ref: 3a47c8bfbe9298fed2b6dcc5ac19a7af4c96c52f dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4