Building a hobby OS with Bochs and Qemu
Hobby Time

Reading and understanding the complete Linux kernel is a challenging project. A hobby kernel lets you implement standard OS features yourself in a few hundred lines of code.
Everyone who works professionally with Linux is used to building software from the source code, perhaps implementing small changes, automating routine work with shell scripts, or developing their own software in one of the many current programming languages. Tinkering with your own, completely new operating system, on the other hand, is a pretty unusual pastime. If you start from scratch, it will take a long time before your system is useful for anything.
If you are looking for a challenging amateur project (for example, if you are a computer science student) or you want a better understanding of the theoretical basics of interrupts, memory management, scheduling, and other OS features, working on your own kernel can provide valuable insights. Linus Torvalds actually created Linux through a similar tinkering project. In 1991, he posted in a Minix news group, "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones." [1]
A development environment for an operating system is more complex than one for an application, because you cannot simply compile the source code and run it on a trial basis. Instead, you need to create a bootable disk that can be used to boot a VM or emulated PC. It makes the work easier if there are debugging possibilities. The Qemu [2] and Bochs [3] emulation tools have proven useful for building a virtual environment.
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