GDB debugging :

GDB_debugging :

Compile Source Code with -g to load debugging symbols :

  Example :  gcc -g -o hellow helloworld.c


GDB Debugging :

   $ gdb  a.out 

gdb) b main
                 
gdb) c 
                                          
gdb) list
                                          
gdb) print x 
                                          
gdb) x/20i $pc


GDB Target Debugging :

Run command on board (target_machine) :  $ sudo ./gdbserver.i686 host:2345 a.out
 
Run in our local machine for debugging:  $ gdb  a.out 

                                          gdb) target remote target_machine_IP:2345
                                          
					  gdb) b main
                                          
                                          gdb) c 
                                          
                                          gdb) list
                                          
				          gdb) print x 
                                          
Will print next 20 instructions	on target gdb) x/20i $pc

/sys/kernel/debug/gpio current running GPIO pins in kernel , like 21,23,80 how we interface port numbers for applications