dlls/winedos/devices.c

   1 /*
   2  * DOS devices
   3  *
   4  * Copyright 1999 Ove Kåven
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include "wine/winbase16.h"
  24 #include "msdos.h"
  25 #include "miscemu.h"
  26 #include "dosexe.h"
  27 #include "wine/debug.h"
  28
  29 #include "pshpack1.h"
  30
  31 typedef struct {
  32   BYTE ljmp1;
  33   RMCBPROC strategy;
  34   BYTE ljmp2;
  35   RMCBPROC interrupt;
  36 } WINEDEV_THUNK;
  37
  38 typedef struct {
  39   BYTE size; /* length of header + data */
  40   BYTE unit; /* unit (block devices only) */
  41   BYTE command;
  42   WORD status;
  43   BYTE reserved[8];
  44 } REQUEST_HEADER;
  45
  46 typedef struct {
  47   REQUEST_HEADER hdr;
  48   BYTE media; /* media descriptor from BPB */
  49   SEGPTR buffer;
  50   WORD count; /* byte/sector count */
  51   WORD sector; /* starting sector (block devices) */
  52   DWORD volume; /* volume ID (block devices) */
  53 } REQ_IO;
  54
  55 typedef struct {
  56   REQUEST_HEADER hdr;
  57   BYTE data;
  58 } REQ_SAFEINPUT;
  59
  60 #include "poppack.h"
  61
  62 #define CON_BUFFER 128
  63
  64 enum strategy { SYSTEM_STRATEGY_NUL, SYSTEM_STRATEGY_CON, NB_SYSTEM_STRATEGIES };
  65
  66 static void *strategy_data[NB_SYSTEM_STRATEGIES];
  67
  68 #define NONEXT ((DWORD)-1)
  69
  70 #define ATTR_STDIN     0x0001
  71 #define ATTR_STDOUT    0x0002
  72 #define ATTR_NUL       0x0004
  73 #define ATTR_CLOCK     0x0008
  74 #define ATTR_FASTCON   0x0010
  75 #define ATTR_RAW       0x0020
  76 #define ATTR_NOTEOF    0x0040
  77 #define ATTR_DEVICE    0x0080
  78 #define ATTR_REMOVABLE 0x0800
  79 #define ATTR_NONIBM    0x2000 /* block devices */
  80 #define ATTR_UNTILBUSY 0x2000 /* char devices */
  81 #define ATTR_IOCTL     0x4000
  82 #define ATTR_CHAR      0x8000
  83
  84 #define CMD_INIT       0
  85 #define CMD_MEDIACHECK 1 /* block devices */
  86 #define CMD_BUILDBPB   2 /* block devices */
  87 #define CMD_INIOCTL    3
  88 #define CMD_INPUT      4 /* read data */
  89 #define CMD_SAFEINPUT  5 /* "non-destructive input no wait", char devices */
  90 #define CMD_INSTATUS   6 /* char devices */
  91 #define CMD_INFLUSH    7 /* char devices */
  92 #define CMD_OUTPUT     8 /* write data */
  93 #define CMD_SAFEOUTPUT 9 /* write data with verify */
  94 #define CMD_OUTSTATUS 10 /* char devices */
  95 #define CMD_OUTFLUSH  11 /* char devices */
  96 #define CMD_OUTIOCTL  12
  97 #define CMD_DEVOPEN   13
  98 #define CMD_DEVCLOSE  14
  99 #define CMD_REMOVABLE 15 /* block devices */
 100 #define CMD_UNTILBUSY 16 /* output until busy */
 101
 102 #define STAT_MASK  0x00FF
 103 #define STAT_DONE  0x0100
 104 #define STAT_BUSY  0x0200
 105 #define STAT_ERROR 0x8000
 106
 107 #define LJMP 0xea
 108
 109
 110 /* prototypes */
 111 static void WINAPI nul_strategy(CONTEXT86*ctx);
 112 static void WINAPI nul_interrupt(CONTEXT86*ctx);
 113 static void WINAPI con_strategy(CONTEXT86*ctx);
 114 static void WINAPI con_interrupt(CONTEXT86*ctx);
 115
 116 /* devices */
 117 typedef struct
 118 {
 119     char name[8];
 120     WORD attr;
 121     RMCBPROC strategy;
 122     RMCBPROC interrupt;
 123 } WINEDEV;
 124
 125 static WINEDEV devs[] =
 126 {
 127   { "NUL     ",
 128     ATTR_CHAR|ATTR_NUL|ATTR_DEVICE,
 129     nul_strategy, nul_interrupt },
 130
 131   { "CON     ",
 132     ATTR_CHAR|ATTR_STDIN|ATTR_STDOUT|ATTR_FASTCON|ATTR_NOTEOF|ATTR_DEVICE,
 133     con_strategy, con_interrupt }
 134 };
 135
 136 #define NR_DEVS (sizeof(devs)/sizeof(WINEDEV))
 137
 138 /* DOS data segment */
 139 typedef struct
 140 {
 141     DOS_LISTOFLISTS    lol;
 142     DOS_DEVICE_HEADER  dev[NR_DEVS-1];
 143     WINEDEV_THUNK      thunk[NR_DEVS];
 144     REQ_IO             req;
 145     BYTE               buffer[CON_BUFFER];
 146
 147 } DOS_DATASEG;
 148
 149 #define DOS_DATASEG_OFF(xxx) FIELD_OFFSET(DOS_DATASEG, xxx)
 150
 151 DWORD DOS_LOLSeg;
 152
 153 struct _DOS_LISTOFLISTS * DOSMEM_LOL()
 154 {
 155     return PTR_REAL_TO_LIN(HIWORD(DOS_LOLSeg),0);
 156 }
 157
 158
 159 /* the device implementations */
 160 static void do_lret(CONTEXT86*ctx)
 161 {
 162   WORD *stack = CTX_SEG_OFF_TO_LIN(ctx, ctx->SegSs, ctx->Esp);
 163
 164   ctx->Eip   = *(stack++);
 165   ctx->SegCs = *(stack++);
 166   ctx->Esp  += 2*sizeof(WORD);
 167 }
 168
 169 static void do_strategy(CONTEXT86*ctx, int id, int extra)
 170 {
 171   REQUEST_HEADER *hdr = CTX_SEG_OFF_TO_LIN(ctx, ctx->SegEs, ctx->Ebx);
 172   void **hdr_ptr = strategy_data[id];
 173
 174   if (!hdr_ptr) {
 175     hdr_ptr = calloc(1,sizeof(void *)+extra);
 176     strategy_data[id] = hdr_ptr;
 177   }
 178   *hdr_ptr = hdr;
 179   do_lret(ctx);
 180 }
 181
 182 static REQUEST_HEADER * get_hdr(int id, void**extra)
 183 {
 184   void **hdr_ptr = strategy_data[id];
 185   if (extra)
 186     *extra = hdr_ptr ? (void*)(hdr_ptr+1) : (void *)NULL;
 187   return hdr_ptr ? *hdr_ptr : (void *)NULL;
 188 }
 189
 190 static void WINAPI nul_strategy(CONTEXT86*ctx)
 191 {
 192   do_strategy(ctx, SYSTEM_STRATEGY_NUL, 0);
 193 }
 194
 195 static void WINAPI nul_interrupt(CONTEXT86*ctx)
 196 {
 197   REQUEST_HEADER *hdr = get_hdr(SYSTEM_STRATEGY_NUL, NULL);
 198   /* eat everything and recycle nothing */
 199   switch (hdr->command) {
 200   case CMD_INPUT:
 201     ((REQ_IO*)hdr)->count = 0;
 202     hdr->status = STAT_DONE;
 203     break;
 204   case CMD_SAFEINPUT:
 205     hdr->status = STAT_DONE|STAT_BUSY;
 206     break;
 207   default:
 208     hdr->status = STAT_DONE;
 209   }
 210   do_lret(ctx);
 211 }
 212
 213 static void WINAPI con_strategy(CONTEXT86*ctx)
 214 {
 215   do_strategy(ctx, SYSTEM_STRATEGY_CON, sizeof(int));
 216 }
 217
 218 static void WINAPI con_interrupt(CONTEXT86*ctx)
 219 {
 220   int *scan;
 221   REQUEST_HEADER *hdr = get_hdr(SYSTEM_STRATEGY_CON,(void **)&scan);
 222   BIOSDATA *bios = BIOS_DATA;
 223   WORD CurOfs = bios->NextKbdCharPtr;
 224   DOS_LISTOFLISTS *lol = DOSMEM_LOL();
 225   DOS_DATASEG *dataseg = (DOS_DATASEG *)lol;
 226   BYTE *linebuffer = dataseg->buffer;
 227   BYTE *curbuffer = (lol->offs_unread_CON) ?
 228     (((BYTE*)dataseg) + lol->offs_unread_CON) : (BYTE*)NULL;
 229   DOS_DEVICE_HEADER *con = dataseg->dev;
 230
 231   switch (hdr->command) {
 232   case CMD_INPUT:
 233     {
 234       REQ_IO *io = (REQ_IO *)hdr;
 235       WORD count = io->count, len = 0;
 236       BYTE *buffer = CTX_SEG_OFF_TO_LIN(ctx,
 237                                         SELECTOROF(io->buffer),
 238                                         (DWORD)OFFSETOF(io->buffer));
 239
 240       hdr->status = STAT_BUSY;
 241       /* first, check whether we already have data in line buffer */
 242       if (curbuffer) {
 243         /* yep, copy as much as we can */
 244         BYTE data = 0;
 245         while ((len<count) && (data != '\r')) {
 246           data = *curbuffer++;
 247           buffer[len++] = data;
 248         }
 249         if (data == '\r') {
 250           /* line buffer emptied */
 251           lol->offs_unread_CON = 0;
 252           curbuffer = NULL;
 253           /* if we're not in raw mode, call it a day */
 254           if (!(con->attr & ATTR_RAW)) {
 255             hdr->status = STAT_DONE;
 256             io->count = len;
 257             break;
 258           }
 259         } else {
 260           /* still some data left */
 261           lol->offs_unread_CON = curbuffer - (BYTE*)lol;
 262           /* but buffer was filled, we're done */
 263           hdr->status = STAT_DONE;
 264           io->count = len;
 265           break;
 266         }
 267       }
 268
 269       /* if we're in raw mode, we just need to fill the buffer */
 270       if (con->attr & ATTR_RAW) {
 271         while (len<count) {
 272           WORD data;
 273
 274           /* do we have a waiting scancode? */
 275           if (*scan) {
 276             /* yes, store scancode in buffer */
 277             buffer[len++] = *scan;
 278             *scan = 0;
 279             if (len==count) break;
 280           }
 281
 282           /* check for new keyboard input */
 283           while (CurOfs == bios->FirstKbdCharPtr) {
 284             /* no input available yet, so wait... */
 285             DOSVM_Wait( ctx );
 286           }
 287           /* read from keyboard queue (call int16?) */
 288           data = ((WORD*)bios)[CurOfs];
 289           CurOfs += 2;
 290           if (CurOfs >= bios->KbdBufferEnd) CurOfs = bios->KbdBufferStart;
 291           bios->NextKbdCharPtr = CurOfs;
 292           /* if it's an extended key, save scancode */
 293           if (LOBYTE(data) == 0) *scan = HIBYTE(data);
 294           /* store ASCII char in buffer */
 295           buffer[len++] = LOBYTE(data);
 296         }
 297       } else {
 298         /* we're not in raw mode, so we need to do line input... */
 299         while (TRUE) {
 300           WORD data;
 301           /* check for new keyboard input */
 302           while (CurOfs == bios->FirstKbdCharPtr) {
 303             /* no input available yet, so wait... */
 304             DOSVM_Wait( ctx );
 305           }
 306           /* read from keyboard queue (call int16?) */
 307           data = ((WORD*)bios)[CurOfs];
 308           CurOfs += 2;
 309           if (CurOfs >= bios->KbdBufferEnd) CurOfs = bios->KbdBufferStart;
 310           bios->NextKbdCharPtr = CurOfs;
 311
 312           if (LOBYTE(data) == '\r') {
 313             /* it's the return key, we're done */
 314             linebuffer[len++] = LOBYTE(data);
 315             break;
 316           }
 317           else if (LOBYTE(data) >= ' ') {
 318             /* a character */
 319             if ((len+1)<CON_BUFFER) {
 320               linebuffer[len] = LOBYTE(data);
 321               WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), &linebuffer[len++], 1, NULL, NULL);
 322             }
 323             /* else beep, but I don't like noise */
 324           }
 325           else switch (LOBYTE(data)) {
 326           case '\b':
 327             if (len>0) {
 328               len--;
 329               WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), "\b \b", 3, NULL, NULL);
 330             }
 331             break;
 332           }
 333         }
 334         if (len > count) {
 335           /* save rest of line for later */
 336           lol->offs_unread_CON = linebuffer - (BYTE*)lol + count;
 337           len = count;
 338         }
 339         memcpy(buffer, linebuffer, len);
 340       }
 341       hdr->status = STAT_DONE;
 342       io->count = len;
 343     }
 344     break;
 345   case CMD_SAFEINPUT:
 346     if (curbuffer) {
 347       /* some line input waiting */
 348       hdr->status = STAT_DONE;
 349       ((REQ_SAFEINPUT*)hdr)->data = *curbuffer;
 350     }
 351     else if (con->attr & ATTR_RAW) {
 352       if (CurOfs == bios->FirstKbdCharPtr) {
 353         /* no input */
 354         hdr->status = STAT_DONE|STAT_BUSY;
 355       } else {
 356         /* some keyboard input waiting */
 357         hdr->status = STAT_DONE;
 358         ((REQ_SAFEINPUT*)hdr)->data = ((BYTE*)bios)[CurOfs];
 359       }
 360     } else {
 361       /* no line input */
 362       hdr->status = STAT_DONE|STAT_BUSY;
 363     }
 364     break;
 365   case CMD_INSTATUS:
 366     if (curbuffer) {
 367       /* we have data */
 368       hdr->status = STAT_DONE;
 369     }
 370     else if (con->attr & ATTR_RAW) {
 371       if (CurOfs == bios->FirstKbdCharPtr) {
 372         /* no input */
 373         hdr->status = STAT_DONE|STAT_BUSY;
 374       } else {
 375         /* some keyboard input waiting */
 376         hdr->status = STAT_DONE;
 377       }
 378     } else {
 379       /* no line input */
 380       hdr->status = STAT_DONE|STAT_BUSY;
 381     }
 382
 383     break;
 384   case CMD_INFLUSH:
 385     /* flush line and keyboard queue */
 386     lol->offs_unread_CON = 0;
 387     bios->NextKbdCharPtr = bios->FirstKbdCharPtr;
 388     break;
 389   case CMD_OUTPUT:
 390   case CMD_SAFEOUTPUT:
 391     {
 392       REQ_IO *io = (REQ_IO *)hdr;
 393       BYTE *buffer = CTX_SEG_OFF_TO_LIN(ctx,
 394                                         SELECTOROF(io->buffer),
 395                                         (DWORD)OFFSETOF(io->buffer));
 396       DWORD result = 0;
 397       WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), buffer, io->count, &result, NULL);
 398       io->count = result;
 399       hdr->status = STAT_DONE;
 400     }
 401     break;
 402   default:
 403     hdr->status = STAT_DONE;
 404   }
 405   do_lret(ctx);
 406 }
 407
 408 static void InitListOfLists(DOS_LISTOFLISTS *DOS_LOL)
 409 {
 410 /*
 411 Output of DOS 6.22:
 412
 413 0133:0020                    6A 13-33 01 CC 00 33 01 59 00         j.3...3.Y.
 414 0133:0030  70 00 00 00 72 02 00 02-6D 00 33 01 00 00 2E 05   p...r...m.3.....
 415 0133:0040  00 00 FC 04 00 00 03 08-92 21 11 E0 04 80 C6 0D   .........!......
 416 0133:0050  CC 0D 4E 55 4C 20 20 20-20 20 00 00 00 00 00 00   ..NUL     ......
 417 0133:0060  00 4B BA C1 06 14 00 00-00 03 01 00 04 70 CE FF   .K...........p..
 418 0133:0070  FF 00 00 00 00 00 00 00-00 01 00 00 0D 05 00 00   ................
 419 0133:0080  00 FF FF 00 00 00 00 FE-00 00 F8 03 FF 9F 70 02   ..............p.
 420 0133:0090  D0 44 C8 FD D4 44 C8 FD-D4 44 C8 FD D0 44 C8 FD   .D...D...D...D..
 421 0133:00A0  D0 44 C8 FD D0 44                                 .D...D
 422 */
 423   DOS_LOL->CX_Int21_5e01                = 0x0;
 424   DOS_LOL->LRU_count_FCB_cache  = 0x0;
 425   DOS_LOL->LRU_count_FCB_open           = 0x0;
 426   DOS_LOL->OEM_func_handler             = -1; /* not available */
 427   DOS_LOL->INT21_offset         = 0x0;
 428   DOS_LOL->sharing_retry_count  = 3;
 429   DOS_LOL->sharing_retry_delay  = 1;
 430   DOS_LOL->ptr_disk_buf         = 0x0;
 431   DOS_LOL->offs_unread_CON              = 0x0;
 432   DOS_LOL->seg_first_MCB                = 0x0;
 433   DOS_LOL->ptr_first_DPB                = 0x0;
 434   DOS_LOL->ptr_first_SysFileTable       = 0x0;
 435   DOS_LOL->ptr_clock_dev_hdr            = 0x0;
 436   DOS_LOL->ptr_CON_dev_hdr              = 0x0;
 437   DOS_LOL->max_byte_per_sec             = 512;
 438   DOS_LOL->ptr_disk_buf_info            = 0x0;
 439   DOS_LOL->ptr_array_CDS                = 0x0;
 440   DOS_LOL->ptr_sys_FCB          = 0x0;
 441   DOS_LOL->nr_protect_FCB               = 0x0;
 442   DOS_LOL->nr_block_dev         = 0x0;
 443   DOS_LOL->nr_avail_drive_letters       = 26; /* A - Z */
 444   DOS_LOL->nr_drives_JOINed             = 0x0;
 445   DOS_LOL->ptr_spec_prg_names           = 0x0;
 446   DOS_LOL->ptr_SETVER_prg_list  = 0x0; /* no SETVER list */
 447   DOS_LOL->DOS_HIGH_A20_func_offs       = 0x0;
 448   DOS_LOL->PSP_last_exec                = 0x0;
 449   DOS_LOL->BUFFERS_val          = 99; /* maximum: 99 */
 450   DOS_LOL->BUFFERS_nr_lookahead = 8; /* maximum: 8 */
 451   DOS_LOL->boot_drive                   = 3; /* C: */
 452   DOS_LOL->flag_DWORD_moves             = 0x01; /* i386+ */
 453   DOS_LOL->size_extended_mem            = 0xf000; /* very high value */
 454 }
 455
 456 void DOSDEV_InstallDOSDevices(void)
 457 {
 458   DOS_DATASEG *dataseg;
 459   WORD seg;
 460   WORD selector;
 461   unsigned int n;
 462
 463   /* allocate DOS data segment or something */
 464   dataseg = DOSVM_AllocDataUMB( sizeof(DOS_DATASEG), &seg, &selector );
 465
 466   DOS_LOLSeg = MAKESEGPTR( seg, 0 );
 467   DOSMEM_LOL()->wine_rm_lol =
 468       MAKESEGPTR( seg, FIELD_OFFSET(DOS_LISTOFLISTS, ptr_first_DPB) );
 469   DOSMEM_LOL()->wine_pm_lol =
 470       MAKESEGPTR( selector, FIELD_OFFSET(DOS_LISTOFLISTS, ptr_first_DPB) );
 471
 472   /* initialize the magnificent List Of Lists */
 473   InitListOfLists(&dataseg->lol);
 474
 475   /* Set up first device (NUL) */
 476   dataseg->lol.NUL_dev.next_dev  = MAKESEGPTR(seg, DOS_DATASEG_OFF(dev[0]));
 477   dataseg->lol.NUL_dev.attr      = devs[0].attr;
 478   dataseg->lol.NUL_dev.strategy  = DOS_DATASEG_OFF(thunk[0].ljmp1);
 479   dataseg->lol.NUL_dev.interrupt = DOS_DATASEG_OFF(thunk[0].ljmp2);
 480   memcpy(dataseg->lol.NUL_dev.name, devs[0].name, 8);
 481
 482   /* Set up the remaining devices */
 483   for (n = 1; n < NR_DEVS; n++)
 484   {
 485     dataseg->dev[n-1].next_dev  = (n+1) == NR_DEVS ? NONEXT :
 486                                   MAKESEGPTR(seg, DOS_DATASEG_OFF(dev[n]));
 487     dataseg->dev[n-1].attr      = devs[n].attr;
 488     dataseg->dev[n-1].strategy  = DOS_DATASEG_OFF(thunk[n].ljmp1);
 489     dataseg->dev[n-1].interrupt = DOS_DATASEG_OFF(thunk[n].ljmp2);
 490     memcpy(dataseg->dev[n-1].name, devs[n].name, 8);
 491   }
 492
 493   /* Set up thunks */
 494   for (n = 0; n < NR_DEVS; n++)
 495   {
 496     dataseg->thunk[n].ljmp1     = LJMP;
 497     dataseg->thunk[n].strategy  = (RMCBPROC)DPMI_AllocInternalRMCB(devs[n].strategy);
 498     dataseg->thunk[n].ljmp2     = LJMP;
 499     dataseg->thunk[n].interrupt = (RMCBPROC)DPMI_AllocInternalRMCB(devs[n].interrupt);
 500   }
 501
 502   /* CON is device 1 */
 503   dataseg->lol.ptr_CON_dev_hdr = MAKESEGPTR(seg, DOS_DATASEG_OFF(dev[0]));
 504 }
 505
 506 DWORD DOSDEV_Console(void)
 507 {
 508   return DOSMEM_LOL()->ptr_CON_dev_hdr;
 509 }
 510
 511 DWORD DOSDEV_FindCharDevice(char*name)
 512 {
 513   SEGPTR cur_ptr = MAKESEGPTR(HIWORD(DOS_LOLSeg), FIELD_OFFSET(DOS_LISTOFLISTS,NUL_dev));
 514   DOS_DEVICE_HEADER *cur = PTR_REAL_TO_LIN(SELECTOROF(cur_ptr),OFFSETOF(cur_ptr));
 515   char dname[8];
 516   int cnt;
 517
 518   /* get first 8 characters */
 519   strncpy(dname,name,8);
 520   /* if less than 8 characters, pad with spaces */
 521   for (cnt=0; cnt<8; cnt++)
 522     if (!dname[cnt]) dname[cnt]=' ';
 523
 524   /* search for char devices with the right name */
 525   while (cur &&
 526          ((!(cur->attr & ATTR_CHAR)) ||
 527           memcmp(cur->name,dname,8))) {
 528     cur_ptr = cur->next_dev;
 529     if (cur_ptr == NONEXT) cur=NULL;
 530     else cur = PTR_REAL_TO_LIN(SELECTOROF(cur_ptr),OFFSETOF(cur_ptr));
 531   }
 532   return cur_ptr;
 533 }
 534
 535 static void DOSDEV_DoReq(void*req, DWORD dev)
 536 {
 537   REQUEST_HEADER *hdr = (REQUEST_HEADER *)req;
 538   DOS_DEVICE_HEADER *dhdr;
 539   CONTEXT86 ctx;
 540   char *phdr;
 541
 542   dhdr = PTR_REAL_TO_LIN(SELECTOROF(dev),OFFSETOF(dev));
 543   phdr = ((char*)DOSMEM_LOL()) + DOS_DATASEG_OFF(req);
 544
 545   /* copy request to request scratch area */
 546   memcpy(phdr, req, hdr->size);
 547
 548   /* prepare to call device driver */
 549   memset(&ctx, 0, sizeof(ctx));
 550   ctx.EFlags |= V86_FLAG;
 551
 552   /* ES:BX points to request for strategy routine */
 553   ctx.SegEs = HIWORD(DOS_LOLSeg);
 554   ctx.Ebx   = DOS_DATASEG_OFF(req);
 555
 556   /* call strategy routine */
 557   ctx.SegCs = SELECTOROF(dev);
 558   ctx.Eip   = dhdr->strategy;
 559   DPMI_CallRMProc(&ctx, 0, 0, 0);
 560
 561   /* call interrupt routine */
 562   ctx.SegCs = SELECTOROF(dev);
 563   ctx.Eip   = dhdr->interrupt;
 564   DPMI_CallRMProc(&ctx, 0, 0, 0);
 565
 566   /* completed, copy request back */
 567   memcpy(req, phdr, hdr->size);
 568
 569   if (hdr->status & STAT_ERROR) {
 570     switch (hdr->status & STAT_MASK) {
 571     case 0x0F: /* invalid disk change */
 572       /* this error seems to fit the bill */
 573       SetLastError(ER_NotSameDevice);
 574       break;
 575     default:
 576       SetLastError((hdr->status & STAT_MASK) + 0x13);
 577       break;
 578     }
 579   }
 580 }
 581
 582 static int DOSDEV_IO(unsigned cmd, DWORD dev, DWORD buf, int buflen)
 583 {
 584   REQ_IO req;
 585
 586   req.hdr.size=sizeof(req);
 587   req.hdr.unit=0; /* not dealing with block devices yet */
 588   req.hdr.command=cmd;
 589   req.hdr.status=STAT_BUSY;
 590   req.media=0; /* not dealing with block devices yet */
 591   req.buffer=buf;
 592   req.count=buflen;
 593   req.sector=0; /* block devices */
 594   req.volume=0; /* block devices */
 595
 596   DOSDEV_DoReq(&req, dev);
 597
 598   return req.count;
 599 }
 600
 601 int DOSDEV_Peek(DWORD dev, BYTE*data)
 602 {
 603   REQ_SAFEINPUT req;
 604
 605   req.hdr.size=sizeof(req);
 606   req.hdr.unit=0; /* not dealing with block devices yet */
 607   req.hdr.command=CMD_SAFEINPUT;
 608   req.hdr.status=STAT_BUSY;
 609   req.data=0;
 610
 611   DOSDEV_DoReq(&req, dev);
 612
 613   if (req.hdr.status & STAT_BUSY) return 0;
 614
 615   *data = req.data;
 616   return 1;
 617 }
 618
 619 int DOSDEV_Read(DWORD dev, DWORD buf, int buflen)
 620 {
 621   return DOSDEV_IO(CMD_INPUT, dev, buf, buflen);
 622 }
 623
 624 int DOSDEV_Write(DWORD dev, DWORD buf, int buflen, int verify)
 625 {
 626   return DOSDEV_IO(verify?CMD_SAFEOUTPUT:CMD_OUTPUT, dev, buf, buflen);
 627 }
 628
 629 int DOSDEV_IoctlRead(DWORD dev, DWORD buf, int buflen)
 630 {
 631   return DOSDEV_IO(CMD_INIOCTL, dev, buf, buflen);
 632 }
 633
 634 int DOSDEV_IoctlWrite(DWORD dev, DWORD buf, int buflen)
 635 {
 636   return DOSDEV_IO(CMD_OUTIOCTL, dev, buf, buflen);
 637 }