ref: a5a6a1562abd6457b6fa65f0bfa8ab5ede7af5d6 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4