ref: dfa90ed5c09a923e19d6d1f1e2ccb4f61fca5d43 dir: /sys/src/libc/sparc/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4