libk  x86.syscall.64.s

File arch/x86.syscall.64.s from the latest check-in


;; x86.64.s: common x86-64 ABI impl
; vim: ft=nasm

%macro sys 1-8
; syscall64 wrapper, ex. `sys sys.write, 1, msg, msg.len`
	%assign i 0
	%rep %0
		mov sys.reg. %+ i, %1 ; i'm actually shocked this worked
		%rotate 1
		%assign i i+1
	%endrep 
	syscall
%endmacro

%macro sys.prep 1-8
	; for when we need to modify parameters before we
	; make the actual call.
	%assign i 0
	%rep %0
		mov sys.reg. %+ i, %1
		%rotate 1
		%assign i i+1
	%endrep
%endmacro

; syscall ops
%define sys.call syscall

; register order for syscall convention
%define sys.reg.n 7
%define sys.reg.ret rax
%define sys.reg.0 rax
%define sys.reg.1 rdi
%define sys.reg.2 rsi
%define sys.reg.3 rdx
%define sys.reg.4 r10
%define sys.reg.5 r8
%define sys.reg.6 r9