ref: 1ef7217b96c4ef6ca86eb8d958d9a06c2d9f12b9 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4