ieee.c

早期freebsd实现

  asection *s;
  ieee->w.r.section_part = bfd_tell(abfd);
  for (s = abfd->sections; s != (asection *)NULL; s=s->next) {
      if (s != &bfd_abs_section) 
      {
	
	ieee_write_byte(abfd, ieee_section_type_enum);
	ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);

	if (abfd->flags & EXEC_P) 
	{
	  /* This image is executable, so output absolute sections */
	  ieee_write_byte(abfd, ieee_variable_A_enum);
	  ieee_write_byte(abfd, ieee_variable_S_enum);
	}
	else  
	{
	  ieee_write_byte(abfd, ieee_variable_C_enum);
	}

	switch (s->flags &(SEC_CODE | SEC_DATA | SEC_ROM)) 
	{
	case SEC_CODE | SEC_LOAD:
	case SEC_CODE:
	  ieee_write_byte(abfd, ieee_variable_P_enum);
	  break;
	case SEC_DATA:
	default:
	  ieee_write_byte(abfd, ieee_variable_D_enum);
	  break;
	case SEC_ROM:
	case SEC_ROM | SEC_DATA:
	case SEC_ROM | SEC_LOAD:
	case SEC_ROM | SEC_DATA | SEC_LOAD:

	  ieee_write_byte(abfd, ieee_variable_R_enum);
	}


	ieee_write_id(abfd, s->name);
#if 0
	ieee_write_int(abfd, 0); /* Parent */
	ieee_write_int(abfd, 0); /* Brother */
	ieee_write_int(abfd, 0); /* Context */
#endif
	/* Alignment */
	ieee_write_byte(abfd, ieee_section_alignment_enum);
	ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
	ieee_write_int(abfd, 1 << s->alignment_power);

	/* Size */
	ieee_write_2bytes(abfd, ieee_section_size_enum);
	ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
	ieee_write_int(abfd, s->_raw_size);
	if (abfd->flags & EXEC_P) {
	    /* Relocateable sections don't have asl records */
	    /* Vma */
	    ieee_write_2bytes(abfd, ieee_section_base_address_enum);
	    ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
	    ieee_write_int(abfd, s->vma);
	  }
      }
      
    }
}



static void 
DEFUN(do_with_relocs,(abfd, s),
      bfd *abfd AND
      asection *s)
{
  unsigned int relocs_to_go = s->reloc_count;


  bfd_byte *stream = ieee_per_section(s)->data;
  arelent **p = s->orelocation;

  bfd_size_type current_byte_index = 0;

  qsort(s->orelocation,
	relocs_to_go,
	sizeof(arelent **),
	comp);

  /* Output the section preheader */
  ieee_write_byte(abfd, ieee_set_current_section_enum);
  ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);

  ieee_write_twobyte(abfd, ieee_set_current_pc_enum);
  ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
  ieee_write_expression(abfd, 0, s->symbol, 0, 0);

  if (relocs_to_go == 0) 
      {
	/* If there arn't any relocations then output the load constant byte
	   opcode rather than the load with relocation opcode */

	while (current_byte_index < s->_raw_size) {
	  bfd_size_type run;
	  unsigned int MAXRUN  = 32;
	  run = MAXRUN;
	  if (run > s->_raw_size - current_byte_index) {
	    run = s->_raw_size - current_byte_index;
	  }

	  if (run != 0) {
	    ieee_write_byte(abfd, ieee_load_constant_bytes_enum);
	    /* Output a stream of bytes */
	    ieee_write_int(abfd, run);
	    bfd_write((PTR)(stream + current_byte_index), 
		      1,
		      run,
		      abfd);
	    current_byte_index += run;
	  }
	}
      }
  else 
      {
	ieee_write_byte(abfd, ieee_load_with_relocation_enum);


	/* Output the data stream as the longest sequence of bytes
	   possible, allowing for the a reasonable packet size and
	   relocation stuffs */

	if ((PTR)stream == (PTR)NULL) {
	  /* Outputting a section without data, fill it up */
	  stream = (uint8e_type *)(bfd_alloc(abfd, s->_raw_size));
	  memset((PTR)stream, 0, s->_raw_size);
	}
	while (current_byte_index < s->_raw_size) {
	  bfd_size_type run;
	  unsigned int MAXRUN = 32;
	  if (relocs_to_go) {
	    run = (*p)->address - current_byte_index;
	  }
	  else {
	    run = MAXRUN;
	  }
	  if (run > s->_raw_size - current_byte_index) {
	    run = s->_raw_size - current_byte_index;
	  }

	  if (run != 0) {
	    /* Output a stream of bytes */
	    ieee_write_int(abfd, run);
	    bfd_write((PTR)(stream + current_byte_index), 
		      1,
		      run,
		      abfd);
	    current_byte_index += run;
	  }
	  /* Output any relocations here */
	  if (relocs_to_go && (*p) && (*p)->address == current_byte_index) {
	    while (relocs_to_go && (*p) && (*p)->address == current_byte_index) {

	      arelent *r = *p;
	      bfd_vma ov;

#if 0
	      if (r->howto->pc_relative) {
		r->addend += current_byte_index ;
	      }
#endif

	      switch (r->howto->size) {
	      case 2:

		ov = bfd_get_32(abfd,
				stream+current_byte_index);
		current_byte_index +=4;
		break;
	      case 1:
		ov = bfd_get_16(abfd,
				stream+current_byte_index);
		current_byte_index +=2;
		break;
	      case 0:
		ov = bfd_get_8(abfd,
			       stream+current_byte_index);
		current_byte_index ++;
		break;
	      default:
		ov = 0;
		BFD_FAIL();
	      }
	      ieee_write_byte(abfd, ieee_function_either_open_b_enum);
	      abort();
	    
	      if (r->sym_ptr_ptr != (asymbol **)NULL) {
		ieee_write_expression(abfd, r->addend + ov,
				      *(r->sym_ptr_ptr),
				      r->howto->pc_relative, s->index);
	      }
	      else {
		ieee_write_expression(abfd, r->addend + ov,
				      (asymbol *)NULL,
				      r->howto->pc_relative, s->index);
	      }

	      if (1 || r->howto->size != 2) {
		ieee_write_byte(abfd, ieee_comma);
		ieee_write_int(abfd, 1<< r->howto->size);
	      }
	      ieee_write_byte(abfd,
			      ieee_function_either_close_b_enum);

	      relocs_to_go --;
	      p++;
	    }

	  }
	}
      }
}

/* If there are no relocations in the output section then we can
be clever about how we write. We block items up into a max of 127
bytes */

static void 
DEFUN(do_as_repeat, (abfd, s),
      bfd *abfd AND
      asection *s)
{
  ieee_write_byte(abfd, ieee_set_current_section_enum);
  ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
  ieee_write_byte(abfd, ieee_set_current_pc_enum >> 8);
 ieee_write_byte(abfd, ieee_set_current_pc_enum  & 0xff);
  ieee_write_byte(abfd, s->index + IEEE_SECTION_NUMBER_BASE);
  ieee_write_int(abfd,  s->vma );

  ieee_write_byte(abfd,ieee_repeat_data_enum);
  ieee_write_int(abfd, s->_raw_size);
  ieee_write_byte(abfd, ieee_load_constant_bytes_enum);
  ieee_write_byte(abfd, 1);
  ieee_write_byte(abfd, 0);
}

static void 
DEFUN(do_without_relocs, (abfd, s),
      bfd *abfd AND
      asection *s)
{
  bfd_byte *stream = ieee_per_section(s)->data;

  if (stream == 0 || ((s->flags & SEC_LOAD) == 0)) 
      {
	do_as_repeat(abfd, s);
      }
  else 
      {
	unsigned int i;
	for (i = 0; i < s->_raw_size; i++) {
	  if (stream[i] != 0) {
	    do_with_relocs(abfd, s);
	    return;
	  }
	}
	do_as_repeat(abfd, s);
      }
  
}


static unsigned char *output_ptr_start;
static unsigned char *output_ptr;
static unsigned char *output_ptr_end;
static unsigned char *input_ptr_start;
static unsigned char *input_ptr;
static unsigned char *input_ptr_end;
static bfd *input_bfd;
static bfd *output_bfd;
static int output_buffer;

static void fill()
{
  bfd_read((PTR)input_ptr_start, 1, input_ptr_end - input_ptr_start, input_bfd);
  input_ptr = input_ptr_start;
}
static void flush()
{
  bfd_write((PTR)(output_ptr_start),1,output_ptr - output_ptr_start, output_bfd);
  output_ptr = output_ptr_start;
  output_buffer++;
}

#define THIS() ( *input_ptr )
#define NEXT() { input_ptr++; if (input_ptr == input_ptr_end) fill(); }
#define OUT(x) { *output_ptr++ = (x); if(output_ptr == output_ptr_end)  flush(); }

static void write_int(value)
int value;
{
  if (value >= 0 && value <= 127) {
    OUT(value);
  }
  else {
    unsigned int length;
    /* How many significant bytes ? */
    /* FIXME FOR LONGER INTS */
    if (value & 0xff000000) {
      length = 4;
    }
    else if (value & 0x00ff0000) {
      length  = 3;
    }
    else if (value & 0x0000ff00) {
      length = 2;
    }
    else length = 1;

    OUT((int)ieee_number_repeat_start_enum + length);
    switch (length) {
    case 4:
      OUT( value >> 24);
    case 3:
      OUT( value >> 16);
    case 2:
      OUT( value >> 8);
    case 1:
      OUT( value);
    }

  }
}
static void copy_id() 
{
  int length  = THIS();
  char ch;
  OUT(length);
  NEXT();
  while (length--) {
    ch = THIS();
    OUT(ch);
    NEXT();
  }
}
#define VAR(x) ((x | 0x80))
static void copy_expression()
{
  int stack[10];
  int *tos = stack;
  int value = 0;
  while (1) {
    switch (THIS()) {
    case 0x84:
      NEXT();
      value =  THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      *tos ++ = value;
      break;
    case 0x83:
      NEXT();
      value =  THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      *tos ++ = value;
      break;
    case 0x82:	
      NEXT();
      value =  THIS(); NEXT();
      value = (value << 8) | THIS(); NEXT();
      *tos ++ = value;
      break;
    case 0x81:
      NEXT();
      value =  THIS(); NEXT();
      *tos ++ = value;
      break;
      case 0x80:
      NEXT();
      *tos ++ = 0;
      break;
    default:
      if (THIS() >0x84) {
	/* Not a number, just bug out with the answer */
	write_int(*(--tos));
	return;
      }
      *tos++ = THIS();
NEXT();
      value = 0;
      break;
    case 0xa5:
      /* PLUS anything */
	{
	  int value = *(--tos);
	  value += *(--tos);
	  *tos++ = value;
	  NEXT();
	}
      break;
    case VAR('R') :
	{
	  int section_number ;
	  ieee_data_type *ieee;
	  asection *s;
	  NEXT();
	  section_number = THIS();
	
	  NEXT();
	  ieee= IEEE_DATA(input_bfd);
	  s = 	ieee->section_table[section_number];
	  if (s->output_section) {
	    value = s->output_section->vma ;
	  } else { value = 0; }
	  value += s->output_offset;
	  *tos++ = value;
	  value = 0;
	}
      break;
    case 0x90:
	{	
	  NEXT();
	  write_int(*(--tos));
	  OUT(0x90);
	  return;

	}
    }
  }

}

/* Drop the int in the buffer, and copy a null into the gap, which we
   will overwrite later */

struct output_buffer_struct {
unsigned  char *ptrp;
  int buffer;
} ;

static void
DEFUN(fill_int,(buf),
      struct output_buffer_struct *buf)
{
  if (buf->buffer == output_buffer) {
    /* Still a chance to output the size */
    int value = output_ptr - buf->ptrp + 3;
    buf->ptrp[0] =  value >> 24;
    buf->ptrp[1] =  value >> 16;
    buf->ptrp[2] =  value >> 8;
    buf->ptrp[3] =  value >> 0;
  }

}
static void
DEFUN(drop_int,(buf),
      struct output_buffer_struct *buf)
{
  int type = THIS();
  int ch;
  if (type <= 0x84) {
    NEXT();
    switch(type) {
    case 0x84: ch = THIS(); NEXT();
    case 0x83: ch = THIS(); NEXT();
    case 0x82: ch = THIS(); NEXT();
    case 0x81: ch = THIS(); NEXT();
    case 0x80: break;
    }
  }
  OUT(0x84);
  buf->ptrp = output_ptr;
  buf->buffer  = output_buffer;
  OUT(0);OUT(0);OUT(0);OUT(0);
}

static void copy_int()
{
  int type = THIS();
  int ch;
  if (type <= 0x84) {
    OUT(type);
    NEXT();
    switch(type) {
    case 0x84: ch = THIS(); NEXT(); OUT(ch);
    case 0x83: ch = THIS(); NEXT(); OUT(ch);
    case 0x82: ch = THIS(); NEXT(); OUT(ch);
    case 0x81: ch = THIS(); NEXT(); OUT(ch);
    case 0x80: break;
    }
  }
}

#define ID copy_id()
#define INT copy_int()
#define EXP copy_expression()
static void copy_till_end();
#define INTn(q) copy_int()
#define EXPn(q) copy_expression()
static void f1_record()
{
  int ch;
  /* ATN record */
  NEXT();
  ch = THIS();
  switch (ch)
      {
      default:
	OUT(0xf1); OUT(ch);
	break;
      case 0xc9:
	NEXT();
	OUT(0xf1); OUT(0xc9);
	INT; INT; ch = THIS(); 
	switch (ch) 
	    {
	    case 0x16: NEXT();break;
	    case 0x01: NEXT();break;
	    case 0x00: NEXT(); INT; break;
	    case 0x03: NEXT(); INT; break;
	    case 0x13: EXPn(instruction address); break;
	    default:
	      break;
	    }
	break;
      case 0xd8:
	/* EXternal ref */
	NEXT();	
	OUT(0xf1); OUT(0xd8);
	EXP ; EXP; EXP; EXP;
	break;
      case 0xce:
	NEXT();
	OUT(0xf1);OUT(0xce); INT; INT; ch = THIS(); INT;
	switch (ch) {
	case 0x01:
	  INT; INT; break;
	case 0x02:
	  INT; break;
	case 0x04:
	  EXPn(external function); break;
	case 0x05:
	  break;
	case 0x07: INTn(line number); INT;
	case 0x08: break;
	case 0x0a: INTn(locked register); INT; break;
	case 0x3f: copy_till_end(); break;