gdb-2.5.1

1 files changed, 607 insertions, 0 deletions

diff --git a/gdb/remote.c b/gdb/remote.c
new file mode 100644
index 0000000..23f27df
--- /dev/null
+++ b/gdb/remote.c
@@ -0,0 +1,607 @@
+/* Memory-access and commands for inferior process, for GDB.
+   Copyright (C)  1988 Free Software Foundation, Inc.
+
+GDB is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY.  No author or distributor accepts responsibility to anyone
+for the consequences of using it or for whether it serves any
+particular purpose or works at all, unless he says so in writing.
+Refer to the GDB General Public License for full details.
+
+Everyone is granted permission to copy, modify and redistribute GDB,
+but only under the conditions described in the GDB General Public
+License.  A copy of this license is supposed to have been given to you
+along with GDB so you can know your rights and responsibilities.  It
+should be in a file named COPYING.  Among other things, the copyright
+notice and this notice must be preserved on all copies.
+
+In other words, go ahead and share GDB, but don't try to stop
+anyone else from sharing it farther.  Help stamp out software hoarding!
+*/
+
+/* 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.
+
+	There is no immediate reply to step or cont.
+	The reply comes when the machine stops.
+	It is		SAA		AA is the "signal number"
+
+	kill req	k
+*/
+
+#include <stdio.h>
+#include <signal.h>
+
+#include "defs.h"
+#include "initialize.h"
+#include "param.h"
+#include "frame.h"
+#include "inferior.h"
+
+#include <sys/wait.h>
+#include <sys/ioctl.h>
+#include <a.out.h>
+#include <sys/file.h>
+#include <sgtty.h>
+
+int kiodebug;
+
+int icache;
+
+/* Descriptor for I/O to remote machine.  */
+int remote_desc;
+
+#define	PBUFSIZ	300
+
+static void remote_send ();
+static void putpkt ();
+static void getpkt ();
+static void dcache_flush ();
+
+START_FILE
+
+/* Open a connection to a remote debugger.
+   NAME is the filename used for communication.  */
+
+void
+remote_open (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  struct sgttyb sg;
+
+  remote_debugging = 0;
+  dcache_init ();
+
+  remote_desc = open (name, O_RDWR);
+  if (remote_desc < 0)
+    perror_with_name (name);
+
+  ioctl (remote_desc, TIOCGETP, &sg);
+  sg.sg_flags = RAW;
+  ioctl (remote_desc, TIOCSETP, &sg);
+
+  if (from_tty)
+    printf ("Remote debugging using %s\n", name);
+  remote_debugging = 1;
+}
+
+/* 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;
+}
+
+/* Tell the remote machine to resume.  */
+
+int
+remote_resume (step, signal)
+     int step, signal;
+{
+  char buf[PBUFSIZ];
+
+  dcache_flush ();
+
+  strcpy (buf, step ? "s": "c");
+
+  putpkt (buf);
+}
+
+/* Wait until the remote machine stops, then return,
+   storing status in STATUS just as `wait' would.  */
+
+int
+remote_wait (status)
+     union wait *status;
+{
+  char buf[PBUFSIZ];
+
+  status->w_status = 0;
+  getpkt (buf);
+  if (buf[0] == 'E')
+    error ("Remote failure reply: %s", buf);
+  if (buf[0] != 'S')
+    error ("Invalid remote reply: %s", buf);
+  status->w_stopval = WSTOPPED;
+  status->w_stopsig = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
+}
+
+/* Read the remote registers into the block REGS.  */
+
+void
+remote_fetch_registers (regs)
+     char *regs;
+{
+  char buf[PBUFSIZ];
+  int i;
+  char *p;
+
+  sprintf (buf, "g");
+  remote_send (buf);
+
+  /* Reply describes registers byte by byte,
+     each byte encoded as two hex characters.  */
+
+  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;
+    }
+}
+
+/* Store the remote registers from the contents of the block REGS.  */
+
+void
+remote_store_registers (regs)
+     char *regs;
+{
+  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++ = (regs[i] > 4) & 0xf;
+      *p++ = regs[i] & 0xf;
+    }
+
+  remote_send (buf);
+}
+
+/* Read a word from remote address ADDR and return it.
+   This goes through the data cache.  */
+
+int
+remote_fetch_word (addr)
+     CORE_ADDR addr;
+{
+  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;
+	}
+    }
+  return dcache_fetch (addr);
+}
+
+/* Write a word WORD into remote address ADDR.
+   This goes through the data cache.  */
+
+void
+remote_store_word (addr, word)
+     CORE_ADDR addr;
+     int word;
+{
+  dcache_poke (addr, word);
+}
+
+/* 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.  */
+
+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);
+
+  /* Command describes registers byte by byte,
+     each byte encoded as two hex characters.  */
+
+  p = buf + strlen (buf);
+  for (i = 0; i < len; i++)
+    {
+      *p++ = (myaddr[i] > 4) & 0xf;
+      *p++ = myaddr[i] & 0xf;
+    }
+
+  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.  */
+
+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 registers byte by byte,
+     each byte encoded as two hex characters.  */
+
+  p = buf;
+  for (i = 0; i < REGISTER_BYTES; 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;
+    }
+}
+
+/*
+
+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
+	'$' or '#'
+
+	CSUM1 and CSUM2 are ascii hex representation of an 8-bit 
+	checksum of <data>, the most significant nibble is sent first.
+	the hex digits 0-9,a-f are used.
+
+Receiver responds with:
+
+	+	- if CSUM is correct and ready for next packet
+	-	- if CSUM is incorrect
+
+*/
+
+/* Send the command in BUF to the remote machine,
+   and read the reply into BUF.
+   Report an error if we get an error reply.  */
+
+static void
+remote_send (buf)
+     char *buf;
+{
+  int i;
+  putpkt (buf);
+  getpkt (buf);
+
+  if (buf[0] == 'E')
+    error ("Remote failure reply: %s", buf);
+}
+
+/* Send a packet to the remote machine, with error checking.
+   The data of the packet is in BUF.  */
+
+static void
+putpkt (buf)
+     char *buf;
+{
+  int i;
+  char csum = 0;
+  char buf2[500];
+  char buf3[1];
+  int cnt = strlen (buf);
+  char *p;
+
+  if (kiodebug)
+    fprintf (stderr, "Sending packet: %s\n", buf);
+
+  /* Copy the packet into buffer BUF2, encapsulating it
+     and giving it a checksum.  */
+
+  p = buf2;
+  *p++ = '$';
+
+  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 {
+    write (remote_desc, buf2, p - buf2);
+    read (remote_desc, buf3, 1);
+  } while (buf3[0] != '+');
+}
+
+static int
+readchar ()
+{
+  char buf[1];
+  while (read (remote_desc, buf, 1) != 1) ;
+  return buf[0] & 0x7f;
+}
+
+/* Read a packet from the remote machine, with error checking,
+   and store it in BUF.  */
+
+static void
+getpkt (buf)
+     char *buf;
+{
+  char *bp;
+  char csum = 0;
+  int c, c1, c2;
+  extern kiodebug;
+
+  while (1)
+    {
+      while ((c = readchar()) != '$');
+
+      bp = buf;
+      while (1)
+	{
+	  c = readchar ();
+	  if (c == '#')
+	    break;
+	  *bp++ = c;
+	  csum += c;
+	}
+      *bp = 0;
+
+      c1 = fromhex (readchar ());
+      c2 = fromhex (readchar ());
+      if (csum == (c1 << 4) + c2)
+	break;
+      printf ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=%s\n",
+	      (c1 << 4) + c2, csum, buf);
+      write (remote_desc, "-", 1);
+    }
+
+  write (remote_desc, "+", 1);
+
+  if (kiodebug)
+    fprintf (stderr,"Packet received :%s\n", buf);
+}
+
+/* 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);
+}
+
+static initialize ()
+{
+}
+
+END_FILE