Linux.Desktop.Hacks [Electronic resources] نسخه متنی

Hack 8. Jazz Up Your Debian System Boot

Boot Debian with an optional graphics screen
and progress bar, and spiff up your text consoles by running them in
graphics mode.

Here's how to add a graphical boot splash to your Debian distribution, the
only popular Linux distribution that lacks a built-in boot splash.
Windows and Mac OS X have a graphical boot process, as do all the
most popular versions of Linux, including Fedora Core (Red Hat),
SUSE, and Mandrake. Debian lacks one. (OK, to be perfectly fair, so
does Slackware, but currently there's no simple
solution for bringing a graphical boot screen to Slackware.)
Here's how to bring your Debian system up-to-date
with the rest.

You must use a 2.6 version of the Linux kernel for the boot splash to
work. If you are using a 2.4 or earlier version of the Linux kernel
and are not willing to upgrade to a 2.6 version, you cannot use this
hack. This hack also assumes you know how to configure, build, and
install a new Linux kernel, and that you already have chosen a
version of the 2.6 Linux kernel source code and have that source code
on your hard drive. [Hack #88]
provides instructions on how to build and install a Linux kernel if
you have never done so. Once you know how to build and install a
Linux kernel, you will need to build your kernel with support for
frame-buffer graphics, frame-buffer graphics-based consoles, and
graphical boot splash screens to make this hack work.

The boot splash portion of this hack gives
you a choice of booting in
silent mode or verbose
mode. Silent mode displays a graphical background (such
as a picture of Tux, the official Linux penguin), and a progress bar
to give you a rough idea of where you are during the boot process.
You can press F2 at any time to switch to verbose mode, where you see
exactly what is happening at boot time. When the boot process is
finished, all your virtual consoles work in frame-buffer graphics
mode.

Whether you boot to a console or to a graphical login manager, you
always have a number of virtual text consoles available to you. You
can switch between them by pressing Ctrl-Alt-F1 to get to the first
virtual console, Ctrl-Alt-F2 to get to the second, and so on. The
difference between a frame-buffer console and a normal console is
that the frame-buffer console works in graphics mode, which allows
you to display more text on the screen (using smaller fonts), yet
keep the text very sharp and readable. The consoles are still
primarily for text-based use, but because they are running in
graphics mode, you can also have a graphical background behind the
text.

At the time of this writing, two substantially different types of
patch sets to the Linux kernel are available for boot splash support.
The patch set you need for this particular hack is the one that works
now, but it is slowly being phased out in favor of an approach that
requires far fewer patches to the kernel. This latter approach
isn't quite ready for Debian yet. Keep your eye on
the web site http://alioth.debian.org/. I have been
working with other Debian developers to create a more modern boot
splash package, and it should eventually show up on that site.

For now, however, you need to work with what's out
there. Even so, it's difficult if not impossible to
find kernels prepatched or precompiled with the kind of frame-buffer
boot splash support you need for this older approach to boot splash.
So, you have to patch and compile your own Linux kernel to make this
work. You can download a patch from http://www.bootsplash.de/files.

Log in as root and change to the directory
/usr/src:

$ su -
Password: 
# cd /usr/src

Choose the patch that matches the 2.6 kernel you are using, and
download that patch to the directory /usr/src.
For this example, let's assume you are using the
Linux kernel 2.6.8.1, so download the file
bootsplash-3.1.4-sp3-2.6.8.1.diff.

It's always good practice to do a dry run with the
patch process just to make sure the patch will
apply cleanly:

# cd /usr/src/linux-2.6.8.1
# cat ../bootsplash-3.1.4-sp3-2.6.8.1.diff | patch -p1 --dry-run
patching file drivers/char/keyboard.c
patching file drivers/char/n_tty.c
patching file drivers/char/vt.c
patching file drivers/video/Kconfig
patching file drivers/video/Makefile
patching file drivers/video/bootsplash/Kconfig
patching file drivers/video/bootsplash/Makefile
patching file drivers/video/bootsplash/bootsplash.c
patching file drivers/video/bootsplash/bootsplash.h
patching file drivers/video/bootsplash/decode-jpg.c
patching file drivers/video/bootsplash/decode-jpg.h
patching file drivers/video/bootsplash/render.c
patching file drivers/video/console/fbcon.c
patching file drivers/video/console/fbcon.h
patching file include/linux/console_struct.h
patching file include/linux/fb.h
patching file kernel/panic.c

It looks like there are no errors. Do it again for real by running
the patch command, without the
-dry-run option:

# cat ../bootsplash-3.1.4-sp3-2.6.8.1.diff | patch -p1
patching file drivers/char/keyboard.c
patching file drivers/char/n_tty.c
patching file drivers/char/vt.c
patching file drivers/video/Kconfig
patching file drivers/video/Makefile
patching file drivers/video/bootsplash/Kconfig
patching file drivers/video/bootsplash/Makefile
etc...

Now it's time to configure the kernel. Because this
hack assumes you have already configured and compiled this kernel
without the boot splash feature, all you need to do is configure the
boot splash feature and the other kernel features on which boot
splash depends.

1.9.1. make menuconfig

When you use make menuconfig to
configure your kernel,
you have to follow the menu options. Here are the menu steps you
should follow to set up your kernel to support boot splash and the
frame buffer:

Select Device DriversGraphics supportSupport for
frame buffer devices.

Select the "VESA VGA graphics
support" option and press Y.

Select "Video mode selection
support" and press Y (you should see the selection
show [*]).

Select "Console display driver
support" and press Enter.

Select "Video mode selection
support" and press Y, after which you should see
[*].

Select "Framebuffer Console
support" and press Y, after which you should see
<*>.

Exit from this menu. Now select Bootsplash Configuration, and when
you see the only selection, "Bootup splash
screen," press Y (you should see the selection show
[*]).

You might see a frame-buffer driver specifically written for your video card and be tempted to use it instead of the VESA VGA driver. This can lead to serious problems if you also use an accelerated graphics driver for your video card. For example, never select "nVidia riva" frame-buffer support if you plan to use the third-party NVIDIA accelerated graphics drivers. These two drivers do not play well together, and you're sure to have video crashes.

If your system uses an initial RAM disk
(initrd), now create that initial RAM disk as
you normally would. Make a note of the name of the
initrd file you create. You'll
need it later. It's easiest to remember it if you
put the kernel version in the name, such as
initrd.img-2.6.8.1. For example, create the
initrd file with a command such as this
(assuming your root partition is /dev/hda1):

# mkinitrd -o initrd.img-2.6.8.1 -r /dev/hda1 2.6.8.1

1.9.2. Install Boot Splash and the Boot Splash init Scripts

Now that your kernel has support for frame buffers, frame-buffer
consoles, and boot splash, you must install the boot splash utilities
and boot splash startup scripts.

Use your favorite editor to modify your
/etc/apt/sources.list file to include the
following line:

deb http://www.bootsplash.de//image/library/english/10060_debian unstable main

Then update the package database and install the necessary files:

# apt-get update
# apt-get install sysv-rc-bootsplash
# apt-get install bootsplash bootsplash-theme-newlinux

If you are running a Debian-based distribution instead of true-blue Debian, you will probably have problems installing these packages. You must convert your Debian-based distribution into a true Debian system for these instructions to work. This process isn't difficult, but it is different for each Debian-based product, and an explanation of the necessary steps is beyond the scope of this book.

When Debian installs the bootsplash
package, the installation dialog presents a list of existing
initrd images it finds, and it asks you to make
a choice about your initrd file. If you created
an initrd file called
initrd.img-2.6.8.1, as in the previous example,
select that file from the list. In this case, the installation
program will append the boot splash information to your existing
initrd file.

If you do not have or need an initrd file for
this kernel, select none from the list. In this
latter case, the configuration program creates an
initrd file for you called
initrd.splash.

1.9.3. Set Up Your Bootloader

Most people use either LILO or GRUB
as their
bootloaders, so let's take a look at both. But
first, you must decide what screen resolution and color depth you
want for your frame-buffer consoles. The bootloader uses a command
something like the following:

vga=791

The decimal number 791 sets the console to
1024x768 with 64,000 colors. This is usually the safest number to use
(not all video cards support all combinations of resolutions and
color depths). You can experiment with others. Table 1-1 shows you which numbers represent the various
resolutions and color depths.

The LILO bootloader is controlled by the settings in the
/etc/lilo.conf file. These settings determine
which operating system or kernel version your machine boots with, and
which configuration options are passed to Linux at boot time.

Here is a sample entry in the /etc/lilo.conf
file that supports the boot splash and frame-buffer console. Notice
the line that sets the vga mode to the decimal
number 791. This number specifically refers to the
frame-buffer console resolution 1024x768 at 16-bit (64,000 colors)
color depth (see Table 1-1). The line
append="splash=silent" tells the boot splash
sequence not to show all the steps Linux takes during boot time.
Instead, you will see a progress bar. If you would rather see all the
boot information, change that line to
append="splash=verbose". If you choose
"splash=silent", you can still press the F2 key
during the boot process to switch to verbose mode. However, once you
press F2 to switch to verbose mode, you cannot switch back to silent
mode.

If you have an initrd image, such as
initrd.img-2.6.8.1, set up your LILO entry like
this (substitute your kernel version where appropriate):

image=/boot/vmlinuz-2.6.8.1
label=Linux
root=/dev/hda1
initrd=/boot/initrd.img-2.6.8.1
append="splash=silent"
vga=791

If you do not have an initrd image and you
selected none during boot splash configuration,
set up your LILO entry more like this (substitute your kernel version
where appropriate):

image=/boot/vmlinuz-2.6.8.1
label=Linux
root=/dev/hda1
initrd=/boot/initrd.splash
append="splash=silent"
vga=791

Whenever you modify your /etc/lilo.conf file,
you must run the command lilo for the changes to
take effect.

Always include a known working boot configuration in your lilo.conf file in case the new one does not work. That way you can reboot and choose the working selection to make changes to fix any problems you find.

If you use GRUB as your bootloader, you should have a directory
called /boot/grub on your system. This directory
contains the files GRUB needs to work, such as the GRUB configuration
file. The grub.conf file is the one that
determines which operating systems or Linux versions you can choose,
and this is the file you will need to modify to enable the boot
splash.

Here is a sample entry in the grub.conf file,
assuming you have an initrd file and you chose
it during boot splash configuration:

title Debian Splash
root (hd0,0)
kernel /boot/vmlinuz-2.6.8-1 ro root=/dev/hda1 vga=791 splash="silent"
initrd /boot/initrd.img-2.6.8-1

Here is a sample entry in the grub.conf file,
assuming you chose none during boot splash
configuration:

title Debian Splash
root (hd0,0)
kernel /boot/vmlinuz-2.6.8-1 ro root=/dev/hda1 vga=791 splash="silent"
initrd /boot/initrd.splash

Unlike with LILO, changes in grub.conf
automatically take effect.

Always include a known working boot configuration in your grub.conf file in case the new one does not work. That way you can reboot and choose the working selection to make changes to fix any problems. GRUB also gives you the opportunity to boot to a working kernel even if there is no definition for it in the grub.conf file. Read the info file on GRUB for instructions for performing special operations such as this.

1.9.4. Reboot

Once you have your Linux kernel compiled to support frame-buffer
consoles and you have set up your bootloader properly, it is time to
reboot. If everything goes according to plan, you should see Tux, the
Linux penguin, and a progress bar that fills as the boot sequence
proceeds. When your system has finished booting, it will take you
either to the first text console or the graphical login manager,
depending on how you have your system configured. When you shut down
the machine, you should also see the splash screen and the progress
bar. In either case, you can press F2 to switch from silent mode to
verbose mode. You cannot switch back, however. Once you are in
verbose mode, you stay in verbose mode for the duration of that boot
or shutdown sequence.

1.9.5. Graphical Consoles

If you normally boot into a text console,
you should notice that you
now have a graphical background picture of Tux, the official Linux
penguin. If you boot to a graphical login manager, press Ctrl-Alt-F1
to get to the first console to see this new feature.

You can control how many consoles display this background by editing
the file /etc/default/bootsplash. Edit the
following line to include whichever consoles you want to display the
background:

BOOTSPLASH_TTYS="1 2 3 4 5"

Even if you do not include the number 0 in the list, console 0 (the
first console) will always have the background image.