ref: 5c7923fd0f305f45deb57c4d95e94cc1a8dc7cfa dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4