1 /* Remote debugging interface for MIPS remote debugging protocol.
2 Copyright 1993 Free Software Foundation, Inc.
3 Contributed by Cygnus Support. Written by Ian Lance Taylor
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
31 #include "remote-utils.h"
36 /* Prototypes for local functions. */
39 mips_readchar
PARAMS ((int timeout
));
42 mips_receive_header
PARAMS ((unsigned char *hdr
, int *pgarbage
, int ch
,
46 mips_receive_trailer
PARAMS ((unsigned char *trlr
, int *pgarbage
, int *pch
,
49 static int mips_cksum
PARAMS ((const unsigned char *hdr
,
50 const unsigned char *data
,
54 mips_send_packet
PARAMS ((const char *s
, int get_ack
));
56 static int mips_receive_packet
PARAMS ((char *buff
, int));
59 mips_request
PARAMS ((char cmd
, unsigned int addr
, unsigned int data
,
63 mips_initialize
PARAMS ((void));
66 mips_open
PARAMS ((char *name
, int from_tty
));
69 mips_close
PARAMS ((int quitting
));
72 mips_detach
PARAMS ((char *args
, int from_tty
));
75 mips_resume
PARAMS ((int pid
, int step
, int siggnal
));
78 mips_wait
PARAMS ((int pid
, WAITTYPE
*status
));
81 mips_map_regno
PARAMS ((int regno
));
84 mips_fetch_registers
PARAMS ((int regno
));
87 mips_prepare_to_store
PARAMS ((void));
90 mips_store_registers
PARAMS ((int regno
));
93 mips_fetch_word
PARAMS ((CORE_ADDR addr
));
96 mips_store_word
PARAMS ((CORE_ADDR addr
, int value
));
99 mips_xfer_memory
PARAMS ((CORE_ADDR memaddr
, char *myaddr
, int len
,
100 int write
, struct target_ops
*ignore
));
103 mips_files_info
PARAMS ((struct target_ops
*ignore
));
106 mips_load
PARAMS ((char *args
, int from_tty
));
109 mips_create_inferior
PARAMS ((char *execfile
, char *args
, char **env
));
112 mips_mourn_inferior
PARAMS ((void));
114 /* A forward declaration. */
115 extern struct target_ops mips_ops
;
117 /* The MIPS remote debugging interface is built on top of a simple
118 packet protocol. Each packet is organized as follows:
120 SYN The first character is always a SYN (ASCII 026, or ^V). SYN
121 may not appear anywhere else in the packet. Any time a SYN is
122 seen, a new packet should be assumed to have begun.
125 This byte contains the upper five bits of the logical length
126 of the data section, plus a single bit indicating whether this
127 is a data packet or an acknowledgement. The documentation
128 indicates that this bit is 1 for a data packet, but the actual
129 board uses 1 for an acknowledgement. The value of the byte is
130 0x40 + (ack ? 0x20 : 0) + (len >> 6)
131 (we always have 0 <= len < 1024). Acknowledgement packets do
132 not carry data, and must have a data length of 0.
134 LEN1 This byte contains the lower six bits of the logical length of
135 the data section. The value is
138 SEQ This byte contains the six bit sequence number of the packet.
141 An acknowlegment packet contains the sequence number of the
142 packet being acknowledged plus 1 module 64. Data packets are
143 transmitted in sequence. There may only be one outstanding
144 unacknowledged data packet at a time. The sequence numbers
145 are independent in each direction. If an acknowledgement for
146 the previous packet is received (i.e., an acknowledgement with
147 the sequence number of the packet just sent) the packet just
148 sent should be retransmitted. If no acknowledgement is
149 received within a timeout period, the packet should be
150 retransmitted. This has an unfortunate failure condition on a
151 high-latency line, as a delayed acknowledgement may lead to an
152 endless series of duplicate packets.
154 DATA The actual data bytes follow. The following characters are
155 escaped inline with DLE (ASCII 020, or ^P):
161 The additional DLE characters are not counted in the logical
162 length stored in the TYPE_LEN and LEN1 bytes.
167 These bytes contain an 18 bit checksum of the complete
168 contents of the packet excluding the SEQ byte and the
169 CSUM[123] bytes. The checksum is simply the twos complement
170 addition of all the bytes treated as unsigned characters. The
171 values of the checksum bytes are:
172 CSUM1: 0x40 + ((cksum >> 12) & 0x3f)
173 CSUM2: 0x40 + ((cksum >> 6) & 0x3f)
174 CSUM3: 0x40 + (cksum & 0x3f)
176 It happens that the MIPS remote debugging protocol always
177 communicates with ASCII strings. Because of this, this
178 implementation doesn't bother to handle the DLE quoting mechanism,
179 since it will never be required. */
181 /* The SYN character which starts each packet. */
184 /* The 0x40 used to offset each packet (this value ensures that all of
185 the header and trailer bytes, other than SYN, are printable ASCII
187 #define HDR_OFFSET 0x40
189 /* The indices of the bytes in the packet header. */
190 #define HDR_INDX_SYN 0
191 #define HDR_INDX_TYPE_LEN 1
192 #define HDR_INDX_LEN1 2
193 #define HDR_INDX_SEQ 3
196 /* The data/ack bit in the TYPE_LEN header byte. */
197 #define TYPE_LEN_DA_BIT 0x20
198 #define TYPE_LEN_DATA 0
199 #define TYPE_LEN_ACK TYPE_LEN_DA_BIT
201 /* How to compute the header bytes. */
202 #define HDR_SET_SYN(data, len, seq) (SYN)
203 #define HDR_SET_TYPE_LEN(data, len, seq) \
205 + ((data) ? TYPE_LEN_DATA : TYPE_LEN_ACK) \
206 + (((len) >> 6) & 0x1f))
207 #define HDR_SET_LEN1(data, len, seq) (HDR_OFFSET + ((len) & 0x3f))
208 #define HDR_SET_SEQ(data, len, seq) (HDR_OFFSET + (seq))
210 /* Check that a header byte is reasonable. */
211 #define HDR_CHECK(ch) (((ch) & HDR_OFFSET) == HDR_OFFSET)
213 /* Get data from the header. These macros evaluate their argument
215 #define HDR_IS_DATA(hdr) \
216 (((hdr)[HDR_INDX_TYPE_LEN] & TYPE_LEN_DA_BIT) == TYPE_LEN_DATA)
217 #define HDR_GET_LEN(hdr) \
218 ((((hdr)[HDR_INDX_TYPE_LEN] & 0x1f) << 6) + (((hdr)[HDR_INDX_LEN1] & 0x3f)))
219 #define HDR_GET_SEQ(hdr) ((hdr)[HDR_INDX_SEQ] & 0x3f)
221 /* The maximum data length. */
222 #define DATA_MAXLEN 1023
224 /* The trailer offset. */
225 #define TRLR_OFFSET HDR_OFFSET
227 /* The indices of the bytes in the packet trailer. */
228 #define TRLR_INDX_CSUM1 0
229 #define TRLR_INDX_CSUM2 1
230 #define TRLR_INDX_CSUM3 2
231 #define TRLR_LENGTH 3
233 /* How to compute the trailer bytes. */
234 #define TRLR_SET_CSUM1(cksum) (TRLR_OFFSET + (((cksum) >> 12) & 0x3f))
235 #define TRLR_SET_CSUM2(cksum) (TRLR_OFFSET + (((cksum) >> 6) & 0x3f))
236 #define TRLR_SET_CSUM3(cksum) (TRLR_OFFSET + (((cksum) ) & 0x3f))
238 /* Check that a trailer byte is reasonable. */
239 #define TRLR_CHECK(ch) (((ch) & TRLR_OFFSET) == TRLR_OFFSET)
241 /* Get data from the trailer. This evaluates its argument multiple
243 #define TRLR_GET_CKSUM(trlr) \
244 ((((trlr)[TRLR_INDX_CSUM1] & 0x3f) << 12) \
245 + (((trlr)[TRLR_INDX_CSUM2] & 0x3f) << 6) \
246 + ((trlr)[TRLR_INDX_CSUM3] & 0x3f))
248 /* The sequence number modulos. */
249 #define SEQ_MODULOS (64)
251 /* Set to 1 if the target is open. */
252 static int mips_is_open
;
254 /* Set to 1 while the connection is being initialized. */
255 static int mips_initializing
;
257 /* The next sequence number to send. */
258 static int mips_send_seq
;
260 /* The next sequence number we expect to receive. */
261 static int mips_receive_seq
;
263 /* The time to wait before retransmitting a packet, in seconds. */
264 static int mips_retransmit_wait
= 3;
266 /* The number of times to try retransmitting a packet before giving up. */
267 static int mips_send_retries
= 10;
269 /* The number of garbage characters to accept when looking for an
270 SYN for the next packet. */
271 static int mips_syn_garbage
= 1050;
273 /* The time to wait for a packet, in seconds. */
274 static int mips_receive_wait
= 5;
276 /* Set if we have sent a packet to the board but have not yet received
278 static int mips_need_reply
= 0;
280 /* Handle used to access serial I/O stream. */
281 static serial_t mips_desc
;
283 /* Handle low-level error that we can't recover from. Note that just
284 error()ing out from target_wait or some such low-level place will cause
285 all hell to break loose--the rest of GDB will tend to get left in an
286 inconsistent state. */
289 mips_error (va_alist
)
296 target_terminal_ours ();
297 wrap_here(""); /* Force out any buffered output */
298 gdb_flush (gdb_stdout
);
300 fprintf_filtered (gdb_stderr
, error_pre_print
);
301 string
= va_arg (args
, char *);
302 vfprintf_filtered (gdb_stderr
, string
, args
);
303 fprintf_filtered (gdb_stderr
, "\n");
306 /* Clean up in such a way that mips_close won't try to talk to the
307 board (it almost surely won't work since we weren't able to talk to
310 SERIAL_CLOSE (mips_desc
);
312 printf_unfiltered ("Ending remote MIPS debugging.\n");
313 target_mourn_inferior ();
315 return_to_top_level (RETURN_ERROR
);
318 /* Read a character from the remote, aborting on error. Returns
319 SERIAL_TIMEOUT on timeout (since that's what SERIAL_READCHAR
320 returns). FIXME: If we see the string "<IDT>" from the board, then
321 we are debugging on the main console port, and we have somehow
322 dropped out of remote debugging mode. In this case, we
323 automatically go back in to remote debugging mode. This is a hack,
324 put in because I can't find any way for a program running on the
325 remote board to terminate without also ending remote debugging
326 mode. I assume users won't have any trouble with this; for one
327 thing, the IDT documentation generally assumes that the remote
328 debugging port is not the console port. This is, however, very
329 convenient for DejaGnu when you only have one connected serial
333 mips_readchar (timeout
)
337 static int state
= 0;
338 static char nextstate
[5] = { '<', 'I', 'D', 'T', '>' };
340 ch
= SERIAL_READCHAR (mips_desc
, timeout
);
341 if (ch
== SERIAL_EOF
)
342 mips_error ("End of file from remote");
343 if (ch
== SERIAL_ERROR
)
344 mips_error ("Error reading from remote: %s", safe_strerror (errno
));
345 if (sr_get_debug () > 1)
347 if (ch
!= SERIAL_TIMEOUT
)
348 printf_filtered ("Read '%c' %d 0x%x\n", ch
, ch
, ch
);
350 printf_filtered ("Timed out in read\n");
353 /* If we have seen <IDT> and we either time out, or we see a @
354 (which was echoed from a packet we sent), reset the board as
355 described above. The first character in a packet after the SYN
356 (which is not echoed) is always an @ unless the packet is more
357 than 64 characters long, which ours never are. */
358 if ((ch
== SERIAL_TIMEOUT
|| ch
== '@')
360 && ! mips_initializing
)
362 if (sr_get_debug () > 0)
363 printf_filtered ("Reinitializing MIPS debugging mode\n");
364 SERIAL_WRITE (mips_desc
, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
372 mips_error ("Remote board reset");
375 if (ch
== nextstate
[state
])
383 /* Get a packet header, putting the data in the supplied buffer.
384 PGARBAGE is a pointer to the number of garbage characters received
385 so far. CH is the last character received. Returns 0 for success,
386 or -1 for timeout. */
389 mips_receive_header (hdr
, pgarbage
, ch
, timeout
)
399 /* Wait for a SYN. mips_syn_garbage is intended to prevent
400 sitting here indefinitely if the board sends us one garbage
401 character per second. ch may already have a value from the
402 last time through the loop. */
405 ch
= mips_readchar (timeout
);
406 if (ch
== SERIAL_TIMEOUT
)
410 /* Printing the character here lets the user of gdb see
411 what the program is outputting, if the debugging is
412 being done on the console port. FIXME: Perhaps this
413 should be filtered? */
414 if (! mips_initializing
|| sr_get_debug () > 0)
416 putchar_unfiltered (ch
);
417 gdb_flush (gdb_stdout
);
421 if (*pgarbage
> mips_syn_garbage
)
422 mips_error ("Remote debugging protocol failure");
426 /* Get the packet header following the SYN. */
427 for (i
= 1; i
< HDR_LENGTH
; i
++)
429 ch
= mips_readchar (timeout
);
430 if (ch
== SERIAL_TIMEOUT
)
433 /* Make sure this is a header byte. */
434 if (ch
== SYN
|| ! HDR_CHECK (ch
))
440 /* If we got the complete header, we can return. Otherwise we
441 loop around and keep looking for SYN. */
447 /* Get a packet header, putting the data in the supplied buffer.
448 PGARBAGE is a pointer to the number of garbage characters received
449 so far. The last character read is returned in *PCH. Returns 0
450 for success, -1 for timeout, -2 for error. */
453 mips_receive_trailer (trlr
, pgarbage
, pch
, timeout
)
462 for (i
= 0; i
< TRLR_LENGTH
; i
++)
464 ch
= mips_readchar (timeout
);
466 if (ch
== SERIAL_TIMEOUT
)
468 if (! TRLR_CHECK (ch
))
475 /* Get the checksum of a packet. HDR points to the packet header.
476 DATA points to the packet data. LEN is the length of DATA. */
479 mips_cksum (hdr
, data
, len
)
480 const unsigned char *hdr
;
481 const unsigned char *data
;
484 register const unsigned char *p
;
490 /* The initial SYN is not included in the checksum. */
504 /* Send a packet containing the given ASCII string. */
507 mips_send_packet (s
, get_ack
)
512 unsigned char *packet
;
517 if (len
> DATA_MAXLEN
)
518 mips_error ("MIPS protocol data packet too long: %s", s
);
520 packet
= (unsigned char *) alloca (HDR_LENGTH
+ len
+ TRLR_LENGTH
+ 1);
522 packet
[HDR_INDX_SYN
] = HDR_SET_SYN (1, len
, mips_send_seq
);
523 packet
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (1, len
, mips_send_seq
);
524 packet
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (1, len
, mips_send_seq
);
525 packet
[HDR_INDX_SEQ
] = HDR_SET_SEQ (1, len
, mips_send_seq
);
527 memcpy (packet
+ HDR_LENGTH
, s
, len
);
529 cksum
= mips_cksum (packet
, packet
+ HDR_LENGTH
, len
);
530 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
531 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
532 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
534 /* Increment the sequence number. This will set mips_send_seq to
535 the sequence number we expect in the acknowledgement. */
536 mips_send_seq
= (mips_send_seq
+ 1) % SEQ_MODULOS
;
541 /* We can only have one outstanding data packet, so we just wait for
542 the acknowledgement here. Keep retransmitting the packet until
543 we get one, or until we've tried too many times. */
544 for (try = 0; try < mips_send_retries
; try++)
549 if (sr_get_debug () > 0)
551 packet
[HDR_LENGTH
+ len
+ TRLR_LENGTH
] = '\0';
552 printf_filtered ("Writing \"%s\"\n", packet
+ 1);
555 if (SERIAL_WRITE (mips_desc
, packet
,
556 HDR_LENGTH
+ len
+ TRLR_LENGTH
) != 0)
557 mips_error ("write to target failed: %s", safe_strerror (errno
));
563 unsigned char hdr
[HDR_LENGTH
+ 1];
564 unsigned char trlr
[TRLR_LENGTH
+ 1];
568 /* Get the packet header. If we time out, resend the data
570 err
= mips_receive_header (hdr
, &garbage
, ch
, mips_retransmit_wait
);
576 /* If we get a data packet, assume it is a duplicate and
577 ignore it. FIXME: If the acknowledgement is lost, this
578 data packet may be the packet the remote sends after the
580 if (HDR_IS_DATA (hdr
))
583 /* If the length is not 0, this is a garbled packet. */
584 if (HDR_GET_LEN (hdr
) != 0)
587 /* Get the packet trailer. */
588 err
= mips_receive_trailer (trlr
, &garbage
, &ch
,
589 mips_retransmit_wait
);
591 /* If we timed out, resend the data packet. */
595 /* If we got a bad character, reread the header. */
599 /* If the checksum does not match the trailer checksum, this
600 is a bad packet; ignore it. */
601 if (mips_cksum (hdr
, (unsigned char *) NULL
, 0)
602 != TRLR_GET_CKSUM (trlr
))
605 if (sr_get_debug () > 0)
607 hdr
[HDR_LENGTH
] = '\0';
608 trlr
[TRLR_LENGTH
] = '\0';
609 printf_filtered ("Got ack %d \"%s%s\"\n",
610 HDR_GET_SEQ (hdr
), hdr
+ 1, trlr
);
613 /* If this ack is for the current packet, we're done. */
614 seq
= HDR_GET_SEQ (hdr
);
615 if (seq
== mips_send_seq
)
618 /* If this ack is for the last packet, resend the current
620 if ((seq
+ 1) % SEQ_MODULOS
== mips_send_seq
)
623 /* Otherwise this is a bad ack; ignore it. Increment the
624 garbage count to ensure that we do not stay in this loop
630 mips_error ("Remote did not acknowledge packet");
633 /* Receive and acknowledge a packet, returning the data in BUFF (which
634 should be DATA_MAXLEN + 1 bytes). The protocol documentation
635 implies that only the sender retransmits packets, so this code just
636 waits silently for a packet. It returns the length of the received
637 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
638 don't print an error message and return -1. */
641 mips_receive_packet (buff
, throw_error
)
648 unsigned char ack
[HDR_LENGTH
+ TRLR_LENGTH
+ 1];
655 unsigned char hdr
[HDR_LENGTH
];
656 unsigned char trlr
[TRLR_LENGTH
];
660 if (mips_receive_header (hdr
, &garbage
, ch
, mips_receive_wait
) != 0)
663 mips_error ("Timed out waiting for remote packet");
670 /* An acknowledgement is probably a duplicate; ignore it. */
671 if (! HDR_IS_DATA (hdr
))
673 if (sr_get_debug () > 0)
674 printf_filtered ("Ignoring unexpected ACK\n");
678 /* If this is the wrong sequence number, ignore it. */
679 if (HDR_GET_SEQ (hdr
) != mips_receive_seq
)
681 if (sr_get_debug () > 0)
682 printf_filtered ("Ignoring sequence number %d (want %d)\n",
683 HDR_GET_SEQ (hdr
), mips_receive_seq
);
687 len
= HDR_GET_LEN (hdr
);
689 for (i
= 0; i
< len
; i
++)
693 rch
= mips_readchar (mips_receive_wait
);
699 if (rch
== SERIAL_TIMEOUT
)
702 mips_error ("Timed out waiting for remote packet");
711 if (sr_get_debug () > 0)
712 printf_filtered ("Got new SYN after %d chars (wanted %d)\n",
717 err
= mips_receive_trailer (trlr
, &garbage
, &ch
, mips_receive_wait
);
721 mips_error ("Timed out waiting for packet");
727 if (sr_get_debug () > 0)
728 printf_filtered ("Got SYN when wanted trailer\n");
732 if (mips_cksum (hdr
, buff
, len
) == TRLR_GET_CKSUM (trlr
))
735 if (sr_get_debug () > 0)
736 printf_filtered ("Bad checksum; data %d, trailer %d\n",
737 mips_cksum (hdr
, buff
, len
),
738 TRLR_GET_CKSUM (trlr
));
740 /* The checksum failed. Send an acknowledgement for the
741 previous packet to tell the remote to resend the packet. */
742 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
743 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
744 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
745 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
747 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
749 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
750 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
751 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
753 if (sr_get_debug () > 0)
755 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
756 printf_filtered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
760 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
763 mips_error ("write to target failed: %s", safe_strerror (errno
));
769 if (sr_get_debug () > 0)
772 printf_filtered ("Got packet \"%s\"\n", buff
);
775 /* We got the packet. Send an acknowledgement. */
776 mips_receive_seq
= (mips_receive_seq
+ 1) % SEQ_MODULOS
;
778 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
779 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
780 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
781 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
783 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
785 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
786 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
787 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
789 if (sr_get_debug () > 0)
791 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
792 printf_filtered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
796 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
799 mips_error ("write to target failed: %s", safe_strerror (errno
));
807 /* Optionally send a request to the remote system and optionally wait
808 for the reply. This implements the remote debugging protocol,
809 which is built on top of the packet protocol defined above. Each
810 request has an ADDR argument and a DATA argument. The following
811 requests are defined:
813 \0 don't send a request; just wait for a reply
814 i read word from instruction space at ADDR
815 d read word from data space at ADDR
816 I write DATA to instruction space at ADDR
817 D write DATA to data space at ADDR
818 r read register number ADDR
819 R set register number ADDR to value DATA
820 c continue execution (if ADDR != 1, set pc to ADDR)
821 s single step (if ADDR != 1, set pc to ADDR)
823 The read requests return the value requested. The write requests
824 return the previous value in the changed location. The execution
825 requests return a UNIX wait value (the approximate signal which
826 caused execution to stop is in the upper eight bits).
828 If PERR is not NULL, this function waits for a reply. If an error
829 occurs, it sets *PERR to 1 and sets errno according to what the
830 target board reports. */
833 mips_request (cmd
, addr
, data
, perr
)
839 char buff
[DATA_MAXLEN
+ 1];
849 fatal ("mips_request: Trying to send command before reply");
850 sprintf (buff
, "0x0 %c 0x%x 0x%x", cmd
, addr
, data
);
851 mips_send_packet (buff
, 1);
855 if (perr
== (int *) NULL
)
858 if (! mips_need_reply
)
859 fatal ("mips_request: Trying to get reply before command");
863 len
= mips_receive_packet (buff
, 1);
866 if (sscanf (buff
, "0x%x %c 0x%x 0x%x",
867 &rpid
, &rcmd
, &rerrflg
, &rresponse
) != 4
868 || (cmd
!= '\0' && rcmd
!= cmd
))
869 mips_error ("Bad response from remote board");
875 /* FIXME: This will returns MIPS errno numbers, which may or may
876 not be the same as errno values used on other systems. If
877 they stick to common errno values, they will be the same, but
878 if they don't, they must be translated. */
888 /* Initialize a new connection to the MIPS board, and make sure we are
896 char buff
[DATA_MAXLEN
+ 1];
899 if (mips_initializing
)
902 mips_initializing
= 1;
905 mips_receive_seq
= 0;
907 /* The board seems to want to send us a packet. I don't know what
908 it means. The packet seems to be triggered by a carriage return
909 character, although perhaps any character would do. */
911 SERIAL_WRITE (mips_desc
, &cr
, 1);
913 hold_wait
= mips_receive_wait
;
914 mips_receive_wait
= 3;
916 if (mips_receive_packet (buff
, 0) < 0)
920 /* We did not receive the packet we expected; try resetting the
921 board and trying again. */
922 printf_filtered ("Failed to initialize; trying to reset board\n");
924 SERIAL_WRITE (mips_desc
, &cc
, 1);
926 SERIAL_WRITE (mips_desc
, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
929 SERIAL_WRITE (mips_desc
, &cr
, 1);
931 mips_receive_packet (buff
, 1);
933 mips_receive_wait
= hold_wait
;
934 mips_initializing
= 0;
936 /* If this doesn't call error, we have connected; we don't care if
937 the request itself succeeds or fails. */
938 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err
);
941 /* Open a connection to the remote board. */
944 mips_open (name
, from_tty
)
950 "To open a MIPS remote debugging connection, you need to specify what serial\n\
951 device is attached to the target board (e.g., /dev/ttya).");
953 target_preopen (from_tty
);
956 unpush_target (&mips_ops
);
958 mips_desc
= SERIAL_OPEN (name
);
959 if (mips_desc
== (serial_t
) NULL
)
960 perror_with_name (name
);
962 SERIAL_RAW (mips_desc
);
969 printf_unfiltered ("Remote MIPS debugging using %s\n", name
);
970 push_target (&mips_ops
); /* Switch to using remote target now */
972 /* FIXME: Should we call start_remote here? */
975 /* Close a connection to the remote board. */
978 mips_close (quitting
)
987 /* Get the board out of remote debugging mode. */
988 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err
);
990 SERIAL_CLOSE (mips_desc
);
994 /* Detach from the remote board. */
997 mips_detach (args
, from_tty
)
1002 error ("Argument given to \"detach\" when remotely debugging.");
1006 printf_unfiltered ("Ending remote MIPS debugging.\n");
1009 /* Tell the target board to resume. This does not wait for a reply
1013 mips_resume (pid
, step
, siggnal
)
1014 int pid
, step
, siggnal
;
1017 mips_error ("Can't send signals to a remote system. Try `handle %d ignore'.",
1020 mips_request (step
? 's' : 'c',
1026 /* Wait until the remote stops, and return a wait status. */
1029 mips_wait (pid
, status
)
1036 /* If we have not sent a single step or continue command, then the
1037 board is waiting for us to do something. Return a status
1038 indicating that it is stopped. */
1039 if (! mips_need_reply
)
1041 WSETSTOP (*status
, SIGTRAP
);
1045 rstatus
= mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err
);
1047 mips_error ("Remote failure: %s", safe_strerror (errno
));
1049 /* FIXME: The target board uses numeric signal values which are
1050 those used on MIPS systems. If the host uses different signal
1051 values, we need to translate here. I believe all Unix systems
1052 use the same values for the signals the board can return, which
1053 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1055 /* FIXME: The target board uses a standard Unix wait status int. If
1056 the host system does not, we must translate here. */
1063 /* We have to map between the register numbers used by gdb and the
1064 register numbers used by the debugging protocol. This function
1065 assumes that we are using tm-mips.h. */
1067 #define REGNO_OFFSET 96
1070 mips_map_regno (regno
)
1075 if (regno
>= FP0_REGNUM
&& regno
< FP0_REGNUM
+ 32)
1076 return regno
- FP0_REGNUM
+ 32;
1080 return REGNO_OFFSET
+ 0;
1082 return REGNO_OFFSET
+ 1;
1084 return REGNO_OFFSET
+ 2;
1086 return REGNO_OFFSET
+ 3;
1088 return REGNO_OFFSET
+ 4;
1090 return REGNO_OFFSET
+ 5;
1092 /* FIXME: Is there a way to get the status register? */
1097 /* Fetch the remote registers. */
1100 mips_fetch_registers (regno
)
1103 unsigned LONGEST val
;
1108 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1109 mips_fetch_registers (regno
);
1113 val
= mips_request ('r', (unsigned int) mips_map_regno (regno
),
1114 (unsigned int) 0, &err
);
1116 mips_error ("Can't read register %d: %s", regno
, safe_strerror (errno
));
1119 char buf
[MAX_REGISTER_RAW_SIZE
];
1121 /* We got the number the register holds, but gdb expects to see a
1122 value in the target byte ordering. */
1123 store_unsigned_integer (buf
, REGISTER_RAW_SIZE (regno
), val
);
1124 supply_register (regno
, buf
);
1128 /* Prepare to store registers. The MIPS protocol can store individual
1129 registers, so this function doesn't have to do anything. */
1132 mips_prepare_to_store ()
1136 /* Store remote register(s). */
1139 mips_store_registers (regno
)
1146 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1147 mips_store_registers (regno
);
1151 mips_request ('R', (unsigned int) mips_map_regno (regno
),
1152 (unsigned int) read_register (regno
),
1155 mips_error ("Can't write register %d: %s", regno
, safe_strerror (errno
));
1158 /* Fetch a word from the target board. */
1161 mips_fetch_word (addr
)
1167 val
= mips_request ('d', (unsigned int) addr
, (unsigned int) 0, &err
);
1170 /* Data space failed; try instruction space. */
1171 val
= mips_request ('i', (unsigned int) addr
, (unsigned int) 0, &err
);
1173 mips_error ("Can't read address 0x%x: %s", addr
, safe_strerror (errno
));
1178 /* Store a word to the target board. */
1181 mips_store_word (addr
, val
)
1187 mips_request ('D', (unsigned int) addr
, (unsigned int) val
, &err
);
1190 /* Data space failed; try instruction space. */
1191 mips_request ('I', (unsigned int) addr
, (unsigned int) val
, &err
);
1193 mips_error ("Can't write address 0x%x: %s", addr
, safe_strerror (errno
));
1197 /* Read or write LEN bytes from inferior memory at MEMADDR,
1198 transferring to or from debugger address MYADDR. Write to inferior
1199 if SHOULD_WRITE is nonzero. Returns length of data written or
1200 read; 0 for error. Note that protocol gives us the correct value
1201 for a longword, since it transfers values in ASCII. We want the
1202 byte values, so we have to swap the longword values. */
1205 mips_xfer_memory (memaddr
, myaddr
, len
, write
, ignore
)
1210 struct target_ops
*ignore
;
1213 /* Round starting address down to longword boundary. */
1214 register CORE_ADDR addr
= memaddr
&~ 3;
1215 /* Round ending address up; get number of longwords that makes. */
1216 register int count
= (((memaddr
+ len
) - addr
) + 3) / 4;
1217 /* Allocate buffer of that many longwords. */
1218 register char *buffer
= alloca (count
* 4);
1222 /* Fill start and end extra bytes of buffer with existing data. */
1223 if (addr
!= memaddr
|| len
< 4)
1225 /* Need part of initial word -- fetch it. */
1226 store_unsigned_integer (&buffer
[0], 4, mips_fetch_word (addr
));
1231 /* Need part of last word -- fetch it. FIXME: we do this even
1232 if we don't need it. */
1233 store_unsigned_integer (&buffer
[(count
- 1) * 4], 4,
1234 mips_fetch_word (addr
+ (count
- 1) * 4));
1237 /* Copy data to be written over corresponding part of buffer */
1239 memcpy ((char *) buffer
+ (memaddr
& 3), myaddr
, len
);
1241 /* Write the entire buffer. */
1243 for (i
= 0; i
< count
; i
++, addr
+= 4)
1245 mips_store_word (addr
, extract_unsigned_integer (&buffer
[i
*4], 4));
1246 /* FIXME: Do we want a QUIT here? */
1251 /* Read all the longwords */
1252 for (i
= 0; i
< count
; i
++, addr
+= 4)
1254 store_unsigned_integer (&buffer
[i
*4], 4, mips_fetch_word (addr
));
1258 /* Copy appropriate bytes out of the buffer. */
1259 memcpy (myaddr
, buffer
+ (memaddr
& 3), len
);
1264 /* Print info on this target. */
1267 mips_files_info (ignore
)
1268 struct target_ops
*ignore
;
1270 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1273 /* Kill the process running on the board. This will actually only
1274 work if we are doing remote debugging over the console input. I
1275 think that if IDT/sim had the remote debug interrupt enabled on the
1276 right port, we could interrupt the process with a break signal. */
1288 SERIAL_WRITE (mips_desc
, &cc
, 1);
1290 target_mourn_inferior ();
1295 /* Start running on the target board. */
1298 mips_create_inferior (execfile
, args
, env
)
1306 mips_error ("Can't pass arguments to remote MIPS board.");
1308 if (execfile
== 0 || exec_bfd
== 0)
1309 mips_error ("No exec file specified");
1311 entry_pt
= (CORE_ADDR
) bfd_get_start_address (exec_bfd
);
1313 init_wait_for_inferior ();
1315 /* FIXME: Should we set inferior_pid here? */
1317 proceed (entry_pt
, -1, 0);
1320 /* Clean up after a process. Actually nothing to do. */
1323 mips_mourn_inferior ()
1325 unpush_target (&mips_ops
);
1326 generic_mourn_inferior ();
1329 /* The target vector. */
1331 struct target_ops mips_ops
=
1333 "mips", /* to_shortname */
1334 "Remote MIPS debugging over serial line", /* to_longname */
1335 "Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1336 Specify the serial device it is connected to (e.g., /dev/ttya).", /* to_doc */
1337 mips_open
, /* to_open */
1338 mips_close
, /* to_close */
1339 NULL
, /* to_attach */
1340 mips_detach
, /* to_detach */
1341 mips_resume
, /* to_resume */
1342 mips_wait
, /* to_wait */
1343 mips_fetch_registers
, /* to_fetch_registers */
1344 mips_store_registers
, /* to_store_registers */
1345 mips_prepare_to_store
, /* to_prepare_to_store */
1346 mips_xfer_memory
, /* to_xfer_memory */
1347 mips_files_info
, /* to_files_info */
1348 NULL
, /* to_insert_breakpoint */
1349 NULL
, /* to_remove_breakpoint */
1350 NULL
, /* to_terminal_init */
1351 NULL
, /* to_terminal_inferior */
1352 NULL
, /* to_terminal_ours_for_output */
1353 NULL
, /* to_terminal_ours */
1354 NULL
, /* to_terminal_info */
1355 mips_kill
, /* to_kill */
1356 generic_load
, /* to_load */
1357 NULL
, /* to_lookup_symbol */
1358 mips_create_inferior
, /* to_create_inferior */
1359 mips_mourn_inferior
, /* to_mourn_inferior */
1360 NULL
, /* to_can_run */
1361 NULL
, /* to_notice_signals */
1362 process_stratum
, /* to_stratum */
1364 1, /* to_has_all_memory */
1365 1, /* to_has_memory */
1366 1, /* to_has_stack */
1367 1, /* to_has_registers */
1368 1, /* to_has_execution */
1369 NULL
, /* sections */
1370 NULL
, /* sections_end */
1371 OPS_MAGIC
/* to_magic */
1375 _initialize_remote_mips ()
1377 add_target (&mips_ops
);
1380 add_set_cmd ("timeout", no_class
, var_zinteger
,
1381 (char *) &mips_receive_wait
,
1382 "Set timeout in seconds for remote MIPS serial I/O.",
1387 add_set_cmd ("retransmit-timeout", no_class
, var_zinteger
,
1388 (char *) &mips_retransmit_wait
,
1389 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1390 This is the number of seconds to wait for an acknowledgement to a packet\n\
1391 before resending the packet.", &setlist
),
This page took 0.056902 seconds and 5 git commands to generate.