How Linux Works

Configuring and Compiling the Kernel

You need to configure the options that you want to have in your kernel before you build it. Your goal is to have an appropriate .config file in your kernel source distribution. Here's an excerpt of a typical .config file:

# CONFIG_HIGHMEM64G is not set
# CONFIG_MATH_EMULATION is not set
CONFIG_MTRR=y
CONFIG_HAVE_DEC_LOCK=y

This file isn't easy to write with a text editor, so there are several configuration utilities that generate the file for you. An easy, standard way to set up a kernel is to run this command:

make menuconfig

After some initial setup, make menuconfig runs a text-based menu interface that is shown in Figure 10-1. The box in the center of the screen contains the options at the current configuration ...