Kernel mode setting
This article or section needs expansion. Kernel Mode Setting KMS is a method for setting display resolution and depth in the kernel space rather than user space. The Linux kernel's implementation of KMS enables native resolution in the framebuffer and allows for instant console tty switching.
KMS also enables newer technologies such as DRI2 which will help reduce artifacts and increase 3D performance, even kernel space power-saving. Previously, setting up the video card was the job of the X server. Because of this, it was not easily possible to have fancy graphics in virtual consoles. This makes fancy graphics during bootup, virtual console and X fast switching possible, among other things. KMS is typically initialized after the initramfs stage.
However it is possible to already enable KMS during the initramfs stage. If you are using a custom EDID file not applicable for the built-in resolutionsyou should embed it into initramfs as well:. Then regenerate the initramfs. See Linux console Fonts for how to change your console font to a large font. The Terminus font terminus-font is available in many sizes, such as tern which is larger. Alternatively, disabling modesetting might switch to lower resolution and make fonts appear larger.
Polling for connected display devices on older systems can be quite expensive. Poll will happen periodically and can in worst cases take several hundred milliseconds, depending on the hardware. This will cause visible stalls, for example in video playback. These stalls might happen even when your video is on HDP output but you have other non HDP outputs in your hw configuration.
If you experience stalls in display output occurring every 10 seconds, disabling polling might help. If you see an error code of 0x 2 while booting up, you will get about 10 lines of text, the last part denoting that error codeuse:.
If your native resolution is not automatically configured or no display at all is detected, then your monitor might send none or just a skewed EDID file. The kernel will try to catch this case and will set one of the most typical resolutions. In case you have the EDID file for your monitor you merely need to explicitly enforce it see below. However most often one does not have direct access to a sane file and it is necessary to either extract an existing one and fix it or to generate a new one.
Other solutions are outlined in details in this article. Extracting an existing one is in most cases easier, e. After having prepared your EDID place it in a folder, e. To load it at boot, specify the following in the kernel command line :. For the built-in resolutions, refer to the table below.
The Name column specifies the name which one is supposed to use in order to enforce its usage. From the nouveau wiki :.
You may want to disable KMS for various reasons, such as getting a blank screen or a "no signal" error from the display, when using the Catalyst driver, etc. To disable KMS add nomodeset as a kernel parameter. See Kernel parameters for more info. Along with nomodeset kernel parameter, for Intel graphics card you need to add i For Nvidia Optimus dual-graphics system, you need to add all the three kernel parameters i.
Reason: KMS and rootless X 1.If the system is plugged into an Ethernet network with a DHCP server, it is very likely that the networking configuration has already been set up automatically.
If so, then the many included network-aware commands on the installation CD such as sshscppingirssiwgetand linksamong others, will work immediately. If networking has been configured, the ifconfig command should list one or more network interfaces besides lo. In the example below eth0 shows up:. As a result of the shift towards predictable network interface namesthe interface name on the system can be quite different from the old eth0 naming convention.
Recent installation media might show regular network interfaces names like eno0ens1or enp5s0. Look for the interface in the ifconfig output that has an IP address related to the local network.
As an alternative to ifconfigthe ip command can be used to determine interface names.
Kernel mode setting
The following example shows the output of ip addr of another system so the information shown is different from the previous example :. The output above may be a bit more complicated to read than alternative. The interface name in the above example directly follows the number; it is eno1.
In the remainder of this document, the handbook will assume that the operating network interface is called eth0. If the Internet is accessed through a proxy, then it is necessary to set up proxy information during the installation.
It is very easy to define a proxy: just define a variable which contains the proxy server information. In most cases, it is sufficient to define the variables using the server hostname. As an example, we assume the proxy is called proxy.
This ensures that the network is functioning properly and that the network packets are reaching the net, DNS name resolution is working correctly, etc. If this all works, then the remainder of this chapter can be skipped to jump right to the next step of the installation instructions Preparing the disks.
If the network doesn't work immediately, some installation media allow the user to use net-setup for regular or wireless networkspppoe-setup for ADSL users or pptp for PPTP users.
If the installation medium does not contain any of these tools, continue with the Manual network configuration. The simplest way to set up networking if it didn't get configured automatically is to run the net-setup script:. When all is done, the network connection should work. Test the network connection as stated before. If the tests are positive, congratulations! Skip the rest of this section and continue with Preparing the disks. If the network still doesn't work, continue with Manual network configuration.
Use the provided pppoe-setup script to configure the connection. If the Ethernet device does not exist, the appropriate network modules need to be loaded. In that case continue with Manual network configuration as it will explain how to load the appropriate network modules there. If everything worked, continue with Preparing the disks. But first make sure that the configuration is correct. When all that is done, run pptp along with the options that couldn't be set in options.
Now continue with Preparing the disks. When the Installation CD boots, it tries to detect all the hardware devices and loads the appropriate kernel modules drivers to support the hardware. In the vast majority of cases, it does a very good job.
However, in some cases, it may not auto-load the kernel modules needed.In recent years, power management has become one of the differentiating features in the quest for finding the perfect laptop. Yet, the operating system must support the various power saving functionalities too.
This guide covers the configuration of a Gentoo system to manage power-hungry resources in a flexible-yet-automated manner. This document describes the setup of power management features for laptops. Although some of the information in this guide can be applied to power management for servers, it is not the intention of this document to go that route.
Please be careful when applying this on a non-laptop system. Within this document, the primary focus will be on laptop mode tools since it offers a complete set of functionalities. However, we will also refer to other tools that might offer a more detailed approach on individual settings.
In such cases, the feature from the laptop mode tools must be disabled so that both tools do not fight over the same resource control. There are different kernel sources in Portage sys-kernel. For newer Intel Core series of processors based on the Sandy Bridge microarchitecture or neweruse the Intel P-state driver. In this case, the userspaceondemandand conservative governors are unnecessary.
The performance governor should be selected as the default. For Intel processors used in laptops since you may want to enable additional advanced features - Thermal and powercap sysfs. For RAPL enablement use:. Build and install the new kernel if necessary and reboot. It comes to no surprise that installation of the Laptop mode tools software is easily done via:.
However, this package takes on additional, optional settings through USE flag configuration. So let's first take a look at the supported USE flags and what they mean to the package.
Observe there are two USE flags that seem to collide: acpi and apm. So what is the deal? Depending on the system, either acpi or apm will need to be set.
In the remainder of this guide, it is assumed the laptop is recent enough to use ACPI. Having laptop-mode-tools installed on the system does not automatically enable the power management features that may be needed. This is the main configuration file for the package and is pretty well described through comments. But it is not the only configuration file to work with. The laptop-mode-tools package supports plugins or modules which have their own configuration file s.
Now, one of the important settings in each configuration file is if the laptop-mode-tools package should govern a particular setting or not.This article describes the manual configuration and setup of the Linux kernel. For a method that sets 'safe defaults' see the genkernel article. This can be done in one of three ways:. Install the kernel sources with the symlink USE flag active.
If necessary, it can still be modified later with the following two methods:. Setting the symlink with the eselect tool:. This outputs the available kernel sources. The asterisk indicates the chosen sources. To change the kernel sources, e. There are also several scripts to create miscellaneous default configurations.
These can make deeper configuration more time efficient. Run the following command for a full list of make targets:. This article describes the configuration using the make menuconfig tool, but the procedure is similar for the other menus.
In the shown menu the blue bar indicates the position of the cursor. As an alternative the Esc key can be pressed twice to exit the application.
Pressing an associated letter key A - Z will move the position of the cursor lines that have characters in bold. The YMN keys are excluded from navigation in this way; they are sanctified for other purposes. If a line begins with a Y, M, or N, the next character will be bold and capable of being jumped to. See the Kernel Modules article for differentiation.
Most options have a description, which see by pressing the H key or choosing Help in the menu bar. See the hardware detection article and the articles in the Hardware category. As shown below, the search result will show numbers in front of the matches. Pressing 1 in the example below would make menuconfig jump straight to the option Bluetooth device drivers in the menu structure.
It does nothing on its own, but sets various required configuration options for typical installations. For more information, read the help information available through the kernel configuration system as described earlier in this guide. For processors with multiple cores, make all the cores do the work.
Kernel ModeSetting (short: KMS)
The same for config and System. These symlinks are handy, because they always point to the newest kernel without changing the file path e. Change the system's bootloader configuration to pick up at boot the new kernel. Use the following procedure to get an overview of the kernel configuration settings that deviate from the default. Keep in mind that the modification of one configuration setting may alter additional configuration settings. The search function in make menuconfig can be used to look up the symbols and their interpretations.
When you're done, clean up:.
Jump to: navigationsearch. This page contains changes which are not marked for translation.Xorg is the X Window server which allows users to have a graphical environment at their fingertips.
This guide explains what Xorg is, how to install it, and the various configuration options. An average user may be frightened at the thought of having to type in commands at a command-line interface CLI.
Why wouldn't they be able to point-and-click their way through the freedom provided by Gentoo and Linux in general? Well, of course they can! Gentoo offers a wide variety of flashy graphical interfaces such as window managers and desktop environments which can be installed on top of an existing installation. One of the biggest surprises users who are new to Linux come across: graphical user interfaces are nothing more than an application or in some cases a suite of applications which are run on a system.
It is not part of the Linux kernel or any other internals of the system. That said, GUIs are powerful tools that unlock the graphical abilities of a workstation. As standards are important, a standard for drawing and moving windows on a screen, interacting with the user through mouse, keyboard, and other basic, yet important aspects has been created and named the X Window Systemcommonly abbreviated as X11 or just X. It is used on Unix, Linux, and Unix-like operating systems throughout the world.
The application that provides Linux users with the ability to run graphical user interfaces and that uses the X11 standard is Xorg-X11, a fork of the XFree86 project.Gentoo Linux - manual Linux kernel config alterations
XFree86 has decided to use a license that might not be compatible with the GPL license; the use of Xorg is therefore recommended. XFree86 packages are no longer provided through the Gentoo repository. The X. It is an open source Xbased desktop infrastructure. Xorg provides an interface between your hardware and the graphical software you want to run. Besides that, Xorg is also fully network-aware, meaning you are able to run an application on one system while viewing it on a different one.
Before you can install Xorg, you need to prepare your system for it. First, we'll set up the kernel to support input devices and video cards.
Read the Kernel Configuration Guide if you don't know how to setup your kernel. Modern open source video drivers rely on kernel mode setting KMS.Links : forums. Copyright Gentoo Foundation, Inc.
Hosting by Gossamer Threads Inc. Quick Search :. View previous topic :: View next topic. One other thing you really want to try with uefi boot is using UUID based disk mounts in fstab. Back to top.
Sometimes new ram slots are deceptive about ram sticks having been installed correctly. One of the other major lessons one has to learn when approaching uefi setup is how the framebuffer kernel config must be entirely different when using uefi boot.
You should not need to add nomodeset to the kernel boot flags with uefi. Describing the differences of every kernel option between a legacy non uefi system and a uefi framebuffer config could be challenging but perhaps providing the kernel config from my own k intel with an nvidia that runs the nvidia binary drivers could be worthwhile perspective to investigate the differences on your own.
It the past they are usually about 10 lines long per boot entry. MUCH shorter that the grub-mkconfig generated grub. I'll try to figure out the monitor issue tomorrow.
So I tried to "emerge gcc" and the system did not crash. But it got stuck at: Code:. Which kernel config did you use? If you created your own config Like i imagine many people do and I used to do it from scratch you may be missing some chipset drivers. Only using the sysrescuecd kernel config as a template allowed me to configure a kernel that provided that driver module.
While that's only one example you may need to be more attentive to any differences between the kernel driver modules loaded in lsmod while booted from sysrescuecd and your own kconfig while booted without sysrescuecd. You should consider buying a workstation mainboard.It also provides native-resolution VTs on some laptops and netbooks which, prior to this, would use some standard mode, e.
So from Squeeze on, no hand modification should be necessary anymore. Known bugs Are any of these also applicable to radeon? This is a kernel bug. The same problem occured in a desktop system with G link After last ca.
Therefore the workaround mentioned in the previous point was not applicable any more. Setting of i modeset to 1 still caused blank screen, as soon as the i module is loaded. After more investigations I've found, that the problem is related to framebuffer console. If KMS is switched on, the framebuffer console support must be selected.
Maybe with initial ramdisk, compiling it as module would be sufficient, but I've not checked it. KMS is required for using the xserver-xorg-video-nouveau package.
Blacklist the nouveau kernel module, e. Section "Device" Identifier "n" Driver "nv" EndSection If you want to use the proprietary driver, the nvidia-kernel-common package blacklists nouveau for you. Wiki Login. Hosting provided by Metropolitan Area Network Darmstadt.