# About

![Tests](https://github.com/ObKo/stm32-cmake/workflows/Tests/badge.svg)

This project is used to develop applications for the STM32 - ST's ARM Cortex-Mx MCUs. 
It uses cmake and GCC, along with newlib (libc), STM32Cube. Supports F0 F1 F2 F3 F4 F7 G0 G4 H7 L0 L1 L4 L5 device families.

## Requirements

* cmake >= 3.13
* GCC toolchain with newlib (optional).
* STM32Cube package for appropriate STM32 family.

## Project contains

* CMake toolchain file, that configures cmake to use the arm toolchain: [cmake/stm32_gcc.cmake](cmake/stm32_gcc.cmake).
* CMake module that contains useful functions: [cmake/stm32/common.cmake](cmake/stm32/common.cmake)
* CMake modules that contains information about each family - RAM/flash sizes, CPU types, device types and device naming (e.g. it can tell that STM32F407VG is F4 family with 1MB flash, 128KB RAM with CMSIS type F407xx)
* CMake toolchain file that can generate a tunable linker script [cmake/stm32/linker_ld.cmake](cmake/stm32/linker_ld.cmake)
* CMake module to find and configure CMSIS library [cmake/FindCMSIS.cmake](cmake/FindCMSIS.cmake)
* CMake module to find and configure STM32 HAL library [cmake/FindHAL.cmake](cmake/FindHAL.cmake)
* CMake modules for various libraries/RTOSes
* CMake project template and [examples](examples)
* Some testing project to check cmake scripts working properly [tests](tests)

## Examples

* `template` ([examples/template](examples/template)) - project template, empty source linked compiled with CMSIS.
* `custom-linker-script` ([examples/custom-linker-script](examples/custom-linker-script)) - similar to `template` but using custom linker script.
* `fetch-cube` ([examples/fetch-cube](examples/fetch-cube)) - example of using FetchContent for fetching STM32Cube from ST's git.
* `fetch-cmsis-hal` ([examples/fetch-cmsis-hal](examples/fetch-cmsis-hal)) - example of using FetchContent for fetching STM32 CMSIS and HAL from ST's git.
* `blinky` ([examples/blinky](examples/blinky)) - blink led using STM32 HAL library and SysTick.
* `freertos` ([examples/freertos](examples/freertos)) - blink led using STM32 HAL library and FreeRTOS.

# Usage

First of all you need to configure toolchain and library pathes using CMake varibles. 
You can do this by passing values through command line during cmake run or by setting variables inside your CMakeLists.txt

## Configuration

* `TOOLCHAIN_PREFIX` - where toolchain is located, **default**: `/usr`
* `TARGET_TRIPLET` - toolchain target triplet, **default**: `arm-none-eabi`
* `STM32_CUBE_<FAMILY>_PATH` - path to STM32Cube directory, where `<FAMILY>` is one of `F0 G0 L0 F1 L1 F2 F3 F4 G4 L4 F7 H7` **default**: `/opt/STM32Cube<FAMILY>`

## Common usage

First thing that you need to do after toolchain configration in your `CMakeLists.txt` script is to find CMSIS package:
```
find_package(CMSIS COMPONENTS STM32F4 REQUIRED)
```
You can specify STM32 family or even specific device (`STM32F407VG`) in `COMPONENTS` or omit `COMPONENTS` totally - in that case stm32-cmake will find ALL sources for ALL families and ALL chips (you'll need ALL STM32Cube packages somewhere).

Each STM32 device can be categorized into family and device type groups, for example STM32F407VG is device from `F4` family, with type `F407xx`.

***Note**: Some devices in STM32H7 family has two different cores (Cortex-M7 and Cortex-M4).
For those device the name used must include the core name e.g STM32H7_M7 and STM32H7_M4.

CMSIS consists of three main components:

* Family-specific headers, e.g. `stm32f4xx.h`
* Device type-specific startup sources (e.g. `startup_stm32f407xx.s`)
* Device-specific linker scripts which requires information about memory sizes

stm32-cmake uses modern CMake features notably imported targets and target properties.
Every CMSIS component is CMake's target (aka library), which defines compiler definitions, compiler flags, include dirs, sources, etc. to build and propagates them as dependencies. So in simple use-case all you need is to link your executable with library `CMSIS::STM32::<device>`:
```
add_executable(stm32-template main.c)
target_link_libraries(stm32-template CMSIS::STM32::F407VG)
```
That will add include directories, startup source, linker script and compiler flags to your executable.

CMSIS creates following targets:

* `CMSIS::STM32::<FAMILY>` (e.g. `CMSIS::STM32::F4`) - common includes, compiler flags and defines for family
* `CMSIS::STM32::<TYPE>` (e.g. `CMSIS::STM32::F407xx`) - common startup source for device type, depends on `CMSIS::STM32::<FAMILY>`
* `CMSIS::STM32::<DEVICE>` (e.g. `CMSIS::STM32::F407VG`) - linker script for device, depends on `CMSIS::STM32::<TYPE>`

So, if you don't need linker script, you can link only `CMSIS::STM32::<TYPE>` library and provide own script using `stm32_add_linker_script` function

***Note**: For H7 family, because of it multi-cores architecture, all H7 targets also have a suffix (::M7 or ::M4).
For example, targets created for STM32H747BI will look like `CMSIS::STM32::H7::M7`, `CMSIS::STM32::H7::M4`, `CMSIS::STM32::H747BI::M7`, `CMSIS::STM32::H747BI::M4`, etc.*

Also, there is special library `STM32::NoSys` which adds `--specs=nosys.specs` to compiler flags.

## HAL

STM32 HAL can be used similar to CMSIS.
```
find_package(HAL COMPONENTS STM32F4 REQUIRED)
set(CMAKE_INCLUDE_CURRENT_DIR TRUE)
```
*`CMAKE_INCLUDE_CURRENT_DIR` here because HAL requires `stm32<family>xx_hal_conf.h` file being in include headers path.*

HAL module will search all drivers supported by family and create following targets:

* `HAL::STM32::<FAMILY>` (e.g. `HAL::STM32::F4`) - common HAL source, depends on `CMSIS::STM32::<FAMILY>`
* `HAL::STM32::<FAMILY>::<DRIVER>` (e.g. `HAL::STM32::F4::GPIO`) - HAL driver <DRIVER>, depends on `HAL::STM32::<FAMILY>`
* `HAL::STM32::<FAMILY>::<DRIVER>Ex` (e.g. `HAL::STM32::F4::ADCEx`) - HAL Extension driver , depends on `HAL::STM32::<FAMILY>::<DRIVER>`
* `HAL::STM32::<FAMILY>::LL_<DRIVER>` (e.g. `HAL::STM32::F4::LL_ADC`) - HAL LL (Low-Level) driver , depends on `HAL::STM32::<FAMILY>`

***Note**: Targets for STM32H7 will look like `HAL::STM32::<FAMILY>::[M7|M4]`, `HAL::STM32::<FAMILY>::[M7|M4]::<DRIVER>`, etc.*

Here is typical usage:

```
add_executable(stm32-blinky-f4 blinky.c stm32f4xx_hal_conf.h)
target_link_libraries(stm32-blinky-f4 
    HAL::STM32::F4::RCC
    HAL::STM32::F4::GPIO
    HAL::STM32::F4::CORTEX
    CMSIS::STM32::F407VG
    STM32::NoSys 
)
```

### Building

```
    $ cmake -DCMAKE_TOOLCHAIN_FILE=<path_to_gcc_stm32.cmake> -DCMAKE_BUILD_TYPE=Debug <path_to_sources>
    $ make
```

## Linker script & variables

CMSIS package will generate linker script for your device automatically (target `CMSIS::STM32::<DEVICE>`). To specify a custom linker script, use `stm32_add_linker_script` function.

## Useful cmake function

* `stm32_get_chip_info(<chip> [FAMILY <family>] [TYPE <type>] [DEVICE <device>])` - classify device using name, will return device family (into `<family>` variable), type (`<type>`) and canonical name (`<device>`, uppercase without any package codes)
* `stm32_get_memory_info((CHIP <chip>)|(DEVICE <device> TYPE <type>) [FLASH|RAM|CCRAM|STACK|HEAP] [SIZE <size>] [ORIGIN <origin>])` - get information about device memories (into `<size>` and `<origin>`). Linker script generator uses values from this function
* `stm32_get_devices_by_family(DEVICES [FAMILY <family>])` - return into `DEVICES` all supported devices by family (or all devices if `<family>` is empty)

# Additional CMake modules

stm32-cmake contains additional CMake modules for finding and configuring various libraries and RTOSes used in embedded world.

## FreeRTOS

[cmake/FindFreeRTOS](cmake/FindFreeRTOS) - finds FreeRTOS sources in location specified by `FREERTOS_PATH` (*default*: `/opt/FreeRTOS`) variable and format them as `IMPORTED` targets. `FREERTOS_PATH` can be either the path to the whole [FreeRTOS/FreeRTOS](https://github.com/FreeRTOS/FreeRTOS) github repo, or the path to FreeRTOS-Kernel (usually located in the subfolder `FreeRTOS` on a downloaded release)
Typical usage:

```
find_package(FreeRTOS COMPONENTS ARM_CM4F REQUIRED)
target_link_libraries(... FreeRTOS::ARM_CM4F)
```

Following FreeRTOS ports supported: `ARM_CM0`, `ARM_CM3`, `ARM_CM4F`, `ARM_CM7`.

Other FreeRTOS libraries:

* `FreeRTOS::Coroutine` - co-routines (`croutines.c`)
* `FreeRTOS::EventGroups` - event groups (`event_groups.c`)
* `FreeRTOS::StreamBuffer` - stream buffer (`stream_buffer.c`)
* `FreeRTOS::Timers` - timers (`timers.c`)
* `FreeRTOS::Heap::<N>` - heap implementation (`heap_<N>.c`), `<N>`: [1-5]