Handbook:AMD64/Blocks/Kernel

Architecture specific kernel configuration

Make sure to select IA32 Emulation if 32-bit programs should be supported (CONFIG_IA32_EMULATION). Gentoo installs a multilib system (mixed 32-bit/64-bit computing) by default, so unless a no-multilib profile is used, this option is required.

KERNEL Selecting processor types and features

Processor type and features  --->
   [ ] Machine Check / overheating reporting 
   [ ]   Intel MCE Features
   [ ]   AMD MCE Features
   Processor family (AMD-Opteron/Athlon64)  --->
      ( ) Opteron/Athlon64/Hammer/K8
      ( ) Intel P4 / older Netburst based Xeon
      ( ) Core 2/newer Xeon
      ( ) Intel Atom
      ( ) Generic-x86-64
Executable file formats / Emulations  --->
   [*] IA32 Emulation

Enable GPT partition label support if that was used previously when partitioning the disk (CONFIG_PARTITION_ADVANCED and CONFIG_EFI_PARTITION):

KERNEL Enable support for GPT

-*- Enable the block layer --->
   Partition Types --->
      [*] Advanced partition selection
      [*] EFI GUID Partition support

Enable EFI stub support and EFI variables in the Linux kernel if UEFI is used to boot the system (CONFIG_EFI, CONFIG_EFI_STUB, CONFIG_EFI_MIXED, and CONFIG_EFI_VARS):

KERNEL Enable support for UEFI

Processor type and features  --->
    [*] EFI runtime service support 
    [*]   EFI stub support
    [*]     EFI mixed-mode support
 
Firmware Drivers  --->
    EFI (Extensible Firmware Interface) Support  --->
        <*> EFI Variable Support via sysfs

Compiling and installing

With the configuration now done, it is time to compile and install the kernel. Exit the configuration and start the compilation process:

root #make && make modules_install

Note
It is possible to enable parallel builds using make -jX with X being an integer number of parallel tasks that the build process is allowed to launch. This is similar to the instructions about /etc/portage/make.conf earlier, with the MAKEOPTS variable.

When the kernel has finished compiling, copy the kernel image to /boot/. This is handled by the make install command:

root #make install

This will copy the kernel image into /boot/ together with the System.map file and the kernel configuration file.