ref: e778313180c86a9a3b25b0188b1c5b2f8c3d6b08 dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4