ldso/ldso/m68k/dl-sysdep.h

   1 /*
   2  * Various assembly language/system dependent hacks that are required
   3  * so that we can minimize the amount of platform specific code.
   4  * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
   5  */
   6
   7 /* Define this if the system uses RELOCA.  */
   8 #define ELF_USES_RELOCA
   9 #include <elf.h>
  10 /* Initialization sequence for a GOT.  */
  11 #define INIT_GOT(GOT_BASE,MODULE) \
  12 do { \
  13         GOT_BASE[2] = (unsigned long) _dl_linux_resolve; \
  14         GOT_BASE[1] = (unsigned long) (MODULE); \
  15 } while(0)
  16
  17 /* Here we define the magic numbers that this dynamic loader should accept */
  18 #define MAGIC1 EM_68K
  19 #undef  MAGIC2
  20
  21 /* Used for error messages */
  22 #define ELF_TARGET "m68k"
  23
  24 /* Need bootstrap relocations */
  25 #define ARCH_NEEDS_BOOTSTRAP_RELOCS
  26
  27 struct elf_resolve;
  28 extern unsigned long _dl_linux_resolver (struct elf_resolve *, int);
  29
  30 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
  31    TLS variable, so undefined references should not be allowed to
  32    define the value.
  33    ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
  34    of the main executable's symbols, as for a COPY reloc.  */
  35 #define elf_machine_type_class(type) \
  36   ((((type) == R_68K_JMP_SLOT        \
  37      || (type) == R_68K_TLS_DTPMOD32 \
  38      || (type) == R_68K_TLS_DTPREL32 \
  39      || (type) == R_68K_TLS_TPREL32) * ELF_RTYPE_CLASS_PLT)     \
  40    | (((type) == R_68K_COPY) * ELF_RTYPE_CLASS_COPY))
  41
  42 /* Return the link-time address of _DYNAMIC.  Conveniently, this is the
  43    first element of the GOT.  This must be inlined in a function which
  44    uses global data.  */
  45 static __always_inline Elf32_Addr
  46 elf_machine_dynamic (void)
  47 {
  48         Elf32_Addr got;
  49
  50         __asm__ ("move.l _DYNAMIC@GOT.w(%%a5), %0"
  51                         : "=a" (got));
  52         return got;
  53 }
  54
  55 #ifdef __mcoldfire__
  56 #define PCREL_OP(OP, SRC, DST, TMP, PC) \
  57   "move.l #" SRC " - ., " TMP "\n\t" OP " (-8, " PC ", " TMP "), " DST
  58 #else
  59 #define PCREL_OP(OP, SRC, DST, TMP, PC) \
  60   OP " " SRC "(" PC "), " DST
  61 #endif
  62
  63 /* Return the run-time load address of the shared object.  */
  64 static __always_inline Elf32_Addr
  65 elf_machine_load_address (void)
  66 {
  67         Elf32_Addr addr;
  68         __asm__ (PCREL_OP ("lea", "_dl_start", "%0", "%0", "%%pc") "\n\t"
  69                         "sub.l _dl_start@GOT.w(%%a5), %0"
  70                         : "=a" (addr));
  71         return addr;
  72 }
  73
  74 static __always_inline void
  75 elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr,
  76                       Elf32_Word relative_count)
  77 {
  78          Elf32_Rela * rpnt = (void *)rel_addr;
  79         --rpnt;
  80         do {
  81                 Elf32_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset);
  82
  83                 *reloc_addr = load_off + rpnt->r_addend;
  84         } while (--relative_count);
  85 }