I'm not sure whether this is the right place for such a post, but I'd like to have someone look at the bootloader I wrote: https://gitlab.com/SopaXorzTaker/tohloo-loader.
It can load a flat binary from a FAT32 partition and the Makefile allows creating an appropriate disk image for it (with a partition table and such).
Larger files (> 64KB) can be loaded too.
The repo also contains a very bare-bones dummy kernel to test whether it works properly.
The kernel is loaded to 17c0:0000, leaving the stack at 07c0:[ffff ... 0000] (that might be too much, isn't it?
).