gdb/ser-go32.c

   1 /* Remote serial interface for local (hardwired) serial ports for GO32.
   2    Copyright (C) 1992-2024 Free Software Foundation, Inc.
   3
   4    Contributed by Nigel Stephens, Algorithmics Ltd. (nigel@algor.co.uk).
   5
   6    This version uses DPMI interrupts to handle buffered i/o
   7    without the separate "asynctsr" program.
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  23
  24 #include "cli/cli-cmds.h"
  25 #include "serial.h"
  26 /*
  27  * NS16550 UART registers
  28  */
  29
  30 #define COM1ADDR        0x3f8
  31 #define COM2ADDR        0x2f8
  32 #define COM3ADDR        0x3e8
  33 #define COM4ADDR        0x3e0
  34
  35 #define com_data        0       /* data register (R/W) */
  36 #define com_dlbl        0       /* divisor latch low (W) */
  37 #define com_ier         1       /* interrupt enable (W) */
  38 #define com_dlbh        1       /* divisor latch high (W) */
  39 #define com_iir         2       /* interrupt identification (R) */
  40 #define com_fifo        2       /* FIFO control (W) */
  41 #define com_lctl        3       /* line control register (R/W) */
  42 #define com_cfcr        3       /* line control register (R/W) */
  43 #define com_mcr         4       /* modem control register (R/W) */
  44 #define com_lsr         5       /* line status register (R/W) */
  45 #define com_msr         6       /* modem status register (R/W) */
  46
  47 /*
  48  * Constants for computing 16 bit baud rate divisor (lower byte
  49  * in com_dlbl, upper in com_dlbh) from 1.8432MHz crystal.  Divisor is
  50  * 1.8432 MHz / (16 * X) for X bps.  If the baud rate can't be set
  51  * to within +- (desired_rate*SPEED_TOLERANCE/1000) bps, we fail.
  52  */
  53 #define COMTICK         (1843200/16)
  54 #define SPEED_TOLERANCE 30      /* thousandths; real == desired +- 3.0% */
  55
  56 /* interrupt enable register */
  57 #define IER_ERXRDY      0x1     /* int on rx ready */
  58 #define IER_ETXRDY      0x2     /* int on tx ready */
  59 #define IER_ERLS        0x4     /* int on line status change */
  60 #define IER_EMSC        0x8     /* int on modem status change */
  61
  62 /* interrupt identification register */
  63 #define IIR_FIFO_MASK   0xc0    /* set if FIFOs are enabled */
  64 #define IIR_IMASK       0xf     /* interrupt cause mask */
  65 #define IIR_NOPEND      0x1     /* nothing pending */
  66 #define IIR_RLS         0x6     /* receive line status */
  67 #define IIR_RXRDY       0x4     /* receive ready */
  68 #define IIR_RXTOUT      0xc     /* receive timeout */
  69 #define IIR_TXRDY       0x2     /* transmit ready */
  70 #define IIR_MLSC        0x0     /* modem status */
  71
  72
  73 /* fifo control register */
  74 #define FIFO_ENABLE     0x01    /* enable fifo */
  75 #define FIFO_RCV_RST    0x02    /* reset receive fifo */
  76 #define FIFO_XMT_RST    0x04    /* reset transmit fifo */
  77 #define FIFO_DMA_MODE   0x08    /* enable dma mode */
  78 #define FIFO_TRIGGER_1  0x00    /* trigger at 1 char */
  79 #define FIFO_TRIGGER_4  0x40    /* trigger at 4 chars */
  80 #define FIFO_TRIGGER_8  0x80    /* trigger at 8 chars */
  81 #define FIFO_TRIGGER_14 0xc0    /* trigger at 14 chars */
  82
  83 /* character format control register */
  84 #define CFCR_DLAB       0x80    /* divisor latch */
  85 #define CFCR_SBREAK     0x40    /* send break */
  86 #define CFCR_PZERO      0x30    /* zero parity */
  87 #define CFCR_PONE       0x20    /* one parity */
  88 #define CFCR_PEVEN      0x10    /* even parity */
  89 #define CFCR_PODD       0x00    /* odd parity */
  90 #define CFCR_PENAB      0x08    /* parity enable */
  91 #define CFCR_STOPB      0x04    /* 2 stop bits */
  92 #define CFCR_8BITS      0x03    /* 8 data bits */
  93 #define CFCR_7BITS      0x02    /* 7 data bits */
  94 #define CFCR_6BITS      0x01    /* 6 data bits */
  95 #define CFCR_5BITS      0x00    /* 5 data bits */
  96
  97 /* modem control register */
  98 #define MCR_LOOPBACK    0x10    /* loopback */
  99 #define MCR_IENABLE     0x08    /* output 2 = int enable */
 100 #define MCR_DRS         0x04    /* output 1 = xxx */
 101 #define MCR_RTS         0x02    /* enable RTS */
 102 #define MCR_DTR         0x01    /* enable DTR */
 103
 104 /* line status register */
 105 #define LSR_RCV_FIFO    0x80    /* error in receive fifo */
 106 #define LSR_TSRE        0x40    /* transmitter empty */
 107 #define LSR_TXRDY       0x20    /* transmitter ready */
 108 #define LSR_BI          0x10    /* break detected */
 109 #define LSR_FE          0x08    /* framing error */
 110 #define LSR_PE          0x04    /* parity error */
 111 #define LSR_OE          0x02    /* overrun error */
 112 #define LSR_RXRDY       0x01    /* receiver ready */
 113 #define LSR_RCV_MASK    0x1f
 114
 115 /* modem status register */
 116 #define MSR_DCD         0x80
 117 #define MSR_RI          0x40
 118 #define MSR_DSR         0x20
 119 #define MSR_CTS         0x10
 120 #define MSR_DDCD        0x08
 121 #define MSR_TERI        0x04
 122 #define MSR_DDSR        0x02
 123 #define MSR_DCTS        0x01
 124
 125 #include <time.h>
 126 #include <dos.h>
 127 #include <go32.h>
 128 #include <dpmi.h>
 129 typedef unsigned long u_long;
 130
 131 /* 16550 rx fifo trigger point */
 132 #define FIFO_TRIGGER    FIFO_TRIGGER_4
 133
 134 /* input buffer size */
 135 #define CBSIZE  4096
 136
 137 #define RAWHZ   18
 138
 139 #ifdef DOS_STATS
 140 #define CNT_RX          16
 141 #define CNT_TX          17
 142 #define CNT_STRAY       18
 143 #define CNT_ORUN        19
 144 #define NCNT            20
 145
 146 static int intrcnt;
 147 static size_t cnts[NCNT];
 148 static char *cntnames[NCNT] =
 149 {
 150   /* h/w interrupt counts.  */
 151   "mlsc", "nopend", "txrdy", "?3",
 152   "rxrdy", "?5", "rls", "?7",
 153   "?8", "?9", "?a", "?b",
 154   "rxtout", "?d", "?e", "?f",
 155   /* s/w counts.  */
 156   "rxcnt", "txcnt", "stray", "swoflo"
 157 };
 158
 159 #define COUNT(x) cnts[x]++
 160 #else
 161 #define COUNT(x)
 162 #endif
 163
 164 /* Main interrupt controller port addresses.  */
 165 #define ICU_BASE        0x20
 166 #define ICU_OCW2        (ICU_BASE + 0)
 167 #define ICU_MASK        (ICU_BASE + 1)
 168
 169 /* Original interrupt controller mask register.  */
 170 unsigned char icu_oldmask;
 171
 172 /* Maximum of 8 interrupts (we don't handle the slave icu yet).  */
 173 #define NINTR   8
 174
 175 static struct intrupt
 176   {
 177     char inuse;
 178     struct dos_ttystate *port;
 179     _go32_dpmi_seginfo old_rmhandler;
 180     _go32_dpmi_seginfo old_pmhandler;
 181     _go32_dpmi_seginfo new_rmhandler;
 182     _go32_dpmi_seginfo new_pmhandler;
 183     _go32_dpmi_registers regs;
 184   }
 185 intrupts[NINTR];
 186
 187
 188 static struct dos_ttystate
 189   {
 190     int base;
 191     int irq;
 192     int refcnt;
 193     struct intrupt *intrupt;
 194     int fifo;
 195     int baudrate;
 196     unsigned char cbuf[CBSIZE];
 197     unsigned int first;
 198     unsigned int count;
 199     int txbusy;
 200     unsigned char old_mcr;
 201     int ferr;
 202     int perr;
 203     int oflo;
 204     int msr;
 205   }
 206 ports[4] =
 207 {
 208   {
 209     COM1ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 210   }
 211   ,
 212   {
 213     COM2ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 214   }
 215   ,
 216   {
 217     COM3ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 218   }
 219   ,
 220   {
 221     COM4ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 222   }
 223 };
 224
 225 static int dos_open (struct serial *scb, const char *name);
 226 static void dos_raw (struct serial *scb);
 227 static int dos_readchar (struct serial *scb, int timeout);
 228 static int dos_setbaudrate (struct serial *scb, int rate);
 229 static int dos_write (struct serial *scb, const void *buf, size_t count);
 230 static void dos_close (struct serial *scb);
 231 static serial_ttystate dos_get_tty_state (struct serial *scb);
 232 static int dos_set_tty_state (struct serial *scb, serial_ttystate state);
 233 static int dos_baudconv (int rate);
 234
 235 #define inb(p,a)        inportb((p)->base + (a))
 236 #define outb(p,a,v)     outportb((p)->base + (a), (v))
 237 #define disable()       asm volatile ("cli");
 238 #define enable()        asm volatile ("sti");
 239
 240
 241 static int
 242 dos_getc (volatile struct dos_ttystate *port)
 243 {
 244   int c;
 245
 246   if (port->count == 0)
 247     return -1;
 248
 249   c = port->cbuf[port->first];
 250   disable ();
 251   port->first = (port->first + 1) & (CBSIZE - 1);
 252   port->count--;
 253   enable ();
 254   return c;
 255 }
 256
 257
 258 static int
 259 dos_putc (int c, struct dos_ttystate *port)
 260 {
 261   if (port->count >= CBSIZE - 1)
 262     return -1;
 263   port->cbuf[(port->first + port->count) & (CBSIZE - 1)] = c;
 264   port->count++;
 265   return 0;
 266 }
 267 \f
 268
 269
 270 static void
 271 dos_comisr (int irq)
 272 {
 273   struct dos_ttystate *port;
 274   unsigned char iir, lsr, c;
 275
 276   disable ();                   /* Paranoia */
 277   outportb (ICU_OCW2, 0x20);    /* End-Of-Interrupt */
 278 #ifdef DOS_STATS
 279   ++intrcnt;
 280 #endif
 281
 282   port = intrupts[irq].port;
 283   if (!port)
 284     {
 285       COUNT (CNT_STRAY);
 286       return;                   /* not open */
 287     }
 288
 289   while (1)
 290     {
 291       iir = inb (port, com_iir) & IIR_IMASK;
 292       switch (iir)
 293         {
 294
 295         case IIR_RLS:
 296           lsr = inb (port, com_lsr);
 297           goto rx;
 298
 299         case IIR_RXTOUT:
 300         case IIR_RXRDY:
 301           lsr = 0;
 302
 303         rx:
 304           do
 305             {
 306               c = inb (port, com_data);
 307               if (lsr & (LSR_BI | LSR_FE | LSR_PE | LSR_OE))
 308                 {
 309                   if (lsr & (LSR_BI | LSR_FE))
 310                     port->ferr++;
 311                   else if (lsr & LSR_PE)
 312                     port->perr++;
 313                   if (lsr & LSR_OE)
 314                     port->oflo++;
 315                 }
 316
 317               if (dos_putc (c, port) < 0)
 318                 {
 319                   COUNT (CNT_ORUN);
 320                 }
 321               else
 322                 {
 323                   COUNT (CNT_RX);
 324                 }
 325             }
 326           while ((lsr = inb (port, com_lsr)) & LSR_RXRDY);
 327           break;
 328
 329         case IIR_MLSC:
 330           /* could be used to flowcontrol Tx */
 331           port->msr = inb (port, com_msr);
 332           break;
 333
 334         case IIR_TXRDY:
 335           port->txbusy = 0;
 336           break;
 337
 338         case IIR_NOPEND:
 339           /* No more pending interrupts, all done.  */
 340           return;
 341
 342         default:
 343           /* Unexpected interrupt, ignore.  */
 344           break;
 345         }
 346       COUNT (iir);
 347     }
 348 }
 349
 350 #define ISRNAME(x) dos_comisr##x
 351 #define ISR(x) static void ISRNAME(x)(void) {dos_comisr(x);}
 352
 353 ISR (0) ISR (1) ISR (2) ISR (3) /* OK */
 354 ISR (4) ISR (5) ISR (6) ISR (7) /* OK */
 355
 356 typedef void (*isr_t) (void);
 357
 358 static isr_t isrs[NINTR] =
 359   {
 360        ISRNAME (0), ISRNAME (1), ISRNAME (2), ISRNAME (3),
 361        ISRNAME (4), ISRNAME (5), ISRNAME (6), ISRNAME (7)
 362   };
 363 \f
 364
 365
 366 static struct intrupt *
 367 dos_hookirq (unsigned int irq)
 368 {
 369   struct intrupt *intr;
 370   unsigned int vec;
 371   isr_t isr;
 372
 373   if (irq >= NINTR)
 374     return 0;
 375
 376   intr = &intrupts[irq];
 377   if (intr->inuse)
 378     return 0;
 379
 380   vec = 0x08 + irq;
 381   isr = isrs[irq];
 382
 383   /* Setup real mode handler.  */
 384   _go32_dpmi_get_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 385
 386   intr->new_rmhandler.pm_selector = _go32_my_cs ();
 387   intr->new_rmhandler.pm_offset = (u_long) isr;
 388   if (_go32_dpmi_allocate_real_mode_callback_iret (&intr->new_rmhandler,
 389                                                    &intr->regs))
 390     {
 391       return 0;
 392     }
 393
 394   if (_go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->new_rmhandler))
 395     {
 396       return 0;
 397     }
 398
 399   /* Setup protected mode handler.  */
 400   _go32_dpmi_get_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 401
 402   intr->new_pmhandler.pm_selector = _go32_my_cs ();
 403   intr->new_pmhandler.pm_offset = (u_long) isr;
 404   _go32_dpmi_allocate_iret_wrapper (&intr->new_pmhandler);
 405
 406   if (_go32_dpmi_set_protected_mode_interrupt_vector (vec,
 407                                                       &intr->new_pmhandler))
 408     {
 409       return 0;
 410     }
 411
 412   /* Setup interrupt controller mask.  */
 413   disable ();
 414   outportb (ICU_MASK, inportb (ICU_MASK) & ~(1 << irq));
 415   enable ();
 416
 417   intr->inuse = 1;
 418   return intr;
 419 }
 420
 421
 422 static void
 423 dos_unhookirq (struct intrupt *intr)
 424 {
 425   unsigned int irq, vec;
 426   unsigned char mask;
 427
 428   irq = intr - intrupts;
 429   vec = 0x08 + irq;
 430
 431   /* Restore old interrupt mask bit.  */
 432   mask = 1 << irq;
 433   disable ();
 434   outportb (ICU_MASK, inportb (ICU_MASK) | (mask & icu_oldmask));
 435   enable ();
 436
 437   /* Remove real mode handler.  */
 438   _go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 439   _go32_dpmi_free_real_mode_callback (&intr->new_rmhandler);
 440
 441   /* Remove protected mode handler.  */
 442   _go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 443   _go32_dpmi_free_iret_wrapper (&intr->new_pmhandler);
 444   intr->inuse = 0;
 445 }
 446 \f
 447
 448
 449 static int
 450 dos_open (struct serial *scb, const char *name)
 451 {
 452   struct dos_ttystate *port;
 453   int fd, i;
 454
 455   if (strncasecmp (name, "/dev/", 5) == 0)
 456     name += 5;
 457   else if (strncasecmp (name, "\\dev\\", 5) == 0)
 458     name += 5;
 459
 460   if (strlen (name) != 4 || strncasecmp (name, "com", 3) != 0)
 461     {
 462       errno = ENOENT;
 463       return -1;
 464     }
 465
 466   if (name[3] < '1' || name[3] > '4')
 467     {
 468       errno = ENOENT;
 469       return -1;
 470     }
 471
 472   /* FIXME: this is a Bad Idea (tm)!  One should *never* invent file
 473      handles, since they might be already used by other files/devices.
 474      The Right Way to do this is to create a real handle by dup()'ing
 475      some existing one.  */
 476   fd = name[3] - '1';
 477   port = &ports[fd];
 478   if (port->refcnt++ > 0)
 479     {
 480       /* Device already opened another user.  Just point at it.  */
 481       scb->fd = fd;
 482       return 0;
 483     }
 484
 485   /* Force access to ID reg.  */
 486   outb (port, com_cfcr, 0);
 487   outb (port, com_iir, 0);
 488   for (i = 0; i < 17; i++)
 489     {
 490       if ((inb (port, com_iir) & 0x38) == 0)
 491         goto ok;
 492       (void) inb (port, com_data);      /* clear recv */
 493     }
 494   errno = ENODEV;
 495   return -1;
 496
 497 ok:
 498   /* Disable all interrupts in chip.  */
 499   outb (port, com_ier, 0);
 500
 501   /* Tentatively enable 16550 fifo, and see if it responds.  */
 502   outb (port, com_fifo,
 503         FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER);
 504   sleep (1);
 505   port->fifo = ((inb (port, com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK);
 506
 507   /* clear pending status reports.  */
 508   (void) inb (port, com_lsr);
 509   (void) inb (port, com_msr);
 510
 511   /* Enable external interrupt gate (to avoid floating IRQ).  */
 512   outb (port, com_mcr, MCR_IENABLE);
 513
 514   /* Hook up interrupt handler and initialise icu.  */
 515   port->intrupt = dos_hookirq (port->irq);
 516   if (!port->intrupt)
 517     {
 518       outb (port, com_mcr, 0);
 519       outb (port, com_fifo, 0);
 520       errno = ENODEV;
 521       return -1;
 522     }
 523
 524   disable ();
 525
 526   /* record port */
 527   port->intrupt->port = port;
 528   scb->fd = fd;
 529
 530   /* Clear rx buffer, tx busy flag and overflow count.  */
 531   port->first = port->count = 0;
 532   port->txbusy = 0;
 533   port->oflo = 0;
 534
 535   /* Set default baud rate and mode: 9600,8,n,1 */
 536   i = dos_baudconv (port->baudrate = 9600);
 537   outb (port, com_cfcr, CFCR_DLAB);
 538   outb (port, com_dlbl, i & 0xff);
 539   outb (port, com_dlbh, i >> 8);
 540   outb (port, com_cfcr, CFCR_8BITS);
 541
 542   /* Enable all interrupts.  */
 543   outb (port, com_ier, IER_ETXRDY | IER_ERXRDY | IER_ERLS | IER_EMSC);
 544
 545   /* Enable DTR & RTS.  */
 546   outb (port, com_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
 547
 548   enable ();
 549
 550   return 0;
 551 }
 552
 553
 554 static void
 555 dos_close (struct serial *scb)
 556 {
 557   struct dos_ttystate *port;
 558   struct intrupt *intrupt;
 559
 560   if (!scb)
 561     return;
 562
 563   port = &ports[scb->fd];
 564
 565   if (port->refcnt-- > 1)
 566     return;
 567
 568   if (!(intrupt = port->intrupt))
 569     return;
 570
 571   /* Disable interrupts, fifo, flow control.  */
 572   disable ();
 573   port->intrupt = 0;
 574   intrupt->port = 0;
 575   outb (port, com_fifo, 0);
 576   outb (port, com_ier, 0);
 577   enable ();
 578
 579   /* Unhook handler, and disable interrupt gate.  */
 580   dos_unhookirq (intrupt);
 581   outb (port, com_mcr, 0);
 582
 583   /* Check for overflow errors.  */
 584   if (port->oflo)
 585     {
 586       gdb_printf (gdb_stderr,
 587                   "Serial input overruns occurred.\n");
 588       gdb_printf (gdb_stderr, "This system %s handle %d baud.\n",
 589                   port->fifo ? "cannot" : "needs a 16550 to",
 590                   port->baudrate);
 591     }
 592 }
 593 \f
 594
 595 /* Implementation of the serial_ops flush_output method.  */
 596
 597 static int
 598 dos_flush_output (struct serial *scb)
 599 {
 600   return 0;
 601 }
 602
 603 /* Implementation of the serial_ops setparity method.  */
 604
 605 static int
 606 dos_setparity (struct serial *scb, int parity)
 607 {
 608   return 0;
 609 }
 610
 611 /* Implementation of the serial_ops drain_output method.  */
 612
 613 static int
 614 dos_drain_output (struct serial *scb)
 615 {
 616   return 0;
 617 }
 618
 619 static void
 620 dos_raw (struct serial *scb)
 621 {
 622   /* Always in raw mode.  */
 623 }
 624
 625 static int
 626 dos_readchar (struct serial *scb, int timeout)
 627 {
 628   struct dos_ttystate *port = &ports[scb->fd];
 629   long then;
 630   int c;
 631
 632   then = rawclock () + (timeout * RAWHZ);
 633   while ((c = dos_getc (port)) < 0)
 634     {
 635       QUIT;
 636
 637       if (timeout >= 0 && (rawclock () - then) >= 0)
 638         return SERIAL_TIMEOUT;
 639     }
 640
 641   return c;
 642 }
 643
 644
 645 static serial_ttystate
 646 dos_get_tty_state (struct serial *scb)
 647 {
 648   struct dos_ttystate *port = &ports[scb->fd];
 649   struct dos_ttystate *state;
 650
 651   /* Are they asking about a port we opened?  */
 652   if (port->refcnt <= 0)
 653     {
 654       /* We've never heard about this port.  We should fail this call,
 655          unless they are asking about one of the 3 standard handles,
 656          in which case we pretend the handle was open by us if it is
 657          connected to a terminal device.  This is because Unix
 658          terminals use the serial interface, so GDB expects the
 659          standard handles to go through here.  */
 660       if (scb->fd >= 3 || !isatty (scb->fd))
 661         return NULL;
 662     }
 663
 664   state = XNEW (struct dos_ttystate);
 665   *state = *port;
 666   return (serial_ttystate) state;
 667 }
 668
 669 static serial_ttystate
 670 dos_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
 671 {
 672   struct dos_ttystate *state;
 673
 674   state = XNEW (struct dos_ttystate);
 675   *state = *(struct dos_ttystate *) ttystate;
 676
 677   return (serial_ttystate) state;
 678 }
 679
 680 static int
 681 dos_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 682 {
 683   struct dos_ttystate *state;
 684
 685   state = (struct dos_ttystate *) ttystate;
 686   dos_setbaudrate (scb, state->baudrate);
 687   return 0;
 688 }
 689
 690 static int
 691 dos_flush_input (struct serial *scb)
 692 {
 693   struct dos_ttystate *port = &ports[scb->fd];
 694
 695   disable ();
 696   port->first = port->count = 0;
 697   if (port->fifo)
 698     outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_TRIGGER);
 699   enable ();
 700   return 0;
 701 }
 702
 703 static void
 704 dos_print_tty_state (struct serial *scb, serial_ttystate ttystate,
 705                      struct ui_file *stream)
 706 {
 707   /* Nothing to print.  */
 708   return;
 709 }
 710
 711 static int
 712 dos_baudconv (int rate)
 713 {
 714   long x, err;
 715
 716   if (rate <= 0)
 717     return -1;
 718
 719 #define divrnd(n, q)    (((n) * 2 / (q) + 1) / 2) /* Divide and round off.  */
 720   x = divrnd (COMTICK, rate);
 721   if (x <= 0)
 722     return -1;
 723
 724   err = divrnd (1000 * COMTICK, x * rate) - 1000;
 725   if (err < 0)
 726     err = -err;
 727   if (err > SPEED_TOLERANCE)
 728     return -1;
 729 #undef divrnd
 730   return x;
 731 }
 732
 733
 734 static int
 735 dos_setbaudrate (struct serial *scb, int rate)
 736 {
 737   struct dos_ttystate *port = &ports[scb->fd];
 738
 739   if (port->baudrate != rate)
 740     {
 741       int x;
 742       unsigned char cfcr;
 743
 744       x = dos_baudconv (rate);
 745       if (x <= 0)
 746         {
 747           gdb_printf (gdb_stderr, "%d: impossible baudrate\n", rate);
 748           errno = EINVAL;
 749           return -1;
 750         }
 751
 752       disable ();
 753       cfcr = inb (port, com_cfcr);
 754
 755       outb (port, com_cfcr, CFCR_DLAB);
 756       outb (port, com_dlbl, x & 0xff);
 757       outb (port, com_dlbh, x >> 8);
 758       outb (port, com_cfcr, cfcr);
 759       port->baudrate = rate;
 760       enable ();
 761     }
 762
 763   return 0;
 764 }
 765
 766 static int
 767 dos_setstopbits (struct serial *scb, int num)
 768 {
 769   struct dos_ttystate *port = &ports[scb->fd];
 770   unsigned char cfcr;
 771
 772   disable ();
 773   cfcr = inb (port, com_cfcr);
 774
 775   switch (num)
 776     {
 777     case SERIAL_1_STOPBITS:
 778       outb (port, com_cfcr, cfcr & ~CFCR_STOPB);
 779       break;
 780     case SERIAL_1_AND_A_HALF_STOPBITS:
 781     case SERIAL_2_STOPBITS:
 782       outb (port, com_cfcr, cfcr | CFCR_STOPB);
 783       break;
 784     default:
 785       enable ();
 786       return 1;
 787     }
 788   enable ();
 789
 790   return 0;
 791 }
 792
 793 static int
 794 dos_write (struct serial *scb, const void *buf, size_t count)
 795 {
 796   volatile struct dos_ttystate *port = &ports[scb->fd];
 797   size_t fifosize = port->fifo ? 16 : 1;
 798   long then;
 799   size_t cnt;
 800   const char *str = (const char *) buf;
 801
 802   while (count > 0)
 803     {
 804       QUIT;
 805
 806       /* Send the data, fifosize bytes at a time.  */
 807       cnt = fifosize > count ? count : fifosize;
 808       port->txbusy = 1;
 809       /* Francisco Pastor <fpastor.etra-id@etra.es> says OUTSB messes
 810          up the communications with UARTs with FIFOs.  */
 811 #ifdef UART_FIFO_WORKS
 812       outportsb (port->base + com_data, str, cnt);
 813       str += cnt;
 814       count -= cnt;
 815 #else
 816       for ( ; cnt > 0; cnt--, count--)
 817         outportb (port->base + com_data, *str++);
 818 #endif
 819 #ifdef DOS_STATS
 820       cnts[CNT_TX] += cnt;
 821 #endif
 822       /* Wait for transmission to complete (max 1 sec).  */
 823       then = rawclock () + RAWHZ;
 824       while (port->txbusy)
 825         {
 826           if ((rawclock () - then) >= 0)
 827             {
 828               errno = EIO;
 829               return SERIAL_ERROR;
 830             }
 831         }
 832     }
 833   return 0;
 834 }
 835
 836
 837 static int
 838 dos_sendbreak (struct serial *scb)
 839 {
 840   volatile struct dos_ttystate *port = &ports[scb->fd];
 841   unsigned char cfcr;
 842   long then;
 843
 844   cfcr = inb (port, com_cfcr);
 845   outb (port, com_cfcr, cfcr | CFCR_SBREAK);
 846
 847   /* 0.25 sec delay */
 848   then = rawclock () + RAWHZ / 4;
 849   while ((rawclock () - then) < 0)
 850     continue;
 851
 852   outb (port, com_cfcr, cfcr);
 853   return 0;
 854 }
 855
 856
 857 static const struct serial_ops dos_ops =
 858 {
 859   "hardwire",
 860   dos_open,
 861   dos_close,
 862   NULL,                         /* fdopen, not implemented */
 863   dos_readchar,
 864   dos_write,
 865   dos_flush_output,
 866   dos_flush_input,
 867   dos_sendbreak,
 868   dos_raw,
 869   dos_get_tty_state,
 870   dos_copy_tty_state,
 871   dos_set_tty_state,
 872   dos_print_tty_state,
 873   dos_setbaudrate,
 874   dos_setstopbits,
 875   dos_setparity,
 876   dos_drain_output,
 877   (void (*)(struct serial *, int))NULL  /* Change into async mode.  */
 878 };
 879
 880 int
 881 gdb_pipe (int pdes[2])
 882 {
 883   /* No support for pipes.  */
 884   errno = ENOSYS;
 885   return -1;
 886 }
 887
 888 static void
 889 info_serial_command (const char *arg, int from_tty)
 890 {
 891   struct dos_ttystate *port;
 892 #ifdef DOS_STATS
 893   int i;
 894 #endif
 895
 896   for (port = ports; port < &ports[4]; port++)
 897     {
 898       if (port->baudrate == 0)
 899         continue;
 900       gdb_printf ("Port:\tCOM%ld (%sactive)\n", (long)(port - ports) + 1,
 901                   port->intrupt ? "" : "not ");
 902       gdb_printf ("Addr:\t0x%03x (irq %d)\n", port->base, port->irq);
 903       gdb_printf ("16550:\t%s\n", port->fifo ? "yes" : "no");
 904       gdb_printf ("Speed:\t%d baud\n", port->baudrate);
 905       gdb_printf ("Errs:\tframing %d parity %d overflow %d\n\n",
 906                   port->ferr, port->perr, port->oflo);
 907     }
 908
 909 #ifdef DOS_STATS
 910   gdb_printf ("\nTotal interrupts: %d\n", intrcnt);
 911   for (i = 0; i < NCNT; i++)
 912     if (cnts[i])
 913       gdb_printf ("%s:\t%lu\n", cntnames[i], (unsigned long) cnts[i]);
 914 #endif
 915 }
 916
 917 void _initialize_ser_dos ();
 918 void
 919 _initialize_ser_dos ()
 920 {
 921   serial_add_interface (&dos_ops);
 922
 923   /* Save original interrupt mask register.  */
 924   icu_oldmask = inportb (ICU_MASK);
 925
 926   /* Mark fixed motherboard irqs as inuse.  */
 927   intrupts[0].inuse =           /* timer tick */
 928     intrupts[1].inuse =         /* keyboard */
 929     intrupts[2].inuse = 1;      /* slave icu */
 930
 931   add_setshow_zinteger_cmd ("com1base", class_obscure, &ports[0].base, _("\
 932 Set COM1 base i/o port address."), _("\
 933 Show COM1 base i/o port address."), NULL,
 934                             NULL,
 935                             NULL, /* FIXME: i18n: */
 936                             &setlist, &showlist);
 937
 938   add_setshow_zinteger_cmd ("com1irq", class_obscure, &ports[0].irq, _("\
 939 Set COM1 interrupt request."), _("\
 940 Show COM1 interrupt request."), NULL,
 941                             NULL,
 942                             NULL, /* FIXME: i18n: */
 943                             &setlist, &showlist);
 944
 945   add_setshow_zinteger_cmd ("com2base", class_obscure, &ports[1].base, _("\
 946 Set COM2 base i/o port address."), _("\
 947 Show COM2 base i/o port address."), NULL,
 948                             NULL,
 949                             NULL, /* FIXME: i18n: */
 950                             &setlist, &showlist);
 951
 952   add_setshow_zinteger_cmd ("com2irq", class_obscure, &ports[1].irq, _("\
 953 Set COM2 interrupt request."), _("\
 954 Show COM2 interrupt request."), NULL,
 955                             NULL,
 956                             NULL, /* FIXME: i18n: */
 957                             &setlist, &showlist);
 958
 959   add_setshow_zinteger_cmd ("com3base", class_obscure, &ports[2].base, _("\
 960 Set COM3 base i/o port address."), _("\
 961 Show COM3 base i/o port address."), NULL,
 962                             NULL,
 963                             NULL, /* FIXME: i18n: */
 964                             &setlist, &showlist);
 965
 966   add_setshow_zinteger_cmd ("com3irq", class_obscure, &ports[2].irq, _("\
 967 Set COM3 interrupt request."), _("\
 968 Show COM3 interrupt request."), NULL,
 969                             NULL,
 970                             NULL, /* FIXME: i18n: */
 971                             &setlist, &showlist);
 972
 973   add_setshow_zinteger_cmd ("com4base", class_obscure, &ports[3].base, _("\
 974 Set COM4 base i/o port address."), _("\
 975 Show COM4 base i/o port address."), NULL,
 976                             NULL,
 977                             NULL, /* FIXME: i18n: */
 978                             &setlist, &showlist);
 979
 980   add_setshow_zinteger_cmd ("com4irq", class_obscure, &ports[3].irq, _("\
 981 Set COM4 interrupt request."), _("\
 982 Show COM4 interrupt request."), NULL,
 983                             NULL,
 984                             NULL, /* FIXME: i18n: */
 985                             &setlist, &showlist);
 986
 987   add_info ("serial", info_serial_command,
 988             _("Print DOS serial port status."));
 989 }