Bare-metal STM32: vector table, linker script, and startup code from scratch
a day ago
- #low-level-c
- #embedded-systems
- #microcontroller-programming
- Started with an STM32 Nucleo board to explore low-level microcontroller programming.
- Used the 'Hello World' approach (blinking LED) to learn the build system from the ground up.
- Realized that 'embedded' software often involves many abstraction layers, not truly being 'close to the hardware'.
- Implemented a blinky in Rust using HAL, then in C without abstractions to understand underlying mechanics.
- Explained memory-mapped I/O, volatile keyword, and register manipulation for GPIO control.
- Described the hardware boot process: vector table, reset handler, and startup sequence on Cortex-M4.
- Detailed the role of linker scripts in assigning sections to memory regions (flash vs. RAM).
- Explained startup code responsibilities: copying .data, zeroing .bss, and calling main().
- Outlined the toolchain steps: preprocessing, compiling, assembling, linking, and flashing.
- Reflected on the value of deep dives into foundational concepts, especially for automotive embedded systems.