Hack 51 Copy Settings to Other Distributions

Knoppix's intelligent hardware auto-detection can get all of a computer's hardware working out of the box. You can copy and reference the system files Knoppix creates to ease configuration of a new or existing installation.

With new hardware always coming out and with many vendors failing to list their Linux support (or lack thereof) on the box, it can sometimes be difficult to get all of your hardware working under Linux. While scanning the Web for HOWTOs, searching for the module that corresponds to your hardware, and configuring it by hand can be a good learning experience, some people might prefer to simply copy the information they need from a working system. This is where Knoppix comes in. Because of the excellent hardware detection and configuration Knoppix performs, there is a good chance that if the hardware is capable of working on your Linux distribution, it works in Knoppix. Many of the configuration files and modules are common across distributions; if hardware works in Knoppix, in many cases you can simply copy the configuration files and information you need to your distribution without any extra fuss.

5.16.1 Copy X Settings

Even with some of the automated tools that are available to configure X, it still seems to be one of the most problematic configuration files. After spending hours trying to get X to work, booting up Knoppix and having it work automatically might be a bit demoralizing. But you should be rejoicing. X's configuration file is pretty standard across Linux distributions, so you can copy Knoppix's configuration to your distribution almost directly.

Like pretty much every other Linux distribution, Knoppix stores X's configuration in /etc/X11/XF86Config-4. Provided you have a similar version of X on your system, you can copy this file directly to your system and get the same exact configuration that you have in Knoppix. Knoppix does include quite a few fonts in the file, so X might give some warnings about missing font paths if your fonts aren't installed in the same location or aren't installed at all. If you are experienced with X configuration, you don't necessarily need to copy the complete file but can instead reference particular sections, such as the monitor section or input device sections.

For instance, to copy the complete monitor section that Knoppix uses, copy all of the text starting with Section "Monitor" and ending with EndSection to your XF86Config-4 file. Then make sure that in your screen section (this section starts with Section "Screen") the Monitor line has the same monitor name as the name following Identifier in the monitor section you pasted in.

5.16.2 Copy Module Information

For much of the hardware on a system, there aren't many configuration files you need to bother with. You simply need to load the right module for the hardware to start working. Sometimes this means experimentation by loading multiple network card modules one at a time to see which module works best for your network card. Knoppix's kernel has most hardware built as a module so it can load only the modules it needs to work on a particular system. Most distributions by default have heavily modular kernels as well, so you can reference the modules that Knoppix loads and load the same modules on your system to get hardware working. This of course assumes that the same modules are built in your particular kernel.

The command lsmod shows all modules that are currently loaded in a system. Under Knoppix, many different modules are loaded by default, so it's best to have a general idea of which modules you might be considering for a device before digging through the output. For instance, if you are configuring ALSA, most of the relevant modules in the lsmod output are preceded by snd- or reference other modules preceded by snd- in the Used by column. If you are really lazy, you could simply copy the full list of modules and load them all, but it's better to try only the modules you need.

5.16.3 Copy Kernel Configuration

In addition to referencing the modules that Knoppix loads at boot, you can also reference the complete configuration Knoppix uses in its kernel when building your own kernel. Knoppix stores a copy of the configuration file for each kernel it includes in the /boot directory in the format config-kernel_version. If you have a standard, unpatched kernel that's the same revision as the one Knoppix uses, then you can simply copy the configuration file to the root of your kernel source tree and name it .config to start using it. If your kernel source is located at /usr/src/linux-2.4.26, for instance, copy Knoppix's configuration to /usr/src/linux-2.4.26/.config. If your kernel revision is greater than the one Knoppix uses (for instance, you want to build 2.4.26 but the version of Knoppix you have uses a 2.4.25 kernel), then after you copy the configuration file to the kernel source tree and name it .config, you must run the following command from the root of the kernel tree to see new kernel options:

root@ttyp0[linux-2.4.26]#

make oldconfig

Once the configuration is copied and ready, you can edit the configuration and build the kernel as you would normally. Do not use the kernel config for an older revision of the kernel (for instance, Knoppix uses 2.4.26 but you want to use 2.4.24) because, while it might work, problems may arise due to options that exist in the Knoppix kernel that don't exist in the kernel you are building. Also, do not use a configuration for a 2.4 kernel if you are building a 2.6 kernel and vice versa.

Copying some of these settings from Knoppix to your system can definitely save you time when trying to get hardware working. Unfortunately, many of the other configuration files in /etc, such as network settings, are specific to either Debian or Knoppix, so you won't be able to reference those files without making some changes to suit your system, but at least you now have a good start in getting the hardware to work.