Hihope的rk3568是OpenHarmony社区的样板项目，一般测试和验证代码问题都会使用该项目，但OpenHarmony工程庞大，实践中不免出现各种各样的问题。通常我们会使用如下命令编译rk3568项目
./build.sh --product-name rk3568 --ccache --no-prebuild-sdk --enable_notice_collection=false --gn-args build_product_type=DEBUG --gn-args load_test_config=false在编译到内核时可能会报这样的错误：
GEN .tmp_initcalls.lds
LTO vmlinux.o
MODPOST vmlinux.symvers
WARNING: modpost: vmlinux.o(___ksymtab_gpl+rockchip_clk_register_armclk+0x0): Section mismatch in reference from the variable __ksymtab_rockchip_clk_register_armclk to the function .init.text:rockchip_clk_register_armclk()
The symbol rockchip_clk_register_armclk is exported and annotated __init
Fix this by removing the __init annotation of rockchip_clk_register_armclk or drop the export.
MODINFO modules.builtin.modinfo
GEN modules.builtin
LD .tmp_vmlinux.btf
ld.lld: error: undefined symbol: __aarch64_cas4_acq_rel
>>> referenced by hdf_vnode_adapter.c:294 (/home/smile/OpenHarmony-v4.1.1-Release/out/kernel/OBJ/linux-5.10/../../../../drivers/hdf_core/framework/core/adapter/vnode/src/hdf_vnode_adapter.c:294)
>>> vmlinux.o:(HdfVNodeAdapterIoctl)
>>> referenced by hdf_vnode_adapter.c:303 (/home/smile/OpenHarmony-v4.1.1-Release/out/kernel/OBJ/linux-5.10/../../../../drivers/hdf_core/framework/core/adapter/vnode/src/hdf_vnode_adapter.c:303)
>>> vmlinux.o:(HdfVNodeAdapterIoctl)
>>> referenced by hdf_vnode_adapter.c:428 (/home/smile/OpenHarmony-v4.1.1-Release/out/kernel/OBJ/linux-5.10/../../../../drivers/hdf_core/framework/core/adapter/vnode/src/hdf_vnode_adapter.c:428)
>>> vmlinux.o:(HdfDeviceSendEventToClient)
>>> referenced 1 more times
BTF .btf.vmlinux.bin.o
pahole: .tmp_vmlinux.btf: No such file or directory
LD .tmp_vmlinux.kallsyms1
ld.lld: error: .btf.vmlinux.bin.o: unknown file type
make[2]: *** [/home/smile/OpenHarmony-v4.1.1-Release/out/kernel/src_tmp/linux-5.10/Makefile:1225: vmlinux] Error 1
make[1]: *** [arch/arm64/Makefile:208: rk3568-toybrick-x0-linux.img] Error 2
make[1]: Leaving directory '/home/smile/OpenHarmony-v4.1.1-Release/out/kernel/OBJ/linux-5.10'
make: *** [Makefile:192: __sub-make] Error 2这个问题的根本原因在这里有解释 undefined reference to `__aarch64_cas4_sync' error on arm64 native build ，简单来说就是编译器的默认参数有问题，因此可以修改出问题的内核模块编译参数。找到 hdf_vnode_adapter.c 的Makefile文件 drivers/hdf_core/adapter/khdf/linux/manager/Makefile，增加 -mno-outline-atomics 参数，如
ccflags-y += -mno-outline-atomics修改完成后重新编译系统即可。
如果依然不能解决，可以尝试以下三种解决方法，第一种：
删除OBJ/linux-5.10目录后单编内核
cd out/kernel/src_tmp/linux-5.10
rm -rf ../../OBJ/linux-5.10
export KBUILD_OUTPUT=../../OBJ/linux-5.10
./make-ohos.sh TB-RK3568X0第二种：
vim kernel/linux/patches/linux-5.10/rk3568_patch/kernel.patch找到 +MAKE="make LLVM=1 LLVM_IAS=1 CROSS_COMPILE=aarch64-linux-gnu-" ，删除掉CROSS_COMPILE=aarch64-linux-gnu- ，然后重新编译系统。
第三种：
在build.log中找到内核的编译命令行，类似
/usr/bin/env ../../device/board/hihope/rk3568/kernel/build_kernel.sh ../../kernel/linux/linux-5.10 /home/smile/OpenHarmony-v4.1.1-Release/out/rk3568/packages/phone/images /home/smile/OpenHarmony-v4.1.1-Release/device/board/hihope/rk3568 vendor/hihope/rk3568 /home/smile/OpenHarmony-v4.1.1-Release rockchip rk3568 hihope root default disable_lto_O0 enable_ramdisk复制后，进入out/rk3568目录，执行这个复制的命令行。如果编译通过，可以重新尝试编译系统。