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 two characters are hex digits giving a repeat count which
130 stands for that many repititions of the character preceding the '*'.
131 Note that this means that responses cannot contain '*'. Example:
132 "0*03" means the same as "0000". */
138 #include "inferior.h"
143 #include "terminal.h"
145 #include "objfiles.h"
146 #include "gdb-stabs.h"
151 #include <sys/types.h>
157 /* Prototypes for local functions */
160 remote_write_bytes
PARAMS ((CORE_ADDR memaddr
, unsigned char *myaddr
, int len
));
163 remote_read_bytes
PARAMS ((CORE_ADDR memaddr
, unsigned char *myaddr
, int len
));
166 remote_files_info
PARAMS ((struct target_ops
*ignore
));
169 remote_xfer_memory
PARAMS ((CORE_ADDR memaddr
, char *myaddr
, int len
,
170 int should_write
, struct target_ops
*target
));
173 remote_prepare_to_store
PARAMS ((void));
176 remote_fetch_registers
PARAMS ((int regno
));
179 remote_resume
PARAMS ((int pid
, int step
, enum target_signal siggnal
));
182 remote_start_remote
PARAMS ((char *dummy
));
185 remote_open
PARAMS ((char *name
, int from_tty
));
188 remote_close
PARAMS ((int quitting
));
191 remote_store_registers
PARAMS ((int regno
));
194 getpkt
PARAMS ((char *buf
, int forever
));
197 putpkt
PARAMS ((char *buf
));
200 remote_send
PARAMS ((char *buf
));
203 readchar
PARAMS ((int timeout
));
205 static int remote_wait
PARAMS ((int pid
, struct target_waitstatus
*status
));
208 tohex
PARAMS ((int nib
));
211 fromhex
PARAMS ((int a
));
214 remote_detach
PARAMS ((char *args
, int from_tty
));
217 remote_interrupt
PARAMS ((int signo
));
220 remote_interrupt_twice
PARAMS ((int signo
));
223 interrupt_query
PARAMS ((void));
225 extern struct target_ops remote_ops
; /* Forward decl */
227 /* This was 5 seconds, which is a long time to sit and wait.
228 Unless this is going though some terminal server or multiplexer or
229 other form of hairy serial connection, I would think 2 seconds would
231 static int remote_timeout
= 2;
237 /* Descriptor for I/O to remote machine. Initialize it to NULL so that
238 remote_open knows that we don't have a file open when the program
240 serial_t remote_desc
= NULL
;
242 /* Having this larger than 400 causes us to be incompatible with m68k-stub.c
243 and i386-stub.c. Normally, no one would notice because it only matters
244 for writing large chunks of memory (e.g. in downloads). Also, this needs
245 to be more than 400 if required to hold the registers (see below, where
246 we round it up based on REGISTER_BYTES). */
249 /* Maximum number of bytes to read/write at once. The value here
250 is chosen to fill up a packet (the headers account for the 32). */
251 #define MAXBUFBYTES ((PBUFSIZ-32)/2)
253 /* Round up PBUFSIZ to hold all the registers, at least. */
254 /* The blank line after the #if seems to be required to work around a
255 bug in HP's PA compiler. */
256 #if REGISTER_BYTES > MAXBUFBYTES
259 #define PBUFSIZ (REGISTER_BYTES * 2 + 32)
262 /* Should we try the 'P' request? If this is set to one when the stub
263 doesn't support 'P', the only consequence is some unnecessary traffic. */
264 static int stub_supports_P
= 1;
267 /* Clean up connection to a remote debugger. */
271 remote_close (quitting
)
275 SERIAL_CLOSE (remote_desc
);
279 /* Query the remote side for the text, data and bss offsets. */
284 unsigned char buf
[PBUFSIZ
];
286 CORE_ADDR text_addr
, data_addr
, bss_addr
;
287 struct section_offsets
*offs
;
293 if (buf
[0] == '\000')
294 return; /* Return silently. Stub doesn't support this
298 warning ("Remote failure reply: %s", buf
);
302 nvals
= sscanf (buf
, "Text=%lx;Data=%lx;Bss=%lx", &text_addr
, &data_addr
,
305 error ("Malformed response to offset query, %s", buf
);
307 if (symfile_objfile
== NULL
)
310 offs
= (struct section_offsets
*) alloca (sizeof (struct section_offsets
)
311 + symfile_objfile
->num_sections
312 * sizeof (offs
->offsets
));
313 memcpy (offs
, symfile_objfile
->section_offsets
,
314 sizeof (struct section_offsets
)
315 + symfile_objfile
->num_sections
316 * sizeof (offs
->offsets
));
318 /* FIXME: This code assumes gdb-stabs.h is being used; it's broken
319 for xcoff, dwarf, sdb-coff, etc. But there is no simple
320 canonical representation for this stuff. (Just what does "text"
321 as seen by the stub mean, anyway? I think it means all sections
322 with SEC_CODE set, but we currently have no way to deal with that). */
324 ANOFFSET (offs
, SECT_OFF_TEXT
) = text_addr
;
326 /* This is a temporary kludge to force data and bss to use the same offsets
327 because that's what nlmconv does now. The real solution requires changes
328 to the stub and remote.c that I don't have time to do right now. */
330 ANOFFSET (offs
, SECT_OFF_DATA
) = data_addr
;
331 ANOFFSET (offs
, SECT_OFF_BSS
) = data_addr
;
333 objfile_relocate (symfile_objfile
, offs
);
336 /* Stub for catch_errors. */
339 remote_start_remote (dummy
)
342 immediate_quit
= 1; /* Allow user to interrupt it */
344 /* Ack any packet which the remote side has already sent. */
346 SERIAL_WRITE (remote_desc
, "+", 1);
348 get_offsets (); /* Get text, data & bss offsets */
350 putpkt ("?"); /* initiate a query from remote machine */
353 start_remote (); /* Initialize gdb process mechanisms */
358 /* Open a connection to a remote debugger.
359 NAME is the filename used for communication. */
361 static DCACHE
*remote_dcache
;
364 remote_open (name
, from_tty
)
370 "To open a remote debug connection, you need to specify what serial\n\
371 device is attached to the remote system (e.g. /dev/ttya).");
373 target_preopen (from_tty
);
375 unpush_target (&remote_ops
);
377 remote_dcache
= dcache_init (remote_read_bytes
, remote_write_bytes
);
379 remote_desc
= SERIAL_OPEN (name
);
381 perror_with_name (name
);
385 if (SERIAL_SETBAUDRATE (remote_desc
, baud_rate
))
387 SERIAL_CLOSE (remote_desc
);
388 perror_with_name (name
);
392 SERIAL_RAW (remote_desc
);
394 /* If there is something sitting in the buffer we might take it as a
395 response to a command, which would be bad. */
396 SERIAL_FLUSH_INPUT (remote_desc
);
400 puts_filtered ("Remote debugging using ");
401 puts_filtered (name
);
402 puts_filtered ("\n");
404 push_target (&remote_ops
); /* Switch to using remote target now */
406 /* Start out by trying the 'P' request to set registers. We set this each
407 time that we open a new target so that if the user switches from one
408 stub to another, we can (if the target is closed and reopened) cope. */
411 /* Start the remote connection; if error (0), discard this target.
412 In particular, if the user quits, be sure to discard it
413 (we'd be in an inconsistent state otherwise). */
414 if (!catch_errors (remote_start_remote
, (char *)0,
415 "Couldn't establish connection to remote target\n", RETURN_MASK_ALL
))
420 takes a program previously attached to and detaches it.
421 We better not have left any breakpoints
422 in the program or it'll die when it hits one.
423 Close the open connection to the remote debugger.
424 Use this when you want to detach and do something else
428 remote_detach (args
, from_tty
)
433 error ("Argument given to \"detach\" when remotely debugging.");
437 puts_filtered ("Ending remote debugging.\n");
440 /* Convert hex digit A to a number. */
446 if (a
>= '0' && a
<= '9')
448 else if (a
>= 'a' && a
<= 'f')
451 error ("Reply contains invalid hex digit");
454 /* Convert number NIB to a hex digit. */
466 /* Tell the remote machine to resume. */
469 remote_resume (pid
, step
, siggnal
)
471 enum target_signal siggnal
;
477 target_terminal_ours_for_output ();
479 ("Can't send signals to a remote system. %s not sent.\n",
480 target_signal_to_name (siggnal
));
481 target_terminal_inferior ();
484 dcache_flush (remote_dcache
);
486 strcpy (buf
, step
? "s": "c");
491 /* Send ^C to target to halt it. Target will respond, and send us a
495 remote_interrupt (signo
)
498 /* If this doesn't work, try more severe steps. */
499 signal (signo
, remote_interrupt_twice
);
502 printf_unfiltered ("remote_interrupt called\n");
504 SERIAL_WRITE (remote_desc
, "\003", 1); /* Send a ^C */
507 static void (*ofunc
)();
509 /* The user typed ^C twice. */
511 remote_interrupt_twice (signo
)
514 signal (signo
, ofunc
);
518 signal (signo
, remote_interrupt
);
521 /* Ask the user what to do when an interrupt is received. */
526 target_terminal_ours ();
528 if (query ("Interrupted while waiting for the program.\n\
529 Give up (and stop debugging it)? "))
531 target_mourn_inferior ();
532 return_to_top_level (RETURN_QUIT
);
535 target_terminal_inferior ();
538 /* Wait until the remote machine stops, then return,
539 storing status in STATUS just as `wait' would.
540 Returns "pid" (though it's not clear what, if anything, that
541 means in the case of this target). */
544 remote_wait (pid
, status
)
546 struct target_waitstatus
*status
;
548 unsigned char buf
[PBUFSIZ
];
550 status
->kind
= TARGET_WAITKIND_EXITED
;
551 status
->value
.integer
= 0;
557 ofunc
= (void (*)()) signal (SIGINT
, remote_interrupt
);
558 getpkt ((char *) buf
, 1);
559 signal (SIGINT
, ofunc
);
563 case 'E': /* Error of some sort */
564 warning ("Remote failure reply: %s", buf
);
566 case 'T': /* Status with PC, SP, FP, ... */
570 char regs
[MAX_REGISTER_RAW_SIZE
];
572 /* Expedited reply, containing Signal, {regno, reg} repeat */
573 /* format is: 'Tssn...:r...;n...:r...;n...:r...;#cc', where
575 n... = register number
576 r... = register contents
579 p
= &buf
[3]; /* after Txx */
585 regno
= strtol (p
, &p1
, 16); /* Read the register number */
588 warning ("Remote sent badly formed register number: %s\nPacket: '%s'\n",
594 warning ("Malformed packet (missing colon): %s\nPacket: '%s'\n",
597 if (regno
>= NUM_REGS
)
598 warning ("Remote sent bad register number %d: %s\nPacket: '%s'\n",
601 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); i
++)
603 if (p
[0] == 0 || p
[1] == 0)
604 warning ("Remote reply is too short: %s", buf
);
605 regs
[i
] = fromhex (p
[0]) * 16 + fromhex (p
[1]);
610 warning ("Remote register badly formatted: %s", buf
);
612 supply_register (regno
, regs
);
616 case 'S': /* Old style status, just signal only */
617 status
->kind
= TARGET_WAITKIND_STOPPED
;
618 status
->value
.sig
= (enum target_signal
)
619 (((fromhex (buf
[1])) << 4) + (fromhex (buf
[2])));
622 case 'W': /* Target exited */
624 /* The remote process exited. */
625 status
->kind
= TARGET_WAITKIND_EXITED
;
626 status
->value
.integer
= (fromhex (buf
[1]) << 4) + fromhex (buf
[2]);
629 case 'O': /* Console output */
630 fputs_filtered (buf
+ 1, gdb_stdout
);
633 warning ("Invalid remote reply: %s", buf
);
640 /* Number of bytes of registers this stub implements. */
641 static int register_bytes_found
;
643 /* Read the remote registers into the block REGS. */
644 /* Currently we just read all the registers, so we don't use regno. */
647 remote_fetch_registers (regno
)
653 char regs
[REGISTER_BYTES
];
658 /* Unimplemented registers read as all bits zero. */
659 memset (regs
, 0, REGISTER_BYTES
);
661 /* We can get out of synch in various cases. If the first character
662 in the buffer is not a hex character, assume that has happened
663 and try to fetch another packet to read. */
664 while ((buf
[0] < '0' || buf
[0] > '9')
665 && (buf
[0] < 'a' || buf
[0] > 'f'))
668 printf_unfiltered ("Bad register packet; fetching a new packet\n");
672 /* Reply describes registers byte by byte, each byte encoded as two
673 hex characters. Suck them all up, then supply them to the
674 register cacheing/storage mechanism. */
677 for (i
= 0; i
< REGISTER_BYTES
; i
++)
683 warning ("Remote reply is of odd length: %s", buf
);
684 /* Don't change register_bytes_found in this case, and don't
685 print a second warning. */
688 regs
[i
] = fromhex (p
[0]) * 16 + fromhex (p
[1]);
692 if (i
!= register_bytes_found
)
694 register_bytes_found
= i
;
695 #ifdef REGISTER_BYTES_OK
696 if (!REGISTER_BYTES_OK (i
))
697 warning ("Remote reply is too short: %s", buf
);
702 for (i
= 0; i
< NUM_REGS
; i
++)
703 supply_register (i
, ®s
[REGISTER_BYTE(i
)]);
706 /* Prepare to store registers. Since we may send them all (using a
707 'G' request), we have to read out the ones we don't want to change
711 remote_prepare_to_store ()
713 /* Make sure the entire registers array is valid. */
714 read_register_bytes (0, (char *)NULL
, REGISTER_BYTES
);
717 /* Store register REGNO, or all registers if REGNO == -1, from the contents
718 of REGISTERS. FIXME: ignores errors. */
721 remote_store_registers (regno
)
728 if (regno
>= 0 && stub_supports_P
)
730 /* Try storing a single register. */
733 sprintf (buf
, "P%x=", regno
);
734 p
= buf
+ strlen (buf
);
735 regp
= ®isters
[REGISTER_BYTE (regno
)];
736 for (i
= 0; i
< REGISTER_RAW_SIZE (regno
); ++i
)
738 *p
++ = tohex ((regp
[i
] >> 4) & 0xf);
739 *p
++ = tohex (regp
[i
] & 0xf);
745 /* The stub understands the 'P' request. We are done. */
749 /* The stub does not support the 'P' request. Use 'G' instead,
750 and don't try using 'P' in the future (it will just waste our
757 /* Command describes registers byte by byte,
758 each byte encoded as two hex characters. */
761 /* remote_prepare_to_store insures that register_bytes_found gets set. */
762 for (i
= 0; i
< register_bytes_found
; i
++)
764 *p
++ = tohex ((registers
[i
] >> 4) & 0xf);
765 *p
++ = tohex (registers
[i
] & 0xf);
774 /* Use of the data cache is disabled because it loses for looking at
775 and changing hardware I/O ports and the like. Accepting `volatile'
776 would perhaps be one way to fix it, but a better way which would
777 win for more cases would be to use the executable file for the text
778 segment, like the `icache' code below but done cleanly (in some
779 target-independent place, perhaps in target_xfer_memory, perhaps
780 based on assigning each target a speed or perhaps by some simpler
783 /* Read a word from remote address ADDR and return it.
784 This goes through the data cache. */
787 remote_fetch_word (addr
)
793 extern CORE_ADDR text_start
, text_end
;
795 if (addr
>= text_start
&& addr
< text_end
)
798 xfer_core_file (addr
, &buffer
, sizeof (int));
803 return dcache_fetch (remote_dcache
, addr
);
806 /* Write a word WORD into remote address ADDR.
807 This goes through the data cache. */
810 remote_store_word (addr
, word
)
814 dcache_poke (remote_dcache
, addr
, word
);
818 /* Write memory data directly to the remote machine.
819 This does not inform the data cache; the data cache uses this.
820 MEMADDR is the address in the remote memory space.
821 MYADDR is the address of the buffer in our space.
822 LEN is the number of bytes.
824 Returns number of bytes transferred, or 0 for error. */
827 remote_write_bytes (memaddr
, myaddr
, len
)
829 unsigned char *myaddr
;
836 /* FIXME-32x64: Need a version of print_address_numeric which puts the
837 result in a buffer like sprintf. */
838 sprintf (buf
, "M%lx,%x:", (unsigned long) memaddr
, len
);
840 /* We send target system values byte by byte, in increasing byte addresses,
841 each byte encoded as two hex characters. */
843 p
= buf
+ strlen (buf
);
844 for (i
= 0; i
< len
; i
++)
846 *p
++ = tohex ((myaddr
[i
] >> 4) & 0xf);
847 *p
++ = tohex (myaddr
[i
] & 0xf);
856 /* There is no correspondance between what the remote protocol uses
857 for errors and errno codes. We would like a cleaner way of
858 representing errors (big enough to include errno codes, bfd_error
859 codes, and others). But for now just return EIO. */
866 /* Read memory data directly from the remote machine.
867 This does not use the data cache; the data cache uses this.
868 MEMADDR is the address in the remote memory space.
869 MYADDR is the address of the buffer in our space.
870 LEN is the number of bytes.
872 Returns number of bytes transferred, or 0 for error. */
875 remote_read_bytes (memaddr
, myaddr
, len
)
877 unsigned char *myaddr
;
884 if (len
> PBUFSIZ
/ 2 - 1)
887 /* FIXME-32x64: Need a version of print_address_numeric which puts the
888 result in a buffer like sprintf. */
889 sprintf (buf
, "m%lx,%x", (unsigned long) memaddr
, len
);
895 /* There is no correspondance between what the remote protocol uses
896 for errors and errno codes. We would like a cleaner way of
897 representing errors (big enough to include errno codes, bfd_error
898 codes, and others). But for now just return EIO. */
903 /* Reply describes memory byte by byte,
904 each byte encoded as two hex characters. */
907 for (i
= 0; i
< len
; i
++)
909 if (p
[0] == 0 || p
[1] == 0)
910 /* Reply is short. This means that we were able to read only part
911 of what we wanted to. */
913 myaddr
[i
] = fromhex (p
[0]) * 16 + fromhex (p
[1]);
919 /* Read or write LEN bytes from inferior memory at MEMADDR, transferring
920 to or from debugger address MYADDR. Write to inferior if SHOULD_WRITE is
921 nonzero. Returns length of data written or read; 0 for error. */
925 remote_xfer_memory(memaddr
, myaddr
, len
, should_write
, target
)
930 struct target_ops
*target
; /* ignored */
934 int total_xferred
= 0;
938 if (len
> MAXBUFBYTES
)
939 xfersize
= MAXBUFBYTES
;
944 bytes_xferred
= remote_write_bytes (memaddr
,
945 (unsigned char *)myaddr
, xfersize
);
947 bytes_xferred
= remote_read_bytes (memaddr
,
948 (unsigned char *)myaddr
, xfersize
);
950 /* If we get an error, we are done xferring. */
951 if (bytes_xferred
== 0)
954 memaddr
+= bytes_xferred
;
955 myaddr
+= bytes_xferred
;
956 len
-= bytes_xferred
;
957 total_xferred
+= bytes_xferred
;
959 return total_xferred
;
963 /* Enable after 4.12. */
966 remote_search (len
, data
, mask
, startaddr
, increment
, lorange
, hirange
967 addr_found
, data_found
)
975 CORE_ADDR
*addr_found
;
978 if (increment
== -4 && len
== 4)
980 long mask_long
, data_long
;
981 long data_found_long
;
982 CORE_ADDR addr_we_found
;
984 long returned_long
[2];
987 mask_long
= extract_unsigned_integer (mask
, len
);
988 data_long
= extract_unsigned_integer (data
, len
);
989 sprintf (buf
, "t%x:%x,%x", startaddr
, data_long
, mask_long
);
994 /* The stub doesn't support the 't' request. We might want to
995 remember this fact, but on the other hand the stub could be
996 switched on us. Maybe we should remember it only until
997 the next "target remote". */
998 generic_search (len
, data
, mask
, startaddr
, increment
, lorange
,
999 hirange
, addr_found
, data_found
);
1004 /* There is no correspondance between what the remote protocol uses
1005 for errors and errno codes. We would like a cleaner way of
1006 representing errors (big enough to include errno codes, bfd_error
1007 codes, and others). But for now just use EIO. */
1008 memory_error (EIO
, startaddr
);
1011 while (*p
!= '\0' && *p
!= ',')
1012 addr_we_found
= (addr_we_found
<< 4) + fromhex (*p
++);
1014 error ("Protocol error: short return for search");
1016 data_found_long
= 0;
1017 while (*p
!= '\0' && *p
!= ',')
1018 data_found_long
= (data_found_long
<< 4) + fromhex (*p
++);
1019 /* Ignore anything after this comma, for future extensions. */
1021 if (addr_we_found
< lorange
|| addr_we_found
>= hirange
)
1027 *addr_found
= addr_we_found
;
1028 *data_found
= store_unsigned_integer (data_we_found
, len
);
1031 generic_search (len
, data
, mask
, startaddr
, increment
, lorange
,
1032 hirange
, addr_found
, data_found
);
1037 remote_files_info (ignore
)
1038 struct target_ops
*ignore
;
1040 puts_filtered ("Debugging a target over a serial line.\n");
1043 /* Stuff for dealing with the packets which are part of this protocol.
1044 See comment at top of file for details. */
1046 /* Read a single character from the remote end, masking it down to 7 bits. */
1054 ch
= SERIAL_READCHAR (remote_desc
, timeout
);
1059 error ("Remote connection closed");
1061 perror_with_name ("Remote communication error");
1062 case SERIAL_TIMEOUT
:
1069 /* Send the command in BUF to the remote machine,
1070 and read the reply into BUF.
1071 Report an error if we get an error reply. */
1082 error ("Remote failure reply: %s", buf
);
1085 /* Send a packet to the remote machine, with error checking.
1086 The data of the packet is in BUF. */
1093 unsigned char csum
= 0;
1095 int cnt
= strlen (buf
);
1099 /* Copy the packet into buffer BUF2, encapsulating it
1100 and giving it a checksum. */
1102 if (cnt
> sizeof(buf2
) - 5) /* Prosanity check */
1108 for (i
= 0; i
< cnt
; i
++)
1114 *p
++ = tohex ((csum
>> 4) & 0xf);
1115 *p
++ = tohex (csum
& 0xf);
1117 /* Send it over and over until we get a positive ack. */
1121 int started_error_output
= 0;
1126 printf_unfiltered ("Sending packet: %s...", buf2
);
1127 gdb_flush(gdb_stdout
);
1129 if (SERIAL_WRITE (remote_desc
, buf2
, p
- buf2
))
1130 perror_with_name ("putpkt: write failed");
1132 /* read until either a timeout occurs (-2) or '+' is read */
1135 ch
= readchar (remote_timeout
);
1142 case SERIAL_TIMEOUT
:
1144 if (started_error_output
)
1146 putc_unfiltered ('\n');
1147 started_error_output
= 0;
1156 printf_unfiltered("Ack\n");
1158 case SERIAL_TIMEOUT
:
1159 break; /* Retransmit buffer */
1162 unsigned char junkbuf
[PBUFSIZ
];
1164 /* It's probably an old response, and we're out of sync. Just
1165 gobble up the packet and ignore it. */
1166 getpkt (junkbuf
, 0);
1167 continue; /* Now, go look for + */
1172 if (!started_error_output
)
1174 started_error_output
= 1;
1175 printf_unfiltered ("putpkt: Junk: ");
1177 putc_unfiltered (ch
& 0177);
1181 break; /* Here to retransmit */
1185 /* This is wrong. If doing a long backtrace, the user should be
1186 able to get out next time we call QUIT, without anything as violent
1187 as interrupt_query. If we want to provide a way out of here
1188 without getting to the next QUIT, it should be based on hitting
1189 ^C twice as in remote_wait. */
1199 /* Come here after finding the start of the frame. Collect the rest into BUF,
1200 verifying the checksum, length, and handling run-length compression.
1201 Returns 0 on any error, 1 on success. */
1216 c
= readchar (remote_timeout
);
1220 case SERIAL_TIMEOUT
:
1222 puts_filtered ("Timeout in mid-packet, retrying\n");
1226 puts_filtered ("Saw new packet start in middle of old one\n");
1227 return 0; /* Start a new packet, count retries */
1230 unsigned char pktcsum
;
1234 pktcsum
= fromhex (readchar (remote_timeout
)) << 4;
1235 pktcsum
|= fromhex (readchar (remote_timeout
));
1237 if (csum
== pktcsum
)
1240 printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
1242 puts_filtered (buf
);
1243 puts_filtered ("\n");
1247 case '*': /* Run length encoding */
1248 c
= readchar (remote_timeout
);
1250 c
= c
- ' ' + 3; /* Compute repeat count */
1252 if (bp
+ c
- 1 < buf
+ PBUFSIZ
- 1)
1254 memset (bp
, *(bp
- 1), c
);
1260 printf_filtered ("Repeat count %d too large for buffer: ", c
);
1261 puts_filtered (buf
);
1262 puts_filtered ("\n");
1266 if (bp
< buf
+ PBUFSIZ
- 1)
1274 puts_filtered ("Remote packet too long: ");
1275 puts_filtered (buf
);
1276 puts_filtered ("\n");
1283 /* Read a packet from the remote machine, with error checking,
1284 and store it in BUF. BUF is expected to be of size PBUFSIZ.
1285 If FOREVER, wait forever rather than timing out; this is used
1286 while the target is executing user code. */
1289 getpkt (buf
, forever
)
1302 timeout
= remote_timeout
;
1304 #define MAX_TRIES 10
1306 for (tries
= 1; tries
<= MAX_TRIES
; tries
++)
1308 /* This can loop forever if the remote side sends us characters
1309 continuously, but if it pauses, we'll get a zero from readchar
1310 because of timeout. Then we'll count that as a retry. */
1312 /* Note that we will only wait forever prior to the start of a packet.
1313 After that, we expect characters to arrive at a brisk pace. They
1314 should show up within remote_timeout intervals. */
1318 c
= readchar (timeout
);
1320 if (c
== SERIAL_TIMEOUT
)
1323 puts_filtered ("Timed out.\n");
1329 /* We've found the start of a packet, now collect the data. */
1331 val
= read_frame (buf
);
1336 fprintf_unfiltered (gdb_stderr
, "Packet received: %s\n", buf
);
1337 SERIAL_WRITE (remote_desc
, "+", 1);
1341 /* Try the whole thing again. */
1343 SERIAL_WRITE (remote_desc
, "-", 1);
1346 /* We have tried hard enough, and just can't receive the packet. Give up. */
1348 printf_unfiltered ("Ignoring packet error, continuing...\n");
1349 SERIAL_WRITE (remote_desc
, "+", 1);
1356 /* Don't wait for it to die. I'm not really sure it matters whether
1357 we do or not. For the existing stubs, kill is a noop. */
1358 target_mourn_inferior ();
1364 unpush_target (&remote_ops
);
1365 generic_mourn_inferior ();
1368 #ifdef REMOTE_BREAKPOINT
1370 /* On some machines, e.g. 68k, we may use a different breakpoint instruction
1371 than other targets. */
1372 static unsigned char break_insn
[] = REMOTE_BREAKPOINT
;
1374 /* Check that it fits in BREAKPOINT_MAX bytes. */
1375 static unsigned char check_break_insn_size
[BREAKPOINT_MAX
] = REMOTE_BREAKPOINT
;
1377 #else /* No REMOTE_BREAKPOINT. */
1379 /* Same old breakpoint instruction. This code does nothing different
1380 than mem-break.c. */
1381 static unsigned char break_insn
[] = BREAKPOINT
;
1383 #endif /* No REMOTE_BREAKPOINT. */
1385 /* Insert a breakpoint on targets that don't have any better breakpoint
1386 support. We read the contents of the target location and stash it,
1387 then overwrite it with a breakpoint instruction. ADDR is the target
1388 location in the target machine. CONTENTS_CACHE is a pointer to
1389 memory allocated for saving the target contents. It is guaranteed
1390 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1391 is accomplished via BREAKPOINT_MAX). */
1394 remote_insert_breakpoint (addr
, contents_cache
)
1396 char *contents_cache
;
1400 val
= target_read_memory (addr
, contents_cache
, sizeof break_insn
);
1403 val
= target_write_memory (addr
, (char *)break_insn
, sizeof break_insn
);
1409 remote_remove_breakpoint (addr
, contents_cache
)
1411 char *contents_cache
;
1413 return target_write_memory (addr
, contents_cache
, sizeof break_insn
);
1416 /* Define the target subroutine names */
1418 struct target_ops remote_ops
= {
1419 "remote", /* to_shortname */
1420 "Remote serial target in gdb-specific protocol", /* to_longname */
1421 "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
1422 Specify the serial device it is connected to (e.g. /dev/ttya).", /* to_doc */
1423 remote_open
, /* to_open */
1424 remote_close
, /* to_close */
1425 NULL
, /* to_attach */
1426 remote_detach
, /* to_detach */
1427 remote_resume
, /* to_resume */
1428 remote_wait
, /* to_wait */
1429 remote_fetch_registers
, /* to_fetch_registers */
1430 remote_store_registers
, /* to_store_registers */
1431 remote_prepare_to_store
, /* to_prepare_to_store */
1432 remote_xfer_memory
, /* to_xfer_memory */
1433 remote_files_info
, /* to_files_info */
1435 remote_insert_breakpoint
, /* to_insert_breakpoint */
1436 remote_remove_breakpoint
, /* to_remove_breakpoint */
1438 NULL
, /* to_terminal_init */
1439 NULL
, /* to_terminal_inferior */
1440 NULL
, /* to_terminal_ours_for_output */
1441 NULL
, /* to_terminal_ours */
1442 NULL
, /* to_terminal_info */
1443 remote_kill
, /* to_kill */
1444 generic_load
, /* to_load */
1445 NULL
, /* to_lookup_symbol */
1446 NULL
, /* to_create_inferior */
1447 remote_mourn
, /* to_mourn_inferior */
1449 0, /* to_notice_signals */
1450 process_stratum
, /* to_stratum */
1452 1, /* to_has_all_memory */
1453 1, /* to_has_memory */
1454 1, /* to_has_stack */
1455 1, /* to_has_registers */
1456 1, /* to_has_execution */
1457 NULL
, /* sections */
1458 NULL
, /* sections_end */
1459 OPS_MAGIC
/* to_magic */
1463 _initialize_remote ()
1465 add_target (&remote_ops
);