176 lines
4.2 KiB
NASM
176 lines
4.2 KiB
NASM
format ELF64 executable 3
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segment executable readable
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entry R_ENTRY_POINT
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R_ENTRY_POINT:
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; Main function start.
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pop r11 ; Pop argument count from the stack to r13 register.
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cmp r11, 2 ; Compare argument count to argument 0.
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je SKIP ; Skip if equal, write message and exit if unequal.
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_A1_FAILURE_ARGUMENT_COUNT
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mov r14, R_S8_FAILURE_ARGUMENT_COUNT
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call R_F3_WRITE_STRING
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mov rax, R_SYSTEM_CALL_EXIT
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mov rdi, R_FAILURE
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syscall
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SKIP:
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; Open default file in read only mode.
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pop r11 ; Ignore argument 0.
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pop r11 ; Pop argument 1 from the stack to r12 register.
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mov rax, R_SYSTEM_CALL_OPEN
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mov rdi, r11
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xor rsi, rsi
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xor rdx, rdx
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syscall
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mov [R_D8_FILE], rax
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MAIN_LOOP:
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; Read 1 byte from default file.
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mov r12, [R_D8_FILE]
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mov r13, R_D1_BYTE
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call R_F2_READ_CHARACTER
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; Write new line if byte equals "nop" instruction.
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mov r10, rax ; Store stop signal to r10.
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nop
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nop
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nop
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mov r15b, [R_D1_BYTE] ; Store byte data to r15b.
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nop
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nop
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nop
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cmp r15b, 144 ; Compare byte to "nop" instruction.
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jne MAIN_LOOP_SKIP ; Skip if not "nop" instruction.
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_D1_NEW_LINE
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call R_F2_WRITE_CHARACTER
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MAIN_LOOP_SKIP:
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_A1_DIGITS
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sar r15, 4
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add r13, r15
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call R_F2_WRITE_CHARACTER
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_A1_DIGITS
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nop
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nop
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nop
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mov r15b, [R_D1_BYTE]
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nop
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nop
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nop
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and r15, 15
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add r13, r15
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call R_F2_WRITE_CHARACTER
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_D1_SPACE
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call R_F2_WRITE_CHARACTER
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cmp r10, 0 ; Compare stop signal to 0.
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jne MAIN_LOOP ; Loop back if not equal.
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mov r12, R_STANDARD_OUTPUT
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mov r13, R_D1_NEW_LINE
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call R_F2_WRITE_CHARACTER
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; Close default file.
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mov rax, R_SYSTEM_CALL_CLOSE
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mov rdi, [R_D8_FILE]
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syscall
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mov rax, R_SYSTEM_CALL_EXIT
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mov rdi, R_SUCCESS
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syscall
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; Main function end.
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R_F2_READ_CHARACTER:
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mov rax, R_SYSTEM_CALL_READ
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mov rdi, r12
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mov rsi, r13
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mov rdx, 1
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syscall
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ret
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R_F2_WRITE_CHARACTER:
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mov rax, R_SYSTEM_CALL_WRITE
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mov rdi, r12
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mov rsi, r13
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mov rdx, 1
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syscall
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ret
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R_F3_WRITE_STRING:
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mov rax, R_SYSTEM_CALL_WRITE
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mov rdi, r12
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mov rsi, r13
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mov rdx, r14
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syscall
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ret
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segment readable writable
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; Program variables and constants.
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R_D8_FILE dq 0
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nop
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nop
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nop
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R_D1_BYTE db 0
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nop
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nop
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nop
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R_A1_DIGITS db '0123456789ABCDEF', 0
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R_D1_SPACE db 32
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R_D1_NEW_LINE db 10
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; Program strings and string sizes.
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R_A1_FAILURE_ARGUMENT_COUNT db 'Failure: Argument count must be one.', 10, 0
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R_S8_FAILURE_ARGUMENT_COUNT = $-R_A1_FAILURE_ARGUMENT_COUNT
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; GNU/Linux OS system call enumeration.
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R_SYSTEM_CALL_READ = 0
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R_SYSTEM_CALL_WRITE = 1
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R_SYSTEM_CALL_OPEN = 2
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R_SYSTEM_CALL_CLOSE = 3
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R_SYSTEM_CALL_EXIT = 60
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; GNU/Linux OS standard input and output descriptors and exit codes.
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R_STANDARD_INPUT = 0
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R_STANDARD_OUTPUT = 1
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R_SUCCESS = 0
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R_FAILURE = 1
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;~90_
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;~90_
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;~90_41_80_FF_
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;~90_75_13_49_C7_C4_01_00_00_00_49_C7_C5_2E_12_40_00_E8_A8_00_00_00_49_C7_C4_01_00_00_00_49_C7_C5_1C_12_40_00_49_C1_FF_04_4D_01_FD_E8_8E_00_00_00_49_C7_C4_01_00_00_00_49_C7_C5_1C_12_40_00_
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;~90_
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;~90_
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;~90_44_8A_3D_AB_10_00_00_
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;~90_
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;~90_
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;~90_49_83_E7_0F_4D_01_FD_E8_67_00_00_00_49_C7_C4_01_00_00_00_49_C7_C5_2D_12_40_00_E8_54_00_00_00_49_83_FA_00_0F_85_66_FF_FF_FF_49_C7_C4_01_00_00_00_49_C7_C5_2E_12_40_00_E8_37_00_00_00_48_C7_C0_03_00_00_00_48_8B_3D_53_10_00_00_0F_05_48_C7_C0_3C_00_00_00_48_C7_C7_00_00_00_00_0F_05_48_C7_C0_00_00_00_00_4C_89_E7_4C_89_EE_48_C7_C2_01_00_00_00_0F_05_C3_48_C7_C0_01_00_00_00_4C_89_E7_4C_89_EE_48_C7_C2_01_00_00_00_0F_05_C3_48_C7_C0_01_00_00_00_4C_89_E7_4C_89_EE_4C_89_F2_0F_05_C3_00_00_00_00_00_00_00_00_
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;~90_
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;~90_
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;~90_
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;~[1:R_D1_BYTE]=249=F9
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;~90_
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;~90_
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;~90_49_83_E7_0F_4D_01_FD_E8_67_00_00_00_49_C7_C4_01_00_00_00_49_C7_C5_2D_12_40_00_E8_54_00_00_00_49_83_FA_00_0F_85_66_FF_FF_FF_49_C7_C4_01_00_00_00_49_C7_C5_2E_12_40_00_E8_37_00_00_00_48_C7_C0_03_00_00_00_48_8B_3D_53_10_00_00_0F_05_48_C7_C0_3C_00_00_00_48_C7_C7_00_00_00_00_0F_05_48_C7_C0_00_00_00_00_4C_89_E7_4C_89_EE_48_C7_C2_01_00_00_00_0F_05_C3_48_C7_C0_01_00_00_00_4C_89_E7_4C_89_EE_48_C7_C2_01_00_00_00_0F_05_C3_48_C7_C0_01_00_00_00_4C_89_E7_4C_89_EE_4C_89_F2_0F_05_C3_00_00_00_00_00_00_00_00_
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;~90_
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;~90_
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;~90_
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;~[1:R_D1_BYTE]=171=AB
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