Processor MMU fundamentals

Another modern processor architectural feature, specifically for the Cortex-A series CPUs, is the MMU. It allows the software tasks running on the processor to use virtual memory addressing as it performs the address translation back to the physical memory when access is needed. It also implements access management in the address spaces from the processor to the physical memory to prevent and allow read, write, and execute access from tasks to the translated regions of the physical address space. The MMU allows software to be written without any knowledge of the physical address space mapping or whatever else may be running on the processor. It can also make mappings between a continuous virtual address space to a fragmented physical address space. The firmware running on the processor is responsible for setting up the MMU, as well as the address translation tables, to make the desired correspondence between the virtual view of the SoC address map seen by...