MavEtJu's Distorted View of the World

FreeBSD and the Huawei E220 USB 3G Modem

Posted on 2007-12-14 21:00:00, modified on 2007-12-17 07:30:00
Tags: Huawei E220, FreeBSD, Networking, 3G

I'm the lucky owner of a Huawei E220 3G USB modem. For certain degrees of lucky that is: Getting it to work has been an interesting challenge.

The E220 is by default (FreeBSD 6.3-BETA) recognized as an umass(4) (USB Mass Storage Device) device. That's true, there is a memory disk in it. It is recognized as /dev/cd0 and you can mount it with mount_cd9660 /dev/cd0 /mnt, giving you 10 megabytes of space.

But that is not what you bought the E220 for. You want to use it as a modem. You need to change a couple things in your kernel to get it all working. First, add a line to /sys/dev/usb/usbdevs:

    /* HP products */
    product HP2 C500                0x6002  PhotoSmart C500

    /* HUAWEI products */
    product HUAWEI MOBILE           0x1001  Huawei Mobile
   +product HUAWEI E220             0x1003  Huawei E220 HSDPA USB Modem

    /* IBM Corporation */
    product IBM USBCDROMDRIVE       0x4427  USB CD-ROM Drive
And to /sys/dev/usb/usba.c:
    /* Option GlobeTrotter 3G QUAD */
    /* Huawei Mobile */
    { 0, 0 }
See the FreeBSD PR usb/118686 for a full patch.

Second, you have to disable the umass(4) device from your kernel configuration and rebuild a new kernel. Will this break things? Most likely, specially when you have USB disks and sticks. But you will load it as a module, which will undo the damage you just did to it. In your /boot/loader.conf, add the following lines:


ubsa(4) is the USB support for Belkin serial adapter. That sounds more like a modem. Next, reboot the machine and see if all modules are loaded correctly:

    # kldstat
    Id Refs Address    Size     Name
     1   20 0xc0400000 72e17c   kernel
     2    1 0xc0b2f000 e6a4     if_iwi.ko
     3    3 0xc0b3e000 2f9c     firmware.ko
     4    1 0xc0b41000 6cdc     ugen.ko
     5    1 0xc0b48000 75b4     umass.ko
     6    1 0xc0b50000 7958     ng_ubt.ko
     7    2 0xc0b58000 cb78     netgraph.ko
     8    1 0xc0b65000 2ef0     ubsa.ko
     9    2 0xc0b68000 4374     ucom.ko
    10    1 0xc0b6d000 5c304    acpi.ko
    11    1 0xc4868000 30000    iwi_bss.ko

Next, plugin your E220 and see what happens:

    ucom0: HUAWEI Technologies HUAWEI Mobile, rev 1.10/0.00, addr 2
    ucom0: Could not find interrupt in
    device_attach: ucom0 attach returned 6

Yes! No! Something is wrong. But a little bit of finger skill will resolve it:

At the USB modem side of the USB cable (not the computer side!), carefully pull the cable from the modem and when you see this on your screen, plug it back in:

    ucom0: at uhub1 port 1 (addr 2) disconnected
    ucom0: HUAWEI Technologies HUAWEI Mobile, rev 1.10/0.00, addr 2

It's loaded! If it doesn't work at the first go, try it a couple of times more. Once you are without the dreaded "Couldn't find interrupt in" message you are a happy person.

Check /dev/cuaaU0, it exists! If you have comms/minicom installed, you can do this:

    Manufacturer: huawei
    Model: E220
    IMEI: 358191018517800
    +GCAP: +CGSM,+DS,+ES

And if you dial out, you will end up with a whooping 7.2Mbps connection;

    ATDT *90#
    CONNECT 7200000

Now it is time to train ppp(1). Add this to your /etc/ppp/ppp.conf:

	set device /dev/cuaU0
	set speed 57600
	set phone *99\#
	set authname
	set authkey
	set ifaddr
	set vj slotcomp off
	add default HISADDR

And dial:

    $ ppp three
    ppp> dial

That's not good, there should be three capital P's... Going through the PPP log, you will see that the IPCP layer doesn't get initialized properly. Why? No idea. How to resolve it? Put your USB modem in a windows machine, run it once there and put it back into your FreeBSD machine. Why? No idea. It works. The USB modem didn't work with under MacOS/X neither until I did this trick. Why? No idea. It works.

Dial again:

    $ ppp three
    ppp> dial

    $ ifconfig tun0
    tun0: flags=8051 mtu 1500
	    inet --> netmask 0xffffffff
	    Opened by PID 22997

    $ ping
    PING ( 56 data bytes
    64 bytes from icmp_seq=0 ttl=48 time=477.662 ms
    64 bytes from icmp_seq=1 ttl=51 time=416.606 ms
    --- ping statistics ---
    3 packets transmitted, 2 packets received, 33% packet loss
    round-trip min/avg/max/stddev = 416.606/447.134/477.662/30.528 ms

Your console and /var/log/messages will be spammed with "kernel: ucom0: usba_request: STALLED" messages for some reason, but it works.

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From: Edwin Groothuis
Posted on: 2007-12-14 20:40:42
CommentSee for some gory details.
From: Edwin Groothuis
Posted on: 2007-12-16 20:11:43
CommentSee for patches which don't require the taking out of the USB cable anymore but work immediately.

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