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 apps/ex2.subx -o apps/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