Embedded System Architecture and Design Questions

Principles for decomposing firmware into logical components and layers to support robustness and extensibility. Cover hardware abstraction layers and device drivers, separation of platform specific code and application logic, bootloader and update path design, communication stacks and middleware, and clear interface contracts for subsystems. Discuss memory layout implications, power management strategies, testability and observability, and support for multiple hardware variants and protocol versioning. Include considerations for deployment and over the air updates, backward compatibility, and incremental rollout strategies.