Breaking changes in concepts

STM32Cube HAL2 introduces several breaking changes in the concepts and principles underlying the library. Understanding these changes is essential for a successful migration of the application to the new version.

The key improvements include:

• Separation of initialization and configuration APIs, with optimized handle management.

• Division of processes, such as clock management for all sources and IRQ handling for all modes.

• Addition of atomic configuration methods to provide greater granularity in dynamic peripheral setup alongside global configuration.

• HAL2 services now exclusively call LL functions instead of direct register access, improving driver maintenance and upgrades (Knowing that on HAL1 the LL was introduced after the HAL).

• Enhanced lock, state, and error management within drivers to reinforce thread safety and prevent race conditions in certain scenarios.

• Enhanced control services to improve portability, particularly for clock management, providing unitary APIs per peripheral clocks, and for interrupt filtering, allowing dynamic disabling of specific process events.

• Implementation of new coding rules and naming conventions.

The breaking changes have been organized into the following categories, each addressing specific improvements and modifications in the HAL2 migration:

• Optimized initialization and configuration APIs
• Atomic configuration methods
• Specialized clock and IRQ management in HAL2
• HAL implementation built upon LL services
• Improved driver mechanisms
• Enhanced control services
• New coding rules
• Optimized input checks
• HAL refactoring
• Enhanced asserts
• Flash driver refactoring
• RTOS-aware HAL
• Misc. updates