ref: f6bff3c0830c1fe63dc45cd84d0a0a3a67b0cdf0 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4