ref: 2eadf1fa1703e5da4a98ba9c1a2bdc23bd140d8c dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4