ref: 1a55b8d1f0253b4d39b1972978b469a352f0f94b dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4