ldso/ldso/avr32/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  *
   5  * Copyright (C) 2004-2007 Atmel Corporation
   6  *
   7  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   8  */
   9
  10 /* Define this if the system uses RELOCA. */
  11 #define ELF_USES_RELOCA
  12
  13 #include <elf.h>
  14
  15 #define ARCH_NUM 1
  16 #define DT_AVR32_GOTSZ_IDX      (DT_NUM + OS_NUM)
  17
  18 #define ARCH_DYNAMIC_INFO(dpnt, dynamic, debug_addr)                    \
  19         do {                                                            \
  20                 if (dpnt->d_tag == DT_AVR32_GOTSZ)                      \
  21                         dynamic[DT_AVR32_GOTSZ_IDX] = dpnt->d_un.d_val; \
  22         } while (0)
  23
  24 /* Initialization sequence for the application/library GOT. */
  25 #define INIT_GOT(GOT_BASE,MODULE)                                       \
  26         do {                                                            \
  27                 unsigned long _i, _nr_got;                              \
  28                                                                         \
  29                 GOT_BASE[0] = (unsigned long) _dl_linux_resolve;        \
  30                 GOT_BASE[1] = (unsigned long) MODULE;                   \
  31                                                                         \
  32                 /* Add load address displacement to all GOT entries */  \
  33                 _nr_got = MODULE->dynamic_info[DT_AVR32_GOTSZ_IDX] / 4; \
  34                 for (_i = 2; _i < _nr_got; _i++)                                \
  35                         GOT_BASE[_i] += (unsigned long)MODULE->loadaddr;        \
  36         } while (0)
  37
  38 /* Here we define the magic numbers that this dynamic loader should accept */
  39 #define MAGIC1 EM_AVR32
  40 #undef MAGIC2
  41
  42 /* Used for error messages */
  43 #define ELF_TARGET "AVR32"
  44
  45 /* Need bootstrap relocations */
  46 #define ARCH_NEEDS_BOOTSTRAP_RELOCS
  47
  48 unsigned long _dl_linux_resolver(unsigned long got_offset, unsigned long *got);
  49
  50 #define elf_machine_type_class(type)                            \
  51         ((type == R_AVR32_JMP_SLOT) * ELF_RTYPE_CLASS_PLT)
  52
  53 /* AVR32 doesn't need any COPY relocs */
  54 #define DL_NO_COPY_RELOCS
  55
  56 /* Return the link-time address of _DYNAMIC.  Conveniently, this is the
  57    first element of the GOT.  This must be inlined in a function which
  58    uses global data.  */
  59 static __always_inline Elf32_Addr
  60 elf_machine_dynamic (void)
  61 {
  62         register Elf32_Addr *got __asm__("r6");
  63         return *got;
  64 }
  65
  66 /* Return the run-time load address of the shared object.  */
  67 static __always_inline Elf32_Addr
  68 elf_machine_load_address (void)
  69 {
  70         extern void __dl_start __asm__("_dl_start");
  71         Elf32_Addr got_addr = (Elf32_Addr) &__dl_start;
  72         Elf32_Addr pcrel_addr;
  73
  74         __asm__("       lddpc   %0, 2f\n"
  75                "1:      add     %0, pc\n"
  76                "        rjmp    3f\n"
  77                "        .align  2\n"
  78                "2:      .long   _dl_start - 1b\n"
  79                "3:\n"
  80                : "=r"(pcrel_addr) : : "cc");
  81
  82         return pcrel_addr - got_addr;
  83 }
  84
  85 /*
  86  * Perform any RELATIVE relocations specified by DT_RELCOUNT.
  87  * Currently, we don't use that tag, but we might in the future as
  88  * this would reduce the startup time somewhat (although probably not by much).
  89  */
  90 static __always_inline void
  91 elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr,
  92                       Elf32_Word relative_count)
  93 {
  94         Elf32_Rela *rpnt = (void *)rel_addr;
  95
  96         do {
  97                 Elf32_Addr *reloc_addr;
  98                 reloc_addr = (void *)(load_off + (rpnt++)->r_offset);
  99                 *reloc_addr = load_off + rpnt->r_addend;
 100         } while (--relative_count);
 101 }