device transfer

first, how to operate the equipment The operation of the device in Linux is done by means of a file, including open, read, and write. For device files, it is generally called a device node, The node has a property that is the device number (the primary device number, the se

===============================This article is the original site, welcome to reprint!Reprint please indicate the source: http://www.cnblogs.com/gdt-a20 =============================== The kernel developer will be the bus, device, drive the three are abstracted from the software idea, cleverly established the relationship between the two, make it more visualization. Combined with the knowledge that we have learned before, in general, the relationship b

Reference:Http://elinux.org/Device_Tree_Usagehttp://blog.csdn.net/sgmenghuo/article/details/45071615 Basic Data Format The device tree is a simple tree structure that contains nodes and attributes. Properties are described by the form of key-value pairs, a node can contain multiple attributes or child nodes, and a simple. DTS format device tree is shown below. /dts-v1/; /{ Node1 { A-string-prop

Smart Device Security: China's online smart device Security Situation Report in 2017, and the situation report in 2017 Smart Device Security: China's online smart device Security Situation Report in 2017. In recent years, security incidents of online smart devices have occurred from time to time, and CNCERT has continu

./////////////////////////////////////////////////////////////////////////////////////////////////////////////// ////When your device is idle, it will first darken the screen, then turn off the mask (that is, the black screen, you have to press the power key and so on to re-charge it), will eventually turn off the phone's CPU, the purpose is to prevent the device's battery quickly exhausted, but many times, your program may request some unusual behavi

Article Title: linux Device Driver note-character Device Driver. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. ※"Global" means that if a device is enabled multiple times, all file descriptors that open it share the data. "Pe

Device numberThe device number consists of the main device number and the secondary device number. Linux, all devices are files, all devices can find the corresponding files in the/ dev directory. These files, in addition to their names, have different device numbers for eac

From: http://www.cnblogs.com/zhuyp1015/archive/2012/05/22/2514008.html bird1015 blog When writing a Linux kernel driver, if you do not dynamically generate a device number, you need to manually allocate the device number. It is possible that the device number you allocate will be the same as the existing device number

1. device. The device structure is used to describe the device in LDM. Struct device {/* parent device, usually a bus or host device */struct device * parent;/* Private Data Pointer: S

1. Click application in the following figure ].2. Click set to enter the page.3. On the page that appears, click device and click call.4. Click other settings ].5. Here you will see a [call transfer]. Click to enter.6. Let's find a [transfer when no response is answered] here.7. Enter the transferred contact number, or click the contact icon on the right to a

Tags: logout flags function device fun argv hrd none lapThe code is as follows#include #include#include#include#include#includeintDemo_major = -;intDemo_minor =0;intDemo_count =1;structCdev Cdev;Static struct class*Demo_class;Static structDevice *Demo_device;intDemo_open (structInode *INODEP,structFile * Filep)//turn on the device{PRINTK ("%s,%d\n", __func__, __line__); return 0;}intDemo_release (structInod

The character device or block device definition belongs to the device access layer of the operating system, which is not necessarily related to the characteristics of the actual physical device. The driver is under the device access layer, so you only need to provide the dri

See Dr. Zhao Jiong's "Linux 0.11 source code comment" has been two or three weeks, starting from today, some personal summary and sentiment sub-standard inscribed out, chat for memory for later review.In the/linux/boot/bootsect.s of linux0.11 source code, there is a label definition Root_dev! Root_dev:0x000-same type of floppy as boot.! 0x301-first partition on First drive etcRoot_dev = 0x306Here, Root_dev is the device number of the system-specified

According to ldd3, the Linux device model can be considered as an advanced textbook, which is unnecessary for most program authors. But I personally think: For an embedded Linux underlying programmer, this part of content is very important. For example, I learned about ARM9. many bus (such as SPI, IIC, IIS, and so on) have been written into subsystems in Linux, and no driver needs to be written by myself; unlike PCI, USB, and other tutorials on ldd3,

Device number:1, self-allocation of the initiativeMajor = Register_chrdev (0, "First_drv", first_sdv_fops);//RegisterWhen you register your device with the device number 0, the kernel will voluntarily assign a master device number to return.2. Manual designationFind the main device