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include vmm.inc
 
VMMcall _Add_Global_V86_Data_Area, <LinAddr, nBytes, flags>
 
or      eax, eax        ; nonzero if added, zero if error
jz      not_added
 
The _Add_Global_V86_Data_Area service adds a region to the list of regions
available for allocation as global V86 data areas.
 
This service is only available during initialization, and only for Windows
version 3.1 or later.
 
Parameter  Description
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LinAddr    Specifies the linear address of the first byte of the region.
           This address must be less than 100000h, and must not lie between
           the first and last V86 page for the specified virtual machine.
 
nBytes     Specifies the size in bytes of the region.
 
flags      Specifies the operation flags. This parameter must be set to 0.
 
Return Value
 
The EAX register contains a nonzero value if the service is successful.
Otherwise, EAX contains zero to indicate an error such as an invalid region
specification.
 
Comments
 
This service supports virtual devices, such as the virtual MS-DOS manager
and the V86MMGR device, which can manage high memory above the last V86
page. The service lets these devices add available regions which would
otherwise go unused. Typically, such regions are nonpage-aligned fragments
which cannot be used for normal operations requiring page-aligned memory.
 
Calls to this service should be made during processing of the
Sys_Critical_Init message. Virtual devices should not wait for the
Device_Init or Init_Complete messages since most of the allocation of global
V86 data areas is done while processing the Device_Init message.
 
If this service adds a region that is above the last V86 page, virtual
devices should not attempt to allocate the region until the
Sys_Critical_Init message has been processed.
 
Uses
 
EAX
 
See Also
 
_Allocate_Global_V86_Data_Area
 
 
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