ref: 17b80cbcf1d5a7c6afd74c7432ab64c100dbdc2f dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4