In a manner of speaking, when you perform array (“indexed”) type addressing with general registers, you are doing essentially the same thing as the segment registers. In the bad old days of 8-bit and 16-bit programming, many applications required much more data (and occasionally more code) than a 16-bit address could reach. So many CPUs … Read more
So,after vigorously searching on net for the difference or similarity between these two terms,I have come up on a final answer.First of all I would write down the similarities: They both (segmented paging and paged segmentation) are a type of paging/segmentation combined systems (Paging and Segmentation can be combined by dividing each segment into pages). … Read more
The instruction is loading a new EIP value from memory at ds:[40207A]. i.e. there’s a function pointer at address 40207A. (And it pushes a return address because this is a call not just a jmp.) The ds: means the instruction is referencing memory in the Data Segment – and can pretty much be ignored on … Read more
Ok, based on the book Modern Operating Systems 3rd Edition by Andrew S. Tanenbaum and the materials form Open Security Training (opensecuritytraining.info), i manage to understand the segmentation and paging and the answer for my question is: Concepts: 1.1.Segmentation: Segmentation is the division of the memory into pieces (sections) called segments. These segments are independents … Read more
There is what they were intended for, and what they are used for by Windows and Linux. The original intention behind the segment registers was to allow a program to access many different (large) segments of memory that were intended to be independent and part of a persistent virtual store. The idea was taken from … Read more