ref: 72a792f3f7d4cfb0af5d8edddcf13948bfa4d437 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4