Original URL: http://www.theregister.co.uk/2013/06/03/arm_bakes_in_drm_throws_out_handful_of_chips/

Relax, Hollywood, ARM's got your back: New chip 'thwarts' video pirates

Phone GPU shields 1080p footage 'from download to display'

By Bill Ray

Posted in Phones, 3rd June 2013 10:46 GMT

ARM today touted the Mali-V500, its new graphics processing unit for gadgets, which apparently can protect 1080p video from pirates.

The British design biz said the V500 can decode high-definition video without giving the operating system, nor the applications running above it, the chance to copy the footage in transit: in other words, while playing back Hollywood's blockbusters and broadcasters' expensive sitcoms, the images can't be intercepted and siphoned off by copyright pirates - "from download to display".

That capability is built on ARM's TrustZone: a secure execution technology that allows hardware designers to temporarily shift the processor from running general-purpose software to a special ring-fenced area of trusted code that performs sensitive operations - this is software that may not even trust the OS running on the gadget.

So, code in the TrustZone can, for example, boot an authorised operating system on a device - or demand exclusive access to the keyboard thus preventing memory-resident malware sniffing PINs or passwords. The V500 takes that feature further by commandeering the screen to show decoded video that can't be copied - or at least that's the plan.

That requires the V500 to do all the video decoding, which is fine as a single-core version can decrypt and decode 1080 lines of material at 60 frames per second; plonk an eight-core version onto your silicon and 4k comes into reach at 120fps, should one feel such a resolution to be necessary.

The new GPU was announced alongside the Mali-T200 OpenGL ES 3.0-compliant graphics unit for mid-range handhelds, and the Cortex-A12 processor core.

The Cortex-A12 is an evolution of the Cortex-A9, offering more processing for less power and access to ARM's big.LITTLE technology for mid-range devices - big.LITTLE places a low-power core next to a beefier cousin with the latter lying dormant until it's kicked into life to crunch some processor-intensive work, an arrangement that's supposed to stop batteries burning out.

ARM is well aware that while the high-end devices get all the headlines and low-end embedded stuff is fun, the middle is bulging and the new chips are intended to maintain its near-monopoly in that field.

ARM only designs the chips; it's up to its technology licensees how they build the actual chips in your gadgets, and that will depend on where they're to be used - whether they're in TVs, mobile phones, wrist watches, washing machines, etc. A modern smartphone will have more than half a dozen ARM-compatible cores spread though out its chippery, of which the main processor is only one (or two, or eight, depending on the device).

So these new designs, and baked-in copy-protection (aka DRM), are still some way from store shelves; the A12 as much as a year, it's understood.

Even when they arrive they won't make copying films impossible, just harder than it is today. Unbreakable or even tough DRM prevents sales and drives people to file-sharing networks in search of the goods; the trick is to make buying content easier than copying it, which is what ARM is hoping to facilitate with the Mali, but how exactly it works will be up to the manufacturers who use it. ®

Bootnote

For more background information on the TrustZone tech, you can either read through ARM's extensive documentation - or see how this chap apparently exploited a simple bug and compromised a TrustZone kernel on a Motorola device to unlock its bootloader. Easy when you know how.