[OE-core] Questions: Using OE toolchain of different arch.

[Ying-Chun Liu (PaulLiu)]

Dear openembedded-core developers,


I need some help about using OE toolchain from different arch.


For example, on RPi3, we build the rootfs using armhf architecture.

(require  conf/machine/include/arm/arch-armv6.inc)

That means the whole rootfs is built by arm-linux-gnueabihf-*


But when adding TF-A and OPTEE. On RPi3, TF-A and OPTEE runs in 64-bit
mode. And TF-A will then load u-boot (BL33) and runs it in 32-bit mode.
So the rest of the systems still run on 32-bit mode.


The problem is now we want to build TF-A and OPTEE. So we need to
compile it by aarch64 toolchains. That is we should use
CROSS_COMPILE=aarch64-oe-linux-* from aarch64. But however it seems to
me that I cannot do that. I tried to make a recipe for TF-A by chainging
architecture of that recipe but I still don't have aarch64-oe-linux-*
available. Is there a proper way of doing this?

BTW, this is not about ilp32 because we still want the whole system runs
in armhf for compatibility.

Yours,
Paul