ref: 1e8a9ebb0f76b0ebe8eb31d79c44324c1c1ed70f dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4