Transferred from http://blog.csdn.net/yj4231/article/details/7799245
In this paper, a simple analysis of the SYSFS in Linux system, to analyze the SYSFS must analyze the kernel of the Driver-model (drive model), the two are closely related. In the analysis process, this article will take the platform bus and the SPI main controller's platform drive as an example to explain. In fact, the platform mechanism is based on Driver-model, through this article, will also have a simple understanding of th
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
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 (
HP HP notebook does not have wireless network card device in Device Manager how to solve
1, in the Device Manager to view, found no wireless network card;
2, after restart press F10, enter Bios--exit--load setup Defaults, or according to the shortcut key below prompts, press F9 restore default settings;
3, the normal access to the system can be
If the device crashes, you may need to close the application or turn off the device and reopen it. If the device is frozen or slow to respond, press and hold the power button and the down volume key for more than 7 seconds to reboot.Note: If the problem persists, please make the factory data reset. On the main screen, click "Settings" rarr; "Backup and reset" rar
Tag: device stat byte back org appears link line etcVMware replication Virtual machine appears error:no suitable device found:no device found for connection ' System eth0 'Don't say much, just give a solution:1. View Hardware Address[Email protected] ~]# ifconfigEth2 Link encap:ethernetHWaddr 00:0c:29:89:18:58inet addr:192.168.11.200 bcast:192.168.11.255 mask:255
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 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
USB Device cannot stop universal volume device resolution:
Method One: Release clear off the clipboard
Caused "Unable to stop the universal volume device", generally there are reasons, such as the above mentioned reason is the most common, the solution can be released to clear off the Clipboard, you can casually copy anything on the hard drive to release the co
The error is shown in the following figure Umdf hid MiniDriver device Unknown Device
The reason may be that some external mouse, keyboard, camera, card reader, u disk or other USB device drivers should be automatically installed on the system but not installed successfully caused by, the following approach to see.
1. Locate the desktop computer, then righ
Before starting work, first in the PC to download the installation of the assistant, the installation is completed after the mobile phone connection computer, safe mobile end of the assistant;
Connect iphone/ipad/ipod or other devices to the computer side's love-thinking Assistant
The following diagram, the connection after the device jailbreak activation status, product type, serial number, production date warranty date, etc., can be seen;
System
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
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
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
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
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