+
+ /* Serial string handling.
+ * On a real device, the serial string would be loaded
+ * from permanent storage. */
+ if (mod_data.serial_parm) {
+ const char *ch;
+ unsigned len = 0;
+
+ /* Sanity check :
+ * The CB[I] specification limits the serial string to
+ * 12 uppercase hexadecimal characters.
+ * BBB need at least 12 uppercase hexadecimal characters,
+ * with a maximum of 126. */
+ for (ch = mod_data.serial_parm; *ch; ++ch) {
+ ++len;
+ if ((*ch < '0' || *ch > '9') &&
+ (*ch < 'A' || *ch > 'F')) { /* not uppercase hex */
+ WARNING(fsg,
+ "Invalid serial string character: %c; "
+ "Failing back to default\n",
+ *ch);
+ goto fill_serial;
+ }
+ }
+ if (len > 126 ||
+ (mod_data.transport_type == USB_PR_BULK && len < 12) ||
+ (mod_data.transport_type != USB_PR_BULK && len > 12)) {
+ WARNING(fsg,
+ "Invalid serial string length; "
+ "Failing back to default\n");
+ goto fill_serial;
+ }
+ fsg_strings[FSG_STRING_SERIAL - 1].s = mod_data.serial_parm;
+ } else {
+fill_serial:
+ /* Serial number not specified or invalid, make our own.
+ * We just encode it from the driver version string,
+ * 12 characters to comply with both CB[I] and BBB spec.
+ * Warning : Two devices running the same kernel will have
+ * the same fallback serial number. */
+ for (i = 0; i < 12; i += 2) {
+ unsigned char c = DRIVER_VERSION[i / 2];
+
+ if (!c)
+ break;
+ sprintf(&fsg_string_serial[i], "%02X", c);
+ }
+ }
+