ref: 2ae2e5f856f8f95f8d780f9ffe0a0ebb634ffb1a dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4