OSDev.org

I'm new at OS creation and I need some help.

Does anybody know where I can find a FAT (12,16,32
I just want to see what is on disk wit ms windows)
library (OS independent, with source)

How the bootloader load the kernel to the memory if
it's only have 512 bytes and had to read a disk
for what it needs a driver (suporting that file system)


Thanks

>On 2002-02-11 14:07:48, PrzemekG_ wrote:
>I'm new at OS creation and I need some help.
>
>Does anybody know where I can find a FAT (12,16,32
>I just want to see what is on disk wit ms windows)
>library (OS independent, with source)
>
>How the bootloader load the kernel to the memory if
>it's only have 512 bytes and had to read a disk
>for what it needs a driver (suporting that file system)
>
Sorry, I don't know what you mean with the first paragraph,
but I can help you on the second.
The bootloader contained in the first sector loads
some of the sectors after the first, which means
it loads a second bootloader, which may be a little bit larger.
MS DOS specifically has the positions of msdos.sys and io.sys
hardcoded into the bootloader while format /s or sys!

>Sorry, I don't know what you mean with the first paragraph,
>but I can help you on the second.
>The bootloader contained in the first sector loads
>some of the sectors after the first, which means
>it loads a second bootloader, which may be a little bit larger.
>MS DOS specifically has the positions of msdos.sys and io.sys
>hardcoded into the bootloader while format /s or sys!

Sorry for the first paragraph, I said I was looking for a driver
for FAT 12/16/32.

Very nice with a litle boot loader that loads a file but how I do
to load something like MSDOS.SYS and IO.SYS which are visible for
DOS/win (if they are directly after the boot sector)

>Sorry for the first paragraph, I said I was looking for a driver
>for FAT 12/16/32.

Search through the OSs listed in the links of this
page (ie, "OSDev Ring" and "Links" above). Quite a
few OSs implement the FAT file system.

Alternatively, check out www.wotsit.org (might be
.com) for the programmers file format web site. They've
got lots of information about the various FAT file
systems.

>Very nice with a litle boot loader that loads a file but how I do
>to load something like MSDOS.SYS and IO.SYS which are visible for
>DOS/win (if they are directly after the boot sector)

Unless you're writting a DOS emulator, I severly
doubt you actually want to load these (besides,
there's copyright laws). What you do after the
boot sector (and for that matter _in_ the boot
sector) is you own business, dude. You can do/load
whatever you want.

If you're curious about what other OSs usually do,
then I wouldn't use DOS as an example... it's simple,
yes, but it's outdated. The basic concept is
similar, but much more current with Linux and other
32-bit pmode OSs out there. I'd suggest checkin'
out their sources for good, current info.

Jeff