General Kernel Configuration

This page helps with the configuration of the Linux kernel. Remember, configuring the kernel is easy - you just have to know which hardware you have quite well.

General Information

The kernel sources are unpacked in /usr/src (at least on Gentoo).

• Once you are in the kernel source directory, use the following command to configure graphically your kernel:

make menuconfig

• When migrating to a new kernel, copy your old .config file from the old kernel directory to the new one and type:

make oldconfig

Hardware Detection

• There is a nice link at the Gentoo wiki.

• Basically, emerge pciutils lshw usbutils, which gives you lspci, lshw, and lsusb.

Choice of the scheduler

• There is an I/O scheduler in the section Block Layer. This is different from the CPU scheduler. The SD scheduler is a *CPU* scheduler.
• In vanilla-sources, apparently there is no choice for the CPU scheduler. Same is true for ck-sources (where SD scheduler is mandatory).

Real Time Clock (RTC) support

• With recent kernels (2.6.25+), there are two areas for this configuration.
  • Device Drivers -> Character Devices
  • Device Drivers -> Real Time Clock

• If Gentoo hangs when starting (when running the clock init script) and you are using the support in Character Devices, change it to use the one in Real Time Clock (which I guess is newer and better).