Modification and use of configuration memory used during operation of a serial bus

• US 6,643,714 B1
• Filed: 11/16/1999
• Issued: 11/04/2003
• Est. Priority Date: 03/25/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Chrysanthakopoulos, Georgios
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Patel, Niketa
• Application Number:
  US09/441,264
• Time in Patent Office: 1,449 Days
• Field of Search: 710/8, 710/10, 710/2, 710/13, 710/38, 710/19, 710/313, 710/305, 710/1, 340/825, 370/402, 709/227
• US Class Current: 710/8
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: H04L 12/40078 Bus configuration home automation networks H04L12/2803; arrangements for maintenance or administration H04L41/00
• CPC Class Codes: H04L 12/40123 Interconnection of computers and peripherals printer information exchange with computer G06F3/1293

Abstract

Information stored in configuration memory of a first device coupled to a communication bus is exposed to other devices allowing the other devices to ascertain the functionality of the first device. A device driver corresponding to the device can, through an interface, cause a bus driver to alter the contents of the configuration memory thereby changing what information is exposed to other devices. When another device “enumerates” the now-altered configuration memory, the other device will learn of the new functionality and proceed in a normal fashion by loading those drivers necessary to use the newly-added functionality. Conversely, when a device and its corresponding device driver is removed, configuration memory is updated accordingly. The present invention may be beneficially applied to systems adhering to the IEEE 1394 Serial Bus standard.

Claims

1. A method of communicating between a device driver and a bus driver in a computer, the method comprising steps of:

providing, by the device driver to the bus driver, a new unit directory, representative of a newly-altered functionality of an existing device associated with the device driver, to be appended to a configuration memory;

responsive to the new unit directory, dynamically modifying, by the bus driver, the configuration memory to include a pointer to the new unit directory, wherein the pointer is added to a root directory forming a part of the configuration memory; and

providing, by the bus driver to the device driver, a notification that the configuration memory has been modified.

2. The method of claim 1, wherein the step of modifying the configuration memory further comprises steps of:

re-parsing the configuration memory to include the new unit directory; and

re-calculating offsets within the root directory to include the new unit directory, thereby providing the pointer to the new unit directory.

3. The method of claim 1, further comprising a step of:

responsive to the notification that the configuration memory has been modified, providing, by the device driver to the bus driver, a bus reset request that causes the bus driver to initiate a bus reset procedure.

4. A method as recited in claim 1 for removing the new unit directory, further comprising steps of:

ascertaining that the device driver has been removed;

re-parsing the configuration memory to exclude the new unit directory; and

re-calculating offsets within the root directory to exclude the new unit directory.

5. The method of claim 1, wherein the bus driver is an IEEE 1394 Serial Bus compliant bus driver.

6. In a computer comprising a node residing on a communication bus, wherein a configuration memory is associated with the node, a method for exposing a newly-altered functionality of an existing device residing on the communication bus, the method comprising steps of:

providing a device driver and a new unit directory corresponding to the newly-altered functionality of the existing device;

dynamically modifying the configuration memory to include a pointer to the new unit directory in a root directory forming a part of the configuration memory, wherein the configuration memory is exposed to other nodes residing on the communication bus; and

initiating a bus reset procedure that causes the other nodes to enumerate the configuration memory to include the new unit directory.

7. The method of claim 6, wherein the step of modifying the configuration memory further comprises steps of:

re-parsing the configuration memory to include the new unit directory; and

re-calculating offsets within the root directory to include the new unit directory, thereby providing the pointer to the new unit directory.

8. The method of claim 6, further comprising a step, prior to the step of providing the device driver and the new unit directory, of:

creating an object, residing on the computer, representative of the device.

9. A method of claim 8, wherein the step of providing the device driver further comprises loading the device driver in the object representative of the device.

10. The method as recited in claim 8 for testing the device driver, further comprising a step, prior to the step of enumerating the external node, of:

providing, as the device, another computer that emulates functionality of the device.

11. A method as recited in claim 6 for removing the new unit directory, further comprising steps of:

ascertaining that the device driver has been removed;

re-parsing the configuration memory to exclude the new unit directory; and

re-calculating offsets within the root directory to exclude the new unit directory.

12. In a system comprising a communication bus, a computer coupled to the communication bus and at least one device coupled to the communication bus, wherein the computer and the at least one device each comprise a configuration memory that is exposed on the communication bus, a method for exposing a newly-altered functionality of the computer, the method comprising steps of:

providing, by the computer, a device driver and a new unit directory corresponding to the newly-altered functionality of the computer;

dynamically modifying, by the computer, the computer'"'"'s configuration memory to include a pointer to the new unit directory in a root directory forming a part of the computer'"'"'s configuration memory;

enumerating, by the at least one device, the computer'"'"'s configuration memory including the new unit directory; and

loading, by the at least one device and in response to the enumeration by the device of the computer'"'"'s configuration memory, another device driver corresponding to the newly-altered functionality of the computer.

13. The method of claim 12, further comprising a step, prior to the step of enumerating, of:

initiating, by the computer, a bus reset procedure that causes at least one device to enumerate at least the computer'"'"'s configuration memory.

14. The method of claim 12, further comprising a step of:

using, by the at least one device, the newly-altered functionality of the computer via the communication bus and the other bus driver.

15. The method of claim 12, further comprising steps of:

removing, by the computer, the new unit directory from the computer'"'"'s configuration memory; and

enumerating, by the at least one device, the computer'"'"'s configuration memory excluding the new unit directory.

16. The method of claim 12, wherein the at least one device comprises another computer.

17. A computer coupled to a communication bus and having a processor coupled to a memory, the memory storing computer-readable instructions that, when executed by the processor, cause the computer to comprise:

a device driver that provides a new unit directory corresponding to a newly-altered functionality of an existing device residing on the communication bus; and

a bus driver that controls communications between the computer and the communication bus, and that modifies a configuration memory, based on the new unit directory, to include a pointer to the new unit directory in a root directory forming a part of the configuration memory, wherein the configuration memory is exposed to other devices residing on the communication bus.

18. The computer of claim 17, wherein the device driver requests the bus driver to initiate a bus reset procedure that causes the other devices to enumerate the configuration memory including the new unit directory.

19. The computer of claim 17, wherein the bus driver can ascertain when the device driver has been removed and responsively re-parses the configuration memory to exclude the new unit directory and re-calculates offsets within the root directory to exclude the new unit directory.

20. The computer of claim 17, wherein the bus driver is an IEEE 1394 Serial Bus compliant bus driver.

21. A system comprising the computer of claim 17, the system further comprising:

another computer, coupled to the communication bus, as one of the other devices.