I've added a B and b type to the NCI interface, which as a parameter just returns the address or the value of the data pointer to the buffer in an S register. These are needed for the full ncurses interface, amongst other things (I expect). I can, and have, written the C code to make this happen in build_nativecall.pl, but that doesn't help on the x86 platforms which build this stuff up dynamically. They're both disabled as return types, which is actually fine.
Could someone take a look at build_nativecall.pl to see what the C looks like, and thump jit_emit.h appropriately? Thanks. Dan