Describes fast & slow memory concept. (Fast memory is convinient RAM, slow memory is replacement for swap – it’s located on hard drive/SSD/or maybe even in RAM, and it has huge size, and a lot of space for any data which doesn’t need random reads).
This one just shows how some of drivers would be implemented on say host OS and on real x86 machine (and why initial developement is aiming on running inside host OS):


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