arm-none-eabi
arm-none-eabi-gcc --version

Install VSCode

VSCode Extensions

• C/C++ C/C++ for Visual Studio Code
• Cortex-Debug ARM Cortex-M GDB Debugger support for VSCode

Project Setup

Create a new folder for you project and structure it like this:

MyProject/
    .vscode/
    app/
        Inc/
            main.h
        Src/
            main.cpp
    Makefile
    README.md

add the ok-STM32F4 repo as a submodule to your new project

git submodule add https://github.com/scottc11/ok-STM32F4.git
git submodule init
git submodule update

Your new project needs its own make Makefile which includes the ok-STM32F4 Makefile. It should look something like this:

######################################
# target
######################################
TARGET = my-project-name

FLASH_SIZE = $$((256 * 1024)) # 256 kB (Sector 6 and 7 used for config data)
RAM_SIZE = $$((128 * 1024)) # 128 kB

######################################
# building variables
######################################
# debug build?
DEBUG = 1

SERIAL_DEBUG ?= 0

#######################################
# paths
#######################################
# Build path
BUILD_DIR = build
LIB_PATH = ok-STM32F4


CPP_SOURCES += $(shell find app -name '*.cpp')

# C includes
C_INCLUDES += \
-Iapp/Inc \
-Iapp/Tasks/Inc

include $(LIB_PATH)/Makefile

Making changes to git submodules

First, cd into the submodule directory and checkout a new branch with git checkout -b myBranchName

You can now commit changes and push to the remote

USB Bootloader

No external pull-up resistor is required

Bootloader ID: 0x90

Memory location: 0x1FFF76DE

Install dfu-util

brew install dfu-util

To enter bootloader mode, hold down BOOT, then, hold down RESET. Release RESET button (before releasing BOOT)

Run dfu-util -l and you should see the following output:

dfu-util 0.11

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2021 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Found DFU: [0483:df11] ver=2200, devnum=2, cfg=1, intf=0, path="64-1.2", alt=3, name="@Device Feature/0xFFFF0000/01*004 e", serial="STM32FxSTM32"
Found DFU: [0483:df11] ver=2200, devnum=2, cfg=1, intf=0, path="64-1.2", alt=2, name="@OTP Memory /0x1FFF7800/01*512 e,01*016 e", serial="STM32FxSTM32"
Found DFU: [0483:df11] ver=2200, devnum=2, cfg=1, intf=0, path="64-1.2", alt=1, name="@Option Bytes  /0x1FFFC000/01*016 e", serial="STM32FxSTM32"
Found DFU: [0483:df11] ver=2200, devnum=2, cfg=1, intf=0, path="64-1.2", alt=0, name="@Internal Flash  /0x08000000/04*016Kg,01*064Kg,03*128Kg", serial="STM32FxSTM32"

Using dfuse-pack.py (not yet tested)

This file was pulled from the dfu-util repo, and is meant to convert .hex files into .dfu files. Note: Make sure you have the IntelHex python module installed.

Using a .bin file (tested and working)

dfu-util -a 0 -s 0x08000000:leave -D ./path/to/file.bin

GCC Reference:

The __attribute((unused)) is a gcc attribute to indicate to the compiler that the argument args is unused, and it prevents warnings about it.

Preventing compiler optimazation for debugging

Use this __attribute__((optimize("O0"))) to disable optimizations for a function. ex.

void __attribute__((optimize("O0"))) myFunc()
{
    // this will not be optimized
}