ref: b9c1eab2e63e1c9b38d1c6a7a2170016e7f0a56c dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4