ref: 7ad428e5a7b363e6dcd9ecb08457d4a40fedc66f dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4