Easy way to get installed Ubuntu 20.04 LTS that boots in UEFI and BIOS
This is the easy way for you to get an installed Ubuntu system, that boots both in UEFI and BIOS mode, and you can use it in several cases. However,
- if you want to learn how to do it, or
- if you want to be sure of the content (and don't rely on me), or
- if you want hibernation, or
- if you want an encrypted disk (LVM with LUKS encryption),
then you must do it yourself. (In the encrypted disk case, you must create the passphrase yourself during the installation.)
Using a method similar to what is described by C.S.Cameron I have created
- a compressed image file of
- an installed system of Ubuntu 20.04 LTS
- that can boot both in UEFI mode and BIOS mode (alias CSM alias legacy mode).
This compressed image file expands to 15.7 GB, so it fits into drives with size at least 16 GB. It is easy to extract and clone it to an external drive
- with mkusb (only one step),
- but you can use any
- extraction tool,
- plus cloning tool,
- plus a tool to fix the gpt partition table gpt-fix. You may have problems in Windows to find such a tool, and in several cases you can skip it, and the drive will work anyway.
After extraction, cloning and fixing, it is a good idea to expand the root partition, where Ubuntu is installed in order to use the whole drive, when you are using a big drive ( > 16 GB ).
There are more details about this image file
at the following link,
Finally, the installed system has a password, and you are encouraged to change it,