ref: 52a367f3ea8b6fa256b2a9b0e52c5c2d557a9fc3 dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4