参考

Ubuntu20.04 如何降低内核版本
ubuntu降低内核版本

开始

1. 查看当前版本

uname -r

输出如下

5.13.0-40-generic

2. 查找目标版本，我的需求是5.8.0-43(受供应商的硬件限制)

apt-cache search linux| grep 5.8.0-43

然后得到了如下的信息

linux-buildinfo-5.8.0-43-generic - Linux kernel buildinfo for version 5.8.0 on 64 bit x86 SMP
linux-buildinfo-5.8.0-43-lowlatency - Linux kernel buildinfo for version 5.8.0 on 64 bit x86 SMP
linux-cloud-tools-5.8.0-43-generic - Linux kernel version specific cloud tools for version 5.8.0-43
linux-cloud-tools-5.8.0-43-lowlatency - Linux kernel version specific cloud tools for version 5.8.0-43
linux-headers-5.8.0-43-generic - Linux kernel headers for version 5.8.0 on 64 bit x86 SMP
linux-headers-5.8.0-43-lowlatency - Linux kernel headers for version 5.8.0 on 64 bit x86 SMP
linux-hwe-5.8-cloud-tools-5.8.0-43 - Linux kernel version specific cloud tools for version 5.8.0-43
linux-hwe-5.8-headers-5.8.0-43 - Header files related to Linux kernel version 5.8.0
linux-hwe-5.8-tools-5.8.0-43 - Linux kernel version specific tools for version 5.8.0-43
linux-image-5.8.0-43-generic - Signed kernel image generic
linux-image-5.8.0-43-lowlatency - Signed kernel image lowlatency
linux-image-unsigned-5.8.0-43-generic - Linux kernel image for version 5.8.0 on 64 bit x86 SMP
linux-image-unsigned-5.8.0-43-lowlatency - Linux kernel image for version 5.8.0 on 64 bit x86 SMP
linux-modules-5.8.0-43-generic - Linux kernel extra modules for version 5.8.0 on 64 bit x86 SMP
linux-modules-5.8.0-43-lowlatency - Linux kernel extra modules for version 5.8.0 on 64 bit x86 SMP
linux-modules-extra-5.8.0-43-generic - Linux kernel extra modules for version 5.8.0 on 64 bit x86 SMP
linux-tools-5.8.0-43-generic - Linux kernel version specific tools for version 5.8.0-43
linux-tools-5.8.0-43-lowlatency - Linux kernel version specific tools for version 5.8.0-43
linux-modules-nvidia-390-5.8.0-43-generic - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-390-5.8.0-43-lowlatency - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-418-server-5.8.0-43-generic - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-418-server-5.8.0-43-lowlatency - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-450-5.8.0-43-generic - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-450-5.8.0-43-lowlatency - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-450-server-5.8.0-43-generic - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-450-server-5.8.0-43-lowlatency - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-460-5.8.0-43-generic - Linux kernel nvidia modules for version 5.8.0-43
linux-modules-nvidia-460-5.8.0-43-lowlatency - Linux kernel nvidia modules for version 5.8.0-43

3. 安装

sudo apt-get install linux-headers-5.8.0-43-generic linux-image-5.8.0-43-generic

4. 查看此时的内核

dpkg --get-selections | grep linux-image

我的如下

linux-image-5.11.0-27-generic           deinstall
linux-image-5.11.0-37-generic           deinstall
linux-image-5.11.0-40-generic           deinstall
linux-image-5.11.0-41-generic           deinstall
linux-image-5.11.0-43-generic           deinstall
linux-image-5.11.0-44-generic           deinstall
linux-image-5.11.0-46-generic           deinstall
linux-image-5.13.0-25-generic           deinstall
linux-image-5.13.0-27-generic           deinstall
linux-image-5.13.0-28-generic           deinstall
linux-image-5.13.0-30-generic           deinstall
linux-image-5.13.0-35-generic           deinstall
linux-image-5.13.0-37-generic           deinstall
linux-image-5.13.0-39-generic           install
linux-image-5.13.0-40-generic           install
linux-image-5.8.0-43-generic            install
linux-image-generic-hwe-20.04           install

5.切换启动内核版本

sudo gedit /etc/default/grub

设置切换

保存退出后，更新设置

sudo update-grub

6.重启并选择对应版本
选择界面应该如这样（网上找的图，图源ubuntu降低你使用的内核到指定版本）

image.png
选择对应版本，不要选择recovery mode

重启成功后查看

uname -r

我的如下

5.8.0-43-generic

整体测试比较成功。