Apologies for the very late reply, life got busy. I imagine if you googled around a bit more you might have already found your solution so what I post below will make no difference but I will post it to my forum thread anyways for the benefit of others. Anywho, there's a couple methods floating around to convert the Dell branded EM7455 into a 'vanilla' sierra wireless model, here's the first:
Postby ipxon » Thu Dec 01, 2016 7:26 pm
1- Download driver from dell website.
2- Uncompress .exe (with 7zip).
3- enter to folder and edit Configuration.ini and set USBCOMP=8 (change 0 to 8 ).
4- execute .exe (It is in the same folder as the file Configuration.ini).
5- plug card em7455 and open Device administrator. You should see the DELL modem, open a find COM port.
6- Open AT Port (with Putty or other program) and excute this commands:
AT!ENTERCND="A710"
AT!USBPID=9071,9070
AT!USBVID=1199
AT!USBPRODUCT="EM7455"
AT!PRIID="9904802","001.001","Generic-Laptop"
AT!RESET
7- Install Sierra Wireless drivers.
8- Done :D
Credits: baodo.
Good Luck!
I think I tried that first but didn't have luck with the Dell .exe changing the USB composition for whatever reason (maybe because my laptop is a Thinkpad and .exe was looking at my BIOS to confirm it was Dell, I don't remember) so I changed the mode in Linux via a perl script found here: http://git.mork.no/?p=wwan.git;a=blob_plain;f=scripts/swi_setusbcomp.pl . You will need shareable perl and tiny perl packages installed to run that. I used a Ubuntu live disk on a spare flash drive to run it ('sudo perl swi_setusbcomp.pl –usbcomp=6'). You can change the mode to 6 (QMI) or 8 (MBIM) to expose the AT port for changing PID/VID of the device but I only had luck with mode 6 in Ubuntu because it appeared to need QMI for the next piece....
Once you have it in USB mode 6 you need to expose the usb serial port device for the AT port to connect to it. To do this you need to get the qcserial driver to load for the current Dell VID/PID which can be accomplished through this udev rule: https://github.com/fribergr/dw5811e/blob/master/99-dell5811e.rules . Once the udev rule is in place you should be able to run the following to get the AT serial port working:
sudo modprobe qcserial
sudo echo 1 >/sys/bus/usb/devices/usb2/bConfigurationValue
sudo echo "413c 81b6" > /sys/bus/usb-serial/drivers/qcserial/new_id
You should then see 3 'ttyUSB' devices show up under '/dev'. You might need to unplug and re-plug in the modem for the USB serial devices to show up (if all else fails, reboot and run the modeprobe and echo commands again, then for sure they should be there). From there you can use Screen or Minicom or whatever serial terminal emulator you prefer and connect to the AT serial port (connection speed of 115200). I believe it was 'ttyUSB1'. Type 'at' and if you get 'OK', you know you're connected to the correct port (type 'ate' to echo your keystrokes if they are not appearing as you type). From there you can proceed with the steps from the 'dell drivers' method I posted first (you will see I have changed a couple things at the bottom compared to the 'dell driver' method, I will explain the reason):
AT!ENTERCND="A710"
AT!USBPID=9071,9070
AT!USBVID=1199
AT!PRIID="9904609","002.117","GENERIC"
AT!IMAGE=0
AT!RESET
Boot back into windows, install Sierra Wireless drivers from source.sierrawireless.com, and flash with "SWI9X30C_02.20.03.00_00_GENERIC_002.017_000" firmware (latest as of this posting).
The variations I have made on the 'dell driver' method vary in the 'PRIID' and 'IMAGE' commands along with my recommendation to flash the latest firmware. I have chosen that specific PRI ID as it matches the PRI Part Number, Revision, and Customer of the latest Sierra generic firmware (if you are flashing a different version or carrier specific firmware I suggest you update PRIID accordingly to avoid any PRI configuration mismatches). The IMAGE command I have added because I found with my Dell branded EM7455 there were a few different firmwares already loaded in the 4 available slots along with their various PRIs; this was very messy and caused me some headaches with configuration mismatches with PRI settings etc. 'IMAGE=0' avoids all of this by deleting all firmware/PRI from all slots. Thus, my last instruction is to flash the latest Sierra firmware after loading the generic drivers as there will be no firmware if you use available 'IMAGE=0' as I recommend. You will find that if you use this Linux method, after you perform the 'RESET' command, the modem will automatically be back in MBIM mode (as opposed tot he QMI mode before). This lets it work natively with Windows 8/10 since windows uses MBIM.
