W’s of character drivers We already know what drivers are, and why we need them. What is so special about character drivers? If we write drivers for byte-oriented operations (or, in C lingo, character-oriented operations), then we refer to them … Continue reading →

Multiple Data Compression

#include<stdio.h> #include<string.h> #include<stdlib.h> int main() { char *pwd=NULL; int ch=0,i=0,ret; char *buff; pwd=malloc(sizeof(char) *10); buff=malloc(sizeof(char) *10); FILE *fptr = NULL; fptr=fopen(“hello.txt”,”r+”); if(fptr == NULL) { perror(“fopen”); return -1; } else printf(“file is opened successfully\n”); printf(“enter the password\n”); gets(pwd); ch=getc(fptr); while(ch!=EOF) … Continue reading →

@this a program for simple queue to push pop and display the elements of the queue @ 1.1 log @Initial revision @ text @#include”header.h” int main() { void *queue; int f,r; f=r=-1; int ch; do { printf(“1:push\n”); printf(“2:pop\n”); printf(“3:display\n”); printf(“4:exit\n”); … Continue reading →

NULL 1 IT is macrodefined in for the null pointer . 2 NULL CAN BE DEFINED AS ((void*)0) 3 size of NULL= 4BYTES NUL 1 IT IS A USER DEFINED VARIABLE. 2 IST CHAR IN THE ASCII TABLE. 3 IT … Continue reading →

Big and Little Endian Basic Memory Concepts In order to understand the concept of big and little endian, you need to understand memory. Fortunately, we only need a very high level abstraction for memory. You don’t need to know all … Continue reading →

Cortex-A8 Processor The ARM Cortex™-A8 processor, based on the ARMv7 architecture, has the ability to scale in speed from 600MHz to greater than 1GHz. The Cortex-A8 processor can meet the requirements for power-optimized mobile devices needing operation in less than … Continue reading →

1 head 1.1; 2 access; 3 symbols; 4 locks 5 root:1.1; strict; 6 comment @# @; 7 8 9 1.1 10 date 2014.04.19.12.26.46; author root; state Exp; 11 branches; 12 next ; 13 14 15 desc 16 @to print * … Continue reading →

1 head    1.1; 2 access; 3 symbols; 4 locks 5         root:1.1; strict; 6 comment @# @; 7 8 9 1.1 10 date    2014.04.19.12.26.46;    author root;    state Exp; 11 branches; 12 next    ; 13 14 15 desc 16 @to print * … Continue reading →

Malloc :- It is presnt in C library. It allocates memory in user space Vmalloc:- It is shared object. If used in user space act as malloc. If used in kernel space then act as kmalloc. Kmalloc:- It allocates the … Continue reading →

When talking about toolchains, one must distinguish three different machines : the build machine, on which the toolchain is built the host machine, on which the toolchain is executed the target machine, for which the toolchain generates code From these three … Continue reading →

What is Shared Memory? In the discussion of the fork() system call, we mentioned that a parent and its children have separate address spaces. While this would provide a more secured way of executing parent and children processes (because they … Continue reading →

we can exit from superuser by using exit command . exit changing the password of root passwd

By default, Linux builds for the same architecture the host system is running. This is called “native compiling”. An x86 system building an x86 kernel, x86-64 building x86-64, or powerpc building powerpc are all examples of native compiling. Building different … Continue reading →

SHELL :-> “Shell” is the term used for any program which runs others. It wraps around another program .As the name suggest “Shell” the outer covering .for example in windows(OS) windows explorer is shell.In unix circles, shell has specialized to … Continue reading →