ref: 5bfaf253d3ea0f0d60eb12b45b0866a79c5ae66b dir: /sys/src/libc/alpha/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4