1/* $NetBSD: rtld_start.S,v 1.12 2013/12/03 00:19:56 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 1.12 2013/12/03 00:19:56 matt Exp $") 35 36ENTRY_NP(_rtld_start) 37 sub sp, sp, #8 /* make room for obj_main & exit proc */ 38 movs r4, r0 /* save ps_strings */ 39 40 ldr r6, .Lgot 41 ldr r5, .Ldynamic 42 add r6, r6, pc /* r6 = &GOT[0]; pc = &LPIC1; */ 43 adds r0, r6, r5 /* arg0 = &_DYNAMIC */ 44.LPIC1: 45 ldr r5, [r6] /* GOT[0] = &_DYNAMIC */ 46 subs r5, r0, r5 /* relocbase = GOT[0] - &_DYNAMIC */ 47 movs r1, r5 /* arg1 = relocabase */ 48 bl _rtld_relocate_nonplt_self 49 50 movs r1, r5 /* relocbase */ 51 mov r0, sp /* sp */ 52 bl _rtld /* call the shared loader */ 53 movs r3, r0 /* save entry point */ 54 55#ifdef __thumb__ 56 ldr r2, [sp, #0] /* pop r2 = cleanup */ 57 ldr r1, [sp, #4] /* pop r1 = obj_main */ 58 add sp, sp, #8 59#else 60 ldr r2, [sp], #4 /* pop r2 = cleanup */ 61 ldr r1, [sp], #4 /* pop r1 = obj_main */ 62#endif 63 movs r0, r4 /* restore ps_strings */ 64 RETr(r3) 65 66 .align 0 67.Lgot: 68 .word _GLOBAL_OFFSET_TABLE_ - .LPIC1 69.Ldynamic: 70 .word _DYNAMIC(GOTOFF) 71END(_rtld_start) 72 73/* 74 * stack[0] = RA 75 * ip = &GOT[n+3] 76 * lr = &GOT[2] 77 */ 78ARM_ENTRY_NP(_rtld_bind_start) 79 stmdb sp!,{r0-r4,sl,fp} /* 8 byte aligned (lr already saved) */ 80 81 sub r1, ip, lr /* r1 = 4 * (n + 1) */ 82 sub r1, r1, #4 /* r1 = 4 * n */ 83 add r1, r1, r1 /* r1 = 8 * n */ 84 85 ldr r0, [lr, #-4] /* get obj ptr from GOT[1] */ 86 mov r4, ip /* save GOT location */ 87 88 bl _rtld_bind /* Call the binder */ 89 90 str r0, [r4] /* save address in GOT */ 91 mov ip, r0 /* save new address */ 92 93 ldmia sp!,{r0-r4,sl,fp,lr} /* restore the stack */ 94 RETr(ip) /* jump to the new address */ 95END(_rtld_bind_start) 96