ref: 7eb35a779018b510e1d7cfa5be4bb1e3e9a05e7b dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4