ref: 15590e39c6be92d8a9ecb2f00b015dbb9a3dc0b0 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4