ref: 0f50c54b5ec2c8d2ca681021deaedc0cffdf7f1a dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4