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binutils-gdb/bfd/elf32-avr.c
Nick Clifton 4cdc7696f5 Update formatting to ISO-C90
2006-03-03 15:54:23 +00:00

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68 KiB
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/* AVR-specific support for 32-bit ELF
Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2006
Free Software Foundation, Inc.
Contributed by Denis Chertykov <denisc@overta.ru>
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., 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/avr.h"
static reloc_howto_type elf_avr_howto_table[] =
{
HOWTO (R_AVR_NONE, /* 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 */
"R_AVR_NONE", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
HOWTO (R_AVR_32, /* 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 */
"R_AVR_32", /* name */
FALSE, /* partial_inplace */
0xffffffff, /* src_mask */
0xffffffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A 7 bit PC relative relocation. */
HOWTO (R_AVR_7_PCREL, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
7, /* bitsize */
TRUE, /* pc_relative */
3, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_7_PCREL", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
TRUE), /* pcrel_offset */
/* A 13 bit PC relative relocation. */
HOWTO (R_AVR_13_PCREL, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
13, /* bitsize */
TRUE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_13_PCREL", /* name */
FALSE, /* partial_inplace */
0xfff, /* src_mask */
0xfff, /* dst_mask */
TRUE), /* pcrel_offset */
/* A 16 bit absolute relocation. */
HOWTO (R_AVR_16, /* type */
0, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
16, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_16", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A 16 bit absolute relocation for command address. */
HOWTO (R_AVR_16_PM, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
16, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_16_PM", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A low 8 bit absolute relocation of 16 bit address.
For LDI command. */
HOWTO (R_AVR_LO8_LDI, /* type */
0, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_LO8_LDI", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 8 bit absolute relocation of 16 bit address.
For LDI command. */
HOWTO (R_AVR_HI8_LDI, /* type */
8, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HI8_LDI", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 6 bit absolute relocation of 22 bit address.
For LDI command. As well second most significant 8 bit value of
a 32 bit link-time constant. */
HOWTO (R_AVR_HH8_LDI, /* type */
16, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HH8_LDI", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A negative low 8 bit absolute relocation of 16 bit address.
For LDI command. */
HOWTO (R_AVR_LO8_LDI_NEG, /* type */
0, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_LO8_LDI_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A negative high 8 bit absolute relocation of 16 bit address.
For LDI command. */
HOWTO (R_AVR_HI8_LDI_NEG, /* type */
8, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HI8_LDI_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A negative high 6 bit absolute relocation of 22 bit address.
For LDI command. */
HOWTO (R_AVR_HH8_LDI_NEG, /* type */
16, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HH8_LDI_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A low 8 bit absolute relocation of 24 bit program memory address.
For LDI command. */
HOWTO (R_AVR_LO8_LDI_PM, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_LO8_LDI_PM", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 8 bit absolute relocation of 16 bit program memory address.
For LDI command. */
HOWTO (R_AVR_HI8_LDI_PM, /* type */
9, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HI8_LDI_PM", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 8 bit absolute relocation of 24 bit program memory address.
For LDI command. */
HOWTO (R_AVR_HH8_LDI_PM, /* type */
17, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HH8_LDI_PM", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A low 8 bit absolute relocation of a negative 24 bit
program memory address. For LDI command. */
HOWTO (R_AVR_LO8_LDI_PM_NEG, /* type */
1, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_LO8_LDI_PM_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 8 bit absolute relocation of a negative 16 bit
program memory address. For LDI command. */
HOWTO (R_AVR_HI8_LDI_PM_NEG, /* type */
9, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HI8_LDI_PM_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A high 8 bit absolute relocation of a negative 24 bit
program memory address. For LDI command. */
HOWTO (R_AVR_HH8_LDI_PM_NEG, /* type */
17, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_HH8_LDI_PM_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* Relocation for CALL command in ATmega. */
HOWTO (R_AVR_CALL, /* type */
1, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
23, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont,/* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_CALL", /* name */
FALSE, /* partial_inplace */
0xffffffff, /* src_mask */
0xffffffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A 16 bit absolute relocation of 16 bit address.
For LDI command. */
HOWTO (R_AVR_LDI, /* type */
0, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
16, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont,/* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_LDI", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A 6 bit absolute relocation of 6 bit offset.
For ldd/sdd command. */
HOWTO (R_AVR_6, /* type */
0, /* rightshift */
0, /* size (0 = byte, 1 = short, 2 = long) */
6, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont,/* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_6", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* A 6 bit absolute relocation of 6 bit offset.
For sbiw/adiw command. */
HOWTO (R_AVR_6_ADIW, /* type */
0, /* rightshift */
0, /* size (0 = byte, 1 = short, 2 = long) */
6, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont,/* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_6_ADIW", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* Most significant 8 bit value of a 32 bit link-time constant. */
HOWTO (R_AVR_MS8_LDI, /* type */
24, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_MS8_LDI", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE), /* pcrel_offset */
/* Negative most significant 8 bit value of a 32 bit link-time constant. */
HOWTO (R_AVR_MS8_LDI_NEG, /* type */
24, /* rightshift */
1, /* size (0 = byte, 1 = short, 2 = long) */
8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_AVR_MS8_LDI_NEG", /* name */
FALSE, /* partial_inplace */
0xffff, /* src_mask */
0xffff, /* dst_mask */
FALSE) /* pcrel_offset */
};
/* Map BFD reloc types to AVR ELF reloc types. */
struct avr_reloc_map
{
bfd_reloc_code_real_type bfd_reloc_val;
unsigned int elf_reloc_val;
};
static const struct avr_reloc_map avr_reloc_map[] =
{
{ BFD_RELOC_NONE, R_AVR_NONE },
{ BFD_RELOC_32, R_AVR_32 },
{ BFD_RELOC_AVR_7_PCREL, R_AVR_7_PCREL },
{ BFD_RELOC_AVR_13_PCREL, R_AVR_13_PCREL },
{ BFD_RELOC_16, R_AVR_16 },
{ BFD_RELOC_AVR_16_PM, R_AVR_16_PM },
{ BFD_RELOC_AVR_LO8_LDI, R_AVR_LO8_LDI},
{ BFD_RELOC_AVR_HI8_LDI, R_AVR_HI8_LDI },
{ BFD_RELOC_AVR_HH8_LDI, R_AVR_HH8_LDI },
{ BFD_RELOC_AVR_MS8_LDI, R_AVR_MS8_LDI },
{ BFD_RELOC_AVR_LO8_LDI_NEG, R_AVR_LO8_LDI_NEG },
{ BFD_RELOC_AVR_HI8_LDI_NEG, R_AVR_HI8_LDI_NEG },
{ BFD_RELOC_AVR_HH8_LDI_NEG, R_AVR_HH8_LDI_NEG },
{ BFD_RELOC_AVR_MS8_LDI_NEG, R_AVR_MS8_LDI_NEG },
{ BFD_RELOC_AVR_LO8_LDI_PM, R_AVR_LO8_LDI_PM },
{ BFD_RELOC_AVR_HI8_LDI_PM, R_AVR_HI8_LDI_PM },
{ BFD_RELOC_AVR_HH8_LDI_PM, R_AVR_HH8_LDI_PM },
{ BFD_RELOC_AVR_LO8_LDI_PM_NEG, R_AVR_LO8_LDI_PM_NEG },
{ BFD_RELOC_AVR_HI8_LDI_PM_NEG, R_AVR_HI8_LDI_PM_NEG },
{ BFD_RELOC_AVR_HH8_LDI_PM_NEG, R_AVR_HH8_LDI_PM_NEG },
{ BFD_RELOC_AVR_CALL, R_AVR_CALL },
{ BFD_RELOC_AVR_LDI, R_AVR_LDI },
{ BFD_RELOC_AVR_6, R_AVR_6 },
{ BFD_RELOC_AVR_6_ADIW, R_AVR_6_ADIW }
};
/* Meant to be filled one day with the wrap around address for the
specific device. I.e. should get the value 0x4000 for 16k devices,
0x8000 for 32k devices and so on.
We initialize it here with a value of 0x1000000 resulting in
that we will never suggest a wrap-around jump during relaxation.
The logic of the source code later on assumes that in
avr_pc_wrap_around one single bit is set. */
unsigned int avr_pc_wrap_around = 0x10000000;
/* Calculates the effective distance of a pc relative jump/call. */
static int
avr_relative_distance_considering_wrap_around (unsigned int distance)
{
unsigned int wrap_around_mask = avr_pc_wrap_around - 1;
int dist_with_wrap_around = distance & wrap_around_mask;
if (dist_with_wrap_around > ((int) (avr_pc_wrap_around >> 1)))
dist_with_wrap_around -= avr_pc_wrap_around;
return dist_with_wrap_around;
}
static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
bfd_reloc_code_real_type code)
{
unsigned int i;
for (i = 0;
i < sizeof (avr_reloc_map) / sizeof (struct avr_reloc_map);
i++)
{
if (avr_reloc_map[i].bfd_reloc_val == code)
return &elf_avr_howto_table[avr_reloc_map[i].elf_reloc_val];
}
return NULL;
}
/* Set the howto pointer for an AVR ELF reloc. */
static void
avr_info_to_howto_rela (bfd *abfd ATTRIBUTE_UNUSED,
arelent *cache_ptr,
Elf_Internal_Rela *dst)
{
unsigned int r_type;
r_type = ELF32_R_TYPE (dst->r_info);
BFD_ASSERT (r_type < (unsigned int) R_AVR_max);
cache_ptr->howto = &elf_avr_howto_table[r_type];
}
static asection *
elf32_avr_gc_mark_hook (asection *sec,
struct bfd_link_info *info ATTRIBUTE_UNUSED,
Elf_Internal_Rela *rel,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
if (h != NULL)
{
switch (ELF32_R_TYPE (rel->r_info))
{
default:
switch (h->root.type)
{
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
return h->root.u.def.section;
case bfd_link_hash_common:
return h->root.u.c.p->section;
default:
break;
}
}
}
else
return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
return NULL;
}
static bfd_boolean
elf32_avr_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)
{
/* We don't use got and plt entries for avr. */
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
elf32_avr_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, **sym_hashes_end;
const Elf_Internal_Rela *rel;
const Elf_Internal_Rela *rel_end;
if (info->relocatable)
return TRUE;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (abfd);
sym_hashes_end = sym_hashes + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
if (!elf_bad_symtab (abfd))
sym_hashes_end -= symtab_hdr->sh_info;
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;
}
}
return TRUE;
}
/* Perform a single relocation. By default we use the standard BFD
routines, but a few relocs, we have to do them ourselves. */
static bfd_reloc_status_type
avr_final_link_relocate (reloc_howto_type * howto,
bfd * input_bfd,
asection * input_section,
bfd_byte * contents,
Elf_Internal_Rela * rel,
bfd_vma relocation)
{
bfd_reloc_status_type r = bfd_reloc_ok;
bfd_vma x;
bfd_signed_vma srel;
switch (howto->type)
{
case R_AVR_7_PCREL:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation;
srel += rel->r_addend;
srel -= rel->r_offset;
srel -= 2; /* Branch instructions add 2 to the PC... */
srel -= (input_section->output_section->vma +
input_section->output_offset);
if (srel & 1)
return bfd_reloc_outofrange;
if (srel > ((1 << 7) - 1) || (srel < - (1 << 7)))
return bfd_reloc_overflow;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xfc07) | (((srel >> 1) << 3) & 0x3f8);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_13_PCREL:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation;
srel += rel->r_addend;
srel -= rel->r_offset;
srel -= 2; /* Branch instructions add 2 to the PC... */
srel -= (input_section->output_section->vma +
input_section->output_offset);
if (srel & 1)
return bfd_reloc_outofrange;
srel = avr_relative_distance_considering_wrap_around (srel);
/* AVR addresses commands as words. */
srel >>= 1;
/* Check for overflow. */
if (srel < -2048 || srel > 2047)
{
/* Relative distance is too large. */
/* Always apply WRAPAROUND for avr2 and avr4. */
switch (bfd_get_mach (input_bfd))
{
case bfd_mach_avr2:
case bfd_mach_avr4:
break;
default:
return bfd_reloc_overflow;
}
}
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf000) | (srel & 0xfff);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_LO8_LDI:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_LDI:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (((srel > 0) && (srel & 0xffff) > 255)
|| ((srel < 0) && ((-srel) & 0xffff) > 128))
/* Remove offset for data/eeprom section. */
return bfd_reloc_overflow;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_6:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (((srel & 0xffff) > 63) || (srel < 0))
/* Remove offset for data/eeprom section. */
return bfd_reloc_overflow;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xd3f8) | ((srel & 7) | ((srel & (3 << 3)) << 7)
| ((srel & (1 << 5)) << 8));
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_6_ADIW:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (((srel & 0xffff) > 63) || (srel < 0))
/* Remove offset for data/eeprom section. */
return bfd_reloc_overflow;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xff30) | (srel & 0xf) | ((srel & 0x30) << 2);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HI8_LDI:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = (srel >> 8) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HH8_LDI:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = (srel >> 16) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_MS8_LDI:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = (srel >> 24) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_LO8_LDI_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HI8_LDI_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
srel = (srel >> 8) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HH8_LDI_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
srel = (srel >> 16) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_MS8_LDI_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
srel = (srel >> 24) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_LO8_LDI_PM:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HI8_LDI_PM:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
srel = (srel >> 8) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HH8_LDI_PM:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
srel = (srel >> 16) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_LO8_LDI_PM_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HI8_LDI_PM_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
srel = (srel >> 8) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_HH8_LDI_PM_NEG:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
srel = -srel;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
srel = (srel >> 16) & 0xff;
x = bfd_get_16 (input_bfd, contents);
x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
bfd_put_16 (input_bfd, x, contents);
break;
case R_AVR_CALL:
contents += rel->r_offset;
srel = (bfd_signed_vma) relocation + rel->r_addend;
if (srel & 1)
return bfd_reloc_outofrange;
srel = srel >> 1;
x = bfd_get_16 (input_bfd, contents);
x |= ((srel & 0x10000) | ((srel << 3) & 0x1f00000)) >> 16;
bfd_put_16 (input_bfd, x, contents);
bfd_put_16 (input_bfd, (bfd_vma) srel & 0xffff, contents+2);
break;
default:
r = _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset,
relocation, rel->r_addend);
}
return r;
}
/* Relocate an AVR ELF section. */
static bfd_boolean
elf32_avr_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
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;
struct elf_link_hash_entry ** sym_hashes;
Elf_Internal_Rela * rel;
Elf_Internal_Rela * relend;
if (info->relocatable)
return TRUE;
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
relend = relocs + input_section->reloc_count;
for (rel = relocs; rel < relend; rel ++)
{
reloc_howto_type * howto;
unsigned long r_symndx;
Elf_Internal_Sym * sym;
asection * sec;
struct elf_link_hash_entry * h;
bfd_vma relocation;
bfd_reloc_status_type r;
const char * name;
int r_type;
/* This is a final link. */
r_type = ELF32_R_TYPE (rel->r_info);
r_symndx = ELF32_R_SYM (rel->r_info);
howto = elf_avr_howto_table + ELF32_R_TYPE (rel->r_info);
h = NULL;
sym = NULL;
sec = NULL;
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);
name = bfd_elf_string_from_elf_section
(input_bfd, symtab_hdr->sh_link, sym->st_name);
name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
}
else
{
bfd_boolean unresolved_reloc, warned;
RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
r_symndx, symtab_hdr, sym_hashes,
h, sec, relocation,
unresolved_reloc, warned);
name = h->root.root.string;
}
r = avr_final_link_relocate (howto, input_bfd, input_section,
contents, rel, relocation);
if (r != bfd_reloc_ok)
{
const char * msg = (const char *) NULL;
switch (r)
{
case bfd_reloc_overflow:
r = info->callbacks->reloc_overflow
(info, (h ? &h->root : NULL),
name, howto->name, (bfd_vma) 0,
input_bfd, input_section, rel->r_offset);
break;
case bfd_reloc_undefined:
r = info->callbacks->undefined_symbol
(info, name, input_bfd, input_section, rel->r_offset, TRUE);
break;
case bfd_reloc_outofrange:
msg = _("internal error: out of range error");
break;
case bfd_reloc_notsupported:
msg = _("internal error: unsupported relocation error");
break;
case bfd_reloc_dangerous:
msg = _("internal error: dangerous relocation");
break;
default:
msg = _("internal error: unknown error");
break;
}
if (msg)
r = info->callbacks->warning
(info, msg, name, input_bfd, input_section, rel->r_offset);
if (! r)
return FALSE;
}
}
return TRUE;
}
/* The final processing done just before writing out a AVR ELF object
file. This gets the AVR architecture right based on the machine
number. */
static void
bfd_elf_avr_final_write_processing (bfd *abfd,
bfd_boolean linker ATTRIBUTE_UNUSED)
{
unsigned long val;
switch (bfd_get_mach (abfd))
{
default:
case bfd_mach_avr2:
val = E_AVR_MACH_AVR2;
break;
case bfd_mach_avr1:
val = E_AVR_MACH_AVR1;
break;
case bfd_mach_avr3:
val = E_AVR_MACH_AVR3;
break;
case bfd_mach_avr4:
val = E_AVR_MACH_AVR4;
break;
case bfd_mach_avr5:
val = E_AVR_MACH_AVR5;
break;
}
elf_elfheader (abfd)->e_machine = EM_AVR;
elf_elfheader (abfd)->e_flags &= ~ EF_AVR_MACH;
elf_elfheader (abfd)->e_flags |= val;
elf_elfheader (abfd)->e_flags |= EF_AVR_LINKRELAX_PREPARED;
}
/* Set the right machine number. */
static bfd_boolean
elf32_avr_object_p (bfd *abfd)
{
unsigned int e_set = bfd_mach_avr2;
if (elf_elfheader (abfd)->e_machine == EM_AVR
|| elf_elfheader (abfd)->e_machine == EM_AVR_OLD)
{
int e_mach = elf_elfheader (abfd)->e_flags & EF_AVR_MACH;
switch (e_mach)
{
default:
case E_AVR_MACH_AVR2:
e_set = bfd_mach_avr2;
break;
case E_AVR_MACH_AVR1:
e_set = bfd_mach_avr1;
break;
case E_AVR_MACH_AVR3:
e_set = bfd_mach_avr3;
break;
case E_AVR_MACH_AVR4:
e_set = bfd_mach_avr4;
break;
case E_AVR_MACH_AVR5:
e_set = bfd_mach_avr5;
break;
}
}
return bfd_default_set_arch_mach (abfd, bfd_arch_avr,
e_set);
}
/* Enable debugging printout at stdout with a value of 1. */
#define DEBUG_RELAX 0
/* Delete some bytes from a section while changing the size of an instruction.
The parameter "addr" denotes the section-relative offset pointing just
behind the shrinked instruction. "addr+count" point at the first
byte just behind the original unshrinked instruction. */
static bfd_boolean
elf32_avr_relax_delete_bytes (bfd *abfd,
asection *sec,
bfd_vma addr,
int count)
{
Elf_Internal_Shdr *symtab_hdr;
unsigned int sec_shndx;
bfd_byte *contents;
Elf_Internal_Rela *irel, *irelend;
Elf_Internal_Rela *irelalign;
Elf_Internal_Sym *isym;
Elf_Internal_Sym *isymbuf = NULL;
Elf_Internal_Sym *isymend;
bfd_vma toaddr;
struct elf_link_hash_entry **sym_hashes;
struct elf_link_hash_entry **end_hashes;
unsigned int symcount;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
contents = elf_section_data (sec)->this_hdr.contents;
/* The deletion must stop at the next ALIGN reloc for an aligment
power larger than the number of bytes we are deleting. */
irelalign = NULL;
toaddr = sec->size;
irel = elf_section_data (sec)->relocs;
irelend = irel + sec->reloc_count;
/* Actually delete the bytes. */
if (toaddr - addr - count > 0)
memmove (contents + addr, contents + addr + count,
(size_t) (toaddr - addr - count));
sec->size -= count;
/* Adjust all the relocs. */
for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
{
bfd_vma symval;
bfd_vma old_reloc_address;
bfd_vma shrinked_insn_address;
old_reloc_address = (sec->output_section->vma
+ sec->output_offset + irel->r_offset);
shrinked_insn_address = (sec->output_section->vma
+ sec->output_offset + addr - count);
/* Get the new reloc address. */
if ((irel->r_offset > addr
&& irel->r_offset < toaddr))
{
if (DEBUG_RELAX)
printf ("Relocation at address 0x%x needs to be moved.\n"
"Old section offset: 0x%x, New section offset: 0x%x \n",
(unsigned int) old_reloc_address,
(unsigned int) irel->r_offset,
(unsigned int) ((irel->r_offset) - count));
irel->r_offset -= count;
}
/* The reloc's own addresses are now ok. However, we need to readjust
the reloc's addend if two conditions are met:
1.) the reloc is relative to a symbol in this section that
is located in front of the shrinked instruction
2.) symbol plus addend end up behind the shrinked instruction.
This should happen only for local symbols that are progmem related. */
/* Read this BFD's local symbols if we haven't done so already. */
if (isymbuf == NULL && symtab_hdr->sh_info != 0)
{
isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
if (isymbuf == NULL)
isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
symtab_hdr->sh_info, 0,
NULL, NULL, NULL);
if (isymbuf == NULL)
return FALSE;
}
/* Get the value of the symbol referred to by the reloc. */
if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
{
/* A local symbol. */
Elf_Internal_Sym *isym;
asection *sym_sec;
isym = isymbuf + ELF32_R_SYM (irel->r_info);
sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
symval = isym->st_value;
/* If the reloc is absolute, it will not have
a symbol or section associated with it. */
if (sym_sec)
{
symval += sym_sec->output_section->vma
+ sym_sec->output_offset;
if (DEBUG_RELAX)
printf ("Checking if the relocation's "
"addend needs corrections.\n"
"Address of anchor symbol: 0x%x \n"
"Address of relocation target: 0x%x \n"
"Address of relaxed insn: 0x%x \n",
(unsigned int) symval,
(unsigned int) (symval + irel->r_addend),
(unsigned int) shrinked_insn_address);
if (symval <= shrinked_insn_address
&& (symval + irel->r_addend) > shrinked_insn_address)
{
irel->r_addend -= count;
if (DEBUG_RELAX)
printf ("Anchor symbol and relocation target bracket "
"shrinked insn address.\n"
"Need for new addend : 0x%x\n",
(unsigned int) irel->r_addend);
}
}
/* else ... Reference symbol is absolute. No adjustment needed. */
}
/* else ... Reference symbol is extern. No need for adjusting the addend. */
}
/* Adjust the local symbols defined in this section. */
isym = (Elf_Internal_Sym *) symtab_hdr->contents;
isymend = isym + symtab_hdr->sh_info;
for (; isym < isymend; isym++)
{
if (isym->st_shndx == sec_shndx
&& isym->st_value > addr
&& isym->st_value < toaddr)
isym->st_value -= count;
}
/* Now adjust the global symbols defined in this section. */
symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
- symtab_hdr->sh_info);
sym_hashes = elf_sym_hashes (abfd);
end_hashes = sym_hashes + symcount;
for (; sym_hashes < end_hashes; sym_hashes++)
{
struct elf_link_hash_entry *sym_hash = *sym_hashes;
if ((sym_hash->root.type == bfd_link_hash_defined
|| sym_hash->root.type == bfd_link_hash_defweak)
&& sym_hash->root.u.def.section == sec
&& sym_hash->root.u.def.value > addr
&& sym_hash->root.u.def.value < toaddr)
{
sym_hash->root.u.def.value -= count;
}
}
return TRUE;
}
/* This function handles relaxing for the avr.
Many important relaxing opportunities within functions are already
realized by the compiler itself.
Here we try to replace call (4 bytes) -> rcall (2 bytes)
and jump -> rjmp (safes also 2 bytes).
As well we now optimize seqences of
- call/rcall function
- ret
to yield
- jmp/rjmp function
- ret
. In case that within a sequence
- jmp/rjmp label
- ret
the ret could no longer be reached it is optimized away. In order
to check if the ret is no longer needed, it is checked that the ret's address
is not the target of a branch or jump within the same section, it is checked
that there is no skip instruction before the jmp/rjmp and that there
is no local or global label place at the address of the ret.
We refrain from relaxing within sections ".vectors" and
".jumptables" in order to maintain the position of the instructions.
There, however, we substitute jmp/call by a sequence rjmp,nop/rcall,nop
if possible. (In future one could possibly use the space of the nop
for the first instruction of the irq service function.
The .jumptables sections is meant to be used for a future tablejump variant
for the devices with 3-byte program counter where the table itself
contains 4-byte jump instructions whose relative offset must not
be changed. */
static bfd_boolean
elf32_avr_relax_section (bfd *abfd,
asection *sec,
struct bfd_link_info *link_info,
bfd_boolean *again)
{
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Rela *internal_relocs;
Elf_Internal_Rela *irel, *irelend;
bfd_byte *contents = NULL;
Elf_Internal_Sym *isymbuf = NULL;
static asection *last_input_section = NULL;
static Elf_Internal_Rela *last_reloc = NULL;
/* Assume nothing changes. */
*again = FALSE;
/* We don't have to do anything for a relocatable link, if
this section does not have relocs, or if this is not a
code section. */
if (link_info->relocatable
|| (sec->flags & SEC_RELOC) == 0
|| sec->reloc_count == 0
|| (sec->flags & SEC_CODE) == 0)
return TRUE;
/* Check if the object file to relax uses internal symbols so that we
could fix up the relocations. */
if (!(elf_elfheader (abfd)->e_flags & EF_AVR_LINKRELAX_PREPARED))
return TRUE;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
/* Get a copy of the native relocations. */
internal_relocs = (_bfd_elf_link_read_relocs
(abfd, sec, NULL, NULL, link_info->keep_memory));
if (internal_relocs == NULL)
goto error_return;
if (sec != last_input_section)
last_reloc = NULL;
last_input_section = sec;
/* Walk through the relocs looking for relaxing opportunities. */
irelend = internal_relocs + sec->reloc_count;
for (irel = internal_relocs; irel < irelend; irel++)
{
bfd_vma symval;
if ( ELF32_R_TYPE (irel->r_info) != R_AVR_13_PCREL
&& ELF32_R_TYPE (irel->r_info) != R_AVR_7_PCREL
&& ELF32_R_TYPE (irel->r_info) != R_AVR_CALL)
continue;
/* Get the section contents if we haven't done so already. */
if (contents == NULL)
{
/* Get cached copy if it exists. */
if (elf_section_data (sec)->this_hdr.contents != NULL)
contents = elf_section_data (sec)->this_hdr.contents;
else
{
/* Go get them off disk. */
if (! bfd_malloc_and_get_section (abfd, sec, &contents))
goto error_return;
}
}
/* Read this BFD's local symbols if we haven't done so already. */
if (isymbuf == NULL && symtab_hdr->sh_info != 0)
{
isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
if (isymbuf == NULL)
isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
symtab_hdr->sh_info, 0,
NULL, NULL, NULL);
if (isymbuf == NULL)
goto error_return;
}
/* Get the value of the symbol referred to by the reloc. */
if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
{
/* A local symbol. */
Elf_Internal_Sym *isym;
asection *sym_sec;
isym = isymbuf + ELF32_R_SYM (irel->r_info);
sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
symval = isym->st_value;
/* If the reloc is absolute, it will not have
a symbol or section associated with it. */
if (sym_sec)
symval += sym_sec->output_section->vma
+ sym_sec->output_offset;
}
else
{
unsigned long indx;
struct elf_link_hash_entry *h;
/* An external symbol. */
indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
h = elf_sym_hashes (abfd)[indx];
BFD_ASSERT (h != NULL);
if (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
/* This appears to be a reference to an undefined
symbol. Just ignore it--it will be caught by the
regular reloc processing. */
continue;
symval = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
}
/* For simplicity of coding, we are going to modify the section
contents, the section relocs, and the BFD symbol table. We
must tell the rest of the code not to free up this
information. It would be possible to instead create a table
of changes which have to be made, as is done in coff-mips.c;
that would be more work, but would require less memory when
the linker is run. */
switch (ELF32_R_TYPE (irel->r_info))
{
/* Try to turn a 22-bit absolute call/jump into an 13-bit
pc-relative rcall/rjmp. */
case R_AVR_CALL:
{
bfd_vma value = symval + irel->r_addend;
bfd_vma dot, gap;
int distance_short_enough = 0;
/* Get the address of this instruction. */
dot = (sec->output_section->vma
+ sec->output_offset + irel->r_offset);
/* Compute the distance from this insn to the branch target. */
gap = value - dot;
/* If the distance is within -4094..+4098 inclusive, then we can
relax this jump/call. +4098 because the call/jump target
will be closer after the relaxation. */
if ((int) gap >= -4094 && (int) gap <= 4098)
distance_short_enough = 1;
/* Here we handle the wrap-around case. E.g. for a 16k device
we could use a rjmp to jump from address 0x100 to 0x3d00!
In order to make this work properly, we need to fill the
vaiable avr_pc_wrap_around with the appropriate value.
I.e. 0x4000 for a 16k device. */
{
/* Shrinking the code size makes the gaps larger in the
case of wrap-arounds. So we use a heuristical safety
margin to avoid that during relax the distance gets
again too large for the short jumps. Let's assume
a typical code-size reduction due to relax for a
16k device of 600 bytes. So let's use twice the
typical value as safety margin. */
int rgap;
int safety_margin;
int assumed_shrink = 600;
if (avr_pc_wrap_around > 0x4000)
assumed_shrink = 900;
safety_margin = 2 * assumed_shrink;
rgap = avr_relative_distance_considering_wrap_around (gap);
if (rgap >= (-4092 + safety_margin)
&& rgap <= (4094 - safety_margin))
distance_short_enough = 1;
}
if (distance_short_enough)
{
unsigned char code_msb;
unsigned char code_lsb;
if (DEBUG_RELAX)
printf ("shrinking jump/call instruction at address 0x%x"
" in section %s\n\n",
(int) dot, sec->name);
/* Note that we've changed the relocs, section contents,
etc. */
elf_section_data (sec)->relocs = internal_relocs;
elf_section_data (sec)->this_hdr.contents = contents;
symtab_hdr->contents = (unsigned char *) isymbuf;
/* Get the instruction code for relaxing. */
code_lsb = bfd_get_8 (abfd, contents + irel->r_offset);
code_msb = bfd_get_8 (abfd, contents + irel->r_offset + 1);
/* Mask out the relocation bits. */
code_msb &= 0x94;
code_lsb &= 0x0E;
if (code_msb == 0x94 && code_lsb == 0x0E)
{
/* we are changing call -> rcall . */
bfd_put_8 (abfd, 0x00, contents + irel->r_offset);
bfd_put_8 (abfd, 0xD0, contents + irel->r_offset + 1);
}
else if (code_msb == 0x94 && code_lsb == 0x0C)
{
/* we are changeing jump -> rjmp. */
bfd_put_8 (abfd, 0x00, contents + irel->r_offset);
bfd_put_8 (abfd, 0xC0, contents + irel->r_offset + 1);
}
else
abort ();
/* Fix the relocation's type. */
irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
R_AVR_13_PCREL);
/* Check for the vector section. There we don't want to
modify the ordering! */
if (!strcmp (sec->name,".vectors")
|| !strcmp (sec->name,".jumptables"))
{
/* Let's insert a nop. */
bfd_put_8 (abfd, 0x00, contents + irel->r_offset + 2);
bfd_put_8 (abfd, 0x00, contents + irel->r_offset + 3);
}
else
{
/* Delete two bytes of data. */
if (!elf32_avr_relax_delete_bytes (abfd, sec,
irel->r_offset + 2, 2))
goto error_return;
/* That will change things, so, we should relax again.
Note that this is not required, and it may be slow. */
*again = TRUE;
}
}
}
default:
{
unsigned char code_msb;
unsigned char code_lsb;
bfd_vma dot;
code_msb = bfd_get_8 (abfd, contents + irel->r_offset + 1);
code_lsb = bfd_get_8 (abfd, contents + irel->r_offset + 0);
/* Get the address of this instruction. */
dot = (sec->output_section->vma
+ sec->output_offset + irel->r_offset);
/* Here we look for rcall/ret or call/ret sequences that could be
safely replaced by rjmp/ret or jmp/ret */
if (0xd0 == (code_msb & 0xf0))
{
/* This insn is a rcall. */
unsigned char next_insn_msb = 0;
unsigned char next_insn_lsb = 0;
if (irel->r_offset + 3 < sec->size)
{
next_insn_msb =
bfd_get_8 (abfd, contents + irel->r_offset + 3);
next_insn_lsb =
bfd_get_8 (abfd, contents + irel->r_offset + 2);
}
if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
{
/* The next insn is a ret. We now convert the rcall insn
into a rjmp instruction. */
code_msb &= 0xef;
bfd_put_8 (abfd, code_msb, contents + irel->r_offset + 1);
if (DEBUG_RELAX)
printf ("converted rcall/ret sequence at address 0x%x"
" into rjmp/ret sequence. Section is %s\n\n",
(int) dot, sec->name);
*again = TRUE;
break;
}
}
else if ((0x94 == (code_msb & 0xfe))
&& (0x0e == (code_lsb & 0x0e)))
{
/* This insn is a call. */
unsigned char next_insn_msb = 0;
unsigned char next_insn_lsb = 0;
if (irel->r_offset + 5 < sec->size)
{
next_insn_msb =
bfd_get_8 (abfd, contents + irel->r_offset + 5);
next_insn_lsb =
bfd_get_8 (abfd, contents + irel->r_offset + 4);
}
if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
{
/* The next insn is a ret. We now convert the call insn
into a jmp instruction. */
code_lsb &= 0xfd;
bfd_put_8 (abfd, code_lsb, contents + irel->r_offset);
if (DEBUG_RELAX)
printf ("converted call/ret sequence at address 0x%x"
" into jmp/ret sequence. Section is %s\n\n",
(int) dot, sec->name);
*again = TRUE;
break;
}
}
else if ((0xc0 == (code_msb & 0xf0))
|| ((0x94 == (code_msb & 0xfe))
&& (0x0c == (code_lsb & 0x0e))))
{
/* This insn is a rjmp or a jmp. */
unsigned char next_insn_msb = 0;
unsigned char next_insn_lsb = 0;
int insn_size;
if (0xc0 == (code_msb & 0xf0))
insn_size = 2; /* rjmp insn */
else
insn_size = 4; /* jmp insn */
if (irel->r_offset + insn_size + 1 < sec->size)
{
next_insn_msb =
bfd_get_8 (abfd, contents + irel->r_offset
+ insn_size + 1);
next_insn_lsb =
bfd_get_8 (abfd, contents + irel->r_offset
+ insn_size);
}
if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
{
/* The next insn is a ret. We possibly could delete
this ret. First we need to check for preceeding
sbis/sbic/sbrs or cpse "skip" instructions. */
int there_is_preceeding_non_skip_insn = 1;
bfd_vma address_of_ret;
address_of_ret = dot + insn_size;
if (DEBUG_RELAX && (insn_size == 2))
printf ("found rjmp / ret sequence at address 0x%x\n",
(int) dot);
if (DEBUG_RELAX && (insn_size == 4))
printf ("found jmp / ret sequence at address 0x%x\n",
(int) dot);
/* We have to make sure that there is a preceeding insn. */
if (irel->r_offset >= 2)
{
unsigned char preceeding_msb;
unsigned char preceeding_lsb;
preceeding_msb =
bfd_get_8 (abfd, contents + irel->r_offset - 1);
preceeding_lsb =
bfd_get_8 (abfd, contents + irel->r_offset - 2);
/* sbic. */
if (0x99 == preceeding_msb)
there_is_preceeding_non_skip_insn = 0;
/* sbis. */
if (0x9b == preceeding_msb)
there_is_preceeding_non_skip_insn = 0;
/* sbrc */
if ((0xfc == (preceeding_msb & 0xfe)
&& (0x00 == (preceeding_lsb & 0x08))))
there_is_preceeding_non_skip_insn = 0;
/* sbrs */
if ((0xfe == (preceeding_msb & 0xfe)
&& (0x00 == (preceeding_lsb & 0x08))))
there_is_preceeding_non_skip_insn = 0;
/* cpse */
if (0x10 == (preceeding_msb & 0xfc))
there_is_preceeding_non_skip_insn = 0;
if (there_is_preceeding_non_skip_insn == 0)
if (DEBUG_RELAX)
printf ("preceeding skip insn prevents deletion of"
" ret insn at addr 0x%x in section %s\n",
(int) dot + 2, sec->name);
}
else
{
/* There is no previous instruction. */
there_is_preceeding_non_skip_insn = 0;
}
if (there_is_preceeding_non_skip_insn)
{
/* We now only have to make sure that there is no
local label defined at the address of the ret
instruction and that there is no local relocation
in this section pointing to the ret. */
int deleting_ret_is_safe = 1;
unsigned int section_offset_of_ret_insn =
irel->r_offset + insn_size;
Elf_Internal_Sym *isym, *isymend;
unsigned int sec_shndx;
sec_shndx =
_bfd_elf_section_from_bfd_section (abfd, sec);
/* Check for local symbols. */
isym = (Elf_Internal_Sym *) symtab_hdr->contents;
isymend = isym + symtab_hdr->sh_info;
for (; isym < isymend; isym++)
{
if (isym->st_value == section_offset_of_ret_insn
&& isym->st_shndx == sec_shndx)
{
deleting_ret_is_safe = 0;
if (DEBUG_RELAX)
printf ("local label prevents deletion of ret "
"insn at address 0x%x\n",
(int) dot + insn_size);
}
}
/* Now check for global symbols. */
{
int symcount;
struct elf_link_hash_entry **sym_hashes;
struct elf_link_hash_entry **end_hashes;
symcount = (symtab_hdr->sh_size
/ sizeof (Elf32_External_Sym)
- symtab_hdr->sh_info);
sym_hashes = elf_sym_hashes (abfd);
end_hashes = sym_hashes + symcount;
for (; sym_hashes < end_hashes; sym_hashes++)
{
struct elf_link_hash_entry *sym_hash =
*sym_hashes;
if ((sym_hash->root.type == bfd_link_hash_defined
|| sym_hash->root.type ==
bfd_link_hash_defweak)
&& sym_hash->root.u.def.section == sec
&& sym_hash->root.u.def.value == section_offset_of_ret_insn)
{
deleting_ret_is_safe = 0;
if (DEBUG_RELAX)
printf ("global label prevents deletion of "
"ret insn at address 0x%x\n",
(int) dot + insn_size);
}
}
}
/* Now we check for relocations pointing to ret. */
{
Elf_Internal_Rela *irel;
Elf_Internal_Rela *relend;
Elf_Internal_Shdr *symtab_hdr;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
relend = elf_section_data (sec)->relocs
+ sec->reloc_count;
for (irel = elf_section_data (sec)->relocs;
irel < relend; irel++)
{
bfd_vma reloc_target = 0;
bfd_vma symval;
Elf_Internal_Sym *isymbuf = NULL;
/* Read this BFD's local symbols if we haven't
done so already. */
if (isymbuf == NULL && symtab_hdr->sh_info != 0)
{
isymbuf = (Elf_Internal_Sym *)
symtab_hdr->contents;
if (isymbuf == NULL)
isymbuf = bfd_elf_get_elf_syms
(abfd,
symtab_hdr,
symtab_hdr->sh_info, 0,
NULL, NULL, NULL);
if (isymbuf == NULL)
break;
}
/* Get the value of the symbol referred to
by the reloc. */
if (ELF32_R_SYM (irel->r_info)
< symtab_hdr->sh_info)
{
/* A local symbol. */
Elf_Internal_Sym *isym;
asection *sym_sec;
isym = isymbuf
+ ELF32_R_SYM (irel->r_info);
sym_sec = bfd_section_from_elf_index
(abfd, isym->st_shndx);
symval = isym->st_value;
/* If the reloc is absolute, it will not
have a symbol or section associated
with it. */
if (sym_sec)
{
symval +=
sym_sec->output_section->vma
+ sym_sec->output_offset;
reloc_target = symval + irel->r_addend;
}
else
{
reloc_target = symval + irel->r_addend;
/* Reference symbol is absolute. */
}
}
/* else ... reference symbol is extern. */
if (address_of_ret == reloc_target)
{
deleting_ret_is_safe = 0;
if (DEBUG_RELAX)
printf ("ret from "
"rjmp/jmp ret sequence at address"
" 0x%x could not be deleted. ret"
" is target of a relocation.\n",
(int) address_of_ret);
}
}
}
if (deleting_ret_is_safe)
{
if (DEBUG_RELAX)
printf ("unreachable ret instruction "
"at address 0x%x deleted.\n",
(int) dot + insn_size);
/* Delete two bytes of data. */
if (!elf32_avr_relax_delete_bytes (abfd, sec,
irel->r_offset + insn_size, 2))
goto error_return;
/* That will change things, so, we should relax
again. Note that this is not required, and it
may be slow. */
*again = TRUE;
break;
}
}
}
}
break;
}
}
}
if (contents != NULL
&& elf_section_data (sec)->this_hdr.contents != contents)
{
if (! link_info->keep_memory)
free (contents);
else
{
/* Cache the section contents for elf_link_input_bfd. */
elf_section_data (sec)->this_hdr.contents = contents;
}
}
if (internal_relocs != NULL
&& elf_section_data (sec)->relocs != internal_relocs)
free (internal_relocs);
return TRUE;
error_return:
if (isymbuf != NULL
&& symtab_hdr->contents != (unsigned char *) isymbuf)
free (isymbuf);
if (contents != NULL
&& elf_section_data (sec)->this_hdr.contents != contents)
free (contents);
if (internal_relocs != NULL
&& elf_section_data (sec)->relocs != internal_relocs)
free (internal_relocs);
return FALSE;
}
/* This is a version of bfd_generic_get_relocated_section_contents
which uses elf32_avr_relocate_section.
For avr it's essentially a cut and paste taken from the H8300 port.
The author of the relaxation support patch for avr had absolutely no
clue what is happening here but found out that this part of the code
seems to be important. */
static bfd_byte *
elf32_avr_get_relocated_section_contents (bfd *output_bfd,
struct bfd_link_info *link_info,
struct bfd_link_order *link_order,
bfd_byte *data,
bfd_boolean relocatable,
asymbol **symbols)
{
Elf_Internal_Shdr *symtab_hdr;
asection *input_section = link_order->u.indirect.section;
bfd *input_bfd = input_section->owner;
asection **sections = NULL;
Elf_Internal_Rela *internal_relocs = NULL;
Elf_Internal_Sym *isymbuf = NULL;
/* We only need to handle the case of relaxing, or of having a
particular set of section contents, specially. */
if (relocatable
|| elf_section_data (input_section)->this_hdr.contents == NULL)
return bfd_generic_get_relocated_section_contents (output_bfd, link_info,
link_order, data,
relocatable,
symbols);
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
memcpy (data, elf_section_data (input_section)->this_hdr.contents,
(size_t) input_section->size);
if ((input_section->flags & SEC_RELOC) != 0
&& input_section->reloc_count > 0)
{
asection **secpp;
Elf_Internal_Sym *isym, *isymend;
bfd_size_type amt;
internal_relocs = (_bfd_elf_link_read_relocs
(input_bfd, input_section, NULL, NULL, FALSE));
if (internal_relocs == NULL)
goto error_return;
if (symtab_hdr->sh_info != 0)
{
isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
if (isymbuf == NULL)
isymbuf = bfd_elf_get_elf_syms (input_bfd, symtab_hdr,
symtab_hdr->sh_info, 0,
NULL, NULL, NULL);
if (isymbuf == NULL)
goto error_return;
}
amt = symtab_hdr->sh_info;
amt *= sizeof (asection *);
sections = bfd_malloc (amt);
if (sections == NULL && amt != 0)
goto error_return;
isymend = isymbuf + symtab_hdr->sh_info;
for (isym = isymbuf, secpp = sections; isym < isymend; ++isym, ++secpp)
{
asection *isec;
if (isym->st_shndx == SHN_UNDEF)
isec = bfd_und_section_ptr;
else if (isym->st_shndx == SHN_ABS)
isec = bfd_abs_section_ptr;
else if (isym->st_shndx == SHN_COMMON)
isec = bfd_com_section_ptr;
else
isec = bfd_section_from_elf_index (input_bfd, isym->st_shndx);
*secpp = isec;
}
if (! elf32_avr_relocate_section (output_bfd, link_info, input_bfd,
input_section, data, internal_relocs,
isymbuf, sections))
goto error_return;
if (sections != NULL)
free (sections);
if (isymbuf != NULL
&& symtab_hdr->contents != (unsigned char *) isymbuf)
free (isymbuf);
if (elf_section_data (input_section)->relocs != internal_relocs)
free (internal_relocs);
}
return data;
error_return:
if (sections != NULL)
free (sections);
if (isymbuf != NULL
&& symtab_hdr->contents != (unsigned char *) isymbuf)
free (isymbuf);
if (internal_relocs != NULL
&& elf_section_data (input_section)->relocs != internal_relocs)
free (internal_relocs);
return NULL;
}
#define ELF_ARCH bfd_arch_avr
#define ELF_MACHINE_CODE EM_AVR
#define ELF_MACHINE_ALT1 EM_AVR_OLD
#define ELF_MAXPAGESIZE 1
#define TARGET_LITTLE_SYM bfd_elf32_avr_vec
#define TARGET_LITTLE_NAME "elf32-avr"
#define elf_info_to_howto avr_info_to_howto_rela
#define elf_info_to_howto_rel NULL
#define elf_backend_relocate_section elf32_avr_relocate_section
#define elf_backend_gc_mark_hook elf32_avr_gc_mark_hook
#define elf_backend_gc_sweep_hook elf32_avr_gc_sweep_hook
#define elf_backend_check_relocs elf32_avr_check_relocs
#define elf_backend_can_gc_sections 1
#define elf_backend_rela_normal 1
#define elf_backend_final_write_processing \
bfd_elf_avr_final_write_processing
#define elf_backend_object_p elf32_avr_object_p
#define bfd_elf32_bfd_relax_section elf32_avr_relax_section
#define bfd_elf32_bfd_get_relocated_section_contents \
elf32_avr_get_relocated_section_contents
#include "elf32-target.h"
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