On Monday 25 Apr 2011 2:25:10 pm Prabhu nath wrote: > I understand about Linear virtual address and Physical address. How is the > logical address generated ? Can you please explain. > > Thanks, > Prabhu > > On Wed, Apr 20, 2011 at 9:33 PM, mindentropy <mindentropy@xxxxxxxxx> wrote: > > On Wednesday 20 Apr 2011 4:31:08 pm limp wrote: > > > Thanks a lot Dace and Vladimir for your replies. > > > > > > First of all, I forgot to mention that I am talking for x86 > > > architecture. > > > > > > > The CPU registers will contain the virtual addresses. Each and every > > > > time that the CPU tries to access a virtual memory location, then the > > > > address will be translated by the MMU into a physical address. > > > > > > So, AFAIU the translation to physical memory takes place *only* when > > > the ALU of the processor has to do some operation which has memory > > > operands (in this case the CPU needs to deal with the *real* > > > addresses) but not prior to that. > > > > The address translation happens in the following way: > > > > Logical Addr-->|Segmentation Unit|-->Linear Addr -->|Paging unit|--> > > Physical > > Addr. > > > > If the paging unit is not setup then the linear addr is the physical > > addr. > > > > _______________________________________________ > > Kernelnewbies mailing list > > Kernelnewbies@xxxxxxxxxxxxxxxxx > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies In the segmented memory model the memory appears as segments. In this model the program issues a logical address which comprises of a segment:offset address. The offset selects a byte in the segment. The segmentation unit converts it to a linear address. If the paging unit is enabled the linear address passes through the paging unit for further translation. Also please do not top post :) _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
