Path for Linux Device Driver engineers-basic principles and framework of network device drivers
K-Style
Reprinted please indicate from Hengyang Normal College 08 electric 2 K-Style http://blog.csdn.net/ayangke,QQ:843308498 mailbox: yangkeemail@qq.com
1. Linux network subsystem
At the top of the Linux network subsystem is the system call interface layer. It provides a socket Method for applications provided
Device input and output, that is, device I/O, can be divided into two modes: synchronous and asynchronous. For synchronous device I/O, the called API function is always returned after the device I/O is complete. Asynchronous device I/O can be implemented in multiple ways, bu
When writing a Linux Device Driver, you often use the mknod command to manually create a device node (including many examples in ldd3). In fact, the Linux Kernel provides us with a set of functions, it can be used to automatically create a device node in the/dev directory when the module is loaded, and delete the node when the module is detached.
The struct class
Character Device Driver:
1. Generally, we use APIs that dynamically allocate device numbers:
Int alloc_chrdev_region (dev_t * Dev, unsigned int firstminor, unsigned int count, char * Name );
Dev is a function used for output. After successful call, the first number of the allocated range will be saved.
Void unregister_chrdev_region (dev_t first, unsigned int count );
The above function allocates
{Code...} has determined how the mobile device uses the computer version on the mobile terminal.
require(dirname(__FILE__)."/lib/Mobile_Detect.php");$detect = new Mobile_Detect;$deviceType = ($detect->isMobile() ? ($detect->isTablet() ? 'tablet' : 'phone') : 'computer');if($_SERVER["SERVER_NAME"] == "nj.xxx.cn" ){ if($deviceType == "phone") { header("Location:http://m.xxx.cn/"); exit(); }}
DeterminedMobile Devices
At the Mo
When you safely delete a USB flash drive, you will often encounter a message saying "you cannot stop the 'general-purpose volute' device. Please stop the device later ."
In this case, can I forcibly unplug the USB flash drive? Of course not! In this case, if you forcibly remove the USB flash drive, it is easy to damage the USB port of the computer or your USB flash drive. If you have important information o
Android dialing device and dialing device
Design of android Phone Dialer
Shows the running interface.
Procedure:
1. Create an Android project. In Eclipse, choose "File"> "NEW"> "Android Project"
2. Compile the string. xml file. The Code is as follows:1 3. Compile the main. xml file. The Code is as follows:1 4. Click the event to process the button. The Code is as follows:1 package com. example. phone; 2 3
Block device installation, create, map, mount, details, adjust, uninstall, curve map, deleteMake sure your ceph storage cluster is active + clean before working with ceph block devices.vim/etc/hosts172.16.66.144 ceph-clientPerform this quick boot on the admin node.1. On the admin node, install Ceph on your ceph-client node with Ceph-deployCeph-deploy Install Ceph-client2. On the admin node, copy the Ceph configuration file and ceph.client.admin.keyrin
Reprinted from: http://www.yeeyan.com/articles/view/jht/57657
Introduction
Unknown device, no longer headache!
Rule 1: do not lose the drive disc of the device.
Rule 2: exercise caution when saving a backup.
Rule 3: If your driver file is lost, you need to know where to download it.
Congratulations! If you do not care about the above two items, this article can free you from the three serious crimes you ha
Every time I use a USB cable to plug in the computer interface will prompt "device can improve performance" small series always want to know the reason.
Today, when I go to the forum, I understand, share to everyone
is because your motherboard USB port is different has 1.1 of 2.0 of 3.0 because you plug in the USB port is relatively low so there will be a hint you can ignore him can also be inserted into the other mouth to try to plug in a better mo
Device content
As we all know, the device context is a Windows data structure that contains information about the drawing properties of a device, such as a display or printer. All painting calls are performed through the device context object, including the paint brush, bitmap, and painting brush. The
(void *start, size_t length);3. Virtual Memory Area:The virtual memory area is a homogeneous interval in the virtual address space of the process, that is, a contiguous address range with the same characteristics. The memory image of a process consists of the following parts: program code, data, BSS and stack areas, and memory-mapped regions.The Linux kernel uses the VM_AREA_STRUCT structure to describe the virtual memory area. Its main members:unsigned long vm_start; /* Our start address withi
According to the device model described above, another one is created today. Platform device version quot; helloworld quot;
According to the device model described above, another one is created today. The "hello world" of the platform device version ".
If the platform device
Device and platform device have different registration methods.
There are two steps for device registration, and two steps for platform device registration. The first steps are the same and both are initialize devices,
However, the second step is different. device directly c
the MCU, whether the module is ready, whether the MCU can send information to the module, the effective level of the CTS is lowHAYES the RTS in modem, CTS is used for hardware flow control. The meaning of the RTC and CTS of the UART is now usually referred to as the latter, which is used for hard-flow control.RTS, CTS for hard flow control:(now do the serial port use rts/cts must see content, because mtk/)RTS (Require tosend, send request) is an output signal that indicates that the
Asynchronous device I/O is suitable for large data volumes and high performance scenarios, such as servers.
To use Asynchronous device I/O, when calling createfile to open or create a device, make the parameter dwflagsandattributes include file_falg_overlapped, which means that the device to be opened can be accessed a
http://blog.csdn.net/zqixiao_09/article/details/50888795
We have learned the theoretical knowledge of platform devices in front of Linux device driver development--platform device driver, the following will be an example to delve into our learning.
first, the platform driven work process
Platform model-driven programming requires the implementation of Platform_device (
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