Hi, There are 2 type of virtual address. One which needs Page table to do the convertion from VIR to PHY. other which is offset to PHYSICAL_PAGE_OFFSET. [ this is actually also called as logical address ]. One can directly calculate the Physical address if Logical address is given. virtual addess where u need a Page Table to do a conversion. Virtual address - one way fo calculation . [ address got from vmalloc ] CR3 + PGD(Virtual Address ) + PMD ( virtual address )+ PTE ( Virtual address )= Physical address Logical address below is called LOW MEM [ usually get from kmalloc ] Virtual address - PHYSICAL_PAGE_OFFSET = physical address. regards Anirban Roy On Sat, Aug 18, 2018 at 8:18 AM, Abhinav Misra <abhitheextremeeng@gmail.com> wrote:

Hi,

In LDD3 book at Ch-15 they mentioned all types of address used in the kernel. But wrt the book, not able to understand the difference between kernel logical and virtual address.

Can somebody elaborate the same with some eg.

BR,Abhinav

_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies