ref: 57dbe35fb68dda4888fc4c9e8c8d0b3106a8a21c dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4