Subdirectories of Root Directory in Linux

Several subdirectories exist in the root directory. Some of them are listed below.

Directory Description
/bin It contains the essential binary files which are necessary for booting the system and running the basic commands.
/boot It contains the files needed for booting the system.
/dev It contains the device files for system devices such as hard drives, printers, and input-output devices.
/etc It contains system configuration files for various applications and services.
/home It contains the home directories of regular users.
/lib It contains the shared library files needed to run the programs on the system.
/mnt It is typically used as a mount point for temporarily mounting filesystems such as external hard drives, USB drives, and network file systems.
/opt It contains optional application software packages installed by the system administrator.
/root It contains the home directory of the root user.
/sbin It contains system binaries that are used for system administration tasks.
/temp It contains temporary files created by various programs and services on the system.
/var It contains variable data files such as log files and temporary files created by various programs and services on the system.

dialout

将用户加入此分组可以以非root访问 /dev

sudo usermod -a -G dialout ${USERNAME}

根据标识符连接USB设备

  1. 查找设备的唯一标识符： 使用 udevadm 命令来查找设备的唯一标识符（如供应商 ID、产品 ID 和序列号）。

    udevadm info --name=/dev/ttyUSB0 --attribute-walk

    这将显示设备的所有属性。查找包含 idVendor、idProduct 和 serial 的条目。

  2. 创建 udev 规则： 创建一个新的 udev 规则文件，例如 /etc/udev/rules.d/99-usb-serial.rules，并添加以下内容：

    SUBSYSTEM=="tty", ATTRS{idVendor}=="XXXX", ATTRS{idProduct}=="YYYY", ATTRS{serial}=="ZZZZ", SYMLINK+="my_special_device"

    将 XXXX 替换为设备的供应商 ID，将 YYYY 替换为设备的产品 ID，将 ZZZZ 替换为设备的序列号。my_special_device 是您希望为设备创建的符号链接名称。

  3. 重新加载 udev 规则： 重新加载 udev 规则并触发设备：

    sudo udevadm control --reload-rules
sudo udevadm trigger

  4. 在代码中使用符号链接： 在代码中使用符号链接名称来访问设备，而不是使用 /dev/ttyUSBX。

自动启动 systemd

target.service example:

[Unit]
Description=Gesture Recognize Service
After=network.target

[Service]
ExecStart=/usr/bin/python3 /home/user/workspace/dh13_teleop/socket_server.py
WorkingDirectory=/home/user/workspace/teleop
StandardOutput=inherit
StandardError=inherit
Restart=always
User=paxini
Environment=PYTHONUNBUFFERED=1
Environment=LD_LIBRARY_PATH=/home/user/workspace/teleop/SDK/libs:$LD_LIBRARY_PATH

[Install]
WantedBy=multi-user.target


sudo cp ./target.service /etc/systemd/system/target.service
sudo systemctl daemon-reload
sudo systemctl enable target.service
# optional
sudo systemctl start target.service
sudo systemctl status target.service

grub

sudo nano /ect/default/grub

# iommu
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amd_iommu=off" # intel_iommu=off

# update grub config
sudo update-grub

# reboot
sudo reboot

# check iommu status
dmesg | grep -i iommu

Nvidia driver

WiFi driver

# check pci device status
sudo lspci

# check mod/driver status
modinfo mt7921