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RAL RAL ST

Supported STM32 families: F4 · G4 · H5 · H7 · L4 · U5

Register Abstraction Layer module: combines STMicroelectronics' original HAL/LL drivers with Embedbits' own hardware-independent interface layer (Port/). Consumed as a git submodule of Bsp-Ral, one branch per STM32 family/release.

Overview​

Upstream project (Stm32_Drv/)STMicroelectronics/stm32<family>xx_hal_driver (e.g. stm32g4xx_hal_driver)
Embedbits-owned content (Port/)Unified, family-independent function/header naming on top of the ST HAL/LL API
Role in Bsp-RalSource of both Ral_Lib (recommended, Port/-only interface) and HAL_LL_Lib (full ST HAL/LL access)
LicenseSee Stm32_Drv/License.md for the ST-derived driver sources; Embedbits' Port/ layer follows the parent repository's license
Maintenance modelStm32_Drv/ is mirrored from upstream ST per family and must not be modified locally; Port/ is maintained by Embedbits

⚠️ Do not modify Stm32_Drv/ directly — updates are tracked against the original ST repository. Hardware-independent changes belong in Port/.

Branch Structure​

Branch patternPurpose
STM32<family> (e.g. STM32G4, STM32U5, STM32H7)Family branch, derived from master, holding the ST HAL/LL drivers and the Port/ interface for that family
STM32<family>_<major>.x (e.g. STM32G4_1.x)Major release branch, derived from the family branch, tracking an ST HAL major release
STM32<family>_<major>.<minor> (e.g. STM32G4_1.2)Minor/patch release branch, derived from the major release branch

All family branches derive from master.

Repository Structure​

RAL_ST
├── Port                     # Embedbits' hardware-independent interface layer
│   ├── Stm32.h                  # Umbrella include
│   ├── Stm32_tim.h              # Unified timer interface
│   ├── Stm32_i2c.h              # Unified I2C interface
│   ├── Stm32_spi.h              # Unified SPI interface
│   ├── Stm32_gpio.h
│   ├── Stm32_usart.h
│   └── ...                      # One header per peripheral, family-independent naming
└── Stm32_Drv                # Original HAL/LL drivers, unmodified from STMicroelectronics
    ├── Inc                      # HAL/LL headers (e.g. stm32g4xx_ll_tim.h)
    ├── Src                      # HAL/LL sources (e.g. stm32g4xx_ll_tim.c)
    └── License.md

Port/ — unified interface​

Port/ exposes one header per peripheral with function/type naming independent of the STM32 family, so application code can switch STM32 families without changing its own source:

#include "Stm32_tim.h"   // Automatically selects the correct HAL headers based on the target MCU define

Usage​

Both Ral_Lib and HAL_LL_Lib are defined in Bsp-Ral's top-level CMakeLists.txt and consume this module's two directories:

CMake targetPublic include pathIntended use
Ral_LibRAL_ST/Port/Recommended. Stable, hardware-independent API for application/middleware code
HAL_LL_LibRAL_ST/Stm32_Drv/Inc/Full ST HAL/LL access, for internal integration and testing only
# Recommended interface
target_link_libraries(MyApp PRIVATE Ral_Lib)

# Extended low-level access (not recommended for modular projects)
target_link_libraries(MyApp PRIVATE HAL_LL_Lib)
#include "Stm32_tim.h"   // Unified abstraction header, via Ral_Lib

⚠️ Ral_Lib is the only officially supported interface for external projects. Use HAL_LL_Lib only when a direct ST HAL/LL API is explicitly required.

License​

Stm32_Drv/ components are derived from STMicroelectronics HAL/LL drivers under their respective license — see Stm32_Drv/License.md. The Port/ interface layer is original Embedbits code, distributed under the parent Bsp-Ral repository's license.