1/* $OpenBSD: ldasm.S,v 1.28 2019/05/10 13:29:21 guenther Exp $ */ 2 3/* 4 * Copyright (c) 2004 Dale Rahn 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29#define DL_DATA_SIZE (16 * 4) /* XXX */ 30#include <machine/asm.h> 31#include <sys/syscall.h> 32 33 .section .boot.text,"ax",%progbits 34 _ALIGN_TEXT 35 .globl _dl_start 36 .type _dl_start,#function 37_dl_start: 38 mov fp, sp 39 mov r5, sp 40 mov lr, r6 @ save lr 41 sub sp, sp, #4+4+DL_DATA_SIZE 42 add r7, sp, #4 @ dl_data 43 44 mov r0, fp @ original stack 45 mov r1, r7 @ dl_data 46 47 ldr r8, .L_GOT @ calculate address of GOT... 481: add r8, pc, r8 @ into r8 49 50 ldr r2, .L__DYNAMIC @ &_DYNAMIC 51 add r2, r2, r8 52 53 bl _dl_boot_bind 54 55 add r0, r5, #4 @ argv 56 ldr r1, [r5, #0x0] @ envp 57 add r1, r1, #2 58 add r1, fp, r1, lsl #2 59 ldr r2, [r7, #7*4] @ loff from dl_data 60 mov r3, r7 @ dl_data 61 bl _dl_boot 62 63 mov sp, fp 64 mov fp, #0 65 mov lr, r6 66 67 mov r1, r0 68 ldr r0, .L_dl_dtors 69 add r0, r0, r8 70 mov pc, r1 71.L_GOT: 72 .long _GLOBAL_OFFSET_TABLE_-(1b+8) 73.L__DYNAMIC: 74 .long _DYNAMIC(GOTOFF) 75.L_dl_dtors: 76 .long _dl_dtors(GOTOFF) 77END(_dl_start) 78 79 80ENTRY(_dl_bind_start) 81 /* 82 * ip is pointer to got entry for this relocation 83 * lr is pointer to pltgot[2], which is entry -1 of got plt reloc. 84 * return address is on stack 85 */ 86 stmdb sp!, {r0-r4,sl,fp} 87 88 sub r1, ip, lr /* r1 = 4 * (n + 1) */ 89 sub r1, r1, #4 /* r1 = 4 * n */ 90 mov r1, r1, lsr #2 /* r1 = n */ 91 92 ldr r0, [lr, #-4] 93 bl _dl_bind 94 mov ip, r0 95 ldmia sp!, {r0-r4,sl,fp,lr} 96 mov pc, ip 97END(_dl_bind_start) 98