ref: 8ea31ae7b21e9f0c8991b2b861bc51ea3d67c3cd dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4