How to make fast switching between OS with state saving?

Question

linux

Hello, I'm interested in the possibility of implementing switching between 2 installed systems, conditionally Windows and Linux.
Requirements:
1. WITHOUT virtualization. With the exception of the possibilities in which the OS will access the real hardware directly.
2. Saving the state, simple hibernation, after selecting in the bootloader, it should be possible to return to the system (i.e. during hibernation and the next reboot, I do not get into the same OS, but into the bootloader window with a choice of which OS to boot)

Answer 1

This is how hibernation should work. Just put two different OSes and increase the pause to select the OS