Custom DSDT in Kernel. . .
1. |
Background |
The Packard-Bell Dot-M/A (aka Gateway LT3103) is a fine 11.6 inch netbook. But, for reasons on which I can only speculate, the DSDT (Differentiated System Description Table) provided by the BIOS does not include the P-states (performance states) for the Athlon L110 CPU. So AMD's PowerNow! CPU-scaling wizardry does not work with out-of-the-box Ubuntu (or other distro, I suspect). The solution: add a "proper" DSDT to the kernel.
Fixed Kernels for Karmic
AutoStatic kindly provides fixed kernels for Karmic:
- advertised at The Ubuntu Forum Community;
- downloadable from his Web site.
But what about Lucid? And new kernels when they come out?
Adding a Custom DSDT into a Kernel
The process is described:
- more or less completely in a thread on The Ubuntu Forums;
- and the precise Kernel config required is described at the Gentoo Wiki.
2. |
Getting the DSDT |
The required DSDT can be downloaded from Autostatic's Web site.
3. |
Building the New Kernel |
The standard kernel compilation procedure for Ubuntu and Debian is described in the Official Ubuntu Documentation:
- I used the Debian procedure rather than that for Ubuntu.
- Use the .config from the Lucid distro kernel, so only DSDT-related config changes required.
- After make menuconfig, added the DSDT downloaded from AutoStatic by following the Gentoo Wiki instructions mentioned above.
- After installing the .deb packages for the kernel produced,
/usr/share/doc/kernel-package/examples/etc/kernel/postinst.d/initramfs 2.6.32.11+drm33.2-simonhwhich is only half-mentioned in the Official Ubuntu Documentation, to build the initrd. - Then fixed-up the /boot/grub/grub.cfg with required references to said initrd.
4. |
Download The Kernel Packages |