ref: f31c5b3b3b9bc06b2ccbb1db17a731ff1b80fcbf dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4