ref: 38d3a8a38b0cd7b2b4c159c1fb68c3c0622f00c0 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4