ref: 9fd0b3bad12cd5fe2d2c2a5e4173b0077a05f7d3 dir: /sys/src/libc/arm/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4