msdos/devices.c

   1 /*
   2  * DOS devices
   3  *
   4  * Copyright 1999 Ove Kåven
   5  */
   6
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include "wine/winbase16.h"
  10 #include "msdos.h"
  11 #include "miscemu.h"
  12 #include "dosexe.h"
  13 #include "debugtools.h"
  14
  15 #include "pshpack1.h"
  16
  17 typedef struct {
  18   BYTE ljmp1;
  19   RMCBPROC strategy;
  20   BYTE ljmp2;
  21   RMCBPROC interrupt;
  22 } WINEDEV_THUNK;
  23
  24 typedef struct {
  25   BYTE size; /* length of header + data */
  26   BYTE unit; /* unit (block devices only) */
  27   BYTE command;
  28   WORD status;
  29   BYTE reserved[8];
  30 } REQUEST_HEADER;
  31
  32 typedef struct {
  33   REQUEST_HEADER hdr;
  34   BYTE media; /* media descriptor from BPB */
  35   SEGPTR buffer;
  36   WORD count; /* byte/sector count */
  37   WORD sector; /* starting sector (block devices) */
  38   DWORD volume; /* volume ID (block devices) */
  39 } REQ_IO;
  40
  41 typedef struct {
  42   REQUEST_HEADER hdr;
  43   BYTE data;
  44 } REQ_SAFEINPUT;
  45
  46 #include "poppack.h"
  47
  48 #define CON_BUFFER 128
  49
  50 enum strategy { SYSTEM_STRATEGY_NUL, SYSTEM_STRATEGY_CON, NB_SYSTEM_STRATEGIES };
  51
  52 static void *strategy_data[NB_SYSTEM_STRATEGIES];
  53
  54 #define NONEXT ((DWORD)-1)
  55
  56 #define ATTR_STDIN     0x0001
  57 #define ATTR_STDOUT    0x0002
  58 #define ATTR_NUL       0x0004
  59 #define ATTR_CLOCK     0x0008
  60 #define ATTR_FASTCON   0x0010
  61 #define ATTR_RAW       0x0020
  62 #define ATTR_NOTEOF    0x0040
  63 #define ATTR_DEVICE    0x0080
  64 #define ATTR_REMOVABLE 0x0800
  65 #define ATTR_NONIBM    0x2000 /* block devices */
  66 #define ATTR_UNTILBUSY 0x2000 /* char devices */
  67 #define ATTR_IOCTL     0x4000
  68 #define ATTR_CHAR      0x8000
  69
  70 #define CMD_INIT       0
  71 #define CMD_MEDIACHECK 1 /* block devices */
  72 #define CMD_BUILDBPB   2 /* block devices */
  73 #define CMD_INIOCTL    3
  74 #define CMD_INPUT      4 /* read data */
  75 #define CMD_SAFEINPUT  5 /* "non-destructive input no wait", char devices */
  76 #define CMD_INSTATUS   6 /* char devices */
  77 #define CMD_INFLUSH    7 /* char devices */
  78 #define CMD_OUTPUT     8 /* write data */
  79 #define CMD_SAFEOUTPUT 9 /* write data with verify */
  80 #define CMD_OUTSTATUS 10 /* char devices */
  81 #define CMD_OUTFLUSH  11 /* char devices */
  82 #define CMD_OUTIOCTL  12
  83 #define CMD_DEVOPEN   13
  84 #define CMD_DEVCLOSE  14
  85 #define CMD_REMOVABLE 15 /* block devices */
  86 #define CMD_UNTILBUSY 16 /* output until busy */
  87
  88 #define STAT_MASK  0x00FF
  89 #define STAT_DONE  0x0100
  90 #define STAT_BUSY  0x0200
  91 #define STAT_ERROR 0x8000
  92
  93 #define LJMP 0xea
  94
  95
  96 /* prototypes */
  97 static void WINAPI nul_strategy(CONTEXT86*ctx);
  98 static void WINAPI nul_interrupt(CONTEXT86*ctx);
  99 static void WINAPI con_strategy(CONTEXT86*ctx);
 100 static void WINAPI con_interrupt(CONTEXT86*ctx);
 101
 102 /* devices */
 103 typedef struct
 104 {
 105     char name[8];
 106     WORD attr;
 107     RMCBPROC strategy;
 108     RMCBPROC interrupt;
 109
 110 } WINEDEV;
 111
 112 static WINEDEV devs[] =
 113 {
 114   { "NUL     ",
 115     ATTR_CHAR|ATTR_NUL|ATTR_DEVICE,
 116     nul_strategy, nul_interrupt },
 117
 118   { "CON     ",
 119     ATTR_CHAR|ATTR_STDIN|ATTR_STDOUT|ATTR_FASTCON|ATTR_NOTEOF|ATTR_DEVICE,
 120     con_strategy, con_interrupt }
 121 };
 122
 123 #define NR_DEVS (sizeof(devs)/sizeof(WINEDEV))
 124
 125 /* DOS data segment */
 126 typedef struct
 127 {
 128     DOS_LISTOFLISTS    lol;
 129     DOS_DEVICE_HEADER  dev[NR_DEVS-1];
 130     WINEDEV_THUNK      thunk[NR_DEVS];
 131     REQ_IO             req;
 132     BYTE               buffer[CON_BUFFER];
 133
 134 } DOS_DATASEG;
 135
 136 #define DOS_DATASEG_OFF(xxx) FIELD_OFFSET(DOS_DATASEG, xxx)
 137
 138 DWORD DOS_LOLSeg;
 139
 140
 141 /* the device implementations */
 142 static void do_lret(CONTEXT86*ctx)
 143 {
 144   WORD *stack = CTX_SEG_OFF_TO_LIN(ctx, ctx->SegSs, ctx->Esp);
 145
 146   ctx->Eip   = *(stack++);
 147   ctx->SegCs = *(stack++);
 148   ctx->Esp  += 2*sizeof(WORD);
 149 }
 150
 151 static void do_strategy(CONTEXT86*ctx, int id, int extra)
 152 {
 153   REQUEST_HEADER *hdr = CTX_SEG_OFF_TO_LIN(ctx, ctx->SegEs, ctx->Ebx);
 154   void **hdr_ptr = strategy_data[id];
 155
 156   if (!hdr_ptr) {
 157     hdr_ptr = calloc(1,sizeof(void *)+extra);
 158     strategy_data[id] = hdr_ptr;
 159   }
 160   *hdr_ptr = hdr;
 161   do_lret(ctx);
 162 }
 163
 164 static REQUEST_HEADER * get_hdr(int id, void**extra)
 165 {
 166   void **hdr_ptr = strategy_data[id];
 167   if (extra)
 168     *extra = hdr_ptr ? (void*)(hdr_ptr+1) : (void *)NULL;
 169   return hdr_ptr ? *hdr_ptr : (void *)NULL;
 170 }
 171
 172 static void WINAPI nul_strategy(CONTEXT86*ctx)
 173 {
 174   do_strategy(ctx, SYSTEM_STRATEGY_NUL, 0);
 175 }
 176
 177 static void WINAPI nul_interrupt(CONTEXT86*ctx)
 178 {
 179   REQUEST_HEADER *hdr = get_hdr(SYSTEM_STRATEGY_NUL, NULL);
 180   /* eat everything and recycle nothing */
 181   switch (hdr->command) {
 182   case CMD_INPUT:
 183     ((REQ_IO*)hdr)->count = 0;
 184     hdr->status = STAT_DONE;
 185     break;
 186   case CMD_SAFEINPUT:
 187     hdr->status = STAT_DONE|STAT_BUSY;
 188     break;
 189   default:
 190     hdr->status = STAT_DONE;
 191   }
 192   do_lret(ctx);
 193 }
 194
 195 static void WINAPI con_strategy(CONTEXT86*ctx)
 196 {
 197   do_strategy(ctx, SYSTEM_STRATEGY_CON, sizeof(int));
 198 }
 199
 200 static void WINAPI con_interrupt(CONTEXT86*ctx)
 201 {
 202   int *scan;
 203   REQUEST_HEADER *hdr = get_hdr(SYSTEM_STRATEGY_CON,(void **)&scan);
 204   BIOSDATA *bios = DOSMEM_BiosData();
 205   WORD CurOfs = bios->NextKbdCharPtr;
 206   DOS_LISTOFLISTS *lol = DOSMEM_LOL();
 207   DOS_DATASEG *dataseg = (DOS_DATASEG *)lol;
 208   BYTE *linebuffer = dataseg->buffer;
 209   BYTE *curbuffer = (lol->offs_unread_CON) ?
 210     (((BYTE*)dataseg) + lol->offs_unread_CON) : (BYTE*)NULL;
 211   DOS_DEVICE_HEADER *con = dataseg->dev;
 212
 213   switch (hdr->command) {
 214   case CMD_INPUT:
 215     {
 216       REQ_IO *io = (REQ_IO *)hdr;
 217       WORD count = io->count, len = 0;
 218       BYTE *buffer = CTX_SEG_OFF_TO_LIN(ctx,
 219                                         SELECTOROF(io->buffer),
 220                                         (DWORD)OFFSETOF(io->buffer));
 221
 222       hdr->status = STAT_BUSY;
 223       /* first, check whether we already have data in line buffer */
 224       if (curbuffer) {
 225         /* yep, copy as much as we can */
 226         BYTE data = 0;
 227         while ((len<count) && (data != '\r')) {
 228           data = *curbuffer++;
 229           buffer[len++] = data;
 230         }
 231         if (data == '\r') {
 232           /* line buffer emptied */
 233           lol->offs_unread_CON = 0;
 234           curbuffer = NULL;
 235           /* if we're not in raw mode, call it a day*/
 236           if (!(con->attr & ATTR_RAW)) {
 237             hdr->status = STAT_DONE;
 238             io->count = len;
 239             break;
 240           }
 241         } else {
 242           /* still some data left */
 243           lol->offs_unread_CON = curbuffer - (BYTE*)lol;
 244           /* but buffer was filled, we're done */
 245           hdr->status = STAT_DONE;
 246           io->count = len;
 247           break;
 248         }
 249       }
 250
 251       /* if we're in raw mode, we just need to fill the buffer */
 252       if (con->attr & ATTR_RAW) {
 253         while (len<count) {
 254           WORD data;
 255
 256           /* do we have a waiting scancode? */
 257           if (*scan) {
 258             /* yes, store scancode in buffer */
 259             buffer[len++] = *scan;
 260             *scan = 0;
 261             if (len==count) break;
 262           }
 263
 264           /* check for new keyboard input */
 265           while (CurOfs == bios->FirstKbdCharPtr) {
 266             /* no input available yet, so wait... */
 267             DOSVM_Wait( -1, 0 );
 268           }
 269           /* read from keyboard queue (call int16?) */
 270           data = ((WORD*)bios)[CurOfs];
 271           CurOfs += 2;
 272           if (CurOfs >= bios->KbdBufferEnd) CurOfs = bios->KbdBufferStart;
 273           bios->NextKbdCharPtr = CurOfs;
 274           /* if it's an extended key, save scancode */
 275           if (LOBYTE(data) == 0) *scan = HIBYTE(data);
 276           /* store ASCII char in buffer */
 277           buffer[len++] = LOBYTE(data);
 278         }
 279       } else {
 280         /* we're not in raw mode, so we need to do line input... */
 281         while (TRUE) {
 282           WORD data;
 283           /* check for new keyboard input */
 284           while (CurOfs == bios->FirstKbdCharPtr) {
 285             /* no input available yet, so wait... */
 286             DOSVM_Wait( -1, 0 );
 287           }
 288           /* read from keyboard queue (call int16?) */
 289           data = ((WORD*)bios)[CurOfs];
 290           CurOfs += 2;
 291           if (CurOfs >= bios->KbdBufferEnd) CurOfs = bios->KbdBufferStart;
 292           bios->NextKbdCharPtr = CurOfs;
 293
 294           if (LOBYTE(data) == '\r') {
 295             /* it's the return key, we're done */
 296             linebuffer[len++] = LOBYTE(data);
 297             break;
 298           }
 299           else if (LOBYTE(data) >= ' ') {
 300             /* a character */
 301             if ((len+1)<CON_BUFFER) {
 302               linebuffer[len] = LOBYTE(data);
 303               WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), &linebuffer[len++], 1, NULL, NULL);
 304             }
 305             /* else beep, but I don't like noise */
 306           }
 307           else switch (LOBYTE(data)) {
 308           case '\b':
 309             if (len>0) {
 310               len--;
 311               WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), "\b \b", 3, NULL, NULL);
 312             }
 313             break;
 314           }
 315         }
 316         if (len > count) {
 317           /* save rest of line for later */
 318           lol->offs_unread_CON = linebuffer - (BYTE*)lol + count;
 319           len = count;
 320         }
 321         memcpy(buffer, linebuffer, len);
 322       }
 323       hdr->status = STAT_DONE;
 324       io->count = len;
 325     }
 326     break;
 327   case CMD_SAFEINPUT:
 328     if (curbuffer) {
 329       /* some line input waiting */
 330       hdr->status = STAT_DONE;
 331       ((REQ_SAFEINPUT*)hdr)->data = *curbuffer;
 332     }
 333     else if (con->attr & ATTR_RAW) {
 334       if (CurOfs == bios->FirstKbdCharPtr) {
 335         /* no input */
 336         hdr->status = STAT_DONE|STAT_BUSY;
 337       } else {
 338         /* some keyboard input waiting */
 339         hdr->status = STAT_DONE;
 340         ((REQ_SAFEINPUT*)hdr)->data = ((BYTE*)bios)[CurOfs];
 341       }
 342     } else {
 343       /* no line input */
 344       hdr->status = STAT_DONE|STAT_BUSY;
 345     }
 346     break;
 347   case CMD_INSTATUS:
 348     if (curbuffer) {
 349       /* we have data */
 350       hdr->status = STAT_DONE;
 351     }
 352     else if (con->attr & ATTR_RAW) {
 353       if (CurOfs == bios->FirstKbdCharPtr) {
 354         /* no input */
 355         hdr->status = STAT_DONE|STAT_BUSY;
 356       } else {
 357         /* some keyboard input waiting */
 358         hdr->status = STAT_DONE;
 359       }
 360     } else {
 361       /* no line input */
 362       hdr->status = STAT_DONE|STAT_BUSY;
 363     }
 364
 365     break;
 366   case CMD_INFLUSH:
 367     /* flush line and keyboard queue */
 368     lol->offs_unread_CON = 0;
 369     bios->NextKbdCharPtr = bios->FirstKbdCharPtr;
 370     break;
 371   case CMD_OUTPUT:
 372   case CMD_SAFEOUTPUT:
 373     {
 374       REQ_IO *io = (REQ_IO *)hdr;
 375       BYTE *buffer = CTX_SEG_OFF_TO_LIN(ctx,
 376                                         SELECTOROF(io->buffer),
 377                                         (DWORD)OFFSETOF(io->buffer));
 378       DWORD result = 0;
 379       WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), buffer, io->count, &result, NULL);
 380       io->count = result;
 381       hdr->status = STAT_DONE;
 382     }
 383     break;
 384   default:
 385     hdr->status = STAT_DONE;
 386   }
 387   do_lret(ctx);
 388 }
 389
 390 static void InitListOfLists(DOS_LISTOFLISTS *DOS_LOL)
 391 {
 392 /*
 393 Output of DOS 6.22:
 394
 395 0133:0020                    6A 13-33 01 CC 00 33 01 59 00         j.3...3.Y.
 396 0133:0030  70 00 00 00 72 02 00 02-6D 00 33 01 00 00 2E 05   p...r...m.3.....
 397 0133:0040  00 00 FC 04 00 00 03 08-92 21 11 E0 04 80 C6 0D   .........!......
 398 0133:0050  CC 0D 4E 55 4C 20 20 20-20 20 00 00 00 00 00 00   ..NUL     ......
 399 0133:0060  00 4B BA C1 06 14 00 00-00 03 01 00 04 70 CE FF   .K...........p..
 400 0133:0070  FF 00 00 00 00 00 00 00-00 01 00 00 0D 05 00 00   ................
 401 0133:0080  00 FF FF 00 00 00 00 FE-00 00 F8 03 FF 9F 70 02   ..............p.
 402 0133:0090  D0 44 C8 FD D4 44 C8 FD-D4 44 C8 FD D0 44 C8 FD   .D...D...D...D..
 403 0133:00A0  D0 44 C8 FD D0 44                                 .D...D
 404 */
 405   DOS_LOL->CX_Int21_5e01                = 0x0;
 406   DOS_LOL->LRU_count_FCB_cache  = 0x0;
 407   DOS_LOL->LRU_count_FCB_open           = 0x0;
 408   DOS_LOL->OEM_func_handler             = -1; /* not available */
 409   DOS_LOL->INT21_offset         = 0x0;
 410   DOS_LOL->sharing_retry_count  = 3;
 411   DOS_LOL->sharing_retry_delay  = 1;
 412   DOS_LOL->ptr_disk_buf         = 0x0;
 413   DOS_LOL->offs_unread_CON              = 0x0;
 414   DOS_LOL->seg_first_MCB                = 0x0;
 415   DOS_LOL->ptr_first_DPB                = 0x0;
 416   DOS_LOL->ptr_first_SysFileTable       = 0x0;
 417   DOS_LOL->ptr_clock_dev_hdr            = 0x0;
 418   DOS_LOL->ptr_CON_dev_hdr              = 0x0;
 419   DOS_LOL->max_byte_per_sec             = 512;
 420   DOS_LOL->ptr_disk_buf_info            = 0x0;
 421   DOS_LOL->ptr_array_CDS                = 0x0;
 422   DOS_LOL->ptr_sys_FCB          = 0x0;
 423   DOS_LOL->nr_protect_FCB               = 0x0;
 424   DOS_LOL->nr_block_dev         = 0x0;
 425   DOS_LOL->nr_avail_drive_letters       = 26; /* A - Z */
 426   DOS_LOL->nr_drives_JOINed             = 0x0;
 427   DOS_LOL->ptr_spec_prg_names           = 0x0;
 428   DOS_LOL->ptr_SETVER_prg_list  = 0x0; /* no SETVER list */
 429   DOS_LOL->DOS_HIGH_A20_func_offs       = 0x0;
 430   DOS_LOL->PSP_last_exec                = 0x0;
 431   DOS_LOL->BUFFERS_val          = 99; /* maximum: 99 */
 432   DOS_LOL->BUFFERS_nr_lookahead = 8; /* maximum: 8 */
 433   DOS_LOL->boot_drive                   = 3; /* C: */
 434   DOS_LOL->flag_DWORD_moves             = 0x01; /* i386+ */
 435   DOS_LOL->size_extended_mem            = 0xf000; /* very high value */
 436 }
 437
 438 void DOSDEV_InstallDOSDevices(void)
 439 {
 440   DOS_DATASEG *dataseg;
 441   UINT16 seg;
 442   unsigned int n;
 443
 444   /* allocate DOS data segment or something */
 445   DOS_LOLSeg = GlobalDOSAlloc16(sizeof(DOS_DATASEG));
 446   seg = HIWORD(DOS_LOLSeg);
 447   dataseg = PTR_SEG_OFF_TO_LIN(LOWORD(DOS_LOLSeg), 0);
 448
 449   /* initialize the magnificent List Of Lists */
 450   InitListOfLists(&dataseg->lol);
 451
 452   /* Set up first device (NUL) */
 453   dataseg->lol.NUL_dev.next_dev  = PTR_SEG_OFF_TO_SEGPTR(seg, DOS_DATASEG_OFF(dev[0]));
 454   dataseg->lol.NUL_dev.attr      = devs[0].attr;
 455   dataseg->lol.NUL_dev.strategy  = DOS_DATASEG_OFF(thunk[0].ljmp1);
 456   dataseg->lol.NUL_dev.interrupt = DOS_DATASEG_OFF(thunk[0].ljmp2);
 457   memcpy(dataseg->lol.NUL_dev.name, devs[0].name, 8);
 458
 459   /* Set up the remaining devices */
 460   for (n = 1; n < NR_DEVS; n++)
 461   {
 462     dataseg->dev[n-1].next_dev  = (n+1) == NR_DEVS ? NONEXT :
 463                                   PTR_SEG_OFF_TO_SEGPTR(seg, DOS_DATASEG_OFF(dev[n]));
 464     dataseg->dev[n-1].attr      = devs[n].attr;
 465     dataseg->dev[n-1].strategy  = DOS_DATASEG_OFF(thunk[n].ljmp1);
 466     dataseg->dev[n-1].interrupt = DOS_DATASEG_OFF(thunk[n].ljmp2);
 467     memcpy(dataseg->dev[n-1].name, devs[n].name, 8);
 468   }
 469
 470   /* Set up thunks */
 471   for (n = 0; n < NR_DEVS; n++)
 472   {
 473     dataseg->thunk[n].ljmp1     = LJMP;
 474     dataseg->thunk[n].strategy  = (RMCBPROC)DPMI_AllocInternalRMCB(devs[n].strategy);
 475     dataseg->thunk[n].ljmp2     = LJMP;
 476     dataseg->thunk[n].interrupt = (RMCBPROC)DPMI_AllocInternalRMCB(devs[n].interrupt);
 477   }
 478
 479   /* CON is device 1 */
 480   dataseg->lol.ptr_CON_dev_hdr = PTR_SEG_OFF_TO_SEGPTR(seg, DOS_DATASEG_OFF(dev[0]));
 481 }
 482
 483 DWORD DOSDEV_Console(void)
 484 {
 485   return DOSMEM_LOL()->ptr_CON_dev_hdr;
 486 }
 487
 488 DWORD DOSDEV_FindCharDevice(char*name)
 489 {
 490   SEGPTR cur_ptr = PTR_SEG_OFF_TO_SEGPTR(HIWORD(DOS_LOLSeg),
 491                                          FIELD_OFFSET(DOS_LISTOFLISTS,NUL_dev));
 492   DOS_DEVICE_HEADER *cur = DOSMEM_MapRealToLinear(cur_ptr);
 493   char dname[8];
 494   int cnt;
 495
 496   /* get first 8 characters */
 497   strncpy(dname,name,8);
 498   /* if less than 8 characters, pad with spaces */
 499   for (cnt=0; cnt<8; cnt++)
 500     if (!dname[cnt]) dname[cnt]=' ';
 501
 502   /* search for char devices with the right name */
 503   while (cur &&
 504          ((!(cur->attr & ATTR_CHAR)) ||
 505           memcmp(cur->name,dname,8))) {
 506     cur_ptr = cur->next_dev;
 507     if (cur_ptr == NONEXT) cur=NULL;
 508     else cur = DOSMEM_MapRealToLinear(cur_ptr);
 509   }
 510   return cur_ptr;
 511 }
 512
 513 static void DOSDEV_DoReq(void*req, DWORD dev)
 514 {
 515   REQUEST_HEADER *hdr = (REQUEST_HEADER *)req;
 516   DOS_DEVICE_HEADER *dhdr;
 517   CONTEXT86 ctx;
 518   char *phdr;
 519
 520   dhdr = DOSMEM_MapRealToLinear(dev);
 521   phdr = ((char*)DOSMEM_LOL()) + DOS_DATASEG_OFF(req);
 522
 523   /* copy request to request scratch area */
 524   memcpy(phdr, req, hdr->size);
 525
 526   /* prepare to call device driver */
 527   memset(&ctx, 0, sizeof(ctx));
 528
 529   /* ES:BX points to request for strategy routine */
 530   ctx.SegEs = HIWORD(DOS_LOLSeg);
 531   ctx.Ebx   = DOS_DATASEG_OFF(req);
 532
 533   /* call strategy routine */
 534   ctx.SegCs = SELECTOROF(dev);
 535   ctx.Eip   = dhdr->strategy;
 536   DPMI_CallRMProc(&ctx, 0, 0, 0);
 537
 538   /* call interrupt routine */
 539   ctx.SegCs = SELECTOROF(dev);
 540   ctx.Eip   = dhdr->interrupt;
 541   DPMI_CallRMProc(&ctx, 0, 0, 0);
 542
 543   /* completed, copy request back */
 544   memcpy(req, phdr, hdr->size);
 545
 546   if (hdr->status & STAT_ERROR) {
 547     switch (hdr->status & STAT_MASK) {
 548     case 0x0F: /* invalid disk change */
 549       /* this error seems to fit the bill */
 550       SetLastError(ER_NotSameDevice);
 551       break;
 552     default:
 553       SetLastError((hdr->status & STAT_MASK) + 0x13);
 554       break;
 555     }
 556   }
 557 }
 558
 559 static int DOSDEV_IO(unsigned cmd, DWORD dev, DWORD buf, int buflen)
 560 {
 561   REQ_IO req;
 562
 563   req.hdr.size=sizeof(req);
 564   req.hdr.unit=0; /* not dealing with block devices yet */
 565   req.hdr.command=cmd;
 566   req.hdr.status=STAT_BUSY;
 567   req.media=0; /* not dealing with block devices yet */
 568   req.buffer=buf;
 569   req.count=buflen;
 570   req.sector=0; /* block devices */
 571   req.volume=0; /* block devices */
 572
 573   DOSDEV_DoReq(&req, dev);
 574
 575   return req.count;
 576 }
 577
 578 int DOSDEV_Peek(DWORD dev, BYTE*data)
 579 {
 580   REQ_SAFEINPUT req;
 581
 582   req.hdr.size=sizeof(req);
 583   req.hdr.unit=0; /* not dealing with block devices yet */
 584   req.hdr.command=CMD_SAFEINPUT;
 585   req.hdr.status=STAT_BUSY;
 586   req.data=0;
 587
 588   DOSDEV_DoReq(&req, dev);
 589
 590   if (req.hdr.status & STAT_BUSY) return 0;
 591
 592   *data = req.data;
 593   return 1;
 594 }
 595
 596 int DOSDEV_Read(DWORD dev, DWORD buf, int buflen)
 597 {
 598   return DOSDEV_IO(CMD_INPUT, dev, buf, buflen);
 599 }
 600
 601 int DOSDEV_Write(DWORD dev, DWORD buf, int buflen, int verify)
 602 {
 603   return DOSDEV_IO(verify?CMD_SAFEOUTPUT:CMD_OUTPUT, dev, buf, buflen);
 604 }
 605
 606 int DOSDEV_IoctlRead(DWORD dev, DWORD buf, int buflen)
 607 {
 608   return DOSDEV_IO(CMD_INIOCTL, dev, buf, buflen);
 609 }
 610
 611 int DOSDEV_IoctlWrite(DWORD dev, DWORD buf, int buflen)
 612 {
 613   return DOSDEV_IO(CMD_OUTIOCTL, dev, buf, buflen);
 614 }