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Linux-2.6.12-rc2
[linux-2.6/kvm.git] / arch / cris / arch-v10 / kernel / kgdb.c
blob7d368c877ee9e6cb5ed4d01c22ec799a1f38803e
1 /*!**************************************************************************
2 *!
3 *! FILE NAME : kgdb.c
4 *!
5 *! DESCRIPTION: Implementation of the gdb stub with respect to ETRAX 100.
6 *! It is a mix of arch/m68k/kernel/kgdb.c and cris_stub.c.
7 *!
8 *!---------------------------------------------------------------------------
9 *! HISTORY
10 *!
11 *! DATE NAME CHANGES
12 *! ---- ---- -------
13 *! Apr 26 1999 Hendrik Ruijter Initial version.
14 *! May 6 1999 Hendrik Ruijter Removed call to strlen in libc and removed
15 *! struct assignment as it generates calls to
16 *! memcpy in libc.
17 *! Jun 17 1999 Hendrik Ruijter Added gdb 4.18 support. 'X', 'qC' and 'qL'.
18 *! Jul 21 1999 Bjorn Wesen eLinux port
19 *!
20 *! $Log: kgdb.c,v $
21 *! Revision 1.5 2004/10/07 13:59:08 starvik
22 *! Corrected call to set_int_vector
23 *!
24 *! Revision 1.4 2003/04/09 05:20:44 starvik
25 *! Merge of Linux 2.5.67
26 *!
27 *! Revision 1.3 2003/01/21 19:11:08 starvik
28 *! Modified include path for new dir layout
29 *!
30 *! Revision 1.2 2002/11/19 14:35:24 starvik
31 *! Changes from linux 2.4
32 *! Changed struct initializer syntax to the currently prefered notation
33 *!
34 *! Revision 1.1 2001/12/17 13:59:27 bjornw
35 *! Initial revision
36 *!
37 *! Revision 1.6 2001/10/09 13:10:03 matsfg
38 *! Added $ on registers and removed some underscores
39 *!
40 *! Revision 1.5 2001/04/17 13:58:39 orjanf
41 *! * Renamed CONFIG_KGDB to CONFIG_ETRAX_KGDB.
42 *!
43 *! Revision 1.4 2001/02/23 13:45:19 bjornw
44 *! config.h check
45 *!
46 *! Revision 1.3 2001/01/31 18:08:23 orjanf
47 *! Removed kgdb_handle_breakpoint from being the break 8 handler.
48 *!
49 *! Revision 1.2 2001/01/12 14:22:25 orjanf
50 *! Updated kernel debugging support to work with ETRAX 100LX.
51 *!
52 *! Revision 1.1 2000/07/10 16:25:21 bjornw
53 *! Initial revision
54 *!
55 *! Revision 1.1.1.1 1999/12/03 14:57:31 bjornw
56 *! * Initial version of arch/cris, the latest CRIS architecture with an MMU.
57 *! Mostly copied from arch/etrax100 with appropriate renames of files.
58 *! The mm/ subdir is copied from arch/i386.
59 *! This does not compile yet at all.
60 *!
61 *!
62 *! Revision 1.4 1999/07/22 17:25:25 bjornw
63 *! Dont wait for + in putpacket if we havent hit the initial breakpoint yet. Added a kgdb_init function which sets up the break and irq vectors.
64 *!
65 *! Revision 1.3 1999/07/21 19:51:18 bjornw
66 *! Check if the interrupting char is a ctrl-C, ignore otherwise.
67 *!
68 *! Revision 1.2 1999/07/21 18:09:39 bjornw
69 *! Ported to eLinux architecture, and added some kgdb documentation.
70 *!
71 *!
72 *!---------------------------------------------------------------------------
73 *!
74 *! $Id: kgdb.c,v 1.5 2004/10/07 13:59:08 starvik Exp $
75 *!
76 *! (C) Copyright 1999, Axis Communications AB, LUND, SWEDEN
77 *!
78 *!**************************************************************************/
79 /* @(#) cris_stub.c 1.3 06/17/99 */
80
81 /*
82 * kgdb usage notes:
83 * -----------------
84 *
85 * If you select CONFIG_ETRAX_KGDB in the configuration, the kernel will be
86 * built with different gcc flags: "-g" is added to get debug infos, and
87 * "-fomit-frame-pointer" is omitted to make debugging easier. Since the
88 * resulting kernel will be quite big (approx. > 7 MB), it will be stripped
89 * before compresion. Such a kernel will behave just as usually, except if
90 * given a "debug=<device>" command line option. (Only serial devices are
91 * allowed for <device>, i.e. no printers or the like; possible values are
92 * machine depedend and are the same as for the usual debug device, the one
93 * for logging kernel messages.) If that option is given and the device can be
94 * initialized, the kernel will connect to the remote gdb in trap_init(). The
95 * serial parameters are fixed to 8N1 and 115200 bps, for easyness of
96 * implementation.
97 *
98 * To start a debugging session, start that gdb with the debugging kernel
99 * image (the one with the symbols, vmlinux.debug) named on the command line.
100 * This file will be used by gdb to get symbol and debugging infos about the
101 * kernel. Next, select remote debug mode by
102 * target remote <device>
103 * where <device> is the name of the serial device over which the debugged
104 * machine is connected. Maybe you have to adjust the baud rate by
105 * set remotebaud <rate>
106 * or also other parameters with stty:
107 * shell stty ... </dev/...
108 * If the kernel to debug has already booted, it waited for gdb and now
109 * connects, and you'll see a breakpoint being reported. If the kernel isn't
110 * running yet, start it now. The order of gdb and the kernel doesn't matter.
111 * Another thing worth knowing about in the getting-started phase is how to
112 * debug the remote protocol itself. This is activated with
113 * set remotedebug 1
114 * gdb will then print out each packet sent or received. You'll also get some
115 * messages about the gdb stub on the console of the debugged machine.
116 *
117 * If all that works, you can use lots of the usual debugging techniques on
118 * the kernel, e.g. inspecting and changing variables/memory, setting
119 * breakpoints, single stepping and so on. It's also possible to interrupt the
120 * debugged kernel by pressing C-c in gdb. Have fun! :-)
121 *
122 * The gdb stub is entered (and thus the remote gdb gets control) in the
123 * following situations:
124 *
125 * - If breakpoint() is called. This is just after kgdb initialization, or if
126 * a breakpoint() call has been put somewhere into the kernel source.
127 * (Breakpoints can of course also be set the usual way in gdb.)
128 * In eLinux, we call breakpoint() in init/main.c after IRQ initialization.
129 *
130 * - If there is a kernel exception, i.e. bad_super_trap() or die_if_kernel()
131 * are entered. All the CPU exceptions are mapped to (more or less..., see
132 * the hard_trap_info array below) appropriate signal, which are reported
133 * to gdb. die_if_kernel() is usually called after some kind of access
134 * error and thus is reported as SIGSEGV.
135 *
136 * - When panic() is called. This is reported as SIGABRT.
137 *
138 * - If C-c is received over the serial line, which is treated as
139 * SIGINT.
140 *
141 * Of course, all these signals are just faked for gdb, since there is no
142 * signal concept as such for the kernel. It also isn't possible --obviously--
143 * to set signal handlers from inside gdb, or restart the kernel with a
144 * signal.
145 *
146 * Current limitations:
147 *
148 * - While the kernel is stopped, interrupts are disabled for safety reasons
149 * (i.e., variables not changing magically or the like). But this also
150 * means that the clock isn't running anymore, and that interrupts from the
151 * hardware may get lost/not be served in time. This can cause some device
152 * errors...
153 *
154 * - When single-stepping, only one instruction of the current thread is
155 * executed, but interrupts are allowed for that time and will be serviced
156 * if pending. Be prepared for that.
157 *
158 * - All debugging happens in kernel virtual address space. There's no way to
159 * access physical memory not mapped in kernel space, or to access user
160 * space. A way to work around this is using get_user_long & Co. in gdb
161 * expressions, but only for the current process.
162 *
163 * - Interrupting the kernel only works if interrupts are currently allowed,
164 * and the interrupt of the serial line isn't blocked by some other means
165 * (IPL too high, disabled, ...)
166 *
167 * - The gdb stub is currently not reentrant, i.e. errors that happen therein
168 * (e.g. accessing invalid memory) may not be caught correctly. This could
169 * be removed in future by introducing a stack of struct registers.
170 *
171 */
172
173 /*
174 * To enable debugger support, two things need to happen. One, a
175 * call to kgdb_init() is necessary in order to allow any breakpoints
176 * or error conditions to be properly intercepted and reported to gdb.
177 * Two, a breakpoint needs to be generated to begin communication. This
178 * is most easily accomplished by a call to breakpoint().
179 *
180 * The following gdb commands are supported:
181 *
182 * command function Return value
183 *
184 * g return the value of the CPU registers hex data or ENN
185 * G set the value of the CPU registers OK or ENN
186 *
187 * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
188 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
189 *
190 * c Resume at current address SNN ( signal NN)
191 * cAA..AA Continue at address AA..AA SNN
192 *
193 * s Step one instruction SNN
194 * sAA..AA Step one instruction from AA..AA SNN
195 *
196 * k kill
197 *
198 * ? What was the last sigval ? SNN (signal NN)
199 *
200 * bBB..BB Set baud rate to BB..BB OK or BNN, then sets
201 * baud rate
202 *
203 * All commands and responses are sent with a packet which includes a
204 * checksum. A packet consists of
205 *
206 * $<packet info>#<checksum>.
207 *
208 * where
209 * <packet info> :: <characters representing the command or response>
210 * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>>
211 *
212 * When a packet is received, it is first acknowledged with either '+' or '-'.
213 * '+' indicates a successful transfer. '-' indicates a failed transfer.
214 *
215 * Example:
216 *
217 * Host: Reply:
218 * $m0,10#2a +$00010203040506070809101112131415#42
219 *
220 */
221
222
223 #include <linux/string.h>
224 #include <linux/signal.h>
225 #include <linux/kernel.h>
226 #include <linux/delay.h>
227 #include <linux/linkage.h>
228
229 #include <asm/setup.h>
230 #include <asm/ptrace.h>
231
232 #include <asm/arch/svinto.h>
233 #include <asm/irq.h>
234
235 static int kgdb_started = 0;
236
237 /********************************* Register image ****************************/
238 /* Use the order of registers as defined in "AXIS ETRAX CRIS Programmer's
239 Reference", p. 1-1, with the additional register definitions of the
240 ETRAX 100LX in cris-opc.h.
241 There are 16 general 32-bit registers, R0-R15, where R14 is the stack
242 pointer, SP, and R15 is the program counter, PC.
243 There are 16 special registers, P0-P15, where three of the unimplemented
244 registers, P0, P4 and P8, are reserved as zero-registers. A read from
245 any of these registers returns zero and a write has no effect. */
246
247 typedef
248 struct register_image
249 {
250 /* Offset */
251 unsigned int r0; /* 0x00 */
252 unsigned int r1; /* 0x04 */
253 unsigned int r2; /* 0x08 */
254 unsigned int r3; /* 0x0C */
255 unsigned int r4; /* 0x10 */
256 unsigned int r5; /* 0x14 */
257 unsigned int r6; /* 0x18 */
258 unsigned int r7; /* 0x1C */
259 unsigned int r8; /* 0x20 Frame pointer */
260 unsigned int r9; /* 0x24 */
261 unsigned int r10; /* 0x28 */
262 unsigned int r11; /* 0x2C */
263 unsigned int r12; /* 0x30 */
264 unsigned int r13; /* 0x34 */
265 unsigned int sp; /* 0x38 Stack pointer */
266 unsigned int pc; /* 0x3C Program counter */
267
268 unsigned char p0; /* 0x40 8-bit zero-register */
269 unsigned char vr; /* 0x41 Version register */
270
271 unsigned short p4; /* 0x42 16-bit zero-register */
272 unsigned short ccr; /* 0x44 Condition code register */
273
274 unsigned int mof; /* 0x46 Multiply overflow register */
275
276 unsigned int p8; /* 0x4A 32-bit zero-register */
277 unsigned int ibr; /* 0x4E Interrupt base register */
278 unsigned int irp; /* 0x52 Interrupt return pointer */
279 unsigned int srp; /* 0x56 Subroutine return pointer */
280 unsigned int bar; /* 0x5A Breakpoint address register */
281 unsigned int dccr; /* 0x5E Double condition code register */
282 unsigned int brp; /* 0x62 Breakpoint return pointer (pc in caller) */
283 unsigned int usp; /* 0x66 User mode stack pointer */
284 } registers;
285
286 /************** Prototypes for local library functions ***********************/
287
288 /* Copy of strcpy from libc. */
289 static char *gdb_cris_strcpy (char *s1, const char *s2);
290
291 /* Copy of strlen from libc. */
292 static int gdb_cris_strlen (const char *s);
293
294 /* Copy of memchr from libc. */
295 static void *gdb_cris_memchr (const void *s, int c, int n);
296
297 /* Copy of strtol from libc. Does only support base 16. */
298 static int gdb_cris_strtol (const char *s, char **endptr, int base);
299
300 /********************** Prototypes for local functions. **********************/
301 /* Copy the content of a register image into another. The size n is
302 the size of the register image. Due to struct assignment generation of
303 memcpy in libc. */
304 static void copy_registers (registers *dptr, registers *sptr, int n);
305
306 /* Copy the stored registers from the stack. Put the register contents
307 of thread thread_id in the struct reg. */
308 static void copy_registers_from_stack (int thread_id, registers *reg);
309
310 /* Copy the registers to the stack. Put the register contents of thread
311 thread_id from struct reg to the stack. */
312 static void copy_registers_to_stack (int thread_id, registers *reg);
313
314 /* Write a value to a specified register regno in the register image
315 of the current thread. */
316 static int write_register (int regno, char *val);
317
318 /* Write a value to a specified register in the stack of a thread other
319 than the current thread. */
320 static write_stack_register (int thread_id, int regno, char *valptr);
321
322 /* Read a value from a specified register in the register image. Returns the
323 status of the read operation. The register value is returned in valptr. */
324 static int read_register (char regno, unsigned int *valptr);
325
326 /* Serial port, reads one character. ETRAX 100 specific. from debugport.c */
327 int getDebugChar (void);
328
329 /* Serial port, writes one character. ETRAX 100 specific. from debugport.c */
330 void putDebugChar (int val);
331
332 void enableDebugIRQ (void);
333
334 /* Returns the character equivalent of a nibble, bit 7, 6, 5, and 4 of a byte,
335 represented by int x. */
336 static char highhex (int x);
337
338 /* Returns the character equivalent of a nibble, bit 3, 2, 1, and 0 of a byte,
339 represented by int x. */
340 static char lowhex (int x);
341
342 /* Returns the integer equivalent of a hexadecimal character. */
343 static int hex (char ch);
344
345 /* Convert the memory, pointed to by mem into hexadecimal representation.
346 Put the result in buf, and return a pointer to the last character
347 in buf (null). */
348 static char *mem2hex (char *buf, unsigned char *mem, int count);
349
350 /* Convert the array, in hexadecimal representation, pointed to by buf into
351 binary representation. Put the result in mem, and return a pointer to
352 the character after the last byte written. */
353 static unsigned char *hex2mem (unsigned char *mem, char *buf, int count);
354
355 /* Put the content of the array, in binary representation, pointed to by buf
356 into memory pointed to by mem, and return a pointer to
357 the character after the last byte written. */
358 static unsigned char *bin2mem (unsigned char *mem, unsigned char *buf, int count);
359
360 /* Await the sequence $<data>#<checksum> and store <data> in the array buffer
361 returned. */
362 static void getpacket (char *buffer);
363
364 /* Send $<data>#<checksum> from the <data> in the array buffer. */
365 static void putpacket (char *buffer);
366
367 /* Build and send a response packet in order to inform the host the
368 stub is stopped. */
369 static void stub_is_stopped (int sigval);
370
371 /* All expected commands are sent from remote.c. Send a response according
372 to the description in remote.c. */
373 static void handle_exception (int sigval);
374
375 /* Performs a complete re-start from scratch. ETRAX specific. */
376 static void kill_restart (void);
377
378 /******************** Prototypes for global functions. ***********************/
379
380 /* The string str is prepended with the GDB printout token and sent. */
381 void putDebugString (const unsigned char *str, int length); /* used by etrax100ser.c */
382
383 /* The hook for both static (compiled) and dynamic breakpoints set by GDB.
384 ETRAX 100 specific. */
385 void handle_breakpoint (void); /* used by irq.c */
386
387 /* The hook for an interrupt generated by GDB. ETRAX 100 specific. */
388 void handle_interrupt (void); /* used by irq.c */
389
390 /* A static breakpoint to be used at startup. */
391 void breakpoint (void); /* called by init/main.c */
392
393 /* From osys_int.c, executing_task contains the number of the current
394 executing task in osys. Does not know of object-oriented threads. */
395 extern unsigned char executing_task;
396
397 /* The number of characters used for a 64 bit thread identifier. */
398 #define HEXCHARS_IN_THREAD_ID 16
399
400 /* Avoid warning as the internal_stack is not used in the C-code. */
401 #define USEDVAR(name) { if (name) { ; } }
402 #define USEDFUN(name) { void (*pf)(void) = (void *)name; USEDVAR(pf) }
403
404 /********************************** Packet I/O ******************************/
405 /* BUFMAX defines the maximum number of characters in
406 inbound/outbound buffers */
407 #define BUFMAX 512
408
409 /* Run-length encoding maximum length. Send 64 at most. */
410 #define RUNLENMAX 64
411
412 /* Definition of all valid hexadecimal characters */
413 static const char hexchars[] = "0123456789abcdef";
414
415 /* The inbound/outbound buffers used in packet I/O */
416 static char remcomInBuffer[BUFMAX];
417 static char remcomOutBuffer[BUFMAX];
418
419 /* Error and warning messages. */
420 enum error_type
421 {
422 SUCCESS, E01, E02, E03, E04, E05, E06, E07
423 };
424 static char *error_message[] =
425 {
426 "",
427 "E01 Set current or general thread - H[c,g] - internal error.",
428 "E02 Change register content - P - cannot change read-only register.",
429 "E03 Thread is not alive.", /* T, not used. */
430 "E04 The command is not supported - [s,C,S,!,R,d,r] - internal error.",
431 "E05 Change register content - P - the register is not implemented..",
432 "E06 Change memory content - M - internal error.",
433 "E07 Change register content - P - the register is not stored on the stack"
434 };
435 /********************************* Register image ****************************/
436 /* Use the order of registers as defined in "AXIS ETRAX CRIS Programmer's
437 Reference", p. 1-1, with the additional register definitions of the
438 ETRAX 100LX in cris-opc.h.
439 There are 16 general 32-bit registers, R0-R15, where R14 is the stack
440 pointer, SP, and R15 is the program counter, PC.
441 There are 16 special registers, P0-P15, where three of the unimplemented
442 registers, P0, P4 and P8, are reserved as zero-registers. A read from
443 any of these registers returns zero and a write has no effect. */
444 enum register_name
445 {
446 R0, R1, R2, R3,
447 R4, R5, R6, R7,
448 R8, R9, R10, R11,
449 R12, R13, SP, PC,
450 P0, VR, P2, P3,
451 P4, CCR, P6, MOF,
452 P8, IBR, IRP, SRP,
453 BAR, DCCR, BRP, USP
454 };
455
456 /* The register sizes of the registers in register_name. An unimplemented register
457 is designated by size 0 in this array. */
458 static int register_size[] =
459 {
460 4, 4, 4, 4,
461 4, 4, 4, 4,
462 4, 4, 4, 4,
463 4, 4, 4, 4,
464 1, 1, 0, 0,
465 2, 2, 0, 4,
466 4, 4, 4, 4,
467 4, 4, 4, 4
468 };
469
470 /* Contains the register image of the executing thread in the assembler
471 part of the code in order to avoid horrible addressing modes. */
472 static registers reg;
473
474 /* FIXME: Should this be used? Delete otherwise. */
475 /* Contains the assumed consistency state of the register image. Uses the
476 enum error_type for state information. */
477 static int consistency_status = SUCCESS;
478
479 /********************************** Handle exceptions ************************/
480 /* The variable reg contains the register image associated with the
481 current_thread_c variable. It is a complete register image created at
482 entry. The reg_g contains a register image of a task where the general
483 registers are taken from the stack and all special registers are taken
484 from the executing task. It is associated with current_thread_g and used
485 in order to provide access mainly for 'g', 'G' and 'P'.
486 */
487
488 /* Need two task id pointers in order to handle Hct and Hgt commands. */
489 static int current_thread_c = 0;
490 static int current_thread_g = 0;
491
492 /* Need two register images in order to handle Hct and Hgt commands. The
493 variable reg_g is in addition to reg above. */
494 static registers reg_g;
495
496 /********************************** Breakpoint *******************************/
497 /* Use an internal stack in the breakpoint and interrupt response routines */
498 #define INTERNAL_STACK_SIZE 1024
499 static char internal_stack[INTERNAL_STACK_SIZE];
500
501 /* Due to the breakpoint return pointer, a state variable is needed to keep
502 track of whether it is a static (compiled) or dynamic (gdb-invoked)
503 breakpoint to be handled. A static breakpoint uses the content of register
504 BRP as it is whereas a dynamic breakpoint requires subtraction with 2
505 in order to execute the instruction. The first breakpoint is static. */
506 static unsigned char is_dyn_brkp = 0;
507
508 /********************************* String library ****************************/
509 /* Single-step over library functions creates trap loops. */
510
511 /* Copy char s2[] to s1[]. */
512 static char*
513 gdb_cris_strcpy (char *s1, const char *s2)
514 {
515 char *s = s1;
516
517 for (s = s1; (*s++ = *s2++) != '\0'; )
518 ;
519 return (s1);
520 }
521
522 /* Find length of s[]. */
523 static int
524 gdb_cris_strlen (const char *s)
525 {
526 const char *sc;
527
528 for (sc = s; *sc != '\0'; sc++)
529 ;
530 return (sc - s);
531 }
532
533 /* Find first occurrence of c in s[n]. */
534 static void*
535 gdb_cris_memchr (const void *s, int c, int n)
536 {
537 const unsigned char uc = c;
538 const unsigned char *su;
539
540 for (su = s; 0 < n; ++su, --n)
541 if (*su == uc)
542 return ((void *)su);
543 return (NULL);
544 }
545 /******************************* Standard library ****************************/
546 /* Single-step over library functions creates trap loops. */
547 /* Convert string to long. */
548 static int
549 gdb_cris_strtol (const char *s, char **endptr, int base)
550 {
551 char *s1;
552 char *sd;
553 int x = 0;
554
555 for (s1 = (char*)s; (sd = gdb_cris_memchr(hexchars, *s1, base)) != NULL; ++s1)
556 x = x * base + (sd - hexchars);
557
558 if (endptr)
559 {
560 /* Unconverted suffix is stored in endptr unless endptr is NULL. */
561 *endptr = s1;
562 }
563
564 return x;
565 }
566
567 int
568 double_this(int x)
569 {
570 return 2 * x;
571 }
572
573 /********************************* Register image ****************************/
574 /* Copy the content of a register image into another. The size n is
575 the size of the register image. Due to struct assignment generation of
576 memcpy in libc. */
577 static void
578 copy_registers (registers *dptr, registers *sptr, int n)
579 {
580 unsigned char *dreg;
581 unsigned char *sreg;
582
583 for (dreg = (unsigned char*)dptr, sreg = (unsigned char*)sptr; n > 0; n--)
584 *dreg++ = *sreg++;
585 }
586
587 #ifdef PROCESS_SUPPORT
588 /* Copy the stored registers from the stack. Put the register contents
589 of thread thread_id in the struct reg. */
590 static void
591 copy_registers_from_stack (int thread_id, registers *regptr)
592 {
593 int j;
594 stack_registers *s = (stack_registers *)stack_list[thread_id];
595 unsigned int *d = (unsigned int *)regptr;
596
597 for (j = 13; j >= 0; j--)
598 *d++ = s->r[j];
599 regptr->sp = (unsigned int)stack_list[thread_id];
600 regptr->pc = s->pc;
601 regptr->dccr = s->dccr;
602 regptr->srp = s->srp;
603 }
604
605 /* Copy the registers to the stack. Put the register contents of thread
606 thread_id from struct reg to the stack. */
607 static void
608 copy_registers_to_stack (int thread_id, registers *regptr)
609 {
610 int i;
611 stack_registers *d = (stack_registers *)stack_list[thread_id];
612 unsigned int *s = (unsigned int *)regptr;
613
614 for (i = 0; i < 14; i++) {
615 d->r[i] = *s++;
616 }
617 d->pc = regptr->pc;
618 d->dccr = regptr->dccr;
619 d->srp = regptr->srp;
620 }
621 #endif
622
623 /* Write a value to a specified register in the register image of the current
624 thread. Returns status code SUCCESS, E02 or E05. */
625 static int
626 write_register (int regno, char *val)
627 {
628 int status = SUCCESS;
629 registers *current_reg = &reg;
630
631 if (regno >= R0 && regno <= PC) {
632 /* 32-bit register with simple offset. */
633 hex2mem ((unsigned char *)current_reg + regno * sizeof(unsigned int),
634 val, sizeof(unsigned int));
635 }
636 else if (regno == P0 || regno == VR || regno == P4 || regno == P8) {
637 /* Do not support read-only registers. */
638 status = E02;
639 }
640 else if (regno == CCR) {
641 /* 16 bit register with complex offset. (P4 is read-only, P6 is not implemented,
642 and P7 (MOF) is 32 bits in ETRAX 100LX. */
643 hex2mem ((unsigned char *)&(current_reg->ccr) + (regno-CCR) * sizeof(unsigned short),
644 val, sizeof(unsigned short));
645 }
646 else if (regno >= MOF && regno <= USP) {
647 /* 32 bit register with complex offset. (P8 has been taken care of.) */
648 hex2mem ((unsigned char *)&(current_reg->ibr) + (regno-IBR) * sizeof(unsigned int),
649 val, sizeof(unsigned int));
650 }
651 else {
652 /* Do not support nonexisting or unimplemented registers (P2, P3, and P6). */
653 status = E05;
654 }
655 return status;
656 }
657
658 #ifdef PROCESS_SUPPORT
659 /* Write a value to a specified register in the stack of a thread other
660 than the current thread. Returns status code SUCCESS or E07. */
661 static int
662 write_stack_register (int thread_id, int regno, char *valptr)
663 {
664 int status = SUCCESS;
665 stack_registers *d = (stack_registers *)stack_list[thread_id];
666 unsigned int val;
667
668 hex2mem ((unsigned char *)&val, valptr, sizeof(unsigned int));
669 if (regno >= R0 && regno < SP) {
670 d->r[regno] = val;
671 }
672 else if (regno == SP) {
673 stack_list[thread_id] = val;
674 }
675 else if (regno == PC) {
676 d->pc = val;
677 }
678 else if (regno == SRP) {
679 d->srp = val;
680 }
681 else if (regno == DCCR) {
682 d->dccr = val;
683 }
684 else {
685 /* Do not support registers in the current thread. */
686 status = E07;
687 }
688 return status;
689 }
690 #endif
691
692 /* Read a value from a specified register in the register image. Returns the
693 value in the register or -1 for non-implemented registers.
694 Should check consistency_status after a call which may be E05 after changes
695 in the implementation. */
696 static int
697 read_register (char regno, unsigned int *valptr)
698 {
699 registers *current_reg = &reg;
700
701 if (regno >= R0 && regno <= PC) {
702 /* 32-bit register with simple offset. */
703 *valptr = *(unsigned int *)((char *)current_reg + regno * sizeof(unsigned int));
704 return SUCCESS;
705 }
706 else if (regno == P0 || regno == VR) {
707 /* 8 bit register with complex offset. */
708 *valptr = (unsigned int)(*(unsigned char *)
709 ((char *)&(current_reg->p0) + (regno-P0) * sizeof(char)));
710 return SUCCESS;
711 }
712 else if (regno == P4 || regno == CCR) {
713 /* 16 bit register with complex offset. */
714 *valptr = (unsigned int)(*(unsigned short *)
715 ((char *)&(current_reg->p4) + (regno-P4) * sizeof(unsigned short)));
716 return SUCCESS;
717 }
718 else if (regno >= MOF && regno <= USP) {
719 /* 32 bit register with complex offset. */
720 *valptr = *(unsigned int *)((char *)&(current_reg->p8)
721 + (regno-P8) * sizeof(unsigned int));
722 return SUCCESS;
723 }
724 else {
725 /* Do not support nonexisting or unimplemented registers (P2, P3, and P6). */
726 consistency_status = E05;
727 return E05;
728 }
729 }
730
731 /********************************** Packet I/O ******************************/
732 /* Returns the character equivalent of a nibble, bit 7, 6, 5, and 4 of a byte,
733 represented by int x. */
734 static inline char
735 highhex(int x)
736 {
737 return hexchars[(x >> 4) & 0xf];
738 }
739
740 /* Returns the character equivalent of a nibble, bit 3, 2, 1, and 0 of a byte,
741 represented by int x. */
742 static inline char
743 lowhex(int x)
744 {
745 return hexchars[x & 0xf];
746 }
747
748 /* Returns the integer equivalent of a hexadecimal character. */
749 static int
750 hex (char ch)
751 {
752 if ((ch >= 'a') && (ch <= 'f'))
753 return (ch - 'a' + 10);
754 if ((ch >= '0') && (ch <= '9'))
755 return (ch - '0');
756 if ((ch >= 'A') && (ch <= 'F'))
757 return (ch - 'A' + 10);
758 return (-1);
759 }
760
761 /* Convert the memory, pointed to by mem into hexadecimal representation.
762 Put the result in buf, and return a pointer to the last character
763 in buf (null). */
764
765 static int do_printk = 0;
766
767 static char *
768 mem2hex(char *buf, unsigned char *mem, int count)
769 {
770 int i;
771 int ch;
772
773 if (mem == NULL) {
774 /* Bogus read from m0. FIXME: What constitutes a valid address? */
775 for (i = 0; i < count; i++) {
776 *buf++ = '0';
777 *buf++ = '0';
778 }
779 } else {
780 /* Valid mem address. */
781 for (i = 0; i < count; i++) {
782 ch = *mem++;
783 *buf++ = highhex (ch);
784 *buf++ = lowhex (ch);
785 }
786 }
787
788 /* Terminate properly. */
789 *buf = '\0';
790 return (buf);
791 }
792
793 /* Convert the array, in hexadecimal representation, pointed to by buf into
794 binary representation. Put the result in mem, and return a pointer to
795 the character after the last byte written. */
796 static unsigned char*
797 hex2mem (unsigned char *mem, char *buf, int count)
798 {
799 int i;
800 unsigned char ch;
801 for (i = 0; i < count; i++) {
802 ch = hex (*buf++) << 4;
803 ch = ch + hex (*buf++);
804 *mem++ = ch;
805 }
806 return (mem);
807 }
808
809 /* Put the content of the array, in binary representation, pointed to by buf
810 into memory pointed to by mem, and return a pointer to the character after
811 the last byte written.
812 Gdb will escape $, #, and the escape char (0x7d). */
813 static unsigned char*
814 bin2mem (unsigned char *mem, unsigned char *buf, int count)
815 {
816 int i;
817 unsigned char *next;
818 for (i = 0; i < count; i++) {
819 /* Check for any escaped characters. Be paranoid and
820 only unescape chars that should be escaped. */
821 if (*buf == 0x7d) {
822 next = buf + 1;
823 if (*next == 0x3 || *next == 0x4 || *next == 0x5D) /* #, $, ESC */
824 {
825 buf++;
826 *buf += 0x20;
827 }
828 }
829 *mem++ = *buf++;
830 }
831 return (mem);
832 }
833
834 /* Await the sequence $<data>#<checksum> and store <data> in the array buffer
835 returned. */
836 static void
837 getpacket (char *buffer)
838 {
839 unsigned char checksum;
840 unsigned char xmitcsum;
841 int i;
842 int count;
843 char ch;
844 do {
845 while ((ch = getDebugChar ()) != '$')
846 /* Wait for the start character $ and ignore all other characters */;
847 checksum = 0;
848 xmitcsum = -1;
849 count = 0;
850 /* Read until a # or the end of the buffer is reached */
851 while (count < BUFMAX) {
852 ch = getDebugChar ();
853 if (ch == '#')
854 break;
855 checksum = checksum + ch;
856 buffer[count] = ch;
857 count = count + 1;
858 }
859 buffer[count] = '\0';
860
861 if (ch == '#') {
862 xmitcsum = hex (getDebugChar ()) << 4;
863 xmitcsum += hex (getDebugChar ());
864 if (checksum != xmitcsum) {
865 /* Wrong checksum */
866 putDebugChar ('-');
867 }
868 else {
869 /* Correct checksum */
870 putDebugChar ('+');
871 /* If sequence characters are received, reply with them */
872 if (buffer[2] == ':') {
873 putDebugChar (buffer[0]);
874 putDebugChar (buffer[1]);
875 /* Remove the sequence characters from the buffer */
876 count = gdb_cris_strlen (buffer);
877 for (i = 3; i <= count; i++)
878 buffer[i - 3] = buffer[i];
879 }
880 }
881 }
882 } while (checksum != xmitcsum);
883 }
884
885 /* Send $<data>#<checksum> from the <data> in the array buffer. */
886
887 static void
888 putpacket(char *buffer)
889 {
890 int checksum;
891 int runlen;
892 int encode;
893
894 do {
895 char *src = buffer;
896 putDebugChar ('$');
897 checksum = 0;
898 while (*src) {
899 /* Do run length encoding */
900 putDebugChar (*src);
901 checksum += *src;
902 runlen = 0;
903 while (runlen < RUNLENMAX && *src == src[runlen]) {
904 runlen++;
905 }
906 if (runlen > 3) {
907 /* Got a useful amount */
908 putDebugChar ('*');
909 checksum += '*';
910 encode = runlen + ' ' - 4;
911 putDebugChar (encode);
912 checksum += encode;
913 src += runlen;
914 }
915 else {
916 src++;
917 }
918 }
919 putDebugChar ('#');
920 putDebugChar (highhex (checksum));
921 putDebugChar (lowhex (checksum));
922 } while(kgdb_started && (getDebugChar() != '+'));
923 }
924
925 /* The string str is prepended with the GDB printout token and sent. Required
926 in traditional implementations. */
927 void
928 putDebugString (const unsigned char *str, int length)
929 {
930 remcomOutBuffer[0] = 'O';
931 mem2hex(&remcomOutBuffer[1], (unsigned char *)str, length);
932 putpacket(remcomOutBuffer);
933 }
934
935 /********************************** Handle exceptions ************************/
936 /* Build and send a response packet in order to inform the host the
937 stub is stopped. TAAn...:r...;n...:r...;n...:r...;
938 AA = signal number
939 n... = register number (hex)
940 r... = register contents
941 n... = `thread'
942 r... = thread process ID. This is a hex integer.
943 n... = other string not starting with valid hex digit.
944 gdb should ignore this n,r pair and go on to the next.
945 This way we can extend the protocol. */
946 static void
947 stub_is_stopped(int sigval)
948 {
949 char *ptr = remcomOutBuffer;
950 int regno;
951
952 unsigned int reg_cont;
953 int status;
954
955 /* Send trap type (converted to signal) */
956
957 *ptr++ = 'T';
958 *ptr++ = highhex (sigval);
959 *ptr++ = lowhex (sigval);
960
961 /* Send register contents. We probably only need to send the
962 * PC, frame pointer and stack pointer here. Other registers will be
963 * explicitely asked for. But for now, send all.
964 */
965
966 for (regno = R0; regno <= USP; regno++) {
967 /* Store n...:r...; for the registers in the buffer. */
968
969 status = read_register (regno, &reg_cont);
970
971 if (status == SUCCESS) {
972
973 *ptr++ = highhex (regno);
974 *ptr++ = lowhex (regno);
975 *ptr++ = ':';
976
977 ptr = mem2hex(ptr, (unsigned char *)&reg_cont,
978 register_size[regno]);
979 *ptr++ = ';';
980 }
981
982 }
983
984 #ifdef PROCESS_SUPPORT
985 /* Store the registers of the executing thread. Assume that both step,
986 continue, and register content requests are with respect to this
987 thread. The executing task is from the operating system scheduler. */
988
989 current_thread_c = executing_task;
990 current_thread_g = executing_task;
991
992 /* A struct assignment translates into a libc memcpy call. Avoid
993 all libc functions in order to prevent recursive break points. */
994 copy_registers (&reg_g, &reg, sizeof(registers));
995
996 /* Store thread:r...; with the executing task TID. */
997 gdb_cris_strcpy (&remcomOutBuffer[pos], "thread:");
998 pos += gdb_cris_strlen ("thread:");
999 remcomOutBuffer[pos++] = highhex (executing_task);
1000 remcomOutBuffer[pos++] = lowhex (executing_task);
1001 gdb_cris_strcpy (&remcomOutBuffer[pos], ";");
1002 #endif
1003
1004 /* null-terminate and send it off */
1005
1006 *ptr = 0;
1007
1008 putpacket (remcomOutBuffer);
1009 }
1010
1011 /* All expected commands are sent from remote.c. Send a response according
1012 to the description in remote.c. */
1013 static void
1014 handle_exception (int sigval)
1015 {
1016 /* Avoid warning of not used. */
1017
1018 USEDFUN(handle_exception);
1019 USEDVAR(internal_stack[0]);
1020
1021 /* Send response. */
1022
1023 stub_is_stopped (sigval);
1024
1025 for (;;) {
1026 remcomOutBuffer[0] = '\0';
1027 getpacket (remcomInBuffer);
1028 switch (remcomInBuffer[0]) {
1029 case 'g':
1030 /* Read registers: g
1031 Success: Each byte of register data is described by two hex digits.
1032 Registers are in the internal order for GDB, and the bytes
1033 in a register are in the same order the machine uses.
1034 Failure: void. */
1035
1036 {
1037 #ifdef PROCESS_SUPPORT
1038 /* Use the special register content in the executing thread. */
1039 copy_registers (&reg_g, &reg, sizeof(registers));
1040 /* Replace the content available on the stack. */
1041 if (current_thread_g != executing_task) {
1042 copy_registers_from_stack (current_thread_g, &reg_g);
1043 }
1044 mem2hex ((unsigned char *)remcomOutBuffer, (unsigned char *)&reg_g, sizeof(registers));
1045 #else
1046 mem2hex(remcomOutBuffer, (char *)&reg, sizeof(registers));
1047 #endif
1048 }
1049 break;
1050
1051 case 'G':
1052 /* Write registers. GXX..XX
1053 Each byte of register data is described by two hex digits.
1054 Success: OK
1055 Failure: void. */
1056 #ifdef PROCESS_SUPPORT
1057 hex2mem ((unsigned char *)&reg_g, &remcomInBuffer[1], sizeof(registers));
1058 if (current_thread_g == executing_task) {
1059 copy_registers (&reg, &reg_g, sizeof(registers));
1060 }
1061 else {
1062 copy_registers_to_stack(current_thread_g, &reg_g);
1063 }
1064 #else
1065 hex2mem((char *)&reg, &remcomInBuffer[1], sizeof(registers));
1066 #endif
1067 gdb_cris_strcpy (remcomOutBuffer, "OK");
1068 break;
1069
1070 case 'P':
1071 /* Write register. Pn...=r...
1072 Write register n..., hex value without 0x, with value r...,
1073 which contains a hex value without 0x and two hex digits
1074 for each byte in the register (target byte order). P1f=11223344 means
1075 set register 31 to 44332211.
1076 Success: OK
1077 Failure: E02, E05 */
1078 {
1079 char *suffix;
1080 int regno = gdb_cris_strtol (&remcomInBuffer[1], &suffix, 16);
1081 int status;
1082 #ifdef PROCESS_SUPPORT
1083 if (current_thread_g != executing_task)
1084 status = write_stack_register (current_thread_g, regno, suffix+1);
1085 else
1086 #endif
1087 status = write_register (regno, suffix+1);
1088
1089 switch (status) {
1090 case E02:
1091 /* Do not support read-only registers. */
1092 gdb_cris_strcpy (remcomOutBuffer, error_message[E02]);
1093 break;
1094 case E05:
1095 /* Do not support non-existing registers. */
1096 gdb_cris_strcpy (remcomOutBuffer, error_message[E05]);
1097 break;
1098 case E07:
1099 /* Do not support non-existing registers on the stack. */
1100 gdb_cris_strcpy (remcomOutBuffer, error_message[E07]);
1101 break;
1102 default:
1103 /* Valid register number. */
1104 gdb_cris_strcpy (remcomOutBuffer, "OK");
1105 break;
1106 }
1107 }
1108 break;
1109
1110 case 'm':
1111 /* Read from memory. mAA..AA,LLLL
1112 AA..AA is the address and LLLL is the length.
1113 Success: XX..XX is the memory content. Can be fewer bytes than
1114 requested if only part of the data may be read. m6000120a,6c means
1115 retrieve 108 byte from base address 6000120a.
1116 Failure: void. */
1117 {
1118 char *suffix;
1119 unsigned char *addr = (unsigned char *)gdb_cris_strtol(&remcomInBuffer[1],
1120 &suffix, 16); int length = gdb_cris_strtol(suffix+1, 0, 16);
1121
1122 mem2hex(remcomOutBuffer, addr, length);
1123 }
1124 break;
1125
1126 case 'X':
1127 /* Write to memory. XAA..AA,LLLL:XX..XX
1128 AA..AA is the start address, LLLL is the number of bytes, and
1129 XX..XX is the binary data.
1130 Success: OK
1131 Failure: void. */
1132 case 'M':
1133 /* Write to memory. MAA..AA,LLLL:XX..XX
1134 AA..AA is the start address, LLLL is the number of bytes, and
1135 XX..XX is the hexadecimal data.
1136 Success: OK
1137 Failure: void. */
1138 {
1139 char *lenptr;
1140 char *dataptr;
1141 unsigned char *addr = (unsigned char *)gdb_cris_strtol(&remcomInBuffer[1],
1142 &lenptr, 16);
1143 int length = gdb_cris_strtol(lenptr+1, &dataptr, 16);
1144 if (*lenptr == ',' && *dataptr == ':') {
1145 if (remcomInBuffer[0] == 'M') {
1146 hex2mem(addr, dataptr + 1, length);
1147 }
1148 else /* X */ {
1149 bin2mem(addr, dataptr + 1, length);
1150 }
1151 gdb_cris_strcpy (remcomOutBuffer, "OK");
1152 }
1153 else {
1154 gdb_cris_strcpy (remcomOutBuffer, error_message[E06]);
1155 }
1156 }
1157 break;
1158
1159 case 'c':
1160 /* Continue execution. cAA..AA
1161 AA..AA is the address where execution is resumed. If AA..AA is
1162 omitted, resume at the present address.
1163 Success: return to the executing thread.
1164 Failure: will never know. */
1165 if (remcomInBuffer[1] != '\0') {
1166 reg.pc = gdb_cris_strtol (&remcomInBuffer[1], 0, 16);
1167 }
1168 enableDebugIRQ();
1169 return;
1170
1171 case 's':
1172 /* Step. sAA..AA
1173 AA..AA is the address where execution is resumed. If AA..AA is
1174 omitted, resume at the present address. Success: return to the
1175 executing thread. Failure: will never know.
1176
1177 Should never be invoked. The single-step is implemented on
1178 the host side. If ever invoked, it is an internal error E04. */
1179 gdb_cris_strcpy (remcomOutBuffer, error_message[E04]);
1180 putpacket (remcomOutBuffer);
1181 return;
1182
1183 case '?':
1184 /* The last signal which caused a stop. ?
1185 Success: SAA, where AA is the signal number.
1186 Failure: void. */
1187 remcomOutBuffer[0] = 'S';
1188 remcomOutBuffer[1] = highhex (sigval);
1189 remcomOutBuffer[2] = lowhex (sigval);
1190 remcomOutBuffer[3] = 0;
1191 break;
1192
1193 case 'D':
1194 /* Detach from host. D
1195 Success: OK, and return to the executing thread.
1196 Failure: will never know */
1197 putpacket ("OK");
1198 return;
1199
1200 case 'k':
1201 case 'r':
1202 /* kill request or reset request.
1203 Success: restart of target.
1204 Failure: will never know. */
1205 kill_restart ();
1206 break;
1207
1208 case 'C':
1209 case 'S':
1210 case '!':
1211 case 'R':
1212 case 'd':
1213 /* Continue with signal sig. Csig;AA..AA
1214 Step with signal sig. Ssig;AA..AA
1215 Use the extended remote protocol. !
1216 Restart the target system. R0
1217 Toggle debug flag. d
1218 Search backwards. tAA:PP,MM
1219 Not supported: E04 */
1220 gdb_cris_strcpy (remcomOutBuffer, error_message[E04]);
1221 break;
1222 #ifdef PROCESS_SUPPORT
1223
1224 case 'T':
1225 /* Thread alive. TXX
1226 Is thread XX alive?
1227 Success: OK, thread XX is alive.
1228 Failure: E03, thread XX is dead. */
1229 {
1230 int thread_id = (int)gdb_cris_strtol (&remcomInBuffer[1], 0, 16);
1231 /* Cannot tell whether it is alive or not. */
1232 if (thread_id >= 0 && thread_id < number_of_tasks)
1233 gdb_cris_strcpy (remcomOutBuffer, "OK");
1234 }
1235 break;
1236
1237 case 'H':
1238 /* Set thread for subsequent operations: Hct
1239 c = 'c' for thread used in step and continue;
1240 t can be -1 for all threads.
1241 c = 'g' for thread used in other operations.
1242 t = 0 means pick any thread.
1243 Success: OK
1244 Failure: E01 */
1245 {
1246 int thread_id = gdb_cris_strtol (&remcomInBuffer[2], 0, 16);
1247 if (remcomInBuffer[1] == 'c') {
1248 /* c = 'c' for thread used in step and continue */
1249 /* Do not change current_thread_c here. It would create a mess in
1250 the scheduler. */
1251 gdb_cris_strcpy (remcomOutBuffer, "OK");
1252 }
1253 else if (remcomInBuffer[1] == 'g') {
1254 /* c = 'g' for thread used in other operations.
1255 t = 0 means pick any thread. Impossible since the scheduler does
1256 not allow that. */
1257 if (thread_id >= 0 && thread_id < number_of_tasks) {
1258 current_thread_g = thread_id;
1259 gdb_cris_strcpy (remcomOutBuffer, "OK");
1260 }
1261 else {
1262 /* Not expected - send an error message. */
1263 gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
1264 }
1265 }
1266 else {
1267 /* Not expected - send an error message. */
1268 gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
1269 }
1270 }
1271 break;
1272
1273 case 'q':
1274 case 'Q':
1275 /* Query of general interest. qXXXX
1276 Set general value XXXX. QXXXX=yyyy */
1277 {
1278 int pos;
1279 int nextpos;
1280 int thread_id;
1281
1282 switch (remcomInBuffer[1]) {
1283 case 'C':
1284 /* Identify the remote current thread. */
1285 gdb_cris_strcpy (&remcomOutBuffer[0], "QC");
1286 remcomOutBuffer[2] = highhex (current_thread_c);
1287 remcomOutBuffer[3] = lowhex (current_thread_c);
1288 remcomOutBuffer[4] = '\0';
1289 break;
1290 case 'L':
1291 gdb_cris_strcpy (&remcomOutBuffer[0], "QM");
1292 /* Reply with number of threads. */
1293 if (os_is_started()) {
1294 remcomOutBuffer[2] = highhex (number_of_tasks);
1295 remcomOutBuffer[3] = lowhex (number_of_tasks);
1296 }
1297 else {
1298 remcomOutBuffer[2] = highhex (0);
1299 remcomOutBuffer[3] = lowhex (1);
1300 }
1301 /* Done with the reply. */
1302 remcomOutBuffer[4] = lowhex (1);
1303 pos = 5;
1304 /* Expects the argument thread id. */
1305 for (; pos < (5 + HEXCHARS_IN_THREAD_ID); pos++)
1306 remcomOutBuffer[pos] = remcomInBuffer[pos];
1307 /* Reply with the thread identifiers. */
1308 if (os_is_started()) {
1309 /* Store the thread identifiers of all tasks. */
1310 for (thread_id = 0; thread_id < number_of_tasks; thread_id++) {
1311 nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
1312 for (; pos < nextpos; pos ++)
1313 remcomOutBuffer[pos] = lowhex (0);
1314 remcomOutBuffer[pos++] = lowhex (thread_id);
1315 }
1316 }
1317 else {
1318 /* Store the thread identifier of the boot task. */
1319 nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
1320 for (; pos < nextpos; pos ++)
1321 remcomOutBuffer[pos] = lowhex (0);
1322 remcomOutBuffer[pos++] = lowhex (current_thread_c);
1323 }
1324 remcomOutBuffer[pos] = '\0';
1325 break;
1326 default:
1327 /* Not supported: "" */
1328 /* Request information about section offsets: qOffsets. */
1329 remcomOutBuffer[0] = 0;
1330 break;
1331 }
1332 }
1333 break;
1334 #endif /* PROCESS_SUPPORT */
1335
1336 default:
1337 /* The stub should ignore other request and send an empty
1338 response ($#<checksum>). This way we can extend the protocol and GDB
1339 can tell whether the stub it is talking to uses the old or the new. */
1340 remcomOutBuffer[0] = 0;
1341 break;
1342 }
1343 putpacket(remcomOutBuffer);
1344 }
1345 }
1346
1347 /* The jump is to the address 0x00000002. Performs a complete re-start
1348 from scratch. */
1349 static void
1350 kill_restart ()
1351 {
1352 __asm__ volatile ("jump 2");
1353 }
1354
1355 /********************************** Breakpoint *******************************/
1356 /* The hook for both a static (compiled) and a dynamic breakpoint set by GDB.
1357 An internal stack is used by the stub. The register image of the caller is
1358 stored in the structure register_image.
1359 Interactive communication with the host is handled by handle_exception and
1360 finally the register image is restored. */
1361
1362 void kgdb_handle_breakpoint(void);
1363
1364 asm ("
1365 .global kgdb_handle_breakpoint
1366 kgdb_handle_breakpoint:
1367 ;;
1368 ;; Response to the break-instruction
1369 ;;
1370 ;; Create a register image of the caller
1371 ;;
1372 move $dccr,[reg+0x5E] ; Save the flags in DCCR before disable interrupts
1373 di ; Disable interrupts
1374 move.d $r0,[reg] ; Save R0
1375 move.d $r1,[reg+0x04] ; Save R1
1376 move.d $r2,[reg+0x08] ; Save R2
1377 move.d $r3,[reg+0x0C] ; Save R3
1378 move.d $r4,[reg+0x10] ; Save R4
1379 move.d $r5,[reg+0x14] ; Save R5
1380 move.d $r6,[reg+0x18] ; Save R6
1381 move.d $r7,[reg+0x1C] ; Save R7
1382 move.d $r8,[reg+0x20] ; Save R8
1383 move.d $r9,[reg+0x24] ; Save R9
1384 move.d $r10,[reg+0x28] ; Save R10
1385 move.d $r11,[reg+0x2C] ; Save R11
1386 move.d $r12,[reg+0x30] ; Save R12
1387 move.d $r13,[reg+0x34] ; Save R13
1388 move.d $sp,[reg+0x38] ; Save SP (R14)
1389 ;; Due to the old assembler-versions BRP might not be recognized
1390 .word 0xE670 ; move brp,$r0
1391 subq 2,$r0 ; Set to address of previous instruction.
1392 move.d $r0,[reg+0x3c] ; Save the address in PC (R15)
1393 clear.b [reg+0x40] ; Clear P0
1394 move $vr,[reg+0x41] ; Save special register P1
1395 clear.w [reg+0x42] ; Clear P4
1396 move $ccr,[reg+0x44] ; Save special register CCR
1397 move $mof,[reg+0x46] ; P7
1398 clear.d [reg+0x4A] ; Clear P8
1399 move $ibr,[reg+0x4E] ; P9,
1400 move $irp,[reg+0x52] ; P10,
1401 move $srp,[reg+0x56] ; P11,
1402 move $dtp0,[reg+0x5A] ; P12, register BAR, assembler might not know BAR
1403 ; P13, register DCCR already saved
1404 ;; Due to the old assembler-versions BRP might not be recognized
1405 .word 0xE670 ; move brp,r0
1406 ;; Static (compiled) breakpoints must return to the next instruction in order
1407 ;; to avoid infinite loops. Dynamic (gdb-invoked) must restore the instruction
1408 ;; in order to execute it when execution is continued.
1409 test.b [is_dyn_brkp] ; Is this a dynamic breakpoint?
1410 beq is_static ; No, a static breakpoint
1411 nop
1412 subq 2,$r0 ; rerun the instruction the break replaced
1413 is_static:
1414 moveq 1,$r1
1415 move.b $r1,[is_dyn_brkp] ; Set the state variable to dynamic breakpoint
1416 move.d $r0,[reg+0x62] ; Save the return address in BRP
1417 move $usp,[reg+0x66] ; USP
1418 ;;
1419 ;; Handle the communication
1420 ;;
1421 move.d internal_stack+1020,$sp ; Use the internal stack which grows upward
1422 moveq 5,$r10 ; SIGTRAP
1423 jsr handle_exception ; Interactive routine
1424 ;;
1425 ;; Return to the caller
1426 ;;
1427 move.d [reg],$r0 ; Restore R0
1428 move.d [reg+0x04],$r1 ; Restore R1
1429 move.d [reg+0x08],$r2 ; Restore R2
1430 move.d [reg+0x0C],$r3 ; Restore R3
1431 move.d [reg+0x10],$r4 ; Restore R4
1432 move.d [reg+0x14],$r5 ; Restore R5
1433 move.d [reg+0x18],$r6 ; Restore R6
1434 move.d [reg+0x1C],$r7 ; Restore R7
1435 move.d [reg+0x20],$r8 ; Restore R8
1436 move.d [reg+0x24],$r9 ; Restore R9
1437 move.d [reg+0x28],$r10 ; Restore R10
1438 move.d [reg+0x2C],$r11 ; Restore R11
1439 move.d [reg+0x30],$r12 ; Restore R12
1440 move.d [reg+0x34],$r13 ; Restore R13
1441 ;;
1442 ;; FIXME: Which registers should be restored?
1443 ;;
1444 move.d [reg+0x38],$sp ; Restore SP (R14)
1445 move [reg+0x56],$srp ; Restore the subroutine return pointer.
1446 move [reg+0x5E],$dccr ; Restore DCCR
1447 move [reg+0x66],$usp ; Restore USP
1448 jump [reg+0x62] ; A jump to the content in register BRP works.
1449 nop ;
1450 ");
1451
1452 /* The hook for an interrupt generated by GDB. An internal stack is used
1453 by the stub. The register image of the caller is stored in the structure
1454 register_image. Interactive communication with the host is handled by
1455 handle_exception and finally the register image is restored. Due to the
1456 old assembler which does not recognise the break instruction and the
1457 breakpoint return pointer hex-code is used. */
1458
1459 void kgdb_handle_serial(void);
1460
1461 asm ("
1462 .global kgdb_handle_serial
1463 kgdb_handle_serial:
1464 ;;
1465 ;; Response to a serial interrupt
1466 ;;
1467
1468 move $dccr,[reg+0x5E] ; Save the flags in DCCR
1469 di ; Disable interrupts
1470 move.d $r0,[reg] ; Save R0
1471 move.d $r1,[reg+0x04] ; Save R1
1472 move.d $r2,[reg+0x08] ; Save R2
1473 move.d $r3,[reg+0x0C] ; Save R3
1474 move.d $r4,[reg+0x10] ; Save R4
1475 move.d $r5,[reg+0x14] ; Save R5
1476 move.d $r6,[reg+0x18] ; Save R6
1477 move.d $r7,[reg+0x1C] ; Save R7
1478 move.d $r8,[reg+0x20] ; Save R8
1479 move.d $r9,[reg+0x24] ; Save R9
1480 move.d $r10,[reg+0x28] ; Save R10
1481 move.d $r11,[reg+0x2C] ; Save R11
1482 move.d $r12,[reg+0x30] ; Save R12
1483 move.d $r13,[reg+0x34] ; Save R13
1484 move.d $sp,[reg+0x38] ; Save SP (R14)
1485 move $irp,[reg+0x3c] ; Save the address in PC (R15)
1486 clear.b [reg+0x40] ; Clear P0
1487 move $vr,[reg+0x41] ; Save special register P1,
1488 clear.w [reg+0x42] ; Clear P4
1489 move $ccr,[reg+0x44] ; Save special register CCR
1490 move $mof,[reg+0x46] ; P7
1491 clear.d [reg+0x4A] ; Clear P8
1492 move $ibr,[reg+0x4E] ; P9,
1493 move $irp,[reg+0x52] ; P10,
1494 move $srp,[reg+0x56] ; P11,
1495 move $dtp0,[reg+0x5A] ; P12, register BAR, assembler might not know BAR
1496 ; P13, register DCCR already saved
1497 ;; Due to the old assembler-versions BRP might not be recognized
1498 .word 0xE670 ; move brp,r0
1499 move.d $r0,[reg+0x62] ; Save the return address in BRP
1500 move $usp,[reg+0x66] ; USP
1501
1502 ;; get the serial character (from debugport.c) and check if it is a ctrl-c
1503
1504 jsr getDebugChar
1505 cmp.b 3, $r10
1506 bne goback
1507 nop
1508
1509 ;;
1510 ;; Handle the communication
1511 ;;
1512 move.d internal_stack+1020,$sp ; Use the internal stack
1513 moveq 2,$r10 ; SIGINT
1514 jsr handle_exception ; Interactive routine
1515
1516 goback:
1517 ;;
1518 ;; Return to the caller
1519 ;;
1520 move.d [reg],$r0 ; Restore R0
1521 move.d [reg+0x04],$r1 ; Restore R1
1522 move.d [reg+0x08],$r2 ; Restore R2
1523 move.d [reg+0x0C],$r3 ; Restore R3
1524 move.d [reg+0x10],$r4 ; Restore R4
1525 move.d [reg+0x14],$r5 ; Restore R5
1526 move.d [reg+0x18],$r6 ; Restore R6
1527 move.d [reg+0x1C],$r7 ; Restore R7
1528 move.d [reg+0x20],$r8 ; Restore R8
1529 move.d [reg+0x24],$r9 ; Restore R9
1530 move.d [reg+0x28],$r10 ; Restore R10
1531 move.d [reg+0x2C],$r11 ; Restore R11
1532 move.d [reg+0x30],$r12 ; Restore R12
1533 move.d [reg+0x34],$r13 ; Restore R13
1534 ;;
1535 ;; FIXME: Which registers should be restored?
1536 ;;
1537 move.d [reg+0x38],$sp ; Restore SP (R14)
1538 move [reg+0x56],$srp ; Restore the subroutine return pointer.
1539 move [reg+0x5E],$dccr ; Restore DCCR
1540 move [reg+0x66],$usp ; Restore USP
1541 reti ; Return from the interrupt routine
1542 nop
1543 ");
1544
1545 /* Use this static breakpoint in the start-up only. */
1546
1547 void
1548 breakpoint(void)
1549 {
1550 kgdb_started = 1;
1551 is_dyn_brkp = 0; /* This is a static, not a dynamic breakpoint. */
1552 __asm__ volatile ("break 8"); /* Jump to handle_breakpoint. */
1553 }
1554
1555 /* initialize kgdb. doesn't break into the debugger, but sets up irq and ports */
1556
1557 void
1558 kgdb_init(void)
1559 {
1560 /* could initialize debug port as well but it's done in head.S already... */
1561
1562 /* breakpoint handler is now set in irq.c */
1563 set_int_vector(8, kgdb_handle_serial);
1564
1565 enableDebugIRQ();
1566 }
1567
1568 /****************************** End of file **********************************/
kernel-based virtual machine