* Makefile.in: Add fhandler_mem.o to the dependencies.

* dtable.cc (dtable::build_fhandler): Add case for FH_MEM.
        * fhandler.h: Add FH_MEM device type.  Add class fhandler_dev_mem.
        * fhandler_mem.cc: New file. Implementation of class fhandler_dev_mem.
        * path.cc: Add /dev/mem to windows_device_names.
        (get_device_number): Add FH_MEM type.

winsup/cygwin/fhandler.h

@@ -41,6 +41,8 @@ details. */
 
      fhandler_dev_random  /dev/[u]random implementation (fhandler_random.cc)
 
+     fhandler_dev_mem     /dev/mem implementation (fhandler_mem.cc)
+
      fhandler_proc	  Interesting possibility, not implemented yet
 */
 
@@ -94,8 +96,9 @@ enum
   FH_NULL    = 0x00000013,	/* is the null device */
   FH_ZERO    = 0x00000014,	/* is the zero device */
   FH_RANDOM  = 0x00000015,	/* is a random device */
+  FH_MEM     = 0x00000016,	/* is a mem device */
 
-  FH_NDEV    = 0x00000016,	/* Maximum number of devices */
+  FH_NDEV    = 0x00000017,	/* Maximum number of devices */
   FH_DEVMASK = 0x00000fff,	/* devices live here */
   FH_BAD     = 0xffffffff
 };
@@ -761,6 +764,26 @@ public:
   void dump ();
 };
 
+class fhandler_dev_mem: public fhandler_base
+{
+protected:
+  unsigned long pos;
+
+public:
+  fhandler_dev_mem (const char *name, int unit);
+  ~fhandler_dev_mem (void);
+
+  int open (const char *path, int flags, mode_t mode = 0);
+  int write (const void *ptr, size_t ulen);
+  int read (void *ptr, size_t ulen);
+  off_t lseek (off_t offset, int whence);
+  int close (void);
+  int fstat (struct stat *buf);
+  int dup (fhandler_base *child);
+
+  void dump ();
+};
+
 class fhandler_windows: public fhandler_base
 {
 private: