ref: 2e0e69ea2dff85bf9c9edf3ed00fd1c45278be1f dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4