ref: d7d0dcfcc65fc4f8ab0b8c213469ecb91ea9f7e9 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4