1 | #
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2 | # Copyright (c) 2006 Martin Decky
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3 | # All rights reserved.
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4 | #
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5 | # Redistribution and use in source and binary forms, with or without
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6 | # modification, are permitted provided that the following conditions
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7 | # are met:
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8 | #
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9 | # - Redistributions of source code must retain the above copyright
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10 | # notice, this list of conditions and the following disclaimer.
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11 | # - Redistributions in binary form must reproduce the above copyright
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12 | # notice, this list of conditions and the following disclaimer in the
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13 | # documentation and/or other materials provided with the distribution.
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14 | # - The name of the author may not be used to endorse or promote products
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15 | # derived from this software without specific prior written permission.
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16 | #
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17 | # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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18 | # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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19 | # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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20 | # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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21 | # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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22 | # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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23 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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24 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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26 | # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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27 | #
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28 |
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29 | #include "regname.h"
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30 |
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31 | .set noat
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32 | .set noreorder
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33 | .set nomacro
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34 |
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35 | .text
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36 |
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37 | .global halt
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38 | .global memcpy
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39 | .global jump_to_kernel
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40 |
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41 | halt:
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42 | b halt
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43 | nop
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44 |
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45 | memcpy:
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46 | addiu $v0,$a1,3
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47 | li $v1,-4 # 0xfffffffffffffffc
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48 | and $v0,$v0,$v1
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49 | beq $a1,$v0,3f
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50 | move $t0,$a0
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51 |
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52 | 0:
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53 | beq $a2,$zero,2f
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54 | move $a3,$zero
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55 |
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56 | 1:
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57 | addu $v0,$a1,$a3
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58 | lbu $a0,0($v0)
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59 | addu $v1,$t0,$a3
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60 | addiu $a3,$a3,1
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61 | bne $a3,$a2,1b
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62 | sb $a0,0($v1)
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63 |
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64 | 2:
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65 | jr $ra
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66 | move $v0,$a1
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67 |
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68 | 3:
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69 | addiu $v0,$a0,3
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70 | and $v0,$v0,$v1
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71 | bne $a0,$v0,0b
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72 | srl $t1,$a2,2
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73 |
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74 | beq $t1,$zero,5f
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75 | move $a3,$zero
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76 |
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77 | move $a3,$zero
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78 | move $a0,$zero
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79 | 4:
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80 | addu $v0,$a1,$a0
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81 | lw $v1,0($v0)
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82 | addiu $a3,$a3,1
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83 | addu $v0,$t0,$a0
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84 | sw $v1,0($v0)
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85 | bne $a3,$t1,4b
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86 | addiu $a0,$a0,4
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87 |
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88 | 5:
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89 | andi $a2,$a2,0x3
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90 | beq $a2,$zero,2b
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91 | nop
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92 |
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93 | sll $v0,$a3,2
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94 | addu $t1,$v0,$t0
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95 | move $a3,$zero
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96 | addu $t0,$v0,$a1
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97 | 6:
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98 | addu $v0,$t0,$a3
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99 | lbu $a0,0($v0)
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100 | addu $v1,$t1,$a3
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101 | addiu $a3,$a3,1
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102 | bne $a3,$a2,6b
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103 | sb $a0,0($v1)
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104 |
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105 | jr $ra
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106 | move $v0,$a1
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107 |
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108 | jump_to_kernel:
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109 | #
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110 | # TODO
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111 | # Make sure that the I-cache, D-cache and memory are mutually coherent
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112 | # before passing control to the copied code.
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113 | #
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114 | j $a0
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115 | nop
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