android-tools-conf: replace sysfs implementation with configfs

The android-tools-conf recipe used /sys/class/android_usb/android0/,
an interface exported by the out-of-tree android.c USB gadget driver
that Google carried in Android kernels but never submitted to mainline
Linux. It was never part of any upstream kernel release.

The configfs-based USB gadget framework (CONFIG_USB_CONFIGFS) was
merged into mainline Linux with kernel 3.10 (June 2013) and is the
correct interface for all upstream kernels since then. Additionally,
Google's Generic Kernel Image (GKI) initiative dropped android.c from
Android common kernels starting with kernel 5.10 (Android 12, 2021),
so even custom BSPs targeting modern Android cannot use this interface.

Remove android-tools-conf and rename android-tools-conf-configfs to
android-tools-conf, since the configfs-based implementation is the
only correct one for any modern kernel. Backward compatibility is
preserved via PROVIDES/RPROVIDES retaining the old
android-tools-conf-configfs name.

AI-Generated: Uses GitHub Copilot (Claude Sonnet 4.6)
Signed-off-by: Etienne Cordonnier <ecordonnier@snap.com>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-oe/recipes-devtools/android-tools/android-tools-conf/10-adbd-configfs.conf

@@ -0,0 +1,7 @@
+[Service]
+# adbd uses sd_notify to signal readiness; ExecStartPost runs only after
+# READY=1 is sent, so no delay is needed before activating the UDC.
+Environment=ANDROID_GADGET_UDC_DELAY=0
+ExecStartPre=/usr/bin/android-gadget-setup
+ExecStartPost=/usr/bin/android-gadget-start
+ExecStopPost=/usr/bin/android-gadget-cleanup

meta-oe/recipes-devtools/android-tools/android-tools-conf/android-gadget-cleanup

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+[ -d /sys/kernel/config/usb_gadget ] || exit 0
+
+cd /sys/kernel/config/usb_gadget
+
+cd adb
+
+echo -n "" > UDC || true
+
+killall adbd || true
+
+umount /dev/usb-ffs/adb
+
+rm configs/c.1/ffs.usb0
+
+rmdir configs/c.1/strings/0x409
+rmdir configs/c.1
+
+rmdir functions/ffs.usb0
+rmdir strings/0x409
+
+cd ..
+rmdir adb

meta-oe/recipes-devtools/android-tools/android-tools-conf/android-gadget-setup

@@ -1,37 +1,40 @@
 #!/bin/sh
 
-[ ! -e /dev/pts ] && mkdir -p /dev/pts
-[ ! -e /dev/pts/0 ] && mount devpts /dev/pts -t devpts
+set -e
 
-# TODO enable the lines below once we have support for getprop
-# retrieve the product info from Android
-# manufacturer=$(getprop ro.product.manufacturer Android)
-# model=$(getprop ro.product.model Android)
-# serial=$(getprop ro.serialno 0123456789ABCDEF)
+conf="Conf 1"
+manufacturer=RPB
+model="Android device"
+product=0xd002
+serial=0123456789ABCDEF
+vendor=0x18d1
 
-#below are now needed in order to use FunctionFS for ADB, tested to work with 3.4+ kernels
-if grep -q functionfs /proc/filesystems; then
-    mkdir -p /dev/usb-ffs/adb
-    mount -t functionfs adb /dev/usb-ffs/adb
-    #android-gadget-setup doesn't provide below 2 and without them it won't work, so we provide them here.
-    echo adb > /sys/class/android_usb/android0/f_ffs/aliases
-    echo ffs > /sys/class/android_usb/android0/functions
+if [ -r /etc/android-gadget-setup.machine ] ; then
+	. /etc/android-gadget-setup.machine
 fi
 
-manufacturer="$(cat /system/build.prop | grep -o 'ro.product.manufacturer=.*' | cut -d'=' -f 2)"
-model="$(cat /system/build.prop | grep -o 'ro.product.model=.*' | cut -d'=' -f 2)"
-# get the device serial number from /proc/cmdline directly(since we have no getprop on
-# GNU/Linux)
-serial="$(cat /proc/cmdline | sed 's/.*androidboot.serialno=//' | sed 's/ .*//')"
+[ -d /sys/kernel/config/usb_gadget ] || modprobe libcomposite
 
-echo $serial > /sys/class/android_usb/android0/iSerial
-echo $manufacturer > /sys/class/android_usb/android0/iManufacturer
-echo $model > /sys/class/android_usb/android0/iProduct
+cd /sys/kernel/config/usb_gadget
 
-echo "0" > /sys/class/android_usb/android0/enable
-echo "18d1" > /sys/class/android_usb/android0/idVendor
-echo "D002" > /sys/class/android_usb/android0/idProduct
-echo "adb" > /sys/class/android_usb/android0/functions
-echo "1" >  /sys/class/android_usb/android0/enable
+[ -d adb ] && /usr/bin/android-gadget-cleanup || true
 
-sleep 4
+mkdir adb
+cd adb
+
+mkdir configs/c.1
+mkdir functions/ffs.usb0
+mkdir strings/0x409
+mkdir configs/c.1/strings/0x409
+echo -n "$vendor"  > idVendor
+echo -n "$product" > idProduct
+echo "$serial" > strings/0x409/serialnumber
+echo "$manufacturer" > strings/0x409/manufacturer
+echo "$model" > strings/0x409/product
+echo "$conf" > configs/c.1/strings/0x409/configuration
+ln -s functions/ffs.usb0 configs/c.1
+
+mkdir -p /dev/usb-ffs/adb
+ADB_UID=$(id -u adb)
+ADB_GID=$(id -g adb)
+mount -t functionfs usb0 /dev/usb-ffs/adb -o "uid=$ADB_UID,gid=$ADB_GID"

meta-oe/recipes-devtools/android-tools/android-tools-conf/android-gadget-start

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+set -e
+
+# Wait for adbd to open ep0 before activating the UDC. Without systemd
+# sd_notify synchronisation there is no other signal that adbd is ready, so
+# a fixed delay is used. When this script is invoked via ExecStartPost in a
+# Type=notify service, adbd has already sent READY=1 before this runs and
+# no delay is needed; set ANDROID_GADGET_UDC_DELAY=0 in that case (e.g. via
+# a systemd drop-in Environment= line).
+ANDROID_GADGET_UDC_DELAY="${ANDROID_GADGET_UDC_DELAY:-10}"
+sleep "$ANDROID_GADGET_UDC_DELAY"
+
+ls /sys/class/udc/ | head -n 1 | xargs echo -n > /sys/kernel/config/usb_gadget/adb/UDC
+
+echo "Setting UDC $(ls /sys/class/udc/ | head -n 1) for USB ADB Gadget usage"