iomega device drivers

Original URL: http://www.cnblogs.com/geneil/archive/2011/12/04/2275372.htmlIn addition to the ability to read and write devices, most drivers also require the ability to control hardware.First, in user space, using the IOCTL system call to control the device , the prototype is as follows:int ioctl (int fd,unsigned long cmd,...);/*FD: File descriptorCMD: Control command...: Optional parameter: Insert *ARGP,

---restore content starts---Linux device driversOne, the role of device-drivenThe most popular explanation for device drivers is " Drive hardware Device Actions ". Drive and the underlying hardware directly to deal with, according to the specific work of the hardware

File Drivers/base/platform. c/*** platform_get_irq-Get an IRQ for a device * @ Dev: platform device * @ num: IRQ Number Index */INT platform_get_irq (struct platform_device * Dev, unsigned int num) {struct resource * r = platform_get_resource (Dev, ioresource_irq, num); return r? R-> Start: 0 ;} Platform_get_resource (Dev, ioresource_irq, num) obtains the resourc

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if_port; unsigned char DMA; Interface information Drivers/net/net_init.c void Ltalk_setup (struct net_device *dev); void Fs_setup (struct net_device *dev); void Fddi_setup (struct net_device *dev); void Hippi_setup (struct net_device *dev); void Tr_setup (struct net_device *dev); unsigned short hard_header_len; For the Ethernet interface, this value

contiguous and the corresponding data block on disk is also adjacent, then the general block layer can be merged with them, this way to produce a larger memory area is the physical segment.Common block Layer:1. The common block layer is a kernel component that handles requests from all block devices in the systemI\O Scheduler:1. Block device drivers can transmit one sector at a time, but the block i\o laye

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1. Compiling and installing the driverIn Linux systems, drivers are usually encoded using the kernel module's program structure, so compiling and installing a driver is essentially compiling and installing a kernel module.Put the file memdev.c makefile into the virtual machine, make get the. ko fileCP. KO RootfsStart the Development BoardInsmod *.ko2. Create a Device fileWith character

based on the Sbull program in the Linux device driver book to Linux Block device driver summary analysis.Start by understanding the core data structures in this block device:struct Sbull_dev {int size; /* Device Size in sectors */U8 *data; /* The data array */Short users; /* How many users * *Short Media_change; /* Flag a media change? */spinlock_t lock; /* for m

function. Linux-2.6.30.4/ARCH/ARM/mach-s3c2440/mach-smdk2440.c Static void _ initsmdk2440_machine_init (void) { S3c24xx_fb_set_platdata ( smdk2440_fb_info ); Initi_i2c0_set_platdata (null ); Platform_add_devices (smdk2440_devices, array_size (smdk2440_devices )); //Add the platform devices in the above list to the system bus Smdk_machine_init (); } Linux-2.6.30.4/ARCH/ARM/plat-s3c24xx/common-smdk.c Void _ init smdk_machine_init (void) { ...... Initi_device_nand.dev.platform_data = smdk_nand_i

available to the driver) struct Pt_reg *regs are very rarely used. It holds the processor context snapshot before the processor enters the interrupt code The interrupt processing routine should return a value. Used to indicate whether an interrupt was actually handled. If the processing routine finds that its device does need to be processed, it should return irq_handled. Otherwise. The return value should be Irq_none Ena

time. Windows allows windows-based applications to multitask by using a VxD. A VxD handles interrupts in connection with Windows and performs I/O operations for applications that require I/O operations and does not affect the execution of other applications. Most VXD management hardware devices, there are also some VxD to manage or replace related software, such as the normal ROM BIOS. A VxD can contain device-related code that must be executed on th

holds the processor context snapshot before the processor enters the interrupt code The interrupt processing routine should return a value that indicates whether an interrupt was actually handled, and if the processing routine finds that its device does need to be processed, it should return irq_handled, otherwise the return value should be Irq_none Enable and disable interrupts sometimes

4.linux Network device driver architecture -------------------------------------- | Packet Sending | Packet Reception | -----> Network Protocol interface Layer | Dev_queue_xmit () | Netif_rx () | | -------------------------------------- | Structural Body Net_device | -----> Network Device interface layer -----------------------

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

reader doesn't necessarily believe:Generic_make_request () is ultimately handled by calling the REQUEST_QUEUE.MAKE_REQUEST_FN function to complete the request described by bio.By the end of the story, we can now explain why we've listed the inexplicable data structure.For block device drivers, it is the REQUEST_QUEUE.MAKE_REQUEST_FN function that handles all requests on this block device.In other words, as

}};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

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