ref: 6aa7ebcf495bff8f6a4c7ebcac28058bd0b06aae dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4