~IOCTL Method
Overview
Objective: To implement various types of hardware control through the device driver
User space call prototype: int IOCTL (int fd, unsigned long cmd ,...);
FD refers to the file descriptor.
"... "Represents an optional parameter, use "... "You can disable the logic check during compilation.
Used to use char * argp;
Optional parameters can be null, integer, or pointer. When a pointer is used, an
My blog: http://blog.csdn.net/muyang_ren
Function: The Development Board dynamically loads the LED driver module and passes the test program.
System: Ubuntu 14.04
Driver cross-compilation kernel: linux-2.6.32.2 // build cross-Compilation
Development Board: mini2440 (128 M nandflash) // for how to download Linux to the Development Board, click. For Linux rootfs, select rootfs_rtm_2440.img (Disk Directory: i
Today, we will go to Chapter 6 advanced character driver operations in Linux Device Drivers (version 3rd.
I. IOCTL
In addition to reading and writing capabilities, most devices can perform operations beyond simple data transmission. Therefore, device drivers must also be able to perform various hardware control operations. these operations are often supported by the ioctl method, which has a prototype different from the user space version:
int (*ioc
NVIDIA has released Nvidia Driver 334.21, a graphics card Driver for Linux users. This new Driver supports GeForce GTX 750 Ti, GeForce GTX 750, GeForce GTX 745, and GeForce gtx titan. In addition, NVIDIA 334.21 has brought a lot of bug fixes. View the release log for details.
Note: It is risky to install the video card dri
Summary previous we analyzed a virtual hardware network driver sample. From here we see some of the interfaces of the network devices. In fact, the function of network device driver and block device driver is similar, both sending and receiving packets (data request).Of course they are actually very different.1. IntroductionFirst, the block device has a device no
How to detach a win7 video card driver _ How to detach a video card driverSome users often encounter video card problems caused by incompatibility problems when using the win7 system. If you encounter this problem, you can update or uninstall the video card driver. So how can I unmount the graphics card driver in Win7? It is difficult for general users. The follo
This concept emerged when the new sysfs management device driver was adopted in linux2.6 and can be intuitively understood under the/sys directory.
Bus indicates the bus type, such as I2C, IDE, USB... many bus types such as platform, including MTD devices;
Device records device resources, specific to the NAND driver, is added in the board-osk.c struct platform_device osk5912_nand_device;
IPhone 4S is connected to a computer and cannot recognize iPhone devices: Apple mobile device USB driver Driver Installation failure shows yellow exclamation mark Solution
Apple mobile device USB driver Driver Installation failure shows a yellow exclamation point, cannot charge, let alone iTunes.
The correct soluti
ADB self-made universal driver method, exclusive secret
This article from: http://kraft.iteye.com/blog/1275276
Android often encounters a mobile phone that cannot find the ADB driver, or to adapt to multiple drivers, there is actually a very simple solution.Use the Official Google Android driver as the blueprint to add your own devices.
Prepare notepad to open ex
The audio driver is implemented in the wavedev2 mode. This is a single-layer driver mode, and all platform-related functions are implemented in hwctxt. H and hwctxt. in CPP, it also includes MIDI support, software mixer support, S/pdif interface, gain class interface, forcespeaker interface, and so on.
(1) software implementation of the audio system
Audio Device Drivers transmit audio data streams through
Wait Queue:
In Linux driver programming, waiting queues can be used to implement blocking of processes.
The wait queue can be thought of as a container for the save process, and the process is placed in a wait queue when the process is blocked;
When the process is awakened, the process is fetched from the wait queue.
waiting for the definition and initialization of the queue wait_queue_head_t Declare_wait_queue_head:
The Linux 2.6 kernel provides the
MongoDB samus Driver (2), mongodbsamus driver
The driver connection method mentioned in the previous article. This article provides the complete link code and instance
Complete database link
1 static IMongo _ mongo = null; 2 public writable drive () // This class integrates the IDisposable Interface 3 {4 if (_ mongo = null) 5 {6 var connectionString = new mongoon
Update the NIC Driver and fix the blue screen netr28x. sys Driver file error when the win7 Ralink RT3290 Nic is sleeping on the computer and when the NIC is started.
Update the NIC Driver and fix the blue screen netr28x. sys driver error when the win7 Ralink RT3290 Nic is sleeping on the computer and when the NIC is
Linux Device Driver Article 4: Driver debugging methods, linux Article 4
In the previous article, we probably talked about how to write a simple character device driver. We are not a god, but there will certainly be a problem when writing code. We need to continuously debug it during the code writing process. In common c applications, we often use printf to outpu
Continue to drive learning based on the progress of the previous article .......
Main references: http://blog.csdn.net/dg1683wen/article/details/6861044
First, build the kernel source code tree. I am using the friendly arm comes with Linux source code: linux-2.6.35.7-20120912.tgz
First copy the kernel source code linux-2.6.35.7-20120912.tgz to the Ubuntu system directory/home/liuhui8989/linuxshare
Unzip: Tar zxvf linux-2.6.35.7-20120912.tgz to get the linux-2.6.35.7 folder.
Start to build the so
If the system needs to be re-installed in case of a computer failure, if the random drive disk is lost, such as the motherboard driver, NIC driver, and graphics card driver.
In particular, some old machines, motherboard integrated Nic, graphics card. Even if Win2000/WINXP is installed, some devices cannot be automatically driven.
In this case, we can consider u
The ADCTSC registers are shared between the ADC Driver and the touch-screen driver. How can one register be used when processing them? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. You guys give me directions
I wrote an ADC digital-to-analog conversion driver for the embedded linux test chamber, bu
Non-professional study notes. Thank you!
Driver support routines (driverProgramDevelopment support routine)
Driver support routines are routines that the Windows operating system provides for kernel-mode drivers to use.Drivers do not use Microsoft Win32 routines; instead, they use the driver support routines that this section describes.The
This morning, I am going to play a game similar to running a kart under fedora, but the driver does not support 3D. So I started the Driver Installation trip early in the morning. There are a lot of online materials, but they are not practical, after finding a solution, I will share my experience with you. My uname-R is 2.6.35.6-45. fc14.i686. PAE
Error message:
Error: You appear to be running an
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