all the powerfull eye-candy apps. But that takes processing power. So SoC provider would separate processing on two cores, puting stack on the other core. Since this other core do not demand any application except PS, you would like to run some nice lightweight OS like eCos, or similar that have good RT performances to assure timing requirements for L1 and inter-CPU communication. If there would be satisfying performance on one core, there would certanly be interest to save money by rejecting the other. And to figure out how to separate closed source, how to keep legacy RTOS and RT apps, etc... And since more powerful cores are appearing, L4 comes into play on big doors (not to mention that it's the worlds first formally verified kernel). BR, Drasko