Even if lspci found the device and iwconfig did not, then the hardware driver is not installed properly. Do the following to install driver
# emerge ieee80211 ipw3945 ipw3945d wireless-tools
that will install driver for the wireless device Intel Corporation PRO/Wireless 3945ABG Network. However, you will need to recompile the kernel to suit the requirment. Look at the complain during the installation of the ieee80211 ebuild. You will need to disable and enable something, namely the portion associated with the tag CONFIG_IEEE80211 (under networking) need to be no, and for flag CONFIG_NET_RADIO, you need to build that into the kernel (I did, you can try as module). CONFIG_NET_RADIO is embedded in Device Drivers -> Network Device Support -> Wireless LAN (non-hamradio)
If everything goes fine with the emerge, then when you do a iwconfig, you will find eth1 given eth0 is your wired network. Only when iwconfig shows the wireless network, you are in business to configure. I believe other distribution users can download ipw3945 and compile the driver yourself with a little more work - I welcome you to drop me a line at email@example.com
to share your experience.
The following website has most of the information I used during my exploration process
(do a google search on that since I am not allow to post the link yet)
Then, in /etc/conf.d/net file add in the following lines
config_eth1=( "dhcp" )
dhcp_eth1="nodns nontp nonis"
given eth1 is the wireless device reported by iwconfig. My iwconfig shows
vr conf.d # iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
eth1 IEEE 802.11g ESSID:"yournetworkname" Nickname:"yournetworkname"
Mode:Managed Frequency:2.412 GHz Access Point: 00:60:B3:F3:18:27
Bit Rate:48 Mb/s Tx-Power:15 dBm
Retry limit:15 RTS thr
ff Fragment thr
Link Quality=65/100 Signal level=-67 dBm Noise level=-69 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:1200 Missed beacon:0
Then, in directory /etc/init.d directory, create another link to point net.lo to net.eth1 just like you did for net.eth0
The emerge process for the wireless-tools will also put a wireless config file at /etc/conf.d/wireless.example
You can edit the file to specify the needed information for your wireless network. The second link above will tell you all you need to know on this.
If you are generous and did not set a key to access you wireless resources, then you basically just copy wireless.example file to /etc/conf.d/example with all the line commented out. Maybe you also don't need it but I have not tried it.
Then, you need to turn off the wired interface using the command
then unplug the network wire from the notebook before you turn on the wireless interface at eth1 by
# /etc/init.d/net.eth1 start
You are online...... wirelessly..... that simple......
Do not get fooled with lspci report!! - like I did..... confused me for a day or two....