ref: c029a0c9130b7a9b5a9c3883e813dd8d8a0a770d dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4