binutils-gdb/bfd/aout-cris.c

/* BFD backend for CRIS a.out binaries.
   Copyright (C) 2000 Free Software Foundation, Inc.
   Contributed by Axis Communications AB.
   Written by Hans-Peter Nilsson.

This file is part of BFD, the Binary File Descriptor library.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* See info in the file PORTING for documentation of these macros and
   functions.  Beware; some of the information there is outdated.  */

#define N_HEADER_IN_TEXT(x) 0
#define BYTES_IN_WORD 4
#define N_TXTOFF(x) 32
#define ENTRY_CAN_BE_ZERO
#define TEXT_START_ADDR 0

/* If you change this to 4, you can not link to an address N*4+2.  */
#define SEGMENT_SIZE 2

/* For some reason, if the a.out file has Z_MAGIC, then
   adata(abfd).exec_bytes_size is not used, but rather
   adata(abfd).zmagic_disk_block_size, even though the exec_header is
   *not* included in the text segment.  A simple workaround is to
   #define ZMAGIC_DISK_BLOCK_SIZE, which is used if defined; otherwise
   TARGET_PAGE_SIZE is used. */
#define ZMAGIC_DISK_BLOCK_SIZE N_TXTOFF (0)

/* It seems odd at first to set a page-size this low, but gives greater
   freedom in where things can be linked.  The drawback is that you have
   to set alignment and padding in linker scripts.  */
#define TARGET_PAGE_SIZE SEGMENT_SIZE
#define TARGETNAME "a.out-cris"

/* N_SHARED_LIB gets this reasonable default as of 1999-07-12, but we
   have to work with 2.9.1.  Note that N_SHARED_LIB is used in a
   SUN-specific context, not applicable to CRIS.  */
#define N_SHARED_LIB(x) 0

/* The definition here seems not used; just provided as a convention.  */
#define DEFAULT_ARCH bfd_arch_cris

/* ??? Spacing might be essential for the parameters in this macro.
   Do Not Change.  */
#define MY(OP) CAT (cris_aout_,OP)
#define NAME(x,y) CAT3(cris_aout,_32_,y)

#include "bfd.h"

/* Version 1 of the header.  */
#define MY_exec_hdr_flags 1

#define MY_write_object_contents MY(write_object_contents)
static boolean MY(write_object_contents) PARAMS ((bfd *));

/* Forward this, so we can use a pointer to it in PARAMS.  */
struct reloc_ext_external;

#define MY_swap_ext_reloc_out MY(swap_ext_reloc_out)
static void MY(swap_ext_reloc_out) PARAMS ((bfd *, arelent *,
					    struct reloc_ext_external *));

#define MY_swap_ext_reloc_in MY(swap_ext_reloc_in)
static void MY(swap_ext_reloc_in) PARAMS ((bfd *, struct
					   reloc_ext_external *,
					   arelent *, asymbol **,
					   bfd_size_type));

#define MY_set_sizes MY(set_sizes)
static boolean MY(set_sizes) PARAMS ((bfd *));

/* To set back reloc_size to ext, we make MY(set_sizes) be called
   through this construct.  Note that MY_set_arch_mach is only called
   through SET_ARCH_MACH.  The default bfd_default_set_arch_mach will
   not call set_sizes.  */

#define MY_set_arch_mach NAME (aout, set_arch_mach)
#define SET_ARCH_MACH(BFD, EXEC) \
 MY_set_arch_mach (BFD, DEFAULT_ARCH, N_MACHTYPE (EXEC))

/* These macros describe the binary layout of the reloc information we
   use in a file.  */
#define RELOC_EXT_BITS_EXTERN_LITTLE 0x80
#define RELOC_EXT_BITS_TYPE_LITTLE 3
#define RELOC_EXT_BITS_TYPE_SH_LITTLE 0

#ifndef MY_get_section_contents
#define MY_get_section_contents aout_32_get_section_contents
#endif

/* Include generic functions (some are overridden above).  */
#include "aout32.c"
#include "aout-target.h"


/* We need our own version to set header flags.  */

static boolean
MY(write_object_contents) (abfd)
     bfd *abfd;
{
  struct external_exec exec_bytes;
  struct internal_exec *execp = exec_hdr (abfd);

  /* We set the reloc type to RELOC_EXT_SIZE, although setting it at all
     seems unnecessary when inspecting as and ld behavior (not an
     exhaustive inspection).  The default write_object_contents
     definition sets RELOC_EXT_SIZE, so we follow suite and set it too.  */
  obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;

  /* Setting N_SET_MACHTYPE and using N_SET_FLAGS is not performed by
     the default definition.  */
  if (bfd_get_arch(abfd) == bfd_arch_cris)
    N_SET_MACHTYPE(*execp, M_CRIS);

  N_SET_FLAGS (*execp, aout_backend_info (abfd)->exec_hdr_flags);

  WRITE_HEADERS (abfd, execp);

  return true;
}


/* We need our own for these reasons:
   - Assert that a normal 8, 16 or 32 reloc is output. 
   - Fix what seems to be a weak-bug (perhaps there for valid reasons).  */ 

static void
MY(swap_ext_reloc_out) (abfd, g, natptr)
     bfd *abfd;
     arelent *g;
     struct reloc_ext_external *natptr;
{
  int r_index;
  int r_extern;
  unsigned int r_type;
  unsigned int r_addend;
  asymbol *sym = *(g->sym_ptr_ptr);
  asection *output_section = sym->section->output_section;

  PUT_WORD (abfd, g->address, natptr->r_address);

  r_type = (unsigned int) g->howto->type;

  r_addend = g->addend;
  if ((sym->flags & BSF_SECTION_SYM) != 0)
    r_addend += (*(g->sym_ptr_ptr))->section->output_section->vma;

  /* If this relocation is relative to a symbol then set the
     r_index to the symbols index, and the r_extern bit.

     Absolute symbols can come in in two ways, either as an offset
     from the abs section, or as a symbol which has an abs value.
     check for that here.  */

  if (bfd_is_abs_section (bfd_get_section (sym)))
    {
      r_extern = 0;
      r_index = N_ABS;
    }
  else if ((sym->flags & BSF_SECTION_SYM) == 0)
    {
      if (bfd_is_und_section (bfd_get_section (sym))
	  /* Remember to check for weak symbols; they count as global.  */
	  || (sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0)
	r_extern = 1;
      else
	r_extern = 0;
      r_index = (*(g->sym_ptr_ptr))->KEEPIT;
    }
  else
    {
      /* Just an ordinary section.  */
      r_extern = 0;
      r_index = output_section->target_index;
    }

  /* The relocation type is the same as the canonical ones, but only
     the first 3 are used: RELOC_8, RELOC_16, RELOC_32.
     We may change this later, but assert this for the moment.  */
  if (r_type > 2)
    {
      (*_bfd_error_handler) (_("%s: Invalid relocation type exported: %d"),
			     bfd_get_filename (abfd), r_type);
    
      bfd_set_error (bfd_error_wrong_format);
    }

  /* Now the fun stuff.  */
  natptr->r_index[2] = r_index >> 16;
  natptr->r_index[1] = r_index >> 8;
  natptr->r_index[0] = r_index;
  natptr->r_type[0] =
     (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0)
      | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE);

  PUT_WORD (abfd, r_addend, natptr->r_addend);
}


/* We need our own to assert that a normal 8, 16 or 32 reloc is input.  */

static void
MY(swap_ext_reloc_in) (abfd, bytes, cache_ptr, symbols, symcount)
     bfd *abfd;
     struct reloc_ext_external *bytes;
     arelent *cache_ptr;
     asymbol **symbols;
     bfd_size_type symcount;
{
  unsigned int r_index;
  int r_extern;
  unsigned int r_type;
  struct aoutdata *su = &(abfd->tdata.aout_data->a);

  cache_ptr->address = (GET_SWORD (abfd, bytes->r_address));

  /* Now the fun stuff.  */
  r_index =  (bytes->r_index[2] << 16)
    | (bytes->r_index[1] << 8)
    |  bytes->r_index[0];
  r_extern = (0 != (bytes->r_type[0] & RELOC_EXT_BITS_EXTERN_LITTLE));
  r_type = ((bytes->r_type[0]) >> RELOC_EXT_BITS_TYPE_SH_LITTLE)
    & RELOC_EXT_BITS_TYPE_LITTLE;

  if (r_type > 2)
    {
      (*_bfd_error_handler) (_("%s: Invalid relocation type imported: %d"),
			     bfd_get_filename (abfd), r_type);
    
      bfd_set_error(bfd_error_wrong_format);
    }
    
  cache_ptr->howto =  howto_table_ext + r_type;

  if (r_extern && r_index > symcount)
    {
      (*_bfd_error_handler)
        (_("%s: Bad relocation record imported: %d"),
         bfd_get_filename (abfd), r_index);
    
      bfd_set_error (bfd_error_wrong_format);

      /* We continue, so we can catch further errors.  */
      r_extern = 0;
      r_index = N_ABS;
    }

  /* Magically uses r_extern, symbols etc.  Ugly, but it's what's in the
     default.  */
  MOVE_ADDRESS (GET_SWORD (abfd, bytes->r_addend));
}


/* We use the same as the default, except that we also set
   "obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;", to avoid changing
   NAME (aout, set_arch_mach) in aoutx.  */

static boolean
MY(set_sizes) (abfd)
     bfd *abfd;
{
  /* Just as the default in aout-target.h (with some #ifdefs folded)...  */

  adata(abfd).page_size = TARGET_PAGE_SIZE;
  adata(abfd).segment_size = SEGMENT_SIZE;
  adata(abfd).zmagic_disk_block_size = ZMAGIC_DISK_BLOCK_SIZE;
  adata(abfd).exec_bytes_size = EXEC_BYTES_SIZE;

  /* ... except for that we have the extended reloc.  The alternative
     would be to add a check on bfd_arch_cris in NAME (aout,
     set_arch_mach) in aoutx.h, but I don't want to do that since
     target-specific things should not be added there.  */

  obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;
  
  return true;
}

/*
 * Local variables:
 * eval: (c-set-style "gnu")
 * indent-tabs-mode: t
 * End:
 */