EM7455 Carrier Switching


I was following this thread: https://forum.sierrawireless.com/t/mc7354-how-to-update-firmware-using-at-commands/8699/1 (MC7354 firmware update), but wanted to create a different once for 7455, specifically EM7455.

I understand that the basic flow is to install the correct firmware file from here:
source.sierrawireless.com/resour … -packages/

This will install the correct firmware, and PRI file for the carrier. All will work, and the carrier is happy because we are using the certified firmware.

Based on the other thread, 4 PRI files can be stored on the card, but only 1 firmware file. Makes sense due to size.

For EM7455, Generic, Verizon, AT&T, and Rogers all use the same firmware.

So, on EM7455 with that firmware, can we switch carrier compatibility/certification by simple activating a different PRI? At least between AT&T, Verizon, Rogers, and say T-Mobile (generic)?

And do the same instructions apply from the other thread with regards on how to make the PRI change with AT commands?

Thank you,

To add a bit of clarification also:

Does the firmware for EM7455 contain all 4 PRI’s, or is only a single PRI installed?

And in order to change the PRI must we use the NVU file and install that anytime the carrier is changed?

The examples from the other thread all show 4 PRI’s present, but wondering if the same is true for 7455, or if we can pre-load 4 PRI’s to make changing carrier simple when in production?

Thanks again,

The EM7455 can hold 4 complete firmware images (i.e. 4 different firmware versions) and 50 PRIs. The actual slot selection is still a bit magic to me, but I believe the idea is that the firmware will do the selection for you when you change to another carrier already supported by one of the PRI images already on the modem.

You can use the documented AT commands to look at the avalable images and PRIs, or you can use QMI. Like for example:

root@miraculix:/tmp#  qmicli -p --device-open-mbim  -d /dev/cdc-wdm0  --dms-list-stored-images
[/dev/cdc-wdm0] Device list of stored images retrieved:

        [0] Type:    'modem'
            Maximum: '4'

                Unique ID:     '3F:5F:3F:00:00:00:00:00:00:00:00:00:00:00:00:00'
                Build ID:      ''
                Storage index: '1'
                Failure count: '0'

                >>>>>>>>>> [CURRENT] <<<<<<<<<<
                Unique ID:     '3F:5F:3F:00:00:00:00:00:00:00:00:00:00:00:00:00'
                Build ID:      ''
                Storage index: '2'
                Failure count: '0'

        [1] Type:    'pri'
            Maximum: '50'

                >>>>>>>>>> [CURRENT] <<<<<<<<<<
                Unique ID:     '30:30:32:2E:30:30:37:5F:30:30:30:00:00:00:00:00'
                Build ID:      ''

                Unique ID:     '30:30:32:2E:30:30:36:5F:30:30:30:00:00:00:00:00'
                Build ID:      ''

I have no idea why this modem has the ORANGE PRI or the firmware image (which isn’t used by any PRI as you can see). This is a Lenovo EM7455 delivered as part of a preconfigured a Lenovo laptop, and it came exactly like this. It was provided with a “Lenovo” SIM though, so I guess the Orange PRI could be related to that. I haven’t used it or looked at what operator it is from. Could be Orange, I guess?