Datasheet

VIPER / VIPER-Lite Embedded Linux Development Kit Quickstart Software configuration

Software configuration

If you are using a VIPER-Lite you need to carry out some additional configuration. This

primarily involves informing the Linux kernel of the reduced CPU speed.

The VIPER-Lite is a reduced power VIPER derivative based around the 200MHz

PXA255 processor. You can inform the Linux kernel of the reduced maximum CPU

speed by adding the following to the default kernel command line:

"cpu_pxa25x.max_frequency=199065"

For more information, see Default command line

on page 20.

This limits the available CPU frequencies to 200MHz. For a discussion of CPU clock

frequency scaling, see page 22

The VIPER-Lite Flash image available in the /images/ folder on the

Development Kit CD and the image loaded onto the board by default

already contains the modified kernel command line.

Using software images for a VIPER on a VIPER-Lite causes a 200MHz

processor to run at 400MHz, which may damage your board permanently.