Device files: block Device file B: A device that is randomly accessed by block;character device file C : by character, linear device;Common block device file B: HDDDevice file name for the hard disk device:IDE, ATA:HDSATA, SCSI, U
Linux MTD (Memory technology Device) subsystem analysisFor Atheros Char deviceRead the Linux MTD Source code Analysis to this part of the overall understanding, combined with the existing code, analysis of how Atheros MTD is used.Linux kernel:2.6.31.Atheros platform:qca9890???Refer to the Linux MTD Source code Analysis , where MTD is divided into 4 layers, from top to bottom: Character device node, characte
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
A new set of driver management and registration mechanisms have been introduced from Linux 2.6:P latform_device and Platform_driver.Most of the device drivers in Linux can use this mechanism, the device is represented by Platform_device, and the driver is registered with Platform_driver.Compared with the traditional device driver mechanism (registration via Drive
Brief introduction
A block device driver accesses a device primarily by transmitting a fixed-size random data
Linux kernel video block devices are basic device types that differ from character devices
The Linux block device driver interface allows the block d
Using asynchronous notifications in device drivers can make access to the device accessible to the application by the driver when it is accessible. Therefore, applications that use nonblocking I/O do not need to poll the device for access, and blocking access can be superseded by asynchronous notifications like "break". Asynchronous notifications are similar to t
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 (
Main device number and secondary device number
Those names are called special files, device files, or nodes that are simply called file system trees, and they are usually located in the/dev directory
Typically, the main device number identifies the driver that corresponds to the
This article is mainly about why Apple launched iOS 5 in August 2011 to reject the Udid of the app acquisition device and the Udid replacement program, especially to remind developers that Apple App Store prohibits access to the Udid app shelves (recommended: app is Apple app Store rejected for n reasons), the following first to understand the next udid.What is Udid?The full name of Udid is unique device Id
In this walkthrough, you will use Visual Basic or Visual C #Generate a simple windows form applicationProgram,Then run the application on the Pocket PC simulation program.This walkthrough demonstrates the main differences between desktop programming and device programming,That is, you must specify the target device.During this drill, the device is a built-in simulation program of the Pocket PC 2003.--------
0. Preface Graduate life all are on the right track, I also started a new study, because really do not want to make storage, so decided to study with the elder brother device driver, read the book two weeks, finally a little clue, began to record it!1. Preparatory workA) View the kernel versionUname-rb) Install kernel source tree (http://www.cnblogs.com/Jezze/archive/2011/12/23/2299871.html) Download the source code in www.linux.org, here is the. xz
Devices in the system that can randomly (and do not need to sequentially) access fixed-size data slices (chunks) are called block devices, which are called blocks. The most common block devices are hard disks, and in addition, there are many other block devices, such as floppy drives, CD-ROM drives, flash memory, and so on. Note that they are all used in a way that installs the file system-this is also the general way to access the block device.Another basic
10.1 turning the device on and off10.1.1 The definition of a device -anything that can be communicated with in Windows.(1) common equipment and uses
Equipment
Use
function to open the device
File
Permanently store any data
CreateFile (Pszname is a pathname or a UNC path name)
Directory
Settings f
From one point of view, the role of a device driver is to provide a mechanism, not a policy. When writing drivers, programmers should pay particular attention to the following basic concept: When writing kernel code to access hardware, do not impose any specific policy on the user. Because different users have different needs, the driver should handle the problem of how to make the hardware available, and how to use the hardware problem left to the up
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