ref: 7faa0a6225f7f6d3b4a5b9c0b0ce919a8d7056a2 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4