ref: 6ad06b36b2a61ce20cb6a6e4c5fd15ec8ac142f8 dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4