ref: 41fb60c4bc05b9e85c2e4495e15a9b17ba3e8ada dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4