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
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 (
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
The tty core code tty_io.c contains the following lines of code:
/* * Ok, now we can initialize the rest of the tty devices and can count * on memory allocations, interrupts etc.. */static int __init tty_init(void){ cdev_init(tty_cdev, tty_fops); if (cdev_add(tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty")
Several system-level terminal devices are created here. They are not real physical devices. Each of them creates these
The biggest feature of Linux devices is that device operations are like file operations. In the application layer, a hardware device is just a device file. Applications can operate hardware devices like operating files, such as open (), close (), read (), and write.
Below is a simple implementation of the character device
Azure IoT technology research series 3-device-to-cloud, cloud-to-device communications, azureiot
In the previous blog, we registered the simulated device to Azure IoT Hub: We got the unique identifier of the device.
Azure IoT technology research series 2-device registration
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
Linux Device Driver Programming-Linux general technology-Linux programming and kernel information-complex device driver-the following is a detailed description. The complex device drivers mentioned here involve PCI, USB, network devices, Block devices, and so on (strictly speaking, these devices are not in the same concept, for example, they are tied with Block d
In the Rt-thread 2.0.0 formal version of the introduction of PIN devices as miscellaneous devices, its device driver files pin.c in Rt-thread-2.0.1\components\drivers\misc, mainly for the operation of Chip Gpio, such as light led, Keys and so on. At the same time for the corresponding chip platform, you need to write the underlying GPIO driver, such as GPIO.C.One, in PIN.C defines a static PIN device object
Unable to uninstall the device. This device may be required when the computer is started
Network2008-03-03 13:36:52 Read2437 Comment1 Font Size:LargeMediumSmallSubscription
Some problems occur after a new Nic is installed.When setting the IP address, a dialog box is displayed: the IP address you entered for this network adapter has been assigned to another adapter ...... It probably means that the origi
One: Platform bus1.1 OverviewA realistic Linux device driver usually needs to be hooked up on a bus, which is not a problem for devices that are attached to PCI,USB,IIC,SPI, but in embedded systems,The Independent peripheral controller integrated in the SOC system, the peripherals attached to the SOC memory space are not attached to such a bus. Based on this background, Linux invented a kind of virtual bus, called Platform Bus, the correspondingThe
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
I. What is IOCTL?IOCTL is a function used by the device driver to manage the device's I/O channels. The management of the I/O channel is to control some features of the device, such as the Serial Transmission baud rate and the motor speed. The number of calls is as follows:
Int IOCTL (int fd, IND cmd ,...); FD is the File Identifier returned by the open function when the user program opens the
Path for Linux Device Driver engineers-device model (top) Underlying model
K-style
Reprinted please indicate from Hengyang Normal University 08 electric 2 Y-kee http://blog.csdn.net/ayangke,QQ:843308498
I. Important knowledge points
1. sysfs File System
The sysfs file system is a special file system similar to the proc file system. It exists in the memory and is mounted to the memory by the kernel when th
1. Overview
2. system initialization platform device
3. The driver uses platform device
1. Overview
The Linux-2.6.11 introduces the concept of a device model that mounts most device drivers to a virtual bus.
Its purpose is:
1) provides friendly user interfaces. You can find the corresponding drivers and devices und
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.