http://doc.lunar-linux.org/api.php?action=feedcontributions&feedformat=atom&user=RicsiTdarl 2026-04-04T08:18:03Z User contributions MediaWiki 1.18.1 http://doc.lunar-linux.org/Installation:The_kernel_commandline_/dev_params_mini-HowTo 2008-01-22T17:51:52Z

<p>RicsiTdarl: dombobasz</p> <hr /> <div>darbocroc<br /> =A little background=<br /> <br /> Every box needs a set of device nodes in order to work. Currently there are 2 ways of creating these nodes: statically or dynamically.<br /> <br /> ==Static device nodes==<br /> <br /> /dev content is permanent, on a real permanent filesystem (like ext3, XFS, reiser...). All the needed nodes are present, or are created with a mknod command. You can also create nodes with the makedev utility.<br /> <br /> ==Dynamic device nodes==<br /> <br /> Nodes are created from hotplug events, e.g., on the fly. Here, depending on your kernel, you have 2 choices:<br /> <br /> ===devfs===<br /> devfs' device nodes are created in kernel space, on a virtual fs. It is therefore part of the kernel tree source.<br /> <br /> ===udev===<br /> udev's device nodes are created in userspace, and by a userland application, thus outside the kernel tree. udev can lie on any filesystem, permanent or not, but due to its nature, is normally on a virtual filesystem, like ramfs -this is Lunar's case.<br /> <br /> Altough devfs is still currently in 2.6 it &quot;will be removed real soon&quot; (TM). So basically we can think of 2 defaults: for 2.4, devfs is mainly used; on 2.6, udev will be mainly used. A smaller portion of users still have static (on real fs) nodes.<br /> <br /> =What commandline options can be used=<br /> <br /> To tell Lunar what type of device nodes I want to use there is a commandline switch that is dev=, that can take 4 values:<br /> * dev=static<br /> * dev=devfs<br /> * dev=udev<br /> * no commandline whatsoever<br /> <br /> The options are quite self explaining. A good thing to take in mind is that they behave differently depending on your kernel.<br /> <br /> ==2.4 kernels==<br /> <br /> valid dev= values are:<br /> * dev=devfs<br /> * dev=static<br /> <br /> If dev=udev was passed to a 2.4 kernel on boot, a warning message will be displayed, and it will fallback to normal 2.4 behaviour: if no dev= commandline has been supplied, or its value is not correct, it shall fall through:<br /> <br /> * Test for dev=devfs, and if devfs' binary is there, try to boot with it.<br /> * If there's no devfs installed, boot as if a static dev was present.<br /> <br /> ==2.6 kernels==<br /> <br /> valid dev= values are:<br /> <br /> * dev=udev<br /> * dev=devfs<br /> * dev=static<br /> <br /> And are tested in exactly this order if no valid dev= is supplied or no commandline is supplied whatsoever.<br /> <br /> <br /> =Adding the params: bootloaders=<br /> <br /> ==lilo==<br /> To add a commandline param in lilo, you have to use the append label. Taking dev=udev as an example:<br /> <br /> image=/boot/vmlinuz<br /> label=awesomekernel<br /> root=/dev/hda2<br /> append=&quot;dev=udev video=radeonfb:1152x864-16@60&quot;<br /> <br /> If you have prompt set in your lilo.conf, you can even write the option just before the kernel you want loads.<br /> <br /> ==grub==<br /> To add a commandline param in grub, all you have to do it put it behind the kernel placement, on the kernel label's line:<br /> <br /> title awesomekernel<br /> root (hd0,1)<br /> kernel /boot/vmlinuz root=/dev/hda1 dev=udev video=radeonfb:1152x864-16@60<br /> <br /> Don't forget that in grub you can edit the kernel label line on boot, just like lilo.<br /> <br /> Copyleft Jaime Buffery, 2004-2005<br /> nestu AT lunar-linux DOT org</div>

RicsiTdarl