Home opinion-and-analysis Open Sauce Windows 8 will lock out GNU/Linux on ARM devices

Author's Opinion

The views in this column are those of the author and do not necessarily reflect the views of iTWire.

Have your say and comment below.

Get all your tech news delivered to your mail box five days a week
iTWire UPDATE - it's FREE!


Microsoft has made it clear that it will use the secure boot feature available with Windows 8 to lock out other operating systems from ARM devices which are running this version of its operating system.


The specifications in the company's Windows Hardware Certification Requirements make this clear, according to tech blogger Glynn Moody.

The issue of secure boot on Windows 8 was raised in September when Linux developer Matthew Garrett pointed out that this feature, implemented as per the Unified Extensible Firmware Interface guidelines, could be used to ensure that only Microsoft operating systems were loadable on a given device.

The system firmware can contain one or more signed keys and any executable that is not signed by these keys cannot boot on said system. Another set of keys - called Pkek - allows for communication between the operating system and the firmware.

An operating system with matching Pkek keys can add more keys to a whitelist - or a blacklist. In the latter case, any executable which has a key on the blacklist will not boot.

The Linux Foundation later provided a list of ways in which this could be bypassed, provided hardware vendors cooperated.

The Windows Hardware Certification Requirements (PDF) say, on Page 116:

20. MANDATORY: On non-ARM systems, the platform MUST implement the ability for a physically present user to select between two Secure Boot modes in firmware setup: "Custom" and "Standard". Custom Mode allows for more flexibility as specified in the following:

a) It shall be possible for a physically present user to use the Custom Mode firmware setup option to modify the contents of the Secure Boot signature databases and the PK.

b) If the user ends up deleting the PK then, upon exiting the Custom Mode firmware setup, the system will be operating in Setup Mode with Secure Boot turned off.

c) The firmware setup shall indicate if Secure Boot is turned on, and if it is operated in Standard or Custom Mode. The firmware setup must provide an option to return from Custom to Standard Mode which restores the factory defaults.

On an ARM system, it is forbidden to enable Custom Mode. Only Standard Mode may be enable (sic).

ITWIRE SERIES - REVENUE-CRITICAL APPS UNDERPERFORMING?

Avoid War Room Scenarios and improve handling of critical application problems:

• Track all transactions, end-to-end, all the time and know what your users experience 24/7

• View code level details with context and repair problems quickly

• Fix problems in minutes before they wreak havoc

• Optimize your most important applications, Java, .NET, PHP, C/C++ and many more

Start your free trial today!

CLICK FOR FREE TRIAL!

ITWIRE SERIES - IS YOUR BACKUP STRATEGY COSTING YOU CLIENTS?

Where are your clients backing up to right now?

Is your DR strategy as advanced as the rest of your service portfolio?

What areas of your business could be improved if you outsourced your backups to a trusted source?

Read the industry whitepaper and discover where to turn to for managed backup

FIND OUT MORE!

Sam Varghese

website statistics

A professional journalist with decades of experience, Sam for nine years used DOS and then Windows, which led him to start experimenting with GNU/Linux in 1998. Since then he has written widely about the use of both free and open source software, and the people behind the code. His personal blog is titled Irregular Expression.

Connect