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 | * To enable debugger support, two things need to happen. One, a |
---|
33 | * call to set_debug_traps() is necessary in order to allow any breakpoints |
---|
34 | * or error conditions to be properly intercepted and reported to gdb. |
---|
35 | * Two, a breakpoint needs to be generated to begin communication. This |
---|
36 | * is most easily accomplished by a call to breakpoint(). Breakpoint() |
---|
37 | * simulates a breakpoint by executing a trap #1. The breakpoint instruction |
---|
38 | * is hardwired to trap #1 because not to do so is a compatibility problem-- |
---|
39 | * there either should be a standard breakpoint instruction, or the protocol |
---|
40 | * should be extended to provide some means to communicate which breakpoint |
---|
41 | * instruction is in use (or have the stub insert the breakpoint). |
---|
42 | * |
---|
43 | * Some explanation is probably necessary to explain how exceptions are |
---|
44 | * handled. When an exception is encountered the 68000 pushes the current |
---|
45 | * program counter and status register onto the supervisor stack and then |
---|
46 | * transfers execution to a location specified in it's vector table. |
---|
47 | * The handlers for the exception vectors are hardwired to jmp to an address |
---|
48 | * given by the relation: (exception - 256) * 6. These are decending |
---|
49 | * addresses starting from -6, -12, -18, ... By allowing 6 bytes for |
---|
50 | * each entry, a jsr, jmp, bsr, ... can be used to enter the exception |
---|
51 | * handler. Using a jsr to handle an exception has an added benefit of |
---|
52 | * allowing a single handler to service several exceptions and use the |
---|
53 | * return address as the key differentiation. The vector number can be |
---|
54 | * computed from the return address by [ exception = (addr + 1530) / 6 ]. |
---|
55 | * The sole purpose of the routine _catchException is to compute the |
---|
56 | * exception number and push it on the stack in place of the return address. |
---|
57 | * The external function exceptionHandler() is |
---|
58 | * used to attach a specific handler to a specific m68k exception. |
---|
59 | * For 68020 machines, the ability to have a return address around just |
---|
60 | * so the vector can be determined is not necessary because the '020 pushes an |
---|
61 | * extra word onto the stack containing the vector offset |
---|
62 | * |
---|
63 | * Because gdb will sometimes write to the stack area to execute function |
---|
64 | * calls, this program cannot rely on using the supervisor stack so it |
---|
65 | * uses it's own stack area reserved in the int array remcomStack. |
---|
66 | * |
---|
67 | ************* |
---|
68 | * |
---|
69 | * The following gdb commands are supported: |
---|
70 | * |
---|
71 | * command function Return value |
---|
72 | * |
---|
73 | * g return the value of the CPU registers hex data or ENN |
---|
74 | * G set the value of the CPU registers OK or ENN |
---|
75 | * |
---|
76 | * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN |
---|
77 | * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN |
---|
78 | * |
---|
79 | * c Resume at current address SNN ( signal NN) |
---|
80 | * cAA..AA Continue at address AA..AA SNN |
---|
81 | * |
---|
82 | * s Step one instruction SNN |
---|
83 | * sAA..AA Step one instruction from AA..AA SNN |
---|
84 | * |
---|
85 | * k kill |
---|
86 | * |
---|
87 | * ? What was the last sigval ? SNN (signal NN) |
---|
88 | * |
---|
89 | * All commands and responses are sent with a packet which includes a |
---|
90 | * checksum. A packet consists of |
---|
91 | * |
---|
92 | * $<packet info>#<checksum>. |
---|
93 | * |
---|
94 | * where |
---|
95 | * <packet info> :: <characters representing the command or response> |
---|
96 | * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> |
---|
97 | * |
---|
98 | * When a packet is received, it is first acknowledged with either '+' or '-'. |
---|
99 | * '+' indicates a successful transfer. '-' indicates a failed transfer. |
---|
100 | * |
---|
101 | * Example: |
---|
102 | * |
---|
103 | * Host: Reply: |
---|
104 | * $m0,10#2a +$00010203040506070809101112131415#42 |
---|
105 | * |
---|
106 | * $Id$ |
---|
107 | * |
---|
108 | ****************************************************************************/ |
---|
109 | |
---|
110 | #include <stdio.h> |
---|
111 | #include <string.h> |
---|
112 | #include <setjmp.h> |
---|
113 | |
---|
114 | #include <bsp.h> |
---|
115 | #include <debugport.h> |
---|
116 | |
---|
117 | /************************************************************************ |
---|
118 | * |
---|
119 | * external low-level support routines |
---|
120 | */ |
---|
121 | typedef void (*ExceptionHook)(int); /* pointer to function with int parm */ |
---|
122 | typedef void (*Function)(void); /* pointer to a function */ |
---|
123 | |
---|
124 | /* assign an exception handler */ |
---|
125 | Function exceptionHandler(int vector, Function handler); |
---|
126 | extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */ |
---|
127 | |
---|
128 | int putDebugChar(char ch); |
---|
129 | char getDebugChar(void); |
---|
130 | |
---|
131 | /************************/ |
---|
132 | /* FORWARD DECLARATIONS */ |
---|
133 | /************************/ |
---|
134 | static int hex(char ch); |
---|
135 | static void getpacket(char *buffer); |
---|
136 | static void putpacket(char *buffer); |
---|
137 | static char* mem2hex(char *mem, char *buf, int count); |
---|
138 | static char* hex2mem(char *buf, char *mem, int count); |
---|
139 | static void handle_buserror(void); |
---|
140 | static int computeSignal(int exceptionVector); |
---|
141 | static int hexToInt(char **ptr, int *intValue); |
---|
142 | void handle_exception(int exceptionVector); |
---|
143 | static void initializeRemcomErrorFrame(void); |
---|
144 | |
---|
145 | void set_debug_traps(void); |
---|
146 | void breakpoint(void); |
---|
147 | |
---|
148 | /************************************************************************/ |
---|
149 | /* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ |
---|
150 | /* at least NUMREGBYTES*2 are needed for register packets */ |
---|
151 | #define BUFMAX 400 |
---|
152 | |
---|
153 | static bool initialized = false; /* boolean flag. != 0 means we've been initialized */ |
---|
154 | |
---|
155 | int remote_debug; |
---|
156 | /* debug > 0 prints ill-formed commands in valid packets & checksum errors */ |
---|
157 | |
---|
158 | static const char hexchars[]="0123456789abcdef"; |
---|
159 | |
---|
160 | /* there are 180 bytes of registers on a 68020 w/68881 */ |
---|
161 | /* many of the fpa registers are 12 byte (96 bit) registers */ |
---|
162 | #define NUMREGBYTES 180 |
---|
163 | enum regnames {D0,D1,D2,D3,D4,D5,D6,D7, |
---|
164 | A0,A1,A2,A3,A4,A5,A6,A7, |
---|
165 | PS,PC, |
---|
166 | FP0,FP1,FP2,FP3,FP4,FP5,FP6,FP7, |
---|
167 | FPCONTROL,FPSTATUS,FPIADDR |
---|
168 | }; |
---|
169 | |
---|
170 | |
---|
171 | /* We keep a whole frame cache here. "Why?", I hear you cry, "doesn't |
---|
172 | GDB handle that sort of thing?" Well, yes, I believe the only |
---|
173 | reason for this cache is to save and restore floating point state |
---|
174 | (fsave/frestore). A cleaner way to do this would be to make the |
---|
175 | fsave data part of the registers which GDB deals with like any |
---|
176 | other registers. This should not be a performance problem if the |
---|
177 | ability to read individual registers is added to the protocol. */ |
---|
178 | |
---|
179 | typedef struct FrameStruct |
---|
180 | { |
---|
181 | struct FrameStruct *previous; |
---|
182 | int exceptionPC; /* pc value when this frame created */ |
---|
183 | int exceptionVector; /* cpu vector causing exception */ |
---|
184 | short frameSize; /* size of cpu frame in words */ |
---|
185 | short sr; /* for 68000, this not always sr */ |
---|
186 | int pc; |
---|
187 | short format; |
---|
188 | int fsaveHeader; |
---|
189 | int morejunk[0]; /* exception frame, fp save... */ |
---|
190 | } Frame; |
---|
191 | |
---|
192 | #define FRAMESIZE 500 |
---|
193 | int gdbFrameStack[FRAMESIZE]; |
---|
194 | static Frame *lastFrame; |
---|
195 | |
---|
196 | /* |
---|
197 | * these should not be static cuz they can be used outside this module |
---|
198 | */ |
---|
199 | int registers[NUMREGBYTES/4]; |
---|
200 | int superStack; |
---|
201 | |
---|
202 | #define STACKSIZE 10000 |
---|
203 | int remcomStack[STACKSIZE/sizeof(int)]; |
---|
204 | static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; |
---|
205 | |
---|
206 | /* |
---|
207 | * In many cases, the system will want to continue exception processing |
---|
208 | * when a continue command is given. |
---|
209 | * oldExceptionHook is a function to invoke in this case. |
---|
210 | */ |
---|
211 | |
---|
212 | static ExceptionHook oldExceptionHook; |
---|
213 | |
---|
214 | #if (defined(__mc68020__) && !defined(__mcpu32__)) |
---|
215 | /* the size of the exception stack on the 68020 varies with the type of |
---|
216 | * exception. The following table is the number of WORDS used |
---|
217 | * for each exception format. |
---|
218 | */ |
---|
219 | const short exceptionSize[] = { 4,4,6,4,4,4,4,4,29,10,16,46,12,4,4,4 }; |
---|
220 | #endif |
---|
221 | |
---|
222 | #if defined(__mc68332__) |
---|
223 | static const short exceptionSize[] = { 4,4,6,4,4,4,4,4,4,4,4,4,16,4,4,4 }; |
---|
224 | #endif |
---|
225 | |
---|
226 | /************* jump buffer used for setjmp/longjmp **************************/ |
---|
227 | jmp_buf remcomEnv; |
---|
228 | |
---|
229 | /*************************** ASSEMBLY CODE MACROS *************************/ |
---|
230 | /* */ |
---|
231 | |
---|
232 | #if defined(__HAVE_68881__) |
---|
233 | |
---|
234 | /* do an fsave, then remember the address to begin a restore from */ |
---|
235 | #define SAVE_FP_REGS() \ |
---|
236 | asm(" fsave %a0@-"); \ |
---|
237 | asm(" fmovemx %fp0-%fp7,registers+72"); \ |
---|
238 | asm(" fmoveml %fpcr/%fpsr/%fpi,registers+168"); |
---|
239 | |
---|
240 | #define RESTORE_FP_REGS() \ |
---|
241 | asm(" \n\ |
---|
242 | fmoveml registers+168,%fpcr/%fpsr/%fpi \n\ |
---|
243 | fmovemx registers+72,%fp0-%fp7 \n\ |
---|
244 | cmpl #-1,%a0@ | skip frestore flag set ? \n\ |
---|
245 | beq skip_frestore \n\ |
---|
246 | frestore %a0@+ \n\ |
---|
247 | skip_frestore: \n\ |
---|
248 | "); |
---|
249 | |
---|
250 | #else |
---|
251 | |
---|
252 | #define SAVE_FP_REGS() |
---|
253 | #define RESTORE_FP_REGS() |
---|
254 | |
---|
255 | #endif /* __HAVE_68881__ */ |
---|
256 | |
---|
257 | void return_to_super(void); |
---|
258 | void return_to_user(void); |
---|
259 | |
---|
260 | asm("\n\ |
---|
261 | .text\n\ |
---|
262 | \n\ |
---|
263 | .globl return_to_super\n\ |
---|
264 | .align 4\n\ |
---|
265 | return_to_super:\n\ |
---|
266 | movel registers+60,%sp /* get new stack pointer */ \n\ |
---|
267 | movel lastFrame,%a0 /* get last frame info */ \n\ |
---|
268 | bra return_to_any\n\ |
---|
269 | \n\ |
---|
270 | .globl return_to_user\n\ |
---|
271 | .align 4\n\ |
---|
272 | \n\ |
---|
273 | return_to_user:\n\ |
---|
274 | movel registers+60,%a0 /* get usp */ \n\ |
---|
275 | movel %a0,%usp /* set usp */ \n\ |
---|
276 | movel superStack,%sp /* get original stack pointer */ \n\ |
---|
277 | \n\ |
---|
278 | return_to_any:\n\ |
---|
279 | movel lastFrame,%a0 /* get last frame info */ \n\ |
---|
280 | movel %a0@+,lastFrame /* link in previous frame */ \n\ |
---|
281 | addql #8,%a0 /* skip over pc, vector#*/ \n\ |
---|
282 | movew %a0@+,%d0 /* get # of words in cpu frame */ \n\ |
---|
283 | addw %d0,%a0 /* point to end of data */ \n\ |
---|
284 | addw %d0,%a0 /* point to end of data */ \n\ |
---|
285 | movel %a0,%a1 \n\ |
---|
286 | # \n\ |
---|
287 | # copy the stack frame \n\ |
---|
288 | subql #1,%d0\n\ |
---|
289 | \n\ |
---|
290 | copyUserLoop: \n\ |
---|
291 | movew %a1@-,%sp@- \n\ |
---|
292 | dbf %d0,copyUserLoop \n\ |
---|
293 | "); |
---|
294 | RESTORE_FP_REGS() |
---|
295 | asm("\n\ |
---|
296 | moveml registers,%d0-%d7/%a0-%a6\n\ |
---|
297 | rte /* pop and go! */\n\ |
---|
298 | "); |
---|
299 | |
---|
300 | #define DISABLE_INTERRUPTS() asm(" oriw #0x0700,%sr"); |
---|
301 | #define BREAKPOINT() asm(" trap #1"); |
---|
302 | |
---|
303 | /* this function is called immediately when a level 7 interrupt occurs */ |
---|
304 | /* if the previous interrupt level was 7 then we're already servicing */ |
---|
305 | /* this interrupt and an rte is in order to return to the debugger. */ |
---|
306 | /* For the 68000, the offset for sr is 6 due to the jsr return address */ |
---|
307 | asm("\n\ |
---|
308 | .text\n\ |
---|
309 | .globl _debug_level7\n\ |
---|
310 | .align 4\n\ |
---|
311 | \n\ |
---|
312 | _debug_level7:\n\ |
---|
313 | movew %d0,%sp@-\n\ |
---|
314 | "); |
---|
315 | |
---|
316 | #if (defined(__mc68020__) && !defined(__mcpu32__)) || defined(__mc68332__) |
---|
317 | asm("\n\ |
---|
318 | movew %sp@(2),%d0\n\ |
---|
319 | "); |
---|
320 | #else |
---|
321 | asm("\n\ |
---|
322 | movew %sp@(6),%d0\n\ |
---|
323 | "); |
---|
324 | #endif |
---|
325 | asm("\n\ |
---|
326 | andiw #0x700,%d0\n\ |
---|
327 | cmpiw #0x700,%d0\n\ |
---|
328 | beq _already7\n\ |
---|
329 | movew %sp@+,%d0 \n\ |
---|
330 | bra _catchException\n\ |
---|
331 | _already7:\n\ |
---|
332 | movew %sp@+,%d0\n\ |
---|
333 | "); |
---|
334 | #if defined (__mc68000__) && !(defined(__mc68020__) && !defined(__mcpu32__)) |
---|
335 | asm("\n\ |
---|
336 | lea %sp@(4),%sp"); /* pull off 68000 return address */ |
---|
337 | #endif |
---|
338 | asm("\n\ |
---|
339 | rte\n\ |
---|
340 | "); |
---|
341 | |
---|
342 | extern void _catchException(void); |
---|
343 | |
---|
344 | #if (defined(__mc68020__) && !defined(__mcpu32__)) || defined(__mc68332__) |
---|
345 | /* This function is called when a 68020 exception occurs. It saves |
---|
346 | * all the cpu and fpcp regs in the _registers array, creates a frame on a |
---|
347 | * linked list of frames which has the cpu and fpcp stack frames needed |
---|
348 | * to properly restore the context of these processors, and invokes |
---|
349 | * an exception handler (remcom_handler). |
---|
350 | * |
---|
351 | * stack on entry: stack on exit: |
---|
352 | * N bytes of junk exception # MSWord |
---|
353 | * Exception Format Word exception # MSWord |
---|
354 | * Program counter LSWord |
---|
355 | * Program counter MSWord |
---|
356 | * Status Register |
---|
357 | * |
---|
358 | * |
---|
359 | */ |
---|
360 | asm(" \n\ |
---|
361 | .text\n\ |
---|
362 | \n\ |
---|
363 | .globl _catchException\n\ |
---|
364 | .align 4\n\ |
---|
365 | _catchException:\n\ |
---|
366 | "); |
---|
367 | |
---|
368 | DISABLE_INTERRUPTS(); |
---|
369 | |
---|
370 | asm("\n\ |
---|
371 | moveml %d0-%d7/%a0-%a6,registers /* save registers */\n\ |
---|
372 | movel lastFrame,%a0 /* last frame pointer */\n\ |
---|
373 | "); |
---|
374 | SAVE_FP_REGS(); |
---|
375 | asm("\n\ |
---|
376 | lea registers,%a5 /* get address of registers */\n\ |
---|
377 | movew %sp@,%d1 /* get status register */\n\ |
---|
378 | movew %d1,%a5@(66) /* save sr */ \n\ |
---|
379 | movel %sp@(2),%a4 /* save pc in %a4 for later use */\n\ |
---|
380 | movel %a4,%a5@(68) /* save pc in _regisers[] */\n\ |
---|
381 | \n\ |
---|
382 | #\n\ |
---|
383 | # figure out how many bytes in the stack frame\n\ |
---|
384 | #\n\ |
---|
385 | movew %sp@(6),%d0 /* get '020 exception format */\n\ |
---|
386 | movew %d0,%d2 /* make a copy of format word */\n\ |
---|
387 | andiw #0xf000,%d0 /* mask off format type */\n\ |
---|
388 | rolw #5,%d0 /* rotate into the low byte *2 */\n\ |
---|
389 | lea exceptionSize,%a1 \n\ |
---|
390 | addw %d0,%a1 /* index into the table */\n\ |
---|
391 | movew %a1@,%d0 /* get number of words in frame */\n\ |
---|
392 | movew %d0,%d3 /* save it */\n\ |
---|
393 | subw %d0,%a0 /* adjust save pointer */\n\ |
---|
394 | subw %d0,%a0 /* adjust save pointer(bytes) */\n\ |
---|
395 | movel %a0,%a1 /* copy save pointer */\n\ |
---|
396 | subql #1,%d0 /* predecrement loop counter */\n\ |
---|
397 | #\n\ |
---|
398 | # copy the frame\n\ |
---|
399 | #\n\ |
---|
400 | saveFrameLoop:\n\ |
---|
401 | movew %sp@+,%a1@+\n\ |
---|
402 | dbf %d0,saveFrameLoop\n\ |
---|
403 | #\n\ |
---|
404 | # now that the stack has been clenaed,\n\ |
---|
405 | # save the %a7 in use at time of exception\n\ |
---|
406 | \n\ |
---|
407 | movel %sp,superStack /* save supervisor %sp */\n\ |
---|
408 | andiw #0x2000,%d1 /* were we in supervisor mode ? */\n\ |
---|
409 | beq userMode \n\ |
---|
410 | movel %a7,%a5@(60) /* save %a7 */\n\ |
---|
411 | bra a7saveDone\n\ |
---|
412 | userMode: \n\ |
---|
413 | movel %usp,%a1 \n\ |
---|
414 | movel %a1,%a5@(60) /* save user stack pointer */\n\ |
---|
415 | a7saveDone:\n\ |
---|
416 | \n\ |
---|
417 | #\n\ |
---|
418 | # save size of frame\n\ |
---|
419 | movew %d3,%a0@-\n\ |
---|
420 | \n\ |
---|
421 | #\n\ |
---|
422 | # compute exception number\n\ |
---|
423 | andl #0xfff,%d2 /* mask off vector offset */\n\ |
---|
424 | lsrw #2,%d2 /* divide by 4 to get vect num */\n\ |
---|
425 | movel %d2,%a0@- /* save it */\n\ |
---|
426 | #\n\ |
---|
427 | # save pc causing exception\n\ |
---|
428 | movel %a4,%a0@-\n\ |
---|
429 | #\n\ |
---|
430 | # save old frame link and set the new value\n\ |
---|
431 | movel lastFrame,%a1 /* last frame pointer */\n\ |
---|
432 | movel %a1,%a0@- /* save pointer to prev frame */\n\ |
---|
433 | movel %a0,lastFrame\n\ |
---|
434 | \n\ |
---|
435 | movel %d2,%sp@- /* push exception num */\n\ |
---|
436 | movel exceptionHook,%a0 /* get address of handler */\n\ |
---|
437 | jbsr %a0@ /* and call it */\n\ |
---|
438 | clrl %sp@ /* replace exception num parm with frame ptr */\n\ |
---|
439 | jbsr _returnFromException /* jbsr, but never returns */\n\ |
---|
440 | \n\ |
---|
441 | "); |
---|
442 | |
---|
443 | #else /* mc68000 */ |
---|
444 | |
---|
445 | /* This function is called when an exception occurs. It translates the |
---|
446 | * return address found on the stack into an exception vector # which |
---|
447 | * is then handled by either handle_exception or a system handler. |
---|
448 | * _catchException provides a front end for both. |
---|
449 | * |
---|
450 | * stack on entry: stack on exit: |
---|
451 | * Program counter MSWord exception # MSWord |
---|
452 | * Program counter LSWord exception # MSWord |
---|
453 | * Status Register |
---|
454 | * Return Address MSWord |
---|
455 | * Return Address LSWord |
---|
456 | */ |
---|
457 | asm("\n\ |
---|
458 | .text\n\ |
---|
459 | .globl _catchException\n\ |
---|
460 | .align 4\n\ |
---|
461 | _catchException:\n\ |
---|
462 | "); |
---|
463 | DISABLE_INTERRUPTS(); |
---|
464 | asm("\n\ |
---|
465 | moveml %d0-%d7/%a0-%a6,registers /* save registers */\n\ |
---|
466 | movel lastFrame,%a0 /* last frame pointer */\n\ |
---|
467 | "); |
---|
468 | |
---|
469 | SAVE_FP_REGS(); |
---|
470 | asm("\n\ |
---|
471 | moveq.l #0,%d2\n\ |
---|
472 | movew %sp@+,%d2\n\ |
---|
473 | lea registers,%a5 /* get address of registers */\n\ |
---|
474 | \n\ |
---|
475 | moveql #3,%d3 /* assume a three word frame */\n\ |
---|
476 | \n\ |
---|
477 | cmpiw #3,%d2 /* bus error or address error ? */\n\ |
---|
478 | bgt normal /* if >3 then normal error */\n\ |
---|
479 | movel %sp@+,%a0@- /* copy error info to frame buff*/\n\ |
---|
480 | movel %sp@+,%a0@- /* these are never used */\n\ |
---|
481 | moveql #7,%d3 /* this is a 7 word frame */\n\ |
---|
482 | \n\ |
---|
483 | normal: \n\ |
---|
484 | movew %sp@+,%d1 /* pop status register */\n\ |
---|
485 | movel %sp@+,%a4 /* pop program counter */\n\ |
---|
486 | \n\ |
---|
487 | cmpiw #33,%d2 /* trap #1, breakpoint ? */\n\ |
---|
488 | bne not_breakpoint\n\ |
---|
489 | \n\ |
---|
490 | subql #2,%a4 /* trap leaves the pc after the trap */\n\ |
---|
491 | \n\ |
---|
492 | not_breakpoint:\n\ |
---|
493 | movew %d1,%a5@(66) /* save sr */ \n\ |
---|
494 | movel %a4,%a5@(68) /* save pc in _regisers[] */\n\ |
---|
495 | movel %a4,%a0@- /* copy pc to frame buffer */\n\ |
---|
496 | movew %d1,%a0@- /* copy sr to frame buffer */\n\ |
---|
497 | \n\ |
---|
498 | movel %sp,superStack /* save supervisor %sp */\n\ |
---|
499 | \n\ |
---|
500 | andiw #0x2000,%d1 /* were we in supervisor mode ? */\n\ |
---|
501 | beq userMode \n\ |
---|
502 | movel %a7,%a5@(60) /* save %a7 */\n\ |
---|
503 | bra saveDone \n\ |
---|
504 | userMode:\n\ |
---|
505 | movel %usp,%a1 /* save user stack pointer */\n\ |
---|
506 | movel %a1,%a5@(60) /* save user stack pointer */\n\ |
---|
507 | saveDone:\n\ |
---|
508 | \n\ |
---|
509 | movew %d3,%a0@- /* push frame size in words */\n\ |
---|
510 | movel %d2,%a0@- /* push vector number */\n\ |
---|
511 | movel %a4,%a0@- /* push exception pc */\n\ |
---|
512 | \n\ |
---|
513 | #\n\ |
---|
514 | # save old frame link and set the new value\n\ |
---|
515 | #\n\ |
---|
516 | movel lastFrame,%a1 /* last frame pointer */\n\ |
---|
517 | movel %a1,%a0@- /* save pointer to prev frame */\n\ |
---|
518 | movel %a0,lastFrame\n\ |
---|
519 | \n\ |
---|
520 | movel %d2,%sp@- /* push exception num */\n\ |
---|
521 | movel exceptionHook,%a0 /* get address of handler */\n\ |
---|
522 | \n\ |
---|
523 | jbsr %a0@ /* and call it */\n\ |
---|
524 | clrl %sp@ /* replace exception num parm with frame ptr */\n\ |
---|
525 | jbsr _returnFromException /* jbsr, but never returns */\n\ |
---|
526 | "); |
---|
527 | #endif |
---|
528 | |
---|
529 | /* |
---|
530 | * remcomHandler is a front end for handle_exception. It moves the |
---|
531 | * stack pointer into an area reserved for debugger use in case the |
---|
532 | * breakpoint happened in supervisor mode. |
---|
533 | */ |
---|
534 | asm("remcomHandler:"); |
---|
535 | asm(" addl #4,%sp"); /* pop off return address */ |
---|
536 | asm(" movel %sp@+,%d0"); /* get the exception number */ |
---|
537 | asm(" movel stackPtr,%sp"); /* move to remcom stack area */ |
---|
538 | asm(" movel %d0,%sp@-"); /* push exception onto stack */ |
---|
539 | asm(" jbsr handle_exception"); /* this never returns */ |
---|
540 | asm(" rts"); /* return */ |
---|
541 | |
---|
542 | void _returnFromException(Frame *frame) |
---|
543 | { |
---|
544 | /* if no passed in frame, use the last one */ |
---|
545 | if (! frame) |
---|
546 | { |
---|
547 | frame = lastFrame; |
---|
548 | frame->frameSize = 4; |
---|
549 | frame->format = 0; |
---|
550 | frame->fsaveHeader = -1; /* restore regs, but we dont have fsave info*/ |
---|
551 | } |
---|
552 | |
---|
553 | #if defined(__mc68000__) && !(defined(__mc68020__) && !defined(__mcpu32__)) |
---|
554 | /* a 68000 cannot use the internal info pushed onto a bus error |
---|
555 | * or address error frame when doing an RTE so don't put this info |
---|
556 | * onto the stack or the stack will creep every time this happens. |
---|
557 | */ |
---|
558 | frame->frameSize=3; |
---|
559 | #endif |
---|
560 | |
---|
561 | /* throw away any frames in the list after this frame */ |
---|
562 | lastFrame = frame; |
---|
563 | |
---|
564 | frame->sr = registers[(int) PS]; |
---|
565 | frame->pc = registers[(int) PC]; |
---|
566 | |
---|
567 | if (registers[(int) PS] & 0x2000) |
---|
568 | { |
---|
569 | /* return to supervisor mode... */ |
---|
570 | return_to_super(); |
---|
571 | } |
---|
572 | else |
---|
573 | { /* return to user mode */ |
---|
574 | return_to_user(); |
---|
575 | } |
---|
576 | } |
---|
577 | |
---|
578 | int hex(char ch) |
---|
579 | { |
---|
580 | if ((ch >= 'a') && (ch <= 'f')) return (ch-'a'+10); |
---|
581 | if ((ch >= '0') && (ch <= '9')) return (ch-'0'); |
---|
582 | if ((ch >= 'A') && (ch <= 'F')) return (ch-'A'+10); |
---|
583 | return (-1); |
---|
584 | } |
---|
585 | |
---|
586 | /* scan for the sequence $<data>#<checksum> */ |
---|
587 | void getpacket(char *buffer) |
---|
588 | { |
---|
589 | unsigned char checksum; |
---|
590 | unsigned char xmitcsum; |
---|
591 | int i; |
---|
592 | int count; |
---|
593 | char ch; |
---|
594 | |
---|
595 | do { |
---|
596 | /* wait around for the start character, ignore all other characters */ |
---|
597 | while ((ch = (getDebugChar() & 0x7f)) != '$'); |
---|
598 | checksum = 0; |
---|
599 | xmitcsum = -1; |
---|
600 | |
---|
601 | count = 0; |
---|
602 | |
---|
603 | /* now, read until a # or end of buffer is found */ |
---|
604 | while (count < BUFMAX) { |
---|
605 | ch = getDebugChar() & 0x7f; |
---|
606 | if (ch == '#') break; |
---|
607 | checksum = checksum + ch; |
---|
608 | buffer[count] = ch; |
---|
609 | count = count + 1; |
---|
610 | } |
---|
611 | buffer[count] = 0; |
---|
612 | |
---|
613 | if (ch == '#') { |
---|
614 | xmitcsum = hex(getDebugChar() & 0x7f) << 4; |
---|
615 | xmitcsum += hex(getDebugChar() & 0x7f); |
---|
616 | if ((remote_debug ) && (checksum != xmitcsum)) { |
---|
617 | debug_port_printf ("bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n", |
---|
618 | checksum,xmitcsum,buffer); |
---|
619 | } |
---|
620 | |
---|
621 | if (checksum != xmitcsum) putDebugChar('-'); /* failed checksum */ |
---|
622 | else { |
---|
623 | putDebugChar('+'); /* successful transfer */ |
---|
624 | /* if a sequence char is present, reply the sequence ID */ |
---|
625 | if (buffer[2] == ':') { |
---|
626 | putDebugChar( buffer[0] ); |
---|
627 | putDebugChar( buffer[1] ); |
---|
628 | /* remove sequence chars from buffer */ |
---|
629 | count = strlen(buffer); |
---|
630 | for (i=3; i <= count; i++) buffer[i-3] = buffer[i]; |
---|
631 | } |
---|
632 | } |
---|
633 | } |
---|
634 | } while (checksum != xmitcsum); |
---|
635 | } |
---|
636 | |
---|
637 | /* send the packet in buffer. The host get's one chance to read it. |
---|
638 | This routine does not wait for a positive acknowledge. */ |
---|
639 | |
---|
640 | void |
---|
641 | putpacket(char *buffer) |
---|
642 | { |
---|
643 | unsigned char checksum; |
---|
644 | int count; |
---|
645 | char ch; |
---|
646 | |
---|
647 | /* $<packet info>#<checksum>. */ |
---|
648 | do { |
---|
649 | putDebugChar('$'); |
---|
650 | checksum = 0; |
---|
651 | count = 0; |
---|
652 | |
---|
653 | while ((ch=buffer[count])) { |
---|
654 | if (! putDebugChar(ch)) return; |
---|
655 | checksum += ch; |
---|
656 | count += 1; |
---|
657 | } |
---|
658 | |
---|
659 | putDebugChar('#'); |
---|
660 | putDebugChar(hexchars[checksum >> 4]); |
---|
661 | putDebugChar(hexchars[checksum % 16]); |
---|
662 | |
---|
663 | } while (1 == 0); /* (getDebugChar() != '+'); */ |
---|
664 | |
---|
665 | } |
---|
666 | |
---|
667 | char remcomInBuffer[BUFMAX]; |
---|
668 | char remcomOutBuffer[BUFMAX]; |
---|
669 | static short error; |
---|
670 | |
---|
671 | /* convert the memory pointed to by mem into hex, placing result in buf */ |
---|
672 | /* return a pointer to the last char put in buf (null) */ |
---|
673 | char *mem2hex(char *mem, char *buf, int count) |
---|
674 | { |
---|
675 | int i; |
---|
676 | unsigned char ch; |
---|
677 | |
---|
678 | if (remote_debug) |
---|
679 | debug_port_printf("mem=0x%x, count=0x%x\n", mem, count); |
---|
680 | |
---|
681 | for (i=0;i<count;i++) { |
---|
682 | ch = *mem++; |
---|
683 | *buf++ = hexchars[ch >> 4]; |
---|
684 | *buf++ = hexchars[ch % 16]; |
---|
685 | } |
---|
686 | *buf = 0; |
---|
687 | return(buf); |
---|
688 | } |
---|
689 | |
---|
690 | /* convert the hex array pointed to by buf into binary to be placed in mem */ |
---|
691 | /* return a pointer to the character AFTER the last byte written */ |
---|
692 | char *hex2mem(char *buf, char *mem, int count) |
---|
693 | { |
---|
694 | int i; |
---|
695 | unsigned char ch; |
---|
696 | |
---|
697 | if (remote_debug) |
---|
698 | debug_port_printf("mem=0x%x, count=0x%x\n", mem, count); |
---|
699 | |
---|
700 | for (i=0;i<count;i++) { |
---|
701 | ch = hex(*buf++) << 4; |
---|
702 | ch = ch + hex(*buf++); |
---|
703 | *mem++ = ch; |
---|
704 | } |
---|
705 | return(mem); |
---|
706 | } |
---|
707 | |
---|
708 | /* a bus error has occurred, perform a longjmp |
---|
709 | to return execution and allow handling of the error */ |
---|
710 | |
---|
711 | void handle_buserror() |
---|
712 | { |
---|
713 | longjmp(remcomEnv,1); |
---|
714 | } |
---|
715 | |
---|
716 | /* this function takes the 68000 exception number and attempts to |
---|
717 | translate this number into a unix compatible signal value */ |
---|
718 | int computeSignal(int exceptionVector) |
---|
719 | { |
---|
720 | int sigval; |
---|
721 | switch (exceptionVector) { |
---|
722 | case 2 : sigval = 10; break; /* bus error */ |
---|
723 | case 3 : sigval = 10; break; /* address error */ |
---|
724 | case 4 : sigval = 4; break; /* illegal instruction */ |
---|
725 | case 5 : sigval = 8; break; /* zero divide */ |
---|
726 | case 6 : sigval = 8; break; /* chk instruction */ |
---|
727 | case 7 : sigval = 8; break; /* trapv instruction */ |
---|
728 | case 8 : sigval = 11; break; /* privilege violation */ |
---|
729 | case 9 : sigval = 5; break; /* trace trap */ |
---|
730 | case 10: sigval = 4; break; /* line 1010 emulator */ |
---|
731 | case 11: sigval = 4; break; /* line 1111 emulator */ |
---|
732 | |
---|
733 | /* Coprocessor protocol violation. Using a standard MMU or FPU |
---|
734 | this cannot be triggered by software. Call it a SIGBUS. */ |
---|
735 | case 13: sigval = 10; break; |
---|
736 | |
---|
737 | case 31: sigval = 2; break; /* interrupt */ |
---|
738 | case 33: sigval = 5; break; /* breakpoint */ |
---|
739 | |
---|
740 | /* This is a trap #8 instruction. Apparently it is someone's software |
---|
741 | convention for some sort of SIGFPE condition. Whose? How many |
---|
742 | people are being screwed by having this code the way it is? |
---|
743 | Is there a clean solution? */ |
---|
744 | case 40: sigval = 8; break; /* floating point err */ |
---|
745 | |
---|
746 | case 48: sigval = 8; break; /* floating point err */ |
---|
747 | case 49: sigval = 8; break; /* floating point err */ |
---|
748 | case 50: sigval = 8; break; /* zero divide */ |
---|
749 | case 51: sigval = 8; break; /* underflow */ |
---|
750 | case 52: sigval = 8; break; /* operand error */ |
---|
751 | case 53: sigval = 8; break; /* overflow */ |
---|
752 | case 54: sigval = 8; break; /* NAN */ |
---|
753 | default: |
---|
754 | sigval = 7; /* "software generated"*/ |
---|
755 | } |
---|
756 | return (sigval); |
---|
757 | } |
---|
758 | |
---|
759 | /**********************************************/ |
---|
760 | /* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ |
---|
761 | /* RETURN NUMBER OF CHARS PROCESSED */ |
---|
762 | /**********************************************/ |
---|
763 | int hexToInt(char **ptr, int *intValue) |
---|
764 | { |
---|
765 | int numChars = 0; |
---|
766 | int hexValue; |
---|
767 | |
---|
768 | *intValue = 0; |
---|
769 | |
---|
770 | while (**ptr) |
---|
771 | { |
---|
772 | hexValue = hex(**ptr); |
---|
773 | if (hexValue >=0) |
---|
774 | { |
---|
775 | *intValue = (*intValue <<4) | hexValue; |
---|
776 | numChars ++; |
---|
777 | } |
---|
778 | else |
---|
779 | break; |
---|
780 | |
---|
781 | (*ptr)++; |
---|
782 | } |
---|
783 | |
---|
784 | return (numChars); |
---|
785 | } |
---|
786 | |
---|
787 | /* |
---|
788 | * This function does all command procesing for interfacing to gdb. |
---|
789 | */ |
---|
790 | void handle_exception(int exceptionVector) |
---|
791 | { |
---|
792 | int sigval; |
---|
793 | int addr, length; |
---|
794 | char * ptr; |
---|
795 | int newPC; |
---|
796 | Frame *frame; |
---|
797 | |
---|
798 | if (remote_debug) |
---|
799 | printf("vector=%d, sr=0x%x, pc=0x%x\n", |
---|
800 | exceptionVector, |
---|
801 | registers[ PS ], |
---|
802 | registers[ PC ]); |
---|
803 | |
---|
804 | /* reply to host that an exception has occurred */ |
---|
805 | sigval = computeSignal( exceptionVector ); |
---|
806 | remcomOutBuffer[0] = 'S'; |
---|
807 | remcomOutBuffer[1] = hexchars[sigval >> 4]; |
---|
808 | remcomOutBuffer[2] = hexchars[sigval % 16]; |
---|
809 | remcomOutBuffer[3] = 0; |
---|
810 | |
---|
811 | putpacket(remcomOutBuffer); |
---|
812 | |
---|
813 | while (1==1) { |
---|
814 | error = 0; |
---|
815 | remcomOutBuffer[0] = 0; |
---|
816 | getpacket(remcomInBuffer); |
---|
817 | switch (remcomInBuffer[0]) { |
---|
818 | case '?' : remcomOutBuffer[0] = 'S'; |
---|
819 | remcomOutBuffer[1] = hexchars[sigval >> 4]; |
---|
820 | remcomOutBuffer[2] = hexchars[sigval % 16]; |
---|
821 | remcomOutBuffer[3] = 0; |
---|
822 | break; |
---|
823 | case 'd' : |
---|
824 | remote_debug = !(remote_debug); /* toggle debug flag */ |
---|
825 | debug_port_printf("debug mode "); |
---|
826 | if (remote_debug) |
---|
827 | { |
---|
828 | debug_port_printf("on\n"); |
---|
829 | } |
---|
830 | else |
---|
831 | { |
---|
832 | debug_port_printf("off\n"); |
---|
833 | } |
---|
834 | break; |
---|
835 | case 'g' : /* return the value of the CPU registers */ |
---|
836 | mem2hex((char*) registers, remcomOutBuffer, NUMREGBYTES); |
---|
837 | break; |
---|
838 | case 'G' : /* set the value of the CPU registers - return OK */ |
---|
839 | hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES); |
---|
840 | strcpy(remcomOutBuffer,"OK"); |
---|
841 | break; |
---|
842 | |
---|
843 | /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ |
---|
844 | case 'm' : |
---|
845 | if (setjmp(remcomEnv) == 0) |
---|
846 | { |
---|
847 | exceptionHandler(2,handle_buserror); |
---|
848 | |
---|
849 | /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ |
---|
850 | ptr = &remcomInBuffer[1]; |
---|
851 | if (hexToInt(&ptr,&addr)) |
---|
852 | if (*(ptr++) == ',') |
---|
853 | if (hexToInt(&ptr,&length)) |
---|
854 | { |
---|
855 | ptr = 0; |
---|
856 | mem2hex((char*) addr, remcomOutBuffer, length); |
---|
857 | } |
---|
858 | |
---|
859 | if (ptr) |
---|
860 | { |
---|
861 | strcpy(remcomOutBuffer,"E01"); |
---|
862 | if (remote_debug) |
---|
863 | printf("malformed read memory command: %s",remcomInBuffer); |
---|
864 | } |
---|
865 | } |
---|
866 | else { |
---|
867 | exceptionHandler(2,_catchException); |
---|
868 | strcpy(remcomOutBuffer,"E03"); |
---|
869 | if (remote_debug) |
---|
870 | printf("bus error"); |
---|
871 | } |
---|
872 | |
---|
873 | /* restore handler for bus error */ |
---|
874 | exceptionHandler(2,_catchException); |
---|
875 | break; |
---|
876 | |
---|
877 | /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ |
---|
878 | case 'M' : |
---|
879 | if (setjmp(remcomEnv) == 0) { |
---|
880 | exceptionHandler(2,handle_buserror); |
---|
881 | |
---|
882 | /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ |
---|
883 | ptr = &remcomInBuffer[1]; |
---|
884 | if (hexToInt(&ptr,&addr)) |
---|
885 | if (*(ptr++) == ',') |
---|
886 | if (hexToInt(&ptr,&length)) |
---|
887 | if (*(ptr++) == ':') |
---|
888 | { |
---|
889 | hex2mem(ptr, (char*) addr, length); |
---|
890 | ptr = 0; |
---|
891 | strcpy(remcomOutBuffer,"OK"); |
---|
892 | } |
---|
893 | if (ptr) |
---|
894 | { |
---|
895 | strcpy(remcomOutBuffer,"E02"); |
---|
896 | if (remote_debug) |
---|
897 | printf("malformed write memory command: %s",remcomInBuffer); |
---|
898 | } |
---|
899 | } |
---|
900 | else { |
---|
901 | exceptionHandler(2,_catchException); |
---|
902 | strcpy(remcomOutBuffer,"E03"); |
---|
903 | if (remote_debug) |
---|
904 | printf("bus error"); |
---|
905 | } |
---|
906 | |
---|
907 | /* restore handler for bus error */ |
---|
908 | exceptionHandler(2,_catchException); |
---|
909 | break; |
---|
910 | |
---|
911 | /* cAA..AA Continue at address AA..AA(optional) */ |
---|
912 | /* sAA..AA Step one instruction from AA..AA(optional) */ |
---|
913 | case 'c' : |
---|
914 | case 's' : |
---|
915 | /* try to read optional parameter, pc unchanged if no parm */ |
---|
916 | ptr = &remcomInBuffer[1]; |
---|
917 | if (hexToInt(&ptr,&addr)) |
---|
918 | registers[ PC ] = addr; |
---|
919 | |
---|
920 | newPC = registers[ PC]; |
---|
921 | |
---|
922 | /* clear the trace bit */ |
---|
923 | registers[ PS ] &= 0x7fff; |
---|
924 | |
---|
925 | /* set the trace bit if we're stepping */ |
---|
926 | if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x8000; |
---|
927 | |
---|
928 | /* |
---|
929 | * look for newPC in the linked list of exception frames. |
---|
930 | * if it is found, use the old frame it. otherwise, |
---|
931 | * fake up a dummy frame in returnFromException(). |
---|
932 | */ |
---|
933 | if (remote_debug) debug_port_printf("new pc = 0x%x\n",newPC); |
---|
934 | |
---|
935 | frame = lastFrame; |
---|
936 | while (frame) |
---|
937 | { |
---|
938 | if (remote_debug) |
---|
939 | debug_port_printf("frame at 0x%x has pc=0x%x, except#=%d\n", |
---|
940 | frame,frame->exceptionPC, |
---|
941 | (unsigned int) frame->exceptionVector); |
---|
942 | if (frame->exceptionPC == newPC) break; /* bingo! a match */ |
---|
943 | /* |
---|
944 | * for a breakpoint instruction, the saved pc may |
---|
945 | * be off by two due to re-executing the instruction |
---|
946 | * replaced by the trap instruction. Check for this. |
---|
947 | */ |
---|
948 | if ((frame->exceptionVector == 33) && |
---|
949 | (frame->exceptionPC == newPC)) break; |
---|
950 | if (frame == frame->previous) |
---|
951 | { |
---|
952 | frame = 0; /* no match found */ |
---|
953 | break; |
---|
954 | } |
---|
955 | frame = frame->previous; |
---|
956 | } |
---|
957 | |
---|
958 | /* |
---|
959 | * If we found a match for the PC AND we are not returning |
---|
960 | * as a result of a breakpoint (33), |
---|
961 | * trace exception (9), nmi (31), jmp to |
---|
962 | * the old exception handler as if this code never ran. |
---|
963 | */ |
---|
964 | if (frame) |
---|
965 | { |
---|
966 | if ((frame->exceptionVector != 9) && |
---|
967 | (frame->exceptionVector != 31) && |
---|
968 | (frame->exceptionVector != 33)) |
---|
969 | { |
---|
970 | /* |
---|
971 | * invoke the previous handler. |
---|
972 | */ |
---|
973 | if (oldExceptionHook) |
---|
974 | (*oldExceptionHook) (frame->exceptionVector); |
---|
975 | newPC = registers[ PC ]; /* pc may have changed */ |
---|
976 | if (newPC != frame->exceptionPC) |
---|
977 | { |
---|
978 | if (remote_debug) |
---|
979 | debug_port_printf("frame at 0x%x has pc=0x%x, except#=%d\n", |
---|
980 | frame,frame->exceptionPC, |
---|
981 | (unsigned int) frame->exceptionVector); |
---|
982 | /* re-use the last frame, we're skipping it (longjump?)*/ |
---|
983 | frame = (Frame *) 0; |
---|
984 | _returnFromException( frame ); /* this is a jump */ |
---|
985 | } |
---|
986 | } |
---|
987 | } |
---|
988 | |
---|
989 | /* if we couldn't find a frame, create one */ |
---|
990 | if (frame == 0) |
---|
991 | { |
---|
992 | frame = lastFrame -1 ; |
---|
993 | |
---|
994 | /* by using a bunch of print commands with breakpoints, |
---|
995 | it's possible for the frame stack to creep down. If it creeps |
---|
996 | too far, give up and reset it to the top. Normal use should |
---|
997 | not see this happen. |
---|
998 | */ |
---|
999 | if ((unsigned int) (frame-2) < (unsigned int) &gdbFrameStack) |
---|
1000 | { |
---|
1001 | initializeRemcomErrorFrame(); |
---|
1002 | frame = lastFrame; |
---|
1003 | } |
---|
1004 | frame->previous = lastFrame; |
---|
1005 | lastFrame = frame; |
---|
1006 | frame = 0; /* null so _return... will properly initialize it */ |
---|
1007 | } |
---|
1008 | |
---|
1009 | _returnFromException( frame ); /* this is a jump */ |
---|
1010 | |
---|
1011 | break; |
---|
1012 | |
---|
1013 | /* kill the program */ |
---|
1014 | case 'k' : |
---|
1015 | /* reset the board */ |
---|
1016 | WATCHDOG_TRIGGER(); |
---|
1017 | while (1 == 1); |
---|
1018 | break; |
---|
1019 | |
---|
1020 | } /* switch */ |
---|
1021 | |
---|
1022 | /* reply to the request */ |
---|
1023 | putpacket(remcomOutBuffer); |
---|
1024 | } |
---|
1025 | } |
---|
1026 | |
---|
1027 | void initializeRemcomErrorFrame() |
---|
1028 | { |
---|
1029 | lastFrame = ((Frame *) &gdbFrameStack[FRAMESIZE-1]) - 1; |
---|
1030 | lastFrame->previous = lastFrame; |
---|
1031 | } |
---|
1032 | |
---|
1033 | /* this function is used to set up exception handlers for tracing and |
---|
1034 | breakpoints */ |
---|
1035 | void set_debug_traps() |
---|
1036 | { |
---|
1037 | extern void _debug_level7(void); |
---|
1038 | extern void remcomHandler(void); |
---|
1039 | |
---|
1040 | int exception; |
---|
1041 | |
---|
1042 | initializeRemcomErrorFrame(); |
---|
1043 | stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; |
---|
1044 | |
---|
1045 | registers[ PC ] = 0x400; |
---|
1046 | registers[ PS ] = 0x2700; |
---|
1047 | |
---|
1048 | for (exception = 2; exception <= 30; exception++) |
---|
1049 | exceptionHandler(exception,_catchException); |
---|
1050 | |
---|
1051 | /* level 7 interrupt */ |
---|
1052 | exceptionHandler(31,_debug_level7); |
---|
1053 | |
---|
1054 | for (exception = 32; exception <= 47; exception++) |
---|
1055 | exceptionHandler(exception,_catchException); |
---|
1056 | |
---|
1057 | /* exclude the unassigned, reserved vector locations */ |
---|
1058 | |
---|
1059 | for (exception = 64; exception <= 255; exception++) |
---|
1060 | exceptionHandler(exception,_catchException); |
---|
1061 | |
---|
1062 | if (oldExceptionHook != (ExceptionHook) remcomHandler) |
---|
1063 | { |
---|
1064 | oldExceptionHook = exceptionHook; |
---|
1065 | exceptionHook = (ExceptionHook) remcomHandler; |
---|
1066 | } |
---|
1067 | |
---|
1068 | initialized = true; |
---|
1069 | |
---|
1070 | #if defined(UPDATE_DISPLAY) |
---|
1071 | UPDATE_DISPLAY("gdb "); |
---|
1072 | #endif |
---|
1073 | } |
---|
1074 | |
---|
1075 | /* This function will generate a breakpoint exception. It is used at the |
---|
1076 | beginning of a program to sync up with a debugger and can be used |
---|
1077 | otherwise as a quick means to stop program execution and "break" into |
---|
1078 | the debugger. */ |
---|
1079 | |
---|
1080 | void breakpoint() |
---|
1081 | { |
---|
1082 | if (initialized) BREAKPOINT(); |
---|
1083 | } |
---|