ref: 1ee1bfaa8c5644092e0c1ca3985ee74813bbfb1d dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4