OpenWRT 64bit compile for ARM chip

Hello

I have one question about OpenWRT cross-compile.
Q1: if openwrt support 64bit packages compile?
Q2: if Q1 is yes. How to configure and generate the 64bit toolchain under staging_dir/toolchain-arm_xxx_gcc-8.3.0_musl_eabi?

thanks a lot.

Thanks,
QG

fixed it already.