MicroQuickJS, https://github.com/bellard/mquickjs/blob/main/README.md.
> MicroQuickJS is a Javascript engine targetted at embedded systems. It compiles and runs Javascript programs with as low as 10 kB of RAM. The whole engine requires about 100 kB of ROM (ARM Thumb-2 code) including the C library. The speed is comparable to QuickJS.
>
> MicroQuickJS only supports a subset of Javascript close to ES5. It implements a stricter mode where some error prone or inefficient Javascript constructs are forbidden.