ref: a0ba4c1f03a3f99fb17a9edf9b4448db49bb6c46 dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4