usb-ctrl/usb-ctrl

#!/bin/sh

setup_image()
{
	set -x
	local storage="$1"
	local sz_mb="$2"
	# create the backing store
	dd if=/dev/zero of="$storage" bs=1M seek="$sz_mb" count=0 2>/dev/null
	# this shows up as 23FC-F676 in /dev/disk/by-uuid
	local diskid=0x23FCF676
	mkdosfs -n 'OPENBMC-FW' -i $diskid -I "$storage" >/dev/null 2>&1
}

mount_image()
{
	set -x
	local storage="$1"
	local stormnt="$2"
	mkdir -p $stormnt || exit 1
	mount -o loop -t vfat "$storage" "$stormnt"
}

cleanup_image()
{
	set -x
	local storage="$1"
	local stormnt="$2"
	umount -f "$stormnt"
	rm -f "$storage"
	rmdir "$stormnt"
}

ecm()
{
	set -x
	local name="$1"
	local on="$2"
	if [ "$on" = "on" ]; then
		usb_insert "${name}" ecm
	elif [ "$on" = "off" ]; then
		usb_eject "${name}" ecm
	else
		echo "Unknown ecm command"
		usage
	fi
}

GADGET_BASE=/sys/kernel/config/usb_gadget

which_dev()
{
	local in_use="$(cat $GADGET_BASE/*/UDC)"
	cd /sys/class/udc
	for D in *; do
		case "$in_use" in
			*"$D"*) ;;
			*) echo "$D"; return 0;;
		esac
	done
	return 1
}

usb_ms_insert()
{
	usb_insert "$1" mass_storage "$2" "$3"
}

usb_ms_eject()
{
	usb_eject "$1" mass_storage
}

## $1: 	device syspath to provide usb-gadget configure,
## 		e.g. functions/mass_storage.usb0/lun.0/
##
## $2:  optional usb gadget interface type, e.g. usb|usb-ro|hdd|cdrom.
##		if $2 not specified or illegal, then using 'usb-ro' as default
usb_set_interface_type()
{
	local usb_gadget_syspath="$1"
	local interface_type="${2:-'usb-ro'}"

	# defining target variables to configure interface type
	local removable=
	local ro=
	local cdrom=

	if [ ! -d ${usb_gadget_syspath} ]; then
		echo "Device syspath ${usb_gadget_syspath} does not exist" >&2
		return 1
	fi

	case "${interface_type}" in
		hdd)
			removable=0
			ro=0
			cdrom=0
			;;
		usb)
			removable=1
			ro=0
			cdrom=0
			;;

		cdrom)
			removable=1
			ro=1
			cdrom=1
			;;
		usb-ro)
			removable=1
			ro=1
			cdrom=0
			;;
		*)
			echo "No mass-storage interface type specified or illegal" >&2
			echo "Configuring interface type to 'usb-ro'" >&2
			removable=1
			ro=1
			cdrom=0
			;;
	esac

    echo $removable > ${usb_gadget_syspath}removable
    echo $ro > ${usb_gadget_syspath}ro
    echo $cdrom > ${usb_gadget_syspath}cdrom
}

## $1: device name, e.g. usb0, usb1
## $2: device type defined in kernel, e.g. mass_storage, ecm
## $3: optional storage file, e.g. /dev/nbd1, /tmp/boot.iso
## $4: optional mass storage interface type, e.g. usb|usb-ro|hdd|cdrom.
##     if interface type not specified then using 'usb-ro' as default
usb_insert()
{
	local name="$1"
	local dev_type="$2"
	local storage="$3"
	local interface_type="${4:-'usb-ro'}"

	if [ -d $GADGET_BASE/"${name}" ]; then
		echo "Device ${name} already exists" >&2
		return 1
	fi
	mkdir $GADGET_BASE/"${name}"
	cd $GADGET_BASE/"${name}"

	echo 0x1d6b > idVendor	# Linux Foundation
	echo 0x0105 > idProduct # FunctionFS Gadget
	mkdir strings/0x409
	local machineid=$(cat /etc/machine-id)
	local data="OpenBMC USB gadget device serial number"
	local serial=$( echo -n "${machineid}${data}${machineid}" | \
		sha256sum | cut -b 0-12 )
	echo $serial > strings/0x409/serialnumber
	echo OpenBMC > strings/0x409/manufacturer
	echo "OpenBMC USB Device" > strings/0x409/product

	mkdir configs/c.1
	mkdir functions/"${dev_type}"."${name}"
	if [ "${dev_type}" = "mass_storage" ]; then
		echo "${storage}" > "functions/${dev_type}.${name}/lun.0/file"
		usb_set_interface_type \
			"functions/${dev_type}.${name}/lun.0/" "${interface_type}"
	fi
	mkdir configs/c.1/strings/0x409

	echo "Conf 1" > configs/c.1/strings/0x409/configuration
	echo 120 > configs/c.1/MaxPower
	ln -s functions/"${dev_type}"."${name}" configs/c.1
	local dev=$(which_dev)
	echo $dev > UDC
}

## $1: device name, e.g. usb0, usb1
## $2: device type defined in kernel, e.g. mass_storage, ecm
usb_eject()
{
	local name="$1"
	local dev_type="$2"

	echo '' > $GADGET_BASE/"${name}"/UDC

	rm -f $GADGET_BASE/"${name}"/configs/c.1/"${dev_type}"."${name}"
	rmdir $GADGET_BASE/"${name}"/configs/c.1/strings/0x409
	rmdir $GADGET_BASE/"${name}"/configs/c.1
	rmdir $GADGET_BASE/"${name}"/functions/"${dev_type}"."${name}"
	rmdir $GADGET_BASE/"${name}"/strings/0x409
	rmdir $GADGET_BASE/"${name}"
}

usage()
{
	echo "Usage: $0 <action> ..."
	echo "       $0 setup <file> <sizeMB>"
	echo "       $0 insert <name> <file> [<type=usb|usb-ro|hdd|cdrom>]"
	echo "       $0 eject <name>"
	echo "       $0 mount <file> <mnt>"
	echo "       $0 cleanup <file> <mnt>"
	echo "       $0 ecm <name> <on|off>"
	exit 1
}

echo "$#: $0 $@"
case "$1" in
	insert)
		shift
		usb_ms_insert "$@"
		;;
	eject)
		shift
		usb_ms_eject "$@"
		;;
	setup)
		shift
		setup_image "$@"
		;;
	mount)
		shift
		mount_image "$@"
		;;
	cleanup)
		shift
		cleanup_image "$@"
		;;
	ecm)
		shift
		ecm "$@"
		;;
	*)
		usage
		;;
esac
exit $?