1 /* Remote debugging interface for MIPS remote debugging protocol.
2 Copyright 1993, 1994 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 extern char *mips_read_processor_type
PARAMS ((void));
38 extern void mips_set_processor_type_command
PARAMS ((char *, int));
41 /* Prototypes for local functions. */
43 static int mips_readchar
PARAMS ((int timeout
));
45 static int mips_receive_header
PARAMS ((unsigned char *hdr
, int *pgarbage
,
46 int ch
, int timeout
));
48 static int mips_receive_trailer
PARAMS ((unsigned char *trlr
, int *pgarbage
,
49 int *pch
, int timeout
));
51 static int mips_cksum
PARAMS ((const unsigned char *hdr
,
52 const unsigned char *data
,
55 static void mips_send_packet
PARAMS ((const char *s
, int get_ack
));
57 static int mips_receive_packet
PARAMS ((char *buff
, int throw_error
,
60 static int mips_request
PARAMS ((char cmd
, unsigned int addr
,
61 unsigned int data
, int *perr
, int timeout
));
63 static void mips_initialize
PARAMS ((void));
65 static void mips_open
PARAMS ((char *name
, int from_tty
));
67 static void mips_close
PARAMS ((int quitting
));
69 static void mips_detach
PARAMS ((char *args
, int from_tty
));
71 static void mips_resume
PARAMS ((int pid
, int step
,
72 enum target_signal siggnal
));
74 static int mips_wait
PARAMS ((int pid
, struct target_waitstatus
*status
));
76 static int mips_map_regno
PARAMS ((int regno
));
78 static void mips_fetch_registers
PARAMS ((int regno
));
80 static void mips_prepare_to_store
PARAMS ((void));
82 static void mips_store_registers
PARAMS ((int regno
));
84 static int mips_fetch_word
PARAMS ((CORE_ADDR addr
));
86 static int mips_store_word
PARAMS ((CORE_ADDR addr
, int value
,
89 static int mips_xfer_memory
PARAMS ((CORE_ADDR memaddr
, char *myaddr
, int len
,
90 int write
, struct target_ops
*ignore
));
92 static void mips_files_info
PARAMS ((struct target_ops
*ignore
));
94 static void mips_create_inferior
PARAMS ((char *execfile
, char *args
,
97 static void mips_mourn_inferior
PARAMS ((void));
99 /* A forward declaration. */
100 extern struct target_ops mips_ops
;
102 /* The MIPS remote debugging interface is built on top of a simple
103 packet protocol. Each packet is organized as follows:
105 SYN The first character is always a SYN (ASCII 026, or ^V). SYN
106 may not appear anywhere else in the packet. Any time a SYN is
107 seen, a new packet should be assumed to have begun.
110 This byte contains the upper five bits of the logical length
111 of the data section, plus a single bit indicating whether this
112 is a data packet or an acknowledgement. The documentation
113 indicates that this bit is 1 for a data packet, but the actual
114 board uses 1 for an acknowledgement. The value of the byte is
115 0x40 + (ack ? 0x20 : 0) + (len >> 6)
116 (we always have 0 <= len < 1024). Acknowledgement packets do
117 not carry data, and must have a data length of 0.
119 LEN1 This byte contains the lower six bits of the logical length of
120 the data section. The value is
123 SEQ This byte contains the six bit sequence number of the packet.
126 An acknowlegment packet contains the sequence number of the
127 packet being acknowledged plus 1 module 64. Data packets are
128 transmitted in sequence. There may only be one outstanding
129 unacknowledged data packet at a time. The sequence numbers
130 are independent in each direction. If an acknowledgement for
131 the previous packet is received (i.e., an acknowledgement with
132 the sequence number of the packet just sent) the packet just
133 sent should be retransmitted. If no acknowledgement is
134 received within a timeout period, the packet should be
135 retransmitted. This has an unfortunate failure condition on a
136 high-latency line, as a delayed acknowledgement may lead to an
137 endless series of duplicate packets.
139 DATA The actual data bytes follow. The following characters are
140 escaped inline with DLE (ASCII 020, or ^P):
146 The additional DLE characters are not counted in the logical
147 length stored in the TYPE_LEN and LEN1 bytes.
152 These bytes contain an 18 bit checksum of the complete
153 contents of the packet excluding the SEQ byte and the
154 CSUM[123] bytes. The checksum is simply the twos complement
155 addition of all the bytes treated as unsigned characters. The
156 values of the checksum bytes are:
157 CSUM1: 0x40 + ((cksum >> 12) & 0x3f)
158 CSUM2: 0x40 + ((cksum >> 6) & 0x3f)
159 CSUM3: 0x40 + (cksum & 0x3f)
161 It happens that the MIPS remote debugging protocol always
162 communicates with ASCII strings. Because of this, this
163 implementation doesn't bother to handle the DLE quoting mechanism,
164 since it will never be required. */
166 /* The SYN character which starts each packet. */
169 /* The 0x40 used to offset each packet (this value ensures that all of
170 the header and trailer bytes, other than SYN, are printable ASCII
172 #define HDR_OFFSET 0x40
174 /* The indices of the bytes in the packet header. */
175 #define HDR_INDX_SYN 0
176 #define HDR_INDX_TYPE_LEN 1
177 #define HDR_INDX_LEN1 2
178 #define HDR_INDX_SEQ 3
181 /* The data/ack bit in the TYPE_LEN header byte. */
182 #define TYPE_LEN_DA_BIT 0x20
183 #define TYPE_LEN_DATA 0
184 #define TYPE_LEN_ACK TYPE_LEN_DA_BIT
186 /* How to compute the header bytes. */
187 #define HDR_SET_SYN(data, len, seq) (SYN)
188 #define HDR_SET_TYPE_LEN(data, len, seq) \
190 + ((data) ? TYPE_LEN_DATA : TYPE_LEN_ACK) \
191 + (((len) >> 6) & 0x1f))
192 #define HDR_SET_LEN1(data, len, seq) (HDR_OFFSET + ((len) & 0x3f))
193 #define HDR_SET_SEQ(data, len, seq) (HDR_OFFSET + (seq))
195 /* Check that a header byte is reasonable. */
196 #define HDR_CHECK(ch) (((ch) & HDR_OFFSET) == HDR_OFFSET)
198 /* Get data from the header. These macros evaluate their argument
200 #define HDR_IS_DATA(hdr) \
201 (((hdr)[HDR_INDX_TYPE_LEN] & TYPE_LEN_DA_BIT) == TYPE_LEN_DATA)
202 #define HDR_GET_LEN(hdr) \
203 ((((hdr)[HDR_INDX_TYPE_LEN] & 0x1f) << 6) + (((hdr)[HDR_INDX_LEN1] & 0x3f)))
204 #define HDR_GET_SEQ(hdr) ((hdr)[HDR_INDX_SEQ] & 0x3f)
206 /* The maximum data length. */
207 #define DATA_MAXLEN 1023
209 /* The trailer offset. */
210 #define TRLR_OFFSET HDR_OFFSET
212 /* The indices of the bytes in the packet trailer. */
213 #define TRLR_INDX_CSUM1 0
214 #define TRLR_INDX_CSUM2 1
215 #define TRLR_INDX_CSUM3 2
216 #define TRLR_LENGTH 3
218 /* How to compute the trailer bytes. */
219 #define TRLR_SET_CSUM1(cksum) (TRLR_OFFSET + (((cksum) >> 12) & 0x3f))
220 #define TRLR_SET_CSUM2(cksum) (TRLR_OFFSET + (((cksum) >> 6) & 0x3f))
221 #define TRLR_SET_CSUM3(cksum) (TRLR_OFFSET + (((cksum) ) & 0x3f))
223 /* Check that a trailer byte is reasonable. */
224 #define TRLR_CHECK(ch) (((ch) & TRLR_OFFSET) == TRLR_OFFSET)
226 /* Get data from the trailer. This evaluates its argument multiple
228 #define TRLR_GET_CKSUM(trlr) \
229 ((((trlr)[TRLR_INDX_CSUM1] & 0x3f) << 12) \
230 + (((trlr)[TRLR_INDX_CSUM2] & 0x3f) << 6) \
231 + ((trlr)[TRLR_INDX_CSUM3] & 0x3f))
233 /* The sequence number modulos. */
234 #define SEQ_MODULOS (64)
236 /* Set to 1 if the target is open. */
237 static int mips_is_open
;
239 /* Set to 1 while the connection is being initialized. */
240 static int mips_initializing
;
242 /* The next sequence number to send. */
243 static int mips_send_seq
;
245 /* The next sequence number we expect to receive. */
246 static int mips_receive_seq
;
248 /* The time to wait before retransmitting a packet, in seconds. */
249 static int mips_retransmit_wait
= 3;
251 /* The number of times to try retransmitting a packet before giving up. */
252 static int mips_send_retries
= 10;
254 /* The number of garbage characters to accept when looking for an
255 SYN for the next packet. */
256 static int mips_syn_garbage
= 1050;
258 /* The time to wait for a packet, in seconds. */
259 static int mips_receive_wait
= 5;
261 /* Set if we have sent a packet to the board but have not yet received
263 static int mips_need_reply
= 0;
265 /* Handle used to access serial I/O stream. */
266 static serial_t mips_desc
;
268 /* Handle low-level error that we can't recover from. Note that just
269 error()ing out from target_wait or some such low-level place will cause
270 all hell to break loose--the rest of GDB will tend to get left in an
271 inconsistent state. */
274 mips_error (va_alist
)
281 target_terminal_ours ();
282 wrap_here(""); /* Force out any buffered output */
283 gdb_flush (gdb_stdout
);
285 fprintf_filtered (gdb_stderr
, error_pre_print
);
286 string
= va_arg (args
, char *);
287 vfprintf_filtered (gdb_stderr
, string
, args
);
288 fprintf_filtered (gdb_stderr
, "\n");
291 /* Clean up in such a way that mips_close won't try to talk to the
292 board (it almost surely won't work since we weren't able to talk to
295 SERIAL_CLOSE (mips_desc
);
297 printf_unfiltered ("Ending remote MIPS debugging.\n");
298 target_mourn_inferior ();
300 return_to_top_level (RETURN_ERROR
);
303 /* Read a character from the remote, aborting on error. Returns
304 SERIAL_TIMEOUT on timeout (since that's what SERIAL_READCHAR
305 returns). FIXME: If we see the string "<IDT>" from the board, then
306 we are debugging on the main console port, and we have somehow
307 dropped out of remote debugging mode. In this case, we
308 automatically go back in to remote debugging mode. This is a hack,
309 put in because I can't find any way for a program running on the
310 remote board to terminate without also ending remote debugging
311 mode. I assume users won't have any trouble with this; for one
312 thing, the IDT documentation generally assumes that the remote
313 debugging port is not the console port. This is, however, very
314 convenient for DejaGnu when you only have one connected serial
318 mips_readchar (timeout
)
322 static int state
= 0;
323 static char nextstate
[5] = { '<', 'I', 'D', 'T', '>' };
327 ch
= SERIAL_READCHAR (mips_desc
, timeout
);
328 if (ch
== SERIAL_EOF
)
329 mips_error ("End of file from remote");
330 if (ch
== SERIAL_ERROR
)
331 mips_error ("Error reading from remote: %s", safe_strerror (errno
));
332 if (sr_get_debug () > 1)
334 /* Don't use _filtered; we can't deal with a QUIT out of
335 target_wait, and I think this might be called from there. */
336 if (ch
!= SERIAL_TIMEOUT
)
337 printf_unfiltered ("Read '%c' %d 0x%x\n", ch
, ch
, ch
);
339 printf_unfiltered ("Timed out in read\n");
342 /* If we have seen <IDT> and we either time out, or we see a @
343 (which was echoed from a packet we sent), reset the board as
344 described above. The first character in a packet after the SYN
345 (which is not echoed) is always an @ unless the packet is more
346 than 64 characters long, which ours never are. */
347 if ((ch
== SERIAL_TIMEOUT
|| ch
== '@')
349 && ! mips_initializing
)
351 if (sr_get_debug () > 0)
352 /* Don't use _filtered; we can't deal with a QUIT out of
353 target_wait, and I think this might be called from there. */
354 printf_unfiltered ("Reinitializing MIPS debugging mode\n");
355 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
363 mips_error ("Remote board reset");
366 if (ch
== nextstate
[state
])
374 /* Get a packet header, putting the data in the supplied buffer.
375 PGARBAGE is a pointer to the number of garbage characters received
376 so far. CH is the last character received. Returns 0 for success,
377 or -1 for timeout. */
380 mips_receive_header (hdr
, pgarbage
, ch
, timeout
)
390 /* Wait for a SYN. mips_syn_garbage is intended to prevent
391 sitting here indefinitely if the board sends us one garbage
392 character per second. ch may already have a value from the
393 last time through the loop. */
396 ch
= mips_readchar (timeout
);
397 if (ch
== SERIAL_TIMEOUT
)
401 /* Printing the character here lets the user of gdb see
402 what the program is outputting, if the debugging is
403 being done on the console port. Don't use _filtered;
404 we can't deal with a QUIT out of target_wait. */
405 if (! mips_initializing
|| sr_get_debug () > 0)
407 if (ch
< 0x20 && ch
!= '\n')
409 putchar_unfiltered ('^');
410 putchar_unfiltered (ch
+ 0x40);
413 putchar_unfiltered (ch
);
414 gdb_flush (gdb_stdout
);
418 if (*pgarbage
> mips_syn_garbage
)
419 mips_error ("Remote debugging protocol failure");
423 /* Get the packet header following the SYN. */
424 for (i
= 1; i
< HDR_LENGTH
; i
++)
426 ch
= mips_readchar (timeout
);
427 if (ch
== SERIAL_TIMEOUT
)
430 /* Make sure this is a header byte. */
431 if (ch
== SYN
|| ! HDR_CHECK (ch
))
437 /* If we got the complete header, we can return. Otherwise we
438 loop around and keep looking for SYN. */
444 /* Get a packet header, putting the data in the supplied buffer.
445 PGARBAGE is a pointer to the number of garbage characters received
446 so far. The last character read is returned in *PCH. Returns 0
447 for success, -1 for timeout, -2 for error. */
450 mips_receive_trailer (trlr
, pgarbage
, pch
, timeout
)
459 for (i
= 0; i
< TRLR_LENGTH
; i
++)
461 ch
= mips_readchar (timeout
);
463 if (ch
== SERIAL_TIMEOUT
)
465 if (! TRLR_CHECK (ch
))
472 /* Get the checksum of a packet. HDR points to the packet header.
473 DATA points to the packet data. LEN is the length of DATA. */
476 mips_cksum (hdr
, data
, len
)
477 const unsigned char *hdr
;
478 const unsigned char *data
;
481 register const unsigned char *p
;
487 /* The initial SYN is not included in the checksum. */
501 /* Send a packet containing the given ASCII string. */
504 mips_send_packet (s
, get_ack
)
509 unsigned char *packet
;
514 if (len
> DATA_MAXLEN
)
515 mips_error ("MIPS protocol data packet too long: %s", s
);
517 packet
= (unsigned char *) alloca (HDR_LENGTH
+ len
+ TRLR_LENGTH
+ 1);
519 packet
[HDR_INDX_SYN
] = HDR_SET_SYN (1, len
, mips_send_seq
);
520 packet
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (1, len
, mips_send_seq
);
521 packet
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (1, len
, mips_send_seq
);
522 packet
[HDR_INDX_SEQ
] = HDR_SET_SEQ (1, len
, mips_send_seq
);
524 memcpy (packet
+ HDR_LENGTH
, s
, len
);
526 cksum
= mips_cksum (packet
, packet
+ HDR_LENGTH
, len
);
527 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
528 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
529 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
531 /* Increment the sequence number. This will set mips_send_seq to
532 the sequence number we expect in the acknowledgement. */
533 mips_send_seq
= (mips_send_seq
+ 1) % SEQ_MODULOS
;
538 /* We can only have one outstanding data packet, so we just wait for
539 the acknowledgement here. Keep retransmitting the packet until
540 we get one, or until we've tried too many times. */
541 for (try = 0; try < mips_send_retries
; try++)
546 if (sr_get_debug () > 0)
548 /* Don't use _filtered; we can't deal with a QUIT out of
549 target_wait, and I think this might be called from there. */
550 packet
[HDR_LENGTH
+ len
+ TRLR_LENGTH
] = '\0';
551 printf_unfiltered ("Writing \"%s\"\n", packet
+ 1);
554 if (SERIAL_WRITE (mips_desc
, packet
,
555 HDR_LENGTH
+ len
+ TRLR_LENGTH
) != 0)
556 mips_error ("write to target failed: %s", safe_strerror (errno
));
562 unsigned char hdr
[HDR_LENGTH
+ 1];
563 unsigned char trlr
[TRLR_LENGTH
+ 1];
567 /* Get the packet header. If we time out, resend the data
569 err
= mips_receive_header (hdr
, &garbage
, ch
, mips_retransmit_wait
);
575 /* If we get a data packet, assume it is a duplicate and
576 ignore it. FIXME: If the acknowledgement is lost, this
577 data packet may be the packet the remote sends after the
579 if (HDR_IS_DATA (hdr
))
582 /* If the length is not 0, this is a garbled packet. */
583 if (HDR_GET_LEN (hdr
) != 0)
586 /* Get the packet trailer. */
587 err
= mips_receive_trailer (trlr
, &garbage
, &ch
,
588 mips_retransmit_wait
);
590 /* If we timed out, resend the data packet. */
594 /* If we got a bad character, reread the header. */
598 /* If the checksum does not match the trailer checksum, this
599 is a bad packet; ignore it. */
600 if (mips_cksum (hdr
, (unsigned char *) NULL
, 0)
601 != TRLR_GET_CKSUM (trlr
))
604 if (sr_get_debug () > 0)
606 hdr
[HDR_LENGTH
] = '\0';
607 trlr
[TRLR_LENGTH
] = '\0';
608 /* Don't use _filtered; we can't deal with a QUIT out of
609 target_wait, and I think this might be called from there. */
610 printf_unfiltered ("Got ack %d \"%s%s\"\n",
611 HDR_GET_SEQ (hdr
), hdr
+ 1, trlr
);
614 /* If this ack is for the current packet, we're done. */
615 seq
= HDR_GET_SEQ (hdr
);
616 if (seq
== mips_send_seq
)
619 /* If this ack is for the last packet, resend the current
621 if ((seq
+ 1) % SEQ_MODULOS
== mips_send_seq
)
624 /* Otherwise this is a bad ack; ignore it. Increment the
625 garbage count to ensure that we do not stay in this loop
631 mips_error ("Remote did not acknowledge packet");
634 /* Receive and acknowledge a packet, returning the data in BUFF (which
635 should be DATA_MAXLEN + 1 bytes). The protocol documentation
636 implies that only the sender retransmits packets, so this code just
637 waits silently for a packet. It returns the length of the received
638 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
639 don't print an error message and return -1. */
642 mips_receive_packet (buff
, throw_error
, timeout
)
650 unsigned char ack
[HDR_LENGTH
+ TRLR_LENGTH
+ 1];
657 unsigned char hdr
[HDR_LENGTH
];
658 unsigned char trlr
[TRLR_LENGTH
];
662 if (mips_receive_header (hdr
, &garbage
, ch
, timeout
) != 0)
665 mips_error ("Timed out waiting for remote packet");
672 /* An acknowledgement is probably a duplicate; ignore it. */
673 if (! HDR_IS_DATA (hdr
))
675 /* Don't use _filtered; we can't deal with a QUIT out of
676 target_wait, and I think this might be called from there. */
677 if (sr_get_debug () > 0)
678 printf_unfiltered ("Ignoring unexpected ACK\n");
682 /* If this is the wrong sequence number, ignore it. */
683 if (HDR_GET_SEQ (hdr
) != mips_receive_seq
)
685 /* Don't use _filtered; we can't deal with a QUIT out of
686 target_wait, and I think this might be called from there. */
687 if (sr_get_debug () > 0)
688 printf_unfiltered ("Ignoring sequence number %d (want %d)\n",
689 HDR_GET_SEQ (hdr
), mips_receive_seq
);
693 len
= HDR_GET_LEN (hdr
);
695 for (i
= 0; i
< len
; i
++)
699 rch
= mips_readchar (timeout
);
705 if (rch
== SERIAL_TIMEOUT
)
708 mips_error ("Timed out waiting for remote packet");
717 /* Don't use _filtered; we can't deal with a QUIT out of
718 target_wait, and I think this might be called from there. */
719 if (sr_get_debug () > 0)
720 printf_unfiltered ("Got new SYN after %d chars (wanted %d)\n",
725 err
= mips_receive_trailer (trlr
, &garbage
, &ch
, timeout
);
729 mips_error ("Timed out waiting for packet");
735 /* Don't use _filtered; we can't deal with a QUIT out of
736 target_wait, and I think this might be called from there. */
737 if (sr_get_debug () > 0)
738 printf_unfiltered ("Got SYN when wanted trailer\n");
742 if (mips_cksum (hdr
, buff
, len
) == TRLR_GET_CKSUM (trlr
))
745 if (sr_get_debug () > 0)
746 /* Don't use _filtered; we can't deal with a QUIT out of
747 target_wait, and I think this might be called from there. */
748 printf_unfiltered ("Bad checksum; data %d, trailer %d\n",
749 mips_cksum (hdr
, buff
, len
),
750 TRLR_GET_CKSUM (trlr
));
752 /* The checksum failed. Send an acknowledgement for the
753 previous packet to tell the remote to resend the packet. */
754 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
755 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
756 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
757 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
759 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
761 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
762 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
763 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
765 if (sr_get_debug () > 0)
767 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
768 /* Don't use _filtered; we can't deal with a QUIT out of
769 target_wait, and I think this might be called from there. */
770 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
774 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
777 mips_error ("write to target failed: %s", safe_strerror (errno
));
783 if (sr_get_debug () > 0)
786 /* Don't use _filtered; we can't deal with a QUIT out of
787 target_wait, and I think this might be called from there. */
788 printf_unfiltered ("Got packet \"%s\"\n", buff
);
791 /* We got the packet. Send an acknowledgement. */
792 mips_receive_seq
= (mips_receive_seq
+ 1) % SEQ_MODULOS
;
794 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
795 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
796 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
797 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
799 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
801 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
802 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
803 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
805 if (sr_get_debug () > 0)
807 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
808 /* Don't use _filtered; we can't deal with a QUIT out of
809 target_wait, and I think this might be called from there. */
810 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
814 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
817 mips_error ("write to target failed: %s", safe_strerror (errno
));
825 /* Optionally send a request to the remote system and optionally wait
826 for the reply. This implements the remote debugging protocol,
827 which is built on top of the packet protocol defined above. Each
828 request has an ADDR argument and a DATA argument. The following
829 requests are defined:
831 \0 don't send a request; just wait for a reply
832 i read word from instruction space at ADDR
833 d read word from data space at ADDR
834 I write DATA to instruction space at ADDR
835 D write DATA to data space at ADDR
836 r read register number ADDR
837 R set register number ADDR to value DATA
838 c continue execution (if ADDR != 1, set pc to ADDR)
839 s single step (if ADDR != 1, set pc to ADDR)
841 The read requests return the value requested. The write requests
842 return the previous value in the changed location. The execution
843 requests return a UNIX wait value (the approximate signal which
844 caused execution to stop is in the upper eight bits).
846 If PERR is not NULL, this function waits for a reply. If an error
847 occurs, it sets *PERR to 1 and sets errno according to what the
848 target board reports. */
851 mips_request (cmd
, addr
, data
, perr
, timeout
)
858 char buff
[DATA_MAXLEN
+ 1];
868 fatal ("mips_request: Trying to send command before reply");
869 sprintf (buff
, "0x0 %c 0x%x 0x%x", cmd
, addr
, data
);
870 mips_send_packet (buff
, 1);
874 if (perr
== (int *) NULL
)
877 if (! mips_need_reply
)
878 fatal ("mips_request: Trying to get reply before command");
882 len
= mips_receive_packet (buff
, 1, timeout
);
885 if (sscanf (buff
, "0x%x %c 0x%x 0x%x",
886 &rpid
, &rcmd
, &rerrflg
, &rresponse
) != 4
887 || (cmd
!= '\0' && rcmd
!= cmd
))
888 mips_error ("Bad response from remote board");
894 /* FIXME: This will returns MIPS errno numbers, which may or may
895 not be the same as errno values used on other systems. If
896 they stick to common errno values, they will be the same, but
897 if they don't, they must be translated. */
908 mips_initialize_cleanups (arg
)
911 mips_initializing
= 0;
914 /* Initialize a new connection to the MIPS board, and make sure we are
921 char buff
[DATA_MAXLEN
+ 1];
923 struct cleanup
*old_cleanups
= make_cleanup (mips_initialize_cleanups
, NULL
);
925 /* What is this code doing here? I don't see any way it can happen, and
926 it might mean mips_initializing didn't get cleared properly.
927 So I'll make it a warning. */
928 if (mips_initializing
)
930 warning ("internal error: mips_initialize called twice");
934 mips_initializing
= 1;
937 mips_receive_seq
= 0;
939 /* The board seems to want to send us a packet. I don't know what
940 it means. The packet seems to be triggered by a carriage return
941 character, although perhaps any character would do. */
943 /* FIXME check the result from this */
944 SERIAL_WRITE (mips_desc
, &cr
, 1);
946 if (mips_receive_packet (buff
, 0, 3) < 0)
950 /* We did not receive the packet we expected; try resetting the
951 board and trying again. */
952 printf_filtered ("Failed to initialize; trying to reset board\n");
954 SERIAL_WRITE (mips_desc
, &cc
, 1);
956 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
959 SERIAL_WRITE (mips_desc
, &cr
, 1);
961 mips_receive_packet (buff
, 1, 3);
963 do_cleanups (old_cleanups
);
965 /* If this doesn't call error, we have connected; we don't care if
966 the request itself succeeds or fails. */
967 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err
,
971 /* Open a connection to the remote board. */
974 mips_open (name
, from_tty
)
982 "To open a MIPS remote debugging connection, you need to specify what serial\n\
983 device is attached to the target board (e.g., /dev/ttya).");
985 target_preopen (from_tty
);
988 unpush_target (&mips_ops
);
990 mips_desc
= SERIAL_OPEN (name
);
991 if (mips_desc
== (serial_t
) NULL
)
992 perror_with_name (name
);
996 if (SERIAL_SETBAUDRATE (mips_desc
, baud_rate
))
998 SERIAL_CLOSE (mips_desc
);
999 perror_with_name (name
);
1003 SERIAL_RAW (mips_desc
);
1010 printf_unfiltered ("Remote MIPS debugging using %s\n", name
);
1012 /* Switch to using remote target now. */
1013 push_target (&mips_ops
);
1015 /* FIXME: Should we call start_remote here? */
1017 /* Try to figure out the processor model if possible. */
1018 ptype
= mips_read_processor_type ();
1020 mips_set_processor_type_command (strsave (ptype
), 0);
1023 /* Close a connection to the remote board. */
1026 mips_close (quitting
)
1035 /* Get the board out of remote debugging mode. */
1036 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err
,
1039 SERIAL_CLOSE (mips_desc
);
1043 /* Detach from the remote board. */
1046 mips_detach (args
, from_tty
)
1051 error ("Argument given to \"detach\" when remotely debugging.");
1055 printf_unfiltered ("Ending remote MIPS debugging.\n");
1058 /* Tell the target board to resume. This does not wait for a reply
1062 mips_resume (pid
, step
, siggnal
)
1064 enum target_signal siggnal
;
1066 if (siggnal
!= TARGET_SIGNAL_0
)
1068 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1069 target_signal_to_name (siggnal
));
1071 mips_request (step
? 's' : 'c',
1078 /* Return the signal corresponding to SIG, where SIG is the number which
1079 the MIPS protocol uses for the signal. */
1081 mips_signal_from_protocol (sig
)
1084 /* We allow a few more signals than the IDT board actually returns, on
1085 the theory that there is at least *some* hope that perhaps the numbering
1086 for these signals is widely agreed upon. */
1089 return TARGET_SIGNAL_UNKNOWN
;
1091 /* Don't want to use target_signal_from_host because we are converting
1092 from MIPS signal numbers, not host ones. Our internal numbers
1093 match the MIPS numbers for the signals the board can return, which
1094 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1095 return (enum target_signal
) sig
;
1098 /* Wait until the remote stops, and return a wait status. */
1101 mips_wait (pid
, status
)
1103 struct target_waitstatus
*status
;
1108 /* If we have not sent a single step or continue command, then the
1109 board is waiting for us to do something. Return a status
1110 indicating that it is stopped. */
1111 if (! mips_need_reply
)
1113 status
->kind
= TARGET_WAITKIND_STOPPED
;
1114 status
->value
.sig
= TARGET_SIGNAL_TRAP
;
1118 /* No timeout; we sit here as long as the program continues to execute. */
1119 rstatus
= mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err
, -1);
1121 mips_error ("Remote failure: %s", safe_strerror (errno
));
1123 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1124 and so on, because the constants we want here are determined by the
1125 MIPS protocol and have nothing to do with what host we are running on. */
1126 if ((rstatus
& 0377) == 0)
1128 status
->kind
= TARGET_WAITKIND_EXITED
;
1129 status
->value
.integer
= (((rstatus
) >> 8) & 0377);
1131 else if ((rstatus
& 0377) == 0177)
1133 status
->kind
= TARGET_WAITKIND_STOPPED
;
1134 status
->value
.sig
= mips_signal_from_protocol (((rstatus
) >> 8) & 0377);
1138 status
->kind
= TARGET_WAITKIND_SIGNALLED
;
1139 status
->value
.sig
= mips_signal_from_protocol (rstatus
& 0177);
1145 /* We have to map between the register numbers used by gdb and the
1146 register numbers used by the debugging protocol. This function
1147 assumes that we are using tm-mips.h. */
1149 #define REGNO_OFFSET 96
1152 mips_map_regno (regno
)
1157 if (regno
>= FP0_REGNUM
&& regno
< FP0_REGNUM
+ 32)
1158 return regno
- FP0_REGNUM
+ 32;
1162 return REGNO_OFFSET
+ 0;
1164 return REGNO_OFFSET
+ 1;
1166 return REGNO_OFFSET
+ 2;
1168 return REGNO_OFFSET
+ 3;
1170 return REGNO_OFFSET
+ 4;
1172 return REGNO_OFFSET
+ 5;
1174 /* FIXME: Is there a way to get the status register? */
1179 /* Fetch the remote registers. */
1182 mips_fetch_registers (regno
)
1185 unsigned LONGEST val
;
1190 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1191 mips_fetch_registers (regno
);
1195 if (regno
== FP_REGNUM
|| regno
== ZERO_REGNUM
)
1196 /* FP_REGNUM on the mips is a hack which is just supposed to read
1197 zero (see also mips-nat.c). */
1201 val
= mips_request ('r', (unsigned int) mips_map_regno (regno
),
1202 (unsigned int) 0, &err
, mips_receive_wait
);
1204 mips_error ("Can't read register %d: %s", regno
,
1205 safe_strerror (errno
));
1209 char buf
[MAX_REGISTER_RAW_SIZE
];
1211 /* We got the number the register holds, but gdb expects to see a
1212 value in the target byte ordering. */
1213 store_unsigned_integer (buf
, REGISTER_RAW_SIZE (regno
), val
);
1214 supply_register (regno
, buf
);
1218 /* Prepare to store registers. The MIPS protocol can store individual
1219 registers, so this function doesn't have to do anything. */
1222 mips_prepare_to_store ()
1226 /* Store remote register(s). */
1229 mips_store_registers (regno
)
1236 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1237 mips_store_registers (regno
);
1241 mips_request ('R', (unsigned int) mips_map_regno (regno
),
1242 (unsigned int) read_register (regno
),
1243 &err
, mips_receive_wait
);
1245 mips_error ("Can't write register %d: %s", regno
, safe_strerror (errno
));
1248 /* Fetch a word from the target board. */
1251 mips_fetch_word (addr
)
1257 val
= mips_request ('d', (unsigned int) addr
, (unsigned int) 0, &err
,
1261 /* Data space failed; try instruction space. */
1262 val
= mips_request ('i', (unsigned int) addr
, (unsigned int) 0, &err
,
1265 mips_error ("Can't read address 0x%x: %s", addr
, safe_strerror (errno
));
1270 /* Store a word to the target board. Returns errno code or zero for
1271 success. If OLD_CONTENTS is non-NULL, put the old contents of that
1272 memory location there. */
1275 mips_store_word (addr
, val
, old_contents
)
1281 unsigned int oldcontents
;
1283 oldcontents
= mips_request ('D', (unsigned int) addr
, (unsigned int) val
,
1288 /* Data space failed; try instruction space. */
1289 oldcontents
= mips_request ('I', (unsigned int) addr
,
1290 (unsigned int) val
, &err
,
1295 if (old_contents
!= NULL
)
1296 store_unsigned_integer (old_contents
, 4, oldcontents
);
1300 /* Read or write LEN bytes from inferior memory at MEMADDR,
1301 transferring to or from debugger address MYADDR. Write to inferior
1302 if SHOULD_WRITE is nonzero. Returns length of data written or
1303 read; 0 for error. Note that protocol gives us the correct value
1304 for a longword, since it transfers values in ASCII. We want the
1305 byte values, so we have to swap the longword values. */
1308 mips_xfer_memory (memaddr
, myaddr
, len
, write
, ignore
)
1313 struct target_ops
*ignore
;
1316 /* Round starting address down to longword boundary. */
1317 register CORE_ADDR addr
= memaddr
&~ 3;
1318 /* Round ending address up; get number of longwords that makes. */
1319 register int count
= (((memaddr
+ len
) - addr
) + 3) / 4;
1320 /* Allocate buffer of that many longwords. */
1321 register char *buffer
= alloca (count
* 4);
1327 /* Fill start and end extra bytes of buffer with existing data. */
1328 if (addr
!= memaddr
|| len
< 4)
1330 /* Need part of initial word -- fetch it. */
1331 store_unsigned_integer (&buffer
[0], 4, mips_fetch_word (addr
));
1336 /* Need part of last word -- fetch it. FIXME: we do this even
1337 if we don't need it. */
1338 store_unsigned_integer (&buffer
[(count
- 1) * 4], 4,
1339 mips_fetch_word (addr
+ (count
- 1) * 4));
1342 /* Copy data to be written over corresponding part of buffer */
1344 memcpy ((char *) buffer
+ (memaddr
& 3), myaddr
, len
);
1346 /* Write the entire buffer. */
1348 for (i
= 0; i
< count
; i
++, addr
+= 4)
1350 status
= mips_store_word (addr
,
1351 extract_unsigned_integer (&buffer
[i
*4], 4),
1353 /* Report each kilobyte (we download 32-bit words at a time) */
1356 printf_unfiltered ("*");
1364 /* FIXME: Do we want a QUIT here? */
1367 printf_unfiltered ("\n");
1371 /* Read all the longwords */
1372 for (i
= 0; i
< count
; i
++, addr
+= 4)
1374 store_unsigned_integer (&buffer
[i
*4], 4, mips_fetch_word (addr
));
1378 /* Copy appropriate bytes out of the buffer. */
1379 memcpy (myaddr
, buffer
+ (memaddr
& 3), len
);
1384 /* Print info on this target. */
1387 mips_files_info (ignore
)
1388 struct target_ops
*ignore
;
1390 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1393 /* Kill the process running on the board. This will actually only
1394 work if we are doing remote debugging over the console input. I
1395 think that if IDT/sim had the remote debug interrupt enabled on the
1396 right port, we could interrupt the process with a break signal. */
1408 SERIAL_WRITE (mips_desc
, &cc
, 1);
1410 target_mourn_inferior ();
1415 /* Start running on the target board. */
1418 mips_create_inferior (execfile
, args
, env
)
1428 Can't pass arguments to remote MIPS board; arguments ignored.");
1429 /* And don't try to use them on the next "run" command. */
1430 execute_command ("set args", 0);
1433 if (execfile
== 0 || exec_bfd
== 0)
1434 error ("No executable file specified");
1436 entry_pt
= (CORE_ADDR
) bfd_get_start_address (exec_bfd
);
1438 init_wait_for_inferior ();
1440 /* FIXME: Should we set inferior_pid here? */
1442 proceed (entry_pt
, TARGET_SIGNAL_DEFAULT
, 0);
1445 /* Clean up after a process. Actually nothing to do. */
1448 mips_mourn_inferior ()
1450 unpush_target (&mips_ops
);
1451 generic_mourn_inferior ();
1454 /* We can write a breakpoint and read the shadow contents in one
1457 /* The IDT board uses an unusual breakpoint value, and sometimes gets
1458 confused when it sees the usual MIPS breakpoint instruction. */
1460 #define BREAK_INSN (0x00000a0d)
1461 #define BREAK_INSN_SIZE (4)
1463 /* Insert a breakpoint on targets that don't have any better breakpoint
1464 support. We read the contents of the target location and stash it,
1465 then overwrite it with a breakpoint instruction. ADDR is the target
1466 location in the target machine. CONTENTS_CACHE is a pointer to
1467 memory allocated for saving the target contents. It is guaranteed
1468 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1469 is accomplished via BREAKPOINT_MAX). */
1472 mips_insert_breakpoint (addr
, contents_cache
)
1474 char *contents_cache
;
1478 return mips_store_word (addr
, BREAK_INSN
, contents_cache
);
1482 mips_remove_breakpoint (addr
, contents_cache
)
1484 char *contents_cache
;
1486 return target_write_memory (addr
, contents_cache
, BREAK_INSN_SIZE
);
1489 /* The target vector. */
1491 struct target_ops mips_ops
=
1493 "mips", /* to_shortname */
1494 "Remote MIPS debugging over serial line", /* to_longname */
1496 Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1497 The argument is the device it is connected to or, if it contains a colon,\n\
1498 HOST:PORT to access a board over a network", /* to_doc */
1499 mips_open
, /* to_open */
1500 mips_close
, /* to_close */
1501 NULL
, /* to_attach */
1502 mips_detach
, /* to_detach */
1503 mips_resume
, /* to_resume */
1504 mips_wait
, /* to_wait */
1505 mips_fetch_registers
, /* to_fetch_registers */
1506 mips_store_registers
, /* to_store_registers */
1507 mips_prepare_to_store
, /* to_prepare_to_store */
1508 mips_xfer_memory
, /* to_xfer_memory */
1509 mips_files_info
, /* to_files_info */
1510 mips_insert_breakpoint
, /* to_insert_breakpoint */
1511 mips_remove_breakpoint
, /* to_remove_breakpoint */
1512 NULL
, /* to_terminal_init */
1513 NULL
, /* to_terminal_inferior */
1514 NULL
, /* to_terminal_ours_for_output */
1515 NULL
, /* to_terminal_ours */
1516 NULL
, /* to_terminal_info */
1517 mips_kill
, /* to_kill */
1518 generic_load
, /* to_load */
1519 NULL
, /* to_lookup_symbol */
1520 mips_create_inferior
, /* to_create_inferior */
1521 mips_mourn_inferior
, /* to_mourn_inferior */
1522 NULL
, /* to_can_run */
1523 NULL
, /* to_notice_signals */
1525 process_stratum
, /* to_stratum */
1527 1, /* to_has_all_memory */
1528 1, /* to_has_memory */
1529 1, /* to_has_stack */
1530 1, /* to_has_registers */
1531 1, /* to_has_execution */
1532 NULL
, /* sections */
1533 NULL
, /* sections_end */
1534 OPS_MAGIC
/* to_magic */
1538 _initialize_remote_mips ()
1540 add_target (&mips_ops
);
1543 add_set_cmd ("timeout", no_class
, var_zinteger
,
1544 (char *) &mips_receive_wait
,
1545 "Set timeout in seconds for remote MIPS serial I/O.",
1550 add_set_cmd ("retransmit-timeout", no_class
, var_zinteger
,
1551 (char *) &mips_retransmit_wait
,
1552 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1553 This is the number of seconds to wait for an acknowledgement to a packet\n\
1554 before resending the packet.", &setlist
),