ref: 94e26e7576fabcaacd8fa8f75c4f87f9eb6e56f3 dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4