Hi,

I have a DELL Inspiron 1501 with "Dell Wireless 1490 - 802.11a/b/g" as wireless card and m running on a Debian. I have loaded the bcm43xx kernel module said to be the appropriate driver.

My problem is that I cannot find any WLAN interface on my system:

Any help would be appreciated.

bcm43xx is for Broadcom 43xx cards, so it works if your card is one of those. It's said to be a tricky card, but don't worry - it's easy to get working nevertheless.

Since Broadcom doesn't provide Linux drivers and refuses to tell much details about the whole thing, you'll have two possibilities here:
1) use the bcm43xx driver (which is native), but to make it work for the card, you need to obtain a few files off a Windows driver with a program called fwcutter ("firmware cutter"). Basically you cut some "firmware" off the Windows driver, put it in a directory where bcm43xx finds the data and have the card working, or
2) install ndiswrapper, and use it to install an appropriate Windows driver to be used for the card (bcm-something.inf and .sys) - if you can, install binary ndiswrapper and ndiswrapper-utils deb files, or if you can't, install the kernel source/headers for your current kernel version and compile ndiswrapper from source (easy, really). Version 1.47 or later should work for this card.

For both ndiswrapper and fwcutter there is a lot of information around. Here at LQ there are loads of threads and posts about how to get bcm43xx cards working, either with ndiswrapper or the native driver. I'd prefer the native driver (because then you only need to get the "firmware data" and it works without installing anything else), but ndiswrapper works also (then you'll just have to install ndiswrapper, possibly compiling it from source -- if you take this path, remember to blacklist the bcm43xx module because it could prevent ndiswrapper from working properly).

In addition (I'm not sure if you have the driver working or not, the above text is for you if you don't have) you're not using ifconfig for wireless devices, but iwconfig (to connect to a network) and iwlist (to scan for networks);
The above as root shows the available networks, if any, if your card works. Or there's a problem with the driver, it says the device doesn't support scanning or something...if eth1 is not your wireless device, change it to the proper one (like wlan0 for example).

Yes, sorry I forgot to tell I have bcm43xx-fwcutter package installed.
I am not trying this solution yet, because I am using solution 1 and don't think the problem comes from here.
I actually don't know either because I could not test it, since I know no way of testing it without having a WLAN interface somewhere. So I assume it works, and that the problem is the missing interface.
I have already tried (result after the ifconfig in my first post):
The problem is actually here. I have no eth1, so I cannot try iwlist on it. As shown above I apparently have 3 interfaces only. Trying iwlist on lo or sit0 is nonsense and eth0 is my ethernet interface, so it won't be better. If I try anyway on either of these 3 I get the "no wireless extensions." error message and same thing if I try inventing new interfaces like eth1 or wlan0.
Usually interfaces exist before they are used, or before they get a driver. So changing anything about my driver won't change anything on the fact that I simply have no existing WLAN interface, will it?

If I look in /sys/class/net I have my 3 interfaces lo, eth0 and sit0. eth0 has all its config inside, a pointer to the appropriate PCI device, and so on, but here I have nothing speaking about my WLAN interface and its PCI device that I am positive does exist:
And if I look in the HAL device manager, I can see my ethernet PCI device, and it does have a child element in the tree-view called "network interface" and that is eth0. And a few lines below, I can see my WLAN PCI device, but this one has no child element.

There must be somewhere I can create and configure a new interface.