1. Article purpose[edit source]
The purpose of this article is to explain how to configure an USB remote server with STM32MP157x-DKx 
, managed by Linux on Cortex®-A7.
The Goal are to transform STM32MP157x-DKx board on an USB remote server, manage USB device on a PC while the USB device are connected to a remote server on network.
To configure a STM32MP157x-DKx board on an USB remote server we will use USBIP to
This article provides step-by-step instructions to:
- explain how to transform a linux board on an USB remote server with USBIP
- configure Linux software to enable USBIP server (aka USB remote server),
- configure PC client to connect to USBIP server.
- to further, manage power for USB device on server with uhubctl tool
2. Configure STM32 MPU board with USBIP[edit source]
2.1. Overview[edit source]
USB/IP Project aims to develop a general USB device sharing system over IP network. To share USB devices between computers with their full functionality, USB/IP encapsulates "USB I/O messages" into TCP/IP payloads and transmits them between computers. [1]
2.2. step by step on server[edit source]
The Installation of USBIP server are made on Linux embedded board.
The following chapter will show how to configure manually on board the USBIP service and how to enable it on STM32 MPU board on which all the configuration, file, and service are present.
2.2.1. Manual setup[edit source]
Before to use the usbip command you need to load the kernel modules associated to usbip:
modprobe usbip-core modprobe usbip-host
Start the usbip server:
usbipd -D
To make available an usb device connected to Linux embedded board you need to bind the device.
List available usb device:
usbip list -l - busid 2-1.1 (03f0:e207) HP, Inc : unknown product (03f0:e207)
Bind this specific device to be visible by a PC client (here device 2-1.1):
usbip bind -b 2-1.1
(to automate the binding of new usb device, see the next section Automated setup)
2.2.2. Automated setup (available by default on STM32 MPU Board)[edit source]
All the configurations, files, services are present on STM32 MPU board by default.
- Automate server startup via systemd
Create on board a service dedicated to start usbip server
Content of /lib/systemd/system/usbip.service
[Unit]
Description=USB-IP Bindind
After=network.target
Wants=network.target
[Service]
Type=forking
ExecStartPre=-/sbin/modprobe usbip-core
ExecStartPre=-/sbin/modprobe usbip-host
ExecStart=/usr/sbin/usbipd -D
ExecStop=/usr/sbin/stm32mp-usbip-bind-unbind.sh unload
[Install]
WantedBy=multi-user.target
Start systemd usbip service:
systemctl daemon-reload systemctl start usbip
- Automate binding of new usb device
The binding of new usb device can be made by a script which bind or unbind the usb device following if it's plugged or unplugged.
This script must be called by an udev rules for the case of plug/unplug of device.
Content of script: /usr/sbin/stm32mp-usbip-bind-unbind.sh
#!/bin/sh -
#echo "Parameter number $#" >> /tmp/usbip.log
action=$1
devpath=$2
#echo "Parameter: $1" >> /tmp/usbip.log
#echo "Parameter: $2" >> /tmp/usbip.log
case $1 in
unload)
modprobe -r usbip-core
modprobe -r usbip-host
kill -9 `pgrep usbipd`
exit 0
;;
esac
subpath=$(echo $2 | sed "s|.*/\([^/]*\)|\1|")
#echo "subpath >$subpath<" >> /tmp/usbip.log
if $(echo $subpath | grep -q ":");
then
#echo "No valid path" >> /tmp/usbip.log
exit 0
fi
# if usbip-core are not loaded, do nothing
if [ -z "$(cat /proc/modules | grep usbip_core)" ]; then
#echo "no module usbip_core loaded" >> /tmp/usbip.log
exit 0
fi
case $1 in
add)
#echo ">>> bind $subpath" >> /tmp/usbip.log
usbip bind -b $subpath
;;
remove)
#echo "<<< unbind $subpath" >> /tmp/usbip.log
usbip unbind -b $subpath
;;
esac
Content of udev rules: /etc/udev/rules.d/99-usb-usbip.rules
ACTION=="remove", SUBSYSTEM=="usb", RUN+="/usr/sbin/stm32mp-usbip-bind-unbind.sh remove %p"
ACTION=="add", SUBSYSTEM=="usb", DRIVER=="usb", RUN+="/usr/sbin/stm32mp-usbip-bind-unbind.sh add %p"
2.3. step by step on PC client[edit source]
2.3.1. On Windows[edit source]
An USBIP client exist for windows and are available via Github usbip-win
2.3.1.1. Installation[edit source]
For installation, follow instruction specified on README.md.
2.3.1.2. Usage[edit source]
User action:
- List usb device available on specificy server
usbip.exe list -l -r <usbip server ip>
- Attach an usb device available on specificy server (here 2-1)
usbip.exe list -r <usbip server ip> -b 2-1
- List attached usb device on host PC
usbip.exe port
- Detach a specific attached usb device on host PC
List attached device on host PC and detach it (here 00) usbip detach -p 00
2.3.2. On Linux[edit source]
2.3.2.1. Installation[edit source]
On Ubuntu, you need to install some pre-requisite package:
sudo apt-get install sysfsutils libwrap0-dev libglib2.0-dev libtool automake autoconf pkg-config linux-tools-generic
For having a translation of usb device name and ID you need to insatll a specific harware data base
wget http://www.linux-usb.org/usb.ids sudo mkdir -p /usr/share/hwdata/ sudo cp usb.ids /usr/share/hwdata/
2.3.2.2. Usage[edit source]
Before to use the usbip command you need to load the kernel modules associated to usbip:
sudo modprobe usbip-core modprobe vhci-hcd
- List usb remote device available on specific server:
sudo usbip list -r <server IP>
- Attach an usb remote device available on specific server:
sudo usbip attach -r <server IP> -b <USB ID>
- Detach a specific attached usb device on host PC
List usb device attached
sudo usbip port
Detach specific usb device attached as 00
sudo usbip detach -p 00
3. Configure STM32 MPU board to add usb power management with uhubctl[edit source]
3.1. Overview[edit source]
uhubctl is utility to control USB power per-port on smart USB hubs. Smart hub is defined as one that implements per-port power switching.[2]
3.2. Usage[edit source]
uhubctl Current status for hub 2-1 [0424:2514] Port 1: 0507 power highspeed suspend enable connect [03f0:e207 Hewlett Packard HP Webcam HD 2300] Port 2: 0100 power Port 3: 0100 power Port 4: 0100 power Current status for hub 2 [1d6b:0002 Linux 5.9.0-rc4 ehci_hcd EHCI Host Controller 5800d000.usbh-ehci] Port 1: 0503 power highspeed enable connect [0424:2514] Port 2: 0100 power Current status for hub 1 [1d6b:0002 Linux 5.9.0-rc4 dwc2_hsotg DWC OTG Controller 49000000.usb-otg] Port 1: 0000 off
On hub 2-1 Port 1 a usb webcam are plugged:
cat /sys/class/video4linux/video1/name HP Webcam HD 2300: HP Webcam HD
To power Off the usb webcam connected on this port:
uhubctl -a off -p 1 -l 2-1 Current status for hub 2-1 [0424:2514] Port 1: 0507 power highspeed suspend enable connect [03f0:e207 Hewlett Packard HP Webcam HD 2300] Sent power off request New status for hub 2-1 [0424:2514] Port 1: 0000 off uhubctl Current status for hub 2-1 [0424:2514] Port 1: 0503 power highspeed enable connect [03f0:e207] Port 2: 0100 power Port 3: 0100 power Port 4: 0100 power Current status for hub 2 [1d6b:0002 Linux 5.9.0-rc4 ehci_hcd EHCI Host Controller 5800d000.usbh-ehci] Port 1: 0503 power highspeed enable connect [0424:2514] Port 2: 0100 power Current status for hub 1 [1d6b:0002 Linux 5.9.0-rc4 dwc2_hsotg DWC OTG Controller 49000000.usb-otg] Port 1: 0000 off
To power On the usb webcam connected on this port:
uhubctl -a on -p 1 -l 2-1 Current status for hub 2-1 [0424:2514] Port 1: 0507 power highspeed suspend enable connect [03f0:e207 Hewlett Packard HP Webcam HD 2300] Sent power on request New status for hub 2-1 [0424:2514] Port 1: 0503 power highspeed enable connect [03f0:e207 Hewlett Packard HP Webcam HD 2300] uhubctl Current status for hub 2-1 [0424:2514] Port 1: 0507 power highspeed suspend enable connect [03f0:e207 Hewlett Packard HP Webcam HD 2300] Port 2: 0100 power Port 3: 0100 power Port 4: 0100 power Current status for hub 2 [1d6b:0002 Linux 5.9.0-rc4 ehci_hcd EHCI Host Controller 5800d000.usbh-ehci] Port 1: 0503 power highspeed enable connect [0424:2514] Port 2: 0100 power Current status for hub 1 [1d6b:0002 Linux 5.9.0-rc4 dwc2_hsotg DWC OTG Controller 49000000.usb-otg] Port 1: 0000 off
4. References[edit source]