ref: f3f4111f3e9f9fec452c9550c9c2bb5905c2f09d dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4