This is a target package, and as such config/functions set all sorts of
"target compiler" options, but atf needs to be build with the
"kernel compiler", e.g. aarch64 and not armv8a.
So unset all the wrong envvars from the wrong toolchain to not confuse
the atf build system.
Using one for all yields all sorts of issues:
build/gcc-aarch64-14.2.0/.x86_64-linux-gnu/./gcc/xgcc -Bbuild/gcc-aarch64-14.2.0/.x86_64-linux-gnu/./gcc/ -Btoolchain/aarch64-none-elf/bin/ -Btoolchain/aarch64-none-elf/lib/ -isystem toolchain/aarch64-none-elf/include -isystem toolchain/aarch64-none-elf/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -Dinhibit_libc -I. -I. -I../.././gcc -Ibuild/gcc-aarch64-14.2.0/libgcc -Ibuild/gcc-aarch64-14.2.0/libgcc/. -Ibuild/gcc-aarch64-14.2.0/libgcc/../gcc -Ibuild/gcc-aarch64-14.2.0/libgcc/../include -DHAVE_CC_TLS -o cpuinfo.o -MT cpuinfo.o -MD -MP -MF cpuinfo.dep -c build/gcc-aarch64-14.2.0/libgcc/config/aarch64/cpuinfo.c -fvisibility=hidden -DHIDE_EXPORTS
In file included from toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/features.h:548,
from toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/bits/libc-header-start.h:33,
from toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/stdint.h:26,
from build/gcc-aarch64-14.2.0/.x86_64-linux-gnu/gcc/include/stdint.h:9,
from toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/elf.h:24,
from toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/sys/auxv.h:22,
from build/gcc-aarch64-14.2.0/libgcc/config/aarch64/cpuinfo.c:28:
toolchain/armv8a-libreelec-linux-gnueabihf/sysroot/usr/include/gnu/stubs.h:7:11: fatal error: gnu/stubs-soft.h: No such file or directory
7 | # include <gnu/stubs-soft.h>
| ^~~~~~~~~~~~~~~~~~
compilation terminated.
Notice the mix of paths from two architectures.
Additionally the armv8a fpu config leaks into aarch64.
