USB urb (USB request block)
Kernel 2.6.29.4The USB device driver code communicates with all USB devices through urb. Urb uses the struct urb structure description (include/Linux/USB. h ).
Urb sends or receives data asynchronously from a specific endpoint of the same USB device. A USB device driver can allocate multiple URBS to one endpoint or reuse a single urb to multiple different endpoints Based on the d
processor can be considered as peripherals compared with the ARM core, after successful registration, the ldd0 directory appears in the SYS/Device directory.
If (RET)
Printk (kern_notice "unable to register LDD/N ");
Printk (kern_notice "Mount ldw. OK! /Nbus device is ldd0! /Nyou can see me in sys/module/, sys/devices/and sys/bus /!/N ");
Return ret;
}
Static void ldd_bus_exit (void)
{
Device_unregister ( ldd_bus );
Bus_unregister ( ldd_bus_type );
}
Module_init (ldd_bus_init );
Module_exit
This chapter is a concrete example of the complete process of developing and testing a Linux driver. Especially test Linux drivers. In this example of counting the number of words, the emphasis is on the implementation of the algorithm: the Linux driver, not how to count. What is the 6.1Linux drive?Linuxthe way the driver works and how it is accessed isLinuxone o
Basic Principles
Through framebuffer, the application uses MMAP to map the video memory to the virtual address space of the application. The data to be displayed can be displayed on the screen after being written to the memory space;
The driver allocates system memory as the memory for display; implements interfaces in the file_operations structure to serve the application; implements interfaces in the fb_ops structure to control and operate the LD
Through the first article, we already know that the whole SPI drive architecture can be divided into three parts: Protocol driver, general interface layer and controller driver. The controller driver is responsible for the data sending and receiving work at the lowest level, in order to complete the data sending and receiving work, the controller
Obtain the database connection through Driver and the driver database connection
Take a look at the file. There is a properties configuration file under the current package, and there is a lib folder under the root directory, which contains the mySql driver jar package
Driver: an interface. The database vendor must pr
In the previous blog post, we have compiled the First_drv.ko file by makefile, which is a driver module that can be installed in Ubuntu.Execution in/work/my_drivers/first_drv/1th/directory: Insmod First_drv.koIf you are executing this command in a normal user state, you can see that the system reminds us: insmod:error inserting ' First_drv.ko ':-1 operation not permittedThis is because installing the driver
The relationship between device and driver in linux driver development-Linux general technology-Linux programming and kernel information. The following is a detailed description. Yesterday I saw a piece of news titled "Housewives use LINUX". If we saw this news 10 years ago, we would be surprised to say, "I rely on it, housewives also use LINUX ", but now housewives use LINUX is not new to us because LINUX
Hyper-V Virtual Machine installation and nic cannot be found, driver cannot be installed Solution
I recently used a virtual machine in win2008 and encountered some problems during use. Now I have recorded the installation process and handling methods.
1. Install hyper-V. Right-click my computer and choose manage → Server Manager → role → add role on the right → select hyper-V for Installation
2. Choose "start"> "Management Tools"> "hyper-V ".
3. First
Before analyzing the driver, we will analyze the model of the IIC subsystem. There are 2 ways to IIC device drivers, one of which is to write user-driven through a universal driver. The other is to add a IIC device driver directly to the IIC subsystem, such as a driver for AT24C02.
Next we'll learn how to write a I
Knowledge Point analysis:Microsoft UAA (Microsoft Universal Audio Architecture) bus driver is Microsoft's system-level support driver for HD Audio standard HD Audio bus (High Definition Audio. The new HD Audio card driver and Modem driver are both developed based on the HD Audio bus.This problem does not occur if y
Buzzer driver source code in the/driver/char/buzzer/x210-buzzer.c file, the source code is as follows#include The driver module code for the buzzer is as above. As with other driver module code, the function in Module_init is the function that runs when the driver module is
Adding a driver to the android kernel is actually adding a driver to the Linux kernel. It mainly adds vertex information to two files, one is the kconfig file and the other is the MAKEFILE file. For example, if the driver you added is placed in the xxx directory under the DRIVERS directory, the kconfig and makefile files under the directory will be repaired.
Spec
between the device and the drive, through the platform bus, the device and the driver is separate registration, through the platform bus probe to detect and match the device at any time, such as matching on the device driver registration;C: Due to the above advantages, a driver can be used for several similar devices;3:platform Bus and platform bus device
Original unofficial Microsoft SQL Server Driver for PHP (sqlsrv)Here is unofficial modified builds of Microsoft ' s sqlsrv and pdo_sqlsrv drivers for PHP, version 3.0, for:
PHP 5.6 for Windows vista/2008 and above (+ +)
PHP 5.5 for Windows vista/2008 and above (+ +)
PHP 5.3 and 5.4 for Windows xp/2003 and aboveMicrosoft's version 3.0 driver does not run on xp/2003 because it had a hard-code
host, only one device can communicate with the host at the same time. Manage the external USB device via the USB host controller. USB controller is actually composed of USB controller hardware +USB Controller software. The USB host controller is divided into 3 kinds: UHCI, OHCI, EHCI. UHCI and OHCI Support USB1.1 protocol; EHCI supports USB2.0 protocol. UHCI, its hardware is simple, so the software is relatively complex, and OHCI, its hardware has more performance, contrary to the software to
Access to the character device is performed through the device name in the file system. Those device names are simply nodes that are called file system trees, and they are typically located in the/dev directory. Device files for character device drivers can be identified by ' C ' in the first column of the ls-l command output. Block devices are also located in/dev, identified by the character ' B 'CRW-RW----1 root root 253, 0 2013-09-11 20:33 Usbmon0CRW-RW----1 root root 253, 1 2013-09-11 20:33
Access to the character device is done through the device name in the file system. Those device names are simply nodes that are called file system trees, and they are typically located in the/dev folder.Device files for character device drivers can be identified by ' C ' in the first column of the ls-l command output. Block devices are the same in/dev, identified by the character ' B ' crw-rw----1 root root 253, 0 2013-09-11 20:33 usbmon0 CRW-RW----1 root root 253, 1 2013-09-11 20:33 usbmo
One, what does the main device number and the secondary device number mean? Linu kernel is if the main device number to find the driver, the secondary device number to find the device.A: Usually a main device number represents a driver, for example, in a block device, a master device number represents a EMMC device, the different secondary device number represents a different partitionThe Linux kernel allow
A new device driver model-platform (platform) device driver, platform device driver (platform_device) and platform driver (Platform_driver) is introduced into the Linux2.6 kernel, The introduction of platform devices makes Linux device drivers more portable.First, platform equipmentPlatform Device structure:1 structPla
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