Browse Prior Art Database

Physical Inventory from client off via logical external USB host device

IP.com Disclosure Number: IPCOM000011750D
Original Publication Date: 2003-Mar-12
Included in the Prior Art Database: 2003-Mar-12
Document File: 3 page(s) / 94K

Publishing Venue

IBM

Abstract

Physical inventory of personal computers and computer device contents is very important to large enterprise customers. This information is used in their asset security plan, account records, and is essential to support team. The most widely used method requires an operational computer since most of the inventory applications either remotely query across the network or run locally on the client and send a file across the network. Another method is a physical inventory, provides information about the system unit but does not provide information about the actual device contents. To obtain that information, the person conducting the inventory would have to have access to passwords (boot, HDD, screen saver), which typically violates security policies. The use of the admin password is not an option, since it's limited to preboot environment. This disclosure explains how a low cost USB device can attach to a turned off computer and pull out the inventory information.

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Physical Inventory from client off via logical external USB host device

    Today's computers have at least one USB port on front bezel of the computer for easy access to portable devices. The design point of USB is that power to the USB peripheral devices is provide by the system power supply/battery. This disclosure explains how an internal USB Asset Information Device to be accessed by an external system or device through the existing USB ports no matter what the system power state.

      An USB Asset Information device is added to the system board which contains non-volatile storage (Flash, EEPROM, etc) and stores asset information. This device is connected to all of the USB ports on the system, but only consumes one of these ports when the system is on (on a modern system with 6 USB ports, 5 would be external and the sixth port would have the USB device).

Fig. 1 USB VPD Device Wiring Diagram

      Inside this USB Asset Information Device, power can come from either the System +5V or the +5V from any one of the ports. The micro-controller firmware controls the "MUX and Pass Through" device based upon the power signal coming from the system and from each of the ports. When there is system power, ports 1 through 5 is in pass through mode and port 0 is connected to the USB Device. When there is no system power, the port supplying power to the device is connected to the USB Device and all other ports are connected to nothing.

      This configuration allows for an external device that has a USB host controller and power to access the asset information that the USB Device controls. The external device can be another computer

System +5V

D+ (1)

D- (1)

System Ground

D+ (2)

D- (2)

D+ (3)

D- (3)

D+ (4)

D- (4)

D+ (5)

D- (5)

+5V (1)

+5V (2)

+5V (3)

+5V (4)

+5V (5)

D+ (5)

D- (5)

D+ (1)

D- (1)

D+ (2)

D- (2)

D+ (3)

D- (3)

D+ (4)

D- (4)

D+ (0)

D- (0)

P1

 USB Host Controller #1

Gnd (1)

Gnd (2)

Gnd (3)

Gnd (4)

Gnd (5)

P2

 USB Host Controller #2

P3

  USB Asset Information Device

 USB Host Controller #3

P4

P5

EEPROM

1

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system, a PDA class device or an inventory gathering device. We will concentrate our focus on the inventory gathering device.

      1) System Active or in low power state When the system is on, (see fig 1), the system power supply provides power to USB bus and to USB Asset Information Device. An Inventory Gathering Device would appear as another USB device connected to the system and would rely upon system software to transfer asset information from the USB Asset Information Device to the Inventory Gathering Device.

      Therefore in normal operation the USB port on the front of the box looks and acts exactly like an industry standard USB port. External devices can attach to it and the system will provide power and the system host controller can read and write to the device.

      Since the Inventory Gathering Device (IGD) has two modes, it checks f...