binutils-gdb/bfd/nlm32-ppc.c

/* Support for 32-bit PowerPC NLM (NetWare Loadable Module)
   Copyright 1994, 1995, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   2007 Free Software Foundation, Inc.

   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 3 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., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"

/* The format of a PowerPC NLM changed.  Define OLDFORMAT to get the
   old format.  */

#define ARCH_SIZE 32

#include "nlm/ppc-ext.h"
#define Nlm_External_Fixed_Header	Nlm32_powerpc_External_Fixed_Header

#include "libnlm.h"

#ifdef OLDFORMAT

/* The prefix header is only used in the old format.  */

/* PowerPC NLM's have a prefix header before the standard NLM.  This
   function reads it in, verifies the version, and seeks the bfd to
   the location before the regular NLM header.  */

static bfd_boolean
nlm_powerpc_backend_object_p (bfd *abfd)
{
  struct nlm32_powerpc_external_prefix_header s;

  if (bfd_bread (& s, (bfd_size_type) sizeof s, abfd) != sizeof s)
    return FALSE;

  if (memcmp (s.signature, NLM32_POWERPC_SIGNATURE, sizeof s.signature) != 0
      || H_GET_32 (abfd, s.headerVersion) != NLM32_POWERPC_HEADER_VERSION)
    return FALSE;

  return TRUE;
}

/* Write out the prefix.  */

static bfd_boolean
nlm_powerpc_write_prefix (bfd *abfd)
{
  struct nlm32_powerpc_external_prefix_header s;

  memset (&s, 0, sizeof s);
  memcpy (s.signature, NLM32_POWERPC_SIGNATURE, sizeof s.signature);
  H_PUT_32 (abfd, NLM32_POWERPC_HEADER_VERSION, s.headerVersion);
  H_PUT_32 (abfd, 0, s.origins);

  /* FIXME: What should we do about the date?  */

  if (bfd_bwrite (& s, (bfd_size_type) sizeof s, abfd) != sizeof s)
    return FALSE;

  return TRUE;
}

/* This reloc handling is only applicable to the old format.  */

/* How to process the various reloc types.  PowerPC NLMs use XCOFF
   reloc types, and I have just copied the XCOFF reloc table here.  */

static reloc_howto_type nlm_powerpc_howto_table[] =
{
  /* Standard 32 bit relocation.  */
  HOWTO (0,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_POS",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,            /* Source mask.  */
	 0xffffffff,            /* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* 32 bit relocation, but store negative value.  */
  HOWTO (1,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 -2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_NEG",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,            /* Source mask.  */
	 0xffffffff,            /* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* 32 bit PC relative relocation.  */
  HOWTO (2,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 TRUE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_REL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,            /* Source mask.  */
	 0xffffffff,            /* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* 16 bit TOC relative relocation.  */
  HOWTO (3,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 1,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_TOC",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* I don't really know what this is.  */
  HOWTO (4,	                /* Type.  */
	 1,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RTB",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,	        /* Source mask.  */
	 0xffffffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* External TOC relative symbol.  */
  HOWTO (5,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_GL",                /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Local TOC relative symbol.  */
  HOWTO (6,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_TCL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  { 7 },

  /* Non modifiable absolute branch.  */
  HOWTO (8,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 26,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_BA",                /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0x3fffffc,	        /* Source mask.  */
	 0x3fffffc,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  { 9 },

  /* Non modifiable relative branch.  */
  HOWTO (0xa,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 26,	                /* Bitsize.  */
	 TRUE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_BR",                /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0x3fffffc,	        /* Source mask.  */
	 0x3fffffc,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  { 0xb },

  /* Indirect load.  */
  HOWTO (0xc,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RL",                /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Load address.  */
  HOWTO (0xd,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RLA",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  { 0xe },

  /* Non-relocating reference.  */
  HOWTO (0xf,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_REF",               /* Name.  */
	 FALSE,	                /* Partial_inplace.  */
	 0,		        /* Source mask.  */
	 0,     	   	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  { 0x10 },
  { 0x11 },

  /* TOC relative indirect load.  */
  HOWTO (0x12,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_TRL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* TOC relative load address.  */
  HOWTO (0x13,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_TRLA",              /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable relative branch.  */
  HOWTO (0x14,	                /* Type.  */
	 1,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RRTBI",             /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,	        /* Source mask.  */
	 0xffffffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable absolute branch.  */
  HOWTO (0x15,	                /* Type.  */
	 1,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 32,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RRTBA",             /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffffffff,	        /* Source mask.  */
	 0xffffffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable call absolute indirect.  */
  HOWTO (0x16,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_CAI",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable call relative.  */
  HOWTO (0x17,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_REL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable branch absolute.  */
  HOWTO (0x18,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RBA",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable branch absolute.  */
  HOWTO (0x19,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_RBAC",              /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable branch relative.  */
  HOWTO (0x1a,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 26,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_REL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE),                /* PC rel offset.  */

  /* Modifiable branch absolute.  */
  HOWTO (0x1b,	                /* Type.  */
	 0,	                /* Rightshift.  */
	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
	 16,	                /* Bitsize.  */
	 FALSE,	                /* PC relative.  */
	 0,	                /* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,		        /* Special_function.  */
	 "R_REL",               /* Name.  */
	 TRUE,	                /* Partial_inplace.  */
	 0xffff,	        /* Source mask.  */
	 0xffff,        	/* Dest mask.  */
	 FALSE)                 /* PC rel offset.  */
};

#define HOWTO_COUNT (sizeof nlm_powerpc_howto_table		\
		     / sizeof nlm_powerpc_howto_table[0])

/* Read a PowerPC NLM reloc.  */

static bfd_boolean
nlm_powerpc_read_reloc (bfd *abfd,
			nlmNAME (symbol_type) *sym,
			asection **secp,
			arelent *rel)
{
  struct nlm32_powerpc_external_reloc ext;
  bfd_vma l_vaddr;
  unsigned long l_symndx;
  int l_rtype;
  int l_rsecnm;
  asection *code_sec, *data_sec, *bss_sec;

  /* Read the reloc from the file.  */
  if (bfd_bread (&ext, (bfd_size_type) sizeof ext, abfd) != sizeof ext)
    return FALSE;

  /* Swap in the fields.  */
  l_vaddr = H_GET_32 (abfd, ext.l_vaddr);
  l_symndx = H_GET_32 (abfd, ext.l_symndx);
  l_rtype = H_GET_16 (abfd, ext.l_rtype);
  l_rsecnm = H_GET_16 (abfd, ext.l_rsecnm);

  /* Get the sections now, for convenience.  */
  code_sec = bfd_get_section_by_name (abfd, NLM_CODE_NAME);
  data_sec = bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);
  bss_sec = bfd_get_section_by_name (abfd, NLM_UNINITIALIZED_DATA_NAME);

  /* Work out the arelent fields.  */
  if (sym != NULL)
    /* This is an import.  sym_ptr_ptr is filled in by
       nlm_canonicalize_reloc.  */
    rel->sym_ptr_ptr = NULL;
  else
    {
      asection *sec;

      if (l_symndx == 0)
	sec = code_sec;
      else if (l_symndx == 1)
	sec = data_sec;
      else if (l_symndx == 2)
	sec = bss_sec;
      else
	{
	  bfd_set_error (bfd_error_bad_value);
	  return FALSE;
	}

      rel->sym_ptr_ptr = sec->symbol_ptr_ptr;
    }

  rel->addend = 0;

  BFD_ASSERT ((l_rtype & 0xff) < HOWTO_COUNT);

  rel->howto = nlm_powerpc_howto_table + (l_rtype & 0xff);

  BFD_ASSERT (rel->howto->name != NULL
	      && ((l_rtype & 0x8000) != 0
		  ? (rel->howto->complain_on_overflow
		     == complain_overflow_signed)
		  : (rel->howto->complain_on_overflow
		     == complain_overflow_bitfield))
	      && ((l_rtype >> 8) & 0x1f) == rel->howto->bitsize - 1);

  if (l_rsecnm == 0)
    *secp = code_sec;
  else if (l_rsecnm == 1)
    {
      *secp = data_sec;
      l_vaddr -= code_sec->size;
    }
  else
    {
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  rel->address = l_vaddr;

  return TRUE;
}

#else /* not OLDFORMAT */

/* There is only one type of reloc in a PowerPC NLM.  */

static reloc_howto_type nlm_powerpc_howto =
  HOWTO (0,			/* Type.  */
	 0,			/* Rightshift.  */
	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
	 32,			/* Bitsize.  */
	 FALSE,			/* PC relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 0,			/* Special_function.  */
	 "32",			/* Name.  */
	 TRUE,			/* Partial_inplace.  */
	 0xffffffff,		/* Source mask.  */
	 0xffffffff,		/* Dest mask.  */
	 FALSE);		/* PC rel_offset.  */

/* Read a PowerPC NLM reloc.  */

static bfd_boolean
nlm_powerpc_read_reloc (bfd *abfd,
			nlmNAME (symbol_type) *sym,
			asection **secp,
			arelent *rel)
{
  bfd_byte temp[4];
  bfd_vma val;
  const char *name;

  if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
    return FALSE;

  val = bfd_get_32 (abfd, temp);

  /* The value is a word offset into either the code or data segment.
     This is the location which needs to be adjusted.

     The high bit is 0 if the value is an offset into the data
     segment, or 1 if the value is an offset into the text segment.

     If this is a relocation fixup rather than an imported symbol (the
     sym argument is NULL), then the second most significant bit is 0
     if the address of the data segment should be added to the
     location addressed by the value, or 1 if the address of the text
     segment should be added.

     If this is an imported symbol, the second most significant bit is
     not used and must be 0.  */

  if ((val & NLM_HIBIT) == 0)
    name = NLM_INITIALIZED_DATA_NAME;
  else
    {
      name = NLM_CODE_NAME;
      val &=~ NLM_HIBIT;
    }
  *secp = bfd_get_section_by_name (abfd, name);

  if (sym == NULL)
    {
      if ((val & (NLM_HIBIT >> 1)) == 0)
	name = NLM_INITIALIZED_DATA_NAME;
      else
	{
	  name = NLM_CODE_NAME;
	  val &=~ (NLM_HIBIT >> 1);
	}
      rel->sym_ptr_ptr = bfd_get_section_by_name (abfd, name)->symbol_ptr_ptr;
    }

  rel->howto   = & nlm_powerpc_howto;
  rel->address = val << 2;
  rel->addend  = 0;

  return TRUE;
}

#endif /* not OLDFORMAT */

/* Mangle PowerPC NLM relocs for output.  */

static bfd_boolean
nlm_powerpc_mangle_relocs (bfd *abfd ATTRIBUTE_UNUSED,
			   asection *sec ATTRIBUTE_UNUSED,
			   const void * data ATTRIBUTE_UNUSED,
			   bfd_vma offset ATTRIBUTE_UNUSED,
			   bfd_size_type count ATTRIBUTE_UNUSED)
{
  return TRUE;
}

/* Read a PowerPC NLM import record */

static bfd_boolean
nlm_powerpc_read_import (bfd * abfd, nlmNAME (symbol_type) * sym)
{
  struct nlm_relent *nlm_relocs;	/* Relocation records for symbol.  */
  bfd_size_type rcount;			/* Number of relocs.  */
  bfd_byte temp[NLM_TARGET_LONG_SIZE];	/* Temporary 32-bit value.  */
  unsigned char symlength;		/* Length of symbol name.  */
  char *name;

  if (bfd_bread (& symlength, (bfd_size_type) sizeof (symlength), abfd)
      != sizeof (symlength))
    return FALSE;
  sym -> symbol.the_bfd = abfd;
  name = bfd_alloc (abfd, (bfd_size_type) symlength + 1);
  if (name == NULL)
    return FALSE;
  if (bfd_bread (name, (bfd_size_type) symlength, abfd) != symlength)
    return FALSE;
  name[symlength] = '\0';
  sym -> symbol.name = name;
  sym -> symbol.flags = 0;
  sym -> symbol.value = 0;
  sym -> symbol.section = bfd_und_section_ptr;
  if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd)
      != sizeof (temp))
    return FALSE;
  rcount = H_GET_32 (abfd, temp);
  nlm_relocs = bfd_alloc (abfd, rcount * sizeof (struct nlm_relent));
  if (nlm_relocs == NULL)
    return FALSE;
  sym -> relocs = nlm_relocs;
  sym -> rcnt = 0;
  while (sym -> rcnt < rcount)
    {
      asection *section;

      if (! nlm_powerpc_read_reloc (abfd, sym, &section, &nlm_relocs -> reloc))
	return FALSE;
      nlm_relocs -> section = section;
      nlm_relocs++;
      sym -> rcnt++;
    }
  return TRUE;
}

#ifndef OLDFORMAT

/* Write a PowerPC NLM reloc.  */

static bfd_boolean
nlm_powerpc_write_import (bfd * abfd, asection * sec, arelent * rel)
{
  asymbol *sym;
  bfd_vma val;
  bfd_byte temp[4];

  /* PowerPC NetWare only supports one kind of reloc.  */
  if (rel->addend != 0
      || rel->howto == NULL
      || rel->howto->rightshift != 0
      || rel->howto->size != 2
      || rel->howto->bitsize != 32
      || rel->howto->bitpos != 0
      || rel->howto->pc_relative
      || (rel->howto->src_mask != 0xffffffff && rel->addend != 0)
      || rel->howto->dst_mask != 0xffffffff)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return FALSE;
    }

  sym = *rel->sym_ptr_ptr;

  /* The value we write out is the offset into the appropriate
     segment, rightshifted by two.  This offset is the section vma,
     adjusted by the vma of the lowest section in that segment, plus
     the address of the relocation.  */
  val = bfd_get_section_vma (abfd, sec) + rel->address;
  if ((val & 3) != 0)
    {
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }
  val >>= 2;

  /* The high bit is 0 if the reloc is in the data section, or 1 if
     the reloc is in the code section.  */
  if (bfd_get_section_flags (abfd, sec) & SEC_DATA)
    val -= nlm_get_data_low (abfd);
  else
    {
      val -= nlm_get_text_low (abfd);
      val |= NLM_HIBIT;
    }

  if (! bfd_is_und_section (bfd_get_section (sym)))
    {
      /* This is an internal relocation fixup.  The second most
	 significant bit is 0 if this is a reloc against the data
	 segment, or 1 if it is a reloc against the text segment.  */
      if (bfd_get_section_flags (abfd, bfd_get_section (sym)) & SEC_CODE)
	val |= NLM_HIBIT >> 1;
    }

  bfd_put_32 (abfd, val, temp);
  if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
    return FALSE;

  return TRUE;
}

#else /* OLDFORMAT */

/* This is used for the reloc handling in the old format.  */

/* Write a PowerPC NLM reloc.  */

static bfd_boolean
nlm_powerpc_write_reloc (bfd *abfd,
			 asection *sec,
			 arelent *rel,
			 int indx)
{
  struct nlm32_powerpc_external_reloc ext;
  asection *code_sec, *data_sec, *bss_sec;
  asymbol *sym;
  asection *symsec;
  unsigned long l_symndx;
  int l_rtype;
  int l_rsecnm;
  reloc_howto_type *howto;
  bfd_size_type address;

  /* Get the sections now, for convenience.  */
  code_sec = bfd_get_section_by_name (abfd, NLM_CODE_NAME);
  data_sec = bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);
  bss_sec = bfd_get_section_by_name (abfd, NLM_UNINITIALIZED_DATA_NAME);

  sym = *rel->sym_ptr_ptr;
  symsec = bfd_get_section (sym);
  if (indx != -1)
    {
      BFD_ASSERT (bfd_is_und_section (symsec));
      l_symndx = indx + 3;
    }
  else
    {
      if (symsec == code_sec)
	l_symndx = 0;
      else if (symsec == data_sec)
	l_symndx = 1;
      else if (symsec == bss_sec)
	l_symndx = 2;
      else
	{
	  bfd_set_error (bfd_error_bad_value);
	  return FALSE;
	}
    }

  H_PUT_32 (abfd, l_symndx, ext.l_symndx);

  for (howto = nlm_powerpc_howto_table;
       howto < nlm_powerpc_howto_table + HOWTO_COUNT;
       howto++)
    {
      if (howto->rightshift == rel->howto->rightshift
	  && howto->size == rel->howto->size
	  && howto->bitsize == rel->howto->bitsize
	  && howto->pc_relative == rel->howto->pc_relative
	  && howto->bitpos == rel->howto->bitpos
	  && (howto->partial_inplace == rel->howto->partial_inplace
	      || (! rel->howto->partial_inplace
		  && rel->addend == 0))
	  && (howto->src_mask == rel->howto->src_mask
	      || (rel->howto->src_mask == 0
		  && rel->addend == 0))
	  && howto->dst_mask == rel->howto->dst_mask
	  && howto->pcrel_offset == rel->howto->pcrel_offset)
	break;
    }
  if (howto >= nlm_powerpc_howto_table + HOWTO_COUNT)
    {
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  l_rtype = howto->type;
  if (howto->complain_on_overflow == complain_overflow_signed)
    l_rtype |= 0x8000;
  l_rtype |= (howto->bitsize - 1) << 8;
  H_PUT_16 (abfd, l_rtype, ext.l_rtype);

  address = rel->address;

  if (sec == code_sec)
    l_rsecnm = 0;
  else if (sec == data_sec)
    {
      l_rsecnm = 1;
      address += code_sec->size;
    }
  else
    {
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  H_PUT_16 (abfd, l_rsecnm, ext.l_rsecnm);
  H_PUT_32 (abfd, address, ext.l_vaddr);

  if (bfd_bwrite (&ext, (bfd_size_type) sizeof ext, abfd) != sizeof ext)
    return FALSE;

  return TRUE;
}

/* Write a PowerPC NLM import.  */

static bfd_boolean
nlm_powerpc_write_import (bfd * abfd, asection * sec, arelent * rel)
{
  return nlm_powerpc_write_reloc (abfd, sec, rel, -1);
}

#endif /* OLDFORMAT */

/* Write a PowerPC NLM external symbol.  This routine keeps a static
   count of the symbol index.  FIXME: I don't know if this is
   necessary, and the index never gets reset.  */

static bfd_boolean
nlm_powerpc_write_external (bfd *abfd,
			    bfd_size_type count,
			    asymbol *sym,
			    struct reloc_and_sec *relocs)
{
  unsigned int i;
  bfd_byte len;
  unsigned char temp[NLM_TARGET_LONG_SIZE];
#ifdef OLDFORMAT
  static int indx;
#endif

  len = strlen (sym->name);
  if ((bfd_bwrite (&len, (bfd_size_type) sizeof (bfd_byte), abfd)
       != sizeof (bfd_byte))
      || bfd_bwrite (sym->name, (bfd_size_type) len, abfd) != len)
    return FALSE;

  bfd_put_32 (abfd, count, temp);
  if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
    return FALSE;

  for (i = 0; i < count; i++)
    {
#ifndef OLDFORMAT
      if (! nlm_powerpc_write_import (abfd, relocs[i].sec, relocs[i].rel))
	return FALSE;
#else
      if (! nlm_powerpc_write_reloc (abfd, relocs[i].sec,
				     relocs[i].rel, indx))
	return FALSE;
#endif
    }

#ifdef OLDFORMAT
  ++indx;
#endif

  return TRUE;
}

#ifndef OLDFORMAT

/* PowerPC Netware uses a word offset, not a byte offset, for public
   symbols.  */

/* Set the section for a public symbol.  */

static bfd_boolean
nlm_powerpc_set_public_section (bfd *abfd, nlmNAME (symbol_type) *sym)
{
  if (sym->symbol.value & NLM_HIBIT)
    {
      sym->symbol.value &= ~NLM_HIBIT;
      sym->symbol.flags |= BSF_FUNCTION;
      sym->symbol.section =
	bfd_get_section_by_name (abfd, NLM_CODE_NAME);
    }
  else
    sym->symbol.section =
      bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);

  sym->symbol.value <<= 2;

  return TRUE;
}

/* Get the offset to write out for a public symbol.  */

static bfd_vma
nlm_powerpc_get_public_offset (bfd *abfd, asymbol *sym)
{
  bfd_vma offset;
  asection *sec;

  offset = bfd_asymbol_value (sym);
  sec = bfd_get_section (sym);
  if (sec->flags & SEC_CODE)
    {
      offset -= nlm_get_text_low (abfd);
      offset |= NLM_HIBIT;
    }
  else if (sec->flags & (SEC_DATA | SEC_ALLOC))
    {
      /* SEC_ALLOC is for the .bss section.  */
      offset -= nlm_get_data_low (abfd);
    }
  else
    {
      /* We can't handle an exported symbol that is not in the code or
	 data segment.  */
      bfd_set_error (bfd_error_invalid_operation);
      /* FIXME: No way to return error.  */
      abort ();
    }

  return offset;
}

#endif /* ! defined (OLDFORMAT) */

#include "nlmswap.h"

static const struct nlm_backend_data nlm32_powerpc_backend =
{
  "NetWare PowerPC Module \032",
  sizeof (Nlm32_powerpc_External_Fixed_Header),
#ifndef OLDFORMAT
  0,	/* Optional_prefix_size.  */
#else
  sizeof (struct nlm32_powerpc_external_prefix_header),
#endif
  bfd_arch_powerpc,
  0,
  FALSE,
#ifndef OLDFORMAT
  0,	/* Backend_object_p.  */
  0,	/* Write_prefix.  */
#else
  nlm_powerpc_backend_object_p,
  nlm_powerpc_write_prefix,
#endif
  nlm_powerpc_read_reloc,
  nlm_powerpc_mangle_relocs,
  nlm_powerpc_read_import,
  nlm_powerpc_write_import,
#ifndef OLDFORMAT
  nlm_powerpc_set_public_section,
  nlm_powerpc_get_public_offset,
#else
  0,	/* Set_public_section.  */
  0,	/* Get_public_offset.  */
#endif
  nlm_swap_fixed_header_in,
  nlm_swap_fixed_header_out,
  nlm_powerpc_write_external,
  0,	/* Write_export.  */
};

#define TARGET_BIG_NAME			"nlm32-powerpc"
#define TARGET_BIG_SYM			nlmNAME (powerpc_vec)
#define TARGET_BACKEND_DATA		& nlm32_powerpc_backend

#include "nlm-target.h"