ref: a0b7b3ecbbcf24a3c79ac91f8fbf6d5c0ddd7710 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4