Genkernel

Genkernel is a tool for building a general-purpose modular Linux kernel for Gentoo Linux. Genkernel compiles the kernel with all available device drivers built as modules, then copies these to an init RAM disk that is passed to the kernel at boot time, providing automatic hardware detection. It is designed to allow users with little or no experience configuring a Linux kernel to easily set up a working kernel. Also, non-trivial hard disk setups like LVM over dm-crypt for full disk encryption make usage of an initrd inevitable; here genkernel saves tedious work, too.

The main reason for genkernel is the fact that you have to configure and build your own kernel during the installation of Gentoo, this can be a problem for new Linux users. Experienced Linux users generally prefer to configure and build their kernel manually, because genkernel tries to configure the kernel as safely as possible which causes the kernel to grow very large. However, one can choose to use a custom kernel configuration and use genkernel to compile it, and still benefit from other features such as the initrd builder.