1/* $NetBSD: brk.S,v 1.15 2008/11/06 13:42:55 nakayama Exp $ */ 2 3/* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Header: brk.s,v 1.3 92/06/25 12:56:05 mccanne Exp 36 */ 37 38#include <machine/asm.h> 39#if defined(SYSLIBC_SCCS) && !defined(lint) 40#if 0 41 .asciz "@(#)brk.s 8.1 (Berkeley) 6/4/93" 42#else 43 RCSID("$NetBSD: brk.S,v 1.15 2008/11/06 13:42:55 nakayama Exp $") 44#endif 45#endif /* SYSLIBC_SCCS and not lint */ 46 47#include "SYS.h" 48 49 .globl CURBRK 50 .globl _C_LABEL(__minbrk) 51 .globl _end 52 53#ifdef WEAK_ALIAS 54WEAK_ALIAS(brk, _brk) 55#endif 56 57 .data 58_C_LABEL(__minbrk): 59 .long _end ! lower brk limit; also for gmon code 60 .text 61 62ENTRY(_brk) 63#ifdef PIC 64 PIC_PROLOGUE(%o5,%o4) 65 set _C_LABEL(__minbrk), %o4 66 ld [%o5 + %o4], %o4 67 ld [%o4], %o1 ! %o1 = minbrk 68 cmp %o1, %o0 ! if (minbrk > %o0) 69 bgu,a 0f 70 mov %o1, %o0 ! %o0 = minbrk 710: 72 mov %o0, %o2 ! save argument to syscall 73 mov SYS_break, %g1 74 t ST_SYSCALL 75 set CURBRK, %o3 76 bcc,a 1f 77 ld [%o5 + %o3], %o4 78 ERROR() 791: 80 retl ! success, return 0 & record new break 81 st %o2, [%o4] 82#else 83 sethi %hi(_C_LABEL(__minbrk)), %o1 ! %o1 = minbrk 84 ld [%o1 + %lo(_C_LABEL(__minbrk))], %o1 85 cmp %o1, %o0 ! if (minbrk > %o0) 86 bgu,a 0f 87 mov %o1, %o0 ! %o0 = minbrk 880: 89 mov %o0, %o2 ! save argument to syscall 90 mov SYS_break, %g1 91 t ST_SYSCALL 92 bcc,a 1f 93 sethi %hi(CURBRK), %g1 94 ERROR() 951: 96 retl ! success, return 0 & record new break 97 st %o2, [%g1 + %lo(CURBRK)] 98#endif 99