[personal profile] mjg59
Since there are probably going to be some questions about this in the near future:

The UEFI secure boot protocol is part of recent UEFI specification releases. It permits one or more signing keys to be installed into a system firmware. Once enabled, secure boot prevents executables or drivers from being loaded unless they're signed by one of these keys. Another set of keys (Pkek) permits communication between an OS and the firmware. An OS with a Pkek matching that installed in the firmware may add additional keys to the whitelist. Alternatively, it may add keys to a blacklist. Binaries signed with a blacklisted key will not load.

There is no centralised signing authority for these UEFI keys. If a vendor key is installed on a machine, the only way to get code signed with that key is to get the vendor to perform the signing. A machine may have several keys installed, but if you are unable to get any of them to sign your binary then it won't be installable.

This impacts both software and hardware vendors. An OS vendor cannot boot their software on a system unless it's signed with a key that's included in the system firmware. A hardware vendor cannot run their hardware inside the EFI environment unless their drivers are signed with a key that's included in the system firmware. If you install a new graphics card that either has unsigned drivers, or drivers that are signed with a key that's not in your system firmware, you'll get no graphics support in the firmware.

Microsoft requires that machines conforming to the Windows 8 logo program and running a client version of Windows 8 ship with secure boot enabled. The two alternatives here are for Windows to be signed with a Microsoft key and for the public part of that key to be included with all systems, or alternatively for each OEM to include their own key and sign the pre-installed versions of Windows. The second approach would make it impossible to run boxed copies of Windows on Windows logo hardware, and also impossible to install new versions of Windows unless your OEM provided a new signed copy. The former seems more likely.

A system that ships with only OEM and Microsoft keys will not boot a generic copy of Linux.

Now, obviously, we could provide signed versions of Linux. This poses several problems. Firstly, we'd need a non-GPL bootloader. Grub 2 is released under the GPLv3, which explicitly requires that we provide the signing keys. Grub is under GPLv2 which lacks the explicit requirement for keys, but it could be argued that the requirement for the scripts used to control compilation includes that. It's a grey area, and exploiting it would be a pretty good show of bad faith. Secondly, in the near future the design of the kernel will mean that the kernel itself is part of the bootloader. This means that kernels will also have to be signed. Making it impossible for users or developers to build their own kernels is not practical. Finally, if we self-sign, it's still necessary to get our keys included by ever OEM.

There's no indication that Microsoft will prevent vendors from providing firmware support for disabling this feature and running unsigned code. However, experience indicates that many firmware vendors and OEMs are interested in providing only the minimum of firmware functionality required for their market. It's almost certainly the case that some systems will ship with the option of disabling this. Equally, it's almost certainly the case that some systems won't.

It's probably not worth panicking yet. But it is worth being concerned.
From: (Anonymous)
"... it may actually be more productive to buy Windows laptops and then return them if/when you find that they don't meet your requirements--because processing returns actually costs the vendor something."

Most OEM's already charge you a re-stocking fee if you return a computer.
From: (Anonymous)
Make it clear in the order that you expect linux support, if it arrives without it, it's false advertising. A good credit card will void the restock fee AND yell at the seller for it.
From: [identity profile] http://identi.ca/rozzin
"Most OEM's already charge you a re-stocking fee if you return a computer."

It looks like some big vendors, like Best Buy, don't. Coincidentally, these big vendors are also the ones with the most power to affect manufacturers.

I don't know whether Best Buy eats the cost of returns, or if they use whatever clout they have to make the OEMs eat the cost. It probably doesn't matter though, does it? If Best Buy bears the cost of a certain brand being returned more often, then Best Buy has an incentive to replace that brand with one with a better return-rate--and the OEM has an incentive to fix their problems so that Best Buy doesn't stop stocking/selling them. If Best Buy gets the OEMs to eat the cost of returns, then the OEMs have a more direct incentive to figure out how to reduce their return-rates. Best Buy apparently gathers data on why people return things, also.

So..., other reasons why return-rates shouldn't be expected to influence the market?


Matthew Garrett

About Matthew

Power management, mobile and firmware developer on Linux. Security developer at Nebula. Member of the Linux Foundation Technical Advisory Board. Ex-biologist. @mjg59 on Twitter. Content here should not be interpreted as the opinion of my employer.

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