Add cellular modem (wwan) support

board/aarch64/bananapi-bpi-r4/README.md

@@ -87,6 +87,45 @@ Infix ships with the following factory defaults.
 > are bridged into the LAN as access points.  WiFi is not included with the board
 > and is not part of the factory default configuration.
 
+## SIM Card Installation
+
+The BPI-R4 has three SIM holders, one per PCIe slot:
+
+| Slot     | PCIe socket | Typical use              |
+|----------|-------------|--------------------------|
+| **SIM1** | M.2 Key-B   | 4G/5G WWAN modem         |
+| **SIM2** | mPCIe #1    | Cellular or other modem  |
+| **SIM3** | mPCIe #2    | Cellular or other modem  |
+
+All three take **nano-SIM (4FF)** cards.
+
+> [!NOTE]
+> The official Banana Pi pages show an older board revision with a sliding
+> "sled" holder.  Newer boards ship with a fixed friction-fit holder instead:
+> there is no lid to lift and no spring eject.  The [closest matching photo on
+> bananapi.org][15] shows the current mechanism.
+
+### Inserting a SIM
+
+1. Orient the card with the gold contacts facing the PCB (printed
+   side up) and the cut corner pointing toward the M.2/mPCIe socket,
+   which on this board is also toward the outer edge.  The silkscreen
+   next to each holder shows the same outline.
+2. Push the SIM straight in until it is fully seated.  There is no
+   click and the holder is not spring-loaded, so press firmly until
+   the contacts engage and the rear edge of the card sits flush with
+   the holder.
+3. A SIM that still protrudes is not fully inserted; push again.
+
+### Removing a SIM
+
+The friction grip on these holders is tight.  Gently pry the card out
+with a fingernail or a thin plastic spudger.  Avoid metal tweezers
+near the contacts.  Removing the front panel of the metal case is
+absolutely necessary to access the SIM holder.
+
+For software configuration once the modem is recognised, see the
+[Cellular Modem User's Guide][16].
 
 ## Getting Started
 
@@ -358,3 +397,6 @@ make aarch64
 [12]: https://github.com/frank-w/u-boot/releases
 [13]: https://github.com/frank-w/u-boot/releases/download/CI-BUILD-2026-01-bpi-2026.01-2026-01-15_2013/bpi-r4_spim-nand_bl2.img
 [14]: https://github.com/frank-w/u-boot/releases/download/CI-BUILD-2026-01-bpi-2026.01-2026-01-15_2013/bpi-r4_spim-nand_fip.bin
+[15]: https://docs.banana-pi.org/bpi-r4/bpi-r4_4g5g_2.jpg
+[16]: https://www.kernelkit.org/infix/latest/modem/
+

board/aarch64/bananapi-bpi-r4/rootfs/usr/share/product/bananapi,bpi-r4-2g5/etc/factory-config.cfg

@@ -10,6 +10,13 @@
         "state": {
           "admin-state": "unlocked"
         }
+      },
+      {
+        "name": "USB2",
+        "class": "infix-hardware:usb",
+        "state": {
+          "admin-state": "unlocked"
+        }
       }
     ]
   },
@@ -366,7 +373,7 @@
     ]
   },
   "infix-meta:meta": {
-    "version": "1.7"
+    "version": "1.8"
   },
   "infix-services:mdns": {
     "enabled": true

board/aarch64/bananapi-bpi-r4/rootfs/usr/share/product/bananapi,bpi-r4/etc/factory-config.cfg

@@ -10,6 +10,13 @@
         "state": {
           "admin-state": "unlocked"
         }
+      },
+      {
+        "name": "USB2",
+        "class": "infix-hardware:usb",
+        "state": {
+          "admin-state": "unlocked"
+        }
       }
     ]
   },
@@ -358,7 +365,7 @@
     ]
   },
   "infix-meta:meta": {
-    "version": "1.7"
+    "version": "1.8"
   },
   "infix-services:mdns": {
     "enabled": true

board/common/rootfs/etc/default/confd

@@ -1 +1,5 @@
 CONFD_TIMEOUT=60
+#DEBUG=1
+
+# -v debug
+CONFD_ARGS=""

board/common/rootfs/etc/iproute2/rt_addrprotos

@@ -5,3 +5,4 @@
 4 static
 5 dhcp
 6 random
+7 wwan

board/common/rootfs/usr/libexec/infix/init.d/00-probe

@@ -620,6 +620,73 @@ def probe_ptp_capabilities(out):
         out.setdefault("interfaces", {}).update(ifaces)
 
 
+def _usb_root_from_sysfs(dev_path):
+    p = dev_path
+    while p not in ("/", "/sys"):
+        parent = os.path.realpath(os.path.join(p, ".."))
+        basename = os.path.basename(parent)
+        if basename.startswith("usb") and basename[3:].isdigit():
+            return parent
+        p = parent
+    return None
+
+
+def _read_usb_vid_pid(dev_path):
+    p = dev_path
+    while p not in ("/", "/sys"):
+        try:
+            vid = open(os.path.join(p, "idVendor")).read().strip()
+            pid = open(os.path.join(p, "idProduct")).read().strip()
+            return vid, pid
+        except OSError:
+            pass
+        p = os.path.dirname(p)
+    return "", ""
+
+
+def probe_modems(out):
+    """devpath is the USB bus root; ModemManager matches by path prefix.
+    seen_roots deduplicates cdc-wdm and ttyUSB ports of the same physical modem."""
+    seen_roots = set()
+    modems = []
+    idx = 0
+
+    def add_modem(dev_path):
+        nonlocal idx
+        usb_root = _usb_root_from_sysfs(dev_path)
+        if usb_root is None or usb_root in seen_roots:
+            return
+        seen_roots.add(usb_root)
+        vid, pid = _read_usb_vid_pid(dev_path)
+        modems.append({
+            "index": idx,
+            "name": "modem%d" % idx,
+            "devpath": usb_root,
+            "vid": vid,
+            "pid": pid,
+        })
+        idx += 1
+
+    for cls_dir, prefix in (("/sys/class/usbmisc", "cdc-wdm"),
+                             ("/sys/class/tty", "ttyUSB")):
+        try:
+            entries = os.listdir(cls_dir)
+        except OSError:
+            continue
+        for entry in entries:
+            if not entry.startswith(prefix):
+                continue
+            try:
+                dev_path = os.path.realpath(
+                    os.path.join(cls_dir, entry, "device"))
+                add_modem(dev_path)
+            except OSError:
+                pass
+
+    if modems:
+        out["modem"] = modems
+
+
 def main():
     out = {
         "vendor": None,
@@ -647,6 +714,7 @@ def main():
 
     probe_wifi_radios(out)
     probe_ptp_capabilities(out)
+    probe_modems(out)
 
     if not out["factory-password-hash"]:
         sys.stdout.write("\n\n\033[31mCRITICAL BOOTSTRAP ERROR\n" +

configs/aarch64_defconfig

@@ -149,6 +149,7 @@ INFIX_HOME="https://github.com/kernelkit/infix/"
 INFIX_DOC="https://www.kernelkit.org/infix/"
 INFIX_SUPPORT="mailto:kernelkit@googlegroups.com"
 BR2_PACKAGE_FEATURE_GPS=y
+BR2_PACKAGE_FEATURE_MODEM=y
 BR2_PACKAGE_FEATURE_WIFI=y
 BR2_PACKAGE_FEATURE_WIFI_MEDIATEK=y
 BR2_PACKAGE_FEATURE_WIFI_QUALCOMM=y

doc/ChangeLog.md

@@ -10,21 +10,26 @@ All notable changes to the project are documented in this file.
 
 - Add Wi-Fi roaming for fast, seamless handoff between access points that
   share an SSID: 802.11k, 802.11v and 802.11r (over-the-air FT).  See the
-  [Wi-Fi][wifi] guide for details
+  [Wi-Fi User's Guide][wifi] for details
 - Add Wi-Fi 802.11s mesh support, letting access points form a wireless
   backhaul between each other without cabling
 - Add band steering for dual-band access points, nudging dual-band
   clients onto the faster 5/6 GHz band
 - Add `legacy-rates` option to re-enable 802.11b rates on 2.4 GHz for
   old IoT devices (disabled by default)
+- Add cellular modem (WWAN) support for USB-attached MBIM/QMI modems,
+  including USB dongles, mPCIe cards, and M.2 Key-B modules.  Multiple
+  APNs per modem, SIM PIN configuration, and NMEA routing from modem
+  GPS to gpsd.  See the [Modem User's Guide][modem] for details
 
 ### Fixes
 
 - Firewall masquerade no longer enables the global IPv4/IPv6 forwarding
   sysctls.  You must now enable IP forwarding explicitly on the interfaces
   that should route traffic; enabling NAT alone is no longer enough
 
-[wifi]: wifi.md
+[wifi]:  https://www.kernelkit.org/infix/latest/wifi/
+[modem]: https://www.kernelkit.org/infix/latest/modem/
 
 [v26.05.0][] - 2026-05-29
 -------------------------
@@ -83,9 +88,9 @@ All notable changes to the project are documented in this file.
   show`, which were not expanded, so `show interface` and other operational
   reads failed.  Ranges are now expanded and listed correctly
 
-[ethernet]: ethernet.md#restricting-advertised-link-modes
+[ethernet]: https://www.kernelkit.org/infix/latest/ethernet/#restricting-advertised-link-modes
 [BPI-R3]:   https://docs.banana-pi.org/en/BPI-R3/BananaPi_BPI-R3
-[AcerConnectVero]: ../board/aarch64/acer-connect-vero-w6m/
+[AcerConnectVero]: https://github.com/kernelkit/infix/tree/main/board/aarch64/acer-connect-vero-w6m/
 
 [v26.04.0][] - 2026-04-30
 -------------------------

doc/README.md

@@ -23,6 +23,7 @@ regression test system solely relies on NETCONF and RESTCONF.
    - [Network Configuration](networking.md)
    - [Wi-Fi](wifi.md)
    - [DHCP Server](dhcp.md)
+   - [Cellular Modem (WWAN)](modem.md)
    - [Syslog Support](syslog.md)
  - **Infix In-Depth**
    - [Boot Procedure](boot.md)