Their motivation is explained in the first post of the series[1]

[1] https://www.grisp.org/blog/posts/2025-06-23-jit-arm32.1#why-...

For their real motivation[0], click on hardware at the top of the page.

Their existing hardware is aarch32. It really is that simple.

0. https://www.grisp.org/hardware

loved them complaining about having "only" 16 registers