Linux Device Drivers 3 examples

1 files changed, 40 insertions, 0 deletions

diff --git a/misc-modules/hellop.c b/misc-modules/hellop.c
new file mode 100644
index 0000000..88eaa67
--- /dev/null
+++ b/misc-modules/hellop.c
@@ -0,0 +1,40 @@
+/*                                                     
+ * $Id: hellop.c,v 1.4 2004/09/26 07:02:43 gregkh Exp $ 
+ */                                                    
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+MODULE_LICENSE("Dual BSD/GPL");
+
+/*                                                        
+ * These lines, although not shown in the book,           
+ * are needed to make hello.c run properly even when      
+ * your kernel has version support enabled                
+ */                                                       
+                                                          
+
+/*
+ * A couple of parameters that can be passed in: how many times we say
+ * hello, and to whom.
+ */
+static char *whom = "world";
+static int howmany = 1;
+module_param(howmany, int, S_IRUGO);
+module_param(whom, charp, S_IRUGO);
+
+static int hello_init(void)
+{
+	int i;
+	for (i = 0; i < howmany; i++)
+		printk(KERN_ALERT "(%d) Hello, %s\n", i, whom);
+	return 0;
+}
+
+static void hello_exit(void)
+{
+	printk(KERN_ALERT "Goodbye, cruel world\n");
+}
+
+module_init(hello_init);
+module_exit(hello_exit);