可以使用此链接下载Linux kernel 5.4的主线包。根据您的操作系统类型，按顺序下载并安装软件包：
- linux-headers-5.4.0-xxxxxx_all.deb
- linux-headers-5.4.0-xxx-generic(/lowlatency)_xxx_amd64.deb
- linux-modules-5.4.0-xxx-generic(/lowlatency)_xxx_amd64.deb
- linux-image-xxx-5.4.0-xxx-generic(/lowlatency)_xxx_amd64.deb
注意：
generic用于支持通用硬件系统，lowlatency用于低延迟硬件系统，amd64用于64位系统，armhf或arm64版本支持其他硬件。
下载并安装
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2019-11-25/linux-headers-5.4.0-999_5.4.0-999.201911242102_all.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2019-11-25/linux-headers-5.4.0-999-generic_5.4.0-999.201911242102_amd64.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2019-11-25/linux-image-unsigned-5.4.0-999-generic_5.4.0-999.201911242102_amd64.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2019-11-25/linux-modules-5.4.0-999-generic_5.4.0-999.201911242102_amd64.deb
sudo dpkg -i *.deb
重启
reboot