Loading...
Note: File does not exist in v6.13.7.
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/gdb-stub.h>
134#include <asm/exceptions.h>
135#include <asm/debugger.h>
136#include <asm/serial-regs.h>
137#include <asm/busctl-regs.h>
138#include <unit/leds.h>
139#include <unit/serial.h>
140
141/* define to use F7F7 rather than FF which is subverted by JTAG debugger */
142#undef GDBSTUB_USE_F7F7_AS_BREAKPOINT
143
144/*
145 * BUFMAX defines the maximum number of characters in inbound/outbound buffers
146 * at least NUMREGBYTES*2 are needed for register packets
147 */
148#define BUFMAX 2048
149
150static const char gdbstub_banner[] =
151 "Linux/MN10300 GDB Stub (c) RedHat 2007\n";
152
153u8 gdbstub_rx_buffer[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
154u32 gdbstub_rx_inp;
155u32 gdbstub_rx_outp;
156u8 gdbstub_busy;
157u8 gdbstub_rx_overflow;
158u8 gdbstub_rx_unget;
159
160static u8 gdbstub_flush_caches;
161static char input_buffer[BUFMAX];
162static char output_buffer[BUFMAX];
163static char trans_buffer[BUFMAX];
164
165struct gdbstub_bkpt {
166 u8 *addr; /* address of breakpoint */
167 u8 len; /* size of breakpoint */
168 u8 origbytes[7]; /* original bytes */
169};
170
171static struct gdbstub_bkpt gdbstub_bkpts[256];
172
173/*
174 * local prototypes
175 */
176static void getpacket(char *buffer);
177static int putpacket(char *buffer);
178static int computeSignal(enum exception_code excep);
179static int hex(unsigned char ch);
180static int hexToInt(char **ptr, int *intValue);
181static unsigned char *mem2hex(const void *mem, char *buf, int count,
182 int may_fault);
183static const char *hex2mem(const char *buf, void *_mem, int count,
184 int may_fault);
185
186/*
187 * Convert ch from a hex digit to an int
188 */
189static int hex(unsigned char ch)
190{
191 if (ch >= 'a' && ch <= 'f')
192 return ch - 'a' + 10;
193 if (ch >= '0' && ch <= '9')
194 return ch - '0';
195 if (ch >= 'A' && ch <= 'F')
196 return ch - 'A' + 10;
197 return -1;
198}
199
200#ifdef CONFIG_GDBSTUB_DEBUGGING
201
202void debug_to_serial(const char *p, int n)
203{
204 __debug_to_serial(p, n);
205 /* gdbstub_console_write(NULL, p, n); */
206}
207
208void gdbstub_printk(const char *fmt, ...)
209{
210 va_list args;
211 int len;
212
213 /* Emit the output into the temporary buffer */
214 va_start(args, fmt);
215 len = vsnprintf(trans_buffer, sizeof(trans_buffer), fmt, args);
216 va_end(args);
217 debug_to_serial(trans_buffer, len);
218}
219
220#endif
221
222static inline char *gdbstub_strcpy(char *dst, const char *src)
223{
224 int loop = 0;
225 while ((dst[loop] = src[loop]))
226 loop++;
227 return dst;
228}
229
230/*
231 * scan for the sequence $<data>#<checksum>
232 */
233static void getpacket(char *buffer)
234{
235 unsigned char checksum;
236 unsigned char xmitcsum;
237 unsigned char ch;
238 int count, i, ret, error;
239
240 for (;;) {
241 /*
242 * wait around for the start character,
243 * ignore all other characters
244 */
245 do {
246 gdbstub_io_rx_char(&ch, 0);
247 } while (ch != '$');
248
249 checksum = 0;
250 xmitcsum = -1;
251 count = 0;
252 error = 0;
253
254 /*
255 * now, read until a # or end of buffer is found
256 */
257 while (count < BUFMAX) {
258 ret = gdbstub_io_rx_char(&ch, 0);
259 if (ret < 0)
260 error = ret;
261
262 if (ch == '#')
263 break;
264 checksum += ch;
265 buffer[count] = ch;
266 count++;
267 }
268
269 if (error == -EIO) {
270 gdbstub_proto("### GDB Rx Error - Skipping packet"
271 " ###\n");
272 gdbstub_proto("### GDB Tx NAK\n");
273 gdbstub_io_tx_char('-');
274 continue;
275 }
276
277 if (count >= BUFMAX || error)
278 continue;
279
280 buffer[count] = 0;
281
282 /* read the checksum */
283 ret = gdbstub_io_rx_char(&ch, 0);
284 if (ret < 0)
285 error = ret;
286 xmitcsum = hex(ch) << 4;
287
288 ret = gdbstub_io_rx_char(&ch, 0);
289 if (ret < 0)
290 error = ret;
291 xmitcsum |= hex(ch);
292
293 if (error) {
294 if (error == -EIO)
295 gdbstub_io("### GDB Rx Error -"
296 " Skipping packet\n");
297 gdbstub_io("### GDB Tx NAK\n");
298 gdbstub_io_tx_char('-');
299 continue;
300 }
301
302 /* check the checksum */
303 if (checksum != xmitcsum) {
304 gdbstub_io("### GDB Tx NAK\n");
305 gdbstub_io_tx_char('-'); /* failed checksum */
306 continue;
307 }
308
309 gdbstub_proto("### GDB Rx '$%s#%02x' ###\n", buffer, checksum);
310 gdbstub_io("### GDB Tx ACK\n");
311 gdbstub_io_tx_char('+'); /* successful transfer */
312
313 /*
314 * if a sequence char is present,
315 * reply the sequence ID
316 */
317 if (buffer[2] == ':') {
318 gdbstub_io_tx_char(buffer[0]);
319 gdbstub_io_tx_char(buffer[1]);
320
321 /*
322 * remove sequence chars from buffer
323 */
324 count = 0;
325 while (buffer[count])
326 count++;
327 for (i = 3; i <= count; i++)
328 buffer[i - 3] = buffer[i];
329 }
330
331 break;
332 }
333}
334
335/*
336 * send the packet in buffer.
337 * - return 0 if successfully ACK'd
338 * - return 1 if abandoned due to new incoming packet
339 */
340static int putpacket(char *buffer)
341{
342 unsigned char checksum;
343 unsigned char ch;
344 int count;
345
346 /*
347 * $<packet info>#<checksum>.
348 */
349 gdbstub_proto("### GDB Tx $'%s'#?? ###\n", buffer);
350
351 do {
352 gdbstub_io_tx_char('$');
353 checksum = 0;
354 count = 0;
355
356 while ((ch = buffer[count]) != 0) {
357 gdbstub_io_tx_char(ch);
358 checksum += ch;
359 count += 1;
360 }
361
362 gdbstub_io_tx_char('#');
363 gdbstub_io_tx_char(hex_asc_hi(checksum));
364 gdbstub_io_tx_char(hex_asc_lo(checksum));
365
366 } while (gdbstub_io_rx_char(&ch, 0),
367 ch == '-' && (gdbstub_io("### GDB Rx NAK\n"), 0),
368 ch != '-' && ch != '+' &&
369 (gdbstub_io("### GDB Rx ??? %02x\n", ch), 0),
370 ch != '+' && ch != '$');
371
372 if (ch == '+') {
373 gdbstub_io("### GDB Rx ACK\n");
374 return 0;
375 }
376
377 gdbstub_io("### GDB Tx Abandoned\n");
378 gdbstub_rx_unget = ch;
379 return 1;
380}
381
382/*
383 * While we find nice hex chars, build an int.
384 * Return number of chars processed.
385 */
386static int hexToInt(char **ptr, int *intValue)
387{
388 int numChars = 0;
389 int hexValue;
390
391 *intValue = 0;
392
393 while (**ptr) {
394 hexValue = hex(**ptr);
395 if (hexValue < 0)
396 break;
397
398 *intValue = (*intValue << 4) | hexValue;
399 numChars++;
400
401 (*ptr)++;
402 }
403
404 return (numChars);
405}
406
407#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
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 */
415static struct gdb_bp_save {
416 u8 *addr;
417 u8 opcode[2];
418} step_bp[2];
419
420static 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
441static int __gdbstub_mark_bp(u8 *addr, int ix)
442{
443 /* vmalloc area */
444 if (((u8 *) VMALLOC_START <= addr) && (addr < (u8 *) VMALLOC_END))
445 goto okay;
446 /* SRAM, SDRAM */
447 if (((u8 *) 0x80000000UL <= addr) && (addr < (u8 *) 0xa0000000UL))
448 goto okay;
449 return 0;
450
451okay:
452 if (gdbstub_read_byte(addr + 0, &step_bp[ix].opcode[0]) < 0 ||
453 gdbstub_read_byte(addr + 1, &step_bp[ix].opcode[1]) < 0)
454 return 0;
455
456 step_bp[ix].addr = addr;
457 return 1;
458}
459
460static inline void __gdbstub_restore_bp(void)
461{
462#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
463 if (step_bp[0].addr) {
464 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
465 gdbstub_write_byte(step_bp[0].opcode[1], step_bp[0].addr + 1);
466 }
467 if (step_bp[1].addr) {
468 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
469 gdbstub_write_byte(step_bp[1].opcode[1], step_bp[1].addr + 1);
470 }
471#else
472 if (step_bp[0].addr)
473 gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
474 if (step_bp[1].addr)
475 gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
476#endif
477
478 gdbstub_flush_caches = 1;
479
480 step_bp[0].addr = NULL;
481 step_bp[0].opcode[0] = 0;
482 step_bp[0].opcode[1] = 0;
483 step_bp[1].addr = NULL;
484 step_bp[1].opcode[0] = 0;
485 step_bp[1].opcode[1] = 0;
486}
487
488/*
489 * emulate single stepping by means of breakpoint instructions
490 */
491static int gdbstub_single_step(struct pt_regs *regs)
492{
493 unsigned size;
494 uint32_t x;
495 uint8_t cur, *pc, *sp;
496
497 step_bp[0].addr = NULL;
498 step_bp[0].opcode[0] = 0;
499 step_bp[0].opcode[1] = 0;
500 step_bp[1].addr = NULL;
501 step_bp[1].opcode[0] = 0;
502 step_bp[1].opcode[1] = 0;
503 x = 0;
504
505 pc = (u8 *) regs->pc;
506 sp = (u8 *) (regs + 1);
507 if (gdbstub_read_byte(pc, &cur) < 0)
508 return -EFAULT;
509
510 gdbstub_bkpt("Single Step from %p { %02x }\n", pc, cur);
511
512 gdbstub_flush_caches = 1;
513
514 size = gdbstub_insn_sizes[cur];
515 if (size > 0) {
516 if (!__gdbstub_mark_bp(pc + size, 0))
517 goto fault;
518 } else {
519 switch (cur) {
520 /* Bxx (d8,PC) */
521 case 0xc0 ... 0xca:
522 if (gdbstub_read_byte(pc + 1, (u8 *) &x) < 0)
523 goto fault;
524 if (!__gdbstub_mark_bp(pc + 2, 0))
525 goto fault;
526 if ((x < 0 || x > 2) &&
527 !__gdbstub_mark_bp(pc + (s8) x, 1))
528 goto fault;
529 break;
530
531 /* LXX (d8,PC) */
532 case 0xd0 ... 0xda:
533 if (!__gdbstub_mark_bp(pc + 1, 0))
534 goto fault;
535 if (regs->pc != regs->lar &&
536 !__gdbstub_mark_bp((u8 *) regs->lar, 1))
537 goto fault;
538 break;
539
540 /* SETLB - loads the next for bytes into the LIR
541 * register */
542 case 0xdb:
543 if (!__gdbstub_mark_bp(pc + 1, 0))
544 goto fault;
545 break;
546
547 /* JMP (d16,PC) or CALL (d16,PC) */
548 case 0xcc:
549 case 0xcd:
550 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
551 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0)
552 goto fault;
553 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
554 goto fault;
555 break;
556
557 /* JMP (d32,PC) or CALL (d32,PC) */
558 case 0xdc:
559 case 0xdd:
560 if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
561 gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0 ||
562 gdbstub_read_byte(pc + 3, ((u8 *) &x) + 2) < 0 ||
563 gdbstub_read_byte(pc + 4, ((u8 *) &x) + 3) < 0)
564 goto fault;
565 if (!__gdbstub_mark_bp(pc + (s32) x, 0))
566 goto fault;
567 break;
568
569 /* RETF */
570 case 0xde:
571 if (!__gdbstub_mark_bp((u8 *) regs->mdr, 0))
572 goto fault;
573 break;
574
575 /* RET */
576 case 0xdf:
577 if (gdbstub_read_byte(pc + 2, (u8 *) &x) < 0)
578 goto fault;
579 sp += (s8)x;
580 if (gdbstub_read_byte(sp + 0, ((u8 *) &x) + 0) < 0 ||
581 gdbstub_read_byte(sp + 1, ((u8 *) &x) + 1) < 0 ||
582 gdbstub_read_byte(sp + 2, ((u8 *) &x) + 2) < 0 ||
583 gdbstub_read_byte(sp + 3, ((u8 *) &x) + 3) < 0)
584 goto fault;
585 if (!__gdbstub_mark_bp((u8 *) x, 0))
586 goto fault;
587 break;
588
589 case 0xf0:
590 if (gdbstub_read_byte(pc + 1, &cur) < 0)
591 goto fault;
592
593 if (cur >= 0xf0 && cur <= 0xf7) {
594 /* JMP (An) / CALLS (An) */
595 switch (cur & 3) {
596 case 0: x = regs->a0; break;
597 case 1: x = regs->a1; break;
598 case 2: x = regs->a2; break;
599 case 3: x = regs->a3; break;
600 }
601 if (!__gdbstub_mark_bp((u8 *) x, 0))
602 goto fault;
603 } else if (cur == 0xfc) {
604 /* RETS */
605 if (gdbstub_read_byte(
606 sp + 0, ((u8 *) &x) + 0) < 0 ||
607 gdbstub_read_byte(
608 sp + 1, ((u8 *) &x) + 1) < 0 ||
609 gdbstub_read_byte(
610 sp + 2, ((u8 *) &x) + 2) < 0 ||
611 gdbstub_read_byte(
612 sp + 3, ((u8 *) &x) + 3) < 0)
613 goto fault;
614 if (!__gdbstub_mark_bp((u8 *) x, 0))
615 goto fault;
616 } else if (cur == 0xfd) {
617 /* RTI */
618 if (gdbstub_read_byte(
619 sp + 4, ((u8 *) &x) + 0) < 0 ||
620 gdbstub_read_byte(
621 sp + 5, ((u8 *) &x) + 1) < 0 ||
622 gdbstub_read_byte(
623 sp + 6, ((u8 *) &x) + 2) < 0 ||
624 gdbstub_read_byte(
625 sp + 7, ((u8 *) &x) + 3) < 0)
626 goto fault;
627 if (!__gdbstub_mark_bp((u8 *) x, 0))
628 goto fault;
629 } else {
630 if (!__gdbstub_mark_bp(pc + 2, 0))
631 goto fault;
632 }
633
634 break;
635
636 /* potential 3-byte conditional branches */
637 case 0xf8:
638 if (gdbstub_read_byte(pc + 1, &cur) < 0)
639 goto fault;
640 if (!__gdbstub_mark_bp(pc + 3, 0))
641 goto fault;
642
643 if (cur >= 0xe8 && cur <= 0xeb) {
644 if (gdbstub_read_byte(
645 pc + 2, ((u8 *) &x) + 0) < 0)
646 goto fault;
647 if ((x < 0 || x > 3) &&
648 !__gdbstub_mark_bp(pc + (s8) x, 1))
649 goto fault;
650 }
651 break;
652
653 case 0xfa:
654 if (gdbstub_read_byte(pc + 1, &cur) < 0)
655 goto fault;
656
657 if (cur == 0xff) {
658 /* CALLS (d16,PC) */
659 if (gdbstub_read_byte(
660 pc + 2, ((u8 *) &x) + 0) < 0 ||
661 gdbstub_read_byte(
662 pc + 3, ((u8 *) &x) + 1) < 0)
663 goto fault;
664 if (!__gdbstub_mark_bp(pc + (s16) x, 0))
665 goto fault;
666 } else {
667 if (!__gdbstub_mark_bp(pc + 4, 0))
668 goto fault;
669 }
670 break;
671
672 case 0xfc:
673 if (gdbstub_read_byte(pc + 1, &cur) < 0)
674 goto fault;
675 if (cur == 0xff) {
676 /* CALLS (d32,PC) */
677 if (gdbstub_read_byte(
678 pc + 2, ((u8 *) &x) + 0) < 0 ||
679 gdbstub_read_byte(
680 pc + 3, ((u8 *) &x) + 1) < 0 ||
681 gdbstub_read_byte(
682 pc + 4, ((u8 *) &x) + 2) < 0 ||
683 gdbstub_read_byte(
684 pc + 5, ((u8 *) &x) + 3) < 0)
685 goto fault;
686 if (!__gdbstub_mark_bp(
687 pc + (s32) x, 0))
688 goto fault;
689 } else {
690 if (!__gdbstub_mark_bp(
691 pc + 6, 0))
692 goto fault;
693 }
694 break;
695
696 }
697 }
698
699 gdbstub_bkpt("Step: %02x at %p; %02x at %p\n",
700 step_bp[0].opcode[0], step_bp[0].addr,
701 step_bp[1].opcode[0], step_bp[1].addr);
702
703 if (step_bp[0].addr) {
704#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
705 if (gdbstub_write_byte(0xF7, step_bp[0].addr + 0) < 0 ||
706 gdbstub_write_byte(0xF7, step_bp[0].addr + 1) < 0)
707 goto fault;
708#else
709 if (gdbstub_write_byte(0xFF, step_bp[0].addr + 0) < 0)
710 goto fault;
711#endif
712 }
713
714 if (step_bp[1].addr) {
715#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
716 if (gdbstub_write_byte(0xF7, step_bp[1].addr + 0) < 0 ||
717 gdbstub_write_byte(0xF7, step_bp[1].addr + 1) < 0)
718 goto fault;
719#else
720 if (gdbstub_write_byte(0xFF, step_bp[1].addr + 0) < 0)
721 goto fault;
722#endif
723 }
724
725 return 0;
726
727 fault:
728 /* uh-oh - silly address alert, try and restore things */
729 __gdbstub_restore_bp();
730 return -EFAULT;
731}
732#endif /* CONFIG_GDBSTUB_ALLOW_SINGLE_STEP */
733
734#ifdef CONFIG_GDBSTUB_CONSOLE
735
736void gdbstub_console_write(struct console *con, const char *p, unsigned n)
737{
738 static const char gdbstub_cr[] = { 0x0d };
739 char outbuf[26];
740 int qty;
741 u8 busy;
742
743 busy = gdbstub_busy;
744 gdbstub_busy = 1;
745
746 outbuf[0] = 'O';
747
748 while (n > 0) {
749 qty = 1;
750
751 while (n > 0 && qty < 20) {
752 mem2hex(p, outbuf + qty, 2, 0);
753 qty += 2;
754 if (*p == 0x0a) {
755 mem2hex(gdbstub_cr, outbuf + qty, 2, 0);
756 qty += 2;
757 }
758 p++;
759 n--;
760 }
761
762 outbuf[qty] = 0;
763 putpacket(outbuf);
764 }
765
766 gdbstub_busy = busy;
767}
768
769static kdev_t gdbstub_console_dev(struct console *con)
770{
771 return MKDEV(1, 3); /* /dev/null */
772}
773
774static struct console gdbstub_console = {
775 .name = "gdb",
776 .write = gdbstub_console_write,
777 .device = gdbstub_console_dev,
778 .flags = CON_PRINTBUFFER,
779 .index = -1,
780};
781
782#endif
783
784/*
785 * Convert the memory pointed to by mem into hex, placing result in buf.
786 * - if successful, return a pointer to the last char put in buf (NUL)
787 * - in case of mem fault, return NULL
788 * may_fault is non-zero if we are reading from arbitrary memory, but is
789 * currently not used.
790 */
791static
792unsigned char *mem2hex(const void *_mem, char *buf, int count, int may_fault)
793{
794 const u8 *mem = _mem;
795 u8 ch[4];
796
797 if ((u32) mem & 1 && count >= 1) {
798 if (gdbstub_read_byte(mem, ch) != 0)
799 return 0;
800 buf = hex_byte_pack(buf, ch[0]);
801 mem++;
802 count--;
803 }
804
805 if ((u32) mem & 3 && count >= 2) {
806 if (gdbstub_read_word(mem, ch) != 0)
807 return 0;
808 buf = hex_byte_pack(buf, ch[0]);
809 buf = hex_byte_pack(buf, ch[1]);
810 mem += 2;
811 count -= 2;
812 }
813
814 while (count >= 4) {
815 if (gdbstub_read_dword(mem, ch) != 0)
816 return 0;
817 buf = hex_byte_pack(buf, ch[0]);
818 buf = hex_byte_pack(buf, ch[1]);
819 buf = hex_byte_pack(buf, ch[2]);
820 buf = hex_byte_pack(buf, ch[3]);
821 mem += 4;
822 count -= 4;
823 }
824
825 if (count >= 2) {
826 if (gdbstub_read_word(mem, ch) != 0)
827 return 0;
828 buf = hex_byte_pack(buf, ch[0]);
829 buf = hex_byte_pack(buf, ch[1]);
830 mem += 2;
831 count -= 2;
832 }
833
834 if (count >= 1) {
835 if (gdbstub_read_byte(mem, ch) != 0)
836 return 0;
837 buf = hex_byte_pack(buf, ch[0]);
838 }
839
840 *buf = 0;
841 return buf;
842}
843
844/*
845 * convert the hex array pointed to by buf into binary to be placed in mem
846 * return a pointer to the character AFTER the last byte written
847 * may_fault is non-zero if we are reading from arbitrary memory, but is
848 * currently not used.
849 */
850static
851const char *hex2mem(const char *buf, void *_mem, int count, int may_fault)
852{
853 u8 *mem = _mem;
854 union {
855 u32 val;
856 u8 b[4];
857 } ch;
858
859 if ((u32) mem & 1 && count >= 1) {
860 ch.b[0] = hex(*buf++) << 4;
861 ch.b[0] |= hex(*buf++);
862 if (gdbstub_write_byte(ch.val, mem) != 0)
863 return 0;
864 mem++;
865 count--;
866 }
867
868 if ((u32) mem & 3 && count >= 2) {
869 ch.b[0] = hex(*buf++) << 4;
870 ch.b[0] |= hex(*buf++);
871 ch.b[1] = hex(*buf++) << 4;
872 ch.b[1] |= hex(*buf++);
873 if (gdbstub_write_word(ch.val, mem) != 0)
874 return 0;
875 mem += 2;
876 count -= 2;
877 }
878
879 while (count >= 4) {
880 ch.b[0] = hex(*buf++) << 4;
881 ch.b[0] |= hex(*buf++);
882 ch.b[1] = hex(*buf++) << 4;
883 ch.b[1] |= hex(*buf++);
884 ch.b[2] = hex(*buf++) << 4;
885 ch.b[2] |= hex(*buf++);
886 ch.b[3] = hex(*buf++) << 4;
887 ch.b[3] |= hex(*buf++);
888 if (gdbstub_write_dword(ch.val, mem) != 0)
889 return 0;
890 mem += 4;
891 count -= 4;
892 }
893
894 if (count >= 2) {
895 ch.b[0] = hex(*buf++) << 4;
896 ch.b[0] |= hex(*buf++);
897 ch.b[1] = hex(*buf++) << 4;
898 ch.b[1] |= hex(*buf++);
899 if (gdbstub_write_word(ch.val, mem) != 0)
900 return 0;
901 mem += 2;
902 count -= 2;
903 }
904
905 if (count >= 1) {
906 ch.b[0] = hex(*buf++) << 4;
907 ch.b[0] |= hex(*buf++);
908 if (gdbstub_write_byte(ch.val, mem) != 0)
909 return 0;
910 }
911
912 return buf;
913}
914
915/*
916 * This table contains the mapping between MN10300 exception codes, and
917 * signals, which are primarily what GDB understands. It also indicates
918 * which hardware traps we need to commandeer when initializing the stub.
919 */
920static const struct excep_to_sig_map {
921 enum exception_code excep; /* MN10300 exception code */
922 unsigned char signo; /* Signal that we map this into */
923} excep_to_sig_map[] = {
924 { EXCEP_ITLBMISS, SIGSEGV },
925 { EXCEP_DTLBMISS, SIGSEGV },
926 { EXCEP_TRAP, SIGTRAP },
927 { EXCEP_ISTEP, SIGTRAP },
928 { EXCEP_IBREAK, SIGTRAP },
929 { EXCEP_OBREAK, SIGTRAP },
930 { EXCEP_UNIMPINS, SIGILL },
931 { EXCEP_UNIMPEXINS, SIGILL },
932 { EXCEP_MEMERR, SIGSEGV },
933 { EXCEP_MISALIGN, SIGSEGV },
934 { EXCEP_BUSERROR, SIGBUS },
935 { EXCEP_ILLINSACC, SIGSEGV },
936 { EXCEP_ILLDATACC, SIGSEGV },
937 { EXCEP_IOINSACC, SIGSEGV },
938 { EXCEP_PRIVINSACC, SIGSEGV },
939 { EXCEP_PRIVDATACC, SIGSEGV },
940 { EXCEP_FPU_DISABLED, SIGFPE },
941 { EXCEP_FPU_UNIMPINS, SIGFPE },
942 { EXCEP_FPU_OPERATION, SIGFPE },
943 { EXCEP_WDT, SIGALRM },
944 { EXCEP_NMI, SIGQUIT },
945 { EXCEP_IRQ_LEVEL0, SIGINT },
946 { EXCEP_IRQ_LEVEL1, SIGINT },
947 { EXCEP_IRQ_LEVEL2, SIGINT },
948 { EXCEP_IRQ_LEVEL3, SIGINT },
949 { EXCEP_IRQ_LEVEL4, SIGINT },
950 { EXCEP_IRQ_LEVEL5, SIGINT },
951 { EXCEP_IRQ_LEVEL6, SIGINT },
952 { 0, 0}
953};
954
955/*
956 * convert the MN10300 exception code into a UNIX signal number
957 */
958static int computeSignal(enum exception_code excep)
959{
960 const struct excep_to_sig_map *map;
961
962 for (map = excep_to_sig_map; map->signo; map++)
963 if (map->excep == excep)
964 return map->signo;
965
966 return SIGHUP; /* default for things we don't know about */
967}
968
969static u32 gdbstub_fpcr, gdbstub_fpufs_array[32];
970
971/*
972 *
973 */
974static void gdbstub_store_fpu(void)
975{
976#ifdef CONFIG_FPU
977
978 asm volatile(
979 "or %2,epsw\n"
980#ifdef CONFIG_MN10300_PROC_MN103E010
981 "nop\n"
982 "nop\n"
983#endif
984 "mov %1, a1\n"
985 "fmov fs0, (a1+)\n"
986 "fmov fs1, (a1+)\n"
987 "fmov fs2, (a1+)\n"
988 "fmov fs3, (a1+)\n"
989 "fmov fs4, (a1+)\n"
990 "fmov fs5, (a1+)\n"
991 "fmov fs6, (a1+)\n"
992 "fmov fs7, (a1+)\n"
993 "fmov fs8, (a1+)\n"
994 "fmov fs9, (a1+)\n"
995 "fmov fs10, (a1+)\n"
996 "fmov fs11, (a1+)\n"
997 "fmov fs12, (a1+)\n"
998 "fmov fs13, (a1+)\n"
999 "fmov fs14, (a1+)\n"
1000 "fmov fs15, (a1+)\n"
1001 "fmov fs16, (a1+)\n"
1002 "fmov fs17, (a1+)\n"
1003 "fmov fs18, (a1+)\n"
1004 "fmov fs19, (a1+)\n"
1005 "fmov fs20, (a1+)\n"
1006 "fmov fs21, (a1+)\n"
1007 "fmov fs22, (a1+)\n"
1008 "fmov fs23, (a1+)\n"
1009 "fmov fs24, (a1+)\n"
1010 "fmov fs25, (a1+)\n"
1011 "fmov fs26, (a1+)\n"
1012 "fmov fs27, (a1+)\n"
1013 "fmov fs28, (a1+)\n"
1014 "fmov fs29, (a1+)\n"
1015 "fmov fs30, (a1+)\n"
1016 "fmov fs31, (a1+)\n"
1017 "fmov fpcr, %0\n"
1018 : "=d"(gdbstub_fpcr)
1019 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE)
1020 : "a1"
1021 );
1022#endif
1023}
1024
1025/*
1026 *
1027 */
1028static void gdbstub_load_fpu(void)
1029{
1030#ifdef CONFIG_FPU
1031
1032 asm volatile(
1033 "or %1,epsw\n"
1034#ifdef CONFIG_MN10300_PROC_MN103E010
1035 "nop\n"
1036 "nop\n"
1037#endif
1038 "mov %0, a1\n"
1039 "fmov (a1+), fs0\n"
1040 "fmov (a1+), fs1\n"
1041 "fmov (a1+), fs2\n"
1042 "fmov (a1+), fs3\n"
1043 "fmov (a1+), fs4\n"
1044 "fmov (a1+), fs5\n"
1045 "fmov (a1+), fs6\n"
1046 "fmov (a1+), fs7\n"
1047 "fmov (a1+), fs8\n"
1048 "fmov (a1+), fs9\n"
1049 "fmov (a1+), fs10\n"
1050 "fmov (a1+), fs11\n"
1051 "fmov (a1+), fs12\n"
1052 "fmov (a1+), fs13\n"
1053 "fmov (a1+), fs14\n"
1054 "fmov (a1+), fs15\n"
1055 "fmov (a1+), fs16\n"
1056 "fmov (a1+), fs17\n"
1057 "fmov (a1+), fs18\n"
1058 "fmov (a1+), fs19\n"
1059 "fmov (a1+), fs20\n"
1060 "fmov (a1+), fs21\n"
1061 "fmov (a1+), fs22\n"
1062 "fmov (a1+), fs23\n"
1063 "fmov (a1+), fs24\n"
1064 "fmov (a1+), fs25\n"
1065 "fmov (a1+), fs26\n"
1066 "fmov (a1+), fs27\n"
1067 "fmov (a1+), fs28\n"
1068 "fmov (a1+), fs29\n"
1069 "fmov (a1+), fs30\n"
1070 "fmov (a1+), fs31\n"
1071 "fmov %2, fpcr\n"
1072 :
1073 : "g" (&gdbstub_fpufs_array), "i"(EPSW_FE), "d"(gdbstub_fpcr)
1074 : "a1"
1075 );
1076#endif
1077}
1078
1079/*
1080 * set a software breakpoint
1081 */
1082int gdbstub_set_breakpoint(u8 *addr, int len)
1083{
1084 int bkpt, loop, xloop;
1085
1086#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1087 len = (len + 1) & ~1;
1088#endif
1089
1090 gdbstub_bkpt("setbkpt(%p,%d)\n", addr, len);
1091
1092 for (bkpt = 255; bkpt >= 0; bkpt--)
1093 if (!gdbstub_bkpts[bkpt].addr)
1094 break;
1095 if (bkpt < 0)
1096 return -ENOSPC;
1097
1098 for (loop = 0; loop < len; loop++)
1099 if (gdbstub_read_byte(&addr[loop],
1100 &gdbstub_bkpts[bkpt].origbytes[loop]
1101 ) < 0)
1102 return -EFAULT;
1103
1104 gdbstub_flush_caches = 1;
1105
1106#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1107 for (loop = 0; loop < len; loop++)
1108 if (gdbstub_write_byte(0xF7, &addr[loop]) < 0)
1109 goto restore;
1110#else
1111 for (loop = 0; loop < len; loop++)
1112 if (gdbstub_write_byte(0xFF, &addr[loop]) < 0)
1113 goto restore;
1114#endif
1115
1116 gdbstub_bkpts[bkpt].addr = addr;
1117 gdbstub_bkpts[bkpt].len = len;
1118
1119 gdbstub_bkpt("Set BKPT[%02x]: %p-%p {%02x%02x%02x%02x%02x%02x%02x}\n",
1120 bkpt,
1121 gdbstub_bkpts[bkpt].addr,
1122 gdbstub_bkpts[bkpt].addr + gdbstub_bkpts[bkpt].len - 1,
1123 gdbstub_bkpts[bkpt].origbytes[0],
1124 gdbstub_bkpts[bkpt].origbytes[1],
1125 gdbstub_bkpts[bkpt].origbytes[2],
1126 gdbstub_bkpts[bkpt].origbytes[3],
1127 gdbstub_bkpts[bkpt].origbytes[4],
1128 gdbstub_bkpts[bkpt].origbytes[5],
1129 gdbstub_bkpts[bkpt].origbytes[6]
1130 );
1131
1132 return 0;
1133
1134restore:
1135 for (xloop = 0; xloop < loop; xloop++)
1136 gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[xloop],
1137 addr + xloop);
1138 return -EFAULT;
1139}
1140
1141/*
1142 * clear a software breakpoint
1143 */
1144int gdbstub_clear_breakpoint(u8 *addr, int len)
1145{
1146 int bkpt, loop;
1147
1148#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
1149 len = (len + 1) & ~1;
1150#endif
1151
1152 gdbstub_bkpt("clearbkpt(%p,%d)\n", addr, len);
1153
1154 for (bkpt = 255; bkpt >= 0; bkpt--)
1155 if (gdbstub_bkpts[bkpt].addr == addr &&
1156 gdbstub_bkpts[bkpt].len == len)
1157 break;
1158 if (bkpt < 0)
1159 return -ENOENT;
1160
1161 gdbstub_bkpts[bkpt].addr = NULL;
1162
1163 gdbstub_flush_caches = 1;
1164
1165 for (loop = 0; loop < len; loop++)
1166 if (gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[loop],
1167 addr + loop) < 0)
1168 return -EFAULT;
1169
1170 return 0;
1171}
1172
1173/*
1174 * This function does all command processing for interfacing to gdb
1175 * - returns 0 if the exception should be skipped, -ERROR otherwise.
1176 */
1177static int gdbstub(struct pt_regs *regs, enum exception_code excep)
1178{
1179 unsigned long *stack;
1180 unsigned long epsw, mdr;
1181 uint32_t zero, ssp;
1182 uint8_t broke;
1183 char *ptr;
1184 int sigval;
1185 int addr;
1186 int length;
1187 int loop;
1188
1189 if (excep == EXCEP_FPU_DISABLED)
1190 return -ENOTSUPP;
1191
1192 gdbstub_flush_caches = 0;
1193
1194 mn10300_set_gdbleds(1);
1195
1196 asm volatile("mov mdr,%0" : "=d"(mdr));
1197 local_save_flags(epsw);
1198 arch_local_change_intr_mask_level(
1199 NUM2EPSW_IM(CONFIG_DEBUGGER_IRQ_LEVEL + 1));
1200
1201 gdbstub_store_fpu();
1202
1203#ifdef CONFIG_GDBSTUB_IMMEDIATE
1204 /* skip the initial pause loop */
1205 if (regs->pc == (unsigned long) __gdbstub_pause)
1206 regs->pc = (unsigned long) start_kernel;
1207#endif
1208
1209 /* if we were single stepping, restore the opcodes hoisted for the
1210 * breakpoint[s] */
1211 broke = 0;
1212#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
1213 if ((step_bp[0].addr && step_bp[0].addr == (u8 *) regs->pc) ||
1214 (step_bp[1].addr && step_bp[1].addr == (u8 *) regs->pc))
1215 broke = 1;
1216
1217 __gdbstub_restore_bp();
1218#endif
1219
1220 if (gdbstub_rx_unget) {
1221 sigval = SIGINT;
1222 if (gdbstub_rx_unget != 3)
1223 goto packet_waiting;
1224 gdbstub_rx_unget = 0;
1225 }
1226
1227 stack = (unsigned long *) regs->sp;
1228 sigval = broke ? SIGTRAP : computeSignal(excep);
1229
1230 /* send information about a BUG() */
1231 if (!user_mode(regs) && excep == EXCEP_SYSCALL15) {
1232 const struct bug_entry *bug;
1233
1234 bug = find_bug(regs->pc);
1235 if (bug)
1236 goto found_bug;
1237 length = snprintf(trans_buffer, sizeof(trans_buffer),
1238 "BUG() at address %lx\n", regs->pc);
1239 goto send_bug_pkt;
1240
1241 found_bug:
1242 length = snprintf(trans_buffer, sizeof(trans_buffer),
1243 "BUG() at address %lx (%s:%d)\n",
1244 regs->pc, bug->file, bug->line);
1245
1246 send_bug_pkt:
1247 ptr = output_buffer;
1248 *ptr++ = 'O';
1249 ptr = mem2hex(trans_buffer, ptr, length, 0);
1250 *ptr = 0;
1251 putpacket(output_buffer);
1252
1253 regs->pc -= 2;
1254 sigval = SIGABRT;
1255 } else if (regs->pc == (unsigned long) __gdbstub_bug_trap) {
1256 regs->pc = regs->mdr;
1257 sigval = SIGABRT;
1258 }
1259
1260 /*
1261 * send a message to the debugger's user saying what happened if it may
1262 * not be clear cut (we can't map exceptions onto signals properly)
1263 */
1264 if (sigval != SIGINT && sigval != SIGTRAP && sigval != SIGILL) {
1265 static const char title[] = "Excep ", tbcberr[] = "BCBERR ";
1266 static const char crlf[] = "\r\n";
1267 char hx;
1268 u32 bcberr = BCBERR;
1269
1270 ptr = output_buffer;
1271 *ptr++ = 'O';
1272 ptr = mem2hex(title, ptr, sizeof(title) - 1, 0);
1273
1274 hx = hex_asc_hi(excep >> 8);
1275 ptr = hex_byte_pack(ptr, hx);
1276 hx = hex_asc_lo(excep >> 8);
1277 ptr = hex_byte_pack(ptr, hx);
1278 hx = hex_asc_hi(excep);
1279 ptr = hex_byte_pack(ptr, hx);
1280 hx = hex_asc_lo(excep);
1281 ptr = hex_byte_pack(ptr, hx);
1282
1283 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1284 *ptr = 0;
1285 putpacket(output_buffer); /* send it off... */
1286
1287 /* BCBERR */
1288 ptr = output_buffer;
1289 *ptr++ = 'O';
1290 ptr = mem2hex(tbcberr, ptr, sizeof(tbcberr) - 1, 0);
1291
1292 hx = hex_asc_hi(bcberr >> 24);
1293 ptr = hex_byte_pack(ptr, hx);
1294 hx = hex_asc_lo(bcberr >> 24);
1295 ptr = hex_byte_pack(ptr, hx);
1296 hx = hex_asc_hi(bcberr >> 16);
1297 ptr = hex_byte_pack(ptr, hx);
1298 hx = hex_asc_lo(bcberr >> 16);
1299 ptr = hex_byte_pack(ptr, hx);
1300 hx = hex_asc_hi(bcberr >> 8);
1301 ptr = hex_byte_pack(ptr, hx);
1302 hx = hex_asc_lo(bcberr >> 8);
1303 ptr = hex_byte_pack(ptr, hx);
1304 hx = hex_asc_hi(bcberr);
1305 ptr = hex_byte_pack(ptr, hx);
1306 hx = hex_asc_lo(bcberr);
1307 ptr = hex_byte_pack(ptr, hx);
1308
1309 ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
1310 *ptr = 0;
1311 putpacket(output_buffer); /* send it off... */
1312 }
1313
1314 /*
1315 * tell the debugger that an exception has occurred
1316 */
1317 ptr = output_buffer;
1318
1319 /*
1320 * Send trap type (converted to signal)
1321 */
1322 *ptr++ = 'T';
1323 ptr = hex_byte_pack(ptr, sigval);
1324
1325 /*
1326 * Send Error PC
1327 */
1328 ptr = hex_byte_pack(ptr, GDB_REGID_PC);
1329 *ptr++ = ':';
1330 ptr = mem2hex(®s->pc, ptr, 4, 0);
1331 *ptr++ = ';';
1332
1333 /*
1334 * Send frame pointer
1335 */
1336 ptr = hex_byte_pack(ptr, GDB_REGID_FP);
1337 *ptr++ = ':';
1338 ptr = mem2hex(®s->a3, ptr, 4, 0);
1339 *ptr++ = ';';
1340
1341 /*
1342 * Send stack pointer
1343 */
1344 ssp = (unsigned long) (regs + 1);
1345 ptr = hex_byte_pack(ptr, GDB_REGID_SP);
1346 *ptr++ = ':';
1347 ptr = mem2hex(&ssp, ptr, 4, 0);
1348 *ptr++ = ';';
1349
1350 *ptr++ = 0;
1351 putpacket(output_buffer); /* send it off... */
1352
1353packet_waiting:
1354 /*
1355 * Wait for input from remote GDB
1356 */
1357 while (1) {
1358 output_buffer[0] = 0;
1359 getpacket(input_buffer);
1360
1361 switch (input_buffer[0]) {
1362 /* request repeat of last signal number */
1363 case '?':
1364 output_buffer[0] = 'S';
1365 output_buffer[1] = hex_asc_hi(sigval);
1366 output_buffer[2] = hex_asc_lo(sigval);
1367 output_buffer[3] = 0;
1368 break;
1369
1370 case 'd':
1371 /* toggle debug flag */
1372 break;
1373
1374 /*
1375 * Return the value of the CPU registers
1376 */
1377 case 'g':
1378 zero = 0;
1379 ssp = (u32) (regs + 1);
1380 ptr = output_buffer;
1381 ptr = mem2hex(®s->d0, ptr, 4, 0);
1382 ptr = mem2hex(®s->d1, ptr, 4, 0);
1383 ptr = mem2hex(®s->d2, ptr, 4, 0);
1384 ptr = mem2hex(®s->d3, ptr, 4, 0);
1385 ptr = mem2hex(®s->a0, ptr, 4, 0);
1386 ptr = mem2hex(®s->a1, ptr, 4, 0);
1387 ptr = mem2hex(®s->a2, ptr, 4, 0);
1388 ptr = mem2hex(®s->a3, ptr, 4, 0);
1389
1390 ptr = mem2hex(&ssp, ptr, 4, 0); /* 8 */
1391 ptr = mem2hex(®s->pc, ptr, 4, 0);
1392 ptr = mem2hex(®s->mdr, ptr, 4, 0);
1393 ptr = mem2hex(®s->epsw, ptr, 4, 0);
1394 ptr = mem2hex(®s->lir, ptr, 4, 0);
1395 ptr = mem2hex(®s->lar, ptr, 4, 0);
1396 ptr = mem2hex(®s->mdrq, ptr, 4, 0);
1397
1398 ptr = mem2hex(®s->e0, ptr, 4, 0); /* 15 */
1399 ptr = mem2hex(®s->e1, ptr, 4, 0);
1400 ptr = mem2hex(®s->e2, ptr, 4, 0);
1401 ptr = mem2hex(®s->e3, ptr, 4, 0);
1402 ptr = mem2hex(®s->e4, ptr, 4, 0);
1403 ptr = mem2hex(®s->e5, ptr, 4, 0);
1404 ptr = mem2hex(®s->e6, ptr, 4, 0);
1405 ptr = mem2hex(®s->e7, ptr, 4, 0);
1406
1407 ptr = mem2hex(&ssp, ptr, 4, 0);
1408 ptr = mem2hex(®s, ptr, 4, 0);
1409 ptr = mem2hex(®s->sp, ptr, 4, 0);
1410 ptr = mem2hex(®s->mcrh, ptr, 4, 0); /* 26 */
1411 ptr = mem2hex(®s->mcrl, ptr, 4, 0);
1412 ptr = mem2hex(®s->mcvf, ptr, 4, 0);
1413
1414 ptr = mem2hex(&gdbstub_fpcr, ptr, 4, 0); /* 29 - FPCR */
1415 ptr = mem2hex(&zero, ptr, 4, 0);
1416 ptr = mem2hex(&zero, ptr, 4, 0);
1417 for (loop = 0; loop < 32; loop++)
1418 ptr = mem2hex(&gdbstub_fpufs_array[loop],
1419 ptr, 4, 0); /* 32 - FS0-31 */
1420
1421 break;
1422
1423 /*
1424 * set the value of the CPU registers - return OK
1425 */
1426 case 'G':
1427 {
1428 const char *ptr;
1429
1430 ptr = &input_buffer[1];
1431 ptr = hex2mem(ptr, ®s->d0, 4, 0);
1432 ptr = hex2mem(ptr, ®s->d1, 4, 0);
1433 ptr = hex2mem(ptr, ®s->d2, 4, 0);
1434 ptr = hex2mem(ptr, ®s->d3, 4, 0);
1435 ptr = hex2mem(ptr, ®s->a0, 4, 0);
1436 ptr = hex2mem(ptr, ®s->a1, 4, 0);
1437 ptr = hex2mem(ptr, ®s->a2, 4, 0);
1438 ptr = hex2mem(ptr, ®s->a3, 4, 0);
1439
1440 ptr = hex2mem(ptr, &ssp, 4, 0); /* 8 */
1441 ptr = hex2mem(ptr, ®s->pc, 4, 0);
1442 ptr = hex2mem(ptr, ®s->mdr, 4, 0);
1443 ptr = hex2mem(ptr, ®s->epsw, 4, 0);
1444 ptr = hex2mem(ptr, ®s->lir, 4, 0);
1445 ptr = hex2mem(ptr, ®s->lar, 4, 0);
1446 ptr = hex2mem(ptr, ®s->mdrq, 4, 0);
1447
1448 ptr = hex2mem(ptr, ®s->e0, 4, 0); /* 15 */
1449 ptr = hex2mem(ptr, ®s->e1, 4, 0);
1450 ptr = hex2mem(ptr, ®s->e2, 4, 0);
1451 ptr = hex2mem(ptr, ®s->e3, 4, 0);
1452 ptr = hex2mem(ptr, ®s->e4, 4, 0);
1453 ptr = hex2mem(ptr, ®s->e5, 4, 0);
1454 ptr = hex2mem(ptr, ®s->e6, 4, 0);
1455 ptr = hex2mem(ptr, ®s->e7, 4, 0);
1456
1457 ptr = hex2mem(ptr, &ssp, 4, 0);
1458 ptr = hex2mem(ptr, &zero, 4, 0);
1459 ptr = hex2mem(ptr, ®s->sp, 4, 0);
1460 ptr = hex2mem(ptr, ®s->mcrh, 4, 0); /* 26 */
1461 ptr = hex2mem(ptr, ®s->mcrl, 4, 0);
1462 ptr = hex2mem(ptr, ®s->mcvf, 4, 0);
1463
1464 ptr = hex2mem(ptr, &zero, 4, 0); /* 29 - FPCR */
1465 ptr = hex2mem(ptr, &zero, 4, 0);
1466 ptr = hex2mem(ptr, &zero, 4, 0);
1467 for (loop = 0; loop < 32; loop++) /* 32 - FS0-31 */
1468 ptr = hex2mem(ptr, &zero, 4, 0);
1469
1470#if 0
1471 /*
1472 * See if the stack pointer has moved. If so, then copy
1473 * the saved locals and ins to the new location.
1474 */
1475 unsigned long *newsp = (unsigned long *) registers[SP];
1476 if (sp != newsp)
1477 sp = memcpy(newsp, sp, 16 * 4);
1478#endif
1479
1480 gdbstub_strcpy(output_buffer, "OK");
1481 }
1482 break;
1483
1484 /*
1485 * mAA..AA,LLLL Read LLLL bytes at address AA..AA
1486 */
1487 case 'm':
1488 ptr = &input_buffer[1];
1489
1490 if (hexToInt(&ptr, &addr) &&
1491 *ptr++ == ',' &&
1492 hexToInt(&ptr, &length)
1493 ) {
1494 if (mem2hex((char *) addr, output_buffer,
1495 length, 1))
1496 break;
1497 gdbstub_strcpy(output_buffer, "E03");
1498 } else {
1499 gdbstub_strcpy(output_buffer, "E01");
1500 }
1501 break;
1502
1503 /*
1504 * MAA..AA,LLLL: Write LLLL bytes at address AA.AA
1505 * return OK
1506 */
1507 case 'M':
1508 ptr = &input_buffer[1];
1509
1510 if (hexToInt(&ptr, &addr) &&
1511 *ptr++ == ',' &&
1512 hexToInt(&ptr, &length) &&
1513 *ptr++ == ':'
1514 ) {
1515 if (hex2mem(ptr, (char *) addr, length, 1))
1516 gdbstub_strcpy(output_buffer, "OK");
1517 else
1518 gdbstub_strcpy(output_buffer, "E03");
1519
1520 gdbstub_flush_caches = 1;
1521 } else {
1522 gdbstub_strcpy(output_buffer, "E02");
1523 }
1524 break;
1525
1526 /*
1527 * cAA..AA Continue at address AA..AA(optional)
1528 */
1529 case 'c':
1530 /* try to read optional parameter, pc unchanged if no
1531 * parm */
1532
1533 ptr = &input_buffer[1];
1534 if (hexToInt(&ptr, &addr))
1535 regs->pc = addr;
1536 goto done;
1537
1538 /*
1539 * kill the program
1540 */
1541 case 'k' :
1542 goto done; /* just continue */
1543
1544 /*
1545 * Reset the whole machine (FIXME: system dependent)
1546 */
1547 case 'r':
1548 break;
1549
1550 /*
1551 * Step to next instruction
1552 */
1553 case 's':
1554 /* Using the T flag doesn't seem to perform single
1555 * stepping (it seems to wind up being caught by the
1556 * JTAG unit), so we have to use breakpoints and
1557 * continue instead.
1558 */
1559#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
1560 if (gdbstub_single_step(regs) < 0)
1561 /* ignore any fault error for now */
1562 gdbstub_printk("unable to set single-step"
1563 " bp\n");
1564 goto done;
1565#else
1566 gdbstub_strcpy(output_buffer, "E01");
1567 break;
1568#endif
1569
1570 /*
1571 * Set baud rate (bBB)
1572 */
1573 case 'b':
1574 do {
1575 int baudrate;
1576
1577 ptr = &input_buffer[1];
1578 if (!hexToInt(&ptr, &baudrate)) {
1579 gdbstub_strcpy(output_buffer, "B01");
1580 break;
1581 }
1582
1583 if (baudrate) {
1584 /* ACK before changing speed */
1585 putpacket("OK");
1586 gdbstub_io_set_baud(baudrate);
1587 }
1588 } while (0);
1589 break;
1590
1591 /*
1592 * Set breakpoint
1593 */
1594 case 'Z':
1595 ptr = &input_buffer[1];
1596
1597 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1598 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1599 !hexToInt(&ptr, &length)
1600 ) {
1601 gdbstub_strcpy(output_buffer, "E01");
1602 break;
1603 }
1604
1605 /* only support software breakpoints */
1606 gdbstub_strcpy(output_buffer, "E03");
1607 if (loop != 0 ||
1608 length < 1 ||
1609 length > 7 ||
1610 (unsigned long) addr < 4096)
1611 break;
1612
1613 if (gdbstub_set_breakpoint((u8 *) addr, length) < 0)
1614 break;
1615
1616 gdbstub_strcpy(output_buffer, "OK");
1617 break;
1618
1619 /*
1620 * Clear breakpoint
1621 */
1622 case 'z':
1623 ptr = &input_buffer[1];
1624
1625 if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
1626 !hexToInt(&ptr, &addr) || *ptr++ != ',' ||
1627 !hexToInt(&ptr, &length)
1628 ) {
1629 gdbstub_strcpy(output_buffer, "E01");
1630 break;
1631 }
1632
1633 /* only support software breakpoints */
1634 gdbstub_strcpy(output_buffer, "E03");
1635 if (loop != 0 ||
1636 length < 1 ||
1637 length > 7 ||
1638 (unsigned long) addr < 4096)
1639 break;
1640
1641 if (gdbstub_clear_breakpoint((u8 *) addr, length) < 0)
1642 break;
1643
1644 gdbstub_strcpy(output_buffer, "OK");
1645 break;
1646
1647 default:
1648 gdbstub_proto("### GDB Unsupported Cmd '%s'\n",
1649 input_buffer);
1650 break;
1651 }
1652
1653 /* reply to the request */
1654 putpacket(output_buffer);
1655 }
1656
1657done:
1658 /*
1659 * Need to flush the instruction cache here, as we may
1660 * have deposited a breakpoint, and the icache probably
1661 * has no way of knowing that a data ref to some location
1662 * may have changed something that is in the instruction
1663 * cache.
1664 * NB: We flush both caches, just to be sure...
1665 */
1666 if (gdbstub_flush_caches)
1667 debugger_local_cache_flushinv();
1668
1669 gdbstub_load_fpu();
1670 mn10300_set_gdbleds(0);
1671 if (excep == EXCEP_NMI)
1672 NMICR = NMICR_NMIF;
1673
1674 touch_softlockup_watchdog();
1675
1676 local_irq_restore(epsw);
1677 return 0;
1678}
1679
1680/*
1681 * Determine if we hit a debugger special breakpoint that needs skipping over
1682 * automatically.
1683 */
1684int at_debugger_breakpoint(struct pt_regs *regs)
1685{
1686 return 0;
1687}
1688
1689/*
1690 * handle event interception
1691 */
1692asmlinkage int debugger_intercept(enum exception_code excep,
1693 int signo, int si_code, struct pt_regs *regs)
1694{
1695 static u8 notfirst = 1;
1696 int ret;
1697
1698 if (gdbstub_busy)
1699 gdbstub_printk("--> gdbstub reentered itself\n");
1700 gdbstub_busy = 1;
1701
1702 if (notfirst) {
1703 unsigned long mdr;
1704 asm("mov mdr,%0" : "=d"(mdr));
1705
1706 gdbstub_entry(
1707 "--> debugger_intercept(%p,%04x) [MDR=%lx PC=%lx]\n",
1708 regs, excep, mdr, regs->pc);
1709
1710 gdbstub_entry(
1711 "PC: %08lx EPSW: %08lx SSP: %08lx mode: %s\n",
1712 regs->pc, regs->epsw, (unsigned long) &ret,
1713 user_mode(regs) ? "User" : "Super");
1714 gdbstub_entry(
1715 "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
1716 regs->d0, regs->d1, regs->d2, regs->d3);
1717 gdbstub_entry(
1718 "a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
1719 regs->a0, regs->a1, regs->a2, regs->a3);
1720 gdbstub_entry(
1721 "e0: %08lx e1: %08lx e2: %08lx e3: %08lx\n",
1722 regs->e0, regs->e1, regs->e2, regs->e3);
1723 gdbstub_entry(
1724 "e4: %08lx e5: %08lx e6: %08lx e7: %08lx\n",
1725 regs->e4, regs->e5, regs->e6, regs->e7);
1726 gdbstub_entry(
1727 "lar: %08lx lir: %08lx mdr: %08lx usp: %08lx\n",
1728 regs->lar, regs->lir, regs->mdr, regs->sp);
1729 gdbstub_entry(
1730 "cvf: %08lx crl: %08lx crh: %08lx drq: %08lx\n",
1731 regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
1732 gdbstub_entry(
1733 "threadinfo=%p task=%p)\n",
1734 current_thread_info(), current);
1735 } else {
1736 notfirst = 1;
1737 }
1738
1739 ret = gdbstub(regs, excep);
1740
1741 gdbstub_entry("<-- debugger_intercept()\n");
1742 gdbstub_busy = 0;
1743 return ret;
1744}
1745
1746/*
1747 * handle the GDB stub itself causing an exception
1748 */
1749asmlinkage void gdbstub_exception(struct pt_regs *regs,
1750 enum exception_code excep)
1751{
1752 unsigned long mdr;
1753
1754 asm("mov mdr,%0" : "=d"(mdr));
1755 gdbstub_entry("--> gdbstub exception({%p},%04x) [MDR=%lx]\n",
1756 regs, excep, mdr);
1757
1758 while ((unsigned long) regs == 0xffffffff) {}
1759
1760 /* handle guarded memory accesses where we know it might fault */
1761 if (regs->pc == (unsigned) gdbstub_read_byte_guard) {
1762 regs->pc = (unsigned) gdbstub_read_byte_cont;
1763 goto fault;
1764 }
1765
1766 if (regs->pc == (unsigned) gdbstub_read_word_guard) {
1767 regs->pc = (unsigned) gdbstub_read_word_cont;
1768 goto fault;
1769 }
1770
1771 if (regs->pc == (unsigned) gdbstub_read_dword_guard) {
1772 regs->pc = (unsigned) gdbstub_read_dword_cont;
1773 goto fault;
1774 }
1775
1776 if (regs->pc == (unsigned) gdbstub_write_byte_guard) {
1777 regs->pc = (unsigned) gdbstub_write_byte_cont;
1778 goto fault;
1779 }
1780
1781 if (regs->pc == (unsigned) gdbstub_write_word_guard) {
1782 regs->pc = (unsigned) gdbstub_write_word_cont;
1783 goto fault;
1784 }
1785
1786 if (regs->pc == (unsigned) gdbstub_write_dword_guard) {
1787 regs->pc = (unsigned) gdbstub_write_dword_cont;
1788 goto fault;
1789 }
1790
1791 gdbstub_printk("\n### GDB stub caused an exception ###\n");
1792
1793 /* something went horribly wrong */
1794 console_verbose();
1795 show_registers(regs);
1796
1797 panic("GDB Stub caused an unexpected exception - can't continue\n");
1798
1799 /* we caught an attempt by the stub to access silly memory */
1800fault:
1801 gdbstub_entry("<-- gdbstub exception() = EFAULT\n");
1802 regs->d0 = -EFAULT;
1803 return;
1804}
1805
1806/*
1807 * send an exit message to GDB
1808 */
1809void gdbstub_exit(int status)
1810{
1811 unsigned char checksum;
1812 unsigned char ch;
1813 int count;
1814
1815 gdbstub_busy = 1;
1816 output_buffer[0] = 'W';
1817 output_buffer[1] = hex_asc_hi(status);
1818 output_buffer[2] = hex_asc_lo(status);
1819 output_buffer[3] = 0;
1820
1821 gdbstub_io_tx_char('$');
1822 checksum = 0;
1823 count = 0;
1824
1825 while ((ch = output_buffer[count]) != 0) {
1826 gdbstub_io_tx_char(ch);
1827 checksum += ch;
1828 count += 1;
1829 }
1830
1831 gdbstub_io_tx_char('#');
1832 gdbstub_io_tx_char(hex_asc_hi(checksum));
1833 gdbstub_io_tx_char(hex_asc_lo(checksum));
1834
1835 /* make sure the output is flushed, or else RedBoot might clobber it */
1836 gdbstub_io_tx_flush();
1837
1838 gdbstub_busy = 0;
1839}
1840
1841/*
1842 * initialise the GDB stub
1843 */
1844asmlinkage void __init gdbstub_init(void)
1845{
1846#ifdef CONFIG_GDBSTUB_IMMEDIATE
1847 unsigned char ch;
1848 int ret;
1849#endif
1850
1851 gdbstub_busy = 1;
1852
1853 printk(KERN_INFO "%s", gdbstub_banner);
1854
1855 gdbstub_io_init();
1856
1857 gdbstub_entry("--> gdbstub_init\n");
1858
1859 /* try to talk to GDB (or anyone insane enough to want to type GDB
1860 * protocol by hand) */
1861 gdbstub_io("### GDB Tx ACK\n");
1862 gdbstub_io_tx_char('+'); /* 'hello world' */
1863
1864#ifdef CONFIG_GDBSTUB_IMMEDIATE
1865 gdbstub_printk("GDB Stub waiting for packet\n");
1866
1867 /* in case GDB is started before us, ACK any packets that are already
1868 * sitting there (presumably "$?#xx")
1869 */
1870 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '$');
1871 do { gdbstub_io_rx_char(&ch, 0); } while (ch != '#');
1872 /* eat first csum byte */
1873 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1874 /* eat second csum byte */
1875 do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
1876
1877 gdbstub_io("### GDB Tx NAK\n");
1878 gdbstub_io_tx_char('-'); /* NAK it */
1879
1880#else
1881 printk("GDB Stub ready\n");
1882#endif
1883
1884 gdbstub_busy = 0;
1885 gdbstub_entry("<-- gdbstub_init\n");
1886}
1887
1888/*
1889 * register the console at a more appropriate time
1890 */
1891#ifdef CONFIG_GDBSTUB_CONSOLE
1892static int __init gdbstub_postinit(void)
1893{
1894 printk(KERN_NOTICE "registering console\n");
1895 register_console(&gdbstub_console);
1896 return 0;
1897}
1898
1899__initcall(gdbstub_postinit);
1900#endif
1901
1902/*
1903 * handle character reception on GDB serial port
1904 * - jump into the GDB stub if BREAK is detected on the serial line
1905 */
1906asmlinkage void gdbstub_rx_irq(struct pt_regs *regs, enum exception_code excep)
1907{
1908 char ch;
1909 int ret;
1910
1911 gdbstub_entry("--> gdbstub_rx_irq\n");
1912
1913 do {
1914 ret = gdbstub_io_rx_char(&ch, 1);
1915 if (ret != -EIO && ret != -EAGAIN) {
1916 if (ret != -EINTR)
1917 gdbstub_rx_unget = ch;
1918 gdbstub(regs, excep);
1919 }
1920 } while (ret != -EAGAIN);
1921
1922 gdbstub_entry("<-- gdbstub_rx_irq\n");
1923}