--- qemu/vl.c	2004-11-26 13:09:07.000000000 -0600
+++ qemu-orig/vl.c	2004-11-26 13:47:37.000000000 -0600
@@ -112,6 +112,7 @@
 int bios_size;
 static DisplayState display_state;
 int nographic;
+char *pidfile;
 int64_t ticks_per_sec;
 int boot_device = 'c';
 int ram_size;
@@ -188,6 +189,12 @@
 #endif
 }
 
+/* Remove PID file. Called on normal exit */
+
+static void remove_pidfile (void) {
+   unlink (pidfile);
+}
+
 void init_ioports(void)
 {
     int i;
@@ -2533,6 +2540,7 @@
            "Debug/Expert options:\n"
            "-monitor dev    redirect the monitor to char device 'dev'\n"
            "-serial dev     redirect the serial port to char device 'dev'\n"
+           "-pidfile file   Write PID to 'file'\n"
            "-S              freeze CPU at startup (use 'c' to start execution)\n"
            "-s              wait gdb connection to port %d\n"
            "-p port         change gdb connection port\n"
@@ -2590,6 +2598,7 @@
     QEMU_OPTION_boot,
     QEMU_OPTION_snapshot,
     QEMU_OPTION_m,
+    QEMU_OPTION_pidfile,
     QEMU_OPTION_nographic,
     QEMU_OPTION_enable_audio,
 
@@ -2646,6 +2655,7 @@
     { "boot", HAS_ARG, QEMU_OPTION_boot },
     { "snapshot", 0, QEMU_OPTION_snapshot },
     { "m", HAS_ARG, QEMU_OPTION_m },
+    { "pidfile", HAS_ARG, QEMU_OPTION_pidfile },
     { "nographic", 0, QEMU_OPTION_nographic },
     { "enable-audio", 0, QEMU_OPTION_enable_audio },
 
@@ -2760,6 +2770,8 @@
     int net_if_type, nb_tun_fds, tun_fds[MAX_NICS];
     int optind;
     const char *r, *optarg;
+    FILE *pidfile_stream;
+    struct stat pidstat;
     CharDriverState *monitor_hd;
     char monitor_device[128];
     char serial_devices[MAX_SERIAL_PORTS][128];
@@ -3007,6 +3019,30 @@
                     exit(1);
                 }
                 break;
+            case QEMU_OPTION_pidfile:
+            	/* Try to write our PID to the named file */
+            	if ( stat(optarg, &pidstat) < 0 ) {
+            	   if ( errno == ENOENT ) {
+            	      if ( (pidfile_stream = fopen (optarg, "w+")) == NULL ) {
+            	         perror ("Opening pidfile");
+            	         exit(1);
+            	      }
+            	      fprintf (pidfile_stream, "%d\n", getpid());
+            	      fclose (pidfile_stream);
+            	      pidfile = malloc (strlen(optarg));
+            	      if (!pidfile) {
+            	         perror("Saving PID filename");
+            	         exit(1);
+            	      }
+            	      strncpy (pidfile, optarg, strlen(optarg));
+            	      atexit(remove_pidfile);
+            	   }
+            	}
+            	else {
+            	   fprintf (stderr, "%s already exists. Remove it and try again.\n", optarg);
+            	   exit(1);
+            	}
+            	break;
             case QEMU_OPTION_d:
                 {
                     int mask;