ref: c5d08a602c35ac24b7c7ccfe5b53c8dfa12ef94e dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4