First thanks for your reply.But I compile the kernel directly,then hang on ubuntu18.04 rootfs.I compile the kernel through bitbake in the yocto project.The operation steps are as follows:
MACHINE=imx8mqevk DISTRO=fsl-imx-xwayland source ./fsl-setup-release.sh -b bld-xwayland/
bitbake -c compile -f -v linux-imx
bitbake linux-imx -c compile_kernelmodules -f -v
bitbake -c deploy -f -v linux-imx
then Replace the previous kernel with the generated kernel,mount Ubuntu18.04 rootfs。
please give me some advise,thanks!