ref: 3f5db0b7f757a6ccbfe2d22a8bab67d27dd9235c dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4