ROS2入门教程-构建实时Linux

说明：

• 介绍如何构建实时Linux

步骤：

• 在主目录中创建一个目录

mkdir ~/kernel

• 进入目录

cd ~/kernel

• 用浏览器访问https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/并查看版本是否存在

• 使用wget下载

wget https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/linux-5.4.78.tar.gz

• 解压

tar -xzf linux-5.4.78.tar.gz

• 下载与我们刚刚在http://cdn.kernel.org/pub/linux/kernel/projects/rt/5.4/下载的内核版本匹配的 rt_preempt 补丁

wget http://cdn.kernel.org/pub/linux/kernel/projects/rt/5.4/older/patch-5.4.78-rt44.patch.gz

• 解压

gunzip patch-5.4.78-rt44.patch.gz

• 进入linux目录

cd linux-5.4.78/

• 使用实时补丁修补内核

patch -p1 < ../patch-5.4.78-rt44.patch

• 复制Ubuntu配置

cp /boot/config-5.4.0-54-generic .config

• 打开软件和更新。在 Ubuntu 软件菜单中勾选“源代码”框

• 安装工具

sudo apt-get build-dep linux
sudo apt-get install libncurses-dev flex bison openssl libssl-dev dkms libelf-dev libudev-dev libpci-dev libiberty-dev autoconf fakeroot

• 启用所有 Ubuntu 配置

yes '' | make oldconfig

• 在内核中启用rt_preempt

make menuconfig

• 设置以下内容

# Enable CONFIG_PREEMPT_RT
 -> General Setup
  -> Preemption Model (Fully Preemptible Kernel (Real-Time))
   (X) Fully Preemptible Kernel (Real-Time)

# Enable CONFIG_HIGH_RES_TIMERS
 -> General setup
  -> Timers subsystem
   [*] High Resolution Timer Support

# Enable CONFIG_NO_HZ_FULL
 -> General setup
  -> Timers subsystem
   -> Timer tick handling (Full dynticks system (tickless))
    (X) Full dynticks system (tickless)

# Set CONFIG_HZ_1000 (note: this is no longer in the General Setup menu, go back twice)
 -> Processor type and features
  -> Timer frequency (1000 HZ)
   (X) 1000 HZ

# Set CPU_FREQ_DEFAULT_GOV_PERFORMANCE [=y]
 ->  Power management and ACPI options
  -> CPU Frequency scaling
   -> CPU Frequency scaling (CPU_FREQ [=y])
    -> Default CPUFreq governor (<choice> [=y])
     (X) performance

• 保存并退出 menuconfig

• 构建内核

make -j `nproc` deb-pkg

• 检查 debian 包

ls ../*deb
../linux-headers-5.4.78-rt41_5.4.78-rt44-1_amd64.deb  ../linux-image-5.4.78-rt44-dbg_5.4.78-rt44-1_amd64.deb
../linux-image-5.4.78-rt41_5.4.78-rt44-1_amd64.deb    ../linux-libc-dev_5.4.78-rt44-1_amd64.deb

• 安装所有内核 debian 包

sudo dpkg -i ../*.deb

• 重新启动系统并检查新的内核版本

sudo reboot
uname -a
Linux ros2host 5.4.78-rt44 #1 SMP PREEMPT_RT Fri Nov 6 10:37:59 CET 2020 x86_64 xx