https://github.com/akkartik/mu/blob/main/linux/ex2.subx

     1 # Add 3 and 4, and return the result in the exit code.
     2 #
     3 # To run:
     4 #   $ bootstrap/bootstrap translate ex2.subx -o ex2
     5 #   $ bootstrap/bootstrap run ex2
     6 # Expected result:
     7 #   $ echo $?
     8 #   2
     9
    10 == code
    11
    12 Entry:
    13 # ebx = 3
    14 bb/copy-to-ebx  3/imm32
    15 # add 4 to ebx
    16 81 0/subop/add 3/mod/direct 3/rm32/ebx 4/imm32
    17 # exit(ebx)
    18 e8/call  syscall_exit/disp32
    19
    20 # . . vim:nowrap:textwidth=0