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SMP Programming Addendum
How to Use the SMP Programming Addendum Introduction to OS/2 Warp Server Version 4 Advanced Platform Specific Drivers (PSDs) High Memory Support Raw File System Processor Management and Performance Functions Application Considerations Device Drivers In OS/2 Warp Server for SMP New Device Helper (DevHlp) Routines Kernel Debugger The ICAT Debugger Software Trace Facility (STRACE) View and Set Program Type For Executable File (MARKEXE) Data Types Errors Generic IOCtl Commands Sample Source Code for a PSD Comments, Please! Glossary Notices

Generic IOCtl Commands

OS/2 device drivers are used to access the I/O hardware. The IOCtl functions provide a method for an application, or subsystem, to send device-specific control commands to a physical device driver. These IOCtls are subfunctions that are issued through the DosDevIOCtl API function request. The DosDevIOCtl function request can be used only by OS/2 applications; the INT 21h IOCtl request can be used only by DOS applications.

Category and Function Fields

The category and function fields are as follows. Each code is contained in a byte:

Category Codes

0xxx xxxx: OS/2-defined
1xxx xxxx: User-defined
_xxx xxxx: Code

Function Codes

0xxx xxxx: Return error, if unsupported
1xxx xxxx: Ignore, if unsupported
x0xx xxxx: Intercepted by the OS/2 operating system
x1xx xxxx: Passed to driver
xx0x xxxx: Sends data and commands to device
xx1x xxxx: Queries data and information from device
___x xxxx: Subfunction

Note: The send/query data bit is intended only to standardize the function set; it plays no critical role. Some functions can contain both command and query elements. Such commands are defined as sends data.

Category 08h Logical Disk Control IOCtl Commands

The following is a summary of Category 08h IOCtl Commands:

Function	Description	Name
00h	Lock Drive	DSK_LOCKDRIVE
01h	Unlock Drive	DSK_UNLOCKDRIVE
02h	Redetermine Media	DSK_REDETERMINEMEDIA
03h	Set Logical Map	DSK_SETLOGICALMAP
04h	Begin Format	DSK_BEGINFORMAT
20h	Block Removable	DSK_BLOCKREMOVABLE
21h	Query Logical Map	DSK_GETLOGICALMAP
22h	Reserved
40h	Removable Media Control	DSK_UNLOCKEJECTMEDIA
43h	Set Device Parameters	DSK_SETDEVICEPARAMS
44h	Write Logical Track	DSK_WRITETRACK
45h	Format and Verify Track	DSK_FORMATVERIFY
5Dh	Diskette Control	DSK_DISKETTECONTROL
5Eh	Reserved
5Fh	Reserved
60h	Query Media Sense	DSK_QUERYMEDIASENSE
63h	Query Device Parameters	DSK_GETDEVICEPARAMS
64h	Read Logical Track	DSK_READTRACK
65h	Verify Logical Track	DSK_VERIFYTRACK
66h	Status	DSK_GETLOCKSTATUS