Freestanding is not a flag: building a bare-metal benchmark harness for Cortex-M4F

Fri, 17 Jul 2026 06:00:10 +0200

I wanted to know two things about a routine on a Cortex-M4F: how many cycles it costs, and how many bytes of flash it adds. Both answers are only worth having if nothing else in the image contributes to either figure.

That became nucleo-bench: a bare-metal benchmarking harness for the STM32F446RE. You hand it an algorithm, it runs the thing a few million times with the core’s cycle counter running, and it tells you what that cost. No operating system, no vendor hardware abstraction layer, no vendor startup code.

Embedded on Christian Grölings Blog

Freestanding is not a flag: building a bare-metal benchmark harness for Cortex-M4F