#!/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"