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,
61 int *perr, int timeout));
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, struct target_waitstatus *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, char *old_contents));
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 /* Don't use _filtered; we can't deal with a QUIT out of
349 target_wait, and I think this might be called from there. */
350 if (ch != SERIAL_TIMEOUT)
351 printf_unfiltered ("Read '%c' %d 0x%x\n", ch, ch, ch);
353 printf_unfiltered ("Timed out in read\n");
356 /* If we have seen <IDT> and we either time out, or we see a @
357 (which was echoed from a packet we sent), reset the board as
358 described above. The first character in a packet after the SYN
359 (which is not echoed) is always an @ unless the packet is more
360 than 64 characters long, which ours never are. */
361 if ((ch == SERIAL_TIMEOUT || ch == '@')
363 && ! mips_initializing)
365 if (sr_get_debug () > 0)
366 /* Don't use _filtered; we can't deal with a QUIT out of
367 target_wait, and I think this might be called from there. */
368 printf_unfiltered ("Reinitializing MIPS debugging mode\n");
369 SERIAL_WRITE (mips_desc, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
377 mips_error ("Remote board reset");
380 if (ch == nextstate[state])
388 /* Get a packet header, putting the data in the supplied buffer.
389 PGARBAGE is a pointer to the number of garbage characters received
390 so far. CH is the last character received. Returns 0 for success,
391 or -1 for timeout. */
394 mips_receive_header (hdr, pgarbage, ch, timeout)
404 /* Wait for a SYN. mips_syn_garbage is intended to prevent
405 sitting here indefinitely if the board sends us one garbage
406 character per second. ch may already have a value from the
407 last time through the loop. */
410 ch = mips_readchar (timeout);
411 if (ch == SERIAL_TIMEOUT)
415 /* Printing the character here lets the user of gdb see
416 what the program is outputting, if the debugging is
417 being done on the console port. Don't use _filtered;
418 we can't deal with a QUIT out of target_wait. */
419 if (! mips_initializing || sr_get_debug () > 0)
421 putchar_unfiltered (ch);
422 gdb_flush (gdb_stdout);
426 if (*pgarbage > mips_syn_garbage)
427 mips_error ("Remote debugging protocol failure");
431 /* Get the packet header following the SYN. */
432 for (i = 1; i < HDR_LENGTH; i++)
434 ch = mips_readchar (timeout);
435 if (ch == SERIAL_TIMEOUT)
438 /* Make sure this is a header byte. */
439 if (ch == SYN || ! HDR_CHECK (ch))
445 /* If we got the complete header, we can return. Otherwise we
446 loop around and keep looking for SYN. */
452 /* Get a packet header, putting the data in the supplied buffer.
453 PGARBAGE is a pointer to the number of garbage characters received
454 so far. The last character read is returned in *PCH. Returns 0
455 for success, -1 for timeout, -2 for error. */
458 mips_receive_trailer (trlr, pgarbage, pch, timeout)
467 for (i = 0; i < TRLR_LENGTH; i++)
469 ch = mips_readchar (timeout);
471 if (ch == SERIAL_TIMEOUT)
473 if (! TRLR_CHECK (ch))
480 /* Get the checksum of a packet. HDR points to the packet header.
481 DATA points to the packet data. LEN is the length of DATA. */
484 mips_cksum (hdr, data, len)
485 const unsigned char *hdr;
486 const unsigned char *data;
489 register const unsigned char *p;
495 /* The initial SYN is not included in the checksum. */
509 /* Send a packet containing the given ASCII string. */
512 mips_send_packet (s, get_ack)
517 unsigned char *packet;
522 if (len > DATA_MAXLEN)
523 mips_error ("MIPS protocol data packet too long: %s", s);
525 packet = (unsigned char *) alloca (HDR_LENGTH + len + TRLR_LENGTH + 1);
527 packet[HDR_INDX_SYN] = HDR_SET_SYN (1, len, mips_send_seq);
528 packet[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (1, len, mips_send_seq);
529 packet[HDR_INDX_LEN1] = HDR_SET_LEN1 (1, len, mips_send_seq);
530 packet[HDR_INDX_SEQ] = HDR_SET_SEQ (1, len, mips_send_seq);
532 memcpy (packet + HDR_LENGTH, s, len);
534 cksum = mips_cksum (packet, packet + HDR_LENGTH, len);
535 packet[HDR_LENGTH + len + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
536 packet[HDR_LENGTH + len + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
537 packet[HDR_LENGTH + len + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
539 /* Increment the sequence number. This will set mips_send_seq to
540 the sequence number we expect in the acknowledgement. */
541 mips_send_seq = (mips_send_seq + 1) % SEQ_MODULOS;
546 /* We can only have one outstanding data packet, so we just wait for
547 the acknowledgement here. Keep retransmitting the packet until
548 we get one, or until we've tried too many times. */
549 for (try = 0; try < mips_send_retries; try++)
554 if (sr_get_debug () > 0)
556 /* Don't use _filtered; we can't deal with a QUIT out of
557 target_wait, and I think this might be called from there. */
558 packet[HDR_LENGTH + len + TRLR_LENGTH] = '\0';
559 printf_unfiltered ("Writing \"%s\"\n", packet + 1);
562 if (SERIAL_WRITE (mips_desc, packet,
563 HDR_LENGTH + len + TRLR_LENGTH) != 0)
564 mips_error ("write to target failed: %s", safe_strerror (errno));
570 unsigned char hdr[HDR_LENGTH + 1];
571 unsigned char trlr[TRLR_LENGTH + 1];
575 /* Get the packet header. If we time out, resend the data
577 err = mips_receive_header (hdr, &garbage, ch, mips_retransmit_wait);
583 /* If we get a data packet, assume it is a duplicate and
584 ignore it. FIXME: If the acknowledgement is lost, this
585 data packet may be the packet the remote sends after the
587 if (HDR_IS_DATA (hdr))
590 /* If the length is not 0, this is a garbled packet. */
591 if (HDR_GET_LEN (hdr) != 0)
594 /* Get the packet trailer. */
595 err = mips_receive_trailer (trlr, &garbage, &ch,
596 mips_retransmit_wait);
598 /* If we timed out, resend the data packet. */
602 /* If we got a bad character, reread the header. */
606 /* If the checksum does not match the trailer checksum, this
607 is a bad packet; ignore it. */
608 if (mips_cksum (hdr, (unsigned char *) NULL, 0)
609 != TRLR_GET_CKSUM (trlr))
612 if (sr_get_debug () > 0)
614 hdr[HDR_LENGTH] = '\0';
615 trlr[TRLR_LENGTH] = '\0';
616 /* Don't use _filtered; we can't deal with a QUIT out of
617 target_wait, and I think this might be called from there. */
618 printf_unfiltered ("Got ack %d \"%s%s\"\n",
619 HDR_GET_SEQ (hdr), hdr + 1, trlr);
622 /* If this ack is for the current packet, we're done. */
623 seq = HDR_GET_SEQ (hdr);
624 if (seq == mips_send_seq)
627 /* If this ack is for the last packet, resend the current
629 if ((seq + 1) % SEQ_MODULOS == mips_send_seq)
632 /* Otherwise this is a bad ack; ignore it. Increment the
633 garbage count to ensure that we do not stay in this loop
639 mips_error ("Remote did not acknowledge packet");
642 /* Receive and acknowledge a packet, returning the data in BUFF (which
643 should be DATA_MAXLEN + 1 bytes). The protocol documentation
644 implies that only the sender retransmits packets, so this code just
645 waits silently for a packet. It returns the length of the received
646 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
647 don't print an error message and return -1. */
650 mips_receive_packet (buff, throw_error, timeout)
658 unsigned char ack[HDR_LENGTH + TRLR_LENGTH + 1];
665 unsigned char hdr[HDR_LENGTH];
666 unsigned char trlr[TRLR_LENGTH];
670 if (mips_receive_header (hdr, &garbage, ch, timeout) != 0)
673 mips_error ("Timed out waiting for remote packet");
680 /* An acknowledgement is probably a duplicate; ignore it. */
681 if (! HDR_IS_DATA (hdr))
683 /* Don't use _filtered; we can't deal with a QUIT out of
684 target_wait, and I think this might be called from there. */
685 if (sr_get_debug () > 0)
686 printf_unfiltered ("Ignoring unexpected ACK\n");
690 /* If this is the wrong sequence number, ignore it. */
691 if (HDR_GET_SEQ (hdr) != mips_receive_seq)
693 /* Don't use _filtered; we can't deal with a QUIT out of
694 target_wait, and I think this might be called from there. */
695 if (sr_get_debug () > 0)
696 printf_unfiltered ("Ignoring sequence number %d (want %d)\n",
697 HDR_GET_SEQ (hdr), mips_receive_seq);
701 len = HDR_GET_LEN (hdr);
703 for (i = 0; i < len; i++)
707 rch = mips_readchar (timeout);
713 if (rch == SERIAL_TIMEOUT)
716 mips_error ("Timed out waiting for remote packet");
725 /* Don't use _filtered; we can't deal with a QUIT out of
726 target_wait, and I think this might be called from there. */
727 if (sr_get_debug () > 0)
728 printf_unfiltered ("Got new SYN after %d chars (wanted %d)\n",
733 err = mips_receive_trailer (trlr, &garbage, &ch, timeout);
737 mips_error ("Timed out waiting for packet");
743 /* Don't use _filtered; we can't deal with a QUIT out of
744 target_wait, and I think this might be called from there. */
745 if (sr_get_debug () > 0)
746 printf_unfiltered ("Got SYN when wanted trailer\n");
750 if (mips_cksum (hdr, buff, len) == TRLR_GET_CKSUM (trlr))
753 if (sr_get_debug () > 0)
754 /* Don't use _filtered; we can't deal with a QUIT out of
755 target_wait, and I think this might be called from there. */
756 printf_unfiltered ("Bad checksum; data %d, trailer %d\n",
757 mips_cksum (hdr, buff, len),
758 TRLR_GET_CKSUM (trlr));
760 /* The checksum failed. Send an acknowledgement for the
761 previous packet to tell the remote to resend the packet. */
762 ack[HDR_INDX_SYN] = HDR_SET_SYN (0, 0, mips_receive_seq);
763 ack[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq);
764 ack[HDR_INDX_LEN1] = HDR_SET_LEN1 (0, 0, mips_receive_seq);
765 ack[HDR_INDX_SEQ] = HDR_SET_SEQ (0, 0, mips_receive_seq);
767 cksum = mips_cksum (ack, (unsigned char *) NULL, 0);
769 ack[HDR_LENGTH + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
770 ack[HDR_LENGTH + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
771 ack[HDR_LENGTH + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
773 if (sr_get_debug () > 0)
775 ack[HDR_LENGTH + TRLR_LENGTH] = '\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 ("Writing ack %d \"%s\"\n", mips_receive_seq,
782 if (SERIAL_WRITE (mips_desc, ack, HDR_LENGTH + TRLR_LENGTH) != 0)
785 mips_error ("write to target failed: %s", safe_strerror (errno));
791 if (sr_get_debug () > 0)
794 /* Don't use _filtered; we can't deal with a QUIT out of
795 target_wait, and I think this might be called from there. */
796 printf_unfiltered ("Got packet \"%s\"\n", buff);
799 /* We got the packet. Send an acknowledgement. */
800 mips_receive_seq = (mips_receive_seq + 1) % SEQ_MODULOS;
802 ack[HDR_INDX_SYN] = HDR_SET_SYN (0, 0, mips_receive_seq);
803 ack[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq);
804 ack[HDR_INDX_LEN1] = HDR_SET_LEN1 (0, 0, mips_receive_seq);
805 ack[HDR_INDX_SEQ] = HDR_SET_SEQ (0, 0, mips_receive_seq);
807 cksum = mips_cksum (ack, (unsigned char *) NULL, 0);
809 ack[HDR_LENGTH + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
810 ack[HDR_LENGTH + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
811 ack[HDR_LENGTH + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
813 if (sr_get_debug () > 0)
815 ack[HDR_LENGTH + TRLR_LENGTH] = '\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 ("Writing ack %d \"%s\"\n", mips_receive_seq,
822 if (SERIAL_WRITE (mips_desc, ack, HDR_LENGTH + TRLR_LENGTH) != 0)
825 mips_error ("write to target failed: %s", safe_strerror (errno));
833 /* Optionally send a request to the remote system and optionally wait
834 for the reply. This implements the remote debugging protocol,
835 which is built on top of the packet protocol defined above. Each
836 request has an ADDR argument and a DATA argument. The following
837 requests are defined:
839 \0 don't send a request; just wait for a reply
840 i read word from instruction space at ADDR
841 d read word from data space at ADDR
842 I write DATA to instruction space at ADDR
843 D write DATA to data space at ADDR
844 r read register number ADDR
845 R set register number ADDR to value DATA
846 c continue execution (if ADDR != 1, set pc to ADDR)
847 s single step (if ADDR != 1, set pc to ADDR)
849 The read requests return the value requested. The write requests
850 return the previous value in the changed location. The execution
851 requests return a UNIX wait value (the approximate signal which
852 caused execution to stop is in the upper eight bits).
854 If PERR is not NULL, this function waits for a reply. If an error
855 occurs, it sets *PERR to 1 and sets errno according to what the
856 target board reports. */
859 mips_request (cmd, addr, data, perr, timeout)
866 char buff[DATA_MAXLEN + 1];
876 fatal ("mips_request: Trying to send command before reply");
877 sprintf (buff, "0x0 %c 0x%x 0x%x", cmd, addr, data);
878 mips_send_packet (buff, 1);
882 if (perr == (int *) NULL)
885 if (! mips_need_reply)
886 fatal ("mips_request: Trying to get reply before command");
890 len = mips_receive_packet (buff, 1, timeout);
893 if (sscanf (buff, "0x%x %c 0x%x 0x%x",
894 &rpid, &rcmd, &rerrflg, &rresponse) != 4
895 || (cmd != '\0' && rcmd != cmd))
896 mips_error ("Bad response from remote board");
902 /* FIXME: This will returns MIPS errno numbers, which may or may
903 not be the same as errno values used on other systems. If
904 they stick to common errno values, they will be the same, but
905 if they don't, they must be translated. */
916 mips_initialize_cleanups (arg)
919 mips_initializing = 0;
922 /* Initialize a new connection to the MIPS board, and make sure we are
929 char buff[DATA_MAXLEN + 1];
931 struct cleanup *old_cleanups = make_cleanup (mips_initialize_cleanups, NULL);
933 /* What is this code doing here? I don't see any way it can happen, and
934 it might mean mips_initializing didn't get cleared properly.
935 So I'll make it a warning. */
936 if (mips_initializing)
938 warning ("internal error: mips_initialize called twice");
942 mips_initializing = 1;
945 mips_receive_seq = 0;
947 /* The board seems to want to send us a packet. I don't know what
948 it means. The packet seems to be triggered by a carriage return
949 character, although perhaps any character would do. */
951 SERIAL_WRITE (mips_desc, &cr, 1);
953 if (mips_receive_packet (buff, 0, 3) < 0)
957 /* We did not receive the packet we expected; try resetting the
958 board and trying again. */
959 printf_filtered ("Failed to initialize; trying to reset board\n");
961 SERIAL_WRITE (mips_desc, &cc, 1);
963 SERIAL_WRITE (mips_desc, "\rdb tty0\r", sizeof "\rdb tty0\r" - 1);
966 SERIAL_WRITE (mips_desc, &cr, 1);
968 mips_receive_packet (buff, 1, 3);
970 do_cleanups (old_cleanups);
972 /* If this doesn't call error, we have connected; we don't care if
973 the request itself succeeds or fails. */
974 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err,
978 /* Open a connection to the remote board. */
981 mips_open (name, from_tty)
987 "To open a MIPS remote debugging connection, you need to specify what serial\n\
988 device is attached to the target board (e.g., /dev/ttya).");
990 target_preopen (from_tty);
993 unpush_target (&mips_ops);
995 mips_desc = SERIAL_OPEN (name);
996 if (mips_desc == (serial_t) NULL)
997 perror_with_name (name);
999 SERIAL_RAW (mips_desc);
1006 printf_unfiltered ("Remote MIPS debugging using %s\n", name);
1007 push_target (&mips_ops); /* Switch to using remote target now */
1009 /* FIXME: Should we call start_remote here? */
1012 /* Close a connection to the remote board. */
1015 mips_close (quitting)
1024 /* Get the board out of remote debugging mode. */
1025 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err,
1028 SERIAL_CLOSE (mips_desc);
1032 /* Detach from the remote board. */
1035 mips_detach (args, from_tty)
1040 error ("Argument given to \"detach\" when remotely debugging.");
1044 printf_unfiltered ("Ending remote MIPS debugging.\n");
1047 /* Tell the target board to resume. This does not wait for a reply
1051 mips_resume (pid, step, siggnal)
1053 enum target_signal siggnal;
1055 if (siggnal != TARGET_SIGNAL_0)
1057 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1058 target_signal_to_name (siggnal));
1060 mips_request (step ? 's' : 'c',
1067 /* Return the signal corresponding to SIG, where SIG is the number which
1068 the MIPS protocol uses for the signal. */
1070 mips_signal_from_protocol (sig)
1073 /* We allow a few more signals than the IDT board actually returns, on
1074 the theory that there is at least *some* hope that perhaps the numbering
1075 for these signals is widely agreed upon. */
1078 return TARGET_SIGNAL_UNKNOWN;
1080 /* Don't want to use target_signal_from_host because we are converting
1081 from MIPS signal numbers, not host ones. Our internal numbers
1082 match the MIPS numbers for the signals the board can return, which
1083 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1084 return (enum target_signal) sig;
1087 /* Wait until the remote stops, and return a wait status. */
1090 mips_wait (pid, status)
1092 struct target_waitstatus *status;
1097 /* If we have not sent a single step or continue command, then the
1098 board is waiting for us to do something. Return a status
1099 indicating that it is stopped. */
1100 if (! mips_need_reply)
1102 status->kind = TARGET_WAITKIND_STOPPED;
1103 status->value.sig = TARGET_SIGNAL_TRAP;
1107 /* No timeout; we sit here as long as the program continues to execute. */
1108 rstatus = mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err, -1);
1110 mips_error ("Remote failure: %s", safe_strerror (errno));
1112 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1113 and so on, because the constants we want here are determined by the
1114 MIPS protocol and have nothing to do with what host we are running on. */
1115 if ((rstatus & 0377) == 0)
1117 status->kind = TARGET_WAITKIND_EXITED;
1118 status->value.integer = (((rstatus) >> 8) & 0377);
1120 else if ((rstatus & 0377) == 0177)
1122 status->kind = TARGET_WAITKIND_STOPPED;
1123 status->value.sig = mips_signal_from_protocol (((rstatus) >> 8) & 0377);
1127 status->kind = TARGET_WAITKIND_SIGNALLED;
1128 status->value.sig = mips_signal_from_protocol (rstatus & 0177);
1134 /* We have to map between the register numbers used by gdb and the
1135 register numbers used by the debugging protocol. This function
1136 assumes that we are using tm-mips.h. */
1138 #define REGNO_OFFSET 96
1141 mips_map_regno (regno)
1146 if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
1147 return regno - FP0_REGNUM + 32;
1151 return REGNO_OFFSET + 0;
1153 return REGNO_OFFSET + 1;
1155 return REGNO_OFFSET + 2;
1157 return REGNO_OFFSET + 3;
1159 return REGNO_OFFSET + 4;
1161 return REGNO_OFFSET + 5;
1163 /* FIXME: Is there a way to get the status register? */
1168 /* Fetch the remote registers. */
1171 mips_fetch_registers (regno)
1174 unsigned LONGEST val;
1179 for (regno = 0; regno < NUM_REGS; regno++)
1180 mips_fetch_registers (regno);
1184 val = mips_request ('r', (unsigned int) mips_map_regno (regno),
1185 (unsigned int) 0, &err, mips_receive_wait);
1187 mips_error ("Can't read register %d: %s", regno, safe_strerror (errno));
1190 char buf[MAX_REGISTER_RAW_SIZE];
1192 /* We got the number the register holds, but gdb expects to see a
1193 value in the target byte ordering. */
1194 store_unsigned_integer (buf, REGISTER_RAW_SIZE (regno), val);
1195 supply_register (regno, buf);
1199 /* Prepare to store registers. The MIPS protocol can store individual
1200 registers, so this function doesn't have to do anything. */
1203 mips_prepare_to_store ()
1207 /* Store remote register(s). */
1210 mips_store_registers (regno)
1217 for (regno = 0; regno < NUM_REGS; regno++)
1218 mips_store_registers (regno);
1222 mips_request ('R', (unsigned int) mips_map_regno (regno),
1223 (unsigned int) read_register (regno),
1224 &err, mips_receive_wait);
1226 mips_error ("Can't write register %d: %s", regno, safe_strerror (errno));
1229 /* Fetch a word from the target board. */
1232 mips_fetch_word (addr)
1238 val = mips_request ('d', (unsigned int) addr, (unsigned int) 0, &err,
1242 /* Data space failed; try instruction space. */
1243 val = mips_request ('i', (unsigned int) addr, (unsigned int) 0, &err,
1246 mips_error ("Can't read address 0x%x: %s", addr, safe_strerror (errno));
1251 /* Store a word to the target board. Returns errno code or zero for
1252 success. If OLD_CONTENTS is non-NULL, put the old contents of that
1253 memory location there. */
1256 mips_store_word (addr, val, old_contents)
1262 unsigned int oldcontents;
1264 oldcontents = mips_request ('D', (unsigned int) addr, (unsigned int) val,
1269 /* Data space failed; try instruction space. */
1270 oldcontents = mips_request ('I', (unsigned int) addr,
1271 (unsigned int) val, &err,
1276 if (old_contents != NULL)
1277 store_unsigned_integer (old_contents, 4, oldcontents);
1281 /* Read or write LEN bytes from inferior memory at MEMADDR,
1282 transferring to or from debugger address MYADDR. Write to inferior
1283 if SHOULD_WRITE is nonzero. Returns length of data written or
1284 read; 0 for error. Note that protocol gives us the correct value
1285 for a longword, since it transfers values in ASCII. We want the
1286 byte values, so we have to swap the longword values. */
1289 mips_xfer_memory (memaddr, myaddr, len, write, ignore)
1294 struct target_ops *ignore;
1297 /* Round starting address down to longword boundary. */
1298 register CORE_ADDR addr = memaddr &~ 3;
1299 /* Round ending address up; get number of longwords that makes. */
1300 register int count = (((memaddr + len) - addr) + 3) / 4;
1301 /* Allocate buffer of that many longwords. */
1302 register char *buffer = alloca (count * 4);
1308 /* Fill start and end extra bytes of buffer with existing data. */
1309 if (addr != memaddr || len < 4)
1311 /* Need part of initial word -- fetch it. */
1312 store_unsigned_integer (&buffer[0], 4, mips_fetch_word (addr));
1317 /* Need part of last word -- fetch it. FIXME: we do this even
1318 if we don't need it. */
1319 store_unsigned_integer (&buffer[(count - 1) * 4], 4,
1320 mips_fetch_word (addr + (count - 1) * 4));
1323 /* Copy data to be written over corresponding part of buffer */
1325 memcpy ((char *) buffer + (memaddr & 3), myaddr, len);
1327 /* Write the entire buffer. */
1329 for (i = 0; i < count; i++, addr += 4)
1331 status = mips_store_word (addr,
1332 extract_unsigned_integer (&buffer[i*4], 4),
1339 /* FIXME: Do we want a QUIT here? */
1344 /* Read all the longwords */
1345 for (i = 0; i < count; i++, addr += 4)
1347 store_unsigned_integer (&buffer[i*4], 4, mips_fetch_word (addr));
1351 /* Copy appropriate bytes out of the buffer. */
1352 memcpy (myaddr, buffer + (memaddr & 3), len);
1357 /* Print info on this target. */
1360 mips_files_info (ignore)
1361 struct target_ops *ignore;
1363 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1366 /* Kill the process running on the board. This will actually only
1367 work if we are doing remote debugging over the console input. I
1368 think that if IDT/sim had the remote debug interrupt enabled on the
1369 right port, we could interrupt the process with a break signal. */
1381 SERIAL_WRITE (mips_desc, &cc, 1);
1383 target_mourn_inferior ();
1388 /* Start running on the target board. */
1391 mips_create_inferior (execfile, args, env)
1401 Can't pass arguments to remote MIPS board; arguments ignored.");
1402 /* And don't try to use them on the next "run" command. */
1403 execute_command ("set args", 0);
1406 if (execfile == 0 || exec_bfd == 0)
1407 error ("No executable file specified");
1409 entry_pt = (CORE_ADDR) bfd_get_start_address (exec_bfd);
1411 init_wait_for_inferior ();
1413 /* FIXME: Should we set inferior_pid here? */
1415 proceed (entry_pt, TARGET_SIGNAL_DEFAULT, 0);
1418 /* Clean up after a process. Actually nothing to do. */
1421 mips_mourn_inferior ()
1423 unpush_target (&mips_ops);
1424 generic_mourn_inferior ();
1427 /* We can write a breakpoint and read the shadow contents in one
1430 /* The IDT board uses an unusual breakpoint value, and sometimes gets
1431 confused when it sees the usual MIPS breakpoint instruction. */
1433 #if TARGET_BYTE_ORDER == BIG_ENDIAN
1434 static unsigned char break_insn[] = {0, 0, 0x0a, 0x0d};
1436 static unsigned char break_insn[] = {0x0d, 0x0a, 0, 0};
1439 /* Insert a breakpoint on targets that don't have any better breakpoint
1440 support. We read the contents of the target location and stash it,
1441 then overwrite it with a breakpoint instruction. ADDR is the target
1442 location in the target machine. CONTENTS_CACHE is a pointer to
1443 memory allocated for saving the target contents. It is guaranteed
1444 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1445 is accomplished via BREAKPOINT_MAX). */
1448 mips_insert_breakpoint (addr, contents_cache)
1450 char *contents_cache;
1455 mips_store_word (addr,
1456 extract_unsigned_integer (break_insn, sizeof break_insn),
1461 mips_remove_breakpoint (addr, contents_cache)
1463 char *contents_cache;
1465 return target_write_memory (addr, contents_cache, sizeof break_insn);
1468 /* The target vector. */
1470 struct target_ops mips_ops =
1472 "mips", /* to_shortname */
1473 "Remote MIPS debugging over serial line", /* to_longname */
1475 Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1476 The argument is the device it is connected to or, if it contains a colon,\n\
1477 HOST:PORT to access a board over a network", /* to_doc */
1478 mips_open, /* to_open */
1479 mips_close, /* to_close */
1480 NULL, /* to_attach */
1481 mips_detach, /* to_detach */
1482 mips_resume, /* to_resume */
1483 mips_wait, /* to_wait */
1484 mips_fetch_registers, /* to_fetch_registers */
1485 mips_store_registers, /* to_store_registers */
1486 mips_prepare_to_store, /* to_prepare_to_store */
1487 mips_xfer_memory, /* to_xfer_memory */
1488 mips_files_info, /* to_files_info */
1489 mips_insert_breakpoint, /* to_insert_breakpoint */
1490 mips_remove_breakpoint, /* to_remove_breakpoint */
1491 NULL, /* to_terminal_init */
1492 NULL, /* to_terminal_inferior */
1493 NULL, /* to_terminal_ours_for_output */
1494 NULL, /* to_terminal_ours */
1495 NULL, /* to_terminal_info */
1496 mips_kill, /* to_kill */
1497 generic_load, /* to_load */
1498 NULL, /* to_lookup_symbol */
1499 mips_create_inferior, /* to_create_inferior */
1500 mips_mourn_inferior, /* to_mourn_inferior */
1501 NULL, /* to_can_run */
1502 NULL, /* to_notice_signals */
1503 process_stratum, /* to_stratum */
1505 1, /* to_has_all_memory */
1506 1, /* to_has_memory */
1507 1, /* to_has_stack */
1508 1, /* to_has_registers */
1509 1, /* to_has_execution */
1510 NULL, /* sections */
1511 NULL, /* sections_end */
1512 OPS_MAGIC /* to_magic */
1516 _initialize_remote_mips ()
1518 add_target (&mips_ops);
1521 add_set_cmd ("timeout", no_class, var_zinteger,
1522 (char *) &mips_receive_wait,
1523 "Set timeout in seconds for remote MIPS serial I/O.",
1528 add_set_cmd ("retransmit-timeout", no_class, var_zinteger,
1529 (char *) &mips_retransmit_wait,
1530 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1531 This is the number of seconds to wait for an acknowledgement to a packet\n\
1532 before resending the packet.", &setlist),