1*0a6a1f1dSLionel Sambuc/* $NetBSD: __syscall.S,v 1.1 2014/08/10 05:47:37 matt Exp $ */ 2*0a6a1f1dSLionel Sambuc 3*0a6a1f1dSLionel Sambuc/*- 4*0a6a1f1dSLionel Sambuc * Copyright (c) 2014 The NetBSD Foundation, Inc. 5*0a6a1f1dSLionel Sambuc * All rights reserved. 6*0a6a1f1dSLionel Sambuc * 7*0a6a1f1dSLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation 8*0a6a1f1dSLionel Sambuc * by Matt Thomas of 3am Software Foundry. 9*0a6a1f1dSLionel Sambuc * 10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without 11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions 12*0a6a1f1dSLionel Sambuc * are met: 13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright 14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer. 15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright 16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the 17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution. 18*0a6a1f1dSLionel Sambuc * 19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE. 30*0a6a1f1dSLionel Sambuc */ 31*0a6a1f1dSLionel Sambuc 32*0a6a1f1dSLionel Sambuc#include "SYS.h" 33*0a6a1f1dSLionel Sambuc 34*0a6a1f1dSLionel Sambuc#ifndef FUNCNAME 35*0a6a1f1dSLionel Sambuc#define FUNCNAME __syscall 36*0a6a1f1dSLionel Sambuc#define SYSTRAP_SYSCALL SYSTRAP(__syscall) 37*0a6a1f1dSLionel Sambuc#endif 38*0a6a1f1dSLionel Sambuc 39*0a6a1f1dSLionel Sambuc#if SYS_MAXSYSARGS > 8 40*0a6a1f1dSLionel Sambuc#error SYS_MAXSYSARGS is greater than 8 41*0a6a1f1dSLionel Sambuc#endif 42*0a6a1f1dSLionel Sambuc 43*0a6a1f1dSLionel SambucENTRY(FUNCNAME) 44*0a6a1f1dSLionel Sambuc /* 45*0a6a1f1dSLionel Sambuc * AAPCS64 supplies the first 8 arguments in registers but since 46*0a6a1f1dSLionel Sambuc * the first argument is the syscall #, we only have room for 7 47*0a6a1f1dSLionel Sambuc * arguments. Thus if the syscall uses all 8 arguments, the last 48*0a6a1f1dSLionel Sambuc * argument will have been placed on the stack. Rather than 49*0a6a1f1dSLionel Sambuc * complicating the kernel syscall code to deal with that, we fixup 50*0a6a1f1dSLionel Sambuc * things here. 51*0a6a1f1dSLionel Sambuc * 52*0a6a1f1dSLionel Sambuc * First we move the syscall number to x17 freeing a register. 53*0a6a1f1dSLionel Sambuc * Then we move the rest of the arguments to their proper register. 54*0a6a1f1dSLionel Sambuc * Finally, load x7 from the stack. 55*0a6a1f1dSLionel Sambuc * 56*0a6a1f1dSLionel Sambuc * Now everything looks as if the syscall wrapper was directly called. 57*0a6a1f1dSLionel Sambuc * (unless it was for pipe, fork, vfork, ptrace, or __clone). 58*0a6a1f1dSLionel Sambuc */ 59*0a6a1f1dSLionel Sambuc mov x17, x0 60*0a6a1f1dSLionel Sambuc mov x0, x1 61*0a6a1f1dSLionel Sambuc mov x1, x2 62*0a6a1f1dSLionel Sambuc mov x2, x3 63*0a6a1f1dSLionel Sambuc mov x3, x4 64*0a6a1f1dSLionel Sambuc mov x4, x5 65*0a6a1f1dSLionel Sambuc mov x5, x6 66*0a6a1f1dSLionel Sambuc mov x6, x7 67*0a6a1f1dSLionel Sambuc ldr x7, [sp, #0] 68*0a6a1f1dSLionel Sambuc SYSTRAP_SYSCALL 69*0a6a1f1dSLionel Sambuc _INVOKE_CERROR() 70*0a6a1f1dSLionel Sambuc ret 71*0a6a1f1dSLionel SambucEND(FUNCNAME) 72