I been listening to the SecurityNow! podcast raving about the coolness of the Yubikey, created by Swedish startup Yubico. It seems like the device has captured the imagination of quite a few people, and I have been kind of curious about it. So I was quite pleasantly surprised when I got one a few days ago, since we are testing it as a new way to authenticate to our VPN at work.
Monthly Archives: February 2009
Unknown to most, IBM has one of the world’s longest records of using virtual platforms for software and firmware development and verification. This project has been ongoing since at least the days of the zSeries 900 machines, through z990, z9, and now z10. An excellent article on this virtual platform and its uses is found in the IBM Journal of Research and Development, number 1, 2009, . It is called “IBM System z10 Firmware Simulation”, by Körner et al.
A common question from simulation users to us simulation providers is “can I simulate a machine with N cores”, where N is “large”. As if running lots of cores was a simulation system or even a hardware problem. In almost all cases, the problem is with software. Creating an arbitrary configuration in a virtual platform is easy. Creating a software stack for that arbitrary platform is a lot harder, since an SMP software stack needs to understand about the cores and how they communicate.
Essentially, what you need is a hardware design that has addressing room for lots of cores, and a software stack that is capable of using lots of cores — even if such configurations do not exist in hardware. Unfortunately, since software is normally written to run on real existing machines, there tends to be unexpected limitations even where scalability should be feasible “in principle”.
Here is the story of how I convinced Linux to handle more than two cores in a virtual MPC8641D machine.