Creating and writing to reserved sectors

[collisiondetection]

My operating system is currently just a bootloader (I've spent more time researching and theorizing than actual programming). One thing on my wishlist is a filesystem-independent bootloader.

I am aware that GRUB accomplishes this by keeping a "Stage 1.5" in the reserved area of a disk, but I wonder how it is possible to format a disk (a FAT12 floppy disk, for example) with reserved sectors in which I can place files into.

Does anybody know of a program (or system utility built into some OS I'm not aware of) that can format disks with certain filesystems and with reserved sectors?

[b.zaar]

Grub uses reserved sectors on a partitioned disk. A FAT12 floppy isn't really large enough to include reserved sectors as well as the file system.

[mikegonta]

Grub uses reserved sectors on a partitioned disk. A FAT12 floppy isn't really large enough to include reserved sectors as well as the file system.

Those are hidden sectors. You can reserve as many sectors as you want on any FAT file system (as long as you leave some of the available sectors
available for data of course).

[collisiondetection]

Yes, but how does one accomplish this? I know how GRUB does it - I'm just stumped figuring out how to do it myself.

[embryo2]

Yes, but how does one accomplish this? I know how GRUB does it - I'm just stumped figuring out how to do it myself.

Read about FAT format and just write your data accordingly. To write a sector you have BIOS functions. Just use them. You already have a bootloader, then the rest is relatively simple. Or you can write required bytes as a file under your preferred OS and next to copy the file to the beginning of a disk. Under Linux it is the dd program that can help you. Under WindowsXP it is the HxD program. May be there are other programs. Just google for them.

[iansjack]

http://superuser.com/questions/323210/h ... te-the-mbr

[mikegonta]

Under Linux it is the dd program that can help you.

The Windows version of DD works on all versions up to and including Windows 7.

Under WindowsXP it is the HxD program.

They are obviously two totally different programs (HxD is not a replacement for DD), however HxD is an excellent disk editor and
works on all versions up to and including Windows 7. Both programs probably also work on Windows 10, however I can not personally verify that.

[alexander]

Under Linux it is the dd program that can help you.

The Windows version of DD works on all versions up to and including Windows 7.

Under WindowsXP it is the HxD program.

They are obviously two totally different programs (HxD is not a replacement for DD), however HxD is an excellent disk editor and
works on all versions up to and including Windows 7. Both programs probably also work on Windows 10, however I can not personally verify that.

I can confirm that HxD works flawlessly on Windows 10

[mikegonta]

Under Linux it is the dd program that can help you.

The Windows version of DD works on all versions up to and including Windows 7.

Under WindowsXP it is the HxD program.

They are obviously two totally different programs (HxD is not a replacement for DD), however HxD is an excellent disk editor and
works on all versions up to and including Windows 7. Both programs probably also work on Windows 10, however I can not personally verify that.

I can confirm that HxD works flawlessly on Windows 10

How about DD for Windows on Win10?

[alexander]

How about DD for Windows on Win10?

I'll see if I can test that for you.

Edit:I assume you are talking about: http://www.chrysocome.net/dd and not https://sourceforge.net/projects/windd/