ref: 8cfd549d118fbec88f3cd8d7740e5b94fbcf9a2d dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4