sim/common/dv-pal.c

   1 /* The common simulator framework for GDB, the GNU Debugger.
   2
   3    Copyright 2002-2024 Free Software Foundation, Inc.
   4
   5    Contributed by Andrew Cagney and Red Hat.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 /* This must come before any other includes.  */
  23 #include "defs.h"
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28
  29 #include "sim-main.h"
  30 #include "hw-main.h"
  31 #include "sim-io.h"
  32
  33 /* NOTE: pal is naughty and grubs around looking at things outside of
  34    its immediate domain */
  35 #include "hw-tree.h"
  36
  37 /* DEVICE
  38
  39
  40    pal - glue logic device containing assorted junk
  41
  42
  43    DESCRIPTION
  44
  45
  46    Typical hardware dependant hack.  This device allows the firmware
  47    to gain access to all the things the firmware needs (but the OS
  48    doesn't).
  49
  50    The pal contains the following registers:
  51
  52    |0   reset register (write, 8bit)
  53    |4   processor id register (read, 8bit)
  54    |8   interrupt register (8 - port, 9 - level) (write, 16bit)
  55    |12  processor count register (read, 8bit)
  56
  57    |16  tty input fifo register (read, 8bit)
  58    |20  tty input status register (read, 8bit)
  59    |24  tty output fifo register (write, 8bit)
  60    |28  tty output status register (read, 8bit)
  61
  62    |32  countdown register (read/write, 32bit, big-endian)
  63    |36  countdown value register (read, 32bit, big-endian)
  64    |40  timer register (read/write, 32bit, big-endian)
  65    |44  timer value register (read, 32bit, big-endian)
  66
  67    RESET (write): halts the simulator.  The value written to the
  68    register is used as an exit status.
  69
  70    PROCESSOR ID (read): returns the processor identifier (0 .. N-1) of
  71    the processor performing the read.
  72
  73    INTERRUPT (write): This register must be written using a two byte
  74    store.  The low byte specifies a port and the upper byte specifies
  75    the a level.  LEVEL is driven on the specified port.  By
  76    convention, the pal's interrupt ports (int0, int1, ...) are wired
  77    up to the corresponding processor's level sensative external
  78    interrupt pin.  Eg: A two byte write to address 8 of 0x0102
  79    (big-endian) will result in processor 2's external interrupt pin
  80    being asserted.
  81
  82    PROCESSOR COUNT (read): returns the total number of processors
  83    active in the current simulation.
  84
  85    TTY INPUT FIFO (read): if the TTY input status register indicates a
  86    character is available by being nonzero, returns the next available
  87    character from the pal's tty input port.
  88
  89    TTY OUTPUT FIFO (write): if the TTY output status register
  90    indicates the output fifo is not full by being nonzero, outputs the
  91    character written to the tty's output port.
  92
  93    COUNDOWN (read/write): The countdown registers provide a
  94    non-repeating timed interrupt source.  Writing a 32 bit big-endian
  95    zero value to this register clears the countdown timer.  Writing a
  96    non-zero 32 bit big-endian value to this register sets the
  97    countdown timer to expire in VALUE ticks (ticks is target
  98    dependant).  Reading the countdown register returns the last value
  99    written.
 100
 101    COUNTDOWN VALUE (read): Reading this 32 bit big-endian register
 102    returns the number of ticks remaining until the countdown timer
 103    expires.
 104
 105    TIMER (read/write): The timer registers provide a periodic timed
 106    interrupt source.  Writing a 32 bit big-endian zero value to this
 107    register clears the periodic timer.  Writing a 32 bit non-zero
 108    value to this register sets the periodic timer to triger every
 109    VALUE ticks (ticks is target dependant).  Reading the timer
 110    register returns the last value written.
 111
 112    TIMER VALUE (read): Reading this 32 bit big-endian register returns
 113    the number of ticks until the next periodic interrupt.
 114
 115
 116    PROPERTIES
 117
 118
 119    reg = <address> <size> (required)
 120
 121    Specify the address (within the parent bus) that this device is to
 122    be located.
 123
 124    poll? = <boolean>
 125
 126    If present and true, indicates that the device should poll its
 127    input.
 128
 129
 130    PORTS
 131
 132
 133    int[0..NR_PROCESSORS] (output)
 134
 135    Driven as a result of a write to the interrupt-port /
 136    interrupt-level register pair.
 137
 138
 139    countdown
 140
 141    Driven whenever the countdown counter reaches zero.
 142
 143
 144    timer
 145
 146    Driven whenever the timer counter reaches zero.
 147
 148
 149    BUGS
 150
 151
 152    At present the common simulator framework does not support input
 153    polling.
 154
 155    */
 156
 157
 158 enum {
 159   hw_pal_reset_register = 0x0,
 160   hw_pal_cpu_nr_register = 0x4,
 161   hw_pal_int_register = 0x8,
 162   hw_pal_nr_cpu_register = 0xa,
 163   hw_pal_read_fifo = 0x10,
 164   hw_pal_read_status = 0x14,
 165   hw_pal_write_fifo = 0x18,
 166   hw_pal_write_status = 0x1a,
 167   hw_pal_countdown = 0x20,
 168   hw_pal_countdown_value = 0x24,
 169   hw_pal_timer = 0x28,
 170   hw_pal_timer_value = 0x2c,
 171   hw_pal_address_mask = 0x3f,
 172 };
 173
 174
 175 typedef struct _hw_pal_console_buffer {
 176   char buffer;
 177   int status;
 178 } hw_pal_console_buffer;
 179
 180 typedef struct _hw_pal_counter {
 181   struct hw_event *handler;
 182   int64_t start;
 183   uint32_t delta;
 184   int periodic_p;
 185 } hw_pal_counter;
 186
 187
 188 typedef struct _hw_pal_device {
 189   hw_pal_console_buffer input;
 190   hw_pal_console_buffer output;
 191   hw_pal_counter countdown;
 192   hw_pal_counter timer;
 193   struct hw *disk;
 194   do_hw_poll_read_method *reader;
 195 } hw_pal_device;
 196
 197 enum {
 198   COUNTDOWN_PORT,
 199   TIMER_PORT,
 200   INT_PORT,
 201 };
 202
 203 static const struct hw_port_descriptor hw_pal_ports[] = {
 204   { "countdown", COUNTDOWN_PORT, 0, output_port, },
 205   { "timer", TIMER_PORT, 0, output_port, },
 206   { "int", INT_PORT, MAX_NR_PROCESSORS, output_port, },
 207   { NULL, 0, 0, 0 }
 208 };
 209
 210
 211 /* countdown and simple timer */
 212
 213 static void
 214 do_counter_event (struct hw *me,
 215                   void *data)
 216 {
 217   hw_pal_counter *counter = (hw_pal_counter *) data;
 218   if (counter->periodic_p)
 219     {
 220       HW_TRACE ((me, "timer expired"));
 221       counter->start = hw_event_queue_time (me);
 222       hw_port_event (me, TIMER_PORT, 1);
 223       hw_event_queue_schedule (me, counter->delta, do_counter_event, counter);
 224     }
 225   else
 226     {
 227       HW_TRACE ((me, "countdown expired"));
 228       counter->delta = 0;
 229       hw_port_event (me, COUNTDOWN_PORT, 1);
 230     }
 231 }
 232
 233 static void
 234 do_counter_read (struct hw *me,
 235                  hw_pal_device *pal,
 236                  const char *reg,
 237                  hw_pal_counter *counter,
 238                  uint32_t *word,
 239                  unsigned nr_bytes)
 240 {
 241   uint32_t val;
 242   if (nr_bytes != 4)
 243     hw_abort (me, "%s - bad read size must be 4 bytes", reg);
 244   val = counter->delta;
 245   HW_TRACE ((me, "read - %s %ld", reg, (long) val));
 246   *word = H2BE_4 (val);
 247 }
 248
 249 static void
 250 do_counter_value (struct hw *me,
 251                   hw_pal_device *pal,
 252                   const char *reg,
 253                   hw_pal_counter *counter,
 254                   uint32_t *word,
 255                   unsigned nr_bytes)
 256 {
 257   uint32_t val;
 258   if (nr_bytes != 4)
 259     hw_abort (me, "%s - bad read size must be 4 bytes", reg);
 260   if (counter->delta != 0)
 261     val = (counter->start + counter->delta
 262            - hw_event_queue_time (me));
 263   else
 264     val = 0;
 265   HW_TRACE ((me, "read - %s %ld", reg, (long) val));
 266   *word = H2BE_4 (val);
 267 }
 268
 269 static void
 270 do_counter_write (struct hw *me,
 271                   hw_pal_device *pal,
 272                   const char *reg,
 273                   hw_pal_counter *counter,
 274                   const uint32_t *word,
 275                   unsigned nr_bytes)
 276 {
 277   if (nr_bytes != 4)
 278     hw_abort (me, "%s - bad write size must be 4 bytes", reg);
 279   if (counter->handler != NULL)
 280     {
 281       hw_event_queue_deschedule (me, counter->handler);
 282       counter->handler = NULL;
 283     }
 284   counter->delta = BE2H_4 (*word);
 285   counter->start = hw_event_queue_time (me);
 286   HW_TRACE ((me, "write - %s %ld", reg, (long) counter->delta));
 287   if (counter->delta > 0)
 288     hw_event_queue_schedule (me, counter->delta, do_counter_event, counter);
 289 }
 290
 291
 292
 293
 294 /* check the console for an available character */
 295 static void
 296 scan_hw_pal (struct hw *me)
 297 {
 298   hw_pal_device *hw_pal = (hw_pal_device *)hw_data (me);
 299   char c;
 300   int count;
 301   count = do_hw_poll_read (me, hw_pal->reader, 0/*STDIN*/, &c, sizeof (c));
 302   switch (count)
 303     {
 304     case HW_IO_NOT_READY:
 305     case HW_IO_EOF:
 306       hw_pal->input.buffer = 0;
 307       hw_pal->input.status = 0;
 308       break;
 309     default:
 310       hw_pal->input.buffer = c;
 311       hw_pal->input.status = 1;
 312     }
 313 }
 314
 315 /* write the character to the hw_pal */
 316
 317 static void
 318 write_hw_pal (struct hw *me,
 319               char val)
 320 {
 321   hw_pal_device *hw_pal = (hw_pal_device *) hw_data (me);
 322   sim_io_write_stdout (hw_system (me), &val, 1);
 323   hw_pal->output.buffer = val;
 324   hw_pal->output.status = 1;
 325 }
 326
 327
 328 /* Reads/writes */
 329
 330 static unsigned
 331 hw_pal_io_read_buffer (struct hw *me,
 332                        void *dest,
 333                        int space,
 334                        unsigned_word addr,
 335                        unsigned nr_bytes)
 336 {
 337   hw_pal_device *hw_pal = (hw_pal_device *) hw_data (me);
 338   unsigned_1 *byte = (unsigned_1 *) dest;
 339   memset (dest, 0, nr_bytes);
 340   switch (addr & hw_pal_address_mask)
 341     {
 342
 343     case hw_pal_cpu_nr_register:
 344       *byte = CPU_INDEX (hw_system_cpu (me));
 345       HW_TRACE ((me, "read - cpu-nr %d\n", *byte));
 346       break;
 347
 348     case hw_pal_nr_cpu_register:
 349       if (hw_tree_find_property (me, "/openprom/options/smp") == NULL)
 350         {
 351           *byte = 1;
 352           HW_TRACE ((me, "read - nr-cpu %d (not defined)\n", *byte));
 353         }
 354       else
 355         {
 356           *byte = hw_tree_find_integer_property (me, "/openprom/options/smp");
 357           HW_TRACE ((me, "read - nr-cpu %d\n", *byte));
 358         }
 359       break;
 360
 361     case hw_pal_read_fifo:
 362       *byte = hw_pal->input.buffer;
 363       HW_TRACE ((me, "read - input-fifo %d\n", *byte));
 364       break;
 365
 366     case hw_pal_read_status:
 367       scan_hw_pal (me);
 368       *byte = hw_pal->input.status;
 369       HW_TRACE ((me, "read - input-status %d\n", *byte));
 370       break;
 371
 372     case hw_pal_write_fifo:
 373       *byte = hw_pal->output.buffer;
 374       HW_TRACE ((me, "read - output-fifo %d\n", *byte));
 375       break;
 376
 377     case hw_pal_write_status:
 378       *byte = hw_pal->output.status;
 379       HW_TRACE ((me, "read - output-status %d\n", *byte));
 380       break;
 381
 382     case hw_pal_countdown:
 383       do_counter_read (me, hw_pal, "countdown",
 384                        &hw_pal->countdown, dest, nr_bytes);
 385       break;
 386
 387     case hw_pal_countdown_value:
 388       do_counter_value (me, hw_pal, "countdown-value",
 389                         &hw_pal->countdown, dest, nr_bytes);
 390       break;
 391
 392     case hw_pal_timer:
 393       do_counter_read (me, hw_pal, "timer",
 394                        &hw_pal->timer, dest, nr_bytes);
 395       break;
 396
 397     case hw_pal_timer_value:
 398       do_counter_value (me, hw_pal, "timer-value",
 399                         &hw_pal->timer, dest, nr_bytes);
 400       break;
 401
 402     default:
 403       HW_TRACE ((me, "read - ???\n"));
 404       break;
 405
 406     }
 407   return nr_bytes;
 408 }
 409
 410
 411 static unsigned
 412 hw_pal_io_write_buffer (struct hw *me,
 413                         const void *source,
 414                         int space,
 415                         unsigned_word addr,
 416                         unsigned nr_bytes)
 417 {
 418   hw_pal_device *hw_pal = (hw_pal_device*) hw_data (me);
 419   unsigned_1 *byte = (unsigned_1 *) source;
 420
 421   switch (addr & hw_pal_address_mask)
 422     {
 423
 424     case hw_pal_reset_register:
 425       hw_halt (me, sim_exited, byte[0]);
 426       break;
 427
 428     case hw_pal_int_register:
 429       hw_port_event (me,
 430                      INT_PORT + byte[0], /*port*/
 431                      (nr_bytes > 1 ? byte[1] : 0)); /* val */
 432       break;
 433
 434     case hw_pal_read_fifo:
 435       hw_pal->input.buffer = byte[0];
 436       HW_TRACE ((me, "write - input-fifo %d\n", byte[0]));
 437       break;
 438
 439     case hw_pal_read_status:
 440       hw_pal->input.status = byte[0];
 441       HW_TRACE ((me, "write - input-status %d\n", byte[0]));
 442       break;
 443
 444     case hw_pal_write_fifo:
 445       write_hw_pal (me, byte[0]);
 446       HW_TRACE ((me, "write - output-fifo %d\n", byte[0]));
 447       break;
 448
 449     case hw_pal_write_status:
 450       hw_pal->output.status = byte[0];
 451       HW_TRACE ((me, "write - output-status %d\n", byte[0]));
 452       break;
 453
 454     case hw_pal_countdown:
 455       do_counter_write (me, hw_pal, "countdown",
 456                         &hw_pal->countdown, source, nr_bytes);
 457       break;
 458
 459     case hw_pal_timer:
 460       do_counter_write (me, hw_pal, "timer",
 461                         &hw_pal->timer, source, nr_bytes);
 462       break;
 463
 464     }
 465   return nr_bytes;
 466 }
 467
 468
 469 /* instances of the hw_pal struct hw */
 470
 471 #if NOT_YET
 472 static void
 473 hw_pal_instance_delete_callback (hw_instance *instance)
 474 {
 475   /* nothing to delete, the hw_pal is attached to the struct hw */
 476   return;
 477 }
 478 #endif
 479
 480 #if NOT_YET
 481 static int
 482 hw_pal_instance_read_callback (hw_instance *instance,
 483                               void *buf,
 484                               unsigned_word len)
 485 {
 486   DITRACE (pal, ("read - %s (%ld)", (const char*) buf, (long int) len));
 487   return sim_io_read_stdin (buf, len);
 488 }
 489 #endif
 490
 491 #if NOT_YET
 492 static int
 493 hw_pal_instance_write_callback (hw_instance *instance,
 494                                 const void *buf,
 495                                 unsigned_word len)
 496 {
 497   int i;
 498   const char *chp = buf;
 499   hw_pal_device *hw_pal = hw_instance_data (instance);
 500   DITRACE (pal, ("write - %s (%ld)", (const char*) buf, (long int) len));
 501   for (i = 0; i < len; i++)
 502     write_hw_pal (hw_pal, chp[i]);
 503   sim_io_flush_stdoutput ();
 504   return i;
 505 }
 506 #endif
 507
 508 #if NOT_YET
 509 static const hw_instance_callbacks hw_pal_instance_callbacks = {
 510   hw_pal_instance_delete_callback,
 511   hw_pal_instance_read_callback,
 512   hw_pal_instance_write_callback,
 513 };
 514 #endif
 515
 516 #if 0
 517 static hw_instance *
 518 hw_pal_create_instance (struct hw *me,
 519                         const char *path,
 520                         const char *args)
 521 {
 522   return hw_create_instance_from (me, NULL,
 523                                       hw_data (me),
 524                                       path, args,
 525                                       &hw_pal_instance_callbacks);
 526 }
 527 #endif
 528
 529
 530 static void
 531 hw_pal_attach_address (struct hw *me,
 532                        int level,
 533                        int space,
 534                        address_word addr,
 535                        address_word nr_bytes,
 536                        struct hw *client)
 537 {
 538   hw_pal_device *pal = (hw_pal_device*) hw_data (me);
 539   pal->disk = client;
 540 }
 541
 542
 543 #if 0
 544 static hw_callbacks const hw_pal_callbacks = {
 545   { generic_hw_init_address, },
 546   { hw_pal_attach_address, }, /* address */
 547   { hw_pal_io_read_buffer_callback,
 548       hw_pal_io_write_buffer_callback, },
 549   { NULL, }, /* DMA */
 550   { NULL, NULL, hw_pal_interrupt_ports }, /* interrupt */
 551   { generic_hw_unit_decode,
 552     generic_hw_unit_encode,
 553     generic_hw_address_to_attach_address,
 554     generic_hw_size_to_attach_size },
 555   hw_pal_create_instance,
 556 };
 557 #endif
 558
 559
 560 static void
 561 hw_pal_finish (struct hw *hw)
 562 {
 563   /* create the descriptor */
 564   hw_pal_device *hw_pal = HW_ZALLOC (hw, hw_pal_device);
 565   hw_pal->output.status = 1;
 566   hw_pal->output.buffer = '\0';
 567   hw_pal->input.status = 0;
 568   hw_pal->input.buffer = '\0';
 569   set_hw_data (hw, hw_pal);
 570   set_hw_attach_address (hw, hw_pal_attach_address);
 571   set_hw_io_read_buffer (hw, hw_pal_io_read_buffer);
 572   set_hw_io_write_buffer (hw, hw_pal_io_write_buffer);
 573   set_hw_ports (hw, hw_pal_ports);
 574   /* attach ourselves */
 575   do_hw_attach_regs (hw);
 576   /* If so configured, enable polled input */
 577   if (hw_find_property (hw, "poll?") != NULL
 578       && hw_find_boolean_property (hw, "poll?"))
 579     {
 580       hw_pal->reader = sim_io_poll_read;
 581     }
 582   else
 583     {
 584       hw_pal->reader = sim_io_read;
 585     }
 586   /* tag the periodic timer */
 587   hw_pal->timer.periodic_p = 1;
 588 }
 589
 590
 591 const struct hw_descriptor dv_pal_descriptor[] = {
 592   { "pal", hw_pal_finish, },
 593   { NULL, NULL },
 594 };