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pascal@13691
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1 .text
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pascal@13691
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2 .code16
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pascal@13691
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3 .org 0
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pascal@13691
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4
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pascal@13691
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5 CODESZ = 0x8000 // 16 sectors = 32Kb
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pascal@13691
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6 #define EXEADRS(x) x+0xE0
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pascal@13691
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7 #define EXESTR(x) x-0x20
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pascal@13691
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8
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pascal@13691
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9 .globl _start
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pascal@13691
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10 _start:
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pascal@13691
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11 decw %bp // Magic number: MZ
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pascal@13691
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12 popw %dx
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pascal@13691
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13 jmp start // Bytes on last page of file
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pascal@13691
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14 .word (CODESZ+511)/512 // Pages in file
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pascal@13691
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15 .word 0 // Relocations
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pascal@13691
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16 .word (end_header-_start)/16 // Size of header in paragraphs
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pascal@13691
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17 .word 4064-(CODESZ/16) // Minimum extra paragraphs needed
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pascal@13691
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18 .word 4064-(CODESZ/16) // Maximum extra paragraphs needed
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pascal@13691
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19 .word 0xFFF0 // Initial (relative) SS value
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pascal@13691
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20 .word 0xFFFE // Initial SP value
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pascal@13691
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21 .word 0 // Checksum
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pascal@13729
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22 .word EXEADRS(exestart) // Initial IP value
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pascal@13691
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23 .word 0xFFF0 // Initial (relative) CS value
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pascal@13691
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24 .word 0x001C // File address of relocation table
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pascal@13691
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25 .word 0 // Overlay number
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pascal@13691
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26 initramfssize:
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pascal@13691
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27 .word 0
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pascal@13691
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28 id:
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pascal@13691
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29 .word 0
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pascal@13691
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30 end_header:
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pascal@13691
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31
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pascal@13691
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32 chksum:
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pascal@13697
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33 .word 0
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pascal@13691
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34 comstart:
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pascal@13691
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35 .word 0
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pascal@13691
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36
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pascal@13691
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37 /////////////////////// Master Boot Record code //////////////////////////////
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pascal@13691
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38
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pascal@13691
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39 start:
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pascal@13691
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40 incw %bp
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pascal@13691
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41 pushw %dx // restore SP
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pascal@13713
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42 pushw $0
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pascal@13713
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43 popw %ds
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pascal@13713
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44 movw $0x7C00, %bx
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pascal@13713
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45 pushfw
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pascal@13713
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46 pushw %ds
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pascal@13713
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47 pushw %bx
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pascal@13691
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48 pushaw
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pascal@13691
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49 movw %sp, %bp
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pascal@13691
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50 pushw %es
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pascal@13691
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51 call setreg
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pascal@13691
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52 rep
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pascal@13691
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53 movsw
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pascal@13691
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54 ljmp $0, $0x0600+start2
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pascal@13691
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55
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pascal@13699
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56 readsector2:
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pascal@13699
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57 incw %cx
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pascal@13699
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58 readsector1:
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pascal@13699
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59 movw %cx, (%bx)
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pascal@13699
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60 incw %cx
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pascal@13699
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61 movw $0x201, %ax
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pascal@13699
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62 int $0x13
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pascal@13691
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63 setreg:
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pascal@13691
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64 cld
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pascal@13713
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65 pushw %ds
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pascal@13713
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66 popw %es
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pascal@13699
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67 movw %bx, %si
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pascal@13691
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68 movw $0x0600, %di
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pascal@13691
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69 movw $0x0100, %cx
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pascal@13691
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70 return:
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pascal@13691
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71 ret
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pascal@13691
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72 start2:
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pascal@13691
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73 movw $0x80, %dx
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pascal@13691
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74 dxloop:
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pascal@13699
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75 call readsector1
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pascal@13691
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76 repe
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pascal@13691
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77 cmpsw
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pascal@13691
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78 je dxfound
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pascal@13691
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79 next:
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pascal@13699
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80 xorw %cx, %cx
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pascal@13699
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81 xchgw %ax, %dx
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pascal@13699
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82 addb $0x7D, %al // try every hard disk
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pascal@13699
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83 andb $0x83, %al // and floppy disk
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pascal@13699
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84 cmpb $0x80, %al
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pascal@13699
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85 xchgw %ax, %dx
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pascal@13691
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86 jnz dxloop
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pascal@13691
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87 fail:
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pascal@13713
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88 movw $0x0600+noloader, %si
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pascal@13713
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89 call putslp
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pascal@13713
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90 stop:
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pascal@13713
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91 hlt
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pascal@13713
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92 jmp stop
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pascal@13691
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93 dxfound:
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pascal@13691
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94 movw %dx, 10(%bp)
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pascal@13699
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95 call readsector2
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pascal@13699
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96 lodsw
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pascal@13713
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97 shrw $1, %ax
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pascal@13699
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98 jz fail // read fail or not isohydrid
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pascal@13691
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99 popw %es
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pascal@13691
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100 popa
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pascal@13713
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101 iret
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pascal@13691
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102
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pascal@13713
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103
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pascal@13691
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104 ////////////////////////////// DOS EXE code ///////////////////////////////////
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pascal@13691
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105
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pascal@13713
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106 help:
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pascal@13729
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107 .ascii "SliTaz GNU/L" // SliTaz GNU/Linux boot loader
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pascal@13729
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108 .byte EXESTR(iloader)
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pascal@13713
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109 no386:
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pascal@13713
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110 .ascii "No 386" // No 386+
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pascal@13713
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111 .byte EXESTR(plus)
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pascal@13713
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112 ERRvcpi:
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pascal@13713
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113 .ascii "No EMM386/VCPI 4" // No EMM386/VCPI 4.0+
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pascal@13713
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114 .byte EXESTR(dot0)
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pascal@13713
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115 chkerr:
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pascal@13713
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116 .ascii "Broken ISO image fil" // Broken ISO image file.
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pascal@13713
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117 .byte EXESTR(eeol)
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pascal@13713
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118 vm86modemsg:
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pascal@13713
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119 .ascii "vm86" // vm86 mode.
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pascal@13713
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120 .byte EXESTR(mode)
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pascal@13713
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121 rmPaging:
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pascal@13713
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122 .ascii "Invalid: paging + " // Invalid: paging + real mode.
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pascal@13713
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123 realmodemsg:
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pascal@13713
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124 .ascii "real" // real mode.
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pascal@13729
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125 // --------------- Must be in 00A0 011F range ------------------------
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pascal@13713
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126 mode:
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pascal@13713
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127 .ascii " mod"
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pascal@13713
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128 eeol:
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pascal@13713
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129 .ascii "e"
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pascal@13713
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130 .byte EXESTR(eol)
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pascal@13713
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131 noloader:
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pascal@13729
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132 .ascii "No isol" // No isolinux boot loader
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pascal@13729
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133 iloader:
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pascal@13729
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134 .ascii "inux boot loader"
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pascal@13697
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135 eol:
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pascal@13713
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136 .ascii "."
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pascal@13713
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137 eol2:
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pascal@13713
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138 .asciz "\r\n"
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pascal@13691
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139 noDOS3:
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pascal@13713
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140 .ascii "No DOS 3" // No DOS 3.0+
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pascal@13713
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141 dot0:
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pascal@13713
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142 .ascii ".0"
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pascal@13713
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143 plus:
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pascal@13713
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144 .ascii "+"
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pascal@13713
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145 .byte EXESTR(eol2)
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pascal@13729
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146 // -------------------------------------------------------------------
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pascal@13697
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147
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pascal@13729
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148 exestart:
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pascal@13699
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149 cld
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pascal@13697
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150 movw $0x100, %si
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pascal@13713
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151 movw -127(%si), %ax
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pascal@13729
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152 cwd // clear dx
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pascal@13713
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153 pushw %dx // dos exit
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pascal@13713
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154 cmpw $0x2F20, %ax
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pascal@13729
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155 movw $0x1000+EXESTR(help), %ax
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pascal@13691
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156 je abort
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pascal@13729
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157 pushfw // save flags
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pascal@13729
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158 // bits 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
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pascal@13729
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159 // flags 0 NT IOPL OF DF IF TF SF ZF 0 AF 0 PF 1 CF
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pascal@13729
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160 // movb $0x10, %ah
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pascal@13729
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161 pushw %ax
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pascal@13729
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162 popfw // < 286 : flags[12..15] are forced 1
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pascal@13729
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163 pushfw // = 286 : flags[12..15] are forced 0
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pascal@13729
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164 popw %cx // > 286 : only flags[15] is forced 0
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pascal@13729
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165 popfw // restore flags
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pascal@13729
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166 addb %ah, %ch // test F0 and 00 cases
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pascal@13729
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167 cmpb %ah, %ch
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pascal@13729
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168 movb $EXESTR(no386), %al
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pascal@13729
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169 jbe abort // C=8086/80186, Z=80286
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pascal@13729
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170 #if 1
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pascal@13697
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171 movw (%si), %cx
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pascal@13729
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172 jcxz is386
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pascal@13729
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173 #endif
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pascal@13697
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174 movw $0x7FE0/2, %cx
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pascal@13697
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175 chklp:
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pascal@13697
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176 lodsw
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pascal@13697
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177 addw %ax, %dx
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pascal@13697
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178 loop chklp
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pascal@13713
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179 movb $EXESTR(chkerr), %al
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pascal@13729
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180 je is386 // dx == 0 ?
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pascal@13691
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181 abort:
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pascal@13691
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182 puts:
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pascal@13713
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183 movb $1, %ah
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pascal@13713
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184 xchgw %ax, %si
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pascal@13713
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185 putslp:
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pascal@13713
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186 lodsb
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pascal@13713
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187 orb %al, %al
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pascal@13713
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188 jz moveret
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pascal@13713
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189 js puts
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pascal@13713
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190 movw $7, %bx
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pascal@13713
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191 movb $0xE, %ah
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pascal@13713
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192 int $0x10
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pascal@13713
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193 jmp putslp
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pascal@13691
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194
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pascal@13691
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195 is386:
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pascal@13697
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196 movl %cr0, %eax
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pascal@13691
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197 andb $1, %al
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pascal@13691
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198 jne tstvcpi
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pascal@13691
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199 shll $1, %eax
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pascal@13713
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200 movb $EXESTR(rmPaging), %al
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pascal@13691
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201 jc abort
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pascal@13713
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202 movb $EXESTR(realmodemsg), %al
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pascal@13691
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203 realmode:
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pascal@13691
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204 call puts
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pascal@13699
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205 movb $0x30, %ah
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pascal@13699
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206 int $0x21
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pascal@13699
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207 cmpb $3, %al
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pascal@13713
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208 movb $EXESTR(noDOS3), %al
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pascal@13713
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209 jb abort
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pascal@13691
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210 movw EXEADRS(comstart), %ax // .com address
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pascal@13691
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211 movw $moveend-move, %cx
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pascal@13691
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212 movw $EXEADRS(move), %si
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pascal@13691
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213 movw $0xC000, %di
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pascal@13691
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214 jmp move2
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pascal@13691
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215 move:
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pascal@13691
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216 movb $0x80, %ch
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pascal@13691
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217 xchgw %ax, %si
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pascal@13691
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218 movw $0x0100, %di
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pascal@13691
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219 move2:
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pascal@13691
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220 pushw %di
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pascal@13691
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221 rep
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pascal@13691
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222 movsb
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pascal@13713
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223 moveret:
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pascal@13691
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224 ret
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pascal@13691
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225 moveend:
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pascal@13713
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226
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pascal@13713
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227 VersionVCPI:
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pascal@13713
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228 cmpb $0x40, %dl // >= 4.0 ?
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pascal@13713
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229 jb NoVCPI
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pascal@13713
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230 movb $EXESTR(vm86modemsg), %al
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pascal@13713
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231 jmp realmode
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pascal@13713
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232 tstvcpi:
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pascal@13713
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233 pushw %ds
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pascal@13713
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234 movw %cx, %ds // %cx = 0
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pascal@13713
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235 movw 0x67*4+2, %ds
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pascal@13713
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236 movw $10, %si
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pascal@13713
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237 lodsw
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pascal@13713
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238 xorw $0x4D45, %ax // EM(MX) or EM(MQ)
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pascal@13713
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239 xchgw %ax, %dx
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pascal@13713
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240 lodsw // si += 2
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pascal@13713
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241 lodsw
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pascal@13713
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242 xorw $0x5858, %ax // XX
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pascal@13713
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243 orw %ax, %dx
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pascal@13713
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244 lodsw
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pascal@13713
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245 popw %ds
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pascal@13713
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246 xorw $0x3058, %ax // X0
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pascal@13713
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247 orw %ax, %dx
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pascal@13713
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248 movw $EXEADRS(CmdVCPI), %si
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pascal@13713
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249 ChkVCPI:
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pascal@13713
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250 NoVCPI:
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pascal@13713
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251 xchgw %ax, %dx
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pascal@13713
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252 movb $EXESTR(ERRvcpi), %al
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pascal@13713
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253 jne abort
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pascal@13713
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254 lodsb
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pascal@13713
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255 shlw $8, %ax
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pascal@13713
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256 je VersionVCPI
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pascal@13713
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257 int $0x67
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pascal@13713
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258 testb %ah, %ah
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pascal@13713
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259 jmp ChkVCPI
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pascal@13713
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260 CmdVCPI:
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pascal@13713
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261 .byte 0x40 // status
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pascal@13713
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262 .byte 0xDE // vcpi present ?
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pascal@13713
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263 .byte 0x46 // version
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pascal@13713
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264 .byte 0
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pascal@13713
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265
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pascal@13691
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266 .org 440
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pascal@13691
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267 //////////////////////////// partition table //////////////////////////////////
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pascal@13691
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268
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