1 | /* |
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2 | * This is based on the mvme-crt0.S file from libgloss/rs6000. |
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3 | * crt0.S -- startup file for PowerPC systems. |
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4 | * |
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5 | * (c) 1998, Radstone Technology plc. |
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6 | * |
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7 | * |
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8 | * This is an unpublished work the copyright in which vests |
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9 | * in Radstone Technology plc. All rights reserved. |
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10 | * |
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11 | * The information contained herein is the property of Radstone |
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12 | * Technology plc. and is supplied without liability for |
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13 | * errors or omissions and no part may be reproduced, used or |
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14 | * disclosed except as authorized by contract or other written |
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15 | * permission. The copyright and the foregoing |
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16 | * restriction on reproduction, use and disclosure extend to |
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17 | * all the media in which this information may be |
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18 | * embodied. |
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19 | * |
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20 | * Copyright (c) 1995 Cygnus Support |
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21 | * |
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22 | * The authors hereby grant permission to use, copy, modify, distribute, |
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23 | * and license this software and its documentation for any purpose, provided |
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24 | * that existing copyright notices are retained in all copies and that this |
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25 | * notice is included verbatim in any distributions. No written agreement, |
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26 | * license, or royalty fee is required for any of the authorized uses. |
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27 | * Modifications to this software may be copyrighted by their authors |
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28 | * and need not follow the licensing terms described here, provided that |
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29 | * the new terms are clearly indicated on the first page of each file where |
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30 | * they apply. |
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31 | * |
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32 | * $Id$ |
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33 | */ |
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34 | |
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35 | #include <ppc-asm.h> |
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36 | #include <bsp.h> |
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37 | |
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38 | .file "start.s" |
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39 | |
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40 | .extern FUNC_NAME(atexit) |
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41 | .globl FUNC_NAME(__atexit) |
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42 | .section ".sdata","aw" |
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43 | .align 2 |
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44 | FUNC_NAME(__atexit): /* tell C's eabi-ctor's we have an atexit function */ |
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45 | .long FUNC_NAME(atexit)@fixup /* and that it is to register __do_global_dtors */ |
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46 | |
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47 | .section ".fixup","aw" |
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48 | .align 2 |
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49 | .long FUNC_NAME(__atexit) |
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50 | |
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51 | .text |
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52 | .globl _start |
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53 | .type _start,@function |
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54 | _start: |
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55 | /* Set MSR */ |
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56 | /* |
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57 | * Enable data and instruction address translation and floating point |
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58 | */ |
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59 | li r3,MSR_IR | MSR_DR | MSR_FP |
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60 | mtmsr r3 |
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61 | |
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62 | /* |
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63 | * The caches are already flushed by the firmware so just enable |
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64 | */ |
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65 | mfspr r3,HID0 |
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66 | #if PPC_USE_DATA_CACHE |
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67 | /* |
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68 | * Enable data and instruction cache |
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69 | */ |
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70 | ori r3,r3 ,H0_60X_ICE | H0_60X_DCE |
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71 | #else |
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72 | /* |
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73 | * Enable instruction cache only |
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74 | */ |
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75 | ori r3,r3 ,H0_60X_ICE |
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76 | #endif |
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77 | mtspr HID0,r3 |
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78 | |
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79 | /* clear bss */ |
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80 | lis r6,__bss_start@h |
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81 | ori r6,r6,__bss_start@l |
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82 | lis r7,__bss_end@h |
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83 | ori r7,r7,__bss_end@l |
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84 | |
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85 | cmplw 1,r6,r7 |
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86 | bc 4,4,.Lbss_done |
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87 | |
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88 | subf r8,r6,r7 /* number of bytes to zero */ |
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89 | srwi r9,r8,2 /* number of words to zero */ |
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90 | mtctr r9 |
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91 | li r0,0 /* zero to clear memory */ |
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92 | addi r6,r6,-4 /* adjust so we can use stwu */ |
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93 | .Lbss_loop: |
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94 | stwu r0,4(r6) /* zero bss */ |
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95 | bdnz .Lbss_loop |
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96 | |
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97 | .Lbss_done: |
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98 | |
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99 | /* clear sbss */ |
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100 | lis r6,__sbss_start@h |
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101 | ori r6,r6,__sbss_start@l |
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102 | lis r7,__sbss_end@h |
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103 | ori r7,r7,__sbss_end@l |
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104 | |
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105 | cmplw 1,r6,r7 |
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106 | bc 4,4,.Lsbss_done |
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107 | |
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108 | subf r8,r6,r7 /* number of bytes to zero */ |
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109 | srwi r9,r8,2 /* number of words to zero */ |
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110 | mtctr r9 |
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111 | li r0,0 /* zero to clear memory */ |
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112 | addi r6,r6,-4 /* adjust so we can use stwu */ |
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113 | .Lsbss_loop: |
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114 | stwu r0,4(r6) /* zero sbss */ |
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115 | bdnz .Lsbss_loop |
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116 | |
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117 | .Lsbss_done: |
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118 | |
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119 | lis sp,__stack@h |
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120 | ori sp,sp,__stack@l |
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121 | |
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122 | /* set up initial stack frame */ |
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123 | addi sp,sp,-4 /* make sure we don't overwrite debug mem */ |
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124 | lis r0,0 |
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125 | stw r0,0(sp) /* clear back chain */ |
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126 | stwu sp,-56(sp) /* push another stack frame */ |
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127 | |
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128 | lis r5,environ@ha |
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129 | la r5,environ@l(r5) /* environp */ |
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130 | li r4, 0 /* argv */ |
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131 | li r3, 0 /* argc */ |
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132 | /* Let her rip */ |
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133 | bl FUNC_NAME(boot_card) |
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134 | |
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135 | /* |
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136 | * This should never get reached |
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137 | */ |
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138 | /* |
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139 | * Return MSR to its reset state |
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140 | */ |
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141 | li r3,0 |
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142 | mtmsr r3 |
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143 | isync |
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144 | |
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145 | /* |
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146 | * Call reset entry point |
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147 | */ |
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148 | lis r3,0xfff0 |
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149 | ori r3,r3,0x100 |
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150 | mtlr r3 |
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151 | blr |
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152 | .Lstart: |
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153 | .size _start,.Lstart-_start |
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154 | |
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155 | .comm environ,4,4 |
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