Em7455 AT!USBCUSTOM=1,1,0000400F (RNDIS)

IoT Modules
1

i would like to enable, RNDIS mode, on EM7455,
will serial ports on ttyUSB0-2 still be avaible (for AT commands) in RNDIS mode?
here is my !USBCOMP

- 1:Generic, 2:USBIF-MBIM, 3:RNDIS
config type 2/3 should only be used for specific Sierra PIDs: 68B1, 9068
customized VID/PID should use config type 1
- DIAG - 0x00000001,
ADB - 0x00000002,
NMEA - 0x00000004,
MODEM - 0x00000008,
RMNET0 - 0x00000100,
RMNET1 - 0x00000400,
MBIM - 0x00001000,
RNDIS - 0x00004000,
UBIST - 0x00200000

im in the Generic mode, this is the bitmask: 0000400F.

2

didn’t you already set it?
How is your test result?

3

i havent set it yet. i want to do it, but im not sure if the ttyUSB* will still be there, and im not sure if
echo VID PID /sys/bus/usb-serial/ will work to re-enable it.

4

i don’t see such option in AT command use guide:

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5

its not in the manual, not sure the reason for it.
maybe it’s because its for engineering mode lvl2 (AT+ENTERCND=“A710”), and
im in the engineering mode lvl3 (AT!OPENLOCK) ?

6

ok, then i don’t think you should use it

7

i cant get dhclient or udhcpc lease when i use AT!CUSTOM=0000100F(MBIM) or AT!CUSTOM=0000010F(RMNET), thats the only option i think that might do it.
in any case, ive read a post on this site, that was talking about old Gobi drivers.
do you think that might work?

8

did you follow this document?

Yes, you can try the old Gobi drive on RMNET interface(QMI)

9

i dont think i’ve looked at that doc. yet, ill do it now.

10

BTW, what kernel version are you using?

11

kernel version: 5.15.52-1
EM7455 kernel version: 3.10.0+

12

The DHCP server feature, or lack there-of, is a modem firmware thing. Switching drivers won’t make any difference.

You don’t explain why you want a dhclient or udhcpc lease, so I suspect that is based on some misunderstanding. IMHO, you should never use DHCP to propagate IP address configuration from modem firmware to host, even when supported (which it is not on the EM7455). Using DHCP here is an ugly hack, and can never work as good as the native (QMI or MBIM) methods.

13

EM7455 kernel version: 3.10.0+

You mean your host platform is kernel v3.10?

14

i want to have EM7455 on a local net address: 192.168.., same as those plug and play mobile hot spots.
those hot spot mobile devices give a host an address, such as 192.168.1.50, and the mobile host spot acts as a gateway to internet using 2/3/4g

ive seen a commercial device like this for a kiosk, with this exact capability, and it had em 7455 in it.
i think those devices might’ve ran as cdc-either, but im not sure.

i dont remember the company name that had that product.
i want to be able to reproduce that same network behavior.

15

kernel version of the machine EM7455 connected to is: 5.15.52-1
kernel version EM7455 running on is: 3.10.0+ (when i access EM7455 from Android Debug Bridge)

16

This is not a supported mode on the EM7455.

Which doesn’t mean it can’t be done. Just that it’s not supported. And I’m will to bet more than one beer that no one else has tried, so you’ll have the pleasure of being the very first guniea pig. Might still survive - who knows?

17

thank you for the encouragement :slight_smile:

EM7455 is running a bridge internally (can also be put into NAT), this is the bridge from inside of EM7455:

bridge0 Link encap:Ethernet HWaddr [DE:AD:BE:EF:FF:FF] // i redacted the address
inet addr:192.168.225.1 Bcast:192.168.225.255 Mask:255.255.255.0

it also has rmnet_data0 which can be brought up. rmnet_data0, is the interface thats connected to the service provider, it gets all the correct ip,dns etc… (so theres no need for the host OS, that EM7455 plugged into, to have a modem manager)

i think this might be a qualcomm thing, as it has QCMAP_CLI command (in ADB), which switches on a few things.

ill go pester qualcomm, see what they say :slight_smile:

cheers!

18

done, read this: EM7455 exposing LAN interface