ref: 8d8b64cd2cd5141a3957d8fb24f7b5ea61db6eda dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4