ref: 150ee7fe6eea076c1c5daac8d7d2e5f63d8ffd2c dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4