* configure.ac: On MinGW, define USE_WIN32API and link with

	-lws2_32.
	* ser-tcp.c (<winsock2.h>): Include, for Windows.
	(ETIMEDOUT): Define, for Windows.
	(ioctl): Likewise.
	(closesocket): Define, for POSIX.
	(net_open): Adjust for differences in socket functions between
	Windows and UNIX.
	(net_close): Likweise.
	(net_read_prim): New function.
	(net_write_prim): Likewise.
	(_initialize_ser_tcp): Initialize winsock.  Fill in read_prim and
	write_prim.
	* ser-unix.h (ser_unix_readcchar): Remove.
	(ser_unix_read_prim): Declare.
	(ser_unix_write_prim): Likewise.
	* ser-unix.c (generic_readchar): Move to ser-base.c.
	(ser_unix_wait_for): Likewise.
	(do_unix_readchar): Likewise.
	(ser_unix_readchar): Likewise.
	(_initialize_ser_hardwire): Initialize read_prim and write_prim.
	(ser_unix_read_prim): New function.
	(ser_unix_write_prim): Likewise.
	* ser-base.h (generic_readchar): Declare.
	(ser_base_readchar): Likewise.
	* ser-base.c (<winsock2.h>): Include, for windows.
	(fd_event): Use the read primitive specified by the serial
	interface.
	(ser_base_wait_for): Moved from ser-unix.c
	(do_ser_base_read_char): Likewise.
	(generic_readchar): Likewise.
	(ser_base_readchar): Likewise.
	(ser_base_write): Use the write primitive specified by the serial
	interface.
	* ser-pipe.c (_initialize_ser_pipe): Use ser_base_readchar, not
	ser_unix_readchar.  Initialize read_prim and write_prim.
	* serial.c (struct serial_ops): Add read_prim and write_prim.
	* configure: Regenerate.

10 files changed, 347 insertions, 208 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 86a6b568e1e..af6d7e55a07 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,44 @@
+2005-04-20  Mark Mitchell  <mark@codesourcery.com>
+
+	* configure.ac: On MinGW, define USE_WIN32API and link with
+	-lws2_32.
+	* ser-tcp.c (<winsock2.h>): Include, for Windows.
+	(ETIMEDOUT): Define, for Windows.
+	(ioctl): Likewise.
+	(closesocket): Define, for POSIX.
+	(net_open): Adjust for differences in socket functions between
+	Windows and UNIX.
+	(net_close): Likweise.
+	(net_read_prim): New function.
+	(net_write_prim): Likewise.
+	(_initialize_ser_tcp): Initialize winsock.  Fill in read_prim and
+	write_prim.
+	* ser-unix.h (ser_unix_readcchar): Remove.
+	(ser_unix_read_prim): Declare.
+	(ser_unix_write_prim): Likewise.
+	* ser-unix.c (generic_readchar): Move to ser-base.c.
+	(ser_unix_wait_for): Likewise.
+	(do_unix_readchar): Likewise.
+	(ser_unix_readchar): Likewise.
+	(_initialize_ser_hardwire): Initialize read_prim and write_prim.
+	(ser_unix_read_prim): New function.
+	(ser_unix_write_prim): Likewise.
+	* ser-base.h (generic_readchar): Declare.
+	(ser_base_readchar): Likewise.
+	* ser-base.c (<winsock2.h>): Include, for windows.
+	(fd_event): Use the read primitive specified by the serial
+	interface.
+	(ser_base_wait_for): Moved from ser-unix.c
+	(do_ser_base_read_char): Likewise.
+	(generic_readchar): Likewise.
+	(ser_base_readchar): Likewise.
+	(ser_base_write): Use the write primitive specified by the serial
+	interface.
+	* ser-pipe.c (_initialize_ser_pipe): Use ser_base_readchar, not
+	ser_unix_readchar.  Initialize read_prim and write_prim.
+	* serial.c (struct serial_ops): Add read_prim and write_prim.
+	* configure: Regenerate.
+
 2005-04-19  Ben Elliston  <bje@au.ibm.com>
 
 	* c-lang.c (c_create_fundamental_type): Comment fix.
diff --git a/gdb/configure b/gdb/configure
index 39af594c879..cd0acf79819 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -20034,6 +20034,18 @@ if test x$gdb_cv_os_cygwin = xyes; then
     esac
 fi
 
+# The ser-tcp.c module requires sockets.
+case ${host} in
+  *mingw32*)
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_WIN32API 1
+_ACEOF
+
+    WIN32LIBS="$WIN32LIBS -lws2_32"
+    ;;
+esac
+
 
 LIBGUI="../libgui/src/libgui.a"
 GUI_CFLAGS_X="-I${srcdir}/../libgui/src"
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 6113b0dc89f..554c46530d1 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1187,6 +1187,18 @@ if test x$gdb_cv_os_cygwin = xyes; then
 	;;
     esac
 fi
+
+# The ser-tcp.c module requires sockets.
+case ${host} in
+  *mingw32*)
+    AC_DEFINE(USE_WIN32API, 1,
+              [Define if we should use the Windows API, instead of the 
+	       POSIX API.  On Windows, we use the Windows API when 
+	       building for MinGW, but the POSIX API when building 
+	       for Cygwin.])
+    WIN32LIBS="$WIN32LIBS -lws2_32"
+    ;;
+esac	    
 AC_SUBST(WIN32LIBS)
 
 LIBGUI="../libgui/src/libgui.a"
diff --git a/gdb/ser-base.c b/gdb/ser-base.c
index b17b11ad61a..07ec503b89f 100644
--- a/gdb/ser-base.c
+++ b/gdb/ser-base.c
@@ -24,6 +24,9 @@
 #include "serial.h"
 #include "ser-unix.h"
 #include "event-loop.h"
+#ifdef USE_WIN32API
+#include <winsock2.h>
+#endif
 
 static timer_handler_func push_event;
 static handler_func fd_event;
@@ -136,11 +139,7 @@ fd_event (int error, void *context)
          pull characters out of the buffer.  See also
          generic_readchar(). */
       int nr;
-      do
-	{
-	  nr = read (scb->fd, scb->buf, BUFSIZ);
-	}
-      while (nr == -1 && errno == EINTR);
+      nr = scb->ops->read_prim (scb, BUFSIZ);
       if (nr == 0)
 	{
 	  scb->bufcnt = SERIAL_EOF;
@@ -174,6 +173,181 @@ push_event (void *context)
   reschedule (scb);
 }
 
+/* Wait for input on scb, with timeout seconds.  Returns 0 on success,
+   otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */
+
+static int
+ser_base_wait_for (struct serial *scb, int timeout)
+{
+  while (1)
+    {
+      int numfds;
+      struct timeval tv;
+      fd_set readfds, exceptfds;
+
+      /* NOTE: Some OS's can scramble the READFDS when the select()
+         call fails (ex the kernel with Red Hat 5.2).  Initialize all
+         arguments before each call. */
+
+      tv.tv_sec = timeout;
+      tv.tv_usec = 0;
+
+      FD_ZERO (&readfds);
+      FD_ZERO (&exceptfds);
+      FD_SET (scb->fd, &readfds);
+      FD_SET (scb->fd, &exceptfds);
+
+      if (timeout >= 0)
+	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
+      else
+	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0);
+
+      if (numfds <= 0)
+	{
+	  if (numfds == 0)
+	    return SERIAL_TIMEOUT;
+	  else if (errno == EINTR)
+	    continue;
+	  else
+	    return SERIAL_ERROR;	/* Got an error from select or poll */
+	}
+
+      return 0;
+    }
+}
+
+/* Read a character with user-specified timeout.  TIMEOUT is number of seconds
+   to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
+   char if successful.  Returns -2 if timeout expired, EOF if line dropped
+   dead, or -3 for any other error (see errno in that case). */
+
+static int
+do_ser_base_readchar (struct serial *scb, int timeout)
+{
+  int status;
+  int delta;
+
+  /* We have to be able to keep the GUI alive here, so we break the
+     original timeout into steps of 1 second, running the "keep the
+     GUI alive" hook each time through the loop.
+
+     Also, timeout = 0 means to poll, so we just set the delta to 0,
+     so we will only go through the loop once.  */
+
+  delta = (timeout == 0 ? 0 : 1);
+  while (1)
+    {
+      /* N.B. The UI may destroy our world (for instance by calling
+         remote_stop,) in which case we want to get out of here as
+         quickly as possible.  It is not safe to touch scb, since
+         someone else might have freed it.  The
+         deprecated_ui_loop_hook signals that we should exit by
+         returning 1.  */
+
+      if (deprecated_ui_loop_hook)
+	{
+	  if (deprecated_ui_loop_hook (0))
+	    return SERIAL_TIMEOUT;
+	}
+
+      status = ser_base_wait_for (scb, delta);
+      if (timeout > 0)
+        timeout -= delta;
+
+      /* If we got a character or an error back from wait_for, then we can 
+         break from the loop before the timeout is completed. */
+      if (status != SERIAL_TIMEOUT)
+	break;
+
+      /* If we have exhausted the original timeout, then generate
+         a SERIAL_TIMEOUT, and pass it out of the loop. */
+      else if (timeout == 0)
+	{
+	  status = SERIAL_TIMEOUT;
+	  break;
+	}
+    }
+
+  if (status < 0)
+    return status;
+
+  status = scb->ops->read_prim (scb, BUFSIZ);
+
+  if (status <= 0)
+    {
+      if (status == 0)
+	/* 0 chars means timeout.  (We may need to distinguish between EOF
+	   & timeouts someday.)  */
+	return SERIAL_TIMEOUT;	
+      else
+	/* Got an error from read.  */
+	return SERIAL_ERROR;	
+    }
+
+  scb->bufcnt = status;
+  scb->bufcnt--;
+  scb->bufp = scb->buf;
+  return *scb->bufp++;
+}
+
+/* Perform operations common to both old and new readchar. */
+
+/* Return the next character from the input FIFO.  If the FIFO is
+   empty, call the SERIAL specific routine to try and read in more
+   characters.
+
+   Initially data from the input FIFO is returned (fd_event()
+   pre-reads the input into that FIFO.  Once that has been emptied,
+   further data is obtained by polling the input FD using the device
+   specific readchar() function.  Note: reschedule() is called after
+   every read.  This is because there is no guarentee that the lower
+   level fd_event() poll_event() code (which also calls reschedule())
+   will be called. */
+
+int
+generic_readchar (struct serial *scb, int timeout,
+		  int (do_readchar) (struct serial *scb, int timeout))
+{
+  int ch;
+  if (scb->bufcnt > 0)
+    {
+      ch = *scb->bufp;
+      scb->bufcnt--;
+      scb->bufp++;
+    }
+  else if (scb->bufcnt < 0)
+    {
+      /* Some errors/eof are are sticky. */
+      ch = scb->bufcnt;
+    }
+  else
+    {
+      ch = do_readchar (scb, timeout);
+      if (ch < 0)
+	{
+	  switch ((enum serial_rc) ch)
+	    {
+	    case SERIAL_EOF:
+	    case SERIAL_ERROR:
+	      /* Make the error/eof stick. */
+	      scb->bufcnt = ch;
+	      break;
+	    case SERIAL_TIMEOUT:
+	      scb->bufcnt = 0;
+	      break;
+	    }
+	}
+    }
+  reschedule (scb);
+  return ch;
+}
+
+int
+ser_base_readchar (struct serial *scb, int timeout)
+{
+  return generic_readchar (scb, timeout, do_ser_base_readchar);
+}
+
 int
 ser_base_write (struct serial *scb, const char *str, int len)
 {
@@ -181,7 +355,7 @@ ser_base_write (struct serial *scb, const char *str, int len)
 
   while (len > 0)
     {
-      cc = write (scb->fd, str, len);
+      cc = scb->ops->write_prim (scb, str, len); 
 
       if (cc < 0)
 	return 1;
diff --git a/gdb/ser-base.h b/gdb/ser-base.h
index 5467fc8fc19..860462911af 100644
--- a/gdb/ser-base.h
+++ b/gdb/ser-base.h
@@ -25,6 +25,9 @@
 struct serial;
 struct ui_file;
 
+extern int generic_readchar (struct serial *scb, int timeout,
+			     int (*do_readchar) (struct serial *scb,
+						 int timeout));
 extern void reschedule (struct serial *scb);
 extern int ser_base_flush_output (struct serial *scb);
 extern int ser_base_flush_input (struct serial *scb);
@@ -46,5 +49,6 @@ extern int ser_base_drain_output (struct serial *scb);
 extern int ser_base_write (struct serial *scb, const char *str, int len);
 
 extern void ser_base_async (struct serial *scb, int async_p);
+extern int ser_base_readchar (struct serial *scb, int timeout);
 
 #endif
diff --git a/gdb/ser-pipe.c b/gdb/ser-pipe.c
index b6bb8d5f4eb..f127f5d1f6d 100644
--- a/gdb/ser-pipe.c
+++ b/gdb/ser-pipe.c
@@ -144,7 +144,7 @@ _initialize_ser_pipe (void)
   ops->next = 0;
   ops->open = pipe_open;
   ops->close = pipe_close;
-  ops->readchar = ser_unix_readchar;
+  ops->readchar = ser_base_readchar;
   ops->write = ser_base_write;
   ops->flush_output = ser_base_flush_output;
   ops->flush_input = ser_base_flush_input;
@@ -158,5 +158,7 @@ _initialize_ser_pipe (void)
   ops->setstopbits = ser_base_setstopbits;
   ops->drain_output = ser_base_drain_output;
   ops->async = ser_base_async;
+  ops->read_prim = ser_unix_read_prim;
+  ops->write_prim = ser_unix_write_prim;
   serial_add_interface (ops);
 }
diff --git a/gdb/ser-tcp.c b/gdb/ser-tcp.c
index f908d258b5f..abe6ed4a35b 100644
--- a/gdb/ser-tcp.c
+++ b/gdb/ser-tcp.c
@@ -34,11 +34,19 @@
 #endif
 
 #include <sys/time.h>
+
+#ifdef USE_WIN32API
+#include <winsock2.h>
+#define ETIMEDOUT WSAETIMEDOUT
+#define close closesocket
+#define ioctl ioctlsocket
+#else
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <sys/socket.h>
 #include <netinet/tcp.h>
+#endif
 
 #include <signal.h>
 #include "gdb_string.h"
@@ -62,6 +70,11 @@ net_open (struct serial *scb, const char *name)
   int use_udp;
   struct hostent *hostent;
   struct sockaddr_in sockaddr;
+#ifdef USE_WIN32API
+  u_long ioarg;
+#else
+  int ioarg;
+#endif
 
   use_udp = 0;
   if (strncmp (name, "udp:", 4) == 0)
@@ -108,14 +121,25 @@ net_open (struct serial *scb, const char *name)
 	  sizeof (struct in_addr));
 
   /* set socket nonblocking */
-  tmp = 1;
-  ioctl (scb->fd, FIONBIO, &tmp);
+  ioarg = 1;
+  ioctl (scb->fd, FIONBIO, &ioarg);
 
   /* Use Non-blocking connect.  connect() will return 0 if connected already. */
   n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr));
 
-  if (n < 0 && errno != EINPROGRESS)
+  if (n < 0
+#ifdef USE_WIN32API
+      /* Under Windows, calling "connect" with a non-blocking socket
+	 results in WSAEWOULDBLOCK, not WSAEINPROGRESS.  */
+      && WSAGetLastError() != WSAEWOULDBLOCK
+#else
+      && errno != EINPROGRESS
+#endif
+      )
     {
+#ifdef USE_WIN32API
+      errno = WSAGetLastError();
+#endif
       net_close (scb);
       return -1;
     }
@@ -165,7 +189,11 @@ net_open (struct serial *scb, const char *name)
   {
     int res, err, len;
     len = sizeof(err);
-    res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, &err, &len);
+    /* On Windows, the fourth parameter to getsockopt is a "char *";
+       on UNIX systems it is generally "void *".  The cast to "void *"
+       is OK everywhere, since in C "void *" can be implicitly
+       converted to any pointer type.  */
+    res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len);
     if (res < 0 || err)
       {
 	if (err)
@@ -176,8 +204,8 @@ net_open (struct serial *scb, const char *name)
   } 
 
   /* turn off nonblocking */
-  tmp = 0;
-  ioctl (scb->fd, FIONBIO, &tmp);
+  ioarg = 0;
+  ioctl (scb->fd, FIONBIO, &ioarg);
 
   if (use_udp == 0)
     {
@@ -206,16 +234,35 @@ net_close (struct serial *scb)
   scb->fd = -1;
 }
 
+static int
+net_read_prim (struct serial *scb, size_t count)
+{
+  return recv (scb->fd, scb->buf, count, 0);
+}
+
+static int
+net_write_prim (struct serial *scb, const void *buf, size_t count)
+{
+  return send (scb->fd, buf, count, 0);
+}
+
 void
 _initialize_ser_tcp (void)
 {
-  struct serial_ops *ops = XMALLOC (struct serial_ops);
+  struct serial_ops *ops;
+#ifdef USE_WIN32API
+  WSADATA wsa_data;
+  if (WSAStartup (MAKEWORD (1, 0), &wsa_data) != 0)
+    /* WinSock is unavailable.  */
+    return;
+#endif
+  ops = XMALLOC (struct serial_ops);
   memset (ops, 0, sizeof (struct serial_ops));
   ops->name = "tcp";
   ops->next = 0;
   ops->open = net_open;
   ops->close = net_close;
-  ops->readchar = ser_unix_readchar;
+  ops->readchar = ser_base_readchar;
   ops->write = ser_base_write;
   ops->flush_output = ser_base_flush_output;
   ops->flush_input = ser_base_flush_input;
@@ -229,5 +276,7 @@ _initialize_ser_tcp (void)
   ops->setstopbits = ser_base_setstopbits;
   ops->drain_output = ser_base_drain_output;
   ops->async = ser_base_async;
+  ops->read_prim = net_read_prim;
+  ops->write_prim = net_write_prim;
   serial_add_interface (ops);
 }
diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index 14df459b723..b76a6bcc17e 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -70,9 +70,6 @@ static void hardwire_raw (struct serial *scb);
 static int wait_for (struct serial *scb, int timeout);
 static int hardwire_readchar (struct serial *scb, int timeout);
 static int do_hardwire_readchar (struct serial *scb, int timeout);
-static int generic_readchar (struct serial *scb, int timeout,
-			     int (*do_readchar) (struct serial *scb,
-						 int timeout));
 static int rate_to_code (int rate);
 static int hardwire_setbaudrate (struct serial *scb, int rate);
 static void hardwire_close (struct serial *scb);
@@ -422,7 +419,7 @@ hardwire_raw (struct serial *scb)
  */
 
 /* FIXME: cagney/1999-09-16: Don't replace this with the equivalent
-   ser_unix*() until the old TERMIOS/SGTTY/... timer code has been
+   ser_base*() until the old TERMIOS/SGTTY/... timer code has been
    flushed. . */
 
 /* NOTE: cagney/1999-09-30: Much of the code below is dead.  The only
@@ -542,13 +539,13 @@ wait_for (struct serial *scb, int timeout)
    dropped dead, or SERIAL_ERROR for any other error (see errno in that case).  */
 
 /* FIXME: cagney/1999-09-16: Don't replace this with the equivalent
-   ser_unix*() until the old TERMIOS/SGTTY/... timer code has been
+   ser_base*() until the old TERMIOS/SGTTY/... timer code has been
    flushed. */
 
 /* NOTE: cagney/1999-09-16: This function is not identical to
-   ser_unix_readchar() as part of replacing it with ser_unix*()
+   ser_base_readchar() as part of replacing it with ser_base*()
    merging will be required - this code handles the case where read()
-   times out due to no data while ser_unix_readchar() doesn't expect
+   times out due to no data while ser_base_readchar() doesn't expect
    that. */
 
 static int
@@ -863,191 +860,7 @@ hardwire_close (struct serial *scb)
   close (scb->fd);
   scb->fd = -1;
 }
-
 
-/* Wait for input on scb, with timeout seconds.  Returns 0 on success,
-   otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */
-
-static int
-ser_unix_wait_for (struct serial *scb, int timeout)
-{
-  while (1)
-    {
-      int numfds;
-      struct timeval tv;
-      fd_set readfds, exceptfds;
-
-      /* NOTE: Some OS's can scramble the READFDS when the select()
-         call fails (ex the kernel with Red Hat 5.2).  Initialize all
-         arguments before each call. */
-
-      tv.tv_sec = timeout;
-      tv.tv_usec = 0;
-
-      FD_ZERO (&readfds);
-      FD_ZERO (&exceptfds);
-      FD_SET (scb->fd, &readfds);
-      FD_SET (scb->fd, &exceptfds);
-
-      if (timeout >= 0)
-	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
-      else
-	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0);
-
-      if (numfds <= 0)
-	{
-	  if (numfds == 0)
-	    return SERIAL_TIMEOUT;
-	  else if (errno == EINTR)
-	    continue;
-	  else
-	    return SERIAL_ERROR;	/* Got an error from select or poll */
-	}
-
-      return 0;
-    }
-}
-
-/* Read a character with user-specified timeout.  TIMEOUT is number of seconds
-   to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
-   char if successful.  Returns -2 if timeout expired, EOF if line dropped
-   dead, or -3 for any other error (see errno in that case). */
-
-static int
-do_unix_readchar (struct serial *scb, int timeout)
-{
-  int status;
-  int delta;
-
-  /* We have to be able to keep the GUI alive here, so we break the
-     original timeout into steps of 1 second, running the "keep the
-     GUI alive" hook each time through the loop.
-
-     Also, timeout = 0 means to poll, so we just set the delta to 0,
-     so we will only go through the loop once.  */
-
-  delta = (timeout == 0 ? 0 : 1);
-  while (1)
-    {
-
-      /* N.B. The UI may destroy our world (for instance by calling
-         remote_stop,) in which case we want to get out of here as
-         quickly as possible.  It is not safe to touch scb, since
-         someone else might have freed it.  The
-         deprecated_ui_loop_hook signals that we should exit by
-         returning 1.  */
-
-      if (deprecated_ui_loop_hook)
-	{
-	  if (deprecated_ui_loop_hook (0))
-	    return SERIAL_TIMEOUT;
-	}
-
-      status = ser_unix_wait_for (scb, delta);
-      if (timeout > 0)
-        timeout -= delta;
-
-      /* If we got a character or an error back from wait_for, then we can 
-         break from the loop before the timeout is completed. */
-
-      if (status != SERIAL_TIMEOUT)
-	{
-	  break;
-	}
-
-      /* If we have exhausted the original timeout, then generate
-         a SERIAL_TIMEOUT, and pass it out of the loop. */
-
-      else if (timeout == 0)
-	{
-	  status = SERIAL_TIMEOUT;
-	  break;
-	}
-    }
-
-  if (status < 0)
-    return status;
-
-  while (1)
-    {
-      status = read (scb->fd, scb->buf, BUFSIZ);
-      if (status != -1 || errno != EINTR)
-	break;
-    }
-
-  if (status <= 0)
-    {
-      if (status == 0)
-	return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
-				   distinguish between EOF & timeouts
-				   someday] */
-      else
-	return SERIAL_ERROR;	/* Got an error from read */
-    }
-
-  scb->bufcnt = status;
-  scb->bufcnt--;
-  scb->bufp = scb->buf;
-  return *scb->bufp++;
-}
-
-/* Perform operations common to both old and new readchar. */
-
-/* Return the next character from the input FIFO.  If the FIFO is
-   empty, call the SERIAL specific routine to try and read in more
-   characters.
-
-   Initially data from the input FIFO is returned (fd_event()
-   pre-reads the input into that FIFO.  Once that has been emptied,
-   further data is obtained by polling the input FD using the device
-   specific readchar() function.  Note: reschedule() is called after
-   every read.  This is because there is no guarentee that the lower
-   level fd_event() poll_event() code (which also calls reschedule())
-   will be called. */
-
-static int
-generic_readchar (struct serial *scb, int timeout,
-		  int (do_readchar) (struct serial *scb, int timeout))
-{
-  int ch;
-  if (scb->bufcnt > 0)
-    {
-      ch = *scb->bufp;
-      scb->bufcnt--;
-      scb->bufp++;
-    }
-  else if (scb->bufcnt < 0)
-    {
-      /* Some errors/eof are are sticky. */
-      ch = scb->bufcnt;
-    }
-  else
-    {
-      ch = do_readchar (scb, timeout);
-      if (ch < 0)
-	{
-	  switch ((enum serial_rc) ch)
-	    {
-	    case SERIAL_EOF:
-	    case SERIAL_ERROR:
-	      /* Make the error/eof stick. */
-	      scb->bufcnt = ch;
-	      break;
-	    case SERIAL_TIMEOUT:
-	      scb->bufcnt = 0;
-	      break;
-	    }
-	}
-    }
-  reschedule (scb);
-  return ch;
-}
-
-int
-ser_unix_readchar (struct serial *scb, int timeout)
-{
-  return generic_readchar (scb, timeout, do_unix_readchar);
-}
 
 void
 _initialize_ser_hardwire (void)
@@ -1058,7 +871,7 @@ _initialize_ser_hardwire (void)
   ops->next = 0;
   ops->open = hardwire_open;
   ops->close = hardwire_close;
-  /* FIXME: Don't replace this with the equivalent ser_unix*() until
+  /* FIXME: Don't replace this with the equivalent ser_base*() until
      the old TERMIOS/SGTTY/... timer code has been flushed. cagney
      1999-09-16. */
   ops->readchar = hardwire_readchar;
@@ -1075,5 +888,29 @@ _initialize_ser_hardwire (void)
   ops->setstopbits = hardwire_setstopbits;
   ops->drain_output = hardwire_drain_output;
   ops->async = ser_base_async;
+  ops->read_prim = ser_unix_read_prim;
+  ops->write_prim = ser_unix_write_prim;
   serial_add_interface (ops);
 }
+
+int
+ser_unix_read_prim (struct serial *scb, size_t count)
+{
+  int status;
+
+  while (1)
+    {
+      status = read (scb->fd, scb->buf, count);
+      if (status != -1 || errno != EINTR)
+	break;
+    }
+  return status;
+}
+
+int
+ser_unix_write_prim (struct serial *scb, const void *buf, size_t len)
+{
+  /* ??? Historically, GDB has not retried calls to "write" that
+     result in EINTR.  */
+  return write (scb->fd, buf, len);
+}
diff --git a/gdb/ser-unix.h b/gdb/ser-unix.h
index 5ba01f964a9..03dbdef04f9 100644
--- a/gdb/ser-unix.h
+++ b/gdb/ser-unix.h
@@ -22,6 +22,8 @@
 #ifndef SER_UNIX_H
 #define SER_UNIX_H
 
-extern int ser_unix_readchar (struct serial *scb, int timeout);
+extern int ser_unix_read_prim (struct serial *scb, size_t count);
+extern int ser_unix_write_prim (struct serial *scb, const void *buf, 
+				size_t count);
 
 #endif
diff --git a/gdb/serial.h b/gdb/serial.h
index d83b2011448..89b66b452cf 100644
--- a/gdb/serial.h
+++ b/gdb/serial.h
@@ -232,6 +232,12 @@ struct serial_ops
        the specified function when ever there is something
        interesting.  */
     void (*async) (struct serial *scb, int async_p);
+    /* Perform a low-level read operation, reading (at most) COUNT
+       bytes into SCB->BUF.  */
+    int (*read_prim)(struct serial *scb, size_t count);
+    /* Perform a low-level write operation, writing (at most) COUNT
+       bytes from BUF.  */
+    int (*write_prim)(struct serial *scb, const void *buf, size_t count);
   };
 
 /* Add a new serial interface to the interface list */