Just my 2 cents - I think the jumplist of the kernel should be copied to RAM during the initialization, and the official way to call the kernel should be to use precisely this RAM copy of the jump list (think of AmigaOS library base structure). Same for the BASIC jumplist. This way it would be easier to extend the OS from the 'usermode', and the GUI could easily provide the 'terminal emulation' - imagine the C256 BASIC within the GEOS application window.
Just my 2 cents - I think the jumplist of the kernel should be copied to RAM during the initialization, and the official way to call the kernel should be to use precisely this RAM copy of the jump list (think of AmigaOS library base structure). Same for the BASIC jumplist. This way it would be easier to extend the OS from the 'usermode', and the GUI could easily provide the 'terminal emulation' - imagine the C256 BASIC within the GEOS application window.