From 19765f5229668571b2a86c42cd2a1faa8e374208 Mon Sep 17 00:00:00 2001 From: Iain Sandoe Date: Thu, 23 Feb 2012 16:29:56 +0000 Subject: deal with endian-ness in mach-o non-scattered relocs. BFD: * mach-o.c (bfd_mach_o_swap_in_non_scattered_reloc): New. (bfd_mach_o_canonicalize_one_reloc): Swap non-scattered reloc bit-fields when target and host differ in endian-ness. When PAIRs are non-scattered find the 'symbol' from the preceding reloc. Add FIXME re. reloc symbols on section boundaries. (bfd_mach_o_swap_out_non_scattered_reloc): New. (bfd_mach_o_write_relocs): Use bfd_mach_o_encode_non_scattered_reloc. include/mach-o: * external.h: Add comments about relocations fields. Add macros for non-scattered relocations. Move scattered relocation macros to here. * reloc.h: Remove macros related to external representation of reloc fields. --- include/mach-o/external.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'include/mach-o/external.h') diff --git a/include/mach-o/external.h b/include/mach-o/external.h index ad419ef..41a2932 100644 --- a/include/mach-o/external.h +++ b/include/mach-o/external.h @@ -116,6 +116,45 @@ struct mach_o_reloc_info_external }; #define BFD_MACH_O_RELENT_SIZE 8 +/* Relocations are based on 'address' being a section offset and an assumption + that sections are never more than 2^24-1 bytes in size. Relocation data + also carry information on type/size/PC-relative/extern and whether scattered + or not [stored in the MSB of the r_address]. */ + +#define BFD_MACH_O_SR_SCATTERED 0x80000000 + +/* For a non-scattered reloc, the relocation info is found in r_symbolnum. + Bytes 1 to 3 contain the symbol number (0xffffff, in a non-scattered PAIR). + Byte 4 contains the relocation info - but with differing bit-positions + dependent on target endian-ness - as below. */ + +#define BFD_MACH_O_LE_PCREL 0x01 +#define BFD_MACH_O_LE_LENGTH_SHIFT 1 +#define BFD_MACH_O_LE_EXTERN 0x08 +#define BFD_MACH_O_LE_TYPE_SHIFT 4 + +#define BFD_MACH_O_BE_PCREL 0x80 +#define BFD_MACH_O_BE_LENGTH_SHIFT 5 +#define BFD_MACH_O_BE_EXTERN 0x10 +#define BFD_MACH_O_BE_TYPE_SHIFT 0 + +/* The field sizes are the same for both BE and LE. */ +#define BFD_MACH_O_LENGTH_MASK 0x03 +#define BFD_MACH_O_TYPE_MASK 0x0f + +/* For a scattered reloc entry the info is contained in r_address. There + is no need to discriminate on target endian-ness, since the design was + arranged to produce the same layout on both. Scattered relocations are + only used for local items, therefore there is no 'extern' field. */ + +#define BFD_MACH_O_SR_PCREL 0x40000000 +#define BFD_MACH_O_GET_SR_LENGTH(s) (((s) >> 28) & 0x3) +#define BFD_MACH_O_GET_SR_TYPE(s) (((s) >> 24) & 0x0f) +#define BFD_MACH_O_GET_SR_ADDRESS(s) ((s) & 0x00ffffff) +#define BFD_MACH_O_SET_SR_LENGTH(l) (((l) & 0x3) << 28) +#define BFD_MACH_O_SET_SR_TYPE(t) (((t) & 0xf) << 24) +#define BFD_MACH_O_SET_SR_ADDRESS(s) ((s) & 0x00ffffff) + struct mach_o_symtab_command_external { unsigned char symoff[4]; /* File offset of the symbol table. */ -- cgit v1.1