swi_setusbcomp

Query and change the USB composition of Sierra Wireless cellular modems when the device is stuck in MBIM-only mode and no AT or QMI serial ports are available.

Originally written by Bjørn Mork (2015, GPLv2) as a one-off hack. The same functionality is now built into qmicli via --dms-swi-get-usb-composition and --dms-swi-set-usb-composition, but this standalone Perl script remains useful on minimal systems or when you want a single file with no build dependencies beyond Perl modules.

The Problem

Sierra Wireless (now Semtech) Qualcomm-based modems expose multiple USB interfaces to the host. Which interfaces appear — diagnostic (DM), NMEA/GPS, AT command port, QMI, MBIM, RMNET, ECM, etc. — is controlled by a setting called USB composition.

Common scenarios where composition becomes a problem on Linux:

Scenario	Symptom
Windows driver or Sierra application changed composition	Modem enumerates as MBIM-only; no `/dev/ttyUSB*` or AT port
Firmware defaults to composition 9 (MBIM only)	`NetworkManager`/`ModemManager` works, but `qmicli` and AT tools cannot run
MBIM-only PID lock (some EM7455/MC7455 units)	Even after reset, only `/dev/cdc-wdm0` appears

Normally you would fix this with AT commands:

AT!USBCOMP=1,1,100D    # newer MC/EM series (bitmask style)
AT!UDUSBCOMP=8         # older modules (index style)
AT!RESET

But if the modem is in MBIM-only mode, there is no AT port. The QMI control channel is also gone. What remains is the MBIM control device (/dev/cdc-wdm*), driven by the Linux cdc_mbim kernel driver.

This script reaches the modem through that MBIM channel by tunneling QMI messages inside a vendor-specific MBIM service — the same mechanism later adopted by libqmi's --device-open-mbim mode.

What This Script Does

Opens an MBIM control device (default /dev/cdc-wdm0) and verifies it is served by the cdc_mbim driver.
Establishes an MBIM session (OPEN / OPEN_DONE).
Tunnels QMI over MBIM using the Qualcomm EXT_QMUX vendor service.
Allocates a QMI DMS (Device Management Service) client ID.
Sends QMI_DMS_SWI_GET_USB_COMPOSITION (0x555B) to read the current composition and the list of supported compositions.
Optionally sends QMI_DMS_SWI_SET_USB_COMPOSITION (0x555C) to change the composition.
Cleans up (releases DMS client, MBIM CLOSE) and exits.

Without --usbcomp, the script only displays the current and supported compositions. With --usbcomp=N, it attempts to switch to composition N if the modem reports it as supported.

Supported Hardware

Tested and documented primarily on Qualcomm-based Sierra Wireless modules in the MC/EM series, including:

MC7354, MC7710, MC7455
EM7455, EM7565
Similar modules exposing MBIM via cdc_mbim

The script requires:

An MBIM control character device (/dev/cdc-wdm*)
The Qualcomm EXT_QMUX MBIM vendor service (UUID d1a30bc2-f97a-6e43-bf65-c7e24fb0f0d3)

You can verify the QMI-over-MBIM service is present:

mbimcli -d /dev/cdc-wdm0 --query-device-services

Look for a service named qmi with the UUID above and CID msg (1).

Not supported: modems that only expose a QMI (qmi_wwan) interface with no MBIM channel, or modems lacking the EXT_QMUX service.

Requirements

System

Linux with the cdc_mbim kernel driver
Root privileges (the /dev/cdc-wdm* device is typically restricted)
Perl 5 with these modules:
- UUID::Tiny
- IPC::Shareable
- JSON
- Getopt::Long (core)
- Fcntl (core)
- sys/ioctl.ph (from perl-base / perl-dev on Debian/Ubuntu)

Optional tools (for diagnosis, not required by the script)

mbimcli — from libmbim
qmicli — from libqmi
mmcli — from ModemManager

Installation

1. Get the script

git clone https://github.com/mavstuff/swi_setusbcomp.git
cd swi_setusbcomp
chmod +x scripts_swi_setusbcomp.pl

Or download the script directly from the original upstream.

2. Install dependencies

Pick the instructions for your distribution. All examples assume you run the script as root (or with sudo).

Debian, Ubuntu, Raspberry Pi OS, Armbian

sudo apt update
sudo apt install perl libuuid-tiny-perl libipc-shareable-perl libjson-perl

OpenWrt

Ensure MBIM kernel support is present, then install Perl and core modules:

opkg update
opkg install perl perlbase-essential perlbase-json-pp perlbase-getopt perlbase-fcntl \
             kmod-usb-net-cdc-mbim

UUID::Tiny and IPC::Shareable are not packaged in the default OpenWrt feeds. Options:

Entware (recommended on routers with USB storage) — see below
cpanminus on device — needs extra flash/RAM and build tools:

opkg install perlbase-extutils perlbase-io make gcc
curl -L https://cpanmin.us | perl - --notest UUID::Tiny IPC::Shareable

Copy the script to the router (scp) or download it with wget if space is tight.

Entware (OpenWrt, DD-WRT, AsusWRT-Merlin, Synology, …)

Entware provides opkg packages for embedded devices with more storage than stock OpenWrt.

/opt/bin/opkg update
/opt/bin/opkg install perl perl-json

Install the remaining modules via CPAN (see Entware Perl wiki):

/opt/bin/opkg install perl-dev make gcc
/opt/bin/perl -MCPAN -e 'install UUID::Tiny'
/opt/bin/perl -MCPAN -e 'install IPC::Shareable'

Run the script with /opt/bin/perl scripts_swi_setusbcomp.pl.

Alpine Linux

Common in containers, industrial gateways, and minimal embedded images:

apk add perl perl-json perl-dev make gcc musl-dev
cpanm --notest UUID::Tiny IPC::Shareable

Alpine ships perl-json but not perl-uuid-tiny or perl-ipc-shareable; cpanm (from perl-app-cpanminus) is the shortest path.

Arch Linux

Most modules are in the official extra repository; UUID::Tiny is AUR-only.

sudo pacman -S perl perl-json perl-ipc-shareable cpanminus
cpanm --notest UUID::Tiny

Or install perl-uuid-tiny from the AUR (yay -S perl-uuid-tiny / paru -S perl-uuid-tiny).

CentOS, Rocky Linux, AlmaLinux, RHEL

CentOS 7 / RHEL 7 — enable EPEL first, then install:

sudo yum install epel-release
sudo yum install perl perl-JSON perl-UUID-Tiny perl-IPC-Shareable

If yum cannot find a module, use CPAN:

sudo yum install perl-CPAN gcc make
sudo cpan UUID::Tiny IPC::Shareable

CentOS Stream 8/9, Rocky 8/9, AlmaLinux 8/9, RHEL 8/9 — dnf can resolve packages by Perl module name:

sudo dnf install perl 'perl(UUID::Tiny)' 'perl(IPC::Shareable)' 'perl(JSON)'

Enable EPEL on RHEL if packages are missing: sudo dnf install epel-release.

Fedora

sudo dnf install perl 'perl(UUID::Tiny)' 'perl(IPC::Shareable)' 'perl(JSON)'

openSUSE Leap / Tumbleweed

sudo zypper refresh
sudo zypper install perl perl-JSON perl-UUID-Tiny perl-IPC-Shareable

Search if a package name differs on your release: zypper search perl-IPC-Shareable.

SUSE Linux Enterprise (SLES)

Base SLES images ship a minimal Perl set. Enable SUSE Package Hub for community packages:

sudo SUSEConnect -p sle-packagehub/<version>/x86_64   # adjust version/arch
sudo zypper refresh
sudo zypper install perl perl-JSON perl-UUID-Tiny

perl-IPC-Shareable may not be in Package Hub for every SLES release. If zypper install perl-IPC-Shareable fails:

sudo zypper install perl-CPAN gcc make
sudo cpan IPC::Shareable

Alternatively, add the devel:languages:perl OBS repository for your SLE service pack (see software.opensuse.org).

Yocto / Buildroot / custom embedded images

These build systems do not share one package manager. Typical approaches:

Yocto: add perl, perl-module-json, and CPAN recipes (or a custom layer) for UUID::Tiny and IPC::Shareable to your image; ensure cdc_mbim is enabled in the kernel config (CONFIG_USB_NET_CDC_MBIM).
Buildroot: enable BR2_PACKAGE_PERL and required Perl module packages in menuconfig, or install modules at first boot with cpanm if your rootfs is writable.
Prebuilt vendor SDK: many LTE gateway BSPs ship Debian- or OpenWrt-based rootfs — use the matching section above.

If Perl module installation on the target is impractical, run the script from a chroot or NFS root with a fuller userspace, or use qmicli --device-open-mbim from a cross-built libqmi instead.

Usage on Linux

scripts_swi_setusbcomp.pl [options]

Options

Option	Description
`--device=<path>`	MBIM control device (default: `/dev/cdc-wdm0`)
`--usbcomp=<num>`	Change USB composition to index `<num>`
`--verbose`	Print QMI subsystem versions and composition table (default: on)
`--noverbose`	Suppress extra output
`--debug`	Hex-dump all MBIM/QMI traffic and decode message headers
`--help`	Show usage and exit

Examples

Show current composition and all supported modes (read-only):

sudo ./scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0

Example output:

MBIM OPEN succeeded
MBIM QMI support verified
supports 12 QMI subsystems:
  QMI_CTL (1.0)
  QMI_WDS (1.67)
  ...
Got QMI DMS client ID '1'
Current USB composition: 9
USB compositions:
    6 - DM   NMEA  AT    QMI                              SUPPORTED
    8 - DM   NMEA  AT    MBIM                             SUPPORTED
  * 9 - MBIM                                                  SUPPORTED

Switch from MBIM-only (9) to DM+NMEA+AT+QMI (6) — common fix for MC7354:

sudo ./scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0 --usbcomp=6

Switch to DM+NMEA+AT+MBIM (8) — keeps MBIM networking while restoring AT/QMI ports:

sudo ./scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0 --usbcomp=8

Debug a failing session:

sudo ./scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0 --debug

After any composition change, reset or power-cycle the modem for the new USB layout to take effect (see After Changing Composition).

Usage on Android (via ADB)

This script can run on Android when the device exposes a Linux-style /dev/cdc-wdm* node backed by the cdc_mbim kernel driver. That is common on embedded/industrial Android boards and rooted setups with an external USB LTE modem (OTG), but not on typical consumer phones where the built-in modem is managed by the proprietary RIL stack.

When it works

Setup	Likely to work?
AOSP / industrial tablet with USB or M.2 LTE modem	Yes, if `cdc_mbim` is in the kernel and `ueventd` creates `/dev/cdc-wdm*`
Rooted phone/tablet + USB LTE dongle (OTG)	Yes, with root and kernel driver support
Stock phone, internal modem only	No — no `/dev/cdc-wdm0` for userspace; use a PC instead
Termux without root	No — this script opens `/dev/cdc-wdm0` directly; `termux-usb` cannot substitute without code changes

The script is not Termux-USB compatible as-is: it expects a standard character device node, not an Android USB file descriptor.

Prerequisites

On the host PC:

Android platform-tools (adb)
USB debugging enabled on the Android device

On the Android device:

Root (su) or an eng/userdebug build with adb root — required to open /dev/cdc-wdm*
Kernel modules cdc_mbim and cdc_wdm (check with lsmod or cat /proc/modules)
Perl 5 with UUID::Tiny, IPC::Shareable, and JSON — Termux is the practical way to get these on Android

1. Connect and verify the modem

From your PC:

adb devices
adb shell getprop ro.build.type          # userdebug/eng helps for adb root

Check that the MBIM control device exists:

adb shell su -c 'ls -l /dev/cdc-wdm*'
adb shell su -c 'readlink -f /sys/class/usbmisc/cdc-wdm0/device/driver'

The driver symlink should end in cdc_mbim. If you see /sys/class/usbmisc/cdc-wdm0 in sysfs but no /dev/cdc-wdm0, the Android ueventd rules are missing. Add to ueventd.rc (custom ROM / vendor image):

/dev/cdc-wdm*  0660  radio  radio

See cdc-wdm support on AOSP and vendor guides (e.g. Quectel Android RIL).

Confirm the modem enumerates:

adb shell su -c 'lsusb'
adb shell su -c 'dmesg | grep -i mbim'

2. Install Perl in Termux

Install Termux on the device (GitHub build recommended if you need run-as from adb). Inside Termux:

pkg update
pkg install perl make clang
curl -L https://cpanmin.us | perl - App::cpanminus
cpanm --notest UUID::Tiny IPC::Shareable JSON

To drive Termux from adb without typing on the device (rooted, or debuggable Termux build):

adb shell -tt run-as com.termux \
  files/usr/bin/env \
    PATH=/data/data/com.termux/files/usr/bin \
    LD_PRELOAD=/data/data/com.termux/files/usr/lib/libtermux-exec.so \
    HOME=/data/data/com.termux/files/home \
    bash -lic 'cpanm --notest UUID::Tiny IPC::Shareable JSON'

3. Copy the script to the device

From your PC, in the repository directory:

adb push scripts_swi_setusbcomp.pl /data/local/tmp/
adb shell su -c 'chmod 755 /data/local/tmp/scripts_swi_setusbcomp.pl'

4. Release the modem from the Android telephony stack

The RIL daemon (rild) may hold the modem open. Stop it before running the script (embedded devices only — this disables cellular on the device until reboot):

adb root                              # eng/userdebug builds only
adb shell stop ril-daemon
# or, with su:
adb shell su -c 'setprop ctl.stop ril-daemon'

On SELinux-enforced builds you may need permissive mode for testing:

adb shell su -c 'setenforce 0'

5. Run the script

Using Termux's Perl as root (typical path):

# Query current composition
adb shell su -c '/data/data/com.termux/files/usr/bin/perl /data/local/tmp/scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0'

# Change composition (example: switch to DM+NMEA+AT+MBIM)
adb shell su -c '/data/data/com.termux/files/usr/bin/perl /data/local/tmp/scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0 --usbcomp=8'

If Perl is installed elsewhere, adjust the path. Debug output:

adb shell su -c '/data/data/com.termux/files/usr/bin/perl /data/local/tmp/scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0 --debug'

6. Reset the modem

Power-cycle the USB modem or reset via AT/QMI if available, then reboot the Android device or restart rild:

adb shell su -c 'setprop ctl.start ril-daemon'
adb reboot

Verify the new composition after re-enumeration:

adb shell su -c '/data/data/com.termux/files/usr/bin/perl /data/local/tmp/scripts_swi_setusbcomp.pl --device=/dev/cdc-wdm0'

Android-specific troubleshooting

Symptom	What to try
`Permission denied` on `/dev/cdc-wdm0`	Run via `su`; check node owner (`radio` group) and SELinux context (`radio_device`)
No `/dev/cdc-wdm0` node	Fix `ueventd.rc`; confirm `cdc_mbim` bound in `dmesg`
`only MBIM devices are supported`	Driver is `qmi_wwan`, not `cdc_mbim` — wrong USB composition or driver
`Failed to verify QMI vendor specific MBIM service`	Modem firmware lacks EXT_QMUX over MBIM; try `mbimcli --query-device-services` via cross-built libmbim
`open /dev/cdc-wdm0: Device or resource busy`	Stop `rild`, ModemManager-like services, or other apps using the modem
Termux Perl not found from `su`	Use the full path `/data/data/com.termux/files/usr/bin/perl` (shown above)
`run-as com.termux` fails	Install the debuggable Termux APK from GitHub releases, or use root

Easier alternative on Android

If you can move the modem to a Linux PC (or the Android device runs a Linux chroot/VM with USB passthrough), use qmicli there instead:

qmicli -d /dev/cdc-wdm0 --device-open-mbim --dms-swi-get-usb-composition
qmicli -d /dev/cdc-wdm0 --device-open-mbim --dms-swi-set-usb-composition=8

USB Composition Reference

The script embeds Sierra Wireless composition indices 0–22. The modem firmware reports which indices are actually supported; unsupported ones are marked NOT SUPPORTED in the listing.

Index	Interfaces	Typical use
0	HIP, DM, NMEA, AT, MDM1, MDM2, MDM3, MS	Legacy
1	HIP, DM, NMEA, AT, MDM1, MS	Legacy
2	HIP, DM, NMEA, AT, NIC1, MS	Legacy
3	HIP, DM, NMEA, AT, MDM1, NIC1, MS	Legacy
4	HIP, DM, NMEA, AT, NIC1, NIC2, NIC3, MS	Legacy
5	HIP, DM, NMEA, AT, ECM1, MS	Legacy ECM
6	DM, NMEA, AT, QMI	Classic Linux QMI setup
7	DM, NMEA, AT, RMNET1, RMNET2, RMNET3	RMNET data channels
8	DM, NMEA, AT, MBIM	MBIM + management ports (recommended on modern kernels)
9	MBIM	MBIM-only (problematic if you need AT/QMI)
10	NMEA, MBIM	GPS + MBIM
11	DM, MBIM	Diagnostic + MBIM
12	DM, NMEA, MBIM	Diagnostic + GPS + MBIM
13–22	Dual-config (comp6/comp7 paired with comp8–comp12)	Boot-time composition switching

Interface abbreviations

Abbr	Meaning
HIP	Host Interface Protocol (legacy Sierra)
DM	Diagnostic / DM port (`/dev/ttyUSB*`, often first port)
NMEA	GPS NMEA output
AT	AT command port
MDM1–3	Modem network interfaces (QMI/WWAN)
NIC1–3	Network interface (CDC-NCM/ECM)
ECM1	CDC-ECM network
QMI	QMI control (`/dev/cdc-wdm*` via `qmi_wwan`)
MBIM	MBIM control + data (`/dev/cdc-wdm*` + `wwan0` via `cdc_mbim`)
RMNET1–3	Qualcomm RMNET data channels
MS	Mass Storage (firmware update mode)

On newer firmware (MC7455/EM7455 and later), Sierra also documents compositions via bitmask with AT!USBCOMP. The numeric indices above (6, 8, 9, etc.) map to the same logical layouts but use the older index scheme understood by the QMI vendor commands.

How It Works

Architecture overview

┌─────────────┐     MBIM protocol      ┌──────────────────┐
│   Script    │ ◄──────────────────►  │  /dev/cdc-wdm0   │
│  (parent)   │   read/write           │  (cdc_mbim drv)  │
└──────┬──────┘                        └────────┬─────────┘
       │ fork()                               │
┌──────▼──────┐                               │
│   Reader    │ ◄── async MBIM responses ─────┘
│   (child)   │
└──────┬──────┘
       │ IPC::Shareable
       ▼
  lastmbim / lastqmi  (shared between processes)

The parent process writes MBIM requests; a forked child continuously reads responses and decodes them into shared memory. This avoids blocking on bidirectional I/O on a single file descriptor.

MBIM layer

The script implements a minimal MBIM client:

OPEN / OPEN_DONE — negotiate MaxControlTransfer size (default 4096 bytes, overridden by IOCTL_WDM_MAX_COMMAND ioctl when available)
COMMAND / COMMAND_DONE — send service requests
CLOSE / CLOSE_DONE — tear down session

QMI-over-MBIM tunnel (EXT_QMUX)

Qualcomm defines a vendor MBIM service that carries raw QMUX/QMI payloads:

Property	Value
Service name	EXT_QMUX
UUID	`d1a30bc2-f97a-6e43-bf65-c7e24fb0f0d3`
CID	1
Operation	MBIM Set (type=1) with QMUX buffer as InformationBuffer
Response	Raw QMUX response in COMMAND_DONE InformationBuffer

This tunnel is documented in the libmbim MBIM protocol notes and was reverse-engineered for the MC7710 by Bjørn Mork (Sierra Wireless forum discussion).

Sierra Wireless QMI DMS vendor messages

Message	ID	Direction	TLVs
SWI Get USB Composition	`0x555B`	Request: none	Response: `0x10` = current (uint8), `0x11` = supported list (count + uint8[])
SWI Set USB Composition	`0x555C`	Request: `0x01` = new index (uint8)	Response: standard QMI result TLV `0x02`
SWI Set FCC Authentication	`0x555F`	(referenced in code comments, not implemented)	—

These messages were added to libqmi in October 2017 (libqmi-devel patch), vendor ID 0x1199 (Sierra Wireless).

Execution flow

Validate $device is a character device with cdc_mbim driver.
fork() — child runs read_mbim() loop until CLOSE_DONE.
Parent sends MBIM OPEN, waits for OPEN_DONE (0x80000001).
Parent sends QMI_CTL GET_VERSION_INFO (0x0021) via EXT_QMUX to verify tunnel works.
Parent sends QMI_CTL GET_CLIENT_ID (0x0022, TLV 0x01 = DMS service) → stores DMS CID.
Parent sends DMS SWI GET USB COMPOSITION (0x555B) → prints current + supported list.
If --usbcomp=N given and valid: sends DMS SWI SET USB COMPOSITION (0x555C, TLV 0x01 = N).
quit(): releases DMS CID (0x0023), sends MBIM CLOSE, waits for child exit.

After Changing Composition

A composition change is stored in modem NVRAM but does not re-enumerate USB interfaces immediately. You must reset the module:

Using qmicli (if available after reset)

sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=offline
sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=reset

Using ModemManager

sudo mmcli -m 0 --reset

Physical reset

USB disconnect/reconnect
Module power cycle
Laptop embedded modem hard reset

After reset, verify with lsusb, mmcli -L, or run the script again without --usbcomp to confirm the new composition is active. You should see additional /dev/ttyUSB* ports and/or a qmi_wwan interface depending on the chosen mode.

Troubleshooting

`'/dev/cdc-wdm0' is not a character device`

The MBIM device node does not exist. Check ls -l /dev/cdc-wdm* and dmesg for USB enumeration errors. The modem may be in QDL/firmware-download mode (PID 0x9070) instead of runtime mode.

`only MBIM devices are supported` (wrong driver)

The device is not handled by cdc_mbim — it may be in QMI mode (qmi_wwan) or serial-only mode. In that case you can use qmicli or AT commands directly and do not need this script.

`Failed to verify QMI vendor specific MBIM service`

The modem's MBIM stack does not expose EXT_QMUX. Run mbimcli -d /dev/cdc-wdm0 --query-device-services to confirm. Some non-Qualcomm or heavily locked firmware builds omit this service.

`USB composition 'N' is not supported`

The firmware only allows a subset of compositions (often 6, 8, and 9 on MC7455/EM7455). The script refuses to send an unsupported value. Use the read-only listing to see what your module reports.

`Failed to change USB composition`

The QMI request returned an error. Run with --debug to inspect the raw response. Common causes: modem busy (stop NetworkManager/ModemManager first), insufficient permissions, or firmware restrictions.

Composition reverts after reboot

Some units have USB PID–locked compositions stored in NV memory. If qmicli --dms-swi-set-usb-composition and this script both succeed but the modem returns to MBIM-only, the module may need an NVU profile change. See MC7455 stuck in MBIM-only USB composition for advanced recovery (custom NVU files, parsecwe.pl, etc.).

Stop ModemManager from interfering

sudo systemctl stop ModemManager
# run script
sudo systemctl start ModemManager

Alternatives

qmicli (recommended for most users)

Since libqmi 1.20, the officially supported approach:

# Query (works in MBIM mode)
sudo qmicli -d /dev/cdc-wdm0 --device-open-mbim --dms-swi-get-usb-composition

# Set
sudo qmicli -d /dev/cdc-wdm0 --device-open-mbim --dms-swi-set-usb-composition=8

# Reset
sudo qmicli -d /dev/cdc-wdm0 --device-open-mbim --dms-set-operating-mode=reset

With a recent libqmi, --device-open-mbim is often the default when the device is MBIM-capable.

AT commands (when AT port is available)

AT!ENTERCND="A710"       # unlock protected commands (password varies by module)
AT!UDUSBCOMP=?           # list compositions (older modules)
AT!UDUSBCOMP=8           # set composition 8
AT!USBCOMP=?             # list compositions (MC7455/EM7455+)
AT!USBCOMP=1,1,100D      # set via bitmask (diag,nmea,modem,mbim)
AT!RESET

Sierra Wireless tools

SWI Connect / Skylight (Windows) — can change composition via GUI
Sierra Linux QMI SDK — documents USBCompParams() / USBCompConfig() vendor APIs

References

Resource	URL
Original script (Bjørn Mork)	https://git.mork.no/?p=wwan.git;a=blob_plain;f=scripts/swi_setusbcomp.pl
libqmi patch adding SWI USB composition support	https://lists.freedesktop.org/archives/libqmi-devel/2017-October/002504.html
Author's disclaimer (not a supported tool)	https://lists.freedesktop.org/archives/libqmi-devel/2017-June/002364.html
MC7710 MBIM-only recovery (EXT_QMUX discovery)	https://forum.sierrawireless.com/t/my-mc7710-cant-work-on-linux-after-plug-in-it-to-windows8/7986
MC7455 MBIM-only PID lock discussion	https://forum.sierrawireless.com/t/mc7455-stuck-in-mbim-only-usb-composition/8499
Osmocom Sierra Wireless wiki	https://projects.osmocom.org/projects/quectel-modems/wiki/Sierra_Wireless_Modems
MBIM protocol + Qualcomm QMI tunnel	https://modemmanager.org/docs/libmbim/mbim-protocol/
qmicli man page	https://www.freedesktop.org/software/libqmi/man/latest/qmicli.1.html
AT!UDUSBCOMP reference	https://m2msupport.net/m2msupport/atudusbcomp-set-the-usb-interface-configuration-for-the-sierra-wireless-modems/
Sierra USB customization (Legato)	https://source.sierrawireless.com/resources/legato/howtos/customizeusb/
cdc-wdm device nodes on AOSP	http://paldan.altervista.org/cdc-wdm-support-now-added-in-aosp-hikey/
Quectel Android RIL / ueventd setup	https://www.quectel.com/content/uploads/2024/02/Quectel_Android_RIL_Driver_User_Guide_V2.0-1-4.pdf
Termux Perl setup	https://www.perlmonks.org/?node_id=1211709
Termux via adb (`run-as`)	https://android.stackexchange.com/questions/225260/termux-running-termux-via-adb-without-any-direct-interaction-with-the-device

Author's note

Bjørn Mork described this script as a "simple run-once hack" that was "never intended to be a tool", and wrote: "I don't recommend it ;-)". It has nonetheless proven invaluable for recovering modems stranded in MBIM-only mode and served as the reference implementation for the libqmi vendor commands.

Name		Name	Last commit message	Last commit date
Latest commit History 4 Commits
README.md		README.md
scripts_swi_setusbcomp.pl		scripts_swi_setusbcomp.pl

Folders and files

Latest commit

History

Repository files navigation

swi_setusbcomp

Table of Contents

The Problem

What This Script Does

Supported Hardware

Requirements

System

Optional tools (for diagnosis, not required by the script)

Installation

1. Get the script

2. Install dependencies

Debian, Ubuntu, Raspberry Pi OS, Armbian

OpenWrt

Entware (OpenWrt, DD-WRT, AsusWRT-Merlin, Synology, …)

Alpine Linux

Arch Linux

CentOS, Rocky Linux, AlmaLinux, RHEL

Fedora

openSUSE Leap / Tumbleweed

SUSE Linux Enterprise (SLES)

Yocto / Buildroot / custom embedded images

Usage on Linux

Options

Examples

Usage on Android (via ADB)

When it works

Prerequisites

1. Connect and verify the modem

2. Install Perl in Termux

3. Copy the script to the device

4. Release the modem from the Android telephony stack

5. Run the script

6. Reset the modem

Android-specific troubleshooting

Easier alternative on Android

USB Composition Reference

Interface abbreviations

How It Works

Architecture overview

MBIM layer

QMI-over-MBIM tunnel (EXT_QMUX)

Sierra Wireless QMI DMS vendor messages

Execution flow

After Changing Composition

Using qmicli (if available after reset)

Using ModemManager

Physical reset

Troubleshooting

'/dev/cdc-wdm0' is not a character device

only MBIM devices are supported (wrong driver)

Failed to verify QMI vendor specific MBIM service

USB composition 'N' is not supported

Failed to change USB composition

Composition reverts after reboot

Stop ModemManager from interfering

Alternatives

qmicli (recommended for most users)

AT commands (when AT port is available)

Sierra Wireless tools

References

Author's note

License

About

Resources

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Uh oh!

Contributors

Uh oh!

Languages

`'/dev/cdc-wdm0' is not a character device`

`only MBIM devices are supported` (wrong driver)

`Failed to verify QMI vendor specific MBIM service`

`USB composition 'N' is not supported`

`Failed to change USB composition`

Packages