QEMU 4.0 adds micro:bit emulation support

Unlike existing micro:bit simulators, QEMU performs full-system emulation and actually runs the same ARM code as the real hardware. The MakeCode editor for JavaScript development includes a micro:bit simulator:

This simulator does not execute any ARM code and is therefore not running the same CPU instructions as a real micro:bit. Unlike the MakeCode simulator, QEMU emulates the micro:bit CPU and boots from the same ARM code as the real micro:bit board.

Source: www.qemu.org