aarch64: Add public syscall ABI

We use largely the same ABI as Linux: a syscall is invoked with the
"svc #0" instruction, passing arguments the same way as for a regular
function call.  Specifically, up to 8 arguments are passed in the x0-x7
registers, and the rest are placed on the stack (this is only necessary
for the vm_map() syscall).  w8 should contain the (negative) Mach trap
number.  A syscall preserves all registers except for x0, which upon
returning contains the return value.
Message-ID: <20240415090149.38358-4-bugaevc@gmail.com>

0 files changed, 0 insertions, 0 deletions