Add to include/linux/myservice.h #include <linux/errno.h> Because if syscalls need to return error codes, it gets them from errno.h dave On Thu, 2004-05-20 at 02:04, bunty wrote: > 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. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
