Booting DOS from a USB thumbdrive

From PrgmrWiki

first, fdisk the drive, create a primary partition that is 32M, make it bootable and type fat16 (type 06)

next, install dosemu. edit your ~/.dosemurc to include the line:

$_hdimage = "drives/c drives/d /dev/sdc1"


then edit ~/dosemu/drive_c/autoexec.bat and comment out (add a rem) the following line:

lredir e: linux\fs/media/cdrom c

(otherwise it sees the last disk in hdimage as a cdrom drive)


now run dosemu

sudo dosemu

and from within dosemu, format /s (like the old days)

Z:
format /s E:
exitemu

(you must first go to the Z drive because otherwise the sys program doesn't have the correct path for command.com and friends)

once you are back in linux, you need to run

install-mbr /dev/sdc

(of course, sdc is whatever your usb drive shows up as)

from here, you can mount it as a normal thumbdrive within Linux, add whatever you need (the only reason I do this is to flash my bios) unmount, and the thing should boot just fine.

Honestly, I'm not sure if the size was critical or if the install-mbr step was critical, but I spent a lot of time screwing with it in an attempt to flash my new tyan board, so I thought I'd document the steps that worked. It is possible that some of these steps are unnecessary, but when done in this order, they are sufficient.