Linux Device Drivers 3 examples

1 files changed, 48 insertions, 0 deletions

diff --git a/misc-modules/kdatasize.c b/misc-modules/kdatasize.c
new file mode 100644
index 0000000..4ac8895
--- /dev/null
+++ b/misc-modules/kdatasize.c
@@ -0,0 +1,48 @@
+/*
+ * kdatasize.c -- print the size of common data items from kernel space
+ * This runs with any Linux kernel (not any Unix, because of <linux/types.h>)
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/utsname.h>
+#include <linux/errno.h>
+
+static void data_cleanup(void)
+{
+	/* never called */
+}
+
+int data_init(void)
+{
+	/* print information and return an error */
+	printk("arch   Size:  char  short  int  long   ptr long-long "
+		" u8 u16 u32 u64\n");
+	printk("%-12s  %3i   %3i   %3i   %3i   %3i   %3i      "
+		"%3i %3i %3i %3i\n",
+		system_utsname.machine,
+		(int)sizeof(char), (int)sizeof(short), (int)sizeof(int),
+		(int)sizeof(long),
+		(int)sizeof(void *), (int)sizeof(long long), (int)sizeof(__u8),
+		(int)sizeof(__u16), (int)sizeof(__u32), (int)sizeof(__u64));
+	return -ENODEV;
+}
+
+module_init(data_init);
+module_exit(data_cleanup);
+
+MODULE_LICENSE("Dual BSD/GPL");