Embedded Programming with Modern C++ Cookbook

How to do it...

The Raspberry PI has a number of peripheral devices that are accessible over MMIO. To demonstrate how MMIO works, our application will access the system timer:

1. In your working ~/test directory, create a subdirectory called timer.
2. Use your favorite text editor to create a file named timer.cpp in the timer subdirectory.
3. Put the required headers, constants, and declarations of types into timer.cpp: 

#include <iostream>#include <chrono>#include <system_error>#include <thread>#include <fcntl.h>#include <sys/mman.h>constexpr uint32_t kTimerBase = 0x3F003000;struct SystemTimer {  uint32_t CS;  uint32_t counter_lo;  uint32_t counter_hi;};

4. Add the main function, which contains all the logic of the program:

int main() { int memfd = ...