Translations:Handbook:X86/Blocks/Kernel/2/en

Architecture specific kernel configuration

Make sure to select IA32 Emulation and 32-bit time_t if 32-bit programs should be supported (CONFIG_IA32_EMULATION and CONFIG_COMPAT_32BIT_TIME). Gentoo installs a multilib system (mixed 32-bit/64-bit computing) by default, so unless a no-multilib profile is used, these options are 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
Binary Emulations --->
   [*] IA32 Emulation
General architecture-dependent options  --->
   [*] Provide system calls for 32-bit time_t

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

KERNEL Enable support for UEFI

Processor type and features  --->
    [*] EFI runtime service support 
    [*]   EFI stub support
    [*]     EFI mixed-mode support
 
Device Drivers
    Graphics support  --->
        Frame buffer Devices  --->
            <*> Support for frame buffer devices  --->
                [*]   EFI-based Framebuffer Support

File Systems
    Pseudo filesystems  --->
        <*> EFI Variable filesystem

To enable the Kernel options for the use of SOF Firmware covered earlier:

KERNEL Enabling SOF Firmware support (CONFIG_SND_SOC_SOF_TOPLEVEL, CONFIG_SND_SOC_SOF_PCI, CONFIG_SND_SOC_SOF_ACPI, CONFIG_SND_SOC_SOF_AMD_TOPLEVEL, CONFIG_SND_SOC_SOF_INTEL_TOPLEVEL)

Device Drivers --->
  Sound card support --->
    Advanced Linux Sound Architecture --->
      <M> ALSA for SoC audio support --->
        [*] Sound Open Firmware Support --->
            <M> SOF PCI enumeration support
            <M> SOF ACPI enumeration support
            <M> SOF support for AMD audio DSPs
            [*] SOF support for Intel audio DSPs

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 command will copy the kernel image to /boot. If sys-kernel/installkernel is installed it will call /sbin/installkernel instead and delegate the kernel installation. Instead of simply copying the kernel to /boot, Installkernel installs each kernel with its version number in the file name. Additionally, installkernel provides a framework for automatically accomplishing various tasks relating to kernel installation, such as: generating an initramfs, building an Unified Kernel Image, and updating the bootloader configuration.