Kings Langley, UK The first Linux port to a multi-threaded processor architecture has been carried out by the Metagence division of Imagination Technologies for its META RISC/DSP processor family.
META is a licensable multi-threaded programmable general-purpose processor/DSP intellectual property (IP) core that allows real-time response while supporting efficient multi-function operation.
The family provide general purpose processing, complex DSP and multimedia capabilities, real-time operation and reduced power consumption. The processors are being used in a number of consumer products including digital radio and digital TV.
Ian Oliver, vice-president of development systems/tools, at Metagence, said, “Porting Linux to META was an excellent way to ensure the effectiveness of both the processor architecture and the CodeScape tool chain. Only a handful of processors in history have proved themselves capable of running Linux. To make things really interesting we skipped µClinux, which is a cut down Linux for micro-controllers, and went straight for kernel 2.4.18 with full virtual memory so we could demonstrate the effectiveness of the cache and MMU on the META core. This port now enables META partners to benefit from the wealth of drivers and applications available to run under Linux.”
Metagence says there have been problems running Linux on DSP as most lack either the general purpose computing capability required and/or a good cache and MMU. Systems developers have tended to use multi-core solutions.
META can run Linux on one hardware thread while running real-time DSP tasks on the other threads. Which says Metagence means it can also re-allocate MIPS on the fly so that each thread can be delivered the guaranteed share of processing resource and response time that it needs, while never clocking the processor faster than is required.
As everything is on one core, synchronisation and communication between the tasks is supported within the processor architecture in the instruction set, which makes it more efficient to implement.
Through Imagination's Ensigma division, Metagence has access to libraries of proprietary DSP code covering areas such as audio codecs and effects, video codecs, DAB digital radio, digital TV, speech processing and additional radio baseband processing.