Today I have officially published the PHC kernel for Ubuntu 10.10 Maverick Meerkat. The Linux PHC project provides cpufreq kernel modules for undervolting Intel and AMD processors on a Linux platforms. This gives you the ability to save energy, lower the CPU temperature and expand battery time.
Linux PHC usually doesn't need a custom kernel, as it only provides some additional kernel modules, which can be compiled out-of-tree. Unfortunately the Ubuntu kernel is that much optimized for fast booting so the default cpufreq kernel modules like acpi-cpufreq (used for Intel processors) and powernow-k8 (used for AMD processors) are compiled-in and can't be replaced by other kernel modules like Linux PHC ones. To workaround this problem I started to build special -phc kernels, which are prepared for use with Linux PHC. Strictly speaking they contain cpufreq modules like acpi-cpufreq and powernow-k8 in module form instead of compiled-in. Moreover to make it easier to install and receive updates for -phc kernels we provide a PPA on Launchpad.