Linux character device-simple character device model
Linux character Devices
I. Use the character Device Driver
1. Compile/install the driverIn Linux, drivers generally use the program structure of the kernel module for encoding. Therefore, the essence of compiling/installing a driver is to compile/install a kernel module.
2. Character
In the Linux device driver first: Introduction to the device driver briefly describes the character driver, this article briefly describes how to write a simple character device driver. This article draws on the source code in the LDD, realizes a hardware device-independent character
The complex device drivers mentioned here involve PCI, USB, network devices, block devices, and so on (strictly speaking, these devices are conceptually not parallel, for example, a character device is tied to a block device, and a PCI, USB device, etc. may be part of a character d
A Linux device model can be better understood through various stages of a device's life cycle in the kernel. I will analyze the source code of ldquo and sculld to understand the integration of each link in the Linux device model. The integration of the (PCI Bus) in ldd3 serves as a reference, because embedded Linux uses less PCI bus. First, you must familiarize yourself with the source code of ldquo and scu
PCI device creation process
This part is divided into two parts for learning. One is to refer to the previous articles, analyze the source code of ld1_and sculld, and the other is to refer to ldd3 to learn PCI.
Part 1Ldd_bus declares the ldd_bus_type of a bus_type structure:
Struct bus_type ldd_bus_type = {
. Name = "LDD ",
. Match = ldd_match,
. Uevent = ldd_uevent,
};
The code for adding ldd_bus_type to and detaching from the kernel is as follows:
As there are too many notes in Chapter 10, I will post the previous notes first.
1. functions used to open various devices
Device
Function used to open a device
File
Createfile (pszname is the path name or UNC path name)
Directory
Createfile (pszname is the path name or UNC path name ). if you specify the file_flag_backup_semantics flag when calling createfile, Windows al
First, we know that the driver is part of the kernel, so what role does the driver play in the kernel?The role of the device driver in the kernel: they are separate "black boxes" that enable a particular hardware to respond to a well-defined internal programming interface that completely hides the work details of the device. (Plainly, the driver does not have any implementation details that are invisible to
2.1Network Driver StructureThe architecture 1 of the Linux Network Driver is shown in.It can be divided into four layers:(1) Protocol Interface Layer
(2) network device interface layer
(3) Device Driver Function Layer
(4) network device and media layer.
Network Driver Focus: completes the device driver Function Layer
I
Article Title: linux Device Driver note-character Device Driver. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
※"Global" means that if a device is enabled multiple times, all file descriptors that open it share the data. "Pe
How to use the device tree of linux drivers and how to use the device tree of linux drivers
The Device Tree describes the hardware from the software perspective, and DTS is the Device Tree source file. DTC is responsible for converting DTS to DTB, and DTB is the binary form of DTS for machine use.
The
1. device. The device structure is used to describe the device in LDM.
Struct device {/* parent device, usually a bus or host device */struct device * parent;/* Private Data Pointer: S
first, how to operate the equipment
The operation of the device in Linux is done by means of a file, including open, read, and write.
For device files, it is generally called a device node,
The node has a property that is the device number (the primary device number, the se
Song Baohua Barry Song 1. ARM Device Tree Origin
Linus Torvalds's ARM Linux mailing list on March 17, 2011 declared "This whole arm thing is a f*cking pain", triggering an earthquake in the arm Linux community, followed by a series of arm communities Significant revisions to the column. In the past of Arm Linux, arch/arm/plat-xxx and arch/arm/mach-xxx were filled with a lot of junk code, and quite a few of the code was just describing board-level det
Reference:Http://elinux.org/Device_Tree_Usagehttp://blog.csdn.net/sgmenghuo/article/details/45071615 Basic Data Format
The device tree is a simple tree structure that contains nodes and attributes. Properties are described by the form of key-value pairs, a node can contain multiple attributes or child nodes, and a simple. DTS format device tree is shown below.
/dts-v1/;
/{
Node1 {
A-string-prop
The city I miss is dusk
Why do I always passionately devoted to you
Once gave me happiness also gave me trauma
Once gave me hope and gave me despair
I'm in a strange crowd in a faraway city
Feel your Distant sorrow
My fantasies.
Your sorrow, like my despair, so long,,,, this is today's melody, straight into the bottom of my heart ~~~~~~~~~~~~~~~~In the Linux system, the I²c drive consists of 3 parts, namely, the I²c core, the I²c bus drive and the I²C
Smart Device Security: China's online smart device Security Situation Report in 2017, and the situation report in 2017
Smart Device Security: China's online smart device Security Situation Report in 2017. In recent years, security incidents of online smart devices have occurred from time to time, and CNCERT has continu
From: Http://www.hovercool.com/en/Class_create,_device_create,_device_create_fileWhen I started writing Linux device drivers, I used the Mknod command to manually create device nodes (including many examples in ldd3), and in fact the Linux kernel now provides us with a set of functions that can be used to automatically load the module The corresponding device nod
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
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