ref: 96985d0bf8d0f0d5cebfa9e7671ea887f2bc67bc dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4