/*
 * COPYRIGHT:       GPLv2+ - See COPYING in the top level directory
 * PROJECT:         ReactOS Virtual DOS Machine
 * FILE:            subsystems/mvdm/ntvdm/dos/dos32krnl/himem.h
 * PURPOSE:         DOS XMS Driver and UMB Provider
 * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
 *                  Hermes Belusca-Maito (hermes.belusca@sfr.fr)
 */

#ifndef _HIMEM_H_
#define _HIMEM_H_

/* DEFINITIONS ****************************************************************/

#define XMS_ADDRESS     0x110000        // Just above HMA
#define XMS_BLOCK_SIZE  1024
#define XMS_BLOCKS      ((MAX_ADDRESS - XMS_ADDRESS) / XMS_BLOCK_SIZE)
#define XMS_MAX_HANDLES 16              // Specification: min 1, max 128, default 32

#define XMS_STATUS_SUCCESS              0x00
#define XMS_STATUS_NOT_IMPLEMENTED      0x80
#define XMS_STATUS_A20_ERROR            0x82
#define XMS_STATUS_HMA_DOES_NOT_EXIST   0x90
#define XMS_STATUS_HMA_IN_USE           0x91
#define XMS_STATUS_HMA_MIN_SIZE         0x92
#define XMS_STATUS_HMA_NOT_ALLOCATED    0x93
#define XMS_STATUS_A20_STILL_ENABLED    0x94
#define XMS_STATUS_OUT_OF_MEMORY        0xA0
#define XMS_STATUS_OUT_OF_HANDLES       0xA1
#define XMS_STATUS_INVALID_HANDLE       0xA2
#define XMS_STATUS_BAD_SRC_HANDLE       0xA3
#define XMS_STATUS_BAD_DEST_HANDLE      0xA4
#define XMS_STATUS_BAD_SRC_OFFSET       0xA5
#define XMS_STATUS_BAD_DEST_OFFSET      0xA6
#define XMS_STATUS_NOT_LOCKED           0xAA
#define XMS_STATUS_LOCKED               0xAB
#define XMS_STATUS_LOCK_OVERFLOW        0xAC
#define XMS_STATUS_CANNOT_LOCK          0xAD
#define XMS_STATUS_SMALLER_UMB          0xB0
#define XMS_STATUS_OUT_OF_UMBS          0xB1
#define XMS_STATUS_INVALID_UMB          0xB2

typedef struct _XMS_HANDLE
{
    BYTE Handle;
    BYTE LockCount;
    WORD Size;
    DWORD Address;
} XMS_HANDLE, *PXMS_HANDLE;

#pragma pack(push, 1)
typedef struct _XMS_COPY_DATA
{
    DWORD Count;
    WORD SourceHandle;
    DWORD SourceOffset;
    WORD DestHandle;
    DWORD DestOffset;
} XMS_COPY_DATA, *PXMS_COPY_DATA;
#pragma pack(pop)

/* FUNCTIONS ******************************************************************/

BOOLEAN XmsGetDriverEntry(PDWORD Pointer);
VOID XmsInitialize(VOID);
VOID XmsCleanup(VOID);

#endif /* _HIMEM_H_ */