Embedded Programming with Modern C++ Cookbook

How it works...

Power management is part of the Linux kernel; that is why we cannot use a Docker container to work with it. Docker virtualization is lightweight and uses the kernel of the host operating system.

We cannot use the real Raspberry Pi board either, because it does not provide any sleep modes at all because of hardware limitations. QEMU, however, provides full virtualization, including power management in the kernel we use to emulate Raspberry Pi.

Linux provides access to its power management functions through the sysfs interface. Applications can read and write text files in the /sys/power directory. Access to power-management functions is limited for the root user; that is why we need to get the root shell once we log into the ...