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c906108c SS |
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 | * Also, need to assign exceptionHook and oldExceptionHook. | |
47 | * | |
48 | * Because gdb will sometimes write to the stack area to execute function | |
49 | * calls, this program cannot rely on using the supervisor stack so it | |
50 | * uses it's own stack area reserved in the int array remcomStack. | |
51 | * | |
52 | ************* | |
53 | * | |
54 | * The following gdb commands are supported: | |
55 | * | |
56 | * command function Return value | |
57 | * | |
58 | * g return the value of the CPU registers hex data or ENN | |
59 | * G set the value of the CPU registers OK or ENN | |
60 | * | |
61 | * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN | |
62 | * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN | |
63 | * | |
64 | * c Resume at current address SNN ( signal NN) | |
65 | * cAA..AA Continue at address AA..AA SNN | |
66 | * | |
67 | * s Step one instruction SNN | |
68 | * sAA..AA Step one instruction from AA..AA SNN | |
69 | * | |
70 | * k kill | |
71 | * | |
72 | * ? What was the last sigval ? SNN (signal NN) | |
73 | * | |
74 | * All commands and responses are sent with a packet which includes a | |
75 | * checksum. A packet consists of | |
76 | * | |
77 | * $<packet info>#<checksum>. | |
78 | * | |
79 | * where | |
80 | * <packet info> :: <characters representing the command or response> | |
81 | * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> | |
82 | * | |
83 | * When a packet is received, it is first acknowledged with either '+' or '-'. | |
84 | * '+' indicates a successful transfer. '-' indicates a failed transfer. | |
85 | * | |
86 | * Example: | |
87 | * | |
88 | * Host: Reply: | |
89 | * $m0,10#2a +$00010203040506070809101112131415#42 | |
90 | * | |
91 | ****************************************************************************/ | |
92 | ||
93 | #include <stdio.h> | |
94 | #include <string.h> | |
95 | ||
96 | /************************************************************************ | |
97 | * | |
98 | * external low-level support routines | |
99 | */ | |
100 | typedef void (*ExceptionHook)(int); /* pointer to function with int parm */ | |
101 | typedef void (*Function)(); /* pointer to a function */ | |
102 | ||
103 | extern void putDebugChar(); /* write a single character */ | |
104 | extern int getDebugChar(); /* read and return a single char */ | |
105 | ||
106 | extern Function exceptionHandler(); /* assign an exception handler */ | |
107 | extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */ | |
108 | ||
109 | /************************************************************************/ | |
110 | /* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ | |
111 | /* at least NUMREGBYTES*2 are needed for register packets */ | |
112 | #define BUFMAX 400 | |
113 | ||
114 | static char initialized; /* boolean flag. != 0 means we've been initialized */ | |
115 | ||
116 | int remote_debug; | |
117 | /* debug > 0 prints ill-formed commands in valid packets & checksum errors */ | |
118 | ||
119 | void waitabit(); | |
120 | ||
121 | static const char hexchars[]="0123456789abcdef"; | |
122 | ||
123 | /* Number of registers. */ | |
124 | #define NUMREGS 16 | |
125 | ||
126 | /* Number of bytes of registers. */ | |
127 | #define NUMREGBYTES (NUMREGS * 4) | |
128 | ||
129 | enum regnames {EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI, | |
130 | PC /* also known as eip */, | |
131 | PS /* also known as eflags */, | |
132 | CS, SS, DS, ES, FS, GS}; | |
133 | ||
134 | /* | |
135 | * these should not be static cuz they can be used outside this module | |
136 | */ | |
137 | int registers[NUMREGS]; | |
138 | ||
139 | #define STACKSIZE 10000 | |
140 | int remcomStack[STACKSIZE/sizeof(int)]; | |
141 | static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; | |
142 | ||
143 | /* | |
144 | * In many cases, the system will want to continue exception processing | |
145 | * when a continue command is given. | |
146 | * oldExceptionHook is a function to invoke in this case. | |
147 | */ | |
148 | ||
149 | static ExceptionHook oldExceptionHook; | |
150 | ||
151 | /*************************** ASSEMBLY CODE MACROS *************************/ | |
152 | /* */ | |
153 | ||
154 | extern void | |
155 | return_to_prog (); | |
156 | ||
157 | /* Restore the program's registers (including the stack pointer, which | |
158 | means we get the right stack and don't have to worry about popping our | |
159 | return address and any stack frames and so on) and return. */ | |
160 | asm(".text"); | |
161 | asm(".globl _return_to_prog"); | |
162 | asm("_return_to_prog:"); | |
163 | asm(" movw _registers+44, %ss"); | |
164 | asm(" movl _registers+16, %esp"); | |
165 | asm(" movl _registers+4, %ecx"); | |
166 | asm(" movl _registers+8, %edx"); | |
167 | asm(" movl _registers+12, %ebx"); | |
168 | asm(" movl _registers+20, %ebp"); | |
169 | asm(" movl _registers+24, %esi"); | |
170 | asm(" movl _registers+28, %edi"); | |
171 | asm(" movw _registers+48, %ds"); | |
172 | asm(" movw _registers+52, %es"); | |
173 | asm(" movw _registers+56, %fs"); | |
174 | asm(" movw _registers+60, %gs"); | |
175 | asm(" movl _registers+36, %eax"); | |
176 | asm(" pushl %eax"); /* saved eflags */ | |
177 | asm(" movl _registers+40, %eax"); | |
178 | asm(" pushl %eax"); /* saved cs */ | |
179 | asm(" movl _registers+32, %eax"); | |
180 | asm(" pushl %eax"); /* saved eip */ | |
181 | asm(" movl _registers, %eax"); | |
182 | /* use iret to restore pc and flags together so | |
183 | that trace flag works right. */ | |
184 | asm(" iret"); | |
185 | ||
186 | #define BREAKPOINT() asm(" int $3"); | |
187 | ||
188 | /* Put the error code here just in case the user cares. */ | |
189 | int gdb_i386errcode; | |
190 | /* Likewise, the vector number here (since GDB only gets the signal | |
191 | number through the usual means, and that's not very specific). */ | |
192 | int gdb_i386vector = -1; | |
193 | ||
194 | /* GDB stores segment registers in 32-bit words (that's just the way | |
195 | m-i386v.h is written). So zero the appropriate areas in registers. */ | |
196 | #define SAVE_REGISTERS1() \ | |
197 | asm ("movl %eax, _registers"); \ | |
198 | asm ("movl %ecx, _registers+4"); \ | |
199 | asm ("movl %edx, _registers+8"); \ | |
200 | asm ("movl %ebx, _registers+12"); \ | |
201 | asm ("movl %ebp, _registers+20"); \ | |
202 | asm ("movl %esi, _registers+24"); \ | |
203 | asm ("movl %edi, _registers+28"); \ | |
204 | asm ("movw $0, %ax"); \ | |
205 | asm ("movw %ds, _registers+48"); \ | |
206 | asm ("movw %ax, _registers+50"); \ | |
207 | asm ("movw %es, _registers+52"); \ | |
208 | asm ("movw %ax, _registers+54"); \ | |
209 | asm ("movw %fs, _registers+56"); \ | |
210 | asm ("movw %ax, _registers+58"); \ | |
211 | asm ("movw %gs, _registers+60"); \ | |
212 | asm ("movw %ax, _registers+62"); | |
213 | #define SAVE_ERRCODE() \ | |
214 | asm ("popl %ebx"); \ | |
215 | asm ("movl %ebx, _gdb_i386errcode"); | |
216 | #define SAVE_REGISTERS2() \ | |
217 | asm ("popl %ebx"); /* old eip */ \ | |
218 | asm ("movl %ebx, _registers+32"); \ | |
219 | asm ("popl %ebx"); /* old cs */ \ | |
220 | asm ("movl %ebx, _registers+40"); \ | |
221 | asm ("movw %ax, _registers+42"); \ | |
222 | asm ("popl %ebx"); /* old eflags */ \ | |
223 | asm ("movl %ebx, _registers+36"); \ | |
224 | /* Now that we've done the pops, we can save the stack pointer."); */ \ | |
225 | asm ("movw %ss, _registers+44"); \ | |
226 | asm ("movw %ax, _registers+46"); \ | |
227 | asm ("movl %esp, _registers+16"); | |
228 | ||
229 | /* See if mem_fault_routine is set, if so just IRET to that address. */ | |
230 | #define CHECK_FAULT() \ | |
231 | asm ("cmpl $0, _mem_fault_routine"); \ | |
232 | asm ("jne mem_fault"); | |
233 | ||
234 | asm (".text"); | |
235 | asm ("mem_fault:"); | |
236 | /* OK to clobber temp registers; we're just going to end up in set_mem_err. */ | |
237 | /* Pop error code from the stack and save it. */ | |
238 | asm (" popl %eax"); | |
239 | asm (" movl %eax, _gdb_i386errcode"); | |
240 | ||
241 | asm (" popl %eax"); /* eip */ | |
242 | /* We don't want to return there, we want to return to the function | |
243 | pointed to by mem_fault_routine instead. */ | |
244 | asm (" movl _mem_fault_routine, %eax"); | |
245 | asm (" popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits). */ | |
246 | asm (" popl %edx"); /* eflags */ | |
247 | ||
248 | /* Remove this stack frame; when we do the iret, we will be going to | |
249 | the start of a function, so we want the stack to look just like it | |
250 | would after a "call" instruction. */ | |
251 | asm (" leave"); | |
252 | ||
253 | /* Push the stuff that iret wants. */ | |
254 | asm (" pushl %edx"); /* eflags */ | |
255 | asm (" pushl %ecx"); /* cs */ | |
256 | asm (" pushl %eax"); /* eip */ | |
257 | ||
258 | /* Zero mem_fault_routine. */ | |
259 | asm (" movl $0, %eax"); | |
260 | asm (" movl %eax, _mem_fault_routine"); | |
261 | ||
262 | asm ("iret"); | |
263 | ||
264 | #define CALL_HOOK() asm("call _remcomHandler"); | |
265 | ||
266 | /* This function is called when a i386 exception occurs. It saves | |
267 | * all the cpu regs in the _registers array, munges the stack a bit, | |
268 | * and invokes an exception handler (remcom_handler). | |
269 | * | |
270 | * stack on entry: stack on exit: | |
271 | * old eflags vector number | |
272 | * old cs (zero-filled to 32 bits) | |
273 | * old eip | |
274 | * | |
275 | */ | |
276 | extern void _catchException3(); | |
277 | asm(".text"); | |
278 | asm(".globl __catchException3"); | |
279 | asm("__catchException3:"); | |
280 | SAVE_REGISTERS1(); | |
281 | SAVE_REGISTERS2(); | |
282 | asm ("pushl $3"); | |
283 | CALL_HOOK(); | |
284 | ||
285 | /* Same thing for exception 1. */ | |
286 | extern void _catchException1(); | |
287 | asm(".text"); | |
288 | asm(".globl __catchException1"); | |
289 | asm("__catchException1:"); | |
290 | SAVE_REGISTERS1(); | |
291 | SAVE_REGISTERS2(); | |
292 | asm ("pushl $1"); | |
293 | CALL_HOOK(); | |
294 | ||
295 | /* Same thing for exception 0. */ | |
296 | extern void _catchException0(); | |
297 | asm(".text"); | |
298 | asm(".globl __catchException0"); | |
299 | asm("__catchException0:"); | |
300 | SAVE_REGISTERS1(); | |
301 | SAVE_REGISTERS2(); | |
302 | asm ("pushl $0"); | |
303 | CALL_HOOK(); | |
304 | ||
305 | /* Same thing for exception 4. */ | |
306 | extern void _catchException4(); | |
307 | asm(".text"); | |
308 | asm(".globl __catchException4"); | |
309 | asm("__catchException4:"); | |
310 | SAVE_REGISTERS1(); | |
311 | SAVE_REGISTERS2(); | |
312 | asm ("pushl $4"); | |
313 | CALL_HOOK(); | |
314 | ||
315 | /* Same thing for exception 5. */ | |
316 | extern void _catchException5(); | |
317 | asm(".text"); | |
318 | asm(".globl __catchException5"); | |
319 | asm("__catchException5:"); | |
320 | SAVE_REGISTERS1(); | |
321 | SAVE_REGISTERS2(); | |
322 | asm ("pushl $5"); | |
323 | CALL_HOOK(); | |
324 | ||
325 | /* Same thing for exception 6. */ | |
326 | extern void _catchException6(); | |
327 | asm(".text"); | |
328 | asm(".globl __catchException6"); | |
329 | asm("__catchException6:"); | |
330 | SAVE_REGISTERS1(); | |
331 | SAVE_REGISTERS2(); | |
332 | asm ("pushl $6"); | |
333 | CALL_HOOK(); | |
334 | ||
335 | /* Same thing for exception 7. */ | |
336 | extern void _catchException7(); | |
337 | asm(".text"); | |
338 | asm(".globl __catchException7"); | |
339 | asm("__catchException7:"); | |
340 | SAVE_REGISTERS1(); | |
341 | SAVE_REGISTERS2(); | |
342 | asm ("pushl $7"); | |
343 | CALL_HOOK(); | |
344 | ||
345 | /* Same thing for exception 8. */ | |
346 | extern void _catchException8(); | |
347 | asm(".text"); | |
348 | asm(".globl __catchException8"); | |
349 | asm("__catchException8:"); | |
350 | SAVE_REGISTERS1(); | |
351 | SAVE_ERRCODE(); | |
352 | SAVE_REGISTERS2(); | |
353 | asm ("pushl $8"); | |
354 | CALL_HOOK(); | |
355 | ||
356 | /* Same thing for exception 9. */ | |
357 | extern void _catchException9(); | |
358 | asm(".text"); | |
359 | asm(".globl __catchException9"); | |
360 | asm("__catchException9:"); | |
361 | SAVE_REGISTERS1(); | |
362 | SAVE_REGISTERS2(); | |
363 | asm ("pushl $9"); | |
364 | CALL_HOOK(); | |
365 | ||
366 | /* Same thing for exception 10. */ | |
367 | extern void _catchException10(); | |
368 | asm(".text"); | |
369 | asm(".globl __catchException10"); | |
370 | asm("__catchException10:"); | |
371 | SAVE_REGISTERS1(); | |
372 | SAVE_ERRCODE(); | |
373 | SAVE_REGISTERS2(); | |
374 | asm ("pushl $10"); | |
375 | CALL_HOOK(); | |
376 | ||
377 | /* Same thing for exception 12. */ | |
378 | extern void _catchException12(); | |
379 | asm(".text"); | |
380 | asm(".globl __catchException12"); | |
381 | asm("__catchException12:"); | |
382 | SAVE_REGISTERS1(); | |
383 | SAVE_ERRCODE(); | |
384 | SAVE_REGISTERS2(); | |
385 | asm ("pushl $12"); | |
386 | CALL_HOOK(); | |
387 | ||
388 | /* Same thing for exception 16. */ | |
389 | extern void _catchException16(); | |
390 | asm(".text"); | |
391 | asm(".globl __catchException16"); | |
392 | asm("__catchException16:"); | |
393 | SAVE_REGISTERS1(); | |
394 | SAVE_REGISTERS2(); | |
395 | asm ("pushl $16"); | |
396 | CALL_HOOK(); | |
397 | ||
398 | /* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff. */ | |
399 | ||
400 | /* Same thing for exception 13. */ | |
401 | extern void _catchException13 (); | |
402 | asm (".text"); | |
403 | asm (".globl __catchException13"); | |
404 | asm ("__catchException13:"); | |
405 | CHECK_FAULT(); | |
406 | SAVE_REGISTERS1(); | |
407 | SAVE_ERRCODE(); | |
408 | SAVE_REGISTERS2(); | |
409 | asm ("pushl $13"); | |
410 | CALL_HOOK(); | |
411 | ||
412 | /* Same thing for exception 11. */ | |
413 | extern void _catchException11 (); | |
414 | asm (".text"); | |
415 | asm (".globl __catchException11"); | |
416 | asm ("__catchException11:"); | |
417 | CHECK_FAULT(); | |
418 | SAVE_REGISTERS1(); | |
419 | SAVE_ERRCODE(); | |
420 | SAVE_REGISTERS2(); | |
421 | asm ("pushl $11"); | |
422 | CALL_HOOK(); | |
423 | ||
424 | /* Same thing for exception 14. */ | |
425 | extern void _catchException14 (); | |
426 | asm (".text"); | |
427 | asm (".globl __catchException14"); | |
428 | asm ("__catchException14:"); | |
429 | CHECK_FAULT(); | |
430 | SAVE_REGISTERS1(); | |
431 | SAVE_ERRCODE(); | |
432 | SAVE_REGISTERS2(); | |
433 | asm ("pushl $14"); | |
434 | CALL_HOOK(); | |
435 | ||
436 | /* | |
437 | * remcomHandler is a front end for handle_exception. It moves the | |
438 | * stack pointer into an area reserved for debugger use. | |
439 | */ | |
440 | asm("_remcomHandler:"); | |
441 | asm(" popl %eax"); /* pop off return address */ | |
442 | asm(" popl %eax"); /* get the exception number */ | |
443 | asm(" movl _stackPtr, %esp"); /* move to remcom stack area */ | |
444 | asm(" pushl %eax"); /* push exception onto stack */ | |
445 | asm(" call _handle_exception"); /* this never returns */ | |
446 | ||
447 | void _returnFromException() | |
448 | { | |
449 | return_to_prog (); | |
450 | } | |
451 | ||
452 | int hex(ch) | |
453 | char ch; | |
454 | { | |
455 | if ((ch >= 'a') && (ch <= 'f')) return (ch-'a'+10); | |
456 | if ((ch >= '0') && (ch <= '9')) return (ch-'0'); | |
457 | if ((ch >= 'A') && (ch <= 'F')) return (ch-'A'+10); | |
458 | return (-1); | |
459 | } | |
460 | ||
461 | ||
462 | /* scan for the sequence $<data>#<checksum> */ | |
463 | void getpacket(buffer) | |
464 | char * buffer; | |
465 | { | |
466 | unsigned char checksum; | |
467 | unsigned char xmitcsum; | |
468 | int i; | |
469 | int count; | |
470 | char ch; | |
471 | ||
472 | do { | |
473 | /* wait around for the start character, ignore all other characters */ | |
474 | while ((ch = (getDebugChar() & 0x7f)) != '$'); | |
475 | checksum = 0; | |
476 | xmitcsum = -1; | |
477 | ||
478 | count = 0; | |
479 | ||
480 | /* now, read until a # or end of buffer is found */ | |
481 | while (count < BUFMAX) { | |
482 | ch = getDebugChar() & 0x7f; | |
483 | if (ch == '#') break; | |
484 | checksum = checksum + ch; | |
485 | buffer[count] = ch; | |
486 | count = count + 1; | |
487 | } | |
488 | buffer[count] = 0; | |
489 | ||
490 | if (ch == '#') { | |
491 | xmitcsum = hex(getDebugChar() & 0x7f) << 4; | |
492 | xmitcsum += hex(getDebugChar() & 0x7f); | |
493 | if ((remote_debug ) && (checksum != xmitcsum)) { | |
494 | fprintf (stderr ,"bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n", | |
495 | checksum,xmitcsum,buffer); | |
496 | } | |
497 | ||
498 | if (checksum != xmitcsum) putDebugChar('-'); /* failed checksum */ | |
499 | else { | |
500 | putDebugChar('+'); /* successful transfer */ | |
501 | /* if a sequence char is present, reply the sequence ID */ | |
502 | if (buffer[2] == ':') { | |
503 | putDebugChar( buffer[0] ); | |
504 | putDebugChar( buffer[1] ); | |
505 | /* remove sequence chars from buffer */ | |
506 | count = strlen(buffer); | |
507 | for (i=3; i <= count; i++) buffer[i-3] = buffer[i]; | |
508 | } | |
509 | } | |
510 | } | |
511 | } while (checksum != xmitcsum); | |
512 | ||
513 | } | |
514 | ||
515 | /* send the packet in buffer. */ | |
516 | ||
517 | ||
518 | void putpacket(buffer) | |
519 | char * buffer; | |
520 | { | |
521 | unsigned char checksum; | |
522 | int count; | |
523 | char ch; | |
524 | ||
525 | /* $<packet info>#<checksum>. */ | |
526 | do { | |
527 | putDebugChar('$'); | |
528 | checksum = 0; | |
529 | count = 0; | |
530 | ||
531 | while (ch=buffer[count]) { | |
532 | putDebugChar(ch); | |
533 | checksum += ch; | |
534 | count += 1; | |
535 | } | |
536 | ||
537 | putDebugChar('#'); | |
538 | putDebugChar(hexchars[checksum >> 4]); | |
539 | putDebugChar(hexchars[checksum % 16]); | |
540 | ||
541 | } while ((getDebugChar() & 0x7f) != '+'); | |
542 | ||
543 | } | |
544 | ||
545 | char remcomInBuffer[BUFMAX]; | |
546 | char remcomOutBuffer[BUFMAX]; | |
547 | static short error; | |
548 | ||
549 | ||
550 | void debug_error(format, parm) | |
551 | char * format; | |
552 | char * parm; | |
553 | { | |
554 | if (remote_debug) fprintf (stderr,format,parm); | |
555 | } | |
556 | ||
557 | /* Address of a routine to RTE to if we get a memory fault. */ | |
558 | static void (*volatile mem_fault_routine)() = NULL; | |
559 | ||
560 | /* Indicate to caller of mem2hex or hex2mem that there has been an | |
561 | error. */ | |
562 | static volatile int mem_err = 0; | |
563 | ||
564 | void | |
565 | set_mem_err () | |
566 | { | |
567 | mem_err = 1; | |
568 | } | |
569 | ||
570 | /* These are separate functions so that they are so short and sweet | |
571 | that the compiler won't save any registers (if there is a fault | |
572 | to mem_fault, they won't get restored, so there better not be any | |
573 | saved). */ | |
574 | int | |
575 | get_char (addr) | |
576 | char *addr; | |
577 | { | |
578 | return *addr; | |
579 | } | |
580 | ||
581 | void | |
582 | set_char (addr, val) | |
583 | char *addr; | |
584 | int val; | |
585 | { | |
586 | *addr = val; | |
587 | } | |
588 | ||
589 | /* convert the memory pointed to by mem into hex, placing result in buf */ | |
590 | /* return a pointer to the last char put in buf (null) */ | |
591 | /* If MAY_FAULT is non-zero, then we should set mem_err in response to | |
592 | a fault; if zero treat a fault like any other fault in the stub. */ | |
593 | char* mem2hex(mem, buf, count, may_fault) | |
594 | char* mem; | |
595 | char* buf; | |
596 | int count; | |
597 | int may_fault; | |
598 | { | |
599 | int i; | |
600 | unsigned char ch; | |
601 | ||
602 | if (may_fault) | |
603 | mem_fault_routine = set_mem_err; | |
604 | for (i=0;i<count;i++) { | |
605 | ch = get_char (mem++); | |
606 | if (may_fault && mem_err) | |
607 | return (buf); | |
608 | *buf++ = hexchars[ch >> 4]; | |
609 | *buf++ = hexchars[ch % 16]; | |
610 | } | |
611 | *buf = 0; | |
612 | if (may_fault) | |
613 | mem_fault_routine = NULL; | |
614 | return(buf); | |
615 | } | |
616 | ||
617 | /* convert the hex array pointed to by buf into binary to be placed in mem */ | |
618 | /* return a pointer to the character AFTER the last byte written */ | |
619 | char* hex2mem(buf, mem, count, may_fault) | |
620 | char* buf; | |
621 | char* mem; | |
622 | int count; | |
623 | int may_fault; | |
624 | { | |
625 | int i; | |
626 | unsigned char ch; | |
627 | ||
628 | if (may_fault) | |
629 | mem_fault_routine = set_mem_err; | |
630 | for (i=0;i<count;i++) { | |
631 | ch = hex(*buf++) << 4; | |
632 | ch = ch + hex(*buf++); | |
633 | set_char (mem++, ch); | |
634 | if (may_fault && mem_err) | |
635 | return (mem); | |
636 | } | |
637 | if (may_fault) | |
638 | mem_fault_routine = NULL; | |
639 | return(mem); | |
640 | } | |
641 | ||
642 | /* this function takes the 386 exception vector and attempts to | |
643 | translate this number into a unix compatible signal value */ | |
644 | int computeSignal( exceptionVector ) | |
645 | int exceptionVector; | |
646 | { | |
647 | int sigval; | |
648 | switch (exceptionVector) { | |
649 | case 0 : sigval = 8; break; /* divide by zero */ | |
650 | case 1 : sigval = 5; break; /* debug exception */ | |
651 | case 3 : sigval = 5; break; /* breakpoint */ | |
652 | case 4 : sigval = 16; break; /* into instruction (overflow) */ | |
653 | case 5 : sigval = 16; break; /* bound instruction */ | |
654 | case 6 : sigval = 4; break; /* Invalid opcode */ | |
655 | case 7 : sigval = 8; break; /* coprocessor not available */ | |
656 | case 8 : sigval = 7; break; /* double fault */ | |
657 | case 9 : sigval = 11; break; /* coprocessor segment overrun */ | |
658 | case 10 : sigval = 11; break; /* Invalid TSS */ | |
659 | case 11 : sigval = 11; break; /* Segment not present */ | |
660 | case 12 : sigval = 11; break; /* stack exception */ | |
661 | case 13 : sigval = 11; break; /* general protection */ | |
662 | case 14 : sigval = 11; break; /* page fault */ | |
663 | case 16 : sigval = 7; break; /* coprocessor error */ | |
664 | default: | |
665 | sigval = 7; /* "software generated"*/ | |
666 | } | |
667 | return (sigval); | |
668 | } | |
669 | ||
670 | /**********************************************/ | |
671 | /* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ | |
672 | /* RETURN NUMBER OF CHARS PROCESSED */ | |
673 | /**********************************************/ | |
674 | int hexToInt(char **ptr, int *intValue) | |
675 | { | |
676 | int numChars = 0; | |
677 | int hexValue; | |
678 | ||
679 | *intValue = 0; | |
680 | ||
681 | while (**ptr) | |
682 | { | |
683 | hexValue = hex(**ptr); | |
684 | if (hexValue >=0) | |
685 | { | |
686 | *intValue = (*intValue <<4) | hexValue; | |
687 | numChars ++; | |
688 | } | |
689 | else | |
690 | break; | |
691 | ||
692 | (*ptr)++; | |
693 | } | |
694 | ||
695 | return (numChars); | |
696 | } | |
697 | ||
698 | /* | |
699 | * This function does all command procesing for interfacing to gdb. | |
700 | */ | |
701 | void handle_exception(int exceptionVector) | |
702 | { | |
703 | int sigval; | |
704 | int addr, length; | |
705 | char * ptr; | |
706 | int newPC; | |
707 | ||
708 | gdb_i386vector = exceptionVector; | |
709 | ||
710 | if (remote_debug) printf("vector=%d, sr=0x%x, pc=0x%x\n", | |
711 | exceptionVector, | |
712 | registers[ PS ], | |
713 | registers[ PC ]); | |
714 | ||
715 | /* reply to host that an exception has occurred */ | |
716 | sigval = computeSignal( exceptionVector ); | |
717 | remcomOutBuffer[0] = 'S'; | |
718 | remcomOutBuffer[1] = hexchars[sigval >> 4]; | |
719 | remcomOutBuffer[2] = hexchars[sigval % 16]; | |
720 | remcomOutBuffer[3] = 0; | |
721 | ||
722 | putpacket(remcomOutBuffer); | |
723 | ||
724 | while (1==1) { | |
725 | error = 0; | |
726 | remcomOutBuffer[0] = 0; | |
727 | getpacket(remcomInBuffer); | |
728 | switch (remcomInBuffer[0]) { | |
729 | case '?' : remcomOutBuffer[0] = 'S'; | |
730 | remcomOutBuffer[1] = hexchars[sigval >> 4]; | |
731 | remcomOutBuffer[2] = hexchars[sigval % 16]; | |
732 | remcomOutBuffer[3] = 0; | |
733 | break; | |
734 | case 'd' : remote_debug = !(remote_debug); /* toggle debug flag */ | |
735 | break; | |
736 | case 'g' : /* return the value of the CPU registers */ | |
737 | mem2hex((char*) registers, remcomOutBuffer, NUMREGBYTES, 0); | |
738 | break; | |
739 | case 'G' : /* set the value of the CPU registers - return OK */ | |
740 | hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES, 0); | |
741 | strcpy(remcomOutBuffer,"OK"); | |
742 | break; | |
743 | case 'P' : /* set the value of a single CPU register - return OK */ | |
744 | { | |
745 | int regno; | |
746 | ||
747 | ptr = &remcomInBuffer[1]; | |
748 | if (hexToInt (&ptr, ®no) && *ptr++ == '=') | |
749 | if (regno >= 0 && regno < NUMREGS) | |
750 | { | |
751 | hex2mem (ptr, (char *)®isters[regno], 4, 0); | |
752 | strcpy(remcomOutBuffer,"OK"); | |
753 | break; | |
754 | } | |
755 | ||
756 | strcpy (remcomOutBuffer, "E01"); | |
757 | break; | |
758 | } | |
759 | ||
760 | /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ | |
761 | case 'm' : | |
762 | /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ | |
763 | ptr = &remcomInBuffer[1]; | |
764 | if (hexToInt(&ptr,&addr)) | |
765 | if (*(ptr++) == ',') | |
766 | if (hexToInt(&ptr,&length)) | |
767 | { | |
768 | ptr = 0; | |
769 | mem_err = 0; | |
770 | mem2hex((char*) addr, remcomOutBuffer, length, 1); | |
771 | if (mem_err) { | |
772 | strcpy (remcomOutBuffer, "E03"); | |
773 | debug_error ("memory fault"); | |
774 | } | |
775 | } | |
776 | ||
777 | if (ptr) | |
778 | { | |
779 | strcpy(remcomOutBuffer,"E01"); | |
780 | debug_error("malformed read memory command: %s",remcomInBuffer); | |
781 | } | |
782 | break; | |
783 | ||
784 | /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ | |
785 | case 'M' : | |
786 | /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ | |
787 | ptr = &remcomInBuffer[1]; | |
788 | if (hexToInt(&ptr,&addr)) | |
789 | if (*(ptr++) == ',') | |
790 | if (hexToInt(&ptr,&length)) | |
791 | if (*(ptr++) == ':') | |
792 | { | |
793 | mem_err = 0; | |
794 | hex2mem(ptr, (char*) addr, length, 1); | |
795 | ||
796 | if (mem_err) { | |
797 | strcpy (remcomOutBuffer, "E03"); | |
798 | debug_error ("memory fault"); | |
799 | } else { | |
800 | strcpy(remcomOutBuffer,"OK"); | |
801 | } | |
802 | ||
803 | ptr = 0; | |
804 | } | |
805 | if (ptr) | |
806 | { | |
807 | strcpy(remcomOutBuffer,"E02"); | |
808 | debug_error("malformed write memory command: %s",remcomInBuffer); | |
809 | } | |
810 | break; | |
811 | ||
812 | /* cAA..AA Continue at address AA..AA(optional) */ | |
813 | /* sAA..AA Step one instruction from AA..AA(optional) */ | |
814 | case 'c' : | |
815 | case 's' : | |
816 | /* try to read optional parameter, pc unchanged if no parm */ | |
817 | ptr = &remcomInBuffer[1]; | |
818 | if (hexToInt(&ptr,&addr)) | |
819 | registers[ PC ] = addr; | |
820 | ||
821 | newPC = registers[ PC]; | |
822 | ||
823 | /* clear the trace bit */ | |
824 | registers[ PS ] &= 0xfffffeff; | |
825 | ||
826 | /* set the trace bit if we're stepping */ | |
827 | if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x100; | |
828 | ||
829 | /* | |
830 | * If we found a match for the PC AND we are not returning | |
831 | * as a result of a breakpoint (33), | |
832 | * trace exception (9), nmi (31), jmp to | |
833 | * the old exception handler as if this code never ran. | |
834 | */ | |
835 | #if 0 | |
836 | /* Don't really think we need this, except maybe for protection | |
837 | exceptions. */ | |
838 | /* | |
839 | * invoke the previous handler. | |
840 | */ | |
841 | if (oldExceptionHook) | |
842 | (*oldExceptionHook) (frame->exceptionVector); | |
843 | newPC = registers[ PC ]; /* pc may have changed */ | |
844 | #endif /* 0 */ | |
845 | ||
846 | _returnFromException(); /* this is a jump */ | |
847 | ||
848 | break; | |
849 | ||
850 | /* kill the program */ | |
851 | case 'k' : /* do nothing */ | |
852 | #if 0 | |
853 | /* Huh? This doesn't look like "nothing". | |
854 | m68k-stub.c and sparc-stub.c don't have it. */ | |
855 | BREAKPOINT(); | |
856 | #endif | |
857 | break; | |
858 | } /* switch */ | |
859 | ||
860 | /* reply to the request */ | |
861 | putpacket(remcomOutBuffer); | |
862 | } | |
863 | } | |
864 | ||
865 | /* this function is used to set up exception handlers for tracing and | |
866 | breakpoints */ | |
867 | void set_debug_traps() | |
868 | { | |
869 | extern void remcomHandler(); | |
870 | int exception; | |
871 | ||
872 | stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; | |
873 | ||
874 | exceptionHandler (0, _catchException0); | |
875 | exceptionHandler (1, _catchException1); | |
876 | exceptionHandler (3, _catchException3); | |
877 | exceptionHandler (4, _catchException4); | |
878 | exceptionHandler (5, _catchException5); | |
879 | exceptionHandler (6, _catchException6); | |
880 | exceptionHandler (7, _catchException7); | |
881 | exceptionHandler (8, _catchException8); | |
882 | exceptionHandler (9, _catchException9); | |
883 | exceptionHandler (10, _catchException10); | |
884 | exceptionHandler (11, _catchException11); | |
885 | exceptionHandler (12, _catchException12); | |
886 | exceptionHandler (13, _catchException13); | |
887 | exceptionHandler (14, _catchException14); | |
888 | exceptionHandler (16, _catchException16); | |
889 | ||
890 | if (exceptionHook != remcomHandler) | |
891 | { | |
892 | oldExceptionHook = exceptionHook; | |
893 | exceptionHook = remcomHandler; | |
894 | } | |
895 | ||
896 | /* In case GDB is started before us, ack any packets (presumably | |
897 | "$?#xx") sitting there. */ | |
898 | putDebugChar ('+'); | |
899 | ||
900 | initialized = 1; | |
901 | ||
902 | } | |
903 | ||
904 | /* This function will generate a breakpoint exception. It is used at the | |
905 | beginning of a program to sync up with a debugger and can be used | |
906 | otherwise as a quick means to stop program execution and "break" into | |
907 | the debugger. */ | |
908 | ||
909 | void breakpoint() | |
910 | { | |
911 | if (initialized) | |
912 | #if 0 | |
913 | handle_exception(3); | |
914 | #else | |
915 | BREAKPOINT(); | |
916 | #endif | |
917 | waitabit(); | |
918 | } | |
919 | ||
920 | int waitlimit = 1000000; | |
921 | ||
922 | void | |
923 | waitabit() | |
924 | { | |
925 | int i; | |
926 | for (i = 0; i < waitlimit; i++) ; | |
927 | } |