Changes between Version 6 and Version 7 of Dev/KernelHack/COINS/worklog/201111

Timestamp:

Nov 25, 2011 1:33:19 AM (13 years ago)

Author:

mitty

Comment:

--

Dev/KernelHack/COINS/worklog/201111

@@ -1597 +1597 @@
 Nov 16 14:56:24 ubuntu-lucid kernel: [ 7335.090496] stackmod is unloaded
 }}}
+
+ = 11/20 =
+ == fs/char_dev.c ==
+ * struct cdev *cdev_alloc(void)
+{{{
+ * cdev_alloc() - allocate a cdev structure
+ *
+ * Allocates and returns a cdev structure, or NULL on failure.
+}}}
+ * void cdev_init(struct cdev *cdev, const struct file_operations *fops)
+{{{
+ * cdev_init() - initialize a cdev structure
+ * @cdev: the structure to initialize
+ * @fops: the file_operations for this device
+ *
+ * Initializes @cdev, remembering @fops, making it ready to add to the
+ * system with cdev_add().
+}}}
+ * int cdev_add(struct cdev *p, dev_t dev, unsigned count)
+{{{
+ * cdev_add() - add a char device to the system
+ * @p: the cdev structure for the device
+ * @dev: the first device number for which this device is responsible
+ * @count: the number of consecutive minor numbers corresponding to this
+ *         device
+ *
+ * cdev_add() adds the device represented by @p to the system, making it
+ * live immediately.  A negative error code is returned on failure.
+}}}
+ * void cdev_del(struct cdev *p)
+{{{
+ * cdev_del() - remove a cdev from the system
+ * @p: the cdev structure to be removed
+ *
+ * cdev_del() removes @p from the system, possibly freeing the structure
+ * itself.
+}}}
+
+ == stackmod with open/close/read/write skeleton ==
+ * 参考
+  * drivers/char/raw.c -> register_chrdev_region, cdev_init
+  * include/linux/cdev.h -> struct cdev
+  * include/linux/fs.h -> struct file_operations
+
+ * s0711489@ubuntu-lucid64:~$ sudo insmod stackmod.ko
+{{{
+Nov 20 17:47:12 ubuntu-lucid64 kernel: [ 4074.120567] stackmod is loaded
+Nov 20 17:47:12 ubuntu-lucid64 kernel: [ 4074.120571] stackmod: 128 entry, major is 251, minor is 0
+Nov 20 17:47:12 ubuntu-lucid64 kernel: [ 4074.120576] stackmod is added successfully
+}}}
+
+ * s0711489@ubuntu-lucid64:~$ grep stack /proc/devices
+{{{
+251 stackmod
+}}}
+
+ * s0711489@ubuntu-lucid64:~$ sudo mknod /dev/stack c 251 0
+ * s0711489@ubuntu-lucid64:~$ ls -l /dev/stack
+{{{
+crw-r--r-- 1 root root 251, 0 2011-11-20 17:50 /dev/stack
+}}}
+
+ * s0711489@ubuntu-lucid64:~$ cat /dev/stack
+{{{
+Nov 20 17:50:56 ubuntu-lucid64 kernel: [ 4297.683404] stackmod is opened
+Nov 20 17:50:56 ubuntu-lucid64 kernel: [ 4297.683424] stackmod is read
+Nov 20 17:50:56 ubuntu-lucid64 kernel: [ 4297.683428] stackmod is released
+}}}
+
+ * s0711489@ubuntu-lucid64:~$ sudo sh -c "echo 1 > /dev/stack"
+{{{
+^C
+}}}
+{{{
+(snip)
+
+Nov 20 17:51:43 ubuntu-lucid64 kernel: [ 4343.961818] stackmod is written
+Nov 20 17:51:43 ubuntu-lucid64 kernel: [ 4343.961818] stackmod is written
+Nov 20 17:51:43 ubuntu-lucid64 kernel: [ 4343.965238] stackmod is released
+}}}
+
+ * s0711489@ubuntu-lucid64:~$ sudo dd if=/dev/null of=/dev/stack
+{{{
+0+0 records in
+0+0 records out
+0 bytes (0 B) copied, 2.3001e-05 s, 0.0 kB/s
+}}}
+{{{
+Nov 20 17:52:58 ubuntu-lucid64 kernel: [ 4419.365245] stackmod is opened
+Nov 20 17:52:58 ubuntu-lucid64 kernel: [ 4419.365281] stackmod is released
+}}}