Use the following to run boot sector code paused at the start.
qemu-system-x86_64 -net none -drive file=src/boot_sect.o,format=rawDisassembly command options that I seem to forget every time.
ndisasm -b16 -o7c00h -a <file>
objdump -D -b binary --adjust-vma=0x7c00 -m i8086 -Mintel <file>