ref: 015f7f51129c6cddac5d9e8bd66a4c8a2dbb87e8 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4