ref: a4c6dc1d3d3a2ef3ec4d4ac49b16ec039c353cd7 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4