1 /* Remote debugging interface for MIPS remote debugging protocol.
2 Copyright 1993, 1994, 1995 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"
34 #ifdef ANSI_PROTOTYPES
40 extern char *mips_read_processor_type
PARAMS ((void));
42 extern void mips_set_processor_type_command
PARAMS ((char *, int));
45 /* Prototypes for local functions. */
47 static int mips_readchar
PARAMS ((int timeout
));
49 static int mips_receive_header
PARAMS ((unsigned char *hdr
, int *pgarbage
,
50 int ch
, int timeout
));
52 static int mips_receive_trailer
PARAMS ((unsigned char *trlr
, int *pgarbage
,
53 int *pch
, int timeout
));
55 static int mips_cksum
PARAMS ((const unsigned char *hdr
,
56 const unsigned char *data
,
59 static void mips_send_packet
PARAMS ((const char *s
, int get_ack
));
61 static int mips_receive_packet
PARAMS ((char *buff
, int throw_error
,
64 static int mips_request
PARAMS ((char cmd
, unsigned int addr
,
65 unsigned int data
, int *perr
, int timeout
));
67 static void mips_initialize
PARAMS ((void));
69 static void mips_open
PARAMS ((char *name
, int from_tty
));
71 static void mips_close
PARAMS ((int quitting
));
73 static void mips_detach
PARAMS ((char *args
, int from_tty
));
75 static void mips_resume
PARAMS ((int pid
, int step
,
76 enum target_signal siggnal
));
78 static int mips_wait
PARAMS ((int pid
, struct target_waitstatus
*status
));
80 static int mips_map_regno
PARAMS ((int regno
));
82 static void mips_fetch_registers
PARAMS ((int regno
));
84 static void mips_prepare_to_store
PARAMS ((void));
86 static void mips_store_registers
PARAMS ((int regno
));
88 static int mips_fetch_word
PARAMS ((CORE_ADDR addr
));
90 static int mips_store_word
PARAMS ((CORE_ADDR addr
, int value
,
93 static int mips_xfer_memory
PARAMS ((CORE_ADDR memaddr
, char *myaddr
, int len
,
94 int write
, struct target_ops
*ignore
));
96 static void mips_files_info
PARAMS ((struct target_ops
*ignore
));
98 static void mips_create_inferior
PARAMS ((char *execfile
, char *args
,
101 static void mips_mourn_inferior
PARAMS ((void));
103 /* A forward declaration. */
104 extern struct target_ops mips_ops
;
106 /* The MIPS remote debugging interface is built on top of a simple
107 packet protocol. Each packet is organized as follows:
109 SYN The first character is always a SYN (ASCII 026, or ^V). SYN
110 may not appear anywhere else in the packet. Any time a SYN is
111 seen, a new packet should be assumed to have begun.
114 This byte contains the upper five bits of the logical length
115 of the data section, plus a single bit indicating whether this
116 is a data packet or an acknowledgement. The documentation
117 indicates that this bit is 1 for a data packet, but the actual
118 board uses 1 for an acknowledgement. The value of the byte is
119 0x40 + (ack ? 0x20 : 0) + (len >> 6)
120 (we always have 0 <= len < 1024). Acknowledgement packets do
121 not carry data, and must have a data length of 0.
123 LEN1 This byte contains the lower six bits of the logical length of
124 the data section. The value is
127 SEQ This byte contains the six bit sequence number of the packet.
130 An acknowlegment packet contains the sequence number of the
131 packet being acknowledged plus 1 modulo 64. Data packets are
132 transmitted in sequence. There may only be one outstanding
133 unacknowledged data packet at a time. The sequence numbers
134 are independent in each direction. If an acknowledgement for
135 the previous packet is received (i.e., an acknowledgement with
136 the sequence number of the packet just sent) the packet just
137 sent should be retransmitted. If no acknowledgement is
138 received within a timeout period, the packet should be
139 retransmitted. This has an unfortunate failure condition on a
140 high-latency line, as a delayed acknowledgement may lead to an
141 endless series of duplicate packets.
143 DATA The actual data bytes follow. The following characters are
144 escaped inline with DLE (ASCII 020, or ^P):
150 The additional DLE characters are not counted in the logical
151 length stored in the TYPE_LEN and LEN1 bytes.
156 These bytes contain an 18 bit checksum of the complete
157 contents of the packet excluding the SEQ byte and the
158 CSUM[123] bytes. The checksum is simply the twos complement
159 addition of all the bytes treated as unsigned characters. The
160 values of the checksum bytes are:
161 CSUM1: 0x40 + ((cksum >> 12) & 0x3f)
162 CSUM2: 0x40 + ((cksum >> 6) & 0x3f)
163 CSUM3: 0x40 + (cksum & 0x3f)
165 It happens that the MIPS remote debugging protocol always
166 communicates with ASCII strings. Because of this, this
167 implementation doesn't bother to handle the DLE quoting mechanism,
168 since it will never be required. */
170 /* The SYN character which starts each packet. */
173 /* The 0x40 used to offset each packet (this value ensures that all of
174 the header and trailer bytes, other than SYN, are printable ASCII
176 #define HDR_OFFSET 0x40
178 /* The indices of the bytes in the packet header. */
179 #define HDR_INDX_SYN 0
180 #define HDR_INDX_TYPE_LEN 1
181 #define HDR_INDX_LEN1 2
182 #define HDR_INDX_SEQ 3
185 /* The data/ack bit in the TYPE_LEN header byte. */
186 #define TYPE_LEN_DA_BIT 0x20
187 #define TYPE_LEN_DATA 0
188 #define TYPE_LEN_ACK TYPE_LEN_DA_BIT
190 /* How to compute the header bytes. */
191 #define HDR_SET_SYN(data, len, seq) (SYN)
192 #define HDR_SET_TYPE_LEN(data, len, seq) \
194 + ((data) ? TYPE_LEN_DATA : TYPE_LEN_ACK) \
195 + (((len) >> 6) & 0x1f))
196 #define HDR_SET_LEN1(data, len, seq) (HDR_OFFSET + ((len) & 0x3f))
197 #define HDR_SET_SEQ(data, len, seq) (HDR_OFFSET + (seq))
199 /* Check that a header byte is reasonable. */
200 #define HDR_CHECK(ch) (((ch) & HDR_OFFSET) == HDR_OFFSET)
202 /* Get data from the header. These macros evaluate their argument
204 #define HDR_IS_DATA(hdr) \
205 (((hdr)[HDR_INDX_TYPE_LEN] & TYPE_LEN_DA_BIT) == TYPE_LEN_DATA)
206 #define HDR_GET_LEN(hdr) \
207 ((((hdr)[HDR_INDX_TYPE_LEN] & 0x1f) << 6) + (((hdr)[HDR_INDX_LEN1] & 0x3f)))
208 #define HDR_GET_SEQ(hdr) ((hdr)[HDR_INDX_SEQ] & 0x3f)
210 /* The maximum data length. */
211 #define DATA_MAXLEN 1023
213 /* The trailer offset. */
214 #define TRLR_OFFSET HDR_OFFSET
216 /* The indices of the bytes in the packet trailer. */
217 #define TRLR_INDX_CSUM1 0
218 #define TRLR_INDX_CSUM2 1
219 #define TRLR_INDX_CSUM3 2
220 #define TRLR_LENGTH 3
222 /* How to compute the trailer bytes. */
223 #define TRLR_SET_CSUM1(cksum) (TRLR_OFFSET + (((cksum) >> 12) & 0x3f))
224 #define TRLR_SET_CSUM2(cksum) (TRLR_OFFSET + (((cksum) >> 6) & 0x3f))
225 #define TRLR_SET_CSUM3(cksum) (TRLR_OFFSET + (((cksum) ) & 0x3f))
227 /* Check that a trailer byte is reasonable. */
228 #define TRLR_CHECK(ch) (((ch) & TRLR_OFFSET) == TRLR_OFFSET)
230 /* Get data from the trailer. This evaluates its argument multiple
232 #define TRLR_GET_CKSUM(trlr) \
233 ((((trlr)[TRLR_INDX_CSUM1] & 0x3f) << 12) \
234 + (((trlr)[TRLR_INDX_CSUM2] & 0x3f) << 6) \
235 + ((trlr)[TRLR_INDX_CSUM3] & 0x3f))
237 /* The sequence number modulos. */
238 #define SEQ_MODULOS (64)
240 /* Set to 1 if the target is open. */
241 static int mips_is_open
;
243 /* Set to 1 while the connection is being initialized. */
244 static int mips_initializing
;
246 /* The next sequence number to send. */
247 static int mips_send_seq
;
249 /* The next sequence number we expect to receive. */
250 static int mips_receive_seq
;
252 /* The time to wait before retransmitting a packet, in seconds. */
253 static int mips_retransmit_wait
= 3;
255 /* The number of times to try retransmitting a packet before giving up. */
256 static int mips_send_retries
= 10;
258 /* The number of garbage characters to accept when looking for an
259 SYN for the next packet. */
260 static int mips_syn_garbage
= 1050;
262 /* The time to wait for a packet, in seconds. */
263 static int mips_receive_wait
= 5;
265 /* Set if we have sent a packet to the board but have not yet received
267 static int mips_need_reply
= 0;
269 /* Handle used to access serial I/O stream. */
270 static serial_t mips_desc
;
272 /* Handle low-level error that we can't recover from. Note that just
273 error()ing out from target_wait or some such low-level place will cause
274 all hell to break loose--the rest of GDB will tend to get left in an
275 inconsistent state. */
278 #ifdef ANSI_PROTOTYPES
279 mips_error (char *string
, ...)
281 mips_error (va_alist
)
287 #ifdef ANSI_PROTOTYPES
288 va_start (args
, string
);
292 string
= va_arg (args
, char *);
295 target_terminal_ours ();
296 wrap_here(""); /* Force out any buffered output */
297 gdb_flush (gdb_stdout
);
299 fprintf_filtered (gdb_stderr
, error_pre_print
);
300 vfprintf_filtered (gdb_stderr
, string
, args
);
301 fprintf_filtered (gdb_stderr
, "\n");
304 /* Clean up in such a way that mips_close won't try to talk to the
305 board (it almost surely won't work since we weren't able to talk to
308 SERIAL_CLOSE (mips_desc
);
310 printf_unfiltered ("Ending remote MIPS debugging.\n");
311 target_mourn_inferior ();
313 return_to_top_level (RETURN_ERROR
);
316 /* Read a character from the remote, aborting on error. Returns
317 SERIAL_TIMEOUT on timeout (since that's what SERIAL_READCHAR
318 returns). FIXME: If we see the string "<IDT>" from the board, then
319 we are debugging on the main console port, and we have somehow
320 dropped out of remote debugging mode. In this case, we
321 automatically go back in to remote debugging mode. This is a hack,
322 put in because I can't find any way for a program running on the
323 remote board to terminate without also ending remote debugging
324 mode. I assume users won't have any trouble with this; for one
325 thing, the IDT documentation generally assumes that the remote
326 debugging port is not the console port. This is, however, very
327 convenient for DejaGnu when you only have one connected serial
331 mips_readchar (timeout
)
335 static int state
= 0;
336 static char nextstate
[5] = { '<', 'I', 'D', 'T', '>' };
337 #ifdef MAINTENANCE_CMDS
341 if (i
== -1 && watchdog
> 0)
347 ch
= SERIAL_READCHAR (mips_desc
, timeout
);
348 #ifdef MAINTENANCE_CMDS
349 if (ch
== SERIAL_TIMEOUT
&& timeout
== -1) /* Watchdog went off */
351 target_mourn_inferior ();
352 error ("Watchdog has expired. Target detached.\n");
355 if (ch
== SERIAL_EOF
)
356 mips_error ("End of file from remote");
357 if (ch
== SERIAL_ERROR
)
358 mips_error ("Error reading from remote: %s", safe_strerror (errno
));
359 if (sr_get_debug () > 1)
361 /* Don't use _filtered; we can't deal with a QUIT out of
362 target_wait, and I think this might be called from there. */
363 if (ch
!= SERIAL_TIMEOUT
)
364 printf_unfiltered ("Read '%c' %d 0x%x\n", ch
, ch
, ch
);
366 printf_unfiltered ("Timed out in read\n");
369 /* If we have seen <IDT> and we either time out, or we see a @
370 (which was echoed from a packet we sent), reset the board as
371 described above. The first character in a packet after the SYN
372 (which is not echoed) is always an @ unless the packet is more
373 than 64 characters long, which ours never are. */
374 if ((ch
== SERIAL_TIMEOUT
|| ch
== '@')
376 && ! mips_initializing
)
378 if (sr_get_debug () > 0)
379 /* Don't use _filtered; we can't deal with a QUIT out of
380 target_wait, and I think this might be called from there. */
381 printf_unfiltered ("Reinitializing MIPS debugging mode\n");
382 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
390 /* At this point, about the only thing we can do is abort the command
391 in progress and get back to command level as quickly as possible. */
393 error ("Remote board reset, debug protocol re-initialized.");
396 if (ch
== nextstate
[state
])
404 /* Get a packet header, putting the data in the supplied buffer.
405 PGARBAGE is a pointer to the number of garbage characters received
406 so far. CH is the last character received. Returns 0 for success,
407 or -1 for timeout. */
410 mips_receive_header (hdr
, pgarbage
, ch
, timeout
)
420 /* Wait for a SYN. mips_syn_garbage is intended to prevent
421 sitting here indefinitely if the board sends us one garbage
422 character per second. ch may already have a value from the
423 last time through the loop. */
426 ch
= mips_readchar (timeout
);
427 if (ch
== SERIAL_TIMEOUT
)
431 /* Printing the character here lets the user of gdb see
432 what the program is outputting, if the debugging is
433 being done on the console port. Don't use _filtered;
434 we can't deal with a QUIT out of target_wait. */
435 if (! mips_initializing
|| sr_get_debug () > 0)
437 if (ch
< 0x20 && ch
!= '\n')
439 putchar_unfiltered ('^');
440 putchar_unfiltered (ch
+ 0x40);
443 putchar_unfiltered (ch
);
444 gdb_flush (gdb_stdout
);
448 if (*pgarbage
> mips_syn_garbage
)
449 mips_error ("Remote debugging protocol failure");
453 /* Get the packet header following the SYN. */
454 for (i
= 1; i
< HDR_LENGTH
; i
++)
456 ch
= mips_readchar (timeout
);
457 if (ch
== SERIAL_TIMEOUT
)
460 /* Make sure this is a header byte. */
461 if (ch
== SYN
|| ! HDR_CHECK (ch
))
467 /* If we got the complete header, we can return. Otherwise we
468 loop around and keep looking for SYN. */
474 /* Get a packet header, putting the data in the supplied buffer.
475 PGARBAGE is a pointer to the number of garbage characters received
476 so far. The last character read is returned in *PCH. Returns 0
477 for success, -1 for timeout, -2 for error. */
480 mips_receive_trailer (trlr
, pgarbage
, pch
, timeout
)
489 for (i
= 0; i
< TRLR_LENGTH
; i
++)
491 ch
= mips_readchar (timeout
);
493 if (ch
== SERIAL_TIMEOUT
)
495 if (! TRLR_CHECK (ch
))
502 /* Get the checksum of a packet. HDR points to the packet header.
503 DATA points to the packet data. LEN is the length of DATA. */
506 mips_cksum (hdr
, data
, len
)
507 const unsigned char *hdr
;
508 const unsigned char *data
;
511 register const unsigned char *p
;
517 /* The initial SYN is not included in the checksum. */
531 /* Send a packet containing the given ASCII string. */
534 mips_send_packet (s
, get_ack
)
539 unsigned char *packet
;
544 if (len
> DATA_MAXLEN
)
545 mips_error ("MIPS protocol data packet too long: %s", s
);
547 packet
= (unsigned char *) alloca (HDR_LENGTH
+ len
+ TRLR_LENGTH
+ 1);
549 packet
[HDR_INDX_SYN
] = HDR_SET_SYN (1, len
, mips_send_seq
);
550 packet
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (1, len
, mips_send_seq
);
551 packet
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (1, len
, mips_send_seq
);
552 packet
[HDR_INDX_SEQ
] = HDR_SET_SEQ (1, len
, mips_send_seq
);
554 memcpy (packet
+ HDR_LENGTH
, s
, len
);
556 cksum
= mips_cksum (packet
, packet
+ HDR_LENGTH
, len
);
557 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
558 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
559 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
561 /* Increment the sequence number. This will set mips_send_seq to
562 the sequence number we expect in the acknowledgement. */
563 mips_send_seq
= (mips_send_seq
+ 1) % SEQ_MODULOS
;
568 /* We can only have one outstanding data packet, so we just wait for
569 the acknowledgement here. Keep retransmitting the packet until
570 we get one, or until we've tried too many times. */
571 for (try = 0; try < mips_send_retries
; try++)
576 if (sr_get_debug () > 0)
578 /* Don't use _filtered; we can't deal with a QUIT out of
579 target_wait, and I think this might be called from there. */
580 packet
[HDR_LENGTH
+ len
+ TRLR_LENGTH
] = '\0';
581 printf_unfiltered ("Writing \"%s\"\n", packet
+ 1);
584 if (SERIAL_WRITE (mips_desc
, packet
,
585 HDR_LENGTH
+ len
+ TRLR_LENGTH
) != 0)
586 mips_error ("write to target failed: %s", safe_strerror (errno
));
592 unsigned char hdr
[HDR_LENGTH
+ 1];
593 unsigned char trlr
[TRLR_LENGTH
+ 1];
597 /* Get the packet header. If we time out, resend the data
599 err
= mips_receive_header (hdr
, &garbage
, ch
, mips_retransmit_wait
);
605 /* If we get a data packet, assume it is a duplicate and
606 ignore it. FIXME: If the acknowledgement is lost, this
607 data packet may be the packet the remote sends after the
609 if (HDR_IS_DATA (hdr
))
612 /* If the length is not 0, this is a garbled packet. */
613 if (HDR_GET_LEN (hdr
) != 0)
616 /* Get the packet trailer. */
617 err
= mips_receive_trailer (trlr
, &garbage
, &ch
,
618 mips_retransmit_wait
);
620 /* If we timed out, resend the data packet. */
624 /* If we got a bad character, reread the header. */
628 /* If the checksum does not match the trailer checksum, this
629 is a bad packet; ignore it. */
630 if (mips_cksum (hdr
, (unsigned char *) NULL
, 0)
631 != TRLR_GET_CKSUM (trlr
))
634 if (sr_get_debug () > 0)
636 hdr
[HDR_LENGTH
] = '\0';
637 trlr
[TRLR_LENGTH
] = '\0';
638 /* Don't use _filtered; we can't deal with a QUIT out of
639 target_wait, and I think this might be called from there. */
640 printf_unfiltered ("Got ack %d \"%s%s\"\n",
641 HDR_GET_SEQ (hdr
), hdr
+ 1, trlr
);
644 /* If this ack is for the current packet, we're done. */
645 seq
= HDR_GET_SEQ (hdr
);
646 if (seq
== mips_send_seq
)
649 /* If this ack is for the last packet, resend the current
651 if ((seq
+ 1) % SEQ_MODULOS
== mips_send_seq
)
654 /* Otherwise this is a bad ack; ignore it. Increment the
655 garbage count to ensure that we do not stay in this loop
661 mips_error ("Remote did not acknowledge packet");
664 /* Receive and acknowledge a packet, returning the data in BUFF (which
665 should be DATA_MAXLEN + 1 bytes). The protocol documentation
666 implies that only the sender retransmits packets, so this code just
667 waits silently for a packet. It returns the length of the received
668 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
669 don't print an error message and return -1. */
672 mips_receive_packet (buff
, throw_error
, timeout
)
680 unsigned char ack
[HDR_LENGTH
+ TRLR_LENGTH
+ 1];
687 unsigned char hdr
[HDR_LENGTH
];
688 unsigned char trlr
[TRLR_LENGTH
];
692 if (mips_receive_header (hdr
, &garbage
, ch
, timeout
) != 0)
695 mips_error ("Timed out waiting for remote packet");
702 /* An acknowledgement is probably a duplicate; ignore it. */
703 if (! HDR_IS_DATA (hdr
))
705 /* Don't use _filtered; we can't deal with a QUIT out of
706 target_wait, and I think this might be called from there. */
707 if (sr_get_debug () > 0)
708 printf_unfiltered ("Ignoring unexpected ACK\n");
712 /* If this is the wrong sequence number, ignore it. */
713 if (HDR_GET_SEQ (hdr
) != mips_receive_seq
)
715 /* Don't use _filtered; we can't deal with a QUIT out of
716 target_wait, and I think this might be called from there. */
717 if (sr_get_debug () > 0)
718 printf_unfiltered ("Ignoring sequence number %d (want %d)\n",
719 HDR_GET_SEQ (hdr
), mips_receive_seq
);
723 len
= HDR_GET_LEN (hdr
);
725 for (i
= 0; i
< len
; i
++)
729 rch
= mips_readchar (timeout
);
735 if (rch
== SERIAL_TIMEOUT
)
738 mips_error ("Timed out waiting for remote packet");
747 /* Don't use _filtered; we can't deal with a QUIT out of
748 target_wait, and I think this might be called from there. */
749 if (sr_get_debug () > 0)
750 printf_unfiltered ("Got new SYN after %d chars (wanted %d)\n",
755 err
= mips_receive_trailer (trlr
, &garbage
, &ch
, timeout
);
759 mips_error ("Timed out waiting for packet");
765 /* Don't use _filtered; we can't deal with a QUIT out of
766 target_wait, and I think this might be called from there. */
767 if (sr_get_debug () > 0)
768 printf_unfiltered ("Got SYN when wanted trailer\n");
772 if (mips_cksum (hdr
, buff
, len
) == TRLR_GET_CKSUM (trlr
))
775 if (sr_get_debug () > 0)
776 /* Don't use _filtered; we can't deal with a QUIT out of
777 target_wait, and I think this might be called from there. */
778 printf_unfiltered ("Bad checksum; data %d, trailer %d\n",
779 mips_cksum (hdr
, buff
, len
),
780 TRLR_GET_CKSUM (trlr
));
782 /* The checksum failed. Send an acknowledgement for the
783 previous packet to tell the remote to resend the packet. */
784 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
785 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
786 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
787 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
789 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
791 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
792 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
793 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
795 if (sr_get_debug () > 0)
797 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
798 /* Don't use _filtered; we can't deal with a QUIT out of
799 target_wait, and I think this might be called from there. */
800 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
804 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
807 mips_error ("write to target failed: %s", safe_strerror (errno
));
813 if (sr_get_debug () > 0)
816 /* Don't use _filtered; we can't deal with a QUIT out of
817 target_wait, and I think this might be called from there. */
818 printf_unfiltered ("Got packet \"%s\"\n", buff
);
821 /* We got the packet. Send an acknowledgement. */
822 mips_receive_seq
= (mips_receive_seq
+ 1) % SEQ_MODULOS
;
824 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
825 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
826 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
827 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
829 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
831 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
832 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
833 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
835 if (sr_get_debug () > 0)
837 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
838 /* Don't use _filtered; we can't deal with a QUIT out of
839 target_wait, and I think this might be called from there. */
840 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
844 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
847 mips_error ("write to target failed: %s", safe_strerror (errno
));
855 /* Optionally send a request to the remote system and optionally wait
856 for the reply. This implements the remote debugging protocol,
857 which is built on top of the packet protocol defined above. Each
858 request has an ADDR argument and a DATA argument. The following
859 requests are defined:
861 \0 don't send a request; just wait for a reply
862 i read word from instruction space at ADDR
863 d read word from data space at ADDR
864 I write DATA to instruction space at ADDR
865 D write DATA to data space at ADDR
866 r read register number ADDR
867 R set register number ADDR to value DATA
868 c continue execution (if ADDR != 1, set pc to ADDR)
869 s single step (if ADDR != 1, set pc to ADDR)
871 The read requests return the value requested. The write requests
872 return the previous value in the changed location. The execution
873 requests return a UNIX wait value (the approximate signal which
874 caused execution to stop is in the upper eight bits).
876 If PERR is not NULL, this function waits for a reply. If an error
877 occurs, it sets *PERR to 1 and sets errno according to what the
878 target board reports. */
881 mips_request (cmd
, addr
, data
, perr
, timeout
)
888 char buff
[DATA_MAXLEN
+ 1];
898 fatal ("mips_request: Trying to send command before reply");
899 sprintf (buff
, "0x0 %c 0x%x 0x%x", cmd
, addr
, data
);
900 mips_send_packet (buff
, 1);
904 if (perr
== (int *) NULL
)
907 if (! mips_need_reply
)
908 fatal ("mips_request: Trying to get reply before command");
912 len
= mips_receive_packet (buff
, 1, timeout
);
915 if (sscanf (buff
, "0x%x %c 0x%x 0x%x",
916 &rpid
, &rcmd
, &rerrflg
, &rresponse
) != 4
917 || (cmd
!= '\0' && rcmd
!= cmd
))
918 mips_error ("Bad response from remote board");
924 /* FIXME: This will returns MIPS errno numbers, which may or may
925 not be the same as errno values used on other systems. If
926 they stick to common errno values, they will be the same, but
927 if they don't, they must be translated. */
938 mips_initialize_cleanups (arg
)
941 mips_initializing
= 0;
944 /* Initialize a new connection to the MIPS board, and make sure we are
951 char buff
[DATA_MAXLEN
+ 1];
953 struct cleanup
*old_cleanups
= make_cleanup (mips_initialize_cleanups
, NULL
);
955 /* What is this code doing here? I don't see any way it can happen, and
956 it might mean mips_initializing didn't get cleared properly.
957 So I'll make it a warning. */
958 if (mips_initializing
)
960 warning ("internal error: mips_initialize called twice");
964 mips_initializing
= 1;
967 mips_receive_seq
= 0;
969 /* The board seems to want to send us a packet. I don't know what
970 it means. The packet seems to be triggered by a carriage return
971 character, although perhaps any character would do. */
973 /* FIXME check the result from this */
974 SERIAL_WRITE (mips_desc
, &cr
, 1);
976 if (mips_receive_packet (buff
, 0, 3) < 0)
980 /* We did not receive the packet we expected; try resetting the
981 board and trying again. */
982 printf_filtered ("Failed to initialize; trying to reset board\n");
984 SERIAL_WRITE (mips_desc
, &cc
, 1);
986 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
989 SERIAL_WRITE (mips_desc
, &cr
, 1);
991 mips_receive_packet (buff
, 1, 3);
993 do_cleanups (old_cleanups
);
995 /* If this doesn't call error, we have connected; we don't care if
996 the request itself succeeds or fails. */
997 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err
,
1001 /* Open a connection to the remote board. */
1004 mips_open (name
, from_tty
)
1012 "To open a MIPS remote debugging connection, you need to specify what serial\n\
1013 device is attached to the target board (e.g., /dev/ttya).");
1015 target_preopen (from_tty
);
1018 unpush_target (&mips_ops
);
1020 mips_desc
= SERIAL_OPEN (name
);
1021 if (mips_desc
== (serial_t
) NULL
)
1022 perror_with_name (name
);
1024 if (baud_rate
!= -1)
1026 if (SERIAL_SETBAUDRATE (mips_desc
, baud_rate
))
1028 SERIAL_CLOSE (mips_desc
);
1029 perror_with_name (name
);
1033 SERIAL_RAW (mips_desc
);
1040 printf_unfiltered ("Remote MIPS debugging using %s\n", name
);
1042 /* Switch to using remote target now. */
1043 push_target (&mips_ops
);
1045 /* FIXME: Should we call start_remote here? */
1047 /* Try to figure out the processor model if possible. */
1048 ptype
= mips_read_processor_type ();
1050 mips_set_processor_type_command (strsave (ptype
), 0);
1052 /* This is really the job of start_remote however, that makes an assumption
1053 that the target is about to print out a status message of some sort. That
1054 doesn't happen here (in fact, it may not be possible to get the monitor to
1055 send the appropriate packet). */
1057 flush_cached_frames ();
1058 registers_changed ();
1059 stop_pc
= read_pc ();
1060 set_current_frame (create_new_frame (read_fp (), stop_pc
));
1061 select_frame (get_current_frame (), 0);
1062 print_stack_frame (selected_frame
, -1, 1);
1065 /* Close a connection to the remote board. */
1068 mips_close (quitting
)
1077 /* Get the board out of remote debugging mode. */
1078 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err
,
1081 SERIAL_CLOSE (mips_desc
);
1085 /* Detach from the remote board. */
1088 mips_detach (args
, from_tty
)
1093 error ("Argument given to \"detach\" when remotely debugging.");
1097 printf_unfiltered ("Ending remote MIPS debugging.\n");
1100 /* Tell the target board to resume. This does not wait for a reply
1104 mips_resume (pid
, step
, siggnal
)
1106 enum target_signal siggnal
;
1108 if (siggnal
!= TARGET_SIGNAL_0
)
1110 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1111 target_signal_to_name (siggnal
));
1113 mips_request (step
? 's' : 'c',
1120 /* Return the signal corresponding to SIG, where SIG is the number which
1121 the MIPS protocol uses for the signal. */
1123 mips_signal_from_protocol (sig
)
1126 /* We allow a few more signals than the IDT board actually returns, on
1127 the theory that there is at least *some* hope that perhaps the numbering
1128 for these signals is widely agreed upon. */
1131 return TARGET_SIGNAL_UNKNOWN
;
1133 /* Don't want to use target_signal_from_host because we are converting
1134 from MIPS signal numbers, not host ones. Our internal numbers
1135 match the MIPS numbers for the signals the board can return, which
1136 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1137 return (enum target_signal
) sig
;
1140 /* Wait until the remote stops, and return a wait status. */
1143 mips_wait (pid
, status
)
1145 struct target_waitstatus
*status
;
1150 /* If we have not sent a single step or continue command, then the
1151 board is waiting for us to do something. Return a status
1152 indicating that it is stopped. */
1153 if (! mips_need_reply
)
1155 status
->kind
= TARGET_WAITKIND_STOPPED
;
1156 status
->value
.sig
= TARGET_SIGNAL_TRAP
;
1160 /* No timeout; we sit here as long as the program continues to execute. */
1161 rstatus
= mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err
, -1);
1163 mips_error ("Remote failure: %s", safe_strerror (errno
));
1165 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1166 and so on, because the constants we want here are determined by the
1167 MIPS protocol and have nothing to do with what host we are running on. */
1168 if ((rstatus
& 0377) == 0)
1170 status
->kind
= TARGET_WAITKIND_EXITED
;
1171 status
->value
.integer
= (((rstatus
) >> 8) & 0377);
1173 else if ((rstatus
& 0377) == 0177)
1175 status
->kind
= TARGET_WAITKIND_STOPPED
;
1176 status
->value
.sig
= mips_signal_from_protocol (((rstatus
) >> 8) & 0377);
1180 status
->kind
= TARGET_WAITKIND_SIGNALLED
;
1181 status
->value
.sig
= mips_signal_from_protocol (rstatus
& 0177);
1187 /* We have to map between the register numbers used by gdb and the
1188 register numbers used by the debugging protocol. This function
1189 assumes that we are using tm-mips.h. */
1191 #define REGNO_OFFSET 96
1194 mips_map_regno (regno
)
1199 if (regno
>= FP0_REGNUM
&& regno
< FP0_REGNUM
+ 32)
1200 return regno
- FP0_REGNUM
+ 32;
1204 return REGNO_OFFSET
+ 0;
1206 return REGNO_OFFSET
+ 1;
1208 return REGNO_OFFSET
+ 2;
1210 return REGNO_OFFSET
+ 3;
1212 return REGNO_OFFSET
+ 4;
1214 return REGNO_OFFSET
+ 5;
1216 /* FIXME: Is there a way to get the status register? */
1221 /* Fetch the remote registers. */
1224 mips_fetch_registers (regno
)
1227 unsigned LONGEST val
;
1232 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1233 mips_fetch_registers (regno
);
1237 if (regno
== FP_REGNUM
|| regno
== ZERO_REGNUM
)
1238 /* FP_REGNUM on the mips is a hack which is just supposed to read
1239 zero (see also mips-nat.c). */
1243 val
= mips_request ('r', (unsigned int) mips_map_regno (regno
),
1244 (unsigned int) 0, &err
, mips_receive_wait
);
1246 mips_error ("Can't read register %d: %s", regno
,
1247 safe_strerror (errno
));
1251 char buf
[MAX_REGISTER_RAW_SIZE
];
1253 /* We got the number the register holds, but gdb expects to see a
1254 value in the target byte ordering. */
1255 store_unsigned_integer (buf
, REGISTER_RAW_SIZE (regno
), val
);
1256 supply_register (regno
, buf
);
1260 /* Prepare to store registers. The MIPS protocol can store individual
1261 registers, so this function doesn't have to do anything. */
1264 mips_prepare_to_store ()
1268 /* Store remote register(s). */
1271 mips_store_registers (regno
)
1278 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1279 mips_store_registers (regno
);
1283 mips_request ('R', (unsigned int) mips_map_regno (regno
),
1284 (unsigned int) read_register (regno
),
1285 &err
, mips_receive_wait
);
1287 mips_error ("Can't write register %d: %s", regno
, safe_strerror (errno
));
1290 /* Fetch a word from the target board. */
1293 mips_fetch_word (addr
)
1299 val
= mips_request ('d', (unsigned int) addr
, (unsigned int) 0, &err
,
1303 /* Data space failed; try instruction space. */
1304 val
= mips_request ('i', (unsigned int) addr
, (unsigned int) 0, &err
,
1307 mips_error ("Can't read address 0x%x: %s", addr
, safe_strerror (errno
));
1312 /* Store a word to the target board. Returns errno code or zero for
1313 success. If OLD_CONTENTS is non-NULL, put the old contents of that
1314 memory location there. */
1317 mips_store_word (addr
, val
, old_contents
)
1323 unsigned int oldcontents
;
1325 oldcontents
= mips_request ('D', (unsigned int) addr
, (unsigned int) val
,
1330 /* Data space failed; try instruction space. */
1331 oldcontents
= mips_request ('I', (unsigned int) addr
,
1332 (unsigned int) val
, &err
,
1337 if (old_contents
!= NULL
)
1338 store_unsigned_integer (old_contents
, 4, oldcontents
);
1342 /* Read or write LEN bytes from inferior memory at MEMADDR,
1343 transferring to or from debugger address MYADDR. Write to inferior
1344 if SHOULD_WRITE is nonzero. Returns length of data written or
1345 read; 0 for error. Note that protocol gives us the correct value
1346 for a longword, since it transfers values in ASCII. We want the
1347 byte values, so we have to swap the longword values. */
1350 mips_xfer_memory (memaddr
, myaddr
, len
, write
, ignore
)
1355 struct target_ops
*ignore
;
1358 /* Round starting address down to longword boundary. */
1359 register CORE_ADDR addr
= memaddr
&~ 3;
1360 /* Round ending address up; get number of longwords that makes. */
1361 register int count
= (((memaddr
+ len
) - addr
) + 3) / 4;
1362 /* Allocate buffer of that many longwords. */
1363 register char *buffer
= alloca (count
* 4);
1369 /* Fill start and end extra bytes of buffer with existing data. */
1370 if (addr
!= memaddr
|| len
< 4)
1372 /* Need part of initial word -- fetch it. */
1373 store_unsigned_integer (&buffer
[0], 4, mips_fetch_word (addr
));
1378 /* Need part of last word -- fetch it. FIXME: we do this even
1379 if we don't need it. */
1380 store_unsigned_integer (&buffer
[(count
- 1) * 4], 4,
1381 mips_fetch_word (addr
+ (count
- 1) * 4));
1384 /* Copy data to be written over corresponding part of buffer */
1386 memcpy ((char *) buffer
+ (memaddr
& 3), myaddr
, len
);
1388 /* Write the entire buffer. */
1390 for (i
= 0; i
< count
; i
++, addr
+= 4)
1392 status
= mips_store_word (addr
,
1393 extract_unsigned_integer (&buffer
[i
*4], 4),
1395 /* Report each kilobyte (we download 32-bit words at a time) */
1398 printf_unfiltered ("*");
1406 /* FIXME: Do we want a QUIT here? */
1409 printf_unfiltered ("\n");
1413 /* Read all the longwords */
1414 for (i
= 0; i
< count
; i
++, addr
+= 4)
1416 store_unsigned_integer (&buffer
[i
*4], 4, mips_fetch_word (addr
));
1420 /* Copy appropriate bytes out of the buffer. */
1421 memcpy (myaddr
, buffer
+ (memaddr
& 3), len
);
1426 /* Print info on this target. */
1429 mips_files_info (ignore
)
1430 struct target_ops
*ignore
;
1432 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1435 /* Kill the process running on the board. This will actually only
1436 work if we are doing remote debugging over the console input. I
1437 think that if IDT/sim had the remote debug interrupt enabled on the
1438 right port, we could interrupt the process with a break signal. */
1450 SERIAL_WRITE (mips_desc
, &cc
, 1);
1452 target_mourn_inferior ();
1457 /* Start running on the target board. */
1460 mips_create_inferior (execfile
, args
, env
)
1470 Can't pass arguments to remote MIPS board; arguments ignored.");
1471 /* And don't try to use them on the next "run" command. */
1472 execute_command ("set args", 0);
1475 if (execfile
== 0 || exec_bfd
== 0)
1476 error ("No executable file specified");
1478 entry_pt
= (CORE_ADDR
) bfd_get_start_address (exec_bfd
);
1480 init_wait_for_inferior ();
1482 /* FIXME: Should we set inferior_pid here? */
1484 proceed (entry_pt
, TARGET_SIGNAL_DEFAULT
, 0);
1487 /* Clean up after a process. Actually nothing to do. */
1490 mips_mourn_inferior ()
1492 unpush_target (&mips_ops
);
1493 generic_mourn_inferior ();
1496 /* We can write a breakpoint and read the shadow contents in one
1499 /* The IDT board uses an unusual breakpoint value, and sometimes gets
1500 confused when it sees the usual MIPS breakpoint instruction. */
1502 #define BREAK_INSN (0x00000a0d)
1503 #define BREAK_INSN_SIZE (4)
1505 /* Insert a breakpoint on targets that don't have any better breakpoint
1506 support. We read the contents of the target location and stash it,
1507 then overwrite it with a breakpoint instruction. ADDR is the target
1508 location in the target machine. CONTENTS_CACHE is a pointer to
1509 memory allocated for saving the target contents. It is guaranteed
1510 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1511 is accomplished via BREAKPOINT_MAX). */
1514 mips_insert_breakpoint (addr
, contents_cache
)
1516 char *contents_cache
;
1520 return mips_store_word (addr
, BREAK_INSN
, contents_cache
);
1524 mips_remove_breakpoint (addr
, contents_cache
)
1526 char *contents_cache
;
1528 return target_write_memory (addr
, contents_cache
, BREAK_INSN_SIZE
);
1531 /* The target vector. */
1533 struct target_ops mips_ops
=
1535 "mips", /* to_shortname */
1536 "Remote MIPS debugging over serial line", /* to_longname */
1538 Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1539 The argument is the device it is connected to or, if it contains a colon,\n\
1540 HOST:PORT to access a board over a network", /* to_doc */
1541 mips_open
, /* to_open */
1542 mips_close
, /* to_close */
1543 NULL
, /* to_attach */
1544 mips_detach
, /* to_detach */
1545 mips_resume
, /* to_resume */
1546 mips_wait
, /* to_wait */
1547 mips_fetch_registers
, /* to_fetch_registers */
1548 mips_store_registers
, /* to_store_registers */
1549 mips_prepare_to_store
, /* to_prepare_to_store */
1550 mips_xfer_memory
, /* to_xfer_memory */
1551 mips_files_info
, /* to_files_info */
1552 mips_insert_breakpoint
, /* to_insert_breakpoint */
1553 mips_remove_breakpoint
, /* to_remove_breakpoint */
1554 NULL
, /* to_terminal_init */
1555 NULL
, /* to_terminal_inferior */
1556 NULL
, /* to_terminal_ours_for_output */
1557 NULL
, /* to_terminal_ours */
1558 NULL
, /* to_terminal_info */
1559 mips_kill
, /* to_kill */
1560 generic_load
, /* to_load */
1561 NULL
, /* to_lookup_symbol */
1562 mips_create_inferior
, /* to_create_inferior */
1563 mips_mourn_inferior
, /* to_mourn_inferior */
1564 NULL
, /* to_can_run */
1565 NULL
, /* to_notice_signals */
1567 process_stratum
, /* to_stratum */
1569 1, /* to_has_all_memory */
1570 1, /* to_has_memory */
1571 1, /* to_has_stack */
1572 1, /* to_has_registers */
1573 1, /* to_has_execution */
1574 NULL
, /* sections */
1575 NULL
, /* sections_end */
1576 OPS_MAGIC
/* to_magic */
1580 _initialize_remote_mips ()
1582 add_target (&mips_ops
);
1585 add_set_cmd ("timeout", no_class
, var_zinteger
,
1586 (char *) &mips_receive_wait
,
1587 "Set timeout in seconds for remote MIPS serial I/O.",
1592 add_set_cmd ("retransmit-timeout", no_class
, var_zinteger
,
1593 (char *) &mips_retransmit_wait
,
1594 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1595 This is the number of seconds to wait for an acknowledgement to a packet\n\
1596 before resending the packet.", &setlist
),