In order to prevent the creation of hardware emulators of protected output devices, Vista requires a Hardware Functionality Scan (HFS) that can be used to uniquely fingerprint a hardware device to ensure that it's (probably) genuine. In order to do this, the driver on the host PC performs an operation in the hardware (for example rendering 3D content in a graphics card) that produces a result that's unique to that device type.
In order for this to work, the spec requires that the operational details of
the device be kept confidential. Obviously anyone who knows enough about the workings of a device to operate it and to write a third-party driver for it (for example one for an open-source OS, or in general just any non-Windows OS) will also know enough to fake the HFS process. The only way to protect the HFS process therefore is to not release any technical details on the device beyond a minimum required for web site reviews and comparison with other products.
If the writer is correct, this might be one of the more insidious goals Microsoft hopes to achieve with its new OS. "Protected output devices" obviously means all audio and video interfaces, which will probably make the driver situation for these kinds of devices even worse than it is currently.
I must assume "Protected Output Devices" are something that the media industry has been pushing to prevent unauthorized duplication of copyrighted media…
It’s interesting how that fits into Microsoft’s needs so effectively.
Obviously anyone who knows enough about the workings of a device to operate it and to write a third-party driver for it (for example one for an open-source OS, or in general just any non-Windows OS) will also know enough to fake the HFS process. The only way to protect the HFS process therefore is to not release any technical details on the device beyond a minimum required for web site reviews and comparison with other products.
This isn’t obvious, it isn’t even correct.
Knowing how to operate something doesn’t mean you know how it works
Many false claims about surviving the destruction of the World Trade Center include descriptions of escaping from an elevator inspired by movie cliches. All these people had of course /operated/ an elevator, but they had little idea how it really worked. Real elevators aren’t like the movies, but these people described what they’d seen in movies not what’s really there.
Knowing how something works doesn’t mean you can imitate it
The technical manuals for modern (surface chip) credit cards and SecurID dongles are readily available (not all of the information is intended for public consumption, but that’s beside the point). With such manuals you can create a saleable product that works with the card or dongle as intended. Yet these manuals are hardly useful for cloning a card or dongle.
In order to render a textured triangle with the ATI 3D hardware in my laptop, I’d need to know how to upload textures and vertices, and how to program the shader units. I wouldn’t need to know what happens when the Windows Radeon driver sends undocumented opcode 0x76FE to the card, nor would I need to know which hardware approximation of the sine function is used in ATI cards. Those facts are irrelevant to the Free Software developers, but they could easily be used by HSF to check that the hardware is genuine.
Quote:
If the writer is correct, this might be one of the more insidious goals Microsoft hopes to achieve with its new OS. "Protected output devices" obviously means all audio and video interfaces, which will probably make the driver situation for these kinds of devices even worse than it is currently.
The writer doesn’t understand this technology at all, and seems to be writing based on their interpretation of other mis-informed rants they found on the Internet. HFS doesn’t make any difference to whether hardware suppliers will provide any documentation, assistance, or source code to Free Software projects. The promise of good out of box support, a supply contract for the XBox 360 or a cross-promotion deal is much more important to that relationship.
