ref: e51c4bc6e493a9cd0d9e9d7f1d24c57ae77bab65 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4