ref: f31e1f4e4272beae2bc8a40ee2d5fb5a3061a3d3 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4