EM7455 Firmware Upgrade on Linux

I have EM7455 Module. I want to upgrade modem through Ubuntu. I have downloaded AT&T, Generic and Sprint modems version is “SWI9X30C_02.32.11.00”. But these have three different PRI’s. As per my understanding EM7455 module can store 4 firmwares and 50 PRI’s. During my firmware upgrade, can I specify modem firmware(.cwe) and with all supported PRI’s(.nuv) files on a same directory to upgrade. Is it will upgrade modem and all PRI’s on the modem?

Thanks in advance,

Yes, MC74xx can store up to 4 firmware binaries and 50 PRIs.

One CWE file can work with multiple matching PRI for each carrier. One carrier can have only one PRI.

On Linux, you can put one matching pair of CWE+NVU in one folder. If the CWE is already on the module, it will not be downloaded repeatedly. Repeat with this method, you can download one CWE and multiple NVU files.

You can issue 'AT!IMAGE?" to check all the firmware and PRIs on the module; ‘AT!IMPREF?’ will show you the currently used firmware and PRI. AT!IMPREF= will let you switch between different carriers.

Thanks dwen for reply.

I have one more query. As you said, MC74xx can store up to 4 fimrwares. If we update with the latest firmware, is will update current running firmware or update with old firmwares? If it’s not updating current firmware, how do I can make to upgrade only current firmware?

Thanks and Regards,

You can download as many as 4 firmware binaries (CWE) on to the module, the last downloaded CWE+NVU pair is set as the “Active” firmware and PRI.

If your desired firmware is already on the module but NVU is not, you can still put both the CWE and NVU in the “path”, CWE won’t actually transferred and flashed again. Only NVU will be downloaded and flashed

Also if your desired CWE and NVU are both on the module but they are not currently active, you can use “AT!IMPREF=” followed by a module reset to make both of them “Active”, for example:

Hi dwen,

Thanks for reply.

I would like to load 4 firmware’s for different carries as mentioned below.

  • fw1 for AT&T and T-Mobile PRI.
  • fw2 for VZW
  • fw3 for Sprint
  • fw4 for Vodafone

Please provide information for my below queries.

  • If VZW SIM is inserted, is device loads fw2 automatically?
  • Inserted VZW SIM and tried to upgrade for VZW new firmware(fw5). Is this new firmware fw5 will overwrite fw2?


  1. When MPREF is set “AUTO-SIM”, if VZW SIM is detected and fw2 is already on the module, the device will load fw2 if it is not already “active”.

  2. There is an algorithm in the module that choose the right slot to overwrite when fw5 is to be downloaded, mostly based on the image age, not necessarily fw2. but for sure VZW PRI will be overwritten. You may take the control by deleting an image with AT!image=0, 0, command so fw5 will be written to an empty slot. For details, please check with at!image=? command