ts' - The output section does not have the `SEC_HAS_CONTENTS' attribute, so nothing can be written to it. * and some more too This routine is front end to the back end function `_bfd_set_section_contents'. 2.6.5.15 `bfd_get_section_contents' ................................... *Synopsis* bfd_boolean bfd_get_section_contents (bfd *abfd, asection *section, void *location, file_ptr offset, bfd_size_type count); *Description* Read data from SECTION in BFD ABFD into memory starting at LOCATION. The data is read at an offset of OFFSET from the start of the input section, and is read for COUNT bytes. If the contents of a constructor with the `SEC_CONSTRUCTOR' flag set are requested or if the section does not have the `SEC_HAS_CONTENTS' flag set, then the LOCATION is filled with zeroes. If no errors occur, `TRUE' is returned, else `FALSE'. 2.6.5.16 `bfd_malloc_and_get_section' ..................................... *Synopsis* bfd_boolean bfd_malloc_and_get_section (bfd *abfd, asection *section, bfd_byte **buf); *Description* Read all data from SECTION in BFD ABFD into a buffer, *BUF, malloc'd by this function. 2.6.5.17 `bfd_copy_private_section_data' ........................................ *Synopsis* bfd_boolean bfd_copy_private_section_data (bfd *ibfd, asection *isec, bfd *obfd, asection *osec); *Description* Copy private section information from ISEC in the BFD IBFD to the section OSEC in the BFD OBFD. Return `TRUE' on success, `FALSE' on error. Possible error returns are: * `bfd_error_no_memory' - Not enough memory exists to create private data for OSEC. #define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ BFD_SEND (obfd, _bfd_copy_private_section_data, \ (ibfd, isection, obfd, osection)) 2.6.5.18 `bfd_generic_is_group_section' ....................................... *Synopsis* bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec); *Description* Returns TRUE if SEC is a member of a group. 2.6.5.19 `bfd_generic_discard_group' .................................... *Synopsis* bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group); *Description* Remove all members of GROUP from the output.  File: bfd.info, Node: Symbols, Next: Archives, Prev: Sections, Up: BFD front end 2.7 Symbols =========== BFD tries to maintain as much symbol information as it can when it moves information from file to file. BFD passes information to applications though the `asymbol' structure. When the application requests the symbol table, BFD reads the table in the native form and translates parts of it into the internal format. To maintain more than the information passed to applications, some targets keep some information "behind the scenes" in a structure only the particular back end knows about. For example, the coff back end keeps the original symbol table structure as well as the canonical structure when a BFD is read in. On output, the coff back end can reconstruct the output symbol table so that no information is lost, even information unique to coff which BFD doesn't know or understand. If a coff symbol table were read, but were written through an a.out back end, all the coff specific information would be lost. The symbol table of a BFD is not necessarily read in until a canonicalize request is made. Then the BFD back end fills in a table provided by the application with pointers to the canonical information. To output symbols, the application provides BFD with a table of pointers to pointers to `asymbol's. This allows applications like the linker to output a symbol as it was read, since the "behind the scenes" information will be still available. * Menu: * Reading Symbols:: * Writing Symbols:: * Mini Symbols:: * typedef asymbol:: * symbol handling functions::  File: bfd.info, Node: Reading Symbols, Next: Writing Symbols, Prev: Symbols, Up: Symbols 2.7.1 Reading symbols --------------------- There are two stages to reading a symbol table from a BFD: allocating storage, and the actual reading process. This is an excerpt from an application which reads the symbol table: long storage_needed; asymbol **symbol_table; long number_of_symbols; long i; storage_needed = bfd_get_symtab_upper_bound (abfd); if (storage_needed < 0) FAIL if (storage_needed == 0) return; symbol_table = xmalloc (storage_needed); ... number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); if (number_of_symbols < 0) FAIL for (i = 0; i < number_of_symbols; i++) process_symbol (symbol_table[i]); All storage for the symbols themselves is in an objalloc connected to the BFD; it is freed when the BFD is closed.  File: bfd.info, Node: Writing Symbols, Next: Mini Symbols, Prev: Reading Symbols, Up: Symbols 2.7.2 Writing symbols --------------------- Writing of a symbol table is automatic when a BFD open for writing is closed. The application attaches a vector of pointers to pointers to symbols to the BFD being written, and fills in the symbol count. The close and cleanup code reads through the table provided and performs all the necessary operations. The BFD output code must always be provided with an "owned" symbol: one which has come from another BFD, or one which has been created using `bfd_make_empty_symbol'. Here is an example showing the creation of a symbol table with only one element: #include "bfd.h" int main (void) { bfd *abfd; asymbol *ptrs[2]; asymbol *new; abfd = bfd_openw ("foo","a.out-sunos-big"); bfd_set_format (abfd, bfd_object); new = bfd_make_empty_symbol (abfd); new->name = "dummy_symbol"; new->section = bfd_make_section_old_way (abfd, ".text"); new->flags = BSF_GLOBAL; new->value = 0x12345; ptrs[0] = new; ptrs[1] = 0; bfd_set_symtab (abfd, ptrs, 1); bfd_close (abfd); return 0; } ./makesym nm foo 00012345 A dummy_symbol Many formats cannot represent arbitrary symbol information; for instance, the `a.out' object format does not allow an arbitrary number of sections. A symbol pointing to a section which is not one of `.text', `.data' or `.bss' cannot be described.  File: bfd.info, Node: Mini Symbols, Next: typedef asymbol, Prev: Writing Symbols, Up: Symbols 2.7.3 Mini Symbols ------------------ Mini symbols provide read-only access to the symbol table. They use less memory space, but require more time to access. They can be useful for tools like nm or objdump, which may have to handle symbol tables of extremely large executables. The `bfd_read_minisymbols' function will read the symbols into memory in an internal form. It will return a `void *' pointer to a block of memory, a symbol count, and the size of each symbol. The pointer is allocated using `malloc', and should be freed by the caller when it is no longer needed. The function `bfd_minisymbol_to_symbol' will take a pointer to a minisymbol, and a pointer to a structure returned by `bfd_make_empty_symbol', and return a `asymbol' structure. The return value may or may not be the same as the value from `bfd_make_empty_symbol' which was passed in.  File: bfd.info, Node: typedef asymbol, Next: symbol handling functions, Prev: Mini Symbols, Up: Symbols 2.7.4 typedef asymbol --------------------- An `asymbol' has the form: typedef struct bfd_symbol { /* A pointer to the BFD which owns the symbol. This information is necessary so that a back end can work out what additional information (invisible to the application writer) is carried with the symbol. This field is *almost* redundant, since you can use section->owner instead, except that some symbols point to the global sections bfd_{abs,com,und}_section. This could be fixed by making these globals be per-bfd (or per-target-flavor). FIXME. */ struct bfd *the_bfd; /* Use bfd_asymbol_bfd(sym) to access this field. */ /* The text of the symbol. The name is left alone, and not copied; the application may not alter it. */ const char *name; /* The value of the symbol. This really should be a union of a numeric value with a pointer, since some flags indicate that a pointer to another symbol is stored here. */ symvalue value; /* Attributes of a symbol. */ #define BSF_NO_FLAGS 0x00 /* The symbol has local scope; `static' in `C'. The value is the offset into the section of the data. */ #define BSF_LOCAL (1 << 0) /* The symbol has global scope; initialized data in `C'. The value is the offset into the section of the data. */ #define BSF_GLOBAL (1 << 1) /* The symbol has global scope and is exported. The value is the offset into the section of the data. */ #define BSF_EXPORT BSF_GLOBAL /* No real difference. */ /* A normal C symbol would be one of: `BSF_LOCAL', `BSF_COMMON', `BSF_UNDEFINED' or `BSF_GLOBAL'. */ /* The symbol is a debugging record. The value has an arbitrary meaning, unless BSF_DEBUGGING_RELOC is also set. */ #define BSF_DEBUGGING (1 << 2) /* The symbol denotes a function entry point. Used in ELF, perhaps others someday. */ #define BSF_FUNCTION (1 << 3) /* Used by the linker. */ #define BSF_KEEP (1 << 5) #define BSF_KEEP_G (1 << 6) /* A weak global symbol, overridable without warnings by a regular global symbol of the same name. */ #define BSF_WEAK (1 << 7) /* This symbol was created to point to a section, e.g. ELF's STT_SECTION symbols. */ #define BSF_SECTION_SYM (1 << 8) /* The symbol used to be a common symbol, but now it is allocated. */ #define BSF_OLD_COMMON (1 << 9) /* In some files the type of a symbol sometimes alters its location in an output file - ie in coff a `ISFCN' symbol which is also `C_EXT' symbol appears where it was declared and not at the end of a section. This bit is set by the target BFD part to convey this information. */ #define BSF_NOT_AT_END (1 << 10) /* Signal that the symbol is the label of constructor section. */ #define BSF_CONSTRUCTOR (1 << 11) /* Signal that the symbol is a warning symbol. The name is a warning. The name of the next symbol is the one to warn about; if a reference is made to a symbol with the same name as the next symbol, a warning is issued by the linker. */ #define BSF_WARNING (1 << 12) /* Signal that the symbol is indirect. This symbol is an indirect pointer to the symbol with the same name as the next symbol. */ #define BSF_INDIRECT (1 << 13) /* BSF_FILE marks symbols that contain a file name. This is used for ELF STT_FILE symbols. */ #define BSF_FILE (1 << 14) /* Symbol is from dynamic linking information. */ #define BSF_DYNAMIC (1 << 15) /* The symbol denotes a data object. Used in ELF, and perhaps others someday. */ #define BSF_OBJECT (1 << 16) /* This symbol is a debugging symbol. The value is the offset into the section of the data. BSF_DEBUGGING should be set as well. */ #define BSF_DEBUGGING_RELOC (1 << 17) /* This symbol is thread local. Used in ELF. */ #define BSF_THREAD_LOCAL (1 << 18) /* This symbol represents a complex relocation expression, with the expression tree serialized in the symbol name. */ #define BSF_RELC (1 << 19) /* This symbol represents a signed complex relocation expression, with the expression tree serialized in the symbol name. */ #define BSF_SRELC (1 << 20) /* This symbol was created by bfd_get_synthetic_symtab. */ #define BSF_SYNTHETIC (1 << 21) /* This symbol is an indirect code object. Unrelated to BSF_INDIRECT. The dynamic linker will compute the value of this symbol by calling the function that it points to. BSF_FUNCTION must also be also set. */ #define BSF_GNU_INDIRECT_FUNCTION (1 << 22) /* This symbol is a globally unique data object. The dynamic linker will make sure that in the entire process there is just one symbol with this name and type in use. BSF_OBJECT must also be set. */ #define BSF_GNU_UNIQUE (1 << 23) flagword flags; /* A pointer to the section to which this symbol is relative. This will always be non NULL, there are special sections for undefined and absolute symbols. */ struct bfd_section *section; /* Back end special data. */ union { void *p; bfd_vma i; } udata; } asymbol;  File: bfd.info, Node: symbol handling functions, Prev: typedef asymbol, Up: Symbols 2.7.5 Symbol handling functions ------------------------------- 2.7.5.1 `bfd_get_symtab_upper_bound' .................................... *Description* Return the number of bytes required to store a vector of pointers to `asymbols' for all the symbols in the BFD ABFD, including a terminal NULL pointer. If there are no symbols in the BFD, then return 0. If an error occurs, return -1. #define bfd_get_symtab_upper_bound(abfd) \ BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd)) 2.7.5.2 `bfd_is_local_label' ............................ *Synopsis* bfd_boolean bfd_is_local_label (bfd *abfd, asymbol *sym); *Description* Return TRUE if the given symbol SYM in the BFD ABFD is a compiler generated local label, else return FALSE. 2.7.5.3 `bfd_is_local_label_name' ................................. *Synopsis* bfd_boolean bfd_is_local_label_name (bfd *abfd, const char *name); *Description* Return TRUE if a symbol with the name NAME in the BFD ABFD is a compiler generated local label, else return FALSE. This just checks whether the name has the form of a local label. #define bfd_is_local_label_name(abfd, name) \ BFD_SEND (abfd, _bfd_is_local_label_name, (abfd, name)) 2.7.5.4 `bfd_is_target_special_symbol' ...................................... *Synopsis* bfd_boolean bfd_is_target_special_symbol (bfd *abfd, asymbol *sym); *Description* Return TRUE iff a symbol SYM in the BFD ABFD is something special to the particular target represented by the BFD. Such symbols should normally not be mentioned to the user. #define bfd_is_target_special_symbol(abfd, sym) \ BFD_SEND (abfd, _bfd_is_target_special_symbol, (abfd, sym)) 2.7.5.5 `bfd_canonicalize_symtab' ................................. *Description* Read the symbols from the BFD ABFD, and fills in the vector LOCATION with pointers to the symbols and a trailing NULL. Return the actual number of symbol pointers, not including the NULL. #define bfd_canonicalize_symtab(abfd, location) \ BFD_SEND (abfd, _bfd_canonicalize_symtab, (abfd, location)) 2.7.5.6 `bfd_set_symtab' ........................ *Synopsis* bfd_boolean bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int count); *Description* Arrange that when the output BFD ABFD is closed, the table LOCATION of COUNT pointers to symbols will be written. 2.7.5.7 `bfd_print_symbol_vandf' ................................ *Synopsis* void bfd_print_symbol_vandf (bfd *abfd, void *file, asymbol *symbol); *Description* Print the value and flags of the SYMBOL supplied to the stream FILE. 2.7.5.8 `bfd_make_empty_symbol' ............................... *Description* Create a new `asymbol' structure for the BFD ABFD and return a pointer to it. This routine is necessary because each back end has private information surrounding the `asymbol'. Building your own `asymbol' and pointing to it will not create the private information, and will cause problems later on. #define bfd_make_empty_symbol(abfd) \ BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd)) 2.7.5.9 `_bfd_generic_make_empty_symbol' ........................................ *Synopsis* asymbol *_bfd_generic_make_empty_symbol (bfd *); *Description* Create a new `asymbol' structure for the BFD ABFD and return a pointer to it. Used by core file routines, binary back-end and anywhere else where no private info is needed. 2.7.5.10 `bfd_make_debug_symbol' ................................ *Description* Create a new `asymbol' structure for the BFD ABFD, to be used as a debugging symbol. Further details of its use have yet to be worked out. #define bfd_make_debug_symbol(abfd,ptr,size) \ BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size)) 2.7.5.11 `bfd_decode_symclass' .............................. *Description* Return a character corresponding to the symbol class of SYMBOL, or '?' for an unknown class. *Synopsis* int bfd_decode_symclass (asymbol *symbol); 2.7.5.12 `bfd_is_undefined_symclass' .................................... *Description* Returns non-zero if the class symbol returned by bfd_decode_symclass represents an undefined symbol. Returns zero otherwise. *Synopsis* bfd_boolean bfd_is_undefined_symclass (int symclass); 2.7.5.13 `bfd_symbol_info' .......................... *Description* Fill in the basic info about symbol that nm needs. Additional info may be added by the back-ends after calling this function. *Synopsis* void bfd_symbol_info (asymbol *symbol, symbol_info *ret); 2.7.5.14 `bfd_copy_private_symbol_data' ....................................... *Synopsis* bfd_boolean bfd_copy_private_symbol_data (bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym); *Description* Copy private symbol information from ISYM in the BFD IBFD to the symbol OSYM in the BFD OBFD. Return `TRUE' on success, `FALSE' on error. Possible error returns are: * `bfd_error_no_memory' - Not enough memory exists to create private data for OSEC. #define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \ BFD_SEND (obfd, _bfd_copy_private_symbol_data, \ (ibfd, isymbol, obfd, osymbol))  File: bfd.info, Node: Archives, Next: Formats, Prev: Symbols, Up: BFD front end 2.8 Archives ============ *Description* An archive (or library) is just another BFD. It has a symbol table, although there's not much a user program will do with it. The big difference between an archive BFD and an ordinary BFD is that the archive doesn't have sections. Instead it has a chain of BFDs that are considered its contents. These BFDs can be manipulated like any other. The BFDs contained in an archive opened for reading will all be opened for reading. You may put either input or output BFDs into an archive opened for output; they will be handled correctly when the archive is closed. Use `bfd_openr_next_archived_file' to step through the contents of an archive opened for input. You don't have to read the entire archive if you don't want to! Read it until you find what you want. Archive contents of output BFDs are chained through the `next' pointer in a BFD. The first one is findable through the `archive_head' slot of the archive. Set it with `bfd_set_archive_head' (q.v.). A given BFD may be in only one open output archive at a time. As expected, the BFD archive code is more general than the archive code of any given environment. BFD archives may contain files of different formats (e.g., a.out and coff) and even different architectures. You may even place archives recursively into archives! This can cause unexpected confusion, since some archive formats are more expressive than others. For instance, Intel COFF archives can preserve long filenames; SunOS a.out archives cannot. If you move a file from the first to the second format and back again, the filename may be truncated. Likewise, different a.out environments have different conventions as to how they truncate filenames, whether they preserve directory names in filenames, etc. When interoperating with native tools, be sure your files are homogeneous. Beware: most of these formats do not react well to the presence of spaces in filenames. We do the best we can, but can't always handle this case due to restrictions in the format of archives. Many Unix utilities are braindead in regards to spaces and such in filenames anyway, so this shouldn't be much of a restriction. Archives are supported in BFD in `archive.c'. 2.8.1 Archive functions ----------------------- 2.8.1.1 `bfd_get_next_mapent' ............................. *Synopsis* symindex bfd_get_next_mapent (bfd *abfd, symindex previous, carsym **sym); *Description* Step through archive ABFD's symbol table (if it has one). Successively update SYM with the next symbol's information, returning that symbol's (internal) index into the symbol table. Supply `BFD_NO_MORE_SYMBOLS' as the PREVIOUS entry to get the first one; returns `BFD_NO_MORE_SYMBOLS' when you've already got the last one. A `carsym' is a canonical archive symbol. The only user-visible element is its name, a null-terminated string. 2.8.1.2 `bfd_set_archive_head' .............................. *Synopsis* bfd_boolean bfd_set_archive_head (bfd *output, bfd *new_head); *Description* Set the head of the chain of BFDs contained in the archive OUTPUT to NEW_HEAD. 2.8.1.3 `bfd_openr_next_archived_file' ...................................... *Synopsis* bfd *bfd_openr_next_archived_file (bfd *archive, bfd *previous); *Description* Provided a BFD, ARCHIVE, containing an archive and NULL, open an input BFD on the first contained element and returns that. Subsequent calls should pass the archive and the previous return value to return a created BFD to the next contained element. NULL is returned when there are no more.  File: bfd.info, Node: Formats, Next: Relocations, Prev: Archives, Up: BFD front end 2.9 File formats ================ A format is a BFD concept of high level file contents type. The formats supported by BFD are: * `bfd_object' The BFD may contain data, symbols, relocations and debug info. * `bfd_archive' The BFD contains other BFDs and an optional index. * `bfd_core' The BFD contains the result of an executable core dump. 2.9.1 File format functions --------------------------- 2.9.1.1 `bfd_check_format' .......................... *Synopsis* bfd_boolean bfd_check_format (bfd *abfd, bfd_format format); *Description* Verify if the file attached to the BFD ABFD is compatible with the format FORMAT (i.e., one of `bfd_object', `bfd_archive' or `bfd_core'). If the BFD has been set to a specific target before the call, only the named target and format combination is checked. If the target has not been set, or has been set to `default', then all the known target backends is interrogated to determine a match. If the default target matches, it is used. If not, exactly one target must recognize the file, or an error results. The function returns `TRUE' on success, otherwise `FALSE' with one of the following error codes: * `bfd_error_invalid_operation' - if `format' is not one of `bfd_object', `bfd_archive' or `bfd_core'. * `bfd_error_system_call' - if an error occured during a read - even some file mismatches can cause bfd_error_system_calls. * `file_not_recognised' - none of the backends recognised the file format. * `bfd_error_file_ambiguously_recognized' - more than one backend recognised the file format. 2.9.1.2 `bfd_check_format_matches' .................................. *Synopsis* bfd_boolean bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching); *Description* Like `bfd_check_format', except when it returns FALSE with `bfd_errno' set to `bfd_error_file_ambiguously_recognized'. In that case, if MATCHING is not NULL, it will be filled in with a NULL-terminated list of the names of the formats that matched, allocated with `malloc'. Then the user may choose a format and try again. When done with the list that MATCHING points to, the caller should free it. 2.9.1.3 `bfd_set_format' ........................ *Synopsis* bfd_boolean bfd_set_format (bfd *abfd, bfd_format format); *Description* This function sets the file format of the BFD ABFD to the format FORMAT. If the target set in the BFD does not support the format requested, the format is invalid, or the BFD is not open for writing, then an error occurs. 2.9.1.4 `bfd_format_string' ........................... *Synopsis* const char *bfd_format_string (bfd_format format); *Description* Return a pointer to a const string `invalid', `object', `archive', `core', or `unknown', depending upon the value of FORMAT.  File: bfd.info, Node: Relocations, Next: Core Files, Prev: Formats, Up: BFD front end 2.10 Relocations ================ BFD maintains relocations in much the same way it maintains symbols: they are left alone until required, then read in en-masse and translated into an internal form. A common routine `bfd_perform_relocation' acts upon the canonical form to do the fixup. Relocations are maintained on a per section basis, while symbols are maintained on a per BFD basis. All that a back end has to do to fit the BFD interface is to create a `struct reloc_cache_entry' for each relocation in a particular section, and fill in the right bits of the structures. * Menu: * typedef arelent:: * howto manager::  File: bfd.info, Node: typedef arelent, Next: howto manager, Prev: Relocations, Up: Relocations 2.10.1 typedef arelent ---------------------- This is the structure of a relocation entry: typedef enum bfd_reloc_status { /* No errors detected. */ bfd_reloc_ok, /* The relocation was performed, but there was an overflow. */ bfd_reloc_overflow, /* The address to relocate was not within the section supplied. */ bfd_reloc_outofrange, /* Used by special functions. */ bfd_reloc_continue, /* Unsupported relocation size requested. */ bfd_reloc_notsupported, /* Unused. */ bfd_reloc_other, /* The symbol to relocate against was undefined. */ bfd_reloc_undefined, /* The relocation was performed, but may not be ok - presently generated only when linking i960 coff files with i960 b.out symbols. If this type is returned, the error_message argument to bfd_perform_relocation will be set. */ bfd_reloc_dangerous } bfd_reloc_status_type; typedef struct reloc_cache_entry { /* A pointer into the canonical table of pointers. */ struct bfd_symbol **sym_ptr_ptr; /* offset in section. */ bfd_size_type address; /* addend for relocation value. */ bfd_vma addend; /* Pointer to how to perform the required relocation. */ reloc_howto_type *howto; } arelent; *Description* Here is a description of each of the fields within an `arelent': * `sym_ptr_ptr' The symbol table pointer points to a pointer to the symbol associated with the relocation request. It is the pointer into the table returned by the back end's `canonicalize_symtab' action. *Note Symbols::. The symbol is referenced through a pointer to a pointer so that tools like the linker can fix up all the symbols of the same name by modifying only one pointer. The relocation routine looks in the symbol and uses the base of the section the symbol is attached to and the value of the symbol as the initial relocation offset. If the symbol pointer is zero, then the section provided is looked up. * `address' The `address' field gives the offset in bytes from the base of the section data which owns the relocation record to the first byte of relocatable information. The actual data relocated will be relative to this point; for example, a relocation type which modifies the bottom two bytes of a four byte word would not touch the first byte pointed to in a big endian world. * `addend' The `addend' is a value provided by the back end to be added (!) to the relocation offset. Its interpretation is dependent upon the howto. For example, on the 68k the code: char foo[]; main() { return foo[0x12345678]; } Could be compiled into: linkw fp,#-4 moveb @#12345678,d0 extbl d0 unlk fp rts This could create a reloc pointing to `foo', but leave the offset in the data, something like: RELOCATION RECORDS FOR [.text]: offset type value 00000006 32 _foo 00000000 4e56 fffc ; linkw fp,#-4 00000004 1039 1234 5678 ; moveb @#12345678,d0 0000000a 49c0 ; extbl d0 0000000c 4e5e ; unlk fp 0000000e 4e75 ; rts Using coff and an 88k, some instructions don't have enough space in them to represent the full address range, and pointers have to be loaded in two parts. So you'd get something like: or.u r13,r0,hi16(_foo+0x12345678) ld.b r2,r13,lo16(_foo+0x12345678) jmp r1 This should create two relocs, both pointing to `_foo', and with 0x12340000 in their addend field. The data would consist of: RELOCATION RECORDS FOR [.text]: offset type value 00000002 HVRT16 _foo+0x12340000 00000006 LVRT16 _foo+0x12340000 00000000 5da05678 ; or.u r13,r0,0x5678 00000004 1c4d5678 ; ld.b r2,r13,0x5678 00000008 f400c001 ; jmp r1 The relocation routine digs out the value from the data, adds it to the addend to get the original offset, and then adds the value of `_foo'. Note that all 32 bits have to be kept around somewhere, to cope with carry from bit 15 to bit 16. One further example is the sparc and the a.out format. The sparc has a similar problem to the 88k, in that some instructions don't have room for an entire offset, but on the sparc the parts are created in odd sized lumps. The designers of the a.out format chose to not use the data within the section for storing part of the offset; all the offset is kept within the reloc. Anything in the data should be ignored. save %sp,-112,%sp sethi %hi(_foo+0x12345678),%g2 ldsb [%g2+%lo(_foo+0x12345678)],%i0 ret restore Both relocs contain a pointer to `foo', and the offsets contain junk. RELOCATION RECORDS FOR [.text]: offset type value 00000004 HI22 _foo+0x12345678 00000008 LO10 _foo+0x12345678 00000000 9de3bf90 ; save %sp,-112,%sp 00000004 05000000 ; sethi %hi(_foo+0),%g2 00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0 0000000c 81c7e008 ; ret 00000010 81e80000 ; restore * `howto' The `howto' field can be imagined as a relocation instruction. It is a pointer to a structure which contains information on what to do with all of the other information in the reloc record and data section. A back end would normally have a relocation instruction set and turn relocations into pointers to the correct structure on input - but it would be possible to create each howto field on demand. 2.10.1.1 `enum complain_overflow' ................................. Indicates what sort of overflow checking should be done when performing a relocation. enum complain_overflow { /* Do not complain on overflow. */ complain_overflow_dont, /* Complain if the value overflows when considered as a signed number one bit larger than the field. ie. A bitfield of N bits is allowed to represent -2**n to 2**n-1. */ complain_overflow_bitfield, /* Complain if the value overflows when considered as a signed number. */ complain_overflow_signed, /* Complain if the value overflows when considered as an unsigned number. */ complain_overflow_unsigned }; 2.10.1.2 `reloc_howto_type' ........................... The `reloc_howto_type' is a structure which contains all the information that libbfd needs to know to tie up a back end's data. struct bfd_symbol; /* Forward declaration. */ struct reloc_howto_struct { /* The type field has mainly a documentary use - the back end can do what it wants with it, though normally the back end's external idea of what a reloc number is stored in this field. For example, a PC relative word relocation in a coff environment has the type 023 - because that's what the outside world calls a R_PCRWORD reloc. */ unsigned int type; /* The value the final relocation is shifted right by. This drops unwanted data from the relocation. */ unsigned int rightshift; /* The size of the item to be relocated. This is *not* a power-of-two measure. To get the number of bytes operated on by a type of relocation, use bfd_get_reloc_size. */ int size; /* The number of bits in the item to be relocated. This is used when doing overflow checking. */ unsigned int bitsize; /* The relocation is relative to the field being relocated. */ bfd_boolean pc_relative; /* The bit position of the reloc value in the destination. The relocated value is left shifted by this amount. */ unsigned int bitpos; /* What type of overflow error should be checked for when relocating. */ enum complain_overflow complain_on_overflow; /* If this field is non null, then the supplied function is called rather than the normal function. This allows really strange relocation methods to be accommodated (e.g., i960 callj instructions). */ bfd_reloc_status_type (*special_function) (bfd *, arelent *, struct bfd_symbol *, void *, asection *, bfd *, char **); /* The textual name of the relocation type. */ char *name; /* Some formats record a relocation addend in the section contents rather than with the relocation. For ELF formats this is the distinction between USE_REL and USE_RELA (though the code checks for USE_REL == 1/0). The value of this field is TRUE if the addend is recorded with the section contents; when performing a partial link (ld -r) the section contents (the data) will be modified. The value of this field is FALSE if addends are recorded with the relocation (in arelent.addend); when performing a partial link the relocation will be modified. All relocations for all ELF USE_RELA targets should set this field to FALSE (values of TRUE should be looked on with suspicion). However, the converse is not true: not all relocations of all ELF USE_REL targets set this field to TRUE. Why this is so is peculiar to each particular target. For relocs that aren't used in partial links (e.g. GOT stuff) it doesn't matter what this is set to. */ bfd_boolean partial_inplace; /* src_mask selects the part of the instruction (or data) to be used in the relocation sum. If the target relocations don't have an addend in the reloc, eg. ELF USE_REL, src_mask will normally equal dst_mask to extract the addend from the section contents. If relocations do have an addend in the reloc, eg. ELF USE_RELA, this field should be zero. Non-zero values for ELF USE_RELA targets are bogus as in those cases the value in the dst_mask part of the section contents should be treated as garbage. */ bfd_vma src_mask; /* dst_mask selects which parts of the instruction (or data) are replaced with a relocated value. */ bfd_vma dst_mask; /* When some formats create PC relative instructions, they leave the value of the pc of the place being relocated in the offset slot of the instruction, so that a PC relative relocation can be made just by adding in an ordinary offset (e.g., sun3 a.out). Some formats leave the displacement part of an instruction empty (e.g., m88k bcs); this flag signals the fact. */ bfd_boolean pcrel_offset; }; 2.10.1.3 `The HOWTO Macro' .......................... *Description* The HOWTO define is horrible and will go away. #define HOWTO(C, R, S, B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \ { (unsigned) C, R, S, B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC } *Description* And will be replaced with the totally magic way. But for the moment, we are compatible, so do it this way. #define NEWHOWTO(FUNCTION, NAME, SIZE, REL, IN) \ HOWTO (0, 0, SIZE, 0, REL, 0, complain_overflow_dont, FUNCTION, \ NAME, FALSE, 0, 0, IN) *Description* This is used to fill in an empty howto entry in an array. #define EMPTY_HOWTO(C) \ HOWTO ((C), 0, 0, 0, FALSE, 0, complain_overflow_dont, NULL, \ NULL, FALSE, 0, 0, FALSE) *Description* Helper routine to turn a symbol into a relocation value. #define HOWTO_PREPARE(relocation, symbol) \ { \ if (symbol != NULL) \ { \ if (bfd_is_com_section (symbol->section)) \ { \ relocation = 0; \ } \ else \ { \ relocation = symbol->value; \ } \ } \ } 2.10.1.4 `bfd_get_reloc_size' ............................. *Synopsis* unsigned int bfd_get_reloc_size (reloc_howto_type *); *Description* For a reloc_howto_type that operates on a fixed number of bytes, this returns the number of bytes operated on. 2.10.1.5 `arelent_chain' ........................ *Description* How relocs are tied together in an `asection': typedef struct relent_chain { arelent relent; struct relent_chain *next; } arelent_chain; 2.10.1.6 `bfd_check_overflow' ............................. *Synopsis* bfd_reloc_status_type bfd_check_overflow (enum complain_overflow how, unsigned int bitsize, unsigned int rightshift, unsigned int addrsize, bfd_vma relocation); *Description* Perform overflow checking on RELOCATION which has BITSIZE significant bits and will be shifted right by RIGHTSHIFT bits, on a machine with addresses containing ADDRSIZE significant bits. The result is either of `bfd_reloc_ok' or `bfd_reloc_overflow'. 2.10.1.7 `bfd_perform_relocation' ................................. *Synopsis* bfd_reloc_status_type bfd_perform_relocation (bfd *abfd, arelent *reloc_entry, void *data, asection *input_section, bfd *output_bfd, char **error_message); *Description* If OUTPUT_BFD is supplied to this function, the generated image will be relocatable; the relocations are copied to the output file after they have been changed to reflect the new state of the world. There are two ways of reflecting the results of partial linkage in an output file: by modifying the output data in place, and by modifying the relocation record. Some native formats (e.g., basic a.out and basic coff) have no way of specifying an addend in the relocation type, so the addend has to go in the output data. This is no big deal since in these formats the output data slot will always be big enough for the addend. Complex reloc types with addends were invented to solve just this problem. The ERROR_MESSAGE argument is set to an error message if this return `bfd_reloc_dangerous'. 2.10.1.8 `bfd_install_relocation' ................................. *Synopsis* bfd_reloc_status_type bfd_install_relocation (bfd *abfd, arelent *reloc_entry, void *data, bfd_vma data_start, asection *input_section, char **error_message); *Description* This looks remarkably like `bfd_perform_relocation', except it does not expect that the section contents have been filled in. I.e., it's suitable for use when creating, rather than applying a relocation. For now, this function should be considered reserved for the assembler.  File: bfd.info, Node: howto manager, Prev: typedef arelent, Up: Relocations 2.10.2 The howto manager ------------------------ When an application wants to create a relocation, but doesn't know what the target machine might call it, it can find out by using this bit of code. 2.10.2.1 `bfd_reloc_code_type' .............................. *Description* The insides of a reloc code. The idea is that, eventually, there will be one enumerator for every type of relocation we ever do. Pass one of these values to `bfd_reloc_type_lookup', and it'll return a howto pointer. This does mean that the application must determine the correct enumerator value; you can't get a howto pointer from a random set of attributes. Here are the possible values for `enum bfd_reloc_code_real': -- : BFD_RELOC_64 -- : BFD_RELOC_32 -- : BFD_RELOC_26 -- : BFD_RELOC_24 -- : BFD_RELOC_16 -- : BFD_RELOC_14 -- : BFD_RELOC_8 Basic absolute relocations of N bits. -- : BFD_RELOC_64_PCREL -- : BFD_RELOC_32_PCREL -- : BFD_RELOC_24_PCREL -- : BFD_RELOC_16_PCREL -- : BFD_RELOC_12_PCREL -- : BFD_RELOC_8_PCREL PC-relative relocations. Sometimes these are relative to the address of the relocation itself; sometimes they are relative to the start of the section containing the relocation. It depends on the specific target. The 24-bit relocation is used in some Intel 960 configurations. -- : BFD_RELOC_32_SECREL Section relative relocations. Some targets need this for DWARF2. -- : BFD_RELOC_32_GOT_PCREL -- : BFD_RELOC_16_GOT_PCREL -- : BFD_RELOC_8_GOT_PCREL -- : BFD_RELOC_32_GOTOFF -- : BFD_RELOC_16_GOTOFF -- : BFD_RELOC_LO16_GOTOFF -- : BFD_RELOC_HI16_GOTOFF -- : BFD_RELOC_HI16_S_GOTOFF -- : BFD_RELOC_8_GOTOFF -- : BFD_RELOC_64_PLT_PCREL -- : BFD_RELOC_32_PLT_PCREL -- : BFD_RELOC_24_PLT_PCREL -- : BFD_RELOC_16_PLT_PCREL -- : BFD_RELOC_8_PLT_PCREL -- : BFD_RELOC_64_PLTOFF -- : BFD_RELOC_32_PLTOFF -- : BFD_RELOC_16_PLTOFF -- : BFD_RELOC_LO16_PLTOFF -- : BFD_RELOC_HI16_PLTOFF -- : BFD_RELOC_HI16_S_PLTOFF -- : BFD_RELOC_8_PLTOFF For ELF. -- : BFD_RELOC_68K_GLOB_DAT -- : BFD_RELOC_68K_JMP_SLOT -- : BFD_RELOC_68K_RELATIVE -- : BFD_RELOC_68K_TLS_GD32 -- : BFD_RELOC_68K_TLS_GD16 -- : BFD_RELOC_68K_TLS_GD8 -- : BFD_RELOC_68K_TLS_LDM32 -- : BFD_RELOC_68K_TLS_LDM16 -- : BFD_RELOC_68K_TLS_LDM8 -- : BFD_RELOC_68K_TLS_LDO32 -- : BFD_RELOC_68K_TLS_LDO16 -- : BFD_RELOC_68K_TLS_LDO8 -- : BFD_RELOC_68K_TLS_IE32 -- : BFD_RELOC_68K_TLS_IE16 -- : BFD_RELOC_68K_TLS_IE8 -- : BFD_RELOC_68K_TLS_LE32 -- : BFD_RELOC_68K_TLS_LE16 -- : BFD_RELOC_68K_TLS_LE8 Relocations used by 68K ELF. -- : BFD_RELOC_32_BASEREL -- : BFD_RELOC_16_BASEREL -- : BFD_RELOC_LO16_BASEREL -- : BFD_RELOC_HI16_BASEREL -- : BFD_RELOC_HI16_S_BASEREL -- : BFD_RELOC_8_BASEREL -- : BFD_RELOC_RVA Linkage-table relative. -- : BFD_RELOC_8_FFnn Absolute 8-bit relocation, but used to form an address like 0xFFnn. -- : BFD_RELOC_32_PCREL_S2 -- : BFD_RELOC_16_PCREL_S2 -- : BFD_RELOC_23_PCREL_S2 These PC-relative relocations are stored as word displacements - i.e., byte displacements shifted right two bits. The 30-bit word displacement (<<32_PCREL_S2>> - 32 bits, shifted 2) is used on the SPARC. (SPARC tools generally refer to this as <>.) The signed 16-bit displacement is used on the MIPS, and the 23-bit displacement is used on the Alpha. -- : BFD_RELOC_HI22 -- : BFD_RELOC_LO10 High 22 bits and low 10 bits of 32-bit value, placed into lower bits of the target word. These are used on the SPARC. -- : BFD_RELOC_GPREL16 -- : BFD_RELOC_GPREL32 For systems that allocate a Global Pointer register, these are displacements off that register. These relocation types are handled specially, because the value the register will have is decided relatively late. -- : BFD_RELOC_I960_CALLJ Reloc types used for i960/b.out. -- : BFD_RELOC_NONE -- : BFD_RELOC_SPARC_WDISP22 -- : BFD_RELOC_SPARC22 -- : BFD_RELOC_SPARC13 -- : BFD_RELOC_SPARC_GOT10 -- : BFD_RELOC_SPARC_GOT13 -- : BFD_RELOC_SPARC_GOT22 -- : BFD_RELOC_SPARC_PC10 -- : BFD_RELOC_SPARC_PC22 -- : BFD_RELOC_SPARC_WPLT30 -- : BFD_RELOC_SPARC_COPY -- : BFD_RELOC_SPARC_GLOB_DAT -- : BFD_RELOC_SPARC_JMP_SLOT -- : BFD_RELOC_SPARC_RELATIVE -- : BFD_RELOC_SPARC_UA16 -- : BFD_RELOC_SPARC_UA32 -- : BFD_RELOC_SPARC_UA64 -- : BFD_RELOC_SPARC_GOTDATA_HIX22 -- : BFD_RELOC_SPARC_GOTDATA_LOX10 -- : BFD_RELOC_SPARC_GOTDATA_OP_HIX22 -- : BFD_RELOC_SPARC_GOTDATA_OP_LOX10 -- : BFD_RELOC_SPARC_GOTDATA_OP -- : BFD_RELOC_SPARC_JMP_IREL -- : BFD_RELOC_SPARC_IRELATIVE SPARC ELF relocations. There is probably some overlap with other relocation types already defined. -- : BFD_RELOC_SPARC_BASE13 -- : BFD_RELOC_SPARC_BASE22 I think these are specific to SPARC a.out (e.g., Sun 4). -- : BFD_RELOC_SPARC_64 -- : BFD_RELOC_SPARC_10 -- : BFD_RELOC_SPARC_11 -- : BFD_RELOC_SPARC_OLO10 -- : BFD_RELOC_SPARC_HH22 -- : BFD_RELOC_SPARC_HM10 -- : BFD_RELOC_SPARC_LM22 -- : BFD_RELOC_SPARC_PC_HH22 -- : BFD_RELOC_SPARC_PC_HM10 -- : BFD_RELOC_SPARC_PC_LM22 -- : BFD_RELOC_SPARC_WDISP16 -- : BFD_RELOC_SPARC_WDISP19 -- : BFD_RELOC_SPARC_7 -- : BFD_RELOC_SPARC_6 -- : BFD_RELOC_SPARC_5 -- : BFD_RELOC_SPARC_DISP64 -- : BFD_RELOC_SPARC_PLT32 -- : BFD_RELOC_SPARC_PLT64 -- : BFD_RELOC_SPARC_HIX22 -- : BFD_RELOC_SPARC_LOX10 -- : BFD_RELOC_SPARC_H44 -- : BFD_RELOC_SPARC_M44 -- : BFD_RELOC_SPARC_L44 -- : BFD_RELOC_SPARC_REGISTER SPARC64 relocations -- : BFD_RELOC_SPARC_REV32 SPARC little endian relocation -- : BFD_RELOC_SPARC_TLS_GD_HI22 -- : BFD_RELOC_SPARC_TLS_GD_LO10 -- : BFD_RELOC_SPARC_TLS_GD_ADD -- : BFD_RELOC_SPARC_TLS_GD_CALL -- : BFD_RELOC_SPARC_TLS_LDM_HI22 -- : BFD_RELOC_SPARC_TLS_LDM_LO10 -- : BFD_RELOC_SPARC_TLS_LDM_ADD -- : BFD_RELOC_SPARC_TLS_LDM_CALL -- : BFD_RELOC_SPARC_TLS_LDO_HIX22 -- : BFD_RELOC_SPARC_TLS_LDO_LOX10 -- : BFD_RELOC_SPARC_TLS_LDO_ADD -- : BFD_RELOC_SPARC_TLS_IE_HI22 -- : BFD_RELOC_SPARC_TLS_IE_LO10 -- : BFD_RELOC_SPARC_TLS_IE_LD -- : BFD_RELOC_SPARC_TLS_IE_LDX -- : BFD_RELOC_SPARC_TLS_IE_ADD -- : BFD_RELOC_SPARC_TLS_LE_HIX22 -- : BFD_RELOC_SPARC_TLS_LE_LOX10 -- : BFD_RELOC_SPARC_TLS_DTPMOD32 -- : BFD_RELOC_SPARC_TLS_DTPMOD64 -- : BFD_RELOC_SPARC_TLS_DTPOFF32 -- : BFD_RELOC_SPARC_TLS_DTPOFF64 -- : BFD_RELOC_SPARC_TLS_TPOFF32 -- : BFD_RELOC_SPARC_TLS_TPOFF64 SPARC TLS relocations -- : BFD_RELOC_SPU_IMM7 -- : BFD_RELOC_SPU_IMM8 -- : BFD_RELOC_SPU_IMM10 -- : BFD_RELOC_SPU_IMM10W -- : BFD_RELOC_SPU_IMM16 -- : BFD_RELOC_SPU_IMM16W -- : BFD_RELOC_SPU_IMM18 -- : BFD_RELOC_SPU_PCREL9a -- : BFD_RELOC_SPU_PCREL9b -- : BFD_RELOC_SPU_PCREL16 -- : BFD_RELOC_SPU_LO16 -- : BFD_RELOC_SPU_HI16 -- : BFD_RELOC_SPU_PPU32 -- : BFD_RELOC_SPU_PPU64 -- : BFD_RELOC_SPU_ADD_PIC SPU Relocations. -- : BFD_RELOC_ALPHA_GPDISP_HI16 Alpha ECOFF and ELF relocations. Some of these treat the symbol or "addend" in some special way. For GPDISP_HI16 ("gpdisp") relocations, the symbol is ignored when writing; when reading, it will be the absolute section symbol. The addend is the displacement in bytes of the "lda" instruction from the "ldah" instruction (which is at the address of this reloc). -- : BFD_RELOC_ALPHA_GPDISP_LO16 For GPDISP_LO16 ("ignore") relocations, the symbol is handled as with GPDISP_HI16 relocs. The addend is ignored when writing the relocations out, and is filled in with the file's GP value on reading, for convenience. -- : BFD_RELOC_ALPHA_GPDISP The ELF GPDISP relocation is exactly the same as the GPDISP_HI16 relocation except that there is no accompanying GPDISP_LO16 relocation. -- : BFD_RELOC_ALPHA_LITERAL -- : BFD_RELOC_ALPHA_ELF_LITERAL -- : BFD_RELOC_ALPHA_LITUSE The Alpha LITERAL/LITUSE relocs are produced by a symbol reference; the assembler turns it into a LDQ instruction to load the address of the symbol, and then fills in a register in the real instruction. The LITERAL reloc, at the LDQ instruction, refers to the .lita section symbol. The addend is ignored when writing, but is filled in with the file's GP value on reading, for convenience, as with the GPDISP_LO16 reloc. The ELF_LITERAL reloc is somewhere between 16_GOTOFF and GPDISP_LO16. It should refer to the symbol to be referenced, as with 16_GOTOFF, but it generates output not based on the position within the .got section, but relative to the GP value chosen for the file during the final link stage. The LITUSE reloc, on the instruction using the loaded address, gives information to the linker that it might be able to use to optimize away some literal section references. The symbol is ignored (read as the absolute section symbol), and the "addend" indicates the type of instruction using the register: 1 - "memory" fmt insn 2 - byte-manipulation (byte offset reg) 3 - jsr (target of branch) -- : BFD_RELOC_ALPHA_HINT The HINT relocation indicates a value that should be filled into the "hint" field of a jmp/jsr/ret instruction, for possible branch- prediction logic which may be provided on some processors. -- : BFD_RELOC_ALPHA_LINKAGE The LINKAGE relocation outputs a linkage pair in the object file, which is filled by the linker. -- : BFD_RELOC_ALPHA_CODEADDR The CODEADDR relocation outputs a STO_CA in the object file, which is filled by the linker. -- : BFD_RELOC_ALPHA_GPREL_HI16 -- : BFD_RELOC_ALPHA_GPREL_LO16 The GPREL_HI/LO relocations together form a 32-bit offset from the GP register. -- : BFD_RELOC_ALPHA_BRSGP Like BFD_RELOC_23_PCREL_S2, except that the source and target must share a common GP, and the target address is adjusted for STO_ALPHA_STD_GPLOAD. -- : BFD_RELOC_ALPHA_NOP The NOP relocation outputs a NOP if the longword displacement between two procedure entry points is < 2^21. -- : BFD_RELOC_ALPHA_BSR The BSR relocation outputs a BSR if the longword displacement between two procedure entry points is < 2^21. -- : BFD_RELOC_ALPHA_LDA The LDA relocation outputs a LDA if the longword displacement between two procedure entry points is < 2^16. -- : BFD_RELOC_ALPHA_BOH The BOH relocation outputs a BSR if the longword displacement between two procedure entry points is < 2^21, or else a hint. -- : BFD_RELOC_ALPHA_TLSGD -- : BFD_RELOC_ALPHA_TLSLDM -- : BFD_RELOC_ALPHA_DTPMOD64 -- : BFD_RELOC_ALPHA_GOTDTPREL16 -- : BFD_RELOC_ALPHA_DTPREL64 -- : BFD_RELOC_ALPHA_DTPREL_HI16 -- : BFD_RELOC_ALPHA_DTPREL_LO16 -- : BFD_RELOC_ALPHA_DTPREL16 -- : BFD_RELOC_ALPHA_GOTTPREL16 -- : BFD_RELOC_ALPHA_TPREL64 -- : BFD_RELOC_ALPHA_TPREL_HI16 -- : BFD_RELOC_ALPHA_TPREL_LO16 -- : BFD_RELOC_ALPHA_TPREL16 Alpha thread-local storage relocations. -- : BFD_RELOC_MIPS_JMP Bits 27..2 of the relocation address shifted right 2 bits; simple reloc otherwise. -- : BFD_RELOC_MIPS16_JMP The MIPS16 jump instruction. -- : BFD_RELOC_MIPS16_GPREL MIPS16 GP relative reloc. -- : BFD_RELOC_HI16 High 16 bits of 32-bit value; simple reloc. -- : BFD_RELOC_HI16_S High 16 bits of 32-bit value but the low 16 bits will be sign extended and added to form the final result. If the low 16 bits form a negative number, we need to add one to the high value to compensate for the borrow when the low bits are added. -- : BFD_RELOC_LO16 Low 16 bits. -- : BFD_RELOC_HI16_PCREL High 16 bits of 32-bit pc-relative value -- : BFD_RELOC_HI16_S_PCREL High 16 bits of 32-bit pc-relative value, adjusted -- : BFD_RELOC_LO16_PCREL Low 16 bits of pc-relative value -- : BFD_RELOC_MIPS16_GOT16 -- : BFD_RELOC_MIPS16_CALL16 Equivalent of BFD_RELOC_MIPS_*, but with the MIPS16 layout of 16-bit immediate fields -- : BFD_RELOC_MIPS16_HI16 MIPS16 high 16 bits of 32-bit value. -- : BFD_RELOC_MIPS16_HI16_S MIPS16 high 16 bits of 32-bit value but the low 16 bits will be sign extended and added to form the final result. If the low 16 bits form a negative number, we need to add one to the high value to compensate for the borrow when the low bits are added. -- : BFD_RELOC_MIPS16_LO16 MIPS16 low 16 bits. -- : BFD_RELOC_MIPS_LITERAL Relocation against a MIPS literal section. -- : BFD_RELOC_MIPS_GOT16 -- : BFD_RELOC_MIPS_CALL16 -- : BFD_RELOC_MIPS_GOT_HI16 -- : BFD_RELOC_MIPS_GOT_LO16 -- : BFD_RELOC_MIPS_CALL_HI16 -- : BFD_RELOC_MIPS_CALL_LO16 -- : BFD_RELOC_MIPS_SUB -- : BFD_RELOC_MIPS_GOT_PAGE -- : BFD_RELOC_MIPS_GOT_OFST -- : BFD_RELOC_MIPS_GOT_DISP -- : BFD_RELOC_MIPS_SHIFT5 -- : BFD_RELOC_MIPS_SHIFT6 -- : BFD_RELOC_MIPS_INSERT_A -- : BFD_RELOC_MIPS_INSERT_B -- : BFD_RELOC_MIPS_DELETE -- : BFD_RELOC_MIPS_HIGHEST -- : BFD_RELOC_MIPS_HIGHER -- : BFD_RELOC_MIPS_SCN_DISP -- : BFD_RELOC_MIPS_REL16 -- : BFD_RELOC_MIPS_RELGOT -- : BFD_RELOC_MIPS_JALR -- : BFD_RELOC_MIPS_TLS_DTPMOD32 -- : BFD_RELOC_MIPS_TLS_DTPREL32 -- : BFD_RELOC_MIPS_TLS_DTPMOD64 -- : BFD_RELOC_MIPS_TLS_DTPREL64 -- : BFD_RELOC_MIPS_TLS_GD -- : BFD_RELOC_MIPS_TLS_LDM -- : BFD_RELOC_MIPS_TLS_DTPREL_HI16 -- : BFD_RELOC_MIPS_TLS_DTPREL_LO16 -- : BFD_RELOC_MIPS_TLS_GOTTPREL -- : BFD_RELOC_MIPS_TLS_TPREL32 -- : BFD_RELOC_MIPS_TLS_TPREL64 -- : BFD_RELOC_MIPS_TLS_TPREL_HI16 -- : BFD_RELOC_MIPS_TLS_TPREL_LO16 MIPS ELF relocations. -- : BFD_RELOC_MIPS_COPY -- : BFD_RELOC_MIPS_JUMP_SLOT MIPS ELF relocations (VxWorks and PLT extensions). -- : BFD_RELOC_MOXIE_10_PCREL Moxie ELF relocations. -- : BFD_RELOC_FRV_LABEL16 -- : BFD_RELOC_FRV_LABEL24 -- : BFD_RELOC_FRV_LO16 -- : BFD_RELOC_FRV_HI16 -- : BFD_RELOC_FRV_GPREL12 -- : BFD_RELOC_FRV_GPRELU12 -- : BFD_RELOC_FRV_GPREL32 -- : BFD_RELOC_FRV_GPRELHI -- : BFD_RELOC_FRV_GPRELLO -- : BFD_RELOC_FRV_GOT12 -- : BFD_RELOC_FRV_GOTHI -- : BFD_RELOC_FRV_GOTLO -- : BFD_RELOC_FRV_FUNCDESC -- : BFD_RELOC_FRV_FUNCDESC_GOT12 -- : BFD_RELOC_FRV_FUNCDESC_GOTHI -- : BFD_RELOC_FRV_FUNCDESC_GOTLO -- : BFD_RELOC_FRV_FUNCDESC_VALUE -- : BFD_RELOC_FRV_FUNCDESC_GOTOFF12 -- : BFD_RELOC_FRV_FUNCDESC_GOTOFFHI -- : BFD_RELOC_FRV_FUNCDESC_GOTOFFLO -- : BFD_RELOC_FRV_GOTOFF12 -- : BFD_RELOC_FRV_GOTOFFHI -- : BFD_RELOC_FRV_GOTOFFLO -- : BFD_RELOC_FRV_GETTLSOFF -- : BFD_RELOC_FRV_TLSDESC_VALUE -- : BFD_RELOC_FRV_GOTTLSDESC12 -- : BFD_RELOC_FRV_GOTTLSDESCHI -- : BFD_RELOC_FRV_GOTTLSDESCLO -- : BFD_RELOC_FRV_TLSMOFF12 -- : BFD_RELOC_FRV_TLSMOFFHI -- : BFD_RELOC_FRV_TLSMOFFLO -- : BFD_RELOC_FRV_GOTTLSOFF12 -- : BFD_RELOC_FRV_GOTTLSOFFHI -- : BFD_RELOC_FRV_GOTTLSOFFLO -- : BFD_RELOC_FRV_TLSOFF -- : BFD_RELOC_FRV_TLSDESC_RELAX -- : BFD_RELOC_FRV_GETTLSOFF_RELAX -- : BFD_RELOC_FRV_TLSOFF_RELAX -- : BFD_RELOC_FRV_TLSMOFF Fujitsu Frv Relocations. -- : BFD_RELOC_MN10300_GOTOFF24 This is a 24bit GOT-relative reloc for the mn10300. -- : BFD_RELOC_MN10300_GOT32 This is a 32bit GOT-relative reloc for the mn10300, offset by two bytes in the instruction. -- : BFD_RELOC_MN10300_GOT24 This is a 24bit GOT-relative reloc for the mn10300, offset by two bytes in the instruction. -- : BFD_RELOC_MN10300_GOT16 This is a 16bit GOT-relative reloc for the mn10300, offset by two bytes in the instruction. -- : BFD_RELOC_MN10300_COPY Copy symbol at runtime. -- : BFD_RELOC_MN10300_GLOB_DAT Create GOT entry. -- : BFD_RELOC_MN10300_JMP_SLOT Create PLT entry. -- : BFD_RELOC_MN10300_RELATIVE Adjust by program base. -- : BFD_RELOC_MN10300_SYM_DIFF Together with another reloc targeted at the same location, allows for a value that is the difference of two symbols in the same section. -- : BFD_RELOC_MN10300_ALIGN The addend of this reloc is an alignment power that must be honoured at the offset's location, regardless of linker relaxation. -- : BFD_RELOC_386_GOT32 -- : BFD_RELOC_386_PLT32 -- : BFD_RELOC_386_COPY -- : BFD_RELOC_386_GLOB_DAT -- : BFD_RELOC_386_JUMP_SLOT -- : BFD_RELOC_386_RELATIVE -- : BFD_RELOC_386_GOTOFF -- : BFD_RELOC_386_GOTPC -- : BFD_RELOC_386_TLS_TPOFF -- : BFD_RELOC_386_TLS_IE -- : BFD_RELOC_386_TLS_GOTIE -- : BFD_RELOC_386_TLS_LE -- : BFD_RELOC_386_TLS_GD -- : BFD_RELOC_386_TLS_LDM -- : BFD_RELOC_386_TLS_LDO_32 -- : BFD_RELOC_386_TLS_IE_32 -- : BFD_RELOC_386_TLS_LE_32 -- : BFD_RELOC_386_TLS_DTPMOD32 -- : BFD_RELOC_386_TLS_DTPOFF32 -- : BFD_RELOC_386_TLS_TPOFF32 -- : BFD_RELOC_386_TLS_GOTDESC -- : BFD_RELOC_386_TLS_DESC_CALL -- : BFD_RELOC_386_TLS_DESC -- : BFD_RELOC_386_IRELATIVE i386/elf relocations -- : BFD_RELOC_X86_64_GOT32 -- : BFD_RELOC_X86_64_PLT32 -- : BFD_RELOC_X86_64_COPY -- : BFD_RELOC_X86_64_GLOB_DAT -- : BFD_RELOC_X86_64_JUMP_SLOT -- : BFD_RELOC_X86_64_RELATIVE -- : BFD_RELOC_X86_64_GOTPCREL -- : BFD_RELOC_X86_64_32S -- : BFD_RELOC_X86_64_DTPMOD64 -- : BFD_RELOC_X86_64_DTPOFF64 -- : BFD_RELOC_X86_64_TPOFF64 -- : BFD_RELOC_X86_64_TLSGD -- : BFD_RELOC_X86_64_TLSLD -- : BFD_RELOC_X86_64_DTPOFF32 -- : BFD_RELOC_X86_64_GOTTPOFF -- : BFD_RELOC_X86_64_TPOFF32 -- : BFD_RELOC_X86_64_GOTOFF64 -- : BFD_RELOC_X86_64_GOTPC32 -- : BFD_RELOC_X86_64_GOT64 -- : BFD_RELOC_X86_64_GOTPCREL64 -- : BFD_RELOC_X86_64_GOTPC64 -- : BFD_RELOC_X86_64_GOTPLT64 -- : BFD_RELOC_X86_64_PLTOFF64 -- : BFD_RELOC_X86_64_GOTPC32_TLSDESC -- : BFD_RELOC_X86_64_TLSDESC_CALL -- : BFD_RELOC_X86_64_TLSDESC -- : BFD_RELOC_X86_64_IRELATIVE x86-64/elf relocations -- : BFD_RELOC_NS32K_IMM_8 -- : BFD_RELOC_NS32K_IMM_16 -- : BFD_RELOC_NS32K_IMM_32 -- : BFD_RELOC_NS32K_IMM_8_PCREL -- : BFD_RELOC_NS32K_IMM_16_PCREL -- : BFD_RELOC_NS32K_IMM_32_PCREL -- : BFD_RELOC_NS32K_DISP_8 -- : BFD_RELOC_NS32K_DISP_16 -- : BFD_RELOC_NS32K_DISP_32 -- : BFD_RELOC_NS32K_DISP_8_PCREL -- : BFD_RELOC_NS32K_DISP_16_PCREL -- : BFD_RELOC_NS32K_DISP_32_PCREL ns32k relocations -- : BFD_RELOC_PDP11_DISP_8_PCREL -- : BFD_RELOC_PDP11_DISP_6_PCREL PDP11 relocations -- : BFD_RELOC_PJ_CODE_HI16 -- : BFD_RELOC_PJ_CODE_LO16 -- : BFD_RELOC_PJ_CODE_DIR16 -- : BFD_RELOC_PJ_CODE_DIR32 -- : BFD_RELOC_PJ_CODE_REL16 -- : BFD_RELOC_PJ_CODE_REL32 Picojava relocs. Not all of these appear in object files. -- : BFD_RELOC_PPC_B26 -- : BFD_RELOC_PPC_BA26 -- : BFD_RELOC_PPC_TOC16 -- : BFD_RELOC_PPC_B16 -- : BFD_RELOC_PPC_B16_BRTAKEN -- : BFD_RELOC_PPC_B16_BRNTAKEN -- : BFD_RELOC_PPC_BA16 -- : BFD_RELOC_PPC_BA16_BRTAKEN -- : BFD_RELOC_PPC_BA16_BRNTAKEN -- : BFD_RELOC_PPC_COPY -- : BFD_RELOC_PPC_GLOB_DAT -- : BFD_RELOC_PPC_JMP_SLOT -- : BFD_RELOC_PPC_RELATIVE -- : BFD_RELOC_PPC_LOCAL24PC -- : BFD_RELOC_PPC_EMB_NADDR32 -- : BFD_RELOC_PPC_EMB_NADDR16 -- : BFD_RELOC_PPC_EMB_NADDR16_LO -- : BFD_RELOC_PPC_EMB_NADDR16_HI -- : BFD_RELOC_PPC_EMB_NADDR16_HA -- : BFD_RELOC_PPC_EMB_SDAI16 -- : BFD_RELOC_PPC_EMB_SDA2I16 -- : BFD_RELOC_PPC_EMB_SDA2REL -- : BFD_RELOC_PPC_EMB_SDA21 -- : BFD_RELOC_PPC_EMB_MRKREF -- : BFD_RELOC_PPC_EMB_RELSEC16 -- : BFD_RELOC_PPC_EMB_RELST_LO -- : BFD_RELOC_PPC_EMB_RELST_HI -- : BFD_RELOC_PPC_EMB_RELST_HA -- : BFD_RELOC_PPC_EMB_BIT_FLD -- : BFD_RELOC_PPC_EMB_RELSDA -- : BFD_RELOC_PPC64_HIGHER -- : BFD_RELOC_PPC64_HIGHER_S -- : BFD_RELOC_PPC64_HIGHEST -- : BFD_RELOC_PPC64_HIGHEST_S -- : BFD_RELOC_PPC64_TOC16_LO -- : BFD_RELOC_PPC64_TOC16_HI -- : BFD_RELOC_PPC64_TOC16_HA -- : BFD_RELOC_PPC64_TOC -- : BFD_RELOC_PPC64_PLTGOT16 -- : BFD_RELOC_PPC64_PLTGOT16_LO -- : BFD_RELOC_PPC64_PLTGOT16_HI -- : BFD_RELOC_PPC64_PLTGOT16_HA -- : BFD_RELOC_PPC64_ADDR16_DS -- : BFD_RELOC_PPC64_ADDR16_LO_DS -- : BFD_RELOC_PPC64_GOT16_DS -- : BFD_RELOC_PPC64_GOT16_LO_DS -- : BFD_RELOC_PPC64_PLT16_LO_DS -- : BFD_RELOC_PPC64_SECTOFF_DS -- : BFD_RELOC_PPC64_SECTOFF_LO_DS -- : BFD_RELOC_PPC64_TOC16_DS -- : BFD_RELOC_PPC64_TOC16_LO_DS -- : BFD_RELOC_PPC64_PLTGOT16_DS -- : BFD_RELOC_PPC64_PLTGOT16_LO_DS Power(rs6000) and PowerPC relocations. -- : BFD_RELOC_PPC_TLS -- : BFD_RELOC_PPC_TLSGD -- : BFD_RELOC_PPC_TLSLD -- : BFD_RELOC_PPC_DTPMOD -- : BFD_RELOC_PPC_TPREL16 -- : BFD_RELOC_PPC_TPREL16_LO -- : BFD_RELOC_PPC_TPREL16_HI -- : BFD_RELOC_PPC_TPREL16_HA -- : BFD_RELOC_PPC_TPREL -- : BFD_RELOC_PPC_DTPREL16 -- : BFD_RELOC_PPC_DTPREL16_LO -- : BFD_RELOC_PPC_DTPREL16_HI -- : BFD_RELOC_PPC_DTPREL16_HA -- : BFD_RELOC_PPC_DTPREL -- : BFD_RELOC_PPC_GOT_TLSGD16 -- : BFD_RELOC_PPC_GOT_TLSGD16_LO -- : BFD_RELOC_PPC_GOT_TLSGD16_HI -- : BFD_RELOC_PPC_GOT_TLSGD16_HA -- : BFD_RELOC_PPC_GOT_TLSLD16 -- : BFD_RELOC_PPC_GOT_TLSLD16_LO -- : BFD_RELOC_PPC_GOT_TLSLD16_HI -- : BFD_RELOC_PPC_GOT_TLSLD16_HA -- : BFD_RELOC_PPC_GOT_TPREL16 -- : BFD_RELOC_PPC_GOT_TPREL16_LO -- : BFD_RELOC_PPC_GOT_TPREL16_HI -- : BFD_RELOC_PPC_GOT_TPREL16_HA -- : BFD_RELOC_PPC_GOT_DTPREL16 -- : BFD_RELOC_PPC_GOT_DTPREL16_LO -- : BFD_RELOC_PPC_GOT_DTPREL16_HI -- : BFD_RELOC_PPC_GOT_DTPREL16_HA -- : BFD_RELOC_PPC64_TPREL16_DS -- : BFD_RELOC_PPC64_TPREL16_LO_DS -- : BFD_RELOC_PPC64_TPREL16_HIGHER -- : BFD_RELOC_PPC64_TPREL16_HIGHERA -- : BFD_RELOC_PPC64_TPREL16_HIGHEST -- : BFD_RELOC_PPC64_TPREL16_HIGHESTA -- : BFD_RELOC_PPC64_DTPREL16_DS -- : BFD_RELOC_PPC64_DTPREL16_LO_DS -- : BFD_RELOC_PPC64_DTPREL16_HIGHER -- : BFD_RELOC_PPC64_DTPREL16_HIGHERA -- : BFD_RELOC_PPC64_DTPREL16_HIGHEST -- : BFD_RELOC_PPC64_DTPREL16_HIGHESTA PowerPC and PowerPC64 thread-local storage relocations. -- : BFD_RELOC_I370_D12 IBM 370/390 relocations -- : BFD_RELOC_CTOR The type of reloc used to build a constructor table - at the moment probably a 32 bit wide absolute relocation, but the target can choose. It generally does map to one of the other relocation types. -- : BFD_RELOC_ARM_PCREL_BRANCH ARM 26 bit pc-relative branch. The lowest two bits must be zero and are not stored in the instruction. -- : BFD_RELOC_ARM_PCREL_BLX ARM 26 bit pc-relative branch. The lowest bit must be zero and is not stored in the instruction. The 2nd lowest bit comes from a 1 bit field in the instruction. -- : BFD_RELOC_THUMB_PCREL_BLX Thumb 22 bit pc-relative branch. The lowest bit must be zero and is not stored in the instruction. The 2nd lowest bit comes from a 1 bit field in the instruction. -- : BFD_RELOC_ARM_PCREL_CALL ARM 26-bit pc-relative branch for an unconditional BL or BLX instruction. -- : BFD_RELOC_ARM_PCREL_JUMP ARM 26-bit pc-relative branch for B or conditional BL instruction. -- : BFD_RELOC_THUMB_PCREL_BRANCH7 -- : BFD_RELOC_THUMB_PCREL_BRANCH9 -- : BFD_RELOC_THUMB_PCREL_BRANCH12 -- : BFD_RELOC_THUMB_PCREL_BRANCH20 -- : BFD_RELOC_THUMB_PCREL_BRANCH23 -- : BFD_RELOC_THUMB_PCREL_BRANCH25 Thumb 7-, 9-, 12-, 20-, 23-, and 25-bit pc-relative branches. The lowest bit must be zero and is not stored in the instruction. Note that the corresponding ELF R_ARM_THM_JUMPnn constant has an "nn" one smaller in all cases. Note further that BRANCH23 corresponds to R_ARM_THM_CALL. -- : BFD_RELOC_ARM_OFFSET_IMM 12-bit immediate offset, used in ARM-format ldr and str instructions. -- : B