Search notes:

/sys/firmware/efi

In this directory, the kernel exposes EFI variables to userspace.
The existence of the /sys/firmware/efi directory means that the kernel has (probably) booted in EFI mode.
In order to have this directory, the kernel needs the parameter CONFIG_EFI_VARS_FS to be set.

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/Linux/fh...', 1759408326, '216.73.216.42', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/Linux/fhs/sys/firmware/efi/index(37): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78