--- /dev/null
+/* Remote target communications for serial-line targets in custom GDB protocol
+ Copyright 1988, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* Remote communication protocol.
+
+ A debug packet whose contents are <data>
+ is encapsulated for transmission in the form:
+
+ $ <data> # CSUM1 CSUM2
+
+ <data> must be ASCII alphanumeric and cannot include characters
+ '$' or '#'. If <data> starts with two characters followed by
+ ':', then the existing stubs interpret this as a sequence number.
+
+ CSUM1 and CSUM2 are ascii hex representation of an 8-bit
+ checksum of <data>, the most significant nibble is sent first.
+ the hex digits 0-9,a-f are used.
+
+ Receiver responds with:
+
+ + - if CSUM is correct and ready for next packet
+ - - if CSUM is incorrect
+
+ <data> is as follows:
+ All values are encoded in ascii hex digits.
+
+ Request Packet
+
+ read registers g
+ reply XX....X Each byte of register data
+ is described by two hex digits.
+ Registers are in the internal order
+ for GDB, and the bytes in a register
+ are in the same order the machine uses.
+ or ENN for an error.
+
+ write regs GXX..XX Each byte of register data
+ is described by two hex digits.
+ reply OK for success
+ ENN for an error
+
+ write reg Pn...=r... Write register n... with value r...,
+ which contains two hex digits for each
+ byte in the register (target byte
+ order).
+ reply OK for success
+ ENN for an error
+ (not supported by all stubs).
+
+ read mem mAA..AA,LLLL AA..AA is address, LLLL is length.
+ reply XX..XX XX..XX is mem contents
+ Can be fewer bytes than requested
+ if able to read only part of the data.
+ or ENN NN is errno
+
+ write mem MAA..AA,LLLL:XX..XX
+ AA..AA is address,
+ LLLL is number of bytes,
+ XX..XX is data
+ reply OK for success
+ ENN for an error (this includes the case
+ where only part of the data was
+ written).
+
+ cont cAA..AA AA..AA is address to resume
+ If AA..AA is omitted,
+ resume at same address.
+
+ step sAA..AA AA..AA is address to resume
+ If AA..AA is omitted,
+ resume at same address.
+
+ last signal ? Reply the current reason for stopping.
+ This is the same reply as is generated
+ for step or cont : SAA where AA is the
+ signal number.
+
+ There is no immediate reply to step or cont.
+ The reply comes when the machine stops.
+ It is SAA AA is the "signal number"
+
+ or... TAAn...:r...;n:r...;n...:r...;
+ AA = signal number
+ n... = register number
+ r... = register contents
+ or... WAA The process exited, and AA is
+ the exit status. This is only
+ applicable for certains sorts of
+ targets.
+ kill request k
+
+ toggle debug d toggle debug flag (see 386 & 68k stubs)
+ reset r reset -- see sparc stub.
+ reserved <other> On other requests, the stub should
+ ignore the request and send an empty
+ response ($#<checksum>). This way
+ we can extend the protocol and GDB
+ can tell whether the stub it is
+ talking to uses the old or the new.
+ search tAA:PP,MM Search backwards starting at address
+ AA for a match with pattern PP and
+ mask MM. PP and MM are 4 bytes.
+ Not supported by all stubs.
+
+ general query qXXXX Request info about XXXX.
+ general set QXXXX=yyyy Set value of XXXX to yyyy.
+ query sect offs qOffsets Get section offsets. Reply is
+ Text=xxx;Data=yyy;Bss=zzz
+ console output Otext Send text to stdout. Only comes from
+ remote target.
+
+ Responses can be run-length encoded to save space. A '*' means that
+ the next character is an ASCII encoding giving a repeat count which
+ stands for that many repititions of the character preceding the '*'.
+ The encoding is n+29, yielding a printable character where n >=3
+ (which is where rle starts to win). Don't use an n > 126.
+
+ So
+ "0* " means the same as "0000". */
+
+#include "defs.h"
+#include <string.h>
+#include <fcntl.h>
+#include "frame.h"
+#include "inferior.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "target.h"
+#include "wait.h"
+#include "terminal.h"
+#include "gdbcmd.h"
+#include "objfiles.h"
+#include "gdb-stabs.h"
+
+#include "dcache.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <signal.h>
+#include "serial.h"
+
+/* Prototypes for local functions */
+
+static int
+remote_write_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
+
+static int
+remote_read_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
+
+static void
+remote_files_info PARAMS ((struct target_ops *ignore));
+
+static int
+remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr, int len,
+ int should_write, struct target_ops *target));
+
+static void
+remote_prepare_to_store PARAMS ((void));
+
+static void
+remote_fetch_registers PARAMS ((int regno));
+
+static void
+remote_resume PARAMS ((int pid, int step, enum target_signal siggnal));
+
+static int
+remote_start_remote PARAMS ((char *dummy));
+
+static void
+remote_open PARAMS ((char *name, int from_tty));
+
+static void
+remote_close PARAMS ((int quitting));
+
+static void
+remote_store_registers PARAMS ((int regno));
+
+static void
+getpkt PARAMS ((char *buf, int forever));
+
+static void
+putpkt PARAMS ((char *buf));
+
+static void
+remote_send PARAMS ((char *buf));
+
+static int
+readchar PARAMS ((int timeout));
+
+static int remote_wait PARAMS ((int pid, struct target_waitstatus *status));
+
+static int
+tohex PARAMS ((int nib));
+
+static int
+fromhex PARAMS ((int a));
+
+static void
+remote_detach PARAMS ((char *args, int from_tty));
+
+static void
+remote_interrupt PARAMS ((int signo));
+
+static void
+remote_interrupt_twice PARAMS ((int signo));
+
+static void
+interrupt_query PARAMS ((void));
+
+extern struct target_ops remote_ops; /* Forward decl */
+
+/* This was 5 seconds, which is a long time to sit and wait.
+ Unless this is going though some terminal server or multiplexer or
+ other form of hairy serial connection, I would think 2 seconds would
+ be plenty. */
+static int remote_timeout = 2;
+
+#if 0
+int icache;
+#endif
+
+/* Descriptor for I/O to remote machine. Initialize it to NULL so that
+ remote_open knows that we don't have a file open when the program
+ starts. */
+serial_t remote_desc = NULL;
+
+/* Having this larger than 400 causes us to be incompatible with m68k-stub.c
+ and i386-stub.c. Normally, no one would notice because it only matters
+ for writing large chunks of memory (e.g. in downloads). Also, this needs
+ to be more than 400 if required to hold the registers (see below, where
+ we round it up based on REGISTER_BYTES). */
+#define PBUFSIZ 400
+
+/* Maximum number of bytes to read/write at once. The value here
+ is chosen to fill up a packet (the headers account for the 32). */
+#define MAXBUFBYTES ((PBUFSIZ-32)/2)
+
+/* Round up PBUFSIZ to hold all the registers, at least. */
+/* The blank line after the #if seems to be required to work around a
+ bug in HP's PA compiler. */
+#if REGISTER_BYTES > MAXBUFBYTES
+
+#undef PBUFSIZ
+#define PBUFSIZ (REGISTER_BYTES * 2 + 32)
+#endif
+
+/* Should we try the 'P' request? If this is set to one when the stub
+ doesn't support 'P', the only consequence is some unnecessary traffic. */
+static int stub_supports_P = 1;
+
+\f
+/* Clean up connection to a remote debugger. */
+
+/* ARGSUSED */
+static void
+remote_close (quitting)
+ int quitting;
+{
+ if (remote_desc)
+ SERIAL_CLOSE (remote_desc);
+ remote_desc = NULL;
+}
+
+/* Query the remote side for the text, data and bss offsets. */
+
+static void
+get_offsets ()
+{
+ unsigned char buf[PBUFSIZ];
+ int nvals;
+ CORE_ADDR text_addr, data_addr, bss_addr;
+ struct section_offsets *offs;
+
+ putpkt ("qOffsets");
+
+ getpkt (buf, 0);
+
+ if (buf[0] == '\000')
+ return; /* Return silently. Stub doesn't support this
+ command. */
+ if (buf[0] == 'E')
+ {
+ warning ("Remote failure reply: %s", buf);
+ return;
+ }
+
+ nvals = sscanf (buf, "Text=%lx;Data=%lx;Bss=%lx", &text_addr, &data_addr,
+ &bss_addr);
+ if (nvals != 3)
+ error ("Malformed response to offset query, %s", buf);
+
+ if (symfile_objfile == NULL)
+ return;
+
+ offs = (struct section_offsets *) alloca (sizeof (struct section_offsets)
+ + symfile_objfile->num_sections
+ * sizeof (offs->offsets));
+ memcpy (offs, symfile_objfile->section_offsets,
+ sizeof (struct section_offsets)
+ + symfile_objfile->num_sections
+ * sizeof (offs->offsets));
+
+ /* FIXME: This code assumes gdb-stabs.h is being used; it's broken
+ for xcoff, dwarf, sdb-coff, etc. But there is no simple
+ canonical representation for this stuff. (Just what does "text"
+ as seen by the stub mean, anyway? I think it means all sections
+ with SEC_CODE set, but we currently have no way to deal with that). */
+
+ ANOFFSET (offs, SECT_OFF_TEXT) = text_addr;
+
+ /* This is a temporary kludge to force data and bss to use the same offsets
+ because that's what nlmconv does now. The real solution requires changes
+ to the stub and remote.c that I don't have time to do right now. */
+
+ ANOFFSET (offs, SECT_OFF_DATA) = data_addr;
+ ANOFFSET (offs, SECT_OFF_BSS) = data_addr;
+
+ objfile_relocate (symfile_objfile, offs);
+}
+
+/* Stub for catch_errors. */
+
+static int
+remote_start_remote (dummy)
+ char *dummy;
+{
+ immediate_quit = 1; /* Allow user to interrupt it */
+
+ /* Ack any packet which the remote side has already sent. */
+
+ SERIAL_WRITE (remote_desc, "+", 1);
+
+ get_offsets (); /* Get text, data & bss offsets */
+
+ putpkt ("?"); /* initiate a query from remote machine */
+ immediate_quit = 0;
+
+ start_remote (); /* Initialize gdb process mechanisms */
+
+ return 1;
+}
+
+/* Open a connection to a remote debugger.
+ NAME is the filename used for communication. */
+
+static DCACHE *remote_dcache;
+
+static void
+remote_open (name, from_tty)
+ char *name;
+ int from_tty;
+{
+ if (name == 0)
+ error (
+"To open a remote debug connection, you need to specify what serial\n\
+device is attached to the remote system (e.g. /dev/ttya).");
+
+ target_preopen (from_tty);
+
+ unpush_target (&remote_ops);
+
+ remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);
+
+ remote_desc = SERIAL_OPEN (name);
+ if (!remote_desc)
+ perror_with_name (name);
+
+ if (baud_rate != -1)
+ {
+ if (SERIAL_SETBAUDRATE (remote_desc, baud_rate))
+ {
+ SERIAL_CLOSE (remote_desc);
+ perror_with_name (name);
+ }
+ }
+
+ SERIAL_RAW (remote_desc);
+
+ /* If there is something sitting in the buffer we might take it as a
+ response to a command, which would be bad. */
+ SERIAL_FLUSH_INPUT (remote_desc);
+
+ if (from_tty)
+ {
+ puts_filtered ("Remote debugging using ");
+ puts_filtered (name);
+ puts_filtered ("\n");
+ }
+ push_target (&remote_ops); /* Switch to using remote target now */
+
+ /* Start out by trying the 'P' request to set registers. We set this each
+ time that we open a new target so that if the user switches from one
+ stub to another, we can (if the target is closed and reopened) cope. */
+ stub_supports_P = 1;
+
+ /* Without this, some commands which require an active target (such as kill)
+ won't work. This variable serves (at least) double duty as both the pid
+ of the target process (if it has such), and as a flag indicating that a
+ target is active. These functions should be split out into seperate
+ variables, especially since GDB will someday have a notion of debugging
+ several processes. */
+
+ inferior_pid = 42000;
+
+ /* Start the remote connection; if error (0), discard this target.
+ In particular, if the user quits, be sure to discard it
+ (we'd be in an inconsistent state otherwise). */
+ if (!catch_errors (remote_start_remote, (char *)0,
+ "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
+ pop_target();
+}
+
+/* remote_detach()
+ takes a program previously attached to and detaches it.
+ We better not have left any breakpoints
+ in the program or it'll die when it hits one.
+ Close the open connection to the remote debugger.
+ Use this when you want to detach and do something else
+ with your gdb. */
+
+static void
+remote_detach (args, from_tty)
+ char *args;
+ int from_tty;
+{
+ if (args)
+ error ("Argument given to \"detach\" when remotely debugging.");
+
+ pop_target ();
+ if (from_tty)
+ puts_filtered ("Ending remote debugging.\n");
+}
+
+/* Convert hex digit A to a number. */
+
+static int
+fromhex (a)
+ int a;
+{
+ if (a >= '0' && a <= '9')
+ return a - '0';
+ else if (a >= 'a' && a <= 'f')
+ return a - 'a' + 10;
+ else
+ error ("Reply contains invalid hex digit");
+}
+
+/* Convert number NIB to a hex digit. */
+
+static int
+tohex (nib)
+ int nib;
+{
+ if (nib < 10)
+ return '0'+nib;
+ else
+ return 'a'+nib-10;
+}
+\f
+/* Tell the remote machine to resume. */
+
+static void
+remote_resume (pid, step, siggnal)
+ int pid, step;
+ enum target_signal siggnal;
+{
+ char buf[PBUFSIZ];
+
+ if (siggnal)
+ {
+ target_terminal_ours_for_output ();
+ printf_filtered
+ ("Can't send signals to a remote system. %s not sent.\n",
+ target_signal_to_name (siggnal));
+ target_terminal_inferior ();
+ }
+
+ dcache_flush (remote_dcache);
+
+ strcpy (buf, step ? "s": "c");
+
+ putpkt (buf);
+}
+\f
+/* Send ^C to target to halt it. Target will respond, and send us a
+ packet. */
+
+static void
+remote_interrupt (signo)
+ int signo;
+{
+ /* If this doesn't work, try more severe steps. */
+ signal (signo, remote_interrupt_twice);
+
+ if (remote_debug)
+ printf_unfiltered ("remote_interrupt called\n");
+
+ SERIAL_WRITE (remote_desc, "\003", 1); /* Send a ^C */
+}
+
+static void (*ofunc)();
+
+/* The user typed ^C twice. */
+static void
+remote_interrupt_twice (signo)
+ int signo;
+{
+ signal (signo, ofunc);
+
+ interrupt_query ();
+
+ signal (signo, remote_interrupt);
+}
+
+/* Ask the user what to do when an interrupt is received. */
+
+static void
+interrupt_query ()
+{
+ target_terminal_ours ();
+
+ if (query ("Interrupted while waiting for the program.\n\
+Give up (and stop debugging it)? "))
+ {
+ target_mourn_inferior ();
+ return_to_top_level (RETURN_QUIT);
+ }
+
+ target_terminal_inferior ();
+}
+
+/* Wait until the remote machine stops, then return,
+ storing status in STATUS just as `wait' would.
+ Returns "pid" (though it's not clear what, if anything, that
+ means in the case of this target). */
+
+static int
+remote_wait (pid, status)
+ int pid;
+ struct target_waitstatus *status;
+{
+ unsigned char buf[PBUFSIZ];
+
+ status->kind = TARGET_WAITKIND_EXITED;
+ status->value.integer = 0;
+
+ while (1)
+ {
+ unsigned char *p;
+
+ ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
+ getpkt ((char *) buf, 1);
+ signal (SIGINT, ofunc);
+
+ switch (buf[0])
+ {
+ case 'E': /* Error of some sort */
+ warning ("Remote failure reply: %s", buf);
+ continue;
+ case 'T': /* Status with PC, SP, FP, ... */
+ {
+ int i;
+ long regno;
+ char regs[MAX_REGISTER_RAW_SIZE];
+
+ /* Expedited reply, containing Signal, {regno, reg} repeat */
+ /* format is: 'Tssn...:r...;n...:r...;n...:r...;#cc', where
+ ss = signal number
+ n... = register number
+ r... = register contents
+ */
+
+ p = &buf[3]; /* after Txx */
+
+ while (*p)
+ {
+ unsigned char *p1;
+
+ regno = strtol (p, &p1, 16); /* Read the register number */
+
+ if (p1 == p)
+ warning ("Remote sent badly formed register number: %s\nPacket: '%s'\n",
+ p1, buf);
+
+ p = p1;
+
+ if (*p++ != ':')
+ warning ("Malformed packet (missing colon): %s\nPacket: '%s'\n",
+ p, buf);
+
+ if (regno >= NUM_REGS)
+ warning ("Remote sent bad register number %d: %s\nPacket: '%s'\n",
+ regno, p, buf);
+
+ for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
+ {
+ if (p[0] == 0 || p[1] == 0)
+ warning ("Remote reply is too short: %s", buf);
+ regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+
+ if (*p++ != ';')
+ warning ("Remote register badly formatted: %s", buf);
+
+ supply_register (regno, regs);
+ }
+ }
+ /* fall through */
+ case 'S': /* Old style status, just signal only */
+ status->kind = TARGET_WAITKIND_STOPPED;
+ status->value.sig = (enum target_signal)
+ (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+
+ return inferior_pid;
+ case 'W': /* Target exited */
+ {
+ /* The remote process exited. */
+ status->kind = TARGET_WAITKIND_EXITED;
+ status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
+ return inferior_pid;
+ }
+ case 'O': /* Console output */
+ fputs_filtered (buf + 1, gdb_stdout);
+ continue;
+ default:
+ warning ("Invalid remote reply: %s", buf);
+ continue;
+ }
+ }
+ return inferior_pid;
+}
+
+/* Number of bytes of registers this stub implements. */
+static int register_bytes_found;
+
+/* Read the remote registers into the block REGS. */
+/* Currently we just read all the registers, so we don't use regno. */
+/* ARGSUSED */
+static void
+remote_fetch_registers (regno)
+ int regno;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+ char regs[REGISTER_BYTES];
+
+ sprintf (buf, "g");
+ remote_send (buf);
+
+ /* Unimplemented registers read as all bits zero. */
+ memset (regs, 0, REGISTER_BYTES);
+
+ /* We can get out of synch in various cases. If the first character
+ in the buffer is not a hex character, assume that has happened
+ and try to fetch another packet to read. */
+ while ((buf[0] < '0' || buf[0] > '9')
+ && (buf[0] < 'a' || buf[0] > 'f'))
+ {
+ if (remote_debug)
+ printf_unfiltered ("Bad register packet; fetching a new packet\n");
+ getpkt (buf, 0);
+ }
+
+ /* Reply describes registers byte by byte, each byte encoded as two
+ hex characters. Suck them all up, then supply them to the
+ register cacheing/storage mechanism. */
+
+ p = buf;
+ for (i = 0; i < REGISTER_BYTES; i++)
+ {
+ if (p[0] == 0)
+ break;
+ if (p[1] == 0)
+ {
+ warning ("Remote reply is of odd length: %s", buf);
+ /* Don't change register_bytes_found in this case, and don't
+ print a second warning. */
+ goto supply_them;
+ }
+ regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+
+ if (i != register_bytes_found)
+ {
+ register_bytes_found = i;
+#ifdef REGISTER_BYTES_OK
+ if (!REGISTER_BYTES_OK (i))
+ warning ("Remote reply is too short: %s", buf);
+#endif
+ }
+
+ supply_them:
+ for (i = 0; i < NUM_REGS; i++)
+ supply_register (i, ®s[REGISTER_BYTE(i)]);
+}
+
+/* Prepare to store registers. Since we may send them all (using a
+ 'G' request), we have to read out the ones we don't want to change
+ first. */
+
+static void
+remote_prepare_to_store ()
+{
+ /* Make sure the entire registers array is valid. */
+ read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
+}
+
+/* Store register REGNO, or all registers if REGNO == -1, from the contents
+ of REGISTERS. FIXME: ignores errors. */
+
+static void
+remote_store_registers (regno)
+ int regno;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ if (regno >= 0 && stub_supports_P)
+ {
+ /* Try storing a single register. */
+ char *regp;
+
+ sprintf (buf, "P%x=", regno);
+ p = buf + strlen (buf);
+ regp = ®isters[REGISTER_BYTE (regno)];
+ for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i)
+ {
+ *p++ = tohex ((regp[i] >> 4) & 0xf);
+ *p++ = tohex (regp[i] & 0xf);
+ }
+ *p = '\0';
+ remote_send (buf);
+ if (buf[0] != '\0')
+ {
+ /* The stub understands the 'P' request. We are done. */
+ return;
+ }
+
+ /* The stub does not support the 'P' request. Use 'G' instead,
+ and don't try using 'P' in the future (it will just waste our
+ time). */
+ stub_supports_P = 0;
+ }
+
+ buf[0] = 'G';
+
+ /* Command describes registers byte by byte,
+ each byte encoded as two hex characters. */
+
+ p = buf + 1;
+ /* remote_prepare_to_store insures that register_bytes_found gets set. */
+ for (i = 0; i < register_bytes_found; i++)
+ {
+ *p++ = tohex ((registers[i] >> 4) & 0xf);
+ *p++ = tohex (registers[i] & 0xf);
+ }
+ *p = '\0';
+
+ remote_send (buf);
+}
+
+#if 0
+
+/* Use of the data cache is disabled because it loses for looking at
+ and changing hardware I/O ports and the like. Accepting `volatile'
+ would perhaps be one way to fix it, but a better way which would
+ win for more cases would be to use the executable file for the text
+ segment, like the `icache' code below but done cleanly (in some
+ target-independent place, perhaps in target_xfer_memory, perhaps
+ based on assigning each target a speed or perhaps by some simpler
+ mechanism). */
+
+/* Read a word from remote address ADDR and return it.
+ This goes through the data cache. */
+
+static int
+remote_fetch_word (addr)
+ CORE_ADDR addr;
+{
+#if 0
+ if (icache)
+ {
+ extern CORE_ADDR text_start, text_end;
+
+ if (addr >= text_start && addr < text_end)
+ {
+ int buffer;
+ xfer_core_file (addr, &buffer, sizeof (int));
+ return buffer;
+ }
+ }
+#endif
+ return dcache_fetch (remote_dcache, addr);
+}
+
+/* Write a word WORD into remote address ADDR.
+ This goes through the data cache. */
+
+static void
+remote_store_word (addr, word)
+ CORE_ADDR addr;
+ int word;
+{
+ dcache_poke (remote_dcache, addr, word);
+}
+#endif /* 0 */
+\f
+/* Write memory data directly to the remote machine.
+ This does not inform the data cache; the data cache uses this.
+ MEMADDR is the address in the remote memory space.
+ MYADDR is the address of the buffer in our space.
+ LEN is the number of bytes.
+
+ Returns number of bytes transferred, or 0 for error. */
+
+static int
+remote_write_bytes (memaddr, myaddr, len)
+ CORE_ADDR memaddr;
+ unsigned char *myaddr;
+ int len;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ /* FIXME-32x64: Need a version of print_address_numeric which puts the
+ result in a buffer like sprintf. */
+ sprintf (buf, "M%lx,%x:", (unsigned long) memaddr, len);
+
+ /* We send target system values byte by byte, in increasing byte addresses,
+ each byte encoded as two hex characters. */
+
+ p = buf + strlen (buf);
+ for (i = 0; i < len; i++)
+ {
+ *p++ = tohex ((myaddr[i] >> 4) & 0xf);
+ *p++ = tohex (myaddr[i] & 0xf);
+ }
+ *p = '\0';
+
+ putpkt (buf);
+ getpkt (buf, 0);
+
+ if (buf[0] == 'E')
+ {
+ /* There is no correspondance between what the remote protocol uses
+ for errors and errno codes. We would like a cleaner way of
+ representing errors (big enough to include errno codes, bfd_error
+ codes, and others). But for now just return EIO. */
+ errno = EIO;
+ return 0;
+ }
+ return len;
+}
+
+/* Read memory data directly from the remote machine.
+ This does not use the data cache; the data cache uses this.
+ MEMADDR is the address in the remote memory space.
+ MYADDR is the address of the buffer in our space.
+ LEN is the number of bytes.
+
+ Returns number of bytes transferred, or 0 for error. */
+
+static int
+remote_read_bytes (memaddr, myaddr, len)
+ CORE_ADDR memaddr;
+ unsigned char *myaddr;
+ int len;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ if (len > PBUFSIZ / 2 - 1)
+ abort ();
+
+ /* FIXME-32x64: Need a version of print_address_numeric which puts the
+ result in a buffer like sprintf. */
+ sprintf (buf, "m%lx,%x", (unsigned long) memaddr, len);
+ putpkt (buf);
+ getpkt (buf, 0);
+
+ if (buf[0] == 'E')
+ {
+ /* There is no correspondance between what the remote protocol uses
+ for errors and errno codes. We would like a cleaner way of
+ representing errors (big enough to include errno codes, bfd_error
+ codes, and others). But for now just return EIO. */
+ errno = EIO;
+ return 0;
+ }
+
+ /* Reply describes memory byte by byte,
+ each byte encoded as two hex characters. */
+
+ p = buf;
+ for (i = 0; i < len; i++)
+ {
+ if (p[0] == 0 || p[1] == 0)
+ /* Reply is short. This means that we were able to read only part
+ of what we wanted to. */
+ break;
+ myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+ return i;
+}
+\f
+/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
+ to or from debugger address MYADDR. Write to inferior if SHOULD_WRITE is
+ nonzero. Returns length of data written or read; 0 for error. */
+
+/* ARGSUSED */
+static int
+remote_xfer_memory(memaddr, myaddr, len, should_write, target)
+ CORE_ADDR memaddr;
+ char *myaddr;
+ int len;
+ int should_write;
+ struct target_ops *target; /* ignored */
+{
+ int xfersize;
+ int bytes_xferred;
+ int total_xferred = 0;
+
+ while (len > 0)
+ {
+ if (len > MAXBUFBYTES)
+ xfersize = MAXBUFBYTES;
+ else
+ xfersize = len;
+
+ if (should_write)
+ bytes_xferred = remote_write_bytes (memaddr,
+ (unsigned char *)myaddr, xfersize);
+ else
+ bytes_xferred = remote_read_bytes (memaddr,
+ (unsigned char *)myaddr, xfersize);
+
+ /* If we get an error, we are done xferring. */
+ if (bytes_xferred == 0)
+ break;
+
+ memaddr += bytes_xferred;
+ myaddr += bytes_xferred;
+ len -= bytes_xferred;
+ total_xferred += bytes_xferred;
+ }
+ return total_xferred;
+}
+
+#if 0
+/* Enable after 4.12. */
+
+void
+remote_search (len, data, mask, startaddr, increment, lorange, hirange
+ addr_found, data_found)
+ int len;
+ char *data;
+ char *mask;
+ CORE_ADDR startaddr;
+ int increment;
+ CORE_ADDR lorange;
+ CORE_ADDR hirange;
+ CORE_ADDR *addr_found;
+ char *data_found;
+{
+ if (increment == -4 && len == 4)
+ {
+ long mask_long, data_long;
+ long data_found_long;
+ CORE_ADDR addr_we_found;
+ char buf[PBUFSIZ];
+ long returned_long[2];
+ char *p;
+
+ mask_long = extract_unsigned_integer (mask, len);
+ data_long = extract_unsigned_integer (data, len);
+ sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long);
+ putpkt (buf);
+ getpkt (buf, 0);
+ if (buf[0] == '\0')
+ {
+ /* The stub doesn't support the 't' request. We might want to
+ remember this fact, but on the other hand the stub could be
+ switched on us. Maybe we should remember it only until
+ the next "target remote". */
+ generic_search (len, data, mask, startaddr, increment, lorange,
+ hirange, addr_found, data_found);
+ return;
+ }
+
+ if (buf[0] == 'E')
+ /* There is no correspondance between what the remote protocol uses
+ for errors and errno codes. We would like a cleaner way of
+ representing errors (big enough to include errno codes, bfd_error
+ codes, and others). But for now just use EIO. */
+ memory_error (EIO, startaddr);
+ p = buf;
+ addr_we_found = 0;
+ while (*p != '\0' && *p != ',')
+ addr_we_found = (addr_we_found << 4) + fromhex (*p++);
+ if (*p == '\0')
+ error ("Protocol error: short return for search");
+
+ data_found_long = 0;
+ while (*p != '\0' && *p != ',')
+ data_found_long = (data_found_long << 4) + fromhex (*p++);
+ /* Ignore anything after this comma, for future extensions. */
+
+ if (addr_we_found < lorange || addr_we_found >= hirange)
+ {
+ *addr_found = 0;
+ return;
+ }
+
+ *addr_found = addr_we_found;
+ *data_found = store_unsigned_integer (data_we_found, len);
+ return;
+ }
+ generic_search (len, data, mask, startaddr, increment, lorange,
+ hirange, addr_found, data_found);
+}
+#endif /* 0 */
+\f
+static void
+remote_files_info (ignore)
+ struct target_ops *ignore;
+{
+ puts_filtered ("Debugging a target over a serial line.\n");
+}
+\f
+/* Stuff for dealing with the packets which are part of this protocol.
+ See comment at top of file for details. */
+
+/* Read a single character from the remote end, masking it down to 7 bits. */
+
+static int
+readchar (timeout)
+ int timeout;
+{
+ int ch;
+
+ ch = SERIAL_READCHAR (remote_desc, timeout);
+
+ switch (ch)
+ {
+ case SERIAL_EOF:
+ error ("Remote connection closed");
+ case SERIAL_ERROR:
+ perror_with_name ("Remote communication error");
+ case SERIAL_TIMEOUT:
+ return ch;
+ default:
+ return ch & 0x7f;
+ }
+}
+
+/* Send the command in BUF to the remote machine,
+ and read the reply into BUF.
+ Report an error if we get an error reply. */
+
+static void
+remote_send (buf)
+ char *buf;
+{
+
+ putpkt (buf);
+ getpkt (buf, 0);
+
+ if (buf[0] == 'E')
+ error ("Remote failure reply: %s", buf);
+}
+
+/* Send a packet to the remote machine, with error checking.
+ The data of the packet is in BUF. */
+
+static void
+putpkt (buf)
+ char *buf;
+{
+ int i;
+ unsigned char csum = 0;
+ char buf2[PBUFSIZ];
+ int cnt = strlen (buf);
+ int ch;
+ char *p;
+
+ /* Copy the packet into buffer BUF2, encapsulating it
+ and giving it a checksum. */
+
+ if (cnt > sizeof(buf2) - 5) /* Prosanity check */
+ abort();
+
+ p = buf2;
+ *p++ = '$';
+
+ for (i = 0; i < cnt; i++)
+ {
+ csum += buf[i];
+ *p++ = buf[i];
+ }
+ *p++ = '#';
+ *p++ = tohex ((csum >> 4) & 0xf);
+ *p++ = tohex (csum & 0xf);
+
+ /* Send it over and over until we get a positive ack. */
+
+ while (1)
+ {
+ int started_error_output = 0;
+
+ if (remote_debug)
+ {
+ *p = '\0';
+ printf_unfiltered ("Sending packet: %s...", buf2);
+ gdb_flush(gdb_stdout);
+ }
+ if (SERIAL_WRITE (remote_desc, buf2, p - buf2))
+ perror_with_name ("putpkt: write failed");
+
+ /* read until either a timeout occurs (-2) or '+' is read */
+ while (1)
+ {
+ ch = readchar (remote_timeout);
+
+ if (remote_debug)
+ {
+ switch (ch)
+ {
+ case '+':
+ case SERIAL_TIMEOUT:
+ case '$':
+ if (started_error_output)
+ {
+ putc_unfiltered ('\n');
+ started_error_output = 0;
+ }
+ }
+ }
+
+ switch (ch)
+ {
+ case '+':
+ if (remote_debug)
+ printf_unfiltered("Ack\n");
+ return;
+ case SERIAL_TIMEOUT:
+ break; /* Retransmit buffer */
+ case '$':
+ {
+ unsigned char junkbuf[PBUFSIZ];
+
+ /* It's probably an old response, and we're out of sync. Just
+ gobble up the packet and ignore it. */
+ getpkt (junkbuf, 0);
+ continue; /* Now, go look for + */
+ }
+ default:
+ if (remote_debug)
+ {
+ if (!started_error_output)
+ {
+ started_error_output = 1;
+ printf_unfiltered ("putpkt: Junk: ");
+ }
+ putc_unfiltered (ch & 0177);
+ }
+ continue;
+ }
+ break; /* Here to retransmit */
+ }
+
+#if 0
+ /* This is wrong. If doing a long backtrace, the user should be
+ able to get out next time we call QUIT, without anything as violent
+ as interrupt_query. If we want to provide a way out of here
+ without getting to the next QUIT, it should be based on hitting
+ ^C twice as in remote_wait. */
+ if (quit_flag)
+ {
+ quit_flag = 0;
+ interrupt_query ();
+ }
+#endif
+ }
+}
+
+/* Come here after finding the start of the frame. Collect the rest into BUF,
+ verifying the checksum, length, and handling run-length compression.
+ Returns 0 on any error, 1 on success. */
+
+static int
+read_frame (buf)
+ char *buf;
+{
+ unsigned char csum;
+ char *bp;
+ int c;
+
+ csum = 0;
+ bp = buf;
+
+ while (1)
+ {
+ c = readchar (remote_timeout);
+
+ switch (c)
+ {
+ case SERIAL_TIMEOUT:
+ if (remote_debug)
+ puts_filtered ("Timeout in mid-packet, retrying\n");
+ return 0;
+ case '$':
+ if (remote_debug)
+ puts_filtered ("Saw new packet start in middle of old one\n");
+ return 0; /* Start a new packet, count retries */
+ case '#':
+ {
+ unsigned char pktcsum;
+
+ *bp = '\000';
+
+ pktcsum = fromhex (readchar (remote_timeout)) << 4;
+ pktcsum |= fromhex (readchar (remote_timeout));
+
+ if (csum == pktcsum)
+ return 1;
+
+ printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
+ pktcsum, csum);
+ puts_filtered (buf);
+ puts_filtered ("\n");
+
+ return 0;
+ }
+ case '*': /* Run length encoding */
+ csum += c;
+ c = readchar (remote_timeout);
+ csum += c;
+ c = c - ' ' + 3; /* Compute repeat count */
+
+ if (bp + c - 1 < buf + PBUFSIZ - 1)
+ {
+ memset (bp, *(bp - 1), c);
+ bp += c;
+ continue;
+ }
+
+ *bp = '\0';
+ printf_filtered ("Repeat count %d too large for buffer: ", c);
+ puts_filtered (buf);
+ puts_filtered ("\n");
+ return 0;
+
+ default:
+ if (bp < buf + PBUFSIZ - 1)
+ {
+ *bp++ = c;
+ csum += c;
+ continue;
+ }
+
+ *bp = '\0';
+ puts_filtered ("Remote packet too long: ");
+ puts_filtered (buf);
+ puts_filtered ("\n");
+
+ return 0;
+ }
+ }
+}
+
+/* Read a packet from the remote machine, with error checking,
+ and store it in BUF. BUF is expected to be of size PBUFSIZ.
+ If FOREVER, wait forever rather than timing out; this is used
+ while the target is executing user code. */
+
+static void
+getpkt (buf, forever)
+ char *buf;
+ int forever;
+{
+ char *bp;
+ int c;
+ int tries;
+ int timeout;
+ int val;
+
+ if (forever)
+ timeout = -1;
+ else
+ timeout = remote_timeout;
+
+#define MAX_TRIES 10
+
+ for (tries = 1; tries <= MAX_TRIES; tries++)
+ {
+ /* This can loop forever if the remote side sends us characters
+ continuously, but if it pauses, we'll get a zero from readchar
+ because of timeout. Then we'll count that as a retry. */
+
+ /* Note that we will only wait forever prior to the start of a packet.
+ After that, we expect characters to arrive at a brisk pace. They
+ should show up within remote_timeout intervals. */
+
+ do
+ {
+ c = readchar (timeout);
+
+ if (c == SERIAL_TIMEOUT)
+ {
+ if (remote_debug)
+ puts_filtered ("Timed out.\n");
+ goto retry;
+ }
+ }
+ while (c != '$');
+
+ /* We've found the start of a packet, now collect the data. */
+
+ val = read_frame (buf);
+
+ if (val == 1)
+ {
+ if (remote_debug)
+ fprintf_unfiltered (gdb_stderr, "Packet received: %s\n", buf);
+ SERIAL_WRITE (remote_desc, "+", 1);
+ return;
+ }
+
+ /* Try the whole thing again. */
+retry:
+ SERIAL_WRITE (remote_desc, "-", 1);
+ }
+
+ /* We have tried hard enough, and just can't receive the packet. Give up. */
+
+ printf_unfiltered ("Ignoring packet error, continuing...\n");
+ SERIAL_WRITE (remote_desc, "+", 1);
+}
+\f
+static void
+remote_kill ()
+{
+ putpkt ("k");
+ /* Don't wait for it to die. I'm not really sure it matters whether
+ we do or not. For the existing stubs, kill is a noop. */
+ target_mourn_inferior ();
+}
+
+static void
+remote_mourn ()
+{
+ unpush_target (&remote_ops);
+ generic_mourn_inferior ();
+}
+\f
+#ifdef REMOTE_BREAKPOINT
+
+/* On some machines, e.g. 68k, we may use a different breakpoint instruction
+ than other targets. */
+static unsigned char break_insn[] = REMOTE_BREAKPOINT;
+
+/* Check that it fits in BREAKPOINT_MAX bytes. */
+static unsigned char check_break_insn_size[BREAKPOINT_MAX] = REMOTE_BREAKPOINT;
+
+#else /* No REMOTE_BREAKPOINT. */
+
+/* Same old breakpoint instruction. This code does nothing different
+ than mem-break.c. */
+static unsigned char break_insn[] = BREAKPOINT;
+
+#endif /* No REMOTE_BREAKPOINT. */
+
+/* Insert a breakpoint on targets that don't have any better breakpoint
+ support. We read the contents of the target location and stash it,
+ then overwrite it with a breakpoint instruction. ADDR is the target
+ location in the target machine. CONTENTS_CACHE is a pointer to
+ memory allocated for saving the target contents. It is guaranteed
+ by the caller to be long enough to save sizeof BREAKPOINT bytes (this
+ is accomplished via BREAKPOINT_MAX). */
+
+static int
+remote_insert_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ int val;
+
+ val = target_read_memory (addr, contents_cache, sizeof break_insn);
+
+ if (val == 0)
+ val = target_write_memory (addr, (char *)break_insn, sizeof break_insn);
+
+ return val;
+}
+
+static int
+remote_remove_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ return target_write_memory (addr, contents_cache, sizeof break_insn);
+}
+\f
+/* Define the target subroutine names */
+
+struct target_ops remote_ops = {
+ "remote", /* to_shortname */
+ "Remote serial target in gdb-specific protocol", /* to_longname */
+ "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
+Specify the serial device it is connected to (e.g. /dev/ttya). or telnet port", /* to_doc */
+ remote_open, /* to_open */
+ remote_close, /* to_close */
+ NULL, /* to_attach */
+ remote_detach, /* to_detach */
+ remote_resume, /* to_resume */
+ remote_wait, /* to_wait */
+ remote_fetch_registers, /* to_fetch_registers */
+ remote_store_registers, /* to_store_registers */
+ remote_prepare_to_store, /* to_prepare_to_store */
+ remote_xfer_memory, /* to_xfer_memory */
+ remote_files_info, /* to_files_info */
+
+ remote_insert_breakpoint, /* to_insert_breakpoint */
+ remote_remove_breakpoint, /* to_remove_breakpoint */
+
+ NULL, /* to_terminal_init */
+ NULL, /* to_terminal_inferior */
+ NULL, /* to_terminal_ours_for_output */
+ NULL, /* to_terminal_ours */
+ NULL, /* to_terminal_info */
+ remote_kill, /* to_kill */
+ generic_load, /* to_load */
+ NULL, /* to_lookup_symbol */
+ NULL, /* to_create_inferior */
+ remote_mourn, /* to_mourn_inferior */
+ 0, /* to_can_run */
+ 0, /* to_notice_signals */
+ process_stratum, /* to_stratum */
+ NULL, /* to_next */
+ 1, /* to_has_all_memory */
+ 1, /* to_has_memory */
+ 1, /* to_has_stack */
+ 1, /* to_has_registers */
+ 1, /* to_has_execution */
+ NULL, /* sections */
+ NULL, /* sections_end */
+ OPS_MAGIC /* to_magic */
+};
+
+void
+_initialize_remote ()
+{
+ add_target (&remote_ops);
+}
projects / binutils-gdb.git / commitdiff