Boot manager or boot loader is a small piece of software placed on a system drive which helps boot into the installed operating system. When you start your Windows PC, the UEFI firmware (or BIOS) checks and stars the hardware. After this it looks for an available bootable drive with the boot manager. Then the control is given to the boot manager. If there are multiple operating systems installed, then boot manager shows a menu from which you can select various operating systems or other options.
EFI boot manager code is located on the system drive and is usually modified through the operating system itself. But some advanced users might also want to make some small changes to the boot manager themselves. For editing the EFI boot manager, we can make use of an open-source tool called “EFI Boot Editor”.
EFI Boot Editor is available for Windows, macOS, and Ubuntu Linux. The downloads are targeted towards particular versions of the operating systems so you should download the correct version carefully. In addition, you should always make a backup and boot recovery disk in the case of unwanted outcomes.
In the EFI Boot Editor, we have he options to save the boot manager entries, export the boot manager to a file, import the boot manager from a backup and dump the raw EFI data to a file. It displays the boot manager as well as the various entries for the boot menu.
In the editor, we can change the boot entry’s index number, the description, path and more. For all the entries, you can see the many attributes such as FMP capsule, File capsule, boot to firmware UI, start OS recovery etc. It can also display whether the secure boot is enabled and if vendor keys are installed for the secure boot.
You can download EFI Boot Editor from https://github.com/Neverous/efibooteditor.