ref: 4bc63cf817b5dc2b6c3d8ac4dfd9d76a31b3acdc dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4