Added some comments about what our code do.

diff --git a/hello.c b/hello.c
index 01e8c26..25c722d 100644 (file)
--- a/hello.c
+++ b/hello.c
@@ -1,17 +1,24 @@
+/* Must be included by every module. */
 #include <linux/module.h>
 
+/* Should be declared to not taint the kernel. */
 MODULE_LICENSE("GPL");
 
+/* Our init function: returns 0 if successfull, an error code, otherwise. */
 static int hello_init(void)
 {
+       /* printk is just like printf, but without floating point support. */
        printk(KERN_ALERT "Hello, world!\n");
        return 0;
 }
 
+/* Our exit function: static is good, so we do not pollute namespace. */
 static void hello_exit(void)
 {
+       /* KERN_ALERT is a string macro prepended to our message. */
        printk(KERN_ALERT "Goodbye, cruel world!\n");
 }
 
+/* Here, we declare our module init and exit functions. */
 module_init(hello_init);
 module_exit(hello_exit);