/* Motorola MCore specific support for 32-bit ELF
Copyright (C) 1994-2016 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. */
/* This file is based on a preliminary RCE ELF ABI. The
information may not match the final RCE ELF ABI. */
#include "sysdep.h"
#include "bfd.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/mcore.h"
#include <assert.h>
/* RELA relocs are used here... */
/* Function to set whether a module needs the -mrelocatable bit set. */
static bfd_boolean
mcore_elf_set_private_flags (bfd * abfd, flagword flags)
{
BFD_ASSERT (! elf_flags_init (abfd)
|| elf_elfheader (abfd)->e_flags == flags);
elf_elfheader (abfd)->e_flags = flags;
elf_flags_init (abfd) = TRUE;
return TRUE;
}
/* Merge backend specific data from an object file to the output
object file when linking. */
static bfd_boolean
mcore_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
{
flagword old_flags;
flagword new_flags;
/* Check if we have the same endianness. */
if (! _bfd_generic_verify_endian_match (ibfd, obfd))
return FALSE;
if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour
|| bfd_get_flavour (obfd) != bfd_target_elf_flavour)
return TRUE;
new_flags = elf_elfheader (ibfd)->e_flags;
old_flags = elf_elfheader (obfd)->e_flags;
if (! elf_flags_init (obfd))
{
/* First call, no flags set. */
elf_flags_init (obfd) = TRUE;
elf_elfheader (obfd)->e_flags = new_flags;
}
else if (new_flags == old_flags)
/* Compatible flags are OK. */
;
else
{
/* FIXME */
}
return TRUE;
}
/* Don't pretend we can deal with unsupported relocs. */
static bfd_reloc_status_type
mcore_elf_unsupported_reloc (bfd * abfd,
arelent * reloc_entry,
asymbol * symbol ATTRIBUTE_UNUSED,
void * data ATTRIBUTE_UNUSED,
asection * input_section ATTRIBUTE_UNUSED,
bfd * output_bfd ATTRIBUTE_UNUSED,
char ** error_message ATTRIBUTE_UNUSED)
{
BFD_ASSERT (reloc_entry->howto != (reloc_howto_type *)0);
_bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"),
abfd,
reloc_entry->howto->name,
reloc_entry->howto->type);
return bfd_reloc_notsupported;
}
static reloc_howto_type * mcore_elf_howto_table [(int) R_MCORE_max];
static reloc_howto_type mcore_elf_howto_raw[] =
{
/* This reloc does nothing. */
HOWTO (R_MCORE_NONE, /* type */
0, /* rightshift */
3, /* size (0 = byte, 1 = short, 2 = long) */
0, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
NULL, /* special_function */
"R_MCORE_NONE", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* A standard 32 bit relocation. */
HOWTO (R_MCORE_ADDR32, /* type */
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"ADDR32", /* name *//* For compatibility with coff/pe port. */
FALSE, /* partial_inplace */
0x0, /* src_mask */
0xffffffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* 8 bits + 2 zero bits; jmpi/jsri/lrw instructions.
Should not appear in object files. */
HOWTO (R_MCORE_PCRELIMM8BY4, /* type */
2, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
mcore_elf_unsupported_reloc, /* special_function */
"R_MCORE_PCRELIMM8BY4",/* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
TRUE), /* pcrel_offset */
/* bsr/bt/bf/br instructions; 11 bits + 1 zero bit
Span 2k instructions == 4k bytes.
Only useful pieces at the relocated address are the opcode (5 bits) */
HOWTO (R_MCORE_PCRELIMM11BY2,/* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
11, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_signed, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_MCORE_PCRELIMM11BY2",/* name */
FALSE, /* partial_inplace */
0x0, /* src_mask */
0x7ff, /* dst_mask */
TRUE), /* pcrel_offset */
/* 4 bits + 1 zero bit; 'loopt' instruction only; unsupported. */
HOWTO (R_MCORE_PCRELIMM4BY2, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
4, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
mcore_elf_unsupported_reloc,/* special_function */
"R_MCORE_PCRELIMM4BY2",/* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
TRUE), /* pcrel_offset */
/* 32-bit pc-relative. Eventually this will help support PIC code. */
HOWTO (R_MCORE_PCREL32, /* type */
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_MCORE_PCREL32", /* name */
FALSE, /* partial_inplace */
0x0, /* src_mask */
0xffffffff, /* dst_mask */
TRUE), /* pcrel_offset */
/* Like PCRELIMM11BY2, this relocation indicates that there is a
'jsri' at the specified address. There is a separate relocation
entry for the literal pool entry that it references, but we
might be able to change the jsri to a bsr if the target turns out
to be close enough [even though we won't reclaim the literal pool
entry, we'll get some runtime efficiency back]. Note that this
is a relocation that we are allowed to safely ignore. */
HOWTO (R_MCORE_PCRELJSR_IMM11BY2,/* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
11, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_signed, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_MCORE_PCRELJSR_IMM11BY2", /* name */
FALSE, /* partial_inplace */
0x0, /* src_mask */
0x7ff, /* dst_mask */
TRUE), /* pcrel_offset */
/* GNU extension to record C++ vtable hierarchy. */
HOWTO (R_MCORE_GNU_VTINHERIT, /* type */
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
0, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
NULL, /* special_function */
"R_MCORE_GNU_VTINHERIT", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* GNU extension to record C++ vtable member usage. */
HOWTO (R_MCORE_GNU_VTENTRY, /* type */
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
0, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont,/* complain_on_overflow */
_bfd_elf_rel_vtable_reloc_fn, /* special_function */
"R_MCORE_GNU_VTENTRY", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
HOWTO (R_MCORE_RELATIVE, /* type */
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_signed, /* complain_on_overflow */
NULL, /* special_function */
"R_MCORE_RELATIVE", /* name */
TRUE, /* partial_inplace */
0xffffffff, /* src_mask */
0xffffffff, /* dst_mask */
FALSE) /* pcrel_offset */
};
#ifndef NUM_ELEM
#define NUM_ELEM(a) (sizeof (a) / sizeof (a)[0])
#endif
/* Initialize the mcore_elf_howto_table, so that linear accesses can be done. */
static void
mcore_elf_howto_init (void)
{
unsigned int i;
for (i = NUM_ELEM (mcore_elf_howto_raw); i--;)
{
unsigned int type;
type = mcore_elf_howto_raw[i].type;
BFD_ASSERT (type < NUM_ELEM (mcore_elf_howto_table));
mcore_elf_howto_table [type] = & mcore_elf_howto_raw [i];
}
}
static reloc_howto_type *
mcore_elf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
bfd_reloc_code_real_type code)
{
enum elf_mcore_reloc_type mcore_reloc = R_MCORE_NONE;
switch (code)
{
case BFD_RELOC_NONE: mcore_reloc = R_MCORE_NONE; break;
case BFD_RELOC_32: mcore_reloc = R_MCORE_ADDR32; break;
case BFD_RELOC_MCORE_PCREL_IMM8BY4: mcore_reloc = R_MCORE_PCRELIMM8BY4; break;
case BFD_RELOC_MCORE_PCREL_IMM11BY2: mcore_reloc = R_MCORE_PCRELIMM11BY2; break;
case BFD_RELOC_MCORE_PCREL_IMM4BY2: mcore_reloc = R_MCORE_PCRELIMM4BY2; break;
case BFD_RELOC_32_PCREL: mcore_reloc = R_MCORE_PCREL32; break;
case BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2: mcore_reloc = R_MCORE_PCRELJSR_IMM11BY2; break;
case BFD_RELOC_VTABLE_INHERIT: mcore_reloc = R_MCORE_GNU_VTINHERIT; break;
case BFD_RELOC_VTABLE_ENTRY: mcore_reloc = R_MCORE_GNU_VTENTRY; break;
case BFD_RELOC_RVA: mcore_reloc = R_MCORE_RELATIVE; break;
default:
return NULL;
}
if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])
/* Initialize howto table if needed. */
mcore_elf_howto_init ();
return mcore_elf_howto_table [(int) mcore_reloc];
};
static reloc_howto_type *
mcore_elf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
const char *r_name)
{
unsigned int i;
for (i = 0;
i < sizeof (mcore_elf_howto_raw) / sizeof (mcore_elf_howto_raw[0]);
i++)
if (mcore_elf_howto_raw[i].name != NULL
&& strcasecmp (mcore_elf_howto_raw[i].name, r_name) == 0)
return &mcore_elf_howto_raw[i];
return NULL;
}
/* Set the howto pointer for a RCE ELF reloc. */
static void
mcore_elf_info_to_howto (bfd * abfd ATTRIBUTE_UNUSED,
arelent * cache_ptr,
Elf_Internal_Rela * dst)
{
unsigned int r_type;
if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])
/* Initialize howto table if needed. */
mcore_elf_howto_init ();
r_type = ELF32_R_TYPE (dst->r_info);
if (r_type >= R_MCORE_max)
{
(*_bfd_error_handler) (_("%B: unrecognised MCore reloc number: %d"),
abfd, r_type);
bfd_set_error (bfd_error_bad_value);
r_type = R_MCORE_NONE;
}
cache_ptr->howto = mcore_elf_howto_table [r_type];
}
/* The RELOCATE_SECTION function is called by the ELF backend linker
to handle the relocations for a section.
The relocs are always passed as Rela structures; if the section
actually uses Rel structures, the r_addend field will always be
zero.
This function is responsible for adjust the section contents as
necessary, and (if using Rela relocs and generating a
relocatable output file) adjusting the reloc addend as
necessary.
This function does not have to worry about setting the reloc
address or the reloc symbol index.
LOCAL_SYMS is a pointer to the swapped in local symbols.
LOCAL_SECTIONS is an array giving the section in the input file
corresponding to the st_shndx field of each local symbol.
The global hash table entry for the global symbols can be found
via elf_sym_hashes (input_bfd).
When generating relocatable output, this function must handle
STB_LOCAL/STT_SECTION symbols specially. The output symbol is
going to be the section symbol corresponding to the output
section, which means that the addend must be adjusted
accordingly. */
static bfd_boolean
mcore_elf_relocate_section (bfd * output_bfd,
struct bfd_link_info * info,
bfd * input_bfd,
asection * input_section,
bfd_byte * contents,
Elf_Internal_Rela * relocs,
Elf_Internal_Sym * local_syms,
asection ** local_sections)
{
Elf_Internal_Shdr * symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
struct elf_link_hash_entry ** sym_hashes = elf_sym_hashes (input_bfd);
Elf_Internal_Rela * rel = relocs;
Elf_Internal_Rela * relend = relocs + input_section->reloc_count;
bfd_boolean ret = TRUE;
#ifdef DEBUG
_bfd_error_handler
("mcore_elf_relocate_section called for %B section %A, %ld relocations%s",
input_bfd,
input_section,
(long) input_section->reloc_count,
(bfd_link_relocatable (info)) ? " (relocatable)" : "");
#endif
if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4]) /* Initialize howto table if needed */
mcore_elf_howto_init ();
for (; rel < relend; rel++)
{
enum elf_mcore_reloc_type r_type = (enum elf_mcore_reloc_type) ELF32_R_TYPE (rel->r_info);
bfd_vma offset = rel->r_offset;
bfd_vma addend = rel->r_addend;
bfd_reloc_status_type r = bfd_reloc_other;
asection * sec = NULL;
reloc_howto_type * howto;
bfd_vma relocation;
Elf_Internal_Sym * sym = NULL;
unsigned long r_symndx;
struct elf_link_hash_entry * h = NULL;
unsigned short oldinst = 0;
/* Unknown relocation handling. */
if ((unsigned) r_type >= (unsigned) R_MCORE_max
|| ! mcore_elf_howto_table [(int)r_type])
{
_bfd_error_handler (_("%B: Unknown relocation type %d\n"),
input_bfd, (int) r_type);
bfd_set_error (bfd_error_bad_value);
ret = FALSE;
continue;
}
howto = mcore_elf_howto_table [(int) r_type];
r_symndx = ELF32_R_SYM (rel->r_info);
/* Complain about known relocation that are not yet supported. */
if (howto->special_function == mcore_elf_unsupported_reloc)
{
_bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"),
input_bfd,
howto->name,
(int)r_type);
bfd_set_error (bfd_error_bad_value);
ret = FALSE;
continue;
}
if (r_symndx < symtab_hdr->sh_info)
{
sym = local_syms + r_symndx;
sec = local_sections [r_symndx];
relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
addend = rel->r_addend;
}
else
{
bfd_boolean unresolved_reloc, warned, ignored;
RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
r_symndx, symtab_hdr, sym_hashes,
h, sec, relocation,
unresolved_reloc, warned, ignored);
}
if (sec != NULL && discarded_section (sec))
RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
rel, 1, relend, howto, 0, contents);
if (bfd_link_relocatable (info))
continue;
switch (r_type)
{
default:
break;
case R_MCORE_PCRELJSR_IMM11BY2:
oldinst = bfd_get_16 (input_bfd, contents + offset);
#define MCORE_INST_BSR 0xF800
bfd_put_16 (input_bfd, (bfd_vma) MCORE_INST_BSR, contents + offset);
break;
}
#ifdef DEBUG
fprintf (stderr, "\ttype = %s (%d), symbol index = %ld, offset = %ld, addend = %ld\n",
howto->name, r_type, r_symndx, (long) offset, (long) addend);
#endif
r = _bfd_final_link_relocate
(howto, input_bfd, input_section, contents, offset, relocation, addend);
if (r != bfd_reloc_ok && r_type == R_MCORE_PCRELJSR_IMM11BY2)
{
/* Wasn't ok, back it out and give up. */
bfd_put_16 (input_bfd, (bfd_vma) oldinst, contents + offset);
r = bfd_reloc_ok;
}
if (r != bfd_reloc_ok)
{
ret = FALSE;
switch (r)
{
default:
break;
case bfd_reloc_overflow:
{
const char * name;
if (h != NULL)
name = NULL;
else
{
name = bfd_elf_string_from_elf_section
(input_bfd, symtab_hdr->sh_link, sym->st_name);
if (name == NULL)
break;
if (* name == '\0')
name = bfd_section_name (input_bfd, sec);
}
(*info->callbacks->reloc_overflow)
(info, (h ? &h->root : NULL), name, howto->name,
(bfd_vma) 0, input_bfd, input_section, offset);
}
break;
}
}
}
#ifdef DEBUG
fprintf (stderr, "\n");
#endif
return ret;
}
/* Return the section that should be marked against GC for a given
relocation. */
static asection *
mcore_elf_gc_mark_hook (asection *sec,
struct bfd_link_info *info,
Elf_Internal_Rela *rel,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
if (h != NULL)
switch (ELF32_R_TYPE (rel->r_info))
{
case R_MCORE_GNU_VTINHERIT:
case R_MCORE_GNU_VTENTRY:
return NULL;
}
return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
}
/* Update the got entry reference counts for the section being removed. */
static bfd_boolean
mcore_elf_gc_sweep_hook (bfd * abfd ATTRIBUTE_UNUSED,
struct bfd_link_info * info ATTRIBUTE_UNUSED,
asection * sec ATTRIBUTE_UNUSED,
const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED)
{
return TRUE;
}
/* Look through the relocs for a section during the first phase.
Since we don't do .gots or .plts, we just need to consider the
virtual table relocs for gc. */
static bfd_boolean
mcore_elf_check_relocs (bfd * abfd,
struct bfd_link_info * info,
asection * sec,
const Elf_Internal_Rela * relocs)
{
Elf_Internal_Shdr * symtab_hdr;
struct elf_link_hash_entry ** sym_hashes;
const Elf_Internal_Rela * rel;
const Elf_Internal_Rela * rel_end;
if (bfd_link_relocatable (info))
return TRUE;
symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (abfd);
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
struct elf_link_hash_entry * h;
unsigned long r_symndx;
r_symndx = ELF32_R_SYM (rel->r_info);
if (r_symndx < symtab_hdr->sh_info)
h = NULL;
else
{
h = sym_hashes [r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* PR15323, ref flags aren't set for references in the same
object. */
h->root.non_ir_ref = 1;
}
switch (ELF32_R_TYPE (rel->r_info))
{
/* This relocation describes the C++ object vtable hierarchy.
Reconstruct it for later use during GC. */
case R_MCORE_GNU_VTINHERIT:
if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
return FALSE;
break;
/* This relocation describes which C++ vtable entries are actually
used. Record for later use during GC. */
case R_MCORE_GNU_VTENTRY:
BFD_ASSERT (h != NULL);
if (h != NULL
&& !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
return FALSE;
break;
}
}
return TRUE;
}
static const struct bfd_elf_special_section mcore_elf_special_sections[]=
{
{ STRING_COMMA_LEN (".ctors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
{ STRING_COMMA_LEN (".dtors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
{ NULL, 0, 0, 0, 0 }
};
#define TARGET_BIG_SYM mcore_elf32_be_vec
#define TARGET_BIG_NAME "elf32-mcore-big"
#define TARGET_LITTLE_SYM mcore_elf32_le_vec
#define TARGET_LITTLE_NAME "elf32-mcore-little"
#define ELF_ARCH bfd_arch_mcore
#define ELF_MACHINE_CODE EM_MCORE
#define ELF_MAXPAGESIZE 0x1000 /* 4k, if we ever have 'em */
#define elf_info_to_howto mcore_elf_info_to_howto
#define elf_info_to_howto_rel NULL
#define bfd_elf32_bfd_merge_private_bfd_data mcore_elf_merge_private_bfd_data
#define bfd_elf32_bfd_set_private_flags mcore_elf_set_private_flags
#define bfd_elf32_bfd_reloc_type_lookup mcore_elf_reloc_type_lookup
#define bfd_elf32_bfd_reloc_name_lookup mcore_elf_reloc_name_lookup
#define elf_backend_relocate_section mcore_elf_relocate_section
#define elf_backend_gc_mark_hook mcore_elf_gc_mark_hook
#define elf_backend_gc_sweep_hook mcore_elf_gc_sweep_hook
#define elf_backend_check_relocs mcore_elf_check_relocs
#define elf_backend_special_sections mcore_elf_special_sections
#define elf_backend_can_gc_sections 1
#define elf_backend_rela_normal 1
#include "elf32-target.h"