1028 lines
11 KiB
ArmAsm
1028 lines
11 KiB
ArmAsm
.syntax unified
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.cpu cortex-m0
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.align 2
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.thumb
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.thumb_func
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.text
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.extern cpu6502_dump
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.extern cpu6502_load
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.extern cpu6502_store
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#define T0 r4
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#define T1 r5
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#define PC r6
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#define SR r7
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#define RA r8
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#define RX r9
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#define RY r10
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#define SP r11
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#define FLAG_N (1 << 7)
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#define FLAG_V (1 << 6)
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#define FLAG_D (1 << 3)
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#define FLAG_I (1 << 2)
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#define FLAG_Z (1 << 1)
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#define FLAG_C (1 << 0)
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.macro _ldb
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bl cpu6502_load
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.endm
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.macro _ldw
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mov T0, r0
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bl cpu6502_load
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mov T1, r0
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adds r0, T0, #1
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bl cpu6502_load
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lsls r0, r0, #8
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adds r0, r0, T1
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.endm
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.macro _stb
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bl cpu6502_store
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.endm
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.macro _stw
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mov T0, r0
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mov T1, r1
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bl cpu6502_store
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adds r0, T0, #1
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lsrs r1, T1, #8
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bl cpu6502_store
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.endm
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.macro _push16 reg
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mov r0, SP
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mov r1, \reg
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lsrs r1, r1, #8
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_stb
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mov r0, SP
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subs r0, r0, #1
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mov r1, \reg
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_stb
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mov r0, SP
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subs r0, r0, #2
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mov SP, r0
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.endm
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.macro _decode
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b decode
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.endm
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.macro _fromImm8
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adds PC, PC, #1
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mov r0, PC
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_ldb
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.endm
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.macro _clx flag
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movs T0, #\flag
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bics SR, SR, T0
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adds PC, PC, #1
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.endm
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.macro _sex flag
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movs T0, #\flag
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orrs SR, SR, T0
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adds PC, PC, #1
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.endm
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.macro _ld reg
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_clx (FLAG_N | FLAG_Z)
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mov \reg, r0
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beq 1f
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_sex FLAG_Z
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1:
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movs r1, #0x80
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tst r0, r1
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beq 1f
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_sex FLAG_N
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1:
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adds PC, PC, #1
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.endm
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.macro _resume
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ldr r0, =#r_pc
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ldr PC, [r0]
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ldr r0, =#r_sr
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ldr SR, [r0]
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ldr r0, =#r_a
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ldr T0, [r0]
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mov RA, T0
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ldr r0, =#r_x
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ldr T0, [r0]
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mov RX, T0
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ldr r0, =#r_y
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ldr T0, [r0]
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mov RY, T0
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ldr r0, =#r_sp
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ldr T0, [r0]
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mov SP, T0
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ldr T0, =#op_table
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.endm
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.macro _suspend
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ldr r0, =#r_pc
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str PC, [r0]
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ldr r0, =#r_sr
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str SR, [r0]
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ldr r0, =#r_a
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mov T0, RA
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str T0, [r0]
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ldr r0, =#r_x
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mov T0, RX
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str T0, [r0]
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ldr r0, =#r_y
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mov T0, RY
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str T0, [r0]
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ldr r0, =#r_sp
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mov T0, SP
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str T0, [r0]
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.endm
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op00:
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b quit
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op01:
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b quit
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op02:
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b quit
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op03:
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b quit
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op04:
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b quit
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op05:
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b quit
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op06:
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b quit
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op07:
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b quit
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op08:
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b quit
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op09:
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b quit
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op0a:
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b quit
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op0b:
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b quit
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op0c:
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b quit
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op0d:
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b quit
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op0e:
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b quit
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op0f:
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b quit
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op10:
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b quit
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op11:
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b quit
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op12:
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b quit
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op13:
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b quit
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op14:
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b quit
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op15:
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b quit
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op16:
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b quit
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op17:
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b quit
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op18: // CLC
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_clx FLAG_C
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_decode
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op19:
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b quit
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op1a:
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b quit
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op1b:
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b quit
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op1c:
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b quit
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op1d:
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b quit
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op1e:
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b quit
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op1f:
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b quit
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op20: // JSR
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adds T0, PC, #2
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_push16 T0
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adds r0, PC, #1
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_ldw
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mov PC, r0
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_decode
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op21:
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b quit
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op22:
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b quit
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op23:
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b quit
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op24:
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b quit
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op25:
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b quit
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op26:
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b quit
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op27:
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b quit
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op28:
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b quit
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op29:
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b quit
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op2a:
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b quit
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op2b:
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b quit
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op2c:
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b quit
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op2d:
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b quit
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op2e:
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b quit
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op2f:
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b quit
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op30:
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b quit
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op31:
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b quit
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op32:
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b quit
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op33:
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b quit
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op34:
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b quit
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op35:
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b quit
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op36:
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b quit
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op37:
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b quit
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op38: // SEC
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_sex FLAG_C
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_decode
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op39:
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b quit
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op3a:
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b quit
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op3b:
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b quit
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op3c:
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b quit
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op3d:
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b quit
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op3e:
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b quit
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op3f:
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b quit
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op40:
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b quit
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op41:
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b quit
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op42:
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b quit
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op43:
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b quit
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op44:
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b quit
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op45:
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b quit
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op46:
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b quit
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op47:
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b quit
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op48:
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b quit
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op49:
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b quit
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op4a:
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b quit
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op4b:
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b quit
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op4c:
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b quit
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op4d:
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b quit
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op4e:
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b quit
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op4f:
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b quit
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op50:
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b quit
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op51:
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b quit
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op52:
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b quit
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op53:
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b quit
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op54:
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b quit
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op55:
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b quit
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op56:
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b quit
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op57:
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b quit
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op58: // CLI
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_clx FLAG_I
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_decode
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op59:
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b quit
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op5a:
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b quit
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op5b:
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b quit
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op5c:
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b quit
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op5d:
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b quit
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op5e:
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b quit
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op5f:
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b quit
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op60:
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b quit
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op61:
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b quit
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op62:
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b quit
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op63:
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b quit
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op64:
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b quit
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op65:
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b quit
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op66:
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b quit
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op67:
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b quit
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op68:
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b quit
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op69:
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b quit
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op6a:
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b quit
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op6b:
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b quit
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op6c:
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b quit
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op6d:
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b quit
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op6e:
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b quit
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op6f:
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b quit
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op70:
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b quit
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op71:
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b quit
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op72:
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b quit
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op73:
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b quit
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op74:
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b quit
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op75:
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b quit
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op76:
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b quit
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op77:
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b quit
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op78: // SEI
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_sex FLAG_I
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_decode
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op79:
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b quit
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op7a:
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b quit
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op7b:
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b quit
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op7c:
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b quit
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op7d:
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b quit
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op7e:
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b quit
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op7f:
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b quit
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op80:
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b quit
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op81:
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b quit
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op82:
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b quit
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op83:
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b quit
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op84:
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b quit
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op85:
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b quit
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op86:
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b quit
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op87:
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b quit
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op88:
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b quit
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op89:
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b quit
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op8a:
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b quit
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op8b:
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b quit
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op8c:
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b quit
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op8d:
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b quit
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op8e:
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b quit
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op8f:
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b quit
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op90:
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b quit
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op91:
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b quit
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op92:
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b quit
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op93:
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b quit
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op94:
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b quit
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op95:
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b quit
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op96:
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b quit
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op97:
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b quit
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op98:
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b quit
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op99:
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b quit
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op9a:
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b quit
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op9b:
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b quit
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op9c:
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b quit
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op9d:
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b quit
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op9e:
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b quit
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op9f:
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b quit
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opa0: // LDY - Immediate
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_fromImm8
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_ld RY
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_decode
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opa1:
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b quit
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opa2: // LDX - Immediate
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_fromImm8
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_ld RX
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_decode
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opa3:
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b quit
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opa4:
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b quit
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opa5:
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b quit
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opa6:
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b quit
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opa7:
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b quit
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opa8:
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b quit
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opa9: // LDA - Immediate
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_fromImm8
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_ld RA
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_decode
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opaa:
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b quit
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opab:
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b quit
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opac:
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b quit
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opad:
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b quit
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opae:
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b quit
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opaf:
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b quit
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opb0:
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b quit
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opb1:
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b quit
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opb2:
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b quit
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opb3:
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b quit
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opb4:
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b quit
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opb5:
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b quit
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opb6:
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b quit
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opb7:
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b quit
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opb8: // CLV
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_clx FLAG_V
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_decode
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opb9:
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b quit
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opba:
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b quit
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opbb:
|
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b quit
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opbc:
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b quit
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opbd:
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b quit
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opbe:
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b quit
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opbf:
|
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b quit
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opc0:
|
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b quit
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opc1:
|
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b quit
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opc2:
|
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b quit
|
|
opc3:
|
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b quit
|
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opc4:
|
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b quit
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opc5:
|
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b quit
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opc6:
|
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b quit
|
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opc7:
|
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b quit
|
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opc8:
|
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b quit
|
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opc9:
|
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b quit
|
|
opca:
|
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b quit
|
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opcb:
|
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b quit
|
|
opcc:
|
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b quit
|
|
opcd:
|
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b quit
|
|
opce:
|
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b quit
|
|
opcf:
|
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b quit
|
|
opd0:
|
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b quit
|
|
opd1:
|
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b quit
|
|
opd2:
|
|
b quit
|
|
opd3:
|
|
b quit
|
|
opd4:
|
|
b quit
|
|
opd5:
|
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b quit
|
|
opd6:
|
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b quit
|
|
opd7:
|
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b quit
|
|
opd8: // CLD
|
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_clx FLAG_D
|
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_decode
|
|
opd9:
|
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b quit
|
|
opda:
|
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b quit
|
|
opdb:
|
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b quit
|
|
opdc:
|
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b quit
|
|
opdd:
|
|
b quit
|
|
opde:
|
|
b quit
|
|
opdf:
|
|
b quit
|
|
ope0:
|
|
b quit
|
|
ope1:
|
|
b quit
|
|
ope2:
|
|
b quit
|
|
ope3:
|
|
b quit
|
|
ope4:
|
|
b quit
|
|
ope5:
|
|
b quit
|
|
ope6:
|
|
b quit
|
|
ope7:
|
|
b quit
|
|
ope8:
|
|
b quit
|
|
ope9:
|
|
b quit
|
|
opea:
|
|
b quit
|
|
opeb:
|
|
b quit
|
|
opec:
|
|
b quit
|
|
oped:
|
|
b quit
|
|
opee:
|
|
b quit
|
|
opef:
|
|
b quit
|
|
opf0:
|
|
b quit
|
|
opf1:
|
|
b quit
|
|
opf2:
|
|
b quit
|
|
opf3:
|
|
b quit
|
|
opf4:
|
|
b quit
|
|
opf5:
|
|
b quit
|
|
opf6:
|
|
b quit
|
|
opf7:
|
|
b quit
|
|
opf8: // SED
|
|
_sex FLAG_D
|
|
_decode
|
|
opf9:
|
|
b quit
|
|
opfa:
|
|
b quit
|
|
opfb:
|
|
b quit
|
|
opfc:
|
|
b quit
|
|
opfd:
|
|
b quit
|
|
opfe:
|
|
b quit
|
|
opff:
|
|
b quit
|
|
|
|
.global cpu6502_reset
|
|
.type cpu6502_reset, %function
|
|
cpu6502_reset:
|
|
push {r4-r7,lr}
|
|
movs r4, #0x00
|
|
movs r5, #0x01
|
|
lsls r5, r5, #8
|
|
adds r5, r5, #0xff
|
|
movs r6, #0x30
|
|
ldr r7, =#r_a
|
|
str r4, [r7]
|
|
ldr r7, =#r_x
|
|
str r4, [r7]
|
|
ldr r7, =#r_y
|
|
str r4, [r7]
|
|
ldr r7, =#r_sp
|
|
str r5, [r7]
|
|
ldr r7, =#r_sr
|
|
str r6, [r7]
|
|
ldr r0, =#0xfffc
|
|
_ldw
|
|
ldr r7, =#r_pc
|
|
str r0, [r7]
|
|
pop {r4-r7,pc}
|
|
|
|
.global cpu6502_run
|
|
.type cpu6502_run, %function
|
|
cpu6502_run:
|
|
push {r4-r7,lr}
|
|
mov r0, r8
|
|
mov r1, r9
|
|
mov r2, r10
|
|
mov r3, r11
|
|
mov r4, r12
|
|
push {r0-r4}
|
|
_resume
|
|
_decode
|
|
quit:
|
|
mov r12, r0
|
|
_suspend
|
|
pop {r0-r4}
|
|
mov r8, r0
|
|
mov r9, r1
|
|
mov r10, r2
|
|
mov r11, r3
|
|
mov r0, r12
|
|
mov r12, r4
|
|
pop {r4-r7,pc}
|
|
|
|
// void dump(uint16_t pc);
|
|
.type dump, %function
|
|
dump:
|
|
push {lr}
|
|
_suspend
|
|
ldr r0, =#r_sp
|
|
ldr r1, [r0]
|
|
ldr r0, =#r_sr
|
|
ldr r2, [r0]
|
|
push {r1,r2}
|
|
ldr r3, =#r_pc
|
|
ldr r0, [r3]
|
|
ldr r3, =#r_a
|
|
ldr r1, [r3]
|
|
ldr r3, =#r_x
|
|
ldr r2, [r3]
|
|
ldr r3, =#r_y
|
|
ldr r3, [r3]
|
|
// r0=pc, r1=a, r2=x, r3=y, [sp]=sp, [sp+4]=sr
|
|
bl cpu6502_dump
|
|
mov r0, sp
|
|
adds r0, r0, #8
|
|
mov sp, r0
|
|
pop {pc}
|
|
|
|
// void decode();
|
|
.type decode, %function
|
|
decode:
|
|
bl dump
|
|
mov r0, PC
|
|
_ldb
|
|
lsls r1, r0, #2
|
|
ldr r2, =#op_table
|
|
adds r3, r2, r1
|
|
ldr r1, [r3]
|
|
mov pc, r1
|
|
|
|
.section .rodata
|
|
op_table:
|
|
.long op00
|
|
.long op01
|
|
.long op02
|
|
.long op03
|
|
.long op04
|
|
.long op05
|
|
.long op06
|
|
.long op07
|
|
.long op08
|
|
.long op09
|
|
.long op0a
|
|
.long op0b
|
|
.long op0c
|
|
.long op0d
|
|
.long op0e
|
|
.long op0f
|
|
.long op10
|
|
.long op11
|
|
.long op12
|
|
.long op13
|
|
.long op14
|
|
.long op15
|
|
.long op16
|
|
.long op17
|
|
.long op18
|
|
.long op19
|
|
.long op1a
|
|
.long op1b
|
|
.long op1c
|
|
.long op1d
|
|
.long op1e
|
|
.long op1f
|
|
.long op20
|
|
.long op21
|
|
.long op22
|
|
.long op23
|
|
.long op24
|
|
.long op25
|
|
.long op26
|
|
.long op27
|
|
.long op28
|
|
.long op29
|
|
.long op2a
|
|
.long op2b
|
|
.long op2c
|
|
.long op2d
|
|
.long op2e
|
|
.long op2f
|
|
.long op30
|
|
.long op31
|
|
.long op32
|
|
.long op33
|
|
.long op34
|
|
.long op35
|
|
.long op36
|
|
.long op37
|
|
.long op38
|
|
.long op39
|
|
.long op3a
|
|
.long op3b
|
|
.long op3c
|
|
.long op3d
|
|
.long op3e
|
|
.long op3f
|
|
.long op40
|
|
.long op41
|
|
.long op42
|
|
.long op43
|
|
.long op44
|
|
.long op45
|
|
.long op46
|
|
.long op47
|
|
.long op48
|
|
.long op49
|
|
.long op4a
|
|
.long op4b
|
|
.long op4c
|
|
.long op4d
|
|
.long op4e
|
|
.long op4f
|
|
.long op50
|
|
.long op51
|
|
.long op52
|
|
.long op53
|
|
.long op54
|
|
.long op55
|
|
.long op56
|
|
.long op57
|
|
.long op58
|
|
.long op59
|
|
.long op5a
|
|
.long op5b
|
|
.long op5c
|
|
.long op5d
|
|
.long op5e
|
|
.long op5f
|
|
.long op60
|
|
.long op61
|
|
.long op62
|
|
.long op63
|
|
.long op64
|
|
.long op65
|
|
.long op66
|
|
.long op67
|
|
.long op68
|
|
.long op69
|
|
.long op6a
|
|
.long op6b
|
|
.long op6c
|
|
.long op6d
|
|
.long op6e
|
|
.long op6f
|
|
.long op70
|
|
.long op71
|
|
.long op72
|
|
.long op73
|
|
.long op74
|
|
.long op75
|
|
.long op76
|
|
.long op77
|
|
.long op78
|
|
.long op79
|
|
.long op7a
|
|
.long op7b
|
|
.long op7c
|
|
.long op7d
|
|
.long op7e
|
|
.long op7f
|
|
.long op80
|
|
.long op81
|
|
.long op82
|
|
.long op83
|
|
.long op84
|
|
.long op85
|
|
.long op86
|
|
.long op87
|
|
.long op88
|
|
.long op89
|
|
.long op8a
|
|
.long op8b
|
|
.long op8c
|
|
.long op8d
|
|
.long op8e
|
|
.long op8f
|
|
.long op90
|
|
.long op91
|
|
.long op92
|
|
.long op93
|
|
.long op94
|
|
.long op95
|
|
.long op96
|
|
.long op97
|
|
.long op98
|
|
.long op99
|
|
.long op9a
|
|
.long op9b
|
|
.long op9c
|
|
.long op9d
|
|
.long op9e
|
|
.long op9f
|
|
.long opa0
|
|
.long opa1
|
|
.long opa2
|
|
.long opa3
|
|
.long opa4
|
|
.long opa5
|
|
.long opa6
|
|
.long opa7
|
|
.long opa8
|
|
.long opa9
|
|
.long opaa
|
|
.long opab
|
|
.long opac
|
|
.long opad
|
|
.long opae
|
|
.long opaf
|
|
.long opb0
|
|
.long opb1
|
|
.long opb2
|
|
.long opb3
|
|
.long opb4
|
|
.long opb5
|
|
.long opb6
|
|
.long opb7
|
|
.long opb8
|
|
.long opb9
|
|
.long opba
|
|
.long opbb
|
|
.long opbc
|
|
.long opbd
|
|
.long opbe
|
|
.long opbf
|
|
.long opc0
|
|
.long opc1
|
|
.long opc2
|
|
.long opc3
|
|
.long opc4
|
|
.long opc5
|
|
.long opc6
|
|
.long opc7
|
|
.long opc8
|
|
.long opc9
|
|
.long opca
|
|
.long opcb
|
|
.long opcc
|
|
.long opcd
|
|
.long opce
|
|
.long opcf
|
|
.long opd0
|
|
.long opd1
|
|
.long opd2
|
|
.long opd3
|
|
.long opd4
|
|
.long opd5
|
|
.long opd6
|
|
.long opd7
|
|
.long opd8
|
|
.long opd9
|
|
.long opda
|
|
.long opdb
|
|
.long opdc
|
|
.long opdd
|
|
.long opde
|
|
.long opdf
|
|
.long ope0
|
|
.long ope1
|
|
.long ope2
|
|
.long ope3
|
|
.long ope4
|
|
.long ope5
|
|
.long ope6
|
|
.long ope7
|
|
.long ope8
|
|
.long ope9
|
|
.long opea
|
|
.long opeb
|
|
.long opec
|
|
.long oped
|
|
.long opee
|
|
.long opef
|
|
.long opf0
|
|
.long opf1
|
|
.long opf2
|
|
.long opf3
|
|
.long opf4
|
|
.long opf5
|
|
.long opf6
|
|
.long opf7
|
|
.long opf8
|
|
.long opf9
|
|
.long opfa
|
|
.long opfb
|
|
.long opfc
|
|
.long opfd
|
|
.long opfe
|
|
.long opff
|
|
|
|
.bss
|
|
r_pc: .long 0
|
|
r_a: .long 0
|
|
r_x: .long 0
|
|
r_y: .long 0
|
|
r_sp: .long 0
|
|
r_sr: .long 0
|
|
|