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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 M32R by Michael Snyder, 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 M32R 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 * XAA..AA,LLLL: Write LLLL binary bytes at address OK or ENN | |
63 * AA..AA | |
64 * | |
65 * c Resume at current address SNN ( signal NN) | |
66 * cAA..AA Continue at address AA..AA SNN | |
67 * | |
68 * s Step one instruction SNN | |
69 * sAA..AA Step one instruction from AA..AA SNN | |
70 * | |
71 * k kill | |
72 * | |
73 * ? What was the last sigval ? SNN (signal NN) | |
74 * | |
75 * All commands and responses are sent with a packet which includes a | |
76 * checksum. A packet consists of | |
77 * | |
78 * $<packet info>#<checksum>. | |
79 * | |
80 * where | |
81 * <packet info> :: <characters representing the command or response> | |
82 * <checksum> :: <two hex digits computed as modulo 256 sum of <packetinfo>> | |
83 * | |
84 * When a packet is received, it is first acknowledged with either '+' or '-'. | |
85 * '+' indicates a successful transfer. '-' indicates a failed transfer. | |
86 * | |
87 * Example: | |
88 * | |
89 * Host: Reply: | |
90 * $m0,10#2a +$00010203040506070809101112131415#42 | |
91 * | |
92 ****************************************************************************/ | |
93 | |
94 | |
95 /************************************************************************ | |
96 * | |
97 * external low-level support routines | |
98 */ | |
99 extern void putDebugChar (); /* write a single character */ | |
100 extern int getDebugChar (); /* read and return a single char */ | |
101 extern void exceptionHandler (); /* assign an exception handler */ | |
102 | |
103 /***************************************************************************** | |
104 * BUFMAX defines the maximum number of characters in inbound/outbound buffers | |
105 * at least NUMREGBYTES*2 are needed for register packets | |
106 */ | |
107 #define BUFMAX 400 | |
108 | |
109 static char initialized; /* boolean flag. != 0 means we've been initializ
ed */ | |
110 | |
111 int remote_debug; | |
112 /* debug > 0 prints ill-formed commands in valid packets & checksum errors */ | |
113 | |
114 static const unsigned char hexchars[] = "0123456789abcdef"; | |
115 | |
116 #define NUMREGS 24 | |
117 | |
118 /* Number of bytes of registers. */ | |
119 #define NUMREGBYTES (NUMREGS * 4) | |
120 enum regnames | |
121 { R0, R1, R2, R3, R4, R5, R6, R7, | |
122 R8, R9, R10, R11, R12, R13, R14, R15, | |
123 PSW, CBR, SPI, SPU, BPC, PC, ACCL, ACCH | |
124 }; | |
125 | |
126 enum SYS_calls | |
127 { | |
128 SYS_null, | |
129 SYS_exit, | |
130 SYS_open, | |
131 SYS_close, | |
132 SYS_read, | |
133 SYS_write, | |
134 SYS_lseek, | |
135 SYS_unlink, | |
136 SYS_getpid, | |
137 SYS_kill, | |
138 SYS_fstat, | |
139 SYS_sbrk, | |
140 SYS_fork, | |
141 SYS_execve, | |
142 SYS_wait4, | |
143 SYS_link, | |
144 SYS_chdir, | |
145 SYS_stat, | |
146 SYS_utime, | |
147 SYS_chown, | |
148 SYS_chmod, | |
149 SYS_time, | |
150 SYS_pipe | |
151 }; | |
152 | |
153 static int registers[NUMREGS]; | |
154 | |
155 #define STACKSIZE 8096 | |
156 static unsigned char remcomInBuffer[BUFMAX]; | |
157 static unsigned char remcomOutBuffer[BUFMAX]; | |
158 static int remcomStack[STACKSIZE / sizeof (int)]; | |
159 static int *stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1]; | |
160 | |
161 static unsigned int save_vectors[18]; /* previous exception vectors */ | |
162 | |
163 /* Indicate to caller of mem2hex or hex2mem that there has been an error. */ | |
164 static volatile int mem_err = 0; | |
165 | |
166 /* Store the vector number here (since GDB only gets the signal | |
167 number through the usual means, and that's not very specific). */ | |
168 int gdb_m32r_vector = -1; | |
169 | |
170 #if 0 | |
171 #include "syscall.h" /* for SYS_exit, SYS_write etc. */ | |
172 #endif | |
173 | |
174 /* Global entry points: | |
175 */ | |
176 | |
177 extern void handle_exception (int); | |
178 extern void set_debug_traps (void); | |
179 extern void breakpoint (void); | |
180 | |
181 /* Local functions: | |
182 */ | |
183 | |
184 static int computeSignal (int); | |
185 static void putpacket (unsigned char *); | |
186 static unsigned char *getpacket (void); | |
187 | |
188 static unsigned char *mem2hex (unsigned char *, unsigned char *, int, int); | |
189 static unsigned char *hex2mem (unsigned char *, unsigned char *, int, int); | |
190 static int hexToInt (unsigned char **, int *); | |
191 static unsigned char *bin2mem (unsigned char *, unsigned char *, int, int); | |
192 static void stash_registers (void); | |
193 static void restore_registers (void); | |
194 static int prepare_to_step (int); | |
195 static int finish_from_step (void); | |
196 static unsigned long crc32 (unsigned char *, int, unsigned long); | |
197 | |
198 static void gdb_error (char *, char *); | |
199 static int gdb_putchar (int), gdb_puts (char *), gdb_write (char *, int); | |
200 | |
201 static unsigned char *strcpy (unsigned char *, const unsigned char *); | |
202 static int strlen (const unsigned char *); | |
203 | |
204 /* | |
205 * This function does all command procesing for interfacing to gdb. | |
206 */ | |
207 | |
208 void | |
209 handle_exception (int exceptionVector) | |
210 { | |
211 int sigval, stepping; | |
212 int addr, length, i; | |
213 unsigned char *ptr; | |
214 unsigned char buf[16]; | |
215 int binary; | |
216 | |
217 if (!finish_from_step ()) | |
218 return; /* "false step": let the target continue */ | |
219 | |
220 gdb_m32r_vector = exceptionVector; | |
221 | |
222 if (remote_debug) | |
223 { | |
224 mem2hex ((unsigned char *) &exceptionVector, buf, 4, 0); | |
225 gdb_error ("Handle exception %s, ", buf); | |
226 mem2hex ((unsigned char *) ®isters[PC], buf, 4, 0); | |
227 gdb_error ("PC == 0x%s\n", buf); | |
228 } | |
229 | |
230 /* reply to host that an exception has occurred */ | |
231 sigval = computeSignal (exceptionVector); | |
232 | |
233 ptr = remcomOutBuffer; | |
234 | |
235 *ptr++ = 'T'; /* notify gdb with signo, PC, FP and SP */ | |
236 *ptr++ = hexchars[sigval >> 4]; | |
237 *ptr++ = hexchars[sigval & 0xf]; | |
238 | |
239 *ptr++ = hexchars[PC >> 4]; | |
240 *ptr++ = hexchars[PC & 0xf]; | |
241 *ptr++ = ':'; | |
242 ptr = mem2hex ((unsigned char *) ®isters[PC], ptr, 4, 0); /* PC */ | |
243 *ptr++ = ';'; | |
244 | |
245 *ptr++ = hexchars[R13 >> 4]; | |
246 *ptr++ = hexchars[R13 & 0xf]; | |
247 *ptr++ = ':'; | |
248 ptr = mem2hex ((unsigned char *) ®isters[R13], ptr, 4, 0); /* FP */ | |
249 *ptr++ = ';'; | |
250 | |
251 *ptr++ = hexchars[R15 >> 4]; | |
252 *ptr++ = hexchars[R15 & 0xf]; | |
253 *ptr++ = ':'; | |
254 ptr = mem2hex ((unsigned char *) ®isters[R15], ptr, 4, 0); /* SP */ | |
255 *ptr++ = ';'; | |
256 *ptr++ = 0; | |
257 | |
258 if (exceptionVector == 0) /* simulated SYS call stuff */ | |
259 { | |
260 mem2hex ((unsigned char *) ®isters[PC], buf, 4, 0); | |
261 switch (registers[R0]) | |
262 { | |
263 case SYS_exit: | |
264 gdb_error ("Target program has exited at %s\n", buf); | |
265 ptr = remcomOutBuffer; | |
266 *ptr++ = 'W'; | |
267 sigval = registers[R1] & 0xff; | |
268 *ptr++ = hexchars[sigval >> 4]; | |
269 *ptr++ = hexchars[sigval & 0xf]; | |
270 *ptr++ = 0; | |
271 break; | |
272 case SYS_open: | |
273 gdb_error ("Target attempts SYS_open call at %s\n", buf); | |
274 break; | |
275 case SYS_close: | |
276 gdb_error ("Target attempts SYS_close call at %s\n", buf); | |
277 break; | |
278 case SYS_read: | |
279 gdb_error ("Target attempts SYS_read call at %s\n", buf); | |
280 break; | |
281 case SYS_write: | |
282 if (registers[R1] == 1 || /* write to stdout */ | |
283 registers[R1] == 2) /* write to stderr */ | |
284 { /* (we can do that) */ | |
285 registers[R0] = | |
286 gdb_write ((void *) registers[R2], registers[R3]); | |
287 return; | |
288 } | |
289 else | |
290 gdb_error ("Target attempts SYS_write call at %s\n", buf); | |
291 break; | |
292 case SYS_lseek: | |
293 gdb_error ("Target attempts SYS_lseek call at %s\n", buf); | |
294 break; | |
295 case SYS_unlink: | |
296 gdb_error ("Target attempts SYS_unlink call at %s\n", buf); | |
297 break; | |
298 case SYS_getpid: | |
299 gdb_error ("Target attempts SYS_getpid call at %s\n", buf); | |
300 break; | |
301 case SYS_kill: | |
302 gdb_error ("Target attempts SYS_kill call at %s\n", buf); | |
303 break; | |
304 case SYS_fstat: | |
305 gdb_error ("Target attempts SYS_fstat call at %s\n", buf); | |
306 break; | |
307 default: | |
308 gdb_error ("Target attempts unknown SYS call at %s\n", buf); | |
309 break; | |
310 } | |
311 } | |
312 | |
313 putpacket (remcomOutBuffer); | |
314 | |
315 stepping = 0; | |
316 | |
317 while (1 == 1) | |
318 { | |
319 remcomOutBuffer[0] = 0; | |
320 ptr = getpacket (); | |
321 binary = 0; | |
322 switch (*ptr++) | |
323 { | |
324 default: /* Unknown code. Return an empty reply message.
*/ | |
325 break; | |
326 case 'R': | |
327 if (hexToInt (&ptr, &addr)) | |
328 registers[PC] = addr; | |
329 strcpy (remcomOutBuffer, "OK"); | |
330 break; | |
331 case '!': | |
332 strcpy (remcomOutBuffer, "OK"); | |
333 break; | |
334 case 'X': /* XAA..AA,LLLL:<binary data>#cs */ | |
335 binary = 1; | |
336 case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.
AA return OK */ | |
337 /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ | |
338 { | |
339 if (hexToInt (&ptr, &addr)) | |
340 if (*(ptr++) == ',') | |
341 if (hexToInt (&ptr, &length)) | |
342 if (*(ptr++) == ':') | |
343 { | |
344 mem_err = 0; | |
345 if (binary) | |
346 bin2mem (ptr, (unsigned char *) addr, length, 1); | |
347 else | |
348 hex2mem (ptr, (unsigned char *) addr, length, 1); | |
349 if (mem_err) | |
350 { | |
351 strcpy (remcomOutBuffer, "E03"); | |
352 gdb_error ("memory fault", ""); | |
353 } | |
354 else | |
355 { | |
356 strcpy (remcomOutBuffer, "OK"); | |
357 } | |
358 ptr = 0; | |
359 } | |
360 if (ptr) | |
361 { | |
362 strcpy (remcomOutBuffer, "E02"); | |
363 } | |
364 } | |
365 break; | |
366 case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..
AA */ | |
367 /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ | |
368 if (hexToInt (&ptr, &addr)) | |
369 if (*(ptr++) == ',') | |
370 if (hexToInt (&ptr, &length)) | |
371 { | |
372 ptr = 0; | |
373 mem_err = 0; | |
374 mem2hex ((unsigned char *) addr, remcomOutBuffer, length, | |
375 1); | |
376 if (mem_err) | |
377 { | |
378 strcpy (remcomOutBuffer, "E03"); | |
379 gdb_error ("memory fault", ""); | |
380 } | |
381 } | |
382 if (ptr) | |
383 { | |
384 strcpy (remcomOutBuffer, "E01"); | |
385 } | |
386 break; | |
387 case '?': | |
388 remcomOutBuffer[0] = 'S'; | |
389 remcomOutBuffer[1] = hexchars[sigval >> 4]; | |
390 remcomOutBuffer[2] = hexchars[sigval % 16]; | |
391 remcomOutBuffer[3] = 0; | |
392 break; | |
393 case 'd': | |
394 remote_debug = !(remote_debug); /* toggle debug flag */ | |
395 break; | |
396 case 'g': /* return the value of the CPU registers */ | |
397 mem2hex ((unsigned char *) registers, remcomOutBuffer, NUMREGBYTES, | |
398 0); | |
399 break; | |
400 case 'P': /* set the value of a single CPU register - retu
rn OK */ | |
401 { | |
402 int regno; | |
403 | |
404 if (hexToInt (&ptr, ®no) && *ptr++ == '=') | |
405 if (regno >= 0 && regno < NUMREGS) | |
406 { | |
407 int stackmode; | |
408 | |
409 hex2mem (ptr, (unsigned char *) ®isters[regno], 4, 0); | |
410 /* | |
411 * Since we just changed a single CPU register, let's | |
412 * make sure to keep the several stack pointers consistant. | |
413 */ | |
414 stackmode = registers[PSW] & 0x80; | |
415 if (regno == R15) /* stack pointer changed */ | |
416 { /* need to change SPI or SPU */ | |
417 if (stackmode == 0) | |
418 registers[SPI] = registers[R15]; | |
419 else | |
420 registers[SPU] = registers[R15]; | |
421 } | |
422 else if (regno == SPU) /* "user" stack pointer changed
*/ | |
423 { | |
424 if (stackmode != 0) /* stack in user mode: copy SP *
/ | |
425 registers[R15] = registers[SPU]; | |
426 } | |
427 else if (regno == SPI) /* "interrupt" stack pointer cha
nged */ | |
428 { | |
429 if (stackmode == 0) /* stack in interrupt mode: copy
SP */ | |
430 registers[R15] = registers[SPI]; | |
431 } | |
432 else if (regno == PSW) /* stack mode may have changed!
*/ | |
433 { /* force SP to either SPU or SPI */ | |
434 if (stackmode == 0) /* stack in user mode */ | |
435 registers[R15] = registers[SPI]; | |
436 else /* stack in interrupt mode */ | |
437 registers[R15] = registers[SPU]; | |
438 } | |
439 strcpy (remcomOutBuffer, "OK"); | |
440 break; | |
441 } | |
442 strcpy (remcomOutBuffer, "E01"); | |
443 break; | |
444 } | |
445 case 'G': /* set the value of the CPU registers - return O
K */ | |
446 hex2mem (ptr, (unsigned char *) registers, NUMREGBYTES, 0); | |
447 strcpy (remcomOutBuffer, "OK"); | |
448 break; | |
449 case 's': /* sAA..AA Step one instruction from AA..AA
(optional) */ | |
450 stepping = 1; | |
451 case 'c': /* cAA..AA Continue from address AA..AA(opt
ional) */ | |
452 /* try to read optional parameter, pc unchanged if no parm */ | |
453 if (hexToInt (&ptr, &addr)) | |
454 registers[PC] = addr; | |
455 | |
456 if (stepping) /* single-stepping */ | |
457 { | |
458 if (!prepare_to_step (0)) /* set up for single-step */ | |
459 { | |
460 /* prepare_to_step has already emulated the target insn: | |
461 Send SIGTRAP to gdb, don't resume the target at all. */ | |
462 ptr = remcomOutBuffer; | |
463 *ptr++ = 'T'; /* Simulate stopping with SIGTRAP */ | |
464 *ptr++ = '0'; | |
465 *ptr++ = '5'; | |
466 | |
467 *ptr++ = hexchars[PC >> 4]; /* send PC */ | |
468 *ptr++ = hexchars[PC & 0xf]; | |
469 *ptr++ = ':'; | |
470 ptr = mem2hex ((unsigned char *) ®isters[PC], ptr, 4, 0); | |
471 *ptr++ = ';'; | |
472 | |
473 *ptr++ = hexchars[R13 >> 4]; /* send FP */ | |
474 *ptr++ = hexchars[R13 & 0xf]; | |
475 *ptr++ = ':'; | |
476 ptr = | |
477 mem2hex ((unsigned char *) ®isters[R13], ptr, 4, 0); | |
478 *ptr++ = ';'; | |
479 | |
480 *ptr++ = hexchars[R15 >> 4]; /* send SP */ | |
481 *ptr++ = hexchars[R15 & 0xf]; | |
482 *ptr++ = ':'; | |
483 ptr = | |
484 mem2hex ((unsigned char *) ®isters[R15], ptr, 4, 0); | |
485 *ptr++ = ';'; | |
486 *ptr++ = 0; | |
487 | |
488 break; | |
489 } | |
490 } | |
491 else /* continuing, not single-stepping */ | |
492 { | |
493 /* OK, about to do a "continue". First check to see if the | |
494 target pc is on an odd boundary (second instruction in the | |
495 word). If so, we must do a single-step first, because | |
496 ya can't jump or return back to an odd boundary! */ | |
497 if ((registers[PC] & 2) != 0) | |
498 prepare_to_step (1); | |
499 } | |
500 | |
501 return; | |
502 | |
503 case 'D': /* Detach */ | |
504 #if 0 | |
505 /* I am interpreting this to mean, release the board from control | |
506 by the remote stub. To do this, I am restoring the original | |
507 (or at least previous) exception vectors. | |
508 */ | |
509 for (i = 0; i < 18; i++) | |
510 exceptionHandler (i, save_vectors[i]); | |
511 putpacket ("OK"); | |
512 return; /* continue the inferior */ | |
513 #else | |
514 strcpy (remcomOutBuffer, "OK"); | |
515 break; | |
516 #endif | |
517 case 'q': | |
518 if (*ptr++ == 'C' && | |
519 *ptr++ == 'R' && *ptr++ == 'C' && *ptr++ == ':') | |
520 { | |
521 unsigned long start, len, our_crc; | |
522 | |
523 if (hexToInt (&ptr, (int *) &start) && | |
524 *ptr++ == ',' && hexToInt (&ptr, (int *) &len)) | |
525 { | |
526 remcomOutBuffer[0] = 'C'; | |
527 our_crc = crc32 ((unsigned char *) start, len, 0xffffffff); | |
528 mem2hex ((char *) &our_crc, | |
529 &remcomOutBuffer[1], sizeof (long), 0); | |
530 } /* else do nothing */ | |
531 } /* else do nothing */ | |
532 break; | |
533 | |
534 case 'k': /* kill the program */ | |
535 continue; | |
536 } /* switch */ | |
537 | |
538 /* reply to the request */ | |
539 putpacket (remcomOutBuffer); | |
540 } | |
541 } | |
542 | |
543 /* qCRC support */ | |
544 | |
545 /* Table used by the crc32 function to calcuate the checksum. */ | |
546 static unsigned long crc32_table[256] = { 0, 0 }; | |
547 | |
548 static unsigned long | |
549 crc32 (unsigned char *buf, int len, unsigned long crc) | |
550 { | |
551 if (!crc32_table[1]) | |
552 { | |
553 /* Initialize the CRC table and the decoding table. */ | |
554 int i, j; | |
555 unsigned long c; | |
556 | |
557 for (i = 0; i < 256; i++) | |
558 { | |
559 for (c = i << 24, j = 8; j > 0; --j) | |
560 c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1); | |
561 crc32_table[i] = c; | |
562 } | |
563 } | |
564 | |
565 while (len--) | |
566 { | |
567 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255]; | |
568 buf++; | |
569 } | |
570 return crc; | |
571 } | |
572 | |
573 static int | |
574 hex (unsigned char ch) | |
575 { | |
576 if ((ch >= 'a') && (ch <= 'f')) | |
577 return (ch - 'a' + 10); | |
578 if ((ch >= '0') && (ch <= '9')) | |
579 return (ch - '0'); | |
580 if ((ch >= 'A') && (ch <= 'F')) | |
581 return (ch - 'A' + 10); | |
582 return (-1); | |
583 } | |
584 | |
585 /* scan for the sequence $<data>#<checksum> */ | |
586 | |
587 unsigned char * | |
588 getpacket (void) | |
589 { | |
590 unsigned char *buffer = &remcomInBuffer[0]; | |
591 unsigned char checksum; | |
592 unsigned char xmitcsum; | |
593 int count; | |
594 char ch; | |
595 | |
596 while (1) | |
597 { | |
598 /* wait around for the start character, ignore all other characters */ | |
599 while ((ch = getDebugChar ()) != '$') | |
600 ; | |
601 | |
602 retry: | |
603 checksum = 0; | |
604 xmitcsum = -1; | |
605 count = 0; | |
606 | |
607 /* now, read until a # or end of buffer is found */ | |
608 while (count < BUFMAX - 1) | |
609 { | |
610 ch = getDebugChar (); | |
611 if (ch == '$') | |
612 goto retry; | |
613 if (ch == '#') | |
614 break; | |
615 checksum = checksum + ch; | |
616 buffer[count] = ch; | |
617 count = count + 1; | |
618 } | |
619 buffer[count] = 0; | |
620 | |
621 if (ch == '#') | |
622 { | |
623 ch = getDebugChar (); | |
624 xmitcsum = hex (ch) << 4; | |
625 ch = getDebugChar (); | |
626 xmitcsum += hex (ch); | |
627 | |
628 if (checksum != xmitcsum) | |
629 { | |
630 if (remote_debug) | |
631 { | |
632 unsigned char buf[16]; | |
633 | |
634 mem2hex ((unsigned char *) &checksum, buf, 4, 0); | |
635 gdb_error ("Bad checksum: my count = %s, ", buf); | |
636 mem2hex ((unsigned char *) &xmitcsum, buf, 4, 0); | |
637 gdb_error ("sent count = %s\n", buf); | |
638 gdb_error (" -- Bad buffer: \"%s\"\n", buffer); | |
639 } | |
640 putDebugChar ('-'); /* failed checksum */ | |
641 } | |
642 else | |
643 { | |
644 putDebugChar ('+'); /* successful transfer */ | |
645 | |
646 /* if a sequence char is present, reply the sequence ID */ | |
647 if (buffer[2] == ':') | |
648 { | |
649 putDebugChar (buffer[0]); | |
650 putDebugChar (buffer[1]); | |
651 | |
652 return &buffer[3]; | |
653 } | |
654 | |
655 return &buffer[0]; | |
656 } | |
657 } | |
658 } | |
659 } | |
660 | |
661 /* send the packet in buffer. */ | |
662 | |
663 static void | |
664 putpacket (unsigned char *buffer) | |
665 { | |
666 unsigned char checksum; | |
667 int count; | |
668 char ch; | |
669 | |
670 /* $<packet info>#<checksum>. */ | |
671 do | |
672 { | |
673 putDebugChar ('$'); | |
674 checksum = 0; | |
675 count = 0; | |
676 | |
677 while (ch = buffer[count]) | |
678 { | |
679 putDebugChar (ch); | |
680 checksum += ch; | |
681 count += 1; | |
682 } | |
683 putDebugChar ('#'); | |
684 putDebugChar (hexchars[checksum >> 4]); | |
685 putDebugChar (hexchars[checksum % 16]); | |
686 } | |
687 while (getDebugChar () != '+'); | |
688 } | |
689 | |
690 /* Address of a routine to RTE to if we get a memory fault. */ | |
691 | |
692 static void (*volatile mem_fault_routine) () = 0; | |
693 | |
694 static void | |
695 set_mem_err (void) | |
696 { | |
697 mem_err = 1; | |
698 } | |
699 | |
700 /* Check the address for safe access ranges. As currently defined, | |
701 this routine will reject the "expansion bus" address range(s). | |
702 To make those ranges useable, someone must implement code to detect | |
703 whether there's anything connected to the expansion bus. */ | |
704 | |
705 static int | |
706 mem_safe (unsigned char *addr) | |
707 { | |
708 #define BAD_RANGE_ONE_START ((unsigned char *) 0x600000) | |
709 #define BAD_RANGE_ONE_END ((unsigned char *) 0xa00000) | |
710 #define BAD_RANGE_TWO_START ((unsigned char *) 0xff680000) | |
711 #define BAD_RANGE_TWO_END ((unsigned char *) 0xff800000) | |
712 | |
713 if (addr < BAD_RANGE_ONE_START) | |
714 return 1; /* safe */ | |
715 if (addr < BAD_RANGE_ONE_END) | |
716 return 0; /* unsafe */ | |
717 if (addr < BAD_RANGE_TWO_START) | |
718 return 1; /* safe */ | |
719 if (addr < BAD_RANGE_TWO_END) | |
720 return 0; /* unsafe */ | |
721 } | |
722 | |
723 /* These are separate functions so that they are so short and sweet | |
724 that the compiler won't save any registers (if there is a fault | |
725 to mem_fault, they won't get restored, so there better not be any | |
726 saved). */ | |
727 static int | |
728 get_char (unsigned char *addr) | |
729 { | |
730 #if 1 | |
731 if (mem_fault_routine && !mem_safe (addr)) | |
732 { | |
733 mem_fault_routine (); | |
734 return 0; | |
735 } | |
736 #endif | |
737 return *addr; | |
738 } | |
739 | |
740 static void | |
741 set_char (unsigned char *addr, unsigned char val) | |
742 { | |
743 #if 1 | |
744 if (mem_fault_routine && !mem_safe (addr)) | |
745 { | |
746 mem_fault_routine (); | |
747 return; | |
748 } | |
749 #endif | |
750 *addr = val; | |
751 } | |
752 | |
753 /* Convert the memory pointed to by mem into hex, placing result in buf. | |
754 Return a pointer to the last char put in buf (null). | |
755 If MAY_FAULT is non-zero, then we should set mem_err in response to | |
756 a fault; if zero treat a fault like any other fault in the stub. */ | |
757 | |
758 static unsigned char * | |
759 mem2hex (unsigned char *mem, unsigned char *buf, int count, int may_fault) | |
760 { | |
761 int i; | |
762 unsigned char ch; | |
763 | |
764 if (may_fault) | |
765 mem_fault_routine = set_mem_err; | |
766 for (i = 0; i < count; i++) | |
767 { | |
768 ch = get_char (mem++); | |
769 if (may_fault && mem_err) | |
770 return (buf); | |
771 *buf++ = hexchars[ch >> 4]; | |
772 *buf++ = hexchars[ch % 16]; | |
773 } | |
774 *buf = 0; | |
775 if (may_fault) | |
776 mem_fault_routine = 0; | |
777 return (buf); | |
778 } | |
779 | |
780 /* Convert the hex array pointed to by buf into binary to be placed in mem. | |
781 Return a pointer to the character AFTER the last byte written. */ | |
782 | |
783 static unsigned char * | |
784 hex2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault) | |
785 { | |
786 int i; | |
787 unsigned char ch; | |
788 | |
789 if (may_fault) | |
790 mem_fault_routine = set_mem_err; | |
791 for (i = 0; i < count; i++) | |
792 { | |
793 ch = hex (*buf++) << 4; | |
794 ch = ch + hex (*buf++); | |
795 set_char (mem++, ch); | |
796 if (may_fault && mem_err) | |
797 return (mem); | |
798 } | |
799 if (may_fault) | |
800 mem_fault_routine = 0; | |
801 return (mem); | |
802 } | |
803 | |
804 /* Convert the binary stream in BUF to memory. | |
805 | |
806 Gdb will escape $, #, and the escape char (0x7d). | |
807 COUNT is the total number of bytes to write into | |
808 memory. */ | |
809 static unsigned char * | |
810 bin2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault) | |
811 { | |
812 int i; | |
813 unsigned char ch; | |
814 | |
815 if (may_fault) | |
816 mem_fault_routine = set_mem_err; | |
817 for (i = 0; i < count; i++) | |
818 { | |
819 /* Check for any escaped characters. Be paranoid and | |
820 only unescape chars that should be escaped. */ | |
821 if (*buf == 0x7d) | |
822 { | |
823 switch (*(buf + 1)) | |
824 { | |
825 case 0x3: /* # */ | |
826 case 0x4: /* $ */ | |
827 case 0x5d: /* escape char */ | |
828 buf++; | |
829 *buf |= 0x20; | |
830 break; | |
831 default: | |
832 /* nothing */ | |
833 break; | |
834 } | |
835 } | |
836 | |
837 set_char (mem++, *buf++); | |
838 | |
839 if (may_fault && mem_err) | |
840 return mem; | |
841 } | |
842 | |
843 if (may_fault) | |
844 mem_fault_routine = 0; | |
845 return mem; | |
846 } | |
847 | |
848 /* this function takes the m32r exception vector and attempts to | |
849 translate this number into a unix compatible signal value */ | |
850 | |
851 static int | |
852 computeSignal (int exceptionVector) | |
853 { | |
854 int sigval; | |
855 switch (exceptionVector) | |
856 { | |
857 case 0: | |
858 sigval = 23; | |
859 break; /* I/O trap */ | |
860 case 1: | |
861 sigval = 5; | |
862 break; /* breakpoint */ | |
863 case 2: | |
864 sigval = 5; | |
865 break; /* breakpoint */ | |
866 case 3: | |
867 sigval = 5; | |
868 break; /* breakpoint */ | |
869 case 4: | |
870 sigval = 5; | |
871 break; /* breakpoint */ | |
872 case 5: | |
873 sigval = 5; | |
874 break; /* breakpoint */ | |
875 case 6: | |
876 sigval = 5; | |
877 break; /* breakpoint */ | |
878 case 7: | |
879 sigval = 5; | |
880 break; /* breakpoint */ | |
881 case 8: | |
882 sigval = 5; | |
883 break; /* breakpoint */ | |
884 case 9: | |
885 sigval = 5; | |
886 break; /* breakpoint */ | |
887 case 10: | |
888 sigval = 5; | |
889 break; /* breakpoint */ | |
890 case 11: | |
891 sigval = 5; | |
892 break; /* breakpoint */ | |
893 case 12: | |
894 sigval = 5; | |
895 break; /* breakpoint */ | |
896 case 13: | |
897 sigval = 5; | |
898 break; /* breakpoint */ | |
899 case 14: | |
900 sigval = 5; | |
901 break; /* breakpoint */ | |
902 case 15: | |
903 sigval = 5; | |
904 break; /* breakpoint */ | |
905 case 16: | |
906 sigval = 10; | |
907 break; /* BUS ERROR (alignment) */ | |
908 case 17: | |
909 sigval = 2; | |
910 break; /* INTerrupt */ | |
911 default: | |
912 sigval = 7; | |
913 break; /* "software generated" */ | |
914 } | |
915 return (sigval); | |
916 } | |
917 | |
918 /**********************************************/ | |
919 /* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ | |
920 /* RETURN NUMBER OF CHARS PROCESSED */ | |
921 /**********************************************/ | |
922 static int | |
923 hexToInt (unsigned char **ptr, int *intValue) | |
924 { | |
925 int numChars = 0; | |
926 int hexValue; | |
927 | |
928 *intValue = 0; | |
929 while (**ptr) | |
930 { | |
931 hexValue = hex (**ptr); | |
932 if (hexValue >= 0) | |
933 { | |
934 *intValue = (*intValue << 4) | hexValue; | |
935 numChars++; | |
936 } | |
937 else | |
938 break; | |
939 (*ptr)++; | |
940 } | |
941 return (numChars); | |
942 } | |
943 | |
944 /* | |
945 Table of branch instructions: | |
946 | |
947 10B6 RTE return from trap or exception | |
948 1FCr JMP jump | |
949 1ECr JL jump and link | |
950 7Fxx BRA branch | |
951 FFxxxxxx BRA branch (long) | |
952 B09rxxxx BNEZ branch not-equal-zero | |
953 Br1rxxxx BNE branch not-equal | |
954 7Dxx BNC branch not-condition | |
955 FDxxxxxx BNC branch not-condition (long) | |
956 B0Arxxxx BLTZ branch less-than-zero | |
957 B0Crxxxx BLEZ branch less-equal-zero | |
958 7Exx BL branch and link | |
959 FExxxxxx BL branch and link (long) | |
960 B0Drxxxx BGTZ branch greater-than-zero | |
961 B0Brxxxx BGEZ branch greater-equal-zero | |
962 B08rxxxx BEQZ branch equal-zero | |
963 Br0rxxxx BEQ branch equal | |
964 7Cxx BC branch condition | |
965 FCxxxxxx BC branch condition (long) | |
966 */ | |
967 | |
968 static int | |
969 isShortBranch (unsigned char *instr) | |
970 { | |
971 unsigned char instr0 = instr[0] & 0x7F; /* mask off high bit */ | |
972 | |
973 if (instr0 == 0x10 && instr[1] == 0xB6) /* RTE */ | |
974 return 1; /* return from trap or exception */ | |
975 | |
976 if (instr0 == 0x1E || instr0 == 0x1F) /* JL or JMP */ | |
977 if ((instr[1] & 0xF0) == 0xC0) | |
978 return 2; /* jump thru a register */ | |
979 | |
980 if (instr0 == 0x7C || instr0 == 0x7D || /* BC, BNC, BL, BRA */ | |
981 instr0 == 0x7E || instr0 == 0x7F) | |
982 return 3; /* eight bit PC offset */ | |
983 | |
984 return 0; | |
985 } | |
986 | |
987 static int | |
988 isLongBranch (unsigned char *instr) | |
989 { | |
990 if (instr[0] == 0xFC || instr[0] == 0xFD || /* BRA, BNC, BL, BC */ | |
991 instr[0] == 0xFE || instr[0] == 0xFF) /* 24 bit relative */ | |
992 return 4; | |
993 if ((instr[0] & 0xF0) == 0xB0) /* 16 bit relative */ | |
994 { | |
995 if ((instr[1] & 0xF0) == 0x00 || /* BNE, BEQ */ | |
996 (instr[1] & 0xF0) == 0x10) | |
997 return 5; | |
998 if (instr[0] == 0xB0) /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ, BEQZ */ | |
999 if ((instr[1] & 0xF0) == 0x80 || (instr[1] & 0xF0) == 0x90 || | |
1000 (instr[1] & 0xF0) == 0xA0 || (instr[1] & 0xF0) == 0xB0 || | |
1001 (instr[1] & 0xF0) == 0xC0 || (instr[1] & 0xF0) == 0xD0) | |
1002 return 6; | |
1003 } | |
1004 return 0; | |
1005 } | |
1006 | |
1007 /* if address is NOT on a 4-byte boundary, or high-bit of instr is zero, | |
1008 then it's a 2-byte instruction, else it's a 4-byte instruction. */ | |
1009 | |
1010 #define INSTRUCTION_SIZE(addr) \ | |
1011 ((((int) addr & 2) || (((unsigned char *) addr)[0] & 0x80) == 0) ? 2 : 4) | |
1012 | |
1013 static int | |
1014 isBranch (unsigned char *instr) | |
1015 { | |
1016 if (INSTRUCTION_SIZE (instr) == 2) | |
1017 return isShortBranch (instr); | |
1018 else | |
1019 return isLongBranch (instr); | |
1020 } | |
1021 | |
1022 static int | |
1023 willBranch (unsigned char *instr, int branchCode) | |
1024 { | |
1025 switch (branchCode) | |
1026 { | |
1027 case 0: | |
1028 return 0; /* not a branch */ | |
1029 case 1: | |
1030 return 1; /* RTE */ | |
1031 case 2: | |
1032 return 1; /* JL or JMP */ | |
1033 case 3: /* BC, BNC, BL, BRA (short) */ | |
1034 case 4: /* BC, BNC, BL, BRA (long) */ | |
1035 switch (instr[0] & 0x0F) | |
1036 { | |
1037 case 0xC: /* Branch if Condition Register */ | |
1038 return (registers[CBR] != 0); | |
1039 case 0xD: /* Branch if NOT Condition Register */ | |
1040 return (registers[CBR] == 0); | |
1041 case 0xE: /* Branch and Link */ | |
1042 case 0xF: /* Branch (unconditional) */ | |
1043 return 1; | |
1044 default: /* oops? */ | |
1045 return 0; | |
1046 } | |
1047 case 5: /* BNE, BEQ */ | |
1048 switch (instr[1] & 0xF0) | |
1049 { | |
1050 case 0x00: /* Branch if r1 equal to r2 */ | |
1051 return (registers[instr[0] & 0x0F] == registers[instr[1] & 0x0F]); | |
1052 case 0x10: /* Branch if r1 NOT equal to r2 */ | |
1053 return (registers[instr[0] & 0x0F] != registers[instr[1] & 0x0F]); | |
1054 default: /* oops? */ | |
1055 return 0; | |
1056 } | |
1057 case 6: /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ */ | |
1058 switch (instr[1] & 0xF0) | |
1059 { | |
1060 case 0x80: /* Branch if reg equal to zero */ | |
1061 return (registers[instr[1] & 0x0F] == 0); | |
1062 case 0x90: /* Branch if reg NOT equal to zero */ | |
1063 return (registers[instr[1] & 0x0F] != 0); | |
1064 case 0xA0: /* Branch if reg less than zero */ | |
1065 return (registers[instr[1] & 0x0F] < 0); | |
1066 case 0xB0: /* Branch if reg greater or equal to zero */ | |
1067 return (registers[instr[1] & 0x0F] >= 0); | |
1068 case 0xC0: /* Branch if reg less than or equal to zero */ | |
1069 return (registers[instr[1] & 0x0F] <= 0); | |
1070 case 0xD0: /* Branch if reg greater than zero */ | |
1071 return (registers[instr[1] & 0x0F] > 0); | |
1072 default: /* oops? */ | |
1073 return 0; | |
1074 } | |
1075 default: /* oops? */ | |
1076 return 0; | |
1077 } | |
1078 } | |
1079 | |
1080 static int | |
1081 branchDestination (unsigned char *instr, int branchCode) | |
1082 { | |
1083 switch (branchCode) | |
1084 { | |
1085 default: | |
1086 case 0: /* not a branch */ | |
1087 return 0; | |
1088 case 1: /* RTE */ | |
1089 return registers[BPC] & ~3; /* pop BPC into PC */ | |
1090 case 2: /* JL or JMP */ | |
1091 return registers[instr[1] & 0x0F] & ~3; /* jump thru a register */ | |
1092 case 3: /* BC, BNC, BL, BRA (short, 8-bit relative offse
t) */ | |
1093 return (((int) instr) & ~3) + ((char) instr[1] << 2); | |
1094 case 4: /* BC, BNC, BL, BRA (long, 24-bit relative offse
t) */ | |
1095 return ((int) instr + | |
1096 ((((char) instr[1] << 16) | (instr[2] << 8) | (instr[3])) << | |
1097 2)); | |
1098 case 5: /* BNE, BEQ (16-bit relative offset) */ | |
1099 case 6: /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ (ditto) */ | |
1100 return ((int) instr + ((((char) instr[2] << 8) | (instr[3])) << 2)); | |
1101 } | |
1102 | |
1103 /* An explanatory note: in the last three return expressions, I have | |
1104 cast the most-significant byte of the return offset to char. | |
1105 What this accomplishes is sign extension. If the other | |
1106 less-significant bytes were signed as well, they would get sign | |
1107 extended too and, if negative, their leading bits would clobber | |
1108 the bits of the more-significant bytes ahead of them. There are | |
1109 other ways I could have done this, but sign extension from | |
1110 odd-sized integers is always a pain. */ | |
1111 } | |
1112 | |
1113 static void | |
1114 branchSideEffects (unsigned char *instr, int branchCode) | |
1115 { | |
1116 switch (branchCode) | |
1117 { | |
1118 case 1: /* RTE */ | |
1119 return; /* I <THINK> this is already handled... */ | |
1120 case 2: /* JL (or JMP) */ | |
1121 case 3: /* BL (or BC, BNC, BRA) */ | |
1122 case 4: | |
1123 if ((instr[0] & 0x0F) == 0x0E) /* branch/jump and link */ | |
1124 registers[R14] = (registers[PC] & ~3) + 4; | |
1125 return; | |
1126 default: /* any other branch has no side effects */ | |
1127 return; | |
1128 } | |
1129 } | |
1130 | |
1131 static struct STEPPING_CONTEXT | |
1132 { | |
1133 int stepping; /* true when we've started a single-step */ | |
1134 unsigned long target_addr; /* the instr we're trying to execute */ | |
1135 unsigned long target_size; /* the size of the target instr */ | |
1136 unsigned long noop_addr; /* where we've inserted a no-op, if any */ | |
1137 unsigned long trap1_addr; /* the trap following the target instr */ | |
1138 unsigned long trap2_addr; /* the trap at a branch destination, if any */ | |
1139 unsigned short noop_save; /* instruction overwritten by our no-op */ | |
1140 unsigned short trap1_save; /* instruction overwritten by trap1 */ | |
1141 unsigned short trap2_save; /* instruction overwritten by trap2 */ | |
1142 unsigned short continue_p; /* true if NOT returning to gdb after step */ | |
1143 } stepping; | |
1144 | |
1145 /* Function: prepare_to_step | |
1146 Called from handle_exception to prepare the user program to single-step. | |
1147 Places a trap instruction after the target instruction, with special | |
1148 extra handling for branch instructions and for instructions in the | |
1149 second half-word of a word. | |
1150 | |
1151 Returns: True if we should actually execute the instruction; | |
1152 False if we are going to emulate executing the instruction, | |
1153 in which case we simply report to GDB that the instruction | |
1154 has already been executed. */ | |
1155 | |
1156 #define TRAP1 0x10f1; /* trap #1 instruction */ | |
1157 #define NOOP 0x7000; /* noop instruction */ | |
1158 | |
1159 static unsigned short trap1 = TRAP1; | |
1160 static unsigned short noop = NOOP; | |
1161 | |
1162 static int | |
1163 prepare_to_step (continue_p) | |
1164 int continue_p; /* if this isn't REALLY a single-step (see below
) */ | |
1165 { | |
1166 unsigned long pc = registers[PC]; | |
1167 int branchCode = isBranch ((unsigned char *) pc); | |
1168 unsigned char *p; | |
1169 | |
1170 /* zero out the stepping context | |
1171 (paranoia -- it should already be zeroed) */ | |
1172 for (p = (unsigned char *) &stepping; | |
1173 p < ((unsigned char *) &stepping) + sizeof (stepping); p++) | |
1174 *p = 0; | |
1175 | |
1176 if (branchCode != 0) /* next instruction is a branch */ | |
1177 { | |
1178 branchSideEffects ((unsigned char *) pc, branchCode); | |
1179 if (willBranch ((unsigned char *) pc, branchCode)) | |
1180 registers[PC] = branchDestination ((unsigned char *) pc, branchCode); | |
1181 else | |
1182 registers[PC] = pc + INSTRUCTION_SIZE (pc); | |
1183 return 0; /* branch "executed" -- just notify GDB */ | |
1184 } | |
1185 else if (((int) pc & 2) != 0) /* "second-slot" instruction */ | |
1186 { | |
1187 /* insert no-op before pc */ | |
1188 stepping.noop_addr = pc - 2; | |
1189 stepping.noop_save = *(unsigned short *) stepping.noop_addr; | |
1190 *(unsigned short *) stepping.noop_addr = noop; | |
1191 /* insert trap after pc */ | |
1192 stepping.trap1_addr = pc + 2; | |
1193 stepping.trap1_save = *(unsigned short *) stepping.trap1_addr; | |
1194 *(unsigned short *) stepping.trap1_addr = trap1; | |
1195 } | |
1196 else /* "first-slot" instruction */ | |
1197 { | |
1198 /* insert trap after pc */ | |
1199 stepping.trap1_addr = pc + INSTRUCTION_SIZE (pc); | |
1200 stepping.trap1_save = *(unsigned short *) stepping.trap1_addr; | |
1201 *(unsigned short *) stepping.trap1_addr = trap1; | |
1202 } | |
1203 /* "continue_p" means that we are actually doing a continue, and not | |
1204 being requested to single-step by GDB. Sometimes we have to do | |
1205 one single-step before continuing, because the PC is on a half-word | |
1206 boundary. There's no way to simply resume at such an address. */ | |
1207 stepping.continue_p = continue_p; | |
1208 stepping.stepping = 1; /* starting a single-step */ | |
1209 return 1; | |
1210 } | |
1211 | |
1212 /* Function: finish_from_step | |
1213 Called from handle_exception to finish up when the user program | |
1214 returns from a single-step. Replaces the instructions that had | |
1215 been overwritten by traps or no-ops, | |
1216 | |
1217 Returns: True if we should notify GDB that the target stopped. | |
1218 False if we only single-stepped because we had to before we | |
1219 could continue (ie. we were trying to continue at a | |
1220 half-word boundary). In that case don't notify GDB: | |
1221 just "continue continuing". */ | |
1222 | |
1223 static int | |
1224 finish_from_step (void) | |
1225 { | |
1226 if (stepping.stepping) /* anything to do? */ | |
1227 { | |
1228 int continue_p = stepping.continue_p; | |
1229 unsigned char *p; | |
1230 | |
1231 if (stepping.noop_addr) /* replace instr "under" our no-op */ | |
1232 *(unsigned short *) stepping.noop_addr = stepping.noop_save; | |
1233 if (stepping.trap1_addr) /* replace instr "under" our trap */ | |
1234 *(unsigned short *) stepping.trap1_addr = stepping.trap1_save; | |
1235 if (stepping.trap2_addr) /* ditto our other trap, if any */ | |
1236 *(unsigned short *) stepping.trap2_addr = stepping.trap2_save; | |
1237 | |
1238 for (p = (unsigned char *) &stepping; /* zero out the stepping context
*/ | |
1239 p < ((unsigned char *) &stepping) + sizeof (stepping); p++) | |
1240 *p = 0; | |
1241 | |
1242 return !(continue_p); | |
1243 } | |
1244 else /* we didn't single-step, therefore this must be
a legitimate stop */ | |
1245 return 1; | |
1246 } | |
1247 | |
1248 struct PSWreg | |
1249 { /* separate out the bit flags in the PSW registe
r */ | |
1250 int pad1:16; | |
1251 int bsm:1; | |
1252 int bie:1; | |
1253 int pad2:5; | |
1254 int bc:1; | |
1255 int sm:1; | |
1256 int ie:1; | |
1257 int pad3:5; | |
1258 int c:1; | |
1259 } *psw; | |
1260 | |
1261 /* Upon entry the value for LR to save has been pushed. | |
1262 We unpush that so that the value for the stack pointer saved is correct. | |
1263 Upon entry, all other registers are assumed to have not been modified | |
1264 since the interrupt/trap occured. */ | |
1265 | |
1266 asm ("\n\ | |
1267 stash_registers:\n\ | |
1268 push r0\n\ | |
1269 push r1\n\ | |
1270 seth r1, #shigh(registers)\n\ | |
1271 add3 r1, r1, #low(registers)\n\ | |
1272 pop r0 ; r1\n\ | |
1273 st r0, @(4,r1)\n\ | |
1274 pop r0 ; r0\n\ | |
1275 st r0, @r1\n\ | |
1276 addi r1, #4 ; only add 4 as subsequent saves are `pre inc'\n\ | |
1277 st r2, @+r1\n\ | |
1278 st r3, @+r1\n\ | |
1279 st r4, @+r1\n\ | |
1280 st r5, @+r1\n\ | |
1281 st r6, @+r1\n\ | |
1282 st r7, @+r1\n\ | |
1283 st r8, @+r1\n\ | |
1284 st r9, @+r1\n\ | |
1285 st r10, @+r1\n\ | |
1286 st r11, @+r1\n\ | |
1287 st r12, @+r1\n\ | |
1288 st r13, @+r1 ; fp\n\ | |
1289 pop r0 ; lr (r14)\n\ | |
1290 st r0, @+r1\n\ | |
1291 st sp, @+r1 ; sp contains right value at this point\n\ | |
1292 mvfc r0, cr0\n\ | |
1293 st r0, @+r1 ; cr0 == PSW\n\ | |
1294 mvfc r0, cr1\n\ | |
1295 st r0, @+r1 ; cr1 == CBR\n\ | |
1296 mvfc r0, cr2\n\ | |
1297 st r0, @+r1 ; cr2 == SPI\n\ | |
1298 mvfc r0, cr3\n\ | |
1299 st r0, @+r1 ; cr3 == SPU\n\ | |
1300 mvfc r0, cr6\n\ | |
1301 st r0, @+r1 ; cr6 == BPC\n\ | |
1302 st r0, @+r1 ; PC == BPC\n\ | |
1303 mvfaclo r0\n\ | |
1304 st r0, @+r1 ; ACCL\n\ | |
1305 mvfachi r0\n\ | |
1306 st r0, @+r1 ; ACCH\n\ | |
1307 jmp lr"); | |
1308 | |
1309 /* C routine to clean up what stash_registers did. | |
1310 It is called after calling stash_registers. | |
1311 This is separate from stash_registers as we want to do this in C | |
1312 but doing stash_registers in C isn't straightforward. */ | |
1313 | |
1314 static void | |
1315 cleanup_stash (void) | |
1316 { | |
1317 psw = (struct PSWreg *) ®isters[PSW]; /* fields of PSW register */ | |
1318 psw->sm = psw->bsm; /* fix up pre-trap values of psw fields */ | |
1319 psw->ie = psw->bie; | |
1320 psw->c = psw->bc; | |
1321 registers[CBR] = psw->bc; /* fix up pre-trap "C" register */ | |
1322 | |
1323 #if 0 /* FIXME: Was in previous version. Necessary? | |
1324 (Remember that we use the "rte" insn to retur
n from the | |
1325 trap/interrupt so the values of bsm, bie, bc
are important. */ | |
1326 psw->bsm = psw->bie = psw->bc = 0; /* zero post-trap values */ | |
1327 #endif | |
1328 | |
1329 /* FIXME: Copied from previous version. This can probably be deleted | |
1330 since methinks stash_registers has already done this. */ | |
1331 registers[PC] = registers[BPC]; /* pre-trap PC */ | |
1332 | |
1333 /* FIXME: Copied from previous version. Necessary? */ | |
1334 if (psw->sm) /* copy R15 into (psw->sm ? SPU : SPI) */ | |
1335 registers[SPU] = registers[R15]; | |
1336 else | |
1337 registers[SPI] = registers[R15]; | |
1338 } | |
1339 | |
1340 asm ("\n\ | |
1341 restore_and_return:\n\ | |
1342 seth r0, #shigh(registers+8)\n\ | |
1343 add3 r0, r0, #low(registers+8)\n\ | |
1344 ld r2, @r0+ ; restore r2\n\ | |
1345 ld r3, @r0+ ; restore r3\n\ | |
1346 ld r4, @r0+ ; restore r4\n\ | |
1347 ld r5, @r0+ ; restore r5\n\ | |
1348 ld r6, @r0+ ; restore r6\n\ | |
1349 ld r7, @r0+ ; restore r7\n\ | |
1350 ld r8, @r0+ ; restore r8\n\ | |
1351 ld r9, @r0+ ; restore r9\n\ | |
1352 ld r10, @r0+ ; restore r10\n\ | |
1353 ld r11, @r0+ ; restore r11\n\ | |
1354 ld r12, @r0+ ; restore r12\n\ | |
1355 ld r13, @r0+ ; restore r13\n\ | |
1356 ld r14, @r0+ ; restore r14\n\ | |
1357 ld r15, @r0+ ; restore r15\n\ | |
1358 ld r1, @r0+ ; restore cr0 == PSW\n\ | |
1359 mvtc r1, cr0\n\ | |
1360 ld r1, @r0+ ; restore cr1 == CBR (no-op, because it's read only)\n\ | |
1361 mvtc r1, cr1\n\ | |
1362 ld r1, @r0+ ; restore cr2 == SPI\n\ | |
1363 mvtc r1, cr2\n\ | |
1364 ld r1, @r0+ ; restore cr3 == SPU\n\ | |
1365 mvtc r1, cr3\n\ | |
1366 addi r0, #4 ; skip BPC\n\ | |
1367 ld r1, @r0+ ; restore cr6 (BPC) == PC\n\ | |
1368 mvtc r1, cr6\n\ | |
1369 ld r1, @r0+ ; restore ACCL\n\ | |
1370 mvtaclo r1\n\ | |
1371 ld r1, @r0+ ; restore ACCH\n\ | |
1372 mvtachi r1\n\ | |
1373 seth r0, #shigh(registers)\n\ | |
1374 add3 r0, r0, #low(registers)\n\ | |
1375 ld r1, @(4,r0) ; restore r1\n\ | |
1376 ld r0, @r0 ; restore r0\n\ | |
1377 rte"); | |
1378 | |
1379 /* General trap handler, called after the registers have been stashed. | |
1380 NUM is the trap/exception number. */ | |
1381 | |
1382 static void | |
1383 process_exception (int num) | |
1384 { | |
1385 cleanup_stash (); | |
1386 asm volatile ("\n\ | |
1387 seth r1, #shigh(stackPtr)\n\ | |
1388 add3 r1, r1, #low(stackPtr)\n\ | |
1389 ld r15, @r1 ; setup local stack (protect user stack)\n\ | |
1390 mv r0, %0\n\ | |
1391 bl handle_exception\n\ | |
1392 bl restore_and_return"::"r" (num):"r0", "r1"); | |
1393 } | |
1394 | |
1395 void _catchException0 (); | |
1396 | |
1397 asm ("\n\ | |
1398 _catchException0:\n\ | |
1399 push lr\n\ | |
1400 bl stash_registers\n\ | |
1401 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1402 ldi r0, #0\n\ | |
1403 bl process_exception"); | |
1404 | |
1405 void _catchException1 (); | |
1406 | |
1407 asm ("\n\ | |
1408 _catchException1:\n\ | |
1409 push lr\n\ | |
1410 bl stash_registers\n\ | |
1411 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1412 bl cleanup_stash\n\ | |
1413 seth r1, #shigh(stackPtr)\n\ | |
1414 add3 r1, r1, #low(stackPtr)\n\ | |
1415 ld r15, @r1 ; setup local stack (protect user stack)\n\ | |
1416 seth r1, #shigh(registers + 21*4) ; PC\n\ | |
1417 add3 r1, r1, #low(registers + 21*4)\n\ | |
1418 ld r0, @r1\n\ | |
1419 addi r0, #-4 ; back up PC for breakpoint trap.\n\ | |
1420 st r0, @r1 ; FIXME: what about bp in right slot?\n\ | |
1421 ldi r0, #1\n\ | |
1422 bl handle_exception\n\ | |
1423 bl restore_and_return"); | |
1424 | |
1425 void _catchException2 (); | |
1426 | |
1427 asm ("\n\ | |
1428 _catchException2:\n\ | |
1429 push lr\n\ | |
1430 bl stash_registers\n\ | |
1431 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1432 ldi r0, #2\n\ | |
1433 bl process_exception"); | |
1434 | |
1435 void _catchException3 (); | |
1436 | |
1437 asm ("\n\ | |
1438 _catchException3:\n\ | |
1439 push lr\n\ | |
1440 bl stash_registers\n\ | |
1441 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1442 ldi r0, #3\n\ | |
1443 bl process_exception"); | |
1444 | |
1445 void _catchException4 (); | |
1446 | |
1447 asm ("\n\ | |
1448 _catchException4:\n\ | |
1449 push lr\n\ | |
1450 bl stash_registers\n\ | |
1451 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1452 ldi r0, #4\n\ | |
1453 bl process_exception"); | |
1454 | |
1455 void _catchException5 (); | |
1456 | |
1457 asm ("\n\ | |
1458 _catchException5:\n\ | |
1459 push lr\n\ | |
1460 bl stash_registers\n\ | |
1461 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1462 ldi r0, #5\n\ | |
1463 bl process_exception"); | |
1464 | |
1465 void _catchException6 (); | |
1466 | |
1467 asm ("\n\ | |
1468 _catchException6:\n\ | |
1469 push lr\n\ | |
1470 bl stash_registers\n\ | |
1471 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1472 ldi r0, #6\n\ | |
1473 bl process_exception"); | |
1474 | |
1475 void _catchException7 (); | |
1476 | |
1477 asm ("\n\ | |
1478 _catchException7:\n\ | |
1479 push lr\n\ | |
1480 bl stash_registers\n\ | |
1481 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1482 ldi r0, #7\n\ | |
1483 bl process_exception"); | |
1484 | |
1485 void _catchException8 (); | |
1486 | |
1487 asm ("\n\ | |
1488 _catchException8:\n\ | |
1489 push lr\n\ | |
1490 bl stash_registers\n\ | |
1491 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1492 ldi r0, #8\n\ | |
1493 bl process_exception"); | |
1494 | |
1495 void _catchException9 (); | |
1496 | |
1497 asm ("\n\ | |
1498 _catchException9:\n\ | |
1499 push lr\n\ | |
1500 bl stash_registers\n\ | |
1501 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1502 ldi r0, #9\n\ | |
1503 bl process_exception"); | |
1504 | |
1505 void _catchException10 (); | |
1506 | |
1507 asm ("\n\ | |
1508 _catchException10:\n\ | |
1509 push lr\n\ | |
1510 bl stash_registers\n\ | |
1511 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1512 ldi r0, #10\n\ | |
1513 bl process_exception"); | |
1514 | |
1515 void _catchException11 (); | |
1516 | |
1517 asm ("\n\ | |
1518 _catchException11:\n\ | |
1519 push lr\n\ | |
1520 bl stash_registers\n\ | |
1521 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1522 ldi r0, #11\n\ | |
1523 bl process_exception"); | |
1524 | |
1525 void _catchException12 (); | |
1526 | |
1527 asm ("\n\ | |
1528 _catchException12:\n\ | |
1529 push lr\n\ | |
1530 bl stash_registers\n\ | |
1531 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1532 ldi r0, #12\n\ | |
1533 bl process_exception"); | |
1534 | |
1535 void _catchException13 (); | |
1536 | |
1537 asm ("\n\ | |
1538 _catchException13:\n\ | |
1539 push lr\n\ | |
1540 bl stash_registers\n\ | |
1541 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1542 ldi r0, #13\n\ | |
1543 bl process_exception"); | |
1544 | |
1545 void _catchException14 (); | |
1546 | |
1547 asm ("\n\ | |
1548 _catchException14:\n\ | |
1549 push lr\n\ | |
1550 bl stash_registers\n\ | |
1551 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1552 ldi r0, #14\n\ | |
1553 bl process_exception"); | |
1554 | |
1555 void _catchException15 (); | |
1556 | |
1557 asm ("\n\ | |
1558 _catchException15:\n\ | |
1559 push lr\n\ | |
1560 bl stash_registers\n\ | |
1561 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1562 ldi r0, #15\n\ | |
1563 bl process_exception"); | |
1564 | |
1565 void _catchException16 (); | |
1566 | |
1567 asm ("\n\ | |
1568 _catchException16:\n\ | |
1569 push lr\n\ | |
1570 bl stash_registers\n\ | |
1571 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1572 ldi r0, #16\n\ | |
1573 bl process_exception"); | |
1574 | |
1575 void _catchException17 (); | |
1576 | |
1577 asm ("\n\ | |
1578 _catchException17:\n\ | |
1579 push lr\n\ | |
1580 bl stash_registers\n\ | |
1581 ; Note that at this point the pushed value of `lr' has been popped\n\ | |
1582 ldi r0, #17\n\ | |
1583 bl process_exception"); | |
1584 | |
1585 | |
1586 /* this function is used to set up exception handlers for tracing and | |
1587 breakpoints */ | |
1588 void | |
1589 set_debug_traps (void) | |
1590 { | |
1591 /* extern void remcomHandler(); */ | |
1592 int i; | |
1593 | |
1594 for (i = 0; i < 18; i++) /* keep a copy of old vectors */ | |
1595 if (save_vectors[i] == 0) /* only copy them the first time */ | |
1596 save_vectors[i] = getExceptionHandler (i); | |
1597 | |
1598 stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1]; | |
1599 | |
1600 exceptionHandler (0, _catchException0); | |
1601 exceptionHandler (1, _catchException1); | |
1602 exceptionHandler (2, _catchException2); | |
1603 exceptionHandler (3, _catchException3); | |
1604 exceptionHandler (4, _catchException4); | |
1605 exceptionHandler (5, _catchException5); | |
1606 exceptionHandler (6, _catchException6); | |
1607 exceptionHandler (7, _catchException7); | |
1608 exceptionHandler (8, _catchException8); | |
1609 exceptionHandler (9, _catchException9); | |
1610 exceptionHandler (10, _catchException10); | |
1611 exceptionHandler (11, _catchException11); | |
1612 exceptionHandler (12, _catchException12); | |
1613 exceptionHandler (13, _catchException13); | |
1614 exceptionHandler (14, _catchException14); | |
1615 exceptionHandler (15, _catchException15); | |
1616 exceptionHandler (16, _catchException16); | |
1617 /* exceptionHandler (17, _catchException17); */ | |
1618 | |
1619 initialized = 1; | |
1620 } | |
1621 | |
1622 /* This function will generate a breakpoint exception. It is used at the | |
1623 beginning of a program to sync up with a debugger and can be used | |
1624 otherwise as a quick means to stop program execution and "break" into | |
1625 the debugger. */ | |
1626 | |
1627 #define BREAKPOINT() asm volatile (" trap #2"); | |
1628 | |
1629 void | |
1630 breakpoint (void) | |
1631 { | |
1632 if (initialized) | |
1633 BREAKPOINT (); | |
1634 } | |
1635 | |
1636 /* STDOUT section: | |
1637 Stuff pertaining to simulating stdout by sending chars to gdb to be echoed. | |
1638 Functions: gdb_putchar(char ch) | |
1639 gdb_puts(char *str) | |
1640 gdb_write(char *str, int len) | |
1641 gdb_error(char *format, char *parm) | |
1642 */ | |
1643 | |
1644 /* Function: gdb_putchar(int) | |
1645 Make gdb write a char to stdout. | |
1646 Returns: the char */ | |
1647 | |
1648 static int | |
1649 gdb_putchar (int ch) | |
1650 { | |
1651 char buf[4]; | |
1652 | |
1653 buf[0] = 'O'; | |
1654 buf[1] = hexchars[ch >> 4]; | |
1655 buf[2] = hexchars[ch & 0x0F]; | |
1656 buf[3] = 0; | |
1657 putpacket (buf); | |
1658 return ch; | |
1659 } | |
1660 | |
1661 /* Function: gdb_write(char *, int) | |
1662 Make gdb write n bytes to stdout (not assumed to be null-terminated). | |
1663 Returns: number of bytes written */ | |
1664 | |
1665 static int | |
1666 gdb_write (char *data, int len) | |
1667 { | |
1668 char *buf, *cpy; | |
1669 int i; | |
1670 | |
1671 buf = remcomOutBuffer; | |
1672 buf[0] = 'O'; | |
1673 i = 0; | |
1674 while (i < len) | |
1675 { | |
1676 for (cpy = buf + 1; | |
1677 i < len && cpy < buf + sizeof (remcomOutBuffer) - 3; i++) | |
1678 { | |
1679 *cpy++ = hexchars[data[i] >> 4]; | |
1680 *cpy++ = hexchars[data[i] & 0x0F]; | |
1681 } | |
1682 *cpy = 0; | |
1683 putpacket (buf); | |
1684 } | |
1685 return len; | |
1686 } | |
1687 | |
1688 /* Function: gdb_puts(char *) | |
1689 Make gdb write a null-terminated string to stdout. | |
1690 Returns: the length of the string */ | |
1691 | |
1692 static int | |
1693 gdb_puts (char *str) | |
1694 { | |
1695 return gdb_write (str, strlen (str)); | |
1696 } | |
1697 | |
1698 /* Function: gdb_error(char *, char *) | |
1699 Send an error message to gdb's stdout. | |
1700 First string may have 1 (one) optional "%s" in it, which | |
1701 will cause the optional second string to be inserted. */ | |
1702 | |
1703 static void | |
1704 gdb_error (char *format, char *parm) | |
1705 { | |
1706 char buf[400], *cpy; | |
1707 int len; | |
1708 | |
1709 if (remote_debug) | |
1710 { | |
1711 if (format && *format) | |
1712 len = strlen (format); | |
1713 else | |
1714 return; /* empty input */ | |
1715 | |
1716 if (parm && *parm) | |
1717 len += strlen (parm); | |
1718 | |
1719 for (cpy = buf; *format;) | |
1720 { | |
1721 if (format[0] == '%' && format[1] == 's') /* include second string
*/ | |
1722 { | |
1723 format += 2; /* advance two chars instead of just one */ | |
1724 while (parm && *parm) | |
1725 *cpy++ = *parm++; | |
1726 } | |
1727 else | |
1728 *cpy++ = *format++; | |
1729 } | |
1730 *cpy = '\0'; | |
1731 gdb_puts (buf); | |
1732 } | |
1733 } | |
1734 | |
1735 static unsigned char * | |
1736 strcpy (unsigned char *dest, const unsigned char *src) | |
1737 { | |
1738 unsigned char *ret = dest; | |
1739 | |
1740 if (dest && src) | |
1741 { | |
1742 while (*src) | |
1743 *dest++ = *src++; | |
1744 *dest = 0; | |
1745 } | |
1746 return ret; | |
1747 } | |
1748 | |
1749 static int | |
1750 strlen (const unsigned char *src) | |
1751 { | |
1752 int ret; | |
1753 | |
1754 for (ret = 0; *src; src++) | |
1755 ret++; | |
1756 | |
1757 return ret; | |
1758 } | |
1759 | |
1760 #if 0 | |
1761 void | |
1762 exit (code) | |
1763 int code; | |
1764 { | |
1765 _exit (code); | |
1766 } | |
1767 | |
1768 int | |
1769 atexit (void *p) | |
1770 { | |
1771 return 0; | |
1772 } | |
1773 | |
1774 void | |
1775 abort (void) | |
1776 { | |
1777 _exit (1); | |
1778 } | |
1779 #endif | |
OLD | NEW |