DOSMGR_Instance_Device

include dosmgr.inc
 
mov     esi, OFFSET32 Device_Name
VxDcall DOSMGR_Instance_Device

Instances the installed MS-DOS character device driver. This service is only valid during the Init_Complete message. Uses Flags.

• Clears the carry flag if the device is instanced; otherwise, sets the carry flag to indicate one of the following errors:
  • No device with this name in device list
  • Device is in MS-DOS RAM BIOS (Segment of device == 70h)
  • User overrides with the global setting in SYSTEM.INI

Device_Name

Address of the 8-character device name. This name must exactly match the name as it found in the device header in low memory. Characters must be in uppercase; case conversion is not performed. Names shorter than 8 characters must be padded with spaces. The colon (:) must not be used.

This service applies only to installed character devices (where the device segment is not equal to 70h). It cannot instance devices that are in the MS-DOS RAM BIOS because there is no way to determine their start and end addresses. It is the job of MS-DOS instancing to correctly instance things related to character devices in the MS-DOS RAM BIOS.

This service instances the entire device. It cannot differentiate code and data.

This service is available only during the Init_Complete message. The service is in the ICODE segment so it becomes invalid after the Init_Complete message. Calls to the _AddInstanceItem service are also invalid after Init_Complete.

Do not use this service to instance devices added with the service DOSMGR_Add_Device. To instance an added device, a virtual device must call the _AddInstanceItem service or use the GVDAInstance flag in the _Allocate_Global_V86_Data_Area service.