mdev like a boss

This repo is a stash for notes, scripts and configs for the system running with mdev as a udev replacement.

Quickstart

Gentoo-based system as example.

ebuild-based install

Add foo-overlay via layman and install mdev-bb and mdev-like-a-boss packages, then follow messages after instalation to disable devfs and possible udev scripts.

Manual install

Important

By design devel branch and non-tagged master head supposed to work with latest busybox's mdev. If you want to use older versions, like prior to 1.21 then make sure to use tags, like 20121223.

• Clone repo as root to /opt/mdev:

  git clone https://github.com/slashbeast/mdev-like-a-boss.git /opt/mdev
  

• Build sys-apps/busybox with 'mdev' use flag.

• Copy /opt/mdev/mdev.init to /etc/init.d/mdev, replace the original one if exist, add exec bit and add to sysinit runlevel:

  cp /opt/mdev/mdev.init /etc/init.d/mdev
  chmod 700 /etc/init.d/mdev
  rc-update add mdev sysinit
  

• Remove udev from sysinit runlevel (it can be udev or udevd, depends if Gentoo or Funtoo):

  rc-update del udev sysinit
  

• Copy or symlink /opt/mdev/mdev.conf to /etc/mdev.conf:

  ln -sf /opt/mdev/mdev.conf /etc/mdev.conf
  

• Now you can reboot, mdev should be up and running.

Xorg

Build xorg-server with '-udev' USEFLAG. As we no longer use udev, we can't use evdev. Install mouse and keyboard drivers, and if you use touchpad synaptics as well. The input configuration is not the same as with evdev, we will no longer use 'InputClass' but 'InputDevice' sections. You propably do not need xorg.conf at all. Create /etc/X11/xorg.conf.d/ and copy content of the /opt/mdev/xorg.conf.d/ there. Then adjust the config files as you wish.

Keymaps

One of udev's features is config keymaps when it detect specified vendor. Mdev does not do so, mdev is for /dev, not for all-other-things. In order to make your special keys working you need to assign keycode to them. You can generate proper setkeycodes commands from udev's sources with get-keys.awk script. like:

awk -f keymaps/get-keys.awk /usr/include/linux/input.h /PATH/TO/UDEV/SOURCE/DIR/src/keymap/keymaps/NAME

To make life easier, keymap dir contain already generated scripts from udev-182's keymaps files. All what you need is to put /opt/mdev/keymaps/NAME.sh into one of your startup scripts.

Preserve interfaces names

Mdev does not provide bulitin support for renaming NICs. However there is settle-nics script which will do it using nameif (can be from net-tools or busybox) and ip (can be original iproute2 or busybox's iproute2 implementation). The settle-nics script create /etc/mactab file with detected eth*, wlan*, ath*, wifi*, ra* and usb* interfaces. Any other is ignored, you need to edit this file by hand if you wish add other names.

Random notes

• Keycodes under Xorg may be different than with evdev, for example mute keycode is no longer 121 but 160. Install 'xev' and check your keycodes if you remap or bind them with xmodmap.
• Mdev does not support udev's udisks and so on, Full blown desktop environments may not really like the change, you will lost your DE's automount stuff etc. But there is pmount and you can always config automount script in /etc/mdev.conf
• Unmerging udev may not be good idea, as for example chromium need libudev to compile. Better append sys-fs/udev -* to package.use and put sys-fs/udev-init-scripts-10 into /etc/portage/profile/package.provided. Then you can rebuild udev with all USE flags disabled and remove udev-init-scripts.
• lsusb seems to run /etc/udev/hwids.bin to identify devices. One may need to add udev USE flag to the hwids package if wishes to see the device names.