hw/omap_sx1.c: fix build
[qemu/mini2440/sniper_sniper_test.git] / gdbstub.c
blob99a4772954959c527df7c12b9ac7e4c718769344
1 /*
2 * gdb server stub
4 * Copyright (c) 2003-2005 Fabrice Bellard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA
20 #include "config.h"
21 #include "qemu-common.h"
22 #ifdef CONFIG_USER_ONLY
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <stdarg.h>
26 #include <string.h>
27 #include <errno.h>
28 #include <unistd.h>
29 #include <fcntl.h>
31 #include "qemu.h"
32 #else
33 #include "qemu-char.h"
34 #include "sysemu.h"
35 #include "gdbstub.h"
36 #endif
38 #define MAX_PACKET_LENGTH 4096
40 #include "qemu_socket.h"
43 enum {
44 GDB_SIGNAL_0 = 0,
45 GDB_SIGNAL_INT = 2,
46 GDB_SIGNAL_TRAP = 5,
47 GDB_SIGNAL_UNKNOWN = 143
50 #ifdef CONFIG_USER_ONLY
52 /* Map target signal numbers to GDB protocol signal numbers and vice
53 * versa. For user emulation's currently supported systems, we can
54 * assume most signals are defined.
57 static int gdb_signal_table[] = {
59 TARGET_SIGHUP,
60 TARGET_SIGINT,
61 TARGET_SIGQUIT,
62 TARGET_SIGILL,
63 TARGET_SIGTRAP,
64 TARGET_SIGABRT,
65 -1, /* SIGEMT */
66 TARGET_SIGFPE,
67 TARGET_SIGKILL,
68 TARGET_SIGBUS,
69 TARGET_SIGSEGV,
70 TARGET_SIGSYS,
71 TARGET_SIGPIPE,
72 TARGET_SIGALRM,
73 TARGET_SIGTERM,
74 TARGET_SIGURG,
75 TARGET_SIGSTOP,
76 TARGET_SIGTSTP,
77 TARGET_SIGCONT,
78 TARGET_SIGCHLD,
79 TARGET_SIGTTIN,
80 TARGET_SIGTTOU,
81 TARGET_SIGIO,
82 TARGET_SIGXCPU,
83 TARGET_SIGXFSZ,
84 TARGET_SIGVTALRM,
85 TARGET_SIGPROF,
86 TARGET_SIGWINCH,
87 -1, /* SIGLOST */
88 TARGET_SIGUSR1,
89 TARGET_SIGUSR2,
90 #ifdef TARGET_SIGPWR
91 TARGET_SIGPWR,
92 #else
93 -1,
94 #endif
95 -1, /* SIGPOLL */
96 -1,
97 -1,
98 -1,
99 -1,
107 #ifdef __SIGRTMIN
108 __SIGRTMIN + 1,
109 __SIGRTMIN + 2,
110 __SIGRTMIN + 3,
111 __SIGRTMIN + 4,
112 __SIGRTMIN + 5,
113 __SIGRTMIN + 6,
114 __SIGRTMIN + 7,
115 __SIGRTMIN + 8,
116 __SIGRTMIN + 9,
117 __SIGRTMIN + 10,
118 __SIGRTMIN + 11,
119 __SIGRTMIN + 12,
120 __SIGRTMIN + 13,
121 __SIGRTMIN + 14,
122 __SIGRTMIN + 15,
123 __SIGRTMIN + 16,
124 __SIGRTMIN + 17,
125 __SIGRTMIN + 18,
126 __SIGRTMIN + 19,
127 __SIGRTMIN + 20,
128 __SIGRTMIN + 21,
129 __SIGRTMIN + 22,
130 __SIGRTMIN + 23,
131 __SIGRTMIN + 24,
132 __SIGRTMIN + 25,
133 __SIGRTMIN + 26,
134 __SIGRTMIN + 27,
135 __SIGRTMIN + 28,
136 __SIGRTMIN + 29,
137 __SIGRTMIN + 30,
138 __SIGRTMIN + 31,
139 -1, /* SIGCANCEL */
140 __SIGRTMIN,
141 __SIGRTMIN + 32,
142 __SIGRTMIN + 33,
143 __SIGRTMIN + 34,
144 __SIGRTMIN + 35,
145 __SIGRTMIN + 36,
146 __SIGRTMIN + 37,
147 __SIGRTMIN + 38,
148 __SIGRTMIN + 39,
149 __SIGRTMIN + 40,
150 __SIGRTMIN + 41,
151 __SIGRTMIN + 42,
152 __SIGRTMIN + 43,
153 __SIGRTMIN + 44,
154 __SIGRTMIN + 45,
155 __SIGRTMIN + 46,
156 __SIGRTMIN + 47,
157 __SIGRTMIN + 48,
158 __SIGRTMIN + 49,
159 __SIGRTMIN + 50,
160 __SIGRTMIN + 51,
161 __SIGRTMIN + 52,
162 __SIGRTMIN + 53,
163 __SIGRTMIN + 54,
164 __SIGRTMIN + 55,
165 __SIGRTMIN + 56,
166 __SIGRTMIN + 57,
167 __SIGRTMIN + 58,
168 __SIGRTMIN + 59,
169 __SIGRTMIN + 60,
170 __SIGRTMIN + 61,
171 __SIGRTMIN + 62,
172 __SIGRTMIN + 63,
173 __SIGRTMIN + 64,
174 __SIGRTMIN + 65,
175 __SIGRTMIN + 66,
176 __SIGRTMIN + 67,
177 __SIGRTMIN + 68,
178 __SIGRTMIN + 69,
179 __SIGRTMIN + 70,
180 __SIGRTMIN + 71,
181 __SIGRTMIN + 72,
182 __SIGRTMIN + 73,
183 __SIGRTMIN + 74,
184 __SIGRTMIN + 75,
185 __SIGRTMIN + 76,
186 __SIGRTMIN + 77,
187 __SIGRTMIN + 78,
188 __SIGRTMIN + 79,
189 __SIGRTMIN + 80,
190 __SIGRTMIN + 81,
191 __SIGRTMIN + 82,
192 __SIGRTMIN + 83,
193 __SIGRTMIN + 84,
194 __SIGRTMIN + 85,
195 __SIGRTMIN + 86,
196 __SIGRTMIN + 87,
197 __SIGRTMIN + 88,
198 __SIGRTMIN + 89,
199 __SIGRTMIN + 90,
200 __SIGRTMIN + 91,
201 __SIGRTMIN + 92,
202 __SIGRTMIN + 93,
203 __SIGRTMIN + 94,
204 __SIGRTMIN + 95,
205 -1, /* SIGINFO */
206 -1, /* UNKNOWN */
207 -1, /* DEFAULT */
214 #endif
216 #else
217 /* In system mode we only need SIGINT and SIGTRAP; other signals
218 are not yet supported. */
220 enum {
221 TARGET_SIGINT = 2,
222 TARGET_SIGTRAP = 5
225 static int gdb_signal_table[] = {
228 TARGET_SIGINT,
231 TARGET_SIGTRAP
233 #endif
235 #ifdef CONFIG_USER_ONLY
236 static int target_signal_to_gdb (int sig)
238 int i;
239 for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
240 if (gdb_signal_table[i] == sig)
241 return i;
242 return GDB_SIGNAL_UNKNOWN;
244 #endif
246 static int gdb_signal_to_target (int sig)
248 if (sig < ARRAY_SIZE (gdb_signal_table))
249 return gdb_signal_table[sig];
250 else
251 return -1;
254 //#define DEBUG_GDB
256 typedef struct GDBRegisterState {
257 int base_reg;
258 int num_regs;
259 gdb_reg_cb get_reg;
260 gdb_reg_cb set_reg;
261 const char *xml;
262 struct GDBRegisterState *next;
263 } GDBRegisterState;
265 enum RSState {
266 RS_IDLE,
267 RS_GETLINE,
268 RS_CHKSUM1,
269 RS_CHKSUM2,
270 RS_SYSCALL,
272 typedef struct GDBState {
273 CPUState *c_cpu; /* current CPU for step/continue ops */
274 CPUState *g_cpu; /* current CPU for other ops */
275 CPUState *query_cpu; /* for q{f|s}ThreadInfo */
276 enum RSState state; /* parsing state */
277 char line_buf[MAX_PACKET_LENGTH];
278 int line_buf_index;
279 int line_csum;
280 uint8_t last_packet[MAX_PACKET_LENGTH + 4];
281 int last_packet_len;
282 int signal;
283 #ifdef CONFIG_USER_ONLY
284 int fd;
285 int running_state;
286 #else
287 CharDriverState *chr;
288 #endif
289 } GDBState;
291 /* By default use no IRQs and no timers while single stepping so as to
292 * make single stepping like an ICE HW step.
294 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
296 static GDBState *gdbserver_state;
298 /* This is an ugly hack to cope with both new and old gdb.
299 If gdb sends qXfer:features:read then assume we're talking to a newish
300 gdb that understands target descriptions. */
301 static int gdb_has_xml;
303 #ifdef CONFIG_USER_ONLY
304 /* XXX: This is not thread safe. Do we care? */
305 static int gdbserver_fd = -1;
307 static int get_char(GDBState *s)
309 uint8_t ch;
310 int ret;
312 for(;;) {
313 ret = recv(s->fd, &ch, 1, 0);
314 if (ret < 0) {
315 if (errno == ECONNRESET)
316 s->fd = -1;
317 if (errno != EINTR && errno != EAGAIN)
318 return -1;
319 } else if (ret == 0) {
320 close(s->fd);
321 s->fd = -1;
322 return -1;
323 } else {
324 break;
327 return ch;
329 #endif
331 static gdb_syscall_complete_cb gdb_current_syscall_cb;
333 enum {
334 GDB_SYS_UNKNOWN,
335 GDB_SYS_ENABLED,
336 GDB_SYS_DISABLED,
337 } gdb_syscall_mode;
339 /* If gdb is connected when the first semihosting syscall occurs then use
340 remote gdb syscalls. Otherwise use native file IO. */
341 int use_gdb_syscalls(void)
343 if (gdb_syscall_mode == GDB_SYS_UNKNOWN) {
344 gdb_syscall_mode = (gdbserver_state ? GDB_SYS_ENABLED
345 : GDB_SYS_DISABLED);
347 return gdb_syscall_mode == GDB_SYS_ENABLED;
350 /* Resume execution. */
351 static inline void gdb_continue(GDBState *s)
353 #ifdef CONFIG_USER_ONLY
354 s->running_state = 1;
355 #else
356 vm_start();
357 #endif
360 static void put_buffer(GDBState *s, const uint8_t *buf, int len)
362 #ifdef CONFIG_USER_ONLY
363 int ret;
365 while (len > 0) {
366 ret = send(s->fd, buf, len, 0);
367 if (ret < 0) {
368 if (errno != EINTR && errno != EAGAIN)
369 return;
370 } else {
371 buf += ret;
372 len -= ret;
375 #else
376 qemu_chr_write(s->chr, buf, len);
377 #endif
380 static inline int fromhex(int v)
382 if (v >= '0' && v <= '9')
383 return v - '0';
384 else if (v >= 'A' && v <= 'F')
385 return v - 'A' + 10;
386 else if (v >= 'a' && v <= 'f')
387 return v - 'a' + 10;
388 else
389 return 0;
392 static inline int tohex(int v)
394 if (v < 10)
395 return v + '0';
396 else
397 return v - 10 + 'a';
400 static void memtohex(char *buf, const uint8_t *mem, int len)
402 int i, c;
403 char *q;
404 q = buf;
405 for(i = 0; i < len; i++) {
406 c = mem[i];
407 *q++ = tohex(c >> 4);
408 *q++ = tohex(c & 0xf);
410 *q = '\0';
413 static void hextomem(uint8_t *mem, const char *buf, int len)
415 int i;
417 for(i = 0; i < len; i++) {
418 mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
419 buf += 2;
423 /* return -1 if error, 0 if OK */
424 static int put_packet_binary(GDBState *s, const char *buf, int len)
426 int csum, i;
427 uint8_t *p;
429 for(;;) {
430 p = s->last_packet;
431 *(p++) = '$';
432 memcpy(p, buf, len);
433 p += len;
434 csum = 0;
435 for(i = 0; i < len; i++) {
436 csum += buf[i];
438 *(p++) = '#';
439 *(p++) = tohex((csum >> 4) & 0xf);
440 *(p++) = tohex((csum) & 0xf);
442 s->last_packet_len = p - s->last_packet;
443 put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
445 #ifdef CONFIG_USER_ONLY
446 i = get_char(s);
447 if (i < 0)
448 return -1;
449 if (i == '+')
450 break;
451 #else
452 break;
453 #endif
455 return 0;
458 /* return -1 if error, 0 if OK */
459 static int put_packet(GDBState *s, const char *buf)
461 #ifdef DEBUG_GDB
462 printf("reply='%s'\n", buf);
463 #endif
465 return put_packet_binary(s, buf, strlen(buf));
468 /* The GDB remote protocol transfers values in target byte order. This means
469 we can use the raw memory access routines to access the value buffer.
470 Conveniently, these also handle the case where the buffer is mis-aligned.
472 #define GET_REG8(val) do { \
473 stb_p(mem_buf, val); \
474 return 1; \
475 } while(0)
476 #define GET_REG16(val) do { \
477 stw_p(mem_buf, val); \
478 return 2; \
479 } while(0)
480 #define GET_REG32(val) do { \
481 stl_p(mem_buf, val); \
482 return 4; \
483 } while(0)
484 #define GET_REG64(val) do { \
485 stq_p(mem_buf, val); \
486 return 8; \
487 } while(0)
489 #if TARGET_LONG_BITS == 64
490 #define GET_REGL(val) GET_REG64(val)
491 #define ldtul_p(addr) ldq_p(addr)
492 #else
493 #define GET_REGL(val) GET_REG32(val)
494 #define ldtul_p(addr) ldl_p(addr)
495 #endif
497 #if defined(TARGET_I386)
499 #ifdef TARGET_X86_64
500 static const int gpr_map[16] = {
501 R_EAX, R_EBX, R_ECX, R_EDX, R_ESI, R_EDI, R_EBP, R_ESP,
502 8, 9, 10, 11, 12, 13, 14, 15
504 #else
505 static const int gpr_map[8] = {0, 1, 2, 3, 4, 5, 6, 7};
506 #endif
508 #define NUM_CORE_REGS (CPU_NB_REGS * 2 + 25)
510 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
512 if (n < CPU_NB_REGS) {
513 GET_REGL(env->regs[gpr_map[n]]);
514 } else if (n >= CPU_NB_REGS + 8 && n < CPU_NB_REGS + 16) {
515 /* FIXME: byteswap float values. */
516 #ifdef USE_X86LDOUBLE
517 memcpy(mem_buf, &env->fpregs[n - (CPU_NB_REGS + 8)], 10);
518 #else
519 memset(mem_buf, 0, 10);
520 #endif
521 return 10;
522 } else if (n >= CPU_NB_REGS + 24) {
523 n -= CPU_NB_REGS + 24;
524 if (n < CPU_NB_REGS) {
525 stq_p(mem_buf, env->xmm_regs[n].XMM_Q(0));
526 stq_p(mem_buf + 8, env->xmm_regs[n].XMM_Q(1));
527 return 16;
528 } else if (n == CPU_NB_REGS) {
529 GET_REG32(env->mxcsr);
531 } else {
532 n -= CPU_NB_REGS;
533 switch (n) {
534 case 0: GET_REGL(env->eip);
535 case 1: GET_REG32(env->eflags);
536 case 2: GET_REG32(env->segs[R_CS].selector);
537 case 3: GET_REG32(env->segs[R_SS].selector);
538 case 4: GET_REG32(env->segs[R_DS].selector);
539 case 5: GET_REG32(env->segs[R_ES].selector);
540 case 6: GET_REG32(env->segs[R_FS].selector);
541 case 7: GET_REG32(env->segs[R_GS].selector);
542 /* 8...15 x87 regs. */
543 case 16: GET_REG32(env->fpuc);
544 case 17: GET_REG32((env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11);
545 case 18: GET_REG32(0); /* ftag */
546 case 19: GET_REG32(0); /* fiseg */
547 case 20: GET_REG32(0); /* fioff */
548 case 21: GET_REG32(0); /* foseg */
549 case 22: GET_REG32(0); /* fooff */
550 case 23: GET_REG32(0); /* fop */
551 /* 24+ xmm regs. */
554 return 0;
557 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int i)
559 uint32_t tmp;
561 if (i < CPU_NB_REGS) {
562 env->regs[gpr_map[i]] = ldtul_p(mem_buf);
563 return sizeof(target_ulong);
564 } else if (i >= CPU_NB_REGS + 8 && i < CPU_NB_REGS + 16) {
565 i -= CPU_NB_REGS + 8;
566 #ifdef USE_X86LDOUBLE
567 memcpy(&env->fpregs[i], mem_buf, 10);
568 #endif
569 return 10;
570 } else if (i >= CPU_NB_REGS + 24) {
571 i -= CPU_NB_REGS + 24;
572 if (i < CPU_NB_REGS) {
573 env->xmm_regs[i].XMM_Q(0) = ldq_p(mem_buf);
574 env->xmm_regs[i].XMM_Q(1) = ldq_p(mem_buf + 8);
575 return 16;
576 } else if (i == CPU_NB_REGS) {
577 env->mxcsr = ldl_p(mem_buf);
578 return 4;
580 } else {
581 i -= CPU_NB_REGS;
582 switch (i) {
583 case 0: env->eip = ldtul_p(mem_buf); return sizeof(target_ulong);
584 case 1: env->eflags = ldl_p(mem_buf); return 4;
585 #if defined(CONFIG_USER_ONLY)
586 #define LOAD_SEG(index, sreg)\
587 tmp = ldl_p(mem_buf);\
588 if (tmp != env->segs[sreg].selector)\
589 cpu_x86_load_seg(env, sreg, tmp);
590 #else
591 /* FIXME: Honor segment registers. Needs to avoid raising an exception
592 when the selector is invalid. */
593 #define LOAD_SEG(index, sreg) do {} while(0)
594 #endif
595 case 2: LOAD_SEG(10, R_CS); return 4;
596 case 3: LOAD_SEG(11, R_SS); return 4;
597 case 4: LOAD_SEG(12, R_DS); return 4;
598 case 5: LOAD_SEG(13, R_ES); return 4;
599 case 6: LOAD_SEG(14, R_FS); return 4;
600 case 7: LOAD_SEG(15, R_GS); return 4;
601 /* 8...15 x87 regs. */
602 case 16: env->fpuc = ldl_p(mem_buf); return 4;
603 case 17:
604 tmp = ldl_p(mem_buf);
605 env->fpstt = (tmp >> 11) & 7;
606 env->fpus = tmp & ~0x3800;
607 return 4;
608 case 18: /* ftag */ return 4;
609 case 19: /* fiseg */ return 4;
610 case 20: /* fioff */ return 4;
611 case 21: /* foseg */ return 4;
612 case 22: /* fooff */ return 4;
613 case 23: /* fop */ return 4;
614 /* 24+ xmm regs. */
617 /* Unrecognised register. */
618 return 0;
621 #elif defined (TARGET_PPC)
623 #define NUM_CORE_REGS 71
625 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
627 if (n < 32) {
628 /* gprs */
629 GET_REGL(env->gpr[n]);
630 } else if (n < 64) {
631 /* fprs */
632 stfq_p(mem_buf, env->fpr[n-32]);
633 return 8;
634 } else {
635 switch (n) {
636 case 64: GET_REGL(env->nip);
637 case 65: GET_REGL(env->msr);
638 case 66:
640 uint32_t cr = 0;
641 int i;
642 for (i = 0; i < 8; i++)
643 cr |= env->crf[i] << (32 - ((i + 1) * 4));
644 GET_REG32(cr);
646 case 67: GET_REGL(env->lr);
647 case 68: GET_REGL(env->ctr);
648 case 69: GET_REGL(env->xer);
649 case 70: GET_REG32(0); /* fpscr */
652 return 0;
655 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
657 if (n < 32) {
658 /* gprs */
659 env->gpr[n] = ldtul_p(mem_buf);
660 return sizeof(target_ulong);
661 } else if (n < 64) {
662 /* fprs */
663 env->fpr[n-32] = ldfq_p(mem_buf);
664 return 8;
665 } else {
666 switch (n) {
667 case 64:
668 env->nip = ldtul_p(mem_buf);
669 return sizeof(target_ulong);
670 case 65:
671 ppc_store_msr(env, ldtul_p(mem_buf));
672 return sizeof(target_ulong);
673 case 66:
675 uint32_t cr = ldl_p(mem_buf);
676 int i;
677 for (i = 0; i < 8; i++)
678 env->crf[i] = (cr >> (32 - ((i + 1) * 4))) & 0xF;
679 return 4;
681 case 67:
682 env->lr = ldtul_p(mem_buf);
683 return sizeof(target_ulong);
684 case 68:
685 env->ctr = ldtul_p(mem_buf);
686 return sizeof(target_ulong);
687 case 69:
688 env->xer = ldtul_p(mem_buf);
689 return sizeof(target_ulong);
690 case 70:
691 /* fpscr */
692 return 4;
695 return 0;
698 #elif defined (TARGET_SPARC)
700 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
701 #define NUM_CORE_REGS 86
702 #else
703 #define NUM_CORE_REGS 72
704 #endif
706 #ifdef TARGET_ABI32
707 #define GET_REGA(val) GET_REG32(val)
708 #else
709 #define GET_REGA(val) GET_REGL(val)
710 #endif
712 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
714 if (n < 8) {
715 /* g0..g7 */
716 GET_REGA(env->gregs[n]);
718 if (n < 32) {
719 /* register window */
720 GET_REGA(env->regwptr[n - 8]);
722 #if defined(TARGET_ABI32) || !defined(TARGET_SPARC64)
723 if (n < 64) {
724 /* fprs */
725 GET_REG32(*((uint32_t *)&env->fpr[n - 32]));
727 /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
728 switch (n) {
729 case 64: GET_REGA(env->y);
730 case 65: GET_REGA(GET_PSR(env));
731 case 66: GET_REGA(env->wim);
732 case 67: GET_REGA(env->tbr);
733 case 68: GET_REGA(env->pc);
734 case 69: GET_REGA(env->npc);
735 case 70: GET_REGA(env->fsr);
736 case 71: GET_REGA(0); /* csr */
737 default: GET_REGA(0);
739 #else
740 if (n < 64) {
741 /* f0-f31 */
742 GET_REG32(*((uint32_t *)&env->fpr[n - 32]));
744 if (n < 80) {
745 /* f32-f62 (double width, even numbers only) */
746 uint64_t val;
748 val = (uint64_t)*((uint32_t *)&env->fpr[(n - 64) * 2 + 32]) << 32;
749 val |= *((uint32_t *)&env->fpr[(n - 64) * 2 + 33]);
750 GET_REG64(val);
752 switch (n) {
753 case 80: GET_REGL(env->pc);
754 case 81: GET_REGL(env->npc);
755 case 82: GET_REGL(((uint64_t)GET_CCR(env) << 32) |
756 ((env->asi & 0xff) << 24) |
757 ((env->pstate & 0xfff) << 8) |
758 GET_CWP64(env));
759 case 83: GET_REGL(env->fsr);
760 case 84: GET_REGL(env->fprs);
761 case 85: GET_REGL(env->y);
763 #endif
764 return 0;
767 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
769 #if defined(TARGET_ABI32)
770 abi_ulong tmp;
772 tmp = ldl_p(mem_buf);
773 #else
774 target_ulong tmp;
776 tmp = ldtul_p(mem_buf);
777 #endif
779 if (n < 8) {
780 /* g0..g7 */
781 env->gregs[n] = tmp;
782 } else if (n < 32) {
783 /* register window */
784 env->regwptr[n - 8] = tmp;
786 #if defined(TARGET_ABI32) || !defined(TARGET_SPARC64)
787 else if (n < 64) {
788 /* fprs */
789 *((uint32_t *)&env->fpr[n - 32]) = tmp;
790 } else {
791 /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
792 switch (n) {
793 case 64: env->y = tmp; break;
794 case 65: PUT_PSR(env, tmp); break;
795 case 66: env->wim = tmp; break;
796 case 67: env->tbr = tmp; break;
797 case 68: env->pc = tmp; break;
798 case 69: env->npc = tmp; break;
799 case 70: env->fsr = tmp; break;
800 default: return 0;
803 return 4;
804 #else
805 else if (n < 64) {
806 /* f0-f31 */
807 env->fpr[n] = ldfl_p(mem_buf);
808 return 4;
809 } else if (n < 80) {
810 /* f32-f62 (double width, even numbers only) */
811 *((uint32_t *)&env->fpr[(n - 64) * 2 + 32]) = tmp >> 32;
812 *((uint32_t *)&env->fpr[(n - 64) * 2 + 33]) = tmp;
813 } else {
814 switch (n) {
815 case 80: env->pc = tmp; break;
816 case 81: env->npc = tmp; break;
817 case 82:
818 PUT_CCR(env, tmp >> 32);
819 env->asi = (tmp >> 24) & 0xff;
820 env->pstate = (tmp >> 8) & 0xfff;
821 PUT_CWP64(env, tmp & 0xff);
822 break;
823 case 83: env->fsr = tmp; break;
824 case 84: env->fprs = tmp; break;
825 case 85: env->y = tmp; break;
826 default: return 0;
829 return 8;
830 #endif
832 #elif defined (TARGET_ARM)
834 /* Old gdb always expect FPA registers. Newer (xml-aware) gdb only expect
835 whatever the target description contains. Due to a historical mishap
836 the FPA registers appear in between core integer regs and the CPSR.
837 We hack round this by giving the FPA regs zero size when talking to a
838 newer gdb. */
839 #define NUM_CORE_REGS 26
840 #define GDB_CORE_XML "arm-core.xml"
842 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
844 if (n < 16) {
845 /* Core integer register. */
846 GET_REG32(env->regs[n]);
848 if (n < 24) {
849 /* FPA registers. */
850 if (gdb_has_xml)
851 return 0;
852 memset(mem_buf, 0, 12);
853 return 12;
855 switch (n) {
856 case 24:
857 /* FPA status register. */
858 if (gdb_has_xml)
859 return 0;
860 GET_REG32(0);
861 case 25:
862 /* CPSR */
863 GET_REG32(cpsr_read(env));
865 /* Unknown register. */
866 return 0;
869 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
871 uint32_t tmp;
873 tmp = ldl_p(mem_buf);
875 /* Mask out low bit of PC to workaround gdb bugs. This will probably
876 cause problems if we ever implement the Jazelle DBX extensions. */
877 if (n == 15)
878 tmp &= ~1;
880 if (n < 16) {
881 /* Core integer register. */
882 env->regs[n] = tmp;
883 return 4;
885 if (n < 24) { /* 16-23 */
886 /* FPA registers (ignored). */
887 if (gdb_has_xml)
888 return 0;
889 return 12;
891 switch (n) {
892 case 24:
893 /* FPA status register (ignored). */
894 if (gdb_has_xml)
895 return 0;
896 return 4;
897 case 25:
898 /* CPSR */
899 cpsr_write (env, tmp, 0xffffffff);
900 return 4;
902 /* Unknown register. */
903 return 0;
906 #elif defined (TARGET_M68K)
908 #define NUM_CORE_REGS 18
910 #define GDB_CORE_XML "cf-core.xml"
912 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
914 if (n < 8) {
915 /* D0-D7 */
916 GET_REG32(env->dregs[n]);
917 } else if (n < 16) {
918 /* A0-A7 */
919 GET_REG32(env->aregs[n - 8]);
920 } else {
921 switch (n) {
922 case 16: GET_REG32(env->sr);
923 case 17: GET_REG32(env->pc);
926 /* FP registers not included here because they vary between
927 ColdFire and m68k. Use XML bits for these. */
928 return 0;
931 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
933 uint32_t tmp;
935 tmp = ldl_p(mem_buf);
937 if (n < 8) {
938 /* D0-D7 */
939 env->dregs[n] = tmp;
940 } else if (n < 8) {
941 /* A0-A7 */
942 env->aregs[n - 8] = tmp;
943 } else {
944 switch (n) {
945 case 16: env->sr = tmp; break;
946 case 17: env->pc = tmp; break;
947 default: return 0;
950 return 4;
952 #elif defined (TARGET_MIPS)
954 #define NUM_CORE_REGS 73
956 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
958 if (n < 32) {
959 GET_REGL(env->active_tc.gpr[n]);
961 if (env->CP0_Config1 & (1 << CP0C1_FP)) {
962 if (n >= 38 && n < 70) {
963 if (env->CP0_Status & (1 << CP0St_FR))
964 GET_REGL(env->active_fpu.fpr[n - 38].d);
965 else
966 GET_REGL(env->active_fpu.fpr[n - 38].w[FP_ENDIAN_IDX]);
968 switch (n) {
969 case 70: GET_REGL((int32_t)env->active_fpu.fcr31);
970 case 71: GET_REGL((int32_t)env->active_fpu.fcr0);
973 switch (n) {
974 case 32: GET_REGL((int32_t)env->CP0_Status);
975 case 33: GET_REGL(env->active_tc.LO[0]);
976 case 34: GET_REGL(env->active_tc.HI[0]);
977 case 35: GET_REGL(env->CP0_BadVAddr);
978 case 36: GET_REGL((int32_t)env->CP0_Cause);
979 case 37: GET_REGL(env->active_tc.PC);
980 case 72: GET_REGL(0); /* fp */
981 case 89: GET_REGL((int32_t)env->CP0_PRid);
983 if (n >= 73 && n <= 88) {
984 /* 16 embedded regs. */
985 GET_REGL(0);
988 return 0;
991 /* convert MIPS rounding mode in FCR31 to IEEE library */
992 static unsigned int ieee_rm[] =
994 float_round_nearest_even,
995 float_round_to_zero,
996 float_round_up,
997 float_round_down
999 #define RESTORE_ROUNDING_MODE \
1000 set_float_rounding_mode(ieee_rm[env->active_fpu.fcr31 & 3], &env->active_fpu.fp_status)
1002 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
1004 target_ulong tmp;
1006 tmp = ldtul_p(mem_buf);
1008 if (n < 32) {
1009 env->active_tc.gpr[n] = tmp;
1010 return sizeof(target_ulong);
1012 if (env->CP0_Config1 & (1 << CP0C1_FP)
1013 && n >= 38 && n < 73) {
1014 if (n < 70) {
1015 if (env->CP0_Status & (1 << CP0St_FR))
1016 env->active_fpu.fpr[n - 38].d = tmp;
1017 else
1018 env->active_fpu.fpr[n - 38].w[FP_ENDIAN_IDX] = tmp;
1020 switch (n) {
1021 case 70:
1022 env->active_fpu.fcr31 = tmp & 0xFF83FFFF;
1023 /* set rounding mode */
1024 RESTORE_ROUNDING_MODE;
1025 #ifndef CONFIG_SOFTFLOAT
1026 /* no floating point exception for native float */
1027 SET_FP_ENABLE(env->active_fpu.fcr31, 0);
1028 #endif
1029 break;
1030 case 71: env->active_fpu.fcr0 = tmp; break;
1032 return sizeof(target_ulong);
1034 switch (n) {
1035 case 32: env->CP0_Status = tmp; break;
1036 case 33: env->active_tc.LO[0] = tmp; break;
1037 case 34: env->active_tc.HI[0] = tmp; break;
1038 case 35: env->CP0_BadVAddr = tmp; break;
1039 case 36: env->CP0_Cause = tmp; break;
1040 case 37: env->active_tc.PC = tmp; break;
1041 case 72: /* fp, ignored */ break;
1042 default:
1043 if (n > 89)
1044 return 0;
1045 /* Other registers are readonly. Ignore writes. */
1046 break;
1049 return sizeof(target_ulong);
1051 #elif defined (TARGET_SH4)
1053 /* Hint: Use "set architecture sh4" in GDB to see fpu registers */
1054 /* FIXME: We should use XML for this. */
1056 #define NUM_CORE_REGS 59
1058 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
1060 if (n < 8) {
1061 if ((env->sr & (SR_MD | SR_RB)) == (SR_MD | SR_RB)) {
1062 GET_REGL(env->gregs[n + 16]);
1063 } else {
1064 GET_REGL(env->gregs[n]);
1066 } else if (n < 16) {
1067 GET_REGL(env->gregs[n - 8]);
1068 } else if (n >= 25 && n < 41) {
1069 GET_REGL(env->fregs[(n - 25) + ((env->fpscr & FPSCR_FR) ? 16 : 0)]);
1070 } else if (n >= 43 && n < 51) {
1071 GET_REGL(env->gregs[n - 43]);
1072 } else if (n >= 51 && n < 59) {
1073 GET_REGL(env->gregs[n - (51 - 16)]);
1075 switch (n) {
1076 case 16: GET_REGL(env->pc);
1077 case 17: GET_REGL(env->pr);
1078 case 18: GET_REGL(env->gbr);
1079 case 19: GET_REGL(env->vbr);
1080 case 20: GET_REGL(env->mach);
1081 case 21: GET_REGL(env->macl);
1082 case 22: GET_REGL(env->sr);
1083 case 23: GET_REGL(env->fpul);
1084 case 24: GET_REGL(env->fpscr);
1085 case 41: GET_REGL(env->ssr);
1086 case 42: GET_REGL(env->spc);
1089 return 0;
1092 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
1094 uint32_t tmp;
1096 tmp = ldl_p(mem_buf);
1098 if (n < 8) {
1099 if ((env->sr & (SR_MD | SR_RB)) == (SR_MD | SR_RB)) {
1100 env->gregs[n + 16] = tmp;
1101 } else {
1102 env->gregs[n] = tmp;
1104 return 4;
1105 } else if (n < 16) {
1106 env->gregs[n - 8] = tmp;
1107 return 4;
1108 } else if (n >= 25 && n < 41) {
1109 env->fregs[(n - 25) + ((env->fpscr & FPSCR_FR) ? 16 : 0)] = tmp;
1110 } else if (n >= 43 && n < 51) {
1111 env->gregs[n - 43] = tmp;
1112 return 4;
1113 } else if (n >= 51 && n < 59) {
1114 env->gregs[n - (51 - 16)] = tmp;
1115 return 4;
1117 switch (n) {
1118 case 16: env->pc = tmp;
1119 case 17: env->pr = tmp;
1120 case 18: env->gbr = tmp;
1121 case 19: env->vbr = tmp;
1122 case 20: env->mach = tmp;
1123 case 21: env->macl = tmp;
1124 case 22: env->sr = tmp;
1125 case 23: env->fpul = tmp;
1126 case 24: env->fpscr = tmp;
1127 case 41: env->ssr = tmp;
1128 case 42: env->spc = tmp;
1129 default: return 0;
1132 return 4;
1134 #elif defined (TARGET_CRIS)
1136 #define NUM_CORE_REGS 49
1138 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
1140 uint8_t srs;
1142 srs = env->pregs[PR_SRS];
1143 if (n < 16) {
1144 GET_REG32(env->regs[n]);
1147 if (n >= 21 && n < 32) {
1148 GET_REG32(env->pregs[n - 16]);
1150 if (n >= 33 && n < 49) {
1151 GET_REG32(env->sregs[srs][n - 33]);
1153 switch (n) {
1154 case 16: GET_REG8(env->pregs[0]);
1155 case 17: GET_REG8(env->pregs[1]);
1156 case 18: GET_REG32(env->pregs[2]);
1157 case 19: GET_REG8(srs);
1158 case 20: GET_REG16(env->pregs[4]);
1159 case 32: GET_REG32(env->pc);
1162 return 0;
1165 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
1167 uint32_t tmp;
1169 if (n > 49)
1170 return 0;
1172 tmp = ldl_p(mem_buf);
1174 if (n < 16) {
1175 env->regs[n] = tmp;
1178 if (n >= 21 && n < 32) {
1179 env->pregs[n - 16] = tmp;
1182 /* FIXME: Should support function regs be writable? */
1183 switch (n) {
1184 case 16: return 1;
1185 case 17: return 1;
1186 case 18: env->pregs[PR_PID] = tmp; break;
1187 case 19: return 1;
1188 case 20: return 2;
1189 case 32: env->pc = tmp; break;
1192 return 4;
1194 #elif defined (TARGET_ALPHA)
1196 #define NUM_CORE_REGS 65
1198 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
1200 if (n < 31) {
1201 GET_REGL(env->ir[n]);
1203 else if (n == 31) {
1204 GET_REGL(0);
1206 else if (n<63) {
1207 uint64_t val;
1209 val=*((uint64_t *)&env->fir[n-32]);
1210 GET_REGL(val);
1212 else if (n==63) {
1213 GET_REGL(env->fpcr);
1215 else if (n==64) {
1216 GET_REGL(env->pc);
1218 else {
1219 GET_REGL(0);
1222 return 0;
1225 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
1227 target_ulong tmp;
1228 tmp = ldtul_p(mem_buf);
1230 if (n < 31) {
1231 env->ir[n] = tmp;
1234 if (n > 31 && n < 63) {
1235 env->fir[n - 32] = ldfl_p(mem_buf);
1238 if (n == 64 ) {
1239 env->pc=tmp;
1242 return 8;
1244 #else
1246 #define NUM_CORE_REGS 0
1248 static int cpu_gdb_read_register(CPUState *env, uint8_t *mem_buf, int n)
1250 return 0;
1253 static int cpu_gdb_write_register(CPUState *env, uint8_t *mem_buf, int n)
1255 return 0;
1258 #endif
1260 static int num_g_regs = NUM_CORE_REGS;
1262 #ifdef GDB_CORE_XML
1263 /* Encode data using the encoding for 'x' packets. */
1264 static int memtox(char *buf, const char *mem, int len)
1266 char *p = buf;
1267 char c;
1269 while (len--) {
1270 c = *(mem++);
1271 switch (c) {
1272 case '#': case '$': case '*': case '}':
1273 *(p++) = '}';
1274 *(p++) = c ^ 0x20;
1275 break;
1276 default:
1277 *(p++) = c;
1278 break;
1281 return p - buf;
1284 static const char *get_feature_xml(const char *p, const char **newp)
1286 extern const char *const xml_builtin[][2];
1287 size_t len;
1288 int i;
1289 const char *name;
1290 static char target_xml[1024];
1292 len = 0;
1293 while (p[len] && p[len] != ':')
1294 len++;
1295 *newp = p + len;
1297 name = NULL;
1298 if (strncmp(p, "target.xml", len) == 0) {
1299 /* Generate the XML description for this CPU. */
1300 if (!target_xml[0]) {
1301 GDBRegisterState *r;
1303 snprintf(target_xml, sizeof(target_xml),
1304 "<?xml version=\"1.0\"?>"
1305 "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
1306 "<target>"
1307 "<xi:include href=\"%s\"/>",
1308 GDB_CORE_XML);
1310 for (r = first_cpu->gdb_regs; r; r = r->next) {
1311 strcat(target_xml, "<xi:include href=\"");
1312 strcat(target_xml, r->xml);
1313 strcat(target_xml, "\"/>");
1315 strcat(target_xml, "</target>");
1317 return target_xml;
1319 for (i = 0; ; i++) {
1320 name = xml_builtin[i][0];
1321 if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
1322 break;
1324 return name ? xml_builtin[i][1] : NULL;
1326 #endif
1328 static int gdb_read_register(CPUState *env, uint8_t *mem_buf, int reg)
1330 GDBRegisterState *r;
1332 if (reg < NUM_CORE_REGS)
1333 return cpu_gdb_read_register(env, mem_buf, reg);
1335 for (r = env->gdb_regs; r; r = r->next) {
1336 if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
1337 return r->get_reg(env, mem_buf, reg - r->base_reg);
1340 return 0;
1343 static int gdb_write_register(CPUState *env, uint8_t *mem_buf, int reg)
1345 GDBRegisterState *r;
1347 if (reg < NUM_CORE_REGS)
1348 return cpu_gdb_write_register(env, mem_buf, reg);
1350 for (r = env->gdb_regs; r; r = r->next) {
1351 if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
1352 return r->set_reg(env, mem_buf, reg - r->base_reg);
1355 return 0;
1358 /* Register a supplemental set of CPU registers. If g_pos is nonzero it
1359 specifies the first register number and these registers are included in
1360 a standard "g" packet. Direction is relative to gdb, i.e. get_reg is
1361 gdb reading a CPU register, and set_reg is gdb modifying a CPU register.
1364 void gdb_register_coprocessor(CPUState * env,
1365 gdb_reg_cb get_reg, gdb_reg_cb set_reg,
1366 int num_regs, const char *xml, int g_pos)
1368 GDBRegisterState *s;
1369 GDBRegisterState **p;
1370 static int last_reg = NUM_CORE_REGS;
1372 s = (GDBRegisterState *)qemu_mallocz(sizeof(GDBRegisterState));
1373 s->base_reg = last_reg;
1374 s->num_regs = num_regs;
1375 s->get_reg = get_reg;
1376 s->set_reg = set_reg;
1377 s->xml = xml;
1378 p = &env->gdb_regs;
1379 while (*p) {
1380 /* Check for duplicates. */
1381 if (strcmp((*p)->xml, xml) == 0)
1382 return;
1383 p = &(*p)->next;
1385 /* Add to end of list. */
1386 last_reg += num_regs;
1387 *p = s;
1388 if (g_pos) {
1389 if (g_pos != s->base_reg) {
1390 fprintf(stderr, "Error: Bad gdb register numbering for '%s'\n"
1391 "Expected %d got %d\n", xml, g_pos, s->base_reg);
1392 } else {
1393 num_g_regs = last_reg;
1398 /* GDB breakpoint/watchpoint types */
1399 #define GDB_BREAKPOINT_SW 0
1400 #define GDB_BREAKPOINT_HW 1
1401 #define GDB_WATCHPOINT_WRITE 2
1402 #define GDB_WATCHPOINT_READ 3
1403 #define GDB_WATCHPOINT_ACCESS 4
1405 #ifndef CONFIG_USER_ONLY
1406 static const int xlat_gdb_type[] = {
1407 [GDB_WATCHPOINT_WRITE] = BP_GDB | BP_MEM_WRITE,
1408 [GDB_WATCHPOINT_READ] = BP_GDB | BP_MEM_READ,
1409 [GDB_WATCHPOINT_ACCESS] = BP_GDB | BP_MEM_ACCESS,
1411 #endif
1413 static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
1415 CPUState *env;
1416 int err = 0;
1418 switch (type) {
1419 case GDB_BREAKPOINT_SW:
1420 case GDB_BREAKPOINT_HW:
1421 for (env = first_cpu; env != NULL; env = env->next_cpu) {
1422 err = cpu_breakpoint_insert(env, addr, BP_GDB, NULL);
1423 if (err)
1424 break;
1426 return err;
1427 #ifndef CONFIG_USER_ONLY
1428 case GDB_WATCHPOINT_WRITE:
1429 case GDB_WATCHPOINT_READ:
1430 case GDB_WATCHPOINT_ACCESS:
1431 for (env = first_cpu; env != NULL; env = env->next_cpu) {
1432 err = cpu_watchpoint_insert(env, addr, len, xlat_gdb_type[type],
1433 NULL);
1434 if (err)
1435 break;
1437 return err;
1438 #endif
1439 default:
1440 return -ENOSYS;
1444 static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
1446 CPUState *env;
1447 int err = 0;
1449 switch (type) {
1450 case GDB_BREAKPOINT_SW:
1451 case GDB_BREAKPOINT_HW:
1452 for (env = first_cpu; env != NULL; env = env->next_cpu) {
1453 err = cpu_breakpoint_remove(env, addr, BP_GDB);
1454 if (err)
1455 break;
1457 return err;
1458 #ifndef CONFIG_USER_ONLY
1459 case GDB_WATCHPOINT_WRITE:
1460 case GDB_WATCHPOINT_READ:
1461 case GDB_WATCHPOINT_ACCESS:
1462 for (env = first_cpu; env != NULL; env = env->next_cpu) {
1463 err = cpu_watchpoint_remove(env, addr, len, xlat_gdb_type[type]);
1464 if (err)
1465 break;
1467 return err;
1468 #endif
1469 default:
1470 return -ENOSYS;
1474 static void gdb_breakpoint_remove_all(void)
1476 CPUState *env;
1478 for (env = first_cpu; env != NULL; env = env->next_cpu) {
1479 cpu_breakpoint_remove_all(env, BP_GDB);
1480 #ifndef CONFIG_USER_ONLY
1481 cpu_watchpoint_remove_all(env, BP_GDB);
1482 #endif
1486 static int gdb_handle_packet(GDBState *s, const char *line_buf)
1488 CPUState *env;
1489 const char *p;
1490 int ch, reg_size, type, res, thread;
1491 char buf[MAX_PACKET_LENGTH];
1492 uint8_t mem_buf[MAX_PACKET_LENGTH];
1493 uint8_t *registers;
1494 target_ulong addr, len;
1496 #ifdef DEBUG_GDB
1497 printf("command='%s'\n", line_buf);
1498 #endif
1499 p = line_buf;
1500 ch = *p++;
1501 switch(ch) {
1502 case '?':
1503 /* TODO: Make this return the correct value for user-mode. */
1504 snprintf(buf, sizeof(buf), "T%02xthread:%02x;", GDB_SIGNAL_TRAP,
1505 s->c_cpu->cpu_index+1);
1506 put_packet(s, buf);
1507 /* Remove all the breakpoints when this query is issued,
1508 * because gdb is doing and initial connect and the state
1509 * should be cleaned up.
1511 gdb_breakpoint_remove_all();
1512 break;
1513 case 'c':
1514 if (*p != '\0') {
1515 addr = strtoull(p, (char **)&p, 16);
1516 #if defined(TARGET_I386)
1517 s->c_cpu->eip = addr;
1518 #elif defined (TARGET_PPC)
1519 s->c_cpu->nip = addr;
1520 #elif defined (TARGET_SPARC)
1521 s->c_cpu->pc = addr;
1522 s->c_cpu->npc = addr + 4;
1523 #elif defined (TARGET_ARM)
1524 s->c_cpu->regs[15] = addr;
1525 #elif defined (TARGET_SH4)
1526 s->c_cpu->pc = addr;
1527 #elif defined (TARGET_MIPS)
1528 s->c_cpu->active_tc.PC = addr;
1529 #elif defined (TARGET_CRIS)
1530 s->c_cpu->pc = addr;
1531 #elif defined (TARGET_ALPHA)
1532 s->c_cpu->pc = addr;
1533 #endif
1535 s->signal = 0;
1536 gdb_continue(s);
1537 return RS_IDLE;
1538 case 'C':
1539 s->signal = gdb_signal_to_target (strtoul(p, (char **)&p, 16));
1540 if (s->signal == -1)
1541 s->signal = 0;
1542 gdb_continue(s);
1543 return RS_IDLE;
1544 case 'k':
1545 /* Kill the target */
1546 fprintf(stderr, "\nQEMU: Terminated via GDBstub\n");
1547 exit(0);
1548 case 'D':
1549 /* Detach packet */
1550 gdb_breakpoint_remove_all();
1551 gdb_continue(s);
1552 put_packet(s, "OK");
1553 break;
1554 case 's':
1555 if (*p != '\0') {
1556 addr = strtoull(p, (char **)&p, 16);
1557 #if defined(TARGET_I386)
1558 s->c_cpu->eip = addr;
1559 #elif defined (TARGET_PPC)
1560 s->c_cpu->nip = addr;
1561 #elif defined (TARGET_SPARC)
1562 s->c_cpu->pc = addr;
1563 s->c_cpu->npc = addr + 4;
1564 #elif defined (TARGET_ARM)
1565 s->c_cpu->regs[15] = addr;
1566 #elif defined (TARGET_SH4)
1567 s->c_cpu->pc = addr;
1568 #elif defined (TARGET_MIPS)
1569 s->c_cpu->active_tc.PC = addr;
1570 #elif defined (TARGET_CRIS)
1571 s->c_cpu->pc = addr;
1572 #elif defined (TARGET_ALPHA)
1573 s->c_cpu->pc = addr;
1574 #endif
1576 cpu_single_step(s->c_cpu, sstep_flags);
1577 gdb_continue(s);
1578 return RS_IDLE;
1579 case 'F':
1581 target_ulong ret;
1582 target_ulong err;
1584 ret = strtoull(p, (char **)&p, 16);
1585 if (*p == ',') {
1586 p++;
1587 err = strtoull(p, (char **)&p, 16);
1588 } else {
1589 err = 0;
1591 if (*p == ',')
1592 p++;
1593 type = *p;
1594 if (gdb_current_syscall_cb)
1595 gdb_current_syscall_cb(s->c_cpu, ret, err);
1596 if (type == 'C') {
1597 put_packet(s, "T02");
1598 } else {
1599 gdb_continue(s);
1602 break;
1603 case 'g':
1604 len = 0;
1605 for (addr = 0; addr < num_g_regs; addr++) {
1606 reg_size = gdb_read_register(s->g_cpu, mem_buf + len, addr);
1607 len += reg_size;
1609 memtohex(buf, mem_buf, len);
1610 put_packet(s, buf);
1611 break;
1612 case 'G':
1613 registers = mem_buf;
1614 len = strlen(p) / 2;
1615 hextomem((uint8_t *)registers, p, len);
1616 for (addr = 0; addr < num_g_regs && len > 0; addr++) {
1617 reg_size = gdb_write_register(s->g_cpu, registers, addr);
1618 len -= reg_size;
1619 registers += reg_size;
1621 put_packet(s, "OK");
1622 break;
1623 case 'm':
1624 addr = strtoull(p, (char **)&p, 16);
1625 if (*p == ',')
1626 p++;
1627 len = strtoull(p, NULL, 16);
1628 if (cpu_memory_rw_debug(s->g_cpu, addr, mem_buf, len, 0) != 0) {
1629 put_packet (s, "E14");
1630 } else {
1631 memtohex(buf, mem_buf, len);
1632 put_packet(s, buf);
1634 break;
1635 case 'M':
1636 addr = strtoull(p, (char **)&p, 16);
1637 if (*p == ',')
1638 p++;
1639 len = strtoull(p, (char **)&p, 16);
1640 if (*p == ':')
1641 p++;
1642 hextomem(mem_buf, p, len);
1643 if (cpu_memory_rw_debug(s->g_cpu, addr, mem_buf, len, 1) != 0)
1644 put_packet(s, "E14");
1645 else
1646 put_packet(s, "OK");
1647 break;
1648 case 'p':
1649 /* Older gdb are really dumb, and don't use 'g' if 'p' is avaialable.
1650 This works, but can be very slow. Anything new enough to
1651 understand XML also knows how to use this properly. */
1652 if (!gdb_has_xml)
1653 goto unknown_command;
1654 addr = strtoull(p, (char **)&p, 16);
1655 reg_size = gdb_read_register(s->g_cpu, mem_buf, addr);
1656 if (reg_size) {
1657 memtohex(buf, mem_buf, reg_size);
1658 put_packet(s, buf);
1659 } else {
1660 put_packet(s, "E14");
1662 break;
1663 case 'P':
1664 if (!gdb_has_xml)
1665 goto unknown_command;
1666 addr = strtoull(p, (char **)&p, 16);
1667 if (*p == '=')
1668 p++;
1669 reg_size = strlen(p) / 2;
1670 hextomem(mem_buf, p, reg_size);
1671 gdb_write_register(s->g_cpu, mem_buf, addr);
1672 put_packet(s, "OK");
1673 break;
1674 case 'Z':
1675 case 'z':
1676 type = strtoul(p, (char **)&p, 16);
1677 if (*p == ',')
1678 p++;
1679 addr = strtoull(p, (char **)&p, 16);
1680 if (*p == ',')
1681 p++;
1682 len = strtoull(p, (char **)&p, 16);
1683 if (ch == 'Z')
1684 res = gdb_breakpoint_insert(addr, len, type);
1685 else
1686 res = gdb_breakpoint_remove(addr, len, type);
1687 if (res >= 0)
1688 put_packet(s, "OK");
1689 else if (res == -ENOSYS)
1690 put_packet(s, "");
1691 else
1692 put_packet(s, "E22");
1693 break;
1694 case 'H':
1695 type = *p++;
1696 thread = strtoull(p, (char **)&p, 16);
1697 if (thread == -1 || thread == 0) {
1698 put_packet(s, "OK");
1699 break;
1701 for (env = first_cpu; env != NULL; env = env->next_cpu)
1702 if (env->cpu_index + 1 == thread)
1703 break;
1704 if (env == NULL) {
1705 put_packet(s, "E22");
1706 break;
1708 switch (type) {
1709 case 'c':
1710 s->c_cpu = env;
1711 put_packet(s, "OK");
1712 break;
1713 case 'g':
1714 s->g_cpu = env;
1715 put_packet(s, "OK");
1716 break;
1717 default:
1718 put_packet(s, "E22");
1719 break;
1721 break;
1722 case 'T':
1723 thread = strtoull(p, (char **)&p, 16);
1724 #ifndef CONFIG_USER_ONLY
1725 if (thread > 0 && thread < smp_cpus + 1)
1726 #else
1727 if (thread == 1)
1728 #endif
1729 put_packet(s, "OK");
1730 else
1731 put_packet(s, "E22");
1732 break;
1733 case 'q':
1734 case 'Q':
1735 /* parse any 'q' packets here */
1736 if (!strcmp(p,"qemu.sstepbits")) {
1737 /* Query Breakpoint bit definitions */
1738 snprintf(buf, sizeof(buf), "ENABLE=%x,NOIRQ=%x,NOTIMER=%x",
1739 SSTEP_ENABLE,
1740 SSTEP_NOIRQ,
1741 SSTEP_NOTIMER);
1742 put_packet(s, buf);
1743 break;
1744 } else if (strncmp(p,"qemu.sstep",10) == 0) {
1745 /* Display or change the sstep_flags */
1746 p += 10;
1747 if (*p != '=') {
1748 /* Display current setting */
1749 snprintf(buf, sizeof(buf), "0x%x", sstep_flags);
1750 put_packet(s, buf);
1751 break;
1753 p++;
1754 type = strtoul(p, (char **)&p, 16);
1755 sstep_flags = type;
1756 put_packet(s, "OK");
1757 break;
1758 } else if (strcmp(p,"C") == 0) {
1759 /* "Current thread" remains vague in the spec, so always return
1760 * the first CPU (gdb returns the first thread). */
1761 put_packet(s, "QC1");
1762 break;
1763 } else if (strcmp(p,"fThreadInfo") == 0) {
1764 s->query_cpu = first_cpu;
1765 goto report_cpuinfo;
1766 } else if (strcmp(p,"sThreadInfo") == 0) {
1767 report_cpuinfo:
1768 if (s->query_cpu) {
1769 snprintf(buf, sizeof(buf), "m%x", s->query_cpu->cpu_index+1);
1770 put_packet(s, buf);
1771 s->query_cpu = s->query_cpu->next_cpu;
1772 } else
1773 put_packet(s, "l");
1774 break;
1775 } else if (strncmp(p,"ThreadExtraInfo,", 16) == 0) {
1776 thread = strtoull(p+16, (char **)&p, 16);
1777 for (env = first_cpu; env != NULL; env = env->next_cpu)
1778 if (env->cpu_index + 1 == thread) {
1779 len = snprintf((char *)mem_buf, sizeof(mem_buf),
1780 "CPU#%d [%s]", env->cpu_index,
1781 env->halted ? "halted " : "running");
1782 memtohex(buf, mem_buf, len);
1783 put_packet(s, buf);
1784 break;
1786 break;
1788 #ifdef CONFIG_LINUX_USER
1789 else if (strncmp(p, "Offsets", 7) == 0) {
1790 TaskState *ts = s->c_cpu->opaque;
1792 snprintf(buf, sizeof(buf),
1793 "Text=" TARGET_ABI_FMT_lx ";Data=" TARGET_ABI_FMT_lx
1794 ";Bss=" TARGET_ABI_FMT_lx,
1795 ts->info->code_offset,
1796 ts->info->data_offset,
1797 ts->info->data_offset);
1798 put_packet(s, buf);
1799 break;
1801 #endif
1802 if (strncmp(p, "Supported", 9) == 0) {
1803 snprintf(buf, sizeof(buf), "PacketSize=%x", MAX_PACKET_LENGTH);
1804 #ifdef GDB_CORE_XML
1805 strcat(buf, ";qXfer:features:read+");
1806 #endif
1807 put_packet(s, buf);
1808 break;
1810 #ifdef GDB_CORE_XML
1811 if (strncmp(p, "Xfer:features:read:", 19) == 0) {
1812 const char *xml;
1813 target_ulong total_len;
1815 gdb_has_xml = 1;
1816 p += 19;
1817 xml = get_feature_xml(p, &p);
1818 if (!xml) {
1819 snprintf(buf, sizeof(buf), "E00");
1820 put_packet(s, buf);
1821 break;
1824 if (*p == ':')
1825 p++;
1826 addr = strtoul(p, (char **)&p, 16);
1827 if (*p == ',')
1828 p++;
1829 len = strtoul(p, (char **)&p, 16);
1831 total_len = strlen(xml);
1832 if (addr > total_len) {
1833 snprintf(buf, sizeof(buf), "E00");
1834 put_packet(s, buf);
1835 break;
1837 if (len > (MAX_PACKET_LENGTH - 5) / 2)
1838 len = (MAX_PACKET_LENGTH - 5) / 2;
1839 if (len < total_len - addr) {
1840 buf[0] = 'm';
1841 len = memtox(buf + 1, xml + addr, len);
1842 } else {
1843 buf[0] = 'l';
1844 len = memtox(buf + 1, xml + addr, total_len - addr);
1846 put_packet_binary(s, buf, len + 1);
1847 break;
1849 #endif
1850 /* Unrecognised 'q' command. */
1851 goto unknown_command;
1853 default:
1854 unknown_command:
1855 /* put empty packet */
1856 buf[0] = '\0';
1857 put_packet(s, buf);
1858 break;
1860 return RS_IDLE;
1863 void gdb_set_stop_cpu(CPUState *env)
1865 gdbserver_state->c_cpu = env;
1866 gdbserver_state->g_cpu = env;
1869 #ifndef CONFIG_USER_ONLY
1870 static void gdb_vm_stopped(void *opaque, int reason)
1872 GDBState *s = gdbserver_state;
1873 CPUState *env = s->c_cpu;
1874 char buf[256];
1875 const char *type;
1876 int ret;
1878 if (s->state == RS_SYSCALL)
1879 return;
1881 /* disable single step if it was enable */
1882 cpu_single_step(env, 0);
1884 if (reason == EXCP_DEBUG) {
1885 if (env->watchpoint_hit) {
1886 switch (env->watchpoint_hit->flags & BP_MEM_ACCESS) {
1887 case BP_MEM_READ:
1888 type = "r";
1889 break;
1890 case BP_MEM_ACCESS:
1891 type = "a";
1892 break;
1893 default:
1894 type = "";
1895 break;
1897 snprintf(buf, sizeof(buf),
1898 "T%02xthread:%02x;%swatch:" TARGET_FMT_lx ";",
1899 GDB_SIGNAL_TRAP, env->cpu_index+1, type,
1900 env->watchpoint_hit->vaddr);
1901 put_packet(s, buf);
1902 env->watchpoint_hit = NULL;
1903 return;
1905 tb_flush(env);
1906 ret = GDB_SIGNAL_TRAP;
1907 } else if (reason == EXCP_INTERRUPT) {
1908 ret = GDB_SIGNAL_INT;
1909 } else {
1910 ret = 0;
1912 snprintf(buf, sizeof(buf), "T%02xthread:%02x;", ret, env->cpu_index+1);
1913 put_packet(s, buf);
1915 #endif
1917 /* Send a gdb syscall request.
1918 This accepts limited printf-style format specifiers, specifically:
1919 %x - target_ulong argument printed in hex.
1920 %lx - 64-bit argument printed in hex.
1921 %s - string pointer (target_ulong) and length (int) pair. */
1922 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
1924 va_list va;
1925 char buf[256];
1926 char *p;
1927 target_ulong addr;
1928 uint64_t i64;
1929 GDBState *s;
1931 s = gdbserver_state;
1932 if (!s)
1933 return;
1934 gdb_current_syscall_cb = cb;
1935 s->state = RS_SYSCALL;
1936 #ifndef CONFIG_USER_ONLY
1937 vm_stop(EXCP_DEBUG);
1938 #endif
1939 s->state = RS_IDLE;
1940 va_start(va, fmt);
1941 p = buf;
1942 *(p++) = 'F';
1943 while (*fmt) {
1944 if (*fmt == '%') {
1945 fmt++;
1946 switch (*fmt++) {
1947 case 'x':
1948 addr = va_arg(va, target_ulong);
1949 p += snprintf(p, &buf[sizeof(buf)] - p, TARGET_FMT_lx, addr);
1950 break;
1951 case 'l':
1952 if (*(fmt++) != 'x')
1953 goto bad_format;
1954 i64 = va_arg(va, uint64_t);
1955 p += snprintf(p, &buf[sizeof(buf)] - p, "%" PRIx64, i64);
1956 break;
1957 case 's':
1958 addr = va_arg(va, target_ulong);
1959 p += snprintf(p, &buf[sizeof(buf)] - p, TARGET_FMT_lx "/%x",
1960 addr, va_arg(va, int));
1961 break;
1962 default:
1963 bad_format:
1964 fprintf(stderr, "gdbstub: Bad syscall format string '%s'\n",
1965 fmt - 1);
1966 break;
1968 } else {
1969 *(p++) = *(fmt++);
1972 *p = 0;
1973 va_end(va);
1974 put_packet(s, buf);
1975 #ifdef CONFIG_USER_ONLY
1976 gdb_handlesig(s->c_cpu, 0);
1977 #else
1978 cpu_interrupt(s->c_cpu, CPU_INTERRUPT_EXIT);
1979 #endif
1982 static void gdb_read_byte(GDBState *s, int ch)
1984 int i, csum;
1985 uint8_t reply;
1987 #ifndef CONFIG_USER_ONLY
1988 if (s->last_packet_len) {
1989 /* Waiting for a response to the last packet. If we see the start
1990 of a new command then abandon the previous response. */
1991 if (ch == '-') {
1992 #ifdef DEBUG_GDB
1993 printf("Got NACK, retransmitting\n");
1994 #endif
1995 put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
1997 #ifdef DEBUG_GDB
1998 else if (ch == '+')
1999 printf("Got ACK\n");
2000 else
2001 printf("Got '%c' when expecting ACK/NACK\n", ch);
2002 #endif
2003 if (ch == '+' || ch == '$')
2004 s->last_packet_len = 0;
2005 if (ch != '$')
2006 return;
2008 if (vm_running) {
2009 /* when the CPU is running, we cannot do anything except stop
2010 it when receiving a char */
2011 vm_stop(EXCP_INTERRUPT);
2012 } else
2013 #endif
2015 switch(s->state) {
2016 case RS_IDLE:
2017 if (ch == '$') {
2018 s->line_buf_index = 0;
2019 s->state = RS_GETLINE;
2021 break;
2022 case RS_GETLINE:
2023 if (ch == '#') {
2024 s->state = RS_CHKSUM1;
2025 } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
2026 s->state = RS_IDLE;
2027 } else {
2028 s->line_buf[s->line_buf_index++] = ch;
2030 break;
2031 case RS_CHKSUM1:
2032 s->line_buf[s->line_buf_index] = '\0';
2033 s->line_csum = fromhex(ch) << 4;
2034 s->state = RS_CHKSUM2;
2035 break;
2036 case RS_CHKSUM2:
2037 s->line_csum |= fromhex(ch);
2038 csum = 0;
2039 for(i = 0; i < s->line_buf_index; i++) {
2040 csum += s->line_buf[i];
2042 if (s->line_csum != (csum & 0xff)) {
2043 reply = '-';
2044 put_buffer(s, &reply, 1);
2045 s->state = RS_IDLE;
2046 } else {
2047 reply = '+';
2048 put_buffer(s, &reply, 1);
2049 s->state = gdb_handle_packet(s, s->line_buf);
2051 break;
2052 default:
2053 abort();
2058 #ifdef CONFIG_USER_ONLY
2060 gdb_queuesig (void)
2062 GDBState *s;
2064 s = gdbserver_state;
2066 if (gdbserver_fd < 0 || s->fd < 0)
2067 return 0;
2068 else
2069 return 1;
2073 gdb_handlesig (CPUState *env, int sig)
2075 GDBState *s;
2076 char buf[256];
2077 int n;
2079 s = gdbserver_state;
2080 if (gdbserver_fd < 0 || s->fd < 0)
2081 return sig;
2083 /* disable single step if it was enabled */
2084 cpu_single_step(env, 0);
2085 tb_flush(env);
2087 if (sig != 0)
2089 snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb (sig));
2090 put_packet(s, buf);
2092 /* put_packet() might have detected that the peer terminated the
2093 connection. */
2094 if (s->fd < 0)
2095 return sig;
2097 sig = 0;
2098 s->state = RS_IDLE;
2099 s->running_state = 0;
2100 while (s->running_state == 0) {
2101 n = read (s->fd, buf, 256);
2102 if (n > 0)
2104 int i;
2106 for (i = 0; i < n; i++)
2107 gdb_read_byte (s, buf[i]);
2109 else if (n == 0 || errno != EAGAIN)
2111 /* XXX: Connection closed. Should probably wait for annother
2112 connection before continuing. */
2113 return sig;
2116 sig = s->signal;
2117 s->signal = 0;
2118 return sig;
2121 /* Tell the remote gdb that the process has exited. */
2122 void gdb_exit(CPUState *env, int code)
2124 GDBState *s;
2125 char buf[4];
2127 s = gdbserver_state;
2128 if (gdbserver_fd < 0 || s->fd < 0)
2129 return;
2131 snprintf(buf, sizeof(buf), "W%02x", code);
2132 put_packet(s, buf);
2135 /* Tell the remote gdb that the process has exited due to SIG. */
2136 void gdb_signalled(CPUState *env, int sig)
2138 GDBState *s;
2139 char buf[4];
2141 s = gdbserver_state;
2142 if (gdbserver_fd < 0 || s->fd < 0)
2143 return;
2145 snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb (sig));
2146 put_packet(s, buf);
2149 static void gdb_accept(void)
2151 GDBState *s;
2152 struct sockaddr_in sockaddr;
2153 socklen_t len;
2154 int val, fd;
2156 for(;;) {
2157 len = sizeof(sockaddr);
2158 fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
2159 if (fd < 0 && errno != EINTR) {
2160 perror("accept");
2161 return;
2162 } else if (fd >= 0) {
2163 break;
2167 /* set short latency */
2168 val = 1;
2169 setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof(val));
2171 s = qemu_mallocz(sizeof(GDBState));
2172 if (!s) {
2173 errno = ENOMEM;
2174 perror("accept");
2175 return;
2178 memset (s, 0, sizeof (GDBState));
2179 s->c_cpu = first_cpu;
2180 s->g_cpu = first_cpu;
2181 s->fd = fd;
2182 gdb_has_xml = 0;
2184 gdbserver_state = s;
2186 fcntl(fd, F_SETFL, O_NONBLOCK);
2189 static int gdbserver_open(int port)
2191 struct sockaddr_in sockaddr;
2192 int fd, val, ret;
2194 fd = socket(PF_INET, SOCK_STREAM, 0);
2195 if (fd < 0) {
2196 perror("socket");
2197 return -1;
2200 /* allow fast reuse */
2201 val = 1;
2202 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&val, sizeof(val));
2204 sockaddr.sin_family = AF_INET;
2205 sockaddr.sin_port = htons(port);
2206 sockaddr.sin_addr.s_addr = 0;
2207 ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
2208 if (ret < 0) {
2209 perror("bind");
2210 return -1;
2212 ret = listen(fd, 0);
2213 if (ret < 0) {
2214 perror("listen");
2215 return -1;
2217 return fd;
2220 int gdbserver_start(int port)
2222 gdbserver_fd = gdbserver_open(port);
2223 if (gdbserver_fd < 0)
2224 return -1;
2225 /* accept connections */
2226 gdb_accept();
2227 return 0;
2230 /* Disable gdb stub for child processes. */
2231 void gdbserver_fork(CPUState *env)
2233 GDBState *s = gdbserver_state;
2234 if (gdbserver_fd < 0 || s->fd < 0)
2235 return;
2236 close(s->fd);
2237 s->fd = -1;
2238 cpu_breakpoint_remove_all(env, BP_GDB);
2239 cpu_watchpoint_remove_all(env, BP_GDB);
2241 #else
2242 static int gdb_chr_can_receive(void *opaque)
2244 /* We can handle an arbitrarily large amount of data.
2245 Pick the maximum packet size, which is as good as anything. */
2246 return MAX_PACKET_LENGTH;
2249 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
2251 int i;
2253 for (i = 0; i < size; i++) {
2254 gdb_read_byte(gdbserver_state, buf[i]);
2258 static void gdb_chr_event(void *opaque, int event)
2260 switch (event) {
2261 case CHR_EVENT_RESET:
2262 vm_stop(EXCP_INTERRUPT);
2263 gdb_has_xml = 0;
2264 break;
2265 default:
2266 break;
2270 int gdbserver_start(const char *port)
2272 GDBState *s;
2273 char gdbstub_port_name[128];
2274 int port_num;
2275 char *p;
2276 CharDriverState *chr;
2278 if (!port || !*port)
2279 return -1;
2281 port_num = strtol(port, &p, 10);
2282 if (*p == 0) {
2283 /* A numeric value is interpreted as a port number. */
2284 snprintf(gdbstub_port_name, sizeof(gdbstub_port_name),
2285 "tcp::%d,nowait,nodelay,server", port_num);
2286 port = gdbstub_port_name;
2289 chr = qemu_chr_open("gdb", port);
2290 if (!chr)
2291 return -1;
2293 s = qemu_mallocz(sizeof(GDBState));
2294 if (!s) {
2295 return -1;
2297 s->c_cpu = first_cpu;
2298 s->g_cpu = first_cpu;
2299 s->chr = chr;
2300 gdbserver_state = s;
2301 qemu_chr_add_handlers(chr, gdb_chr_can_receive, gdb_chr_receive,
2302 gdb_chr_event, NULL);
2303 qemu_add_vm_stop_handler(gdb_vm_stopped, NULL);
2304 return 0;
2306 #endif