diff options
Diffstat (limited to 'bfd/elf32-avr.c')
| -rw-r--r-- | bfd/elf32-avr.c | 182 |
1 files changed, 181 insertions, 1 deletions
diff --git a/bfd/elf32-avr.c b/bfd/elf32-avr.c index 3fd43c9..425e2d1 100644 --- a/bfd/elf32-avr.c +++ b/bfd/elf32-avr.c @@ -32,6 +32,15 @@ static bfd_boolean debug_relax = FALSE; /* Enable debugging printout at stdout with this variable. */ static bfd_boolean debug_stubs = FALSE; +static bfd_reloc_status_type +bfd_elf_avr_diff_reloc (bfd *abfd, + arelent *reloc_entry, + asymbol *symbol, + void *data, + asection *input_section, + bfd *output_bfd, + char **error_message); + /* Hash table initialization and handling. Code is taken from the hppa port and adapted to the needs of AVR. */ @@ -557,6 +566,45 @@ static reloc_howto_type elf_avr_howto_table[] = 0xffffff, /* src_mask */ 0xffffff, /* dst_mask */ FALSE), /* pcrel_offset */ + HOWTO (R_AVR_DIFF8, /* type */ + 0, /* rightshift */ + 0, /* size (0 = byte, 1 = short, 2 = long) */ + 8, /* bitsize */ + FALSE, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_bitfield, /* complain_on_overflow */ + bfd_elf_avr_diff_reloc, /* special_function */ + "R_AVR_DIFF8", /* name */ + FALSE, /* partial_inplace */ + 0, /* src_mask */ + 0xff, /* dst_mask */ + FALSE), /* pcrel_offset */ + HOWTO (R_AVR_DIFF16, /* type */ + 0, /* rightshift */ + 1, /* size (0 = byte, 1 = short, 2 = long) */ + 16, /* bitsize */ + FALSE, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_bitfield, /* complain_on_overflow */ + bfd_elf_avr_diff_reloc, /* special_function */ + "R_AVR_DIFF16", /* name */ + FALSE, /* partial_inplace */ + 0, /* src_mask */ + 0xffff, /* dst_mask */ + FALSE), /* pcrel_offset */ + HOWTO (R_AVR_DIFF32, /* 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_avr_diff_reloc, /* special_function */ + "R_AVR_DIFF32", /* name */ + FALSE, /* partial_inplace */ + 0, /* src_mask */ + 0xffffffff, /* dst_mask */ + FALSE) /* pcrel_offset */ }; /* Map BFD reloc types to AVR ELF reloc types. */ @@ -598,7 +646,10 @@ static const struct avr_reloc_map avr_reloc_map[] = { BFD_RELOC_8, R_AVR_8 }, { BFD_RELOC_AVR_8_LO, R_AVR_8_LO8 }, { BFD_RELOC_AVR_8_HI, R_AVR_8_HI8 }, - { BFD_RELOC_AVR_8_HLO, R_AVR_8_HLO8 } + { BFD_RELOC_AVR_8_HLO, R_AVR_8_HLO8 }, + { BFD_RELOC_AVR_DIFF8, R_AVR_DIFF8 }, + { BFD_RELOC_AVR_DIFF16, R_AVR_DIFF16 }, + { BFD_RELOC_AVR_DIFF32, R_AVR_DIFF32 } }; /* Meant to be filled one day with the wrap around address for the @@ -797,6 +848,22 @@ avr_get_stub_addr (bfd_vma srel, return 0x020000; } +/* Perform a diff relocation. Nothing to do, as the difference value is already + written into the section's contents. */ + +static bfd_reloc_status_type +bfd_elf_avr_diff_reloc (bfd *abfd ATTRIBUTE_UNUSED, + arelent *reloc_entry ATTRIBUTE_UNUSED, + asymbol *symbol ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED, + asection *input_section ATTRIBUTE_UNUSED, + bfd *output_bfd ATTRIBUTE_UNUSED, + char **error_message ATTRIBUTE_UNUSED) +{ + return bfd_reloc_ok; +} + + /* Perform a single relocation. By default we use the standard BFD routines, but a few relocs, we have to do them ourselves. */ @@ -1149,6 +1216,13 @@ avr_final_link_relocate (reloc_howto_type * howto, bfd_put_16 (input_bfd, (bfd_vma) srel &0x00ffff, contents); break; + case R_AVR_DIFF8: + case R_AVR_DIFF16: + case R_AVR_DIFF32: + /* Nothing to do here, as contents already contains the diff value. */ + r = bfd_reloc_ok; + break; + default: r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, @@ -1457,6 +1531,104 @@ elf32_avr_object_p (bfd *abfd) e_set); } +/* Returns whether the relocation type passed is a diff reloc. */ + +static bfd_boolean +elf32_avr_is_diff_reloc (Elf_Internal_Rela *irel) +{ + return (ELF32_R_TYPE (irel->r_info) == R_AVR_DIFF8 + ||ELF32_R_TYPE (irel->r_info) == R_AVR_DIFF16 + || ELF32_R_TYPE (irel->r_info) == R_AVR_DIFF32); +} + +/* Reduce the diff value written in the section by count if the shrinked + insn address happens to fall between the two symbols for which this + diff reloc was emitted. */ + +static void +elf32_avr_adjust_diff_reloc_value (bfd *abfd, + struct bfd_section *isec, + Elf_Internal_Rela *irel, + bfd_vma symval, + bfd_vma shrinked_insn_address, + int count) +{ + unsigned char *reloc_contents = NULL; + unsigned char *isec_contents = elf_section_data (isec)->this_hdr.contents; + if (isec_contents == NULL) + { + if (! bfd_malloc_and_get_section (abfd, isec, &isec_contents)) + return; + + elf_section_data (isec)->this_hdr.contents = isec_contents; + } + + reloc_contents = isec_contents + irel->r_offset; + + /* Read value written in object file. */ + bfd_vma x = 0; + switch (ELF32_R_TYPE (irel->r_info)) + { + case R_AVR_DIFF8: + { + x = *reloc_contents; + break; + } + case R_AVR_DIFF16: + { + x = bfd_get_16 (abfd, reloc_contents); + break; + } + case R_AVR_DIFF32: + { + x = bfd_get_32 (abfd, reloc_contents); + break; + } + default: + { + BFD_FAIL(); + } + } + + /* For a diff reloc sym1 - sym2 the diff at assembly time (x) is written + into the object file at the reloc offset. sym2's logical value is + symval (<start_of_section>) + reloc addend. Compute the start and end + addresses and check if the shrinked insn falls between sym1 and sym2. */ + + bfd_vma end_address = symval + irel->r_addend; + bfd_vma start_address = end_address - x; + + /* Reduce the diff value by count bytes and write it back into section + contents. */ + + if (shrinked_insn_address >= start_address && + shrinked_insn_address <= end_address) + { + switch (ELF32_R_TYPE (irel->r_info)) + { + case R_AVR_DIFF8: + { + *reloc_contents = (x - count); + break; + } + case R_AVR_DIFF16: + { + bfd_put_16 (abfd, (x - count) & 0xFFFF, reloc_contents); + break; + } + case R_AVR_DIFF32: + { + bfd_put_32 (abfd, (x - count) & 0xFFFFFFFF, reloc_contents); + break; + } + default: + { + BFD_FAIL(); + } + } + + } +} /* Delete some bytes from a section while changing the size of an instruction. The parameter "addr" denotes the section-relative offset pointing just @@ -1595,6 +1767,14 @@ elf32_avr_relax_delete_bytes (bfd *abfd, if (symval <= shrinked_insn_address && (symval + irel->r_addend) > shrinked_insn_address) { + if (elf32_avr_is_diff_reloc (irel)) + { + elf32_avr_adjust_diff_reloc_value (abfd, isec, irel, + symval, + shrinked_insn_address, + count); + } + irel->r_addend -= count; if (debug_relax) |