1/* 2 * Special support for eabi and SVR4 3 * 4 * Copyright (C) 1995-2020 Free Software Foundation, Inc. 5 * Written By Michael Meissner 6 * 7 * This file is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the 9 * Free Software Foundation; either version 3, or (at your option) any 10 * later version. 11 * 12 * This file is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * Under Section 7 of GPL version 3, you are granted additional 18 * permissions described in the GCC Runtime Library Exception, version 19 * 3.1, as published by the Free Software Foundation. 20 * 21 * You should have received a copy of the GNU General Public License and 22 * a copy of the GCC Runtime Library Exception along with this program; 23 * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 * <http://www.gnu.org/licenses/>. 25 */ 26 27/* Do any initializations needed for the eabi environment */ 28 29 .section ".text" 30 #include "ppc-asm.h" 31 32#ifndef __powerpc64__ 33 34 .section ".got2","aw" 35 .align 2 36.LCTOC1 = . /* +32768 */ 37 38/* Table of addresses */ 39.Ltable = .-.LCTOC1 40 .long .LCTOC1 /* address we are really at */ 41 42.Lsda = .-.LCTOC1 43 .long _SDA_BASE_ /* address of the first small data area */ 44 45.Lsdas = .-.LCTOC1 46 .long __SDATA_START__ /* start of .sdata/.sbss section */ 47 48.Lsdae = .-.LCTOC1 49 .long __SBSS_END__ /* end of .sdata/.sbss section */ 50 51.Lsda2 = .-.LCTOC1 52 .long _SDA2_BASE_ /* address of the second small data area */ 53 54.Lsda2s = .-.LCTOC1 55 .long __SDATA2_START__ /* start of .sdata2/.sbss2 section */ 56 57.Lsda2e = .-.LCTOC1 58 .long __SBSS2_END__ /* end of .sdata2/.sbss2 section */ 59 60#ifdef _RELOCATABLE 61.Lgots = .-.LCTOC1 62 .long __GOT_START__ /* Global offset table start */ 63 64.Lgotm1 = .-.LCTOC1 65 .long _GLOBAL_OFFSET_TABLE_-4 /* end of GOT ptrs before BLCL + 3 reserved words */ 66 67.Lgotm2 = .-.LCTOC1 68 .long _GLOBAL_OFFSET_TABLE_+12 /* start of GOT ptrs after BLCL + 3 reserved words */ 69 70.Lgote = .-.LCTOC1 71 .long __GOT_END__ /* Global offset table end */ 72 73.Lgot2s = .-.LCTOC1 74 .long __GOT2_START__ /* -mrelocatable GOT pointers start */ 75 76.Lgot2e = .-.LCTOC1 77 .long __GOT2_END__ /* -mrelocatable GOT pointers end */ 78 79.Lfixups = .-.LCTOC1 80 .long __FIXUP_START__ /* start of .fixup section */ 81 82.Lfixupe = .-.LCTOC1 83 .long __FIXUP_END__ /* end of .fixup section */ 84 85.Lctors = .-.LCTOC1 86 .long __CTOR_LIST__ /* start of .ctor section */ 87 88.Lctore = .-.LCTOC1 89 .long __CTOR_END__ /* end of .ctor section */ 90 91.Ldtors = .-.LCTOC1 92 .long __DTOR_LIST__ /* start of .dtor section */ 93 94.Ldtore = .-.LCTOC1 95 .long __DTOR_END__ /* end of .dtor section */ 96 97.Lexcepts = .-.LCTOC1 98 .long __EXCEPT_START__ /* start of .gcc_except_table section */ 99 100.Lexcepte = .-.LCTOC1 101 .long __EXCEPT_END__ /* end of .gcc_except_table section */ 102 103.Linit = .-.LCTOC1 104 .long .Linit_p /* address of variable to say we've been called */ 105 106 .text 107 .align 2 108.Lptr: 109 .long .LCTOC1-.Laddr /* PC relative pointer to .got2 */ 110#endif 111 112 .data 113 .align 2 114.Linit_p: 115 .long 0 116 117 .text 118 119FUNC_START(__eabi) 120 121/* Eliminate -mrelocatable code if not -mrelocatable, so that this file can 122 be assembled with other assemblers than GAS. */ 123 124#ifndef _RELOCATABLE 125 addis 10,0,.Linit_p@ha /* init flag */ 126 addis 11,0,.LCTOC1@ha /* load address of .LCTOC1 */ 127 lwz 9,.Linit_p@l(10) /* init flag */ 128 addi 11,11,.LCTOC1@l 129 cmplwi 2,9,0 /* init flag != 0? */ 130 bnelr 2 /* return now, if we've been called already */ 131 stw 1,.Linit_p@l(10) /* store a nonzero value in the done flag */ 132 133#else /* -mrelocatable */ 134 mflr 0 135 bl .Laddr /* get current address */ 136.Laddr: 137 mflr 12 /* real address of .Laddr */ 138 lwz 11,(.Lptr-.Laddr)(12) /* linker generated address of .LCTOC1 */ 139 add 11,11,12 /* correct to real pointer */ 140 lwz 12,.Ltable(11) /* get linker's idea of where .Laddr is */ 141 lwz 10,.Linit(11) /* address of init flag */ 142 subf. 12,12,11 /* calculate difference */ 143 lwzx 9,10,12 /* done flag */ 144 cmplwi 2,9,0 /* init flag != 0? */ 145 mtlr 0 /* restore in case branch was taken */ 146 bnelr 2 /* return now, if we've been called already */ 147 stwx 1,10,12 /* store a nonzero value in the done flag */ 148 beq+ 0,.Lsdata /* skip if we don't need to relocate */ 149 150/* We need to relocate the .got2 pointers. */ 151 152 lwz 3,.Lgot2s(11) /* GOT2 pointers start */ 153 lwz 4,.Lgot2e(11) /* GOT2 pointers end */ 154 add 3,12,3 /* adjust pointers */ 155 add 4,12,4 156 bl FUNC_NAME(__eabi_convert) /* convert pointers in .got2 section */ 157 158/* Fixup the .ctor section for static constructors */ 159 160 lwz 3,.Lctors(11) /* constructors pointers start */ 161 lwz 4,.Lctore(11) /* constructors pointers end */ 162 bl FUNC_NAME(__eabi_convert) /* convert constructors */ 163 164/* Fixup the .dtor section for static destructors */ 165 166 lwz 3,.Ldtors(11) /* destructors pointers start */ 167 lwz 4,.Ldtore(11) /* destructors pointers end */ 168 bl FUNC_NAME(__eabi_convert) /* convert destructors */ 169 170/* Fixup the .gcc_except_table section for G++ exceptions */ 171 172 lwz 3,.Lexcepts(11) /* exception table pointers start */ 173 lwz 4,.Lexcepte(11) /* exception table pointers end */ 174 bl FUNC_NAME(__eabi_convert) /* convert exceptions */ 175 176/* Fixup the addresses in the GOT below _GLOBAL_OFFSET_TABLE_-4 */ 177 178 lwz 3,.Lgots(11) /* GOT table pointers start */ 179 lwz 4,.Lgotm1(11) /* GOT table pointers below _GLOBAL_OFFSET_TABLE-4 */ 180 bl FUNC_NAME(__eabi_convert) /* convert lower GOT */ 181 182/* Fixup the addresses in the GOT above _GLOBAL_OFFSET_TABLE_+12 */ 183 184 lwz 3,.Lgotm2(11) /* GOT table pointers above _GLOBAL_OFFSET_TABLE+12 */ 185 lwz 4,.Lgote(11) /* GOT table pointers end */ 186 bl FUNC_NAME(__eabi_convert) /* convert lower GOT */ 187 188/* Fixup any user initialized pointers now (the compiler drops pointers to */ 189/* each of the relocs that it does in the .fixup section). */ 190 191.Lfix: 192 lwz 3,.Lfixups(11) /* fixup pointers start */ 193 lwz 4,.Lfixupe(11) /* fixup pointers end */ 194 bl FUNC_NAME(__eabi_uconvert) /* convert user initialized pointers */ 195 196.Lsdata: 197 mtlr 0 /* restore link register */ 198#endif /* _RELOCATABLE */ 199 200/* Only load up register 13 if there is a .sdata and/or .sbss section */ 201 lwz 3,.Lsdas(11) /* start of .sdata/.sbss section */ 202 lwz 4,.Lsdae(11) /* end of .sdata/.sbss section */ 203 cmpw 1,3,4 /* .sdata/.sbss section non-empty? */ 204 beq- 1,.Lsda2l /* skip loading r13 */ 205 206 lwz 13,.Lsda(11) /* load r13 with _SDA_BASE_ address */ 207 208/* Only load up register 2 if there is a .sdata2 and/or .sbss2 section */ 209 210.Lsda2l: 211 lwz 3,.Lsda2s(11) /* start of .sdata/.sbss section */ 212 lwz 4,.Lsda2e(11) /* end of .sdata/.sbss section */ 213 cmpw 1,3,4 /* .sdata/.sbss section non-empty? */ 214 beq+ 1,.Ldone /* skip loading r2 */ 215 216 lwz 2,.Lsda2(11) /* load r2 with _SDA2_BASE_ address */ 217 218/* Done adjusting pointers, return by way of doing the C++ global constructors. */ 219 220.Ldone: 221 b FUNC_NAME(__init) /* do any C++ global constructors (which returns to caller) */ 222FUNC_END(__eabi) 223 224/* Special subroutine to convert a bunch of pointers directly. 225 r0 has original link register 226 r3 has low pointer to convert 227 r4 has high pointer to convert 228 r5 .. r10 are scratch registers 229 r11 has the address of .LCTOC1 in it. 230 r12 has the value to add to each pointer 231 r13 .. r31 are unchanged */ 232#ifdef _RELOCATABLE 233FUNC_START(__eabi_convert) 234 cmplw 1,3,4 /* any pointers to convert? */ 235 subf 5,3,4 /* calculate number of words to convert */ 236 bclr 4,4 /* return if no pointers */ 237 238 srawi 5,5,2 239 addi 3,3,-4 /* start-4 for use with lwzu */ 240 mtctr 5 241 242.Lcvt: 243 lwzu 6,4(3) /* pointer to convert */ 244 cmpwi 0,6,0 245 beq- .Lcvt2 /* if pointer is null, don't convert */ 246 247 add 6,6,12 /* convert pointer */ 248 stw 6,0(3) 249.Lcvt2: 250 bdnz+ .Lcvt 251 blr 252 253FUNC_END(__eabi_convert) 254 255/* Special subroutine to convert the pointers the user has initialized. The 256 compiler has placed the address of the initialized pointer into the .fixup 257 section. 258 259 r0 has original link register 260 r3 has low pointer to convert 261 r4 has high pointer to convert 262 r5 .. r10 are scratch registers 263 r11 has the address of .LCTOC1 in it. 264 r12 has the value to add to each pointer 265 r13 .. r31 are unchanged */ 266 267FUNC_START(__eabi_uconvert) 268 cmplw 1,3,4 /* any pointers to convert? */ 269 subf 5,3,4 /* calculate number of words to convert */ 270 bclr 4,4 /* return if no pointers */ 271 272 srawi 5,5,2 273 addi 3,3,-4 /* start-4 for use with lwzu */ 274 mtctr 5 275 276.Lucvt: 277 lwzu 6,4(3) /* next pointer to pointer to convert */ 278 add 6,6,12 /* adjust pointer */ 279 lwz 7,0(6) /* get the pointer it points to */ 280 stw 6,0(3) /* store adjusted pointer */ 281 add 7,7,12 /* adjust */ 282 stw 7,0(6) 283 bdnz+ .Lucvt 284 blr 285 286FUNC_END(__eabi_uconvert) 287#endif 288#endif 289