In 2012 [I was porting OpenEmbedded to target AArch64](http://marcin.juszkiewicz.com.pl/2012/10/08/arm-64-bit-porting-for-openembedded/) so I can say that I did first OE builds **for** that architecture.
But today I did kind of reverse thing:
Build Configuration: BB_VERSION = "1.21.1" BUILD_SYS = "aarch64-linux" NATIVELSBSTRING = "Fedora-21" TARGET_SYS = "arm-oe-linux-gnueabi" MACHINE = "genericarmv7a" DISTRO = "nodistro" DISTRO_VERSION = "nodistro.0" TUNE_FEATURES = "armv7a vfp thumb neon callconvention-hard" TARGET_FPU = "vfp-neon"
Yes — I did build **on** AArch64 machine targeting ARMv7a system. Had to edit one patch (pseudo-native was set to use very old glibc symbols which are not available on 64-bit ARM) but after that build was running just fine.
I did not tested resulting binaries.