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..!