The one I'm using at the moment: https://www.rodsbooks.com/efi-bootloaders/index.html
It is still maintained and updated. It covers most not loaders out there in context of Linux. It is also very practical.
It is still maintained and updated. It covers most not loaders out there in context of Linux. It is also very practical.
The hyperlink on that page to one of my articles should read http://jdebp.eu./FGA/efi-boot-process.html
That is one of several frequently given answers at http://jdebp.eu./FGA/#Boot