User:Sakaki/Sakaki's EFI Install Guide/Final Configuration Steps

Currently, your target system is using a kernel configuration largely based on that shipped with the Gentoo minimal installation image (with some necessary changes imposed by buildkernel, for example to support systemd). Since this configuration is (by design!) lightweight, it leaves many options disabled (including many device drivers). As a result, at this point in the installation a number of features that may be present on your machine (such as Bluetooth, WiFi, touchscreen etc.) may not yet be usable.

In this (penultimate) chapter, we'll address that, by enabling the relevant configuration options and recompiling the kernel (using the buildkernel tool's --menuconfig option).

Unfortunately, it's impossible to be precise about the exact options you'll need to enable, as these vary from machine to machine. Nevertheless, we'll cover a number of the most commonly encountered requirements (and by way of example, provide explicit instructions for WiFi, Bluetooth, touchscreen, audio, and integrated card reader on the CF-AX3).

This section of the tutorial has no precise analogue in the Gentoo manual, although elements of it are reflected in Chapter 7. You may also find it useful to refer to the "Gentoo Kernel Configuration Guide" on the wiki.

We will also address some additional miscellaneous issues at the end of this chapter, namely:
 * pruning your kernel configuration (to remove unused items and make the kernel image smaller);
 * getting suspend and hibernate working properly;
 * setting the system default python interpreter; and
 * disabling sshd (as we no longer need it).

Let's get started!

General Approach
The general approach when looking to enable a feature which is physically supported on your machine (for example, Bluetooth), is as follows:
 * Obviously, check whether the feature already works (it's always possible that your current kernel already has the necessary options enabled or modularized). If it does, great, you're done!
 * Ensure your boot USB key is inserted, then invoke buildkernel --menuconfig</tt> in a terminal (which will run the make menuconfig</tt> tool).
 * Collect as much information as possible about the physical device (vendor name, model name etc.), using tools such as hwinfo</tt>, lspci</tt> and lsusb</tt> (in a separate terminal window).
 * If the device description should match one given in the specific CF-AX3 instructions below, implement the given kernel configuration shorthand fragment (using the buildkernel --menuconfig</tt> interface).
 * Otherwise, search (still via the menuconfig</tt> interface; see the tutorial earlier) for a suitable option, and then enable (or modularize) it (and any dependencies). If you can't find anything suitable this way, do a web search based on the information collected. (Unfortunately, there is no automated tool to do this for you).
 * Once you have made all desired changes, exit and save make menuconfig</tt>, thereby allowing buildkernel</tt> to continue and create a new kernel; and then reboot. With luck, your desired feature should now be operational.
 * If all else fails, invoke buildkernel --menuconfig</tt> again, try modularizing all options under the appropriate sub-menu in the make menuconfig</tt> interface, then save and exit, to create a new kernel as before. If, after a reboot, the desired feature is operational, you should then be able to locate its driver using hwinfo --pci --usb</tt> (after which you can rerun buildkernel --menuconfig</tt> if you like, to turn off all other unneeded items and recompile). This approach (i.e., turn on pretty much everything so that something will work ^-^) is actually the one taken by many Linux distributions (such as Ubuntu) for their 'generic' kernels, so don't feel shy to try it if need be.

Tweaking your kernel configuration to enable machine features is one of the more frustrating tasks you have to do when bringing up a system under Linux. In this tutorial, I've deliberately postponed it till near the end - when you already have all the other elements of a functioning system in place.

To make the process concrete, I'll now lay out the changes necessary to enable the main features of the Panasonic CF-AX3 laptop. You will obviously need to adapt what follows depending on your particular target machine.

<span id="specific_config_recipes">Specific Configuration Recipes (Using CF-AX3 as an Example)
In what follows, we will cover the following (common) features, using the Panasonic CF-AX3 as a (fairly typical) example (it is a reasonably feature-rich Ultrabook, so some of these may apply directly to your system too):
 * 1) WiFi;
 * 2) Bluetooth;
 * 3) Integrated touchscreen;
 * 4) Integrated webcam;
 * 5) Audio;
 * 6) Integrated (SD etc.) card reader;
 * 7) LCD screen backlight.

To reiterate, what follows is simply an example, for a particular PC (the CF-AX3). Where necessary, follow the steps above to set the necessary options for your particular choice of target machine.

<span id="config_prelims">Preliminaries
Ensure your boot USB key is inserted in the target machine, and then (at the terminal within the GNOME session that we opened earlier), issue:

to create a 'last known good' backup of the current kernel (and configuration) on the boot USB key. Although buildkernel</tt> does create a backup of the previous version when it is run, that backup is not persistent, and will be overwritten the next time buildkernel is executed. Keeping a (timestamped) backup via --snapshot-backup</tt> ensures that there's no risk we run buildkernel</tt> twice between reboots, thereby losing our reference point.

Next, issue:

Because you have not specified --ask</tt> here, but you have specified <tt>--menuconfig</tt>, the process will run through by itself (assuming no errors) to the point where you can modify the kernel configuration using the standard <tt>curses</tt>-based <tt>make menuconfig</tt> editor GUI. You can now use that interface to enable specific features as specified in the kernel configuration shorthand 'recipes' given below.

Now, because it will be useful to have a second terminal available (for <tt>emerge</tt> work etc.), open one now within GNOME. Click in the current terminal window (the one showing the <tt>make menuconfig</tt> interface, then press to spawn a new one. In this fresh window, log in as root:

The password required here is the one you set up earlier in the tutorial (and have used when <tt>ssh</tt>-ing in previously).

<span id="config_wifi">WiFi
The CF-AX3 has integrated WiFi, based on an Intel 7260 device. To find out which network controllers you have on your machine, issue the following in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

and observe the output.

In the case of the CF-AX3, this returns:

(your machine will most likely differ).

On the CF-AX3, the built-in Ethernet adaptor is (obviously!) already working under the current kernel configuration, but the Intel 7260 wireless card is not.

Now, while the firmware for this 7260 is already included in (which we installed earlier), using it requires MVM firmware support (which, at the time of writing, the minimal-install kernel configuration has disabled).

Set the following options (within <tt>buildkernel</tt>) to rectify this, and thereby activate WiFi:

Incidentally, the 7260 device also supports WiMAX, but as of the time of writing, the ebuilds for do not, so I have not detailed its activation here.

<span id="config_bluetooth">Bluetooth
Like many modern notebooks, the CF-AX3 has an integrated Bluetooth modem. To see information about your system's Bluetooth hardware, issue in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

To enable it on the CF-AX3, set the following options (this will work for many other machines too):

You must now ensure that the Bluetooth service will start on boot. To do so, issue:

<span id="config_touchscreen">Touchscreen
As is increasingly common, the CF-AX3 has a touchscreen (an eGalaxTouch device in this case). You can generally find out more information about your touchscreen (and touchpad, if present, although this is likely already supported at this point in the install), by issuing in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

To enable the eGalaxTouch device (this will also work for many other touchscreen panels), set the following options:

<span id="config_webcam">Webcam
The CF-AX3 has an integrated webcam (a common feature on many laptops and netbooks). You can find out more information about your machine's webcam by issuing in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

To enable the webcam on the CF-AX3 (this will work for many modern machines, as many webcams are UVC devices), set the following options:

<span id="config_audio">Audio
The CF-AX3 has an integrated Intel HD audio device, accessed on the PCI bus. You can find out more information about your machine's soundcard by issuing in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

As configured, sound works 'out of the box' for the CF-AX3, but the <tt>pulseaudio</tt> sound server complains about lack of high resolution timer support, and insufficiently large buffers. To address these problems on the CF-AX3, set the following options

<span id="config_card_reader">Card Reader
The CF-AX3 has an integrated SD/MMC card reader. You can find out more information about your machine's reader by issuing in the second terminal (the one not displaying the <tt>menuconfig</tt> interface):

Although the necessary kernel options (<tt>MMC_SDHCI</tt> and <tt>MMC_SDHCI_PCI</tt>) for this card are modularized in the minimal install kernel, there is a bug impacting the CF-AX3 (and many other machines) which prevents correct initialization when a card is inserted. To fix this, still in the second terminal, issue:

<span id="config_others">Others
There are a couple of other devices on the CF-AX3 which I have not dealt with here:
 * The CF-AX3 has an i7 processor with Intel's Management Engine; if you really want access to this scarily-out-of-band coprocessor, enable the <tt>INTEL_MEI</tt> setting in the kernel configuration.
 * It also has a number of integrated sensors (geomagnetic, gyroscopic, acceleration etc.); however, these are not generally supported by Linux applications at the moment, so I haven't detailed their setup here.

Of course, as mentioned earlier, your particular target platform will have its own set of devices that may well not have been mentioned here (for example, MemoryStick readers, digital TV receivers etc.), and you should obviously adapt your kernel configuration accordingly.

Lastly, if you find that your early boot splash is being interrupted with the error message "<tt>kvm: already loaded the other module</tt>", then you should ensure that only the KVM option (Intel or AMD) appropriate to your processor is set in the configuration. The relevant options are <tt>CONFIG_KVM_INTEL</tt> and <tt>CONFIG_KVM_AMD</tt>.

<span id="finishing_up_config">Finishing Up
When satisfied with your configuration, exit <tt>menuconfig</tt>, saving changes. Once you have done so, <tt>buildkernel</tt> will automatically create a new kernel with the newly created configuration, sign it, and copy it over to the boot USB key. Wait for the process to complete (you get the message "<tt>All done!</tt>"). Then (leaving the boot USB key inserted) restart your target machine (you can do this from within GNOME, by clicking on the 'power' icon (in the top right of the screen), clicking on the 'power' button in the dropdown menu that then appears, and then clicking on the 'Restart' button in the dialog).

The machine should then power cycle (you will be cleanly logged out of GNOME first). When it restarts, as before, you will need to enter your LUKS keyfile <tt>gpg</tt> passphrase (the one you created earlier), directly at the target machine keyboard to unlock the LUKS partition. You should then be presented with a GNOME login page (as previously). Directly at the target machine, click on your (regular) user name then, when prompted, type in the (regular user) password you set up earlier (ensure you have the correct keyboard settings, if relevant, as discussed above).

You should now be able to use all the features of your machine that you just enabled (such as WiFi etc.).

<span id="config_lcd_backlight">LCD Screen Backlight (Addressing the i915 Regression)
One final note. Like most laptops, the CF-AX3 has a dimmable backlight on its LCD screen. With modern kernels (3.17+) and the i915 graphics driver (as used by many Ultrabooks), you may find that you cannot change the display brightness using the standard GNOME controls. This is a regression; if it affects you, first use the process described in "Preliminaries", above to get a root terminal, then issue:

Locate the line specifying <tt>ADDITIONALKERNELCMDS</tt>. If it is currently commented out (the line starts with a <tt>#</tt> character), then uncomment and edit that line so it reads:

Save and exit the <tt>nano</tt> editor.

Now, ensure that you have the boot USB key inserted, and issue:

to rebuild the kernel. Wait for the process to finish (you receive the message "<tt>All done!</tt>"). Then power cycle the machine as described in "Finishing Up", above.

When you log in again to GNOME, you should find that the screen brightness controls now operate correctly.

<span id="cleaning_kernel_config">Cleaning Up the Kernel Configuration (Optional Step)
As your current Linux kernel is largely derived from the minimal-install image configuration, it contains a lot of modularized and enabled features that are irrelevant to your machine (for example, all the specific x86 platform support drivers for vendors other than yours). While this bloat is mostly harmless, there are a few negative side effects of having features you don't need, for example:
 * the kernel image is larger (which makes boot time slightly longer); even even where most features are modularized, since all modules are copied into the initramfs, which is then integrated into the kernel itself. This can be an important consideration if you choose to migrate your kernel into the (often cramped) Windows EFI system partition (instructions for which are provided later);
 * more code must be (uselessly) compiled each time you upgrade your kernel, which costs time; and
 * more features = a larger attack surface exposed to malware.

Accordingly, you may wish to perform another <tt>buildkernel --menuconfig</tt> run, disabling features that do not apply to you. If so, proceed carefully: deselect some features, complete the build, and reboot; then repeat. This always allows you to fall back to the previous version kernel if something goes wrong, and you find you have chopped out something vital by mistake.

<span id="using_localmodconfig">Several commentators have suggested using <tt>make localmodconfig</tt> to automate this task,   but that can be dangerous (as any modules not currently loaded by the kernel will be purged from the configuration, which can result in filesystem drivers, crypto modules, codepages etc. being dropped). Furthermore, there are lots of 'false positive' loaded modules retained as well (e.g. ATA drivers) when you use this method. The best approach remains to work through manually, and do things methodically; nevertheless if you do wish to try out <tt>localmodconfig</tt> for yourself, proceed as follows:

First, if you don't have a root terminal open already in GNOME, do so now: press the, and type 'terminal', then press. A standard-issue terminal window should open. Become root:

The password required here is the one you set up earlier in the tutorial (and have used when <tt>ssh</tt>-ing in).

Then in this terminal, issue:

to create a 'last known good' backup of the current kernel (and configuration) on the USB boot key (this ensures that there's no risk we lose our 'safe' version, which might otherwise happen were we to run <tt>buildkernel</tt> twice in a row between test reboots).

Now switch to the kernel directory, ask <tt>localmodconfig</tt> to do its magic, then return:

Finally, ensure you have the boot USB key inserted, and create a new kernel based on the stripped-down configuration:

This will allow you to review the proposed configuration for sanity in the <tt>make menuconfig</tt> tool, and make any necessary changes.

When satisfied with your configuration, exit <tt>menuconfig</tt>, saving any changes. Once you have done so, <tt>buildkernel</tt> will automatically create a new kernel with the newly created configuration, sign it, and copy it over to the boot USB key, as before. Once the process completes (you get the message "<tt>All done!</tt>"), leave the USB key inserted and reboot in the normal manner.

This is very much an optional task, so feel free to postpone it for a rainy day (or forever if you like ^-^ !).

<span id="suspend_hibernate">Suspend and Hibernate
At this point, let's take the time to properly configure power management (suspend and hibernate), as this is a useful feature to have operational on your machine.

The default <tt>systemd</tt> power management works well for many systems out of the box. The file determines (inter alia) what behaviour will occur when certain buttons are pressed on the machine, specifically that the 'suspend' key ( on the CF-AX3) will invoke the 'suspend' action (aka 'sleep'), and and that the 'hibernate' key ( on the CF-AX3) will invoke the 'hibernate' action (aka 'suspend to disk').

For the CF-AX3, the 'stock' configuration works perfectly for suspend (simply press and the machine will enter sleep state, with its power button light flashing slowly; slide the power button, and it will resume). However, hibernate requires a little further tweaking (it does work, but the system doesn't fully shutdown after the memory image is written to disk). To get around this, we need to request that <tt>systemd</tt> writes the string "<tt>shutdown</tt>" into, rather than "<tt>platform</tt>" (this may be the case on your system too, but try to see if it works without making any changes first).

To achieve this, we need to use the file (which does not exist by default). If you don't have a root terminal open already in GNOME, do so now: press the, and type 'terminal', then press. A standard-issue terminal window should open. Become root:

The password required here is the one you set up earlier in the tutorial (and have used when <tt>ssh</tt>-ing in).

Then in this terminal, issue:

Put the following text in the file:

Save and exit the <tt>nano</tt> editor (you can also close out the terminal if you have no further use for it).

After this, hibernate should work properly (on the CF-AX3). Press and the machine will write its memory to the LVM swap partition on the LUKS encrypted volume (<tt>buildkernel</tt> conforms the kernel command line to specify this, as noted earlier), and then automatically power off. To resume, ensure that the boot USB key is inserted, and slide the power key. Enter your LUKS password when prompted, log in to GNOME, and you should find your desktop just as you left it. As this feature uses encrypted swap, it is relatively safe to travel with the laptop hibernated in this fashion (you should unplug and carry the boot USB key separately, of course).

<span id="set_default_python">Setting the System Default <tt>python</tt> Interpreter
This is a bit of an odd one, but it does seem to catch people out. Python is a widely used dynamic language. There are two major versions (2.0 and 3.0), and a lot of python scripts that you find on the web use the older version. The problem is that these scripts also often start with a versionless shebang like:

On Gentoo, this will end up invoking Python 3.x (not 2.x), thereby (often) causing the script to break.

It's generally safe to set the default to refer to version 2.7 instead (since scripts that require version 3 will explicitly call it).

To do so, open a root terminal in GNOME (if you don't already have one open): press the, and type 'terminal', then press. A standard-issue terminal window should open. Become root:

The password required here is the one you set up earlier in the tutorial (and have used when <tt>ssh</tt>-ing in).

Then in this terminal, issue:

Your output may very somewhat from the above, but you should see that one of the lines has a '2.7' version (it is <tt>[1]</tt> in the above). Now set it as the default:

That's it! There's no need to run <tt>python-updater</tt> here as we've really just switched a symbolic link, not installed anything new on the machine.

<span id="disabling_sshd">Disabling <tt>sshd</tt>
Up until now, you've been running <tt>sshd</tt> (the secure shell daemon) on your target machine, to allow for simpler configuration via a helper PC. This is no longer required, and running such a service can present security risks. Unless you have good reason to keep it, stop <tt>sshd</tt> now (and ensure it does not restart again on boot).

To do so, open a root terminal in GNOME (if you don't already have one open): press the, and type 'terminal', then press. A standard-issue terminal window should open. Become root:

The password required here is the one you set up earlier in the tutorial (and have used when <tt>ssh</tt>-ing in).

Then in this terminal, issue:

<span id="next_steps">Next Steps
Once you have worked through the above points to your satisfaction, congratulations - you now have a fully functioning dual-boot machine! We'll now cover a few quick points about day-to-day maintenance, cleanup, and other software you might like to install. Click here to go to the next (and final) chapter, "Using Your New Gentoo System".