[Libguestfs] RE: Attempts to install a Windows driver from WinPE

Yuval Kashtan ykashtan at redhat.com
Wed Dec 2 07:05:22 UTC 2009


I have some knowledge with windows and might be able to help

SetupCopyOEMInf is the right API
And it should be possible to track it's whereabouts using filemon and
regmon.

I would have also investigate more into pkgmgr.exe which sounds as a
possibly possible solution (from its description)

Another possible source of info is through the administration guide. I
know it's possible to sysprep a machine with additional drivers for later
discovery by the PnP mechanism and the same mechanism used there might be
useful here as well


BTW - storage pose additional complexity if you want to boot directly from
the new driver (like in the case of moving to virtio), there are
additional required changes (other than just installing the driver, you
have to tell it to load it before other components (something to do with
the CriticalDeviceDatabse
http://technet.microsoft.com/en-us/library/cc976055.aspx)

> -----Original Message-----
> From: Itamar Heim [mailto:iheim at redhat.com]
> Sent: Monday, November 30, 2009 2:33 PM
> To: 'Yuval Kashtan'; 'Yaniv Kaul'
> Subject: FW: Attempts to install a Windows driver from WinPE
> 
> fyi
> 
> -----Original Message-----
> From: Matthew Booth [mailto:mbooth at redhat.com]
> Sent: Monday, November 30, 2009 5:52 AM
> To: libguestfs at redhat.com
> Cc: 'Ayal Baron'; Itamar Heim
> Subject: Attempts to install a Windows driver from WinPE
> 
> One of the things we would really like to be able to do for V2V is to
> install a new driver in a Windows guest. There are a couple of reasons
> for this:
> 
> * The guest may not be bootable without the driver installed, for
> example because the underlying virtual hardware has changed from vmscsi
> to virtio.
> 
> * If the guest can boot, the alternative is to modify the guest to run
> a
> script on next boot. This requires making assumptions about supporting
> software being installed and working correctly on the guest. Certain
> environments, particularly heavily locked-down environments, make this
> an unsafe assumption.
> 
> The Windows PE environment looks perfect for this task. It gives you a
> very lightweight Windows OS which can be customised with additional
> tools. It is specifically for doing installations. I spent Friday
> trying
> to use it to install a driver in a guest. Here's what I tried and why
> it
> didn't work.
> 
> Installing a driver in Windows is 'driven' by a .inf file. From my
> (admittedly limited) understanding, this broadly describes:
> 
> * The files which need to be installed
> * The hardware the driver is compatible with
> 
> The files, including the .inf file itself must be copied in to the
> correct places. In addition, information from the .inf file must be
> written to the registry. It is this last part which causes problems.
> 
>  From reading documentation, it appears that a driver would normally be
> installed using the SetupCopyOEMInf() library call. I wrote a simple
> wrapper round this and installed it in the Windows PE image, along with
> the VirtIO drivers. I booted into Windows PE and attempted to install
> the driver. As you might expect, the drivers were installed into the
> Windows PE image rather than the guest. I then tried setting
> %systemdrive% and %systemroot% to the guest image. This appears to have
> no effect. This is what makes me suspect that the process is primarily
> registry driven.
> 
> I started looking around for ways of using a different registry. I
> discovered the Registry Editor PE plugin to BartPE
> (https://sourceforge.net/projects/regeditpe/) which allows editing the
> registry of a guest. Looking at how it does this, it uses reg.exe to
> load the guests's hives. I confirmed that you can do this.
> Unfortunately
> you don't seem to be able to replace the default hives. The new hives
> are loaded in a different part of the tree, and are therefore ignored.
> 
> This is as far as I've got. Still on my list are:
> 
> * Ask on various Windows mailing lists how to do this
> * Investigate if the packaged .msi containing the drivers is more
> flexible.
> * Look for other, possibly lower level, ways of replacing making a
> process use a different registry.
> 
> Any and all suggestions are gratefully received,
> 
> Matt
> --
> Matthew Booth, RHCA, RHCSS
> Red Hat Engineering, Virtualisation Team
> 
> M:       +44 (0)7977 267231
> GPG ID:  D33C3490
> GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490




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