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Groups > alt.lang.asm > #6618

Re: The Virtual Partition - say goodbye to FAT12

From "Mike Gonta" <mikegonta@gmail.com>
Newsgroups alt.lang.asm, alt.os.development
Subject Re: The Virtual Partition - say goodbye to FAT12
Date 2016-04-01 06:50 -0400
Organization Aioe.org NNTP Server
Message-ID <ndljqo$s9s$1@gioia.aioe.org> (permalink)
References <ndk667$vv8$1@gioia.aioe.org> <qhkrfbhc62mp6kve2n1u6gfj5prnv8o4pt@4ax.com>

Cross-posted to 2 groups.

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"Robert Wessel" wrote:
> "Mike Gonta" wrote:
>
>> http://forum.osdev.org/viewtopic.php?f=1&t=30254
>
Hi Robert,

> What's the point?

The Virtual Partition enables a simple system FAT32 file
system driver to be as as simple as a FAT12 driver.

> No standard OS will respect the limits of this
> modified FAT32 FS, so there's no advantage there, and ...

There are _absolutely_ no modifications to the file system.
The standard OS's format FAT32 one way, this is just an
alternate way and it is fully compatible with the MS FAT32
file system specification.
It works perfectly for me on Windows. It can be
"checked for errors" and even defragmented - no problem.
A much better statement would be that you tried it on
Windows or Linux or Xyz and it didn't work.

There's no executable involved, you simple assemble the
binary (it's in GCC but easily converted to GAS/NASM/FASM
etc.) and transfer it to a flash drive.

The Virtual Partition is completely virtual. There is no
actual partition, even the flash drive is not partitioned
and will work even if it is.

> ... reading the root directory (and let's not forget that
> there is no requirement that a FAT12/16 root directory be
> 9 sectors) looking for a couple of boot files and then
> loading those is hardly that complex.

I agree, but you are describing a boot sector boot loader
that only reads and loads a named file; not a full FAT32
file system driver which is much more complex than a
FAT12/16 driver. The MS FAT32 boot sector boot loader is
actually 2 sectors (the second is loaded by the first)
as compared to the single sector FAT12/16 boot sector
boot loader.

> And if you need more code than you can fit into just the
> boot sector, all three FAT formats provide reserved
> areas in fixed locations that you can use.

With the Virtual Partition the FAT32 boot sector boot loader
that reads and loads a named file from the root directory
is only one sector. This is because it is exactly the same
as a FAT12/16 boot sector (the only technical difference
being the same difference between FAT12 and FAT16 - namely
the size of the FAT table entry: 12 vs. 16. vs 32).


Mike Gonta
look and see - many look but few see

http://mikegonta.com
http://tawk.to/mikegonta

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Thread

The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-03-31 17:51 -0400
  Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-03-31 20:48 -0500
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 06:50 -0400
      Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 11:06 -0500
        Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 13:45 -0400
          Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 17:06 -0500
            Re: The Virtual Partition - say goodbye to FAT12 James Harris <james.harris.1@gmail.com> - 2016-04-01 23:16 +0100
              Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 17:29 -0500
                Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-01 20:24 -0400
                Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-02 00:10 -0500
                Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-02 12:03 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:19 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:08 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:02 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 19:55 -0400
              Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 19:30 -0400
            Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 18:55 -0400
              Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-04 00:40 -0500
  Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-01 09:20 +0200
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 07:01 -0400
      Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-04 10:42 +0200
        Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-05 15:58 -0400
          Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-05 22:19 +0200
            Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-05 18:24 -0400
  Re: The Virtual Partition - say goodbye to FAT12 James Harris <james.harris.1@gmail.com> - 2016-04-01 09:55 +0100
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 07:11 -0400
  Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-01 20:24 -0400
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 21:30 -0400

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