PDRREF:Exported Driver Function Reference

Presentation Device Driver Reference for OS/2

Introduction to OS/2 Presentation Drivers Design Considerations for All Drivers Graphics Engine/Presentation Driver Design Changes Design Considerations for Display Drivers Design Considerations for Hardcopy Drivers Display Drivers Distributed Console Access Facility (DCAF) Architecture Graphics Engine Hardcopy Drivers Queue Drivers Port Drivers Presentation Manager Function Categories Exported Driver Function Reference Mandatory and Simulated Graphics Engine Function Reference Device Support Function Reference DBIDI Command Structures and Command Flow Appendixes A - OS/2 Version Compatibility Considerations B - Syntax Conventions C - Format of the Journal File D - Bit-Map Simulation for 16-Bit Hardcopy Drivers E - Data Types F - Notices Miscellaneous G - Glossary

Reprint Courtesy of International Business Machines Corporation, © International Business Machines Corporation

This chapter describes the entry points that are exported by the dynamic link library of a presentation driver:

EXPORTS
   OS2_PM_DRV_RING_LEVELS      /* All drivers - Optional  */
   OS2_PM_DRV_ENABLE_LEVELS    /* All drivers - Optional  */
   OS2_PM_DRV_ENABLE           /* All drivers - Mandatory */

The functions in this chapter are listed in the following index table. A detailed description of each function follows the table.

Function	Type
DrvInstall	GRE hardcopy
DrvRemove	GRE hardcopy
OS2_PM_DRV_DEVICENAMES	GRE hardcopy
OS2_PM_DRV_DEVMODE	GRE hardcopy
FillLogicalDeviceBlock	exported entry point
FillPhysicalDeviceBlock	exported entry point
DisablePhysicalDeviceBlock	exported entry point
EnableDeviceContext	exported entry point
DisableDeviceContext	exported entry point
SaveDCState	exported entry point
RestoreDCState	exported entry point
ResetDCState	exported entry point
CompleteOpenDC	exported entry point
BeginCloseDC	exported entry point
InstallPMEngineDisplayHooks	exported entry point
QueryDeviceSurface	exported entry point
OS2_PM_DRV_QUERYSCREENRESOLUTIONS	display driver

Enable Levels

This entry point is the address of a table of ring levels required when calling each of the Enable subfunctions. The table is an array of bytes corresponding to the subfunction numbers, terminating with a byte of 0 (that is, an ASCIIZ string). The most significant six bits of each byte are reserved and must be 0. The remaining two bits of each byte represent the ring level to be used when dispatching the corresponding function in the dispatch table.

   00 = End of Table         10 = Ring 2
   01 = Ring-2-Conforming    11 = Ring 3

Any subfunction that does not have a corresponding byte in the table will be dispatched as Ring-2-conforming. This is the most desirable case from the standpoint of system performance.

Subfunction	Type
Unused	0x01
FillLogicalDeviceBlock	0x01
FillPhysicalDeviceBlock	0x03
Unused	0x01
DisablePhysicalDeviceBlock	0x02
All others	0x00

The following example of six bytes would declare FillPhysicalDeviceBlock as Ring 3, DisablePhysicalDeviceBlock as Ring 2, and all other subfunctions as Ring-2-conforming:

  0x01    0x01    0x03    0x01    0x02    0x00

If the address of this table is not exported, all subfunctions will be called as Ring-2-conforming as if the table had contained the single byte 0x00.

Ring Levels

This entry point is the address of a table of ring levels required when dispatching each of the functions hooked in the dispatch table by FillLogicalDeviceBlock. The table is an array of bytes corresponding to the functions in the dispatch table, terminating with a byte of 0 (that is, an ASCIIZ string). The most significant six bits of each byte are reserved and must be 0. The remaining two bits of each byte represent the ring level to be used when dispatching the corresponding function in the dispatch table.

   00 = End of Table         10 = Ring 2
   01 = Ring-2-Conforming    11 = Ring 3

Any function that does not have a corresponding byte in the table will be dispatched as Ring-2-conforming. This is the most desirable case from the standpoint of system performance.

Function	Type
GreGetArcParameters	0x01
GreSetArcParameters	0x01
GreArc	0x03
GrePartialArc	0x02
All others	0x00

The following example of five bytes would declare GreArc as Ring 3, GrePartialArc as Ring 2, and all other functions as Ring-2-conforming:

  0x01    0x01    0x03    0x02    0x00

If the address of this table is not exported, all functions will be dispatched as Ring-2-conforming as if the table had contained the single byte 0x00.

QueryScreenResolutions

• OS2_PM_DRV_QUERYSCREENRESOLUTIONS