ref: f16b11eecfbff855f1ba229b90c4d0ea4c8f69b9 dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4