ref: b3c1fa9ecfbaaacef40f6aa26199cdfd7f6cb9b1 dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4