subsystems/mvdm/ntvdm/hardware/dma.h

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            subsystems/mvdm/ntvdm/hardware/dma.h
   5  * PURPOSE:         ISA DMA - Direct Memory Access Controller emulation -
   6  *                  i8237A compatible with 74LS612 Memory Mapper extension
   7  * PROGRAMMERS:     Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   8  */
   9
  10 #ifndef _DMA_H_
  11 #define _DMA_H_
  12
  13 /* DEFINES ********************************************************************/
  14
  15 #define DMA_CONTROLLERS         2
  16 #define DMA_CONTROLLER_CHANNELS 4 // Each DMA controller has 4 channels
  17
  18 typedef struct _DMA_CHANNEL
  19 {
  20     WORD BaseAddress;
  21     WORD BaseElemCnt;
  22     WORD CurrAddress;
  23     WORD CurrElemCnt;
  24     BYTE Mode;
  25 } DMA_CHANNEL, *PDMA_CHANNEL;
  26
  27 typedef struct _DMA_CONTROLLER
  28 {
  29     DMA_CHANNEL DmaChannel[DMA_CONTROLLER_CHANNELS];
  30
  31     WORD TempAddress;
  32     WORD TempElemCnt;
  33
  34     BYTE TempReg;
  35
  36     BYTE Command;
  37     BYTE Request;
  38     BYTE Mask;
  39     BYTE Status;
  40
  41     BOOLEAN FlipFlop; // 0: LSB ; 1: MSB
  42
  43 } DMA_CONTROLLER, *PDMA_CONTROLLER;
  44
  45 /* 74LS612 Memory Mapper extension */
  46 typedef struct _DMA_PAGE_REGISTER
  47 {
  48     BYTE Page;
  49 } DMA_PAGE_REGISTER, *PDMA_PAGE_REGISTER;
  50
  51 // The 74LS612 contains 16 bytes, each of them being a page register.
  52 // They are accessible via ports 0x80 through 0x8F.
  53
  54 /* FUNCTIONS ******************************************************************/
  55
  56 DWORD DmaRequest(IN WORD      iChannel,
  57                  IN OUT PVOID Buffer,
  58                  IN DWORD     length);
  59
  60 VOID DmaInitialize(VOID);
  61
  62 #endif /* _DMA_H_ */