Those Things about Memory Mapping ... / Memory Mapping 的那些事

I have just learned computer architecture but OS so never linked them at all. These days I finished tracing a sample bootcode and read the arm programming guide. A sentence caught my eye which means every process has its own memory mapping, there are many page tables on runtime. I was too stupid to think there was only one page table where one program occupied part of memory and the code followed the rules in the part of memory, instructions on the bottom, stack on the top... Another impact was that it could allocate new memory by updating the page tables. I never knew it.

Several days after that day, I continuously construct the imagination of the code arrangement in the memory mapping, how the OS deals with the page tables. I only know that one program must ask the OS to get more space.