Picture 802.2. Demolinux with KDE.
|
|
[next] [previous] [top] [last] [contents] [indice ridotto] [translators] [docinfo] [indice analitico] [tome] [part]
There are many GNU/Linux distribution explicitely developed as auto-start CD-ROMs, in addition to the special case of nanoLinux III. In this chapter we mention some of them.
Generally, a distribution of this kind is provided on a file containing the image of the file system, that is copied to a CD-ROM to be used as an auto-start CD. However, often there are also boot diskette images, to be used when it is not possible to start directly from the CD-ROM.
The reproduction of this kind of CD normally requires a very good quality new disk, cabable of storing at least 80 minutes of recording. In a similar way, the use of this kind of CD requires a good quality reader, fast enough and capable of reading also relatively high capacity CDs.
Demolinux, according to its name, is presented as a 'demo' GNU/Linux system to be used on a computer of the i386 architecture.
Demolinux is distributed as an image of an ISO 9660 file system, i.e. that used for the CD-ROMs. Actually, it is a single file of large size that can be used to reproduce the original CD (2). The original URL of this work is <http://www.demolinux.org/DOWNLOAD/>, which is of course reproduced also on other sites.
Demolinux has the purpose to surprise people who do not know GNU/Linux; therefore the preparation of the CD and of whatever is needed to start this demo system, is assumed to be made, probably, by somebody else who wants to create this surprise. The image of Demolinux is prepared to be auto-startable; however, this requires a suitable configuration of the computer firmware (the BIOS). Generally, if you want to be more successful with this presentation, you should prepare a booting diskette.
The CD of Demolinux contains the file .demolinux/images/boot.img, which is an image of the booting diskette. This file must be copied to a diskette; if you have already a GNU/Linux system;, you can just enter a command such as the following, where the first diskette unit is referred to:
# cp diskette_image_file /dev/fd0[Enter]
Clearly, instead of the diskette_image_file you should enter the file to be used (boot.img, as already mentioned before).
If instead you have only a Dos system (a Dos window within MS-Windows would be OK), you should use the program RAWRITE.EXE that can be found in the dosutils/ directory of the CD. Actually, if we assume that the CD is recognised in a Dos system as the drive D:, you could enter the following command:
C:\> D:\DOSUTILS\RAWRITE -f diskette_image_file -d A:[Enter]
With a Dos/MS-Windows system it might be complex to reach the directory .demolinux/images/, because of the initial dot; however, the file boot.img might have been copied to some other location, such as in dosutils/. In this case the command becomes:
C:\> D:\DOSUTILS\RAWRITE -f D:\DOSUTILS\BOOT.IMG -d A:[Enter]
If you decide to start Demolinux by using a diskette, you should not insert the CD-ROM immediately, to avoid independent decisions by the firmware, that could discover that the CD is auto-startable. After starting the CD (that might be a bit slow),the screen appears more or less as in the following picture 802.1.
|
Picture 802.1. Demolinux start-up.
|
To start, you should select one of the available choices, as described on the screen. AS you can guess, you should try to decide which definition you want to try. In normal situations that with 1 024×768 points should be OK, but you might be safer with lower resolutions. If you want to be even safer you should avoid the choices that have an explicit reference to the VESA; standard. You might for instance select the choice 1024:
1024[Enter]
After this the kernel is started, together with a small configuration program, then the CD-ROM (that should by now have been inserted in the reader) is identified and mounted, finally some infomation is requested, such as the nationality and the available keybord.
After the entry of the required information, the operating system is started; to be precise the hardware components are scanned. If a network card is found, some additional data are requested for its configuration (IP address, network mask, predefined router and DNS server). Unfortunately, one cannot be certain that everything has been identified correctly.
In the start phase also the hard disk is scanned, in order to identify the partitions that it contains. If the partitions can be accessed, they are mounted automatically; moreover, if there is a swap partition for the virtual memory, it is used.
Finally, some virtual consoles and the graphical system are activated by presenting a form that allows, in addition to the entry of the user and password, also the selection of the window manager, or a special session type. There are two available users: demo and root; both of them without any password. The pictures 802.2 and 802.3 present two different situations, with a low resolution graphic mode, of how the desktop of Demolinux might appear.
|
Picture 802.2. Demolinux with KDE.
|
|
Picture 802.3. Demolinux with Gnome.
|
The system can be used in a relatively simple way; even the access to the diskette is 'logical' for people who do not know the Unix system. Especially, we refer to diskettes with a Dos-FAT file system.
The limit of all this is clearly the access speed of the CD.
The partitions of the hard disk or of the local hard disks, if they have been identified, are mounted to a directory that is not common, such as /.plume/mnt/hd*. To find exactly its name you should use the command mount in a terminal window, or in an available virtual console.
In addition to demonstrating a GNU/Linux system, demo linux could also be used as an emergency system, to fix the problems of a computer that does not start any more, or to 'browse' the Internet, since the network configuration is done automatically and the system includes a classic browser.
Even if the system is started from CD-ROM, in read only mode, it is better to terminate its usage in the correct mode, to avoid any interferance with the mounted partitions. To do that you can just terminate the work of the graphical session, then when you are in the initial form, you can just select the <Shutdown> button.
As an alternative, if you are confident, you can just select a virtual console, login as a root user and then enter the normal command:
# shutdown -h now[Enter]
Once Demolinux has been started, it is still possible to obtain its partial installation on the hard disk. This can be done by selecting the program corresponding to the icon with an anchor.
Dynebolic is a relatively small auto-startable GNU/Linux system, it is simple and optimised as much as possible to save resources and disk space. The reference site for this product is <http://dynebolic.org>.
Dynebolic, once a CD has been reproduced from its distribution image, starts without requiring any user choices and recognises by itself the available hardware. Once the system start-up procedure is terminated, the user is presented with some open consoles and a very simple graphical desktop<. All the work sessions use the privileges of the root user, without any kind of authentication.
You can configure the keyboard type with the usual command:
# loadkeys uk[Enter]
You can access the network by using two alternative scripts, netconfig or modemconfig: the former one includes the configuration of network interfaces, whereas the latter one establishes a connection to the network by using a modem. These scripts are interactive, therefore you can use them without any argument on the command line.
There is no much more that we can say on Dynebolic, especially because is a GNU/Linux system targeted to the use of the network, with a common graphical browser, where many programs of a standard system are missing, even when they are very simple utilities.
Knoppix is a GNU/Linux system on auto-startable CD-ROM, sufficiently complete (<http://www.knoppix.org/>). There is also a diskette image to be used when the CD-ROM cannot be started directly: it is the /KNOPPIX/boot.img contained in the same CD-ROM.
At boot time it is possible to enter some parameters for the initial configuration; usually the command below can be entered to define immediatelt the keyboard type:
boot: knoppix lang=uk[Enter]
At the end of the system start-up procedure, the program presents some open consoles and a graphical desktop controlled by KDE. The consoles are opened for the root user, whereas the graphical session uses the knoppix user. The root user does not have any password, therefore you can access the system as an administrator, only from the automatically activated consoles.
|
Picture 802.4. KDE started automatically from a Knoppix CD.
|
The network configuration can be entered manually, by using the normal commands.
Unlike other CD-ROM systems, Knoppix, when the system is shut downn, ejects the CD from the reader.
Dynebolic
Knoppix
Demolinux
Appunti di informatica libera 2006.07.01 --- Copyright © 2000-2006 Daniele Giacomini -- <daniele (ad) swlibero·org>
1) Translation last update on 2003.09.11 from Mario Pesce <mario (ad) datamission·co·uk> (original chapter was 33).
2) You should use a new CD with a capacity if at least 80 minutes.
It should be possible to link to this page also with the name common_auto_start_cd_roms.htm
[next] [previous] [top] [last] [contents] [indice ridotto] [translators] [docinfo] [indice analitico]
