Well, you haven't gotten many responses so I'll throw in a little more. If you have a computer booting with EFI, it's a daunting task. I won't say impossible (because I believe it is) but would probably require booting from a 3rd party boot loader and an MBR partition. I started a project like this a very long time ago but once I saw the difficulty in the task, I went a different way.
You can make a bootable DOS CD/DVD/USB Flash much easier and probably achieve your related objectives.
Just make the CD/DVD and use a small dedicated drive formatted with an FAT file system for storage and DOS apps.
I eventually installed MSDOS 6.x in a virtual machine and it was faster than any native DOS machine I'd ever used. It works perfectly and it's fast.
If you want to use it for DOS gaming, I recommend Boxer/DosBox. Boxer is a gaming front end for DosBox. Talk about awesomsauce, this works great for all your old DOS games, and makes it SO SIMPLE to install and use.
If you want to just play around with a genuine DOS interface and some code slinging, then make a DOS VM. You won't be sorry and you'll save yourself several hours and gray hairs. ANYTHING is possible, but I won't do it again.
For having direct access to hardware (for instance, Firmware Updates), then do some googling and download or make a bootable CD/DVD/USB Thumbdrive.
