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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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
330 /* CYGNUS LOCAL jsmith */
331 /* The old code assumed a 5 character identification string, making it
332 a chore to change the string value. However, we need to ensure
333 that the method of ascertaining the length of the string is
334 completely portable, without resorting to calling strlen(). */
337 mips_readchar (timeout
)
341 static int state
= 0;
342 static char nextstate
[] = TARGET_MONITOR_PROMPT
; /* CYGNUS LOCAL jsmith */
343 #ifdef MAINTENANCE_CMDS
347 if (i
== -1 && watchdog
> 0)
351 if (state
== (sizeof(nextstate
) / sizeof(char))) /* CYGNUS LOCAL jsmith */
353 ch
= SERIAL_READCHAR (mips_desc
, timeout
);
354 #ifdef MAINTENANCE_CMDS
355 if (ch
== SERIAL_TIMEOUT
&& timeout
== -1) /* Watchdog went off */
357 target_mourn_inferior ();
358 error ("Watchdog has expired. Target detached.\n");
361 if (ch
== SERIAL_EOF
)
362 mips_error ("End of file from remote");
363 if (ch
== SERIAL_ERROR
)
364 mips_error ("Error reading from remote: %s", safe_strerror (errno
));
365 if (sr_get_debug () > 1)
367 /* Don't use _filtered; we can't deal with a QUIT out of
368 target_wait, and I think this might be called from there. */
369 if (ch
!= SERIAL_TIMEOUT
)
370 printf_unfiltered ("Read '%c' %d 0x%x\n", ch
, ch
, ch
);
372 printf_unfiltered ("Timed out in read\n");
375 /* If we have seen <IDT> and we either time out, or we see a @
376 (which was echoed from a packet we sent), reset the board as
377 described above. The first character in a packet after the SYN
378 (which is not echoed) is always an @ unless the packet is more
379 than 64 characters long, which ours never are. */
380 if ((ch
== SERIAL_TIMEOUT
|| ch
== '@')
381 && state
== (sizeof(nextstate
) / sizeof(char)) /* CYGNUS LOCAL jsmith */
382 && ! mips_initializing
)
384 if (sr_get_debug () > 0)
385 /* Don't use _filtered; we can't deal with a QUIT out of
386 target_wait, and I think this might be called from there. */
387 printf_unfiltered ("Reinitializing MIPS debugging mode\n");
388 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
396 /* At this point, about the only thing we can do is abort the command
397 in progress and get back to command level as quickly as possible. */
399 error ("Remote board reset, debug protocol re-initialized.");
402 if (ch
== nextstate
[state
])
410 /* Get a packet header, putting the data in the supplied buffer.
411 PGARBAGE is a pointer to the number of garbage characters received
412 so far. CH is the last character received. Returns 0 for success,
413 or -1 for timeout. */
416 mips_receive_header (hdr
, pgarbage
, ch
, timeout
)
426 /* Wait for a SYN. mips_syn_garbage is intended to prevent
427 sitting here indefinitely if the board sends us one garbage
428 character per second. ch may already have a value from the
429 last time through the loop. */
432 ch
= mips_readchar (timeout
);
433 if (ch
== SERIAL_TIMEOUT
)
437 /* Printing the character here lets the user of gdb see
438 what the program is outputting, if the debugging is
439 being done on the console port. Don't use _filtered;
440 we can't deal with a QUIT out of target_wait. */
441 if (! mips_initializing
|| sr_get_debug () > 0)
443 if (ch
< 0x20 && ch
!= '\n')
445 putchar_unfiltered ('^');
446 putchar_unfiltered (ch
+ 0x40);
449 putchar_unfiltered (ch
);
450 gdb_flush (gdb_stdout
);
454 if (*pgarbage
> mips_syn_garbage
)
455 mips_error ("Remote debugging protocol failure");
459 /* Get the packet header following the SYN. */
460 for (i
= 1; i
< HDR_LENGTH
; i
++)
462 ch
= mips_readchar (timeout
);
463 if (ch
== SERIAL_TIMEOUT
)
466 /* Make sure this is a header byte. */
467 if (ch
== SYN
|| ! HDR_CHECK (ch
))
473 /* If we got the complete header, we can return. Otherwise we
474 loop around and keep looking for SYN. */
480 /* Get a packet header, putting the data in the supplied buffer.
481 PGARBAGE is a pointer to the number of garbage characters received
482 so far. The last character read is returned in *PCH. Returns 0
483 for success, -1 for timeout, -2 for error. */
486 mips_receive_trailer (trlr
, pgarbage
, pch
, timeout
)
495 for (i
= 0; i
< TRLR_LENGTH
; i
++)
497 ch
= mips_readchar (timeout
);
499 if (ch
== SERIAL_TIMEOUT
)
501 if (! TRLR_CHECK (ch
))
508 /* Get the checksum of a packet. HDR points to the packet header.
509 DATA points to the packet data. LEN is the length of DATA. */
512 mips_cksum (hdr
, data
, len
)
513 const unsigned char *hdr
;
514 const unsigned char *data
;
517 register const unsigned char *p
;
523 /* The initial SYN is not included in the checksum. */
537 /* Send a packet containing the given ASCII string. */
540 mips_send_packet (s
, get_ack
)
545 unsigned char *packet
;
550 if (len
> DATA_MAXLEN
)
551 mips_error ("MIPS protocol data packet too long: %s", s
);
553 packet
= (unsigned char *) alloca (HDR_LENGTH
+ len
+ TRLR_LENGTH
+ 1);
555 packet
[HDR_INDX_SYN
] = HDR_SET_SYN (1, len
, mips_send_seq
);
556 packet
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (1, len
, mips_send_seq
);
557 packet
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (1, len
, mips_send_seq
);
558 packet
[HDR_INDX_SEQ
] = HDR_SET_SEQ (1, len
, mips_send_seq
);
560 memcpy (packet
+ HDR_LENGTH
, s
, len
);
562 cksum
= mips_cksum (packet
, packet
+ HDR_LENGTH
, len
);
563 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
564 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
565 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
567 /* Increment the sequence number. This will set mips_send_seq to
568 the sequence number we expect in the acknowledgement. */
569 mips_send_seq
= (mips_send_seq
+ 1) % SEQ_MODULOS
;
574 /* We can only have one outstanding data packet, so we just wait for
575 the acknowledgement here. Keep retransmitting the packet until
576 we get one, or until we've tried too many times. */
577 for (try = 0; try < mips_send_retries
; try++)
582 if (sr_get_debug () > 0)
584 /* Don't use _filtered; we can't deal with a QUIT out of
585 target_wait, and I think this might be called from there. */
586 packet
[HDR_LENGTH
+ len
+ TRLR_LENGTH
] = '\0';
587 printf_unfiltered ("Writing \"%s\"\n", packet
+ 1);
590 if (SERIAL_WRITE (mips_desc
, packet
,
591 HDR_LENGTH
+ len
+ TRLR_LENGTH
) != 0)
592 mips_error ("write to target failed: %s", safe_strerror (errno
));
598 unsigned char hdr
[HDR_LENGTH
+ 1];
599 unsigned char trlr
[TRLR_LENGTH
+ 1];
603 /* Get the packet header. If we time out, resend the data
605 err
= mips_receive_header (hdr
, &garbage
, ch
, mips_retransmit_wait
);
611 /* If we get a data packet, assume it is a duplicate and
612 ignore it. FIXME: If the acknowledgement is lost, this
613 data packet may be the packet the remote sends after the
615 if (HDR_IS_DATA (hdr
))
618 /* If the length is not 0, this is a garbled packet. */
619 if (HDR_GET_LEN (hdr
) != 0)
622 /* Get the packet trailer. */
623 err
= mips_receive_trailer (trlr
, &garbage
, &ch
,
624 mips_retransmit_wait
);
626 /* If we timed out, resend the data packet. */
630 /* If we got a bad character, reread the header. */
634 /* If the checksum does not match the trailer checksum, this
635 is a bad packet; ignore it. */
636 if (mips_cksum (hdr
, (unsigned char *) NULL
, 0)
637 != TRLR_GET_CKSUM (trlr
))
640 if (sr_get_debug () > 0)
642 hdr
[HDR_LENGTH
] = '\0';
643 trlr
[TRLR_LENGTH
] = '\0';
644 /* Don't use _filtered; we can't deal with a QUIT out of
645 target_wait, and I think this might be called from there. */
646 printf_unfiltered ("Got ack %d \"%s%s\"\n",
647 HDR_GET_SEQ (hdr
), hdr
+ 1, trlr
);
650 /* If this ack is for the current packet, we're done. */
651 seq
= HDR_GET_SEQ (hdr
);
652 if (seq
== mips_send_seq
)
655 /* If this ack is for the last packet, resend the current
657 if ((seq
+ 1) % SEQ_MODULOS
== mips_send_seq
)
660 /* Otherwise this is a bad ack; ignore it. Increment the
661 garbage count to ensure that we do not stay in this loop
667 mips_error ("Remote did not acknowledge packet");
670 /* Receive and acknowledge a packet, returning the data in BUFF (which
671 should be DATA_MAXLEN + 1 bytes). The protocol documentation
672 implies that only the sender retransmits packets, so this code just
673 waits silently for a packet. It returns the length of the received
674 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
675 don't print an error message and return -1. */
678 mips_receive_packet (buff
, throw_error
, timeout
)
686 unsigned char ack
[HDR_LENGTH
+ TRLR_LENGTH
+ 1];
693 unsigned char hdr
[HDR_LENGTH
];
694 unsigned char trlr
[TRLR_LENGTH
];
698 if (mips_receive_header (hdr
, &garbage
, ch
, timeout
) != 0)
701 mips_error ("Timed out waiting for remote packet");
708 /* An acknowledgement is probably a duplicate; ignore it. */
709 if (! HDR_IS_DATA (hdr
))
711 /* Don't use _filtered; we can't deal with a QUIT out of
712 target_wait, and I think this might be called from there. */
713 if (sr_get_debug () > 0)
714 printf_unfiltered ("Ignoring unexpected ACK\n");
718 /* If this is the wrong sequence number, ignore it. */
719 if (HDR_GET_SEQ (hdr
) != mips_receive_seq
)
721 /* Don't use _filtered; we can't deal with a QUIT out of
722 target_wait, and I think this might be called from there. */
723 if (sr_get_debug () > 0)
724 printf_unfiltered ("Ignoring sequence number %d (want %d)\n",
725 HDR_GET_SEQ (hdr
), mips_receive_seq
);
729 len
= HDR_GET_LEN (hdr
);
731 for (i
= 0; i
< len
; i
++)
735 rch
= mips_readchar (timeout
);
741 if (rch
== SERIAL_TIMEOUT
)
744 mips_error ("Timed out waiting for remote packet");
753 /* Don't use _filtered; we can't deal with a QUIT out of
754 target_wait, and I think this might be called from there. */
755 if (sr_get_debug () > 0)
756 printf_unfiltered ("Got new SYN after %d chars (wanted %d)\n",
761 err
= mips_receive_trailer (trlr
, &garbage
, &ch
, timeout
);
765 mips_error ("Timed out waiting for packet");
771 /* Don't use _filtered; we can't deal with a QUIT out of
772 target_wait, and I think this might be called from there. */
773 if (sr_get_debug () > 0)
774 printf_unfiltered ("Got SYN when wanted trailer\n");
778 if (mips_cksum (hdr
, buff
, len
) == TRLR_GET_CKSUM (trlr
))
781 if (sr_get_debug () > 0)
782 /* Don't use _filtered; we can't deal with a QUIT out of
783 target_wait, and I think this might be called from there. */
784 printf_unfiltered ("Bad checksum; data %d, trailer %d\n",
785 mips_cksum (hdr
, buff
, len
),
786 TRLR_GET_CKSUM (trlr
));
788 /* The checksum failed. Send an acknowledgement for the
789 previous packet to tell the remote to resend the packet. */
790 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
791 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
792 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
793 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
795 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
797 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
798 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
799 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
801 if (sr_get_debug () > 0)
803 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
804 /* Don't use _filtered; we can't deal with a QUIT out of
805 target_wait, and I think this might be called from there. */
806 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
810 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
813 mips_error ("write to target failed: %s", safe_strerror (errno
));
819 if (sr_get_debug () > 0)
822 /* Don't use _filtered; we can't deal with a QUIT out of
823 target_wait, and I think this might be called from there. */
824 printf_unfiltered ("Got packet \"%s\"\n", buff
);
827 /* We got the packet. Send an acknowledgement. */
828 mips_receive_seq
= (mips_receive_seq
+ 1) % SEQ_MODULOS
;
830 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
831 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
832 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
833 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
835 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
837 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
838 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
839 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
841 if (sr_get_debug () > 0)
843 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
844 /* Don't use _filtered; we can't deal with a QUIT out of
845 target_wait, and I think this might be called from there. */
846 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
850 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
853 mips_error ("write to target failed: %s", safe_strerror (errno
));
861 /* Optionally send a request to the remote system and optionally wait
862 for the reply. This implements the remote debugging protocol,
863 which is built on top of the packet protocol defined above. Each
864 request has an ADDR argument and a DATA argument. The following
865 requests are defined:
867 \0 don't send a request; just wait for a reply
868 i read word from instruction space at ADDR
869 d read word from data space at ADDR
870 I write DATA to instruction space at ADDR
871 D write DATA to data space at ADDR
872 r read register number ADDR
873 R set register number ADDR to value DATA
874 c continue execution (if ADDR != 1, set pc to ADDR)
875 s single step (if ADDR != 1, set pc to ADDR)
877 The read requests return the value requested. The write requests
878 return the previous value in the changed location. The execution
879 requests return a UNIX wait value (the approximate signal which
880 caused execution to stop is in the upper eight bits).
882 If PERR is not NULL, this function waits for a reply. If an error
883 occurs, it sets *PERR to 1 and sets errno according to what the
884 target board reports. */
887 mips_request (cmd
, addr
, data
, perr
, timeout
)
894 char buff
[DATA_MAXLEN
+ 1];
904 fatal ("mips_request: Trying to send command before reply");
905 sprintf (buff
, "0x0 %c 0x%x 0x%x", cmd
, addr
, data
);
906 mips_send_packet (buff
, 1);
910 if (perr
== (int *) NULL
)
913 if (! mips_need_reply
)
914 fatal ("mips_request: Trying to get reply before command");
918 len
= mips_receive_packet (buff
, 1, timeout
);
921 if (sscanf (buff
, "0x%x %c 0x%x 0x%x",
922 &rpid
, &rcmd
, &rerrflg
, &rresponse
) != 4
923 || (cmd
!= '\0' && rcmd
!= cmd
))
924 mips_error ("Bad response from remote board");
930 /* FIXME: This will returns MIPS errno numbers, which may or may
931 not be the same as errno values used on other systems. If
932 they stick to common errno values, they will be the same, but
933 if they don't, they must be translated. */
944 mips_initialize_cleanups (arg
)
947 mips_initializing
= 0;
950 /* Initialize a new connection to the MIPS board, and make sure we are
957 char buff
[DATA_MAXLEN
+ 1];
959 struct cleanup
*old_cleanups
= make_cleanup (mips_initialize_cleanups
, NULL
);
961 /* What is this code doing here? I don't see any way it can happen, and
962 it might mean mips_initializing didn't get cleared properly.
963 So I'll make it a warning. */
964 if (mips_initializing
)
966 warning ("internal error: mips_initialize called twice");
970 mips_initializing
= 1;
973 mips_receive_seq
= 0;
975 /* The board seems to want to send us a packet. I don't know what
976 it means. The packet seems to be triggered by a carriage return
977 character, although perhaps any character would do. */
979 /* FIXME check the result from this */
980 SERIAL_WRITE (mips_desc
, &cr
, 1);
982 if (mips_receive_packet (buff
, 0, 3) < 0)
986 /* We did not receive the packet we expected; try resetting the
987 board and trying again. */
988 printf_filtered ("Failed to initialize; trying to reset board\n");
990 SERIAL_WRITE (mips_desc
, &cc
, 1);
992 SERIAL_WRITE (mips_desc
, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
995 SERIAL_WRITE (mips_desc
, &cr
, 1);
997 mips_receive_packet (buff
, 1, 3);
999 do_cleanups (old_cleanups
);
1001 /* If this doesn't call error, we have connected; we don't care if
1002 the request itself succeeds or fails. */
1003 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err
,
1007 /* Open a connection to the remote board. */
1010 mips_open (name
, from_tty
)
1018 "To open a MIPS remote debugging connection, you need to specify what serial\n\
1019 device is attached to the target board (e.g., /dev/ttya).");
1021 target_preopen (from_tty
);
1024 unpush_target (&mips_ops
);
1026 mips_desc
= SERIAL_OPEN (name
);
1027 if (mips_desc
== (serial_t
) NULL
)
1028 perror_with_name (name
);
1030 if (baud_rate
!= -1)
1032 if (SERIAL_SETBAUDRATE (mips_desc
, baud_rate
))
1034 SERIAL_CLOSE (mips_desc
);
1035 perror_with_name (name
);
1039 SERIAL_RAW (mips_desc
);
1046 printf_unfiltered ("Remote MIPS debugging using %s\n", name
);
1048 /* Switch to using remote target now. */
1049 push_target (&mips_ops
);
1051 /* FIXME: Should we call start_remote here? */
1053 /* Try to figure out the processor model if possible. */
1054 ptype
= mips_read_processor_type ();
1056 mips_set_processor_type_command (strsave (ptype
), 0);
1058 /* This is really the job of start_remote however, that makes an assumption
1059 that the target is about to print out a status message of some sort. That
1060 doesn't happen here (in fact, it may not be possible to get the monitor to
1061 send the appropriate packet). */
1063 flush_cached_frames ();
1064 registers_changed ();
1065 stop_pc
= read_pc ();
1066 set_current_frame (create_new_frame (read_fp (), stop_pc
));
1067 select_frame (get_current_frame (), 0);
1068 print_stack_frame (selected_frame
, -1, 1);
1071 /* Close a connection to the remote board. */
1074 mips_close (quitting
)
1083 /* Get the board out of remote debugging mode. */
1084 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err
,
1087 SERIAL_CLOSE (mips_desc
);
1091 /* Detach from the remote board. */
1094 mips_detach (args
, from_tty
)
1099 error ("Argument given to \"detach\" when remotely debugging.");
1103 printf_unfiltered ("Ending remote MIPS debugging.\n");
1106 /* Tell the target board to resume. This does not wait for a reply
1110 mips_resume (pid
, step
, siggnal
)
1112 enum target_signal siggnal
;
1114 if (siggnal
!= TARGET_SIGNAL_0
)
1116 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1117 target_signal_to_name (siggnal
));
1119 mips_request (step
? 's' : 'c',
1126 /* Return the signal corresponding to SIG, where SIG is the number which
1127 the MIPS protocol uses for the signal. */
1129 mips_signal_from_protocol (sig
)
1132 /* We allow a few more signals than the IDT board actually returns, on
1133 the theory that there is at least *some* hope that perhaps the numbering
1134 for these signals is widely agreed upon. */
1137 return TARGET_SIGNAL_UNKNOWN
;
1139 /* Don't want to use target_signal_from_host because we are converting
1140 from MIPS signal numbers, not host ones. Our internal numbers
1141 match the MIPS numbers for the signals the board can return, which
1142 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1143 return (enum target_signal
) sig
;
1146 /* Wait until the remote stops, and return a wait status. */
1149 mips_wait (pid
, status
)
1151 struct target_waitstatus
*status
;
1156 /* If we have not sent a single step or continue command, then the
1157 board is waiting for us to do something. Return a status
1158 indicating that it is stopped. */
1159 if (! mips_need_reply
)
1161 status
->kind
= TARGET_WAITKIND_STOPPED
;
1162 status
->value
.sig
= TARGET_SIGNAL_TRAP
;
1166 /* No timeout; we sit here as long as the program continues to execute. */
1167 rstatus
= mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err
, -1);
1169 mips_error ("Remote failure: %s", safe_strerror (errno
));
1171 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1172 and so on, because the constants we want here are determined by the
1173 MIPS protocol and have nothing to do with what host we are running on. */
1174 if ((rstatus
& 0377) == 0)
1176 status
->kind
= TARGET_WAITKIND_EXITED
;
1177 status
->value
.integer
= (((rstatus
) >> 8) & 0377);
1179 else if ((rstatus
& 0377) == 0177)
1181 status
->kind
= TARGET_WAITKIND_STOPPED
;
1182 status
->value
.sig
= mips_signal_from_protocol (((rstatus
) >> 8) & 0377);
1186 status
->kind
= TARGET_WAITKIND_SIGNALLED
;
1187 status
->value
.sig
= mips_signal_from_protocol (rstatus
& 0177);
1193 /* We have to map between the register numbers used by gdb and the
1194 register numbers used by the debugging protocol. This function
1195 assumes that we are using tm-mips.h. */
1197 #define REGNO_OFFSET 96
1200 mips_map_regno (regno
)
1205 if (regno
>= FP0_REGNUM
&& regno
< FP0_REGNUM
+ 32)
1206 return regno
- FP0_REGNUM
+ 32;
1210 return REGNO_OFFSET
+ 0;
1212 return REGNO_OFFSET
+ 1;
1214 return REGNO_OFFSET
+ 2;
1216 return REGNO_OFFSET
+ 3;
1218 return REGNO_OFFSET
+ 4;
1220 return REGNO_OFFSET
+ 5;
1222 /* FIXME: Is there a way to get the status register? */
1227 /* Fetch the remote registers. */
1230 mips_fetch_registers (regno
)
1233 unsigned LONGEST val
;
1238 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1239 mips_fetch_registers (regno
);
1243 if (regno
== FP_REGNUM
|| regno
== ZERO_REGNUM
)
1244 /* FP_REGNUM on the mips is a hack which is just supposed to read
1245 zero (see also mips-nat.c). */
1249 val
= mips_request ('r', (unsigned int) mips_map_regno (regno
),
1250 (unsigned int) 0, &err
, mips_receive_wait
);
1252 mips_error ("Can't read register %d: %s", regno
,
1253 safe_strerror (errno
));
1257 char buf
[MAX_REGISTER_RAW_SIZE
];
1259 /* We got the number the register holds, but gdb expects to see a
1260 value in the target byte ordering. */
1261 store_unsigned_integer (buf
, REGISTER_RAW_SIZE (regno
), val
);
1262 supply_register (regno
, buf
);
1266 /* Prepare to store registers. The MIPS protocol can store individual
1267 registers, so this function doesn't have to do anything. */
1270 mips_prepare_to_store ()
1274 /* Store remote register(s). */
1277 mips_store_registers (regno
)
1284 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1285 mips_store_registers (regno
);
1289 mips_request ('R', (unsigned int) mips_map_regno (regno
),
1290 (unsigned int) read_register (regno
),
1291 &err
, mips_receive_wait
);
1293 mips_error ("Can't write register %d: %s", regno
, safe_strerror (errno
));
1296 /* Fetch a word from the target board. */
1299 mips_fetch_word (addr
)
1305 val
= mips_request ('d', (unsigned int) addr
, (unsigned int) 0, &err
,
1309 /* Data space failed; try instruction space. */
1310 val
= mips_request ('i', (unsigned int) addr
, (unsigned int) 0, &err
,
1313 mips_error ("Can't read address 0x%x: %s", addr
, safe_strerror (errno
));
1318 /* Store a word to the target board. Returns errno code or zero for
1319 success. If OLD_CONTENTS is non-NULL, put the old contents of that
1320 memory location there. */
1323 mips_store_word (addr
, val
, old_contents
)
1329 unsigned int oldcontents
;
1331 oldcontents
= mips_request ('D', (unsigned int) addr
, (unsigned int) val
,
1336 /* Data space failed; try instruction space. */
1337 oldcontents
= mips_request ('I', (unsigned int) addr
,
1338 (unsigned int) val
, &err
,
1343 if (old_contents
!= NULL
)
1344 store_unsigned_integer (old_contents
, 4, oldcontents
);
1348 /* Read or write LEN bytes from inferior memory at MEMADDR,
1349 transferring to or from debugger address MYADDR. Write to inferior
1350 if SHOULD_WRITE is nonzero. Returns length of data written or
1351 read; 0 for error. Note that protocol gives us the correct value
1352 for a longword, since it transfers values in ASCII. We want the
1353 byte values, so we have to swap the longword values. */
1356 mips_xfer_memory (memaddr
, myaddr
, len
, write
, ignore
)
1361 struct target_ops
*ignore
;
1364 /* Round starting address down to longword boundary. */
1365 register CORE_ADDR addr
= memaddr
&~ 3;
1366 /* Round ending address up; get number of longwords that makes. */
1367 register int count
= (((memaddr
+ len
) - addr
) + 3) / 4;
1368 /* Allocate buffer of that many longwords. */
1369 register char *buffer
= alloca (count
* 4);
1375 /* Fill start and end extra bytes of buffer with existing data. */
1376 if (addr
!= memaddr
|| len
< 4)
1378 /* Need part of initial word -- fetch it. */
1379 store_unsigned_integer (&buffer
[0], 4, mips_fetch_word (addr
));
1384 /* Need part of last word -- fetch it. FIXME: we do this even
1385 if we don't need it. */
1386 store_unsigned_integer (&buffer
[(count
- 1) * 4], 4,
1387 mips_fetch_word (addr
+ (count
- 1) * 4));
1390 /* Copy data to be written over corresponding part of buffer */
1392 memcpy ((char *) buffer
+ (memaddr
& 3), myaddr
, len
);
1394 /* Write the entire buffer. */
1396 for (i
= 0; i
< count
; i
++, addr
+= 4)
1398 status
= mips_store_word (addr
,
1399 extract_unsigned_integer (&buffer
[i
*4], 4),
1401 /* Report each kilobyte (we download 32-bit words at a time) */
1404 printf_unfiltered ("*");
1412 /* FIXME: Do we want a QUIT here? */
1415 printf_unfiltered ("\n");
1419 /* Read all the longwords */
1420 for (i
= 0; i
< count
; i
++, addr
+= 4)
1422 store_unsigned_integer (&buffer
[i
*4], 4, mips_fetch_word (addr
));
1426 /* Copy appropriate bytes out of the buffer. */
1427 memcpy (myaddr
, buffer
+ (memaddr
& 3), len
);
1432 /* Print info on this target. */
1435 mips_files_info (ignore
)
1436 struct target_ops
*ignore
;
1438 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1441 /* Kill the process running on the board. This will actually only
1442 work if we are doing remote debugging over the console input. I
1443 think that if IDT/sim had the remote debug interrupt enabled on the
1444 right port, we could interrupt the process with a break signal. */
1456 SERIAL_WRITE (mips_desc
, &cc
, 1);
1458 target_mourn_inferior ();
1463 /* Start running on the target board. */
1466 mips_create_inferior (execfile
, args
, env
)
1476 Can't pass arguments to remote MIPS board; arguments ignored.");
1477 /* And don't try to use them on the next "run" command. */
1478 execute_command ("set args", 0);
1481 if (execfile
== 0 || exec_bfd
== 0)
1482 error ("No executable file specified");
1484 entry_pt
= (CORE_ADDR
) bfd_get_start_address (exec_bfd
);
1486 init_wait_for_inferior ();
1488 /* FIXME: Should we set inferior_pid here? */
1490 proceed (entry_pt
, TARGET_SIGNAL_DEFAULT
, 0);
1493 /* Clean up after a process. Actually nothing to do. */
1496 mips_mourn_inferior ()
1498 unpush_target (&mips_ops
);
1499 generic_mourn_inferior ();
1502 /* We can write a breakpoint and read the shadow contents in one
1505 /* The IDT board uses an unusual breakpoint value, and sometimes gets
1506 confused when it sees the usual MIPS breakpoint instruction. */
1508 #define BREAK_INSN (0x00000a0d)
1509 #define BREAK_INSN_SIZE (4)
1511 /* Insert a breakpoint on targets that don't have any better breakpoint
1512 support. We read the contents of the target location and stash it,
1513 then overwrite it with a breakpoint instruction. ADDR is the target
1514 location in the target machine. CONTENTS_CACHE is a pointer to
1515 memory allocated for saving the target contents. It is guaranteed
1516 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1517 is accomplished via BREAKPOINT_MAX). */
1520 mips_insert_breakpoint (addr
, contents_cache
)
1522 char *contents_cache
;
1526 return mips_store_word (addr
, BREAK_INSN
, contents_cache
);
1530 mips_remove_breakpoint (addr
, contents_cache
)
1532 char *contents_cache
;
1534 return target_write_memory (addr
, contents_cache
, BREAK_INSN_SIZE
);
1537 /* The target vector. */
1539 struct target_ops mips_ops
=
1541 "mips", /* to_shortname */
1542 "Remote MIPS debugging over serial line", /* to_longname */
1544 Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1545 The argument is the device it is connected to or, if it contains a colon,\n\
1546 HOST:PORT to access a board over a network", /* to_doc */
1547 mips_open
, /* to_open */
1548 mips_close
, /* to_close */
1549 NULL
, /* to_attach */
1550 mips_detach
, /* to_detach */
1551 mips_resume
, /* to_resume */
1552 mips_wait
, /* to_wait */
1553 mips_fetch_registers
, /* to_fetch_registers */
1554 mips_store_registers
, /* to_store_registers */
1555 mips_prepare_to_store
, /* to_prepare_to_store */
1556 mips_xfer_memory
, /* to_xfer_memory */
1557 mips_files_info
, /* to_files_info */
1558 mips_insert_breakpoint
, /* to_insert_breakpoint */
1559 mips_remove_breakpoint
, /* to_remove_breakpoint */
1560 NULL
, /* to_terminal_init */
1561 NULL
, /* to_terminal_inferior */
1562 NULL
, /* to_terminal_ours_for_output */
1563 NULL
, /* to_terminal_ours */
1564 NULL
, /* to_terminal_info */
1565 mips_kill
, /* to_kill */
1566 generic_load
, /* to_load */
1567 NULL
, /* to_lookup_symbol */
1568 mips_create_inferior
, /* to_create_inferior */
1569 mips_mourn_inferior
, /* to_mourn_inferior */
1570 NULL
, /* to_can_run */
1571 NULL
, /* to_notice_signals */
1572 0, /* to_thread_alive */
1574 process_stratum
, /* to_stratum */
1576 1, /* to_has_all_memory */
1577 1, /* to_has_memory */
1578 1, /* to_has_stack */
1579 1, /* to_has_registers */
1580 1, /* to_has_execution */
1581 NULL
, /* sections */
1582 NULL
, /* sections_end */
1583 OPS_MAGIC
/* to_magic */
1587 _initialize_remote_mips ()
1589 add_target (&mips_ops
);
1592 add_set_cmd ("timeout", no_class
, var_zinteger
,
1593 (char *) &mips_receive_wait
,
1594 "Set timeout in seconds for remote MIPS serial I/O.",
1599 add_set_cmd ("retransmit-timeout", no_class
, var_zinteger
,
1600 (char *) &mips_retransmit_wait
,
1601 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1602 This is the number of seconds to wait for an acknowledgement to a packet\n\
1603 before resending the packet.", &setlist
),