ref: b7a30fe3d642a6fc0e2ceb58e5f4b2f259a770fd dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4