[256] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Tests for Assembly Library. |
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| 3 | |
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| 4 | ; Include .inc files |
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| 5 | %define INCLUDE_DISPLAY_LIBRARY |
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| 6 | %define INCLUDE_TIME_LIBRARY |
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| 7 | %include "AssemblyLibrary.inc" ; Assembly Library. Must be included first! |
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| 8 | |
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| 9 | |
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| 10 | ; Section containing code |
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| 11 | SECTION .text |
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| 12 | |
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| 13 | ; Program first instruction. |
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[287] | 14 | CPU 486 |
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[256] | 15 | ORG 100h ; Code starts at offset 100h (DOS .COM) |
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| 16 | Start: |
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[287] | 17 | jmp BusMeasurements_Start |
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[256] | 18 | |
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| 19 | ; Include library sources |
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| 20 | %include "AssemblyLibrary.asm" |
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| 21 | |
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[287] | 22 | %macro MOV_TIMING_LOOP 1 |
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| 23 | xor bx, bx ; Offset for memory transfers |
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| 24 | mov dx, OFFSET_TO_NEXT_WORD ; Must be at least 32 (Pentium Cache Line size) |
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| 25 | wbinvd ; Flush and invalidate internal cache |
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| 26 | cli ; Disable interrupts |
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| 27 | START_PRECISE_EVENT_TIMER |
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| 28 | ALIGN 8 |
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| 29 | %%ReadNextWord: |
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| 30 | mov ax, %1 ; 2 bytes |
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| 31 | add bx, dx ; 2 bytes |
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| 32 | jnc SHORT %%ReadNextWord ; 2 bytes |
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| 33 | STOP_PRECISE_EVENT_TIMER |
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| 34 | sti |
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| 35 | %endmacro |
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[256] | 36 | |
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[287] | 37 | |
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[256] | 38 | ;-------------------------------------------------------------------- |
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| 39 | ; Program start |
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| 40 | ;-------------------------------------------------------------------- |
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| 41 | ALIGN JUMP_ALIGN |
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[287] | 42 | BusMeasurements_Start: |
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[256] | 43 | CALL_DISPLAY_LIBRARY InitializeDisplayContext |
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[287] | 44 | xor ax, ax |
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| 45 | mov ds, ax |
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[256] | 46 | |
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[287] | 47 | call MeasureRegAndMemMovDurationDifferenceToAX |
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| 48 | call GetBusCycleTimeToAXfromRegAndMemMovDurationDifferenceInAX |
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| 49 | call GetBusClockRateFromCycleTimeInAX |
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| 50 | mov si, g_szBusMeasurements |
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| 51 | call PrintBusMeasurements |
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[256] | 52 | |
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[287] | 53 | call AssumeVlbCycleTimeToAXfromBusCycleTimeInCX |
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| 54 | call GetBusClockRateFromCycleTimeInAX |
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| 55 | mov si, g_szVlbAssumption |
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| 56 | call PrintBusMeasurements |
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[256] | 57 | |
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| 58 | ; Exit to DOS |
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| 59 | mov ax, 4C00h ; Exit to DOS |
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| 60 | int 21h |
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| 61 | |
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| 62 | |
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[287] | 63 | |
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| 64 | ;-------------------------------------------------------------------- |
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| 65 | ; MeasureRegAndMemMovDurationDifferenceToAX |
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| 66 | ; Parameters: |
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| 67 | ; DS: Segment for memory read tests |
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| 68 | ; Returns: |
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| 69 | ; AX: Difference in register and memory access durations |
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| 70 | ; (Precise Event Timer Ticks) |
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| 71 | ; Corrupts registers: |
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| 72 | ; BX, CX, DX |
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| 73 | ;-------------------------------------------------------------------- |
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| 74 | MeasureRegAndMemMovDurationDifferenceToAX: |
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| 75 | call SystemTimer_IntializePreciseEventTimer |
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| 76 | |
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| 77 | MOV_TIMING_LOOP bx |
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| 78 | call SystemTimer_GetPreciseEventTimerTicksToAX |
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| 79 | xchg cx, ax ; Duration now in CX |
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| 80 | |
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| 81 | MOV_TIMING_LOOP [bx] |
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| 82 | call SystemTimer_GetPreciseEventTimerTicksToAX |
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| 83 | sub ax, cx ; AX = Difference in durations |
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| 84 | sub ax, cx |
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| 85 | ret |
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| 86 | |
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| 87 | |
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| 88 | ;-------------------------------------------------------------------- |
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| 89 | ; We must divide the duration by 4 since the timing loop loads |
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| 90 | ; whole cache line (4 times the bus width) instead of single BYTE. |
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| 91 | ; |
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| 92 | ; GetBusCycleTimeToAXfromRegAndMemMovDurationDifferenceInAX |
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| 93 | ; Parameters: |
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| 94 | ; AX: Difference in register and memory access durations |
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| 95 | ; (Precise Event Timer Ticks) |
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| 96 | ; Returns: |
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| 97 | ; AX: Duration for single BYTE in nanosecs |
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| 98 | ; Corrupts registers: |
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| 99 | ; CX, DX |
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| 100 | ;-------------------------------------------------------------------- |
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| 101 | GetBusCycleTimeToAXfromRegAndMemMovDurationDifferenceInAX: |
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| 102 | mov dx, TIMER_CYCLE_TIME |
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| 103 | mul dx ; DX:AX = Duration in nanosecs |
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| 104 | mov cx, (65536 / OFFSET_TO_NEXT_WORD) * 4 |
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| 105 | div cx ; AX = Duration for single BYTE in nanosecs |
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| 106 | ret |
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| 107 | |
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| 108 | |
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| 109 | ;-------------------------------------------------------------------- |
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| 110 | ; GetBusClockRateFromCycleTimeInAX |
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| 111 | ; Parameters: |
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| 112 | ; AX: Bus Cycle Time in nanosecs |
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| 113 | ; Returns: |
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| 114 | ; CX: Bus Cycle Time in nanosecs |
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| 115 | ; DX: Bus Clock Rate (MHz) |
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| 116 | ; AX: Clock Rate tenths |
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| 117 | ; Corrupts registers: |
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| 118 | ; Nothing |
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| 119 | ;-------------------------------------------------------------------- |
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| 120 | GetBusClockRateFromCycleTimeInAX: |
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| 121 | xchg cx, ax |
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| 122 | xor dx, dx |
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| 123 | mov ax, 1000 |
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| 124 | div cl ; AL = MHz, AH = Remainder |
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| 125 | xchg al, dl ; DX = Bus Clock Rate, AL = 0 |
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| 126 | aad ; AX = 10 * AH (+AL) |
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| 127 | div cl |
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| 128 | xor ah, ah ; AX = Tenths |
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| 129 | ret |
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| 130 | |
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| 131 | |
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| 132 | ;-------------------------------------------------------------------- |
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| 133 | ; AssumeVlbCycleTimeToAXfromBusCycleTimeInCX |
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| 134 | ; Parameters: |
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| 135 | ; CX: Bus Cycle Time in nanosecs |
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| 136 | ; Returns: |
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| 137 | ; AX: Assumed VLB Cycle Time in nanosecs |
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| 138 | ; Corrupts registers: |
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| 139 | ; Nothing |
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| 140 | ;-------------------------------------------------------------------- |
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| 141 | AssumeVlbCycleTimeToAXfromBusCycleTimeInCX: |
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| 142 | mov ax, cx |
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| 143 | cmp al, 24 ; 25 = 40 MHz |
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| 144 | jb SHORT .AssumePentiumSoDivideBy2 |
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| 145 | ret |
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| 146 | .AssumePentiumSoDivideBy2: |
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| 147 | shr ax, 1 |
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| 148 | ret |
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| 149 | |
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| 150 | |
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| 151 | ;-------------------------------------------------------------------- |
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| 152 | ; PrintBusMeasurements |
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| 153 | ; Parameters: |
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| 154 | ; CX: Bus Cycle Time in nanosecs |
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| 155 | ; DX: Bus Clock Rate (MHz) |
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| 156 | ; AX: Clock Rate tenths |
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| 157 | ; SI: Offset to string to format |
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| 158 | ; Returns: |
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| 159 | ; Nothing |
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| 160 | ; Corrupts registers: |
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| 161 | ; AX, DX, BP |
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| 162 | ;-------------------------------------------------------------------- |
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| 163 | PrintBusMeasurements: |
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[256] | 164 | mov bp, sp |
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[287] | 165 | push cx |
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| 166 | push dx |
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[256] | 167 | push ax |
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| 168 | CALL_DISPLAY_LIBRARY FormatNullTerminatedStringFromCSSI |
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| 169 | ret |
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| 170 | |
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| 171 | |
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| 172 | |
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| 173 | ; Section containing initialized data |
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| 174 | SECTION .data |
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| 175 | |
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[287] | 176 | OFFSET_TO_NEXT_WORD EQU 32 ; Must be at least 32 (Pentium Cache Line size) |
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[256] | 177 | |
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[287] | 178 | g_szBusMeasurements: |
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| 179 | db "Detected bus cycle time of %u ns (%u.%u MHz) ",LF,CR,NULL |
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| 180 | g_szVlbAssumption: |
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| 181 | db "Assuming VLB (if exists) cycle time of %u ns (%u.%u MHz) ",LF,CR,NULL |
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[256] | 182 | g_szDashForZero: db "- ",NULL |
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| 183 | |
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| 184 | |
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| 185 | |
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| 186 | ; Section containing uninitialized data |
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| 187 | SECTION .bss |
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