Tuesday, April 6, 2010

Getting Linux for Your Board

After looking at the Linux distribution included with a board or sold by the board vendor, it may make sense to start your project with a Linux distribution created by an open source project or from a commercial vendor. Commercial vendors offer deep support for certain use cases (like graphics on consumer electronics devices or Linux certified for use in telecommunications), and open source projects also focus on certain uses cases along the same lines.

Before you build a Linux distribution from scratch (that’s the next chapter—skip ahead if you’re so inclined), it makes sense to see what’s available elsewhere. As Linux has become more common, many projects have sprung into existence to build Linux in one form or another. This chapter looks at build systems that you can use to create an embedded Linux distribution and the offerings of commercial vendors that supply ready-to-use Linux distributions with training and support.

Although Linux is an open source project and the source code is generally available, having somebody else handle the engineering details particular to the selected board make sense because it relieves your schedule of some tasks in exchange for money. Even very technically adept engineers choose to make this trade-off, because frequently time is more valuable than the amount of money required to get a completed Linux platform in the can. Toward that end, this chapter examines the commercial alternatives for Linux so that if you’re interested in purchasing, you can approach the transaction as an informed customer. Some commercial embedded products track closely to what’s available in open source, whereas others are quite different. For projects that have strict requirements around hardware or software support, the commercial product meeting the requirements is the best choice.

You can obtain a Linux distribution three primary ways:

• From company that sold the board: There’s a feeling of confidence when you purchase from a board vendor. Chances are overwhelming in favor of the Linux distribution working for the board in question. The cost is usually much less than it would be from a commercial vendor. On the downside, many hardware companies aren’t in the software business and don’t have the expertise or motivation to support a software product.

• Via an open source distribution build: Several open source projects exist to build Linux. The software necessary to build something as complex as a Linux isn’t a simple undertaking. Because these projects are open source, the processor support is usually narrow; and the likelihood that the build will work for a specific board (that is, your board) is dicey. Plus, you must overcome a learning curve to use the distribution building software, on top of any learning curve involved in building the software.

• From a commercial vendor: A variety of companies offer Linux products and services. These companies do much the same job as the first two alternatives but offer support and mean less risk than trying to build on your own. In addition, these companies offer Linux features like graphics, quick boot-up, and realtime, which the board vendor may not. The support offered by a commercial vendor is also usually more attentive and focused that that available via open source.

Source of Information : Pro Linux Embedded Systems

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