Ubuntu 20.04 使用源代码安装5.5.19内核

linux内核国内镜像网站，列出来如下：

中科大内核下载镜像站：https://mirrors.ustc.edu.cn/kernel.org/
清华大学内核下载镜像站：https://mirrors.tuna.tsinghua.edu.cn/kernel/
阿里云内核下载镜像站：https://mirrors.aliyun.com/kernel/
网易内核下载镜像站：http://mirrors.163.com/kernel/

sudo uname -r看到内核版本是5.4.0-100-generic。

sudo lsb_release -a看到操作系统版本是Ubuntu 20.04.4。

sudo wget --no-check-certificate https://mirrors.tuna.tsinghua.edu.cn/kernel/v5.x/linux-5.5.19.tar.gz可以下载源代码。

sudo tar -xf linux-5.5.19.tar.gz进行不显示过程的解压。

sudo apt-get install -y libncurses5-dev flex bison libssl-dev dwarves安装依赖包。

安装完成如下：

cd linux-5.5.19进入到源码目录里边。

sudo cp /boot/config-5.4.0-100-generic ./.config将当前内核编译的配置文件复制到源码目录里边，并且改名为.config。

sudo make menuconfig开始配置。

你可以按照自己的需求进行选择内核编译设置，我这里因为想要把TUN/TAP安装上，所以进行下边的操作。
Device Drivers > Network device support > Universal TUN/TAP device driver support按下m键，在<>中有M，要是不清楚如何操作可以参考《Linux学习之Ubuntu 20.04安装内核模块》。

按←→键，选择 < Save >，然后按Enter。

在< Ok >处也是按下Enter。

在< Exit > 处按下Enter。

按←→键，选择 < Exit >，然后按Enter。

一直操作上一个步骤，选择 < Exit >，然后按Enter，直到退回到下边命令行这样。

重新配置一些参数。

sudo sed -i 's/CONFIG_MODULE_SIG=y/CONFIG_MODULE_SIG=n/g' .config  # 把 CONFIG_MODULE_SIG=y  替换成  CONFIG_MODULE_SIG=n
sudo sed -i 's/CONFIG_MODULE_SIG_ALL=y/CONFIG_MODULE_SIG_ALL=n/g' .config
sudo sed -i 's/CONFIG_SYSTEM_TRUSTED_KEYS="debian\/canonical-certs.pem"/CONFIG_SYSTEM_TRUSTED_KEYS=""/g' .config
sudo sed -i 's/CONFIG_SYSTEM_REVOCATION_KEYS="debian\/canonical-revoked-certs.pem"/CONFIG_SYSTEM_REVOCATION_KEYS=""/g' .config
sudo sed -i 's/CONFIG_SYSTEM_TRUSTED_KEYRING=y/CONFIG_SYSTEM_TRUSTED_KEYRING=n/g' .config  # 把 CONFIG_SYSTEM_TRUSTED_KEYRING=y 替换成 CONFIG_SYSTEM_TRUSTED_KEYRING=n 
cat .config | grep "CONFIG_SYSTEM_TRUSTED_KEYRING=n" # 看一下 CONFIG_SYSTEM_TRUSTED_KEYRING 相关字符串是否成功替换。

sudo nohup make -j2 all &开始编译。

sudo ps -aux | grep 58410看一下58410进程是否还在运行，如下图有两行输出，就是还在执行。

sudo ps -aux | grep 58410发现只有一行显示出来，sudo tail -n 20 nohup.out看到后20行也没有报错，这就是编译完了。

sudo make modules_install安装内核。

完成之后，显示如下：

sudo make install进行安装。

sudo grep 'menuentry' /boot/grub/grub.cfg看到

menuentry 'Ubuntu, with Linux 5.5.19' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.5.19-advanced-bbd3ea56-da3b-4e1a-b14e-159e41299ea3' {
menuentry 'Ubuntu, with Linux 5.5.19 (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.5.19-recovery-bbd3ea56-da3b-4e1a-b14e-159e41299ea3' {

/etc/default/grub里边内容如下：

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX="net.ifnames=0 consoleblank=600 console=tty0 console=ttyS0,115200n8 nospectre_v2 nopti noibrs noibpb"

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

现在需要把GRUB_DEFAULT=0修改为GRUB_DEFAULT="gnulinux-advanced-bbd3ea56-da3b-4e1a-b14e-159e41299ea3>gnulinux-5.5.19-advanced-bbd3ea56-da3b-4e1a-b14e-159e41299ea3"，修改之后/etc/default/grub内容如下：

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT="gnulinux-advanced-bbd3ea56-da3b-4e1a-b14e-159e41299ea3>gnulinux-5.5.19-advanced-bbd3ea56-da3b-4e1a-b14e-159e41299ea3"
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX="net.ifnames=0 consoleblank=600 console=tty0 console=ttyS0,115200n8 nospectre_v2 nopti noibrs noibpb"

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

sudo update-grub更新grub，sudo reboot进行重启。

开机之后sudo uname -r可以看到内核版本已经变成5.5.19。