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[deliverable/binutils-gdb.git] / gdb / i386-stub.c
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c906108c
SS		 1/****************************************************************************
2
3 THIS SOFTWARE IS NOT COPYRIGHTED
4
5 HP offers the following for use in the public domain. HP makes no
6 warranty with regard to the software or it's performance and the
7 user accepts the software "AS IS" with all faults.
8
9 HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
10 TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
11 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
12
13****************************************************************************/
14
15/****************************************************************************
16 * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
17 *
18 * Module name: remcom.c $
19 * Revision: 1.34 $
20 * Date: 91/03/09 12:29:49 $
21 * Contributor: Lake Stevens Instrument Division$
22 *
23 * Description: low level support for gdb debugger. $
24 *
25 * Considerations: only works on target hardware $
26 *
27 * Written by: Glenn Engel $
28 * ModuleState: Experimental $
29 *
30 * NOTES: See Below $
31 *
32 * Modified for 386 by Jim Kingdon, Cygnus Support.
33 *
34 * To enable debugger support, two things need to happen. One, a
35 * call to set_debug_traps() is necessary in order to allow any breakpoints
36 * or error conditions to be properly intercepted and reported to gdb.
37 * Two, a breakpoint needs to be generated to begin communication. This
38 * is most easily accomplished by a call to breakpoint(). Breakpoint()
39 * simulates a breakpoint by executing a trap #1.
40 *
41 * The external function exceptionHandler() is
42 * used to attach a specific handler to a specific 386 vector number.
43 * It should use the same privilege level it runs at. It should
44 * install it as an interrupt gate so that interrupts are masked
45 * while the handler runs.
c906108c
SS		 46 *
47 * Because gdb will sometimes write to the stack area to execute function
48 * calls, this program cannot rely on using the supervisor stack so it
49 * uses it's own stack area reserved in the int array remcomStack.
50 *
51 *************
52 *
53 * The following gdb commands are supported:
54 *
55 * command function Return value
56 *
57 * g return the value of the CPU registers hex data or ENN
58 * G set the value of the CPU registers OK or ENN
59 *
60 * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
61 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
62 *
63 * c Resume at current address SNN ( signal NN)
64 * cAA..AA Continue at address AA..AA SNN
65 *
66 * s Step one instruction SNN
67 * sAA..AA Step one instruction from AA..AA SNN
68 *
69 * k kill
70 *
71 * ? What was the last sigval ? SNN (signal NN)
72 *
73 * All commands and responses are sent with a packet which includes a
74 * checksum. A packet consists of
75 *
76 * $<packet info>#<checksum>.
77 *
78 * where
79 * <packet info> :: <characters representing the command or response>
80 * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>>
81 *
82 * When a packet is received, it is first acknowledged with either '+' or '-'.
83 * '+' indicates a successful transfer. '-' indicates a failed transfer.
84 *
85 * Example:
86 *
87 * Host: Reply:
88 * $m0,10#2a +$00010203040506070809101112131415#42
89 *
90 ****************************************************************************/
91
92#include <stdio.h>
93#include <string.h>
94
95/************************************************************************
96 *
97 * external low-level support routines
98 */
c906108c
SS		 99
100extern void putDebugChar(); /* write a single character */
101extern int getDebugChar(); /* read and return a single char */
d4f3574e 102extern void exceptionHandler(); /* assign an exception handler */
c906108c
SS		 103
104/************************************************************************/
105/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
106/* at least NUMREGBYTES*2 are needed for register packets */
107#define BUFMAX 400
108
109static char initialized; /* boolean flag. != 0 means we've been initialized */
110
111int remote_debug;
112/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
113
c906108c
SS		 114static const char hexchars[]="0123456789abcdef";
115
116/* Number of registers. */
117#define NUMREGS 16
118
119/* Number of bytes of registers. */
120#define NUMREGBYTES (NUMREGS * 4)
121
122enum regnames {EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,
123 PC /* also known as eip */,
124 PS /* also known as eflags */,
125 CS, SS, DS, ES, FS, GS};
126
127/*
128 * these should not be static cuz they can be used outside this module
129 */
130int registers[NUMREGS];
131
132#define STACKSIZE 10000
133int remcomStack[STACKSIZE/sizeof(int)];
134static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
135
c906108c
SS		 136/*************************** ASSEMBLY CODE MACROS *************************/
137/* */
138
139extern void
140return_to_prog ();
141
142/* Restore the program's registers (including the stack pointer, which
143 means we get the right stack and don't have to worry about popping our
144 return address and any stack frames and so on) and return. */
145asm(".text");
146asm(".globl _return_to_prog");
147asm("_return_to_prog:");
148asm(" movw _registers+44, %ss");
149asm(" movl _registers+16, %esp");
150asm(" movl _registers+4, %ecx");
151asm(" movl _registers+8, %edx");
152asm(" movl _registers+12, %ebx");
153asm(" movl _registers+20, %ebp");
154asm(" movl _registers+24, %esi");
155asm(" movl _registers+28, %edi");
156asm(" movw _registers+48, %ds");
157asm(" movw _registers+52, %es");
158asm(" movw _registers+56, %fs");
159asm(" movw _registers+60, %gs");
160asm(" movl _registers+36, %eax");
161asm(" pushl %eax"); /* saved eflags */
162asm(" movl _registers+40, %eax");
163asm(" pushl %eax"); /* saved cs */
164asm(" movl _registers+32, %eax");
165asm(" pushl %eax"); /* saved eip */
166asm(" movl _registers, %eax");
167/* use iret to restore pc and flags together so
168 that trace flag works right. */
169asm(" iret");
170
171#define BREAKPOINT() asm(" int $3");
172
173/* Put the error code here just in case the user cares. */
174int gdb_i386errcode;
175/* Likewise, the vector number here (since GDB only gets the signal
176 number through the usual means, and that's not very specific). */
177int gdb_i386vector = -1;
178
179/* GDB stores segment registers in 32-bit words (that's just the way
180 m-i386v.h is written). So zero the appropriate areas in registers. */
181#define SAVE_REGISTERS1() \
182 asm ("movl %eax, _registers"); \
183 asm ("movl %ecx, _registers+4"); \
184 asm ("movl %edx, _registers+8"); \
185 asm ("movl %ebx, _registers+12"); \
186 asm ("movl %ebp, _registers+20"); \
187 asm ("movl %esi, _registers+24"); \
188 asm ("movl %edi, _registers+28"); \
189 asm ("movw $0, %ax"); \
190 asm ("movw %ds, _registers+48"); \
191 asm ("movw %ax, _registers+50"); \
192 asm ("movw %es, _registers+52"); \
193 asm ("movw %ax, _registers+54"); \
194 asm ("movw %fs, _registers+56"); \
195 asm ("movw %ax, _registers+58"); \
196 asm ("movw %gs, _registers+60"); \
197 asm ("movw %ax, _registers+62");
198#define SAVE_ERRCODE() \
199 asm ("popl %ebx"); \
200 asm ("movl %ebx, _gdb_i386errcode");
201#define SAVE_REGISTERS2() \
202 asm ("popl %ebx"); /* old eip */ \
203 asm ("movl %ebx, _registers+32"); \
204 asm ("popl %ebx"); /* old cs */ \
205 asm ("movl %ebx, _registers+40"); \
206 asm ("movw %ax, _registers+42"); \
207 asm ("popl %ebx"); /* old eflags */ \
208 asm ("movl %ebx, _registers+36"); \
209 /* Now that we've done the pops, we can save the stack pointer."); */ \
210 asm ("movw %ss, _registers+44"); \
211 asm ("movw %ax, _registers+46"); \
212 asm ("movl %esp, _registers+16");
213
214/* See if mem_fault_routine is set, if so just IRET to that address. */
215#define CHECK_FAULT() \
216 asm ("cmpl $0, _mem_fault_routine"); \
217 asm ("jne mem_fault");
218
219asm (".text");
220asm ("mem_fault:");
221/* OK to clobber temp registers; we're just going to end up in set_mem_err. */
222/* Pop error code from the stack and save it. */
223asm (" popl %eax");
224asm (" movl %eax, _gdb_i386errcode");
225
226asm (" popl %eax"); /* eip */
227/* We don't want to return there, we want to return to the function
228 pointed to by mem_fault_routine instead. */
229asm (" movl _mem_fault_routine, %eax");
230asm (" popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits). */
231asm (" popl %edx"); /* eflags */
232
233/* Remove this stack frame; when we do the iret, we will be going to
234 the start of a function, so we want the stack to look just like it
235 would after a "call" instruction. */
236asm (" leave");
237
238/* Push the stuff that iret wants. */
239asm (" pushl %edx"); /* eflags */
240asm (" pushl %ecx"); /* cs */
241asm (" pushl %eax"); /* eip */
242
243/* Zero mem_fault_routine. */
244asm (" movl $0, %eax");
245asm (" movl %eax, _mem_fault_routine");
246
247asm ("iret");
248
249#define CALL_HOOK() asm("call _remcomHandler");
250
251/* This function is called when a i386 exception occurs. It saves
252 * all the cpu regs in the _registers array, munges the stack a bit,
253 * and invokes an exception handler (remcom_handler).
254 *
255 * stack on entry: stack on exit:
256 * old eflags vector number
257 * old cs (zero-filled to 32 bits)
258 * old eip
259 *
260 */
261extern void _catchException3();
262asm(".text");
263asm(".globl __catchException3");
264asm("__catchException3:");
265SAVE_REGISTERS1();
266SAVE_REGISTERS2();
267asm ("pushl $3");
268CALL_HOOK();
269
270/* Same thing for exception 1. */
271extern void _catchException1();
272asm(".text");
273asm(".globl __catchException1");
274asm("__catchException1:");
275SAVE_REGISTERS1();
276SAVE_REGISTERS2();
277asm ("pushl $1");
278CALL_HOOK();
279
280/* Same thing for exception 0. */
281extern void _catchException0();
282asm(".text");
283asm(".globl __catchException0");
284asm("__catchException0:");
285SAVE_REGISTERS1();
286SAVE_REGISTERS2();
287asm ("pushl $0");
288CALL_HOOK();
289
290/* Same thing for exception 4. */
291extern void _catchException4();
292asm(".text");
293asm(".globl __catchException4");
294asm("__catchException4:");
295SAVE_REGISTERS1();
296SAVE_REGISTERS2();
297asm ("pushl $4");
298CALL_HOOK();
299
300/* Same thing for exception 5. */
301extern void _catchException5();
302asm(".text");
303asm(".globl __catchException5");
304asm("__catchException5:");
305SAVE_REGISTERS1();
306SAVE_REGISTERS2();
307asm ("pushl $5");
308CALL_HOOK();
309
310/* Same thing for exception 6. */
311extern void _catchException6();
312asm(".text");
313asm(".globl __catchException6");
314asm("__catchException6:");
315SAVE_REGISTERS1();
316SAVE_REGISTERS2();
317asm ("pushl $6");
318CALL_HOOK();
319
320/* Same thing for exception 7. */
321extern void _catchException7();
322asm(".text");
323asm(".globl __catchException7");
324asm("__catchException7:");
325SAVE_REGISTERS1();
326SAVE_REGISTERS2();
327asm ("pushl $7");
328CALL_HOOK();
329
330/* Same thing for exception 8. */
331extern void _catchException8();
332asm(".text");
333asm(".globl __catchException8");
334asm("__catchException8:");
335SAVE_REGISTERS1();
336SAVE_ERRCODE();
337SAVE_REGISTERS2();
338asm ("pushl $8");
339CALL_HOOK();
340
341/* Same thing for exception 9. */
342extern void _catchException9();
343asm(".text");
344asm(".globl __catchException9");
345asm("__catchException9:");
346SAVE_REGISTERS1();
347SAVE_REGISTERS2();
348asm ("pushl $9");
349CALL_HOOK();
350
351/* Same thing for exception 10. */
352extern void _catchException10();
353asm(".text");
354asm(".globl __catchException10");
355asm("__catchException10:");
356SAVE_REGISTERS1();
357SAVE_ERRCODE();
358SAVE_REGISTERS2();
359asm ("pushl $10");
360CALL_HOOK();
361
362/* Same thing for exception 12. */
363extern void _catchException12();
364asm(".text");
365asm(".globl __catchException12");
366asm("__catchException12:");
367SAVE_REGISTERS1();
368SAVE_ERRCODE();
369SAVE_REGISTERS2();
370asm ("pushl $12");
371CALL_HOOK();
372
373/* Same thing for exception 16. */
374extern void _catchException16();
375asm(".text");
376asm(".globl __catchException16");
377asm("__catchException16:");
378SAVE_REGISTERS1();
379SAVE_REGISTERS2();
380asm ("pushl $16");
381CALL_HOOK();
382
383/* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff. */
384
385/* Same thing for exception 13. */
386extern void _catchException13 ();
387asm (".text");
388asm (".globl __catchException13");
389asm ("__catchException13:");
390CHECK_FAULT();
391SAVE_REGISTERS1();
392SAVE_ERRCODE();
393SAVE_REGISTERS2();
394asm ("pushl $13");
395CALL_HOOK();
396
397/* Same thing for exception 11. */
398extern void _catchException11 ();
399asm (".text");
400asm (".globl __catchException11");
401asm ("__catchException11:");
402CHECK_FAULT();
403SAVE_REGISTERS1();
404SAVE_ERRCODE();
405SAVE_REGISTERS2();
406asm ("pushl $11");
407CALL_HOOK();
408
409/* Same thing for exception 14. */
410extern void _catchException14 ();
411asm (".text");
412asm (".globl __catchException14");
413asm ("__catchException14:");
414CHECK_FAULT();
415SAVE_REGISTERS1();
416SAVE_ERRCODE();
417SAVE_REGISTERS2();
418asm ("pushl $14");
419CALL_HOOK();
420
421/*
422 * remcomHandler is a front end for handle_exception. It moves the
423 * stack pointer into an area reserved for debugger use.
424 */
425asm("_remcomHandler:");
426asm(" popl %eax"); /* pop off return address */
427asm(" popl %eax"); /* get the exception number */
428asm(" movl _stackPtr, %esp"); /* move to remcom stack area */
429asm(" pushl %eax"); /* push exception onto stack */
430asm(" call _handle_exception"); /* this never returns */
431
f29d9b6d
C		 432void
433_returnFromException ()
c906108c
SS		 434{
435 return_to_prog ();
436}
437
f29d9b6d
C		 438int
439hex (ch)
440 char ch;
c906108c 441{
f29d9b6d
C		 442 if ((ch >= 'a') && (ch <= 'f'))
443 return (ch - 'a' + 10);
444 if ((ch >= '0') && (ch <= '9'))
445 return (ch - '0');
446 if ((ch >= 'A') && (ch <= 'F'))
447 return (ch - 'A' + 10);
c906108c
SS		 448 return (-1);
449}
450
d4f3574e
SS		 451static char remcomInBuffer[BUFMAX];
452static char remcomOutBuffer[BUFMAX];
453
c906108c 454/* scan for the sequence $<data>#<checksum> */
104c1213
JM		 455
456unsigned char *
fba45db2 457getpacket (void)
c906108c 458{
d4f3574e 459 unsigned char *buffer = &remcomInBuffer[0];
c906108c
SS		 460 unsigned char checksum;
461 unsigned char xmitcsum;
104c1213 462 int count;
c906108c
SS		 463 char ch;
464
104c1213
JM		 465 while (1)
466 {
467 /* wait around for the start character, ignore all other characters */
468 while ((ch = getDebugChar ()) != '$')
469 ;
470
f29d9b6d 471 retry:
104c1213
JM		 472 checksum = 0;
473 xmitcsum = -1;
474 count = 0;
475
476 /* now, read until a # or end of buffer is found */
477 while (count < BUFMAX)
478 {
479 ch = getDebugChar ();
f29d9b6d 480 if (ch == '$')
104c1213
JM		 481 goto retry;
482 if (ch == '#')
483 break;
484 checksum = checksum + ch;
485 buffer[count] = ch;
486 count = count + 1;
487 }
488 buffer[count] = 0;
489
490 if (ch == '#')
491 {
492 ch = getDebugChar ();
493 xmitcsum = hex (ch) << 4;
494 ch = getDebugChar ();
495 xmitcsum += hex (ch);
496
497 if (checksum != xmitcsum)
498 {
499 if (remote_debug)
500 {
501 fprintf (stderr,
f29d9b6d 502 "bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n",
104c1213
JM		 503 checksum, xmitcsum, buffer);
504 }
505 putDebugChar ('-'); /* failed checksum */
506 }
507 else
508 {
509 putDebugChar ('+'); /* successful transfer */
510
511 /* if a sequence char is present, reply the sequence ID */
512 if (buffer[2] == ':')
513 {
514 putDebugChar (buffer[0]);
515 putDebugChar (buffer[1]);
516
517 return &buffer[3];
518 }
519
520 return &buffer[0];
521 }
522 }
c906108c 523 }
c906108c
SS		 524}
525
526/* send the packet in buffer. */
527
f29d9b6d
C		 528void
529putpacket (unsigned char *buffer)
c906108c
SS		 530{
531 unsigned char checksum;
f29d9b6d 532 int count;
c906108c
SS		 533 char ch;
534
535 /* $<packet info>#<checksum>. */
f29d9b6d
C		 536 do
537 {
538 putDebugChar ('$');
539 checksum = 0;
540 count = 0;
c906108c 541
f29d9b6d
C		 542 while (ch = buffer[count])
543 {
544 putDebugChar (ch);
545 checksum += ch;
546 count += 1;
547 }
c906108c 548
f29d9b6d
C		 549 putDebugChar ('#');
550 putDebugChar (hexchars[checksum >> 4]);
551 putDebugChar (hexchars[checksum % 16]);
c906108c 552
f29d9b6d
C		 553 }
554 while (getDebugChar () != '+');
c906108c
SS		 555}
556
f29d9b6d
C		 557void
558debug_error (format, parm)
559 char *format;
560 char *parm;
c906108c 561{
f29d9b6d
C		 562 if (remote_debug)
563 fprintf (stderr, format, parm);
c906108c
SS		 564}
565
566/* Address of a routine to RTE to if we get a memory fault. */
f29d9b6d 567static void (*volatile mem_fault_routine) () = NULL;
c906108c
SS		 568
569/* Indicate to caller of mem2hex or hex2mem that there has been an
570 error. */
571static volatile int mem_err = 0;
572
573void
fba45db2 574set_mem_err (void)
c906108c
SS		 575{
576 mem_err = 1;
577}
578
579/* These are separate functions so that they are so short and sweet
580 that the compiler won't save any registers (if there is a fault
581 to mem_fault, they won't get restored, so there better not be any
582 saved). */
583int
fba45db2 584get_char (char *addr)
c906108c
SS		 585{
586 return *addr;
587}
588
589void
fba45db2 590set_char (char *addr, int val)
c906108c
SS		 591{
592 *addr = val;
593}
594
595/* convert the memory pointed to by mem into hex, placing result in buf */
596/* return a pointer to the last char put in buf (null) */
597/* If MAY_FAULT is non-zero, then we should set mem_err in response to
598 a fault; if zero treat a fault like any other fault in the stub. */
f29d9b6d
C		 599char *
600mem2hex (mem, buf, count, may_fault)
601 char *mem;
602 char *buf;
603 int count;
604 int may_fault;
c906108c 605{
f29d9b6d
C		 606 int i;
607 unsigned char ch;
608
609 if (may_fault)
610 mem_fault_routine = set_mem_err;
611 for (i = 0; i < count; i++)
612 {
613 ch = get_char (mem++);
614 if (may_fault && mem_err)
615 return (buf);
616 *buf++ = hexchars[ch >> 4];
617 *buf++ = hexchars[ch % 16];
618 }
619 *buf = 0;
620 if (may_fault)
621 mem_fault_routine = NULL;
622 return (buf);
c906108c
SS		 623}
624
625/* convert the hex array pointed to by buf into binary to be placed in mem */
626/* return a pointer to the character AFTER the last byte written */
f29d9b6d
C		 627char *
628hex2mem (buf, mem, count, may_fault)
629 char *buf;
630 char *mem;
631 int count;
632 int may_fault;
c906108c 633{
f29d9b6d
C		 634 int i;
635 unsigned char ch;
636
637 if (may_fault)
638 mem_fault_routine = set_mem_err;
639 for (i = 0; i < count; i++)
640 {
641 ch = hex (*buf++) << 4;
642 ch = ch + hex (*buf++);
643 set_char (mem++, ch);
644 if (may_fault && mem_err)
645 return (mem);
646 }
647 if (may_fault)
648 mem_fault_routine = NULL;
649 return (mem);
c906108c
SS		 650}
651
652/* this function takes the 386 exception vector and attempts to
653 translate this number into a unix compatible signal value */
f29d9b6d
C		 654int
655computeSignal (int exceptionVector)
c906108c
SS		 656{
657 int sigval;
f29d9b6d
C		 658 switch (exceptionVector)
659 {
660 case 0:
661 sigval = 8;
662 break; /* divide by zero */
663 case 1:
664 sigval = 5;
665 break; /* debug exception */
666 case 3:
667 sigval = 5;
668 break; /* breakpoint */
669 case 4:
670 sigval = 16;
671 break; /* into instruction (overflow) */
672 case 5:
673 sigval = 16;
674 break; /* bound instruction */
675 case 6:
676 sigval = 4;
677 break; /* Invalid opcode */
678 case 7:
679 sigval = 8;
680 break; /* coprocessor not available */
681 case 8:
682 sigval = 7;
683 break; /* double fault */
684 case 9:
685 sigval = 11;
686 break; /* coprocessor segment overrun */
687 case 10:
688 sigval = 11;
689 break; /* Invalid TSS */
690 case 11:
691 sigval = 11;
692 break; /* Segment not present */
693 case 12:
694 sigval = 11;
695 break; /* stack exception */
696 case 13:
697 sigval = 11;
698 break; /* general protection */
699 case 14:
700 sigval = 11;
701 break; /* page fault */
702 case 16:
703 sigval = 7;
704 break; /* coprocessor error */
c906108c 705 default:
f29d9b6d
C		 706 sigval = 7; /* "software generated" */
707 }
c906108c
SS		 708 return (sigval);
709}
710
711/**********************************************/
712/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
713/* RETURN NUMBER OF CHARS PROCESSED */
714/**********************************************/
f29d9b6d
C		 715int
716hexToInt (char **ptr, int *intValue)
c906108c 717{
f29d9b6d
C		 718 int numChars = 0;
719 int hexValue;
c906108c 720
f29d9b6d 721 *intValue = 0;
c906108c 722
f29d9b6d 723 while (**ptr)
c906108c 724 {
f29d9b6d
C		 725 hexValue = hex (**ptr);
726 if (hexValue >= 0)
727 {
728 *intValue = (*intValue << 4) | hexValue;
729 numChars++;
730 }
731 else
732 break;
733
734 (*ptr)++;
c906108c
SS		 735 }
736
f29d9b6d 737 return (numChars);
c906108c
SS		 738}
739
740/*
741 * This function does all command procesing for interfacing to gdb.
742 */
f29d9b6d
C		 743void
744handle_exception (int exceptionVector)
c906108c 745{
f29d9b6d
C		 746 int sigval, stepping;
747 int addr, length;
748 char *ptr;
749 int newPC;
c906108c
SS		 750
751 gdb_i386vector = exceptionVector;
752
f29d9b6d
C		 753 if (remote_debug)
754 {
755 printf ("vector=%d, sr=0x%x, pc=0x%x\n",
756 exceptionVector, registers[PS], registers[PC]);
757 }
c906108c
SS		 758
759 /* reply to host that an exception has occurred */
f29d9b6d 760 sigval = computeSignal (exceptionVector);
e2a4c6c1
C		 761
762 ptr = remcomOutBuffer;
763
764 *ptr++ = 'T'; /* notify gdb with signo, PC, FP and SP */
765 *ptr++ = hexchars[sigval >> 4];
766 *ptr++ = hexchars[sigval & 0xf];
767
768 *ptr++ = hexchars[ESP];
769 *ptr++ = ':';
770 ptr = mem2hex((char *)&registers[ESP], ptr, 4, 0); /* SP */
771 *ptr++ = ';';
772
773 *ptr++ = hexchars[EBP];
774 *ptr++ = ':';
775 ptr = mem2hex((char *)&registers[EBP], ptr, 4, 0); /* FP */
776 *ptr++ = ';';
777
778 *ptr++ = hexchars[PC];
779 *ptr++ = ':';
780 ptr = mem2hex((char *)&registers[PC], ptr, 4, 0); /* PC */
781 *ptr++ = ';';
782
783 *ptr = '\0'
c906108c 784
f29d9b6d 785 putpacket (remcomOutBuffer);
c906108c 786
104c1213
JM		 787 stepping = 0;
788
f29d9b6d
C		 789 while (1 == 1)
790 {
791 remcomOutBuffer[0] = 0;
792 ptr = getpacket ();
793
794 switch (*ptr++)
795 {
796 case '?':
797 remcomOutBuffer[0] = 'S';
798 remcomOutBuffer[1] = hexchars[sigval >> 4];
799 remcomOutBuffer[2] = hexchars[sigval % 16];
800 remcomOutBuffer[3] = 0;
801 break;
802 case 'd':
803 remote_debug = !(remote_debug); /* toggle debug flag */
804 break;
805 case 'g': /* return the value of the CPU registers */
806 mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES, 0);
807 break;
808 case 'G': /* set the value of the CPU registers - return OK */
809 hex2mem (ptr, (char *) registers, NUMREGBYTES, 0);
810 strcpy (remcomOutBuffer, "OK");
811 break;
812 case 'P': /* set the value of a single CPU register - return OK */
813 {
814 int regno;
815
816 if (hexToInt (&ptr, &regno) && *ptr++ == '=')
817 if (regno >= 0 && regno < NUMREGS)
818 {
819 hex2mem (ptr, (char *) &registers[regno], 4, 0);
820 strcpy (remcomOutBuffer, "OK");
821 break;
822 }
823
824 strcpy (remcomOutBuffer, "E01");
825 break;
826 }
827
828 /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
829 case 'm':
830 /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */
831 if (hexToInt (&ptr, &addr))
832 if (*(ptr++) == ',')
833 if (hexToInt (&ptr, &length))
834 {
835 ptr = 0;
836 mem_err = 0;
837 mem2hex ((char *) addr, remcomOutBuffer, length, 1);
838 if (mem_err)
839 {
840 strcpy (remcomOutBuffer, "E03");
841 debug_error ("memory fault");
c906108c 842 }
f29d9b6d 843 }
c906108c 844
f29d9b6d
C		 845 if (ptr)
846 {
847 strcpy (remcomOutBuffer, "E01");
848 }
849 break;
850
851 /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
852 case 'M':
853 /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */
854 if (hexToInt (&ptr, &addr))
855 if (*(ptr++) == ',')
856 if (hexToInt (&ptr, &length))
857 if (*(ptr++) == ':')
858 {
859 mem_err = 0;
860 hex2mem (ptr, (char *) addr, length, 1);
861
862 if (mem_err)
863 {
864 strcpy (remcomOutBuffer, "E03");
865 debug_error ("memory fault");
866 }
867 else
868 {
869 strcpy (remcomOutBuffer, "OK");
870 }
871
872 ptr = 0;
873 }
874 if (ptr)
875 {
876 strcpy (remcomOutBuffer, "E02");
877 }
878 break;
879
880 /* cAA..AA Continue at address AA..AA(optional) */
881 /* sAA..AA Step one instruction from AA..AA(optional) */
882 case 's':
883 stepping = 1;
884 case 'c':
885 /* try to read optional parameter, pc unchanged if no parm */
886 if (hexToInt (&ptr, &addr))
887 registers[PC] = addr;
c906108c 888
f29d9b6d 889 newPC = registers[PC];
c906108c 890
f29d9b6d
C		 891 /* clear the trace bit */
892 registers[PS] &= 0xfffffeff;
c906108c 893
f29d9b6d
C		 894 /* set the trace bit if we're stepping */
895 if (stepping)
896 registers[PS] |= 0x100;
c906108c 897
f29d9b6d
C		 898 _returnFromException (); /* this is a jump */
899 break;
c906108c 900
f29d9b6d
C		 901 /* kill the program */
902 case 'k': /* do nothing */
c906108c 903#if 0
f29d9b6d
C		 904 /* Huh? This doesn't look like "nothing".
905 m68k-stub.c and sparc-stub.c don't have it. */
906 BREAKPOINT ();
c906108c 907#endif
f29d9b6d
C		 908 break;
909 } /* switch */
c906108c 910
f29d9b6d
C		 911 /* reply to the request */
912 putpacket (remcomOutBuffer);
c906108c
SS		 913 }
914}
915
916/* this function is used to set up exception handlers for tracing and
917 breakpoints */
f29d9b6d
C		 918void
919set_debug_traps (void)
c906108c 920{
f29d9b6d 921 stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1];
c906108c
SS		 922
923 exceptionHandler (0, _catchException0);
924 exceptionHandler (1, _catchException1);
925 exceptionHandler (3, _catchException3);
926 exceptionHandler (4, _catchException4);
927 exceptionHandler (5, _catchException5);
928 exceptionHandler (6, _catchException6);
929 exceptionHandler (7, _catchException7);
930 exceptionHandler (8, _catchException8);
931 exceptionHandler (9, _catchException9);
932 exceptionHandler (10, _catchException10);
933 exceptionHandler (11, _catchException11);
934 exceptionHandler (12, _catchException12);
935 exceptionHandler (13, _catchException13);
936 exceptionHandler (14, _catchException14);
937 exceptionHandler (16, _catchException16);
938
c906108c 939 initialized = 1;
c906108c
SS		 940}
941
942/* This function will generate a breakpoint exception. It is used at the
943 beginning of a program to sync up with a debugger and can be used
944 otherwise as a quick means to stop program execution and "break" into
945 the debugger. */
946
f29d9b6d
C		 947void
948breakpoint (void)
c906108c
SS		 949{
950 if (initialized)
f29d9b6d 951 BREAKPOINT ();
c906108c 952}
GDB Binutils - Deliverables
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