/* Must be included by every module. */
#include <linux/module.h>
+/* Author name comes here. */
+MODULE_AUTHOR("Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>");
+/* Tell a user what this modules does. */
+MODULE_DESCRIPTION("Prints a friendly message.");
+/* Which version is this? */
+MODULE_VERSION("1.4.0");
/* Should be declared to not taint the kernel. */
MODULE_LICENSE("GPL");
+#ifndef SUBJECT
+#define SUBJECT "world"
+#endif
+
+static char *subject = SUBJECT;
+
+/* Define subject as a char pointer parameter. */
+module_param(subject, charp, 0664);
+/* Parameter description. */
+MODULE_PARM_DESC(subject, "Subject to say hello to.");
+
/* Our init function: returns 0 if successfull, an error code, otherwise. */
-static int hello_init(void)
+static int __init hello_init(void)
{
/* printk is just like printf, but without floating point support. */
- printk(KERN_ALERT "Hello, world!\n");
+ printk(KERN_ALERT "Hello, %s!\n", subject);
return 0;
}
/* Our exit function: static is good, so we do not pollute namespace. */
-static void hello_exit(void)
+static void __exit hello_exit(void)
{
/* KERN_ALERT is a string macro prepended to our message. */
- printk(KERN_ALERT "Goodbye, cruel world!\n");
+ printk(KERN_ALERT "Goodbye, cruel %s!\n", subject);
}
/* Here, we declare our module init and exit functions. */