ref: a1bea530d1d28fb1ae27d50f56a2f5fb6c92e3a3 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4