之前寫過 Xorg 1.4 XInput Hotplug，提到 xorg, evdev 可以利用 hal 自動偵測硬體載入 driver 與設定參數，而即將 release 的 Xorg 1.5 又新增了一些可以在 hal policy 裡設定的參數：
- input.x11_driver 可以設定這個 device 要使用的 driver，對應到 xorg.conf 的 Driver 選項
- input.x11_options.
如今我的 /etc/hal/fdi/policy/10-x11-input.fdi 長這樣：
< ?xml version="1.0" encoding="ISO-8859-1"?>
mouse
evdev
<match key="info.capabilities" contains="input.keys">
<merge key="input.x11_options.XkbRules" type="string">base</merge>
<!-- If we're using Linux, we use evdev by default (falling back to
keyboard otherwise). -->
<merge key="input.x11_driver" type="string">keyboard</merge>
<merge key="input.x11_options.XkbModel" type="string">pc105</merge>
<match key="/org/freedesktop/Hal/devices/computer:system.kernel.name"
string="Linux">
<merge key="input.x11_driver" type="string">evdev</merge>
<merge key="input.x11_options.XkbModel" type="string">evdev</merge>
</match>
<merge key="input.x11_options.XkbVariant" type="string" />
<merge key="input.x11_options.XkbLayout" type="string">dvorak</merge>
<merge key="input.x11_options.XkbOptions" type="string">ctrl:nocaps</merge>
</match>
<match key="info.capabilities" contains="input.touchpad">
<merge key="input.x11_driver" type="string">synaptics</merge>
<merge key="input.x11_options.Protocol" type="string">auto-dev</merge>
<merge key="input.x11_options.SHMConfig" type="string">on</merge>
<merge key="input.x11_options.LeftEdge" type="string">1100</merge>
<merge key="input.x11_options.RightEdge" type="string">5800</merge>
<merge key="input.x11_options.TopEdge" type="string">1600</merge>
<merge key="input.x11_options.BottomEdge" type="string">4200</merge>
<merge key="input.x11_options.HorizEdgeScroll" type="string">on</merge>
</match>
我的 /etc/X11/xorg.conf 只剩下必要的：
Section "Device"
Identifier "i915gm"
Driver "intel"
EndSection
Section "Screen"
Identifier "Default Screen"
Device "i915gm"
DefaultDepth 24
SubSection "Display"
Modes "1280x768"
Virtual 1280 1792
EndSubSection
EndSection
X 啟動的 log 如下：
(II) config/hal: Adding input device SynPS/2 Synaptics TouchPad
(II) LoadModule: "synaptics"
(II) Loading /usr/lib/xorg/modules/input//synaptics_drv.so
(II) Module synaptics: vendor="X.Org Foundation"
compiled for 1.4.99.906, module version = 0.15.0
Module class: X.Org XInput Driver
ABI class: X.Org XInput driver, version 2.1
(II) Synaptics touchpad driver version 0.15.0
() Option "Device" "/dev/input/event8"
() Option "SHMConfig" "on"
() Option "LeftEdge" "1100"
() Option "RightEdge" "5800"
() Option "TopEdge" "1600"
() Option "BottomEdge" "4200"
() Option "HorizEdgeScroll" "on"
(--) SynPS/2 Synaptics TouchPad touchpad found
() SynPS/2 Synaptics TouchPad: always reports core events
(II) XINPUT: Adding extended input device "SynPS/2 Synaptics TouchPad" (type: MOUSE)
(--) SynPS/2 Synaptics TouchPad touchpad found
未來各 distro 可以提供預設的 fdi 檔，常見的 input device 都可以隨插即用 
