Hello Ard,<br />KvmTool, Qemu, Xen and CloudHv use the following implementation:<br />PlatformBootManagerLib|ArmPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf<br /><br />Testing:<br />- using kvmtool<br />- not pressing any key during the process<br />I end-up in the boot menu (so not the UEFI shell).<br /><br />When trying with a zero-ed flash.img, kvmtool exits with the following:<br />'PlatformBootManagerUnableToBoot: rebooting after refreshing all boot options'<br />Then the flash is populated and the second attempt reaches the boot menu.<br /><br />With the new PcdUefiShellDefaultBootEnable set to TRUE, we directly reach<br />the UEFI shell.<br /><br />Regards,<br />Pierre