initial USB support


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1597 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/vl.c b/vl.c
index 1ca0c34..d551a4e 100644
--- a/vl.c
+++ b/vl.c
@@ -153,6 +153,7 @@
 #ifdef TARGET_I386
 int win2k_install_hack = 0;
 #endif
+int usb_enabled = 0;
 
 /***********************************************************/
 /* x86 ISA bus support */
@@ -2986,6 +2987,7 @@
     QEMU_OPTION_pidfile,
     QEMU_OPTION_no_kqemu,
     QEMU_OPTION_win2k_hack,
+    QEMU_OPTION_usb,
 };
 
 typedef struct QEMUOption {
@@ -3060,6 +3062,7 @@
     { "full-screen", 0, QEMU_OPTION_full_screen },
     { "pidfile", HAS_ARG, QEMU_OPTION_pidfile },
     { "win2k-hack", 0, QEMU_OPTION_win2k_hack },
+    { "usb", 0, QEMU_OPTION_usb },
     
     /* temporary options */
     { "pci", 0, QEMU_OPTION_pci },
@@ -3646,6 +3649,9 @@
                 kqemu_allowed = 0;
                 break;
 #endif
+            case QEMU_OPTION_usb:
+                usb_enabled = 1;
+                break;
             }
         }
     }