ldso/ldso/mips/dl-startup.h

   1 /* Any assembly language/system dependent hacks needed to setup boot1.c so it
   2  * will work as expected and cope with whatever platform specific wierdness is
   3  * needed for this architecture.
   4  * Copyright (C) 2005 by Joakim Tjernlund
   5  * Copyright (C) 2005 by Erik Andersen
   6  */
   7
   8
   9 #include <sgidefs.h>
  10 #ifndef L_rcrt1
  11 __asm__(""
  12     "   .text\n"
  13     "   .globl  _start\n"
  14     "   .ent    _start\n"
  15     "   .type   _start,@function\n"
  16     "   .hidden _start\n"
  17     "_start:\n"
  18     "   .set noreorder\n"
  19     "   move    $25, $31\n"
  20     "   bal     0f\n"
  21     "   nop\n"
  22     "0:\n"
  23 #if _MIPS_SIM == _MIPS_SIM_ABI32
  24     "   .cpload $31\n"
  25 #else   /* N32 || N64 */
  26     "   .cpsetup $31, $2, 0b\n"
  27 #endif  /* N32 || N64 */
  28     "   move    $31, $25\n"
  29     "   .set reorder\n"
  30 #if _MIPS_SIM == _MIPS_SIM_ABI64
  31     "   dla     $4, _DYNAMIC\n"
  32     "   sd      $4, -0x7ff0($28)\n"
  33 #else   /* O32 || N32 */
  34     "   la      $4, _DYNAMIC\n"
  35     "   sw      $4, -0x7ff0($28)\n"
  36 #endif  /* O32 || N32 */
  37     "   move    $4, $29\n"
  38 #if _MIPS_SIM == _MIPS_SIM_ABI32
  39     "   subu    $29, 16\n"
  40 #endif
  41 #if _MIPS_SIM == _MIPS_SIM_ABI64
  42     "   dla     $8, .coff\n"
  43 #else   /* O32 || N32 */
  44     "   la      $8, .coff\n"
  45 #endif  /* O32 || N32 */
  46 # if !defined __mips_isa_rev || __mips_isa_rev < 6
  47     "   bltzal  $8, .coff\n"
  48     ".coff:\n"
  49 # else
  50     ".coff:\n"
  51     "   lapc $31, .coff\n"
  52 # endif
  53 #if _MIPS_SIM == _MIPS_SIM_ABI64
  54     "   dsubu   $8, $31, $8\n"
  55     "   dla     $25, _dl_start\n"
  56     "   daddu   $25, $8\n"
  57 #else   /* O32 || N32 */
  58     "   subu    $8, $31, $8\n"
  59     "   la      $25, _dl_start\n"
  60     "   addu    $25, $8\n"
  61 #endif  /* O32 || N32 */
  62     "   jalr    $25\n"
  63 #if _MIPS_SIM == _MIPS_SIM_ABI32
  64     "   addiu   $29, 16\n"
  65 #endif
  66     "   move    $16, $28\n"
  67     "   move    $17, $2\n"
  68 #if _MIPS_SIM == _MIPS_SIM_ABI64
  69     "   ld      $2, _dl_skip_args\n"
  70     "   beq     $2, $0, 1f\n"
  71     "   ld      $4, 0($29)\n"
  72     "   dsubu   $4, $2\n"
  73     "   dsll    $2, 2\n"
  74     "   daddu   $29, $2\n"
  75     "   sd      $4, 0($29)\n"
  76     "1:\n"
  77     "   ld      $5, 0($29)\n"
  78     "   dla     $6, 8 ($29)\n"
  79     "   dsll    $7, $5, 2\n"
  80     "   daddu   $7, $7, $6\n"
  81     "   daddu   $7, $7, 4\n"
  82     "   and     $2, $29, -4 * 4\n"
  83     "   sd      $29, -8($2)\n"
  84     "   dsubu   $29, $2, 32\n"
  85     "   ld      $29, 24($29)\n"
  86     "   dla     $2, _dl_fini\n"
  87 #else   /* O32 || N32 */
  88     "   lw      $2, _dl_skip_args\n"
  89     "   beq     $2, $0, 1f\n"
  90     "   lw      $4, 0($29)\n"
  91     "   subu    $4, $2\n"
  92     "   sll     $2, 2\n"
  93     "   addu    $29, $2\n"
  94     "   sw      $4, 0($29)\n"
  95     "1:\n"
  96     "   lw      $5, 0($29)\n"
  97     "   la      $6, 4 ($29)\n"
  98     "   sll     $7, $5, 2\n"
  99     "   addu    $7, $7, $6\n"
 100     "   addu    $7, $7, 4\n"
 101     "   and     $2, $29, -2 * 4\n"
 102     "   sw      $29, -4($2)\n"
 103     "   subu    $29, $2, 32\n"
 104 #if _MIPS_SIM == _MIPS_SIM_ABI32
 105     "   .cprestore 16\n"
 106 #endif
 107     "   lw      $29, 28($29)\n"
 108     "   la      $2, _dl_fini\n"
 109 #endif  /* O32 || N32 */
 110     "   move    $25, $17\n"
 111     "   jr      $25\n"
 112     ".end       _start\n"
 113     ".size      _start, . -_start\n"
 114     "\n\n"
 115     "\n\n"
 116     ".previous\n"
 117 );
 118 #endif
 119
 120 /*
 121  * Get a pointer to the argv array.  On many platforms this can be just
 122  * the address of the first argument, on other platforms we need to
 123  * do something a little more subtle here.
 124  */
 125 #define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long *) ARGS)+1)
 126
 127
 128 /* We can't call functions earlier in the dl startup process */
 129 #define NO_FUNCS_BEFORE_BOOTSTRAP
 130
 131
 132 /*
 133  * Here is a macro to perform the GOT relocation. This is only
 134  * used when bootstrapping the dynamic loader.
 135  */
 136 #define PERFORM_BOOTSTRAP_GOT(tpnt)                                             \
 137 do {                                                                            \
 138         ElfW(Sym) *sym;                                                         \
 139         ElfW(Addr) i;                                                           \
 140         register ElfW(Addr) gp __asm__ ("$28");                                 \
 141         ElfW(Addr) *mipsgot = elf_mips_got_from_gpreg (gp);                     \
 142                                                                                 \
 143         /* Add load address displacement to all local GOT entries */            \
 144         i = 2;                                                                  \
 145         while (i < tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX])                 \
 146                 mipsgot[i++] += tpnt->loadaddr;                                 \
 147                                                                                 \
 148         /* Handle global GOT entries */                                         \
 149         mipsgot += tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX];                 \
 150         sym = (ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB] +                     \
 151                         tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];                 \
 152         i = tpnt->dynamic_info[DT_MIPS_SYMTABNO_IDX] - tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];\
 153                                                                                 \
 154         while (i--) {                                                           \
 155                 if (sym->st_shndx == SHN_UNDEF ||                               \
 156                         sym->st_shndx == SHN_COMMON)                            \
 157                         *mipsgot = tpnt->loadaddr + sym->st_value;              \
 158                 else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&               \
 159                         *mipsgot != sym->st_value)                              \
 160                         *mipsgot += tpnt->loadaddr;                             \
 161                 else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) {            \
 162                         if (sym->st_other == 0)                                 \
 163                                 *mipsgot += tpnt->loadaddr;                     \
 164                 }                                                               \
 165                 else                                                            \
 166                         *mipsgot = tpnt->loadaddr + sym->st_value;              \
 167                                                                                 \
 168                 mipsgot++;                                                      \
 169                 sym++;                                                          \
 170         }                                                                       \
 171 } while (0)
 172
 173 /*
 174  * Here is a macro to perform a relocation.  This is only used when
 175  * bootstrapping the dynamic loader.
 176  */
 177 #if _MIPS_SIM == _MIPS_SIM_ABI64        /* consult with glibc sysdeps/mips/dl-machine.h 1.69 */
 178 #define R_MIPS_BOOTSTRAP_RELOC ((R_MIPS_64 << 8) | R_MIPS_REL32)
 179 #else   /* N32 || O32 */
 180 #define R_MIPS_BOOTSTRAP_RELOC R_MIPS_REL32
 181 #endif
 182 #define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD,SYMTAB)                    \
 183         switch(ELF_R_TYPE((RELP)->r_info)) {                                    \
 184         case R_MIPS_BOOTSTRAP_RELOC:                                            \
 185                 if (SYMTAB) {                                                   \
 186                         if (symtab_index<tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX])\
 187                                 *REL += SYMBOL;                                 \
 188                 }                                                               \
 189                 else {                                                          \
 190                         *REL += LOAD;                                           \
 191                 }                                                               \
 192                 break;                                                          \
 193         case R_MIPS_NONE:                                                       \
 194                 break;                                                          \
 195         default:                                                                \
 196                 _dl_exit(1);                                                    \
 197         }