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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / arch / mn10300 / kernel / gdb-stub.c
blob21891c71d54965ccb770391df6e5a4522658400e
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 static const char hexchars[] = "0123456789abcdef";
167
168 struct gdbstub_bkpt {
169 u8 *addr; /* address of breakpoint */
170 u8 len; /* size of breakpoint */
171 u8 origbytes[7]; /* original bytes */
172 };
173
174 static struct gdbstub_bkpt gdbstub_bkpts[256];
175
176 /*
177 * local prototypes
178 */
179 static void getpacket(char *buffer);
180 static int putpacket(char *buffer);
181 static int computeSignal(enum exception_code excep);
182 static int hex(unsigned char ch);
183 static int hexToInt(char **ptr, int *intValue);
184 static unsigned char *mem2hex(const void *mem, char *buf, int count,
185 int may_fault);
186 static const char *hex2mem(const char *buf, void *_mem, int count,
187 int may_fault);
188
189 /*
190 * Convert ch from a hex digit to an int
191 */
192 static int hex(unsigned char ch)
193 {
194 if (ch >= 'a' && ch <= 'f')
195 return ch - 'a' + 10;
196 if (ch >= '0' && ch <= '9')
197 return ch - '0';
198 if (ch >= 'A' && ch <= 'F')
199 return ch - 'A' + 10;
200 return -1;
201 }
202
203 #ifdef CONFIG_GDBSTUB_DEBUGGING
204
205 void debug_to_serial(const char *p, int n)
206 {
207 __debug_to_serial(p, n);
208 /* gdbstub_console_write(NULL, p, n); */
209 }
210
211 void gdbstub_printk(const char *fmt, ...)
212 {
213 va_list args;
214 int len;
215
216 /* Emit the output into the temporary buffer */
217 va_start(args, fmt);
218 len = vsnprintf(trans_buffer, sizeof(trans_buffer), fmt, args);
219 va_end(args);
220 debug_to_serial(trans_buffer, len);
221 }
222
223 #endif
224
225 static inline char *gdbstub_strcpy(char *dst, const char *src)
226 {
227 int loop = 0;
228 while ((dst[loop] = src[loop]))
229 loop++;
230 return dst;
231 }
232
233 /*
234 * scan for the sequence $<data>#<checksum>
235 */
236 static void getpacket(char *buffer)
237 {
238 unsigned char checksum;
239 unsigned char xmitcsum;
240 unsigned char ch;
241 int count, i, ret, error;
242
243 for (;;) {
244 /*
245 * wait around for the start character,
246 * ignore all other characters
247 */
248 do {
249 gdbstub_io_rx_char(&ch, 0);
250 } while (ch != '$');
251
252 checksum = 0;
253 xmitcsum = -1;
254 count = 0;
255 error = 0;
256
257 /*
258 * now, read until a # or end of buffer is found
259 */
260 while (count < BUFMAX) {
261 ret = gdbstub_io_rx_char(&ch, 0);
262 if (ret < 0)
263 error = ret;
264
265 if (ch == '#')
266 break;
267 checksum += ch;
268 buffer[count] = ch;
269 count++;
270 }
271
272 if (error == -EIO) {
273 gdbstub_proto("### GDB Rx Error - Skipping packet"
274 " ###\n");
275 gdbstub_proto("### GDB Tx NAK\n");
276 gdbstub_io_tx_char('-');
277 continue;
278 }
279
280 if (count >= BUFMAX || error)
281 continue;
282
283 buffer[count] = 0;
284
285 /* read the checksum */
286 ret = gdbstub_io_rx_char(&ch, 0);
287 if (ret < 0)
288 error = ret;
289 xmitcsum = hex(ch) << 4;
290
291 ret = gdbstub_io_rx_char(&ch, 0);
292 if (ret < 0)
293 error = ret;
294 xmitcsum |= hex(ch);
295
296 if (error) {
297 if (error == -EIO)
298 gdbstub_io("### GDB Rx Error -"
299 " Skipping packet\n");
300 gdbstub_io("### GDB Tx NAK\n");
301 gdbstub_io_tx_char('-');
302 continue;
303 }
304
305 /* check the checksum */
306 if (checksum != xmitcsum) {
307 gdbstub_io("### GDB Tx NAK\n");
308 gdbstub_io_tx_char('-'); /* failed checksum */
309 continue;
310 }
311
312 gdbstub_proto("### GDB Rx '$%s#%02x' ###\n", buffer, checksum);
313 gdbstub_io("### GDB Tx ACK\n");
314 gdbstub_io_tx_char('+'); /* successful transfer */
315
316 /*
317 * if a sequence char is present,
318 * reply the sequence ID
319 */
320 if (buffer[2] == ':') {
321 gdbstub_io_tx_char(buffer[0]);
322 gdbstub_io_tx_char(buffer[1]);
323
324 /*
325 * remove sequence chars from buffer
326 */
327 count = 0;
328 while (buffer[count])
329 count++;
330 for (i = 3; i <= count; i++)
331 buffer[i - 3] = buffer[i];
332 }
333
334 break;
335 }
336 }
337
338 /*
339 * send the packet in buffer.
340 * - return 0 if successfully ACK'd
341 * - return 1 if abandoned due to new incoming packet
342 */
343 static int putpacket(char *buffer)
344 {
345 unsigned char checksum;
346 unsigned char ch;
347 int count;
348
349 /*
350 * $<packet info>#<checksum>.
351 */
352 gdbstub_proto("### GDB Tx $'%s'#?? ###\n", buffer);
353
354 do {
355 gdbstub_io_tx_char('$');
356 checksum = 0;
357 count = 0;
358
359 while ((ch = buffer[count]) != 0) {
360 gdbstub_io_tx_char(ch);
361 checksum += ch;
362 count += 1;
363 }
364
365 gdbstub_io_tx_char('#');
366 gdbstub_io_tx_char(hexchars[checksum >> 4]);
367 gdbstub_io_tx_char(hexchars[checksum & 0xf]);
368
369 } while (gdbstub_io_rx_char(&ch, 0),
370 ch == '-' && (gdbstub_io("### GDB Rx NAK\n"), 0),
371 ch != '-' && ch != '+' &&
372 (gdbstub_io("### GDB Rx ??? %02x\n", ch), 0),
373 ch != '+' && ch != '$');
374
375 if (ch == '+') {
376 gdbstub_io("### GDB Rx ACK\n");
377 return 0;
378 }
379
380 gdbstub_io("### GDB Tx Abandoned\n");
381 gdbstub_rx_unget = ch;
382 return 1;
383 }
384
385 /*
386 * While we find nice hex chars, build an int.
387 * Return number of chars processed.
388 */
389 static int hexToInt(char **ptr, int *intValue)
390 {
391 int numChars = 0;
392 int hexValue;
393
394 *intValue = 0;
395
396 while (**ptr) {
397 hexValue = hex(**ptr);
398 if (hexValue < 0)
399 break;
400
401 *intValue = (*intValue << 4) | hexValue;
402 numChars++;
403
404 (*ptr)++;
405 }
406
407 return (numChars);
408 }
409
410 /*
411 * We single-step by setting breakpoints. When an exception
412 * is handled, we need to restore the instructions hoisted
413 * when the breakpoints were set.
414 *
415 * This is where we save the original instructions.
416 */
417 static struct gdb_bp_save {
418 u8 *addr;
419 u8 opcode[2];
420 } step_bp[2];
421
422 static const unsigned char gdbstub_insn_sizes[256] =
423 {
424 /* 1 2 3 4 5 6 7 8 9 a b c d e f */
425 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
426 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
427 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
428 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
429 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
430 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
431 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
432 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
433 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
434 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
435 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
436 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
437 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
438 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
439 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
440 0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
441 };
442
443 static int __gdbstub_mark_bp(u8 *addr, int ix)
444 {
445 if (addr < (u8 *) 0x70000000UL)
446 return 0;
447 /* 70000000-7fffffff: vmalloc area */
448 if (addr < (u8 *) 0x80000000UL)
449 goto okay;
450 if (addr < (u8 *) 0x8c000000UL)
451 return 0;
452 /* 8c000000-93ffffff: SRAM, SDRAM */
453 if (addr < (u8 *) 0x94000000UL)
454 goto okay;
455 return 0;
456
457 okay:
458 if (gdbstub_read_byte(addr + 0, &step_bp[ix].opcode[0]) < 0 ||
459 gdbstub_read_byte(addr + 1, &step_bp[ix].opcode[1]) < 0)
460 return 0;
461
462 step_bp[ix].addr = addr;
463 return 1;
464 }
465
466 static inline void __gdbstub_restore_bp(void)
467 {
468 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
469 if (step_bp[0].addr) {
470 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
471 gdbstub_write_byte(step_bp[0].opcode[1], step_bp[0].addr + 1);
472 }
473 if (step_bp[1].addr) {
474 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
475 gdbstub_write_byte(step_bp[1].opcode[1], step_bp[1].addr + 1);
476 }
477 #else
478 if (step_bp[0].addr)
479 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
480 if (step_bp[1].addr)
481 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
482 #endif
483
484 gdbstub_flush_caches = 1;
485
486 step_bp[0].addr = NULL;
487 step_bp[0].opcode[0] = 0;
488 step_bp[0].opcode[1] = 0;
489 step_bp[1].addr = NULL;
490 step_bp[1].opcode[0] = 0;
491 step_bp[1].opcode[1] = 0;
492 }
493
494 /*
495 * emulate single stepping by means of breakpoint instructions
496 */
497 static int gdbstub_single_step(struct pt_regs *regs)
498 {
499 unsigned size;
500 uint32_t x;
501 uint8_t cur, *pc, *sp;
502
503 step_bp[0].addr = NULL;
504 step_bp[0].opcode[0] = 0;
505 step_bp[0].opcode[1] = 0;
506 step_bp[1].addr = NULL;
507 step_bp[1].opcode[0] = 0;
508 step_bp[1].opcode[1] = 0;
509 x = 0;
510
511 pc = (u8 *) regs->pc;
512 sp = (u8 *) (regs + 1);
513 if (gdbstub_read_byte(pc, &cur) < 0)
514 return -EFAULT;
515
516 gdbstub_bkpt("Single Step from %p { %02x }\n", pc, cur);
517
518 gdbstub_flush_caches = 1;
519
520 size = gdbstub_insn_sizes[cur];
521 if (size > 0) {
522 if (!__gdbstub_mark_bp(pc + size, 0))
523 goto fault;
524 } else {
525 switch (cur) {
526 /* Bxx (d8,PC) */
527 case 0xc0:
528 case 0xc1:
529 case 0xc2:
530 case 0xc3:
531 case 0xc4:
532 case 0xc5:
533 case 0xc6:
534 case 0xc7:
535 case 0xc8:
536 case 0xc9:
537 case 0xca:
538 if (gdbstub_read_byte(pc + 1, (u8 *) &x) < 0)
539 goto fault;
540 if (!__gdbstub_mark_bp(pc + 2, 0))
541 goto fault;
542 if ((x < 0 || x > 2) &&
543 !__gdbstub_mark_bp(pc + (s8) x, 1))
544 goto fault;
545 break;
546
547 /* LXX (d8,PC) */
548 case 0xd0:
549 case 0xd1:
550 case 0xd2:
551 case 0xd3:
552 case 0xd4:
553 case 0xd5:
554 case 0xd6:
555 case 0xd7:
556 case 0xd8:
557 case 0xd9:
558 case 0xda:
559 if (!__gdbstub_mark_bp(pc + 1, 0))
560 goto fault;
561 if (regs->pc != regs->lar &&
562 !__gdbstub_mark_bp((u8 *) regs->lar, 1))
563 goto fault;
564 break;
565
566 /* SETLB - loads the next for bytes into the LIR
567 * register */
568 case 0xdb:
569 if (!__gdbstub_mark_bp(pc + 1, 0))
570 goto fault;
571 break;
572
573 /* JMP (d16,PC) or CALL (d16,PC) */
574 case 0xcc:
575 case 0xcd:
576 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
577 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0)
578 goto fault;
579 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
580 goto fault;
581 break;
582
583 /* JMP (d32,PC) or CALL (d32,PC) */
584 case 0xdc:
585 case 0xdd:
586 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
587 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0 ||
588 gdbstub_read_byte(pc + 3, ((u8 *) &x) + 2) < 0 ||
589 gdbstub_read_byte(pc + 4, ((u8 *) &x) + 3) < 0)
590 goto fault;
591 if (!__gdbstub_mark_bp(pc + (s32) x, 0))
592 goto fault;
593 break;
594
595 /* RETF */
596 case 0xde:
597 if (!__gdbstub_mark_bp((u8 *) regs->mdr, 0))
598 goto fault;
599 break;
600
601 /* RET */
602 case 0xdf:
603 if (gdbstub_read_byte(pc + 2, (u8 *) &x) < 0)
604 goto fault;
605 sp += (s8)x;
606 if (gdbstub_read_byte(sp + 0, ((u8 *) &x) + 0) < 0 ||
607 gdbstub_read_byte(sp + 1, ((u8 *) &x) + 1) < 0 ||
608 gdbstub_read_byte(sp + 2, ((u8 *) &x) + 2) < 0 ||
609 gdbstub_read_byte(sp + 3, ((u8 *) &x) + 3) < 0)
610 goto fault;
611 if (!__gdbstub_mark_bp((u8 *) x, 0))
612 goto fault;
613 break;
614
615 case 0xf0:
616 if (gdbstub_read_byte(pc + 1, &cur) < 0)
617 goto fault;
618
619 if (cur >= 0xf0 && cur <= 0xf7) {
620 /* JMP (An) / CALLS (An) */
621 switch (cur & 3) {
622 case 0: x = regs->a0; break;
623 case 1: x = regs->a1; break;
624 case 2: x = regs->a2; break;
625 case 3: x = regs->a3; break;
626 }
627 if (!__gdbstub_mark_bp((u8 *) x, 0))
628 goto fault;
629 } else if (cur == 0xfc) {
630 /* RETS */
631 if (gdbstub_read_byte(
632 sp + 0, ((u8 *) &x) + 0) < 0 ||
633 gdbstub_read_byte(
634 sp + 1, ((u8 *) &x) + 1) < 0 ||
635 gdbstub_read_byte(
636 sp + 2, ((u8 *) &x) + 2) < 0 ||
637 gdbstub_read_byte(
638 sp + 3, ((u8 *) &x) + 3) < 0)
639 goto fault;
640 if (!__gdbstub_mark_bp((u8 *) x, 0))
641 goto fault;
642 } else if (cur == 0xfd) {
643 /* RTI */
644 if (gdbstub_read_byte(
645 sp + 4, ((u8 *) &x) + 0) < 0 ||
646 gdbstub_read_byte(
647 sp + 5, ((u8 *) &x) + 1) < 0 ||
648 gdbstub_read_byte(
649 sp + 6, ((u8 *) &x) + 2) < 0 ||
650 gdbstub_read_byte(
651 sp + 7, ((u8 *) &x) + 3) < 0)
652 goto fault;
653 if (!__gdbstub_mark_bp((u8 *) x, 0))
654 goto fault;
655 } else {
656 if (!__gdbstub_mark_bp(pc + 2, 0))
657 goto fault;
658 }
659
660 break;
661
662 /* potential 3-byte conditional branches */
663 case 0xf8:
664 if (gdbstub_read_byte(pc + 1, &cur) < 0)
665 goto fault;
666 if (!__gdbstub_mark_bp(pc + 3, 0))
667 goto fault;
668
669 if (cur >= 0xe8 && cur <= 0xeb) {
670 if (gdbstub_read_byte(
671 pc + 2, ((u8 *) &x) + 0) < 0)
672 goto fault;
673 if ((x < 0 || x > 3) &&
674 !__gdbstub_mark_bp(pc + (s8) x, 1))
675 goto fault;
676 }
677 break;
678
679 case 0xfa:
680 if (gdbstub_read_byte(pc + 1, &cur) < 0)
681 goto fault;
682
683 if (cur == 0xff) {
684 /* CALLS (d16,PC) */
685 if (gdbstub_read_byte(
686 pc + 2, ((u8 *) &x) + 0) < 0 ||
687 gdbstub_read_byte(
688 pc + 3, ((u8 *) &x) + 1) < 0)
689 goto fault;
690 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
691 goto fault;
692 } else {
693 if (!__gdbstub_mark_bp(pc + 4, 0))
694 goto fault;
695 }
696 break;
697
698 case 0xfc:
699 if (gdbstub_read_byte(pc + 1, &cur) < 0)
700 goto fault;
701 if (cur == 0xff) {
702 /* CALLS (d32,PC) */
703 if (gdbstub_read_byte(
704 pc + 2, ((u8 *) &x) + 0) < 0 ||
705 gdbstub_read_byte(
706 pc + 3, ((u8 *) &x) + 1) < 0 ||
707 gdbstub_read_byte(
708 pc + 4, ((u8 *) &x) + 2) < 0 ||
709 gdbstub_read_byte(
710 pc + 5, ((u8 *) &x) + 3) < 0)
711 goto fault;
712 if (!__gdbstub_mark_bp(
713 pc + (s32) x, 0))
714 goto fault;
715 } else {
716 if (!__gdbstub_mark_bp(
717 pc + 6, 0))
718 goto fault;
719 }
720 break;
721
722 }
723 }
724
725 gdbstub_bkpt("Step: %02x at %p; %02x at %p\n",
726 step_bp[0].opcode[0], step_bp[0].addr,
727 step_bp[1].opcode[0], step_bp[1].addr);
728
729 if (step_bp[0].addr) {
730 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
731 if (gdbstub_write_byte(0xF7, step_bp[0].addr + 0) < 0 ||
732 gdbstub_write_byte(0xF7, step_bp[0].addr + 1) < 0)
733 goto fault;
734 #else
735 if (gdbstub_write_byte(0xFF, step_bp[0].addr + 0) < 0)
736 goto fault;
737 #endif
738 }
739
740 if (step_bp[1].addr) {
741 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
742 if (gdbstub_write_byte(0xF7, step_bp[1].addr + 0) < 0 ||
743 gdbstub_write_byte(0xF7, step_bp[1].addr + 1) < 0)
744 goto fault;
745 #else
746 if (gdbstub_write_byte(0xFF, step_bp[1].addr + 0) < 0)
747 goto fault;
748 #endif
749 }
750
751 return 0;
752
753 fault:
754 /* uh-oh - silly address alert, try and restore things */
755 __gdbstub_restore_bp();
756 return -EFAULT;
757 }
758
759 #ifdef CONFIG_GDBSTUB_CONSOLE
760
761 void gdbstub_console_write(struct console *con, const char *p, unsigned n)
762 {
763 static const char gdbstub_cr[] = { 0x0d };
764 char outbuf[26];
765 int qty;
766 u8 busy;
767
768 busy = gdbstub_busy;
769 gdbstub_busy = 1;
770
771 outbuf[0] = 'O';
772
773 while (n > 0) {
774 qty = 1;
775
776 while (n > 0 && qty < 20) {
777 mem2hex(p, outbuf + qty, 2, 0);
778 qty += 2;
779 if (*p == 0x0a) {
780 mem2hex(gdbstub_cr, outbuf + qty, 2, 0);
781 qty += 2;
782 }
783 p++;
784 n--;
785 }
786
787 outbuf[qty] = 0;
788 putpacket(outbuf);
789 }
790
791 gdbstub_busy = busy;
792 }
793
794 static kdev_t gdbstub_console_dev(struct console *con)
795 {
796 return MKDEV(1, 3); /* /dev/null */
797 }
798
799 static struct console gdbstub_console = {
800 .name = "gdb",
801 .write = gdbstub_console_write,
802 .device = gdbstub_console_dev,
803 .flags = CON_PRINTBUFFER,
804 .index = -1,
805 };
806
807 #endif
808
809 /*
810 * Convert the memory pointed to by mem into hex, placing result in buf.
811 * - if successful, return a pointer to the last char put in buf (NUL)
812 * - in case of mem fault, return NULL
813 * may_fault is non-zero if we are reading from arbitrary memory, but is
814 * currently not used.
815 */
816 static
817 unsigned char *mem2hex(const void *_mem, char *buf, int count, int may_fault)
818 {
819 const u8 *mem = _mem;
820 u8 ch[4];
821
822 if ((u32) mem & 1 && count >= 1) {
823 if (gdbstub_read_byte(mem, ch) != 0)
824 return 0;
825 *buf++ = hexchars[ch[0] >> 4];
826 *buf++ = hexchars[ch[0] & 0xf];
827 mem++;
828 count--;
829 }
830
831 if ((u32) mem & 3 && count >= 2) {
832 if (gdbstub_read_word(mem, ch) != 0)
833 return 0;
834 *buf++ = hexchars[ch[0] >> 4];
835 *buf++ = hexchars[ch[0] & 0xf];
836 *buf++ = hexchars[ch[1] >> 4];
837 *buf++ = hexchars[ch[1] & 0xf];
838 mem += 2;
839 count -= 2;
840 }
841
842 while (count >= 4) {
843 if (gdbstub_read_dword(mem, ch) != 0)
844 return 0;
845 *buf++ = hexchars[ch[0] >> 4];
846 *buf++ = hexchars[ch[0] & 0xf];
847 *buf++ = hexchars[ch[1] >> 4];
848 *buf++ = hexchars[ch[1] & 0xf];
849 *buf++ = hexchars[ch[2] >> 4];
850 *buf++ = hexchars[ch[2] & 0xf];
851 *buf++ = hexchars[ch[3] >> 4];
852 *buf++ = hexchars[ch[3] & 0xf];
853 mem += 4;
854 count -= 4;
855 }
856
857 if (count >= 2) {
858 if (gdbstub_read_word(mem, ch) != 0)
859 return 0;
860 *buf++ = hexchars[ch[0] >> 4];
861 *buf++ = hexchars[ch[0] & 0xf];
862 *buf++ = hexchars[ch[1] >> 4];
863 *buf++ = hexchars[ch[1] & 0xf];
864 mem += 2;
865 count -= 2;
866 }
867
868 if (count >= 1) {
869 if (gdbstub_read_byte(mem, ch) != 0)
870 return 0;
871 *buf++ = hexchars[ch[0] >> 4];
872 *buf++ = hexchars[ch[0] & 0xf];
873 }
874
875 *buf = 0;
876 return buf;
877 }
878
879 /*
880 * convert the hex array pointed to by buf into binary to be placed in mem
881 * return a pointer to the character AFTER the last byte written
882 * may_fault is non-zero if we are reading from arbitrary memory, but is
883 * currently not used.
884 */
885 static
886 const char *hex2mem(const char *buf, void *_mem, int count, int may_fault)
887 {
888 u8 *mem = _mem;
889 union {
890 u32 val;
891 u8 b[4];
892 } ch;
893
894 if ((u32) mem & 1 && count >= 1) {
895 ch.b[0] = hex(*buf++) << 4;
896 ch.b[0] |= hex(*buf++);
897 if (gdbstub_write_byte(ch.val, mem) != 0)
898 return 0;
899 mem++;
900 count--;
901 }
902
903 if ((u32) mem & 3 && count >= 2) {
904 ch.b[0] = hex(*buf++) << 4;
905 ch.b[0] |= hex(*buf++);
906 ch.b[1] = hex(*buf++) << 4;
907 ch.b[1] |= hex(*buf++);
908 if (gdbstub_write_word(ch.val, mem) != 0)
909 return 0;
910 mem += 2;
911 count -= 2;
912 }
913
914 while (count >= 4) {
915 ch.b[0] = hex(*buf++) << 4;
916 ch.b[0] |= hex(*buf++);
917 ch.b[1] = hex(*buf++) << 4;
918 ch.b[1] |= hex(*buf++);
919 ch.b[2] = hex(*buf++) << 4;
920 ch.b[2] |= hex(*buf++);
921 ch.b[3] = hex(*buf++) << 4;
922 ch.b[3] |= hex(*buf++);
923 if (gdbstub_write_dword(ch.val, mem) != 0)
924 return 0;
925 mem += 4;
926 count -= 4;
927 }
928
929 if (count >= 2) {
930 ch.b[0] = hex(*buf++) << 4;
931 ch.b[0] |= hex(*buf++);
932 ch.b[1] = hex(*buf++) << 4;
933 ch.b[1] |= hex(*buf++);
934 if (gdbstub_write_word(ch.val, mem) != 0)
935 return 0;
936 mem += 2;
937 count -= 2;
938 }
939
940 if (count >= 1) {
941 ch.b[0] = hex(*buf++) << 4;
942 ch.b[0] |= hex(*buf++);
943 if (gdbstub_write_byte(ch.val, mem) != 0)
944 return 0;
945 }
946
947 return buf;
948 }
949
950 /*
951 * This table contains the mapping between MN10300 exception codes, and
952 * signals, which are primarily what GDB understands. It also indicates
953 * which hardware traps we need to commandeer when initializing the stub.
954 */
955 static const struct excep_to_sig_map {
956 enum exception_code excep; /* MN10300 exception code */
957 unsigned char signo; /* Signal that we map this into */
958 } excep_to_sig_map[] = {
959 { EXCEP_ITLBMISS, SIGSEGV },
960 { EXCEP_DTLBMISS, SIGSEGV },
961 { EXCEP_TRAP, SIGTRAP },
962 { EXCEP_ISTEP, SIGTRAP },
963 { EXCEP_IBREAK, SIGTRAP },
964 { EXCEP_OBREAK, SIGTRAP },
965 { EXCEP_UNIMPINS, SIGILL },
966 { EXCEP_UNIMPEXINS, SIGILL },
967 { EXCEP_MEMERR, SIGSEGV },
968 { EXCEP_MISALIGN, SIGSEGV },
969 { EXCEP_BUSERROR, SIGBUS },
970 { EXCEP_ILLINSACC, SIGSEGV },
971 { EXCEP_ILLDATACC, SIGSEGV },
972 { EXCEP_IOINSACC, SIGSEGV },
973 { EXCEP_PRIVINSACC, SIGSEGV },
974 { EXCEP_PRIVDATACC, SIGSEGV },
975 { EXCEP_FPU_DISABLED, SIGFPE },
976 { EXCEP_FPU_UNIMPINS, SIGFPE },
977 { EXCEP_FPU_OPERATION, SIGFPE },
978 { EXCEP_WDT, SIGALRM },
979 { EXCEP_NMI, SIGQUIT },
980 { EXCEP_IRQ_LEVEL0, SIGINT },
981 { EXCEP_IRQ_LEVEL1, SIGINT },
982 { EXCEP_IRQ_LEVEL2, SIGINT },
983 { EXCEP_IRQ_LEVEL3, SIGINT },
984 { EXCEP_IRQ_LEVEL4, SIGINT },
985 { EXCEP_IRQ_LEVEL5, SIGINT },
986 { EXCEP_IRQ_LEVEL6, SIGINT },
987 { 0, 0}
988 };
989
990 /*
991 * convert the MN10300 exception code into a UNIX signal number
992 */
993 static int computeSignal(enum exception_code excep)
994 {
995 const struct excep_to_sig_map *map;
996
997 for (map = excep_to_sig_map; map->signo; map++)
998 if (map->excep == excep)
999 return map->signo;
1000
1001 return SIGHUP; /* default for things we don't know about */
1002 }
1003
1004 static u32 gdbstub_fpcr, gdbstub_fpufs_array[32];
1005
1006 /*
1007 *
1008 */
1009 static void gdbstub_store_fpu(void)
1010 {
1011 #ifdef CONFIG_FPU
1012
1013 asm volatile(
1014 "or %2,epsw\n"
1015 #ifdef CONFIG_MN10300_PROC_MN103E010
1016 "nop\n"
1017 "nop\n"
1018 #endif
1019 "mov %1, a1\n"
1020 "fmov fs0, (a1+)\n"
1021 "fmov fs1, (a1+)\n"
1022 "fmov fs2, (a1+)\n"
1023 "fmov fs3, (a1+)\n"
1024 "fmov fs4, (a1+)\n"
1025 "fmov fs5, (a1+)\n"
1026 "fmov fs6, (a1+)\n"
1027 "fmov fs7, (a1+)\n"
1028 "fmov fs8, (a1+)\n"
1029 "fmov fs9, (a1+)\n"
1030 "fmov fs10, (a1+)\n"
1031 "fmov fs11, (a1+)\n"
1032 "fmov fs12, (a1+)\n"
1033 "fmov fs13, (a1+)\n"
1034 "fmov fs14, (a1+)\n"
1035 "fmov fs15, (a1+)\n"
1036 "fmov fs16, (a1+)\n"
1037 "fmov fs17, (a1+)\n"
1038 "fmov fs18, (a1+)\n"
1039 "fmov fs19, (a1+)\n"
1040 "fmov fs20, (a1+)\n"
1041 "fmov fs21, (a1+)\n"
1042 "fmov fs22, (a1+)\n"
1043 "fmov fs23, (a1+)\n"
1044 "fmov fs24, (a1+)\n"
1045 "fmov fs25, (a1+)\n"
1046 "fmov fs26, (a1+)\n"
1047 "fmov fs27, (a1+)\n"
1048 "fmov fs28, (a1+)\n"
1049 "fmov fs29, (a1+)\n"
1050 "fmov fs30, (a1+)\n"
1051 "fmov fs31, (a1+)\n"
1052 "fmov fpcr, %0\n"
1053 : "=d"(gdbstub_fpcr)
1054 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE)
1055 : "a1"
1056 );
1057 #endif
1058 }
1059
1060 /*
1061 *
1062 */
1063 static void gdbstub_load_fpu(void)
1064 {
1065 #ifdef CONFIG_FPU
1066
1067 asm volatile(
1068 "or %1,epsw\n"
1069 #ifdef CONFIG_MN10300_PROC_MN103E010
1070 "nop\n"
1071 "nop\n"
1072 #endif
1073 "mov %0, a1\n"
1074 "fmov (a1+), fs0\n"
1075 "fmov (a1+), fs1\n"
1076 "fmov (a1+), fs2\n"
1077 "fmov (a1+), fs3\n"
1078 "fmov (a1+), fs4\n"
1079 "fmov (a1+), fs5\n"
1080 "fmov (a1+), fs6\n"
1081 "fmov (a1+), fs7\n"
1082 "fmov (a1+), fs8\n"
1083 "fmov (a1+), fs9\n"
1084 "fmov (a1+), fs10\n"
1085 "fmov (a1+), fs11\n"
1086 "fmov (a1+), fs12\n"
1087 "fmov (a1+), fs13\n"
1088 "fmov (a1+), fs14\n"
1089 "fmov (a1+), fs15\n"
1090 "fmov (a1+), fs16\n"
1091 "fmov (a1+), fs17\n"
1092 "fmov (a1+), fs18\n"
1093 "fmov (a1+), fs19\n"
1094 "fmov (a1+), fs20\n"
1095 "fmov (a1+), fs21\n"
1096 "fmov (a1+), fs22\n"
1097 "fmov (a1+), fs23\n"
1098 "fmov (a1+), fs24\n"
1099 "fmov (a1+), fs25\n"
1100 "fmov (a1+), fs26\n"
1101 "fmov (a1+), fs27\n"
1102 "fmov (a1+), fs28\n"
1103 "fmov (a1+), fs29\n"
1104 "fmov (a1+), fs30\n"
1105 "fmov (a1+), fs31\n"
1106 "fmov %2, fpcr\n"
1107 :
1108 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE), "d"(gdbstub_fpcr)
1109 : "a1"
1110 );
1111 #endif
1112 }
1113
1114 /*
1115 * set a software breakpoint
1116 */
1117 int gdbstub_set_breakpoint(u8 *addr, int len)
1118 {
1119 int bkpt, loop, xloop;
1120
1121 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1122 len = (len + 1) & ~1;
1123 #endif
1124
1125 gdbstub_bkpt("setbkpt(%p,%d)\n", addr, len);
1126
1127 for (bkpt = 255; bkpt >= 0; bkpt--)
1128 if (!gdbstub_bkpts[bkpt].addr)
1129 break;
1130 if (bkpt < 0)
1131 return -ENOSPC;
1132
1133 for (loop = 0; loop < len; loop++)
1134 if (gdbstub_read_byte(&addr[loop],
1135 &gdbstub_bkpts[bkpt].origbytes[loop]
1136 ) < 0)
1137 return -EFAULT;
1138
1139 gdbstub_flush_caches = 1;
1140
1141 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1142 for (loop = 0; loop < len; loop++)
1143 if (gdbstub_write_byte(0xF7, &addr[loop]) < 0)
1144 goto restore;
1145 #else
1146 for (loop = 0; loop < len; loop++)
1147 if (gdbstub_write_byte(0xFF, &addr[loop]) < 0)
1148 goto restore;
1149 #endif
1150
1151 gdbstub_bkpts[bkpt].addr = addr;
1152 gdbstub_bkpts[bkpt].len = len;
1153
1154 gdbstub_bkpt("Set BKPT[%02x]: %p-%p {%02x%02x%02x%02x%02x%02x%02x}\n",
1155 bkpt,
1156 gdbstub_bkpts[bkpt].addr,
1157 gdbstub_bkpts[bkpt].addr + gdbstub_bkpts[bkpt].len - 1,
1158 gdbstub_bkpts[bkpt].origbytes[0],
1159 gdbstub_bkpts[bkpt].origbytes[1],
1160 gdbstub_bkpts[bkpt].origbytes[2],
1161 gdbstub_bkpts[bkpt].origbytes[3],
1162 gdbstub_bkpts[bkpt].origbytes[4],
1163 gdbstub_bkpts[bkpt].origbytes[5],
1164 gdbstub_bkpts[bkpt].origbytes[6]
1165 );
1166
1167 return 0;
1168
1169 restore:
1170 for (xloop = 0; xloop < loop; xloop++)
1171 gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[xloop],
1172 addr + xloop);
1173 return -EFAULT;
1174 }
1175
1176 /*
1177 * clear a software breakpoint
1178 */
1179 int gdbstub_clear_breakpoint(u8 *addr, int len)
1180 {
1181 int bkpt, loop;
1182
1183 #ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1184 len = (len + 1) & ~1;
1185 #endif
1186
1187 gdbstub_bkpt("clearbkpt(%p,%d)\n", addr, len);
1188
1189 for (bkpt = 255; bkpt >= 0; bkpt--)
1190 if (gdbstub_bkpts[bkpt].addr == addr &&
1191 gdbstub_bkpts[bkpt].len == len)
1192 break;
1193 if (bkpt < 0)
1194 return -ENOENT;
1195
1196 gdbstub_bkpts[bkpt].addr = NULL;
1197
1198 gdbstub_flush_caches = 1;
1199
1200 for (loop = 0; loop < len; loop++)
1201 if (gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[loop],
1202 addr + loop) < 0)
1203 return -EFAULT;
1204
1205 return 0;
1206 }
1207
1208 /*
1209 * This function does all command processing for interfacing to gdb
1210 * - returns 1 if the exception should be skipped, 0 otherwise.
1211 */
1212 static int gdbstub(struct pt_regs *regs, enum exception_code excep)
1213 {
1214 unsigned long *stack;
1215 unsigned long epsw, mdr;
1216 uint32_t zero, ssp;
1217 uint8_t broke;
1218 char *ptr;
1219 int sigval;
1220 int addr;
1221 int length;
1222 int loop;
1223
1224 if (excep == EXCEP_FPU_DISABLED)
1225 return 0;
1226
1227 gdbstub_flush_caches = 0;
1228
1229 mn10300_set_gdbleds(1);
1230
1231 asm volatile("mov mdr,%0" : "=d"(mdr));
1232 asm volatile("mov epsw,%0" : "=d"(epsw));
1233 asm volatile("mov %0,epsw"
1234 :: "d"((epsw & ~EPSW_IM) | EPSW_IE | EPSW_IM_1));
1235
1236 gdbstub_store_fpu();
1237
1238 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1239 /* skip the initial pause loop */
1240 if (regs->pc == (unsigned long) __gdbstub_pause)
1241 regs->pc = (unsigned long) start_kernel;
1242 #endif
1243
1244 /* if we were single stepping, restore the opcodes hoisted for the
1245 * breakpoint[s] */
1246 broke = 0;
1247 if ((step_bp[0].addr && step_bp[0].addr == (u8 *) regs->pc) ||
1248 (step_bp[1].addr && step_bp[1].addr == (u8 *) regs->pc))
1249 broke = 1;
1250
1251 __gdbstub_restore_bp();
1252
1253 if (gdbstub_rx_unget) {
1254 sigval = SIGINT;
1255 if (gdbstub_rx_unget != 3)
1256 goto packet_waiting;
1257 gdbstub_rx_unget = 0;
1258 }
1259
1260 stack = (unsigned long *) regs->sp;
1261 sigval = broke ? SIGTRAP : computeSignal(excep);
1262
1263 /* send information about a BUG() */
1264 if (!user_mode(regs) && excep == EXCEP_SYSCALL15) {
1265 const struct bug_entry *bug;
1266
1267 bug = find_bug(regs->pc);
1268 if (bug)
1269 goto found_bug;
1270 length = snprintf(trans_buffer, sizeof(trans_buffer),
1271 "BUG() at address %lx\n", regs->pc);
1272 goto send_bug_pkt;
1273
1274 found_bug:
1275 length = snprintf(trans_buffer, sizeof(trans_buffer),
1276 "BUG() at address %lx (%s:%d)\n",
1277 regs->pc, bug->file, bug->line);
1278
1279 send_bug_pkt:
1280 ptr = output_buffer;
1281 *ptr++ = 'O';
1282 ptr = mem2hex(trans_buffer, ptr, length, 0);
1283 *ptr = 0;
1284 putpacket(output_buffer);
1285
1286 regs->pc -= 2;
1287 sigval = SIGABRT;
1288 } else if (regs->pc == (unsigned long) __gdbstub_bug_trap) {
1289 regs->pc = regs->mdr;
1290 sigval = SIGABRT;
1291 }
1292
1293 /*
1294 * send a message to the debugger's user saying what happened if it may
1295 * not be clear cut (we can't map exceptions onto signals properly)
1296 */
1297 if (sigval != SIGINT && sigval != SIGTRAP && sigval != SIGILL) {
1298 static const char title[] = "Excep ", tbcberr[] = "BCBERR ";
1299 static const char crlf[] = "\r\n";
1300 char hx;
1301 u32 bcberr = BCBERR;
1302
1303 ptr = output_buffer;
1304 *ptr++ = 'O';
1305 ptr = mem2hex(title, ptr, sizeof(title) - 1, 0);
1306
1307 hx = hexchars[(excep & 0xf000) >> 12];
1308 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1309 hx = hexchars[(excep & 0x0f00) >> 8];
1310 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1311 hx = hexchars[(excep & 0x00f0) >> 4];
1312 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1313 hx = hexchars[(excep & 0x000f)];
1314 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1315
1316 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1317 *ptr = 0;
1318 putpacket(output_buffer); /* send it off... */
1319
1320 /* BCBERR */
1321 ptr = output_buffer;
1322 *ptr++ = 'O';
1323 ptr = mem2hex(tbcberr, ptr, sizeof(tbcberr) - 1, 0);
1324
1325 hx = hexchars[(bcberr & 0xf0000000) >> 28];
1326 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1327 hx = hexchars[(bcberr & 0x0f000000) >> 24];
1328 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1329 hx = hexchars[(bcberr & 0x00f00000) >> 20];
1330 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1331 hx = hexchars[(bcberr & 0x000f0000) >> 16];
1332 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1333 hx = hexchars[(bcberr & 0x0000f000) >> 12];
1334 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1335 hx = hexchars[(bcberr & 0x00000f00) >> 8];
1336 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1337 hx = hexchars[(bcberr & 0x000000f0) >> 4];
1338 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1339 hx = hexchars[(bcberr & 0x0000000f)];
1340 *ptr++ = hexchars[hx >> 4]; *ptr++ = hexchars[hx & 0xf];
1341
1342 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1343 *ptr = 0;
1344 putpacket(output_buffer); /* send it off... */
1345 }
1346
1347 /*
1348 * tell the debugger that an exception has occurred
1349 */
1350 ptr = output_buffer;
1351
1352 /*
1353 * Send trap type (converted to signal)
1354 */
1355 *ptr++ = 'T';
1356 *ptr++ = hexchars[sigval >> 4];
1357 *ptr++ = hexchars[sigval & 0xf];
1358
1359 /*
1360 * Send Error PC
1361 */
1362 *ptr++ = hexchars[GDB_REGID_PC >> 4];
1363 *ptr++ = hexchars[GDB_REGID_PC & 0xf];
1364 *ptr++ = ':';
1365 ptr = mem2hex(&regs->pc, ptr, 4, 0);
1366 *ptr++ = ';';
1367
1368 /*
1369 * Send frame pointer
1370 */
1371 *ptr++ = hexchars[GDB_REGID_FP >> 4];
1372 *ptr++ = hexchars[GDB_REGID_FP & 0xf];
1373 *ptr++ = ':';
1374 ptr = mem2hex(&regs->a3, ptr, 4, 0);
1375 *ptr++ = ';';
1376
1377 /*
1378 * Send stack pointer
1379 */
1380 ssp = (unsigned long) (regs + 1);
1381 *ptr++ = hexchars[GDB_REGID_SP >> 4];
1382 *ptr++ = hexchars[GDB_REGID_SP & 0xf];
1383 *ptr++ = ':';
1384 ptr = mem2hex(&ssp, ptr, 4, 0);
1385 *ptr++ = ';';
1386
1387 *ptr++ = 0;
1388 putpacket(output_buffer); /* send it off... */
1389
1390 packet_waiting:
1391 /*
1392 * Wait for input from remote GDB
1393 */
1394 while (1) {
1395 output_buffer[0] = 0;
1396 getpacket(input_buffer);
1397
1398 switch (input_buffer[0]) {
1399 /* request repeat of last signal number */
1400 case '?':
1401 output_buffer[0] = 'S';
1402 output_buffer[1] = hexchars[sigval >> 4];
1403 output_buffer[2] = hexchars[sigval & 0xf];
1404 output_buffer[3] = 0;
1405 break;
1406
1407 case 'd':
1408 /* toggle debug flag */
1409 break;
1410
1411 /*
1412 * Return the value of the CPU registers
1413 */
1414 case 'g':
1415 zero = 0;
1416 ssp = (u32) (regs + 1);
1417 ptr = output_buffer;
1418 ptr = mem2hex(&regs->d0, ptr, 4, 0);
1419 ptr = mem2hex(&regs->d1, ptr, 4, 0);
1420 ptr = mem2hex(&regs->d2, ptr, 4, 0);
1421 ptr = mem2hex(&regs->d3, ptr, 4, 0);
1422 ptr = mem2hex(&regs->a0, ptr, 4, 0);
1423 ptr = mem2hex(&regs->a1, ptr, 4, 0);
1424 ptr = mem2hex(&regs->a2, ptr, 4, 0);
1425 ptr = mem2hex(&regs->a3, ptr, 4, 0);
1426
1427 ptr = mem2hex(&ssp, ptr, 4, 0); /* 8 */
1428 ptr = mem2hex(&regs->pc, ptr, 4, 0);
1429 ptr = mem2hex(&regs->mdr, ptr, 4, 0);
1430 ptr = mem2hex(&regs->epsw, ptr, 4, 0);
1431 ptr = mem2hex(&regs->lir, ptr, 4, 0);
1432 ptr = mem2hex(&regs->lar, ptr, 4, 0);
1433 ptr = mem2hex(&regs->mdrq, ptr, 4, 0);
1434
1435 ptr = mem2hex(&regs->e0, ptr, 4, 0); /* 15 */
1436 ptr = mem2hex(&regs->e1, ptr, 4, 0);
1437 ptr = mem2hex(&regs->e2, ptr, 4, 0);
1438 ptr = mem2hex(&regs->e3, ptr, 4, 0);
1439 ptr = mem2hex(&regs->e4, ptr, 4, 0);
1440 ptr = mem2hex(&regs->e5, ptr, 4, 0);
1441 ptr = mem2hex(&regs->e6, ptr, 4, 0);
1442 ptr = mem2hex(&regs->e7, ptr, 4, 0);
1443
1444 ptr = mem2hex(&ssp, ptr, 4, 0);
1445 ptr = mem2hex(&regs, ptr, 4, 0);
1446 ptr = mem2hex(&regs->sp, ptr, 4, 0);
1447 ptr = mem2hex(&regs->mcrh, ptr, 4, 0); /* 26 */
1448 ptr = mem2hex(&regs->mcrl, ptr, 4, 0);
1449 ptr = mem2hex(&regs->mcvf, ptr, 4, 0);
1450
1451 ptr = mem2hex(&gdbstub_fpcr, ptr, 4, 0); /* 29 - FPCR */
1452 ptr = mem2hex(&zero, ptr, 4, 0);
1453 ptr = mem2hex(&zero, ptr, 4, 0);
1454 for (loop = 0; loop < 32; loop++)
1455 ptr = mem2hex(&gdbstub_fpufs_array[loop],
1456 ptr, 4, 0); /* 32 - FS0-31 */
1457
1458 break;
1459
1460 /*
1461 * set the value of the CPU registers - return OK
1462 */
1463 case 'G':
1464 {
1465 const char *ptr;
1466
1467 ptr = &input_buffer[1];
1468 ptr = hex2mem(ptr, &regs->d0, 4, 0);
1469 ptr = hex2mem(ptr, &regs->d1, 4, 0);
1470 ptr = hex2mem(ptr, &regs->d2, 4, 0);
1471 ptr = hex2mem(ptr, &regs->d3, 4, 0);
1472 ptr = hex2mem(ptr, &regs->a0, 4, 0);
1473 ptr = hex2mem(ptr, &regs->a1, 4, 0);
1474 ptr = hex2mem(ptr, &regs->a2, 4, 0);
1475 ptr = hex2mem(ptr, &regs->a3, 4, 0);
1476
1477 ptr = hex2mem(ptr, &ssp, 4, 0); /* 8 */
1478 ptr = hex2mem(ptr, &regs->pc, 4, 0);
1479 ptr = hex2mem(ptr, &regs->mdr, 4, 0);
1480 ptr = hex2mem(ptr, &regs->epsw, 4, 0);
1481 ptr = hex2mem(ptr, &regs->lir, 4, 0);
1482 ptr = hex2mem(ptr, &regs->lar, 4, 0);
1483 ptr = hex2mem(ptr, &regs->mdrq, 4, 0);
1484
1485 ptr = hex2mem(ptr, &regs->e0, 4, 0); /* 15 */
1486 ptr = hex2mem(ptr, &regs->e1, 4, 0);
1487 ptr = hex2mem(ptr, &regs->e2, 4, 0);
1488 ptr = hex2mem(ptr, &regs->e3, 4, 0);
1489 ptr = hex2mem(ptr, &regs->e4, 4, 0);
1490 ptr = hex2mem(ptr, &regs->e5, 4, 0);
1491 ptr = hex2mem(ptr, &regs->e6, 4, 0);
1492 ptr = hex2mem(ptr, &regs->e7, 4, 0);
1493
1494 ptr = hex2mem(ptr, &ssp, 4, 0);
1495 ptr = hex2mem(ptr, &zero, 4, 0);
1496 ptr = hex2mem(ptr, &regs->sp, 4, 0);
1497 ptr = hex2mem(ptr, &regs->mcrh, 4, 0); /* 26 */
1498 ptr = hex2mem(ptr, &regs->mcrl, 4, 0);
1499 ptr = hex2mem(ptr, &regs->mcvf, 4, 0);
1500
1501 ptr = hex2mem(ptr, &zero, 4, 0); /* 29 - FPCR */
1502 ptr = hex2mem(ptr, &zero, 4, 0);
1503 ptr = hex2mem(ptr, &zero, 4, 0);
1504 for (loop = 0; loop < 32; loop++) /* 32 - FS0-31 */
1505 ptr = hex2mem(ptr, &zero, 4, 0);
1506
1507 #if 0
1508 /*
1509 * See if the stack pointer has moved. If so, then copy
1510 * the saved locals and ins to the new location.
1511 */
1512 unsigned long *newsp = (unsigned long *) registers[SP];
1513 if (sp != newsp)
1514 sp = memcpy(newsp, sp, 16 * 4);
1515 #endif
1516
1517 gdbstub_strcpy(output_buffer, "OK");
1518 }
1519 break;
1520
1521 /*
1522 * mAA..AA,LLLL Read LLLL bytes at address AA..AA
1523 */
1524 case 'm':
1525 ptr = &input_buffer[1];
1526
1527 if (hexToInt(&ptr, &addr) &&
1528 *ptr++ == ',' &&
1529 hexToInt(&ptr, &length)
1530 ) {
1531 if (mem2hex((char *) addr, output_buffer,
1532 length, 1))
1533 break;
1534 gdbstub_strcpy(output_buffer, "E03");
1535 } else {
1536 gdbstub_strcpy(output_buffer, "E01");
1537 }
1538 break;
1539
1540 /*
1541 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA
1542 * return OK
1543 */
1544 case 'M':
1545 ptr = &input_buffer[1];
1546
1547 if (hexToInt(&ptr, &addr) &&
1548 *ptr++ == ',' &&
1549 hexToInt(&ptr, &length) &&
1550 *ptr++ == ':'
1551 ) {
1552 if (hex2mem(ptr, (char *) addr, length, 1))
1553 gdbstub_strcpy(output_buffer, "OK");
1554 else
1555 gdbstub_strcpy(output_buffer, "E03");
1556
1557 gdbstub_flush_caches = 1;
1558 } else {
1559 gdbstub_strcpy(output_buffer, "E02");
1560 }
1561 break;
1562
1563 /*
1564 * cAA..AA Continue at address AA..AA(optional)
1565 */
1566 case 'c':
1567 /* try to read optional parameter, pc unchanged if no
1568 * parm */
1569
1570 ptr = &input_buffer[1];
1571 if (hexToInt(&ptr, &addr))
1572 regs->pc = addr;
1573 goto done;
1574
1575 /*
1576 * kill the program
1577 */
1578 case 'k' :
1579 goto done; /* just continue */
1580
1581 /*
1582 * Reset the whole machine (FIXME: system dependent)
1583 */
1584 case 'r':
1585 break;
1586
1587 /*
1588 * Step to next instruction
1589 */
1590 case 's':
1591 /*
1592 * using the T flag doesn't seem to perform single
1593 * stepping (it seems to wind up being caught by the
1594 * JTAG unit), so we have to use breakpoints and
1595 * continue instead.
1596 */
1597 if (gdbstub_single_step(regs) < 0)
1598 /* ignore any fault error for now */
1599 gdbstub_printk("unable to set single-step"
1600 " bp\n");
1601 goto done;
1602
1603 /*
1604 * Set baud rate (bBB)
1605 */
1606 case 'b':
1607 do {
1608 int baudrate;
1609
1610 ptr = &input_buffer[1];
1611 if (!hexToInt(&ptr, &baudrate)) {
1612 gdbstub_strcpy(output_buffer, "B01");
1613 break;
1614 }
1615
1616 if (baudrate) {
1617 /* ACK before changing speed */
1618 putpacket("OK");
1619 gdbstub_io_set_baud(baudrate);
1620 }
1621 } while (0);
1622 break;
1623
1624 /*
1625 * Set breakpoint
1626 */
1627 case 'Z':
1628 ptr = &input_buffer[1];
1629
1630 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1631 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1632 !hexToInt(&ptr, &length)
1633 ) {
1634 gdbstub_strcpy(output_buffer, "E01");
1635 break;
1636 }
1637
1638 /* only support software breakpoints */
1639 gdbstub_strcpy(output_buffer, "E03");
1640 if (loop != 0 ||
1641 length < 1 ||
1642 length > 7 ||
1643 (unsigned long) addr < 4096)
1644 break;
1645
1646 if (gdbstub_set_breakpoint((u8 *) addr, length) < 0)
1647 break;
1648
1649 gdbstub_strcpy(output_buffer, "OK");
1650 break;
1651
1652 /*
1653 * Clear breakpoint
1654 */
1655 case 'z':
1656 ptr = &input_buffer[1];
1657
1658 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1659 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1660 !hexToInt(&ptr, &length)
1661 ) {
1662 gdbstub_strcpy(output_buffer, "E01");
1663 break;
1664 }
1665
1666 /* only support software breakpoints */
1667 gdbstub_strcpy(output_buffer, "E03");
1668 if (loop != 0 ||
1669 length < 1 ||
1670 length > 7 ||
1671 (unsigned long) addr < 4096)
1672 break;
1673
1674 if (gdbstub_clear_breakpoint((u8 *) addr, length) < 0)
1675 break;
1676
1677 gdbstub_strcpy(output_buffer, "OK");
1678 break;
1679
1680 default:
1681 gdbstub_proto("### GDB Unsupported Cmd '%s'\n",
1682 input_buffer);
1683 break;
1684 }
1685
1686 /* reply to the request */
1687 putpacket(output_buffer);
1688 }
1689
1690 done:
1691 /*
1692 * Need to flush the instruction cache here, as we may
1693 * have deposited a breakpoint, and the icache probably
1694 * has no way of knowing that a data ref to some location
1695 * may have changed something that is in the instruction
1696 * cache.
1697 * NB: We flush both caches, just to be sure...
1698 */
1699 if (gdbstub_flush_caches)
1700 gdbstub_purge_cache();
1701
1702 gdbstub_load_fpu();
1703 mn10300_set_gdbleds(0);
1704 if (excep == EXCEP_NMI)
1705 NMICR = NMICR_NMIF;
1706
1707 touch_softlockup_watchdog();
1708
1709 local_irq_restore(epsw);
1710 return 1;
1711 }
1712
1713 /*
1714 * handle event interception
1715 */
1716 asmlinkage int gdbstub_intercept(struct pt_regs *regs,
1717 enum exception_code excep)
1718 {
1719 static u8 notfirst = 1;
1720 int ret;
1721
1722 if (gdbstub_busy)
1723 gdbstub_printk("--> gdbstub reentered itself\n");
1724 gdbstub_busy = 1;
1725
1726 if (notfirst) {
1727 unsigned long mdr;
1728 asm("mov mdr,%0" : "=d"(mdr));
1729
1730 gdbstub_entry(
1731 "--> gdbstub_intercept(%p,%04x) [MDR=%lx PC=%lx]\n",
1732 regs, excep, mdr, regs->pc);
1733
1734 gdbstub_entry(
1735 "PC: %08lx EPSW: %08lx SSP: %08lx mode: %s\n",
1736 regs->pc, regs->epsw, (unsigned long) &ret,
1737 user_mode(regs) ? "User" : "Super");
1738 gdbstub_entry(
1739 "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
1740 regs->d0, regs->d1, regs->d2, regs->d3);
1741 gdbstub_entry(
1742 "a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
1743 regs->a0, regs->a1, regs->a2, regs->a3);
1744 gdbstub_entry(
1745 "e0: %08lx e1: %08lx e2: %08lx e3: %08lx\n",
1746 regs->e0, regs->e1, regs->e2, regs->e3);
1747 gdbstub_entry(
1748 "e4: %08lx e5: %08lx e6: %08lx e7: %08lx\n",
1749 regs->e4, regs->e5, regs->e6, regs->e7);
1750 gdbstub_entry(
1751 "lar: %08lx lir: %08lx mdr: %08lx usp: %08lx\n",
1752 regs->lar, regs->lir, regs->mdr, regs->sp);
1753 gdbstub_entry(
1754 "cvf: %08lx crl: %08lx crh: %08lx drq: %08lx\n",
1755 regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
1756 gdbstub_entry(
1757 "threadinfo=%p task=%p)\n",
1758 current_thread_info(), current);
1759 } else {
1760 notfirst = 1;
1761 }
1762
1763 ret = gdbstub(regs, excep);
1764
1765 gdbstub_entry("<-- gdbstub_intercept()\n");
1766 gdbstub_busy = 0;
1767 return ret;
1768 }
1769
1770 /*
1771 * handle the GDB stub itself causing an exception
1772 */
1773 asmlinkage void gdbstub_exception(struct pt_regs *regs,
1774 enum exception_code excep)
1775 {
1776 unsigned long mdr;
1777
1778 asm("mov mdr,%0" : "=d"(mdr));
1779 gdbstub_entry("--> gdbstub exception({%p},%04x) [MDR=%lx]\n",
1780 regs, excep, mdr);
1781
1782 while ((unsigned long) regs == 0xffffffff) {}
1783
1784 /* handle guarded memory accesses where we know it might fault */
1785 if (regs->pc == (unsigned) gdbstub_read_byte_guard) {
1786 regs->pc = (unsigned) gdbstub_read_byte_cont;
1787 goto fault;
1788 }
1789
1790 if (regs->pc == (unsigned) gdbstub_read_word_guard) {
1791 regs->pc = (unsigned) gdbstub_read_word_cont;
1792 goto fault;
1793 }
1794
1795 if (regs->pc == (unsigned) gdbstub_read_dword_guard) {
1796 regs->pc = (unsigned) gdbstub_read_dword_cont;
1797 goto fault;
1798 }
1799
1800 if (regs->pc == (unsigned) gdbstub_write_byte_guard) {
1801 regs->pc = (unsigned) gdbstub_write_byte_cont;
1802 goto fault;
1803 }
1804
1805 if (regs->pc == (unsigned) gdbstub_write_word_guard) {
1806 regs->pc = (unsigned) gdbstub_write_word_cont;
1807 goto fault;
1808 }
1809
1810 if (regs->pc == (unsigned) gdbstub_write_dword_guard) {
1811 regs->pc = (unsigned) gdbstub_write_dword_cont;
1812 goto fault;
1813 }
1814
1815 gdbstub_printk("\n### GDB stub caused an exception ###\n");
1816
1817 /* something went horribly wrong */
1818 console_verbose();
1819 show_registers(regs);
1820
1821 panic("GDB Stub caused an unexpected exception - can't continue\n");
1822
1823 /* we caught an attempt by the stub to access silly memory */
1824 fault:
1825 gdbstub_entry("<-- gdbstub exception() = EFAULT\n");
1826 regs->d0 = -EFAULT;
1827 return;
1828 }
1829
1830 /*
1831 * send an exit message to GDB
1832 */
1833 void gdbstub_exit(int status)
1834 {
1835 unsigned char checksum;
1836 unsigned char ch;
1837 int count;
1838
1839 gdbstub_busy = 1;
1840 output_buffer[0] = 'W';
1841 output_buffer[1] = hexchars[(status >> 4) & 0x0F];
1842 output_buffer[2] = hexchars[status & 0x0F];
1843 output_buffer[3] = 0;
1844
1845 gdbstub_io_tx_char('$');
1846 checksum = 0;
1847 count = 0;
1848
1849 while ((ch = output_buffer[count]) != 0) {
1850 gdbstub_io_tx_char(ch);
1851 checksum += ch;
1852 count += 1;
1853 }
1854
1855 gdbstub_io_tx_char('#');
1856 gdbstub_io_tx_char(hexchars[checksum >> 4]);
1857 gdbstub_io_tx_char(hexchars[checksum & 0xf]);
1858
1859 /* make sure the output is flushed, or else RedBoot might clobber it */
1860 gdbstub_io_tx_flush();
1861
1862 gdbstub_busy = 0;
1863 }
1864
1865 /*
1866 * initialise the GDB stub
1867 */
1868 asmlinkage void __init gdbstub_init(void)
1869 {
1870 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1871 unsigned char ch;
1872 int ret;
1873 #endif
1874
1875 gdbstub_busy = 1;
1876
1877 printk(KERN_INFO "%s", gdbstub_banner);
1878
1879 gdbstub_io_init();
1880
1881 gdbstub_entry("--> gdbstub_init\n");
1882
1883 /* try to talk to GDB (or anyone insane enough to want to type GDB
1884 * protocol by hand) */
1885 gdbstub_io("### GDB Tx ACK\n");
1886 gdbstub_io_tx_char('+'); /* 'hello world' */
1887
1888 #ifdef CONFIG_GDBSTUB_IMMEDIATE
1889 gdbstub_printk("GDB Stub waiting for packet\n");
1890
1891 /* in case GDB is started before us, ACK any packets that are already
1892 * sitting there (presumably "$?#xx")
1893 */
1894 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '$');
1895 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '#');
1896 /* eat first csum byte */
1897 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1898 /* eat second csum byte */
1899 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1900
1901 gdbstub_io("### GDB Tx NAK\n");
1902 gdbstub_io_tx_char('-'); /* NAK it */
1903
1904 #else
1905 printk("GDB Stub ready\n");
1906 #endif
1907
1908 gdbstub_busy = 0;
1909 gdbstub_entry("<-- gdbstub_init\n");
1910 }
1911
1912 /*
1913 * register the console at a more appropriate time
1914 */
1915 #ifdef CONFIG_GDBSTUB_CONSOLE
1916 static int __init gdbstub_postinit(void)
1917 {
1918 printk(KERN_NOTICE "registering console\n");
1919 register_console(&gdbstub_console);
1920 return 0;
1921 }
1922
1923 __initcall(gdbstub_postinit);
1924 #endif
1925
1926 /*
1927 * handle character reception on GDB serial port
1928 * - jump into the GDB stub if BREAK is detected on the serial line
1929 */
1930 asmlinkage void gdbstub_rx_irq(struct pt_regs *regs, enum exception_code excep)
1931 {
1932 char ch;
1933 int ret;
1934
1935 gdbstub_entry("--> gdbstub_rx_irq\n");
1936
1937 do {
1938 ret = gdbstub_io_rx_char(&ch, 1);
1939 if (ret != -EIO && ret != -EAGAIN) {
1940 if (ret != -EINTR)
1941 gdbstub_rx_unget = ch;
1942 gdbstub(regs, excep);
1943 }
1944 } while (ret != -EAGAIN);
1945
1946 gdbstub_entry("<-- gdbstub_rx_irq\n");
1947 }
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