:/usr/src/linux-2.6.31.5-0.1/arch/x86/kernel # vi syscall_table_32.S
.long sys_hello

:/usr/src/linux-2.6.31.5-0.1/include/asm # vi unistd_32.h
#define __NR_hello 337

:/usr/src/linux-2.6.31.5-0.1/include/asm # vi unistd_64.h
#define __NR_hello 299
__SYSCALL(__NR_hello, sys_hello)

:/usr/src/linux-2.6.31.5-0.1/include/linux # vi syscalls.h
asmlinkage long sys_hello(int i,int j);

:/usr/src/linux-2.6.31.5-0.1/kernel# vi hello.c
#include<linux/linkage.h>
asmlinkage long sys_hello(int i,int j)
{
return i+j;
}
:/usr/src/linux-2.6.31.5-0.1/kernel#vi Makefile
..........
obj-y += hello.o

obj-y += groups.o
.............

:/usr/src/linux-2.6.31.5-0.1 # make
....
....

GEN .version
CHK include/linux/compile.h
UPD include/linux/compile.h
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
arch/x86/built-in.o: In function `sys_call_table':
(.rodata+0x754): undefined reference to `sys_real_time_rr'
make: *** [.tmp_vmlinux1] Error 1


After few lines are compiled,the above error is generated..
Please help me to know where the changes should be made and how to resolve it.?

Did your kernel compile correctly before you made changes to it?