Introduction

-1.1.2.3 -2005-06-26 +1.2 +2005-07-24 Introduction

-Introduction +Rationale

-Genkernel is designed to allow users who are not previously used to -compiling a kernel to use a similar setup to that one that is used on -the Gentoo Installation CDs which auto-detects your hardware. -

- -

-Some users may also be interested in using genkernel for hardware -which requires initialization and a working kernel before it can be -booted. Because genkernel also automatically compiles your kernel modules, -thus allowing hardware which needs to be loaded with module parameters -to be used. +For users who are not privy to kernel compilation, genkernel is a tool to +automate this process. It can help you create a kernel image akin to those +available on Gentoo Installation CDs, which are designed to auto-detect the +hardware configuration of your system. Some users may also be interested in +using genkernel for hardware requiring initialization and a working kernel +before the system starts up. Since genkernel automatically compiles your kernel +modules, you can use hardware that may require certain module parameters to be +loaded for proper operation.

-Is genkernel for me? +Target Audience

-Genkernel is often a good choice to those who are unused to compiling -their own kernel or those who are not certain about their hardware -configurations. -

- -

-Because genkernel is designed to use a generic configuration, it -should be able to support all of your hardware - however, because all -the drivers and modules have to be compiled as well, compiling a -kernel by yourself is often much faster provided you know what you need. +If you are either uncertain about how to compile a kernel, or are just +unfamiliar with your hardware configuration, genkernel is a very handy tool. +It is designed to take the pain out of the kernel compiling process, and +supports most hardware by default.

-Genkernel does not however, currently support booting the sytem from -LVM2/EVMS2 partitions. Users are recommended to use a manually compiled -kernel for the time being. +However, if you know what drivers are required by your system, you may be able +to further reduce the time taken to compile the kernel. This is possible since +you can direct genkernel to only build drivers relevant to your hardware. +Oftentimes, the number of drivers required by your system will be fewer +(implying a shorter kernel compilation time) than the default configuration +provides.

-Getting genkernel +Installing genkernel

-You can obtain genkernel by simply running emerge genkernel. Don't -forget to use the -k flag for emerge if you are using binary packages, -i.e. GRP. Due to the GRP packages having an older version of genkernel, the -flags are different. As a result, you should consult the -Gentoo Handbook and genkernel --help. +To obtain genkernel, run emerge genkernel from the command line. If you +are using the + +Gentoo Reference Platform (GRP), remember to install binary packages by +passing the -k flag to emerge. Since the GRP is bundled with an older +version of genkernel, the flags may be different. In any case, consult +genkernel --help for help on how to use the version of genkernel +installed on your system.

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+ + + +Working with genkernel

-Supported platforms +How to use genkernel

-As of genkernel 3.0.2, the following platforms should be -supported: alpha, amd64, parisc, parisc64, ppc, ppc64, sparc, sparc64, and x86. +Although there are several ways to run genkernel, the least-intrusive approach +is provided by genkernel all. Here, a generic configuration which works +well for most systems is used. As was mentioned earlier, this approach is not +without drawbacks; most of the modules created are useless to the average user +and may increase compile time. Below is an illustration of a more efficient +approach, achieved by passing certain flags to genkernel as root:

- -

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+# genkernel --bootsplash --no-install --no-clean --menuconfig all
+

- -Genkernel usage -

-Introduction - +

+The above operation causes genkernel to create a bootsplash-enabled kernel +(--bootsplash) that will have to be manually installed +(--no-install). While preparing the kernel source tree, genkernel will +refrain from cleaning out any preexisting object files present in the source +tree (--no-clean). A menu-driven kernel configuration utility will be +displayed that allows the user to select which modules will be built for the +system (--menuconfig). +

-Genkernel is designed to work in three modes: +There are other flags which alter the result provided by genkernel. For +instance, replacing --no install with the --install flag allows +genkernel to automatically install the new kernel in the /boot +directory. Using the --mountboot flag allows genkernel to mount your +/boot partition automatically, if necessary.

"all" mode: this builds the kernel and the initrd
"kernel" mode: this only builds the kernel image
"initrd" mode: this only builds the initrd

+Remember, genkernel is designed to make kernel compilation easy and +stress-free. For this reason, genkernel features several flags to ease the +kernel compilation effort. For example, there are flags to help with kernel +configuration, while others affect the actual compilation. Some flags even help +debug the compilation process. For those interested in further optimization, +there are flags that affect kernel assembling, packaging and even kernel -- gentoo-doc-cvs@gentoo.org mailing list