ref: 90b4fe9cf65bb24b55472ce2e32a7dbc3c5e7f97 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4