How to burn a binary file to sector 0 of a floppy disk inserted via a floppy usb on windows 10 pro 64 bit

Question

Hello guys I am writing an operating system in Assembly 16 bit NASM windows 10 64 bit (to be specific) and compiled it to 2 binary .bin files:
kernel.bin
boot.bin
as you may guess boot.bin loads kernel.bin and makes a filesystem, thats all ok. but the problem is that I need to test it on a real machine to test how the hardware reacts instead of only virtual! so I got floppys (3.5" 1.44MB) it is more than enough but I tried to write the bootloader (boot.bin) to sector 0 of a floppy with a floppy-usb-drive (drive and floppys are working how they should!) I use the following steps for putting the OS on a floppy in cmd:

format A:
nasm -f bin kernel.asm -o KERNEL.BIN` 
copy KERNEL.BIN A:\KERNEL.BIN  
debug boot.bin  
w 100 0 0 1  
q

it boots... but not correct: it says this:

Please remove all media... press any key to reboot...`

and it reboots to windows 10

QUESTION

how can I fix this? I now use dosbox and debug.exe in dosbox (debug.exe from windows 7 x32), like: I copy the kernel and burn the loader but it actually WORKS! and loads my OS!

I'm not sure if modern BIOSes allow booting from floppy disks at all! — Martin Rosenau, Aug 11 '17 at 20:35
Is `boot.bin` exactly 512 bytes in size? Does it contain the boot sector signature in the last two bytes, 55h at offset +1FEh and AAh at offset +1FFh ? — Harry Johnston, Aug 12 '17 at 01:06
I'm unsure how debug.exe a dos program runs from Windows 10 64-bit. When you put the bootloader on the floppy are you doing it through an emulator? — Michael Petch, Aug 12 '17 at 13:59
Michael Petch, as listed in the question, it works and i use it in dosbox and everything works except for error message for booting — Yoran Jansen, Aug 12 '17 at 14:43
To clarify, is that error message coming from the BIOS or from your boot code? Can you successfully boot a VM from the physical floppy drive? Have you tried obtaining a floppy image for, say, FreeDOS and seeing if you can boot that? — Harry Johnston, Aug 13 '17 at 01:13
it comes from my BIOS for sure because my OS doesnt contain anything like that and everything else worlds like you said. — Yoran Jansen, Aug 13 '17 at 07:42

David Hoelzer · Answer 1 · 2017-08-12T11:44:15.230

1

It's quite likely that your system is EFI or uEFI rather than traditional BIOS, especially if it's been made in the last four or five years. You can check the system configuration at boot (Go into BIOS or EFI config) and enable legacy boot mode.

It is also possible that your antivirus software is interfering with you writing to a bootsector silently. Check those logs and make sure that your command line is being run as an administrator.

edited Aug 12 '17 at 11:44

answered Aug 11 '17 at 21:12

David Hoelzer

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Are you certain that your boot sector is valid? Do you attempt any screen output before trying to load your kernel? – David Hoelzer Aug 11 '17 at 23:57
and it works if i put the img in a iso on a cd! so what is wrong? – Yoran Jansen Aug 12 '17 at 09:42
I added a suggestion that applies to physical drives. – David Hoelzer Aug 12 '17 at 11:44
i did every thing you told me but now i get the same result but any says boot device failes. – Yoran Jansen Aug 12 '17 at 12:44
It is possible that your hardware doesn't support booting from a USB Floppy device. – David Hoelzer Aug 12 '17 at 14:07
David Hoelzer, i booted from "diskette drive" ! and it reads properly but doesnt read the bootloader! – Yoran Jansen Aug 12 '17 at 14:43

How to burn a binary file to sector 0 of a floppy disk inserted via a floppy usb on windows 10 pro 64 bit

QUESTION

1 Answers1