| 1 | /* Target-dependent code for the Acorn Risc Machine, for GDB, the GNU Debugger. |
| 2 | Copyright (C) 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "frame.h" |
| 23 | #include "inferior.h" |
| 24 | #include "gdbcmd.h" |
| 25 | #include "gdbcore.h" |
| 26 | #include "symfile.h" |
| 27 | #include "gdb_string.h" |
| 28 | #include "coff/internal.h" /* Internal format of COFF symbols in BFD */ |
| 29 | |
| 30 | /* |
| 31 | The following macros are actually wrong. Neither arm nor thumb can |
| 32 | or should set the lsb on addr. |
| 33 | The thumb addresses are mod 2, so (addr & 2) would be a good heuristic |
| 34 | to use when checking for thumb (see arm_pc_is_thumb() below). |
| 35 | Unfortunately, something else depends on these (incorrect) macros, so |
| 36 | fixing them actually breaks gdb. I didn't have time to investigate. Z.R. |
| 37 | */ |
| 38 | /* Thumb function addresses are odd (bit 0 is set). Here are some |
| 39 | macros to test, set, or clear bit 0 of addresses. */ |
| 40 | #define IS_THUMB_ADDR(addr) ((addr) & 1) |
| 41 | #define MAKE_THUMB_ADDR(addr) ((addr) | 1) |
| 42 | #define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1) |
| 43 | |
| 44 | /* Macros to round N up or down to the next A boundary; A must be |
| 45 | a power of two. */ |
| 46 | #define ROUND_DOWN(n,a) ((n) & ~((a) - 1)) |
| 47 | #define ROUND_UP(n,a) (((n) + (a) - 1) & ~((a) - 1)) |
| 48 | |
| 49 | /* Should call_function allocate stack space for a struct return? */ |
| 50 | /* The system C compiler uses a similar structure return convention to gcc */ |
| 51 | int |
| 52 | arm_use_struct_convention (gcc_p, type) |
| 53 | int gcc_p; |
| 54 | struct type *type; |
| 55 | { |
| 56 | return (TYPE_LENGTH (type) > 4); |
| 57 | } |
| 58 | |
| 59 | /* Set to true if the 32-bit mode is in use. */ |
| 60 | |
| 61 | int arm_apcs_32 = 1; |
| 62 | |
| 63 | /* Flag set by arm_fix_call_dummy that tells whether the target function |
| 64 | is a Thumb function. This flag is checked by arm_push_arguments. |
| 65 | FIXME: Change the PUSH_ARGUMENTS macro (and its use in valops.c) to |
| 66 | pass the function address as an additional parameter. */ |
| 67 | |
| 68 | static int target_is_thumb; |
| 69 | |
| 70 | /* Flag set by arm_fix_call_dummy that tells whether the calling function |
| 71 | is a Thumb function. This flag is checked by arm_pc_is_thumb |
| 72 | and arm_call_dummy_breakpoint_offset. */ |
| 73 | |
| 74 | static int caller_is_thumb; |
| 75 | |
| 76 | /* Tell if the program counter value in MEMADDR is in a Thumb function. */ |
| 77 | |
| 78 | int |
| 79 | arm_pc_is_thumb (memaddr) |
| 80 | bfd_vma memaddr; |
| 81 | { |
| 82 | struct minimal_symbol * sym; |
| 83 | CORE_ADDR sp; |
| 84 | |
| 85 | /* If bit 0 of the address is set, assume this is a Thumb address. */ |
| 86 | if (IS_THUMB_ADDR (memaddr)) |
| 87 | return 1; |
| 88 | |
| 89 | /* Thumb function have a "special" bit set in minimal symbols */ |
| 90 | sym = lookup_minimal_symbol_by_pc (memaddr); |
| 91 | if (sym) |
| 92 | { |
| 93 | return (MSYMBOL_IS_SPECIAL(sym)); |
| 94 | } |
| 95 | else |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | /* Tell if the program counter value in MEMADDR is in a call dummy that |
| 100 | is being called from a Thumb function. */ |
| 101 | |
| 102 | int |
| 103 | arm_pc_is_thumb_dummy (memaddr) |
| 104 | bfd_vma memaddr; |
| 105 | { |
| 106 | CORE_ADDR sp = read_sp(); |
| 107 | |
| 108 | if (PC_IN_CALL_DUMMY (memaddr, sp, sp+64)) |
| 109 | return caller_is_thumb; |
| 110 | else |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | CORE_ADDR |
| 115 | arm_addr_bits_remove (val) |
| 116 | CORE_ADDR val; |
| 117 | { |
| 118 | if (arm_pc_is_thumb (val)) |
| 119 | return (val & (arm_apcs_32 ? 0xfffffffe : 0x03fffffe)); |
| 120 | else |
| 121 | return (val & (arm_apcs_32 ? 0xfffffffc : 0x03fffffc)); |
| 122 | } |
| 123 | |
| 124 | CORE_ADDR |
| 125 | arm_saved_pc_after_call (frame) |
| 126 | struct frame_info *frame; |
| 127 | { |
| 128 | return ADDR_BITS_REMOVE (read_register (LR_REGNUM)); |
| 129 | } |
| 130 | |
| 131 | /* A typical Thumb prologue looks like this: |
| 132 | push {r7, lr} |
| 133 | add sp, sp, #-28 |
| 134 | add r7, sp, #12 |
| 135 | Sometimes the latter instruction may be replaced by: |
| 136 | mov r7, sp |
| 137 | */ |
| 138 | |
| 139 | static CORE_ADDR |
| 140 | thumb_skip_prologue (pc) |
| 141 | CORE_ADDR pc; |
| 142 | { |
| 143 | CORE_ADDR current_pc; |
| 144 | |
| 145 | for (current_pc = pc; current_pc < pc + 20; current_pc += 2) |
| 146 | { |
| 147 | unsigned short insn = read_memory_unsigned_integer (current_pc, 2); |
| 148 | |
| 149 | if ( (insn & 0xfe00) != 0xb400 /* push {..., r7, lr} */ |
| 150 | && (insn & 0xff00) != 0xb000 /* add sp, #simm */ |
| 151 | && (insn & 0xff00) != 0xaf00 /* add r7, sp, #imm */ |
| 152 | && insn != 0x466f /* mov r7, sp */ |
| 153 | && (insn & 0xffc0) != 0x4640) /* mov r0-r7, r8-r15 */ |
| 154 | break; |
| 155 | } |
| 156 | |
| 157 | return current_pc; |
| 158 | } |
| 159 | |
| 160 | /* APCS (ARM procedure call standard) defines the following prologue: |
| 161 | |
| 162 | mov ip, sp |
| 163 | [stmfd sp!, {a1,a2,a3,a4}] |
| 164 | stmfd sp!, {...,fp,ip,lr,pc} |
| 165 | [stfe f7, [sp, #-12]!] |
| 166 | [stfe f6, [sp, #-12]!] |
| 167 | [stfe f5, [sp, #-12]!] |
| 168 | [stfe f4, [sp, #-12]!] |
| 169 | sub fp, ip, #nn // nn == 20 or 4 depending on second ins |
| 170 | */ |
| 171 | |
| 172 | CORE_ADDR |
| 173 | arm_skip_prologue (pc) |
| 174 | CORE_ADDR pc; |
| 175 | { |
| 176 | unsigned long inst; |
| 177 | CORE_ADDR skip_pc; |
| 178 | CORE_ADDR func_addr, func_end; |
| 179 | struct symtab_and_line sal; |
| 180 | |
| 181 | /* See what the symbol table says. */ |
| 182 | if (find_pc_partial_function (pc, NULL, & func_addr, & func_end)) |
| 183 | { |
| 184 | sal = find_pc_line (func_addr, 0); |
| 185 | if (sal.line != 0 && sal.end < func_end) |
| 186 | return sal.end; |
| 187 | } |
| 188 | |
| 189 | /* Check if this is Thumb code. */ |
| 190 | if (arm_pc_is_thumb (pc)) |
| 191 | return thumb_skip_prologue (pc); |
| 192 | |
| 193 | /* Can't find the prologue end in the symbol table, try it the hard way |
| 194 | by disassembling the instructions. */ |
| 195 | skip_pc = pc; |
| 196 | inst = read_memory_integer (skip_pc, 4); |
| 197 | if (inst != 0xe1a0c00d) /* mov ip, sp */ |
| 198 | return pc; |
| 199 | |
| 200 | skip_pc += 4; |
| 201 | inst = read_memory_integer (skip_pc, 4); |
| 202 | if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */ |
| 203 | { |
| 204 | skip_pc += 4; |
| 205 | inst = read_memory_integer (skip_pc, 4); |
| 206 | } |
| 207 | |
| 208 | if ((inst & 0xfffff800) != 0xe92dd800) /* stmfd sp!,{...,fp,ip,lr,pc} */ |
| 209 | return pc; |
| 210 | |
| 211 | skip_pc += 4; |
| 212 | inst = read_memory_integer (skip_pc, 4); |
| 213 | |
| 214 | /* Any insns after this point may float into the code, if it makes |
| 215 | for better instruction scheduling, so we skip them only if |
| 216 | we find them, but still consdier the function to be frame-ful */ |
| 217 | |
| 218 | /* We may have either one sfmfd instruction here, or several stfe insns, |
| 219 | depending on the version of floating point code we support. */ |
| 220 | if ((inst & 0xffbf0fff) == 0xec2d0200) /* sfmfd fn, <cnt>, [sp]! */ |
| 221 | { |
| 222 | skip_pc += 4; |
| 223 | inst = read_memory_integer (skip_pc, 4); |
| 224 | } |
| 225 | else |
| 226 | { |
| 227 | while ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */ |
| 228 | { |
| 229 | skip_pc += 4; |
| 230 | inst = read_memory_integer (skip_pc, 4); |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */ |
| 235 | skip_pc += 4; |
| 236 | |
| 237 | return skip_pc; |
| 238 | } |
| 239 | |
| 240 | |
| 241 | |
| 242 | /* Function: thumb_scan_prologue (helper function for arm_scan_prologue) |
| 243 | This function decodes a Thumb function prologue to determine: |
| 244 | 1) the size of the stack frame |
| 245 | 2) which registers are saved on it |
| 246 | 3) the offsets of saved regs |
| 247 | 4) the offset from the stack pointer to the frame pointer |
| 248 | This information is stored in the "extra" fields of the frame_info. |
| 249 | |
| 250 | A typical Thumb function prologue might look like this: |
| 251 | push {r7, lr} |
| 252 | sub sp, #28, |
| 253 | add r7, sp, #12 |
| 254 | Which would create this stack frame (offsets relative to FP) |
| 255 | old SP -> 24 stack parameters |
| 256 | 20 LR |
| 257 | 16 R7 |
| 258 | R7 -> 0 local variables (16 bytes) |
| 259 | SP -> -12 additional stack space (12 bytes) |
| 260 | The frame size would thus be 36 bytes, and the frame offset would be |
| 261 | 12 bytes. The frame register is R7. */ |
| 262 | |
| 263 | static void |
| 264 | thumb_scan_prologue (fi) |
| 265 | struct frame_info * fi; |
| 266 | { |
| 267 | CORE_ADDR prologue_start; |
| 268 | CORE_ADDR prologue_end; |
| 269 | CORE_ADDR current_pc; |
| 270 | int saved_reg[16]; /* which register has been copied to register n? */ |
| 271 | int i; |
| 272 | |
| 273 | if (find_pc_partial_function (fi->pc, NULL, & prologue_start, & prologue_end)) |
| 274 | { |
| 275 | struct symtab_and_line sal = find_pc_line (prologue_start, 0); |
| 276 | |
| 277 | if (sal.line == 0) /* no line info, use current PC */ |
| 278 | prologue_end = fi->pc; |
| 279 | else if (sal.end < prologue_end) /* next line begins after fn end */ |
| 280 | prologue_end = sal.end; /* (probably means no prologue) */ |
| 281 | } |
| 282 | else |
| 283 | prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */ |
| 284 | /* 16 pushes, an add, and "mv fp,sp" */ |
| 285 | |
| 286 | prologue_end = min (prologue_end, fi->pc); |
| 287 | |
| 288 | /* Initialize the saved register map. When register H is copied to |
| 289 | register L, we will put H in saved_reg[L]. */ |
| 290 | for (i = 0; i < 16; i++) |
| 291 | saved_reg[i] = i; |
| 292 | |
| 293 | /* Search the prologue looking for instructions that set up the |
| 294 | frame pointer, adjust the stack pointer, and save registers. */ |
| 295 | |
| 296 | fi->framesize = 0; |
| 297 | for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2) |
| 298 | { |
| 299 | unsigned short insn; |
| 300 | int regno; |
| 301 | int offset; |
| 302 | |
| 303 | insn = read_memory_unsigned_integer (current_pc, 2); |
| 304 | |
| 305 | if ((insn & 0xfe00) == 0xb400) /* push { rlist } */ |
| 306 | { |
| 307 | /* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says |
| 308 | whether to save LR (R14). */ |
| 309 | int mask = (insn & 0xff) | ((insn & 0x100) << 6); |
| 310 | |
| 311 | /* Calculate offsets of saved R0-R7 and LR. */ |
| 312 | for (regno = LR_REGNUM; regno >= 0; regno--) |
| 313 | if (mask & (1 << regno)) |
| 314 | { |
| 315 | fi->framesize += 4; |
| 316 | fi->fsr.regs[saved_reg[regno]] = -(fi->framesize); |
| 317 | saved_reg[regno] = regno; /* reset saved register map */ |
| 318 | } |
| 319 | } |
| 320 | else if ((insn & 0xff00) == 0xb000) /* add sp, #simm */ |
| 321 | { |
| 322 | offset = (insn & 0x7f) << 2; /* get scaled offset */ |
| 323 | if (insn & 0x80) /* is it signed? */ |
| 324 | offset = -offset; |
| 325 | fi->framesize -= offset; |
| 326 | } |
| 327 | else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */ |
| 328 | { |
| 329 | fi->framereg = THUMB_FP_REGNUM; |
| 330 | fi->frameoffset = (insn & 0xff) << 2; /* get scaled offset */ |
| 331 | } |
| 332 | else if (insn == 0x466f) /* mov r7, sp */ |
| 333 | { |
| 334 | fi->framereg = THUMB_FP_REGNUM; |
| 335 | fi->frameoffset = 0; |
| 336 | saved_reg[THUMB_FP_REGNUM] = SP_REGNUM; |
| 337 | } |
| 338 | else if ((insn & 0xffc0) == 0x4640) /* mov r0-r7, r8-r15 */ |
| 339 | { |
| 340 | int lo_reg = insn & 7; /* dest. register (r0-r7) */ |
| 341 | int hi_reg = ((insn >> 3) & 7) + 8; /* source register (r8-15) */ |
| 342 | saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */ |
| 343 | } |
| 344 | else |
| 345 | break; /* anything else isn't prologue */ |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | /* Function: check_prologue_cache |
| 350 | Check if prologue for this frame's PC has already been scanned. |
| 351 | If it has, copy the relevant information about that prologue and |
| 352 | return non-zero. Otherwise do not copy anything and return zero. |
| 353 | |
| 354 | The information saved in the cache includes: |
| 355 | * the frame register number; |
| 356 | * the size of the stack frame; |
| 357 | * the offsets of saved regs (relative to the old SP); and |
| 358 | * the offset from the stack pointer to the frame pointer |
| 359 | |
| 360 | The cache contains only one entry, since this is adequate |
| 361 | for the typical sequence of prologue scan requests we get. |
| 362 | When performing a backtrace, GDB will usually ask to scan |
| 363 | the same function twice in a row (once to get the frame chain, |
| 364 | and once to fill in the extra frame information). |
| 365 | */ |
| 366 | |
| 367 | static struct frame_info prologue_cache; |
| 368 | |
| 369 | static int |
| 370 | check_prologue_cache (fi) |
| 371 | struct frame_info * fi; |
| 372 | { |
| 373 | int i; |
| 374 | |
| 375 | if (fi->pc == prologue_cache.pc) |
| 376 | { |
| 377 | fi->framereg = prologue_cache.framereg; |
| 378 | fi->framesize = prologue_cache.framesize; |
| 379 | fi->frameoffset = prologue_cache.frameoffset; |
| 380 | for (i = 0; i <= NUM_REGS; i++) |
| 381 | fi->fsr.regs[i] = prologue_cache.fsr.regs[i]; |
| 382 | return 1; |
| 383 | } |
| 384 | else |
| 385 | return 0; |
| 386 | } |
| 387 | |
| 388 | |
| 389 | /* Function: save_prologue_cache |
| 390 | Copy the prologue information from fi to the prologue cache. |
| 391 | */ |
| 392 | |
| 393 | static void |
| 394 | save_prologue_cache (fi) |
| 395 | struct frame_info * fi; |
| 396 | { |
| 397 | int i; |
| 398 | |
| 399 | prologue_cache.pc = fi->pc; |
| 400 | prologue_cache.framereg = fi->framereg; |
| 401 | prologue_cache.framesize = fi->framesize; |
| 402 | prologue_cache.frameoffset = fi->frameoffset; |
| 403 | |
| 404 | for (i = 0; i <= NUM_REGS; i++) |
| 405 | prologue_cache.fsr.regs[i] = fi->fsr.regs[i]; |
| 406 | } |
| 407 | |
| 408 | |
| 409 | /* Function: arm_scan_prologue |
| 410 | This function decodes an ARM function prologue to determine: |
| 411 | 1) the size of the stack frame |
| 412 | 2) which registers are saved on it |
| 413 | 3) the offsets of saved regs |
| 414 | 4) the offset from the stack pointer to the frame pointer |
| 415 | This information is stored in the "extra" fields of the frame_info. |
| 416 | |
| 417 | A typical Arm function prologue might look like this: |
| 418 | mov ip, sp |
| 419 | stmfd sp!, {fp, ip, lr, pc} |
| 420 | sub fp, ip, #4 |
| 421 | sub sp, sp, #16 |
| 422 | Which would create this stack frame (offsets relative to FP): |
| 423 | IP -> 4 (caller's stack) |
| 424 | FP -> 0 PC (points to address of stmfd instruction + 12 in callee) |
| 425 | -4 LR (return address in caller) |
| 426 | -8 IP (copy of caller's SP) |
| 427 | -12 FP (caller's FP) |
| 428 | SP -> -28 Local variables |
| 429 | The frame size would thus be 32 bytes, and the frame offset would be |
| 430 | 28 bytes. */ |
| 431 | |
| 432 | static void |
| 433 | arm_scan_prologue (fi) |
| 434 | struct frame_info * fi; |
| 435 | { |
| 436 | int regno, sp_offset, fp_offset; |
| 437 | CORE_ADDR prologue_start, prologue_end, current_pc; |
| 438 | |
| 439 | /* Check if this function is already in the cache of frame information. */ |
| 440 | if (check_prologue_cache (fi)) |
| 441 | return; |
| 442 | |
| 443 | /* Assume there is no frame until proven otherwise. */ |
| 444 | fi->framereg = SP_REGNUM; |
| 445 | fi->framesize = 0; |
| 446 | fi->frameoffset = 0; |
| 447 | |
| 448 | /* Check for Thumb prologue. */ |
| 449 | if (arm_pc_is_thumb (fi->pc)) |
| 450 | { |
| 451 | thumb_scan_prologue (fi); |
| 452 | save_prologue_cache (fi); |
| 453 | return; |
| 454 | } |
| 455 | |
| 456 | /* Find the function prologue. If we can't find the function in |
| 457 | the symbol table, peek in the stack frame to find the PC. */ |
| 458 | if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) |
| 459 | { |
| 460 | /* Assume the prologue is everything between the first instruction |
| 461 | in the function and the first source line. */ |
| 462 | struct symtab_and_line sal = find_pc_line (prologue_start, 0); |
| 463 | |
| 464 | if (sal.line == 0) /* no line info, use current PC */ |
| 465 | prologue_end = fi->pc; |
| 466 | else if (sal.end < prologue_end) /* next line begins after fn end */ |
| 467 | prologue_end = sal.end; /* (probably means no prologue) */ |
| 468 | } |
| 469 | else |
| 470 | { |
| 471 | /* Get address of the stmfd in the prologue of the callee; the saved |
| 472 | PC is the address of the stmfd + 12. */ |
| 473 | prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12; |
| 474 | prologue_end = prologue_start + 40; /* FIXME: should be big enough */ |
| 475 | } |
| 476 | |
| 477 | /* Now search the prologue looking for instructions that set up the |
| 478 | frame pointer, adjust the stack pointer, and save registers. */ |
| 479 | |
| 480 | sp_offset = fp_offset = 0; |
| 481 | for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4) |
| 482 | { |
| 483 | unsigned int insn = read_memory_unsigned_integer (current_pc, 4); |
| 484 | |
| 485 | if ((insn & 0xffff0000) == 0xe92d0000) /* stmfd sp!, {..., r7, lr} */ |
| 486 | { |
| 487 | int mask = insn & 0xffff; |
| 488 | |
| 489 | /* Calculate offsets of saved registers. */ |
| 490 | for (regno = PC_REGNUM; regno >= 0; regno--) |
| 491 | if (mask & (1 << regno)) |
| 492 | { |
| 493 | sp_offset -= 4; |
| 494 | fi->fsr.regs[regno] = sp_offset; |
| 495 | } |
| 496 | } |
| 497 | else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */ |
| 498 | { |
| 499 | unsigned imm = insn & 0xff; /* immediate value */ |
| 500 | unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ |
| 501 | imm = (imm >> rot) | (imm << (32-rot)); |
| 502 | fp_offset = -imm; |
| 503 | fi->framereg = FP_REGNUM; |
| 504 | } |
| 505 | else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */ |
| 506 | { |
| 507 | unsigned imm = insn & 0xff; /* immediate value */ |
| 508 | unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ |
| 509 | imm = (imm >> rot) | (imm << (32-rot)); |
| 510 | sp_offset -= imm; |
| 511 | } |
| 512 | else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */ |
| 513 | { |
| 514 | sp_offset -= 12; |
| 515 | regno = F0_REGNUM + ((insn >> 12) & 0x07); |
| 516 | fi->fsr.regs[regno] = sp_offset; |
| 517 | } |
| 518 | else if (insn == 0xe1a0c00d) /* mov ip, sp */ |
| 519 | continue; |
| 520 | else |
| 521 | break; /* not a recognized prologue instruction */ |
| 522 | } |
| 523 | |
| 524 | /* The frame size is just the negative of the offset (from the original SP) |
| 525 | of the last thing thing we pushed on the stack. The frame offset is |
| 526 | [new FP] - [new SP]. */ |
| 527 | fi->framesize = -sp_offset; |
| 528 | fi->frameoffset = fp_offset - sp_offset; |
| 529 | |
| 530 | save_prologue_cache (fi); |
| 531 | } |
| 532 | |
| 533 | |
| 534 | /* Function: find_callers_reg |
| 535 | Find REGNUM on the stack. Otherwise, it's in an active register. One thing |
| 536 | we might want to do here is to check REGNUM against the clobber mask, and |
| 537 | somehow flag it as invalid if it isn't saved on the stack somewhere. This |
| 538 | would provide a graceful failure mode when trying to get the value of |
| 539 | caller-saves registers for an inner frame. */ |
| 540 | |
| 541 | static CORE_ADDR |
| 542 | arm_find_callers_reg (fi, regnum) |
| 543 | struct frame_info * fi; |
| 544 | int regnum; |
| 545 | { |
| 546 | for (; fi; fi = fi->next) |
| 547 | |
| 548 | #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */ |
| 549 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 550 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); |
| 551 | else |
| 552 | #endif |
| 553 | if (fi->fsr.regs[regnum] != 0) |
| 554 | return read_memory_integer (fi->fsr.regs[regnum], |
| 555 | REGISTER_RAW_SIZE(regnum)); |
| 556 | return read_register (regnum); |
| 557 | } |
| 558 | |
| 559 | |
| 560 | /* Function: frame_chain |
| 561 | Given a GDB frame, determine the address of the calling function's frame. |
| 562 | This will be used to create a new GDB frame struct, and then |
| 563 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. |
| 564 | For ARM, we save the frame size when we initialize the frame_info. |
| 565 | |
| 566 | The original definition of this function was a macro in tm-arm.h: |
| 567 | { In the case of the ARM, the frame's nominal address is the FP value, |
| 568 | and 12 bytes before comes the saved previous FP value as a 4-byte word. } |
| 569 | |
| 570 | #define FRAME_CHAIN(thisframe) \ |
| 571 | ((thisframe)->pc >= LOWEST_PC ? \ |
| 572 | read_memory_integer ((thisframe)->frame - 12, 4) :\ |
| 573 | 0) |
| 574 | */ |
| 575 | |
| 576 | CORE_ADDR |
| 577 | arm_frame_chain (fi) |
| 578 | struct frame_info * fi; |
| 579 | { |
| 580 | #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */ |
| 581 | CORE_ADDR fn_start, callers_pc, fp; |
| 582 | |
| 583 | /* is this a dummy frame? */ |
| 584 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 585 | return fi->frame; /* dummy frame same as caller's frame */ |
| 586 | |
| 587 | /* is caller-of-this a dummy frame? */ |
| 588 | callers_pc = FRAME_SAVED_PC(fi); /* find out who called us: */ |
| 589 | fp = arm_find_callers_reg (fi, FP_REGNUM); |
| 590 | if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) |
| 591 | return fp; /* dummy frame's frame may bear no relation to ours */ |
| 592 | |
| 593 | if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) |
| 594 | if (fn_start == entry_point_address ()) |
| 595 | return 0; /* in _start fn, don't chain further */ |
| 596 | #endif |
| 597 | CORE_ADDR caller_pc, fn_start; |
| 598 | struct frame_info caller_fi; |
| 599 | int framereg = fi->framereg; |
| 600 | |
| 601 | if (fi->pc < LOWEST_PC) |
| 602 | return 0; |
| 603 | |
| 604 | /* If the caller is the startup code, we're at the end of the chain. */ |
| 605 | caller_pc = FRAME_SAVED_PC (fi); |
| 606 | if (find_pc_partial_function (caller_pc, 0, &fn_start, 0)) |
| 607 | if (fn_start == entry_point_address ()) |
| 608 | return 0; |
| 609 | |
| 610 | /* If the caller is Thumb and the caller is ARM, or vice versa, |
| 611 | the frame register of the caller is different from ours. |
| 612 | So we must scan the prologue of the caller to determine its |
| 613 | frame register number. */ |
| 614 | if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc)) |
| 615 | { |
| 616 | memset (& caller_fi, 0, sizeof (caller_fi)); |
| 617 | caller_fi.pc = caller_pc; |
| 618 | arm_scan_prologue (& caller_fi); |
| 619 | framereg = caller_fi.framereg; |
| 620 | } |
| 621 | |
| 622 | /* If the caller used a frame register, return its value. |
| 623 | Otherwise, return the caller's stack pointer. */ |
| 624 | if (framereg == FP_REGNUM || framereg == THUMB_FP_REGNUM) |
| 625 | return arm_find_callers_reg (fi, framereg); |
| 626 | else |
| 627 | return fi->frame + fi->framesize; |
| 628 | } |
| 629 | |
| 630 | /* Function: init_extra_frame_info |
| 631 | This function actually figures out the frame address for a given pc and |
| 632 | sp. This is tricky because we sometimes don't use an explicit |
| 633 | frame pointer, and the previous stack pointer isn't necessarily recorded |
| 634 | on the stack. The only reliable way to get this info is to |
| 635 | examine the prologue. */ |
| 636 | |
| 637 | void |
| 638 | arm_init_extra_frame_info (fi) |
| 639 | struct frame_info * fi; |
| 640 | { |
| 641 | int reg; |
| 642 | |
| 643 | if (fi->next) |
| 644 | fi->pc = FRAME_SAVED_PC (fi->next); |
| 645 | |
| 646 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); |
| 647 | |
| 648 | #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */ |
| 649 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 650 | { |
| 651 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong |
| 652 | by assuming it's always FP. */ |
| 653 | fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); |
| 654 | fi->framesize = 0; |
| 655 | fi->frameoffset = 0; |
| 656 | return; |
| 657 | } |
| 658 | else |
| 659 | #endif |
| 660 | { |
| 661 | arm_scan_prologue (fi); |
| 662 | |
| 663 | if (!fi->next) /* this is the innermost frame? */ |
| 664 | fi->frame = read_register (fi->framereg); |
| 665 | else /* not the innermost frame */ |
| 666 | /* If we have an FP, the callee saved it. */ |
| 667 | if (fi->framereg == FP_REGNUM || fi->framereg == THUMB_FP_REGNUM) |
| 668 | if (fi->next->fsr.regs[fi->framereg] != 0) |
| 669 | fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg], |
| 670 | 4); |
| 671 | |
| 672 | /* Calculate actual addresses of saved registers using offsets determined |
| 673 | by arm_scan_prologue. */ |
| 674 | for (reg = 0; reg < NUM_REGS; reg++) |
| 675 | if (fi->fsr.regs[reg] != 0) |
| 676 | fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset; |
| 677 | } |
| 678 | } |
| 679 | |
| 680 | |
| 681 | /* Function: frame_saved_pc |
| 682 | Find the caller of this frame. We do this by seeing if LR_REGNUM is saved |
| 683 | in the stack anywhere, otherwise we get it from the registers. |
| 684 | |
| 685 | The old definition of this function was a macro: |
| 686 | #define FRAME_SAVED_PC(FRAME) \ |
| 687 | ADDR_BITS_REMOVE (read_memory_integer ((FRAME)->frame - 4, 4)) |
| 688 | */ |
| 689 | |
| 690 | CORE_ADDR |
| 691 | arm_frame_saved_pc (fi) |
| 692 | struct frame_info * fi; |
| 693 | { |
| 694 | #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */ |
| 695 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 696 | return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); |
| 697 | else |
| 698 | #endif |
| 699 | { |
| 700 | CORE_ADDR pc = arm_find_callers_reg (fi, LR_REGNUM); |
| 701 | return IS_THUMB_ADDR (pc) ? UNMAKE_THUMB_ADDR (pc) : pc; |
| 702 | } |
| 703 | } |
| 704 | |
| 705 | |
| 706 | /* Return the frame address. On ARM, it is R11; on Thumb it is R7. |
| 707 | Examine the Program Status Register to decide which state we're in. */ |
| 708 | |
| 709 | CORE_ADDR |
| 710 | arm_target_read_fp () |
| 711 | { |
| 712 | if (read_register (PS_REGNUM) & 0x20) /* Bit 5 is Thumb state bit */ |
| 713 | return read_register (THUMB_FP_REGNUM); /* R7 if Thumb */ |
| 714 | else |
| 715 | return read_register (FP_REGNUM); /* R11 if ARM */ |
| 716 | } |
| 717 | |
| 718 | |
| 719 | /* Calculate the frame offsets of the saved registers (ARM version). */ |
| 720 | void |
| 721 | arm_frame_find_saved_regs (fi, regaddr) |
| 722 | struct frame_info *fi; |
| 723 | struct frame_saved_regs *regaddr; |
| 724 | { |
| 725 | memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs)); |
| 726 | } |
| 727 | |
| 728 | |
| 729 | void |
| 730 | arm_push_dummy_frame () |
| 731 | { |
| 732 | CORE_ADDR old_sp = read_register (SP_REGNUM); |
| 733 | CORE_ADDR sp = old_sp; |
| 734 | CORE_ADDR fp, prologue_start; |
| 735 | int regnum; |
| 736 | |
| 737 | /* Push the two dummy prologue instructions in reverse order, |
| 738 | so that they'll be in the correct low-to-high order in memory. */ |
| 739 | /* sub fp, ip, #4 */ |
| 740 | sp = push_word (sp, 0xe24cb004); |
| 741 | /* stmdb sp!, {r0-r10, fp, ip, lr, pc} */ |
| 742 | prologue_start = sp = push_word (sp, 0xe92ddfff); |
| 743 | |
| 744 | /* push a pointer to the dummy prologue + 12, because when |
| 745 | stm instruction stores the PC, it stores the address of the stm |
| 746 | instruction itself plus 12. */ |
| 747 | fp = sp = push_word (sp, prologue_start + 12); |
| 748 | sp = push_word (sp, read_register (PC_REGNUM)); /* FIXME: was PS_REGNUM */ |
| 749 | sp = push_word (sp, old_sp); |
| 750 | sp = push_word (sp, read_register (FP_REGNUM)); |
| 751 | |
| 752 | for (regnum = 10; regnum >= 0; regnum --) |
| 753 | sp = push_word (sp, read_register (regnum)); |
| 754 | |
| 755 | write_register (FP_REGNUM, fp); |
| 756 | write_register (THUMB_FP_REGNUM, fp); |
| 757 | write_register (SP_REGNUM, sp); |
| 758 | } |
| 759 | |
| 760 | /* Fix up the call dummy, based on whether the processor is currently |
| 761 | in Thumb or ARM mode, and whether the target function is Thumb |
| 762 | or ARM. There are three different situations requiring three |
| 763 | different dummies: |
| 764 | |
| 765 | * ARM calling ARM: uses the call dummy in tm-arm.h, which has already |
| 766 | been copied into the dummy parameter to this function. |
| 767 | * ARM calling Thumb: uses the call dummy in tm-arm.h, but with the |
| 768 | "mov pc,r4" instruction patched to be a "bx r4" instead. |
| 769 | * Thumb calling anything: uses the Thumb dummy defined below, which |
| 770 | works for calling both ARM and Thumb functions. |
| 771 | |
| 772 | All three call dummies expect to receive the target function address |
| 773 | in R4, with the low bit set if it's a Thumb function. |
| 774 | */ |
| 775 | |
| 776 | void |
| 777 | arm_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p) |
| 778 | char * dummy; |
| 779 | CORE_ADDR pc; |
| 780 | CORE_ADDR fun; |
| 781 | int nargs; |
| 782 | value_ptr * args; |
| 783 | struct type * type; |
| 784 | int gcc_p; |
| 785 | { |
| 786 | static short thumb_dummy[4] = |
| 787 | { |
| 788 | 0xf000, 0xf801, /* bl label */ |
| 789 | 0xdf18, /* swi 24 */ |
| 790 | 0x4720, /* label: bx r4 */ |
| 791 | }; |
| 792 | static unsigned long arm_bx_r4 = 0xe12fff14; /* bx r4 instruction */ |
| 793 | |
| 794 | /* Set flag indicating whether the current PC is in a Thumb function. */ |
| 795 | caller_is_thumb = arm_pc_is_thumb (read_pc()); |
| 796 | |
| 797 | /* If the target function is Thumb, set the low bit of the function address. |
| 798 | And if the CPU is currently in ARM mode, patch the second instruction |
| 799 | of call dummy to use a BX instruction to switch to Thumb mode. */ |
| 800 | target_is_thumb = arm_pc_is_thumb (fun); |
| 801 | if (target_is_thumb) |
| 802 | { |
| 803 | fun |= 1; |
| 804 | if (!caller_is_thumb) |
| 805 | store_unsigned_integer (dummy + 4, sizeof (arm_bx_r4), arm_bx_r4); |
| 806 | } |
| 807 | |
| 808 | /* If the CPU is currently in Thumb mode, use the Thumb call dummy |
| 809 | instead of the ARM one that's already been copied. This will |
| 810 | work for both Thumb and ARM target functions. */ |
| 811 | if (caller_is_thumb) |
| 812 | { |
| 813 | int i; |
| 814 | char *p = dummy; |
| 815 | int len = sizeof (thumb_dummy) / sizeof (thumb_dummy[0]); |
| 816 | |
| 817 | for (i = 0; i < len; i++) |
| 818 | { |
| 819 | store_unsigned_integer (p, sizeof (thumb_dummy[0]), thumb_dummy[i]); |
| 820 | p += sizeof (thumb_dummy[0]); |
| 821 | } |
| 822 | } |
| 823 | |
| 824 | /* Put the target address in r4; the call dummy will copy this to the PC. */ |
| 825 | write_register (4, fun); |
| 826 | } |
| 827 | |
| 828 | |
| 829 | /* Return the offset in the call dummy of the instruction that needs |
| 830 | to have a breakpoint placed on it. This is the offset of the 'swi 24' |
| 831 | instruction, which is no longer actually used, but simply acts |
| 832 | as a place-holder now. |
| 833 | |
| 834 | This implements the CALL_DUMMY_BREAK_OFFSET macro. |
| 835 | */ |
| 836 | |
| 837 | int |
| 838 | arm_call_dummy_breakpoint_offset () |
| 839 | { |
| 840 | if (caller_is_thumb) |
| 841 | return 4; |
| 842 | else |
| 843 | return 8; |
| 844 | } |
| 845 | |
| 846 | |
| 847 | CORE_ADDR |
| 848 | arm_push_arguments(nargs, args, sp, struct_return, struct_addr) |
| 849 | int nargs; |
| 850 | value_ptr * args; |
| 851 | CORE_ADDR sp; |
| 852 | int struct_return; |
| 853 | CORE_ADDR struct_addr; |
| 854 | { |
| 855 | int argreg; |
| 856 | int float_argreg; |
| 857 | int argnum; |
| 858 | int stack_offset; |
| 859 | struct stack_arg { |
| 860 | char *val; |
| 861 | int len; |
| 862 | int offset; |
| 863 | }; |
| 864 | struct stack_arg *stack_args = |
| 865 | (struct stack_arg*)alloca (nargs * sizeof (struct stack_arg)); |
| 866 | int nstack_args = 0; |
| 867 | |
| 868 | |
| 869 | /* Initialize the integer and float register pointers. */ |
| 870 | argreg = A1_REGNUM; |
| 871 | float_argreg = F0_REGNUM; |
| 872 | |
| 873 | /* the struct_return pointer occupies the first parameter-passing reg */ |
| 874 | if (struct_return) |
| 875 | write_register (argreg++, struct_addr); |
| 876 | |
| 877 | /* The offset onto the stack at which we will start copying parameters |
| 878 | (after the registers are used up) begins at 16 in the old ABI. |
| 879 | This leaves room for the "home" area for register parameters. */ |
| 880 | stack_offset = REGISTER_SIZE * 4; |
| 881 | |
| 882 | /* Process args from left to right. Store as many as allowed in |
| 883 | registers, save the rest to be pushed on the stack */ |
| 884 | for(argnum = 0; argnum < nargs; argnum++) |
| 885 | { |
| 886 | char * val; |
| 887 | value_ptr arg = args[argnum]; |
| 888 | struct type * arg_type = check_typedef (VALUE_TYPE (arg)); |
| 889 | struct type * target_type = TYPE_TARGET_TYPE (arg_type); |
| 890 | int len = TYPE_LENGTH (arg_type); |
| 891 | enum type_code typecode = TYPE_CODE (arg_type); |
| 892 | CORE_ADDR regval; |
| 893 | int newarg; |
| 894 | |
| 895 | val = (char *) VALUE_CONTENTS (arg); |
| 896 | |
| 897 | /* If the argument is a pointer to a function, and it's a Thumb |
| 898 | function, set the low bit of the pointer. */ |
| 899 | if (typecode == TYPE_CODE_PTR |
| 900 | && target_type != NULL |
| 901 | && TYPE_CODE (target_type) == TYPE_CODE_FUNC) |
| 902 | { |
| 903 | regval = extract_address (val, len); |
| 904 | if (arm_pc_is_thumb (regval)) |
| 905 | store_address (val, len, MAKE_THUMB_ADDR (regval)); |
| 906 | } |
| 907 | |
| 908 | #define MAPCS_FLOAT 0 /* --mapcs-float not implemented by the compiler yet */ |
| 909 | #if MAPCS_FLOAT |
| 910 | /* Up to four floating point arguments can be passed in floating |
| 911 | point registers on ARM (not on Thumb). */ |
| 912 | if (typecode == TYPE_CODE_FLT |
| 913 | && float_argreg <= ARM_LAST_FP_ARG_REGNUM |
| 914 | && !target_is_thumb) |
| 915 | { |
| 916 | /* This is a floating point value that fits entirely |
| 917 | in a single register. */ |
| 918 | regval = extract_address (val, len); |
| 919 | write_register (float_argreg++, regval); |
| 920 | } |
| 921 | else |
| 922 | #endif |
| 923 | { |
| 924 | /* Copy the argument to general registers or the stack in |
| 925 | register-sized pieces. Large arguments are split between |
| 926 | registers and stack. */ |
| 927 | while (len > 0) |
| 928 | { |
| 929 | if (argreg <= ARM_LAST_ARG_REGNUM) |
| 930 | { |
| 931 | int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE; |
| 932 | regval = extract_address (val, partial_len); |
| 933 | |
| 934 | /* It's a simple argument being passed in a general |
| 935 | register. */ |
| 936 | write_register (argreg, regval); |
| 937 | argreg++; |
| 938 | len -= partial_len; |
| 939 | val += partial_len; |
| 940 | } |
| 941 | else |
| 942 | { |
| 943 | /* keep for later pushing */ |
| 944 | stack_args[nstack_args].val = val; |
| 945 | stack_args[nstack_args++].len = len; |
| 946 | break; |
| 947 | } |
| 948 | } |
| 949 | } |
| 950 | } |
| 951 | /* now do the real stack pushing, process args right to left */ |
| 952 | while(nstack_args--) |
| 953 | { |
| 954 | sp -= stack_args[nstack_args].len; |
| 955 | write_memory(sp, stack_args[nstack_args].val, |
| 956 | stack_args[nstack_args].len); |
| 957 | } |
| 958 | |
| 959 | /* Return adjusted stack pointer. */ |
| 960 | return sp; |
| 961 | } |
| 962 | |
| 963 | void |
| 964 | arm_pop_frame () |
| 965 | { |
| 966 | struct frame_info *frame = get_current_frame(); |
| 967 | int regnum; |
| 968 | |
| 969 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 970 | if (frame->fsr.regs[regnum] != 0) |
| 971 | write_register (regnum, |
| 972 | read_memory_integer (frame->fsr.regs[regnum], 4)); |
| 973 | |
| 974 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
| 975 | write_register (SP_REGNUM, read_register (frame->framereg)); |
| 976 | |
| 977 | flush_cached_frames (); |
| 978 | } |
| 979 | |
| 980 | static void |
| 981 | print_fpu_flags (flags) |
| 982 | int flags; |
| 983 | { |
| 984 | if (flags & (1 << 0)) fputs ("IVO ", stdout); |
| 985 | if (flags & (1 << 1)) fputs ("DVZ ", stdout); |
| 986 | if (flags & (1 << 2)) fputs ("OFL ", stdout); |
| 987 | if (flags & (1 << 3)) fputs ("UFL ", stdout); |
| 988 | if (flags & (1 << 4)) fputs ("INX ", stdout); |
| 989 | putchar ('\n'); |
| 990 | } |
| 991 | |
| 992 | void |
| 993 | arm_float_info () |
| 994 | { |
| 995 | register unsigned long status = read_register (FPS_REGNUM); |
| 996 | int type; |
| 997 | |
| 998 | type = (status >> 24) & 127; |
| 999 | printf ("%s FPU type %d\n", |
| 1000 | (status & (1<<31)) ? "Hardware" : "Software", |
| 1001 | type); |
| 1002 | fputs ("mask: ", stdout); |
| 1003 | print_fpu_flags (status >> 16); |
| 1004 | fputs ("flags: ", stdout); |
| 1005 | print_fpu_flags (status); |
| 1006 | } |
| 1007 | |
| 1008 | static void |
| 1009 | arm_othernames () |
| 1010 | { |
| 1011 | static int toggle; |
| 1012 | static char *original[] = ORIGINAL_REGISTER_NAMES; |
| 1013 | static char *extra_crispy[] = ADDITIONAL_REGISTER_NAMES; |
| 1014 | |
| 1015 | memcpy (reg_names, toggle ? extra_crispy : original, sizeof(original)); |
| 1016 | toggle = !toggle; |
| 1017 | } |
| 1018 | |
| 1019 | /* FIXME: Fill in with the 'right thing', see asm |
| 1020 | template in arm-convert.s */ |
| 1021 | |
| 1022 | void |
| 1023 | convert_from_extended (ptr, dbl) |
| 1024 | void * ptr; |
| 1025 | double * dbl; |
| 1026 | { |
| 1027 | *dbl = *(double*)ptr; |
| 1028 | } |
| 1029 | |
| 1030 | void |
| 1031 | convert_to_extended (dbl, ptr) |
| 1032 | void * ptr; |
| 1033 | double * dbl; |
| 1034 | { |
| 1035 | *(double*)ptr = *dbl; |
| 1036 | } |
| 1037 | |
| 1038 | static int |
| 1039 | condition_true (cond, status_reg) |
| 1040 | unsigned long cond; |
| 1041 | unsigned long status_reg; |
| 1042 | { |
| 1043 | if (cond == INST_AL || cond == INST_NV) |
| 1044 | return 1; |
| 1045 | |
| 1046 | switch (cond) |
| 1047 | { |
| 1048 | case INST_EQ: |
| 1049 | return ((status_reg & FLAG_Z) != 0); |
| 1050 | case INST_NE: |
| 1051 | return ((status_reg & FLAG_Z) == 0); |
| 1052 | case INST_CS: |
| 1053 | return ((status_reg & FLAG_C) != 0); |
| 1054 | case INST_CC: |
| 1055 | return ((status_reg & FLAG_C) == 0); |
| 1056 | case INST_MI: |
| 1057 | return ((status_reg & FLAG_N) != 0); |
| 1058 | case INST_PL: |
| 1059 | return ((status_reg & FLAG_N) == 0); |
| 1060 | case INST_VS: |
| 1061 | return ((status_reg & FLAG_V) != 0); |
| 1062 | case INST_VC: |
| 1063 | return ((status_reg & FLAG_V) == 0); |
| 1064 | case INST_HI: |
| 1065 | return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C); |
| 1066 | case INST_LS: |
| 1067 | return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C); |
| 1068 | case INST_GE: |
| 1069 | return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0)); |
| 1070 | case INST_LT: |
| 1071 | return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0)); |
| 1072 | case INST_GT: |
| 1073 | return (((status_reg & FLAG_Z) == 0) && |
| 1074 | (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0))); |
| 1075 | case INST_LE: |
| 1076 | return (((status_reg & FLAG_Z) != 0) || |
| 1077 | (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0))); |
| 1078 | } |
| 1079 | return 1; |
| 1080 | } |
| 1081 | |
| 1082 | #define submask(x) ((1L << ((x) + 1)) - 1) |
| 1083 | #define bit(obj,st) (((obj) >> (st)) & 1) |
| 1084 | #define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st))) |
| 1085 | #define sbits(obj,st,fn) \ |
| 1086 | ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st)))) |
| 1087 | #define BranchDest(addr,instr) \ |
| 1088 | ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2))) |
| 1089 | #define ARM_PC_32 1 |
| 1090 | |
| 1091 | static unsigned long |
| 1092 | shifted_reg_val (inst, carry, pc_val, status_reg) |
| 1093 | unsigned long inst; |
| 1094 | int carry; |
| 1095 | unsigned long pc_val; |
| 1096 | unsigned long status_reg; |
| 1097 | { |
| 1098 | unsigned long res, shift; |
| 1099 | int rm = bits (inst, 0, 3); |
| 1100 | unsigned long shifttype = bits (inst, 5, 6); |
| 1101 | |
| 1102 | if (bit(inst, 4)) |
| 1103 | { |
| 1104 | int rs = bits (inst, 8, 11); |
| 1105 | shift = (rs == 15 ? pc_val + 8 : read_register (rs)) & 0xFF; |
| 1106 | } |
| 1107 | else |
| 1108 | shift = bits (inst, 7, 11); |
| 1109 | |
| 1110 | res = (rm == 15 |
| 1111 | ? ((pc_val | (ARM_PC_32 ? 0 : status_reg)) |
| 1112 | + (bit (inst, 4) ? 12 : 8)) |
| 1113 | : read_register (rm)); |
| 1114 | |
| 1115 | switch (shifttype) |
| 1116 | { |
| 1117 | case 0: /* LSL */ |
| 1118 | res = shift >= 32 ? 0 : res << shift; |
| 1119 | break; |
| 1120 | |
| 1121 | case 1: /* LSR */ |
| 1122 | res = shift >= 32 ? 0 : res >> shift; |
| 1123 | break; |
| 1124 | |
| 1125 | case 2: /* ASR */ |
| 1126 | if (shift >= 32) shift = 31; |
| 1127 | res = ((res & 0x80000000L) |
| 1128 | ? ~((~res) >> shift) : res >> shift); |
| 1129 | break; |
| 1130 | |
| 1131 | case 3: /* ROR/RRX */ |
| 1132 | shift &= 31; |
| 1133 | if (shift == 0) |
| 1134 | res = (res >> 1) | (carry ? 0x80000000L : 0); |
| 1135 | else |
| 1136 | res = (res >> shift) | (res << (32-shift)); |
| 1137 | break; |
| 1138 | } |
| 1139 | |
| 1140 | return res & 0xffffffff; |
| 1141 | } |
| 1142 | |
| 1143 | |
| 1144 | /* Return number of 1-bits in VAL. */ |
| 1145 | |
| 1146 | static int |
| 1147 | bitcount (val) |
| 1148 | unsigned long val; |
| 1149 | { |
| 1150 | int nbits; |
| 1151 | for (nbits = 0; val != 0; nbits++) |
| 1152 | val &= val - 1; /* delete rightmost 1-bit in val */ |
| 1153 | return nbits; |
| 1154 | } |
| 1155 | |
| 1156 | |
| 1157 | static CORE_ADDR |
| 1158 | thumb_get_next_pc (pc) |
| 1159 | CORE_ADDR pc; |
| 1160 | { |
| 1161 | unsigned long pc_val = ((unsigned long)pc) + 4; /* PC after prefetch */ |
| 1162 | unsigned short inst1 = read_memory_integer (pc, 2); |
| 1163 | CORE_ADDR nextpc = pc + 2; /* default is next instruction */ |
| 1164 | unsigned long offset; |
| 1165 | |
| 1166 | if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */ |
| 1167 | { |
| 1168 | CORE_ADDR sp; |
| 1169 | |
| 1170 | /* Fetch the saved PC from the stack. It's stored above |
| 1171 | all of the other registers. */ |
| 1172 | offset = bitcount (bits (inst1, 0, 7)) * REGISTER_SIZE; |
| 1173 | sp = read_register (SP_REGNUM); |
| 1174 | nextpc = (CORE_ADDR) read_memory_integer (sp + offset, 4); |
| 1175 | nextpc = ADDR_BITS_REMOVE (nextpc); |
| 1176 | if (nextpc == pc) |
| 1177 | error ("Infinite loop detected"); |
| 1178 | } |
| 1179 | else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */ |
| 1180 | { |
| 1181 | unsigned long status = read_register (PS_REGNUM); |
| 1182 | unsigned long cond = bits (inst1, 8, 11); |
| 1183 | if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */ |
| 1184 | nextpc = pc_val + (sbits (inst1, 0, 7) << 1); |
| 1185 | } |
| 1186 | else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */ |
| 1187 | { |
| 1188 | nextpc = pc_val + (sbits (inst1, 0, 10) << 1); |
| 1189 | } |
| 1190 | else if ((inst1 & 0xf800) == 0xf000) /* long branch with link */ |
| 1191 | { |
| 1192 | unsigned short inst2 = read_memory_integer (pc + 2, 2); |
| 1193 | offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1); |
| 1194 | nextpc = pc_val + offset; |
| 1195 | } |
| 1196 | |
| 1197 | return nextpc; |
| 1198 | } |
| 1199 | |
| 1200 | |
| 1201 | CORE_ADDR |
| 1202 | arm_get_next_pc (pc) |
| 1203 | CORE_ADDR pc; |
| 1204 | { |
| 1205 | unsigned long pc_val; |
| 1206 | unsigned long this_instr; |
| 1207 | unsigned long status; |
| 1208 | CORE_ADDR nextpc; |
| 1209 | |
| 1210 | if (arm_pc_is_thumb (pc)) |
| 1211 | return thumb_get_next_pc (pc); |
| 1212 | |
| 1213 | pc_val = (unsigned long) pc; |
| 1214 | this_instr = read_memory_integer (pc, 4); |
| 1215 | status = read_register (PS_REGNUM); |
| 1216 | nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */ |
| 1217 | |
| 1218 | if (condition_true (bits (this_instr, 28, 31), status)) |
| 1219 | { |
| 1220 | switch (bits (this_instr, 24, 27)) |
| 1221 | { |
| 1222 | case 0x0: case 0x1: /* data processing */ |
| 1223 | case 0x2: case 0x3: |
| 1224 | { |
| 1225 | unsigned long operand1, operand2, result = 0; |
| 1226 | unsigned long rn; |
| 1227 | int c; |
| 1228 | |
| 1229 | if (bits (this_instr, 12, 15) != 15) |
| 1230 | break; |
| 1231 | |
| 1232 | if (bits (this_instr, 22, 25) == 0 |
| 1233 | && bits (this_instr, 4, 7) == 9) /* multiply */ |
| 1234 | error ("Illegal update to pc in instruction"); |
| 1235 | |
| 1236 | /* Multiply into PC */ |
| 1237 | c = (status & FLAG_C) ? 1 : 0; |
| 1238 | rn = bits (this_instr, 16, 19); |
| 1239 | operand1 = (rn == 15) ? pc_val + 8 : read_register (rn); |
| 1240 | |
| 1241 | if (bit (this_instr, 25)) |
| 1242 | { |
| 1243 | unsigned long immval = bits (this_instr, 0, 7); |
| 1244 | unsigned long rotate = 2 * bits (this_instr, 8, 11); |
| 1245 | operand2 = ((immval >> rotate) | (immval << (32-rotate))) |
| 1246 | & 0xffffffff; |
| 1247 | } |
| 1248 | else /* operand 2 is a shifted register */ |
| 1249 | operand2 = shifted_reg_val (this_instr, c, pc_val, status); |
| 1250 | |
| 1251 | switch (bits (this_instr, 21, 24)) |
| 1252 | { |
| 1253 | case 0x0: /*and*/ |
| 1254 | result = operand1 & operand2; |
| 1255 | break; |
| 1256 | |
| 1257 | case 0x1: /*eor*/ |
| 1258 | result = operand1 ^ operand2; |
| 1259 | break; |
| 1260 | |
| 1261 | case 0x2: /*sub*/ |
| 1262 | result = operand1 - operand2; |
| 1263 | break; |
| 1264 | |
| 1265 | case 0x3: /*rsb*/ |
| 1266 | result = operand2 - operand1; |
| 1267 | break; |
| 1268 | |
| 1269 | case 0x4: /*add*/ |
| 1270 | result = operand1 + operand2; |
| 1271 | break; |
| 1272 | |
| 1273 | case 0x5: /*adc*/ |
| 1274 | result = operand1 + operand2 + c; |
| 1275 | break; |
| 1276 | |
| 1277 | case 0x6: /*sbc*/ |
| 1278 | result = operand1 - operand2 + c; |
| 1279 | break; |
| 1280 | |
| 1281 | case 0x7: /*rsc*/ |
| 1282 | result = operand2 - operand1 + c; |
| 1283 | break; |
| 1284 | |
| 1285 | case 0x8: case 0x9: case 0xa: case 0xb: /* tst, teq, cmp, cmn */ |
| 1286 | result = (unsigned long) nextpc; |
| 1287 | break; |
| 1288 | |
| 1289 | case 0xc: /*orr*/ |
| 1290 | result = operand1 | operand2; |
| 1291 | break; |
| 1292 | |
| 1293 | case 0xd: /*mov*/ |
| 1294 | /* Always step into a function. */ |
| 1295 | result = operand2; |
| 1296 | break; |
| 1297 | |
| 1298 | case 0xe: /*bic*/ |
| 1299 | result = operand1 & ~operand2; |
| 1300 | break; |
| 1301 | |
| 1302 | case 0xf: /*mvn*/ |
| 1303 | result = ~operand2; |
| 1304 | break; |
| 1305 | } |
| 1306 | nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result); |
| 1307 | |
| 1308 | if (nextpc == pc) |
| 1309 | error ("Infinite loop detected"); |
| 1310 | break; |
| 1311 | } |
| 1312 | |
| 1313 | case 0x4: case 0x5: /* data transfer */ |
| 1314 | case 0x6: case 0x7: |
| 1315 | if (bit (this_instr, 20)) |
| 1316 | { |
| 1317 | /* load */ |
| 1318 | if (bits (this_instr, 12, 15) == 15) |
| 1319 | { |
| 1320 | /* rd == pc */ |
| 1321 | unsigned long rn; |
| 1322 | unsigned long base; |
| 1323 | |
| 1324 | if (bit (this_instr, 22)) |
| 1325 | error ("Illegal update to pc in instruction"); |
| 1326 | |
| 1327 | /* byte write to PC */ |
| 1328 | rn = bits (this_instr, 16, 19); |
| 1329 | base = (rn == 15) ? pc_val + 8 : read_register (rn); |
| 1330 | if (bit (this_instr, 24)) |
| 1331 | { |
| 1332 | /* pre-indexed */ |
| 1333 | int c = (status & FLAG_C) ? 1 : 0; |
| 1334 | unsigned long offset = |
| 1335 | (bit (this_instr, 25) |
| 1336 | ? shifted_reg_val (this_instr, c, pc_val) |
| 1337 | : bits (this_instr, 0, 11)); |
| 1338 | |
| 1339 | if (bit (this_instr, 23)) |
| 1340 | base += offset; |
| 1341 | else |
| 1342 | base -= offset; |
| 1343 | } |
| 1344 | nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base, |
| 1345 | 4); |
| 1346 | |
| 1347 | nextpc = ADDR_BITS_REMOVE (nextpc); |
| 1348 | |
| 1349 | if (nextpc == pc) |
| 1350 | error ("Infinite loop detected"); |
| 1351 | } |
| 1352 | } |
| 1353 | break; |
| 1354 | |
| 1355 | case 0x8: case 0x9: /* block transfer */ |
| 1356 | if (bit (this_instr, 20)) |
| 1357 | { |
| 1358 | /* LDM */ |
| 1359 | if (bit (this_instr, 15)) |
| 1360 | { |
| 1361 | /* loading pc */ |
| 1362 | int offset = 0; |
| 1363 | |
| 1364 | if (bit (this_instr, 23)) |
| 1365 | { |
| 1366 | /* up */ |
| 1367 | unsigned long reglist = bits (this_instr, 0, 14); |
| 1368 | offset = bitcount (reglist) * 4; |
| 1369 | if (bit (this_instr, 24)) /* pre */ |
| 1370 | offset += 4; |
| 1371 | } |
| 1372 | else if (bit (this_instr, 24)) |
| 1373 | offset = -4; |
| 1374 | |
| 1375 | { |
| 1376 | unsigned long rn_val = |
| 1377 | read_register (bits (this_instr, 16, 19)); |
| 1378 | nextpc = |
| 1379 | (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val |
| 1380 | + offset), |
| 1381 | 4); |
| 1382 | } |
| 1383 | nextpc = ADDR_BITS_REMOVE (nextpc); |
| 1384 | if (nextpc == pc) |
| 1385 | error ("Infinite loop detected"); |
| 1386 | } |
| 1387 | } |
| 1388 | break; |
| 1389 | |
| 1390 | case 0xb: /* branch & link */ |
| 1391 | case 0xa: /* branch */ |
| 1392 | { |
| 1393 | nextpc = BranchDest (pc, this_instr); |
| 1394 | |
| 1395 | nextpc = ADDR_BITS_REMOVE (nextpc); |
| 1396 | if (nextpc == pc) |
| 1397 | error ("Infinite loop detected"); |
| 1398 | break; |
| 1399 | } |
| 1400 | |
| 1401 | case 0xc: case 0xd: |
| 1402 | case 0xe: /* coproc ops */ |
| 1403 | case 0xf: /* SWI */ |
| 1404 | break; |
| 1405 | |
| 1406 | default: |
| 1407 | fprintf (stderr, "Bad bit-field extraction\n"); |
| 1408 | return (pc); |
| 1409 | } |
| 1410 | } |
| 1411 | |
| 1412 | return nextpc; |
| 1413 | } |
| 1414 | |
| 1415 | #include "bfd-in2.h" |
| 1416 | #include "libcoff.h" |
| 1417 | |
| 1418 | static int |
| 1419 | gdb_print_insn_arm (memaddr, info) |
| 1420 | bfd_vma memaddr; |
| 1421 | disassemble_info * info; |
| 1422 | { |
| 1423 | if (arm_pc_is_thumb (memaddr)) |
| 1424 | { |
| 1425 | static asymbol * asym; |
| 1426 | static combined_entry_type ce; |
| 1427 | static struct coff_symbol_struct csym; |
| 1428 | static struct _bfd fake_bfd; |
| 1429 | static bfd_target fake_target; |
| 1430 | |
| 1431 | if (csym.native == NULL) |
| 1432 | { |
| 1433 | /* Create a fake symbol vector containing a Thumb symbol. This is |
| 1434 | solely so that the code in print_insn_little_arm() and |
| 1435 | print_insn_big_arm() in opcodes/arm-dis.c will detect the presence |
| 1436 | of a Thumb symbol and switch to decoding Thumb instructions. */ |
| 1437 | |
| 1438 | fake_target.flavour = bfd_target_coff_flavour; |
| 1439 | fake_bfd.xvec = & fake_target; |
| 1440 | ce.u.syment.n_sclass = C_THUMBEXTFUNC; |
| 1441 | csym.native = & ce; |
| 1442 | csym.symbol.the_bfd = & fake_bfd; |
| 1443 | csym.symbol.name = "fake"; |
| 1444 | asym = (asymbol *) & csym; |
| 1445 | } |
| 1446 | |
| 1447 | memaddr = UNMAKE_THUMB_ADDR (memaddr); |
| 1448 | info->symbols = & asym; |
| 1449 | } |
| 1450 | else |
| 1451 | info->symbols = NULL; |
| 1452 | |
| 1453 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) |
| 1454 | return print_insn_big_arm (memaddr, info); |
| 1455 | else |
| 1456 | return print_insn_little_arm (memaddr, info); |
| 1457 | } |
| 1458 | |
| 1459 | /* This function implements the BREAKPOINT_FROM_PC macro. It uses the program |
| 1460 | counter value to determine whether a 16- or 32-bit breakpoint should be |
| 1461 | used. It returns a pointer to a string of bytes that encode a breakpoint |
| 1462 | instruction, stores the length of the string to *lenptr, and adjusts pc |
| 1463 | (if necessary) to point to the actual memory location where the |
| 1464 | breakpoint should be inserted. */ |
| 1465 | |
| 1466 | unsigned char * |
| 1467 | arm_breakpoint_from_pc (pcptr, lenptr) |
| 1468 | CORE_ADDR * pcptr; |
| 1469 | int * lenptr; |
| 1470 | { |
| 1471 | if (arm_pc_is_thumb (*pcptr) || arm_pc_is_thumb_dummy (*pcptr)) |
| 1472 | { |
| 1473 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) |
| 1474 | { |
| 1475 | static char thumb_breakpoint[] = THUMB_BE_BREAKPOINT; |
| 1476 | *pcptr = UNMAKE_THUMB_ADDR (*pcptr); |
| 1477 | *lenptr = sizeof (thumb_breakpoint); |
| 1478 | return thumb_breakpoint; |
| 1479 | } |
| 1480 | else |
| 1481 | { |
| 1482 | static char thumb_breakpoint[] = THUMB_LE_BREAKPOINT; |
| 1483 | *pcptr = UNMAKE_THUMB_ADDR (*pcptr); |
| 1484 | *lenptr = sizeof (thumb_breakpoint); |
| 1485 | return thumb_breakpoint; |
| 1486 | } |
| 1487 | } |
| 1488 | else |
| 1489 | { |
| 1490 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) |
| 1491 | { |
| 1492 | static char arm_breakpoint[] = ARM_BE_BREAKPOINT; |
| 1493 | *lenptr = sizeof (arm_breakpoint); |
| 1494 | return arm_breakpoint; |
| 1495 | } |
| 1496 | else |
| 1497 | { |
| 1498 | static char arm_breakpoint[] = ARM_LE_BREAKPOINT; |
| 1499 | *lenptr = sizeof (arm_breakpoint); |
| 1500 | return arm_breakpoint; |
| 1501 | } |
| 1502 | } |
| 1503 | } |
| 1504 | /* Return non-zero if the PC is inside a call thunk (aka stub or trampoline). |
| 1505 | This implements the IN_SOLIB_CALL_TRAMPOLINE macro. */ |
| 1506 | |
| 1507 | int |
| 1508 | arm_in_call_stub (pc, name) |
| 1509 | CORE_ADDR pc; |
| 1510 | char * name; |
| 1511 | { |
| 1512 | CORE_ADDR start_addr; |
| 1513 | |
| 1514 | /* Find the starting address of the function containing the PC. If the |
| 1515 | caller didn't give us a name, look it up at the same time. */ |
| 1516 | if (find_pc_partial_function (pc, name ? NULL : &name, &start_addr, NULL) == 0) |
| 1517 | return 0; |
| 1518 | |
| 1519 | return strncmp (name, "_call_via_r", 11) == 0; |
| 1520 | } |
| 1521 | |
| 1522 | |
| 1523 | /* If PC is in a Thumb call or return stub, return the address of the target |
| 1524 | PC, which is in a register. The thunk functions are called _called_via_xx, |
| 1525 | where x is the register name. The possible names are r0-r9, sl, fp, ip, |
| 1526 | sp, and lr. */ |
| 1527 | |
| 1528 | CORE_ADDR |
| 1529 | arm_skip_stub (pc) |
| 1530 | CORE_ADDR pc; |
| 1531 | { |
| 1532 | char * name; |
| 1533 | CORE_ADDR start_addr; |
| 1534 | |
| 1535 | /* Find the starting address and name of the function containing the PC. */ |
| 1536 | if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0) |
| 1537 | return 0; |
| 1538 | |
| 1539 | /* Call thunks always start with "_call_via_". */ |
| 1540 | if (strncmp (name, "_call_via_", 10) == 0) |
| 1541 | { |
| 1542 | /* Use the name suffix to determine which register contains |
| 1543 | the target PC. */ |
| 1544 | static char *table[15] = |
| 1545 | { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| 1546 | "r8", "r9", "sl", "fp", "ip", "sp", "lr" |
| 1547 | }; |
| 1548 | int regno; |
| 1549 | |
| 1550 | for (regno = 0; regno <= 14; regno++) |
| 1551 | if (strcmp (&name[10], table[regno]) == 0) |
| 1552 | return read_register (regno); |
| 1553 | } |
| 1554 | return 0; /* not a stub */ |
| 1555 | } |
| 1556 | |
| 1557 | |
| 1558 | void |
| 1559 | _initialize_arm_tdep () |
| 1560 | { |
| 1561 | tm_print_insn = gdb_print_insn_arm; |
| 1562 | |
| 1563 | add_com ("othernames", class_obscure, arm_othernames, |
| 1564 | "Switch to the other set of register names."); |
| 1565 | |
| 1566 | /* ??? Maybe this should be a boolean. */ |
| 1567 | add_show_from_set (add_set_cmd ("apcs32", no_class, |
| 1568 | var_zinteger, (char *)&arm_apcs_32, |
| 1569 | "Set usage of ARM 32-bit mode.\n", &setlist), |
| 1570 | & showlist); |
| 1571 | |
| 1572 | } |
| 1573 | |
| 1574 | /* Test whether the coff symbol specific value corresponds to a Thumb function */ |
| 1575 | int |
| 1576 | coff_sym_is_thumb(int val) |
| 1577 | { |
| 1578 | return (val == C_THUMBEXT || |
| 1579 | val == C_THUMBSTAT || |
| 1580 | val == C_THUMBEXTFUNC || |
| 1581 | val == C_THUMBSTATFUNC || |
| 1582 | val == C_THUMBLABEL); |
| 1583 | } |