Cheatcodes for Porteus
Popolarmente noti come cheatcodes, i parametri di boot vengono usati per modificare il processo di boot di un sistema operativo. Per quanto riguarda Porteus e solo per mia comodità personale, riporto in questa pagina il testo originale pubblicato sul sito degli autori.
Warning: This document may be irrelevant to the Porteus version you are using (cheatcodes may change between releases). A copy of it can be found at /boot/docs/cheatcodes.txt on the Porteus ISO you have downloaded so please rely on it rather than this version.
Boot parameters (also known as cheatcodes) are used to affect the booting process of Porteus. The cheatcodes listed here are only those that are specific to Porteus (see the final note for information on cheatcodes that apply to all linux distributions, including Porteus). You can use these parameters to disable desired kinds of hardware detection, start Porteus from a specific location, load additional modules, etc.
Reboot your computer and wait several seconds until the graphical Porteus logo appears with a boot menu. Choose your desired menu entry and hit Tab, which will allow you to edit the command line. Add your desired boot argument from the list below to affect booting the way you like. Here's an example of what the boot line would look like, adding the noauto and copy2ram cheatcodes to a standard Porteus boot option (which already has some other cheatcodes by default):
APPEND initrd=initrd.xz xfce changes=/porteus/ noauto copy2ram
These cheatcodes can also be added to the APPEND line of your /boot/syslinux/porteus.cfg entries (or other bootloader config files) to apply them automatically on every boot.
... This cheatcode will prevent the system from loading any modules at startup other than the 'base' modules included with the default ISO (000-kernel.xzm, 001-core.xzm, etc). This is useful in debugging to see if problems you are having are associated with some module you've added to the system.
... All changes made in Porteus are kept in memory until you reboot. With this boot parameter, you tell Porteus to use a device (or a file or directory) other than your memory for storing changes. You can, for example, format your disk partition /dev/sdb2 with some Linux filesystem (eg. xfs) and then use 'changes=/dev/sdb2' to store all changes to that partition. This way you won't lose your changes after reboot.
... If you use a file image instead of a device, and the image contains a valid filesystem, Porteus will mount it on a loop device and will store changes to it.
... If you use a directory, Porteus will save changes to it (it will make a 'changes' subdirectory there). This should only be used for linux filesystems, if changes need to be saved to a FAT or NTFS partition, a savefile container has to be used.
... Keep saved changes in a read-only state. This is useful when you have your system set up exactly how you like it and do not want to save any other changes you might make during a live session. This cheatcode should be used in conjunction with the 'changes=' or 'changes=EXIT:' cheatcodes. Example: 'changes=/path/file.dat changes-ro' NOTE: remove the 'changes-ro' cheatcode from the bootloader config to start saving changes as normal (effective after a reboot).
... Execute specified command(s) in runlevel 3 (before logging in to a graphical interface). Use semicolons (;) as command separators with no spaces.
... If you need to use spaces in the command line, replace them with '~'. For example, 'cliexec=echo~Shutting~power;poweroff' will echo your text with spaces instead of '~'. NOTE: to start graphical applications please use 'guiexec=' cheatcode instead.
... Copy all modules to RAM. You'll need at least 256MB of RAM to boot Porteus properly. 64-bit Porteus with KDE-4 requires at least 768MB of RAM for this. Copy2ram slows down the boot phase but speeds up Porteus!
Reminder: the 'noeject' cheatcode can be used together with 'copy2ram' to prevent unmounting of your booting media (CD/DVD disc, usb, card readers, etc). You can also use the 'rammod' cheatcode to selectively load modules to RAM - see the 'rammod' description below.
... Start the shell several times during the boot to perform debugging actions.
... To be used for devices which need extra time to settle up. Example: 'delay=5' will cause a 5 second delay before Porteus starts booting.
... This cheatcode lets you load modules from one or more external folders that are located outside of the /porteus directory. Multiple folders can be specified, with full paths separated by a semicolon without any spaces. Examples: 'extramod=/mnt/sdb3/porteus-modules' 'extramod=/mnt/sdb3/porteus-modules;/mnt/sdc4/inkscape_modules'
... Loads Porteus from the specified device, folder or ISO file. Examples: 'from=/dev/sdb2' will attempt to load unpacked Porteus ISO from the second partition on your second drive. 'from=/mnt/sda2/linux-testing' will attempt to load unpacked ISO from the 'linux-testing' folder placed on the second partition. 'from=/linux-ISO/porteus.iso' will attempt to load the Porteus data from an ISO file placed inside the 'linux-ISO' folder.
If the destination partition is not provided with this cheatcode, the booting script will search through all available devices for your data.
... Enables a filesystem check for ext(2,3,4) and reiserfs partitions during boot time before anything is mounted by Porteus. XFS does not need fsck as a check is performed automatically during the mount operation. NOTE: On some systems, you will need to use the 'delay=' cheatcode in order to allow your devices to settle up. This should only be needed to fsck usb flash drives.
... Execute specified command(s) in runlevel 4, when the graphical interface is loaded; unlike 'cliexec' this cheatcode can be used to start graphical applications. Use semicolons (;) as command separators with no spaces.
... If you need to use spaces in the command line, replace them with '~'. Example: 'guiexec=firefox~kernel.org' will open the firefox browser on the 'kernel.org' website.
... Specifies the preferred keyboard layout for KDE/LXDE/XFCE or other desktop. A full list of supported layouts can be found in the /etc/X11/xkb/symbols folder. Up to 3 layouts are supported. Example: 'kmap=ara,us' will set the arabic keyboard layout at startup. 'kmap=ara,us' will keep arabic layout as default with possibility of switching to 'us' by 'alt+shift' key combination. Keyboard layout variants are also supported. Example: 'kmap=pl:qwertz' will set the polish keyboard layout with 'qwertz' as a variant.
... Load optional modules from /optional/ directory on the booting media. Additional modules can be listed, separated by semicolons, without spaces. Exampe: 'load=gimp;inkscape' would search for and load any modules in the /porteus/optional folder that contain the strings 'gimp' or 'inkscape'.
... Lets you specify the name of the user (could be also 'root') which will be autologged into GUI session. If username is not provided then booting stops on the lxdm/kdm login screen.
... This cheatcode will allow you to customize your filesystem mount options. By default, the mount options for all filesystems in Porteus are: "noatime,nodiratime,suid,dev,exec,async". Each option must be separated wtih a comma "," with no spaces between any characters. Example: 'mopt=realtime,sync,users,nosuid,noexec' See 'man mount' for more information on specific mount options.
... Do not mount any devices during startup. Every disk needs to be mounted manually in order to access it.
... Do not discover any optical devices during startup.
... Do not eject CD/DVD disc during boot time and shutdown.
NOTE: when the 'copy2ram' cheatcode is used with 'noeject', this will prevent the unmounting of your booting media (CD/DVD disc, usb, card readers, etc). To eject the CD you will have to umount /mnt/sr0 manually and issue the command 'eject /dev/sr0' from a console.
... Do not discover any hard drives during startup.
... Disable specified hardware autodetection in the case of hangups. None of your hardware will be detected, and you'll have to use the "modprobe" command after logging in to text mode and load all needed drivers manually.
... Disable loading of any modules specified. This affects all the modules on the Porteus booting mendia, including /base and /modules folders, so using noload=kde will disable loading of all modules with 'kde' in the name. It is useful with the copy2ram cheatcode, because any un-used module is not copied to ram. Multiple modules can be listed, but they must be separated by semicolons, with no spaces. Example: 'noload=lxde;devel' will prevent the loading of any modules with a name containing the strings 'lxde' or 'devel'
... Do not bind "magic folders" during boot time. Useful when something went wrong with your Porteus configuration and you want to boot into true 'Always Fresh' mode.
... This boot parameter will prevent Porteus from automatically establishing a network connection on start-up. Note that this cheatcode makes some modifications to your system which must be manually restored, so it is recommended that you only use this cheatcode in "Always Fresh" mode. If you've ignored this advice and need to recover your network connection, please run the following:
chmod +x /etc/rc.d/rc.inet1 /etc/rc.d/rc.networkmanager sed -i 's/Hidden=true//g' /etc/xdg/autostart/nm-applet.desktop
... Do not copy files from your rootcopy directory at boot-up. Like the 'nomagic' cheatcode, this is useful if something went wrong with your Porteus configuration and you want to boot into true 'Always Fresh' mode.
... Prevents the automatic use of an existing swap partition. By default, Porteus searches your attached drives for partitions that are formatted as swap, and will mount them for use within Porteus. The 'noswap' cheatcode disables this behaviour.
... Initialize PXE services (tftpd, dhcpcd, nfs server) which will allow you to boot Porteus on other computers over a network. This cheatcode should be used on the server side.
NOTE: the 'storage=' cheatcode can be used together with 'pxe' to let the clients store persistent changes on the server. See the 'storage=' description for details.
... Will let you set a custom size for the tmpfs partition which is used as the root (/) of your live filesystem when changes are not saved on a real filesystem (i.e., Always Fresh mode). The default value is 60% of available RAM memory. Example: 'ramsize=40%'
... Specify module(s) or folder(s) containing modules which should be copied to RAM when using the 'copy2ram' cheatcode. This allows you to have the speed benefit of 'copy2ram' for the modules you use the most, without occupying your RAM with those modules that you make use of less often. Any modules that are not specified will be mounted in place on the block device, so your device will remain mounted while Porteus is running.
You can use a full or partial names for your search string, but keep in mind that all modules and folders that match your string will be loaded into RAM; if you have extra modules in a folder named 'lxde' and you use 'rammod=lxde', then the module 003-lxde.xzm from /porteus/base will be loaded in addition to all modules in the 'lxde' folder.
NOTE: 'rammod' cannot be used without 'copy2ram', and it also will not load modules from /porteus/optional or external locations unless you also specify these modules with the 'load=' or 'extramod=' cheatcodes.
Examples: 'rammod=001;002;004;firefox' 'extramod=/mnt/sdb3/porteus/gimp rammod=001;002;gimp'
... Copy files from specified directory directly to the live filesystem. This directory will be used instead of the traditional /porteus/rootcopy. Example: 'rootcopy=/mnt/sda5/porteus-files'
... This cheatcode specifies the *.sgn file which Porteus will search for. This is useful when you want to store several Porteus editions on one disk/disc. Example: 'sgnfile=porteus-usb.sgn'
... This cheatcode takes action only when used together with the 'pxe' cheatcode. It tells the server to store persistent changes from the clients in a specified folder. Changes must be saved on a real and writable filesystem (wont work with aufs). Separate folders for each client will be created with the name '/path/folder/client-xxxx' where xxxx is the last 4 characters of the clients' NIC MAC address. This cheatcode should be used on the server side. Example: 'storage=/mnt/sda3/pxe-clients'
... Tell Porteus the correct timezone for your location. By default, this assumes that your hardware clock is set to localtime. To use a timezone with a hardware clock set to UTC time instead, also add the 'utc' cheatcode. A full listing of available timezones can be found in the file /usr/sbin/timeconfig. Example: 'timezone=Europe/Warsaw' Example: 'timezone=Factory'
... Tell Porteus that your hardware clock is set to UTC time and not to localtime. Most computers that have Windows installed on them use localtime instead of UTC time, but many UNIX machines use UTC instead. This cheatcode is normally used together with the 'timezone' cheatcode. Example: 'timezone=Europe/Warsaw utc'
... Automatically detects AMD or nVidia video cards and loads the proprietary drivers at startup. You must have a module containing the appropriate graphics driver (nVidia or amd-catalyst) stored in your /porteus/optional/ directory. These modules are available in the download section of the Porteus website (www.porteus.org/download) for each edition and version of Porteus. If you compile your own driver, please note that the module's name must begin with the string 'nVidia-' or 'amd-catalyst' because the startup script searches for the driver modules by name.
This cheatcode allows users to easily switch back and forth bewteen different hardware configurations while using the proprietary drivers because both driver modules can sit side by side in /porteus/optional/ without interfering with one another. They are only activated when needed.
... This parameter sets the system's Master Volume channel to the value specified (as a percentage). You will be able to raise or lower the volume after you boot up as normal. The default value is 75%. Example: 'volume=0%' will boot into your chosen GUI silently.
... enable the use of zram, which is a compressed block device inside your RAM that acts as a swap partition. Zram operates faster than using swap on a hard drive and creates more (virtual) memory than using RAM alone because the data inside is compressed. This will provide a performance boost on systems with low RAM, but it uses more processor cycles (to compress and decompress the data) than regular swap. Example: 'zram=33%' will set aside 33% of your RAM as a zram device.
SPECIAL NOTE FOR USING CHEATCODES WITH 'LABEL' AND 'UUID':
If you specify a LABEL or UUID with a cheatcode, remember that all portions of these commands are case sensitive. You should use a unique label for each of your partitions if you wish to use device labels with your cheatcodes. Use the 'blkid' command to view your device's UUID and LABEL. Using UUID and LABEL can be quite handy because they are unique to your device, and your data will be found and properly mapped on different hardware configurations. Every cheatcode which contains a /path can take advantage of 'UUID:' and 'LABEL:' extensions.
SPECIAL NOTE FOR USING CHANGES CHEATCODE WITH 'EXIT:' EXTENSION:
The 'EXIT:' extension tells the 'changes=' cheatcode to keep all of the files that have been added/deleted/modified during the live session stored in memory until you reboot/shutdown. Your RAM works as a buffor which gets dumped on the drive only once, when the session is finished.
'changes=EXIT:' cheatcode has following advantages:
- Porteus works as fast as in 'Always Fresh' mode as all modifications to files and folders are performed in RAM.
- reduced number of read/write cycles should extend the life of SSD drives and usb sticks.
The only disadvantage of the 'EXIT:' extension is that the session does not get saved in cases where you experience a hang (kernel crash) or power interrupt. Please use with caution!
While you are running a session with changes=EXIT, you can use the 'dump-session' command (run as root from the command line) to move all of your changes from RAM to your storage media. This will reduce the risk of data loss and free up your RAM.
NOTE FOR THE LILO USERS:
If the LILO bootloader has been installed, you will get a text menu with the standard boot options (KDE, LXDE, Always Fresh, etc). Use your arrow key to highlight your desired entry (if you are using the first entry (KDE), press down, then up to highlight KDE). The name of your boot option is added to the 'boot:' line, and you can type your cheatcodes after that. For example:
boot: KDE debug noauto
would boot into KDE with all of the standard codes used for KDE, plus debug and noauto. If you want to use LILO with custom cheatcodes at every boot without manually entering them each time, you must modify the /boot/syslinux/lilo.conf and then repeat installation by running /boot/Porteus-installer-for-Linux.com utility as LILO must reload it's configuration.
The cheatcodes listed above are those that are unique to Porteus. There are literally hundreds of other kernel boot parameters that can be used. For more information on these parameters visit: www.kernel.org/doc/Documentation/kernel-parameters.txt
Non si tratta tanto di pensare di più quanto di pensare diversamente.
Jean Marie Domenach