This could be easily done. The emulator core supports memory mapped IO, but uvm32 only uses this to map an extra block of RAM from the host (for a framebuffer, or a separare memory heap). You can trap the writes here: https://github.com/ringtailsoftware/uvm32/blob/main/uvm32/uv... and the reads here https://github.com/ringtailsoftware/uvm32/blob/main/uvm32/uv...