ref: 2aa2f9f359a84b25c0a2ed488c4d0319c9ea8c55 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4