1 ## print out a (global variable) string to stdout
 2 #
 3 # To run (from the subx directory):
 4 #   $ subx translate examples/ex6.subx -o examples/ex6
 5 #   $ subx run examples/ex6
 6 #   Hello, world!
 7 
 8 == code
 9 # instruction                     effective address                                                   operand     displacement    immediate
10 # op          subop               mod             rm32          base        index         scale       r32
11 # 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
12 
13   # syscall(write, stdout, X, size)
14     # fd = 1 (stdout)
15   bb/copy-to-EBX  1/imm32
16     # initialize X (location to write result to)
17   b9/copy-to-ECX  X/imm32
18     # initialize size
19   8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           2/r32/EDX   Size/disp32     .                 # copy *size to EDX
20     # syscall
21   b8/copy-to-EAX  4/imm32/write
22   cd/syscall  0x80/imm8
23 
24   # syscall(exit, EBX)
25   b8/copy-to-EAX  1/imm32/exit
26   cd/syscall  0x80/imm8
27 
28 == data
29 
30 Size:  # size of string
31   0e 00 00 00  # 14
32 X:  # string to print
33   48 65 6c 6c 6f 2c 20 77 6f 72 6c 64 21 0a       00
34 # H  e  l  l  o  ,  ␣  w  o  r  l  d  !  newline  null
35 
36 # vim:nowrap:textwidth=0