ref: f5bbb69877c377e1ff5e4a8cf1bfb3fc8e39b85a dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4