ref: 2d16ebcd8973c4f4f4884a8768f7c71ee6fc58f4 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4