ref: afd27e993ccd1a5faeb3ab2044ed7d8c2fb2f0c0 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4