915 lines
30 KiB
Plaintext
915 lines
30 KiB
Plaintext
@section Relocations
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BFD maintains relocations in much the same way it maintains
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symbols: they are left alone until required, then read in
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en-mass and translated into an internal form. A common
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routine @code{bfd_perform_relocation} acts upon the
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canonical form to do the fixup.
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Relocations are maintained on a per section basis,
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while symbols are maintained on a per BFD basis.
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All that a back end has to do to fit the BFD interface is to create
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a @code{struct reloc_cache_entry} for each relocation
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in a particular section, and fill in the right bits of the structures.
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@menu
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* typedef arelent::
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* howto manager::
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@end menu
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@*
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@node typedef arelent, howto manager, Relocations, Relocations
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@subsection typedef arelent
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This is the structure of a relocation entry:
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@*
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.
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@example
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typedef enum bfd_reloc_status
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@{
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/* No errors detected */
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bfd_reloc_ok,
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/* The relocation was performed, but there was an overflow. */
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bfd_reloc_overflow,
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/* The address to relocate was not within the section supplied. */
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bfd_reloc_outofrange,
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/* Used by special functions */
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bfd_reloc_continue,
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/* Unsupported relocation size requested. */
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bfd_reloc_notsupported,
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/* Unused */
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bfd_reloc_other,
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/* The symbol to relocate against was undefined. */
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bfd_reloc_undefined,
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/* The relocation was performed, but may not be ok - presently
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generated only when linking i960 coff files with i960 b.out
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symbols. If this type is returned, the error_message argument
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to bfd_perform_relocation will be set. */
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bfd_reloc_dangerous
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@}
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bfd_reloc_status_type;
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typedef struct reloc_cache_entry
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@{
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/* A pointer into the canonical table of pointers */
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struct symbol_cache_entry **sym_ptr_ptr;
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/* offset in section */
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bfd_size_type address;
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/* addend for relocation value */
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bfd_vma addend;
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/* Pointer to how to perform the required relocation */
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reloc_howto_type *howto;
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@} arelent;
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@end example
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@strong{Description}@*
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Here is a description of each of the fields within an @code{arelent}:
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@itemize @bullet
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@item
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@code{sym_ptr_ptr}
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@end itemize
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The symbol table pointer points to a pointer to the symbol
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associated with the relocation request. It is
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the pointer into the table returned by the back end's
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@code{get_symtab} action. @xref{Symbols}. The symbol is referenced
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through a pointer to a pointer so that tools like the linker
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can fix up all the symbols of the same name by modifying only
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one pointer. The relocation routine looks in the symbol and
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uses the base of the section the symbol is attached to and the
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value of the symbol as the initial relocation offset. If the
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symbol pointer is zero, then the section provided is looked up.
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@itemize @bullet
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@item
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@code{address}
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@end itemize
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The @code{address} field gives the offset in bytes from the base of
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the section data which owns the relocation record to the first
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byte of relocatable information. The actual data relocated
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will be relative to this point; for example, a relocation
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type which modifies the bottom two bytes of a four byte word
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would not touch the first byte pointed to in a big endian
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world.
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@itemize @bullet
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@item
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@code{addend}
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@end itemize
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The @code{addend} is a value provided by the back end to be added (!)
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to the relocation offset. Its interpretation is dependent upon
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the howto. For example, on the 68k the code:
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@example
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char foo[];
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main()
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@{
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return foo[0x12345678];
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@}
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@end example
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Could be compiled into:
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@example
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linkw fp,#-4
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moveb @@#12345678,d0
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extbl d0
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unlk fp
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rts
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@end example
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This could create a reloc pointing to @code{foo}, but leave the
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offset in the data, something like:
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@example
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RELOCATION RECORDS FOR [.text]:
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offset type value
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00000006 32 _foo
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00000000 4e56 fffc ; linkw fp,#-4
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00000004 1039 1234 5678 ; moveb @@#12345678,d0
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0000000a 49c0 ; extbl d0
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0000000c 4e5e ; unlk fp
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0000000e 4e75 ; rts
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@end example
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Using coff and an 88k, some instructions don't have enough
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space in them to represent the full address range, and
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pointers have to be loaded in two parts. So you'd get something like:
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@example
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or.u r13,r0,hi16(_foo+0x12345678)
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ld.b r2,r13,lo16(_foo+0x12345678)
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jmp r1
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@end example
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This should create two relocs, both pointing to @code{_foo}, and with
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0x12340000 in their addend field. The data would consist of:
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@example
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RELOCATION RECORDS FOR [.text]:
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offset type value
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00000002 HVRT16 _foo+0x12340000
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00000006 LVRT16 _foo+0x12340000
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00000000 5da05678 ; or.u r13,r0,0x5678
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00000004 1c4d5678 ; ld.b r2,r13,0x5678
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00000008 f400c001 ; jmp r1
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@end example
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The relocation routine digs out the value from the data, adds
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it to the addend to get the original offset, and then adds the
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value of @code{_foo}. Note that all 32 bits have to be kept around
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somewhere, to cope with carry from bit 15 to bit 16.
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One further example is the sparc and the a.out format. The
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sparc has a similar problem to the 88k, in that some
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instructions don't have room for an entire offset, but on the
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sparc the parts are created in odd sized lumps. The designers of
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the a.out format chose to not use the data within the section
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for storing part of the offset; all the offset is kept within
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the reloc. Anything in the data should be ignored.
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@example
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save %sp,-112,%sp
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sethi %hi(_foo+0x12345678),%g2
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ldsb [%g2+%lo(_foo+0x12345678)],%i0
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ret
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restore
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@end example
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Both relocs contain a pointer to @code{foo}, and the offsets
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contain junk.
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@example
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RELOCATION RECORDS FOR [.text]:
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offset type value
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00000004 HI22 _foo+0x12345678
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00000008 LO10 _foo+0x12345678
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00000000 9de3bf90 ; save %sp,-112,%sp
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00000004 05000000 ; sethi %hi(_foo+0),%g2
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00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0
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0000000c 81c7e008 ; ret
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00000010 81e80000 ; restore
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@end example
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@itemize @bullet
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@item
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@code{howto}
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@end itemize
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The @code{howto} field can be imagined as a
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relocation instruction. It is a pointer to a structure which
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contains information on what to do with all of the other
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information in the reloc record and data section. A back end
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would normally have a relocation instruction set and turn
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relocations into pointers to the correct structure on input -
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but it would be possible to create each howto field on demand.
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@*
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@subsubsection @code{enum complain_overflow}
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Indicates what sort of overflow checking should be done when
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performing a relocation.
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@*
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.
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@example
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enum complain_overflow
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@{
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/* Do not complain on overflow. */
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complain_overflow_dont,
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/* Complain if the bitfield overflows, whether it is considered
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as signed or unsigned. */
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complain_overflow_bitfield,
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/* Complain if the value overflows when considered as signed
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number. */
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complain_overflow_signed,
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/* Complain if the value overflows when considered as an
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unsigned number. */
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complain_overflow_unsigned
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@};
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@end example
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@subsubsection @code{reloc_howto_type}
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The @code{reloc_howto_type} is a structure which contains all the
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information that libbfd needs to know to tie up a back end's data.
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@*
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.struct symbol_cache_entry; /* Forward declaration */
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@example
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struct reloc_howto_struct
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@{
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/* The type field has mainly a documentary use - the back end can
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do what it wants with it, though normally the back end's
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external idea of what a reloc number is stored
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in this field. For example, a PC relative word relocation
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in a coff environment has the type 023 - because that's
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what the outside world calls a R_PCRWORD reloc. */
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unsigned int type;
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/* The value the final relocation is shifted right by. This drops
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unwanted data from the relocation. */
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unsigned int rightshift;
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/* The size of the item to be relocated. This is *not* a
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power-of-two measure. To get the number of bytes operated
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on by a type of relocation, use bfd_get_reloc_size. */
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int size;
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/* The number of bits in the item to be relocated. This is used
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when doing overflow checking. */
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unsigned int bitsize;
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/* Notes that the relocation is relative to the location in the
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data section of the addend. The relocation function will
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subtract from the relocation value the address of the location
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being relocated. */
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boolean pc_relative;
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/* The bit position of the reloc value in the destination.
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The relocated value is left shifted by this amount. */
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unsigned int bitpos;
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/* What type of overflow error should be checked for when
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relocating. */
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enum complain_overflow complain_on_overflow;
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/* If this field is non null, then the supplied function is
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called rather than the normal function. This allows really
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strange relocation methods to be accomodated (e.g., i960 callj
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instructions). */
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bfd_reloc_status_type (*special_function)
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PARAMS ((bfd *abfd,
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arelent *reloc_entry,
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struct symbol_cache_entry *symbol,
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PTR data,
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asection *input_section,
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bfd *output_bfd,
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char **error_message));
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/* The textual name of the relocation type. */
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char *name;
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/* When performing a partial link, some formats must modify the
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relocations rather than the data - this flag signals this.*/
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boolean partial_inplace;
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/* The src_mask selects which parts of the read in data
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are to be used in the relocation sum. E.g., if this was an 8 bit
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bit of data which we read and relocated, this would be
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0x000000ff. When we have relocs which have an addend, such as
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sun4 extended relocs, the value in the offset part of a
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relocating field is garbage so we never use it. In this case
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the mask would be 0x00000000. */
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bfd_vma src_mask;
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/* The dst_mask selects which parts of the instruction are replaced
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into the instruction. In most cases src_mask == dst_mask,
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except in the above special case, where dst_mask would be
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0x000000ff, and src_mask would be 0x00000000. */
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bfd_vma dst_mask;
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/* When some formats create PC relative instructions, they leave
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the value of the pc of the place being relocated in the offset
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slot of the instruction, so that a PC relative relocation can
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be made just by adding in an ordinary offset (e.g., sun3 a.out).
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Some formats leave the displacement part of an instruction
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empty (e.g., m88k bcs); this flag signals the fact.*/
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boolean pcrel_offset;
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@};
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@end example
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@findex The HOWTO Macro
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@subsubsection @code{The HOWTO Macro}
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@strong{Description}@*
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The HOWTO define is horrible and will go away.
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@example
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#define HOWTO(C, R,S,B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \
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@{(unsigned)C,R,S,B, P, BI, O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC@}
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@end example
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@*
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@strong{Description}@*
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And will be replaced with the totally magic way. But for the
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moment, we are compatible, so do it this way.
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@example
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#define NEWHOWTO( FUNCTION, NAME,SIZE,REL,IN) HOWTO(0,0,SIZE,0,REL,0,complain_overflow_dont,FUNCTION, NAME,false,0,0,IN)
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@end example
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@*
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@strong{Description}@*
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Helper routine to turn a symbol into a relocation value.
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@example
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#define HOWTO_PREPARE(relocation, symbol) \
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@{ \
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if (symbol != (asymbol *)NULL) @{ \
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if (bfd_is_com_section (symbol->section)) @{ \
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relocation = 0; \
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@} \
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else @{ \
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relocation = symbol->value; \
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@} \
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@} \
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@}
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@end example
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@*
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@findex bfd_get_reloc_size
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@subsubsection @code{bfd_get_reloc_size}
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@strong{Synopsis}
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@example
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int bfd_get_reloc_size (reloc_howto_type *);
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@end example
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@strong{Description}@*
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For a reloc_howto_type that operates on a fixed number of bytes,
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this returns the number of bytes operated on.
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@*
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@findex arelent_chain
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@subsubsection @code{arelent_chain}
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@strong{Description}@*
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How relocs are tied together in an @code{asection}:
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@example
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typedef struct relent_chain @{
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arelent relent;
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struct relent_chain *next;
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@} arelent_chain;
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@end example
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@*
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@findex bfd_perform_relocation
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@subsubsection @code{bfd_perform_relocation}
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@strong{Synopsis}
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@example
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bfd_reloc_status_type
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bfd_perform_relocation
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(bfd *abfd,
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arelent *reloc_entry,
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PTR data,
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asection *input_section,
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bfd *output_bfd,
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char **error_message);
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@end example
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@strong{Description}@*
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If @var{output_bfd} is supplied to this function, the
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generated image will be relocatable; the relocations are
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copied to the output file after they have been changed to
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reflect the new state of the world. There are two ways of
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reflecting the results of partial linkage in an output file:
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by modifying the output data in place, and by modifying the
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relocation record. Some native formats (e.g., basic a.out and
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basic coff) have no way of specifying an addend in the
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relocation type, so the addend has to go in the output data.
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This is no big deal since in these formats the output data
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slot will always be big enough for the addend. Complex reloc
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types with addends were invented to solve just this problem.
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The @var{error_message} argument is set to an error message if
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this return @code{bfd_reloc_dangerous}.
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@*
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@findex bfd_install_relocation
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@subsubsection @code{bfd_install_relocation}
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@strong{Synopsis}
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@example
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bfd_reloc_status_type
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bfd_install_relocation
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(bfd *abfd,
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arelent *reloc_entry,
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PTR data, bfd_vma data_start,
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asection *input_section,
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char **error_message);
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@end example
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@strong{Description}@*
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This looks remarkably like @code{bfd_perform_relocation}, except it
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does not expect that the section contents have been filled in.
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I.e., it's suitable for use when creating, rather than applying
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a relocation.
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For now, this function should be considered reserved for the
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assembler.
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@*
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@node howto manager, , typedef arelent, Relocations
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@section The howto manager
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When an application wants to create a relocation, but doesn't
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know what the target machine might call it, it can find out by
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using this bit of code.
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@*
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@findex bfd_reloc_code_type
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@subsubsection @code{bfd_reloc_code_type}
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@strong{Description}@*
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The insides of a reloc code. The idea is that, eventually, there
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will be one enumerator for every type of relocation we ever do.
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Pass one of these values to @code{bfd_reloc_type_lookup}, and it'll
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return a howto pointer.
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This does mean that the application must determine the correct
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enumerator value; you can't get a howto pointer from a random set
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of attributes.
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@*
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Here are the possible values for @code{enum bfd_reloc_code_real}:
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@deffn {} BFD_RELOC_64
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@deffnx {} BFD_RELOC_32
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@deffnx {} BFD_RELOC_26
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@deffnx {} BFD_RELOC_24
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@deffnx {} BFD_RELOC_16
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@deffnx {} BFD_RELOC_14
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@deffnx {} BFD_RELOC_8
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Basic absolute relocations of N bits.
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@end deffn
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@deffn {} BFD_RELOC_64_PCREL
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@deffnx {} BFD_RELOC_32_PCREL
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@deffnx {} BFD_RELOC_24_PCREL
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@deffnx {} BFD_RELOC_16_PCREL
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@deffnx {} BFD_RELOC_12_PCREL
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@deffnx {} BFD_RELOC_8_PCREL
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PC-relative relocations. Sometimes these are relative to the address
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of the relocation itself; sometimes they are relative to the start of
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the section containing the relocation. It depends on the specific target.
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The 24-bit relocation is used in some Intel 960 configurations.
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@end deffn
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@deffn {} BFD_RELOC_32_GOT_PCREL
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@deffnx {} BFD_RELOC_16_GOT_PCREL
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@deffnx {} BFD_RELOC_8_GOT_PCREL
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@deffnx {} BFD_RELOC_32_GOTOFF
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@deffnx {} BFD_RELOC_16_GOTOFF
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@deffnx {} BFD_RELOC_LO16_GOTOFF
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@deffnx {} BFD_RELOC_HI16_GOTOFF
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@deffnx {} BFD_RELOC_HI16_S_GOTOFF
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@deffnx {} BFD_RELOC_8_GOTOFF
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@deffnx {} BFD_RELOC_32_PLT_PCREL
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@deffnx {} BFD_RELOC_24_PLT_PCREL
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@deffnx {} BFD_RELOC_16_PLT_PCREL
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@deffnx {} BFD_RELOC_8_PLT_PCREL
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@deffnx {} BFD_RELOC_32_PLTOFF
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@deffnx {} BFD_RELOC_16_PLTOFF
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@deffnx {} BFD_RELOC_LO16_PLTOFF
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@deffnx {} BFD_RELOC_HI16_PLTOFF
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@deffnx {} BFD_RELOC_HI16_S_PLTOFF
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@deffnx {} BFD_RELOC_8_PLTOFF
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For ELF.
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@end deffn
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@deffn {} BFD_RELOC_68K_GLOB_DAT
|
|
@deffnx {} BFD_RELOC_68K_JMP_SLOT
|
|
@deffnx {} BFD_RELOC_68K_RELATIVE
|
|
Relocations used by 68K ELF.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_32_BASEREL
|
|
@deffnx {} BFD_RELOC_16_BASEREL
|
|
@deffnx {} BFD_RELOC_LO16_BASEREL
|
|
@deffnx {} BFD_RELOC_HI16_BASEREL
|
|
@deffnx {} BFD_RELOC_HI16_S_BASEREL
|
|
@deffnx {} BFD_RELOC_8_BASEREL
|
|
@deffnx {} BFD_RELOC_RVA
|
|
Linkage-table relative.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_8_FFnn
|
|
Absolute 8-bit relocation, but used to form an address like 0xFFnn.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_32_PCREL_S2
|
|
@deffnx {} BFD_RELOC_16_PCREL_S2
|
|
@deffnx {} 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 <<WDISP30>>.) The
|
|
signed 16-bit displacement is used on the MIPS, and the 23-bit
|
|
displacement is used on the Alpha.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_HI22
|
|
@deffnx {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_GPREL16
|
|
@deffnx {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_I960_CALLJ
|
|
Reloc types used for i960/b.out.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_NONE
|
|
@deffnx {} BFD_RELOC_SPARC_WDISP22
|
|
@deffnx {} BFD_RELOC_SPARC22
|
|
@deffnx {} BFD_RELOC_SPARC13
|
|
@deffnx {} BFD_RELOC_SPARC_GOT10
|
|
@deffnx {} BFD_RELOC_SPARC_GOT13
|
|
@deffnx {} BFD_RELOC_SPARC_GOT22
|
|
@deffnx {} BFD_RELOC_SPARC_PC10
|
|
@deffnx {} BFD_RELOC_SPARC_PC22
|
|
@deffnx {} BFD_RELOC_SPARC_WPLT30
|
|
@deffnx {} BFD_RELOC_SPARC_COPY
|
|
@deffnx {} BFD_RELOC_SPARC_GLOB_DAT
|
|
@deffnx {} BFD_RELOC_SPARC_JMP_SLOT
|
|
@deffnx {} BFD_RELOC_SPARC_RELATIVE
|
|
@deffnx {} BFD_RELOC_SPARC_UA32
|
|
SPARC ELF relocations. There is probably some overlap with other
|
|
relocation types already defined.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_SPARC_BASE13
|
|
@deffnx {} BFD_RELOC_SPARC_BASE22
|
|
I think these are specific to SPARC a.out (e.g., Sun 4).
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_SPARC_64
|
|
@deffnx {} BFD_RELOC_SPARC_10
|
|
@deffnx {} BFD_RELOC_SPARC_11
|
|
@deffnx {} BFD_RELOC_SPARC_OLO10
|
|
@deffnx {} BFD_RELOC_SPARC_HH22
|
|
@deffnx {} BFD_RELOC_SPARC_HM10
|
|
@deffnx {} BFD_RELOC_SPARC_LM22
|
|
@deffnx {} BFD_RELOC_SPARC_PC_HH22
|
|
@deffnx {} BFD_RELOC_SPARC_PC_HM10
|
|
@deffnx {} BFD_RELOC_SPARC_PC_LM22
|
|
@deffnx {} BFD_RELOC_SPARC_WDISP16
|
|
@deffnx {} BFD_RELOC_SPARC_WDISP19
|
|
@deffnx {} BFD_RELOC_SPARC_GLOB_JMP
|
|
@deffnx {} BFD_RELOC_SPARC_7
|
|
@deffnx {} BFD_RELOC_SPARC_6
|
|
@deffnx {} BFD_RELOC_SPARC_5
|
|
Some relocations we're using for SPARC V9 -- subject to change.
|
|
@end deffn
|
|
@deffn {} 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).
|
|
@end deffn
|
|
@deffn {} 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.
|
|
@end deffn
|
|
@deffn {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_ALPHA_LITERAL
|
|
@deffnx {} BFD_RELOC_ALPHA_ELF_LITERAL
|
|
@deffnx {} 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)
|
|
|
|
The GNU linker currently doesn't do any of this optimizing.
|
|
@end deffn
|
|
@deffn {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_ALPHA_LINKAGE
|
|
The LINKAGE relocation outputs a linkage pair in the object file,
|
|
which is filled by the linker.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_ALPHA_CODEADDR
|
|
The CODEADDR relocation outputs a STO_CA in the object file,
|
|
which is filled by the linker.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS_JMP
|
|
Bits 27..2 of the relocation address shifted right 2 bits;
|
|
simple reloc otherwise.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS16_JMP
|
|
The MIPS16 jump instruction.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS16_GPREL
|
|
MIPS16 GP relative reloc.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_HI16
|
|
High 16 bits of 32-bit value; simple reloc.
|
|
@end deffn
|
|
@deffn {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_LO16
|
|
Low 16 bits.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_PCREL_HI16_S
|
|
Like BFD_RELOC_HI16_S, but PC relative.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_PCREL_LO16
|
|
Like BFD_RELOC_LO16, but PC relative.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS_GPREL
|
|
Relocation relative to the global pointer.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS_LITERAL
|
|
Relocation against a MIPS literal section.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MIPS_GOT16
|
|
@deffnx {} BFD_RELOC_MIPS_CALL16
|
|
@deffnx {} BFD_RELOC_MIPS_GPREL32
|
|
@deffnx {} BFD_RELOC_MIPS_GOT_HI16
|
|
@deffnx {} BFD_RELOC_MIPS_GOT_LO16
|
|
@deffnx {} BFD_RELOC_MIPS_CALL_HI16
|
|
@deffnx {} BFD_RELOC_MIPS_CALL_LO16
|
|
MIPS ELF relocations.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_386_GOT32
|
|
@deffnx {} BFD_RELOC_386_PLT32
|
|
@deffnx {} BFD_RELOC_386_COPY
|
|
@deffnx {} BFD_RELOC_386_GLOB_DAT
|
|
@deffnx {} BFD_RELOC_386_JUMP_SLOT
|
|
@deffnx {} BFD_RELOC_386_RELATIVE
|
|
@deffnx {} BFD_RELOC_386_GOTOFF
|
|
@deffnx {} BFD_RELOC_386_GOTPC
|
|
i386/elf relocations
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_NS32K_IMM_8
|
|
@deffnx {} BFD_RELOC_NS32K_IMM_16
|
|
@deffnx {} BFD_RELOC_NS32K_IMM_32
|
|
@deffnx {} BFD_RELOC_NS32K_IMM_8_PCREL
|
|
@deffnx {} BFD_RELOC_NS32K_IMM_16_PCREL
|
|
@deffnx {} BFD_RELOC_NS32K_IMM_32_PCREL
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_8
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_16
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_32
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_8_PCREL
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_16_PCREL
|
|
@deffnx {} BFD_RELOC_NS32K_DISP_32_PCREL
|
|
ns32k relocations
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_PPC_B26
|
|
@deffnx {} BFD_RELOC_PPC_BA26
|
|
@deffnx {} BFD_RELOC_PPC_TOC16
|
|
@deffnx {} BFD_RELOC_PPC_B16
|
|
@deffnx {} BFD_RELOC_PPC_B16_BRTAKEN
|
|
@deffnx {} BFD_RELOC_PPC_B16_BRNTAKEN
|
|
@deffnx {} BFD_RELOC_PPC_BA16
|
|
@deffnx {} BFD_RELOC_PPC_BA16_BRTAKEN
|
|
@deffnx {} BFD_RELOC_PPC_BA16_BRNTAKEN
|
|
@deffnx {} BFD_RELOC_PPC_COPY
|
|
@deffnx {} BFD_RELOC_PPC_GLOB_DAT
|
|
@deffnx {} BFD_RELOC_PPC_JMP_SLOT
|
|
@deffnx {} BFD_RELOC_PPC_RELATIVE
|
|
@deffnx {} BFD_RELOC_PPC_LOCAL24PC
|
|
@deffnx {} BFD_RELOC_PPC_EMB_NADDR32
|
|
@deffnx {} BFD_RELOC_PPC_EMB_NADDR16
|
|
@deffnx {} BFD_RELOC_PPC_EMB_NADDR16_LO
|
|
@deffnx {} BFD_RELOC_PPC_EMB_NADDR16_HI
|
|
@deffnx {} BFD_RELOC_PPC_EMB_NADDR16_HA
|
|
@deffnx {} BFD_RELOC_PPC_EMB_SDAI16
|
|
@deffnx {} BFD_RELOC_PPC_EMB_SDA2I16
|
|
@deffnx {} BFD_RELOC_PPC_EMB_SDA2REL
|
|
@deffnx {} BFD_RELOC_PPC_EMB_SDA21
|
|
@deffnx {} BFD_RELOC_PPC_EMB_MRKREF
|
|
@deffnx {} BFD_RELOC_PPC_EMB_RELSEC16
|
|
@deffnx {} BFD_RELOC_PPC_EMB_RELST_LO
|
|
@deffnx {} BFD_RELOC_PPC_EMB_RELST_HI
|
|
@deffnx {} BFD_RELOC_PPC_EMB_RELST_HA
|
|
@deffnx {} BFD_RELOC_PPC_EMB_BIT_FLD
|
|
@deffnx {} BFD_RELOC_PPC_EMB_RELSDA
|
|
Power(rs6000) and PowerPC relocations.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_CTOR
|
|
The type of reloc used to build a contructor 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.
|
|
@end deffn
|
|
@deffn {} 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.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_ARM_IMMEDIATE
|
|
@deffnx {} BFD_RELOC_ARM_OFFSET_IMM
|
|
@deffnx {} BFD_RELOC_ARM_SHIFT_IMM
|
|
@deffnx {} BFD_RELOC_ARM_SWI
|
|
@deffnx {} BFD_RELOC_ARM_MULTI
|
|
@deffnx {} BFD_RELOC_ARM_CP_OFF_IMM
|
|
@deffnx {} BFD_RELOC_ARM_ADR_IMM
|
|
@deffnx {} BFD_RELOC_ARM_LDR_IMM
|
|
@deffnx {} BFD_RELOC_ARM_LITERAL
|
|
@deffnx {} BFD_RELOC_ARM_IN_POOL
|
|
@deffnx {} BFD_RELOC_ARM_OFFSET_IMM8
|
|
@deffnx {} BFD_RELOC_ARM_HWLITERAL
|
|
@deffnx {} BFD_RELOC_ARM_THUMB_ADD
|
|
@deffnx {} BFD_RELOC_ARM_THUMB_IMM
|
|
@deffnx {} BFD_RELOC_ARM_THUMB_SHIFT
|
|
@deffnx {} BFD_RELOC_ARM_THUMB_OFFSET
|
|
These relocs are only used within the ARM assembler. They are not
|
|
(at present) written to any object files.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_SH_PCDISP8BY2
|
|
@deffnx {} BFD_RELOC_SH_PCDISP12BY2
|
|
@deffnx {} BFD_RELOC_SH_IMM4
|
|
@deffnx {} BFD_RELOC_SH_IMM4BY2
|
|
@deffnx {} BFD_RELOC_SH_IMM4BY4
|
|
@deffnx {} BFD_RELOC_SH_IMM8
|
|
@deffnx {} BFD_RELOC_SH_IMM8BY2
|
|
@deffnx {} BFD_RELOC_SH_IMM8BY4
|
|
@deffnx {} BFD_RELOC_SH_PCRELIMM8BY2
|
|
@deffnx {} BFD_RELOC_SH_PCRELIMM8BY4
|
|
@deffnx {} BFD_RELOC_SH_SWITCH16
|
|
@deffnx {} BFD_RELOC_SH_SWITCH32
|
|
@deffnx {} BFD_RELOC_SH_USES
|
|
@deffnx {} BFD_RELOC_SH_COUNT
|
|
@deffnx {} BFD_RELOC_SH_ALIGN
|
|
@deffnx {} BFD_RELOC_SH_CODE
|
|
@deffnx {} BFD_RELOC_SH_DATA
|
|
@deffnx {} BFD_RELOC_SH_LABEL
|
|
Hitachi SH relocs. Not all of these appear in object files.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_D10V_10_PCREL_R
|
|
Mitsubishi D10V relocs.
|
|
This is a 10-bit reloc with the right 2 bits
|
|
assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_D10V_10_PCREL_L
|
|
Mitsubishi D10V relocs.
|
|
This is a 10-bit reloc with the right 2 bits
|
|
assumed to be 0. This is the same as the previous reloc
|
|
except it is in the left container, i.e.,
|
|
shifted left 15 bits.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_D10V_18
|
|
This is an 18-bit reloc with the right 2 bits
|
|
assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_D10V_18_PCREL
|
|
This is an 18-bit reloc with the right 2 bits
|
|
assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_24
|
|
Mitsubishi M32R relocs.
|
|
This is a 24 bit absolute address.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_10_PCREL
|
|
This is a 10-bit pc-relative reloc with the right 2 bits assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_18_PCREL
|
|
This is an 18-bit reloc with the right 2 bits assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_26_PCREL
|
|
This is a 26-bit reloc with the right 2 bits assumed to be 0.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_HI16_ULO
|
|
This is a 16-bit reloc containing the high 16 bits of an address
|
|
used when the lower 16 bits are treated as unsigned.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_HI16_SLO
|
|
This is a 16-bit reloc containing the high 16 bits of an address
|
|
used when the lower 16 bits are treated as signed.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_LO16
|
|
This is a 16-bit reloc containing the lower 16 bits of an address.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_M32R_SDA16
|
|
This is a 16-bit reloc containing the small data area offset for use in
|
|
add3, load, and store instructions.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MN10300_32_PCREL
|
|
This is a 32bit pcrel reloc for the mn10300, offset by two bytes in the
|
|
instruction.
|
|
@end deffn
|
|
@deffn {} BFD_RELOC_MN10300_16_PCREL
|
|
This is a 16bit pcrel reloc for the mn10300, offset by two bytes in the
|
|
instruction.
|
|
@end deffn
|
|
.
|
|
@example
|
|
typedef enum bfd_reloc_code_real bfd_reloc_code_real_type;
|
|
@end example
|
|
@findex bfd_reloc_type_lookup
|
|
@subsubsection @code{bfd_reloc_type_lookup}
|
|
@strong{Synopsis}
|
|
@example
|
|
reloc_howto_type *
|
|
bfd_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code);
|
|
@end example
|
|
@strong{Description}@*
|
|
Return a pointer to a howto structure which, when
|
|
invoked, will perform the relocation @var{code} on data from the
|
|
architecture noted.
|
|
@*
|
|
@findex bfd_default_reloc_type_lookup
|
|
@subsubsection @code{bfd_default_reloc_type_lookup}
|
|
@strong{Synopsis}
|
|
@example
|
|
reloc_howto_type *bfd_default_reloc_type_lookup
|
|
(bfd *abfd, bfd_reloc_code_real_type code);
|
|
@end example
|
|
@strong{Description}@*
|
|
Provides a default relocation lookup routine for any architecture.
|
|
@*
|
|
@findex bfd_get_reloc_code_name
|
|
@subsubsection @code{bfd_get_reloc_code_name}
|
|
@strong{Synopsis}
|
|
@example
|
|
const char *bfd_get_reloc_code_name (bfd_reloc_code_real_type code);
|
|
@end example
|
|
@strong{Description}@*
|
|
Provides a printable name for the supplied relocation code.
|
|
Useful mainly for printing error messages.
|
|
@*
|
|
@findex bfd_generic_relax_section
|
|
@subsubsection @code{bfd_generic_relax_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
boolean bfd_generic_relax_section
|
|
(bfd *abfd,
|
|
asection *section,
|
|
struct bfd_link_info *,
|
|
boolean *);
|
|
@end example
|
|
@strong{Description}@*
|
|
Provides default handling for relaxing for back ends which
|
|
don't do relaxing -- i.e., does nothing.
|
|
@*
|
|
@findex bfd_generic_get_relocated_section_contents
|
|
@subsubsection @code{bfd_generic_get_relocated_section_contents}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_byte *
|
|
bfd_generic_get_relocated_section_contents (bfd *abfd,
|
|
struct bfd_link_info *link_info,
|
|
struct bfd_link_order *link_order,
|
|
bfd_byte *data,
|
|
boolean relocateable,
|
|
asymbol **symbols);
|
|
@end example
|
|
@strong{Description}@*
|
|
Provides default handling of relocation effort for back ends
|
|
which can't be bothered to do it efficiently.
|
|
@*
|