1 /* MN10300 GDB stub
2 *
3 * Originally written by Glenn Engel, Lake Stevens Instrument Division
4 *
5 * Contributed by HP Systems
6 *
7 * Modified for SPARC by Stu Grossman, Cygnus Support.
8 *
9 * Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
10 * Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
11 *
12 * Copyright (C) 1995 Andreas Busse
13 *
14 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
15 * Modified for Linux/mn10300 by David Howells <dhowells@redhat.com>
16 */
17
18 /*
19 * To enable debugger support, two things need to happen. One, a
20 * call to set_debug_traps() is necessary in order to allow any breakpoints
21 * or error conditions to be properly intercepted and reported to gdb.
22 * Two, a breakpoint needs to be generated to begin communication. This
23 * is most easily accomplished by a call to breakpoint(). Breakpoint()
24 * simulates a breakpoint by executing a BREAK instruction.
25 *
26 *
27 * The following gdb commands are supported:
28 *
29 * command function Return value
30 *
31 * g return the value of the CPU registers hex data or ENN
32 * G set the value of the CPU registers OK or ENN
33 *
34 * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
35 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
36 *
37 * c Resume at current address SNN ( signal NN)
38 * cAA..AA Continue at address AA..AA SNN
39 *
40 * s Step one instruction SNN
41 * sAA..AA Step one instruction from AA..AA SNN
42 *
43 * k kill
44 *
45 * ? What was the last sigval ? SNN (signal NN)
46 *
47 * bBB..BB Set baud rate to BB..BB OK or BNN, then sets
48 * baud rate
49 *
50 * All commands and responses are sent with a packet which includes a
51 * checksum. A packet consists of
52 *
53 * $<packet info>#<checksum>.
54 *
55 * where
56 * <packet info> :: <characters representing the command or response>
57 * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>>
58 *
59 * When a packet is received, it is first acknowledged with either '+' or '-'.
60 * '+' indicates a successful transfer. '-' indicates a failed transfer.
61 *
62 * Example:
63 *
64 * Host: Reply:
65 * $m0,10#2a +$00010203040506070809101112131415#42
66 *
67 *
68 * ==============
69 * MORE EXAMPLES:
70 * ==============
71 *
72 * For reference -- the following are the steps that one
73 * company took (RidgeRun Inc) to get remote gdb debugging
74 * going. In this scenario the host machine was a PC and the
75 * target platform was a Galileo EVB64120A MIPS evaluation
76 * board.
77 *
78 * Step 1:
79 * First download gdb-5.0.tar.gz from the internet.
80 * and then build/install the package.
81 *
82 * Example:
83 * $ tar zxf gdb-5.0.tar.gz
84 * $ cd gdb-5.0
85 * $ ./configure --target=am33_2.0-linux-gnu
86 * $ make
87 * $ install
88 * am33_2.0-linux-gnu-gdb
89 *
90 * Step 2:
91 * Configure linux for remote debugging and build it.
92 *
93 * Example:
94 * $ cd ~/linux
95 * $ make menuconfig <go to "Kernel Hacking" and turn on remote debugging>
96 * $ make dep; make vmlinux
97 *
98 * Step 3:
99 * Download the kernel to the remote target and start
100 * the kernel running. It will promptly halt and wait
101 * for the host gdb session to connect. It does this
102 * since the "Kernel Hacking" option has defined
103 * CONFIG_REMOTE_DEBUG which in turn enables your calls
104 * to:
105 * set_debug_traps();
106 * breakpoint();
107 *
108 * Step 4:
109 * Start the gdb session on the host.
110 *
111 * Example:
112 * $ am33_2.0-linux-gnu-gdb vmlinux
113 * (gdb) set remotebaud 115200
114 * (gdb) target remote /dev/ttyS1
115 * ...at this point you are connected to
116 * the remote target and can use gdb
117 * in the normal fasion. Setting
118 * breakpoints, single stepping,
119 * printing variables, etc.
120 *
121 */
122
123 #include <linux/string.h>
124 #include <linux/kernel.h>
125 #include <linux/signal.h>
126 #include <linux/sched.h>
127 #include <linux/mm.h>
128 #include <linux/console.h>
129 #include <linux/init.h>
130 #include <linux/bug.h>
131
132 #include <asm/pgtable.h>
133 #include <asm/system.h>
134 #include <asm/gdb-stub.h>
135 #include <asm/exceptions.h>
136 #include <asm/cacheflush.h>
137 #include <asm/serial-regs.h>
138 #include <asm/busctl-regs.h>
139 #include <asm/unit/leds.h>
140 #include <asm/unit/serial.h>
141
142 /* define to use F7F7 rather than FF which is subverted by JTAG debugger */
143 #undef GDBSTUB_USE_F7F7_AS_BREAKPOINT
144
145 /*
146 * BUFMAX defines the maximum number of characters in inbound/outbound buffers
147 * at least NUMREGBYTES*2 are needed for register packets
148 */
149 #define BUFMAX 2048
150
151 static const char gdbstub_banner[] =
152 "Linux/MN10300 GDB Stub (c) RedHat 2007\n";
153
154 u8 gdbstub_rx_buffer[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
155 u32 gdbstub_rx_inp;
156 u32 gdbstub_rx_outp;
157 u8 gdbstub_busy;
158 u8 gdbstub_rx_overflow;
159 u8 gdbstub_rx_unget;
160
161 static u8 gdbstub_flush_caches;
162 static char input_buffer[BUFMAX];
163 static char output_buffer[BUFMAX];
164 static char trans_buffer[BUFMAX];
165
166 struct gdbstub_bkpt {
167 u8 *addr; /* address of breakpoint */
168 u8 len; /* size of breakpoint */
169 u8 origbytes[7]; /* original bytes */
170 };
171
172 static struct gdbstub_bkpt gdbstub_bkpts[256];
173
174 /*
175 * local prototypes
176 */
177 static void getpacket(char *buffer);
178 static int putpacket(char *buffer);
179 static int computeSignal(enum exception_code excep);
180 static int hex(unsigned char ch);
181 static int hexToInt(char **ptr, int *intValue);
182 static unsigned char *mem2hex(const void *mem, char *buf, int count,
183 int may_fault);
184 static const char *hex2mem(const char *buf, void *_mem, int count,
185 int may_fault);
186
187 /*
188 * Convert ch from a hex digit to an int
189 */
hex(unsigned char ch)190 static int hex(unsigned char ch)
191 {
192 if (ch >= 'a' && ch <= 'f')
193 return ch - 'a' + 10;
194 if (ch >= '0' && ch <= '9')
195 return ch - '0';
196 if (ch >= 'A' && ch <= 'F')
197 return ch - 'A' + 10;
198 return -1;
199 }
200
201 #ifdef CONFIG_GDBSTUB_DEBUGGING
202
debug_to_serial(const char * p,int n)203 void debug_to_serial(const char *p, int n)
204 {
205 __debug_to_serial(p, n);
206 /* gdbstub_console_write(NULL, p, n); */
207 }
208
gdbstub_printk(const char * fmt,...)209 void gdbstub_printk(const char *fmt, ...)
210 {
211 va_list args;
212 int len;
213
214 /* Emit the output into the temporary buffer */
215 va_start(args, fmt);
216 len = vsnprintf(trans_buffer, sizeof(trans_buffer), fmt, args);
217 va_end(args);
218 debug_to_serial(trans_buffer, len);
219 }
220
221 #endif
222
gdbstub_strcpy(char * dst,const char * src)223 static inline char *gdbstub_strcpy(char *dst, const char *src)
224 {
225 int loop = 0;
226 while ((dst[loop] = src[loop]))
227 loop++;
228 return dst;
229 }
230
231 /*
232 * scan for the sequence $<data>#<checksum>
233 */
getpacket(char * buffer)234 static void getpacket(char *buffer)
235 {
236 unsigned char checksum;
237 unsigned char xmitcsum;
238 unsigned char ch;
239 int count, i, ret, error;
240
241 for (;;) {
242 /*
243 * wait around for the start character,
244 * ignore all other characters
245 */
246 do {
247 gdbstub_io_rx_char(&ch, 0);
248 } while (ch != '$');
249
250 checksum = 0;
251 xmitcsum = -1;
252 count = 0;
253 error = 0;
254
255 /*
256 * now, read until a # or end of buffer is found
257 */
258 while (count < BUFMAX) {
259 ret = gdbstub_io_rx_char(&ch, 0);
260 if (ret < 0)
261 error = ret;
262
263 if (ch == '#')
264 break;
265 checksum += ch;
266 buffer[count] = ch;
267 count++;
268 }
269
270 if (error == -EIO) {
271 gdbstub_proto("### GDB Rx Error - Skipping packet"
272 " ###\n");
273 gdbstub_proto("### GDB Tx NAK\n");
274 gdbstub_io_tx_char('-');
275 continue;
276 }
277
278 if (count >= BUFMAX || error)
279 continue;
280
281 buffer[count] = 0;
282
283 /* read the checksum */
284 ret = gdbstub_io_rx_char(&ch, 0);
285 if (ret < 0)
286 error = ret;
287 xmitcsum = hex(ch) << 4;
288
289 ret = gdbstub_io_rx_char(&ch, 0);
290 if (ret < 0)
291 error = ret;
292 xmitcsum |= hex(ch);
293
294 if (error) {
295 if (error == -EIO)
296 gdbstub_io("### GDB Rx Error -"
297 " Skipping packet\n");
298 gdbstub_io("### GDB Tx NAK\n");
299 gdbstub_io_tx_char('-');
300 continue;
301 }
302
303 /* check the checksum */
304 if (checksum != xmitcsum) {
305 gdbstub_io("### GDB Tx NAK\n");
306 gdbstub_io_tx_char('-'); /* failed checksum */
307 continue;
308 }
309
310 gdbstub_proto("### GDB Rx '$%s#%02x' ###\n", buffer, checksum);
311 gdbstub_io("### GDB Tx ACK\n");
312 gdbstub_io_tx_char('+'); /* successful transfer */
313
314 /*
315 * if a sequence char is present,
316 * reply the sequence ID
317 */
318 if (buffer[2] == ':') {
319 gdbstub_io_tx_char(buffer[0]);
320 gdbstub_io_tx_char(buffer[1]);
321
322 /*
323 * remove sequence chars from buffer
324 */
325 count = 0;
326 while (buffer[count])
327 count++;
328 for (i = 3; i <= count; i++)
329 buffer[i - 3] = buffer[i];
330 }
331
332 break;
333 }
334 }
335
336 /*
337 * send the packet in buffer.
338 * - return 0 if successfully ACK'd
339 * - return 1 if abandoned due to new incoming packet
340 */
putpacket(char * buffer)341 static int putpacket(char *buffer)
342 {
343 unsigned char checksum;
344 unsigned char ch;
345 int count;
346
347 /*
348 * $<packet info>#<checksum>.
349 */
350 gdbstub_proto("### GDB Tx $'%s'#?? ###\n", buffer);
351
352 do {
353 gdbstub_io_tx_char('$');
354 checksum = 0;
355 count = 0;
356
357 while ((ch = buffer[count]) != 0) {
358 gdbstub_io_tx_char(ch);
359 checksum += ch;
360 count += 1;
361 }
362
363 gdbstub_io_tx_char('#');
364 gdbstub_io_tx_char(hex_asc_hi(checksum));
365 gdbstub_io_tx_char(hex_asc_lo(checksum));
366
367 } while (gdbstub_io_rx_char(&ch, 0),
368 ch == '-' && (gdbstub_io("### GDB Rx NAK\n"), 0),
369 ch != '-' && ch != '+' &&
370 (gdbstub_io("### GDB Rx ??? %02x\n", ch), 0),
371 ch != '+' && ch != '$');
372
373 if (ch == '+') {
374 gdbstub_io("### GDB Rx ACK\n");
375 return 0;
376 }
377
378 gdbstub_io("### GDB Tx Abandoned\n");
379 gdbstub_rx_unget = ch;
380 return 1;
381 }
382
383 /*
384 * While we find nice hex chars, build an int.
385 * Return number of chars processed.
386 */
hexToInt(char ** ptr,int * intValue)387 static int hexToInt(char **ptr, int *intValue)
388 {
389 int numChars = 0;
390 int hexValue;
391
392 *intValue = 0;
393
394 while (**ptr) {
395 hexValue = hex(**ptr);
396 if (hexValue < 0)
397 break;
398
399 *intValue = (*intValue << 4) | hexValue;
400 numChars++;
401
402 (*ptr)++;
403 }
404
405 return (numChars);
406 }
407
408 /*
409 * We single-step by setting breakpoints. When an exception
410 * is handled, we need to restore the instructions hoisted
411 * when the breakpoints were set.
412 *
413 * This is where we save the original instructions.
414 */
415 static struct gdb_bp_save {
416 u8 *addr;
417 u8 opcode[2];
418 } step_bp[2];
419
420 static const unsigned char gdbstub_insn_sizes[256] =
421 {
422 /* 1 2 3 4 5 6 7 8 9 a b c d e f */
423 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
424 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
425 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
426 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
427 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
428 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
429 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
430 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
431 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
432 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
433 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
434 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
435 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
436 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
437 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
438 0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
439 };
440
__gdbstub_mark_bp(u8 * addr,int ix)441 static int __gdbstub_mark_bp(u8 *addr, int ix)
442 {
443 if (addr < (u8 *) 0x70000000UL)
444 return 0;
445 /* 70000000-7fffffff: vmalloc area */
446 if (addr < (u8 *) 0x80000000UL)
447 goto okay;
448 if (addr < (u8 *) 0x8c000000UL)
449 return 0;
450 /* 8c000000-93ffffff: SRAM, SDRAM */
451 if (addr < (u8 *) 0x94000000UL)
452 goto okay;
453 return 0;
454
455 okay:
456 if (gdbstub_read_byte(addr + 0, &step_bp[ix].opcode[0]) < 0 ||
457 gdbstub_read_byte(addr + 1, &step_bp[ix].opcode[1]) < 0)
458 return 0;
459
460 step_bp[ix].addr = addr;
461 return 1;
462 }
463
__gdbstub_restore_bp(void)464 static inline void __gdbstub_restore_bp(void)
465 {
466 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
467 if (step_bp[0].addr) {
468 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
469 gdbstub_write_byte(step_bp[0].opcode[1], step_bp[0].addr + 1);
470 }
471 if (step_bp[1].addr) {
472 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
473 gdbstub_write_byte(step_bp[1].opcode[1], step_bp[1].addr + 1);
474 }
475 #else
476 if (step_bp[0].addr)
477 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
478 if (step_bp[1].addr)
479 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
480 #endif
481
482 gdbstub_flush_caches = 1;
483
484 step_bp[0].addr = NULL;
485 step_bp[0].opcode[0] = 0;
486 step_bp[0].opcode[1] = 0;
487 step_bp[1].addr = NULL;
488 step_bp[1].opcode[0] = 0;
489 step_bp[1].opcode[1] = 0;
490 }
491
492 /*
493 * emulate single stepping by means of breakpoint instructions
494 */
gdbstub_single_step(struct pt_regs * regs)495 static int gdbstub_single_step(struct pt_regs *regs)
496 {
497 unsigned size;
498 uint32_t x;
499 uint8_t cur, *pc, *sp;
500
501 step_bp[0].addr = NULL;
502 step_bp[0].opcode[0] = 0;
503 step_bp[0].opcode[1] = 0;
504 step_bp[1].addr = NULL;
505 step_bp[1].opcode[0] = 0;
506 step_bp[1].opcode[1] = 0;
507 x = 0;
508
509 pc = (u8 *) regs->pc;
510 sp = (u8 *) (regs + 1);
511 if (gdbstub_read_byte(pc, &cur) < 0)
512 return -EFAULT;
513
514 gdbstub_bkpt("Single Step from %p { %02x }\n", pc, cur);
515
516 gdbstub_flush_caches = 1;
517
518 size = gdbstub_insn_sizes[cur];
519 if (size > 0) {
520 if (!__gdbstub_mark_bp(pc + size, 0))
521 goto fault;
522 } else {
523 switch (cur) {
524 /* Bxx (d8,PC) */
525 case 0xc0 ... 0xca:
526 if (gdbstub_read_byte(pc + 1, (u8 *) &x) < 0)
527 goto fault;
528 if (!__gdbstub_mark_bp(pc + 2, 0))
529 goto fault;
530 if ((x < 0 || x > 2) &&
531 !__gdbstub_mark_bp(pc + (s8) x, 1))
532 goto fault;
533 break;
534
535 /* LXX (d8,PC) */
536 case 0xd0 ... 0xda:
537 if (!__gdbstub_mark_bp(pc + 1, 0))
538 goto fault;
539 if (regs->pc != regs->lar &&
540 !__gdbstub_mark_bp((u8 *) regs->lar, 1))
541 goto fault;
542 break;
543
544 /* SETLB - loads the next for bytes into the LIR
545 * register */
546 case 0xdb:
547 if (!__gdbstub_mark_bp(pc + 1, 0))
548 goto fault;
549 break;
550
551 /* JMP (d16,PC) or CALL (d16,PC) */
552 case 0xcc:
553 case 0xcd:
554 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
555 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0)
556 goto fault;
557 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
558 goto fault;
559 break;
560
561 /* JMP (d32,PC) or CALL (d32,PC) */
562 case 0xdc:
563 case 0xdd:
564 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
565 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0 ||
566 gdbstub_read_byte(pc + 3, ((u8 *) &x) + 2) < 0 ||
567 gdbstub_read_byte(pc + 4, ((u8 *) &x) + 3) < 0)
568 goto fault;
569 if (!__gdbstub_mark_bp(pc + (s32) x, 0))
570 goto fault;
571 break;
572
573 /* RETF */
574 case 0xde:
575 if (!__gdbstub_mark_bp((u8 *) regs->mdr, 0))
576 goto fault;
577 break;
578
579 /* RET */
580 case 0xdf:
581 if (gdbstub_read_byte(pc + 2, (u8 *) &x) < 0)
582 goto fault;
583 sp += (s8)x;
584 if (gdbstub_read_byte(sp + 0, ((u8 *) &x) + 0) < 0 ||
585 gdbstub_read_byte(sp + 1, ((u8 *) &x) + 1) < 0 ||
586 gdbstub_read_byte(sp + 2, ((u8 *) &x) + 2) < 0 ||
587 gdbstub_read_byte(sp + 3, ((u8 *) &x) + 3) < 0)
588 goto fault;
589 if (!__gdbstub_mark_bp((u8 *) x, 0))
590 goto fault;
591 break;
592
593 case 0xf0:
594 if (gdbstub_read_byte(pc + 1, &cur) < 0)
595 goto fault;
596
597 if (cur >= 0xf0 && cur <= 0xf7) {
598 /* JMP (An) / CALLS (An) */
599 switch (cur & 3) {
600 case 0: x = regs->a0; break;
601 case 1: x = regs->a1; break;
602 case 2: x = regs->a2; break;
603 case 3: x = regs->a3; break;
604 }
605 if (!__gdbstub_mark_bp((u8 *) x, 0))
606 goto fault;
607 } else if (cur == 0xfc) {
608 /* RETS */
609 if (gdbstub_read_byte(
610 sp + 0, ((u8 *) &x) + 0) < 0 ||
611 gdbstub_read_byte(
612 sp + 1, ((u8 *) &x) + 1) < 0 ||
613 gdbstub_read_byte(
614 sp + 2, ((u8 *) &x) + 2) < 0 ||
615 gdbstub_read_byte(
616 sp + 3, ((u8 *) &x) + 3) < 0)
617 goto fault;
618 if (!__gdbstub_mark_bp((u8 *) x, 0))
619 goto fault;
620 } else if (cur == 0xfd) {
621 /* RTI */
622 if (gdbstub_read_byte(
623 sp + 4, ((u8 *) &x) + 0) < 0 ||
624 gdbstub_read_byte(
625 sp + 5, ((u8 *) &x) + 1) < 0 ||
626 gdbstub_read_byte(
627 sp + 6, ((u8 *) &x) + 2) < 0 ||
628 gdbstub_read_byte(
629 sp + 7, ((u8 *) &x) + 3) < 0)
630 goto fault;
631 if (!__gdbstub_mark_bp((u8 *) x, 0))
632 goto fault;
633 } else {
634 if (!__gdbstub_mark_bp(pc + 2, 0))
635 goto fault;
636 }
637
638 break;
639
640 /* potential 3-byte conditional branches */
641 case 0xf8:
642 if (gdbstub_read_byte(pc + 1, &cur) < 0)
643 goto fault;
644 if (!__gdbstub_mark_bp(pc + 3, 0))
645 goto fault;
646
647 if (cur >= 0xe8 && cur <= 0xeb) {
648 if (gdbstub_read_byte(
649 pc + 2, ((u8 *) &x) + 0) < 0)
650 goto fault;
651 if ((x < 0 || x > 3) &&
652 !__gdbstub_mark_bp(pc + (s8) x, 1))
653 goto fault;
654 }
655 break;
656
657 case 0xfa:
658 if (gdbstub_read_byte(pc + 1, &cur) < 0)
659 goto fault;
660
661 if (cur == 0xff) {
662 /* CALLS (d16,PC) */
663 if (gdbstub_read_byte(
664 pc + 2, ((u8 *) &x) + 0) < 0 ||
665 gdbstub_read_byte(
666 pc + 3, ((u8 *) &x) + 1) < 0)
667 goto fault;
668 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
669 goto fault;
670 } else {
671 if (!__gdbstub_mark_bp(pc + 4, 0))
672 goto fault;
673 }
674 break;
675
676 case 0xfc:
677 if (gdbstub_read_byte(pc + 1, &cur) < 0)
678 goto fault;
679 if (cur == 0xff) {
680 /* CALLS (d32,PC) */
681 if (gdbstub_read_byte(
682 pc + 2, ((u8 *) &x) + 0) < 0 ||
683 gdbstub_read_byte(
684 pc + 3, ((u8 *) &x) + 1) < 0 ||
685 gdbstub_read_byte(
686 pc + 4, ((u8 *) &x) + 2) < 0 ||
687 gdbstub_read_byte(
688 pc + 5, ((u8 *) &x) + 3) < 0)
689 goto fault;
690 if (!__gdbstub_mark_bp(
691 pc + (s32) x, 0))
692 goto fault;
693 } else {
694 if (!__gdbstub_mark_bp(
695 pc + 6, 0))
696 goto fault;
697 }
698 break;
699
700 }
701 }
702
703 gdbstub_bkpt("Step: %02x at %p; %02x at %p\n",
704 step_bp[0].opcode[0], step_bp[0].addr,
705 step_bp[1].opcode[0], step_bp[1].addr);
706
707 if (step_bp[0].addr) {
708 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
709 if (gdbstub_write_byte(0xF7, step_bp[0].addr + 0) < 0 ||
710 gdbstub_write_byte(0xF7, step_bp[0].addr + 1) < 0)
711 goto fault;
712 #else
713 if (gdbstub_write_byte(0xFF, step_bp[0].addr + 0) < 0)
714 goto fault;
715 #endif
716 }
717
718 if (step_bp[1].addr) {
719 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
720 if (gdbstub_write_byte(0xF7, step_bp[1].addr + 0) < 0 ||
721 gdbstub_write_byte(0xF7, step_bp[1].addr + 1) < 0)
722 goto fault;
723 #else
724 if (gdbstub_write_byte(0xFF, step_bp[1].addr + 0) < 0)
725 goto fault;
726 #endif
727 }
728
729 return 0;
730
731 fault:
732 /* uh-oh - silly address alert, try and restore things */
733 __gdbstub_restore_bp();
734 return -EFAULT;
735 }
736
737 #ifdef CONFIG_GDBSTUB_CONSOLE
738
gdbstub_console_write(struct console * con,const char * p,unsigned n)739 void gdbstub_console_write(struct console *con, const char *p, unsigned n)
740 {
741 static const char gdbstub_cr[] = { 0x0d };
742 char outbuf[26];
743 int qty;
744 u8 busy;
745
746 busy = gdbstub_busy;
747 gdbstub_busy = 1;
748
749 outbuf[0] = 'O';
750
751 while (n > 0) {
752 qty = 1;
753
754 while (n > 0 && qty < 20) {
755 mem2hex(p, outbuf + qty, 2, 0);
756 qty += 2;
757 if (*p == 0x0a) {
758 mem2hex(gdbstub_cr, outbuf + qty, 2, 0);
759 qty += 2;
760 }
761 p++;
762 n--;
763 }
764
765 outbuf[qty] = 0;
766 putpacket(outbuf);
767 }
768
769 gdbstub_busy = busy;
770 }
771
gdbstub_console_dev(struct console * con)772 static kdev_t gdbstub_console_dev(struct console *con)
773 {
774 return MKDEV(1, 3); /* /dev/null */
775 }
776
777 static struct console gdbstub_console = {
778 .name = "gdb",
779 .write = gdbstub_console_write,
780 .device = gdbstub_console_dev,
781 .flags = CON_PRINTBUFFER,
782 .index = -1,
783 };
784
785 #endif
786
787 /*
788 * Convert the memory pointed to by mem into hex, placing result in buf.
789 * - if successful, return a pointer to the last char put in buf (NUL)
790 * - in case of mem fault, return NULL
791 * may_fault is non-zero if we are reading from arbitrary memory, but is
792 * currently not used.
793 */
794 static
mem2hex(const void * _mem,char * buf,int count,int may_fault)795 unsigned char *mem2hex(const void *_mem, char *buf, int count, int may_fault)
796 {
797 const u8 *mem = _mem;
798 u8 ch[4];
799
800 if ((u32) mem & 1 && count >= 1) {
801 if (gdbstub_read_byte(mem, ch) != 0)
802 return 0;
803 buf = pack_hex_byte(buf, ch[0]);
804 mem++;
805 count--;
806 }
807
808 if ((u32) mem & 3 && count >= 2) {
809 if (gdbstub_read_word(mem, ch) != 0)
810 return 0;
811 buf = pack_hex_byte(buf, ch[0]);
812 buf = pack_hex_byte(buf, ch[1]);
813 mem += 2;
814 count -= 2;
815 }
816
817 while (count >= 4) {
818 if (gdbstub_read_dword(mem, ch) != 0)
819 return 0;
820 buf = pack_hex_byte(buf, ch[0]);
821 buf = pack_hex_byte(buf, ch[1]);
822 buf = pack_hex_byte(buf, ch[2]);
823 buf = pack_hex_byte(buf, ch[3]);
824 mem += 4;
825 count -= 4;
826 }
827
828 if (count >= 2) {
829 if (gdbstub_read_word(mem, ch) != 0)
830 return 0;
831 buf = pack_hex_byte(buf, ch[0]);
832 buf = pack_hex_byte(buf, ch[1]);
833 mem += 2;
834 count -= 2;
835 }
836
837 if (count >= 1) {
838 if (gdbstub_read_byte(mem, ch) != 0)
839 return 0;
840 buf = pack_hex_byte(buf, ch[0]);
841 }
842
843 *buf = 0;
844 return buf;
845 }
846
847 /*
848 * convert the hex array pointed to by buf into binary to be placed in mem
849 * return a pointer to the character AFTER the last byte written
850 * may_fault is non-zero if we are reading from arbitrary memory, but is
851 * currently not used.
852 */
853 static
hex2mem(const char * buf,void * _mem,int count,int may_fault)854 const char *hex2mem(const char *buf, void *_mem, int count, int may_fault)
855 {
856 u8 *mem = _mem;
857 union {
858 u32 val;
859 u8 b[4];
860 } ch;
861
862 if ((u32) mem & 1 && count >= 1) {
863 ch.b[0] = hex(*buf++) << 4;
864 ch.b[0] |= hex(*buf++);
865 if (gdbstub_write_byte(ch.val, mem) != 0)
866 return 0;
867 mem++;
868 count--;
869 }
870
871 if ((u32) mem & 3 && count >= 2) {
872 ch.b[0] = hex(*buf++) << 4;
873 ch.b[0] |= hex(*buf++);
874 ch.b[1] = hex(*buf++) << 4;
875 ch.b[1] |= hex(*buf++);
876 if (gdbstub_write_word(ch.val, mem) != 0)
877 return 0;
878 mem += 2;
879 count -= 2;
880 }
881
882 while (count >= 4) {
883 ch.b[0] = hex(*buf++) << 4;
884 ch.b[0] |= hex(*buf++);
885 ch.b[1] = hex(*buf++) << 4;
886 ch.b[1] |= hex(*buf++);
887 ch.b[2] = hex(*buf++) << 4;
888 ch.b[2] |= hex(*buf++);
889 ch.b[3] = hex(*buf++) << 4;
890 ch.b[3] |= hex(*buf++);
891 if (gdbstub_write_dword(ch.val, mem) != 0)
892 return 0;
893 mem += 4;
894 count -= 4;
895 }
896
897 if (count >= 2) {
898 ch.b[0] = hex(*buf++) << 4;
899 ch.b[0] |= hex(*buf++);
900 ch.b[1] = hex(*buf++) << 4;
901 ch.b[1] |= hex(*buf++);
902 if (gdbstub_write_word(ch.val, mem) != 0)
903 return 0;
904 mem += 2;
905 count -= 2;
906 }
907
908 if (count >= 1) {
909 ch.b[0] = hex(*buf++) << 4;
910 ch.b[0] |= hex(*buf++);
911 if (gdbstub_write_byte(ch.val, mem) != 0)
912 return 0;
913 }
914
915 return buf;
916 }
917
918 /*
919 * This table contains the mapping between MN10300 exception codes, and
920 * signals, which are primarily what GDB understands. It also indicates
921 * which hardware traps we need to commandeer when initializing the stub.
922 */
923 static const struct excep_to_sig_map {
924 enum exception_code excep; /* MN10300 exception code */
925 unsigned char signo; /* Signal that we map this into */
926 } excep_to_sig_map[] = {
927 { EXCEP_ITLBMISS, SIGSEGV },
928 { EXCEP_DTLBMISS, SIGSEGV },
929 { EXCEP_TRAP, SIGTRAP },
930 { EXCEP_ISTEP, SIGTRAP },
931 { EXCEP_IBREAK, SIGTRAP },
932 { EXCEP_OBREAK, SIGTRAP },
933 { EXCEP_UNIMPINS, SIGILL },
934 { EXCEP_UNIMPEXINS, SIGILL },
935 { EXCEP_MEMERR, SIGSEGV },
936 { EXCEP_MISALIGN, SIGSEGV },
937 { EXCEP_BUSERROR, SIGBUS },
938 { EXCEP_ILLINSACC, SIGSEGV },
939 { EXCEP_ILLDATACC, SIGSEGV },
940 { EXCEP_IOINSACC, SIGSEGV },
941 { EXCEP_PRIVINSACC, SIGSEGV },
942 { EXCEP_PRIVDATACC, SIGSEGV },
943 { EXCEP_FPU_DISABLED, SIGFPE },
944 { EXCEP_FPU_UNIMPINS, SIGFPE },
945 { EXCEP_FPU_OPERATION, SIGFPE },
946 { EXCEP_WDT, SIGALRM },
947 { EXCEP_NMI, SIGQUIT },
948 { EXCEP_IRQ_LEVEL0, SIGINT },
949 { EXCEP_IRQ_LEVEL1, SIGINT },
950 { EXCEP_IRQ_LEVEL2, SIGINT },
951 { EXCEP_IRQ_LEVEL3, SIGINT },
952 { EXCEP_IRQ_LEVEL4, SIGINT },
953 { EXCEP_IRQ_LEVEL5, SIGINT },
954 { EXCEP_IRQ_LEVEL6, SIGINT },
955 { 0, 0}
956 };
957
958 /*
959 * convert the MN10300 exception code into a UNIX signal number
960 */
computeSignal(enum exception_code excep)961 static int computeSignal(enum exception_code excep)
962 {
963 const struct excep_to_sig_map *map;
964
965 for (map = excep_to_sig_map; map->signo; map++)
966 if (map->excep == excep)
967 return map->signo;
968
969 return SIGHUP; /* default for things we don't know about */
970 }
971
972 static u32 gdbstub_fpcr, gdbstub_fpufs_array[32];
973
974 /*
975 *
976 */
gdbstub_store_fpu(void)977 static void gdbstub_store_fpu(void)
978 {
979 #ifdef CONFIG_FPU
980
981 asm volatile(
982 "or %2,epsw\n"
983 #ifdef CONFIG_MN10300_PROC_MN103E010
984 "nop\n"
985 "nop\n"
986 #endif
987 "mov %1, a1\n"
988 "fmov fs0, (a1+)\n"
989 "fmov fs1, (a1+)\n"
990 "fmov fs2, (a1+)\n"
991 "fmov fs3, (a1+)\n"
992 "fmov fs4, (a1+)\n"
993 "fmov fs5, (a1+)\n"
994 "fmov fs6, (a1+)\n"
995 "fmov fs7, (a1+)\n"
996 "fmov fs8, (a1+)\n"
997 "fmov fs9, (a1+)\n"
998 "fmov fs10, (a1+)\n"
999 "fmov fs11, (a1+)\n"
1000 "fmov fs12, (a1+)\n"
1001 "fmov fs13, (a1+)\n"
1002 "fmov fs14, (a1+)\n"
1003 "fmov fs15, (a1+)\n"
1004 "fmov fs16, (a1+)\n"
1005 "fmov fs17, (a1+)\n"
1006 "fmov fs18, (a1+)\n"
1007 "fmov fs19, (a1+)\n"
1008 "fmov fs20, (a1+)\n"
1009 "fmov fs21, (a1+)\n"
1010 "fmov fs22, (a1+)\n"
1011 "fmov fs23, (a1+)\n"
1012 "fmov fs24, (a1+)\n"
1013 "fmov fs25, (a1+)\n"
1014 "fmov fs26, (a1+)\n"
1015 "fmov fs27, (a1+)\n"
1016 "fmov fs28, (a1+)\n"
1017 "fmov fs29, (a1+)\n"
1018 "fmov fs30, (a1+)\n"
1019 "fmov fs31, (a1+)\n"
1020 "fmov fpcr, %0\n"
1021 : "=d"(gdbstub_fpcr)
1022 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE)
1023 : "a1"
1024 );
1025 #endif
1026 }
1027
1028 /*
1029 *
1030 */
gdbstub_load_fpu(void)1031 static void gdbstub_load_fpu(void)
1032 {
1033 #ifdef CONFIG_FPU
1034
1035 asm volatile(
1036 "or %1,epsw\n"
1037 #ifdef CONFIG_MN10300_PROC_MN103E010
1038 "nop\n"
1039 "nop\n"
1040 #endif
1041 "mov %0, a1\n"
1042 "fmov (a1+), fs0\n"
1043 "fmov (a1+), fs1\n"
1044 "fmov (a1+), fs2\n"
1045 "fmov (a1+), fs3\n"
1046 "fmov (a1+), fs4\n"
1047 "fmov (a1+), fs5\n"
1048 "fmov (a1+), fs6\n"
1049 "fmov (a1+), fs7\n"
1050 "fmov (a1+), fs8\n"
1051 "fmov (a1+), fs9\n"
1052 "fmov (a1+), fs10\n"
1053 "fmov (a1+), fs11\n"
1054 "fmov (a1+), fs12\n"
1055 "fmov (a1+), fs13\n"
1056 "fmov (a1+), fs14\n"
1057 "fmov (a1+), fs15\n"
1058 "fmov (a1+), fs16\n"
1059 "fmov (a1+), fs17\n"
1060 "fmov (a1+), fs18\n"
1061 "fmov (a1+), fs19\n"
1062 "fmov (a1+), fs20\n"
1063 "fmov (a1+), fs21\n"
1064 "fmov (a1+), fs22\n"
1065 "fmov (a1+), fs23\n"
1066 "fmov (a1+), fs24\n"
1067 "fmov (a1+), fs25\n"
1068 "fmov (a1+), fs26\n"
1069 "fmov (a1+), fs27\n"
1070 "fmov (a1+), fs28\n"
1071 "fmov (a1+), fs29\n"
1072 "fmov (a1+), fs30\n"
1073 "fmov (a1+), fs31\n"
1074 "fmov %2, fpcr\n"
1075 :
1076 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE), "d"(gdbstub_fpcr)
1077 : "a1"
1078 );
1079 #endif
1080 }
1081
1082 /*
1083 * set a software breakpoint
1084 */
gdbstub_set_breakpoint(u8 * addr,int len)1085 int gdbstub_set_breakpoint(u8 *addr, int len)
1086 {
1087 int bkpt, loop, xloop;
1088
1089 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1090 len = (len + 1) & ~1;
1091 #endif
1092
1093 gdbstub_bkpt("setbkpt(%p,%d)\n", addr, len);
1094
1095 for (bkpt = 255; bkpt >= 0; bkpt--)
1096 if (!gdbstub_bkpts[bkpt].addr)
1097 break;
1098 if (bkpt < 0)
1099 return -ENOSPC;
1100
1101 for (loop = 0; loop < len; loop++)
1102 if (gdbstub_read_byte(&addr[loop],
1103 &gdbstub_bkpts[bkpt].origbytes[loop]
1104 ) < 0)
1105 return -EFAULT;
1106
1107 gdbstub_flush_caches = 1;
1108
1109 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1110 for (loop = 0; loop < len; loop++)
1111 if (gdbstub_write_byte(0xF7, &addr[loop]) < 0)
1112 goto restore;
1113 #else
1114 for (loop = 0; loop < len; loop++)
1115 if (gdbstub_write_byte(0xFF, &addr[loop]) < 0)
1116 goto restore;
1117 #endif
1118
1119 gdbstub_bkpts[bkpt].addr = addr;
1120 gdbstub_bkpts[bkpt].len = len;
1121
1122 gdbstub_bkpt("Set BKPT[%02x]: %p-%p {%02x%02x%02x%02x%02x%02x%02x}\n",
1123 bkpt,
1124 gdbstub_bkpts[bkpt].addr,
1125 gdbstub_bkpts[bkpt].addr + gdbstub_bkpts[bkpt].len - 1,
1126 gdbstub_bkpts[bkpt].origbytes[0],
1127 gdbstub_bkpts[bkpt].origbytes[1],
1128 gdbstub_bkpts[bkpt].origbytes[2],
1129 gdbstub_bkpts[bkpt].origbytes[3],
1130 gdbstub_bkpts[bkpt].origbytes[4],
1131 gdbstub_bkpts[bkpt].origbytes[5],
1132 gdbstub_bkpts[bkpt].origbytes[6]
1133 );
1134
1135 return 0;
1136
1137 restore:
1138 for (xloop = 0; xloop < loop; xloop++)
1139 gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[xloop],
1140 addr + xloop);
1141 return -EFAULT;
1142 }
1143
1144 /*
1145 * clear a software breakpoint
1146 */
gdbstub_clear_breakpoint(u8 * addr,int len)1147 int gdbstub_clear_breakpoint(u8 *addr, int len)
1148 {
1149 int bkpt, loop;
1150
1151 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1152 len = (len + 1) & ~1;
1153 #endif
1154
1155 gdbstub_bkpt("clearbkpt(%p,%d)\n", addr, len);
1156
1157 for (bkpt = 255; bkpt >= 0; bkpt--)
1158 if (gdbstub_bkpts[bkpt].addr == addr &&
1159 gdbstub_bkpts[bkpt].len == len)
1160 break;
1161 if (bkpt < 0)
1162 return -ENOENT;
1163
1164 gdbstub_bkpts[bkpt].addr = NULL;
1165
1166 gdbstub_flush_caches = 1;
1167
1168 for (loop = 0; loop < len; loop++)
1169 if (gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[loop],
1170 addr + loop) < 0)
1171 return -EFAULT;
1172
1173 return 0;
1174 }
1175
1176 /*
1177 * This function does all command processing for interfacing to gdb
1178 * - returns 1 if the exception should be skipped, 0 otherwise.
1179 */
gdbstub(struct pt_regs * regs,enum exception_code excep)1180 static int gdbstub(struct pt_regs *regs, enum exception_code excep)
1181 {
1182 unsigned long *stack;
1183 unsigned long epsw, mdr;
1184 uint32_t zero, ssp;
1185 uint8_t broke;
1186 char *ptr;
1187 int sigval;
1188 int addr;
1189 int length;
1190 int loop;
1191
1192 if (excep == EXCEP_FPU_DISABLED)
1193 return 0;
1194
1195 gdbstub_flush_caches = 0;
1196
1197 mn10300_set_gdbleds(1);
1198
1199 asm volatile("mov mdr,%0" : "=d"(mdr));
1200 asm volatile("mov epsw,%0" : "=d"(epsw));
1201 asm volatile("mov %0,epsw"
1202 :: "d"((epsw & ~EPSW_IM) | EPSW_IE | EPSW_IM_1));
1203
1204 gdbstub_store_fpu();
1205
1206 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1207 /* skip the initial pause loop */
1208 if (regs->pc == (unsigned long) __gdbstub_pause)
1209 regs->pc = (unsigned long) start_kernel;
1210 #endif
1211
1212 /* if we were single stepping, restore the opcodes hoisted for the
1213 * breakpoint[s] */
1214 broke = 0;
1215 if ((step_bp[0].addr && step_bp[0].addr == (u8 *) regs->pc) ||
1216 (step_bp[1].addr && step_bp[1].addr == (u8 *) regs->pc))
1217 broke = 1;
1218
1219 __gdbstub_restore_bp();
1220
1221 if (gdbstub_rx_unget) {
1222 sigval = SIGINT;
1223 if (gdbstub_rx_unget != 3)
1224 goto packet_waiting;
1225 gdbstub_rx_unget = 0;
1226 }
1227
1228 stack = (unsigned long *) regs->sp;
1229 sigval = broke ? SIGTRAP : computeSignal(excep);
1230
1231 /* send information about a BUG() */
1232 if (!user_mode(regs) && excep == EXCEP_SYSCALL15) {
1233 const struct bug_entry *bug;
1234
1235 bug = find_bug(regs->pc);
1236 if (bug)
1237 goto found_bug;
1238 length = snprintf(trans_buffer, sizeof(trans_buffer),
1239 "BUG() at address %lx\n", regs->pc);
1240 goto send_bug_pkt;
1241
1242 found_bug:
1243 length = snprintf(trans_buffer, sizeof(trans_buffer),
1244 "BUG() at address %lx (%s:%d)\n",
1245 regs->pc, bug->file, bug->line);
1246
1247 send_bug_pkt:
1248 ptr = output_buffer;
1249 *ptr++ = 'O';
1250 ptr = mem2hex(trans_buffer, ptr, length, 0);
1251 *ptr = 0;
1252 putpacket(output_buffer);
1253
1254 regs->pc -= 2;
1255 sigval = SIGABRT;
1256 } else if (regs->pc == (unsigned long) __gdbstub_bug_trap) {
1257 regs->pc = regs->mdr;
1258 sigval = SIGABRT;
1259 }
1260
1261 /*
1262 * send a message to the debugger's user saying what happened if it may
1263 * not be clear cut (we can't map exceptions onto signals properly)
1264 */
1265 if (sigval != SIGINT && sigval != SIGTRAP && sigval != SIGILL) {
1266 static const char title[] = "Excep ", tbcberr[] = "BCBERR ";
1267 static const char crlf[] = "\r\n";
1268 char hx;
1269 u32 bcberr = BCBERR;
1270
1271 ptr = output_buffer;
1272 *ptr++ = 'O';
1273 ptr = mem2hex(title, ptr, sizeof(title) - 1, 0);
1274
1275 hx = hex_asc_hi(excep >> 8);
1276 ptr = pack_hex_byte(ptr, hx);
1277 hx = hex_asc_lo(excep >> 8);
1278 ptr = pack_hex_byte(ptr, hx);
1279 hx = hex_asc_hi(excep);
1280 ptr = pack_hex_byte(ptr, hx);
1281 hx = hex_asc_lo(excep);
1282 ptr = pack_hex_byte(ptr, hx);
1283
1284 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1285 *ptr = 0;
1286 putpacket(output_buffer); /* send it off... */
1287
1288 /* BCBERR */
1289 ptr = output_buffer;
1290 *ptr++ = 'O';
1291 ptr = mem2hex(tbcberr, ptr, sizeof(tbcberr) - 1, 0);
1292
1293 hx = hex_asc_hi(bcberr >> 24);
1294 ptr = pack_hex_byte(ptr, hx);
1295 hx = hex_asc_lo(bcberr >> 24);
1296 ptr = pack_hex_byte(ptr, hx);
1297 hx = hex_asc_hi(bcberr >> 16);
1298 ptr = pack_hex_byte(ptr, hx);
1299 hx = hex_asc_lo(bcberr >> 16);
1300 ptr = pack_hex_byte(ptr, hx);
1301 hx = hex_asc_hi(bcberr >> 8);
1302 ptr = pack_hex_byte(ptr, hx);
1303 hx = hex_asc_lo(bcberr >> 8);
1304 ptr = pack_hex_byte(ptr, hx);
1305 hx = hex_asc_hi(bcberr);
1306 ptr = pack_hex_byte(ptr, hx);
1307 hx = hex_asc_lo(bcberr);
1308 ptr = pack_hex_byte(ptr, hx);
1309
1310 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1311 *ptr = 0;
1312 putpacket(output_buffer); /* send it off... */
1313 }
1314
1315 /*
1316 * tell the debugger that an exception has occurred
1317 */
1318 ptr = output_buffer;
1319
1320 /*
1321 * Send trap type (converted to signal)
1322 */
1323 *ptr++ = 'T';
1324 ptr = pack_hex_byte(ptr, sigval);
1325
1326 /*
1327 * Send Error PC
1328 */
1329 ptr = pack_hex_byte(ptr, GDB_REGID_PC);
1330 *ptr++ = ':';
1331 ptr = mem2hex(®s->pc, ptr, 4, 0);
1332 *ptr++ = ';';
1333
1334 /*
1335 * Send frame pointer
1336 */
1337 ptr = pack_hex_byte(ptr, GDB_REGID_FP);
1338 *ptr++ = ':';
1339 ptr = mem2hex(®s->a3, ptr, 4, 0);
1340 *ptr++ = ';';
1341
1342 /*
1343 * Send stack pointer
1344 */
1345 ssp = (unsigned long) (regs + 1);
1346 ptr = pack_hex_byte(ptr, GDB_REGID_SP);
1347 *ptr++ = ':';
1348 ptr = mem2hex(&ssp, ptr, 4, 0);
1349 *ptr++ = ';';
1350
1351 *ptr++ = 0;
1352 putpacket(output_buffer); /* send it off... */
1353
1354 packet_waiting:
1355 /*
1356 * Wait for input from remote GDB
1357 */
1358 while (1) {
1359 output_buffer[0] = 0;
1360 getpacket(input_buffer);
1361
1362 switch (input_buffer[0]) {
1363 /* request repeat of last signal number */
1364 case '?':
1365 output_buffer[0] = 'S';
1366 output_buffer[1] = hex_asc_hi(sigval);
1367 output_buffer[2] = hex_asc_lo(sigval);
1368 output_buffer[3] = 0;
1369 break;
1370
1371 case 'd':
1372 /* toggle debug flag */
1373 break;
1374
1375 /*
1376 * Return the value of the CPU registers
1377 */
1378 case 'g':
1379 zero = 0;
1380 ssp = (u32) (regs + 1);
1381 ptr = output_buffer;
1382 ptr = mem2hex(®s->d0, ptr, 4, 0);
1383 ptr = mem2hex(®s->d1, ptr, 4, 0);
1384 ptr = mem2hex(®s->d2, ptr, 4, 0);
1385 ptr = mem2hex(®s->d3, ptr, 4, 0);
1386 ptr = mem2hex(®s->a0, ptr, 4, 0);
1387 ptr = mem2hex(®s->a1, ptr, 4, 0);
1388 ptr = mem2hex(®s->a2, ptr, 4, 0);
1389 ptr = mem2hex(®s->a3, ptr, 4, 0);
1390
1391 ptr = mem2hex(&ssp, ptr, 4, 0); /* 8 */
1392 ptr = mem2hex(®s->pc, ptr, 4, 0);
1393 ptr = mem2hex(®s->mdr, ptr, 4, 0);
1394 ptr = mem2hex(®s->epsw, ptr, 4, 0);
1395 ptr = mem2hex(®s->lir, ptr, 4, 0);
1396 ptr = mem2hex(®s->lar, ptr, 4, 0);
1397 ptr = mem2hex(®s->mdrq, ptr, 4, 0);
1398
1399 ptr = mem2hex(®s->e0, ptr, 4, 0); /* 15 */
1400 ptr = mem2hex(®s->e1, ptr, 4, 0);
1401 ptr = mem2hex(®s->e2, ptr, 4, 0);
1402 ptr = mem2hex(®s->e3, ptr, 4, 0);
1403 ptr = mem2hex(®s->e4, ptr, 4, 0);
1404 ptr = mem2hex(®s->e5, ptr, 4, 0);
1405 ptr = mem2hex(®s->e6, ptr, 4, 0);
1406 ptr = mem2hex(®s->e7, ptr, 4, 0);
1407
1408 ptr = mem2hex(&ssp, ptr, 4, 0);
1409 ptr = mem2hex(®s, ptr, 4, 0);
1410 ptr = mem2hex(®s->sp, ptr, 4, 0);
1411 ptr = mem2hex(®s->mcrh, ptr, 4, 0); /* 26 */
1412 ptr = mem2hex(®s->mcrl, ptr, 4, 0);
1413 ptr = mem2hex(®s->mcvf, ptr, 4, 0);
1414
1415 ptr = mem2hex(&gdbstub_fpcr, ptr, 4, 0); /* 29 - FPCR */
1416 ptr = mem2hex(&zero, ptr, 4, 0);
1417 ptr = mem2hex(&zero, ptr, 4, 0);
1418 for (loop = 0; loop < 32; loop++)
1419 ptr = mem2hex(&gdbstub_fpufs_array[loop],
1420 ptr, 4, 0); /* 32 - FS0-31 */
1421
1422 break;
1423
1424 /*
1425 * set the value of the CPU registers - return OK
1426 */
1427 case 'G':
1428 {
1429 const char *ptr;
1430
1431 ptr = &input_buffer[1];
1432 ptr = hex2mem(ptr, ®s->d0, 4, 0);
1433 ptr = hex2mem(ptr, ®s->d1, 4, 0);
1434 ptr = hex2mem(ptr, ®s->d2, 4, 0);
1435 ptr = hex2mem(ptr, ®s->d3, 4, 0);
1436 ptr = hex2mem(ptr, ®s->a0, 4, 0);
1437 ptr = hex2mem(ptr, ®s->a1, 4, 0);
1438 ptr = hex2mem(ptr, ®s->a2, 4, 0);
1439 ptr = hex2mem(ptr, ®s->a3, 4, 0);
1440
1441 ptr = hex2mem(ptr, &ssp, 4, 0); /* 8 */
1442 ptr = hex2mem(ptr, ®s->pc, 4, 0);
1443 ptr = hex2mem(ptr, ®s->mdr, 4, 0);
1444 ptr = hex2mem(ptr, ®s->epsw, 4, 0);
1445 ptr = hex2mem(ptr, ®s->lir, 4, 0);
1446 ptr = hex2mem(ptr, ®s->lar, 4, 0);
1447 ptr = hex2mem(ptr, ®s->mdrq, 4, 0);
1448
1449 ptr = hex2mem(ptr, ®s->e0, 4, 0); /* 15 */
1450 ptr = hex2mem(ptr, ®s->e1, 4, 0);
1451 ptr = hex2mem(ptr, ®s->e2, 4, 0);
1452 ptr = hex2mem(ptr, ®s->e3, 4, 0);
1453 ptr = hex2mem(ptr, ®s->e4, 4, 0);
1454 ptr = hex2mem(ptr, ®s->e5, 4, 0);
1455 ptr = hex2mem(ptr, ®s->e6, 4, 0);
1456 ptr = hex2mem(ptr, ®s->e7, 4, 0);
1457
1458 ptr = hex2mem(ptr, &ssp, 4, 0);
1459 ptr = hex2mem(ptr, &zero, 4, 0);
1460 ptr = hex2mem(ptr, ®s->sp, 4, 0);
1461 ptr = hex2mem(ptr, ®s->mcrh, 4, 0); /* 26 */
1462 ptr = hex2mem(ptr, ®s->mcrl, 4, 0);
1463 ptr = hex2mem(ptr, ®s->mcvf, 4, 0);
1464
1465 ptr = hex2mem(ptr, &zero, 4, 0); /* 29 - FPCR */
1466 ptr = hex2mem(ptr, &zero, 4, 0);
1467 ptr = hex2mem(ptr, &zero, 4, 0);
1468 for (loop = 0; loop < 32; loop++) /* 32 - FS0-31 */
1469 ptr = hex2mem(ptr, &zero, 4, 0);
1470
1471 #if 0
1472 /*
1473 * See if the stack pointer has moved. If so, then copy
1474 * the saved locals and ins to the new location.
1475 */
1476 unsigned long *newsp = (unsigned long *) registers[SP];
1477 if (sp != newsp)
1478 sp = memcpy(newsp, sp, 16 * 4);
1479 #endif
1480
1481 gdbstub_strcpy(output_buffer, "OK");
1482 }
1483 break;
1484
1485 /*
1486 * mAA..AA,LLLL Read LLLL bytes at address AA..AA
1487 */
1488 case 'm':
1489 ptr = &input_buffer[1];
1490
1491 if (hexToInt(&ptr, &addr) &&
1492 *ptr++ == ',' &&
1493 hexToInt(&ptr, &length)
1494 ) {
1495 if (mem2hex((char *) addr, output_buffer,
1496 length, 1))
1497 break;
1498 gdbstub_strcpy(output_buffer, "E03");
1499 } else {
1500 gdbstub_strcpy(output_buffer, "E01");
1501 }
1502 break;
1503
1504 /*
1505 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA
1506 * return OK
1507 */
1508 case 'M':
1509 ptr = &input_buffer[1];
1510
1511 if (hexToInt(&ptr, &addr) &&
1512 *ptr++ == ',' &&
1513 hexToInt(&ptr, &length) &&
1514 *ptr++ == ':'
1515 ) {
1516 if (hex2mem(ptr, (char *) addr, length, 1))
1517 gdbstub_strcpy(output_buffer, "OK");
1518 else
1519 gdbstub_strcpy(output_buffer, "E03");
1520
1521 gdbstub_flush_caches = 1;
1522 } else {
1523 gdbstub_strcpy(output_buffer, "E02");
1524 }
1525 break;
1526
1527 /*
1528 * cAA..AA Continue at address AA..AA(optional)
1529 */
1530 case 'c':
1531 /* try to read optional parameter, pc unchanged if no
1532 * parm */
1533
1534 ptr = &input_buffer[1];
1535 if (hexToInt(&ptr, &addr))
1536 regs->pc = addr;
1537 goto done;
1538
1539 /*
1540 * kill the program
1541 */
1542 case 'k' :
1543 goto done; /* just continue */
1544
1545 /*
1546 * Reset the whole machine (FIXME: system dependent)
1547 */
1548 case 'r':
1549 break;
1550
1551 /*
1552 * Step to next instruction
1553 */
1554 case 's':
1555 /*
1556 * using the T flag doesn't seem to perform single
1557 * stepping (it seems to wind up being caught by the
1558 * JTAG unit), so we have to use breakpoints and
1559 * continue instead.
1560 */
1561 if (gdbstub_single_step(regs) < 0)
1562 /* ignore any fault error for now */
1563 gdbstub_printk("unable to set single-step"
1564 " bp\n");
1565 goto done;
1566
1567 /*
1568 * Set baud rate (bBB)
1569 */
1570 case 'b':
1571 do {
1572 int baudrate;
1573
1574 ptr = &input_buffer[1];
1575 if (!hexToInt(&ptr, &baudrate)) {
1576 gdbstub_strcpy(output_buffer, "B01");
1577 break;
1578 }
1579
1580 if (baudrate) {
1581 /* ACK before changing speed */
1582 putpacket("OK");
1583 gdbstub_io_set_baud(baudrate);
1584 }
1585 } while (0);
1586 break;
1587
1588 /*
1589 * Set breakpoint
1590 */
1591 case 'Z':
1592 ptr = &input_buffer[1];
1593
1594 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1595 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1596 !hexToInt(&ptr, &length)
1597 ) {
1598 gdbstub_strcpy(output_buffer, "E01");
1599 break;
1600 }
1601
1602 /* only support software breakpoints */
1603 gdbstub_strcpy(output_buffer, "E03");
1604 if (loop != 0 ||
1605 length < 1 ||
1606 length > 7 ||
1607 (unsigned long) addr < 4096)
1608 break;
1609
1610 if (gdbstub_set_breakpoint((u8 *) addr, length) < 0)
1611 break;
1612
1613 gdbstub_strcpy(output_buffer, "OK");
1614 break;
1615
1616 /*
1617 * Clear breakpoint
1618 */
1619 case 'z':
1620 ptr = &input_buffer[1];
1621
1622 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1623 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1624 !hexToInt(&ptr, &length)
1625 ) {
1626 gdbstub_strcpy(output_buffer, "E01");
1627 break;
1628 }
1629
1630 /* only support software breakpoints */
1631 gdbstub_strcpy(output_buffer, "E03");
1632 if (loop != 0 ||
1633 length < 1 ||
1634 length > 7 ||
1635 (unsigned long) addr < 4096)
1636 break;
1637
1638 if (gdbstub_clear_breakpoint((u8 *) addr, length) < 0)
1639 break;
1640
1641 gdbstub_strcpy(output_buffer, "OK");
1642 break;
1643
1644 default:
1645 gdbstub_proto("### GDB Unsupported Cmd '%s'\n",
1646 input_buffer);
1647 break;
1648 }
1649
1650 /* reply to the request */
1651 putpacket(output_buffer);
1652 }
1653
1654 done:
1655 /*
1656 * Need to flush the instruction cache here, as we may
1657 * have deposited a breakpoint, and the icache probably
1658 * has no way of knowing that a data ref to some location
1659 * may have changed something that is in the instruction
1660 * cache.
1661 * NB: We flush both caches, just to be sure...
1662 */
1663 if (gdbstub_flush_caches)
1664 gdbstub_purge_cache();
1665
1666 gdbstub_load_fpu();
1667 mn10300_set_gdbleds(0);
1668 if (excep == EXCEP_NMI)
1669 NMICR = NMICR_NMIF;
1670
1671 touch_softlockup_watchdog();
1672
1673 local_irq_restore(epsw);
1674 return 1;
1675 }
1676
1677 /*
1678 * handle event interception
1679 */
gdbstub_intercept(struct pt_regs * regs,enum exception_code excep)1680 asmlinkage int gdbstub_intercept(struct pt_regs *regs,
1681 enum exception_code excep)
1682 {
1683 static u8 notfirst = 1;
1684 int ret;
1685
1686 if (gdbstub_busy)
1687 gdbstub_printk("--> gdbstub reentered itself\n");
1688 gdbstub_busy = 1;
1689
1690 if (notfirst) {
1691 unsigned long mdr;
1692 asm("mov mdr,%0" : "=d"(mdr));
1693
1694 gdbstub_entry(
1695 "--> gdbstub_intercept(%p,%04x) [MDR=%lx PC=%lx]\n",
1696 regs, excep, mdr, regs->pc);
1697
1698 gdbstub_entry(
1699 "PC: %08lx EPSW: %08lx SSP: %08lx mode: %s\n",
1700 regs->pc, regs->epsw, (unsigned long) &ret,
1701 user_mode(regs) ? "User" : "Super");
1702 gdbstub_entry(
1703 "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
1704 regs->d0, regs->d1, regs->d2, regs->d3);
1705 gdbstub_entry(
1706 "a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
1707 regs->a0, regs->a1, regs->a2, regs->a3);
1708 gdbstub_entry(
1709 "e0: %08lx e1: %08lx e2: %08lx e3: %08lx\n",
1710 regs->e0, regs->e1, regs->e2, regs->e3);
1711 gdbstub_entry(
1712 "e4: %08lx e5: %08lx e6: %08lx e7: %08lx\n",
1713 regs->e4, regs->e5, regs->e6, regs->e7);
1714 gdbstub_entry(
1715 "lar: %08lx lir: %08lx mdr: %08lx usp: %08lx\n",
1716 regs->lar, regs->lir, regs->mdr, regs->sp);
1717 gdbstub_entry(
1718 "cvf: %08lx crl: %08lx crh: %08lx drq: %08lx\n",
1719 regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
1720 gdbstub_entry(
1721 "threadinfo=%p task=%p)\n",
1722 current_thread_info(), current);
1723 } else {
1724 notfirst = 1;
1725 }
1726
1727 ret = gdbstub(regs, excep);
1728
1729 gdbstub_entry("<-- gdbstub_intercept()\n");
1730 gdbstub_busy = 0;
1731 return ret;
1732 }
1733
1734 /*
1735 * handle the GDB stub itself causing an exception
1736 */
gdbstub_exception(struct pt_regs * regs,enum exception_code excep)1737 asmlinkage void gdbstub_exception(struct pt_regs *regs,
1738 enum exception_code excep)
1739 {
1740 unsigned long mdr;
1741
1742 asm("mov mdr,%0" : "=d"(mdr));
1743 gdbstub_entry("--> gdbstub exception({%p},%04x) [MDR=%lx]\n",
1744 regs, excep, mdr);
1745
1746 while ((unsigned long) regs == 0xffffffff) {}
1747
1748 /* handle guarded memory accesses where we know it might fault */
1749 if (regs->pc == (unsigned) gdbstub_read_byte_guard) {
1750 regs->pc = (unsigned) gdbstub_read_byte_cont;
1751 goto fault;
1752 }
1753
1754 if (regs->pc == (unsigned) gdbstub_read_word_guard) {
1755 regs->pc = (unsigned) gdbstub_read_word_cont;
1756 goto fault;
1757 }
1758
1759 if (regs->pc == (unsigned) gdbstub_read_dword_guard) {
1760 regs->pc = (unsigned) gdbstub_read_dword_cont;
1761 goto fault;
1762 }
1763
1764 if (regs->pc == (unsigned) gdbstub_write_byte_guard) {
1765 regs->pc = (unsigned) gdbstub_write_byte_cont;
1766 goto fault;
1767 }
1768
1769 if (regs->pc == (unsigned) gdbstub_write_word_guard) {
1770 regs->pc = (unsigned) gdbstub_write_word_cont;
1771 goto fault;
1772 }
1773
1774 if (regs->pc == (unsigned) gdbstub_write_dword_guard) {
1775 regs->pc = (unsigned) gdbstub_write_dword_cont;
1776 goto fault;
1777 }
1778
1779 gdbstub_printk("\n### GDB stub caused an exception ###\n");
1780
1781 /* something went horribly wrong */
1782 console_verbose();
1783 show_registers(regs);
1784
1785 panic("GDB Stub caused an unexpected exception - can't continue\n");
1786
1787 /* we caught an attempt by the stub to access silly memory */
1788 fault:
1789 gdbstub_entry("<-- gdbstub exception() = EFAULT\n");
1790 regs->d0 = -EFAULT;
1791 return;
1792 }
1793
1794 /*
1795 * send an exit message to GDB
1796 */
gdbstub_exit(int status)1797 void gdbstub_exit(int status)
1798 {
1799 unsigned char checksum;
1800 unsigned char ch;
1801 int count;
1802
1803 gdbstub_busy = 1;
1804 output_buffer[0] = 'W';
1805 output_buffer[1] = hex_asc_hi(status);
1806 output_buffer[2] = hex_asc_lo(status);
1807 output_buffer[3] = 0;
1808
1809 gdbstub_io_tx_char('$');
1810 checksum = 0;
1811 count = 0;
1812
1813 while ((ch = output_buffer[count]) != 0) {
1814 gdbstub_io_tx_char(ch);
1815 checksum += ch;
1816 count += 1;
1817 }
1818
1819 gdbstub_io_tx_char('#');
1820 gdbstub_io_tx_char(hex_asc_hi(checksum));
1821 gdbstub_io_tx_char(hex_asc_lo(checksum));
1822
1823 /* make sure the output is flushed, or else RedBoot might clobber it */
1824 gdbstub_io_tx_flush();
1825
1826 gdbstub_busy = 0;
1827 }
1828
1829 /*
1830 * initialise the GDB stub
1831 */
gdbstub_init(void)1832 asmlinkage void __init gdbstub_init(void)
1833 {
1834 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1835 unsigned char ch;
1836 int ret;
1837 #endif
1838
1839 gdbstub_busy = 1;
1840
1841 printk(KERN_INFO "%s", gdbstub_banner);
1842
1843 gdbstub_io_init();
1844
1845 gdbstub_entry("--> gdbstub_init\n");
1846
1847 /* try to talk to GDB (or anyone insane enough to want to type GDB
1848 * protocol by hand) */
1849 gdbstub_io("### GDB Tx ACK\n");
1850 gdbstub_io_tx_char('+'); /* 'hello world' */
1851
1852 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1853 gdbstub_printk("GDB Stub waiting for packet\n");
1854
1855 /* in case GDB is started before us, ACK any packets that are already
1856 * sitting there (presumably "$?#xx")
1857 */
1858 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '$');
1859 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '#');
1860 /* eat first csum byte */
1861 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1862 /* eat second csum byte */
1863 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1864
1865 gdbstub_io("### GDB Tx NAK\n");
1866 gdbstub_io_tx_char('-'); /* NAK it */
1867
1868 #else
1869 printk("GDB Stub ready\n");
1870 #endif
1871
1872 gdbstub_busy = 0;
1873 gdbstub_entry("<-- gdbstub_init\n");
1874 }
1875
1876 /*
1877 * register the console at a more appropriate time
1878 */
1879 #ifdef CONFIG_GDBSTUB_CONSOLE
gdbstub_postinit(void)1880 static int __init gdbstub_postinit(void)
1881 {
1882 printk(KERN_NOTICE "registering console\n");
1883 register_console(&gdbstub_console);
1884 return 0;
1885 }
1886
1887 __initcall(gdbstub_postinit);
1888 #endif
1889
1890 /*
1891 * handle character reception on GDB serial port
1892 * - jump into the GDB stub if BREAK is detected on the serial line
1893 */
gdbstub_rx_irq(struct pt_regs * regs,enum exception_code excep)1894 asmlinkage void gdbstub_rx_irq(struct pt_regs *regs, enum exception_code excep)
1895 {
1896 char ch;
1897 int ret;
1898
1899 gdbstub_entry("--> gdbstub_rx_irq\n");
1900
1901 do {
1902 ret = gdbstub_io_rx_char(&ch, 1);
1903 if (ret != -EIO && ret != -EAGAIN) {
1904 if (ret != -EINTR)
1905 gdbstub_rx_unget = ch;
1906 gdbstub(regs, excep);
1907 }
1908 } while (ret != -EAGAIN);
1909
1910 gdbstub_entry("<-- gdbstub_rx_irq\n");
1911 }
1912