ref: 142bb6d5cfa25b4f8d495ea82e09a1b94efb9f0f dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4