__syscall.S revision 1.1.4.2
1 1.1.4.2 tls /* $NetBSD: __syscall.S,v 1.1.4.2 2014/08/20 00:02:09 tls Exp $ */ 2 1.1.4.2 tls 3 1.1.4.2 tls /*- 4 1.1.4.2 tls * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 1.1.4.2 tls * All rights reserved. 6 1.1.4.2 tls * 7 1.1.4.2 tls * This code is derived from software contributed to The NetBSD Foundation 8 1.1.4.2 tls * by Matt Thomas of 3am Software Foundry. 9 1.1.4.2 tls * 10 1.1.4.2 tls * Redistribution and use in source and binary forms, with or without 11 1.1.4.2 tls * modification, are permitted provided that the following conditions 12 1.1.4.2 tls * are met: 13 1.1.4.2 tls * 1. Redistributions of source code must retain the above copyright 14 1.1.4.2 tls * notice, this list of conditions and the following disclaimer. 15 1.1.4.2 tls * 2. Redistributions in binary form must reproduce the above copyright 16 1.1.4.2 tls * notice, this list of conditions and the following disclaimer in the 17 1.1.4.2 tls * documentation and/or other materials provided with the distribution. 18 1.1.4.2 tls * 19 1.1.4.2 tls * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.1.4.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.1.4.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.1.4.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.1.4.2 tls * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.1.4.2 tls * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.1.4.2 tls * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.1.4.2 tls * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.1.4.2 tls * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.1.4.2 tls * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.1.4.2 tls * POSSIBILITY OF SUCH DAMAGE. 30 1.1.4.2 tls */ 31 1.1.4.2 tls 32 1.1.4.2 tls #include "SYS.h" 33 1.1.4.2 tls 34 1.1.4.2 tls #ifndef FUNCNAME 35 1.1.4.2 tls #define FUNCNAME __syscall 36 1.1.4.2 tls #define SYSTRAP_SYSCALL SYSTRAP(__syscall) 37 1.1.4.2 tls #endif 38 1.1.4.2 tls 39 1.1.4.2 tls #if SYS_MAXSYSARGS > 8 40 1.1.4.2 tls #error SYS_MAXSYSARGS is greater than 8 41 1.1.4.2 tls #endif 42 1.1.4.2 tls 43 1.1.4.2 tls ENTRY(FUNCNAME) 44 1.1.4.2 tls /* 45 1.1.4.2 tls * AAPCS64 supplies the first 8 arguments in registers but since 46 1.1.4.2 tls * the first argument is the syscall #, we only have room for 7 47 1.1.4.2 tls * arguments. Thus if the syscall uses all 8 arguments, the last 48 1.1.4.2 tls * argument will have been placed on the stack. Rather than 49 1.1.4.2 tls * complicating the kernel syscall code to deal with that, we fixup 50 1.1.4.2 tls * things here. 51 1.1.4.2 tls * 52 1.1.4.2 tls * First we move the syscall number to x17 freeing a register. 53 1.1.4.2 tls * Then we move the rest of the arguments to their proper register. 54 1.1.4.2 tls * Finally, load x7 from the stack. 55 1.1.4.2 tls * 56 1.1.4.2 tls * Now everything looks as if the syscall wrapper was directly called. 57 1.1.4.2 tls * (unless it was for pipe, fork, vfork, ptrace, or __clone). 58 1.1.4.2 tls */ 59 1.1.4.2 tls mov x17, x0 60 1.1.4.2 tls mov x0, x1 61 1.1.4.2 tls mov x1, x2 62 1.1.4.2 tls mov x2, x3 63 1.1.4.2 tls mov x3, x4 64 1.1.4.2 tls mov x4, x5 65 1.1.4.2 tls mov x5, x6 66 1.1.4.2 tls mov x6, x7 67 1.1.4.2 tls ldr x7, [sp, #0] 68 1.1.4.2 tls SYSTRAP_SYSCALL 69 1.1.4.2 tls _INVOKE_CERROR() 70 1.1.4.2 tls ret 71 1.1.4.2 tls END(FUNCNAME) 72
Indexes created Fri Oct 17 00:09:41 GMT 2025