Handbook:Parts/Installation/Kernel/ko

소스 코드 설치
주변에 빌드한 모든 배포판의 핵심은 리눅스 커널입니다. 이는 사용자 프로그램과 여러분의 시스템 하드웨어 사이에 있는 계층입니다. 젠투는 사용자에게 최대한 다양한 커널 소스코드를 제공합니다. 설명을 포함한 전체 목록은 커널 개요 페이지에 있습니다.

-기반 시스템에서 젠투는 꾸러미를 추천합니다.

적당한 커널 소스를 선택하고 로 설치하십시오:

를 들여다보면 설치한 커널 소스를 가리키는 심볼릭 링크를 볼 수 있습니다:

이제 커널 소스를 설정하고 컴파일 할 차례입니다. 두가지 방식으로 접근할 수 있습니다:
 * 1) 직접 설정하고 빌드하는 방법, 또는
 * 2)   도구를 사용하여 자동으로 리눅스 커널을 빌드하고 설치하는 방법

환경을 최적화하는 기본적인 선택이자 최상의 방법인 직접 설정 방법을 설명하도록 하겠습니다.

도입부
커널을 직접 설정하는 방법은 리눅스 사용자가 해본 일중에 가장 어려운 과정으로 보입니다. 아니라고 하는것도 조금은 맞습니다 -- 커널을 여러번 설정해본 사람중에는 이게 어려웠는지 기억하는 사람이 없습니다.

그러나 맞는 이야기이기도 합니다. 커널을 직접 설정했을 때 시스템을 아는 것이 현실적입니다. 대부분의 정보는  명령이 들어있는 를 이머지하여 수집할 수 있습니다:

Another source of system information is to run  to see what kernel modules the installation CD uses as it might provide a nice hint on what to enable.

Now go to the kernel source directory and execute. This will fire up menu-driven configuration screen.

The Linux kernel configuration has many, many sections. Let's first list some options that must be activated (otherwise Gentoo will not function, or not function properly without additional tweaks). We also have a Gentoo kernel configuration guide on the Gentoo wiki that might help out further.

필수 옵션 활성화
Make sure that every driver that is vital to the booting of the system (such as SCSI controller, ...) is compiled in the kernel and not as a module, otherwise the system will not be able to boot completely.

Next select the exact processor type. It is also recommended to enable MCE features (if available) so that users are able to be notified of any hardware problems. On some architectures (such as x86_64), these errors are not printed to dmesg, but to. This requires the package.

Also select Maintain a devtmpfs file system to mount at /dev so that critical device files are already available early in the boot process.

Now go to File Systems and select support for the filesystems you use. Don't compile the file system that is used for the root filesystem as module, otherwise the Gentoo system will not be able to mount the partition. Also select Virtual memory and /proc file system.

If PPPoE is used to connect to the Internet, or a dial-up modem is used, then enable the following options:

The two compression options won't harm but are not definitely needed, neither does the PPP over Ethernet option, that might only be used by ppp when configured to do kernel mode PPPoE.

Don't forget to include support in the kernel for the network (Ethernet or wireless) cards.

Most systems also have multiple cores at their disposal, so it is important to activate Symmetric multi-processing support:

If USB input devices (like keyboard or mouse) are used don't forget to enable those as well:

선택: initramfs 빌드
In certain cases it is necessary to build an initramfs - an initial ram-based file system. The most common reason is when important file system locations (like or ) are on separate partitions. With an initramfs, these partitions can be mounted using the tools available inside the initramfs.

Without an initramfs, there is a huge risk that the system will not boot up properly as the tools that are responsible for mounting the file systems need information that resides on those file systems. An initramfs will pull in the necessary files into an archive which is used right after the kernel boots, but before the control is handed over to the init tool. Scripts on the initramfs will then make sure that the partitions are properly mounted before the system continues booting.

To install an initramfs, install first, then have it generate an initramfs:

In order to enable specific support in the initramfs, such as lvm or raid, add in the appropriate options to. See  for more information. In the next example we enables support for LVM and software raid (mdadm):

The initramfs will be stored in. The resulting file can be found by simply listing the files starting with initramfs:

Now continue with Kernel modules.

대안: genkernel 사용
If a manual configuration looks too daunting, then using  is recommended. It will configure and build the kernel automatically.

works by configuring a kernel nearly identically to the way the installation CD kernel is configured. This means that when  is used to build the kernel, the system will generally detect all  hardware at boot-time, just like the installation CD does. Because  doesn't require any manual kernel configuration, it is an ideal solution for those users who may not be comfortable compiling their own kernels.

Now, let's see how to use genkernel. First, emerge the ebuild:

Next, edit the file so that the line containing  as second field has the first field pointing to the right device. If the partitioning example from the handbook is followed, then this device is most likely with the ext2 file system. This would make the entry in the file look like so:

Now, compile the kernel sources by running. Be aware though, as  compiles a kernel that supports almost all hardware, this compilation will take quite a while to finish!

Once genkernel completes, a kernel, full set of modules and initial ram disk (initramfs) will be created. We will use the kernel and initrd when configuring a boot loader later in this document. Write down the names of the kernel and initrd as this information is used when the boot loader configuration file is edited. The initrd will be started immediately after booting to perform hardware autodetection (just like on the installation CD) before the "real" system starts up.

모듈 설정
List the modules that need to be loaded automatically in. Extra options can be added to the modules too if necessary.

To view all available modules, run the following  command. Don't forget to substitute " " with the version of the kernel just compiled:

For instance, to automatically load the module (which is the driver for a specific 3Com network card family), edit the  file and enter the module name in it.

Continue the installation with Configuring the system.

선택: 펌웨어 설치
Some drivers require additional firmware to be installed on the system before they work. This is often the case for network interfaces, especially wireless network interfaces. Most of the firmware is packaged in :