Hi, I m trying to understand how different io memory is mapped to the CPU. While analysing that i was struck at create_mapping function. i have several questions like, 1) Why map_desc.virtual is filled with physical address of the io device. 2) What is a section and why it is needed? 3) I am not understanding "alloc_init_section(pgd, addr, next, phys, type);" what it does? -- With regards, Sandeep Kumar Anantapalli,