>You mean like the config option CONFIG_USB_SERIAL_CONSOLE gives you >today? Why try to reimplement something that is already finished? Not CONFIG_USB_SERIAL_CONSOLE,because I want use usb bus to connect host and target, not usb serial converter. On side of target(embedded device running linux), we regard target as usb device which is serial. On side of host, we need use minicom to open that usb device. Thanks. --http://www.eyou.com --Îȶ¨¿É¿¿µÄµç×ÓÐÅÏä ÓïÒôÓʼþ Òƶ¯ÊéÇ© ÈÕÀú·þÎñ ÍøÂç´æ´¢...ÒÚÓÊδ¾¡ --http://vip.eyou.com --¿ì¿ìµÇ¼ÒÚÓÊVIPÐÅÏä ×¢²áÄúÖÐÒâµÄÓû§Ãû -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/