motorola device drivers

Relationship between Linux Device Drivers and the entire hardware System 1. device classification and features the hardware of a computer system consists of CPU, memory, and peripherals. With the development of the IC (Integratedcircuit) manufacturing process, the current chip integration is getting higher and higher, often integrated into the CPU memory and... r

1.1 Linux device driver classification Linux device drivers occupy a large proportion of the Linux kernel source code, and the length of the source code is increasing, mainly the increase of the driver. During the continuous upgrade of Linux kernel, the structure of driver is still relatively stable. In the 2.0.xx to 2.2.xx changes, the driver's writing has made

The role of a device driver is to provide a mechanism, not a policy.The so-called mechanism is "What functions need to be provided"; the so-called "policy" is "how to use these functions ". The former is designed to focus on details. The latter implements calls without knowing any hardware-related information.Different environments require different methods to use hardware. However, a device driver cannot w

available buffer mapped to disk blocks.Bh_new, this buffer is mapped through get_block (0, and cannot be accessedBh_async_read, which is used by the asynchronous I/O read operation through end_buffer_async_read ().Bh_async_write, which is used by the asynchronous I/O write operation through end_buffer_async_write ().Bh_delay, the buffer has not been associated with the disk BlockBh_boundary, the buffer is in the boundary of the continuous block area -- the next block is no longer consecutive.Bh

straightforward practice. Porting network drivers is much more difficult.Looking back at the growth of Linux along with TCP/IP, most RTOS did not consider the network until the end of 1990s. Even so, old network storage often only has basic functions. For example, you can only process a single session, access only one port at the same time, or support only physical interfaces of a single network media. In some cases, the network structure can be impl

}};static struct Dm9000_plat_data Mini2440_dm9k_pdata = {The number of digits in the data line is 16 bits, and no e2prom is used. Flags = (Dm9000_platf_16bitonly | Dm9000_platf_no_eeprom),. dev_addr = {0x08,0x90,0x90,0x90,0x90,0x90},//mac address};static struct Platform_device Mini2440_device_eth = {. Name = "dm9000",//device name. id =-1,. num_resources = Array_size (Mini2440_dm9k_resource),. Resource = Mini2440_dm9k_resource,//Resources. Dev = {. Pl

Allocating memoryDescribes how memory is used in device drivers;How best to utilize system memory resources.Kmalloc functionThe Kmalloc memory allocation engine is a powerful tool.#include void *kmalloc (size_t size, int flags);Parameter assignment means that flags can control the behavior of Kmalloc in a variety of ways.The flag Gfp_kernel indicates that the memory allocation is performed on behalf of the

completed at the I/O scheduling layer. The kernel provides different types of elevator algorithms, and the elevator algorithm has1 NoOp (Implement simple FIFO, basic direct Merge and sort),2 Anticipatory (delayed I/O requests, optimized ordering of critical sections),3 Deadline (improved for anticipatory disadvantage, reduced delay time),4 CFQ (Uniform allocation of I/O bandwidth, fairness mechanism)PS: In fact, the IO scheduling layer (including the request merge sorting algorithm) is not requ

　　 Step 2: Create the int init_test (void) function) Register the device here: Result = register_chrdev (254, "test", test_fops ); 　　 (2) set test. copy c to the/uclinux/linux/drivers/char directory, and mem in the/uclinux/linux/drivers/char directory. in c, add the following code to the int chr_dev_init () function: # Ifdef CONFIG_T

the device here: Result = register_chrdev (254, "test", test_fops ); 　　 　　 (2) set test. copy c to the/uclinux/linux/drivers/char directory, and mem in the/uclinux/linux/drivers/char directory. in c, add the following code to the int chr_dev_init () function: # Ifdef CONFIG_TESTDRIVE Init_test (); # Endif 　　 (3) add the following code to Makefile in the/uclinux

It may be difficult to put the driver model in the first chapter, but as long as the driver model can be crossed, it will be much easier later. The driver model is the cornerstone of the entire Linux Device Driver. Most people call the driver model a device model, but I have checked the help document of Linux to find the driver-model directory in the documentation directory under the download source code pa

Address: http://blog.csdn.net/gaoling179/article/details/6284770 In the process of developing a DSP using Visual DSP ++, you can quickly develop applications by applying the device drivers and system service programs that come with the system software without writing the underlying drivers. (1) Adi has constructed all the d