ref: 6ddbe25d19bfa5a8c305e9e4292fa3ed0d24426a dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4