Don't get me wrong - great work, it takes real skill to put something like this together and a good understanding of the architecture / platform, but why would anyone adopt this over Multiboot v2 or UEFI? The later are cross-arch/plat compatible and have OSS and industry implementations. Both would allow you to spend time focusing on the kernel design and implementation. You seem to slightly paint yourself into a corner by limiting yourself to legacy BIOS and writing the entire loader in assembly. The later makes supporting PCIe via ECAM a chore as well...
