ref: 4e7fbabfc9f33f6ea5e5a46d5d6d7532d5f68301 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4