Thursday, April 1, 2010

Most Boards Include a Linux Distribution

Unless the selected processor doesn’t have the capability to run Linux, it ships with a Linux distribution in the box or one is available. (Early on in the embedded Linux lifeline, this wasn’t true, and getting Linux for a board involved a Quixotic search or custom engineering.) This principle holds true for COTS boards and prototyping boards for custom hardware. Linux vendors typically vie for information about their product to be included in the packing material for the board, in hopes it will boost sales or interest in their product.

The key is understanding what is packaged for the board. Some board vendors treat their Linux distribution as a check-off requirement, which is marketing speak for something that’s good enough to claim support but not adequate for project development. Other board vendors put a great deal of effort into delivering a Linux distribution that’s ready for development

Linux Distribution Inventory
Sources must be supplied. Sometimes patches are included as well. Make sure you locate all of them and that the patches work.

GCC cross-compiler
Some kernels and root file system components require a certain version of GCC. Understand the requirements necessary to build the kernel and root file system.

C library
The kernel doesn’t require a C library, but the supporting programs, like the configuration system, do. Kernel building has few constraints; for packages in the root file system, anything is possible; but usually there are no special requirements.

Supported devices
Check out what’s on the board.

Supported file systems
Are any of these useful for the project? A file system not supported in the kernel doesn’t mean it’s unavailable, just that it isn’t in this build of the kernel.

Root file system format
How has the root file system been formatted?

Root file system contents
Are sources available? What packages have been supplied?

Source of Information : Pro Linux Embedded Systems

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