ref: 27bdfccc4095a289e1a9bfcc1e98f5cca9c0a9c3 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4