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_create_inferior PARAMS ((char *execfile, char *args, char **env));
110 mips_mourn_inferior PARAMS ((void));
112 /* A forward declaration. */
113 extern struct target_ops mips_ops;
115 /* The MIPS remote debugging interface is built on top of a simple
116 packet protocol. Each packet is organized as follows:
118 SYN The first character is always a SYN (ASCII 026, or ^V). SYN
119 may not appear anywhere else in the packet. Any time a SYN is
120 seen, a new packet should be assumed to have begun.
123 This byte contains the upper five bits of the logical length
124 of the data section, plus a single bit indicating whether this
125 is a data packet or an acknowledgement. The documentation
126 indicates that this bit is 1 for a data packet, but the actual
127 board uses 1 for an acknowledgement. The value of the byte is
128 0x40 + (ack ? 0x20 : 0) + (len >> 6)
129 (we always have 0 <= len < 1024). Acknowledgement packets do
130 not carry data, and must have a data length of 0.
132 LEN1 This byte contains the lower six bits of the logical length of
133 the data section. The value is
136 SEQ This byte contains the six bit sequence number of the packet.
139 An acknowlegment packet contains the sequence number of the
140 packet being acknowledged plus 1 module 64. Data packets are
141 transmitted in sequence. There may only be one outstanding
142 unacknowledged data packet at a time. The sequence numbers
143 are independent in each direction. If an acknowledgement for
144 the previous packet is received (i.e., an acknowledgement with
145 the sequence number of the packet just sent) the packet just
146 sent should be retransmitted. If no acknowledgement is
147 received within a timeout period, the packet should be
148 retransmitted. This has an unfortunate failure condition on a
149 high-latency line, as a delayed acknowledgement may lead to an
150 endless series of duplicate packets.
152 DATA The actual data bytes follow. The following characters are
153 escaped inline with DLE (ASCII 020, or ^P):
159 The additional DLE characters are not counted in the logical
160 length stored in the TYPE_LEN and LEN1 bytes.
165 These bytes contain an 18 bit checksum of the complete
166 contents of the packet excluding the SEQ byte and the
167 CSUM[123] bytes. The checksum is simply the twos complement
168 addition of all the bytes treated as unsigned characters. The
169 values of the checksum bytes are:
170 CSUM1: 0x40 + ((cksum >> 12) & 0x3f)
171 CSUM2: 0x40 + ((cksum >> 6) & 0x3f)
172 CSUM3: 0x40 + (cksum & 0x3f)
174 It happens that the MIPS remote debugging protocol always
175 communicates with ASCII strings. Because of this, this
176 implementation doesn't bother to handle the DLE quoting mechanism,
177 since it will never be required. */
179 /* The SYN character which starts each packet. */
182 /* The 0x40 used to offset each packet (this value ensures that all of
183 the header and trailer bytes, other than SYN, are printable ASCII
185 #define HDR_OFFSET 0x40
187 /* The indices of the bytes in the packet header. */
188 #define HDR_INDX_SYN 0
189 #define HDR_INDX_TYPE_LEN 1
190 #define HDR_INDX_LEN1 2
191 #define HDR_INDX_SEQ 3
194 /* The data/ack bit in the TYPE_LEN header byte. */
195 #define TYPE_LEN_DA_BIT 0x20
196 #define TYPE_LEN_DATA 0
197 #define TYPE_LEN_ACK TYPE_LEN_DA_BIT
199 /* How to compute the header bytes. */
200 #define HDR_SET_SYN(data, len, seq) (SYN)
201 #define HDR_SET_TYPE_LEN(data, len, seq) \
203 + ((data) ? TYPE_LEN_DATA : TYPE_LEN_ACK) \
204 + (((len) >> 6) & 0x1f))
205 #define HDR_SET_LEN1(data, len, seq) (HDR_OFFSET + ((len) & 0x3f))
206 #define HDR_SET_SEQ(data, len, seq) (HDR_OFFSET + (seq))
208 /* Check that a header byte is reasonable. */
209 #define HDR_CHECK(ch) (((ch) & HDR_OFFSET) == HDR_OFFSET)
211 /* Get data from the header. These macros evaluate their argument
213 #define HDR_IS_DATA(hdr) \
214 (((hdr)[HDR_INDX_TYPE_LEN] & TYPE_LEN_DA_BIT) == TYPE_LEN_DATA)
215 #define HDR_GET_LEN(hdr) \
216 ((((hdr)[HDR_INDX_TYPE_LEN] & 0x1f) << 6) + (((hdr)[HDR_INDX_LEN1] & 0x3f)))
217 #define HDR_GET_SEQ(hdr) ((hdr)[HDR_INDX_SEQ] & 0x3f)
219 /* The maximum data length. */
220 #define DATA_MAXLEN 1023
222 /* The trailer offset. */
223 #define TRLR_OFFSET HDR_OFFSET
225 /* The indices of the bytes in the packet trailer. */
226 #define TRLR_INDX_CSUM1 0
227 #define TRLR_INDX_CSUM2 1
228 #define TRLR_INDX_CSUM3 2
229 #define TRLR_LENGTH 3
231 /* How to compute the trailer bytes. */
232 #define TRLR_SET_CSUM1(cksum) (TRLR_OFFSET + (((cksum) >> 12) & 0x3f))
233 #define TRLR_SET_CSUM2(cksum) (TRLR_OFFSET + (((cksum) >> 6) & 0x3f))
234 #define TRLR_SET_CSUM3(cksum) (TRLR_OFFSET + (((cksum) ) & 0x3f))
236 /* Check that a trailer byte is reasonable. */
237 #define TRLR_CHECK(ch) (((ch) & TRLR_OFFSET) == TRLR_OFFSET)
239 /* Get data from the trailer. This evaluates its argument multiple
241 #define TRLR_GET_CKSUM(trlr) \
242 ((((trlr)[TRLR_INDX_CSUM1] & 0x3f) << 12) \
243 + (((trlr)[TRLR_INDX_CSUM2] & 0x3f) << 6) \
244 + ((trlr)[TRLR_INDX_CSUM3] & 0x3f))
246 /* The sequence number modulos. */
247 #define SEQ_MODULOS (64)
249 /* Set to 1 if the target is open. */
250 static int mips_is_open;
252 /* Set to 1 while the connection is being initialized. */
253 static int mips_initializing;
255 /* The next sequence number to send. */
256 static int mips_send_seq;
258 /* The next sequence number we expect to receive. */
259 static int mips_receive_seq;
261 /* The time to wait before retransmitting a packet, in seconds. */
262 static int mips_retransmit_wait = 3;
264 /* The number of times to try retransmitting a packet before giving up. */
265 static int mips_send_retries = 10;
267 /* The number of garbage characters to accept when looking for an
268 SYN for the next packet. */
269 static int mips_syn_garbage = 1050;
271 /* The time to wait for a packet, in seconds. */
272 static int mips_receive_wait = 5;
274 /* Set if we have sent a packet to the board but have not yet received
276 static int mips_need_reply = 0;
278 /* Handle used to access serial I/O stream. */
279 static serial_t mips_desc;
281 /* Handle low-level error that we can't recover from. Note that just
282 error()ing out from target_wait or some such low-level place will cause
283 all hell to break loose--the rest of GDB will tend to get left in an
284 inconsistent state. */
287 mips_error (va_alist)
294 target_terminal_ours ();
295 wrap_here(""); /* Force out any buffered output */
296 gdb_flush (gdb_stdout);
298 fprintf_filtered (gdb_stderr, error_pre_print);
299 string = va_arg (args, char *);
300 vfprintf_filtered (gdb_stderr, string, args);
301 fprintf_filtered (gdb_stderr, "\n");
304 /* Clean up in such a way that mips_close won't try to talk to the
305 board (it almost surely won't work since we weren't able to talk to
308 SERIAL_CLOSE (mips_desc);
310 printf_unfiltered ("Ending remote MIPS debugging.\n");
311 target_mourn_inferior ();
313 return_to_top_level (RETURN_ERROR);
316 /* Read a character from the remote, aborting on error. Returns
317 SERIAL_TIMEOUT on timeout (since that's what SERIAL_READCHAR
318 returns). FIXME: If we see the string "<IDT>" from the board, then
319 we are debugging on the main console port, and we have somehow
320 dropped out of remote debugging mode. In this case, we
321 automatically go back in to remote debugging mode. This is a hack,
322 put in because I can't find any way for a program running on the
323 remote board to terminate without also ending remote debugging
324 mode. I assume users won't have any trouble with this; for one
325 thing, the IDT documentation generally assumes that the remote
326 debugging port is not the console port. This is, however, very
327 convenient for DejaGnu when you only have one connected serial
331 mips_readchar (timeout)
335 static int state = 0;
336 static char nextstate[5] = { '<', 'I', 'D', 'T', '>' };
340 ch = SERIAL_READCHAR (mips_desc, timeout);
341 if (ch == SERIAL_EOF)
342 mips_error ("End of file from remote");
343 if (ch == SERIAL_ERROR)
344 mips_error ("Error reading from remote: %s", safe_strerror (errno));
345 if (sr_get_debug () > 1)
347 /* Don't use _filtered; we can't deal with a QUIT out of
348 target_wait, and I think this might be called from there. */
349 if (ch != SERIAL_TIMEOUT)
350 printf_unfiltered ("Read '%c' %d 0x%x\n", ch, ch, ch);
352 printf_unfiltered ("Timed out in read\n");
355 /* If we have seen <IDT> and we either time out, or we see a @
356 (which was echoed from a packet we sent), reset the board as
357 described above. The first character in a packet after the SYN
358 (which is not echoed) is always an @ unless the packet is more
359 than 64 characters long, which ours never are. */
360 if ((ch == SERIAL_TIMEOUT || ch == '@')
362 && ! mips_initializing)
364 if (sr_get_debug () > 0)
365 /* Don't use _filtered; we can't deal with a QUIT out of
366 target_wait, and I think this might be called from there. */
367 printf_unfiltered ("Reinitializing MIPS debugging mode\n");
368 SERIAL_WRITE (mips_desc, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
376 mips_error ("Remote board reset");
379 if (ch == nextstate[state])
387 /* Get a packet header, putting the data in the supplied buffer.
388 PGARBAGE is a pointer to the number of garbage characters received
389 so far. CH is the last character received. Returns 0 for success,
390 or -1 for timeout. */
393 mips_receive_header (hdr, pgarbage, ch, timeout)
403 /* Wait for a SYN. mips_syn_garbage is intended to prevent
404 sitting here indefinitely if the board sends us one garbage
405 character per second. ch may already have a value from the
406 last time through the loop. */
409 ch = mips_readchar (timeout);
410 if (ch == SERIAL_TIMEOUT)
414 /* Printing the character here lets the user of gdb see
415 what the program is outputting, if the debugging is
416 being done on the console port. Don't use _filtered;
417 we can't deal with a QUIT out of target_wait. */
418 if (! mips_initializing || sr_get_debug () > 0)
420 if (ch < 0x20 && ch != '\n')
422 putchar_unfiltered ('^');
423 putchar_unfiltered (ch + 0x40);
426 putchar_unfiltered (ch);
427 gdb_flush (gdb_stdout);
431 if (*pgarbage > mips_syn_garbage)
432 mips_error ("Remote debugging protocol failure");
436 /* Get the packet header following the SYN. */
437 for (i = 1; i < HDR_LENGTH; i++)
439 ch = mips_readchar (timeout);
440 if (ch == SERIAL_TIMEOUT)
443 /* Make sure this is a header byte. */
444 if (ch == SYN || ! HDR_CHECK (ch))
450 /* If we got the complete header, we can return. Otherwise we
451 loop around and keep looking for SYN. */
457 /* Get a packet header, putting the data in the supplied buffer.
458 PGARBAGE is a pointer to the number of garbage characters received
459 so far. The last character read is returned in *PCH. Returns 0
460 for success, -1 for timeout, -2 for error. */
463 mips_receive_trailer (trlr, pgarbage, pch, timeout)
472 for (i = 0; i < TRLR_LENGTH; i++)
474 ch = mips_readchar (timeout);
476 if (ch == SERIAL_TIMEOUT)
478 if (! TRLR_CHECK (ch))
485 /* Get the checksum of a packet. HDR points to the packet header.
486 DATA points to the packet data. LEN is the length of DATA. */
489 mips_cksum (hdr, data, len)
490 const unsigned char *hdr;
491 const unsigned char *data;
494 register const unsigned char *p;
500 /* The initial SYN is not included in the checksum. */
514 /* Send a packet containing the given ASCII string. */
517 mips_send_packet (s, get_ack)
522 unsigned char *packet;
527 if (len > DATA_MAXLEN)
528 mips_error ("MIPS protocol data packet too long: %s", s);
530 packet = (unsigned char *) alloca (HDR_LENGTH + len + TRLR_LENGTH + 1);
532 packet[HDR_INDX_SYN] = HDR_SET_SYN (1, len, mips_send_seq);
533 packet[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (1, len, mips_send_seq);
534 packet[HDR_INDX_LEN1] = HDR_SET_LEN1 (1, len, mips_send_seq);
535 packet[HDR_INDX_SEQ] = HDR_SET_SEQ (1, len, mips_send_seq);
537 memcpy (packet + HDR_LENGTH, s, len);
539 cksum = mips_cksum (packet, packet + HDR_LENGTH, len);
540 packet[HDR_LENGTH + len + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
541 packet[HDR_LENGTH + len + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
542 packet[HDR_LENGTH + len + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
544 /* Increment the sequence number. This will set mips_send_seq to
545 the sequence number we expect in the acknowledgement. */
546 mips_send_seq = (mips_send_seq + 1) % SEQ_MODULOS;
551 /* We can only have one outstanding data packet, so we just wait for
552 the acknowledgement here. Keep retransmitting the packet until
553 we get one, or until we've tried too many times. */
554 for (try = 0; try < mips_send_retries; try++)
559 if (sr_get_debug () > 0)
561 /* Don't use _filtered; we can't deal with a QUIT out of
562 target_wait, and I think this might be called from there. */
563 packet[HDR_LENGTH + len + TRLR_LENGTH] = '\0';
564 printf_unfiltered ("Writing \"%s\"\n", packet + 1);
567 if (SERIAL_WRITE (mips_desc, packet,
568 HDR_LENGTH + len + TRLR_LENGTH) != 0)
569 mips_error ("write to target failed: %s", safe_strerror (errno));
575 unsigned char hdr[HDR_LENGTH + 1];
576 unsigned char trlr[TRLR_LENGTH + 1];
580 /* Get the packet header. If we time out, resend the data
582 err = mips_receive_header (hdr, &garbage, ch, mips_retransmit_wait);
588 /* If we get a data packet, assume it is a duplicate and
589 ignore it. FIXME: If the acknowledgement is lost, this
590 data packet may be the packet the remote sends after the
592 if (HDR_IS_DATA (hdr))
595 /* If the length is not 0, this is a garbled packet. */
596 if (HDR_GET_LEN (hdr) != 0)
599 /* Get the packet trailer. */
600 err = mips_receive_trailer (trlr, &garbage, &ch,
601 mips_retransmit_wait);
603 /* If we timed out, resend the data packet. */
607 /* If we got a bad character, reread the header. */
611 /* If the checksum does not match the trailer checksum, this
612 is a bad packet; ignore it. */
613 if (mips_cksum (hdr, (unsigned char *) NULL, 0)
614 != TRLR_GET_CKSUM (trlr))
617 if (sr_get_debug () > 0)
619 hdr[HDR_LENGTH] = '\0';
620 trlr[TRLR_LENGTH] = '\0';
621 /* Don't use _filtered; we can't deal with a QUIT out of
622 target_wait, and I think this might be called from there. */
623 printf_unfiltered ("Got ack %d \"%s%s\"\n",
624 HDR_GET_SEQ (hdr), hdr + 1, trlr);
627 /* If this ack is for the current packet, we're done. */
628 seq = HDR_GET_SEQ (hdr);
629 if (seq == mips_send_seq)
632 /* If this ack is for the last packet, resend the current
634 if ((seq + 1) % SEQ_MODULOS == mips_send_seq)
637 /* Otherwise this is a bad ack; ignore it. Increment the
638 garbage count to ensure that we do not stay in this loop
644 mips_error ("Remote did not acknowledge packet");
647 /* Receive and acknowledge a packet, returning the data in BUFF (which
648 should be DATA_MAXLEN + 1 bytes). The protocol documentation
649 implies that only the sender retransmits packets, so this code just
650 waits silently for a packet. It returns the length of the received
651 packet. If THROW_ERROR is nonzero, call error() on errors. If not,
652 don't print an error message and return -1. */
655 mips_receive_packet (buff, throw_error, timeout)
663 unsigned char ack[HDR_LENGTH + TRLR_LENGTH + 1];
670 unsigned char hdr[HDR_LENGTH];
671 unsigned char trlr[TRLR_LENGTH];
675 if (mips_receive_header (hdr, &garbage, ch, timeout) != 0)
678 mips_error ("Timed out waiting for remote packet");
685 /* An acknowledgement is probably a duplicate; ignore it. */
686 if (! HDR_IS_DATA (hdr))
688 /* Don't use _filtered; we can't deal with a QUIT out of
689 target_wait, and I think this might be called from there. */
690 if (sr_get_debug () > 0)
691 printf_unfiltered ("Ignoring unexpected ACK\n");
695 /* If this is the wrong sequence number, ignore it. */
696 if (HDR_GET_SEQ (hdr) != mips_receive_seq)
698 /* Don't use _filtered; we can't deal with a QUIT out of
699 target_wait, and I think this might be called from there. */
700 if (sr_get_debug () > 0)
701 printf_unfiltered ("Ignoring sequence number %d (want %d)\n",
702 HDR_GET_SEQ (hdr), mips_receive_seq);
706 len = HDR_GET_LEN (hdr);
708 for (i = 0; i < len; i++)
712 rch = mips_readchar (timeout);
718 if (rch == SERIAL_TIMEOUT)
721 mips_error ("Timed out waiting for remote packet");
730 /* Don't use _filtered; we can't deal with a QUIT out of
731 target_wait, and I think this might be called from there. */
732 if (sr_get_debug () > 0)
733 printf_unfiltered ("Got new SYN after %d chars (wanted %d)\n",
738 err = mips_receive_trailer (trlr, &garbage, &ch, timeout);
742 mips_error ("Timed out waiting for packet");
748 /* Don't use _filtered; we can't deal with a QUIT out of
749 target_wait, and I think this might be called from there. */
750 if (sr_get_debug () > 0)
751 printf_unfiltered ("Got SYN when wanted trailer\n");
755 if (mips_cksum (hdr, buff, len) == TRLR_GET_CKSUM (trlr))
758 if (sr_get_debug () > 0)
759 /* Don't use _filtered; we can't deal with a QUIT out of
760 target_wait, and I think this might be called from there. */
761 printf_unfiltered ("Bad checksum; data %d, trailer %d\n",
762 mips_cksum (hdr, buff, len),
763 TRLR_GET_CKSUM (trlr));
765 /* The checksum failed. Send an acknowledgement for the
766 previous packet to tell the remote to resend the packet. */
767 ack[HDR_INDX_SYN] = HDR_SET_SYN (0, 0, mips_receive_seq);
768 ack[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq);
769 ack[HDR_INDX_LEN1] = HDR_SET_LEN1 (0, 0, mips_receive_seq);
770 ack[HDR_INDX_SEQ] = HDR_SET_SEQ (0, 0, mips_receive_seq);
772 cksum = mips_cksum (ack, (unsigned char *) NULL, 0);
774 ack[HDR_LENGTH + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
775 ack[HDR_LENGTH + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
776 ack[HDR_LENGTH + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
778 if (sr_get_debug () > 0)
780 ack[HDR_LENGTH + TRLR_LENGTH] = '\0';
781 /* Don't use _filtered; we can't deal with a QUIT out of
782 target_wait, and I think this might be called from there. */
783 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq,
787 if (SERIAL_WRITE (mips_desc, ack, HDR_LENGTH + TRLR_LENGTH) != 0)
790 mips_error ("write to target failed: %s", safe_strerror (errno));
796 if (sr_get_debug () > 0)
799 /* Don't use _filtered; we can't deal with a QUIT out of
800 target_wait, and I think this might be called from there. */
801 printf_unfiltered ("Got packet \"%s\"\n", buff);
804 /* We got the packet. Send an acknowledgement. */
805 mips_receive_seq = (mips_receive_seq + 1) % SEQ_MODULOS;
807 ack[HDR_INDX_SYN] = HDR_SET_SYN (0, 0, mips_receive_seq);
808 ack[HDR_INDX_TYPE_LEN] = HDR_SET_TYPE_LEN (0, 0, mips_receive_seq);
809 ack[HDR_INDX_LEN1] = HDR_SET_LEN1 (0, 0, mips_receive_seq);
810 ack[HDR_INDX_SEQ] = HDR_SET_SEQ (0, 0, mips_receive_seq);
812 cksum = mips_cksum (ack, (unsigned char *) NULL, 0);
814 ack[HDR_LENGTH + TRLR_INDX_CSUM1] = TRLR_SET_CSUM1 (cksum);
815 ack[HDR_LENGTH + TRLR_INDX_CSUM2] = TRLR_SET_CSUM2 (cksum);
816 ack[HDR_LENGTH + TRLR_INDX_CSUM3] = TRLR_SET_CSUM3 (cksum);
818 if (sr_get_debug () > 0)
820 ack[HDR_LENGTH + TRLR_LENGTH] = '\0';
821 /* Don't use _filtered; we can't deal with a QUIT out of
822 target_wait, and I think this might be called from there. */
823 printf_unfiltered ("Writing ack %d \"%s\"\n", mips_receive_seq,
827 if (SERIAL_WRITE (mips_desc, ack, HDR_LENGTH + TRLR_LENGTH) != 0)
830 mips_error ("write to target failed: %s", safe_strerror (errno));
838 /* Optionally send a request to the remote system and optionally wait
839 for the reply. This implements the remote debugging protocol,
840 which is built on top of the packet protocol defined above. Each
841 request has an ADDR argument and a DATA argument. The following
842 requests are defined:
844 \0 don't send a request; just wait for a reply
845 i read word from instruction space at ADDR
846 d read word from data space at ADDR
847 I write DATA to instruction space at ADDR
848 D write DATA to data space at ADDR
849 r read register number ADDR
850 R set register number ADDR to value DATA
851 c continue execution (if ADDR != 1, set pc to ADDR)
852 s single step (if ADDR != 1, set pc to ADDR)
854 The read requests return the value requested. The write requests
855 return the previous value in the changed location. The execution
856 requests return a UNIX wait value (the approximate signal which
857 caused execution to stop is in the upper eight bits).
859 If PERR is not NULL, this function waits for a reply. If an error
860 occurs, it sets *PERR to 1 and sets errno according to what the
861 target board reports. */
864 mips_request (cmd, addr, data, perr, timeout)
871 char buff[DATA_MAXLEN + 1];
881 fatal ("mips_request: Trying to send command before reply");
882 sprintf (buff, "0x0 %c 0x%x 0x%x", cmd, addr, data);
883 mips_send_packet (buff, 1);
887 if (perr == (int *) NULL)
890 if (! mips_need_reply)
891 fatal ("mips_request: Trying to get reply before command");
895 len = mips_receive_packet (buff, 1, timeout);
898 if (sscanf (buff, "0x%x %c 0x%x 0x%x",
899 &rpid, &rcmd, &rerrflg, &rresponse) != 4
900 || (cmd != '\0' && rcmd != cmd))
901 mips_error ("Bad response from remote board");
907 /* FIXME: This will returns MIPS errno numbers, which may or may
908 not be the same as errno values used on other systems. If
909 they stick to common errno values, they will be the same, but
910 if they don't, they must be translated. */
921 mips_initialize_cleanups (arg)
924 mips_initializing = 0;
927 /* Initialize a new connection to the MIPS board, and make sure we are
934 char buff[DATA_MAXLEN + 1];
936 struct cleanup *old_cleanups = make_cleanup (mips_initialize_cleanups, NULL);
938 /* What is this code doing here? I don't see any way it can happen, and
939 it might mean mips_initializing didn't get cleared properly.
940 So I'll make it a warning. */
941 if (mips_initializing)
943 warning ("internal error: mips_initialize called twice");
947 mips_initializing = 1;
950 mips_receive_seq = 0;
952 /* The board seems to want to send us a packet. I don't know what
953 it means. The packet seems to be triggered by a carriage return
954 character, although perhaps any character would do. */
956 /* FIXME check the result from this */
957 SERIAL_WRITE (mips_desc, &cr, 1);
959 if (mips_receive_packet (buff, 0, 3) < 0)
963 /* We did not receive the packet we expected; try resetting the
964 board and trying again. */
965 printf_filtered ("Failed to initialize; trying to reset board\n");
967 SERIAL_WRITE (mips_desc, &cc, 1);
969 SERIAL_WRITE (mips_desc, "\015db tty0\015", sizeof "\015db tty0\015" - 1);
972 SERIAL_WRITE (mips_desc, &cr, 1);
974 mips_receive_packet (buff, 1, 3);
976 do_cleanups (old_cleanups);
978 /* If this doesn't call error, we have connected; we don't care if
979 the request itself succeeds or fails. */
980 mips_request ('r', (unsigned int) 0, (unsigned int) 0, &err,
984 /* Open a connection to the remote board. */
987 mips_open (name, from_tty)
993 "To open a MIPS remote debugging connection, you need to specify what serial\n\
994 device is attached to the target board (e.g., /dev/ttya).");
996 target_preopen (from_tty);
999 unpush_target (&mips_ops);
1001 mips_desc = SERIAL_OPEN (name);
1002 if (mips_desc == (serial_t) NULL)
1003 perror_with_name (name);
1005 if (baud_rate != -1)
1007 if (SERIAL_SETBAUDRATE (mips_desc, baud_rate))
1009 SERIAL_CLOSE (mips_desc);
1010 perror_with_name (name);
1014 SERIAL_RAW (mips_desc);
1021 printf_unfiltered ("Remote MIPS debugging using %s\n", name);
1022 push_target (&mips_ops); /* Switch to using remote target now */
1024 /* FIXME: Should we call start_remote here? */
1027 /* Close a connection to the remote board. */
1030 mips_close (quitting)
1039 /* Get the board out of remote debugging mode. */
1040 mips_request ('x', (unsigned int) 0, (unsigned int) 0, &err,
1043 SERIAL_CLOSE (mips_desc);
1047 /* Detach from the remote board. */
1050 mips_detach (args, from_tty)
1055 error ("Argument given to \"detach\" when remotely debugging.");
1059 printf_unfiltered ("Ending remote MIPS debugging.\n");
1062 /* Tell the target board to resume. This does not wait for a reply
1066 mips_resume (pid, step, siggnal)
1068 enum target_signal siggnal;
1070 if (siggnal != TARGET_SIGNAL_0)
1072 ("Can't send signals to a remote system. Try `handle %s ignore'.",
1073 target_signal_to_name (siggnal));
1075 mips_request (step ? 's' : 'c',
1082 /* Return the signal corresponding to SIG, where SIG is the number which
1083 the MIPS protocol uses for the signal. */
1085 mips_signal_from_protocol (sig)
1088 /* We allow a few more signals than the IDT board actually returns, on
1089 the theory that there is at least *some* hope that perhaps the numbering
1090 for these signals is widely agreed upon. */
1093 return TARGET_SIGNAL_UNKNOWN;
1095 /* Don't want to use target_signal_from_host because we are converting
1096 from MIPS signal numbers, not host ones. Our internal numbers
1097 match the MIPS numbers for the signals the board can return, which
1098 are: SIGINT, SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP. */
1099 return (enum target_signal) sig;
1102 /* Wait until the remote stops, and return a wait status. */
1105 mips_wait (pid, status)
1107 struct target_waitstatus *status;
1112 /* If we have not sent a single step or continue command, then the
1113 board is waiting for us to do something. Return a status
1114 indicating that it is stopped. */
1115 if (! mips_need_reply)
1117 status->kind = TARGET_WAITKIND_STOPPED;
1118 status->value.sig = TARGET_SIGNAL_TRAP;
1122 /* No timeout; we sit here as long as the program continues to execute. */
1123 rstatus = mips_request ('\0', (unsigned int) 0, (unsigned int) 0, &err, -1);
1125 mips_error ("Remote failure: %s", safe_strerror (errno));
1127 /* Translate a MIPS waitstatus. We use constants here rather than WTERMSIG
1128 and so on, because the constants we want here are determined by the
1129 MIPS protocol and have nothing to do with what host we are running on. */
1130 if ((rstatus & 0377) == 0)
1132 status->kind = TARGET_WAITKIND_EXITED;
1133 status->value.integer = (((rstatus) >> 8) & 0377);
1135 else if ((rstatus & 0377) == 0177)
1137 status->kind = TARGET_WAITKIND_STOPPED;
1138 status->value.sig = mips_signal_from_protocol (((rstatus) >> 8) & 0377);
1142 status->kind = TARGET_WAITKIND_SIGNALLED;
1143 status->value.sig = mips_signal_from_protocol (rstatus & 0177);
1149 /* We have to map between the register numbers used by gdb and the
1150 register numbers used by the debugging protocol. This function
1151 assumes that we are using tm-mips.h. */
1153 #define REGNO_OFFSET 96
1156 mips_map_regno (regno)
1161 if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
1162 return regno - FP0_REGNUM + 32;
1166 return REGNO_OFFSET + 0;
1168 return REGNO_OFFSET + 1;
1170 return REGNO_OFFSET + 2;
1172 return REGNO_OFFSET + 3;
1174 return REGNO_OFFSET + 4;
1176 return REGNO_OFFSET + 5;
1178 /* FIXME: Is there a way to get the status register? */
1183 /* Fetch the remote registers. */
1186 mips_fetch_registers (regno)
1189 unsigned LONGEST val;
1194 for (regno = 0; regno < NUM_REGS; regno++)
1195 mips_fetch_registers (regno);
1199 if (regno == FP_REGNUM || regno == ZERO_REGNUM)
1200 /* FP_REGNUM on the mips is a hack which is just supposed to read
1201 zero (see also mips-nat.c). */
1205 val = mips_request ('r', (unsigned int) mips_map_regno (regno),
1206 (unsigned int) 0, &err, mips_receive_wait);
1208 mips_error ("Can't read register %d: %s", regno,
1209 safe_strerror (errno));
1213 char buf[MAX_REGISTER_RAW_SIZE];
1215 /* We got the number the register holds, but gdb expects to see a
1216 value in the target byte ordering. */
1217 store_unsigned_integer (buf, REGISTER_RAW_SIZE (regno), val);
1218 supply_register (regno, buf);
1222 /* Prepare to store registers. The MIPS protocol can store individual
1223 registers, so this function doesn't have to do anything. */
1226 mips_prepare_to_store ()
1230 /* Store remote register(s). */
1233 mips_store_registers (regno)
1240 for (regno = 0; regno < NUM_REGS; regno++)
1241 mips_store_registers (regno);
1245 mips_request ('R', (unsigned int) mips_map_regno (regno),
1246 (unsigned int) read_register (regno),
1247 &err, mips_receive_wait);
1249 mips_error ("Can't write register %d: %s", regno, safe_strerror (errno));
1252 /* Fetch a word from the target board. */
1255 mips_fetch_word (addr)
1261 val = mips_request ('d', (unsigned int) addr, (unsigned int) 0, &err,
1265 /* Data space failed; try instruction space. */
1266 val = mips_request ('i', (unsigned int) addr, (unsigned int) 0, &err,
1269 mips_error ("Can't read address 0x%x: %s", addr, safe_strerror (errno));
1274 /* Store a word to the target board. Returns errno code or zero for
1275 success. If OLD_CONTENTS is non-NULL, put the old contents of that
1276 memory location there. */
1279 mips_store_word (addr, val, old_contents)
1285 unsigned int oldcontents;
1287 oldcontents = mips_request ('D', (unsigned int) addr, (unsigned int) val,
1292 /* Data space failed; try instruction space. */
1293 oldcontents = mips_request ('I', (unsigned int) addr,
1294 (unsigned int) val, &err,
1299 if (old_contents != NULL)
1300 store_unsigned_integer (old_contents, 4, oldcontents);
1304 /* Read or write LEN bytes from inferior memory at MEMADDR,
1305 transferring to or from debugger address MYADDR. Write to inferior
1306 if SHOULD_WRITE is nonzero. Returns length of data written or
1307 read; 0 for error. Note that protocol gives us the correct value
1308 for a longword, since it transfers values in ASCII. We want the
1309 byte values, so we have to swap the longword values. */
1312 mips_xfer_memory (memaddr, myaddr, len, write, ignore)
1317 struct target_ops *ignore;
1320 /* Round starting address down to longword boundary. */
1321 register CORE_ADDR addr = memaddr &~ 3;
1322 /* Round ending address up; get number of longwords that makes. */
1323 register int count = (((memaddr + len) - addr) + 3) / 4;
1324 /* Allocate buffer of that many longwords. */
1325 register char *buffer = alloca (count * 4);
1331 /* Fill start and end extra bytes of buffer with existing data. */
1332 if (addr != memaddr || len < 4)
1334 /* Need part of initial word -- fetch it. */
1335 store_unsigned_integer (&buffer[0], 4, mips_fetch_word (addr));
1340 /* Need part of last word -- fetch it. FIXME: we do this even
1341 if we don't need it. */
1342 store_unsigned_integer (&buffer[(count - 1) * 4], 4,
1343 mips_fetch_word (addr + (count - 1) * 4));
1346 /* Copy data to be written over corresponding part of buffer */
1348 memcpy ((char *) buffer + (memaddr & 3), myaddr, len);
1350 /* Write the entire buffer. */
1352 for (i = 0; i < count; i++, addr += 4)
1354 status = mips_store_word (addr,
1355 extract_unsigned_integer (&buffer[i*4], 4),
1357 /* Report each kilobyte (we download 32-bit words at a time) */
1360 printf_unfiltered ("*");
1368 /* FIXME: Do we want a QUIT here? */
1371 printf_unfiltered ("\n");
1375 /* Read all the longwords */
1376 for (i = 0; i < count; i++, addr += 4)
1378 store_unsigned_integer (&buffer[i*4], 4, mips_fetch_word (addr));
1382 /* Copy appropriate bytes out of the buffer. */
1383 memcpy (myaddr, buffer + (memaddr & 3), len);
1388 /* Print info on this target. */
1391 mips_files_info (ignore)
1392 struct target_ops *ignore;
1394 printf_unfiltered ("Debugging a MIPS board over a serial line.\n");
1397 /* Kill the process running on the board. This will actually only
1398 work if we are doing remote debugging over the console input. I
1399 think that if IDT/sim had the remote debug interrupt enabled on the
1400 right port, we could interrupt the process with a break signal. */
1412 SERIAL_WRITE (mips_desc, &cc, 1);
1414 target_mourn_inferior ();
1419 /* Start running on the target board. */
1422 mips_create_inferior (execfile, args, env)
1432 Can't pass arguments to remote MIPS board; arguments ignored.");
1433 /* And don't try to use them on the next "run" command. */
1434 execute_command ("set args", 0);
1437 if (execfile == 0 || exec_bfd == 0)
1438 error ("No executable file specified");
1440 entry_pt = (CORE_ADDR) bfd_get_start_address (exec_bfd);
1442 init_wait_for_inferior ();
1444 /* FIXME: Should we set inferior_pid here? */
1446 proceed (entry_pt, TARGET_SIGNAL_DEFAULT, 0);
1449 /* Clean up after a process. Actually nothing to do. */
1452 mips_mourn_inferior ()
1454 unpush_target (&mips_ops);
1455 generic_mourn_inferior ();
1458 /* We can write a breakpoint and read the shadow contents in one
1461 /* The IDT board uses an unusual breakpoint value, and sometimes gets
1462 confused when it sees the usual MIPS breakpoint instruction. */
1464 #if TARGET_BYTE_ORDER == BIG_ENDIAN
1465 static unsigned char break_insn[] = {0, 0, 0x0a, 0x0d};
1467 static unsigned char break_insn[] = {0x0d, 0x0a, 0, 0};
1470 /* Insert a breakpoint on targets that don't have any better breakpoint
1471 support. We read the contents of the target location and stash it,
1472 then overwrite it with a breakpoint instruction. ADDR is the target
1473 location in the target machine. CONTENTS_CACHE is a pointer to
1474 memory allocated for saving the target contents. It is guaranteed
1475 by the caller to be long enough to save sizeof BREAKPOINT bytes (this
1476 is accomplished via BREAKPOINT_MAX). */
1479 mips_insert_breakpoint (addr, contents_cache)
1481 char *contents_cache;
1486 mips_store_word (addr,
1487 extract_unsigned_integer (break_insn, sizeof break_insn),
1492 mips_remove_breakpoint (addr, contents_cache)
1494 char *contents_cache;
1496 return target_write_memory (addr, contents_cache, sizeof break_insn);
1499 /* The target vector. */
1501 struct target_ops mips_ops =
1503 "mips", /* to_shortname */
1504 "Remote MIPS debugging over serial line", /* to_longname */
1506 Debug a board using the MIPS remote debugging protocol over a serial line.\n\
1507 The argument is the device it is connected to or, if it contains a colon,\n\
1508 HOST:PORT to access a board over a network", /* to_doc */
1509 mips_open, /* to_open */
1510 mips_close, /* to_close */
1511 NULL, /* to_attach */
1512 mips_detach, /* to_detach */
1513 mips_resume, /* to_resume */
1514 mips_wait, /* to_wait */
1515 mips_fetch_registers, /* to_fetch_registers */
1516 mips_store_registers, /* to_store_registers */
1517 mips_prepare_to_store, /* to_prepare_to_store */
1518 mips_xfer_memory, /* to_xfer_memory */
1519 mips_files_info, /* to_files_info */
1520 mips_insert_breakpoint, /* to_insert_breakpoint */
1521 mips_remove_breakpoint, /* to_remove_breakpoint */
1522 NULL, /* to_terminal_init */
1523 NULL, /* to_terminal_inferior */
1524 NULL, /* to_terminal_ours_for_output */
1525 NULL, /* to_terminal_ours */
1526 NULL, /* to_terminal_info */
1527 mips_kill, /* to_kill */
1528 generic_load, /* to_load */
1529 NULL, /* to_lookup_symbol */
1530 mips_create_inferior, /* to_create_inferior */
1531 mips_mourn_inferior, /* to_mourn_inferior */
1532 NULL, /* to_can_run */
1533 NULL, /* to_notice_signals */
1534 process_stratum, /* to_stratum */
1536 1, /* to_has_all_memory */
1537 1, /* to_has_memory */
1538 1, /* to_has_stack */
1539 1, /* to_has_registers */
1540 1, /* to_has_execution */
1541 NULL, /* sections */
1542 NULL, /* sections_end */
1543 OPS_MAGIC /* to_magic */
1547 _initialize_remote_mips ()
1549 add_target (&mips_ops);
1552 add_set_cmd ("timeout", no_class, var_zinteger,
1553 (char *) &mips_receive_wait,
1554 "Set timeout in seconds for remote MIPS serial I/O.",
1559 add_set_cmd ("retransmit-timeout", no_class, var_zinteger,
1560 (char *) &mips_retransmit_wait,
1561 "Set retransmit timeout in seconds for remote MIPS serial I/O.\n\
1562 This is the number of seconds to wait for an acknowledgement to a packet\n\
1563 before resending the packet.", &setlist),