emul_chirp.c

这个是LINUX下的GDB调度工具的源码

    /* OpenFirmware doesn't define this error */
    error("chirp: invalid ihandle passed to read method");
  }
  else {
    /* do the reads */
    int actual = 0;
    while (actual < args.len) {
      int remaining = args.len - actual;
      int to_read = (remaining <= sizeof(buf) ? remaining : sizeof(buf));
      int nr_read = device_instance_read(ihandle, buf, to_read);
      if (nr_read < 0) {
	actual = nr_read; /* the error */
	break;
      }
      else if (nr_read == 0) {
	break;
      }
      emul_write_buffer(buf,
			args.addr + actual,
			nr_read,
			processor, cia);
      actual += nr_read;
    }
    if (actual >= 0) {
      args.actual = actual;
      if (actual < sizeof(buf))
	buf[actual] = '\0';
      else
	buf[sizeof(buf) - 1] = '\0';
    }
    else {
      switch (actual) {
      case sim_io_eof:
	args.actual = 0;
	break;
      case sim_io_not_ready:
	ASSERT(sim_io_not_ready == -2);
	args.actual = sim_io_not_ready;
	break;
      default:
	error("Bad error value %ld", (long)actual);
	break;
      }
    }
  }
  /* return the result */
  TRACE(trace_os_emul, ("read - out - actual=%ld `%s'\n",
			(long)args.actual,
			((args.actual > 0 && args.actual < sizeof(buf)) ? buf : "")
			));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}

static int
chirp_emul_write(os_emul_data *data,
		 cpu *processor,
		 unsigned_word cia)
{
  struct write_args {
    /*in*/
    unsigned_cell ihandle;
    unsigned_cell addr;
    unsigned_cell len;
    /*out*/
    unsigned_cell actual;
  } args;
  char buf[1024];
  device_instance *ihandle;
  int actual;
  /* get the args */
  if (chirp_read_t2h_args(&args, sizeof(args), 3, 1, data, processor, cia))
    return -1;
  actual = args.len;
  if (actual >= sizeof(buf))
    actual = sizeof(buf) - 1;
  emul_read_buffer(buf,
		   args.addr,
		   actual,
		   processor, cia);
  buf[actual] = '\0';
  ihandle = external_to_device_instance(data->root, args.ihandle);
  TRACE(trace_os_emul, ("write - in - ihandle=0x%lx(0x%lx`%s') `%s' (%ld)\n",
			(unsigned long)args.ihandle,
			(unsigned long)ihandle,
			ihandle_name(ihandle),
			buf, (long)actual));
  if (ihandle == NULL) {
    /* OpenFirmware doesn't define this error */
    error("chirp: invalid ihandle passed to write method");
  }
  else {
    /* write it out */
    actual = device_instance_write(ihandle, buf, actual);
    if (actual < 0)
      args.actual = 0;
    else
      args.actual = actual;
  }
  /* return the result */
  TRACE(trace_os_emul, ("write - out - actual=%ld\n",
			(long)args.actual));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}

static int
chirp_emul_seek(os_emul_data *data,
		cpu *processor,
		unsigned_word cia)
{
  struct seek_args {
    /*in*/
    unsigned_cell ihandle;
    unsigned_cell pos_hi;
    unsigned_cell pos_lo;
    /*out*/
    unsigned_cell status;
  } args;
  int status;
  device_instance *ihandle;
  /* get the args */
  if (chirp_read_t2h_args(&args, sizeof(args), 3, 1, data, processor, cia))
    return -1;
  ihandle = external_to_device_instance(data->root, args.ihandle);
  TRACE(trace_os_emul, ("seek - in - ihandle=0x%lx(0x%lx`%s') pos.hi=0x%lx pos.lo=0x%lx\n",
			(unsigned long)args.ihandle,
			(unsigned long)ihandle,
			ihandle_name(ihandle),
			args.pos_hi, args.pos_lo));
  if (ihandle == NULL) {
    /* OpenFirmware doesn't define this error */
    error("chirp: invalid ihandle passed to seek method");
  }
  else {
    /* seek it out */
    status = device_instance_seek(ihandle, args.pos_hi, args.pos_lo);
    args.status = status;
  }
  /* return the result */
  TRACE(trace_os_emul, ("seek - out - status=%ld\n",
			(long)args.status));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}


/* memory */

static int
chirp_emul_claim(os_emul_data *data,
		 cpu *processor,
		 unsigned_word cia)
{
  /* NOTE: the client interface claim routine is *very* different to
     the "claim" method described in IEEE-1275 appendix A.  The latter
     uses real addresses while this uses virtual (effective)
     addresses. */
  struct claim_args {
    /* in */
    unsigned_cell virt;
    unsigned_cell size;
    unsigned_cell align;
    /* out */
    unsigned_cell baseaddr;
  } args;
  /* read the args */
  if (chirp_read_t2h_args(&args, sizeof(args),
			  3 /*n_args*/, 1 /*n_returns*/,
			  data, processor, cia))
    return -1;
  TRACE(trace_os_emul, ("claim - in - virt=0x%lx size=%ld align=%d\n",
			(unsigned long)args.virt,
			(long int)args.size,
			(int)args.align));
  /* use the memory device to allocate (real) memory at the requested
     address */
  {
    device_instance *memory = tree_find_ihandle_property(data->root, "/chosen/memory");
    unsigned_cell mem_in[3];
    unsigned_cell mem_out[1];
    mem_in[0] = args.align; /*top-of-stack*/
    mem_in[1] = args.size;
    mem_in[2] = args.virt;
    if (device_instance_call_method(memory, "claim",
				    3, mem_in, 1, mem_out) < 0)
      error("chirp: claim failed to allocate memory virt=0x%lx size=%ld align=%d",
	    (unsigned long)args.virt,
	    (long int)args.size,
	    (int)args.align);
    args.baseaddr = mem_out[0];
  }
  /* if using virtual addresses, create a 1-1 map of this address space */
  if (!data->real_mode) {
    error("chirp: claim method does not support virtual mode");
  }
  /* return the base address */
  TRACE(trace_os_emul, ("claim - out - baseaddr=0x%lx\n",
			(unsigned long)args.baseaddr));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}

static int
chirp_emul_release(os_emul_data *data,
		   cpu *processor,
		   unsigned_word cia)
{
  /* NOTE: the client interface release routine is *very* different to
     the "claim" method described in IEEE-1275 appendix A.  The latter
     uses real addresses while this uses virtual (effective)
     addresses. */
  struct claim_args {
    /* in */
    unsigned_cell virt;
    unsigned_cell size;
    /* out */
  } args;
  /* read the args */
  if (chirp_read_t2h_args(&args, sizeof(args),
			  2 /*n_args*/, 0 /*n_returns*/,
			  data, processor, cia))
    return -1;
  TRACE(trace_os_emul, ("release - in - virt=0x%lx size=%ld\n",
			(unsigned long)args.virt,
			(long int)args.size));
  /* use the memory device to release (real) memory at the requested
     address */
  {
    device_instance *memory = tree_find_ihandle_property(data->root, "/chosen/memory");
    unsigned_cell mem_in[2];
    mem_in[0] = args.size;
    mem_in[1] = args.virt;
    if (device_instance_call_method(memory, "release",
				    2, mem_in, 0, NULL) < 0)
      error("chirp: claim failed to release memory virt=0x%lx size=%ld",
	    (unsigned long)args.virt,
	    (long int)args.size);
  }
  /* if using virtual addresses, remove the 1-1 map of this address space */
  if (!data->real_mode) {
    error("chirp: release method does not support virtual mode");
  }
  /* return the base address */
  TRACE(trace_os_emul, ("release - out\n"));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}


/* Control transfer */

static int
chirp_emul_boot(os_emul_data *data,
		cpu *processor,
		unsigned_word cia)
{
  /* unlike OpenFirmware this one can take an argument */
  struct boot_args {
    /*in*/
    unsigned_cell bootspec;
    /*out*/
  } args;
  char bootspec[1024];
  /* read in the arguments */
  if (chirp_read_t2h_args(&args, sizeof(args), -1, 0, data, processor, cia))
    cpu_halt(processor, cia, was_exited, -1);
  if (args.bootspec != 0)
    emul_read_string(bootspec, args.bootspec, sizeof(bootspec),
		     processor, cia);
  else
    strcpy(bootspec, "(null)");
  TRACE(trace_os_emul, ("boot - in bootspec=`%s'\n", bootspec));
  /* just report this and exit */
  printf_filtered("chrp: boot %s called, exiting.\n", bootspec);
  cpu_halt(processor, cia, was_exited, 0);
  return 0;
}

static int
chirp_emul_enter(os_emul_data *data,
		 cpu *processor,
		 unsigned_word cia)
{
  error("chirp: enter method not implemented\n");
  return 0;
}

static int
chirp_emul_exit(os_emul_data *data,
		cpu *processor,
		unsigned_word cia)
{
  /* unlike OpenBoot this one can take an argument */
  struct exit_args {
    /*in*/
    signed_cell status;
    /*out*/
  } args;
  if (chirp_read_t2h_args(&args, sizeof(args), -1, 0, data, processor, cia))
    cpu_halt(processor, cia, was_exited, -1);
  cpu_halt(processor, cia, was_exited, args.status);
  return 0;
}

static int
chirp_emul_chain(os_emul_data *data,
		 cpu *processor,
		 unsigned_word cia)
{
  error("chirp: chain method not implemented\n");
  return 0;
}


/* user interface */

static int
chirp_emul_interpret(os_emul_data *data,
		     cpu *processor,
		     unsigned_word cia)
{
  error("chirp: interpret method not implemented\n");
  return 0;
}

static int
chirp_emul_set_callback(os_emul_data *data,
			cpu *processor,
			unsigned_word cia)
{
  error("chirp: set_callback method not implemented\n");
  return 0;
}

static int
chirp_emul_set_symbol_lookup(os_emul_data *data,
			     cpu *processor,
			     unsigned_word cia)
{
  error("chirp: set_symbol_lookup method not implemented\n");
  return 0;
}


/* Time */

static int
chirp_emul_milliseconds(os_emul_data *data,
			cpu *processor,
			unsigned_word cia)
{
  struct test_args {
    /*in*/
    /*out*/
    unsigned_cell ms;
  } args;
  unsigned64 time;
  /* read in the arguments */
  if (chirp_read_t2h_args(&args, sizeof(args), 1, 1, data, processor, cia))
    return -1;
  /* make up a number */
  time = event_queue_time(psim_event_queue(cpu_system(processor))) / 1000000;
  args.ms = time;
  /* write the arguments back out */
  TRACE(trace_os_emul, ("milliseconds - out - ms=%ld\n",
			(unsigned long)args.ms));
  chirp_write_h2t_args(&args,
		       sizeof(args),
		       data,
		       processor, cia);
  return 0;
}




static chirp_services services[] = {

  /* client interface */
  { "test", chirp_emul_test },

  /* device tree */
  { "peer", chirp_emul_peer },
  { "child", chirp_emul_child },
  { "parent", chirp_emul_parent },
  { "instance-to-package", chirp_emul_instance_to_package },
  { "getproplen", chirp_emul_getproplen },
  { "getprop", chirp_emul_getprop },
  { "nextprop", chirp_emul_nextprop },
  /* { "setprop", chirp_emul_setprop }, */
  { "canon", chirp_emul_canon },
  { "finddevice", chirp_emul_finddevice },
  { "instance-to-path", chirp_emul_instance_to_path },
  { "package-to-path", chirp_emul_package_to_path },
  { "call-method", chirp_emul_call_method },

  /* device I/O */
  { "open", chirp_emul_open },
  { "close", chirp_emul_close },
  { "read", chirp_emul_read },
  { "write", chirp_emul_write },
  { "seek", chirp_emul_seek },
  { "write", chirp_emul_write },

  /* memory */
  { "claim", chirp_emul_claim },
  { "release", chirp_emul_release },

  /* control transfer */
  { "boot", chirp_emul_boot },
  { "enter", chirp_emul_enter },
  { "exit", chirp_emul_exit },
  { "chain", chirp_emul_chain },

  /* user interface */
  { "interpret", chirp_emul_interpret },
  { "set_callback", chirp_emul_set_callback },
  { "set_symbol_lookup", chirp_emul_set_symbol_lookup },

  /* time */
  { "milliseconds", chirp_emul_milliseconds },

  { 0, /* sentinal */ },
};


/* main handlers */

/* Any starting address greater than this is assumed to be an Chirp
   rather than VEA */

#ifndef CHIRP_START_ADDRESS
#define CHIRP_START_ADDRESS 0x80000000
#endif
#ifndef CHIRP_LOAD_BASE
#define CHIRP_LOAD_BASE -1
#endif


typedef struct _chirp_note_desc {
  signed32 real_mode;
  signed32 real_base;
  signed32 real_size;
  signed32 virt_base;
  signed32 virt_size;
  signed32 load_base;
} chirp_note_desc;

typedef enum {
  note_missing,
  note_found,
  note_correct,
} note_found_status;
typedef struct _chirp_note {
  chirp_note_desc desc;
  note_found_status found;
} chirp_note;

typedef struct _chirp_note_head {
  unsigned32 namesz;
  unsigned32 descsz;
  unsigned32 type;
} chirp_note_head;

static void
map_over_chirp_note(bfd *image,
		    asection *sect,
		    PTR obj)
{
  chirp_note *note = (chirp_note*)obj;
  if (strcmp(sect->name, ".note") == 0) {
    chirp_note_head head;
    char name[16];
    /* check the head */
    if (!bfd_get_section_contents(image, sect,
				  &head, 0, sizeof(head)))
      return;
    head.namesz = bfd_get_32(image, (void*)&head.namesz);
    head.descsz = bfd_get_32(image, (void*)&head.descsz);
    head.type = bfd_get_32(image, (void*)&head.type);
    if (head.type != 0x1275)
      return;
    /* check the name field */
    if (head.namesz > sizeof(name)) {
      error("chirp: note name too long (%d > %d)\n", (int)head.namesz, sizeof(name));
    }
    if (!bfd_get_section_contents(image, sect,
				  name, sizeof(head), head.namesz)) {
      error("chirp: note name unreadable\n");
    }
    if (strcmp(name, "PowerPC") != 0) {
      printf_filtered("chirp: note name (%s) not `PowerPC'\n", name);
    }