41 lines
868 B
Plaintext
41 lines
868 B
Plaintext
# Read a character from stdin, save it to a global, write it to stdout.
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#
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# To run (from the subx directory):
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# $ subx translate examples/ex4.subx -o examples/ex4
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# $ subx run examples/ex4
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== code
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# syscall(read, stdin, X, 1)
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# . fd = 0 (stdin)
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bb/copy-to-EBX 0/imm32
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# . data = X (location to write result to)
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b9/copy-to-ECX X/imm32
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# . size = 1 character
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ba/copy-to-EDX 1/imm32
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# . syscall
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b8/copy-to-EAX 3/imm32/read
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cd/syscall 0x80/imm8
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# syscall(write, stdout, X, 1)
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# . fd = 1 (stdout)
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bb/copy-to-EBX 1/imm32
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# . initialize X (location to read from)
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b9/copy-to-ECX X/imm32
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# . size = 1 character
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ba/copy-to-EDX 1/imm32
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# . syscall
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b8/copy-to-EAX 4/imm32/write
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cd/syscall 0x80/imm8
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# syscall(exit, EBX)
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b8/copy-to-EAX 1/imm32/exit
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cd/syscall 0x80/imm8
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== data
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X:
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00 00 00 00 # space for read() to write to
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# . . vim:nowrap:textwidth=0
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