uLisp - ARM Assembler in Lisp

CRANK

21st January 2020This article describes an in-line assembler written in Lisp, as an add-on for uLisp. The project is currently a work in progress, but I thought it would be interesting to describe where I've got to, and I'd be interested to hear suggestions for extensions or improvements.The assembler generates ARM Thumb code, and I've tested it on ARM M0 platforms, such as the Adafruit ItsyBitsy M0, and ARM M4 platforms, such as the Adafruit Metro M4. It is currently restricted to generating one assembler routine with up to three integer parameters, and returning an integer result.uLisp extensionsThe assembler uses a special version of uLisp to which I've added two functions:The assemble function takes a series of 16-bit integer arguments comprising the machine code of the routine being assembled. These are written into RAM. Any argument can also return nil, in which case it is ignored.The call function will then call the assembler routine in RAM, and return the result.The actual ins…