Linux is a variant of the UNIX operating system, and the principle and idea of writing a driver in Linux is similar to that of other Unix systems, but it is very different for drivers in DOS or window environments. Design the driver in the Linux environment, the thought is concise, the operation is convenient, the function is also very formidable, but the support function is few, can only depend on the function in the kernel, some commonly used operat
Introduction plan for linux Device Drivers-general Linux technology-Linux programming and kernel information. For details, see the following section. Ldd2, that is, linux device driver 2nd. This book helps you understand the implementation of most hardware work through the Linux OpenSource OS. It is suitable for C programmer which is not very clear about the underlying hardware mechanism and implementation.
Unfortunately, I have read only the chapter
The original Article from: http://skywalkersoftwaredevelopment.net/blog/a-closer-look-at-content-types-drivers-shapes-and-placement
In this article, we will look at the concepts that enable me to stay awake at night, because my life cannot find out the concepts related to: shapes, content types, parts, fields, drivers and placement. If you have some experience using orchard but still feel a little clumsy ab
1. Copy the fusion folder to the driver/Char directory of the kernel;
2. Configure driver/Char/makefile:
# Makefile for the kernel character device drivers.### This file contains the font map for the default (hardware) font#FONTMAPFILE = cp437.uniobj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o tty_buffer.o tty_port.oobj-$(CONFIG_FUSION_DEVICE) += fusion
3. Configure driver/Char/kconfig:
source "
ZZ: http://www.cnblogs.com/lzjsky/archive/2010/11/19/1881911.html
In different scenarios, many driver writers need to share the memory between the driver and the user program. The two easiest technologies are:
1. The application sends IOCTL to the driver and provides a pointer to the memory. Then the driver and application can share the memory. (Application allocates shared memory)2. The driver allocates memory pages, maps these memory pages to the address space of the specified user mode proces
Introduction: from 2.4 to 2.6, the Linux kernel has greatly changed in terms of the module mechanism, device model, and some core APIs that can be loaded, device driver developers are faced with porting drivers from 2.4 to 2.6 kernels, or enabling drivers to support both 2.4 and 2.6 kernels... news nbsp
Introduction: from 2.4 to 2.6, the Linux kernel has greatly changed in terms of the module mechanism, de
file has a. h file, which is the path of. h Modules: $ (make)-C $ (kernel_dir) m=$ (PWD) modules #$ (make)-i$ (INCLUDE)-C $ (Kernel_dir) m=$ (PWD) modules//if the. C file has an. h file, use this compilation syntax. Phony:modules Cleanc Lean: $ (make)-C $ (kernel_dir) m=$ (PWD) cleanElseobj-M: = gpio-sama5d3-Test.oendifAfter you have finished writing the above two files, save the exit.# makeThe. ko file is generated# insmod ****.ko-------Mount Drive#lsmod--------to view mounted
extracted directory and compile the installation, with the following command:# CD E1000E-1.9.5/SRC# make InstallIn general, the extracted directory will have a readme file, which details the installation of the network card steps, it is strongly recommended to read the Readme, the installation of the Readme step operation generally will not appear problems.The installed files are generally located in the following directory (kernel version takes my example)/lib/modules/2.6.18-194.el5xen/kernel/
); if (!dev->users) check_disk_change (Inode->i_bdev);//Check if the media in the drive changes dev->users++;//increase user Count Spin_unlock (dev->lock); return 0; }To turn off the device function:static int sbull_release (struct inode *inode, struct file *filp) { struct sbull_dev *dev = inode->i_bdev- >bd_disk->private_data; Spin_lock (dev->lock); dev->users--; if (!dev->users) { dev->timer.expires = jiffies + invalidate_delay;//Set timer
In the fourth chapter of the book "Linux device Drivers", we specialize in the debugging technology in driver development.PRINTK is just one of the techniques that requires PRINTK to print messages and write to files on disk, which slows down the entire code execution speed.There are also debugging techniques, and the effect on Code execution speed is smaller than prink.In this, we can have the driver create the file in the proc file system and write
The Windows 7 system greatly enhances the compatibility of the surrounding hardware, itself integrates a lot of drivers, including the printer, scanner, camera, mobile phone, MP3, MP4 player, etc. direct recognition, commonly used models can be used without the installation of Third-party drivers can automatically identify the use. However, occasionally unrecognized hardware, but also to install the driver,
question: I want to know what modules are built into the kernel in the Linux system and what parameters each module has. Is there a way to get a list of built-in modules and device drivers, along with their detailed information?
The modern Linux kernel is growing rapidly over time to support a large number of hardware, file systems, and network functions. During this time, the introduction of the Loadable module (loadable kernel modules,[lkm]) preven
With the release of Linux2.6, the drivers for each device are rewritten to varying degrees due to the new changes made by the 2.6 kernel. For the convenience of Linux enthusiasts, I put my own share out of this worthless file. This article lists the vast majority of changes in the 2.6 kernel with previous versions, but unfortunately the use of individual functions is not listed in detail due to limited time and effort. 1. Use the new entranceMust incl
);
Read-copy-update
Read-copy-update (RCU) is also an advanced mutex mechanism.
Rarely used in drivers
Http://www.rdrop.com/users/paulmck/rclock/intro/rclock_intro.html
Optimized for situations where reads are frequent and rarely written
The protected resource should be accessed through a pointer
When the data structure needs to be modified, the write thread replicates first,
external representation in the Code, the Code does not need to be changed even if the internal data type changes again in the future.
Common macros are:
The official registry cannot statically allocate these additional available device numbers, which can only be used when handling special requirements for device numbers. In fact, for assigning device numbers and creating device files, it is more likely to process device files in a highly dynamic manner.
3.2 dynamically allocat
Document directory
A quick tour of the hardware
The various modules and their interrelations
How URBS keep it all together
Input Handling
Even though UNIX traditionally considers a device as either a "char device" or a "Block device" (as outlined by the 'C' or 'B' in their/DevEntry points), new classes of device are being introduced as technology advances. One of such classes is that of ''usb devices ''.
An USB device is still, at its lowest levels, a ''char devic'' or a ''block devic''
of the LCD controller.
Specifically:
Fill in a fbinfo Structure
Use reigster_framebuffer (fbinfo *) to register the fbinfo structure to the kernel
For the fbinfo structure, the most important thing is its fs_ops member. You need to implement interfaces in fs_ops for specific devices.
Whether to use interrupt handling
Memory Access
If the video card does not have its own video memory, the system memory is allocated as the video memory.
The graphics card comes with a vide
Under Linux, the drive device has character device driver, block device driver and network device drive three kinds, before learning the character device driver, now began to learn block device driver. First of all to compare the two device drivers why not pass, why to split into different types of drivers. Take an example to illustrate the need to introduce block device drivers:If you construct the drive i
);
The filter function is called when the kernel is about to generate an event for the specified Kobject, and if 0 is returned, no event is generated
Bus, device, and driver
Bus
A bus is a channel between a processor and one or more devices
struct BUS_TYPE
Char *name;
struct subsystem Subsys;
struct Kset drivers;
struct Kse
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 device). Some of the more complex data structures and program structures associated with specific device types are also involved in the
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