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# Read a character from stdin, save it to a global, write it to stdout.
#
# To run:
# $ ./subx translate examples/ex4.subx -o examples/ex4
# $ ./subx run examples/ex4
== data 0x0a000000
# the global variable we save to
X:
0/imm32 # space for read() to write to
== code 0x09000000
Entry:
# syscall(read, stdin, X, 1)
# . fd = 0 (stdin)
bb/copy-to-ebx 0/imm32
# . data = X (location to write result to)
b9/copy-to-ecx X/imm32
# . size = 1 character
ba/copy-to-edx 1/imm32
# . syscall
b8/copy-to-eax 3/imm32/read
cd/syscall 0x80/imm8
# syscall(write, stdout, X, 1)
# . fd = 1 (stdout)
bb/copy-to-ebx 1/imm32
# . initialize X (location to read from)
b9/copy-to-ecx X/imm32
# . size = 1 character
ba/copy-to-edx 1/imm32
# . syscall
b8/copy-to-eax 4/imm32/write
cd/syscall 0x80/imm8
# syscall(exit, ebx)
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
# . . vim:nowrap:textwidth=0
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