ref: c430bf65d3c9a6e80d93bf4ece4430cdd6c2d7fa dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4