Observed the following build error:

Building modules, stage 2.
MODPOST 648 modules
ERROR: ".hvc_put_chars" [drivers/char/hvcs.ko] undefined!
ERROR: ".hvc_get_chars" [drivers/char/hvcs.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Regards--
Subrata