esp32sim runs firmware through a modeled boot chain

esp32sim is a Rust emulator that boots ESP32 mask ROMs, the real bootloader and unmodified firmware, with a WebAssembly version for browsers. Board models include displays, input devices and networking. Support is uneven: the project labels ESP32-S3 mature, C3 and C6 draft, and the classic ESP32 early. It is an unofficial development tool, so check the specific chip and peripherals before trusting a result.

mikroverk

Why it matters

Firmware experiments become easier to share when they can run without the physical board.

More context

Try the browser demo first, then a native build for your firmware. Mask ROM files are downloaded separately; the repository documents comparisons with real chips. No exact original publication date was established.

Keep in mind

Emulation coverage varies by hardware block and cannot replace final testing on the target board.

Original read