ref: b6211d31d8c064a9c61bf81e3ab7c5d2dc3aa67d dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4