如何在Yocto环境中调出软件控制台？

Hey there! Let's walk through how to get a software console up and running in your Yocto-built i.MX7 system. Since you already have your pre-built and custom-compiled images booting successfully, and can see output via minicom, you're already in a great spot. Here's what you need to do:

1. Double-Check UART Configuration in Yocto #

First, confirm your Yocto build is set to use the correct UART port for the console. Open your project's local.conf file (or the machine-specific config, like imx7d-phytec-som.conf for PHYTEC boards) and look for this line:

SERIAL_CONSOLE = "115200 ttymxc0"

This sets the baud rate to 115200 and targets the common i.MX7 UART device ttymxc0. If this line is missing, add it and rebuild your image with bitbake <your-image-name>.

2. Enable the Serial Console Service #

Most modern Yocto BSPs use systemd, so we need to make sure the serial getty service is active:

• Log into your board via minicom first (you already know how to do this!).
• Check if the service is running with this command:

  systemctl status serial-getty@ttymxc0.service
  

• If it's inactive or disabled, start it and set it to run on boot:

  sudo systemctl start serial-getty@ttymxc0.service
  sudo systemctl enable serial-getty@ttymxc0.service
  

3. Set Up Auto-Login (Optional Time-Saver) #

If you want to skip the login prompt and jump straight to a shell, configure auto-login:

1. Create a directory for the service override:

   sudo mkdir -p /etc/systemd/system/serial-getty@ttymxc0.service.d
   

2. Create an override.conf file inside that directory with these contents:

   [Service]
   ExecStart=
   ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear %I 115200 linux --autologin root
   

3. Reload systemd and restart the service to apply changes:

   sudo systemctl daemon-reload
   sudo systemctl restart serial-getty@ttymxc0.service
   

4. Test Your Console #

Disconnect and reconnect your minicom session, or reboot the board. You should now see a working shell prompt—either after entering your credentials, or directly if you set up auto-login.

Quick Note on Your x86 C/C++ App #

Since you have x86-based source code, remember you'll need to cross-compile it for the ARM architecture of the i.MX7. The easiest way to do this is to add a custom Yocto recipe (.bb file) for your app:

• Define the source location with SRC_URI.
• List any dependencies with DEPENDS.
• Build it with bitbake <your-app-name> and add it to your image by updating local.conf with IMAGE_INSTALL_append = " your-app-name".

内容的提问来源于stack exchange，提问作者Newbie_SW