sim/ppc/emul_bugapi.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright (C) 1994-1997, Andrew Cagney <cagney@highland.com.au>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, see <http://www.gnu.org/licenses/>.
  17
  18     */
  19
  20
  21 #ifndef _EMUL_BUGAPI_C_
  22 #define _EMUL_BUGAPI_C_
  23
  24 /* Note: this module is called via a table.  There is no benefit in
  25    making it inline */
  26
  27 #include "emul_generic.h"
  28 #include "emul_bugapi.h"
  29
  30 #ifdef HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33
  34 #ifdef HAVE_STDLIB_H
  35 #include <stdlib.h>
  36 #endif
  37
  38 #ifdef HAVE_STRING_H
  39 #include <string.h>
  40 #else
  41 #ifdef HAVE_STRINGS_H
  42 #include <strings.h>
  43 #endif
  44 #endif
  45
  46
  47 /* EMULATION
  48
  49    BUG - Motorola's embeded firmware BUG interface
  50
  51    DESCRIPTION
  52
  53
  54
  55    */
  56
  57
  58 /* from PowerPCBug Debugging Package User's Manual, part 2 of 2 and also bug.S - Dale Rahn */
  59 #define _INCHR          0x000           /* Input character */
  60 #define _INSTAT         0x001           /* Input serial port status */
  61 #define _INLN           0x002           /* Input line (pointer / pointer format) */
  62 #define _READSTR        0x003           /* Input string (pointer / count format) */
  63 #define _READLN         0x004           /* Input line (pointer / count format) */
  64 #define _CHKBRK         0x005           /* Check for break */
  65 #define _DSKRD          0x010           /* Disk read */
  66 #define _DSKWR          0x011           /* Disk write */
  67 #define _DSKCFIG        0x012           /* Disk configure */
  68 #define _DSKFMT         0x014           /* Disk format */
  69 #define _DSKCTRL        0x015           /* Disk control */
  70 #define _NETRD          0x018           /* Read from host */
  71 #define _NETWR          0x019           /* Write to host */
  72 #define _NETCFIG        0x01a           /* Configure network parameters */
  73 #define _NETOPN         0x01b           /* Open file for reading */
  74 #define _NETFRD         0x01c           /* Retreive specified file blocks */
  75 #define _NETCTRL        0x01d           /* Implement special control functions */
  76 #define _OUTCHR         0x020           /* Output character (pointer / pointer format) */
  77 #define _OUTSTR         0x021           /* Output string (pointer / pointer format) */
  78 #define _OUTLN          0x022           /* Output line (pointer / pointer format) */
  79 #define _WRITE          0x023           /* Output string (pointer / count format) */
  80 #define _WRITELN        0x024           /* Output line (pointer / count format) */
  81 #define _WRITDLN        0x025           /* Output line with data (pointer / count format) */
  82 #define _PCRLF          0x026           /* Output carriage return and line feed */
  83 #define _ERASLN         0x027           /* Erase line */
  84 #define _WRITD          0x028           /* Output string with data (pointer / count format) */
  85 #define _SNDBRK         0x029           /* Send break */
  86 #define _DELAY          0x043           /* Timer delay */
  87 #define _RTC_TM         0x050           /* Time initialization for RTC */
  88 #define _RTC_DT         0x051           /* Date initialization for RTC */
  89 #define _RTC_DSP        0x052           /* Display RTC time and date */
  90 #define _RTC_RD         0x053           /* Read the RTC registers */
  91 #define _REDIR          0x060           /* Redirect I/O of a system call function */
  92 #define _REDIR_I        0x061           /* Redirect input */
  93 #define _REDIR_O        0x062           /* Redirect output */
  94 #define _RETURN         0x063           /* Return to PPCbug */
  95 #define _BINDEC         0x064           /* Convert binary to binary coded decimal (BCD) */
  96 #define _CHANGEV        0x067           /* Parse value */
  97 #define _STRCMP         0x068           /* Compare two strings (pointer / count format) */
  98 #define _MULU32         0x069           /* Multiply two 32-bit unsigned integers */
  99 #define _DIVU32         0x06a           /* Divide two 32-bit unsigned integers */
 100 #define _CHK_SUM        0x06b           /* Generate checksum */
 101 #define _BRD_ID         0x070           /* Return pointer to board ID packet */
 102 #define _ENVIRON        0x071           /* Access boot environment parameters */
 103 #define _DIAGFCN        0x074           /* Diagnostic function(s) */
 104 #define _SIOPEPS        0x090           /* Retrieve SCSI pointers */
 105 #define _IOINQ          0x120           /* Port inquire */
 106 #define _IOINFORM       0x124           /* Port inform */
 107 #define _IOCONFIG       0x128           /* Port configure */
 108 #define _IODELETE       0x12c           /* Port delete */
 109 #define _SYMBOLTA       0x130           /* Attach symbol table */
 110 #define _SYMBOLDA       0x131           /* Detach symbol table */
 111
 112 struct bug_map {
 113   int value;
 114   const char *info;
 115 };
 116
 117 static const struct bug_map bug_mapping[] = {
 118   { _INCHR,     ".INCHR -- Input character" },
 119   { _INSTAT,    ".INSTAT -- Input serial port status" },
 120   { _INLN,      ".INLN -- Input line (pointer / pointer format)" },
 121   { _READSTR,   ".READSTR -- Input string (pointer / count format)" },
 122   { _READLN,    ".READLN -- Input line (pointer / count format)" },
 123   { _CHKBRK,    ".CHKBRK -- Check for break" },
 124   { _DSKRD,     ".DSKRD -- Disk read" },
 125   { _DSKWR,     ".DSKWR -- Disk write" },
 126   { _DSKCFIG,   ".DSKCFIG -- Disk configure" },
 127   { _DSKFMT,    ".DSKFMT -- Disk format" },
 128   { _DSKCTRL,   ".DSKCTRL -- Disk control" },
 129   { _NETRD,     ".NETRD -- Read from host" },
 130   { _NETWR,     ".NETWR -- Write to host" },
 131   { _NETCFIG,   ".NETCFIG -- Configure network parameters" },
 132   { _NETOPN,    ".NETOPN -- Open file for reading" },
 133   { _NETFRD,    ".NETFRD -- Retreive specified file blocks" },
 134   { _NETCTRL,   ".NETCTRL -- Implement special control functions" },
 135   { _OUTCHR,    ".OUTCHR -- Output character" },
 136   { _OUTSTR,    ".OUTSTR -- Output string (pointer / pointer format)" },
 137   { _OUTLN,     ".OUTLN -- Output line (pointer / pointer format)" },
 138   { _WRITE,     ".WRITE -- Output string (pointer / count format)" },
 139   { _WRITELN,   ".WRITELN -- Output line (pointer / count format)" },
 140   { _WRITDLN,   ".WRITDLN -- Output line with data (pointer / count format)" },
 141   { _PCRLF,     ".PCRLF -- Output carriage return and line feed" },
 142   { _ERASLN,    ".ERASLN -- Erase line" },
 143   { _WRITD,     ".WRITD -- Output string with data (pointer / count format)" },
 144   { _SNDBRK,    ".SNDBRK -- Send break" },
 145   { _DELAY,     ".DELAY -- Timer delay" },
 146   { _RTC_TM,    ".RTC_TM -- Time initialization for RTC" },
 147   { _RTC_DT,    ".RTC_DT -- Date initialization for RTC" },
 148   { _RTC_DSP,   ".RTC_DSP -- Display RTC time and date" },
 149   { _RTC_RD,    ".RTC_RD -- Read the RTC registers" },
 150   { _REDIR,     ".REDIR -- Redirect I/O of a system call function" },
 151   { _REDIR,     ".REDIR -- Redirect input" },
 152   { _REDIR,     ".REDIR -- Redirect output" },
 153   { _RETURN,    ".RETURN -- Return to PPCbug" },
 154   { _BINDEC,    ".BINDEC -- Convert binary to binary coded decimal (BCD)" },
 155   { _CHANGEV,   ".CHANGEV -- Parse value" },
 156   { _STRCMP,    ".STRCMP -- Compare two strings (pointer / count format)" },
 157   { _MULU32,    ".MULU32 -- Multiply two 32-bit unsigned integers" },
 158   { _DIVU32,    ".DIVU32 -- Divide two 32-bit unsigned integers" },
 159   { _CHK_SUM,   ".CHK_SUM -- Generate checksum" },
 160   { _BRD_ID,    ".BRD_ID -- Return pointer to board ID packet" },
 161   { _ENVIRON,   ".ENVIRON -- Access boot environment parameters" },
 162   { _DIAGFCN,   ".DIAGFCN -- Diagnostic function(s)" },
 163   { _SIOPEPS,   ".SIOPEPS -- Retrieve SCSI pointers" },
 164   { _IOINQ,     ".IOINQ -- Port inquire" },
 165   { _IOINFORM,  ".IOINFORM -- Port inform" },
 166   { _IOCONFIG,  ".IOCONFIG -- Port configure" },
 167   { _IODELETE,  ".IODELETE -- Port delete" },
 168   { _SYMBOLTA,  ".SYMBOLTA -- Attach symbol table" },
 169   { _SYMBOLDA,  ".SYMBOLDA -- Detach symbol table" },
 170 };
 171
 172 #ifndef BUGAPI_END_ADDRESS
 173 #define BUGAPI_END_ADDRESS 0x100000
 174 #endif
 175
 176 enum {
 177   nr_bugapi_disks = 2,
 178 };
 179
 180
 181 struct _os_emul_data {
 182   device *root;
 183   unsigned_word memory_size;
 184   unsigned_word top_of_stack;
 185   int interrupt_prefix;
 186   unsigned_word interrupt_vector_address;
 187   unsigned_word system_call_address;
 188   unsigned_word stall_cpu_loop_address;
 189   int little_endian;
 190   int floating_point_available;
 191   /* I/O devices */
 192   device_instance *output;
 193   device_instance *input;
 194   device_instance *(disk[nr_bugapi_disks]);
 195 };
 196
 197
 198 static os_emul_data *
 199 emul_bugapi_create(device *root,
 200                    bfd *image,
 201                    const char *name)
 202 {
 203   device *node;
 204   os_emul_data *bugapi;
 205   char *filename;
 206
 207   /* check it really is for us */
 208   if (name != NULL
 209       && strcmp(name, "bugapi") != 0
 210       && strcmp(name, "bug") != 0)
 211     return NULL;
 212   if (image != NULL
 213       && name == NULL
 214       && bfd_get_start_address(image) >= BUGAPI_END_ADDRESS)
 215     return NULL;
 216
 217   bugapi = ZALLOC(os_emul_data);
 218
 219   /* options */
 220   emul_add_tree_options(root, image, "bug", "oea",
 221                         1 /*oea-interrupt-prefix*/);
 222
 223   /* add some real hardware, include eeprom memory for the eeprom trap
 224      addresses */
 225   emul_add_tree_hardware(root);
 226   node = tree_parse(root, "/openprom/memory@0xfff00000");
 227   tree_parse(node, "./psim,description \"eeprom trap addresses");
 228   tree_parse(node, "./reg 0xfff00000 0x3000");
 229
 230   bugapi->root = root;
 231
 232   bugapi->memory_size
 233     = tree_find_integer_property(root, "/openprom/options/oea-memory-size");
 234   bugapi->interrupt_prefix =
 235     tree_find_integer_property(root, "/openprom/options/oea-interrupt-prefix");
 236   bugapi->interrupt_vector_address = (bugapi->interrupt_prefix
 237                                       ? MASK(0, 43)
 238                                       : 0);
 239   bugapi->system_call_address = (bugapi->interrupt_vector_address + 0x00c00);
 240   bugapi->stall_cpu_loop_address = (bugapi->system_call_address + 0x000f0);
 241   bugapi->top_of_stack = bugapi->memory_size - 0x1000;
 242   bugapi->little_endian
 243     = tree_find_boolean_property(root, "/options/little-endian?");
 244   bugapi->floating_point_available
 245     = tree_find_boolean_property(root, "/openprom/options/floating-point?");
 246   bugapi->input = NULL;
 247   bugapi->output = NULL;
 248
 249   /* initialization */
 250   if (image != NULL)
 251     tree_parse(root, "/openprom/init/register/0.pc 0x%lx",
 252                (unsigned long)bfd_get_start_address(image));
 253   tree_parse(root, "/openprom/init/register/pc 0x%lx",
 254              (unsigned long)bugapi->stall_cpu_loop_address);
 255   tree_parse(root, "/openprom/init/register/sp 0x%lx",
 256              (unsigned long)(bugapi->top_of_stack - 16));
 257   tree_parse(root, "/openprom/init/register/msr 0x%x",
 258              (msr_recoverable_interrupt
 259               | (bugapi->little_endian
 260                  ? (msr_little_endian_mode
 261                     | msr_interrupt_little_endian_mode)
 262                  : 0)
 263               | (bugapi->floating_point_available
 264                  ? msr_floating_point_available
 265                  : 0)
 266               | (bugapi->interrupt_prefix
 267                  ? msr_interrupt_prefix
 268                  : 0)
 269               ));
 270
 271   /* patch the system call instruction to call this emulation and then
 272      do an rfi */
 273   node = tree_parse(root, "/openprom/init/data@0x%lx",
 274                     (unsigned long)bugapi->system_call_address);
 275   tree_parse(node, "./psim,description \"system-call trap instruction");
 276   tree_parse(node, "./real-address 0x%lx",
 277              (unsigned long)bugapi->system_call_address);
 278   tree_parse(node, "./data 0x%x", emul_call_instruction);
 279   node = tree_parse(root, "/openprom/init/data@0x%lx",
 280                     (unsigned long)bugapi->system_call_address + 4);
 281   tree_parse(node, "./psim,description \"return from interrupt instruction");
 282   tree_parse(node, "./real-address 0x%lx",
 283              (unsigned long)bugapi->system_call_address + 4);
 284   tree_parse(node, "./data 0x%x",
 285              emul_rfi_instruction);
 286
 287   /* patch the end of the system call instruction so that it contains
 288      a loop to self instruction and point all the cpu's at this */
 289   node = tree_parse(root, "/openprom/init/data@0x%lx",
 290                     (unsigned long)bugapi->stall_cpu_loop_address);
 291   tree_parse(node, "./psim,description \"cpu-loop instruction");
 292   tree_parse(node, "./real-address 0x%lx",
 293              (unsigned long)bugapi->stall_cpu_loop_address);
 294   tree_parse(node, "./data 0x%lx",
 295              (unsigned long)emul_loop_instruction);
 296
 297   if (image != NULL)
 298     tree_parse(root, "/openprom/init/stack/stack-type %s",
 299                (image->xvec->flavour == bfd_target_elf_flavour
 300                 ? "ppc-elf"
 301                 : "ppc-xcoff"));
 302
 303   if (image != NULL)
 304     {
 305       filename = tree_quote_property (bfd_get_filename(image));
 306       tree_parse(root, "/openprom/init/load-binary/file-name %s",
 307                  filename);
 308       free (filename);
 309     }
 310
 311   return bugapi;
 312 }
 313
 314 static void
 315 emul_bugapi_init(os_emul_data *bugapi,
 316                  int nr_cpus)
 317 {
 318   int i;
 319   /* get the current input/output devices that were created during
 320      device tree initialization */
 321   bugapi->input = tree_find_ihandle_property(bugapi->root, "/chosen/stdin");
 322   bugapi->output = tree_find_ihandle_property(bugapi->root, "/chosen/stdout");
 323   /* if present, extract the selected disk devices */
 324   for (i = 0; i < nr_bugapi_disks; i++) {
 325     char disk[32];
 326     char *chp;
 327     strcpy(disk, "/chosen/disk0");
 328     ASSERT(sizeof(disk) > strlen(disk));
 329     chp = strchr(disk, '0');
 330     *chp = *chp + i;
 331     if (tree_find_property(bugapi->root, disk) != NULL)
 332       bugapi->disk[i] = tree_find_ihandle_property(bugapi->root, disk);
 333   }
 334 }
 335
 336 static const char *
 337 emul_bugapi_instruction_name(int call_id)
 338 {
 339   static char buffer[40];
 340   int i;
 341
 342   for (i = 0; i < ARRAY_SIZE (bug_mapping); i++)
 343     {
 344       if (bug_mapping[i].value == call_id)
 345         return bug_mapping[i].info;
 346     }
 347
 348   (void) sprintf (buffer, "Unknown bug call 0x%x", call_id);
 349   return buffer;
 350 }
 351
 352 static int
 353 emul_bugapi_do_read(os_emul_data *bugapi,
 354                     cpu *processor,
 355                     unsigned_word cia,
 356                     unsigned_word buf,
 357                     int nbytes)
 358 {
 359   unsigned char *scratch_buffer;
 360   int status;
 361
 362   /* get a tempoary bufer */
 363   scratch_buffer = (unsigned char *) zalloc(nbytes);
 364
 365   /* check if buffer exists by reading it */
 366   emul_read_buffer((void *)scratch_buffer, buf, nbytes, processor, cia);
 367
 368   /* read */
 369   status = device_instance_read(bugapi->input,
 370                                 (void *)scratch_buffer, nbytes);
 371
 372   /* -1 = error, -2 = nothing available - see "serial" [IEEE1275] */
 373   if (status < 0) {
 374     status = 0;
 375   }
 376
 377   if (status > 0) {
 378     emul_write_buffer((void *)scratch_buffer, buf, status, processor, cia);
 379
 380     /* Bugapi chops off the trailing n, but leaves it in the buffer */
 381     if (scratch_buffer[status-1] == '\n' || scratch_buffer[status-1] == '\r')
 382       status--;
 383   }
 384
 385   free(scratch_buffer);
 386   return status;
 387 }
 388
 389 static void
 390 emul_bugapi_do_diskio(os_emul_data *bugapi,
 391                       cpu *processor,
 392                       unsigned_word cia,
 393                       unsigned_word descriptor_addr,
 394                       int call_id)
 395 {
 396   struct dskio_descriptor {
 397     unsigned_1 ctrl_lun;
 398     unsigned_1 dev_lun;
 399     unsigned_2 status;
 400     unsigned_word pbuffer;
 401     unsigned_4 blk_num;
 402     unsigned_2 blk_cnt;
 403     unsigned_1 flag;
 404 #define BUG_FILE_MARK    0x80
 405 #define IGNORE_FILENUM   0x02
 406 #define END_OF_FILE      0x01
 407     unsigned_1 addr_mod;
 408   } descriptor;
 409   int block;
 410   emul_read_buffer(&descriptor, descriptor_addr, sizeof(descriptor),
 411                    processor, cia);
 412   T2H(descriptor.ctrl_lun);
 413   T2H(descriptor.dev_lun);
 414   T2H(descriptor.status);
 415   T2H(descriptor.pbuffer);
 416   T2H(descriptor.blk_num);
 417   T2H(descriptor.blk_cnt);
 418   T2H(descriptor.flag);
 419   T2H(descriptor.addr_mod);
 420   if (descriptor.dev_lun >= nr_bugapi_disks
 421       || bugapi->disk[descriptor.dev_lun] == NULL) {
 422     error("emul_bugapi_do_diskio: attempt to access unconfigured disk /chosen/disk%d",
 423           descriptor.dev_lun);
 424   }
 425   else {
 426     for (block = 0; block < descriptor.blk_cnt; block++) {
 427       device_instance *disk = bugapi->disk[descriptor.dev_lun];
 428       unsigned_1 buf[512]; /*????*/
 429       unsigned_word block_nr = descriptor.blk_num + block;
 430       unsigned_word byte_nr = block_nr * sizeof(buf);
 431       unsigned_word block_addr = descriptor.pbuffer + block*sizeof(buf);
 432       if (device_instance_seek(disk, 0, byte_nr) < 0)
 433         error("emul_bugapi_do_diskio: bad seek\n");
 434       switch (call_id) {
 435       case _DSKRD:
 436         if (device_instance_read(disk, buf, sizeof(buf)) != sizeof(buf))
 437           error("emul_`bugapi_do_diskio: bad read\n");
 438         emul_write_buffer(buf, block_addr, sizeof(buf), processor, cia);
 439         break;
 440       case _DSKWR:
 441         emul_read_buffer(buf, block_addr, sizeof(buf), processor, cia);
 442         if (device_instance_write(disk, buf, sizeof(buf)) != sizeof(buf))
 443           error("emul_bugapi_do_diskio: bad write\n");
 444         break;
 445       default:
 446         error("emul_bugapi_do_diskio: bad switch\n");
 447       }
 448     }
 449   }
 450 }
 451
 452 static void
 453 emul_bugapi_do_write(os_emul_data *bugapi,
 454                      cpu *processor,
 455                      unsigned_word cia,
 456                      unsigned_word buf,
 457                      int nbytes,
 458                      const char *suffix)
 459 {
 460   void *scratch_buffer = NULL;
 461
 462   /* get a tempoary bufer */
 463   if (nbytes > 0)
 464     {
 465       scratch_buffer = zalloc(nbytes);
 466
 467       /* copy in */
 468       emul_read_buffer(scratch_buffer, buf, nbytes,
 469                        processor, cia);
 470
 471       /* write */
 472       device_instance_write(bugapi->output, scratch_buffer, nbytes);
 473
 474       free(scratch_buffer);
 475     }
 476
 477   if (suffix)
 478     device_instance_write(bugapi->output, suffix, strlen(suffix));
 479
 480   flush_stdoutput ();
 481 }
 482
 483 static int
 484 emul_bugapi_instruction_call(cpu *processor,
 485                              unsigned_word cia,
 486                              unsigned_word ra,
 487                              os_emul_data *bugapi)
 488 {
 489   const int call_id = cpu_registers(processor)->gpr[10];
 490   unsigned char uc;
 491
 492 #define MY_INDEX itable_instruction_call
 493   ITRACE (trace_os_emul,
 494           (" 0x%x %s, r3 = 0x%lx, r4 = 0x%lx\n",
 495            call_id, emul_bugapi_instruction_name (call_id),
 496            (long)cpu_registers(processor)->gpr[3],
 497            (long)cpu_registers(processor)->gpr[4]));;
 498
 499   /* check that this isn't an invalid instruction */
 500   if (cia != bugapi->system_call_address)
 501     return 0;
 502
 503   switch (call_id) {
 504   default:
 505     error("emul-bugapi: unimplemented bugapi %s from address 0x%lx\n",
 506           emul_bugapi_instruction_name (call_id), SRR0);
 507     break;
 508
 509   /* read a single character, output r3 = byte */
 510   /* FIXME: Add support to unbuffer input */
 511   case _INCHR:
 512     if (device_instance_read(bugapi->input, (void *)&uc, 1) <= 0)
 513       uc = 0;
 514     cpu_registers(processor)->gpr[3] = uc;
 515     break;
 516
 517   /* read a line of at most 256 bytes, r3 = ptr to 1st byte, output r3 = ptr to last byte+1  */
 518   case _INLN:
 519     cpu_registers(processor)->gpr[3] += emul_bugapi_do_read(bugapi,
 520                                                             processor, cia,
 521                                                             cpu_registers(processor)->gpr[3],
 522                                                             256);
 523     break;
 524
 525   /* output a character, r3 = character */
 526   case _OUTCHR:
 527     {
 528       char out = (char)cpu_registers(processor)->gpr[3];
 529       device_instance_write(bugapi->output, &out, 1);
 530       break;
 531     }
 532
 533   /* output a string, r3 = ptr to 1st byte, r4 = ptr to last byte+1 */
 534   case _OUTSTR:
 535     emul_bugapi_do_write(bugapi,
 536                          processor, cia,
 537                          cpu_registers(processor)->gpr[3],
 538                          cpu_registers(processor)->gpr[4] - cpu_registers(processor)->gpr[3],
 539                          (const char *)0);
 540     break;
 541
 542   /* output a string followed by \r\n, r3 = ptr to 1st byte, r4 = ptr to last byte+1 */
 543   case _OUTLN:
 544
 545     emul_bugapi_do_write(bugapi,
 546                          processor, cia,
 547                          cpu_registers(processor)->gpr[3],
 548                          cpu_registers(processor)->gpr[4] - cpu_registers(processor)->gpr[3],
 549                          "\n");
 550     break;
 551
 552   /* output a \r\n */
 553   case _PCRLF:
 554     device_instance_write(bugapi->output, "\n", 1);
 555     break;
 556
 557   /* read/write blocks of data to/from the disk */
 558   case _DSKWR:
 559   case _DSKRD:
 560     emul_bugapi_do_diskio(bugapi, processor, cia,
 561                           cpu_registers(processor)->gpr[3],
 562                           call_id);
 563     break;
 564
 565   /* return to ppcbug monitor (exiting with gpr[3] as status is not
 566      part of the bug monitor) */
 567   case _RETURN:
 568     cpu_halt(processor, cia, was_exited, cpu_registers(processor)->gpr[3]);
 569     break;
 570   }
 571   return 1;
 572   /* the instruction following this one is a RFI.  Thus by just
 573      continuing the return from system call is performed */
 574 }
 575
 576 const os_emul emul_bugapi = {
 577   "bugapi",
 578   emul_bugapi_create,
 579   emul_bugapi_init,
 580   0, /*system_call*/
 581   emul_bugapi_instruction_call,
 582   0 /*data*/
 583 };
 584
 585 #endif