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 /* Prototypes for local functions. */
39 mips_readchar
PARAMS ((int timeout
));
42 mips_receive_header
PARAMS ((unsigned char *hdr
, int *pgarbage
, int ch
,
46 mips_receive_trailer
PARAMS ((unsigned char *trlr
, int *pgarbage
, int *pch
,
49 static int mips_cksum
PARAMS ((const unsigned char *hdr
,
50 const unsigned char *data
,
54 mips_send_packet
PARAMS ((const char *s
, int get_ack
));
56 static int mips_receive_packet
PARAMS ((char *buff
, int throw_error
,
60 mips_request
PARAMS ((char cmd
, unsigned int addr
, unsigned int data
,
64 mips_initialize
PARAMS ((void));
67 mips_open
PARAMS ((char *name
, int from_tty
));
70 mips_close
PARAMS ((int quitting
));
73 mips_detach
PARAMS ((char *args
, int from_tty
));
75 static void mips_resume
PARAMS ((int pid
, int step
,
76 enum target_signal siggnal
));
79 mips_wait
PARAMS ((int pid
, WAITTYPE
*status
));
82 mips_map_regno
PARAMS ((int regno
));
85 mips_fetch_registers
PARAMS ((int regno
));
88 mips_prepare_to_store
PARAMS ((void));
91 mips_store_registers
PARAMS ((int regno
));
94 mips_fetch_word
PARAMS ((CORE_ADDR addr
));
97 mips_store_word
PARAMS ((CORE_ADDR addr
, int value
));
100 mips_xfer_memory
PARAMS ((CORE_ADDR memaddr
, char *myaddr
, int len
,
101 int write
, struct target_ops
*ignore
));
104 mips_files_info
PARAMS ((struct target_ops
*ignore
));
107 mips_load
PARAMS ((char *args
, int from_tty
));
110 mips_create_inferior
PARAMS ((char *execfile
, char *args
, char **env
));
113 mips_mourn_inferior
PARAMS ((void));
115 /* A forward declaration. */
116 extern struct target_ops mips_ops
;
118 /* The MIPS remote debugging interface is built on top of a simple
119 packet protocol. Each packet is organized as follows:
121 SYN The first character is always a SYN (ASCII 026, or ^V). SYN
122 may not appear anywhere else in the packet. Any time a SYN is
123 seen, a new packet should be assumed to have begun.
126 This byte contains the upper five bits of the logical length
127 of the data section, plus a single bit indicating whether this
128 is a data packet or an acknowledgement. The documentation
129 indicates that this bit is 1 for a data packet, but the actual
130 board uses 1 for an acknowledgement. The value of the byte is
131 0x40 + (ack ? 0x20 : 0) + (len >> 6)
132 (we always have 0 <= len < 1024). Acknowledgement packets do
133 not carry data, and must have a data length of 0.
135 LEN1 This byte contains the lower six bits of the logical length of
136 the data section. The value is
139 SEQ This byte contains the six bit sequence number of the packet.
142 An acknowlegment packet contains the sequence number of the
143 packet being acknowledged plus 1 module 64. Data packets are
144 transmitted in sequence. There may only be one outstanding
145 unacknowledged data packet at a time. The sequence numbers
146 are independent in each direction. If an acknowledgement for
147 the previous packet is received (i.e., an acknowledgement with
148 the sequence number of the packet just sent) the packet just
149 sent should be retransmitted. If no acknowledgement is
150 received within a timeout period, the packet should be
151 retransmitted. This has an unfortunate failure condition on a
152 high-latency line, as a delayed acknowledgement may lead to an
153 endless series of duplicate packets.
155 DATA The actual data bytes follow. The following characters are
156 escaped inline with DLE (ASCII 020, or ^P):
162 The additional DLE characters are not counted in the logical
163 length stored in the TYPE_LEN and LEN1 bytes.
168 These bytes contain an 18 bit checksum of the complete
169 contents of the packet excluding the SEQ byte and the
170 CSUM[123] bytes. The checksum is simply the twos complement
171 addition of all the bytes treated as unsigned characters. The
172 values of the checksum bytes are:
173 CSUM1: 0x40 + ((cksum >> 12) & 0x3f)
174 CSUM2: 0x40 + ((cksum >> 6) & 0x3f)
175 CSUM3: 0x40 + (cksum & 0x3f)
177 It happens that the MIPS remote debugging protocol always
178 communicates with ASCII strings. Because of this, this
179 implementation doesn't bother to handle the DLE quoting mechanism,
180 since it will never be required. */
182 /* The SYN character which starts each packet. */
185 /* The 0x40 used to offset each packet (this value ensures that all of
186 the header and trailer bytes, other than SYN, are printable ASCII
188 #define HDR_OFFSET 0x40
190 /* The indices of the bytes in the packet header. */
191 #define HDR_INDX_SYN 0
192 #define HDR_INDX_TYPE_LEN 1
193 #define HDR_INDX_LEN1 2
194 #define HDR_INDX_SEQ 3
197 /* The data/ack bit in the TYPE_LEN header byte. */
198 #define TYPE_LEN_DA_BIT 0x20
199 #define TYPE_LEN_DATA 0
200 #define TYPE_LEN_ACK TYPE_LEN_DA_BIT
202 /* How to compute the header bytes. */
203 #define HDR_SET_SYN(data, len, seq) (SYN)
204 #define HDR_SET_TYPE_LEN(data, len, seq) \
206 + ((data) ? TYPE_LEN_DATA : TYPE_LEN_ACK) \
207 + (((len) >> 6) & 0x1f))
208 #define HDR_SET_LEN1(data, len, seq) (HDR_OFFSET + ((len) & 0x3f))
209 #define HDR_SET_SEQ(data, len, seq) (HDR_OFFSET + (seq))
211 /* Check that a header byte is reasonable. */
212 #define HDR_CHECK(ch) (((ch) & HDR_OFFSET) == HDR_OFFSET)
214 /* Get data from the header. These macros evaluate their argument
216 #define HDR_IS_DATA(hdr) \
217 (((hdr)[HDR_INDX_TYPE_LEN] & TYPE_LEN_DA_BIT) == TYPE_LEN_DATA)
218 #define HDR_GET_LEN(hdr) \
219 ((((hdr)[HDR_INDX_TYPE_LEN] & 0x1f) << 6) + (((hdr)[HDR_INDX_LEN1] & 0x3f)))
220 #define HDR_GET_SEQ(hdr) ((hdr)[HDR_INDX_SEQ] & 0x3f)
222 /* The maximum data length. */
223 #define DATA_MAXLEN 1023
225 /* The trailer offset. */
226 #define TRLR_OFFSET HDR_OFFSET
228 /* The indices of the bytes in the packet trailer. */
229 #define TRLR_INDX_CSUM1 0
230 #define TRLR_INDX_CSUM2 1
231 #define TRLR_INDX_CSUM3 2
232 #define TRLR_LENGTH 3
234 /* How to compute the trailer bytes. */
235 #define TRLR_SET_CSUM1(cksum) (TRLR_OFFSET + (((cksum) >> 12) & 0x3f))
236 #define TRLR_SET_CSUM2(cksum) (TRLR_OFFSET + (((cksum) >> 6) & 0x3f))
237 #define TRLR_SET_CSUM3(cksum) (TRLR_OFFSET + (((cksum) ) & 0x3f))
239 /* Check that a trailer byte is reasonable. */
240 #define TRLR_CHECK(ch) (((ch) & TRLR_OFFSET) == TRLR_OFFSET)
242 /* Get data from the trailer. This evaluates its argument multiple
244 #define TRLR_GET_CKSUM(trlr) \
245 ((((trlr)[TRLR_INDX_CSUM1] & 0x3f) << 12) \
246 + (((trlr)[TRLR_INDX_CSUM2] & 0x3f) << 6) \
247 + ((trlr)[TRLR_INDX_CSUM3] & 0x3f))
249 /* The sequence number modulos. */
250 #define SEQ_MODULOS (64)
252 /* Set to 1 if the target is open. */
253 static int mips_is_open
;
255 /* Set to 1 while the connection is being initialized. */
256 static int mips_initializing
;
258 /* The next sequence number to send. */
259 static int mips_send_seq
;
261 /* The next sequence number we expect to receive. */
262 static int mips_receive_seq
;
264 /* The time to wait before retransmitting a packet, in seconds. */
265 static int mips_retransmit_wait
= 3;
267 /* The number of times to try retransmitting a packet before giving up. */
268 static int mips_send_retries
= 10;
270 /* The number of garbage characters to accept when looking for an
271 SYN for the next packet. */
272 static int mips_syn_garbage
= 1050;
274 /* The time to wait for a packet, in seconds. */
275 static int mips_receive_wait
= 5;
277 /* Set if we have sent a packet to the board but have not yet received
279 static int mips_need_reply
= 0;
281 /* Handle used to access serial I/O stream. */
282 static serial_t mips_desc
;
284 /* Handle low-level error that we can't recover from. Note that just
285 error()ing out from target_wait or some such low-level place will cause
286 all hell to break loose--the rest of GDB will tend to get left in an
287 inconsistent state. */
290 mips_error (va_alist
)
297 target_terminal_ours ();
298 wrap_here(""); /* Force out any buffered output */
299 gdb_flush (gdb_stdout
);
301 fprintf_filtered (gdb_stderr
, error_pre_print
);
302 string
= va_arg (args
, char *);
303 vfprintf_filtered (gdb_stderr
, string
, args
);
304 fprintf_filtered (gdb_stderr
, "\n");
307 /* Clean up in such a way that mips_close won't try to talk to the
308 board (it almost surely won't work since we weren't able to talk to
311 SERIAL_CLOSE (mips_desc
);
313 printf_unfiltered ("Ending remote MIPS debugging.\n");
314 target_mourn_inferior ();
316 return_to_top_level (RETURN_ERROR
);
319 /* Read a character from the remote, aborting on error. Returns
320 SERIAL_TIMEOUT on timeout (since that's what SERIAL_READCHAR
321 returns). FIXME: If we see the string "<IDT>" from the board, then
322 we are debugging on the main console port, and we have somehow
323 dropped out of remote debugging mode. In this case, we
324 automatically go back in to remote debugging mode. This is a hack,
325 put in because I can't find any way for a program running on the
326 remote board to terminate without also ending remote debugging
327 mode. I assume users won't have any trouble with this; for one
328 thing, the IDT documentation generally assumes that the remote
329 debugging port is not the console port. This is, however, very
330 convenient for DejaGnu when you only have one connected serial
334 mips_readchar (timeout
)
338 static int state
= 0;
339 static char nextstate
[5] = { '<', 'I', 'D', 'T', '>' };
341 ch
= SERIAL_READCHAR (mips_desc
, timeout
);
342 if (ch
== SERIAL_EOF
)
343 mips_error ("End of file from remote");
344 if (ch
== SERIAL_ERROR
)
345 mips_error ("Error reading from remote: %s", safe_strerror (errno
));
346 if (sr_get_debug () > 1)
348 if (ch
!= SERIAL_TIMEOUT
)
349 printf_filtered ("Read '%c' %d 0x%x\n", ch
, ch
, ch
);
351 printf_filtered ("Timed out in read\n");
354 /* If we have seen <IDT> and we either time out, or we see a @
355 (which was echoed from a packet we sent), reset the board as
356 described above. The first character in a packet after the SYN
357 (which is not echoed) is always an @ unless the packet is more
358 than 64 characters long, which ours never are. */
359 if ((ch
== SERIAL_TIMEOUT
|| ch
== '@')
361 && ! mips_initializing
)
363 if (sr_get_debug () > 0)
364 printf_filtered ("Reinitializing MIPS debugging mode\n");
365 SERIAL_WRITE (mips_desc
, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
373 mips_error ("Remote board reset");
376 if (ch
== nextstate
[state
])
384 /* Get a packet header, putting the data in the supplied buffer.
385 PGARBAGE is a pointer to the number of garbage characters received
386 so far. CH is the last character received. Returns 0 for success,
387 or -1 for timeout. */
390 mips_receive_header (hdr
, pgarbage
, ch
, timeout
)
400 /* Wait for a SYN. mips_syn_garbage is intended to prevent
401 sitting here indefinitely if the board sends us one garbage
402 character per second. ch may already have a value from the
403 last time through the loop. */
406 ch
= mips_readchar (timeout
);
407 if (ch
== SERIAL_TIMEOUT
)
411 /* Printing the character here lets the user of gdb see
412 what the program is outputting, if the debugging is
413 being done on the console port. FIXME: Perhaps this
414 should be filtered? */
415 if (! mips_initializing
|| sr_get_debug () > 0)
417 putchar_unfiltered (ch
);
418 gdb_flush (gdb_stdout
);
422 if (*pgarbage
> mips_syn_garbage
)
423 mips_error ("Remote debugging protocol failure");
427 /* Get the packet header following the SYN. */
428 for (i
= 1; i
< HDR_LENGTH
; i
++)
430 ch
= mips_readchar (timeout
);
431 if (ch
== SERIAL_TIMEOUT
)
434 /* Make sure this is a header byte. */
435 if (ch
== SYN
|| ! HDR_CHECK (ch
))
441 /* If we got the complete header, we can return. Otherwise we
442 loop around and keep looking for SYN. */
448 /* Get a packet header, putting the data in the supplied buffer.
449 PGARBAGE is a pointer to the number of garbage characters received
450 so far. The last character read is returned in *PCH. Returns 0
451 for success, -1 for timeout, -2 for error. */
454 mips_receive_trailer (trlr
, pgarbage
, pch
, timeout
)
463 for (i
= 0; i
< TRLR_LENGTH
; i
++)
465 ch
= mips_readchar (timeout
);
467 if (ch
== SERIAL_TIMEOUT
)
469 if (! TRLR_CHECK (ch
))
476 /* Get the checksum of a packet. HDR points to the packet header.
477 DATA points to the packet data. LEN is the length of DATA. */
480 mips_cksum (hdr
, data
, len
)
481 const unsigned char *hdr
;
482 const unsigned char *data
;
485 register const unsigned char *p
;
491 /* The initial SYN is not included in the checksum. */
505 /* Send a packet containing the given ASCII string. */
508 mips_send_packet (s
, get_ack
)
513 unsigned char *packet
;
518 if (len
> DATA_MAXLEN
)
519 mips_error ("MIPS protocol data packet too long: %s", s
);
521 packet
= (unsigned char *) alloca (HDR_LENGTH
+ len
+ TRLR_LENGTH
+ 1);
523 packet
[HDR_INDX_SYN
] = HDR_SET_SYN (1, len
, mips_send_seq
);
524 packet
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (1, len
, mips_send_seq
);
525 packet
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (1, len
, mips_send_seq
);
526 packet
[HDR_INDX_SEQ
] = HDR_SET_SEQ (1, len
, mips_send_seq
);
528 memcpy (packet
+ HDR_LENGTH
, s
, len
);
530 cksum
= mips_cksum (packet
, packet
+ HDR_LENGTH
, len
);
531 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
532 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
533 packet
[HDR_LENGTH
+ len
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
535 /* Increment the sequence number. This will set mips_send_seq to
536 the sequence number we expect in the acknowledgement. */
537 mips_send_seq
= (mips_send_seq
+ 1) % SEQ_MODULOS
;
542 /* We can only have one outstanding data packet, so we just wait for
543 the acknowledgement here. Keep retransmitting the packet until
544 we get one, or until we've tried too many times. */
545 for (try = 0; try < mips_send_retries
; try++)
550 if (sr_get_debug () > 0)
552 packet
[HDR_LENGTH
+ len
+ TRLR_LENGTH
] = '\0';
553 printf_filtered ("Writing \"%s\"\n", packet
+ 1);
556 if (SERIAL_WRITE (mips_desc
, packet
,
557 HDR_LENGTH
+ len
+ TRLR_LENGTH
) != 0)
558 mips_error ("write to target failed: %s", safe_strerror (errno
));
564 unsigned char hdr
[HDR_LENGTH
+ 1];
565 unsigned char trlr
[TRLR_LENGTH
+ 1];
569 /* Get the packet header. If we time out, resend the data
571 err
= mips_receive_header (hdr
, &garbage
, ch
, mips_retransmit_wait
);
577 /* If we get a data packet, assume it is a duplicate and
578 ignore it. FIXME: If the acknowledgement is lost, this
579 data packet may be the packet the remote sends after the
581 if (HDR_IS_DATA (hdr
))
584 /* If the length is not 0, this is a garbled packet. */
585 if (HDR_GET_LEN (hdr
) != 0)
588 /* Get the packet trailer. */
589 err
= mips_receive_trailer (trlr
, &garbage
, &ch
,
590 mips_retransmit_wait
);
592 /* If we timed out, resend the data packet. */
596 /* If we got a bad character, reread the header. */
600 /* If the checksum does not match the trailer checksum, this
601 is a bad packet; ignore it. */
602 if (mips_cksum (hdr
, (unsigned char *) NULL
, 0)
603 != TRLR_GET_CKSUM (trlr
))
606 if (sr_get_debug () > 0)
608 hdr
[HDR_LENGTH
] = '\0';
609 trlr
[TRLR_LENGTH
] = '\0';
610 printf_filtered ("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 if (sr_get_debug () > 0)
676 printf_filtered ("Ignoring unexpected ACK\n");
680 /* If this is the wrong sequence number, ignore it. */
681 if (HDR_GET_SEQ (hdr
) != mips_receive_seq
)
683 if (sr_get_debug () > 0)
684 printf_filtered ("Ignoring sequence number %d (want %d)\n",
685 HDR_GET_SEQ (hdr
), mips_receive_seq
);
689 len
= HDR_GET_LEN (hdr
);
691 for (i
= 0; i
< len
; i
++)
695 rch
= mips_readchar (timeout
);
701 if (rch
== SERIAL_TIMEOUT
)
704 mips_error ("Timed out waiting for remote packet");
713 if (sr_get_debug () > 0)
714 printf_filtered ("Got new SYN after %d chars (wanted %d)\n",
719 err
= mips_receive_trailer (trlr
, &garbage
, &ch
, timeout
);
723 mips_error ("Timed out waiting for packet");
729 if (sr_get_debug () > 0)
730 printf_filtered ("Got SYN when wanted trailer\n");
734 if (mips_cksum (hdr
, buff
, len
) == TRLR_GET_CKSUM (trlr
))
737 if (sr_get_debug () > 0)
738 printf_filtered ("Bad checksum; data %d, trailer %d\n",
739 mips_cksum (hdr
, buff
, len
),
740 TRLR_GET_CKSUM (trlr
));
742 /* The checksum failed. Send an acknowledgement for the
743 previous packet to tell the remote to resend the packet. */
744 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
745 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
746 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
747 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
749 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
751 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
752 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
753 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
755 if (sr_get_debug () > 0)
757 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
758 printf_filtered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
762 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
765 mips_error ("write to target failed: %s", safe_strerror (errno
));
771 if (sr_get_debug () > 0)
774 printf_filtered ("Got packet \"%s\"\n", buff
);
777 /* We got the packet. Send an acknowledgement. */
778 mips_receive_seq
= (mips_receive_seq
+ 1) % SEQ_MODULOS
;
780 ack
[HDR_INDX_SYN
] = HDR_SET_SYN (0, 0, mips_receive_seq
);
781 ack
[HDR_INDX_TYPE_LEN
] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq
);
782 ack
[HDR_INDX_LEN1
] = HDR_SET_LEN1 (0, 0, mips_receive_seq
);
783 ack
[HDR_INDX_SEQ
] = HDR_SET_SEQ (0, 0, mips_receive_seq
);
785 cksum
= mips_cksum (ack
, (unsigned char *) NULL
, 0);
787 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM1
] = TRLR_SET_CSUM1 (cksum
);
788 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM2
] = TRLR_SET_CSUM2 (cksum
);
789 ack
[HDR_LENGTH
+ TRLR_INDX_CSUM3
] = TRLR_SET_CSUM3 (cksum
);
791 if (sr_get_debug () > 0)
793 ack
[HDR_LENGTH
+ TRLR_LENGTH
] = '\0';
794 printf_filtered ("Writing ack %d \"%s\"\n", mips_receive_seq
,
798 if (SERIAL_WRITE (mips_desc
, ack
, HDR_LENGTH
+ TRLR_LENGTH
) != 0)
801 mips_error ("write to target failed: %s", safe_strerror (errno
));
809 /* Optionally send a request to the remote system and optionally wait
810 for the reply. This implements the remote debugging protocol,
811 which is built on top of the packet protocol defined above. Each
812 request has an ADDR argument and a DATA argument. The following
813 requests are defined:
815 \0 don't send a request; just wait for a reply
816 i read word from instruction space at ADDR
817 d read word from data space at ADDR
818 I write DATA to instruction space at ADDR
819 D write DATA to data space at ADDR
820 r read register number ADDR
821 R set register number ADDR to value DATA
822 c continue execution (if ADDR != 1, set pc to ADDR)
823 s single step (if ADDR != 1, set pc to ADDR)
825 The read requests return the value requested. The write requests
826 return the previous value in the changed location. The execution
827 requests return a UNIX wait value (the approximate signal which
828 caused execution to stop is in the upper eight bits).
830 If PERR is not NULL, this function waits for a reply. If an error
831 occurs, it sets *PERR to 1 and sets errno according to what the
832 target board reports. */
835 mips_request (cmd
, addr
, data
, perr
, timeout
)
842 char buff
[DATA_MAXLEN
+ 1];
852 fatal ("mips_request: Trying to send command before reply");
853 sprintf (buff
, "0x0 %c 0x%x 0x%x", cmd
, addr
, data
);
854 mips_send_packet (buff
, 1);
858 if (perr
== (int *) NULL
)
861 if (! mips_need_reply
)
862 fatal ("mips_request: Trying to get reply before command");
866 len
= mips_receive_packet (buff
, 1, timeout
);
869 if (sscanf (buff
, "0x%x %c 0x%x 0x%x",
870 &rpid
, &rcmd
, &rerrflg
, &rresponse
) != 4
871 || (cmd
!= '\0' && rcmd
!= cmd
))
872 mips_error ("Bad response from remote board");
878 /* FIXME: This will returns MIPS errno numbers, which may or may
879 not be the same as errno values used on other systems. If
880 they stick to common errno values, they will be the same, but
881 if they don't, they must be translated. */
891 /* Initialize a new connection to the MIPS board, and make sure we are
898 char buff
[DATA_MAXLEN
+ 1];
901 if (mips_initializing
)
904 mips_initializing
= 1;
907 mips_receive_seq
= 0;
909 /* The board seems to want to send us a packet. I don't know what
910 it means. The packet seems to be triggered by a carriage return
911 character, although perhaps any character would do. */
913 SERIAL_WRITE (mips_desc
, &cr
, 1);
915 if (mips_receive_packet (buff
, 0, 3) < 0)
919 /* We did not receive the packet we expected; try resetting the
920 board and trying again. */
921 printf_filtered ("Failed to initialize; trying to reset board\n");
923 SERIAL_WRITE (mips_desc
, &cc
, 1);
925 SERIAL_WRITE (mips_desc
, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
928 SERIAL_WRITE (mips_desc
, &cr
, 1);
930 mips_receive_packet (buff
, 1, 3);
932 mips_initializing
= 0;
934 /* If this doesn't call error, we have connected; we don't care if
935 the request itself succeeds or fails. */
936 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err
,
940 /* Open a connection to the remote board. */
943 mips_open (name
, from_tty
)
949 "To open a MIPS remote debugging connection, you need to specify what serial\n\
950 device is attached to the target board (e.g., /dev/ttya).");
952 target_preopen (from_tty
);
955 unpush_target (&mips_ops
);
957 mips_desc
= SERIAL_OPEN (name
);
958 if (mips_desc
== (serial_t
) NULL
)
959 perror_with_name (name
);
961 SERIAL_RAW (mips_desc
);
968 printf_unfiltered ("Remote MIPS debugging using %s\n", name
);
969 push_target (&mips_ops
); /* Switch to using remote target now */
971 /* FIXME: Should we call start_remote here? */
974 /* Close a connection to the remote board. */
977 mips_close (quitting
)
986 /* Get the board out of remote debugging mode. */
987 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err
,
990 SERIAL_CLOSE (mips_desc
);
994 /* Detach from the remote board. */
997 mips_detach (args
, from_tty
)
1002 error ("Argument given to \"detach\" when remotely debugging.");
1006 printf_unfiltered ("Ending remote MIPS debugging.\n");
1009 /* Tell the target board to resume. This does not wait for a reply
1013 mips_resume (pid
, step
, siggnal
)
1015 enum target_signal siggnal
;
1017 if (siggnal
!= TARGET_SIGNAL_0
)
1019 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1020 target_signal_to_name (siggnal
));
1022 mips_request (step
? 's' : 'c',
1029 /* Wait until the remote stops, and return a wait status. */
1032 mips_wait (pid
, status
)
1034 struct target_waitstatus
*status
;
1039 /* If we have not sent a single step or continue command, then the
1040 board is waiting for us to do something. Return a status
1041 indicating that it is stopped. */
1042 if (! mips_need_reply
)
1044 status
->kind
= TARGET_WAITKIND_STOPPED
;
1045 status
->value
.sig
= TARGET_SIGNAL_TRAP
;
1049 /* No timeout; we sit here as long as the program continues to execute. */
1050 rstatus
= mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err
, -1);
1052 mips_error ("Remote failure: %s", safe_strerror (errno
));
1054 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1055 and so on, because the constants we want here are determined by the
1056 MIPS protocol and have nothing to do with what host we are running on. */
1057 if ((rstatus
& 0377) == 0)
1059 status
->kind
= TARGET_WAITKIND_EXITED
;
1060 status
->value
.integer
= (((rstatus
) >> 8) & 0377);
1062 else if ((rstatus
& 0377) == 0177)
1064 status
->kind
= TARGET_WAITKIND_STOPPED
;
1065 /* Don't want to use target_signal_from_host because we are converting
1066 from MIPS signal numbers, not host ones. Our internal numbers
1067 match the MIPS numbers for the signals the board can return, which
1068 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1069 status
->value
.sig
= (enum target_signal
) (((rstatus
) >> 8) & 0377);
1073 status
->kind
= TARGET_WAITKIND_SIGNALLED
;
1074 /* Don't want to use target_signal_from_host because we are converting
1075 from MIPS signal numbers, not host ones. Our internal numbers
1076 match the MIPS numbers for the signals the board can return, which
1077 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1078 status
->value
.sig
= (enum target_signal
) (rstatus
& 0177);
1084 /* We have to map between the register numbers used by gdb and the
1085 register numbers used by the debugging protocol. This function
1086 assumes that we are using tm-mips.h. */
1088 #define REGNO_OFFSET 96
1091 mips_map_regno (regno
)
1096 if (regno
>= FP0_REGNUM
&& regno
< FP0_REGNUM
+ 32)
1097 return regno
- FP0_REGNUM
+ 32;
1101 return REGNO_OFFSET
+ 0;
1103 return REGNO_OFFSET
+ 1;
1105 return REGNO_OFFSET
+ 2;
1107 return REGNO_OFFSET
+ 3;
1109 return REGNO_OFFSET
+ 4;
1111 return REGNO_OFFSET
+ 5;
1113 /* FIXME: Is there a way to get the status register? */
1118 /* Fetch the remote registers. */
1121 mips_fetch_registers (regno
)
1124 unsigned LONGEST val
;
1129 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1130 mips_fetch_registers (regno
);
1134 val
= mips_request ('r', (unsigned int) mips_map_regno (regno
),
1135 (unsigned int) 0, &err
, mips_receive_wait
);
1137 mips_error ("Can't read register %d: %s", regno
, safe_strerror (errno
));
1140 char buf
[MAX_REGISTER_RAW_SIZE
];
1142 /* We got the number the register holds, but gdb expects to see a
1143 value in the target byte ordering. */
1144 store_unsigned_integer (buf
, REGISTER_RAW_SIZE (regno
), val
);
1145 supply_register (regno
, buf
);
1149 /* Prepare to store registers. The MIPS protocol can store individual
1150 registers, so this function doesn't have to do anything. */
1153 mips_prepare_to_store ()
1157 /* Store remote register(s). */
1160 mips_store_registers (regno
)
1167 for (regno
= 0; regno
< NUM_REGS
; regno
++)
1168 mips_store_registers (regno
);
1172 mips_request ('R', (unsigned int) mips_map_regno (regno
),
1173 (unsigned int) read_register (regno
),
1174 &err
, mips_receive_wait
);
1176 mips_error ("Can't write register %d: %s", regno
, safe_strerror (errno
));
1179 /* Fetch a word from the target board. */
1182 mips_fetch_word (addr
)
1188 val
= mips_request ('d', (unsigned int) addr
, (unsigned int) 0, &err
,
1192 /* Data space failed; try instruction space. */
1193 val
= mips_request ('i', (unsigned int) addr
, (unsigned int) 0, &err
,
1196 mips_error ("Can't read address 0x%x: %s", addr
, safe_strerror (errno
));
1201 /* Store a word to the target board. */
1204 mips_store_word (addr
, val
)
1210 mips_request ('D', (unsigned int) addr
, (unsigned int) val
, &err
,
1214 /* Data space failed; try instruction space. */
1215 mips_request ('I', (unsigned int) addr
, (unsigned int) val
, &err
,
1218 mips_error ("Can't write address 0x%x: %s", addr
, safe_strerror (errno
));
1222 /* Read or write LEN bytes from inferior memory at MEMADDR,
1223 transferring to or from debugger address MYADDR. Write to inferior
1224 if SHOULD_WRITE is nonzero. Returns length of data written or
1225 read; 0 for error. Note that protocol gives us the correct value
1226 for a longword, since it transfers values in ASCII. We want the
1227 byte values, so we have to swap the longword values. */
1230 mips_xfer_memory (memaddr
, myaddr
, len
, write
, ignore
)
1235 struct target_ops
*ignore
;
1238 /* Round starting address down to longword boundary. */
1239 register CORE_ADDR addr
= memaddr
&~ 3;
1240 /* Round ending address up; get number of longwords that makes. */
1241 register int count
= (((memaddr
+ len
) - addr
) + 3) / 4;
1242 /* Allocate buffer of that many longwords. */
1243 register char *buffer
= alloca (count
* 4);
1247 /* Fill start and end extra bytes of buffer with existing data. */
1248 if (addr
!= memaddr
|| len
< 4)
1250 /* Need part of initial word -- fetch it. */
1251 store_unsigned_integer (&buffer
[0], 4, mips_fetch_word (addr
));
1256 /* Need part of last word -- fetch it. FIXME: we do this even
1257 if we don't need it. */
1258 store_unsigned_integer (&buffer
[(count
- 1) * 4], 4,
1259 mips_fetch_word (addr
+ (count
- 1) * 4));
1262 /* Copy data to be written over corresponding part of buffer */
1264 memcpy ((char *) buffer
+ (memaddr
& 3), myaddr
, len
);
1266 /* Write the entire buffer. */
1268 for (i
= 0; i
< count
; i
++, addr
+= 4)
1270 mips_store_word (addr
, extract_unsigned_integer (&buffer
[i
*4], 4));
1271 /* FIXME: Do we want a QUIT here? */
1276 /* Read all the longwords */
1277 for (i
= 0; i
< count
; i
++, addr
+= 4)
1279 store_unsigned_integer (&buffer
[i
*4], 4, mips_fetch_word (addr
));
1283 /* Copy appropriate bytes out of the buffer. */
1284 memcpy (myaddr
, buffer
+ (memaddr
& 3), len
);
1289 /* Print info on this target. */
1292 mips_files_info (ignore
)
1293 struct target_ops
*ignore
;
1295 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1298 /* Kill the process running on the board. This will actually only
1299 work if we are doing remote debugging over the console input. I
1300 think that if IDT/sim had the remote debug interrupt enabled on the
1301 right port, we could interrupt the process with a break signal. */
1313 SERIAL_WRITE (mips_desc
, &cc
, 1);
1315 target_mourn_inferior ();
1320 /* Start running on the target board. */
1323 mips_create_inferior (execfile
, args
, env
)
1331 mips_error ("Can't pass arguments to remote MIPS board.");
1333 if (execfile
== 0 || exec_bfd
== 0)
1334 mips_error ("No exec file specified");
1336 entry_pt
= (CORE_ADDR
) bfd_get_start_address (exec_bfd
);
1338 init_wait_for_inferior ();
1340 /* FIXME: Should we set inferior_pid here? */
1342 proceed (entry_pt
, TARGET_SIGNAL_DEFAULT
, 0);
1345 /* Clean up after a process. Actually nothing to do. */
1348 mips_mourn_inferior ()
1350 unpush_target (&mips_ops
);
1351 generic_mourn_inferior ();
1354 /* The target vector. */
1356 struct target_ops mips_ops
=
1358 "mips", /* to_shortname */
1359 "Remote MIPS debugging over serial line", /* to_longname */
1360 "Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1361 Specify the serial device it is connected to (e.g., /dev/ttya).", /* to_doc */
1362 mips_open
, /* to_open */
1363 mips_close
, /* to_close */
1364 NULL
, /* to_attach */
1365 mips_detach
, /* to_detach */
1366 mips_resume
, /* to_resume */
1367 mips_wait
, /* to_wait */
1368 mips_fetch_registers
, /* to_fetch_registers */
1369 mips_store_registers
, /* to_store_registers */
1370 mips_prepare_to_store
, /* to_prepare_to_store */
1371 mips_xfer_memory
, /* to_xfer_memory */
1372 mips_files_info
, /* to_files_info */
1373 NULL
, /* to_insert_breakpoint */
1374 NULL
, /* to_remove_breakpoint */
1375 NULL
, /* to_terminal_init */
1376 NULL
, /* to_terminal_inferior */
1377 NULL
, /* to_terminal_ours_for_output */
1378 NULL
, /* to_terminal_ours */
1379 NULL
, /* to_terminal_info */
1380 mips_kill
, /* to_kill */
1381 generic_load
, /* to_load */
1382 NULL
, /* to_lookup_symbol */
1383 mips_create_inferior
, /* to_create_inferior */
1384 mips_mourn_inferior
, /* to_mourn_inferior */
1385 NULL
, /* to_can_run */
1386 NULL
, /* to_notice_signals */
1387 process_stratum
, /* to_stratum */
1389 1, /* to_has_all_memory */
1390 1, /* to_has_memory */
1391 1, /* to_has_stack */
1392 1, /* to_has_registers */
1393 1, /* to_has_execution */
1394 NULL
, /* sections */
1395 NULL
, /* sections_end */
1396 OPS_MAGIC
/* to_magic */
1400 _initialize_remote_mips ()
1402 add_target (&mips_ops
);
1405 add_set_cmd ("timeout", no_class
, var_zinteger
,
1406 (char *) &mips_receive_wait
,
1407 "Set timeout in seconds for remote MIPS serial I/O.",
1412 add_set_cmd ("retransmit-timeout", no_class
, var_zinteger
,
1413 (char *) &mips_retransmit_wait
,
1414 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1415 This is the number of seconds to wait for an acknowledgement to a packet\n\
1416 before resending the packet.", &setlist
),