ref: a2eddf4d2d3e9ed1bd1ee2edf46d4737d8504dd2 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4