ref: 2d1fbbdafa37080ddaacb76ac1e4f5a413ef2dc3 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4