ref: 79efc5604f1df979bd1a1f5c0ee8d1d7e8bf2b61 dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4