1/* $NetBSD: rtld_start.S,v 1.11 2012/08/13 02:53:25 matt Exp $ */ 2 3/*- 4 * Copyright (c) 1998, 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Thomas and by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <machine/asm.h> 33 34RCSID("$NetBSD: rtld_start.S,v 1.11 2012/08/13 02:53:25 matt Exp $") 35 36 .text 37 .align 0 38 .globl _rtld_start 39 .type _rtld_start,%function 40_rtld_start: 41 sub sp, sp, #8 /* make room for obj_main & exit proc */ 42 mov r4, r0 /* save ps_strings */ 43 44 ldr sl, .L2 45 ldr r5, .L2+4 46 ldr r0, .L2+8 47.L1: 48 add sl, pc, sl 49 ldr r5, [sl, r5] 50 ldr r0, [sl, r0] 51 52 sub r1, sl, r5 /* relocbase */ 53 add r0, r1, r0 /* &_DYNAMIC */ 54 bl _rtld_relocate_nonplt_self 55 56 sub r1, sl, r5 /* relocbase */ 57 mov r0, sp /* sp */ 58 bl _rtld /* call the shared loader */ 59 mov r3, r0 /* save entry point */ 60 61 ldr r2, [sp], #4 /* pop r2 = cleanup */ 62 ldr r1, [sp], #4 /* pop r1 = obj_main */ 63 mov r0, r4 /* restore ps_strings */ 64#ifdef _ARM_ARCH_4T 65 bx r3 /* jump to the entry point */ 66#else 67 mov pc, r3 /* jump to the entry point */ 68#endif 69.L2: 70 .word _GLOBAL_OFFSET_TABLE_ - (.L1+8) 71 .word _GLOBAL_OFFSET_TABLE_(GOT) 72 .word _DYNAMIC(GOT) 73 74 .align 0 75 .globl _rtld_bind_start 76 .type _rtld_bind_start,%function 77/* 78 * stack[0] = RA 79 * ip = &GOT[n+3] 80 * lr = &GOT[2] 81 */ 82_rtld_bind_start: 83 stmdb sp!,{r0-r4,sl,fp} /* 8 byte aligned (lr already saved) */ 84 85 sub r1, ip, lr /* r1 = 4 * (n + 1) */ 86 sub r1, r1, #4 /* r1 = 4 * n */ 87 add r1, r1, r1 /* r1 = 8 * n */ 88 89 ldr r0, [lr, #-4] /* get obj ptr from GOT[1] */ 90 mov r4, ip /* save GOT location */ 91 92 bl _rtld_bind /* Call the binder */ 93 94 str r0, [r4] /* save address in GOT */ 95 mov ip, r0 /* save new address */ 96 97 ldmia sp!,{r0-r4,sl,fp,lr} /* restore the stack */ 98#ifdef _ARM_ARCH_4T 99 bx ip /* jump to the new address */ 100#else 101 mov pc, ip /* jump to the new address */ 102#endif 103 104