ref: 4e91e4a2dbab9d79e1047cfc2094a438561b5a21 dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4