ref: 5ecf69d7c7a8fea2dc4d392318cbee5b45cba6ad dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4