ref: 3cdaf6ea5f649e9b89608d7fbd2ddb0e5cb52af4 dir: /sys/src/libc/alpha/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4