Accessing files on FAT32 partition at boot time

Is it possible to access files on a FAT32 parition during boot time from a
PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I tried
playing around with dependencies and load order, but that didn't seem to do
anything. If I re-start the driver after the system has fully booted, I am
able to open the file.

David
Wed May 07 16:33:39 CDT 2008

Could you supply any less information?

What are the names of the boot and system volumes? What are the symbolic
links to those volumes? What is the name of the volume containing the file
you want to access? What symbolic links? What type of drive contains the
file you want to open? Is it removable? Is it USB, 1394, ATAPI, SCSI,
iSCSI, etc.?

Do you know how to use diskview, objdir, devicetree, and winobj? How about
ProcessMonitor, but I don't think it will help you during the boot sequence?
They are all available for free on osronline or sysinternals.


"Michael" <Michael@discussions.microsoft.com> wrote in message
news:81D38A2D-ADD7-4820-8C85-0AC76C3D06A4@microsoft.com...
> Is it possible to access files on a FAT32 parition during boot time from a
> PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I
> tried
> playing around with dependencies and load order, but that didn't seem to
> do
> anything. If I re-start the driver after the system has fully booted, I
> am
> able to open the file.

Pavel
Wed May 07 20:19:20 CDT 2008

"Michael" <Michael@discussions.microsoft.com> wrote in message
news:81D38A2D-ADD7-4820-8C85-0AC76C3D06A4@microsoft.com...
> Is it possible to access files on a FAT32 parition during boot time from a
> PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I
> tried
> playing around with dependencies and load order, but that didn't seem to
> do
> anything. If I re-start the driver after the system has fully booted, I
> am
> able to open the file.

During boot, only the system disk is available immediately,
other disks come later.
Due to boot optimization, your driver may start early
and the load order does not control this completely.
Try to be more flexible. If your driver can wait, delay
whatever it does, until that disk becomes available.

Regards,
--PA

Maxim
Thu May 08 04:05:06 CDT 2008

> During boot, only the system disk is available immediately,
> other disks come later.

No filesystems are available at Boot startup phase.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

Maxim
Thu May 08 04:07:32 CDT 2008

No ways.

No filesystems are available on Boot startup phase, and only SystemRoot is
available on System startup phase.

Also, on both phases, only the System registry is available.

So, do not use files in the driver, and do not use registry outside System.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

"Michael" <Michael@discussions.microsoft.com> wrote in message
news:81D38A2D-ADD7-4820-8C85-0AC76C3D06A4@microsoft.com...
> Is it possible to access files on a FAT32 parition during boot time from a
> PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I tried
> playing around with dependencies and load order, but that didn't seem to do
> anything. If I re-start the driver after the system has fully booted, I am
> able to open the file.

Koen
Thu May 08 04:30:55 CDT 2008

On 7 mei, 21:47, Michael <Mich...@discussions.microsoft.com> wrote:
> Is it possible to access files on a FAT32 parition during boot time from a=

> PnP driver? =A0ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. =A0=
I tried
> playing around with dependencies and load order, but that didn't seem to d=
o
> anything. =A0If I re-start the driver after the system has fully booted, I=
am
> able to open the file.

Michael,

Have you tried setting HKEY_LOCAL_MACHINE\System\CurrentControlSet
\Services\FastFat\Start to 0 ?
This did the trick for my driver...

Success,

Koen

Michael
Thu May 08 09:18:00 CDT 2008

Thanks everyone for all of the suggestions. What is the correct way to
postpone accessing the filesystem? If I just poll on the ZwCreateFile()
call, this seems to block the system from ever fully booting. Is there a way
to be notified through a callback when the filesystem is accessible?

"Pavel A." wrote:

> "Michael" <Michael@discussions.microsoft.com> wrote in message
> news:81D38A2D-ADD7-4820-8C85-0AC76C3D06A4@microsoft.com...
> > Is it possible to access files on a FAT32 parition during boot time from a
> > PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I
> > tried
> > playing around with dependencies and load order, but that didn't seem to
> > do
> > anything. If I re-start the driver after the system has fully booted, I
> > am
> > able to open the file.
>
> During boot, only the system disk is available immediately,
> other disks come later.
> Due to boot optimization, your driver may start early
> and the load order does not control this completely.
> Try to be more flexible. If your driver can wait, delay
> whatever it does, until that disk becomes available.
>
> Regards,
> --PA
>
>
>

Michael
Thu May 08 09:40:01 CDT 2008

Setting FastFat\Start to 0 seems to have done the trick! Are there any
potential side effects from doing this? Thanks!


"Koen" wrote:

> On 7 mei, 21:47, Michael <Mich...@discussions.microsoft.com> wrote:
> > Is it possible to access files on a FAT32 parition during boot time from a
> > PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I tried
> > playing around with dependencies and load order, but that didn't seem to do
> > anything. If I re-start the driver after the system has fully booted, I am
> > able to open the file.
>
> Michael,
>
> Have you tried setting HKEY_LOCAL_MACHINE\System\CurrentControlSet
> \Services\FastFat\Start to 0 ?
> This did the trick for my driver...
>
> Success,
>
> Koen
>

Koen
Thu May 08 10:14:45 CDT 2008

On 8 mei, 16:40, Michael <Mich...@discussions.microsoft.com> wrote:
> Setting FastFat\Start to 0 seems to have done the trick! =A0Are there any
> potential side effects from doing this? =A0Thanks!
>
>
>
> "Koen" wrote:
> > On 7 mei, 21:47, Michael <Mich...@discussions.microsoft.com> wrote:
> > > Is it possible to access files on a FAT32 parition during boot time fr=
om a
> > > PnP driver? =A0ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME.=
=A0I tried
> > > playing around with dependencies and load order, but that didn't seem =
to do
> > > anything. =A0If I re-start the driver after the system has fully boote=
d, I am
> > > able to open the file.
>
> > Michael,
>
> > Have you tried setting HKEY_LOCAL_MACHINE\System\CurrentControlSet
> > \Services\FastFat\Start to 0 ?
> > This did the trick for my driver...
>
> > Success,
>
> > Koen- Tekst uit oorspronkelijk bericht niet weergeven -
>
> - Tekst uit oorspronkelijk bericht weergeven -

No idea about possible side effects. However, we've been running our
systems (2000, XP and 2003 Server) with this setting for years and
never encountered any problems.

Koen

Maxim
Thu May 08 13:55:04 CDT 2008

Look at IoRegisterDriverReinitialization

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

"Michael" <Michael@discussions.microsoft.com> wrote in message
news:C5E4B7C7-B4E3-4A8D-84DA-C0087D233CD0@microsoft.com...
> Thanks everyone for all of the suggestions. What is the correct way to
> postpone accessing the filesystem? If I just poll on the ZwCreateFile()
> call, this seems to block the system from ever fully booting. Is there a way
> to be notified through a callback when the filesystem is accessible?
>
> "Pavel A." wrote:
>
> > "Michael" <Michael@discussions.microsoft.com> wrote in message
> > news:81D38A2D-ADD7-4820-8C85-0AC76C3D06A4@microsoft.com...
> > > Is it possible to access files on a FAT32 parition during boot time from
a
> > > PnP driver? ZwCreateFile() is returning STATUS_UNRECOGNIZED_VOLUME. I
> > > tried
> > > playing around with dependencies and load order, but that didn't seem to
> > > do
> > > anything. If I re-start the driver after the system has fully booted, I
> > > am
> > > able to open the file.
> >
> > During boot, only the system disk is available immediately,
> > other disks come later.
> > Due to boot optimization, your driver may start early
> > and the load order does not control this completely.
> > Try to be more flexible. If your driver can wait, delay
> > whatever it does, until that disk becomes available.
> >
> > Regards,
> > --PA
> >
> >
> >