ref: fdd3e1808fc2ec0f6a2d2c5dd8cec914a0b20476 dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4