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xmm7360 / xmm7360-usb-modeswitch

Tools for the Fibocom L850-GL / Intel XMM7360 LTE modem
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Kick the modem into USB mode without ACPI #4

Closed abrasive closed 4 years ago

abrasive commented 5 years ago

I used the ACPI reset on my laptop to get the modem to reboot itself and come up in USB mode. That probably won't work on all machines, because ACPI.

Writing a full PCI driver is impossible, because the device doesn't accept MBIM commands over PCI; instead they seem to go through a complicated translation layer into a much more compact, ASN.1 BER-ish RPC format. Very unpleasant. But we do understand enough to send AT commands, which is all we need to enable the USB interface.

So one could build a tool that brings up the PCI interface and sends those commands.

abrasive commented 5 years ago

Restarting the modem when it's in PCI-only mode, by issuing AT+CFUN=15, or using several of the production commands, causes the modem to go into crashdump state (status word 0xbadc0ded). There is another option, which is the Intel reboot-to-firmware MBIM command, which I know this modem accepts over USB. But using that means bringing up the PCI RPC interface and then finding which RPC command performs the reboot sigh Or maybe it's just grumpy because the RPC interface isn't up at reboot time?

abrasive commented 4 years ago

There is no evident way to do this. Giving up.