This C program snippet as follows intends to copy some memory, say 1,024 bytes, using the usual memcpy(3) glibc API, from a source location 300 KB into the program to a destination location 400 KB into the program. As Application 1 is the program at the low end of physical memory (see the preceding memory map), it starts at the 0x0 physical offset.
We understand that on a modern OS nothing will start at address 0x0; that's the canonical NULL memory location! Keep in mind that this is just a fictional example for learning purposes
First, let's see the correct usage case.
Refer to the following pseudocode:
phy_offset = 0x0;src = phy_offset + (300*1024); /* = 0x0004 b000 */dest = phy_offset + (400*1024); /* = 0x0006 4000 */n = 1024; ...
