ref: 9a7c53250770fdeedf8bb3e9a9f5dd63c8c90f99 dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4