HP 8530p HP Business Notebook Computer EFI Guidelines - White paper - Page 4

EFI architecture Caution - The EFI partition is not protected and can therefore be deleted. - Backing up the computer using the Windows® Vista® Complete PC Backup does not back up the EFI partition. For these reasons, HP recommends that you do not place additional data on the EFI partition. Because the partition is not backed up, corruption or failure of the partition will result in loss of all data on the partition, plus loss of EFI functionality. Volume name The volume name is HP_TOOLS. Directories and descriptions The EFI partition file and folder structure are similar to the Windows file and folder structure. EFI application installation should follow the rules established by this white paper. HP EFI application SoftPaqs unbundle into the C:\swsetup directory. The EFI software installation then searches for the FAT32 partition labeled HP_TOOLS and installs itself into the following directory: :\Hewlett-Packard\softwarename For example, Quicklook.efi and its digital signature are placed in the following directory: :\Hewlett-Packard\Quicklook\quicklook.efi If the EFI application installation does not find a partition named HP_TOOLS, the installation fails and an error message is displayed. How BIOS launches EFI applications The launch algorithm of the EFI BIOS application enumerates all FAT32 partitions and launches only the first instance of the application. The application search algorithm searches only the volume labeled HP_TOOLS for the predetermined name and path of the application. When an EFI application is launched, it has as much control of the system resources as the BIOS does. Because EFI applications reside on the public hard drive partition which is easily accessible and therefore insecure, BIOS launches only EFI applications signed by HP. Caution To reduce security vulnerability, execute only HP-signed EFI applications. For HP-signed EFI applications All HP EFI applications contain two files stored on the EFI partition under the same subdirectory as the EFI application: filename.efi and filename.sig. 4