SMPProgAdd - Generic IOCtl Commands

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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

Category 09h Physical Disk Control IOCtl Commands

Category 09h is used to access physical partitionable hard disks. The handle used for Category 09h command is returned by the DosPhysicalDisk (Function 2) API function. (See the OS/2 Control Program Programming Reference for more information). This handle is used to tell the system which physical disk is accessed by the IOCtl command.

The Physical Disk Control commands relate to the entire partitionable hard disk. Direct track and sector I/O start at the beginning of the physical drive. PDSK_GETPHYSDEVICEPARAMS, describes the entire physical device.

The following is a summary of Category 09h IOCtl Commands:

Function	Description	Name
00h	Lock Physical Drive	PDSK_LOCKPHYSDRIVE
01h	Unlock Physical Drive	PDSK_UNLOCKPHYSDRIVE
44h	Write Physical Track	PDSK_WRITEPHYSTRACK
63h	Query Physical Device Parameters	PDSK_GETPHYSDEVICEPARAMS
64h	Read Physical Track	PDSK_READPHYSTRACK
65h	Verify Physical Track	PDSK_VERIFYPHYSTRACK