Also interesting for people interested in the pedagogy of assembly languages and low level computing: This looks interesting: https://keleshev.com/compiling-to-assembly-from-scratch/

In the same vein, I like to recommend this paper: http://scheme2006.cs.uchicago.edu/11-ghuloum.pdf ... and have used that plus what I've written here: https://github.com/jackrusher/toy-bootloader ... to get quickly take students from nothing to booting a VM image of their own construction.