ref: 056eb9f7d8b1a577f7029e3d0e6d40cf6c2e86b0 dir: /sys/src/libc/68000/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4