1 | /* crt0.S -- startup file for frv. |
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2 | * |
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3 | * Copyright (c) 2002, 2003 Red Hat, Inc |
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4 | * |
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5 | * The authors hereby grant permission to use, copy, modify, distribute, |
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6 | * and license this software and its documentation for any purpose, provided |
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7 | * that existing copyright notices are retained in all copies and that this |
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8 | * notice is included verbatim in any distributions. No written agreement, |
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9 | * license, or royalty fee is required for any of the authorized uses. |
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10 | * Modifications to this software may be copyrighted by their authors |
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11 | * and need not follow the licensing terms described here, provided that |
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12 | * the new terms are clearly indicated on the first page of each file where |
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13 | * they apply. |
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14 | */ |
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15 | |
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16 | #include <frv-asm.h> |
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17 | |
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18 | /* statically store .Lcall's address so we can see if we are running |
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19 | at the location we were linked for or a different location. */ |
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20 | .data |
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21 | .type EXT(__start_cmp),@object |
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22 | .size EXT(__start_cmp),4 |
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23 | .p2align 2 |
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24 | EXT(__start_cmp): |
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25 | .picptr .Lcall |
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26 | |
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27 | .globl __start |
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28 | .weak _start |
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29 | .text |
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30 | .type __start,@function |
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31 | __start: |
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32 | _start: |
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33 | call .Lcall /* set up _gp in a pic-friendly manor */ |
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34 | .Lcall: movsg lr, gr4 |
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35 | P(sethi) #gprelhi(.Lcall), gr5 |
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36 | setlo #gprello(.Lcall), gr5 |
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37 | P(sub) gr4, gr5, gr16 |
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38 | |
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39 | #if ! __FRV_FDPIC__ |
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40 | sethi #gprelhi(EXT(_stack)), sp /* load up stack pointer */ |
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41 | P(setlo) #gprello(EXT(_stack)), sp |
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42 | setlos #0, fp /* zero fp to allow unwinders to stop */ |
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43 | P(add) sp, gr16, sp |
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44 | |
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45 | #define FDPIC(...) |
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46 | #else |
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47 | #define FDPIC(...) __VA_ARGS__ |
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48 | |
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49 | /* The assembler will rightfully claim that |
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50 | #hi/lo(__stacksize) are unsafe for PIC, but since __stacksize |
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51 | is absolute, and we don't want it to be relocated, we should |
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52 | be fine. */ |
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53 | |
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54 | sethi #gprelhi(EXT(__end)), gr6 |
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55 | P(sethi) #hi(EXT(__stacksize+7)), gr5 |
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56 | setlo #gprello(EXT(__end)), gr6 |
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57 | P(setlo) #lo(EXT(__stacksize+7)), gr5 |
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58 | add gr6, gr16, gr6 |
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59 | add gr6, gr5, gr5 |
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60 | andi gr5, -8, sp |
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61 | |
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62 | /* Using GPREL to compute _GLOBAL_OFFSET_TABLE_'s will force |
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63 | the entire program to relocate as a unit, which is fine for |
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64 | frv-elf. */ |
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65 | |
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66 | P(sethi) #gprelhi(EXT(_GLOBAL_OFFSET_TABLE_)), gr15 |
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67 | setlo #gprello(EXT(_GLOBAL_OFFSET_TABLE_)), gr15 |
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68 | /* We compute the value in a call-saved register (that happens |
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69 | to be the PIC register in the EABI, and copy it to gr15 before |
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70 | every call. */ |
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71 | add gr15, gr16, gr17 |
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72 | #endif |
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73 | |
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74 | sethi #gprelhi(EXT(__start_cmp)), gr5 |
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75 | setlo #gprello(EXT(__start_cmp)), gr5 |
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76 | ld @(gr5,gr16), gr6 |
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77 | subcc gr4, gr6, gr8, icc0 |
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78 | beq icc0, 0, .Lfixed |
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79 | |
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80 | P(st) gr4, @(gr5, gr16) /* update so if we restart no need to fixup */ |
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81 | setlos 4, gr11 |
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82 | |
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83 | #if ! __FRV_FDPIC__ |
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84 | |
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85 | /* fixup the .ctors list */ |
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86 | sethi #gprelhi(EXT(__CTOR_LIST__)), gr9 |
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87 | P(sethi) #gprelhi(EXT(__CTOR_END__)), gr10 |
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88 | setlo #gprello(EXT(__CTOR_LIST__)), gr9 |
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89 | P(setlo) #gprello(EXT(__CTOR_END__)), gr10 |
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90 | add gr9, gr16, gr9 |
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91 | P(add) gr10, gr16, gr10 |
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92 | addi gr9, 4, gr9 |
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93 | P(subi) gr10, 4, gr10 |
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94 | call EXT(__frv_fixptrs) |
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95 | |
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96 | /* fixup the .dtors list */ |
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97 | P(sethi) #gprelhi(EXT(__DTOR_LIST__)), gr9 |
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98 | sethi #gprelhi(EXT(__DTOR_END__)), gr10 |
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99 | P(setlo) #gprello(EXT(__DTOR_LIST__)), gr9 |
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100 | setlo #gprello(EXT(__DTOR_END__)), gr10 |
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101 | P(add) gr9, gr16, gr9 |
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102 | add gr10, gr16, gr10 |
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103 | P(addi) gr9, 4, gr9 |
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104 | subi gr10, 4, gr10 |
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105 | call EXT(__frv_fixptrs) |
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106 | #endif /* ! __FRV_FDPIC__ */ |
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107 | |
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108 | /* fixup the user .rofixup list */ |
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109 | P(sethi) #gprelhi(EXT(__ROFIXUP_LIST__)), gr9 |
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110 | sethi #gprelhi(EXT(__ROFIXUP_END__)), gr10 |
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111 | P(setlo) #gprello(EXT(__ROFIXUP_LIST__)), gr9 |
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112 | setlo #gprello(EXT(__ROFIXUP_END__)), gr10 |
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113 | P(add) gr9, gr16, gr9 |
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114 | add gr10, gr16, gr10 |
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115 | FDPIC(mov gr17, gr15) |
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116 | call EXT(__frv_fix_usrptrs) |
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117 | |
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118 | .Lfixed: |
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119 | |
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120 | /* HSR flags */ |
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121 | #define HSR_ICE 0x80000000 /* Instruction cache enable */ |
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122 | #define HSR_DCE 0x40000000 /* Data cache enable */ |
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123 | #define HSR_CBM 0x08000000 /* Cache copy back mode */ |
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124 | #define HSR_EIMM 0x04000000 /* Enable Instruction MMU */ |
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125 | #define HSR_EDMM 0x02000000 /* Enable Data MMU */ |
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126 | #define HSR_EMEM 0x00800000 /* Enable MMU miss exception mask */ |
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127 | #define HSR_RME 0x00400000 /* Ram mode enable */ |
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128 | #define HSR_SA 0x00001000 /* Start address */ |
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129 | #define HSR_FRN 0x00000800 /* Number of FPRs */ |
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130 | #define HSR_GRN 0x00000400 /* Number of GPRs */ |
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131 | #define HSR_FRHE 0x00000200 /* FR Higher Enable */ |
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132 | #define HSR_FRLE 0x00000100 /* FR Lower Enable */ |
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133 | #define HSR_GRHE 0x00000080 /* GR Higher Enable */ |
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134 | #define HSR_GRLE 0x00000040 /* GR Lower Enable */ |
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135 | |
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136 | #ifndef HSR_CLEAR |
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137 | #define HSR_CLEAR 0 |
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138 | #endif |
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139 | |
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140 | #ifndef HSR_SET |
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141 | #ifndef FRV_NO_CACHE |
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142 | #define HSR_SET (HSR_ICE|HSR_DCE|HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE) |
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143 | #else |
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144 | #define HSR_SET (HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE) |
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145 | #endif |
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146 | #endif |
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147 | |
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148 | /* PSR flags */ |
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149 | #define PSR_ICE 0x00010000 /* In circuit emulation mode */ |
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150 | #define PSR_NEM 0x00004000 /* Non-exception mode */ |
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151 | #define PSR_CM 0x00002000 /* Conditional mode */ |
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152 | #define PSR_BE 0x00001000 /* Big endian mode */ |
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153 | #define PSR_EF 0x00000100 /* Enable floating point */ |
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154 | #define PSR_EM 0x00000080 /* Enable media instructions */ |
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155 | #define PSR_S 0x00000004 /* Enable supervisor mode */ |
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156 | #define PSR_PS 0x00000002 /* Previous supervisor mode */ |
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157 | #define PSR_ET 0x00000001 /* Enable interrupts */ |
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158 | |
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159 | #ifndef PSR_CLEAR |
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160 | #if __FRV_FPR__ |
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161 | #define PSR_CLEAR 0 |
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162 | #else |
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163 | #define PSR_CLEAR (PSR_EF|PSR_EM) |
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164 | #endif |
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165 | #endif |
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166 | |
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167 | #ifndef PSR_SET |
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168 | #if __FRV_FPR__ |
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169 | #define PSR_SET (PSR_NEM|PSR_CM|PSR_EF|PSR_EM) |
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170 | #else |
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171 | #define PSR_SET (PSR_NEM|PSR_CM) |
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172 | #endif |
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173 | #endif |
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174 | |
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175 | /* Enable floating point */ |
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176 | movsg hsr0, gr4 |
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177 | P(sethi) #hi(HSR_SET), gr5 |
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178 | setlo #lo(HSR_SET), gr5 |
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179 | P(sethi) #hi(~HSR_CLEAR), gr6 |
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180 | setlo #lo(~HSR_CLEAR), gr6 |
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181 | or gr4, gr5, gr4 |
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182 | and gr4, gr6, gr4 |
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183 | movgs gr4, hsr0 |
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184 | |
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185 | movsg psr, gr4 |
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186 | P(sethi) #hi(PSR_SET), gr5 |
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187 | setlo #lo(PSR_SET), gr5 |
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188 | P(sethi) #hi(~PSR_CLEAR), gr6 |
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189 | setlo #lo(~PSR_CLEAR), gr6 |
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190 | or gr4, gr5, gr4 |
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191 | and gr4, gr6, gr4 |
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192 | movgs gr4, psr |
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193 | |
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194 | /* zero the bss area */ |
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195 | P(sethi) #gprelhi(__bss_start), gr8 |
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196 | sethi #gprelhi(__end), gr4 |
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197 | P(setlo) #gprello(__bss_start), gr8 |
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198 | setlo #gprello(__end), gr4 |
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199 | P(add) gr8, gr16, gr8 |
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200 | add gr4, gr16, gr4 |
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201 | P(setlos) #0, gr9 |
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202 | sub gr4, gr8, gr10 |
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203 | FDPIC(mov gr17, gr15) |
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204 | call EXT(memset) |
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205 | |
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206 | P(setlos) #0, gr8 /* zero argc, argv, envp */ |
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207 | setlos #0, gr9 |
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208 | P(setlos) #0, gr10 |
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209 | |
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210 | FDPIC(mov gr17, gr15) |
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211 | call EXT(main) |
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212 | FDPIC(mov gr17, gr15) |
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213 | call EXT(exit) |
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214 | .Lend: |
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215 | .size __start,(.Lend-__start) |
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216 | |
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217 | #if ! __FRV_FDPIC__ |
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218 | /* Routine to adjust pointers |
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219 | gr8 = difference to adjust by |
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220 | gr9 = starting address |
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221 | gr10 = ending address + 4 |
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222 | gr11 = amount to add to the pointer each iteration. */ |
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223 | .globl EXT(__frv_fixptrs) |
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224 | .type EXT(__frv_fixptrs),@function |
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225 | EXT(__frv_fixptrs): |
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226 | P(sub) gr9, gr11, gr9 |
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227 | sub gr10, gr11, gr10 |
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228 | .Lloop2: |
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229 | cmp gr10, gr9, icc0 |
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230 | bls icc0, 0, .Lret2 |
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231 | |
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232 | ldu @(gr9,gr11), gr5 |
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233 | add gr8, gr5, gr5 |
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234 | P(st) gr5, @(gr9,gr0) |
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235 | bra .Lloop2 |
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236 | |
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237 | .Lret2: ret |
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238 | .Lend2: |
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239 | .size EXT(__frv_fixptrs),.Lend2-EXT(__frv_fixptrs) |
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240 | #endif /* ! __FRV_FDPIC__ */ |
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241 | |
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242 | /* Routine to adjust statically initialized pointers |
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243 | Note since these are pointers to pointers, they |
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244 | need to be adjusted themsevles. |
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245 | |
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246 | gr8 = difference to adjust by |
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247 | gr9 = starting address |
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248 | gr10 = ending address + 4 |
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249 | gr11 = amount to add to the pointer each iteration. */ |
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250 | .globl EXT(__frv_fix_usrptrs) |
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251 | .type EXT(__frv_fix_usrptrs),@function |
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252 | EXT(__frv_fix_usrptrs): |
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253 | P(sub) gr9, gr11, gr9 |
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254 | sub gr10, gr11, gr10 |
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255 | .Lloop3: |
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256 | cmp gr10, gr9, icc0 |
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257 | bls icc0, 0, .Lret3 |
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258 | |
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259 | ldu @(gr9,gr11), gr5 |
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260 | ld @(gr5, gr8), gr6 |
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261 | cmp gr6, gr0, icc0 /* skip pointers initialized to 0 */ |
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262 | beq icc0, 0, .Lloop3 |
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263 | |
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264 | add gr8, gr6, gr6 |
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265 | P(st) gr6, @(gr5,gr8) |
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266 | bra .Lloop3 |
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267 | |
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268 | .Lret3: ret |
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269 | .Lend3: |
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270 | .size EXT(__frv_fix_usrptrs),.Lend3-EXT(__frv_fix_usrptrs) |
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271 | |
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272 | .section .data |
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273 | .global __dso_handle |
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274 | .weak __dso_handle |
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275 | __dso_handle: |
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276 | .long 0 |
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