ref: 1f3f4cd06bccbaa68e34a7e5d5008c8e788e5db2 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4