hello,
i want to implement my own system in linux kernel. so i used the
http://www.csee.umbc.edu/courses/undergraduate/CMSC421/fall02/burt/projects/howto_add_systemcall.html
webpage that describes how to add syscall but getting errors.
i am using redhat linux with kernel 2.4.20-8.
i go through the page. but unable to add syscall. what i did from that webpage
1)create /usr/include/sys/myservice-user.h file with contents
#include <linux/unistd.h>
_syscall2(int, myservice, int, arg1, char*, arg2);
2)create a entry in linux-2.4.24/arch/i386/kernel file as at end
.long SYMBOL_NAME(sys_myservice) /*259*/
3) create a entry in linux-2.4.24/include/asm/unistd.h file
#define __NR_myservice 259
4) write a file myservice.c in linux-2.4.24/kernel/
#include <linux/myservice.h>
asmlinkage int sys_myservice (int arg1, char* arg2) {
return(1);
}
5)write a file myservice.h in linux-2.4.24/include/linux/
#ifndef __LINUX_MYSERVICE_H
#define __LINUX_MYSERVICE_H
#include <linux/linkage.h>
#endif
6) compile kernel. boot that iamge and run the user-app.c program
#include <sys/myservice-user.h>
main() {
myservice(1, "hi");
}
it gives error
/tmp/ccfvjthg.o(.text+0x23): In function `myservice':
: undefined reference to `errno'
collect2: ld returned 1 exit status
what should do?
also please tell me to add syscall require kernel to be built and boot it and
execute that syscal fron user program? cause i did same.
regards,
parag.
