Hi All ! I have compiled the skull driver of the example source of ldd2-1.0.1 , which is aiding Linux Device Drivers book . I sucessfully compiled it , but I get the below error when I execute insmod . [root@skull]# insmod skull.o skull.o: unresolved symbol __io_virt_debug I did check the exported symbols and got the below output . [root@skull]# cat /proc/ksyms|grep _io_virt* c02113b0 __io_virt_debug_R__ver___io_virt_debug I'am unable to understand how to export the proper symbol. For your information . [root@skull]# uname -a Linux LEARNER 2.4.16 #17 SMP Sat Sep 28 13:23:25 IST 2002 i586 unknown Kindly help me resolve this problem . TIA Cheers ! ________________________________________________________________________ Missed your favourite TV serial last night? Try the new, Yahoo! TV. visit http://in.tv.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/