sbrk.S revision 171061
1/* $NetBSD: sbrk.S,v 1.7 2003/08/07 16:42:05 agc Exp $ */ 2 3/*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * from: @(#)sbrk.s 5.1 (Berkeley) 4/23/90 32 */ 33 34#include <machine/asm.h> 35__FBSDID("$FreeBSD: head/lib/libc/arm/sys/sbrk.S 171061 2007-06-27 02:45:37Z kan $"); 36#include "SYS.h" 37 38 .globl _C_LABEL(_end) 39 40#ifdef WEAK_ALIAS 41WEAK_ALIAS(sbrk, _sbrk) 42#endif 43 44 .data 45 .align 0 46 .globl CURBRK 47 .type CURBRK,#object 48CURBRK: 49 .word _C_LABEL(_end) 50 51/* 52 * Change the data segment size 53 */ 54ENTRY(_sbrk) 55#ifdef PIC 56 /* Setup the GOT */ 57 ldr r3, .Lgot 58 add r3, pc, r3 59.L1: 60 ldr r2, .Lcurbrk 61 ldr r2, [r3, r2] 62#else 63 ldr r2, .Lcurbrk 64#endif 65 /* Get the current brk address */ 66 ldr r1, [r2] 67 68 /* Calculate new value */ 69 mov r3, r0 70 add r0, r0, r1 71 SYSTRAP(break) 72 bcs PIC_SYM(CERROR, PLT) 73 74 /* Store new curbrk value */ 75 ldr r0, [r2] 76 add r1, r0, r3 77 str r1, [r2] 78 79 /* Return old curbrk value */ 80 RET 81 82 .align 0 83#ifdef PIC 84.Lgot: 85 .word _GLOBAL_OFFSET_TABLE_ - (.L1+4) 86#endif 87.Lcurbrk: 88 .word PIC_SYM(CURBRK, GOT) 89