--- /dev/null
+/* Remote target communications for serial-line targets in custom GDB protocol
+ Copyright 1988, 1991, 1992 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.
+ 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
+
+ read mem mAA..AA,LLLL AA..AA is address, LLLL is length.
+ reply XX..XX XX..XX is mem contents
+ 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
+
+ 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... TAAPPPPPPPPFFFFFFFF
+ where AA is the signal number,
+ PPPPPPPP is the PC (PC_REGNUM), and
+ FFFFFFFF is the frame ptr (FP_REGNUM).
+
+ kill req k
+*/
+
+#include "defs.h"
+#include <string.h>
+#include "serial.h"
+#include "frame.h"
+#include "inferior.h"
+#include "target.h"
+#include "wait.h"
+#include "terminal.h"
+#include "gdbcmd.h"
+
+#include <signal.h>
+
+static int kiodebug = 0;
+static int timeout = 5;
+
+#define PBUFSIZ 1024
+
+/* 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. */
+#if REGISTER_BYTES > MAXBUFBYTES
+#undef PBUFSIZ
+#define PBUFSIZ (REGISTER_BYTES * 2 + 32)
+#endif
+\f
+/* 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)
+ printf ("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");
+ return -1;
+}
+
+/* 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. */
+
+/* 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);
+ char 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++ = '$';
+
+ for (i = 0; i < cnt; i++)
+ {
+ csum += buf[i];
+ *p++ = buf[i];
+ }
+ *p++ = '#';
+ *p++ = tohex ((csum >> 4) & 0xf);
+ *p++ = tohex (csum & 0xf);
+
+ /* Send it over and over until we get a positive ack. */
+
+ do {
+ if (kiodebug)
+ {
+ *p = '\0';
+ printf ("Sending packet: %s...", buf2); fflush(stdout);
+ }
+ serial_write (buf2, p - buf2);
+
+ /* read until either a timeout occurs (\0) or '+' is read */
+ do {
+ ch = readchar ();
+ if (kiodebug) {
+ if (ch == '+')
+ printf("Ack\n");
+ else
+ printf ("%02X%c ", ch&0xFF, ch);
+ }
+ } while ((ch != '+') && (ch != '\0'));
+ } while (ch != '+');
+}
+
+/* Read a packet from the remote machine, with error checking,
+ and store it in BUF. BUF is expected to be of size PBUFSIZ. */
+
+static void
+getpkt (buf)
+ char *buf;
+{
+ char *bp;
+ unsigned char csum;
+ int c;
+ unsigned char c1, c2;
+
+ while (1)
+ {
+ /* Force csum to be zero here because of possible error retry. */
+ csum = 0;
+
+ while ((c = readchar()) != '$');
+
+ bp = buf;
+ while (1)
+ {
+ c = readchar ();
+ if (c == '#')
+ break;
+ if (bp >= buf+PBUFSIZ-1)
+ {
+ *bp = '\0';
+ printf_filtered ("Remote packet too long: %s\n", buf);
+ goto whole;
+ }
+ *bp++ = c;
+ csum += c;
+ }
+ *bp = 0;
+
+ c1 = fromhex (readchar ());
+ c2 = fromhex (readchar ());
+ if ((csum & 0xff) == (c1 << 4) + c2)
+ break;
+ printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=%s\n",
+ (c1 << 4) + c2, csum & 0xff, buf);
+ /* Try the whole thing again. */
+whole:
+ serial_write ("-", 1);
+ }
+
+#if 0
+ immediate_quit--;
+#endif
+
+ serial_write ("+", 1);
+
+ if (kiodebug)
+ fprintf (stderr,"Packet received: %s\n", buf);
+}
+
+static void
+remote_resume (step, siggnal)
+ int step, siggnal;
+{
+ char buf[PBUFSIZ];
+
+ if (siggnal)
+ error ("Can't send signals to a remote system. Try `handle %d ignore'.",
+ siggnal);
+
+#if 0
+ dcache_flush ();
+#endif
+
+ strcpy (buf, step ? "s": "c");
+
+ putpkt (buf);
+}
+
+/* Send ^C to target to halt it. Target will respond, and send us a
+ packet. */
+
+void remote_interrupt(signo)
+ int signo;
+{
+
+ if (kiodebug)
+ printf ("remote_interrupt called\n");
+
+ serial_write ("\003", 1); /* Send a ^C */
+}
+
+
+/* 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 (status)
+ WAITTYPE *status;
+{
+ unsigned char buf[PBUFSIZ];
+ void (*ofunc)();
+ unsigned char *p;
+ int i;
+ char regs[REGISTER_RAW_SIZE (PC_REGNUM) + REGISTER_RAW_SIZE (FP_REGNUM)];
+
+ WSETEXIT ((*status), 0);
+
+ ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
+ getpkt ((char *) buf);
+ signal (SIGINT, ofunc);
+
+ if (buf[0] == 'E')
+ error ("Remote failure reply: %s", buf);
+ if (buf[0] == 'T')
+ {
+ /* Expedited reply, containing Signal, PC, and FP. */
+ p = &buf[3]; /* after Txx */
+ for (i = 0; i < sizeof (regs); i++)
+ {
+ if (p[0] == 0 || p[1] == 0)
+ error ("Remote reply is too short: %s", buf);
+ regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+ supply_register (PC_REGNUM, ®s[0]);
+ supply_register (FP_REGNUM, ®s[REGISTER_RAW_SIZE (PC_REGNUM)]);
+ }
+ else if (buf[0] != 'S')
+ error ("Invalid remote reply: %s", buf);
+
+ WSETSTOP ((*status), (((fromhex (buf[1])) << 4) + (fromhex (buf[2]))));
+
+ return 0;
+}
+
+/* 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);
+
+ if (buf[0] == 'E')
+ error ("Remote failure reply: %s", buf);
+}
+
+/* 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);
+
+ /* 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 || p[1] == 0)
+ error ("Remote reply is too short: %s", buf);
+ regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+ for (i = 0; i < NUM_REGS; i++)
+ supply_register (i, ®s[REGISTER_BYTE(i)]);
+}
+
+/* Prepare to store registers. Since we send them all, we have to
+ read out the ones we don't want to change first. */
+
+static void
+remote_prepare_to_store ()
+{
+ remote_fetch_registers (-1);
+}
+
+/* Store the remote registers from the contents of the block REGISTERS.
+ FIXME, eventually just store one register if that's all that is needed. */
+
+/* ARGSUSED */
+static void
+remote_store_registers (regno)
+ int regno;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ buf[0] = 'G';
+
+ /* Command describes registers byte by byte,
+ each byte encoded as two hex characters. */
+
+ p = buf + 1;
+ for (i = 0; i < REGISTER_BYTES; i++)
+ {
+ *p++ = tohex ((registers[i] >> 4) & 0xf);
+ *p++ = tohex (registers[i] & 0xf);
+ }
+ *p = '\0';
+
+ remote_send (buf);
+}
+
+\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. */
+
+static void
+remote_write_bytes (memaddr, myaddr, len)
+ CORE_ADDR memaddr;
+ char *myaddr;
+ int len;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ if (len > PBUFSIZ / 2 - 20)
+ abort ();
+
+ sprintf (buf, "M%x,%x:", 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';
+
+ remote_send (buf);
+}
+
+/* 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. */
+
+static void
+remote_read_bytes (memaddr, myaddr, len)
+ CORE_ADDR memaddr;
+ char *myaddr;
+ int len;
+{
+ char buf[PBUFSIZ];
+ int i;
+ char *p;
+
+ if (len > PBUFSIZ / 2 - 1)
+ abort ();
+
+ sprintf (buf, "m%x,%x", memaddr, len);
+ remote_send (buf);
+
+ /* 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)
+ error ("Remote reply is too short: %s", buf);
+ myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+ p += 2;
+ }
+}
+\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 origlen = len;
+ int xfersize;
+ while (len > 0)
+ {
+ if (len > MAXBUFBYTES)
+ xfersize = MAXBUFBYTES;
+ else
+ xfersize = len;
+
+ if (should_write)
+ remote_write_bytes(memaddr, myaddr, xfersize);
+ else
+ remote_read_bytes (memaddr, myaddr, xfersize);
+ memaddr += xfersize;
+ myaddr += xfersize;
+ len -= xfersize;
+ }
+ return origlen; /* no error possible */
+}
+
+static void
+remote_files_info (ignore)
+struct target_ops *ignore;
+{
+ printf ("Debugging a target over a serial line.\n");
+}
+\f
+/*
+
+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 '#'
+
+ 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
+
+*/
+
+/* Read a single character from the remote end.
+ (If supported, we actually read many characters and buffer them up.) */
+
+static int
+readchar ()
+{
+ static int inbuf_index, inbuf_count;
+#define INBUFSIZE PBUFSIZ
+ static char inbuf[INBUFSIZE];
+
+ if (inbuf_index >= inbuf_count)
+ {
+ /* Time to do another read... */
+ inbuf_index = 0;
+ inbuf_count = 0;
+ inbuf[0] = 0; /* Just in case */
+ if ((inbuf[inbuf_index] = serial_readchar (timeout)) < 0)
+ inbuf_count = -1;
+ else
+ inbuf_count = 1;
+ }
+
+ /* Just return the next character from the buffer. */
+ return inbuf[inbuf_index++] & 0x7f;
+}
+
+
+\f
+/* The data cache leads to incorrect results because it doesn't know about
+ volatile variables, thus making it impossible to debug functions which
+ use hardware registers. Therefore it is #if 0'd out. Effect on
+ performance is some, for backtraces of functions with a few
+ arguments each. For functions with many arguments, the stack
+ frames don't fit in the cache blocks, which makes the cache less
+ helpful. Disabling the cache is a big performance win for fetching
+ large structures, because the cache code fetched data in 16-byte
+ chunks. */
+#if 0
+/* The data cache records all the data read from the remote machine
+ since the last time it stopped.
+
+ Each cache block holds 16 bytes of data
+ starting at a multiple-of-16 address. */
+
+#define DCACHE_SIZE 64 /* Number of cache blocks */
+
+struct dcache_block {
+ struct dcache_block *next, *last;
+ unsigned int addr; /* Address for which data is recorded. */
+ int data[4];
+};
+
+struct dcache_block dcache_free, dcache_valid;
+
+/* Free all the data cache blocks, thus discarding all cached data. */
+
+static void
+dcache_flush ()
+{
+ register struct dcache_block *db;
+
+ while ((db = dcache_valid.next) != &dcache_valid)
+ {
+ remque (db);
+ insque (db, &dcache_free);
+ }
+}
+
+/*
+ * If addr is present in the dcache, return the address of the block
+ * containing it.
+ */
+
+struct dcache_block *
+dcache_hit (addr)
+{
+ register struct dcache_block *db;
+
+ if (addr & 3)
+ abort ();
+
+ /* Search all cache blocks for one that is at this address. */
+ db = dcache_valid.next;
+ while (db != &dcache_valid)
+ {
+ if ((addr & 0xfffffff0) == db->addr)
+ return db;
+ db = db->next;
+ }
+ return NULL;
+}
+
+/* Return the int data at address ADDR in dcache block DC. */
+
+int
+dcache_value (db, addr)
+ struct dcache_block *db;
+ unsigned int addr;
+{
+ if (addr & 3)
+ abort ();
+ return (db->data[(addr>>2)&3]);
+}
+
+/* Get a free cache block, put it on the valid list,
+ and return its address. The caller should store into the block
+ the address and data that it describes. */
+
+struct dcache_block *
+dcache_alloc ()
+{
+ register struct dcache_block *db;
+
+ if ((db = dcache_free.next) == &dcache_free)
+ /* If we can't get one from the free list, take last valid */
+ db = dcache_valid.last;
+
+ remque (db);
+ insque (db, &dcache_valid);
+ return (db);
+}
+
+/* Return the contents of the word at address ADDR in the remote machine,
+ using the data cache. */
+
+int
+dcache_fetch (addr)
+ CORE_ADDR addr;
+{
+ register struct dcache_block *db;
+
+ db = dcache_hit (addr);
+ if (db == 0)
+ {
+ db = dcache_alloc ();
+ remote_read_bytes (addr & ~0xf, db->data, 16);
+ db->addr = addr & ~0xf;
+ }
+ return (dcache_value (db, addr));
+}
+
+/* Write the word at ADDR both in the data cache and in the remote machine. */
+
+dcache_poke (addr, data)
+ CORE_ADDR addr;
+ int data;
+{
+ register struct dcache_block *db;
+
+ /* First make sure the word is IN the cache. DB is its cache block. */
+ db = dcache_hit (addr);
+ if (db == 0)
+ {
+ db = dcache_alloc ();
+ remote_read_bytes (addr & ~0xf, db->data, 16);
+ db->addr = addr & ~0xf;
+ }
+
+ /* Modify the word in the cache. */
+ db->data[(addr>>2)&3] = data;
+
+ /* Send the changed word. */
+ remote_write_bytes (addr, &data, 4);
+}
+
+/* Initialize the data cache. */
+
+dcache_init ()
+{
+ register i;
+ register struct dcache_block *db;
+
+ db = (struct dcache_block *) xmalloc (sizeof (struct dcache_block) *
+ DCACHE_SIZE);
+ dcache_free.next = dcache_free.last = &dcache_free;
+ dcache_valid.next = dcache_valid.last = &dcache_valid;
+ for (i=0;i<DCACHE_SIZE;i++,db++)
+ insque (db, &dcache_free);
+}
+#endif /* 0 */
+
+/* Define the target subroutine names */
+
+struct target_ops remote_ops = {
+ "remote-ser", /* to_shortname */
+ "Remote serial target in gdb-specific protocol with serial-packaging routines", /* 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).", /* to_doc */
+ serial_open, /* to_open */
+ serial_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 */
+ NULL, /* to_convert_to_virtual */
+ NULL, /* to_convert_from_virtual */
+ remote_xfer_memory, /* to_xfer_memory */
+ remote_files_info, /* to_files_info */
+ NULL, /* to_insert_breakpoint */
+ NULL, /* 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 */
+ NULL, /* to_kill */
+ NULL, /* to_load */
+ NULL, /* to_lookup_symbol */
+ NULL, /* to_create_inferior */
+ NULL, /* to_mourn_inferior */
+ 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);
+
+ add_show_from_set (
+ add_set_cmd ("remotedebug", no_class, var_boolean, (char *)&kiodebug,
+ "Set debugging of remote serial I/O.\n\
+When enabled, each packet sent or received with the remote target\n\
+is displayed.", &setlist),
+ &showlist);
+}
+
projects / binutils-gdb.git / commitdiff