You probably know intuitively that applications have limited powers in Intel x86 computers and that only operating system code can perform certain tasks, but do you know how this really works? This post takes a look at x86 privilege levels, the mechanism whereby the OS and CPU conspire to restrict what user-mode programs can do.

"Once upon a time, a Linux distribution would be installed with a /dev directory fully populated with device files. Most of them represented hardware which would never be present on the installed system, but they needed to be there just in case. Toward the end of this era, it was not uncommon to find systems with around 20,000 special files in /dev, and the number continued to grow. This scheme was unwieldy at best, and the growing number of hotpluggable devices (and devices in general) threatened to make the whole structure collapse under its own weight. Something, clearly, needed to be done." The solution came in the form of udev, and udev uses rules to determine how it should handle devices. This allows distributors to tweak how they want devices to be handled. "Or maybe not. Udev maintainer Kay Sievers has recently let it be known that he would like all distributors to be using the set of udev rules shipped with the program itself." ComputerWorld dives into the situation.

Last week, we reviewed the Aspire One, Acer's entry into the netbook market. The small but powerful device comes preloaded with either Linux or Windows XP, and we reviewed the Linux version. Even though most people will never need to go beyond the default Linpus Linux offering on the One, more advanced users will quickly hit the wall Acer set up: it has more or less completely locked down the Xfce 4.2.2 installation on the One. This bothered me - this is a powerful machine, so I want a powerful operating system. I went for Ubuntu 8.04.1 - read on for a few thoughts on how well GNOME's user interface fares on a small-screen device such as the One.

As an experiment, Kaj de Vos ported the recently released Genode OS framework to Syllable Server. It does not run on Syllable Desktop yet, as this requires some more deep porting work to the Syllable kernel. Genode is a modular operating system framework with several components that are largely complementary to Syllable. The Syllable project wants to explore the opportunities to integrate these into Syllable.

Intel unveiled a power gate feature incorporating a "turbo" mode for its upcoming Nehalem family of processors. With the turbo mode, in a situation where not all the cores are necessary for a particular workload, the ones that are idle will be turned off and power is channeled to the cores that are active, making them more efficient. Intel also showcased the Nehalem-EX for the expandable server market, which consists of eight-core processors on a single die.

How does OpenSolaris, Sun's effort to free its big-iron OS, fare from a Linux user's point of view? Is it merely a passable curiosity right now, or is it truly worth installing? Linux Format takes OpenSolaris for a test drive, examining the similarities and differences to a typical Linux distro.