There is no reason to write your own x86 bootloader- it's just an exercise in abstracting away the most brain-dead ISA on the planet. What you should do instea

There is no reason to write your own x86 bootloader- it's just an exercise in abstracting away the most brain-dead ISA on the planet. What you should do instead is write the kernel and just load it with GRUB. It allows you to immediately jump into the interesting stuff that makes your kernel unique, makes it easy to test on real hardware without getting a second machine, and makes it possible to dual-boot with it if/when you get that far. I haven't tried this, but it might be fun to write a kernel for some other system- some ARM device, maybe. Any kind of bootloader would be infinitely less encumbered with x86's layer upon layer of compatibility stuff.