ref: 478e7e8b4ded417e4d9da86fe56fd5d6b83aa0ff dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4