Is it possible to boot DOS from USB?

Question

I've got a pc running CentOS, it has no CD or floppy drive. It has an Intel board and I need to upgrade the BIOS because the current version doesn't support CPU vt (however CPU got it) for KVM.

I downloaded the BIOS upgrade from Intel but I don't know how to flash it. I though iflash and bootable USB is the way to go. But I'm really stuck at making a bootable USB stick.

I tried WinImage81 I can't make it write .img to disk, it warns me the format isn't supported on the disk.

Then I tried Win32DiskImage utility and downloaded some MSDOS images but if I write them to the stick they are to small (bios patch won't fit there and I'm not able to resize it) and the laptop can't boot it anyway.

Do you have any suggestion how to upgrade the bios or how to make that usb stick bootable?

Answer 1

If you have a DOS executable/data but not a bootable floppy image, there is a FreeDOS bootable image here: http://derek.chezmarcotte.ca/?p=188

Just uncompress it and write it to the USB drive with dd if=/path/to/image of=/path/to/usbstick (replacing the filenames with those for your system).

If you do have a bootable image already, you can use GRUB to boot it as Ignacio Vazquez-Abrams suggests.

Answer 2

Nah. Put the floppy image in /boot and configure MEMDISK in grub to boot it.

Answer 3

The Rufus program can write a bootable DOS usb. I ran it on a Win7 machine to create a USB to flash a Dell laptop. It worked beautifully. Per https://www.howtogeek.com/136987/how-to-create-a-bootable-dos-usb-drive/ Rufus is a portable app that doesn’t require any installation—you will see the Rufus application as soon as you launch the downloaded .exe file.

Another possibility that I have used is an external floppy drive through a USB port to boot a DOS floppy boot disk. Use the F10 (on some) boot selection menu with the drive plugged in so it can be seen by the BIOS. Pretty limited space, I think my most recent flash file was more than 1.44MB.

Answer 4

Yes it is possible.

I don't know why all the answers mention doing it with FreeDOS, when you ask re MS-DOS. It is possible to do it with MS-DOS

I remember Nero had an option where you could give it an image of a bootable ms dos floppy, and it'd make a bootable CD. Rufus can do a similar thing but for a USB.

Technically a Win9X boot disk is MS-DOS. So if you make such a boot disk(which will involve a minimum or two or three files, COMMAND.COM, IO.SYS and maybe MSDOS.SYS), but is more useful with other files like CONFIG.SYS and AUTOEXEC.BAT and MSCDEX.EXE and MOUSE.EXE and things like that, and you then need to make an image of that boot disk. And then point Rufus to it. Before Rufus people used what was known as the HP USB tool.. But Rufus is great.

This website has images and has been around for over a decade

https://www.allbootdisks.com/download/dos.html

https://www.allbootdisks.com/download/98.html

It says they are CD images https://www.allbootdisks.com/iso.html, but anything you can make a CD/bootable CD of, you can make a USB/bootable USB of, that's the beauty of what Rufus can do for you.

And to do it in 2019 you'd want to turn on 'legacy mode', in your BIOS/UEFI so it doesn't act like a UEFI. Otherwise it will look for an EFI file on the bootable medium(and not find one).

Answer 5

download freedos lite version and extract that use FD12LITE.img file that file can be write through Rufus utility to USB drive.