add a bit about mounting usbfs

svn path=/nixu/trunk/; revision=4516

howto

@@ -83,18 +83,23 @@ NixOS machine (needed for mingetty). Alternatively, do:
 
   Making hotplugging work
 
-Many devices are controlled by so called "hot plugging". The kernel executes
-a program -- usually /sbin/hotplug, but this is configurable at boottime by
-setting the right path in /proc/sys/kernel/hotplug -- when a new device is
-added to the machine. This program makes sure the right kernel modules are
-loaded and optionally, if enabled, sends a message to udev to create the right
-device node in /dev (NOTE: this is not enabled in NixOS right now).
+Many devices (USB, Firewire) are controlled by so called "hot plugging". The
+kernel executes a program -- usually /sbin/hotplug, but this is configurable
+at boottime by setting the right path in /proc/sys/kernel/hotplug -- when a
+new device is added to the machine. This program makes sure the right kernel
+modules are loaded and optionally, if enabled, sends a message to udev to
+create the right device node in /dev (NOTE: this is not enabled in NixOS right
+now).
 
+- mount usbfs (for USB):
+  # mount -t usbfs usbfs /proc/bus/usb
 - install hotplug package
   - make symlinks /etc/hotplug, /etc/hotplug.d, /sbin/hotplug (TODO: make
     this pure)
   - make sure the kernel and additional modules are prepared well (currently
     this is hackish, but workable: see kernelscripts/make-kernel.sh for an
     example)
-  - (optionally:) launch udev
+  - (optionally:) install udev
+    - make a symlink to /etc/udev/udev.conf
+    - launch udev
   - plug in a device