1 /* Remote target communications for serial-line targets in custom GDB protocol
2 Copyright 1988, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program 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
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
20 /* Remote communication protocol.
22 A debug packet whose contents are <data>
23 is encapsulated for transmission in the form:
25 $ <data> # CSUM1 CSUM2
27 <data> must be ASCII alphanumeric and cannot include characters
28 '$' or '#'. If <data> starts with two characters followed by
29 ':', then the existing stubs interpret this as a sequence number.
31 CSUM1 and CSUM2 are ascii hex representation of an 8-bit
32 checksum of <data>, the most significant nibble is sent first.
33 the hex digits 0-9,a-f are used.
35 Receiver responds with:
37 + - if CSUM is correct and ready for next packet
38 - - if CSUM is incorrect
41 All values are encoded in ascii hex digits.
46 reply XX....X Each byte of register data
47 is described by two hex digits.
48 Registers are in the internal order
49 for GDB, and the bytes in a register
50 are in the same order the machine uses.
53 write regs GXX..XX Each byte of register data
54 is described by two hex digits.
58 write reg Pn...=r... Write register n... with value r...,
59 which contains two hex digits for each
60 byte in the register (target byte
64 (not supported by all stubs).
66 read mem mAA..AA,LLLL AA..AA is address, LLLL is length.
67 reply XX..XX XX..XX is mem contents
68 Can be fewer bytes than requested
69 if able to read only part of the data.
72 write mem MAA..AA,LLLL:XX..XX
74 LLLL is number of bytes,
77 ENN for an error (this includes the case
78 where only part of the data was
81 cont cAA..AA AA..AA is address to resume
83 resume at same address.
85 step sAA..AA AA..AA is address to resume
87 resume at same address.
89 last signal ? Reply the current reason for stopping.
90 This is the same reply as is generated
91 for step or cont : SAA where AA is the
94 There is no immediate reply to step or cont.
95 The reply comes when the machine stops.
96 It is SAA AA is the "signal number"
98 or... TAAn...:r...;n:r...;n...:r...;
100 n... = register number
101 r... = register contents
102 or... WAA The process exited, and AA is
103 the exit status. This is only
104 applicable for certains sorts of
108 toggle debug d toggle debug flag (see 386 & 68k stubs)
109 reset r reset -- see sparc stub.
110 reserved <other> On other requests, the stub should
111 ignore the request and send an empty
112 response ($#<checksum>). This way
113 we can extend the protocol and GDB
114 can tell whether the stub it is
115 talking to uses the old or the new.
116 search tAA:PP,MM Search backwards starting at address
117 AA for a match with pattern PP and
118 mask MM. PP and MM are 4 bytes.
119 Not supported by all stubs.
121 general query qXXXX Request info about XXXX.
122 general set QXXXX=yyyy Set value of XXXX to yyyy.
123 query sect offs qOffsets Get section offsets. Reply is
124 Text=xxx;Data=yyy;Bss=zzz
125 console output Otext Send text to stdout. Only comes from
128 Responses can be run-length encoded to save space. A '*' means that
129 the next character is an ASCII encoding giving a repeat count which
130 stands for that many repititions of the character preceding the '*'.
131 The encoding is n+29, yielding a printable character where n >=3
132 (which is where rle starts to win). Don't use an n > 126.
135 "0* " means the same as "0000". */
141 #include "inferior.h"
146 #include "terminal.h"
148 #include "objfiles.h"
149 #include "gdb-stabs.h"
154 #include <sys/types.h>
160 /* Prototypes for local functions */
163 remote_write_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
166 remote_read_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
169 remote_files_info PARAMS ((struct target_ops *ignore));
172 remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr, int len,
173 int should_write, struct target_ops *target));
176 remote_prepare_to_store PARAMS ((void));
179 remote_fetch_registers PARAMS ((int regno));
182 remote_resume PARAMS ((int pid, int step, enum target_signal siggnal));
185 remote_start_remote PARAMS ((char *dummy));
188 remote_open PARAMS ((char *name, int from_tty));
191 remote_close PARAMS ((int quitting));
194 remote_store_registers PARAMS ((int regno));
197 getpkt PARAMS ((char *buf, int forever));
200 putpkt PARAMS ((char *buf));
203 remote_send PARAMS ((char *buf));
206 readchar PARAMS ((int timeout));
208 static int remote_wait PARAMS ((int pid, struct target_waitstatus *status));
211 tohex PARAMS ((int nib));
214 fromhex PARAMS ((int a));
217 remote_detach PARAMS ((char *args, int from_tty));
220 remote_interrupt PARAMS ((int signo));
223 remote_interrupt_twice PARAMS ((int signo));
226 interrupt_query PARAMS ((void));
228 extern struct target_ops remote_ops; /* Forward decl */
230 /* This was 5 seconds, which is a long time to sit and wait.
231 Unless this is going though some terminal server or multiplexer or
232 other form of hairy serial connection, I would think 2 seconds would
234 static int remote_timeout = 2;
240 /* Descriptor for I/O to remote machine. Initialize it to NULL so that
241 remote_open knows that we don't have a file open when the program
243 serial_t remote_desc = NULL;
245 /* Having this larger than 400 causes us to be incompatible with m68k-stub.c
246 and i386-stub.c. Normally, no one would notice because it only matters
247 for writing large chunks of memory (e.g. in downloads). Also, this needs
248 to be more than 400 if required to hold the registers (see below, where
249 we round it up based on REGISTER_BYTES). */
252 /* Maximum number of bytes to read/write at once. The value here
253 is chosen to fill up a packet (the headers account for the 32). */
254 #define MAXBUFBYTES ((PBUFSIZ-32)/2)
256 /* Round up PBUFSIZ to hold all the registers, at least. */
257 /* The blank line after the #if seems to be required to work around a
258 bug in HP's PA compiler. */
259 #if REGISTER_BYTES > MAXBUFBYTES
262 #define PBUFSIZ (REGISTER_BYTES * 2 + 32)
265 /* Should we try the 'P' request? If this is set to one when the stub
266 doesn't support 'P', the only consequence is some unnecessary traffic. */
267 static int stub_supports_P = 1;
270 /* Clean up connection to a remote debugger. */
274 remote_close (quitting)
278 SERIAL_CLOSE (remote_desc);
282 /* Query the remote side for the text, data and bss offsets. */
289 CORE_ADDR text_addr, data_addr, bss_addr;
290 struct section_offsets *offs;
296 if (buf[0] == '\000')
297 return; /* Return silently. Stub doesn't support this
301 warning ("Remote failure reply: %s", buf);
305 nvals = sscanf (buf, "Text=%lx;Data=%lx;Bss=%lx", &text_addr, &data_addr,
308 error ("Malformed response to offset query, %s", buf);
310 if (symfile_objfile == NULL)
313 offs = (struct section_offsets *) alloca (sizeof (struct section_offsets)
314 + symfile_objfile->num_sections
315 * sizeof (offs->offsets));
316 memcpy (offs, symfile_objfile->section_offsets,
317 sizeof (struct section_offsets)
318 + symfile_objfile->num_sections
319 * sizeof (offs->offsets));
321 /* FIXME: This code assumes gdb-stabs.h is being used; it's broken
322 for xcoff, dwarf, sdb-coff, etc. But there is no simple
323 canonical representation for this stuff. (Just what does "text"
324 as seen by the stub mean, anyway? I think it means all sections
325 with SEC_CODE set, but we currently have no way to deal with that). */
327 ANOFFSET (offs, SECT_OFF_TEXT) = text_addr;
329 /* This is a temporary kludge to force data and bss to use the same offsets
330 because that's what nlmconv does now. The real solution requires changes
331 to the stub and remote.c that I don't have time to do right now. */
333 ANOFFSET (offs, SECT_OFF_DATA) = data_addr;
334 ANOFFSET (offs, SECT_OFF_BSS) = data_addr;
336 objfile_relocate (symfile_objfile, offs);
339 /* Stub for catch_errors. */
342 remote_start_remote (dummy)
345 immediate_quit = 1; /* Allow user to interrupt it */
347 /* Ack any packet which the remote side has already sent. */
349 SERIAL_WRITE (remote_desc, "+", 1);
351 get_offsets (); /* Get text, data & bss offsets */
353 putpkt ("?"); /* initiate a query from remote machine */
356 start_remote (); /* Initialize gdb process mechanisms */
361 /* Open a connection to a remote debugger.
362 NAME is the filename used for communication. */
364 static DCACHE *remote_dcache;
367 remote_open (name, from_tty)
373 "To open a remote debug connection, you need to specify what serial\n\
374 device is attached to the remote system (e.g. /dev/ttya).");
376 target_preopen (from_tty);
378 unpush_target (&remote_ops);
380 remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);
382 remote_desc = SERIAL_OPEN (name);
384 perror_with_name (name);
388 if (SERIAL_SETBAUDRATE (remote_desc, baud_rate))
390 SERIAL_CLOSE (remote_desc);
391 perror_with_name (name);
395 SERIAL_RAW (remote_desc);
397 /* If there is something sitting in the buffer we might take it as a
398 response to a command, which would be bad. */
399 SERIAL_FLUSH_INPUT (remote_desc);
403 puts_filtered ("Remote debugging using ");
404 puts_filtered (name);
405 puts_filtered ("\n");
407 push_target (&remote_ops); /* Switch to using remote target now */
409 /* Start out by trying the 'P' request to set registers. We set this each
410 time that we open a new target so that if the user switches from one
411 stub to another, we can (if the target is closed and reopened) cope. */
414 /* Without this, some commands which require an active target (such as kill)
415 won't work. This variable serves (at least) double duty as both the pid
416 of the target process (if it has such), and as a flag indicating that a
417 target is active. These functions should be split out into seperate
418 variables, especially since GDB will someday have a notion of debugging
419 several processes. */
421 inferior_pid = 42000;
423 /* Start the remote connection; if error (0), discard this target.
424 In particular, if the user quits, be sure to discard it
425 (we'd be in an inconsistent state otherwise). */
426 if (!catch_errors (remote_start_remote, (char *)0,
427 "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
432 takes a program previously attached to and detaches it.
433 We better not have left any breakpoints
434 in the program or it'll die when it hits one.
435 Close the open connection to the remote debugger.
436 Use this when you want to detach and do something else
440 remote_detach (args, from_tty)
445 error ("Argument given to \"detach\" when remotely debugging.");
449 puts_filtered ("Ending remote debugging.\n");
452 /* Convert hex digit A to a number. */
458 if (a >= '0' && a <= '9')
460 else if (a >= 'a' && a <= 'f')
463 error ("Reply contains invalid hex digit %d", a);
466 /* Convert number NIB to a hex digit. */
478 /* Tell the remote machine to resume. */
481 remote_resume (pid, step, siggnal)
483 enum target_signal siggnal;
489 target_terminal_ours_for_output ();
491 ("Can't send signals to a remote system. %s not sent.\n",
492 target_signal_to_name (siggnal));
493 target_terminal_inferior ();
496 dcache_flush (remote_dcache);
498 strcpy (buf, step ? "s": "c");
503 /* Send ^C to target to halt it. Target will respond, and send us a
507 remote_interrupt (signo)
510 /* If this doesn't work, try more severe steps. */
511 signal (signo, remote_interrupt_twice);
514 printf_unfiltered ("remote_interrupt called\n");
516 SERIAL_WRITE (remote_desc, "\003", 1); /* Send a ^C */
519 static void (*ofunc)();
521 /* The user typed ^C twice. */
523 remote_interrupt_twice (signo)
526 signal (signo, ofunc);
530 signal (signo, remote_interrupt);
533 /* Ask the user what to do when an interrupt is received. */
538 target_terminal_ours ();
540 if (query ("Interrupted while waiting for the program.\n\
541 Give up (and stop debugging it)? "))
543 target_mourn_inferior ();
544 return_to_top_level (RETURN_QUIT);
547 target_terminal_inferior ();
550 /* Wait until the remote machine stops, then return,
551 storing status in STATUS just as `wait' would.
552 Returns "pid" (though it's not clear what, if anything, that
553 means in the case of this target). */
556 remote_wait (pid, status)
558 struct target_waitstatus *status;
560 unsigned char buf[PBUFSIZ];
562 status->kind = TARGET_WAITKIND_EXITED;
563 status->value.integer = 0;
569 ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
570 getpkt ((char *) buf, 1);
571 signal (SIGINT, ofunc);
575 case 'E': /* Error of some sort */
576 warning ("Remote failure reply: %s", buf);
578 case 'T': /* Status with PC, SP, FP, ... */
582 char regs[MAX_REGISTER_RAW_SIZE];
584 /* Expedited reply, containing Signal, {regno, reg} repeat */
585 /* format is: 'Tssn...:r...;n...:r...;n...:r...;#cc', where
587 n... = register number
588 r... = register contents
591 p = &buf[3]; /* after Txx */
597 regno = strtol (p, &p1, 16); /* Read the register number */
600 warning ("Remote sent badly formed register number: %s\nPacket: '%s'\n",
606 warning ("Malformed packet (missing colon): %s\nPacket: '%s'\n",
609 if (regno >= NUM_REGS)
610 warning ("Remote sent bad register number %d: %s\nPacket: '%s'\n",
613 for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
615 if (p[0] == 0 || p[1] == 0)
616 warning ("Remote reply is too short: %s", buf);
617 regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
622 warning ("Remote register badly formatted: %s", buf);
624 supply_register (regno, regs);
628 case 'S': /* Old style status, just signal only */
629 status->kind = TARGET_WAITKIND_STOPPED;
630 status->value.sig = (enum target_signal)
631 (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
634 case 'W': /* Target exited */
636 /* The remote process exited. */
637 status->kind = TARGET_WAITKIND_EXITED;
638 status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
641 case 'O': /* Console output */
642 fputs_filtered ((char *)(buf + 1), gdb_stdout);
645 warning ("Invalid remote reply: %s", buf);
651 /* Number of bytes of registers this stub implements. */
652 static int register_bytes_found;
654 /* Read the remote registers into the block REGS. */
655 /* Currently we just read all the registers, so we don't use regno. */
658 remote_fetch_registers (regno)
664 char regs[REGISTER_BYTES];
669 /* Unimplemented registers read as all bits zero. */
670 memset (regs, 0, REGISTER_BYTES);
672 /* We can get out of synch in various cases. If the first character
673 in the buffer is not a hex character, assume that has happened
674 and try to fetch another packet to read. */
675 while ((buf[0] < '0' || buf[0] > '9')
676 && (buf[0] < 'a' || buf[0] > 'f'))
679 printf_unfiltered ("Bad register packet; fetching a new packet\n");
683 /* Reply describes registers byte by byte, each byte encoded as two
684 hex characters. Suck them all up, then supply them to the
685 register cacheing/storage mechanism. */
688 for (i = 0; i < REGISTER_BYTES; i++)
694 warning ("Remote reply is of odd length: %s", buf);
695 /* Don't change register_bytes_found in this case, and don't
696 print a second warning. */
699 regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
703 if (i != register_bytes_found)
705 register_bytes_found = i;
706 #ifdef REGISTER_BYTES_OK
707 if (!REGISTER_BYTES_OK (i))
708 warning ("Remote reply is too short: %s", buf);
713 for (i = 0; i < NUM_REGS; i++)
714 supply_register (i, ®s[REGISTER_BYTE(i)]);
717 /* Prepare to store registers. Since we may send them all (using a
718 'G' request), we have to read out the ones we don't want to change
722 remote_prepare_to_store ()
724 /* Make sure the entire registers array is valid. */
725 read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
728 /* Store register REGNO, or all registers if REGNO == -1, from the contents
729 of REGISTERS. FIXME: ignores errors. */
732 remote_store_registers (regno)
739 if (regno >= 0 && stub_supports_P)
741 /* Try storing a single register. */
744 sprintf (buf, "P%x=", regno);
745 p = buf + strlen (buf);
746 regp = ®isters[REGISTER_BYTE (regno)];
747 for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i)
749 *p++ = tohex ((regp[i] >> 4) & 0xf);
750 *p++ = tohex (regp[i] & 0xf);
756 /* The stub understands the 'P' request. We are done. */
760 /* The stub does not support the 'P' request. Use 'G' instead,
761 and don't try using 'P' in the future (it will just waste our
768 /* Command describes registers byte by byte,
769 each byte encoded as two hex characters. */
772 /* remote_prepare_to_store insures that register_bytes_found gets set. */
773 for (i = 0; i < register_bytes_found; i++)
775 *p++ = tohex ((registers[i] >> 4) & 0xf);
776 *p++ = tohex (registers[i] & 0xf);
785 /* Use of the data cache is disabled because it loses for looking at
786 and changing hardware I/O ports and the like. Accepting `volatile'
787 would perhaps be one way to fix it, but a better way which would
788 win for more cases would be to use the executable file for the text
789 segment, like the `icache' code below but done cleanly (in some
790 target-independent place, perhaps in target_xfer_memory, perhaps
791 based on assigning each target a speed or perhaps by some simpler
794 /* Read a word from remote address ADDR and return it.
795 This goes through the data cache. */
798 remote_fetch_word (addr)
804 extern CORE_ADDR text_start, text_end;
806 if (addr >= text_start && addr < text_end)
809 xfer_core_file (addr, &buffer, sizeof (int));
814 return dcache_fetch (remote_dcache, addr);
817 /* Write a word WORD into remote address ADDR.
818 This goes through the data cache. */
821 remote_store_word (addr, word)
825 dcache_poke (remote_dcache, addr, word);
829 /* Write memory data directly to the remote machine.
830 This does not inform the data cache; the data cache uses this.
831 MEMADDR is the address in the remote memory space.
832 MYADDR is the address of the buffer in our space.
833 LEN is the number of bytes.
835 Returns number of bytes transferred, or 0 for error. */
838 remote_write_bytes (memaddr, myaddr, len)
840 unsigned char *myaddr;
847 /* FIXME-32x64: Need a version of print_address_numeric which puts the
848 result in a buffer like sprintf. */
849 sprintf (buf, "M%lx,%x:", (unsigned long) memaddr, len);
851 /* We send target system values byte by byte, in increasing byte addresses,
852 each byte encoded as two hex characters. */
854 p = buf + strlen (buf);
855 for (i = 0; i < len; i++)
857 *p++ = tohex ((myaddr[i] >> 4) & 0xf);
858 *p++ = tohex (myaddr[i] & 0xf);
867 /* There is no correspondance between what the remote protocol uses
868 for errors and errno codes. We would like a cleaner way of
869 representing errors (big enough to include errno codes, bfd_error
870 codes, and others). But for now just return EIO. */
877 /* Read memory data directly from the remote machine.
878 This does not use the data cache; the data cache uses this.
879 MEMADDR is the address in the remote memory space.
880 MYADDR is the address of the buffer in our space.
881 LEN is the number of bytes.
883 Returns number of bytes transferred, or 0 for error. */
886 remote_read_bytes (memaddr, myaddr, len)
888 unsigned char *myaddr;
895 if (len > PBUFSIZ / 2 - 1)
898 /* FIXME-32x64: Need a version of print_address_numeric which puts the
899 result in a buffer like sprintf. */
900 sprintf (buf, "m%lx,%x", (unsigned long) memaddr, len);
906 /* There is no correspondance between what the remote protocol uses
907 for errors and errno codes. We would like a cleaner way of
908 representing errors (big enough to include errno codes, bfd_error
909 codes, and others). But for now just return EIO. */
914 /* Reply describes memory byte by byte,
915 each byte encoded as two hex characters. */
918 for (i = 0; i < len; i++)
920 if (p[0] == 0 || p[1] == 0)
921 /* Reply is short. This means that we were able to read only part
922 of what we wanted to. */
924 myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
930 /* Read or write LEN bytes from inferior memory at MEMADDR, transferring
931 to or from debugger address MYADDR. Write to inferior if SHOULD_WRITE is
932 nonzero. Returns length of data written or read; 0 for error. */
936 remote_xfer_memory(memaddr, myaddr, len, should_write, target)
941 struct target_ops *target; /* ignored */
945 int total_xferred = 0;
949 if (len > MAXBUFBYTES)
950 xfersize = MAXBUFBYTES;
955 bytes_xferred = remote_write_bytes (memaddr,
956 (unsigned char *)myaddr, xfersize);
958 bytes_xferred = remote_read_bytes (memaddr,
959 (unsigned char *)myaddr, xfersize);
961 /* If we get an error, we are done xferring. */
962 if (bytes_xferred == 0)
965 memaddr += bytes_xferred;
966 myaddr += bytes_xferred;
967 len -= bytes_xferred;
968 total_xferred += bytes_xferred;
970 return total_xferred;
974 /* Enable after 4.12. */
977 remote_search (len, data, mask, startaddr, increment, lorange, hirange
978 addr_found, data_found)
986 CORE_ADDR *addr_found;
989 if (increment == -4 && len == 4)
991 long mask_long, data_long;
992 long data_found_long;
993 CORE_ADDR addr_we_found;
995 long returned_long[2];
998 mask_long = extract_unsigned_integer (mask, len);
999 data_long = extract_unsigned_integer (data, len);
1000 sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long);
1005 /* The stub doesn't support the 't' request. We might want to
1006 remember this fact, but on the other hand the stub could be
1007 switched on us. Maybe we should remember it only until
1008 the next "target remote". */
1009 generic_search (len, data, mask, startaddr, increment, lorange,
1010 hirange, addr_found, data_found);
1015 /* There is no correspondance between what the remote protocol uses
1016 for errors and errno codes. We would like a cleaner way of
1017 representing errors (big enough to include errno codes, bfd_error
1018 codes, and others). But for now just use EIO. */
1019 memory_error (EIO, startaddr);
1022 while (*p != '\0' && *p != ',')
1023 addr_we_found = (addr_we_found << 4) + fromhex (*p++);
1025 error ("Protocol error: short return for search");
1027 data_found_long = 0;
1028 while (*p != '\0' && *p != ',')
1029 data_found_long = (data_found_long << 4) + fromhex (*p++);
1030 /* Ignore anything after this comma, for future extensions. */
1032 if (addr_we_found < lorange || addr_we_found >= hirange)
1038 *addr_found = addr_we_found;
1039 *data_found = store_unsigned_integer (data_we_found, len);
1042 generic_search (len, data, mask, startaddr, increment, lorange,
1043 hirange, addr_found, data_found);
1048 remote_files_info (ignore)
1049 struct target_ops *ignore;
1051 puts_filtered ("Debugging a target over a serial line.\n");
1054 /* Stuff for dealing with the packets which are part of this protocol.
1055 See comment at top of file for details. */
1057 /* Read a single character from the remote end, masking it down to 7 bits. */
1065 ch = SERIAL_READCHAR (remote_desc, timeout);
1070 error ("Remote connection closed");
1072 perror_with_name ("Remote communication error");
1073 case SERIAL_TIMEOUT:
1080 /* Send the command in BUF to the remote machine,
1081 and read the reply into BUF.
1082 Report an error if we get an error reply. */
1093 error ("Remote failure reply: %s", buf);
1096 /* Send a packet to the remote machine, with error checking.
1097 The data of the packet is in BUF. */
1104 unsigned char csum = 0;
1106 int cnt = strlen (buf);
1110 /* Copy the packet into buffer BUF2, encapsulating it
1111 and giving it a checksum. */
1113 if (cnt > sizeof(buf2) - 5) /* Prosanity check */
1119 for (i = 0; i < cnt; i++)
1125 *p++ = tohex ((csum >> 4) & 0xf);
1126 *p++ = tohex (csum & 0xf);
1128 /* Send it over and over until we get a positive ack. */
1132 int started_error_output = 0;
1137 printf_unfiltered ("Sending packet: %s...", buf2);
1138 gdb_flush(gdb_stdout);
1140 if (SERIAL_WRITE (remote_desc, buf2, p - buf2))
1141 perror_with_name ("putpkt: write failed");
1143 /* read until either a timeout occurs (-2) or '+' is read */
1146 ch = readchar (remote_timeout);
1153 case SERIAL_TIMEOUT:
1155 if (started_error_output)
1157 putc_unfiltered ('\n');
1158 started_error_output = 0;
1167 printf_unfiltered("Ack\n");
1169 case SERIAL_TIMEOUT:
1170 break; /* Retransmit buffer */
1173 char junkbuf[PBUFSIZ];
1175 /* It's probably an old response, and we're out of sync. Just
1176 gobble up the packet and ignore it. */
1177 getpkt (junkbuf, 0);
1178 continue; /* Now, go look for + */
1183 if (!started_error_output)
1185 started_error_output = 1;
1186 printf_unfiltered ("putpkt: Junk: ");
1188 putc_unfiltered (ch & 0177);
1192 break; /* Here to retransmit */
1196 /* This is wrong. If doing a long backtrace, the user should be
1197 able to get out next time we call QUIT, without anything as violent
1198 as interrupt_query. If we want to provide a way out of here
1199 without getting to the next QUIT, it should be based on hitting
1200 ^C twice as in remote_wait. */
1210 /* Come here after finding the start of the frame. Collect the rest into BUF,
1211 verifying the checksum, length, and handling run-length compression.
1212 Returns 0 on any error, 1 on success. */
1227 c = readchar (remote_timeout);
1231 case SERIAL_TIMEOUT:
1233 puts_filtered ("Timeout in mid-packet, retrying\n");
1237 puts_filtered ("Saw new packet start in middle of old one\n");
1238 return 0; /* Start a new packet, count retries */
1241 unsigned char pktcsum;
1245 pktcsum = fromhex (readchar (remote_timeout)) << 4;
1246 pktcsum |= fromhex (readchar (remote_timeout));
1248 if (csum == pktcsum)
1253 printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
1255 puts_filtered (buf);
1256 puts_filtered ("\n");
1260 case '*': /* Run length encoding */
1262 c = readchar (remote_timeout);
1264 c = c - ' ' + 3; /* Compute repeat count */
1267 if (c > 0 && c < 255 && bp + c - 1 < buf + PBUFSIZ - 1)
1269 memset (bp, *(bp - 1), c);
1275 printf_filtered ("Repeat count %d too large for buffer: ", c);
1276 puts_filtered (buf);
1277 puts_filtered ("\n");
1281 if (bp < buf + PBUFSIZ - 1)
1289 puts_filtered ("Remote packet too long: ");
1290 puts_filtered (buf);
1291 puts_filtered ("\n");
1298 /* Read a packet from the remote machine, with error checking,
1299 and store it in BUF. BUF is expected to be of size PBUFSIZ.
1300 If FOREVER, wait forever rather than timing out; this is used
1301 while the target is executing user code. */
1304 getpkt (buf, forever)
1317 timeout = remote_timeout;
1319 #define MAX_TRIES 10
1321 for (tries = 1; tries <= MAX_TRIES; tries++)
1323 /* This can loop forever if the remote side sends us characters
1324 continuously, but if it pauses, we'll get a zero from readchar
1325 because of timeout. Then we'll count that as a retry. */
1327 /* Note that we will only wait forever prior to the start of a packet.
1328 After that, we expect characters to arrive at a brisk pace. They
1329 should show up within remote_timeout intervals. */
1333 c = readchar (timeout);
1335 if (c == SERIAL_TIMEOUT)
1338 puts_filtered ("Timed out.\n");
1344 /* We've found the start of a packet, now collect the data. */
1346 val = read_frame (buf);
1351 fprintf_unfiltered (gdb_stderr, "Packet received: %s\n", buf);
1352 SERIAL_WRITE (remote_desc, "+", 1);
1356 /* Try the whole thing again. */
1358 SERIAL_WRITE (remote_desc, "-", 1);
1361 /* We have tried hard enough, and just can't receive the packet. Give up. */
1363 printf_unfiltered ("Ignoring packet error, continuing...\n");
1364 SERIAL_WRITE (remote_desc, "+", 1);
1371 /* Don't wait for it to die. I'm not really sure it matters whether
1372 we do or not. For the existing stubs, kill is a noop. */
1373 target_mourn_inferior ();
1379 unpush_target (&remote_ops);
1380 generic_mourn_inferior ();
1383 #ifdef REMOTE_BREAKPOINT
1385 /* On some machines, e.g. 68k, we may use a different breakpoint instruction
1386 than other targets. */
1387 static unsigned char break_insn[] = REMOTE_BREAKPOINT;
1389 /* Check that it fits in BREAKPOINT_MAX bytes. */
1390 static unsigned char check_break_insn_size[BREAKPOINT_MAX] = REMOTE_BREAKPOINT;
1392 #else /* No REMOTE_BREAKPOINT. */
1394 /* Same old breakpoint instruction. This code does nothing different
1395 than mem-break.c. */
1396 static unsigned char break_insn[] = BREAKPOINT;
1398 #endif /* No REMOTE_BREAKPOINT. */
1400 /* Insert a breakpoint on targets that don't have any better breakpoint
1401 support. We read the contents of the target location and stash it,
1402 then overwrite it with a breakpoint instruction. ADDR is the target
1403 location in the target machine. CONTENTS_CACHE is a pointer to
1404 memory allocated for saving the target contents. It is guaranteed
1405 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1406 is accomplished via BREAKPOINT_MAX). */
1409 remote_insert_breakpoint (addr, contents_cache)
1411 char *contents_cache;
1415 val = target_read_memory (addr, contents_cache, sizeof break_insn);
1418 val = target_write_memory (addr, (char *)break_insn, sizeof break_insn);
1424 remote_remove_breakpoint (addr, contents_cache)
1426 char *contents_cache;
1428 return target_write_memory (addr, contents_cache, sizeof break_insn);
1431 /* Define the target subroutine names */
1433 struct target_ops remote_ops = {
1434 "remote", /* to_shortname */
1435 "Remote serial target in gdb-specific protocol", /* to_longname */
1436 "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
1437 Specify the serial device it is connected to (e.g. /dev/ttya).", /* to_doc */
1438 remote_open, /* to_open */
1439 remote_close, /* to_close */
1440 NULL, /* to_attach */
1441 remote_detach, /* to_detach */
1442 remote_resume, /* to_resume */
1443 remote_wait, /* to_wait */
1444 remote_fetch_registers, /* to_fetch_registers */
1445 remote_store_registers, /* to_store_registers */
1446 remote_prepare_to_store, /* to_prepare_to_store */
1447 remote_xfer_memory, /* to_xfer_memory */
1448 remote_files_info, /* to_files_info */
1450 remote_insert_breakpoint, /* to_insert_breakpoint */
1451 remote_remove_breakpoint, /* to_remove_breakpoint */
1453 NULL, /* to_terminal_init */
1454 NULL, /* to_terminal_inferior */
1455 NULL, /* to_terminal_ours_for_output */
1456 NULL, /* to_terminal_ours */
1457 NULL, /* to_terminal_info */
1458 remote_kill, /* to_kill */
1459 generic_load, /* to_load */
1460 NULL, /* to_lookup_symbol */
1461 NULL, /* to_create_inferior */
1462 remote_mourn, /* to_mourn_inferior */
1464 0, /* to_notice_signals */
1466 process_stratum, /* to_stratum */
1468 1, /* to_has_all_memory */
1469 1, /* to_has_memory */
1470 1, /* to_has_stack */
1471 1, /* to_has_registers */
1472 1, /* to_has_execution */
1473 NULL, /* sections */
1474 NULL, /* sections_end */
1475 OPS_MAGIC /* to_magic */
1479 _initialize_remote ()
1481 add_target (&remote_ops);