ref: 4e8494aad79a124f2b15ede9e7873fed46e1bb0a dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4