ref: 1e0b65c8bfb2f1b6fbc189795b73a6e89b05dc75 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4