OLD | NEW |
| (Empty) |
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 |