0

When I say 'look like', I mean what does the file or directory structure look like for DOS, Linux and EFI?

I need to make a minimal bootable USB stick to get access to hardware flashing, in essentially any operating system. It has taken two days so far and am stumped at the point of making a bootable USB stick in any flavour, basic stuff.

Basically, a MS-DOS boot disk looks pretty straightforward:

AUTOEXEC.BAT
CONFIG.SYS
COMMAND.COM
MSDOS.SYS
IO.SYS

Some combination of these files amounts to a bootable DOS or FreeDOS disk, on a FAT partition. Unfortunately the flashing tool doesn't like DOS, some suggest it needs to run in HIMEM, with no indication of how to do that. None of the images or installers here work. I have tried Rufus, however it doesn't do anything with HIMEM.

My basic understanding of an EFI boot was that there needed to be a FAT partition available with an EFI formatted executable available in it. However I can't find any booting EFI files available anywhere that bring up DOS, Linux or the EFI shell. I don't know what an EFI boot looks like. This I thought would answer all my questions, but alas, I still am no closer.

Finally, again using Rufus, I had it install SysLinux, however it would not boot.

I cannot see a clean resource anywhere describing what these minimal versions should look like, how they can be created, and downloadable examples. It seems like something that should have been cemented decades ago, but I just find myself swimming in bizarrely overcomplicated instructions, requirements to put and entire DVD ISO onto a USB stick, to install or use files that simply don't exist anywhere, or use some utility that to-date I haven't found one that works. Can someone please solve this finally, prepare an instructional on what these minimal versions would look like, where to get them, etc.? I feel like it shouldn't be that hard..!

  • HIMEM is not something Rufus would add – it's a driver you need to list in config.sys yourself. See also loadhigh. – grawity Dec 20 '17 at 17:43
  • 1
    @DavidPostill would you prefer three separate questions? Could you propose a site that is better for this type of question? It is potentially a request for a blog-like response. – J Collins Dec 20 '17 at 17:45
  • @grawity That is what I have established, however there is never any more detail on exactly where to get or what version of HIMEM.SYS I need, where it belongs in the directory structure, what are its dependencies etc. – J Collins Dec 20 '17 at 17:47
  • Where to get it? It is part of MS-DOS itself. You get it automatically whenever you install MS-DOS from the setup disks. – grawity Dec 20 '17 at 17:51
  • 1
    Hirens Boot CD is the template for what you're describing, it can boot Free Dos + a Windows XPE + a Live LINUX version with XWindows along with seamless UEFI support. Hirens doesn't necessarily publish directions how they mint their Boot CD but they freely provide iso's at hiren.info/pages/bootcd-on-usb-disk, you can reverse engineer it to help you determine how to proceed. – 123456789123456789123456789 Dec 20 '17 at 18:38
0

A DOS boot disk is booted using the MBR portion of the disk, prior to ant partition. It has the basic file form of:

AUTOEXEC.BAT
CONFIG.SYS
COMMAND.COM
MSDOS.SYS
IO.SYS

All in the root of the drive. Rufus for instance can create a bootable drive using MS-DOS or FreeDOS. The files listed above

An EFI boot disk need only have a FAT32 partition (as per UEFI standard) that has a single file in a \EFI\boot folder structure, having the extension *.efi:

\EFI\boot\bootx64.efi

as per this answer.

I am still looking for information on what a minimal Linux boot drive would look like or how to achieve it.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.