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| 1 /**************************************************************************** | |
| 2 | |
| 3 THIS SOFTWARE IS NOT COPYRIGHTED | |
| 4 | |
| 5 HP offers the following for use in the public domain. HP makes no | |
| 6 warranty with regard to the software or it's performance and the | |
| 7 user accepts the software "AS IS" with all faults. | |
| 8 | |
| 9 HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD | |
| 10 TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES | |
| 11 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
| 12 | |
| 13 ****************************************************************************/ | |
| 14 | |
| 15 /**************************************************************************** | |
| 16 * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $ | |
| 17 * | |
| 18 * Module name: remcom.c $ | |
| 19 * Revision: 1.34 $ | |
| 20 * Date: 91/03/09 12:29:49 $ | |
| 21 * Contributor: Lake Stevens Instrument Division$ | |
| 22 * | |
| 23 * Description: low level support for gdb debugger. $ | |
| 24 * | |
| 25 * Considerations: only works on target hardware $ | |
| 26 * | |
| 27 * Written by: Glenn Engel $ | |
| 28 * ModuleState: Experimental $ | |
| 29 * | |
| 30 * NOTES: See Below $ | |
| 31 * | |
| 32 * Modified for 386 by Jim Kingdon, Cygnus Support. | |
| 33 * | |
| 34 * To enable debugger support, two things need to happen. One, a | |
| 35 * call to set_debug_traps() is necessary in order to allow any breakpoints | |
| 36 * or error conditions to be properly intercepted and reported to gdb. | |
| 37 * Two, a breakpoint needs to be generated to begin communication. This | |
| 38 * is most easily accomplished by a call to breakpoint(). Breakpoint() | |
| 39 * simulates a breakpoint by executing a trap #1. | |
| 40 * | |
| 41 * The external function exceptionHandler() is | |
| 42 * used to attach a specific handler to a specific 386 vector number. | |
| 43 * It should use the same privilege level it runs at. It should | |
| 44 * install it as an interrupt gate so that interrupts are masked | |
| 45 * while the handler runs. | |
| 46 * | |
| 47 * Because gdb will sometimes write to the stack area to execute function | |
| 48 * calls, this program cannot rely on using the supervisor stack so it | |
| 49 * uses it's own stack area reserved in the int array remcomStack. | |
| 50 * | |
| 51 ************* | |
| 52 * | |
| 53 * The following gdb commands are supported: | |
| 54 * | |
| 55 * command function Return value | |
| 56 * | |
| 57 * g return the value of the CPU registers hex data or ENN | |
| 58 * G set the value of the CPU registers OK or ENN | |
| 59 * | |
| 60 * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN | |
| 61 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN | |
| 62 * | |
| 63 * c Resume at current address SNN ( signal NN) | |
| 64 * cAA..AA Continue at address AA..AA SNN | |
| 65 * | |
| 66 * s Step one instruction SNN | |
| 67 * sAA..AA Step one instruction from AA..AA SNN | |
| 68 * | |
| 69 * k kill | |
| 70 * | |
| 71 * ? What was the last sigval ? SNN (signal NN) | |
| 72 * | |
| 73 * All commands and responses are sent with a packet which includes a | |
| 74 * checksum. A packet consists of | |
| 75 * | |
| 76 * $<packet info>#<checksum>. | |
| 77 * | |
| 78 * where | |
| 79 * <packet info> :: <characters representing the command or response> | |
| 80 * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> | |
| 81 * | |
| 82 * When a packet is received, it is first acknowledged with either '+' or '-'. | |
| 83 * '+' indicates a successful transfer. '-' indicates a failed transfer. | |
| 84 * | |
| 85 * Example: | |
| 86 * | |
| 87 * Host: Reply: | |
| 88 * $m0,10#2a +$00010203040506070809101112131415#42 | |
| 89 * | |
| 90 ****************************************************************************/ | |
| 91 | |
| 92 #include <stdio.h> | |
| 93 #include <string.h> | |
| 94 | |
| 95 /************************************************************************ | |
| 96 * | |
| 97 * external low-level support routines | |
| 98 */ | |
| 99 | |
| 100 extern void putDebugChar(); /* write a single character */ | |
| 101 extern int getDebugChar(); /* read and return a single char */ | |
| 102 extern void exceptionHandler(); /* assign an exception handler */ | |
| 103 | |
| 104 /************************************************************************/ | |
| 105 /* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ | |
| 106 /* at least NUMREGBYTES*2 are needed for register packets */ | |
| 107 #define BUFMAX 400 | |
| 108 | |
| 109 static char initialized; /* boolean flag. != 0 means we've been initialized */ | |
| 110 | |
| 111 int remote_debug; | |
| 112 /* debug > 0 prints ill-formed commands in valid packets & checksum errors */ | |
| 113 | |
| 114 static const char hexchars[]="0123456789abcdef"; | |
| 115 | |
| 116 /* Number of registers. */ | |
| 117 #define NUMREGS 16 | |
| 118 | |
| 119 /* Number of bytes of registers. */ | |
| 120 #define NUMREGBYTES (NUMREGS * 4) | |
| 121 | |
| 122 enum regnames {EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI, | |
| 123 PC /* also known as eip */, | |
| 124 PS /* also known as eflags */, | |
| 125 CS, SS, DS, ES, FS, GS}; | |
| 126 | |
| 127 /* | |
| 128 * these should not be static cuz they can be used outside this module | |
| 129 */ | |
| 130 int registers[NUMREGS]; | |
| 131 | |
| 132 #define STACKSIZE 10000 | |
| 133 int remcomStack[STACKSIZE/sizeof(int)]; | |
| 134 static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; | |
| 135 | |
| 136 /*************************** ASSEMBLY CODE MACROS *************************/ | |
| 137 /* */ | |
| 138 | |
| 139 extern void | |
| 140 return_to_prog (); | |
| 141 | |
| 142 /* Restore the program's registers (including the stack pointer, which | |
| 143 means we get the right stack and don't have to worry about popping our | |
| 144 return address and any stack frames and so on) and return. */ | |
| 145 asm(".text"); | |
| 146 asm(".globl _return_to_prog"); | |
| 147 asm("_return_to_prog:"); | |
| 148 asm(" movw _registers+44, %ss"); | |
| 149 asm(" movl _registers+16, %esp"); | |
| 150 asm(" movl _registers+4, %ecx"); | |
| 151 asm(" movl _registers+8, %edx"); | |
| 152 asm(" movl _registers+12, %ebx"); | |
| 153 asm(" movl _registers+20, %ebp"); | |
| 154 asm(" movl _registers+24, %esi"); | |
| 155 asm(" movl _registers+28, %edi"); | |
| 156 asm(" movw _registers+48, %ds"); | |
| 157 asm(" movw _registers+52, %es"); | |
| 158 asm(" movw _registers+56, %fs"); | |
| 159 asm(" movw _registers+60, %gs"); | |
| 160 asm(" movl _registers+36, %eax"); | |
| 161 asm(" pushl %eax"); /* saved eflags */ | |
| 162 asm(" movl _registers+40, %eax"); | |
| 163 asm(" pushl %eax"); /* saved cs */ | |
| 164 asm(" movl _registers+32, %eax"); | |
| 165 asm(" pushl %eax"); /* saved eip */ | |
| 166 asm(" movl _registers, %eax"); | |
| 167 /* use iret to restore pc and flags together so | |
| 168 that trace flag works right. */ | |
| 169 asm(" iret"); | |
| 170 | |
| 171 #define BREAKPOINT() asm(" int $3"); | |
| 172 | |
| 173 /* Put the error code here just in case the user cares. */ | |
| 174 int gdb_i386errcode; | |
| 175 /* Likewise, the vector number here (since GDB only gets the signal | |
| 176 number through the usual means, and that's not very specific). */ | |
| 177 int gdb_i386vector = -1; | |
| 178 | |
| 179 /* GDB stores segment registers in 32-bit words (that's just the way | |
| 180 m-i386v.h is written). So zero the appropriate areas in registers. */ | |
| 181 #define SAVE_REGISTERS1() \ | |
| 182 asm ("movl %eax, _registers"); \ | |
| 183 asm ("movl %ecx, _registers+4"); \ | |
| 184 asm ("movl %edx, _registers+8"); \ | |
| 185 asm ("movl %ebx, _registers+12"); \ | |
| 186 asm ("movl %ebp, _registers+20"); \ | |
| 187 asm ("movl %esi, _registers+24"); \ | |
| 188 asm ("movl %edi, _registers+28"); \ | |
| 189 asm ("movw $0, %ax"); \ | |
| 190 asm ("movw %ds, _registers+48"); \ | |
| 191 asm ("movw %ax, _registers+50"); \ | |
| 192 asm ("movw %es, _registers+52"); \ | |
| 193 asm ("movw %ax, _registers+54"); \ | |
| 194 asm ("movw %fs, _registers+56"); \ | |
| 195 asm ("movw %ax, _registers+58"); \ | |
| 196 asm ("movw %gs, _registers+60"); \ | |
| 197 asm ("movw %ax, _registers+62"); | |
| 198 #define SAVE_ERRCODE() \ | |
| 199 asm ("popl %ebx"); \ | |
| 200 asm ("movl %ebx, _gdb_i386errcode"); | |
| 201 #define SAVE_REGISTERS2() \ | |
| 202 asm ("popl %ebx"); /* old eip */ \ | |
| 203 asm ("movl %ebx, _registers+32"); \ | |
| 204 asm ("popl %ebx"); /* old cs */ \ | |
| 205 asm ("movl %ebx, _registers+40"); \ | |
| 206 asm ("movw %ax, _registers+42"); \ | |
| 207 asm ("popl %ebx"); /* old eflags */ \ | |
| 208 asm ("movl %ebx, _registers+36"); \ | |
| 209 /* Now that we've done the pops, we can save the stack pointer."); */ \ | |
| 210 asm ("movw %ss, _registers+44"); \ | |
| 211 asm ("movw %ax, _registers+46"); \ | |
| 212 asm ("movl %esp, _registers+16"); | |
| 213 | |
| 214 /* See if mem_fault_routine is set, if so just IRET to that address. */ | |
| 215 #define CHECK_FAULT() \ | |
| 216 asm ("cmpl $0, _mem_fault_routine"); \ | |
| 217 asm ("jne mem_fault"); | |
| 218 | |
| 219 asm (".text"); | |
| 220 asm ("mem_fault:"); | |
| 221 /* OK to clobber temp registers; we're just going to end up in set_mem_err. */ | |
| 222 /* Pop error code from the stack and save it. */ | |
| 223 asm (" popl %eax"); | |
| 224 asm (" movl %eax, _gdb_i386errcode"); | |
| 225 | |
| 226 asm (" popl %eax"); /* eip */ | |
| 227 /* We don't want to return there, we want to return to the function | |
| 228 pointed to by mem_fault_routine instead. */ | |
| 229 asm (" movl _mem_fault_routine, %eax"); | |
| 230 asm (" popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits). */ | |
| 231 asm (" popl %edx"); /* eflags */ | |
| 232 | |
| 233 /* Remove this stack frame; when we do the iret, we will be going to | |
| 234 the start of a function, so we want the stack to look just like it | |
| 235 would after a "call" instruction. */ | |
| 236 asm (" leave"); | |
| 237 | |
| 238 /* Push the stuff that iret wants. */ | |
| 239 asm (" pushl %edx"); /* eflags */ | |
| 240 asm (" pushl %ecx"); /* cs */ | |
| 241 asm (" pushl %eax"); /* eip */ | |
| 242 | |
| 243 /* Zero mem_fault_routine. */ | |
| 244 asm (" movl $0, %eax"); | |
| 245 asm (" movl %eax, _mem_fault_routine"); | |
| 246 | |
| 247 asm ("iret"); | |
| 248 | |
| 249 #define CALL_HOOK() asm("call _remcomHandler"); | |
| 250 | |
| 251 /* This function is called when a i386 exception occurs. It saves | |
| 252 * all the cpu regs in the _registers array, munges the stack a bit, | |
| 253 * and invokes an exception handler (remcom_handler). | |
| 254 * | |
| 255 * stack on entry: stack on exit: | |
| 256 * old eflags vector number | |
| 257 * old cs (zero-filled to 32 bits) | |
| 258 * old eip | |
| 259 * | |
| 260 */ | |
| 261 extern void _catchException3(); | |
| 262 asm(".text"); | |
| 263 asm(".globl __catchException3"); | |
| 264 asm("__catchException3:"); | |
| 265 SAVE_REGISTERS1(); | |
| 266 SAVE_REGISTERS2(); | |
| 267 asm ("pushl $3"); | |
| 268 CALL_HOOK(); | |
| 269 | |
| 270 /* Same thing for exception 1. */ | |
| 271 extern void _catchException1(); | |
| 272 asm(".text"); | |
| 273 asm(".globl __catchException1"); | |
| 274 asm("__catchException1:"); | |
| 275 SAVE_REGISTERS1(); | |
| 276 SAVE_REGISTERS2(); | |
| 277 asm ("pushl $1"); | |
| 278 CALL_HOOK(); | |
| 279 | |
| 280 /* Same thing for exception 0. */ | |
| 281 extern void _catchException0(); | |
| 282 asm(".text"); | |
| 283 asm(".globl __catchException0"); | |
| 284 asm("__catchException0:"); | |
| 285 SAVE_REGISTERS1(); | |
| 286 SAVE_REGISTERS2(); | |
| 287 asm ("pushl $0"); | |
| 288 CALL_HOOK(); | |
| 289 | |
| 290 /* Same thing for exception 4. */ | |
| 291 extern void _catchException4(); | |
| 292 asm(".text"); | |
| 293 asm(".globl __catchException4"); | |
| 294 asm("__catchException4:"); | |
| 295 SAVE_REGISTERS1(); | |
| 296 SAVE_REGISTERS2(); | |
| 297 asm ("pushl $4"); | |
| 298 CALL_HOOK(); | |
| 299 | |
| 300 /* Same thing for exception 5. */ | |
| 301 extern void _catchException5(); | |
| 302 asm(".text"); | |
| 303 asm(".globl __catchException5"); | |
| 304 asm("__catchException5:"); | |
| 305 SAVE_REGISTERS1(); | |
| 306 SAVE_REGISTERS2(); | |
| 307 asm ("pushl $5"); | |
| 308 CALL_HOOK(); | |
| 309 | |
| 310 /* Same thing for exception 6. */ | |
| 311 extern void _catchException6(); | |
| 312 asm(".text"); | |
| 313 asm(".globl __catchException6"); | |
| 314 asm("__catchException6:"); | |
| 315 SAVE_REGISTERS1(); | |
| 316 SAVE_REGISTERS2(); | |
| 317 asm ("pushl $6"); | |
| 318 CALL_HOOK(); | |
| 319 | |
| 320 /* Same thing for exception 7. */ | |
| 321 extern void _catchException7(); | |
| 322 asm(".text"); | |
| 323 asm(".globl __catchException7"); | |
| 324 asm("__catchException7:"); | |
| 325 SAVE_REGISTERS1(); | |
| 326 SAVE_REGISTERS2(); | |
| 327 asm ("pushl $7"); | |
| 328 CALL_HOOK(); | |
| 329 | |
| 330 /* Same thing for exception 8. */ | |
| 331 extern void _catchException8(); | |
| 332 asm(".text"); | |
| 333 asm(".globl __catchException8"); | |
| 334 asm("__catchException8:"); | |
| 335 SAVE_REGISTERS1(); | |
| 336 SAVE_ERRCODE(); | |
| 337 SAVE_REGISTERS2(); | |
| 338 asm ("pushl $8"); | |
| 339 CALL_HOOK(); | |
| 340 | |
| 341 /* Same thing for exception 9. */ | |
| 342 extern void _catchException9(); | |
| 343 asm(".text"); | |
| 344 asm(".globl __catchException9"); | |
| 345 asm("__catchException9:"); | |
| 346 SAVE_REGISTERS1(); | |
| 347 SAVE_REGISTERS2(); | |
| 348 asm ("pushl $9"); | |
| 349 CALL_HOOK(); | |
| 350 | |
| 351 /* Same thing for exception 10. */ | |
| 352 extern void _catchException10(); | |
| 353 asm(".text"); | |
| 354 asm(".globl __catchException10"); | |
| 355 asm("__catchException10:"); | |
| 356 SAVE_REGISTERS1(); | |
| 357 SAVE_ERRCODE(); | |
| 358 SAVE_REGISTERS2(); | |
| 359 asm ("pushl $10"); | |
| 360 CALL_HOOK(); | |
| 361 | |
| 362 /* Same thing for exception 12. */ | |
| 363 extern void _catchException12(); | |
| 364 asm(".text"); | |
| 365 asm(".globl __catchException12"); | |
| 366 asm("__catchException12:"); | |
| 367 SAVE_REGISTERS1(); | |
| 368 SAVE_ERRCODE(); | |
| 369 SAVE_REGISTERS2(); | |
| 370 asm ("pushl $12"); | |
| 371 CALL_HOOK(); | |
| 372 | |
| 373 /* Same thing for exception 16. */ | |
| 374 extern void _catchException16(); | |
| 375 asm(".text"); | |
| 376 asm(".globl __catchException16"); | |
| 377 asm("__catchException16:"); | |
| 378 SAVE_REGISTERS1(); | |
| 379 SAVE_REGISTERS2(); | |
| 380 asm ("pushl $16"); | |
| 381 CALL_HOOK(); | |
| 382 | |
| 383 /* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff. */ | |
| 384 | |
| 385 /* Same thing for exception 13. */ | |
| 386 extern void _catchException13 (); | |
| 387 asm (".text"); | |
| 388 asm (".globl __catchException13"); | |
| 389 asm ("__catchException13:"); | |
| 390 CHECK_FAULT(); | |
| 391 SAVE_REGISTERS1(); | |
| 392 SAVE_ERRCODE(); | |
| 393 SAVE_REGISTERS2(); | |
| 394 asm ("pushl $13"); | |
| 395 CALL_HOOK(); | |
| 396 | |
| 397 /* Same thing for exception 11. */ | |
| 398 extern void _catchException11 (); | |
| 399 asm (".text"); | |
| 400 asm (".globl __catchException11"); | |
| 401 asm ("__catchException11:"); | |
| 402 CHECK_FAULT(); | |
| 403 SAVE_REGISTERS1(); | |
| 404 SAVE_ERRCODE(); | |
| 405 SAVE_REGISTERS2(); | |
| 406 asm ("pushl $11"); | |
| 407 CALL_HOOK(); | |
| 408 | |
| 409 /* Same thing for exception 14. */ | |
| 410 extern void _catchException14 (); | |
| 411 asm (".text"); | |
| 412 asm (".globl __catchException14"); | |
| 413 asm ("__catchException14:"); | |
| 414 CHECK_FAULT(); | |
| 415 SAVE_REGISTERS1(); | |
| 416 SAVE_ERRCODE(); | |
| 417 SAVE_REGISTERS2(); | |
| 418 asm ("pushl $14"); | |
| 419 CALL_HOOK(); | |
| 420 | |
| 421 /* | |
| 422 * remcomHandler is a front end for handle_exception. It moves the | |
| 423 * stack pointer into an area reserved for debugger use. | |
| 424 */ | |
| 425 asm("_remcomHandler:"); | |
| 426 asm(" popl %eax"); /* pop off return address */ | |
| 427 asm(" popl %eax"); /* get the exception number */ | |
| 428 asm(" movl _stackPtr, %esp"); /* move to remcom stack area */ | |
| 429 asm(" pushl %eax"); /* push exception onto stack */ | |
| 430 asm(" call _handle_exception"); /* this never returns */ | |
| 431 | |
| 432 void | |
| 433 _returnFromException () | |
| 434 { | |
| 435 return_to_prog (); | |
| 436 } | |
| 437 | |
| 438 int | |
| 439 hex (ch) | |
| 440 char ch; | |
| 441 { | |
| 442 if ((ch >= 'a') && (ch <= 'f')) | |
| 443 return (ch - 'a' + 10); | |
| 444 if ((ch >= '0') && (ch <= '9')) | |
| 445 return (ch - '0'); | |
| 446 if ((ch >= 'A') && (ch <= 'F')) | |
| 447 return (ch - 'A' + 10); | |
| 448 return (-1); | |
| 449 } | |
| 450 | |
| 451 static char remcomInBuffer[BUFMAX]; | |
| 452 static char remcomOutBuffer[BUFMAX]; | |
| 453 | |
| 454 /* scan for the sequence $<data>#<checksum> */ | |
| 455 | |
| 456 unsigned char * | |
| 457 getpacket (void) | |
| 458 { | |
| 459 unsigned char *buffer = &remcomInBuffer[0]; | |
| 460 unsigned char checksum; | |
| 461 unsigned char xmitcsum; | |
| 462 int count; | |
| 463 char ch; | |
| 464 | |
| 465 while (1) | |
| 466 { | |
| 467 /* wait around for the start character, ignore all other characters */ | |
| 468 while ((ch = getDebugChar ()) != '$') | |
| 469 ; | |
| 470 | |
| 471 retry: | |
| 472 checksum = 0; | |
| 473 xmitcsum = -1; | |
| 474 count = 0; | |
| 475 | |
| 476 /* now, read until a # or end of buffer is found */ | |
| 477 while (count < BUFMAX - 1) | |
| 478 { | |
| 479 ch = getDebugChar (); | |
| 480 if (ch == '$') | |
| 481 goto retry; | |
| 482 if (ch == '#') | |
| 483 break; | |
| 484 checksum = checksum + ch; | |
| 485 buffer[count] = ch; | |
| 486 count = count + 1; | |
| 487 } | |
| 488 buffer[count] = 0; | |
| 489 | |
| 490 if (ch == '#') | |
| 491 { | |
| 492 ch = getDebugChar (); | |
| 493 xmitcsum = hex (ch) << 4; | |
| 494 ch = getDebugChar (); | |
| 495 xmitcsum += hex (ch); | |
| 496 | |
| 497 if (checksum != xmitcsum) | |
| 498 { | |
| 499 if (remote_debug) | |
| 500 { | |
| 501 fprintf (stderr, | |
| 502 "bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n"
, | |
| 503 checksum, xmitcsum, buffer); | |
| 504 } | |
| 505 putDebugChar ('-'); /* failed checksum */ | |
| 506 } | |
| 507 else | |
| 508 { | |
| 509 putDebugChar ('+'); /* successful transfer */ | |
| 510 | |
| 511 /* if a sequence char is present, reply the sequence ID */ | |
| 512 if (buffer[2] == ':') | |
| 513 { | |
| 514 putDebugChar (buffer[0]); | |
| 515 putDebugChar (buffer[1]); | |
| 516 | |
| 517 return &buffer[3]; | |
| 518 } | |
| 519 | |
| 520 return &buffer[0]; | |
| 521 } | |
| 522 } | |
| 523 } | |
| 524 } | |
| 525 | |
| 526 /* send the packet in buffer. */ | |
| 527 | |
| 528 void | |
| 529 putpacket (unsigned char *buffer) | |
| 530 { | |
| 531 unsigned char checksum; | |
| 532 int count; | |
| 533 char ch; | |
| 534 | |
| 535 /* $<packet info>#<checksum>. */ | |
| 536 do | |
| 537 { | |
| 538 putDebugChar ('$'); | |
| 539 checksum = 0; | |
| 540 count = 0; | |
| 541 | |
| 542 while (ch = buffer[count]) | |
| 543 { | |
| 544 putDebugChar (ch); | |
| 545 checksum += ch; | |
| 546 count += 1; | |
| 547 } | |
| 548 | |
| 549 putDebugChar ('#'); | |
| 550 putDebugChar (hexchars[checksum >> 4]); | |
| 551 putDebugChar (hexchars[checksum % 16]); | |
| 552 | |
| 553 } | |
| 554 while (getDebugChar () != '+'); | |
| 555 } | |
| 556 | |
| 557 void | |
| 558 debug_error (format, parm) | |
| 559 char *format; | |
| 560 char *parm; | |
| 561 { | |
| 562 if (remote_debug) | |
| 563 fprintf (stderr, format, parm); | |
| 564 } | |
| 565 | |
| 566 /* Address of a routine to RTE to if we get a memory fault. */ | |
| 567 static void (*volatile mem_fault_routine) () = NULL; | |
| 568 | |
| 569 /* Indicate to caller of mem2hex or hex2mem that there has been an | |
| 570 error. */ | |
| 571 static volatile int mem_err = 0; | |
| 572 | |
| 573 void | |
| 574 set_mem_err (void) | |
| 575 { | |
| 576 mem_err = 1; | |
| 577 } | |
| 578 | |
| 579 /* These are separate functions so that they are so short and sweet | |
| 580 that the compiler won't save any registers (if there is a fault | |
| 581 to mem_fault, they won't get restored, so there better not be any | |
| 582 saved). */ | |
| 583 int | |
| 584 get_char (char *addr) | |
| 585 { | |
| 586 return *addr; | |
| 587 } | |
| 588 | |
| 589 void | |
| 590 set_char (char *addr, int val) | |
| 591 { | |
| 592 *addr = val; | |
| 593 } | |
| 594 | |
| 595 /* convert the memory pointed to by mem into hex, placing result in buf */ | |
| 596 /* return a pointer to the last char put in buf (null) */ | |
| 597 /* If MAY_FAULT is non-zero, then we should set mem_err in response to | |
| 598 a fault; if zero treat a fault like any other fault in the stub. */ | |
| 599 char * | |
| 600 mem2hex (mem, buf, count, may_fault) | |
| 601 char *mem; | |
| 602 char *buf; | |
| 603 int count; | |
| 604 int may_fault; | |
| 605 { | |
| 606 int i; | |
| 607 unsigned char ch; | |
| 608 | |
| 609 if (may_fault) | |
| 610 mem_fault_routine = set_mem_err; | |
| 611 for (i = 0; i < count; i++) | |
| 612 { | |
| 613 ch = get_char (mem++); | |
| 614 if (may_fault && mem_err) | |
| 615 return (buf); | |
| 616 *buf++ = hexchars[ch >> 4]; | |
| 617 *buf++ = hexchars[ch % 16]; | |
| 618 } | |
| 619 *buf = 0; | |
| 620 if (may_fault) | |
| 621 mem_fault_routine = NULL; | |
| 622 return (buf); | |
| 623 } | |
| 624 | |
| 625 /* convert the hex array pointed to by buf into binary to be placed in mem */ | |
| 626 /* return a pointer to the character AFTER the last byte written */ | |
| 627 char * | |
| 628 hex2mem (buf, mem, count, may_fault) | |
| 629 char *buf; | |
| 630 char *mem; | |
| 631 int count; | |
| 632 int may_fault; | |
| 633 { | |
| 634 int i; | |
| 635 unsigned char ch; | |
| 636 | |
| 637 if (may_fault) | |
| 638 mem_fault_routine = set_mem_err; | |
| 639 for (i = 0; i < count; i++) | |
| 640 { | |
| 641 ch = hex (*buf++) << 4; | |
| 642 ch = ch + hex (*buf++); | |
| 643 set_char (mem++, ch); | |
| 644 if (may_fault && mem_err) | |
| 645 return (mem); | |
| 646 } | |
| 647 if (may_fault) | |
| 648 mem_fault_routine = NULL; | |
| 649 return (mem); | |
| 650 } | |
| 651 | |
| 652 /* this function takes the 386 exception vector and attempts to | |
| 653 translate this number into a unix compatible signal value */ | |
| 654 int | |
| 655 computeSignal (int exceptionVector) | |
| 656 { | |
| 657 int sigval; | |
| 658 switch (exceptionVector) | |
| 659 { | |
| 660 case 0: | |
| 661 sigval = 8; | |
| 662 break; /* divide by zero */ | |
| 663 case 1: | |
| 664 sigval = 5; | |
| 665 break; /* debug exception */ | |
| 666 case 3: | |
| 667 sigval = 5; | |
| 668 break; /* breakpoint */ | |
| 669 case 4: | |
| 670 sigval = 16; | |
| 671 break; /* into instruction (overflow) */ | |
| 672 case 5: | |
| 673 sigval = 16; | |
| 674 break; /* bound instruction */ | |
| 675 case 6: | |
| 676 sigval = 4; | |
| 677 break; /* Invalid opcode */ | |
| 678 case 7: | |
| 679 sigval = 8; | |
| 680 break; /* coprocessor not available */ | |
| 681 case 8: | |
| 682 sigval = 7; | |
| 683 break; /* double fault */ | |
| 684 case 9: | |
| 685 sigval = 11; | |
| 686 break; /* coprocessor segment overrun */ | |
| 687 case 10: | |
| 688 sigval = 11; | |
| 689 break; /* Invalid TSS */ | |
| 690 case 11: | |
| 691 sigval = 11; | |
| 692 break; /* Segment not present */ | |
| 693 case 12: | |
| 694 sigval = 11; | |
| 695 break; /* stack exception */ | |
| 696 case 13: | |
| 697 sigval = 11; | |
| 698 break; /* general protection */ | |
| 699 case 14: | |
| 700 sigval = 11; | |
| 701 break; /* page fault */ | |
| 702 case 16: | |
| 703 sigval = 7; | |
| 704 break; /* coprocessor error */ | |
| 705 default: | |
| 706 sigval = 7; /* "software generated" */ | |
| 707 } | |
| 708 return (sigval); | |
| 709 } | |
| 710 | |
| 711 /**********************************************/ | |
| 712 /* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ | |
| 713 /* RETURN NUMBER OF CHARS PROCESSED */ | |
| 714 /**********************************************/ | |
| 715 int | |
| 716 hexToInt (char **ptr, int *intValue) | |
| 717 { | |
| 718 int numChars = 0; | |
| 719 int hexValue; | |
| 720 | |
| 721 *intValue = 0; | |
| 722 | |
| 723 while (**ptr) | |
| 724 { | |
| 725 hexValue = hex (**ptr); | |
| 726 if (hexValue >= 0) | |
| 727 { | |
| 728 *intValue = (*intValue << 4) | hexValue; | |
| 729 numChars++; | |
| 730 } | |
| 731 else | |
| 732 break; | |
| 733 | |
| 734 (*ptr)++; | |
| 735 } | |
| 736 | |
| 737 return (numChars); | |
| 738 } | |
| 739 | |
| 740 /* | |
| 741 * This function does all command procesing for interfacing to gdb. | |
| 742 */ | |
| 743 void | |
| 744 handle_exception (int exceptionVector) | |
| 745 { | |
| 746 int sigval, stepping; | |
| 747 int addr, length; | |
| 748 char *ptr; | |
| 749 int newPC; | |
| 750 | |
| 751 gdb_i386vector = exceptionVector; | |
| 752 | |
| 753 if (remote_debug) | |
| 754 { | |
| 755 printf ("vector=%d, sr=0x%x, pc=0x%x\n", | |
| 756 exceptionVector, registers[PS], registers[PC]); | |
| 757 } | |
| 758 | |
| 759 /* reply to host that an exception has occurred */ | |
| 760 sigval = computeSignal (exceptionVector); | |
| 761 | |
| 762 ptr = remcomOutBuffer; | |
| 763 | |
| 764 *ptr++ = 'T'; /* notify gdb with signo, PC, FP and SP */ | |
| 765 *ptr++ = hexchars[sigval >> 4]; | |
| 766 *ptr++ = hexchars[sigval & 0xf]; | |
| 767 | |
| 768 *ptr++ = hexchars[ESP]; | |
| 769 *ptr++ = ':'; | |
| 770 ptr = mem2hex((char *)®isters[ESP], ptr, 4, 0); /* SP */ | |
| 771 *ptr++ = ';'; | |
| 772 | |
| 773 *ptr++ = hexchars[EBP]; | |
| 774 *ptr++ = ':'; | |
| 775 ptr = mem2hex((char *)®isters[EBP], ptr, 4, 0); /* FP */ | |
| 776 *ptr++ = ';'; | |
| 777 | |
| 778 *ptr++ = hexchars[PC]; | |
| 779 *ptr++ = ':'; | |
| 780 ptr = mem2hex((char *)®isters[PC], ptr, 4, 0); /* PC */ | |
| 781 *ptr++ = ';'; | |
| 782 | |
| 783 *ptr = '\0' | |
| 784 | |
| 785 putpacket (remcomOutBuffer); | |
| 786 | |
| 787 stepping = 0; | |
| 788 | |
| 789 while (1 == 1) | |
| 790 { | |
| 791 remcomOutBuffer[0] = 0; | |
| 792 ptr = getpacket (); | |
| 793 | |
| 794 switch (*ptr++) | |
| 795 { | |
| 796 case '?': | |
| 797 remcomOutBuffer[0] = 'S'; | |
| 798 remcomOutBuffer[1] = hexchars[sigval >> 4]; | |
| 799 remcomOutBuffer[2] = hexchars[sigval % 16]; | |
| 800 remcomOutBuffer[3] = 0; | |
| 801 break; | |
| 802 case 'd': | |
| 803 remote_debug = !(remote_debug); /* toggle debug flag */ | |
| 804 break; | |
| 805 case 'g': /* return the value of the CPU registers */ | |
| 806 mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES, 0); | |
| 807 break; | |
| 808 case 'G': /* set the value of the CPU registers - return O
K */ | |
| 809 hex2mem (ptr, (char *) registers, NUMREGBYTES, 0); | |
| 810 strcpy (remcomOutBuffer, "OK"); | |
| 811 break; | |
| 812 case 'P': /* set the value of a single CPU register - retu
rn OK */ | |
| 813 { | |
| 814 int regno; | |
| 815 | |
| 816 if (hexToInt (&ptr, ®no) && *ptr++ == '=') | |
| 817 if (regno >= 0 && regno < NUMREGS) | |
| 818 { | |
| 819 hex2mem (ptr, (char *) ®isters[regno], 4, 0); | |
| 820 strcpy (remcomOutBuffer, "OK"); | |
| 821 break; | |
| 822 } | |
| 823 | |
| 824 strcpy (remcomOutBuffer, "E01"); | |
| 825 break; | |
| 826 } | |
| 827 | |
| 828 /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ | |
| 829 case 'm': | |
| 830 /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ | |
| 831 if (hexToInt (&ptr, &addr)) | |
| 832 if (*(ptr++) == ',') | |
| 833 if (hexToInt (&ptr, &length)) | |
| 834 { | |
| 835 ptr = 0; | |
| 836 mem_err = 0; | |
| 837 mem2hex ((char *) addr, remcomOutBuffer, length, 1); | |
| 838 if (mem_err) | |
| 839 { | |
| 840 strcpy (remcomOutBuffer, "E03"); | |
| 841 debug_error ("memory fault"); | |
| 842 } | |
| 843 } | |
| 844 | |
| 845 if (ptr) | |
| 846 { | |
| 847 strcpy (remcomOutBuffer, "E01"); | |
| 848 } | |
| 849 break; | |
| 850 | |
| 851 /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ | |
| 852 case 'M': | |
| 853 /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ | |
| 854 if (hexToInt (&ptr, &addr)) | |
| 855 if (*(ptr++) == ',') | |
| 856 if (hexToInt (&ptr, &length)) | |
| 857 if (*(ptr++) == ':') | |
| 858 { | |
| 859 mem_err = 0; | |
| 860 hex2mem (ptr, (char *) addr, length, 1); | |
| 861 | |
| 862 if (mem_err) | |
| 863 { | |
| 864 strcpy (remcomOutBuffer, "E03"); | |
| 865 debug_error ("memory fault"); | |
| 866 } | |
| 867 else | |
| 868 { | |
| 869 strcpy (remcomOutBuffer, "OK"); | |
| 870 } | |
| 871 | |
| 872 ptr = 0; | |
| 873 } | |
| 874 if (ptr) | |
| 875 { | |
| 876 strcpy (remcomOutBuffer, "E02"); | |
| 877 } | |
| 878 break; | |
| 879 | |
| 880 /* cAA..AA Continue at address AA..AA(optional) */ | |
| 881 /* sAA..AA Step one instruction from AA..AA(optional) */ | |
| 882 case 's': | |
| 883 stepping = 1; | |
| 884 case 'c': | |
| 885 /* try to read optional parameter, pc unchanged if no parm */ | |
| 886 if (hexToInt (&ptr, &addr)) | |
| 887 registers[PC] = addr; | |
| 888 | |
| 889 newPC = registers[PC]; | |
| 890 | |
| 891 /* clear the trace bit */ | |
| 892 registers[PS] &= 0xfffffeff; | |
| 893 | |
| 894 /* set the trace bit if we're stepping */ | |
| 895 if (stepping) | |
| 896 registers[PS] |= 0x100; | |
| 897 | |
| 898 _returnFromException (); /* this is a jump */ | |
| 899 break; | |
| 900 | |
| 901 /* kill the program */ | |
| 902 case 'k': /* do nothing */ | |
| 903 #if 0 | |
| 904 /* Huh? This doesn't look like "nothing". | |
| 905 m68k-stub.c and sparc-stub.c don't have it. */ | |
| 906 BREAKPOINT (); | |
| 907 #endif | |
| 908 break; | |
| 909 } /* switch */ | |
| 910 | |
| 911 /* reply to the request */ | |
| 912 putpacket (remcomOutBuffer); | |
| 913 } | |
| 914 } | |
| 915 | |
| 916 /* this function is used to set up exception handlers for tracing and | |
| 917 breakpoints */ | |
| 918 void | |
| 919 set_debug_traps (void) | |
| 920 { | |
| 921 stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1]; | |
| 922 | |
| 923 exceptionHandler (0, _catchException0); | |
| 924 exceptionHandler (1, _catchException1); | |
| 925 exceptionHandler (3, _catchException3); | |
| 926 exceptionHandler (4, _catchException4); | |
| 927 exceptionHandler (5, _catchException5); | |
| 928 exceptionHandler (6, _catchException6); | |
| 929 exceptionHandler (7, _catchException7); | |
| 930 exceptionHandler (8, _catchException8); | |
| 931 exceptionHandler (9, _catchException9); | |
| 932 exceptionHandler (10, _catchException10); | |
| 933 exceptionHandler (11, _catchException11); | |
| 934 exceptionHandler (12, _catchException12); | |
| 935 exceptionHandler (13, _catchException13); | |
| 936 exceptionHandler (14, _catchException14); | |
| 937 exceptionHandler (16, _catchException16); | |
| 938 | |
| 939 initialized = 1; | |
| 940 } | |
| 941 | |
| 942 /* This function will generate a breakpoint exception. It is used at the | |
| 943 beginning of a program to sync up with a debugger and can be used | |
| 944 otherwise as a quick means to stop program execution and "break" into | |
| 945 the debugger. */ | |
| 946 | |
| 947 void | |
| 948 breakpoint (void) | |
| 949 { | |
| 950 if (initialized) | |
| 951 BREAKPOINT (); | |
| 952 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 11969036:
Merge GDB 7.5.1 (Closed)
Base URL: http://git.chromium.org/native_client/nacl-gdb.git@master