Dear, I am using gcc to compile and make executable file with xenomai, but it getting error, so I want to ask how to get it compiled. I am using the code that I got from http://www.cs.ru.nl/lab/xenomai/exercises/ex01/Exercise-1.html I am using the hello world example, and I write it in the file named helloworldRT.c this is how I make it compiled [root@domain.hid Desktop]# gcc -c -I /usr/xenomai/include/ helloworldRT.c <it seems works> [root@domain.hid Desktop]# gcc -o helloworldrt helloworldRT.o helloworldRT.o: In function `demo': helloworldRT.c:(.text+0xe): undefined reference to `rt_printf' helloworldRT.c:(.text+0x13): undefined reference to `rt_task_self' helloworldRT.c:(.text+0x28): undefined reference to `rt_task_inquire' helloworldRT.c:(.text+0x3e): undefined reference to `rt_printf' helloworldRT.o: In function `main': helloworldRT.c:(.text+0x55): undefined reference to `rt_print_auto_init' helloworldRT.c:(.text+0x6d): undefined reference to `rt_printf' helloworldRT.c:(.text+0xb6): undefined reference to `rt_task_create' helloworldRT.c:(.text+0xd2): undefined reference to `rt_task_start' collect2: ld returned 1 exit status <this is the error I got> can somebody tell me how to compile it well? it seems I miss something in the way I compile. Can somebody tell me the right command? Thanks