C is the more classic and popular programming language that as ever existed. Developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories is the language used by Linus Torvals and the huge GNU community to create Linux itself and the most famous programs ever developed in the IT history.

The king of C Cross compiler, the GNU GCC, is installed in your PC linux system, if you don't install it, please see the follow chapter:

Install the ARM9 cross toolchain to compile the Linux Kernel and AT91Bootstrap

To creat the hello.c file and add the following example to the hello.c file.

#include "stdio.h"

int main(void) {
printf("Hello world !\n");
return 0;
}

Compile it typing:

# arm-none-linux-gnueabi-gcc hello.c -o hello

Then copy the "hello" to the CORE9G25 board by USB Disk or TF card, lauch it typing:

# cp /media/mmcblk0p1/hello /home
# chmod /home/hello
# /home/hello
Hello world !