ref: e5c8d1dc55e5fa3ff1ca771cde0beec4b7d6b105 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4