Modifying capability handling in CHERI ISA extension

Hello! I am new to the CHERI project, and am trying to perform an experiment on how the capabilities are handled in the ISA. I have CheriBSD running in qemu, and have successfully cross-compiled some C code to run on it and demonstrated to myself that CHERI blocked an out of bounds memory access. I would like to know where in the source code the ISA is being extended for this functionality. I've looked through the OS code, and it is of course mostly all FreeBSD. If someone could point me in the right direction, I would be very appreciative. Also, if this is not the place to ask about this, please let me know a more appropriate forum. Thank you!