rtld_start.S revision 1.13
1 /* $NetBSD: rtld_start.S,v 1.13 2002/09/12 17:07:25 mycroft Exp $ */ 2 3 /* 4 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 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. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <machine/asm.h> 31 32 /* 33 * Note: we can call ourselves LEAF even though we use callee-saved 34 * registers because we're the root of the call graph. 35 */ 36 LEAF_NOPROFILE(_rtld_start, 0) 37 .set noreorder 38 br pv, 1f 39 1: LDGP(pv) 40 41 /* 42 * Relocate ourself. 43 */ 44 br s2, 2f /* get our PC */ 45 2: ldiq s3, 2b /* get where the linker thought we were */ 46 47 subq s2, s3, a1 /* relocbase */ 48 lda t5, _DYNAMIC 49 addq a1, t5, a0 /* &_DYNAMIC */ 50 51 bsr ra, _rtld_relocate_nonplt_self 52 LDGP(ra) 53 54 /* 55 * Allocate space on the stack for the cleanup and obj_main 56 * entries that _rtld() will provide for us. 57 */ 58 lda sp, -16(sp) 59 60 subq s2, s3, a1 /* relocbase */ 61 mov sp, a0 /* sp */ 62 CALL(_rtld) /* v0 = _rtld(sp, relocbase); */ 63 64 ldq a1, 0(sp) /* cleanup */ 65 ldq a2, 8(sp) /* obj_main */ 66 lda sp, 16(sp) /* pop stack */ 67 68 mov sp, a0 /* stack pointer */ 69 mov s0, a3 /* ps_strings */ 70 71 mov v0, pv /* set up PV for entry point */ 72 73 jsr ra, (v0), 0 /* (*_start)(sp, cleanup, obj, ps_strings); */ 74 ldgp gp, 0(ra) 75 76 CALL(exit) 77 halt 78 END(_rtld_start) 79 80 #define RTLD_BIND_START_PROLOGUE \ 81 /* at_reg already used by PLT code. */ \ 82 .set noat ; \ 83 \ 84 /* \ 85 * Allocate stack frame and preserve all registers that the \ 86 * caller would have normally saved themselves. \ 87 */ \ 88 lda sp, -168(sp) ; \ 89 stq ra, 0(sp) ; \ 90 stq v0, 8(sp) ; \ 91 stq t0, 16(sp) ; \ 92 stq t1, 24(sp) ; \ 93 stq t2, 32(sp) ; \ 94 stq t3, 40(sp) ; \ 95 stq t4, 48(sp) ; \ 96 stq t5, 56(sp) ; \ 97 stq t6, 64(sp) ; \ 98 stq t7, 72(sp) ; \ 99 stq a0, 80(sp) ; \ 100 stq a1, 88(sp) ; \ 101 stq a2, 96(sp) ; \ 102 stq a3, 104(sp) ; \ 103 stq a4, 112(sp) ; \ 104 stq a5, 120(sp) ; \ 105 stq t8, 128(sp) ; \ 106 stq t9, 136(sp) ; \ 107 stq t10, 144(sp) ; \ 108 stq t11, 152(sp) ; \ 109 stq gp, 160(sp) ; \ 110 \ 111 /* \ 112 * Load our global pointer. Note, can't use pv, since it is \ 113 * already used by the PLT code. \ 114 */ \ 115 br t0, 1f ; \ 116 1: LDGP(t0) 117 118 #define RTLD_BIND_START_EPILOGUE \ 119 /* Move the destination address into position. */ \ 120 mov v0, pv ; \ 121 \ 122 /* Restore program registers. */ \ 123 ldq ra, 0(sp) ; \ 124 ldq v0, 8(sp) ; \ 125 ldq t0, 16(sp) ; \ 126 ldq t1, 24(sp) ; \ 127 ldq t2, 32(sp) ; \ 128 ldq t3, 40(sp) ; \ 129 ldq t4, 48(sp) ; \ 130 ldq t5, 56(sp) ; \ 131 ldq t6, 64(sp) ; \ 132 ldq t7, 72(sp) ; \ 133 ldq a0, 80(sp) ; \ 134 ldq a1, 88(sp) ; \ 135 ldq a2, 96(sp) ; \ 136 ldq a3, 104(sp) ; \ 137 ldq a4, 112(sp) ; \ 138 ldq a5, 120(sp) ; \ 139 ldq t8, 128(sp) ; \ 140 ldq t9, 136(sp) ; \ 141 ldq t10, 144(sp) ; \ 142 ldq t11, 152(sp) ; \ 143 ldq gp, 160(sp) ; \ 144 /* XXX LDGP? */ \ 145 \ 146 /* \ 147 * We've patched the PLT; sync the I-stream. \ 148 */ \ 149 imb ; \ 150 \ 151 /* Pop the stack frame and turn control to the destination. */ \ 152 lda sp, 168(sp) ; \ 153 jmp zero, (pv) 154 155 /* 156 * Lazy binding entry point, called via PLT. 157 */ 158 NESTED_NOPROFILE(_rtld_bind_start, 0, 168, ra, 0, 0) 159 160 RTLD_BIND_START_PROLOGUE 161 162 /* Set up the arguments for _rtld_bind. */ 163 subq at_reg, pv, a1 /* calculate offset of reloc entry */ 164 ldq a0, 8(pv) /* object structure */ 165 subq a1, 20, a1 /* = (at - pv - 20) / 12 * 24 */ 166 addq a1, a1, a1 167 168 CALL(_rtld_bind) 169 170 RTLD_BIND_START_EPILOGUE 171 172 END(_rtld_bind_start) 173 174 /* 175 * Lazy binding entry point, called via PLT. This version is for the 176 * old PLT entry format. 177 */ 178 NESTED_NOPROFILE(_rtld_bind_start_old, 0, 168, ra, 0, 0) 179 180 RTLD_BIND_START_PROLOGUE 181 182 /* Set up the arguments for _rtld_bind. */ 183 ldq a0, 8(pv) /* object structure */ 184 mov at_reg, a1 /* offset of reloc entry */ 185 186 CALL(_rtld_bind) 187 188 RTLD_BIND_START_EPILOGUE 189 190 END(_rtld_bind_start_old) 191
Indexes created Thu Oct 02 07:10:07 GMT 2025