arunkumar wrote:i would like to have the information of exactly how a file/program is stored in secondary memory? how it is then loaded into main memory and how execution actually take place there?
You mean by 'secondary memory' a storage device (e.g. hard drive), and by 'main memory' the RAM I assume? Anyway, that of course depends on the operating system, the file system used and the executable format used. There is no 'exactly', there are a myriad of OSes and different fs/exe formats.
In general though, an executable on disk (or another storage device) consists of the actual program code, any predefined data it needs, and an executable header (that's the header of the executable, not a header that
is executable, of course) that tells the operating system everything it needs to load the code and data, and to start running the code. Usually an OS part called a 'loader' will do the actual reading from disk, create the right environment and tell the OS to schedule the code for running. As for execution, it doesn't take place in the memory of course, but inside the CPU.
JAL
