When using Ubuntu Server on the Raspberry Pi, the bootloader is usually U-Boot instead of the familiar grub. This makes pressing shift or other keys into grub potentially ineffective. There are many ways to solve this problem, but first you need to understand the peculiarities of the Raspberry Pi system.
One way to try this is to hold down the shift key. Sometimes, this can trigger the u-boot interface to display the boot options. But if that doesn't work, consider editing/boot/uenv.txtFile. This file contains the boot configuration, and by modifying the parameters in it, we may be able to implement the boot options we want. Run in the terminalsudo nano /boot/uenv.txt, find and modify the relevant configuration parameters, and then save the file.
Another way to try it is to useraspi-configTool. By running in the terminalsudo raspi-config, we can change the bootstrap options in an interactive way. This may involve:"advanced options" > "boot options"and other steps, depending on the version of Ubuntu Server and the configuration of the Raspberry Pi.
If none of the above works, we can look at the boot logs to get a more detailed picture of what happened when the system booted. By runningcat /var/log/boot.logorcat /var/log/syslog, we can check the logs during the boot process so that we can locate the problem. You can also try pressing the space key on startup. Some systems display additional boot options at boot time, which can be viewed via the Space key.
Checking your hardware connections is also a step in troubleshooting. Make sure that the connection of the Raspberry Pi is working properly and that there are no hardware issues so that these issues do not affect the booting process. If all else doesn't work, consider updating the firmware. By runningsudo rpi-updateIt is possible to try updating the firmware of the Raspberry Pi to the latest version, and sometimes this may fix some boot issues.
Before attempting to change the boot options, make sure you read the documentation carefully and understand how the Raspberry Pi system works. This will help us better understand the nature of the problem and thus more effectively address the distress associated with facilitation.
Ubuntu servers on Raspberry Pi typically use U-Boot as a bootloader instead of traditional Grub. As a result, you may have difficulty trying to get into grub. Here are some suggestions:
Hold down the shift key:Some versions of U-Boot support holding down the shift key at boot to display boot options. On startup, try holding down the shift key to see if you are able to get to the boot options interface.
Edit the file:On a Raspberry Pi, the boot configuration is usually stored in/bootTable of Contentsuenv.txtfile. You can try editing this file to view or modify the bootstrap options. Open the file with the following command:
Find out if there are any parameters for the bootstrap option and modify them as needed. Once the file is saved, restart the Raspberry Pi and see if it works.
Use raspi-config to change boot options:On the Raspberry Pi, you can try using tools to change the boot options. Run the following command in the terminal:
Then select"advanced options" > "boot options"Then you can try to change the boot options. Note that this may vary depending on the different versions of Ubuntu Server.
Check out the u-boot documentation:If none of the above works, it is recommended to consult the U-Boot documentation used by the Raspberry Pi to learn how to configure the boot options on that platform.
View the boot logs:Reviewing the logs during the boot process of the Raspberry Pi may help identify the problem. You can check it out/var/logdirectory, such as:/var/log/boot.logor/var/log/syslog
Search the logs for boot-related information to identify possible issues.
Press the space key on startup:Some systems show additional boot options at startup, try pressing the Space key at startup to see if other options are available.
Check the u-boot configuration file:Check the configuration file of the u-boot, which is usually stored in or/boot/config.txtMiddle. Review these files and make sure there are no settings that disable the boot option.
Try using a different shortcut:Try using other shortcuts that might trigger bootstrap options, such as:ctrl + b
Check the hardware connection:Make sure your Raspberry Pi is connected properly and there are no hardware issues. Sometimes boot issues can be related to hardware connections.
Update Firmware:Check that the firmware of the Raspberry Pi is up to date and update to the latest version.
sudo rpi-update