specifics of object oriented software

... the idea of an Objective-C-based framework for drivers, but finally settled on C++ Despite the widespread use of C++ for the development of application software, Mac OS X is still one of the few ... Cocoa Touch are written in the Objective-C language Objective-C is a superset of C, with support for Smalltalk style messages OBJECTIVE-C Objective-C was the language of choice for application development ... application software Application software may need to allocate memory or write a file to disk, and it is the operating system that handles these requests To the user, the involvement of the operating...

Ngày tải lên: 15/03/2014, 02:20

... // // // // // // // // Size of this descriptor in bytes CONFIGURATION descriptor type Total length of data for this cfg Number of interfaces in this cfg Index value of this configuration Configuration ... features of our products Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act If such acts allow unauthorized access to your software ... T10 Vendor ID is not required for a device to be offered for sale Manufacturers also not have to belong to T10 to obtain a Vendor ID As of the time of this document’s publication, there is no cost...

Ngày tải lên: 11/01/2016, 16:48

... media’s controller knows what area of storage corresponds to each address In older systems, software accessed storage media using CHS addressing, where the software specifies a cylinder, head, ... Singh of Microchip Technology, Inc., and to Alan Stern of the Rowland Institute at Harvard For their help in obtaining products used in the writing of the book, thanks to Laurent Guinnard of Ellisys, ... cylinder consists of all of the tracks with the same diameter on all of the platters the head performs the read or write operation on the media The head reads and writes a minimum of a sector’s data...

Ngày tải lên: 06/07/2014, 15:37

... features of our products Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act If such acts allow unauthorized access to your software ... removing the device from its list of attached media See the API documentation provided in the Help directory for a complete list of events The client driver requires a list of the media interface’s required ... the CBW) • The difference between the number of data bytes expected and the number actually transferred • Success or Failure of the command The format of the CSW is shown in Table TABLE 2: COMMAND...

Ngày tải lên: 11/01/2016, 16:46

... without having to reconfigure any software on the host computer USB devices and their corresponding USB device drivers should behave identically regardless of the specific bus topology Built ... structure determines the rate of polling, which can range from through 255 milliseconds This type of transfer is typically used for devices that provide small amounts of data at sporadic, unpredictable ... delayed transfers can be acceptable for these types of device, as long as all of the data is delivered eventually However, in the absence of any other demands for bus bandwidth, Windows CE processes...

Ngày tải lên: 07/10/2013, 00:20

... prompting a user In some cases it may be necessary to specify the precedence order to a greater level of detail; for example, combining vendor- and device-class specifiers In these cases, the GroupX_ID...

Ngày tải lên: 07/10/2013, 00:20

... Utilize USB Organizations Test Resources 45 Analyzer View 46 23 Host Software Testing Strategies ? Schedule availability of Host software –USB mini-driver –Host Test Application ? Request Host Test ... peripheral using sample code ? System Tests –Perform typical use cases with Product software 47 Embedded Software Testing Strategies ? Unit Tests –Driver Install and Uninstall –Enumeration Test ... Architecture of an Embedded USB Device ? USB Device Driver Architecture ? Case Study of a USB Device Driver ? Testing Strategies ? Issues to consider ? Conclusions 19 Architecture of an Embedded...

Ngày tải lên: 13/12/2013, 00:15

... at the beginning of the file, it is increased by one and the number of bytes that have been properly read is given as a return value, If not at the beginning of the file, an end of file (0) is ... twenty-five pins Internally, from the point of view of the CPU, it uses three bytes of memory In a PC, the base address (the one from the first byte of the device) is usually 0x378 In this basic ... return 1; } LEDs to test the use of the parallel port In this section I’ll detail the construction of a piece of hardware that can be used to visualize the state of the parallel port with some...

Ngày tải lên: 23/10/2013, 22:15

... at the beginning of the file, it is increased by one and the number of bytes that have been properly read is given as a return value, If not at the beginning of the file, an end of file (0) is ... twenty-five pins Internally, from the point of view of the CPU, it uses three bytes of memory In a PC, the base address (the one from the first byte of the device) is usually 0x378 In this basic ... return 1; } LEDs to test the use of the parallel port In this section I’ll detail the construction of a piece of hardware that can be used to visualize the state of the parallel port with some...

Ngày tải lên: 13/12/2013, 11:15

... book First of all, note that every software package used in a Linux system has its own release number, and there are often interdependencies across them: you need a particular version of one package ... management, we dissect a few more of the kernel's software interfaces: Chapter 6, "Flow of Time" shows how time is managed in the kernel, and Chapter 7, "Getting Hold of Memory" explains memory allocation ... problem Chapter 10, "Judicious Use of Data Types" offers some additional suggestions about writing kernel software and about portability issues In the second part of this book, we get more ambitious;...

Ngày tải lên: 24/12/2013, 01:17

... The role of individual kernel headers will be introduced throughout the book as each of them is needed Developers working on any large software system (such as the kernel) must be aware of and ... independent operation of programs and protection against unauthorized access to resources This nontrivial task is only possible if the CPU enforces protection of system software from the applications ... trying to something else Several software abstractions (such as kernel timers, introduced in Chapter 6, "Flow of Time") run asynchronously as well Moreover, of course, Linux can run on symmetric...

Ngày tải lên: 24/12/2013, 01:17

... "object" and the functions operating on it to be its "methods," using object- oriented programming terminology to denote actions declared by an object to act on itself This is the first sign of ... *buff, size_t count, loff_t *offp); ssize_t write(struct file *filp, const char *buff, size_t count, loff_t *offp); For both methods, filp is the file pointer and count is the size of the requested ... you write a huge amount of data, the overhead of the linked list is not too bad There is only one list element for every four megabytes of data, and the maximum size of the device is limited...

Ngày tải lên: 24/12/2013, 01:17

... number of bytes of data actually placed in the page buffer, just like the read implementation does for other files Other output values are *eof and *start eof is a simple flag, but the use of the ... int scull_get_info(char *buf, char **start, off_t offset, int len, int unused) { int eof = 0; return scull_read_procmem (buf, start, offset, len, &eof, NULL); } struct proc_dir_entry scull_proc_entry ... that the caller knows your new data is placed at the beginning of the buffer You should then, of course, skip the first offset bytes of data, which will have already been returned in a previous...

Ngày tải lên: 24/12/2013, 01:17

... list of Unix system calls because of the dots, which usually represent not a variable number of arguments In a real system, however, a system call can't actually have a variable number of arguments ... corresponds to one of the possible values for the direction of the transfer The type and number fields are passed as arguments, and the size field is derived by applying sizeof to the dataitem ... implementation of the hosting filesystem (see the chattrcommand) Device driver writers are interested only in the first group of commands, whose magic number is "T.'' Looking at the workings of the other...

Ngày tải lên: 24/12/2013, 01:17

... drivers often need to delay the execution of a particular piece of code for a period of time usually to allow the hardware to accomplish some task In this section we cover a number of different ... fact, task queues are often run as the result of a "software interrupt.'' When running in interrupt mode (or interrupt time) in this way, your code is subject to a number of constraints We will ... The tasklet function is of type void; it returns no value Software support for tasklets is part of , and the tasklet itself must be declared with one of the following: DECLARE_TASKLET(name,...

Ngày tải lên: 24/12/2013, 01:17

... Lookaside Caches A device driver often ends up allocating many objects of the same size, over and over Given that the kernel already maintains a set of memory pools of objects that are all the same ... to the name of the type of structure that will be cached The maximum length for the name is 20 characters, including the trailing terminator The offset is the offset of the first object in the ... memory allocation by creating a set of pools of memory objects of fixed sizes Allocation requests are handled by going to a pool that holds sufficiently large objects, and handing an entire memory...

Ngày tải lên: 24/12/2013, 01:17

... execution of any subsequent read wmb guarantees ordering in write operations, and the mbinstruction guarantees both Each of these functions is a superset of barrier A typical usage of memory ... overview of the capabilities of the architectures that are supported by version 2.4 of the kernel: IA-32 (x86) The architecture supports all the functions described in this chapter Port numbers are of ... returned as individual bit values The actual implementation and software interface of such I/O ports varies from system to system Most of the time I/O pins are controlled by two I/O locations: one...

Ngày tải lên: 24/12/2013, 01:17

... in the design of the hardware itself that says that interrupt lines cannot be shared The problems are on the software side With the arrival of the PCI bus, the writers of system software have ... parallel port connector on the back of your system will create this connection The pinout of the parallel port is shown in Figure 8-1 Pin is the most significant bit of the parallel data byte If you ... a software handler must be configured in the system If the Linux kernel hasn't been told to expect your interrupt, it will simply acknowledge and ignore it Interrupt lines are a precious and often...

Ngày tải lên: 24/12/2013, 01:17

... misc-progs directory of the sample code, and an equivalent kdataalign module is part of misc-modules This is the output of the program on several platforms and the output of the module on the ... *ptr, type _of_ struct, field_name); where ptr is a pointer to the struct list_head being used, type _of_ struct is the type of the structure containing the ptr, and field_name is the name of the list ... matter of fact, the compiler signals type inconsistencies even if the two types are just different names for the same object, like unsigned long and u32 on the PC Interface-Specific Types Most of...

Ngày tải lên: 24/12/2013, 01:17

... version only if the software interface offered by the kernel has changed The software interface, then, can be represented by a function prototype and the exact definition of all the data structures ... about the software interface to a single 32-bit number [45] CRC means "cyclic redundancy check,'' a way of generating a short, unique number from an arbitrary amount of data The issue of version ... modules.conf manpage for the full list of things that can appear in this file Here is an overview of the most common sorts of entries: [44]On older systems, this file is often called /etc/conf.modules...

Ngày tải lên: 21/01/2014, 07:20