1 | /* |
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2 | * Taken from NetBSD and stripped of the relocations not needed on RTEMS. |
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3 | */ |
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4 | |
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5 | /* $NetBSD: ppc_reloc.c,v 1.44 2010/01/13 20:17:22 christos Exp $ */ |
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6 | |
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7 | #include <sys/cdefs.h> |
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8 | |
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9 | #include <errno.h> |
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10 | #include <inttypes.h> |
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11 | #include <stdio.h> |
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12 | #include <sys/types.h> |
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13 | #include <sys/stat.h> |
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14 | |
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15 | #include <rtems/rtl/rtl.h> |
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16 | #include "rtl-bit-alloc.h" |
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17 | #include "rtl-elf.h" |
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18 | #include "rtl-error.h" |
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19 | #include <rtems/rtl/rtl-trace.h> |
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20 | #include "rtl-unwind.h" |
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21 | #include "rtl-unwind-dw2.h" |
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22 | |
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23 | #define ha(x) ((((u_int32_t)(x) & 0x8000) ? \ |
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24 | ((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16) |
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25 | #define l(x) ((u_int32_t)(x) & 0xffff) |
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26 | |
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27 | /* |
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28 | * SDATA allocator. |
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29 | */ |
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30 | static rtems_rtl_bit_alloc* sdata; |
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31 | |
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32 | static Elf_Addr |
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33 | get_sda_base (void) |
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34 | { |
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35 | uint32_t sda_base; |
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36 | __asm__ volatile (" mr %0, 13\n" : "=r" (sda_base)); |
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37 | return sda_base; |
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38 | } |
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39 | |
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40 | /* |
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41 | * Access the variables via asm statements to avoid any fix up issues |
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42 | * generated by the C compiler which thinks they belong in the .sdata |
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43 | * section. |
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44 | */ |
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45 | |
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46 | #define GET_ADDR(_l, _v) \ |
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47 | __asm__ volatile (" lis %0, " #_l "@h\n" \ |
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48 | " ori %0, %0, " #_l "@l\n" : "=r" (_v)) |
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49 | |
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50 | static void* |
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51 | get_sdata_start (void) |
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52 | { |
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53 | #if _ARCH_PPC64 |
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54 | return NULL; |
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55 | #else |
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56 | Elf_Addr addr; |
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57 | GET_ADDR(__SDATA_START__, addr); |
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58 | return (void*) addr; |
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59 | #endif |
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60 | } |
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61 | |
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62 | #if !_ARCH_PPC64 |
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63 | static size_t |
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64 | get_sdata_sbss_size (void) |
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65 | { |
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66 | Elf_Addr sdata_begin; |
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67 | Elf_Addr sbss_end; |
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68 | GET_ADDR(bsp_section_sdata_begin, sdata_begin); |
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69 | GET_ADDR(bsp_section_sbss_end, sbss_end); |
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70 | return sbss_end - sdata_begin; |
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71 | } |
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72 | |
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73 | static size_t |
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74 | get_sdata_libdl_size (void) |
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75 | { |
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76 | Elf_Addr begin; |
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77 | Elf_Addr end; |
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78 | GET_ADDR(bsp_section_sdata_libdl_begin, begin); |
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79 | GET_ADDR(bsp_section_sdata_libdl_end, end); |
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80 | return end - begin; |
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81 | } |
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82 | #endif |
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83 | |
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84 | uint32_t |
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85 | rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj, |
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86 | const Elf_Shdr* shdr) |
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87 | { |
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88 | return 0; |
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89 | } |
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90 | |
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91 | uint32_t |
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92 | rtems_rtl_elf_arch_parse_section (const rtems_rtl_obj* obj, |
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93 | int section, |
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94 | const char* name, |
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95 | const Elf_Shdr* shdr, |
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96 | const uint32_t flags) |
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97 | { |
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98 | #if !_ARCH_PPC64 |
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99 | struct { |
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100 | const char* label; |
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101 | size_t len; |
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102 | } prefix[] = { |
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103 | #define SEPARATED_PREFIX(_p) { _p, sizeof (_p) - 1 } |
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104 | SEPARATED_PREFIX (".sdata"), |
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105 | SEPARATED_PREFIX (".sbss"), |
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106 | }; |
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107 | const size_t prefixes = sizeof (prefix) / sizeof (prefix[0]); |
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108 | size_t p; |
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109 | for (p = 0; p < prefixes; ++p) |
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110 | { |
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111 | if (strncmp (name, prefix[p].label, prefix[p].len) == 0) |
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112 | return flags | RTEMS_RTL_OBJ_SECT_ARCH_ALLOC; |
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113 | } |
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114 | #endif |
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115 | return flags; |
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116 | } |
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117 | |
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118 | bool |
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119 | rtems_rtl_elf_arch_section_alloc (const rtems_rtl_obj* obj, |
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120 | rtems_rtl_obj_sect* sect) |
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121 | { |
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122 | #if _ARCH_PPC64 |
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123 | rtems_rtl_set_error (ENOMEM, ".sdata no supported by ABI"); |
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124 | return false; |
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125 | #else |
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126 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_DETAIL)) |
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127 | printf ("rtl: section: arch: alloc: name=%s size=%zu flags=%08" PRIx32 \ |
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128 | " order=%i link=%d info=%d\n", |
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129 | sect->name, sect->size, sect->flags, sect->load_order, |
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130 | sect->link, sect->info); |
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131 | |
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132 | if (sdata == NULL) |
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133 | { |
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134 | sdata = rtems_rtl_bit_alloc_open (get_sdata_start (), |
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135 | get_sdata_libdl_size (), |
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136 | sizeof (uint32_t), |
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137 | get_sdata_sbss_size ()); |
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138 | if (sdata == NULL) |
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139 | { |
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140 | rtems_rtl_set_error (ENOMEM, "no memory for sdata allocator"); |
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141 | return false; |
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142 | } |
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143 | } |
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144 | |
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145 | sect->base = rtems_rtl_bit_alloc_balloc (sdata, sect->size); |
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146 | if (sect->base == NULL) |
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147 | { |
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148 | rtems_rtl_set_error (ENOMEM, "no .sdata memory: %s", sect->name); |
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149 | return false; |
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150 | } |
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151 | |
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152 | return true; |
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153 | #endif |
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154 | } |
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155 | |
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156 | bool |
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157 | rtems_rtl_elf_arch_section_free (const rtems_rtl_obj* obj, |
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158 | rtems_rtl_obj_sect* sect) |
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159 | { |
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160 | #if !_ARCH_PPC64 |
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161 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_DETAIL)) |
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162 | printf ("rtl: section: arch: free: name=%s size=%zu\n", sect->name, sect->size); |
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163 | if (sdata != NULL) |
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164 | rtems_rtl_bit_alloc_bfree (sdata, sect->base, sect->size); |
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165 | #endif |
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166 | return true; |
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167 | } |
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168 | |
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169 | bool |
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170 | rtems_rtl_elf_rel_resolve_sym (Elf_Word type) |
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171 | { |
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172 | return true; |
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173 | } |
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174 | |
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175 | size_t |
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176 | rtems_rtl_elf_relocate_tramp_max_size (void) |
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177 | { |
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178 | /* |
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179 | * We have 4 instructions and each instruction is 32bits. |
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180 | */ |
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181 | return 4 * 4; |
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182 | } |
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183 | |
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184 | static void* |
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185 | set_veneer (void* tramopline, Elf_Addr target) |
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186 | { |
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187 | /* |
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188 | * http://shell-storm.org/online/Online-Assembler-and-Disassembler/ |
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189 | * |
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190 | * lis 12,0x1234 |
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191 | * ori 12,12,0x5678 |
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192 | * mtctr 12 |
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193 | * bctr |
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194 | */ |
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195 | #if COMPILE_ASM |
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196 | asm volatile (" lis 12,0x1234\n" \ |
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197 | " ori 12,12,0x5678\n" \ |
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198 | " mtctr 12\n" \ |
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199 | " bctr\n"); |
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200 | #endif |
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201 | uint32_t* tramp = (uint32_t*) tramopline; |
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202 | *tramp++ = 0x3d800000 | (target >> 16); |
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203 | *tramp++ = 0x618c0000 | (target & 0xffff); |
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204 | *tramp++ = 0x7d8903a6; |
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205 | *tramp++ = 0x4e800420; |
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206 | return tramp; |
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207 | } |
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208 | |
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209 | static size_t |
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210 | get_veneer_size (int type) |
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211 | { |
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212 | (void) type; |
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213 | return rtems_rtl_elf_relocate_tramp_max_size (); |
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214 | } |
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215 | |
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216 | static bool |
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217 | rtems_rtl_elf_reloc_rela (rtems_rtl_obj* obj, |
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218 | const Elf_Rela* rela, |
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219 | const rtems_rtl_obj_sect* sect, |
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220 | const char* symname, |
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221 | const Elf_Byte syminfo, |
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222 | const Elf_Word symvalue, |
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223 | const bool parsing) |
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224 | { |
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225 | Elf_Addr* where; |
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226 | Elf_Word tmp; |
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227 | uint32_t mask = 0; |
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228 | uint32_t bits = 0; |
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229 | |
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230 | where = (Elf_Addr *)(sect->base + rela->r_offset); |
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231 | switch (ELF_R_TYPE(rela->r_info)) { |
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232 | case R_TYPE(NONE): |
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233 | break; |
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234 | |
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235 | case R_TYPE(32): |
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236 | /* |
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237 | * value:1; Field: word32; Expression: S + A |
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238 | */ |
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239 | if (!parsing) { |
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240 | *where = symvalue + rela->r_addend; |
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241 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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242 | printf ("rtl: ADDR32 %p @ %p in %s\n", |
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243 | (void *)*(where), where, rtems_rtl_obj_oname (obj)); |
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244 | } |
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245 | break; |
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246 | |
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247 | case R_TYPE(14): |
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248 | /* |
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249 | * value:7; Field: low14*; Expression: (S + A) >> 2 |
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250 | */ |
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251 | case R_TYPE(24): |
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252 | /* |
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253 | * value:2; Field: low24*; Expression: (S + A) >> 2 |
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254 | */ |
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255 | if (ELF_R_TYPE(rela->r_info) == R_TYPE(14)) { |
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256 | bits = 14; |
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257 | mask = 0xfffc; |
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258 | } else { |
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259 | bits = 24; |
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260 | mask = 0x3fffffc; |
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261 | } |
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262 | tmp = (symvalue + rela->r_addend) >> 2; |
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263 | if (tmp > ((1<<bits) - 1 )) { |
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264 | Elf_Word tramp_addr; |
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265 | size_t tramp_size = get_veneer_size(ELF_R_TYPE(rela->r_info)); |
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266 | if (parsing) { |
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267 | obj->tramp_size += tramp_size; |
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268 | return true; |
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269 | } |
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270 | tramp_addr = (Elf_Addr) obj->tramp_brk; |
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271 | obj->tramp_brk = set_veneer(obj->tramp_brk, |
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272 | symvalue + rela->r_addend); |
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273 | tmp = *where; |
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274 | tmp &= ~mask; |
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275 | tmp |= (tramp_addr + rela->r_addend) & mask; |
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276 | } |
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277 | else { |
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278 | tmp = *where; |
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279 | tmp &= ~mask; |
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280 | tmp |= (symvalue + rela->r_addend) & mask; |
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281 | } |
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282 | |
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283 | if (!parsing) { |
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284 | *where = tmp; |
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285 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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286 | printf ("rtl: ADDR14/ADDR24 %p @ %p in %s\n", |
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287 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
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288 | } |
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289 | break; |
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290 | |
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291 | case R_TYPE(16_HA): |
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292 | /* |
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293 | * value:6; Field:half16; Expression: #ha(S+A) |
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294 | */ |
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295 | if (!parsing) { |
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296 | tmp = symvalue + rela->r_addend; |
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297 | *(uint16_t *)where = (((tmp >> 16) + ((tmp & 0x8000) ? 1: 0)) & 0xffff); |
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298 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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299 | printf ("rtl: 16_HA %p @ %p in %s\n", |
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300 | (void *)*(where), where, rtems_rtl_obj_oname (obj)); |
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301 | } |
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302 | break; |
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303 | |
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304 | case R_TYPE(16_HI): |
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305 | /* |
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306 | * value:5; Field:half16; Expression: #hi(S+A) |
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307 | */ |
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308 | if (!parsing) { |
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309 | *(uint16_t *)where = ((symvalue + rela->r_addend) >> 16) & 0xffff; |
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310 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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311 | printf ("rtl: 16_HI %p @ %p in %s\n", |
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312 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
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313 | } |
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314 | break; |
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315 | case R_TYPE(16_LO): |
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316 | /* |
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317 | * value:4; Field:half16; Expression: #lo(S+A) |
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318 | */ |
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319 | if (!parsing) { |
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320 | *(uint16_t *)where = (symvalue + (rela->r_addend)) & 0xffff; |
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321 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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322 | printf ("rtl: 16_LO %p @ %p in %s\n", |
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323 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
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324 | } |
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325 | break; |
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326 | |
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327 | case R_TYPE(REL14): |
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328 | /* |
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329 | * value:11; Field:low14*; Expression:(S+A-P)>>2 |
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330 | */ |
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331 | case R_TYPE(REL24): |
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332 | /* |
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333 | * value:10; Field:low24*; Expression:(S+A-P)>>2 |
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334 | */ |
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335 | if (ELF_R_TYPE(rela->r_info) == R_TYPE(REL24)) { |
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336 | mask = 0x3fffffc; |
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337 | bits = 24; |
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338 | } |
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339 | else if (ELF_R_TYPE(rela->r_info) == R_TYPE(REL14)) { |
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340 | mask = 0xfffc; |
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341 | bits = 14; |
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342 | } |
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343 | |
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344 | tmp =((int) (symvalue + rela->r_addend - (Elf_Addr)where)) >> 2; |
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345 | if (((Elf_Sword)tmp > ((1<<(bits-1)) - 1)) || |
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346 | ((Elf_Sword)tmp < -(1<<(bits-1)))) { |
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347 | Elf_Word tramp_addr; |
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348 | size_t tramp_size = get_veneer_size(ELF_R_TYPE(rela->r_info)); |
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349 | if (parsing) { |
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350 | obj->tramp_size += tramp_size; |
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351 | return true; |
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352 | } |
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353 | tramp_addr = (Elf_Addr) obj->tramp_brk; |
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354 | obj->tramp_brk = set_veneer(obj->tramp_brk, |
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355 | symvalue + rela->r_addend); |
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356 | tmp = *where; |
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357 | tmp &= ~mask; |
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358 | tmp |= (tramp_addr + rela->r_addend - (Elf_Addr)where) & mask; |
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359 | } |
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360 | else |
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361 | { |
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362 | tmp = *where; |
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363 | tmp &= ~mask; |
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364 | tmp |= (symvalue + rela->r_addend - (Elf_Addr)where) & mask; |
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365 | } |
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366 | |
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367 | if (!parsing) { |
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368 | *where = tmp; |
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369 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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370 | printf ("rtl: REL24/REL14 %p @ %p in %s\n", |
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371 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
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372 | } |
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373 | break; |
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374 | |
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375 | case R_TYPE(REL32): |
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376 | /* |
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377 | * value:26; Field:word32*; Expression:S+A-P |
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378 | */ |
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379 | if (!parsing) { |
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380 | *where = symvalue + rela->r_addend - (Elf_Addr)where; |
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381 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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382 | printf ("rtl: REL32 %p @ %p in %s\n", |
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383 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
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384 | } |
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385 | break; |
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386 | |
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387 | case R_TYPE(SDAREL16): |
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388 | /* |
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389 | * A sign-extended 16 bit value relative to _SDA_BASE_, for use with |
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390 | * small data items. |
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391 | */ |
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392 | if (!parsing) { |
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393 | Elf_Addr sda_base = get_sda_base (); |
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394 | mask = 0xffff; |
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395 | tmp = *((Elf32_Half*) where); |
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396 | tmp &= ~mask; |
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397 | tmp |= (symvalue + rela->r_addend - sda_base) & mask; |
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398 | *((Elf32_Half*) where) = tmp; |
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399 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
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400 | printf ("rtl: SDAREL16 %p @ %p in %s\n", |
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401 | (void *) (uintptr_t) *((Elf32_Half*) where), |
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402 | where, rtems_rtl_obj_oname (obj)); |
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403 | } |
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404 | break; |
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405 | |
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406 | default: |
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407 | printf ("rtl: reloc unknown: sym = %" PRIu32 ", type = %" PRIu32 ", offset = %p, " |
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408 | "contents = %p\n", |
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409 | ELF_R_SYM(rela->r_info), (uint32_t) ELF_R_TYPE(rela->r_info), |
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410 | (void *)rela->r_offset, (void *)*where); |
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411 | rtems_rtl_set_error (EINVAL, |
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412 | "%s: Unsupported relocation type %" PRId32 |
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413 | "in non-PLT relocations", |
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414 | sect->name, (uint32_t) ELF_R_TYPE(rela->r_info)); |
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415 | return false; |
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416 | } |
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417 | return true; |
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418 | } |
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419 | |
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420 | bool |
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421 | rtems_rtl_elf_relocate_rela_tramp (rtems_rtl_obj* obj, |
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422 | const Elf_Rela* rela, |
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423 | const rtems_rtl_obj_sect* sect, |
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424 | const char* symname, |
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425 | const Elf_Byte syminfo, |
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426 | const Elf_Word symvalue) |
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427 | { |
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428 | return rtems_rtl_elf_reloc_rela (obj, |
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429 | rela, |
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430 | sect, |
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431 | symname, |
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432 | syminfo, |
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433 | symvalue, |
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434 | true); |
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435 | } |
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436 | |
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437 | bool |
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438 | rtems_rtl_elf_relocate_rela (rtems_rtl_obj* obj, |
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439 | const Elf_Rela* rela, |
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440 | const rtems_rtl_obj_sect* sect, |
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441 | const char* symname, |
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442 | const Elf_Byte syminfo, |
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443 | const Elf_Word symvalue) |
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444 | { |
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445 | return rtems_rtl_elf_reloc_rela (obj, |
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446 | rela, |
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447 | sect, |
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448 | symname, |
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449 | syminfo, |
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450 | symvalue, |
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451 | false); |
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452 | } |
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453 | |
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454 | bool |
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455 | rtems_rtl_elf_relocate_rel_tramp (rtems_rtl_obj* obj, |
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456 | const Elf_Rel* rel, |
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457 | const rtems_rtl_obj_sect* sect, |
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458 | const char* symname, |
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459 | const Elf_Byte syminfo, |
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460 | const Elf_Word symvalue) |
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461 | { |
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462 | (void) obj; |
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463 | (void) rel; |
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464 | (void) sect; |
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465 | (void) symname; |
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466 | (void) syminfo; |
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467 | (void) symvalue; |
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468 | rtems_rtl_set_error (EINVAL, "rel type record not supported"); |
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469 | return false; |
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470 | } |
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471 | |
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472 | bool |
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473 | rtems_rtl_elf_relocate_rel (rtems_rtl_obj* obj, |
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474 | const Elf_Rel* rel, |
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475 | const rtems_rtl_obj_sect* sect, |
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476 | const char* symname, |
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477 | const Elf_Byte syminfo, |
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478 | const Elf_Word symvalue) |
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479 | { |
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480 | (void) obj; |
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481 | (void) rel; |
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482 | (void) sect; |
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483 | (void) symname; |
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484 | (void) syminfo; |
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485 | (void) symvalue; |
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486 | rtems_rtl_set_error (EINVAL, "rel type record not supported"); |
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487 | return false; |
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488 | } |
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489 | |
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490 | bool |
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491 | rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj, |
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492 | const char* name, |
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493 | uint32_t flags) |
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494 | { |
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495 | return rtems_rtl_elf_unwind_dw2_parse (obj, name, flags); |
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496 | } |
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497 | |
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498 | bool |
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499 | rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj) |
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500 | { |
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501 | return rtems_rtl_elf_unwind_dw2_register (obj); |
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502 | } |
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503 | |
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504 | bool |
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505 | rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj) |
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506 | { |
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507 | return rtems_rtl_elf_unwind_dw2_deregister (obj); |
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508 | } |
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