diff options
Diffstat (limited to 'bfd/elf32-avr.c')
| -rw-r--r-- | bfd/elf32-avr.c | 1070 |
1 files changed, 1019 insertions, 51 deletions
diff --git a/bfd/elf32-avr.c b/bfd/elf32-avr.c index e5f09c6..0028871 100644 --- a/bfd/elf32-avr.c +++ b/bfd/elf32-avr.c @@ -25,6 +25,92 @@ #include "libbfd.h" #include "elf-bfd.h" #include "elf/avr.h" +#include "elf32-avr.h" + +/* Enable debugging printout at stdout with this variable. */ +static bfd_boolean debug_relax = FALSE; + +/* Enable debugging printout at stdout with this variable. */ +static bfd_boolean debug_stubs = FALSE; + +/* Hash table initialization and handling. Code is taken from the hppa port + and adapted to the needs of AVR. */ + +/* We use two hash tables to hold information for linking avr objects. + + The first is the elf32_avr_link_hash_tablse which is derived from the + stanard ELF linker hash table. We use this as a place to attach the other + hash table and some static information. + + The second is the stub hash table which is derived from the base BFD + hash table. The stub hash table holds the information on the linker + stubs. */ + +struct elf32_avr_stub_hash_entry +{ + /* Base hash table entry structure. */ + struct bfd_hash_entry bh_root; + + /* Offset within stub_sec of the beginning of this stub. */ + bfd_vma stub_offset; + + /* Given the symbol's value and its section we can determine its final + value when building the stubs (so the stub knows where to jump). */ + bfd_vma target_value; + + /* This way we could mark stubs to be no longer necessary. */ + bfd_boolean is_actually_needed; +}; + +struct elf32_avr_link_hash_table +{ + /* The main hash table. */ + struct elf_link_hash_table etab; + + /* The stub hash table. */ + struct bfd_hash_table bstab; + + bfd_boolean no_stubs; + + /* Linker stub bfd. */ + bfd *stub_bfd; + + /* The stub section. */ + asection *stub_sec; + + /* Usually 0, unless we are generating code for a bootloader. Will + be initialized by elf32_avr_size_stubs to the vma offset of the + output section associated with the stub section. */ + bfd_vma vector_base; + + /* Assorted information used by elf32_avr_size_stubs. */ + unsigned int bfd_count; + int top_index; + asection ** input_list; + Elf_Internal_Sym ** all_local_syms; + + /* Tables for mapping vma beyond the 128k boundary to the address of the + corresponding stub. (AMT) + "amt_max_entry_cnt" reflects the number of entries that memory is allocated + for in the "amt_stub_offsets" and "amt_destination_addr" arrays. + "amt_entry_cnt" informs how many of these entries actually contain + useful data. */ + unsigned int amt_entry_cnt; + unsigned int amt_max_entry_cnt; + bfd_vma * amt_stub_offsets; + bfd_vma * amt_destination_addr; +}; + +/* Various hash macros and functions. */ +#define avr_link_hash_table(p) \ + ((struct elf32_avr_link_hash_table *) ((p)->hash)) + +#define avr_stub_hash_entry(ent) \ + ((struct elf32_avr_stub_hash_entry *)(ent)) + +#define avr_stub_hash_lookup(table, string, create, copy) \ + ((struct elf32_avr_stub_hash_entry *) \ + bfd_hash_lookup ((table), (string), (create), (copy))) static reloc_howto_type elf_avr_howto_table[] = { @@ -101,7 +187,8 @@ static reloc_howto_type elf_avr_howto_table[] = 0xffff, /* dst_mask */ FALSE), /* pcrel_offset */ - /* A 16 bit absolute relocation for command address. */ + /* A 16 bit absolute relocation for command address + Will be changed when linker stubs are needed. */ HOWTO (R_AVR_16_PM, /* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -207,7 +294,7 @@ static reloc_howto_type elf_avr_howto_table[] = 0xffff, /* dst_mask */ FALSE), /* pcrel_offset */ /* A low 8 bit absolute relocation of 24 bit program memory address. - For LDI command. */ + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_LO8_LDI_PM, /* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -221,8 +308,8 @@ static reloc_howto_type elf_avr_howto_table[] = 0xffff, /* src_mask */ 0xffff, /* dst_mask */ FALSE), /* pcrel_offset */ - /* A high 8 bit absolute relocation of 16 bit program memory address. - For LDI command. */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_HI8_LDI_PM, /* type */ 9, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -236,8 +323,8 @@ static reloc_howto_type elf_avr_howto_table[] = 0xffff, /* src_mask */ 0xffff, /* dst_mask */ FALSE), /* pcrel_offset */ - /* A high 8 bit absolute relocation of 24 bit program memory address. - For LDI command. */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_HH8_LDI_PM, /* type */ 17, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -251,8 +338,8 @@ static reloc_howto_type elf_avr_howto_table[] = 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. */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_LO8_LDI_PM_NEG, /* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -266,8 +353,8 @@ static reloc_howto_type elf_avr_howto_table[] = 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. */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_HI8_LDI_PM_NEG, /* type */ 9, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -281,8 +368,8 @@ static reloc_howto_type elf_avr_howto_table[] = 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. */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will not be changed when linker stubs are needed. */ HOWTO (R_AVR_HH8_LDI_PM_NEG, /* type */ 17, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ @@ -382,7 +469,37 @@ static reloc_howto_type elf_avr_howto_table[] = FALSE, /* partial_inplace */ 0xffff, /* src_mask */ 0xffff, /* dst_mask */ - FALSE) /* pcrel_offset */ + FALSE), /* pcrel_offset */ + /* A low 8 bit absolute relocation of 24 bit program memory address. + For LDI command. Will be changed when linker stubs are needed. */ + HOWTO (R_AVR_LO8_LDI_GS, /* 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_GS", /* 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. Will be changed when linker stubs are needed. */ + HOWTO (R_AVR_HI8_LDI_GS, /* 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_GS", /* name */ + FALSE, /* partial_inplace */ + 0xffff, /* src_mask */ + 0xffff, /* dst_mask */ + FALSE) /* pcrel_offset */ }; /* Map BFD reloc types to AVR ELF reloc types. */ @@ -393,7 +510,7 @@ struct avr_reloc_map unsigned int elf_reloc_val; }; - static const struct avr_reloc_map avr_reloc_map[] = +static const struct avr_reloc_map avr_reloc_map[] = { { BFD_RELOC_NONE, R_AVR_NONE }, { BFD_RELOC_32, R_AVR_32 }, @@ -410,7 +527,9 @@ struct avr_reloc_map { 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_LO8_LDI_GS, R_AVR_LO8_LDI_GS }, { BFD_RELOC_AVR_HI8_LDI_PM, R_AVR_HI8_LDI_PM }, + { BFD_RELOC_AVR_HI8_LDI_GS, R_AVR_HI8_LDI_GS }, { 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 }, @@ -429,8 +548,101 @@ struct avr_reloc_map 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. */ +static bfd_vma avr_pc_wrap_around = 0x10000000; + +/* If this variable holds a value different from zero, the linker relaxation + machine will try to optimize call/ret sequences by a single jump + instruction. This option could be switched off by a linker switch. */ +static int avr_replace_call_ret_sequences = 1; + +/* Initialize an entry in the stub hash table. */ + +static struct bfd_hash_entry * +stub_hash_newfunc (struct bfd_hash_entry *entry, + struct bfd_hash_table *table, + const char *string) +{ + /* Allocate the structure if it has not already been allocated by a + subclass. */ + if (entry == NULL) + { + entry = bfd_hash_allocate (table, + sizeof (struct elf32_avr_stub_hash_entry)); + if (entry == NULL) + return entry; + } + + /* Call the allocation method of the superclass. */ + entry = bfd_hash_newfunc (entry, table, string); + if (entry != NULL) + { + struct elf32_avr_stub_hash_entry *hsh; + + /* Initialize the local fields. */ + hsh = avr_stub_hash_entry (entry); + hsh->stub_offset = 0; + hsh->target_value = 0; + } + + return entry; +} + +/* Create the derived linker hash table. The AVR ELF port uses the derived + hash table to keep information specific to the AVR ELF linker (without + using static variables). */ + +static struct bfd_link_hash_table * +elf32_avr_link_hash_table_create (bfd *abfd) +{ + struct elf32_avr_link_hash_table *htab; + bfd_size_type amt = sizeof (*htab); + + htab = bfd_malloc (amt); + if (htab == NULL) + return NULL; + + if (!_bfd_elf_link_hash_table_init (&htab->etab, abfd, + _bfd_elf_link_hash_newfunc, + sizeof (struct elf_link_hash_entry))) + { + free (htab); + return NULL; + } + + /* Init the stub hash table too. */ + if (!bfd_hash_table_init (&htab->bstab, stub_hash_newfunc, + sizeof (struct elf32_avr_stub_hash_entry))) + return NULL; -unsigned int avr_pc_wrap_around = 0x10000000; + htab->stub_bfd = NULL; + htab->stub_sec = NULL; + + /* Initialize the address mapping table. */ + htab->amt_stub_offsets = NULL; + htab->amt_destination_addr = NULL; + htab->amt_entry_cnt = 0; + htab->amt_max_entry_cnt = 0; + + return &htab->etab.root; +} + +/* Free the derived linker hash table. */ + +static void +elf32_avr_link_hash_table_free (struct bfd_link_hash_table *btab) +{ + struct elf32_avr_link_hash_table *htab + = (struct elf32_avr_link_hash_table *) btab; + + /* Free the address mapping table. */ + if (htab->amt_stub_offsets != NULL) + free (htab->amt_stub_offsets); + if (htab->amt_destination_addr != NULL) + free (htab->amt_destination_addr); + + bfd_hash_table_free (&htab->bstab); + _bfd_generic_link_hash_table_free (btab); +} /* Calculates the effective distance of a pc relative jump/call. */ @@ -563,20 +775,57 @@ elf32_avr_check_relocs (bfd *abfd, return TRUE; } +static bfd_boolean +avr_stub_is_required_for_16_bit_reloc (bfd_vma relocation) +{ + return (relocation >= 0x020000); +} + +/* Returns the address of the corresponding stub if there is one. + Returns otherwise an address above 0x020000. This function + could also be used, if there is no knowledge on the section where + the destination is found. */ + +static bfd_vma +avr_get_stub_addr (bfd_vma srel, + struct elf32_avr_link_hash_table *htab) +{ + unsigned int index; + bfd_vma stub_sec_addr = + (htab->stub_sec->output_section->vma + + htab->stub_sec->output_offset); + + for (index = 0; index < htab->amt_max_entry_cnt; index ++) + if (htab->amt_destination_addr[index] == srel) + return htab->amt_stub_offsets[index] + stub_sec_addr; + + /* Return an address that could not be reached by 16 bit relocs. */ + return 0x020000; +} + /* 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) +avr_final_link_relocate (reloc_howto_type * howto, + bfd * input_bfd, + asection * input_section, + bfd_byte * contents, + Elf_Internal_Rela * rel, + bfd_vma relocation, + struct elf32_avr_link_hash_table * htab) { bfd_reloc_status_type r = bfd_reloc_ok; bfd_vma x; bfd_signed_vma srel; + bfd_signed_vma reloc_addr; + bfd_boolean use_stubs = FALSE; + /* Usually is 0, unless we are generating code for a bootloader. */ + bfd_signed_vma base_addr = htab->vector_base; + + /* Absolute addr of the reloc in the final excecutable. */ + reloc_addr = rel->r_offset + input_section->output_section->vma + + input_section->output_offset; switch (howto->type) { @@ -747,9 +996,31 @@ avr_final_link_relocate (reloc_howto_type * howto, bfd_put_16 (input_bfd, x, contents); break; + case R_AVR_LO8_LDI_GS: + use_stubs = (!htab->no_stubs); + /* Fall through. */ case R_AVR_LO8_LDI_PM: contents += rel->r_offset; srel = (bfd_signed_vma) relocation + rel->r_addend; + + if (use_stubs + && avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + { + bfd_vma old_srel = srel; + + /* We need to use the address of the stub instead. */ + srel = avr_get_stub_addr (srel, htab); + if (debug_stubs) + printf ("LD: Using jump stub (at 0x%x) with destination 0x%x for " + "reloc at address 0x%x.\n", + (unsigned int) srel, + (unsigned int) old_srel, + (unsigned int) reloc_addr); + + if (avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + return bfd_reloc_outofrange; + } + if (srel & 1) return bfd_reloc_outofrange; srel = srel >> 1; @@ -758,9 +1029,31 @@ avr_final_link_relocate (reloc_howto_type * howto, bfd_put_16 (input_bfd, x, contents); break; + case R_AVR_HI8_LDI_GS: + use_stubs = (!htab->no_stubs); + /* Fall through. */ case R_AVR_HI8_LDI_PM: contents += rel->r_offset; srel = (bfd_signed_vma) relocation + rel->r_addend; + + if (use_stubs + && avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + { + bfd_vma old_srel = srel; + + /* We need to use the address of the stub instead. */ + srel = avr_get_stub_addr (srel, htab); + if (debug_stubs) + printf ("LD: Using jump stub (at 0x%x) with destination 0x%x for " + "reloc at address 0x%x.\n", + (unsigned int) srel, + (unsigned int) old_srel, + (unsigned int) reloc_addr); + + if (avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + return bfd_reloc_outofrange; + } + if (srel & 1) return bfd_reloc_outofrange; srel = srel >> 1; @@ -832,6 +1125,35 @@ avr_final_link_relocate (reloc_howto_type * howto, bfd_put_16 (input_bfd, (bfd_vma) srel & 0xffff, contents+2); break; + case R_AVR_16_PM: + use_stubs = (!htab->no_stubs); + contents += rel->r_offset; + srel = (bfd_signed_vma) relocation + rel->r_addend; + + if (use_stubs + && avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + { + bfd_vma old_srel = srel; + + /* We need to use the address of the stub instead. */ + srel = avr_get_stub_addr (srel,htab); + if (debug_stubs) + printf ("LD: Using jump stub (at 0x%x) with destination 0x%x for " + "reloc at address 0x%x.\n", + (unsigned int) srel, + (unsigned int) old_srel, + (unsigned int) reloc_addr); + + if (avr_stub_is_required_for_16_bit_reloc (srel - base_addr)) + return bfd_reloc_outofrange; + } + + if (srel & 1) + return bfd_reloc_outofrange; + srel = srel >> 1; + bfd_put_16 (input_bfd, (bfd_vma) srel &0x00ffff, contents); + break; + default: r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, @@ -857,6 +1179,7 @@ elf32_avr_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, struct elf_link_hash_entry ** sym_hashes; Elf_Internal_Rela * rel; Elf_Internal_Rela * relend; + struct elf32_avr_link_hash_table * htab = avr_link_hash_table (info); if (info->relocatable) return TRUE; @@ -908,7 +1231,7 @@ elf32_avr_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, } r = avr_final_link_relocate (howto, input_bfd, input_section, - contents, rel, relocation); + contents, rel, relocation, htab); if (r != bfd_reloc_ok) { @@ -989,6 +1312,10 @@ bfd_elf_avr_final_write_processing (bfd *abfd, case bfd_mach_avr5: val = E_AVR_MACH_AVR5; break; + + case bfd_mach_avr6: + val = E_AVR_MACH_AVR6; + break; } elf_elfheader (abfd)->e_machine = EM_AVR; @@ -1031,6 +1358,10 @@ elf32_avr_object_p (bfd *abfd) case E_AVR_MACH_AVR5: e_set = bfd_mach_avr5; break; + + case E_AVR_MACH_AVR6: + e_set = bfd_mach_avr6; + break; } } return bfd_default_set_arch_mach (abfd, bfd_arch_avr, @@ -1038,9 +1369,6 @@ elf32_avr_object_p (bfd *abfd) } -/* 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 @@ -1099,7 +1427,7 @@ elf32_avr_relax_delete_bytes (bfd *abfd, if ((irel->r_offset > addr && irel->r_offset < toaddr)) { - if (DEBUG_RELAX) + 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, @@ -1115,11 +1443,11 @@ elf32_avr_relax_delete_bytes (bfd *abfd, the reloc's addend, i.e. the reloc's value 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. - + 2.) symbol plus addend end up behind the shrinked instruction. + The most common case where this happens are relocs relative to the section-start symbol. - + This step needs to be done for all of the sections of the bfd. */ { @@ -1134,11 +1462,11 @@ elf32_avr_relax_delete_bytes (bfd *abfd, + sec->output_offset + addr - count); irelend = elf_section_data (isec)->relocs + isec->reloc_count; - for (irel = elf_section_data (isec)->relocs; + for (irel = elf_section_data (isec)->relocs; irel < irelend; irel++) { - /* Read this BFD's local symbols if we haven't done + /* Read this BFD's local symbols if we haven't done so already. */ if (isymbuf == NULL && symtab_hdr->sh_info != 0) { @@ -1164,11 +1492,11 @@ elf32_avr_relax_delete_bytes (bfd *abfd, /* If the reloc is absolute, it will not have a symbol or section associated with it. */ if (sym_sec == sec) - { + { symval += sym_sec->output_section->vma + sym_sec->output_offset; - if (DEBUG_RELAX) + if (debug_relax) printf ("Checking if the relocation's " "addend needs corrections.\n" "Address of anchor symbol: 0x%x \n" @@ -1183,15 +1511,15 @@ elf32_avr_relax_delete_bytes (bfd *abfd, { irel->r_addend -= count; - if (DEBUG_RELAX) + if (debug_relax) printf ("Relocation's addend needed to be fixed \n"); } } /* else...Reference symbol is absolute. No adjustment needed. */ - } - /* else...Reference symbol is extern. No need for adjusting + } + /* else...Reference symbol is extern. No need for adjusting the addend. */ - } + } } } @@ -1258,7 +1586,7 @@ elf32_avr_relax_delete_bytes (bfd *abfd, contains 4-byte jump instructions whose relative offset must not be changed. */ -static bfd_boolean +static bfd_boolean elf32_avr_relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info, @@ -1271,10 +1599,37 @@ elf32_avr_relax_section (bfd *abfd, Elf_Internal_Sym *isymbuf = NULL; static asection *last_input_section = NULL; static Elf_Internal_Rela *last_reloc = NULL; + struct elf32_avr_link_hash_table *htab; + + htab = avr_link_hash_table (link_info); /* Assume nothing changes. */ *again = FALSE; + if ((!htab->no_stubs) && (sec == htab->stub_sec)) + { + /* We are just relaxing the stub section. + Let's calculate the size needed again. */ + bfd_size_type last_estimated_stub_section_size = htab->stub_sec->size; + + if (debug_relax) + printf ("Relaxing the stub section. Size prior to this pass: %i\n", + (int) last_estimated_stub_section_size); + + elf32_avr_size_stubs (htab->stub_sec->output_section->owner, + link_info, FALSE); + + /* Check if the number of trampolines changed. */ + if (last_estimated_stub_section_size != htab->stub_sec->size) + *again = TRUE; + + if (debug_relax) + printf ("Size of stub section after this pass: %i\n", + (int) htab->stub_sec->size); + + return TRUE; + } + /* 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. */ @@ -1441,7 +1796,7 @@ elf32_avr_relax_section (bfd *abfd, unsigned char code_msb; unsigned char code_lsb; - if (DEBUG_RELAX) + if (debug_relax) printf ("shrinking jump/call instruction at address 0x%x" " in section %s\n\n", (int) dot, sec->name); @@ -1516,8 +1871,9 @@ elf32_avr_relax_section (bfd *abfd, + 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)) + safely replaced by rjmp/ret or jmp/ret. */ + if (((code_msb & 0xf0) == 0xd0) + && avr_replace_call_ret_sequences) { /* This insn is a rcall. */ unsigned char next_insn_msb = 0; @@ -1537,7 +1893,7 @@ elf32_avr_relax_section (bfd *abfd, into a rjmp instruction. */ code_msb &= 0xef; bfd_put_8 (abfd, code_msb, contents + irel->r_offset + 1); - if (DEBUG_RELAX) + 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); @@ -1546,7 +1902,8 @@ elf32_avr_relax_section (bfd *abfd, } } else if ((0x94 == (code_msb & 0xfe)) - && (0x0e == (code_lsb & 0x0e))) + && (0x0e == (code_lsb & 0x0e)) + && avr_replace_call_ret_sequences) { /* This insn is a call. */ unsigned char next_insn_msb = 0; @@ -1567,7 +1924,7 @@ elf32_avr_relax_section (bfd *abfd, code_lsb &= 0xfd; bfd_put_8 (abfd, code_lsb, contents + irel->r_offset); - if (DEBUG_RELAX) + 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); @@ -1610,10 +1967,10 @@ elf32_avr_relax_section (bfd *abfd, address_of_ret = dot + insn_size; - if (DEBUG_RELAX && (insn_size == 2)) + if (debug_relax && (insn_size == 2)) printf ("found rjmp / ret sequence at address 0x%x\n", (int) dot); - if (DEBUG_RELAX && (insn_size == 4)) + if (debug_relax && (insn_size == 4)) printf ("found jmp / ret sequence at address 0x%x\n", (int) dot); @@ -1650,7 +2007,7 @@ elf32_avr_relax_section (bfd *abfd, there_is_preceeding_non_skip_insn = 0; if (there_is_preceeding_non_skip_insn == 0) - if (DEBUG_RELAX) + 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); @@ -1686,7 +2043,7 @@ elf32_avr_relax_section (bfd *abfd, && isym->st_shndx == sec_shndx) { deleting_ret_is_safe = 0; - if (DEBUG_RELAX) + if (debug_relax) printf ("local label prevents deletion of ret " "insn at address 0x%x\n", (int) dot + insn_size); @@ -1715,7 +2072,7 @@ elf32_avr_relax_section (bfd *abfd, && sym_hash->root.u.def.value == section_offset_of_ret_insn) { deleting_ret_is_safe = 0; - if (DEBUG_RELAX) + if (debug_relax) printf ("global label prevents deletion of " "ret insn at address 0x%x\n", (int) dot + insn_size); @@ -1792,7 +2149,7 @@ elf32_avr_relax_section (bfd *abfd, if (address_of_ret == reloc_target) { deleting_ret_is_safe = 0; - if (DEBUG_RELAX) + if (debug_relax) printf ("ret from " "rjmp/jmp ret sequence at address" " 0x%x could not be deleted. ret" @@ -1804,7 +2161,7 @@ elf32_avr_relax_section (bfd *abfd, if (deleting_ret_is_safe) { - if (DEBUG_RELAX) + if (debug_relax) printf ("unreachable ret instruction " "at address 0x%x deleted.\n", (int) dot + insn_size); @@ -1972,6 +2329,614 @@ elf32_avr_get_relocated_section_contents (bfd *output_bfd, } +/* Determines the hash entry name for a particular reloc. It consists of + the identifier of the symbol section and the added reloc addend and + symbol offset relative to the section the symbol is attached to. */ + +static char * +avr_stub_name (const asection *symbol_section, + const bfd_vma symbol_offset, + const Elf_Internal_Rela *rela) +{ + char *stub_name; + bfd_size_type len; + + len = 8 + 1 + 8 + 1 + 1; + stub_name = bfd_malloc (len); + + sprintf (stub_name, "%08x+%08x", + symbol_section->id & 0xffffffff, + (unsigned int) ((rela->r_addend & 0xffffffff) + symbol_offset)); + + return stub_name; +} + + +/* Add a new stub entry to the stub hash. Not all fields of the new + stub entry are initialised. */ + +static struct elf32_avr_stub_hash_entry * +avr_add_stub (const char *stub_name, + struct elf32_avr_link_hash_table *htab) +{ + struct elf32_avr_stub_hash_entry *hsh; + + /* Enter this entry into the linker stub hash table. */ + hsh = avr_stub_hash_lookup (&htab->bstab, stub_name, TRUE, FALSE); + + if (hsh == NULL) + { + (*_bfd_error_handler) (_("%B: cannot create stub entry %s"), + NULL, stub_name); + return NULL; + } + + hsh->stub_offset = 0; + return hsh; +} + +/* We assume that there is already space allocated for the stub section + contents and that before building the stubs the section size is + initialized to 0. We assume that within the stub hash table entry, + the absolute position of the jmp target has been written in the + target_value field. We write here the offset of the generated jmp insn + relative to the trampoline section start to the stub_offset entry in + the stub hash table entry. */ + +static bfd_boolean +avr_build_one_stub (struct bfd_hash_entry *bh, void *in_arg) +{ + struct elf32_avr_stub_hash_entry *hsh; + struct bfd_link_info *info; + struct elf32_avr_link_hash_table *htab; + bfd *stub_bfd; + bfd_byte *loc; + bfd_vma target; + bfd_vma starget; + + /* Basic opcode */ + bfd_vma jmp_insn = 0x0000940c; + + /* Massage our args to the form they really have. */ + hsh = avr_stub_hash_entry (bh); + + if (!hsh->is_actually_needed) + return TRUE; + + info = (struct bfd_link_info *) in_arg; + + htab = avr_link_hash_table (info); + + target = hsh->target_value; + + /* Make a note of the offset within the stubs for this entry. */ + hsh->stub_offset = htab->stub_sec->size; + loc = htab->stub_sec->contents + hsh->stub_offset; + + stub_bfd = htab->stub_sec->owner; + + if (debug_stubs) + printf ("Building one Stub. Address: 0x%x, Offset: 0x%x\n", + (unsigned int) target, + (unsigned int) hsh->stub_offset); + + /* We now have to add the information on the jump target to the bare + opcode bits already set in jmp_insn. */ + + /* Check for the alignment of the address. */ + if (target & 1) + return FALSE; + + starget = target >> 1; + jmp_insn |= ((starget & 0x10000) | ((starget << 3) & 0x1f00000)) >> 16; + bfd_put_16 (stub_bfd, jmp_insn, loc); + bfd_put_16 (stub_bfd, (bfd_vma) starget & 0xffff, loc + 2); + + htab->stub_sec->size += 4; + + /* Now add the entries in the address mapping table if there is still + space left. */ + { + unsigned int nr; + + nr = htab->amt_entry_cnt + 1; + if (nr <= htab->amt_max_entry_cnt) + { + htab->amt_entry_cnt = nr; + + htab->amt_stub_offsets[nr - 1] = hsh->stub_offset; + htab->amt_destination_addr[nr - 1] = target; + } + } + + return TRUE; +} + +static bfd_boolean +avr_mark_stub_not_to_be_necessary (struct bfd_hash_entry *bh, + void *in_arg) +{ + struct elf32_avr_stub_hash_entry *hsh; + struct elf32_avr_link_hash_table *htab; + + htab = in_arg; + hsh = avr_stub_hash_entry (bh); + hsh->is_actually_needed = FALSE; + + return TRUE; +} + +static bfd_boolean +avr_size_one_stub (struct bfd_hash_entry *bh, void *in_arg) +{ + struct elf32_avr_stub_hash_entry *hsh; + struct elf32_avr_link_hash_table *htab; + int size; + + /* Massage our args to the form they really have. */ + hsh = avr_stub_hash_entry (bh); + htab = in_arg; + + if (hsh->is_actually_needed) + size = 4; + else + size = 0; + + htab->stub_sec->size += size; + return TRUE; +} + +void +elf32_avr_setup_params (struct bfd_link_info *info, + bfd *avr_stub_bfd, + asection *avr_stub_section, + bfd_boolean no_stubs, + bfd_boolean deb_stubs, + bfd_boolean deb_relax, + bfd_vma pc_wrap_around, + bfd_boolean call_ret_replacement) +{ + struct elf32_avr_link_hash_table *htab = avr_link_hash_table(info); + + htab->stub_sec = avr_stub_section; + htab->stub_bfd = avr_stub_bfd; + htab->no_stubs = no_stubs; + + debug_relax = deb_relax; + debug_stubs = deb_stubs; + avr_pc_wrap_around = pc_wrap_around; + avr_replace_call_ret_sequences = call_ret_replacement; +} + + +/* Set up various things so that we can make a list of input sections + for each output section included in the link. Returns -1 on error, + 0 when no stubs will be needed, and 1 on success. It also sets + information on the stubs bfd and the stub section in the info + struct. */ + +int +elf32_avr_setup_section_lists (bfd *output_bfd, + struct bfd_link_info *info) +{ + bfd *input_bfd; + unsigned int bfd_count; + int top_id, top_index; + asection *section; + asection **input_list, **list; + bfd_size_type amt; + struct elf32_avr_link_hash_table *htab = avr_link_hash_table(info); + + if (htab->no_stubs) + return 0; + + /* Count the number of input BFDs and find the top input section id. */ + for (input_bfd = info->input_bfds, bfd_count = 0, top_id = 0; + input_bfd != NULL; + input_bfd = input_bfd->link_next) + { + bfd_count += 1; + for (section = input_bfd->sections; + section != NULL; + section = section->next) + if (top_id < section->id) + top_id = section->id; + } + + htab->bfd_count = bfd_count; + + /* We can't use output_bfd->section_count here to find the top output + section index as some sections may have been removed, and + strip_excluded_output_sections doesn't renumber the indices. */ + for (section = output_bfd->sections, top_index = 0; + section != NULL; + section = section->next) + if (top_index < section->index) + top_index = section->index; + + htab->top_index = top_index; + amt = sizeof (asection *) * (top_index + 1); + input_list = bfd_malloc (amt); + htab->input_list = input_list; + if (input_list == NULL) + return -1; + + /* For sections we aren't interested in, mark their entries with a + value we can check later. */ + list = input_list + top_index; + do + *list = bfd_abs_section_ptr; + while (list-- != input_list); + + for (section = output_bfd->sections; + section != NULL; + section = section->next) + if ((section->flags & SEC_CODE) != 0) + input_list[section->index] = NULL; + + return 1; +} + + +/* Read in all local syms for all input bfds, and create hash entries + for export stubs if we are building a multi-subspace shared lib. + Returns -1 on error, 0 otherwise. */ + +static int +get_local_syms (bfd *input_bfd, struct bfd_link_info *info) +{ + unsigned int bfd_indx; + Elf_Internal_Sym *local_syms, **all_local_syms; + struct elf32_avr_link_hash_table *htab = avr_link_hash_table (info); + + /* We want to read in symbol extension records only once. To do this + we need to read in the local symbols in parallel and save them for + later use; so hold pointers to the local symbols in an array. */ + bfd_size_type amt = sizeof (Elf_Internal_Sym *) * htab->bfd_count; + all_local_syms = bfd_zmalloc (amt); + htab->all_local_syms = all_local_syms; + if (all_local_syms == NULL) + return -1; + + /* Walk over all the input BFDs, swapping in local symbols. + If we are creating a shared library, create hash entries for the + export stubs. */ + for (bfd_indx = 0; + input_bfd != NULL; + input_bfd = input_bfd->link_next, bfd_indx++) + { + Elf_Internal_Shdr *symtab_hdr; + + /* We'll need the symbol table in a second. */ + symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; + if (symtab_hdr->sh_info == 0) + continue; + + /* We need an array of the local symbols attached to the input bfd. */ + local_syms = (Elf_Internal_Sym *) symtab_hdr->contents; + if (local_syms == NULL) + { + local_syms = bfd_elf_get_elf_syms (input_bfd, symtab_hdr, + symtab_hdr->sh_info, 0, + NULL, NULL, NULL); + /* Cache them for elf_link_input_bfd. */ + symtab_hdr->contents = (unsigned char *) local_syms; + } + if (local_syms == NULL) + return -1; + + all_local_syms[bfd_indx] = local_syms; + } + + return 0; +} + +#define ADD_DUMMY_STUBS_FOR_DEBUGGING 0 + +bfd_boolean +elf32_avr_size_stubs (bfd *output_bfd, + struct bfd_link_info *info, + bfd_boolean is_prealloc_run) +{ + struct elf32_avr_link_hash_table *htab; + int stub_changed = 0; + + htab = avr_link_hash_table (info); + + /* At this point we initialize htab->vector_base + To the start of the text output section. */ + htab->vector_base = htab->stub_sec->output_section->vma; + + if (get_local_syms (info->input_bfds, info)) + { + if (htab->all_local_syms) + goto error_ret_free_local; + return FALSE; + } + + if (ADD_DUMMY_STUBS_FOR_DEBUGGING) + { + struct elf32_avr_stub_hash_entry *test; + + test = avr_add_stub ("Hugo",htab); + test->target_value = 0x123456; + test->stub_offset = 13; + + test = avr_add_stub ("Hugo2",htab); + test->target_value = 0x84210; + test->stub_offset = 14; + } + + while (1) + { + bfd *input_bfd; + unsigned int bfd_indx; + + /* We will have to re-generate the stub hash table each time anything + in memory has changed. */ + + bfd_hash_traverse (&htab->bstab, avr_mark_stub_not_to_be_necessary, htab); + for (input_bfd = info->input_bfds, bfd_indx = 0; + input_bfd != NULL; + input_bfd = input_bfd->link_next, bfd_indx++) + { + Elf_Internal_Shdr *symtab_hdr; + asection *section; + Elf_Internal_Sym *local_syms; + + /* We'll need the symbol table in a second. */ + symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; + if (symtab_hdr->sh_info == 0) + continue; + + local_syms = htab->all_local_syms[bfd_indx]; + + /* Walk over each section attached to the input bfd. */ + for (section = input_bfd->sections; + section != NULL; + section = section->next) + { + Elf_Internal_Rela *internal_relocs, *irelaend, *irela; + + /* If there aren't any relocs, then there's nothing more + to do. */ + if ((section->flags & SEC_RELOC) == 0 + || section->reloc_count == 0) + continue; + + /* If this section is a link-once section that will be + discarded, then don't create any stubs. */ + if (section->output_section == NULL + || section->output_section->owner != output_bfd) + continue; + + /* Get the relocs. */ + internal_relocs + = _bfd_elf_link_read_relocs (input_bfd, section, NULL, NULL, + info->keep_memory); + if (internal_relocs == NULL) + goto error_ret_free_local; + + /* Now examine each relocation. */ + irela = internal_relocs; + irelaend = irela + section->reloc_count; + for (; irela < irelaend; irela++) + { + unsigned int r_type, r_indx; + struct elf32_avr_stub_hash_entry *hsh; + asection *sym_sec; + bfd_vma sym_value; + bfd_vma destination; + struct elf_link_hash_entry *hh; + char *stub_name; + + r_type = ELF32_R_TYPE (irela->r_info); + r_indx = ELF32_R_SYM (irela->r_info); + + /* Only look for 16 bit GS relocs. No other reloc will need a + stub. */ + if (!((r_type == R_AVR_16_PM) + || (r_type == R_AVR_LO8_LDI_GS) + || (r_type == R_AVR_HI8_LDI_GS))) + continue; + + /* Now determine the call target, its name, value, + section. */ + sym_sec = NULL; + sym_value = 0; + destination = 0; + hh = NULL; + if (r_indx < symtab_hdr->sh_info) + { + /* It's a local symbol. */ + Elf_Internal_Sym *sym; + Elf_Internal_Shdr *hdr; + + sym = local_syms + r_indx; + hdr = elf_elfsections (input_bfd)[sym->st_shndx]; + sym_sec = hdr->bfd_section; + if (ELF_ST_TYPE (sym->st_info) != STT_SECTION) + sym_value = sym->st_value; + destination = (sym_value + irela->r_addend + + sym_sec->output_offset + + sym_sec->output_section->vma); + } + else + { + /* It's an external symbol. */ + int e_indx; + + e_indx = r_indx - symtab_hdr->sh_info; + hh = elf_sym_hashes (input_bfd)[e_indx]; + + while (hh->root.type == bfd_link_hash_indirect + || hh->root.type == bfd_link_hash_warning) + hh = (struct elf_link_hash_entry *) + (hh->root.u.i.link); + + if (hh->root.type == bfd_link_hash_defined + || hh->root.type == bfd_link_hash_defweak) + { + sym_sec = hh->root.u.def.section; + sym_value = hh->root.u.def.value; + if (sym_sec->output_section != NULL) + destination = (sym_value + irela->r_addend + + sym_sec->output_offset + + sym_sec->output_section->vma); + } + else if (hh->root.type == bfd_link_hash_undefweak) + { + if (! info->shared) + continue; + } + else if (hh->root.type == bfd_link_hash_undefined) + { + if (! (info->unresolved_syms_in_objects == RM_IGNORE + && (ELF_ST_VISIBILITY (hh->other) + == STV_DEFAULT))) + continue; + } + else + { + bfd_set_error (bfd_error_bad_value); + + error_ret_free_internal: + if (elf_section_data (section)->relocs == NULL) + free (internal_relocs); + goto error_ret_free_local; + } + } + + if (! avr_stub_is_required_for_16_bit_reloc + (destination - htab->vector_base)) + { + if (!is_prealloc_run) + /* We are having a reloc that does't need a stub. */ + continue; + + /* We don't right now know if a stub will be needed. + Let's rather be on the safe side. */ + } + + /* Get the name of this stub. */ + stub_name = avr_stub_name (sym_sec, sym_value, irela); + + if (!stub_name) + goto error_ret_free_internal; + + + hsh = avr_stub_hash_lookup (&htab->bstab, + stub_name, + FALSE, FALSE); + if (hsh != NULL) + { + /* The proper stub has already been created. Mark it + to be used and write the possibly changed destination + value. */ + hsh->is_actually_needed = TRUE; + hsh->target_value = destination; + free (stub_name); + continue; + } + + hsh = avr_add_stub (stub_name, htab); + if (hsh == NULL) + { + free (stub_name); + goto error_ret_free_internal; + } + + hsh->is_actually_needed = TRUE; + hsh->target_value = destination; + + if (debug_stubs) + printf ("Adding stub with destination 0x%x to the" + " hash table.\n", (unsigned int) destination); + if (debug_stubs) + printf ("(Pre-Alloc run: %i)\n", is_prealloc_run); + + stub_changed = TRUE; + } + + /* We're done with the internal relocs, free them. */ + if (elf_section_data (section)->relocs == NULL) + free (internal_relocs); + } + } + + /* Re-Calculate the number of needed stubs. */ + htab->stub_sec->size = 0; + bfd_hash_traverse (&htab->bstab, avr_size_one_stub, htab); + + if (!stub_changed) + break; + + stub_changed = FALSE; + } + + free (htab->all_local_syms); + return TRUE; + + error_ret_free_local: + free (htab->all_local_syms); + return FALSE; +} + + +/* Build all the stubs associated with the current output file. The + stubs are kept in a hash table attached to the main linker hash + table. We also set up the .plt entries for statically linked PIC + functions here. This function is called via hppaelf_finish in the + linker. */ + +bfd_boolean +elf32_avr_build_stubs (struct bfd_link_info *info) +{ + asection *stub_sec; + struct bfd_hash_table *table; + struct elf32_avr_link_hash_table *htab; + bfd_size_type total_size = 0; + + htab = avr_link_hash_table (info); + + /* In case that there were several stub sections: */ + for (stub_sec = htab->stub_bfd->sections; + stub_sec != NULL; + stub_sec = stub_sec->next) + { + bfd_size_type size; + + /* Allocate memory to hold the linker stubs. */ + size = stub_sec->size; + total_size += size; + + stub_sec->contents = bfd_zalloc (htab->stub_bfd, size); + if (stub_sec->contents == NULL && size != 0) + return FALSE; + stub_sec->size = 0; + } + + /* Allocate memory for the adress mapping table. */ + htab->amt_entry_cnt = 0; + htab->amt_max_entry_cnt = total_size / 4; + htab->amt_stub_offsets = bfd_malloc (sizeof (bfd_vma) + * htab->amt_max_entry_cnt); + htab->amt_destination_addr = bfd_malloc (sizeof (bfd_vma) + * htab->amt_max_entry_cnt ); + + if (debug_stubs) + printf ("Allocating %i entries in the AMT\n", htab->amt_max_entry_cnt); + + /* Build the stubs as directed by the stub hash table. */ + table = &htab->bstab; + bfd_hash_traverse (table, avr_build_one_stub, info); + + if (debug_stubs) + printf ("Final Stub section Size: %i\n", (int) htab->stub_sec->size); + + return TRUE; +} + #define ELF_ARCH bfd_arch_avr #define ELF_MACHINE_CODE EM_AVR #define ELF_MACHINE_ALT1 EM_AVR_OLD @@ -1980,6 +2945,9 @@ elf32_avr_get_relocated_section_contents (bfd *output_bfd, #define TARGET_LITTLE_SYM bfd_elf32_avr_vec #define TARGET_LITTLE_NAME "elf32-avr" +#define bfd_elf32_bfd_link_hash_table_create elf32_avr_link_hash_table_create +#define bfd_elf32_bfd_link_hash_table_free elf32_avr_link_hash_table_free + #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 |