Building with the attached random configuration file,
drivers/built-in.o: In function `smsusb_submit_urb':
smsusb.c:(.text+0xa8fdc): undefined reference to `smscore_getbuffer'
drivers/built-in.o: In function `smsusb_onresponse':
smsusb.c:(.text+0xa902f): undefined reference to
`smsendian_handle_message_header'
smsusb.c:(.text+0xa909e): undefined reference to `smscore_translate_msg'
smsusb.c:(.text+0xa90a5): undefined reference to `smsendian_handle_rx_message'
smsusb.c:(.text+0xa90b0): undefined reference to `smscore_onresponse'
drivers/built-in.o: In function `smsusb_stop_streaming':
smsusb.c:(.text+0xa90f2): undefined reference to `smscore_putbuffer'
drivers/built-in.o: In function `smsusb_term_device':
smsusb.c:(.text+0xa922a): undefined reference to `smscore_unregister_device'
drivers/built-in.o: In function `smsusb_sendrequest':
smsusb.c:(.text+0xa9281): undefined reference to `smscore_translate_msg'
smsusb.c:(.text+0xa9288): undefined reference to `smsendian_handle_tx_message'
smsusb.c:(.text+0xa928f): undefined reference to
`smsendian_handle_message_header'
drivers/built-in.o: In function `smsusb_init_device':
smsusb.c:(.text+0xa93de): undefined reference to `sms_get_board'
smsusb.c:(.text+0xa94aa): undefined reference to `smscore_register_device'
smsusb.c:(.text+0xa94c0): undefined reference to `smscore_set_board_id'
smsusb.c:(.text+0xa9512): undefined reference to `smscore_start_device'
drivers/built-in.o: In function `smsusb_probe':
smsusb.c:(.text+0xa9550): undefined reference to `sms_get_board'
smsusb.c:(.text+0xa9575): undefined reference to `sms_get_board'
smsusb.c:(.text+0xa964b): undefined reference to `smscore_registry_getmode'
smsusb.c:(.text+0xa9658): undefined reference to `sms_get_board'
smsusb.c:(.text+0xa966e): undefined reference to `sms_get_board'
smsusb.c:(.text+0xa972b): undefined reference to `sms_board_load_modules'
make: *** [vmlinux] Error 1