BlockDev_Synchronous_Command

include blockdev.inc

mov ax, CmdNum ; command number

mov edi, OFFSET32 bdd ; points to a BlockDev_Device_Descriptor

VXDcall BlockDev_Synchronous_Command

The BlockDev_Synchronous_Command service sends a synchronous command to a specified block device.

Parameters

CmdNum

Specifies a command number. It can be one of the following:

Value Meaning

BD_SC_Get_Version Retrieves the version number for the block device.

bdd

Points to a BlockDev_Device_Descriptor structure.

Return Value

If the carry flag is clear, the EAX, EBX, ECX, EDX, ESI, EDI, and flags are modified as defined by the command. Otherwise, the carry flag is set and the AX register contains the following error value:

Value Meaning

BD_SC_Err_Invalid_Cmd Invalid synchronous command

Comments

Registers in addition to AX and EDI may be used as parameters for specific commands.

Uses

Registers defined by command and flags.