ref: f06d16d9edba690a5938c3a8d3863f0c817f2fad dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4