Is C/C++ pointer keeps absolute memory address, or relative to application, or relative to module?
First you must understand that in C and C++ the value of a pointer is not required to be related to the addresses actually used, as long as pointer arithmetic works with it, the null pointer has an R value of 0 and the implementation manages to bijectively map between machine pointers and language abstract pointers.
Hardware Protection and Type of Hardware Protection
In this article, we are going to learn about hardware protection and it’s the type. so first let’s see the type of hardware which is used in a computer system. we know that a computer system contains the hardware like processor, monitor, RAM and many more, and one thing that the operating system ensures that these devices can not directly accessible by the user.
Difference between Loading and Linking
Linking and Loading are the utility programs that play a important role in the execution of a program. Linking intakes the object codes generated by the assembler and combines them to generate the executable module. On the other hand, the loading loads this executable module to the main memory for execution.
Difference between Internal Fragmentation and External Fragmentation
As processes are loaded and removed from memory, the free memory space is broken into little pieces. It happens after sometimes that processes cannot be allocated to memory blocks considering their small size and memory blocks remains unused. This problem is known as Fragmentation.
Paging
In computer operating systems, paging is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory.In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory.
Logical and Physical Address in Operating System
Logical Address is generated by CPU while a program is running. The logical address is virtual address as it does not exist physically, therefore, it is also known as Virtual Address. This address is used as a reference to access the physical memory location by CPU. Physical Address identifies a physical location of required data in a memory. The user never directly deals with the physical address but can access by its corresponding logical address.
XSM Paging Hardware and Address Translation
The hardware paging scheme of XSM maps the virtual address space of a user mode program to the physical address space of the machine. Read the XSM Virtual Machine Model before proceeding further.
Understanding Shared Libraries in Linux
In programming, a library is an assortment of pre-compiled pieces of code that can be reused in a program. Libraries simplify life for programmers, in that they provide reusable functions, routines, classes, data structures and so on (written by a another programmer), which they can use in their programs.
For instance, if you are building an application that needs to perform math operations, you don’t have to create a new math function for that, you can simply use existing functions in libraries for that programming language.
Examples of libraries in Linux include libc (the standard C library) or glibc (GNU version of the standard C library), libcurl (multiprotocol file transfer library), libcrypt (library used for encryption, hashing, and encoding in C) and many more.
Static, Shared Dynamic and Loadable Linux Libraries
This tutorial discusses the philosophy behind libraries and the creation and use of C/C++ library “shared components” and “plug-ins”. The various technologies and methodologies used and insight to their appropriate application, is also discussed. In this tutorial, all libraries are created using the GNU Linux compiler.Libraries employ a software design also known as “shared components” or “archive libraries”, which groups together multiple compiled object code files into a single file known as a library. Typically C functions/C++ classes and methods which can be shared by more than one application are broken out of the application’s source code, compiled and bundled into a library. The C standard libraries and C++ STL are examples of shared components which can be linked with your code.
Error when installing Makefile
when i got error like this :
nir@nir:~/Downloads/xf86-video-intel-2.17.0$ make
make: *** No targets specified and no makefile found. Stop.