ref: 0c50e1bc3d63f8a62986bbd140f9aef48a0cb076 dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4