ref: 3d0ebdc439039f1e01ee5fa0f75b1de1a12c12f1 dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4