ref: 5e2071caecc32e4c5ff3ee9e0c7ac3cd13bd43c6 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4