gdb/ser-go32.c

   1 /* Remote serial interface for local (hardwired) serial ports for GO32.
   2    Copyright (C) 1992, 1993, 2000, 2001, 2007, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4
   5    Contributed by Nigel Stephens, Algorithmics Ltd. (nigel@algor.co.uk).
   6
   7    This version uses DPMI interrupts to handle buffered i/o
   8    without the separate "asynctsr" program.
   9
  10    This file is part of GDB.
  11
  12    This program is free software; you can redistribute it and/or modify
  13    it under the terms of the GNU General Public License as published by
  14    the Free Software Foundation; either version 3 of the License, or
  15    (at your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  24
  25 #include "defs.h"
  26 #include "gdbcmd.h"
  27 #include "serial.h"
  28 #include "gdb_string.h"
  29
  30
  31 /*
  32  * NS16550 UART registers
  33  */
  34
  35 #define COM1ADDR        0x3f8
  36 #define COM2ADDR        0x2f8
  37 #define COM3ADDR        0x3e8
  38 #define COM4ADDR        0x3e0
  39
  40 #define com_data        0       /* data register (R/W) */
  41 #define com_dlbl        0       /* divisor latch low (W) */
  42 #define com_ier         1       /* interrupt enable (W) */
  43 #define com_dlbh        1       /* divisor latch high (W) */
  44 #define com_iir         2       /* interrupt identification (R) */
  45 #define com_fifo        2       /* FIFO control (W) */
  46 #define com_lctl        3       /* line control register (R/W) */
  47 #define com_cfcr        3       /* line control register (R/W) */
  48 #define com_mcr         4       /* modem control register (R/W) */
  49 #define com_lsr         5       /* line status register (R/W) */
  50 #define com_msr         6       /* modem status register (R/W) */
  51
  52 /*
  53  * Constants for computing 16 bit baud rate divisor (lower byte
  54  * in com_dlbl, upper in com_dlbh) from 1.8432MHz crystal.  Divisor is
  55  * 1.8432 MHz / (16 * X) for X bps.  If the baud rate can't be set
  56  * to within +- (desired_rate*SPEED_TOLERANCE/1000) bps, we fail.
  57  */
  58 #define COMTICK         (1843200/16)
  59 #define SPEED_TOLERANCE 30      /* thousandths; real == desired +- 3.0% */
  60
  61 /* interrupt enable register */
  62 #define IER_ERXRDY      0x1     /* int on rx ready */
  63 #define IER_ETXRDY      0x2     /* int on tx ready */
  64 #define IER_ERLS        0x4     /* int on line status change */
  65 #define IER_EMSC        0x8     /* int on modem status change */
  66
  67 /* interrupt identification register */
  68 #define IIR_FIFO_MASK   0xc0    /* set if FIFOs are enabled */
  69 #define IIR_IMASK       0xf     /* interrupt cause mask */
  70 #define IIR_NOPEND      0x1     /* nothing pending */
  71 #define IIR_RLS         0x6     /* receive line status */
  72 #define IIR_RXRDY       0x4     /* receive ready */
  73 #define IIR_RXTOUT      0xc     /* receive timeout */
  74 #define IIR_TXRDY       0x2     /* transmit ready */
  75 #define IIR_MLSC        0x0     /* modem status */
  76
  77
  78 /* fifo control register */
  79 #define FIFO_ENABLE     0x01    /* enable fifo */
  80 #define FIFO_RCV_RST    0x02    /* reset receive fifo */
  81 #define FIFO_XMT_RST    0x04    /* reset transmit fifo */
  82 #define FIFO_DMA_MODE   0x08    /* enable dma mode */
  83 #define FIFO_TRIGGER_1  0x00    /* trigger at 1 char */
  84 #define FIFO_TRIGGER_4  0x40    /* trigger at 4 chars */
  85 #define FIFO_TRIGGER_8  0x80    /* trigger at 8 chars */
  86 #define FIFO_TRIGGER_14 0xc0    /* trigger at 14 chars */
  87
  88 /* character format control register */
  89 #define CFCR_DLAB       0x80    /* divisor latch */
  90 #define CFCR_SBREAK     0x40    /* send break */
  91 #define CFCR_PZERO      0x30    /* zero parity */
  92 #define CFCR_PONE       0x20    /* one parity */
  93 #define CFCR_PEVEN      0x10    /* even parity */
  94 #define CFCR_PODD       0x00    /* odd parity */
  95 #define CFCR_PENAB      0x08    /* parity enable */
  96 #define CFCR_STOPB      0x04    /* 2 stop bits */
  97 #define CFCR_8BITS      0x03    /* 8 data bits */
  98 #define CFCR_7BITS      0x02    /* 7 data bits */
  99 #define CFCR_6BITS      0x01    /* 6 data bits */
 100 #define CFCR_5BITS      0x00    /* 5 data bits */
 101
 102 /* modem control register */
 103 #define MCR_LOOPBACK    0x10    /* loopback */
 104 #define MCR_IENABLE     0x08    /* output 2 = int enable */
 105 #define MCR_DRS         0x04    /* output 1 = xxx */
 106 #define MCR_RTS         0x02    /* enable RTS */
 107 #define MCR_DTR         0x01    /* enable DTR */
 108
 109 /* line status register */
 110 #define LSR_RCV_FIFO    0x80    /* error in receive fifo */
 111 #define LSR_TSRE        0x40    /* transmitter empty */
 112 #define LSR_TXRDY       0x20    /* transmitter ready */
 113 #define LSR_BI          0x10    /* break detected */
 114 #define LSR_FE          0x08    /* framing error */
 115 #define LSR_PE          0x04    /* parity error */
 116 #define LSR_OE          0x02    /* overrun error */
 117 #define LSR_RXRDY       0x01    /* receiver ready */
 118 #define LSR_RCV_MASK    0x1f
 119
 120 /* modem status register */
 121 #define MSR_DCD         0x80
 122 #define MSR_RI          0x40
 123 #define MSR_DSR         0x20
 124 #define MSR_CTS         0x10
 125 #define MSR_DDCD        0x08
 126 #define MSR_TERI        0x04
 127 #define MSR_DDSR        0x02
 128 #define MSR_DCTS        0x01
 129
 130 #include <time.h>
 131 #include <dos.h>
 132 #include <go32.h>
 133 #include <dpmi.h>
 134 typedef unsigned long u_long;
 135
 136 /* 16550 rx fifo trigger point */
 137 #define FIFO_TRIGGER    FIFO_TRIGGER_4
 138
 139 /* input buffer size */
 140 #define CBSIZE  4096
 141
 142 #define RAWHZ   18
 143
 144 #ifdef DOS_STATS
 145 #define CNT_RX          16
 146 #define CNT_TX          17
 147 #define CNT_STRAY       18
 148 #define CNT_ORUN        19
 149 #define NCNT            20
 150
 151 static int intrcnt;
 152 static int cnts[NCNT];
 153 static char *cntnames[NCNT] =
 154 {
 155   /* h/w interrupt counts.  */
 156   "mlsc", "nopend", "txrdy", "?3",
 157   "rxrdy", "?5", "rls", "?7",
 158   "?8", "?9", "?a", "?b",
 159   "rxtout", "?d", "?e", "?f",
 160   /* s/w counts.  */
 161   "rxcnt", "txcnt", "stray", "swoflo"
 162 };
 163
 164 #define COUNT(x) cnts[x]++
 165 #else
 166 #define COUNT(x)
 167 #endif
 168
 169 /* Main interrupt controller port addresses.  */
 170 #define ICU_BASE        0x20
 171 #define ICU_OCW2        (ICU_BASE + 0)
 172 #define ICU_MASK        (ICU_BASE + 1)
 173
 174 /* Original interrupt controller mask register.  */
 175 unsigned char icu_oldmask;
 176
 177 /* Maximum of 8 interrupts (we don't handle the slave icu yet).  */
 178 #define NINTR   8
 179
 180 static struct intrupt
 181   {
 182     char inuse;
 183     struct dos_ttystate *port;
 184     _go32_dpmi_seginfo old_rmhandler;
 185     _go32_dpmi_seginfo old_pmhandler;
 186     _go32_dpmi_seginfo new_rmhandler;
 187     _go32_dpmi_seginfo new_pmhandler;
 188     _go32_dpmi_registers regs;
 189   }
 190 intrupts[NINTR];
 191
 192
 193 static struct dos_ttystate
 194   {
 195     int base;
 196     int irq;
 197     int refcnt;
 198     struct intrupt *intrupt;
 199     int fifo;
 200     int baudrate;
 201     unsigned char cbuf[CBSIZE];
 202     unsigned int first;
 203     unsigned int count;
 204     int txbusy;
 205     unsigned char old_mcr;
 206     int ferr;
 207     int perr;
 208     int oflo;
 209     int msr;
 210   }
 211 ports[4] =
 212 {
 213   {
 214     COM1ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 215   }
 216   ,
 217   {
 218     COM2ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 219   }
 220   ,
 221   {
 222     COM3ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 223   }
 224   ,
 225   {
 226     COM4ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 227   }
 228 };
 229
 230 static int dos_open (struct serial *scb, const char *name);
 231 static void dos_raw (struct serial *scb);
 232 static int dos_readchar (struct serial *scb, int timeout);
 233 static int dos_setbaudrate (struct serial *scb, int rate);
 234 static int dos_write (struct serial *scb, const char *str, int len);
 235 static void dos_close (struct serial *scb);
 236 static serial_ttystate dos_get_tty_state (struct serial *scb);
 237 static int dos_set_tty_state (struct serial *scb, serial_ttystate state);
 238 static int dos_baudconv (int rate);
 239
 240 #define inb(p,a)        inportb((p)->base + (a))
 241 #define outb(p,a,v)     outportb((p)->base + (a), (v))
 242 #define disable()       asm volatile ("cli");
 243 #define enable()        asm volatile ("sti");
 244
 245
 246 static int
 247 dos_getc (volatile struct dos_ttystate *port)
 248 {
 249   int c;
 250
 251   if (port->count == 0)
 252     return -1;
 253
 254   c = port->cbuf[port->first];
 255   disable ();
 256   port->first = (port->first + 1) & (CBSIZE - 1);
 257   port->count--;
 258   enable ();
 259   return c;
 260 }
 261
 262
 263 static int
 264 dos_putc (int c, struct dos_ttystate *port)
 265 {
 266   if (port->count >= CBSIZE - 1)
 267     return -1;
 268   port->cbuf[(port->first + port->count) & (CBSIZE - 1)] = c;
 269   port->count++;
 270   return 0;
 271 }
 272 \f
 273
 274
 275 static void
 276 dos_comisr (int irq)
 277 {
 278   struct dos_ttystate *port;
 279   unsigned char iir, lsr, c;
 280
 281   disable ();                   /* Paranoia */
 282   outportb (ICU_OCW2, 0x20);    /* End-Of-Interrupt */
 283 #ifdef DOS_STATS
 284   ++intrcnt;
 285 #endif
 286
 287   port = intrupts[irq].port;
 288   if (!port)
 289     {
 290       COUNT (CNT_STRAY);
 291       return;                   /* not open */
 292     }
 293
 294   while (1)
 295     {
 296       iir = inb (port, com_iir) & IIR_IMASK;
 297       switch (iir)
 298         {
 299
 300         case IIR_RLS:
 301           lsr = inb (port, com_lsr);
 302           goto rx;
 303
 304         case IIR_RXTOUT:
 305         case IIR_RXRDY:
 306           lsr = 0;
 307
 308         rx:
 309           do
 310             {
 311               c = inb (port, com_data);
 312               if (lsr & (LSR_BI | LSR_FE | LSR_PE | LSR_OE))
 313                 {
 314                   if (lsr & (LSR_BI | LSR_FE))
 315                     port->ferr++;
 316                   else if (lsr & LSR_PE)
 317                     port->perr++;
 318                   if (lsr & LSR_OE)
 319                     port->oflo++;
 320                 }
 321
 322               if (dos_putc (c, port) < 0)
 323                 {
 324                   COUNT (CNT_ORUN);
 325                 }
 326               else
 327                 {
 328                   COUNT (CNT_RX);
 329                 }
 330             }
 331           while ((lsr = inb (port, com_lsr)) & LSR_RXRDY);
 332           break;
 333
 334         case IIR_MLSC:
 335           /* could be used to flowcontrol Tx */
 336           port->msr = inb (port, com_msr);
 337           break;
 338
 339         case IIR_TXRDY:
 340           port->txbusy = 0;
 341           break;
 342
 343         case IIR_NOPEND:
 344           /* No more pending interrupts, all done.  */
 345           return;
 346
 347         default:
 348           /* Unexpected interrupt, ignore.  */
 349           break;
 350         }
 351       COUNT (iir);
 352     }
 353 }
 354
 355 #define ISRNAME(x) dos_comisr##x
 356 #define ISR(x) static void ISRNAME(x)(void) {dos_comisr(x);}
 357
 358 ISR (0) ISR (1) ISR (2) ISR (3) /* OK */
 359 ISR (4) ISR (5) ISR (6) ISR (7) /* OK */
 360
 361 typedef void (*isr_t) (void);
 362
 363 static isr_t isrs[NINTR] =
 364   {
 365        ISRNAME (0), ISRNAME (1), ISRNAME (2), ISRNAME (3),
 366        ISRNAME (4), ISRNAME (5), ISRNAME (6), ISRNAME (7)
 367   };
 368 \f
 369
 370
 371 static struct intrupt *
 372 dos_hookirq (unsigned int irq)
 373 {
 374   struct intrupt *intr;
 375   unsigned int vec;
 376   isr_t isr;
 377
 378   if (irq >= NINTR)
 379     return 0;
 380
 381   intr = &intrupts[irq];
 382   if (intr->inuse)
 383     return 0;
 384
 385   vec = 0x08 + irq;
 386   isr = isrs[irq];
 387
 388   /* Setup real mode handler.  */
 389   _go32_dpmi_get_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 390
 391   intr->new_rmhandler.pm_selector = _go32_my_cs ();
 392   intr->new_rmhandler.pm_offset = (u_long) isr;
 393   if (_go32_dpmi_allocate_real_mode_callback_iret (&intr->new_rmhandler,
 394                                                    &intr->regs))
 395     {
 396       return 0;
 397     }
 398
 399   if (_go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->new_rmhandler))
 400     {
 401       return 0;
 402     }
 403
 404   /* Setup protected mode handler.  */
 405   _go32_dpmi_get_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 406
 407   intr->new_pmhandler.pm_selector = _go32_my_cs ();
 408   intr->new_pmhandler.pm_offset = (u_long) isr;
 409   _go32_dpmi_allocate_iret_wrapper (&intr->new_pmhandler);
 410
 411   if (_go32_dpmi_set_protected_mode_interrupt_vector (vec,
 412                                                       &intr->new_pmhandler))
 413     {
 414       return 0;
 415     }
 416
 417   /* Setup interrupt controller mask.  */
 418   disable ();
 419   outportb (ICU_MASK, inportb (ICU_MASK) & ~(1 << irq));
 420   enable ();
 421
 422   intr->inuse = 1;
 423   return intr;
 424 }
 425
 426
 427 static void
 428 dos_unhookirq (struct intrupt *intr)
 429 {
 430   unsigned int irq, vec;
 431   unsigned char mask;
 432
 433   irq = intr - intrupts;
 434   vec = 0x08 + irq;
 435
 436   /* Restore old interrupt mask bit.  */
 437   mask = 1 << irq;
 438   disable ();
 439   outportb (ICU_MASK, inportb (ICU_MASK) | (mask & icu_oldmask));
 440   enable ();
 441
 442   /* Remove real mode handler.  */
 443   _go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 444   _go32_dpmi_free_real_mode_callback (&intr->new_rmhandler);
 445
 446   /* Remove protected mode handler.  */
 447   _go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 448   _go32_dpmi_free_iret_wrapper (&intr->new_pmhandler);
 449   intr->inuse = 0;
 450 }
 451 \f
 452
 453
 454 static int
 455 dos_open (struct serial *scb, const char *name)
 456 {
 457   struct dos_ttystate *port;
 458   int fd, i;
 459
 460   if (strncasecmp (name, "/dev/", 5) == 0)
 461     name += 5;
 462   else if (strncasecmp (name, "\\dev\\", 5) == 0)
 463     name += 5;
 464
 465   if (strlen (name) != 4 || strncasecmp (name, "com", 3) != 0)
 466     {
 467       errno = ENOENT;
 468       return -1;
 469     }
 470
 471   if (name[3] < '1' || name[3] > '4')
 472     {
 473       errno = ENOENT;
 474       return -1;
 475     }
 476
 477   /* FIXME: this is a Bad Idea (tm)!  One should *never* invent file
 478      handles, since they might be already used by other files/devices.
 479      The Right Way to do this is to create a real handle by dup()'ing
 480      some existing one.  */
 481   fd = name[3] - '1';
 482   port = &ports[fd];
 483   if (port->refcnt++ > 0)
 484     {
 485       /* Device already opened another user.  Just point at it.  */
 486       scb->fd = fd;
 487       return 0;
 488     }
 489
 490   /* Force access to ID reg.  */
 491   outb (port, com_cfcr, 0);
 492   outb (port, com_iir, 0);
 493   for (i = 0; i < 17; i++)
 494     {
 495       if ((inb (port, com_iir) & 0x38) == 0)
 496         goto ok;
 497       (void) inb (port, com_data);      /* clear recv */
 498     }
 499   errno = ENODEV;
 500   return -1;
 501
 502 ok:
 503   /* Disable all interrupts in chip.  */
 504   outb (port, com_ier, 0);
 505
 506   /* Tentatively enable 16550 fifo, and see if it responds.  */
 507   outb (port, com_fifo,
 508         FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER);
 509   sleep (1);
 510   port->fifo = ((inb (port, com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK);
 511
 512   /* clear pending status reports.  */
 513   (void) inb (port, com_lsr);
 514   (void) inb (port, com_msr);
 515
 516   /* Enable external interrupt gate (to avoid floating IRQ).  */
 517   outb (port, com_mcr, MCR_IENABLE);
 518
 519   /* Hook up interrupt handler and initialise icu.  */
 520   port->intrupt = dos_hookirq (port->irq);
 521   if (!port->intrupt)
 522     {
 523       outb (port, com_mcr, 0);
 524       outb (port, com_fifo, 0);
 525       errno = ENODEV;
 526       return -1;
 527     }
 528
 529   disable ();
 530
 531   /* record port */
 532   port->intrupt->port = port;
 533   scb->fd = fd;
 534
 535   /* Clear rx buffer, tx busy flag and overflow count.  */
 536   port->first = port->count = 0;
 537   port->txbusy = 0;
 538   port->oflo = 0;
 539
 540   /* Set default baud rate and mode: 9600,8,n,1 */
 541   i = dos_baudconv (port->baudrate = 9600);
 542   outb (port, com_cfcr, CFCR_DLAB);
 543   outb (port, com_dlbl, i & 0xff);
 544   outb (port, com_dlbh, i >> 8);
 545   outb (port, com_cfcr, CFCR_8BITS);
 546
 547   /* Enable all interrupts.  */
 548   outb (port, com_ier, IER_ETXRDY | IER_ERXRDY | IER_ERLS | IER_EMSC);
 549
 550   /* Enable DTR & RTS.  */
 551   outb (port, com_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
 552
 553   enable ();
 554
 555   return 0;
 556 }
 557
 558
 559 static void
 560 dos_close (struct serial *scb)
 561 {
 562   struct dos_ttystate *port;
 563   struct intrupt *intrupt;
 564
 565   if (!scb)
 566     return;
 567
 568   port = &ports[scb->fd];
 569
 570   if (port->refcnt-- > 1)
 571     return;
 572
 573   if (!(intrupt = port->intrupt))
 574     return;
 575
 576   /* Disable interrupts, fifo, flow control.  */
 577   disable ();
 578   port->intrupt = 0;
 579   intrupt->port = 0;
 580   outb (port, com_fifo, 0);
 581   outb (port, com_ier, 0);
 582   enable ();
 583
 584   /* Unhook handler, and disable interrupt gate.  */
 585   dos_unhookirq (intrupt);
 586   outb (port, com_mcr, 0);
 587
 588   /* Check for overflow errors.  */
 589   if (port->oflo)
 590     {
 591       fprintf_unfiltered (gdb_stderr,
 592                           "Serial input overruns occurred.\n");
 593       fprintf_unfiltered (gdb_stderr, "This system %s handle %d baud.\n",
 594                           port->fifo ? "cannot" : "needs a 16550 to",
 595                           port->baudrate);
 596     }
 597 }
 598 \f
 599
 600
 601 static int
 602 dos_noop (struct serial *scb)
 603 {
 604   return 0;
 605 }
 606
 607 static void
 608 dos_raw (struct serial *scb)
 609 {
 610   /* Always in raw mode.  */
 611 }
 612
 613 static int
 614 dos_readchar (struct serial *scb, int timeout)
 615 {
 616   struct dos_ttystate *port = &ports[scb->fd];
 617   long then;
 618   int c;
 619
 620   then = rawclock () + (timeout * RAWHZ);
 621   while ((c = dos_getc (port)) < 0)
 622     {
 623       if (timeout >= 0 && (rawclock () - then) >= 0)
 624         return SERIAL_TIMEOUT;
 625     }
 626
 627   return c;
 628 }
 629
 630
 631 static serial_ttystate
 632 dos_get_tty_state (struct serial *scb)
 633 {
 634   struct dos_ttystate *port = &ports[scb->fd];
 635   struct dos_ttystate *state;
 636
 637   /* Are they asking about a port we opened?  */
 638   if (port->refcnt <= 0)
 639     {
 640       /* We've never heard about this port.  We should fail this call,
 641          unless they are asking about one of the 3 standard handles,
 642          in which case we pretend the handle was open by us if it is
 643          connected to a terminal device.  This is beacuse Unix
 644          terminals use the serial interface, so GDB expects the
 645          standard handles to go through here.  */
 646       if (scb->fd >= 3 || !isatty (scb->fd))
 647         return NULL;
 648     }
 649
 650   state = (struct dos_ttystate *) xmalloc (sizeof *state);
 651   *state = *port;
 652   return (serial_ttystate) state;
 653 }
 654
 655 static serial_ttystate
 656 dos_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
 657 {
 658   struct dos_ttystate *state;
 659
 660   state = (struct dos_ttystate *) xmalloc (sizeof *state);
 661   *state = *(struct dos_ttystate *) ttystate;
 662
 663   return (serial_ttystate) state;
 664 }
 665
 666 static int
 667 dos_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 668 {
 669   struct dos_ttystate *state;
 670
 671   state = (struct dos_ttystate *) ttystate;
 672   dos_setbaudrate (scb, state->baudrate);
 673   return 0;
 674 }
 675
 676 static int
 677 dos_noflush_set_tty_state (struct serial *scb, serial_ttystate new_ttystate,
 678                            serial_ttystate old_ttystate)
 679 {
 680   struct dos_ttystate *state;
 681
 682   state = (struct dos_ttystate *) new_ttystate;
 683   dos_setbaudrate (scb, state->baudrate);
 684   return 0;
 685 }
 686
 687 static int
 688 dos_flush_input (struct serial *scb)
 689 {
 690   struct dos_ttystate *port = &ports[scb->fd];
 691
 692   disable ();
 693   port->first = port->count = 0;
 694   if (port->fifo)
 695     outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_TRIGGER);
 696   enable ();
 697   return 0;
 698 }
 699
 700 static void
 701 dos_print_tty_state (struct serial *scb, serial_ttystate ttystate,
 702                      struct ui_file *stream)
 703 {
 704   /* Nothing to print.  */
 705   return;
 706 }
 707
 708 static int
 709 dos_baudconv (int rate)
 710 {
 711   long x, err;
 712
 713   if (rate <= 0)
 714     return -1;
 715
 716 #define divrnd(n, q)    (((n) * 2 / (q) + 1) / 2) /* Divide and round off.  */
 717   x = divrnd (COMTICK, rate);
 718   if (x <= 0)
 719     return -1;
 720
 721   err = divrnd (1000 * COMTICK, x * rate) - 1000;
 722   if (err < 0)
 723     err = -err;
 724   if (err > SPEED_TOLERANCE)
 725     return -1;
 726 #undef divrnd
 727   return x;
 728 }
 729
 730
 731 static int
 732 dos_setbaudrate (struct serial *scb, int rate)
 733 {
 734   struct dos_ttystate *port = &ports[scb->fd];
 735
 736   if (port->baudrate != rate)
 737     {
 738       int x;
 739       unsigned char cfcr;
 740
 741       x = dos_baudconv (rate);
 742       if (x <= 0)
 743         {
 744           fprintf_unfiltered (gdb_stderr, "%d: impossible baudrate\n", rate);
 745           errno = EINVAL;
 746           return -1;
 747         }
 748
 749       disable ();
 750       cfcr = inb (port, com_cfcr);
 751
 752       outb (port, com_cfcr, CFCR_DLAB);
 753       outb (port, com_dlbl, x & 0xff);
 754       outb (port, com_dlbh, x >> 8);
 755       outb (port, com_cfcr, cfcr);
 756       port->baudrate = rate;
 757       enable ();
 758     }
 759
 760   return 0;
 761 }
 762
 763 static int
 764 dos_setstopbits (struct serial *scb, int num)
 765 {
 766   struct dos_ttystate *port = &ports[scb->fd];
 767   unsigned char cfcr;
 768
 769   disable ();
 770   cfcr = inb (port, com_cfcr);
 771
 772   switch (num)
 773     {
 774     case SERIAL_1_STOPBITS:
 775       outb (port, com_cfcr, cfcr & ~CFCR_STOPB);
 776       break;
 777     case SERIAL_1_AND_A_HALF_STOPBITS:
 778     case SERIAL_2_STOPBITS:
 779       outb (port, com_cfcr, cfcr | CFCR_STOPB);
 780       break;
 781     default:
 782       enable ();
 783       return 1;
 784     }
 785   enable ();
 786
 787   return 0;
 788 }
 789
 790 static int
 791 dos_write (struct serial *scb, const char *str, int len)
 792 {
 793   volatile struct dos_ttystate *port = &ports[scb->fd];
 794   int fifosize = port->fifo ? 16 : 1;
 795   long then;
 796   int cnt;
 797
 798   while (len > 0)
 799     {
 800       /* Send the data, fifosize bytes at a time.  */
 801       cnt = fifosize > len ? len : fifosize;
 802       port->txbusy = 1;
 803       /* Francisco Pastor <fpastor.etra-id@etra.es> says OUTSB messes
 804          up the communications with UARTs with FIFOs.  */
 805 #ifdef UART_FIFO_WORKS
 806       outportsb (port->base + com_data, str, cnt);
 807       str += cnt;
 808       len -= cnt;
 809 #else
 810       for ( ; cnt > 0; cnt--, len--)
 811         outportb (port->base + com_data, *str++);
 812 #endif
 813 #ifdef DOS_STATS
 814       cnts[CNT_TX] += cnt;
 815 #endif
 816       /* Wait for transmission to complete (max 1 sec).  */
 817       then = rawclock () + RAWHZ;
 818       while (port->txbusy)
 819         {
 820           if ((rawclock () - then) >= 0)
 821             {
 822               errno = EIO;
 823               return SERIAL_ERROR;
 824             }
 825         }
 826     }
 827   return 0;
 828 }
 829
 830
 831 static int
 832 dos_sendbreak (struct serial *scb)
 833 {
 834   volatile struct dos_ttystate *port = &ports[scb->fd];
 835   unsigned char cfcr;
 836   long then;
 837
 838   cfcr = inb (port, com_cfcr);
 839   outb (port, com_cfcr, cfcr | CFCR_SBREAK);
 840
 841   /* 0.25 sec delay */
 842   then = rawclock () + RAWHZ / 4;
 843   while ((rawclock () - then) < 0)
 844     continue;
 845
 846   outb (port, com_cfcr, cfcr);
 847   return 0;
 848 }
 849
 850
 851 static struct serial_ops dos_ops =
 852 {
 853   "hardwire",
 854   0,
 855   dos_open,
 856   dos_close,
 857   NULL,                         /* fdopen, not implemented */
 858   dos_readchar,
 859   dos_write,
 860   dos_noop,                     /* flush output */
 861   dos_flush_input,
 862   dos_sendbreak,
 863   dos_raw,
 864   dos_get_tty_state,
 865   dos_copy_tty_state,
 866   dos_set_tty_state,
 867   dos_print_tty_state,
 868   dos_noflush_set_tty_state,
 869   dos_setbaudrate,
 870   dos_setstopbits,
 871   dos_noop,                     /* Wait for output to drain.  */
 872   (void (*)(struct serial *, int))NULL  /* Change into async mode.  */
 873 };
 874
 875 int
 876 gdb_pipe (int pdes[2])
 877 {
 878   /* No support for pipes.  */
 879   errno = ENOSYS;
 880   return -1;
 881 }
 882
 883 static void
 884 dos_info (char *arg, int from_tty)
 885 {
 886   struct dos_ttystate *port;
 887 #ifdef DOS_STATS
 888   int i;
 889 #endif
 890
 891   for (port = ports; port < &ports[4]; port++)
 892     {
 893       if (port->baudrate == 0)
 894         continue;
 895       printf_filtered ("Port:\tCOM%ld (%sactive)\n", (long)(port - ports) + 1,
 896                        port->intrupt ? "" : "not ");
 897       printf_filtered ("Addr:\t0x%03x (irq %d)\n", port->base, port->irq);
 898       printf_filtered ("16550:\t%s\n", port->fifo ? "yes" : "no");
 899       printf_filtered ("Speed:\t%d baud\n", port->baudrate);
 900       printf_filtered ("Errs:\tframing %d parity %d overflow %d\n\n",
 901                        port->ferr, port->perr, port->oflo);
 902     }
 903
 904 #ifdef DOS_STATS
 905   printf_filtered ("\nTotal interrupts: %d\n", intrcnt);
 906   for (i = 0; i < NCNT; i++)
 907     if (cnts[i])
 908       printf_filtered ("%s:\t%d\n", cntnames[i], cnts[i]);
 909 #endif
 910 }
 911
 912
 913 void
 914 _initialize_ser_dos (void)
 915 {
 916   serial_add_interface (&dos_ops);
 917
 918   /* Save original interrupt mask register.  */
 919   icu_oldmask = inportb (ICU_MASK);
 920
 921   /* Mark fixed motherboard irqs as inuse.  */
 922   intrupts[0].inuse =           /* timer tick */
 923     intrupts[1].inuse =         /* keyboard */
 924     intrupts[2].inuse = 1;      /* slave icu */
 925
 926   add_setshow_zinteger_cmd ("com1base", class_obscure, &ports[0].base, _("\
 927 Set COM1 base i/o port address."), _("\
 928 Show COM1 base i/o port address."), NULL,
 929                             NULL,
 930                             NULL, /* FIXME: i18n: */
 931                             &setlist, &showlist);
 932
 933   add_setshow_zinteger_cmd ("com1irq", class_obscure, &ports[0].irq, _("\
 934 Set COM1 interrupt request."), _("\
 935 Show COM1 interrupt request."), NULL,
 936                             NULL,
 937                             NULL, /* FIXME: i18n: */
 938                             &setlist, &showlist);
 939
 940   add_setshow_zinteger_cmd ("com2base", class_obscure, &ports[1].base, _("\
 941 Set COM2 base i/o port address."), _("\
 942 Show COM2 base i/o port address."), NULL,
 943                             NULL,
 944                             NULL, /* FIXME: i18n: */
 945                             &setlist, &showlist);
 946
 947   add_setshow_zinteger_cmd ("com2irq", class_obscure, &ports[1].irq, _("\
 948 Set COM2 interrupt request."), _("\
 949 Show COM2 interrupt request."), NULL,
 950                             NULL,
 951                             NULL, /* FIXME: i18n: */
 952                             &setlist, &showlist);
 953
 954   add_setshow_zinteger_cmd ("com3base", class_obscure, &ports[2].base, _("\
 955 Set COM3 base i/o port address."), _("\
 956 Show COM3 base i/o port address."), NULL,
 957                             NULL,
 958                             NULL, /* FIXME: i18n: */
 959                             &setlist, &showlist);
 960
 961   add_setshow_zinteger_cmd ("com3irq", class_obscure, &ports[2].irq, _("\
 962 Set COM3 interrupt request."), _("\
 963 Show COM3 interrupt request."), NULL,
 964                             NULL,
 965                             NULL, /* FIXME: i18n: */
 966                             &setlist, &showlist);
 967
 968   add_setshow_zinteger_cmd ("com4base", class_obscure, &ports[3].base, _("\
 969 Set COM4 base i/o port address."), _("\
 970 Show COM4 base i/o port address."), NULL,
 971                             NULL,
 972                             NULL, /* FIXME: i18n: */
 973                             &setlist, &showlist);
 974
 975   add_setshow_zinteger_cmd ("com4irq", class_obscure, &ports[3].irq, _("\
 976 Set COM4 interrupt request."), _("\
 977 Show COM4 interrupt request."), NULL,
 978                             NULL,
 979                             NULL, /* FIXME: i18n: */
 980                             &setlist, &showlist);
 981
 982   add_info ("serial", dos_info,
 983             _("Print DOS serial port status."));
 984 }