Interposed graphics device driver module processing function requests within module in standard mode, and passing function requests to specialized mode device driver in specialized mode

• US 6,240,468 B1
• Filed: 12/18/1998
• Issued: 05/29/2001
• Est. Priority Date: 12/18/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Capelli, Ronald Bruce
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): Nguyen, Tanh
• Application Number:
  US09/216,485
• Time in Patent Office: 893 Days
• Field of Search: 710/2, 710/5, 710/8, 710/14, 710/15, 710/16, 710/31, 710/38, 710/62, 710/63, 710/64, 710/72, 710/104, 712/43, 712/229, 345/22, 345/23, 345/24
• US Class Current: 710/14
• CPC Class Codes: G09G 5/363 Graphics controllers

Abstract

A module is interposed between the operating system and/or applications of a data processing system and the device driver for a graphics adapter within the data processing system. The interposed module may selectively intercept all graphics device driver function requests or simply pass such requests to a device driver supporting specialized (e.g., non-VGA) graphics modes. Standard (e.g., VGA) graphics mode(s) device driver support is accessible to the interposed module. When a specialized graphics mode is selected, the interposed is inactive and passes graphics function requests to the specialized device driver. When a standard graphics mode is selected, the interposed module is active and intercepts all graphics function requests, processing such request with available standard graphics mode support. Change of the graphics mode from standard to specialized or vice versa results in the interposed module changing from active to inactive or vice versa. Requests to set the graphics mode are similarly passed to the specialized device driver or processed by the interposed module depending on whether a standard or specialized graphics mode is requests. Initialization and termination function requests are both passed to the specialized device driver and processed by the interposed module. The interposed module is preferably implemented in accordance with the GRADD architecture model, with the interposed module implemented as a variant of a GRADD filter.

Claims

1. A method of supporting standard and specialized graphics modes in a data processing system, comprising:

interposing a module between an operating system for the data processing system and a device driver for a graphics adapter within the data processing system, wherein the device driver does not support any standard graphics modes;

during operation of the data processing system, monitoring function requests to the device driver and determining a current graphics mode utilizing the interposed module;

responsive to determining that the current graphics mode is a specialized mode, passing the function requests to the device driver for the graphics adapter through the interposed module for processing by the device driver; and

responsive to determining that the current graphics mode is a standard mode, intercepting the function requests at the interposed module and processing the function requests with available standard device driver support within the interposed module.

2. The method of claim 1, wherein the step of determining a current graphics mode utilizing the interposed module further comprises:

checking an internal state of the interposed module.

3. The method of claim 1, wherein the step of passing the function requests to the device driver for the graphics adapter through the interposed module further comprises:

passing all function requests to the device driver for the graphics adapter while the current graphics mode is any specialized mode.

4. The method of claim 1, wherein the step of intercepting the function requests at the interposed module and processing the function requests with available standard device driver support within the interposed module further comprises:

intercepting all function requests while the current graphics mode is any standard mode and processing the intercepted function requests with the available standard device driver support within the interposed module.

5. The method of claim 1, further comprising:

employing the interposed module to detect changes to the current graphics mode.

6. The method of claim 1, further comprising:

changing an internal state within the interposed module when the current graphics mode is changed from any standard graphics mode to any specialized graphics mode or from any specialized graphics mode to any standard graphics mode.

7. The method of claim 1, further comprising:

responsive to receiving a request for a graphics mode list;

retrieving a specialized mode list of graphics modes supported by the device driver from the device driver at the interposed module;

appending a standard mode list of graphics modes supported by the interposed module with the available standard device driver support to the specialized mode list to form a complete mode list; and

returning the complete mode list from the interposed module.

8. A system for supporting standard and specialized graphics modes in a data processing system, comprising:

a device driver for a graphics adapter, wherein the device driver does not support any standard graphics modes;

a source of function requests for the device driver; and

a module interposed between the device driver and the source, the interposed module;

determining a current graphics mode;

responsive to determining that the current graphics mode is a specialized mode, passing the function requests to the device driver for the graphics adapter through the interposed module for processing by the device driver; and

responsive to determining that the current graphics mode is a standard mode, intercepting the function requests at the interposed module and processing the function requests with available standard device driver support within the interposed module.

9. The system of claim 8, wherein the interposed module checks an internal state to determine the current graphics mode.

10. The system of claim 8, wherein the interposed module is set to a first internal state when the current graphics mode is set to any standard graphics mode.

11. The system of claim 10, wherein the interposed module is set to a second internal state when the current graphics mode is set to any specialized graphics mode.

12. The system of claim 8, wherein the interposed module passes all function requests to the specialized device driver when the current graphics mode is any specialized graphics mode.

13. The system of claim 8, wherein the interposed module intercepts all function requests when the current graphics mode is any standard graphics mode.

14. The system of claim 8, wherein the interposed module, in response to receiving a request for a mode list:

retrieves a specialized mode list of graphics modes supported by the device driver from the device driver;

appends a standard mode list of standard graphics modes supported at the interposed module with the available standard device driver support to the specialized mode list to form a complete mode list; and

returns the complete mode list in response to the mode list request.

15. A computer program product within a computer usable medium for supporting standard and specialized graphics modes in a data processing system, comprising:

instructions for interposing a module between an operating system for the data processing system and a device driver for a graphics adapter within the data processing system, wherein the device driver does not support any standard graphics modes;

instructions, executed during operation of the data processing system, for monitoring function requests to the device driver and for determining a current graphics mode utilizing the interposed module;

instructions, responsive to determining that the current graphics mode is a specialized mode, passing the function requests to the device driver for the graphics adapter through the interposed module for processing by the device driver; and

instructions, responsive to determining that the current graphics mode is a standard mode, intercepting the function requests at the interposed module and processing the function requests with available standard device driver support within the interposed module.

16. The computer program product of claim 15, wherein the instructions for determining a current graphics mode utilizing the interposed module further comprise:

instructions for checking an internal state of the interposed module.

17. The computer program product of claim 15, wherein the instructions for passing the function requests to the device driver for the graphics adapter through the interposed module for processing by the device driver further comprise:

instructions for passing all function requests to the device driver for the graphics adapter while the current graphics mode is any specialized mode.

18. The computer program product of claim 15, wherein the instructions for intercepting the function requests at the interposed module and processing the function requests with available standard device driver support within the interposed module further comprise:

instructions for intercepting all function requests while the current graphics mode is any standard mode.

19. The computer program product of claim 15, further comprising:

instructions for detecting changes to the current graphics mode utilizing the interposed module.

20. The computer program product of claim 15, further comprising:

instructions for changing an internal state within the interposed module when the current graphics mode is changed from any standard graphics mode to any specialized graphics mode or from any specialized graphics mode to any standard graphics mode.