Comment effectuer des transferts DMA sous DOS extender ou environnement DPMI ?

StackOverflow https://stackoverflow.com//questions/11698027

  •  13-12-2019
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Question

Comment un programme peut-il utiliser les transferts DMA lorsqu'il s'exécute dans un environnement DOS extender+DPMI ?

Je veux dire, comment pouvons-nous allouer et obtenir adresse physique du tampon DMA alloué, de manière à fournir cette adresse physique au contrôleur DMA, ou Périphérique maître du bus PCI.

Il y a deux possibilités :

Le prolongateur DOS ou le serveur/hôte DPMI prend en charge la mémoire virtuelle.par exemple Chaussée.

Le prolongateur DOS ou le serveur/hôte DPMI ne prend pas en charge la mémoire virtuelle, mais la pagination est autorisé.par exemple DOS32a.

j'utilise Ouvrez Watcom C compilateur.

L'environnement d'exécution est :

FreeDOS + XMS (pas de EMS/EMM386) + extension DOS (DOS32a)

Pour DJGPP, la solution est ici

Mais cette dernière solution mentionnée, c'est-à-dire via XMS, fonctionnera-t-elle également avec DOS32a ?

La documentation DOS32a indique qu'avant de passer en mode protégé, il alloue tous de la mémoire étendue disponible, puis notre programme peut allouer cette mémoire via la fonction DPMI 501h.

NOTE:Le tampon DMA peut faire environ 1 Mo, je ne peux donc pas utiliser de mémoire conventionnelle pour cela.

Était-ce utile?

La solution

Pour une solution DPMI propre, vous pouvez explorer les fonctions DPMI suivantes (extraits de la liste d'interruptions de Ralf Brown): 

INT 31 P - DPMI 1.0+ - MAP DEVICE IN MEMORY BLOCK
        AX = 0508h
        ESI = memory block handle
        EBX = page-aligned offset within memory block of page(s) to be mapped
        ECX = number of pages to map
        EDX = page-aligned physical address of device
Return: CF clear if successful
        CF set on error
            AX = error code (8001h,8003h,8023h,8025h) (see #03143)
Notes:  only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
        support of this function is optional; hosts are also allowed to support
          the function for some devices but not others

INT 31 P - DPMI 1.0+ - MAP CONVENTIONAL MEMORY IN MEMORY BLOCK
        AX = 0509h
        ESI = memory block handle
        EBX = page-aligned offset within memory block of page(s) to map
        ECX = number of pages to map
        EDX = page-aligned linear address of conventional (below 1M) memory
Return: CF clear if successful
        CF set on error
            AX = error code (8001h,8003h,8023h,8025h) (see #03143)
Notes:  only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
        support of this function is optional

INT 31 P - DPMI 0.9+ - PHYSICAL ADDRESS MAPPING
        AX = 0800h
        BX:CX = physical address (should be above 1 MB)
        SI:DI = size in bytes
Return: CF clear if successful
            BX:CX = linear address which maps the requested physical memory
        CF set on error
            AX = error code (DPMI 1.0+) (8003h,8021h) (see #03143)
Notes:  implementations may refuse this call because it can circumvent protects
        the caller must build an appropriate selector for the memory
        do not use for memory mapped in the first megabyte

Si aucun de ce qui précède ne vous permet de mapper des adresses virtuelles aux adresses physiques, ni d'obtenir des adresses physiques des blocs alloués (par exemple non pris en charge), vous devez examiner les détails de votre mise en œuvre de votre hôte DPMI (par exemple, s'il n'active pas la page. traduction ou il peut être désactivé, alors toutes les adresses sont physiques).

edit : On dirait que vous devriez pouvoir allouer de la mémoire (plus que 1 Mo) et obtenir ses adresses physiques et virtuelles. Tout d'abord, allouez-le en utilisant XMS / Himem.sys et verrouillez-le. Cela vous donnera l'adresse physique. Ensuite, utilisez la fonction DPMI 0x800 pour obtenir l'adresse virtuelle correspondante.

Voici comment (ignorer la version 16 bits (compilée avec Borland / Turbo C / C ++), il est utilisé uniquement pour valider les routines XMS): 

// file: dma.c
//
// Compiling with Open Watcom C/C++ and DOS/32 DOS extender/DPMI host:
//   wcl386.exe /q /we /wx /bcl=dos4g dma.c
//   sb.exe /b /bndmados32.exe dma.exe
// Before running dmados32.exe do "set DOS32A=/EXTMEM:4096"
// to limit the amount of extended (XMS) memory allocated by DOS/32
// at program start (by default it allocates everything).
//
// Compiling with 16-bit Borland/Turbo C/C++:
//   tcc.exe dma.c

#include <stdio.h>
#include <string.h>
#include <dos.h>
#include <limits.h>

#if defined(__WATCOMC__)
#if !defined(__386__)
#error unsupported target, must be 32-bit (DPMI) DOS app
#endif
#elif defined(__TURBOC__)
#if !defined(__SMALL__)
#error unsupported target, must be 16-bit DOS app with small memory model
#endif
#else
#error unsupported compiler
#endif

typedef unsigned uint;
typedef unsigned long ulong;

typedef signed char int8;
typedef unsigned char uint8;

typedef short int16;
typedef unsigned short uint16;

#if UINT_MIN >= 0xFFFFFFFF
typedef int int32;
typedef unsigned uint32;
#else
typedef long int32;
typedef unsigned long uint32;
#endif

#pragma pack(push, 1)

typedef struct tDpmiRmInt
{
  uint32 edi, esi, ebp, resz0, ebx, edx, ecx, eax;
  uint16 flags, es, ds, fs, gs, ip, cs, sp, ss;
} tDpmiRmInt;

#pragma pack(pop)

int RmInt(uint8 IntNumber, tDpmiRmInt* pRegs)
{
#if defined(__WATCOMC__)
  union REGS inregs, outregs;

  memset(&inregs, 0, sizeof(inregs));
  memset(&outregs, 0, sizeof(outregs));

  inregs.w.ax = 0x300;
  inregs.h.bl = IntNumber;
  inregs.h.bh = 0;
  inregs.w.cx = 0;
  inregs.x.edi = (uint32)pRegs;

  return int386(0x31, &inregs, &outregs);
#elif defined(__TURBOC__)
  struct REGPACK regs;

  memset(&regs, 0, sizeof(regs));

  regs.r_ax = (uint16)pRegs->eax;
  regs.r_bx = (uint16)pRegs->ebx;
  regs.r_cx = (uint16)pRegs->ecx;
  regs.r_dx = (uint16)pRegs->edx;
  regs.r_si = (uint16)pRegs->esi;
  regs.r_di = (uint16)pRegs->edi;
  regs.r_bp = (uint16)pRegs->ebp;
  regs.r_flags = pRegs->flags;
  regs.r_ds = pRegs->ds;
  regs.r_es = pRegs->es;

  // No fs, gs (16-bit code)
  // No ss:sp, cs:ip (int*()/intr() functions set the right values)

  intr(IntNumber, &regs);

  memset(pRegs, 0, sizeof(*pRegs));

  pRegs->eax = regs.r_ax;
  pRegs->ebx = regs.r_bx;
  pRegs->ecx = regs.r_cx;
  pRegs->edx = regs.r_dx;
  pRegs->esi = regs.r_si;
  pRegs->edi = regs.r_di;
  pRegs->ebp = regs.r_bp;
  pRegs->flags = regs.r_flags;
  pRegs->ds = regs.r_ds;
  pRegs->es = regs.r_es;

  return regs.r_ax;
#endif
}

int RmFarCall(tDpmiRmInt* pRegs)
{
#if defined(__WATCOMC__)
  union REGS inregs, outregs;

  memset(&inregs, 0, sizeof(inregs));
  memset(&outregs, 0, sizeof(outregs));

  inregs.w.ax = 0x301;
  inregs.h.bh = 0;
  inregs.w.cx = 0;
  inregs.x.edi = (uint32)pRegs;

  return int386(0x31, &inregs, &outregs);
#elif defined(__TURBOC__)
  uint8 code[128];
  uint8* p = code;
  void far* codef = &code[0];
  void (far* f)(void) = (void(far*)(void))codef;

  *p++ = 0x60;                                                            // pusha
  *p++ = 0x1E;                                                            // push  ds
  *p++ = 0x06;                                                            // push  es

  *p++ = 0x68; *p++ = (uint8)pRegs->ds; *p++ = (uint8)(pRegs->ds >> 8);   // push #
  *p++ = 0x1F;                                                            // pop  ds
  *p++ = 0x68; *p++ = (uint8)pRegs->es; *p++ = (uint8)(pRegs->es >> 8);   // push #
  *p++ = 0x07;                                                            // pop  es

  *p++ = 0xb8; *p++ = (uint8)pRegs->eax; *p++ = (uint8)(pRegs->eax >> 8); // mov ax, #
  *p++ = 0xbb; *p++ = (uint8)pRegs->ebx; *p++ = (uint8)(pRegs->ebx >> 8); // mov bx, #
  *p++ = 0xb9; *p++ = (uint8)pRegs->ecx; *p++ = (uint8)(pRegs->ecx >> 8); // mov cx, #
  *p++ = 0xba; *p++ = (uint8)pRegs->edx; *p++ = (uint8)(pRegs->edx >> 8); // mov dx, #
  *p++ = 0xbe; *p++ = (uint8)pRegs->esi; *p++ = (uint8)(pRegs->esi >> 8); // mov si, #
  *p++ = 0xbf; *p++ = (uint8)pRegs->edi; *p++ = (uint8)(pRegs->edi >> 8); // mov di, #
  *p++ = 0xbd; *p++ = (uint8)pRegs->ebp; *p++ = (uint8)(pRegs->ebp >> 8); // mov bp, #

  *p++ = 0x9A; *p++ = (uint8)pRegs->ip; *p++ = (uint8)(pRegs->ip >> 8);
               *p++ = (uint8)pRegs->cs; *p++ = (uint8)(pRegs->cs >> 8);   // call far seg:offs

  *p++ = 0x60;                                                            // pusha
  *p++ = 0x1E;                                                            // push  ds
  *p++ = 0x06;                                                            // push  es
  *p++ = 0x89; *p++ = 0xE5;                                               // mov   bp, sp
  *p++ = 0x8E; *p++ = 0x5E; *p++ = 0x16;                                  // mov   ds, [bp + 0x16]
  *p++ = 0x89; *p++ = 0xEE;                                               // mov   si, bp
  *p++ = 0xFC;                                                            // cld

  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->es; *p++ = (uint8)((uint16)&pRegs->es >> 8);  // mov [], ax (es)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->ds; *p++ = (uint8)((uint16)&pRegs->ds >> 8);  // mov [], ax (ds)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->edi; *p++ = (uint8)((uint16)&pRegs->edi >> 8);  // mov [], ax (di)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->esi; *p++ = (uint8)((uint16)&pRegs->esi >> 8);  // mov [], ax (si)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->ebp; *p++ = (uint8)((uint16)&pRegs->ebp >> 8);  // mov [], ax (bp)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->ebx; *p++ = (uint8)((uint16)&pRegs->ebx >> 8);  // mov [], ax (bx)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->edx; *p++ = (uint8)((uint16)&pRegs->edx >> 8);  // mov [], ax (dx)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->ecx; *p++ = (uint8)((uint16)&pRegs->ecx >> 8);  // mov [], ax (cx)
  *p++ = 0xAD;                                                            // lodsw          
  *p++ = 0xA3; *p++ = (uint8)&pRegs->eax; *p++ = (uint8)((uint16)&pRegs->eax >> 8);  // mov [], ax (ax)

  *p++ = 0x83; *p++ = 0xC4; *p++ = 0x14;                                  // add   sp, 0x14

  *p++ = 0x07;                                                            // pop   es
  *p++ = 0x1F;                                                            // pop   ds
  *p++ = 0x61;                                                            // popa
  *p++ = 0xCB;                                                            // retf

  f();

  return (uint16)pRegs->eax;
#endif
}

struct
{
  uint16 Ip, Cs;
} XmsEntryPoint = { 0 };

int XmsSupported(void)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x4300;
  RmInt(0x2F, &regs);

  return (regs.eax & 0xFF) == 0x80;
}

void XmsInit(void)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x4310;
  RmInt(0x2F, &regs);

  XmsEntryPoint.Cs = regs.es;
  XmsEntryPoint.Ip = (uint16)regs.ebx;
}

int XmsQueryVersions(uint16* pXmsVer, uint16* pHimemVer)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x00 << 8;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  if (pXmsVer != NULL)
    *pXmsVer = (uint16)regs.eax;

  if (pHimemVer != NULL)
    *pHimemVer = (uint16)regs.ebx;

  return (int)(regs.ebx & 0xFF);
}

int XmsQueryFreeMem(uint16* pLargest, uint16* pTotal)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x08 << 8;
  regs.ebx = 0;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  if (pLargest != NULL)
    *pLargest = (uint16)regs.eax;

  if (pTotal != NULL)
    *pTotal = (uint16)regs.edx;

  return (int)(regs.ebx & 0xFF);
}

int XmsAllocMem(uint16* pHandle, uint16 Size)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x09 << 8;
  regs.edx = Size;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  *pHandle = (uint16)regs.edx;

  return (int)(regs.ebx & 0xFF);
}

int XmsFreeMem(uint16 Handle)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x0A << 8;
  regs.edx = Handle;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  return (int)(regs.ebx & 0xFF);
}

int XmsLockMem(uint16 Handle, uint32* pPhysAddr)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x0C << 8;
  regs.edx = Handle;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  *pPhysAddr = ((regs.edx & 0xFFFF) << 16) | (regs.ebx & 0xFFFF);

  return (int)(regs.ebx & 0xFF);
}

#if defined(__TURBOC__)
int XmsCopyMem(uint16 DstHandle, uint32 DstOffs, uint16 SrcHandle, uint32 SrcOffs, uint32 Size)
{
  tDpmiRmInt regs;
#pragma pack(push, 1)
  struct
  {
    uint32 Size;
    uint16 SrcHandle;
    uint32 SrcOffs;
    uint16 DstHandle;
    uint32 DstOffs;
  } emm;
#pragma pack(pop)

  emm.Size      = Size;
  emm.SrcHandle = SrcHandle;
  emm.SrcOffs   = SrcOffs;
  emm.DstHandle = DstHandle;
  emm.DstOffs   = DstOffs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x0B << 8;
  regs.ds = FP_SEG(&emm);
  regs.esi = FP_OFF(&emm);
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  return (int)(regs.ebx & 0xFF);
}
#endif

int XmsUnlockMem(uint16 Handle)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x0D << 8;
  regs.edx = Handle;
  regs.cs = XmsEntryPoint.Cs;
  regs.ip = XmsEntryPoint.Ip;
  RmFarCall(&regs);

  return (int)(regs.ebx & 0xFF);
}

#if defined(__WATCOMC__)
int DpmiMap(void** pPtr, uint32 PhysAddr, uint32 Size)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x800;
  regs.ebx = PhysAddr >> 16;
  regs.ecx = PhysAddr & 0xFFFF;
  regs.esi = Size >> 16;
  regs.edi = Size & 0xFFFF;
  RmInt(0x31, &regs);

  *pPtr = (void*)(((regs.ebx & 0xFFFF) << 16) | (regs.ecx & 0xFFFF));

  return regs.flags & 1;
}

int DpmiUnmap(void* Ptr)
{
  tDpmiRmInt regs;

  memset(&regs, 0, sizeof(regs));
  regs.eax = 0x801;
  regs.ebx = (uint32)Ptr >> 16;
  regs.ecx = (uint32)Ptr & 0xFFFF;
  RmInt(0x31, &regs);

  return regs.flags & 1;
}
#endif

int main(void)
{
  uint16 xmsVer, himemVer;
  uint16 largestFreeSz, totalFreeSz;
  uint16 handle;
  uint32 physAddr;

#if defined(__WATCOMC__)
  {
    uint32 cr0__ = 0, cr3__ = 0;
    __asm
    {
      mov eax, cr0
      mov cr0__, eax
      mov eax, cr3
      mov cr3__, eax
    }
    printf("CR0: 0x%08lX, CR3: 0x%08lX\n", (ulong)cr0__, (ulong)cr3__);
  }
#endif

  if (!XmsSupported())
  {
    printf("XMS unsupported\n");
    goto Exit;
  }
  printf("XMS supported\n");

  XmsInit();
  printf("XMS entry point: 0x%04X:0x%04X\n",
         XmsEntryPoint.Cs, XmsEntryPoint.Ip);

  XmsQueryVersions(&xmsVer, &himemVer);
  printf("XMS version: 0x%X  Himem.sys version: 0x%X\n",
         xmsVer, himemVer);

  XmsQueryFreeMem(&largestFreeSz, &totalFreeSz);
  printf("Largest free block size: %u KB  Total free memory: %u KB\n",
         largestFreeSz, totalFreeSz);

  printf("Allocating the DMA buffer...\n");
  if (XmsAllocMem(&handle, 64))
  {
    printf("Failed to allocate the DMA buffer\n");
    goto Exit;
  }

  XmsQueryFreeMem(&largestFreeSz, &totalFreeSz);
  printf("Largest free block size: %u KB  Total free memory: %u KB\n",
         largestFreeSz, totalFreeSz);

  printf("Locking the DMA buffer...\n");
  if (XmsLockMem(handle, &physAddr))
  {
    printf("Failed to lock the DMA buffer\n");
  }
  else
  {
    printf("The DMA buffer is at physical address: 0x%08lX\n", (ulong)physAddr);

#if defined(__WATCOMC__)
    {
      uint8* ptr;

      printf("Mapping the DMA buffer...\n");

      if (DpmiMap((void**)&ptr, physAddr, 64 * 1024UL))
      {
        printf("Failed to map the DMA buffer\n");
      }
      else
      {
        printf("The DMA buffer is at virtual address: 0x%08lX\n", (ulong)ptr);

        printf("Using the DMA buffer...\n");
        strcpy(ptr, "This is a test string in the DMA buffer.");
        printf("%s\n", ptr);

        DpmiUnmap(ptr);
      }
    }
#elif defined(__TURBOC__)
    {
      char testStr[] = "This is a test string copied to and from the DMA buffer.";
      printf("Using the DMA buffer...\n");
      if (XmsCopyMem(handle, 0, 0, ((uint32)FP_SEG(testStr) << 16) + FP_OFF(testStr), sizeof(testStr)))
      {
        printf("Failed to copy to the DMA buffer\n");
      }
      else
      {
        memset(testStr, 0, sizeof(testStr));
        if (XmsCopyMem(0, ((uint32)FP_SEG(testStr) << 16) + FP_OFF(testStr), handle, 0, sizeof(testStr)))
        {
          printf("Failed to copy from the DMA buffer\n");
        }
        else
        {
          printf("%s\n", testStr);
        }
      }
    }
#endif

    XmsUnlockMem(handle);
  }

  XmsFreeMem(handle);

  XmsQueryFreeMem(&largestFreeSz, &totalFreeSz);
  printf("Largest free block size: %u KB  Total free memory: %u KB\n",
         largestFreeSz, totalFreeSz);

Exit:

  return 0;
}

Sortie d'échantillon (sous DOSBOX): 

CR0: 0x00000001, CR3: 0x00000000
XMS supported
XMS entry point: 0xC83F:0x0010
XMS version: 0x300  Himem.sys version: 0x301
Largest free block size: 11072 KB  Total free memory: 11072 KB
Allocating the DMA buffer...
Largest free block size: 11008 KB  Total free memory: 11008 KB
Locking the DMA buffer...
The DMA buffer is at physical address: 0x00530000
Mapping the DMA buffer...
The DMA buffer is at virtual address: 0x00530000
Using the DMA buffer...
This is a test string in the DMA buffer.
Largest free block size: 11072 KB  Total free memory: 11072 KB

Notez que DOS / 32 ne permet pas la traduction de la page (sauf s'il y a VCPI). Le bit PG de CR0 est 0, CR3 est 0 et les adresses physiques et virtuelles obtenues sont les mêmes, tout parle pour cela. Et ainsi les adresses virtuelles et physiques sont la même chose.

Autres conseils

J'ai écrit une application pour tester AHCI sous DOS (mon environnement était DOS 7.0 + DOS32a + Watcom C) et j'ai répertorié comment j'ai alloué de la mémoire pour le transfert DMA comme ci-dessous pour votre référence.

(1) allouer de la mémoire en mode plat (supposez allouer 1 Ko de mémoire et devrait être MOT aligner)

ptr = (pDWORD)calloc(1024+1, sizeof(BYTE));

où 1024 est ce dont nous avons vraiment besoin et 1 octet est pour la "tolérance", car le pointeur renvoyé peut ne pas être aligné sur le mot et le pire des cas est Ex. ptr pointe vers 0x30000001

(2) ajuster en fonction de l'alignement WORD (2 octets)

if(inputAddr & 1) { inputAddr &= (~2 + 1); inputAddr += 2; }

(3) attribuer le inputAddr ci-dessus aux PRDT Administrateur de base de données(Adresse de la base de données)

Remarques:

1) J'ai utilisé "mode mémoire plate" par "...wpp386 -mf..." dans makefile et "op stub=dos23a.exe" dans le fichier de liaison...

2) où ptr est le pointeur réel vers la partie de mémoire allouée et doit être conservé lors de la libération de mémoire ; entréeAdr est un autre pointeur pointant vers l'adresse mémoire correcte (alignée) pour le transfert de données !

De cette façon, le test de transfert DMA était OK et la mémoire allouée peut atteindre 4 Mo dans cet environnement...

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