start.S revision 132437
1/*- 2 * Copyright (c) 2001 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/boot/ia64/efi/start.S 132437 2004-07-20 07:11:14Z marcel $ 27 */ 28 29 .text 30 31#include <machine/asm.h> 32 33#define EFI_SUCCESS 0 34#define EFI_LOAD_ERROR 1 35#define EFI_BUFFER_TOO_SMALL 5 36 37#define DT_NULL 0 /* Terminating entry. */ 38#define DT_NEEDED 1 /* String table offset of a needed shared 39 library. */ 40#define DT_PLTRELSZ 2 /* Total size in bytes of PLT relocations. */ 41#define DT_PLTGOT 3 /* Processor-dependent address. */ 42#define DT_HASH 4 /* Address of symbol hash table. */ 43#define DT_STRTAB 5 /* Address of string table. */ 44#define DT_SYMTAB 6 /* Address of symbol table. */ 45#define DT_RELA 7 /* Address of ElfNN_Rela relocations. */ 46#define DT_RELASZ 8 /* Total size of ElfNN_Rela relocations. */ 47#define DT_RELAENT 9 /* Size of each ElfNN_Rela relocation entry. */ 48#define DT_STRSZ 10 /* Size of string table. */ 49#define DT_SYMENT 11 /* Size of each symbol table entry. */ 50#define DT_INIT 12 /* Address of initialization function. */ 51#define DT_FINI 13 /* Address of finalization function. */ 52#define DT_SONAME 14 /* String table offset of shared object 53 name. */ 54#define DT_RPATH 15 /* String table offset of library path. */ 55#define DT_SYMBOLIC 16 /* Indicates "symbolic" linking. */ 56#define DT_REL 17 /* Address of ElfNN_Rel relocations. */ 57#define DT_RELSZ 18 /* Total size of ElfNN_Rel relocations. */ 58#define DT_RELENT 19 /* Size of each ElfNN_Rel relocation. */ 59#define DT_PLTREL 20 /* Type of relocation used for PLT. */ 60#define DT_DEBUG 21 /* Reserved (not used). */ 61#define DT_TEXTREL 22 /* Indicates there may be relocations in 62 non-writable segments. */ 63#define DT_JMPREL 23 /* Address of PLT relocations. */ 64 65#define DT_COUNT 24 /* Number of defined d_tag values. */ 66 67#define R_IA64_NONE 0 /* None */ 68#define R_IA64_DIR64MSB 0x26 /* word64 MSB S + A */ 69#define R_IA64_DIR64LSB 0x27 /* word64 LSB S + A */ 70#define R_IA64_FPTR64MSB 0x46 /* word64 MSB @fptr(S + A) */ 71#define R_IA64_FPTR64LSB 0x47 /* word64 LSB @fptr(S + A) */ 72#define R_IA64_REL64MSB 0x6e /* word64 MSB BD + A */ 73#define R_IA64_REL32LSB 0x6d /* word32 LSB BD + A */ 74#define R_IA64_REL64LSB 0x6f /* word64 LSB BD + A */ 75#define R_IA64_IPLTLSB 0x81 /* function descriptor LSB speciaal */ 76 77ENTRY(_start, 2) 78 alloc loc0=ar.pfs,2,3,3,0 79 mov loc1=rp 80 movl loc2=@gprel(ImageBase) 81 ;; 82 add loc2=gp,loc2 83 ;; 84 mov out0=loc2 85 mov out1=in1 86 ;; 87 br.call.sptk.few rp=_reloc // relocate image 88 89 cmp.ne p6,p0=EFI_SUCCESS,r8 // did it work? 90(p6) br.cond.dpnt.few 9f 91 92 mov out0=in0 // image_handle 93 mov out1=in1 // system_table 94 br.call.sptk.few rp=efi_main 959: 96 mov ar.pfs=loc0 97 mov rp=loc1 98 ;; 99 br.ret.sptk.few rp 100END(_start) 101 102 // PLABEL for PE32+ 103 .section .plabel, "a" 104 .align 16 105 .global _start_plabel 106_start_plabel: 107 data16 @iplt(_start) 108 .previous 109 110 // A PE32+ relocation entry for the plabel 111 .section .reloc, "a" 112 data4 _start_plabel 113 data4 12 114 data2 (10 << 12) + 0 115 data2 (10 << 12) + 8 116 .previous 117 118// in0: image base 119// in1: system table 120// 121// XXX Assumes PLT relocations are of type Elf_Rela 122// 123// r2 = address of fptr_storage 124// r3 = address of fptr_storage_end 125// r4 = address of first free fptr 126// 127// r15 = r_offset 128// r16 = r_info -OR- d_tag 129// r17 = r_addend -OR- d_val (=d_ptr) 130// r18 = address of .rela dynamic section 131// r19 = size of .rela section 132// r20 = size of .rela element (Elf_Rela) 133// r21 = address of first PLT relocation 134// r22 = size of PLT relocations 135// r23 = relocation type 136// r24 = address of symbol 137// r28 = R_IA64_IPLTLSB 138// f8 = address of symbol table 139// f9 = size of symtab element 140 141STATIC_ENTRY(_reloc, 2) 142 alloc loc0=ar.pfs,2,2,0,0 143 ;; 144 mov loc1=rp 145 movl r29=@gprel(_DYNAMIC) // find _DYNAMIC etc. 146 ;; 147 add r15=r29,gp 148 movl r29=@gprel(fptr_storage) 149 ;; 150 add r2=r29,gp 151 movl r29=@gprel(fptr_storage_end) 152 ;; 153 add r3=r29,gp 154 mov r4=r2 155 mov r19=0 156 mov r22=0 157 mov r20=24 158 mov r28=R_IA64_IPLTLSB 159 ;; 1601: 161 ld8 r16=[r15],8 // read r15->d_tag 162 ;; 163 ld8 r17=[r15],8 // and r15->d_val 164 ;; 165 cmp.eq p6,p0=DT_NULL,r16 // done? 166(p6) br.cond.dpnt.few 2f 167 ;; 168 cmp.eq p6,p0=DT_RELA,r16 // rela section? 169 ;; 170(p6) add r18=r17,in0 171 cmp.eq p6,p0=DT_RELASZ,r16 // rela section size? 172 ;; 173(p6) mov r19=r17 174 cmp.eq p6,p0=DT_RELAENT,r16 // rela entry size? 175 ;; 176(p6) mov r20=r17 177 cmp.eq p6,p0=DT_JMPREL,r16 // PLT relocs? 178 ;; 179(p6) add r21=r17,in0 180 cmp.eq p6,p0=DT_PLTRELSZ,r16 // PLT relocs size? 181 ;; 182(p6) mov r22=r17 183 cmp.eq p6,p0=DT_SYMTAB,r16 // symbol table? 184 ;; 185(p6) add r29=r17,in0 186 ;; 187(p6) setf.sig f8=r29 188 cmp.eq p6,p0=DT_SYMENT,r16 // symbol entry size? 189 ;; 190(p6) setf.sig f9=r17 191 br.dptk 1b 192 1932: 194 cmp.lt p6,p0=0,r19 195(p6) br.cond.dptk 3f 196 ;; 197 mov r19=r22 198 mov r18=r21 199 mov r21=0 200 mov r22=0 201 ;; 202 cmp.lt p6,p0=0,r19 203(p6) br.cond.dptk 3f 204 ;; 205 mov r8=EFI_SUCCESS 206 br.dptk 9f 2073: 208 ld8 r29=[r18],8 // read r_offset 209 ;; 210 ld8 r16=[r18],8 // read r_info 211 add r15=r29,in0 // relocate r_offset 212 ;; 213 ld8 r17=[r18],8 // read r_addend 214 sub r19=r19,r20 // update relasz 215 extr.u r23=r16,0,32 // ELF64_R_TYPE(r16) 216 ;; 217 cmp.eq p6,p0=R_IA64_NONE,r23 218(p6) br.cond.dpnt.few 2b 219 ;; 220 cmp.eq p6,p0=R_IA64_REL32LSB,r23 221(p6) br.cond.dptk.few 3f 222 ;; 223 cmp.eq p6,p0=R_IA64_REL64LSB,r23 224(p6) br.cond.dptk.few 4f 225 ;; 226 extr.u r29=r16,32,32 // ELF64_R_SYM(r16) 227 ;; 228 setf.sig f10=r29 // so we can multiply 229 ;; 230 xma.lu f10=f10,f9,f8 // f10=symtab + r_sym*syment 231 ;; 232 getf.sig r29=f10 233 ;; 234 add r29=8,r29 // address of st_value 235 ;; 236 ld8 r29=[r29] // read symbol value 237 ;; 238 add r24=r29,in0 // relocate symbol value 239 ;; 240 cmp.eq p6,p0=R_IA64_DIR64LSB,r23 241(p6) br.cond.dptk.few 5f 242 ;; 243 cmp.eq p6,p0=R_IA64_FPTR64LSB,r23 244(p6) br.cond.dptk.few 6f 245 ;; 246 cmp.ne p6,p0=r28,r23 // IPLTLSB 247(p6) br.cond.dptk.few 2b 248 249 // IPLTLSB 250 add r29=r24,r17 // S + A 251 ;; 252 st8 [r15]=r29,8 // fdesc:FP 253 ;; 254 st8 [r15]=gp // fdesc:GP 255 br.cond.sptk.few 2b 256 257 // REL32LSB 2583: 259 add r29=in0,r17 260 ;; 261 st4 [r15]=r29 262 br.cond.sptk.few 2b 263 264 // REL64LSB 2654: 266 add r29=in0,r17 // BD + A 267 ;; 268 st8 [r15]=r29 // word64 269 br.cond.sptk.few 2b 270 271 // DIR64LSB 2725: 273 add r29=r24,r17 // S + A 274 ;; 275 st8 [r15]=r29 // word64 276 br.cond.sptk.few 2b 277 2786: 279 mov r29=r2 // FPTR64LSB 280 ;; 2817: 282 cmp.geu p6,p0=r29,r4 // end of fptrs? 283(p6) br.cond.dpnt.few 8f // can't find existing fptr 284 ld8 r17=[r29] // read function from fptr 285 ;; 286 cmp.eq p6,p0=r24,r17 // same function? 287 ;; 288(p6) st8 [r15]=r29 // reuse fptr 289(p6) br.cond.sptk.few 2b // done 290 add r29=16,r29 // next fptr 291 br.sptk.few 7b 2928: 293 mov r8=EFI_BUFFER_TOO_SMALL // failure return value 294 cmp.geu p6,p0=r4,r3 // space left? 295(p6) br.cond.dpnt.few 9f // bail out 296 st8 [r15]=r4 // install fptr 297 ;; 298 st8 [r4]=r24,8 // write fptr address 299 ;; 300 st8 [r4]=gp,8 // write fptr gp 301 br.cond.sptk.few 2b 302 3039: 304 mov ar.pfs=loc0 305 mov rp=loc1 306 ;; 307 br.ret.sptk.few rp 308END(_reloc) 309 310 .data 311 .align 16 312fptr_storage: 313 .space 1024*16 // XXX 314fptr_storage_end: 315