ref: 4526b1a5dd7f9ecb5b0b472cc4bd6a41b05effcc dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4