Grub Run Efi Shell

Grubby in Fedora patches the configuration when a kernel update is performed and will try to not make any other changes than what is necessary. grub2-install shouldn't be used on EFI systems. However, this is not necessary when changing the configuration with YaST, because YaST will automatically run this command. The primary reason for this is the fact that most new. As the tool matured and grew in utility, Intel released it as open source, available on Github. It's different from that in grub version 1. Take a backup of /etc/default/grub configuration file. The commands and the processes are the same as given in the Updating GRUB 2 Configuration File (BIOS) and Updating GRUB 2 Configuration File (UEFI) sections of this article above. We're going to learn how to fix two of the more common failures. It seems GNU/Linux will never be treated with dignity under UEFI. You are not allowed to post comments on this tracker with your current authentication level. efi is correct. The EFI Shell is accessible from an nPartition console when the nPartition is in an active state but has not booted an operating system. I also had a problem with “failed to get canonical path of /cow” errors. Why Grub may break. BIOSのブートオプションでUEFI shellを選択します。このシェル画面で先ほどgrub-installしたefiファイルを実行します。 > fs1: > cd EFI > cd grub > grubx64. If you use Docker, run matchbox according to matchbox with Docker, but mount the grub group example. How to Access Tools through the EFI Shell. GRUB2 has more advanced features than GRUB Legacy. This industry standard is a set of interfaces between the system firmware, the. GRUB needs to learn to read an EFI GUID Partition Table. But, after hunting around, finding a partial solution at community(dot)linuxmint(dot)com, and piecing it together with another piece of information successfully led to using Mint LiveCD to reinstall grub2. UEFI (Unified Extensible Firmware Interface) is a modern version of firmware created as a replacement for BIOS. After this launch the UEFI Shell from the UEFI setup/menu (in ASUS UEFI BIOS, switch to advanced mode, press Exit in the top right corner and choose "Launch EFI shell from filesystem device"). However, we’re left with a new problem: on (at least) Debian and Ubuntu, grub-install attempts to run efibootmgr to record which disk UEFI should boot from. GRUB Installation for CentOS 5 and 6. The goal of this note is to fix the UEFI Boot Manager (located in the NVRAM) for a Debian installation, by using a Debian Live image to mount a broken system via chroot and then reinstall grub-efi. Device, Driver, and Handle Commands — EFI Shell. I like to help others where I can. that ssh/console thing is very odd. 32-bit x86 PC (i386) support for UEFI. How to and what to expect. efi; To use it in practice: Make a efi\grub directory and put grub. In such cases grub-install will print source_dir does not exist. OK, I Understand. Anyway thanks in advance. The first problem that you write in UNIX style. The process I went through to install grub was first mounting the EFI file, then running this # grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=arch_grub command. PCs with Windows 8 and Windows 8. cfg not found when booting from optical disk - put grub. I am now back on the Live CD LM desktop. efi That will boot into the grub2 menu. These blocks always start with the menuentry keyword followed by a title, list of options, and an opening curly bracket, and end with a closing curly bracket. Microsoft started supporting EFI installation of Windows, with the release of 64-bit Windows Vista. Have a dell Optiplex 945 Need help getting into EFI Shell. The current linux loader does not reset the screen text-mode foreground and background colors to their. grub-efi-amd64 grub2/force_efi_extra_removable boolean true. grub2-install shouldn't be used on EFI systems. Grub2 is a powerful boot loader and supports booting most operating systems. formating and partitioning hard disk during install those ESP's as long as the efi file exists and is added to the EFI shell via efibootmgr. This is an SSD, and there is only one, so I'm not sure what it would be called. I need to use Nvidia software for my video editing software and other purposes. It is worthwhile noting that the UEFI can be disabled on many systems to run using the BIOS instead; this is known as running in Legacy Mode. This may be an issue in which case you can also pass the --removable flag which will ignore your --bootloader-id flag and create /BOOT/BOOTX86. EFI files can be opened with EFI Developer Kit and Microsoft EFI Utilities but frankly, unless you're a hardware developer, there's little use in "opening" an EFI file. In order to boot Manjaro, a Linux-capable boot loader such as GRUB, rEFInd or Syslinux needs to be installed to the Master Boot Record (MBR) or the GUID Partition Table (GPT) of the media containing the Operating System. When the EFI based VM or Server is not booting in hard drive, you will get below message or it will be stuck in GRUB. The command to change the GRUB 2 installation device or boot files is grub-install run as root. is there one setup option to do this ? (2) Does the DOS application incorporating the DOS extender run on this environment ? Ex. EFI/BOOT 目录有 grub efi shell文件. However, this is not necessary when changing the configuration with YaST, because YaST will automatically run this command. imgPTN file that you have already created using MakePartImage. cfg entry actually boot windows? I would be surprised if it does as it is not pointing to the EFI partition so would have no idea where the 'bootmgfw. GRUB2 is now the default boot loader in openSUSE, replacing GRUB Legacy (GRUB versions 0. Run Embedded Unified Extensible Firmware Interface (UEFI) Diagnostics first Lenovo Inc. However, blocklists are UNRELIABLE and their use is discouraged… grub2-install: error: will not proceed with blocklists. If someone delete the EFI partition on the system disk by mistake, the Windows will fail to boot. This is working well, but I would like to have the option to. The problem is not with "the disk isn't bootable," because both the Windows UEFI bootstrap and the Grub UEFI bootstrap are bootable. shows the content of drive hd0 (efi. The command to change the GRUB 2 installation device or boot files is grub-install run as root. This makes it possible to. MORE INFO: I have tried looking around in the settings of the MSI Bios, and have tried looking at commands that exist within the EFI. map to learn. No I do not reach grub. It is also the case that some of Intel's firmware upgrade tools now require "efi-shell" to run. nsh file or change the boot order in the EFI shell. Howto Fix Grub. Menuentry Example. I need next step as. If someone delete the EFI partition on the system disk by mistake, the Windows will fail to boot. When everything is unplugged, turn the PC back on and log into Linux. Alternatively, you can place the grubx64. Standard functions (Boot-time and Runtime services) for application development. I'm new to UEFI application development. Try to hit the F2 key when the screen splash for your controller comes up. Note: It is recommended to read and understand the Unified Extensible Firmware Interface, Partitioning#GUID Partition Table and Arch boot process#Under UEFI pages. See if you can manage to boot into Linux, install GRUB 2, load the efivars module and run efibootmgr to place GRUB in the EFI bootlist (since there's no EFI shell in order to be able to do so. 32-bit x86 PC (i386) support for UEFI. Use custom pre-loader (the second one) which hook UEFI file vertification functions (EFI_SECURITY_ARCH_PROTOCOL. 4 specification facilitates secure update. 查找 bios lock 提取. This tutorial shows you how to use efibootmgr with 5 examples. When everything is unplugged, turn the PC back on and log into Linux. Also, an easier way to accomplish what TrevorH wrote above: cp fs0:\EFI\centos\grubx64. With BIOS, quickly press and hold the Shift key, which will bring up the GNU GRUB menu. This does a lot of work, in order to produce a new version of the /x/boot/grub/grub. I'm an happy user of wimboot from grub2 on my usb stick, I can start windows 10 setup, dart even with files withing an iso file. GRUB needs to learn to read an EFI GUID Partition Table. We use cookies for various purposes including analytics. It seems GNU/Linux will never be treated with dignity under UEFI. When I unmounted the partitions and rebooted, the computer entered the Efi shell. 44d0133a-f938-4ccd-ad06-26ba3d2bf870 is the UUID of the partition containing the file /boot/grub/grub. For boot in CSM (msdos) mode grub has to be installed in MBR. efi is correct. Boot from the EFI boot shell (for Ubuntu system, others may be different): efi\ubuntu\grubx64. 9 can be built with Multiboot2 support which GRUB2 2. The GRUB2 menu will show up and you can boot into your system. cfg not found when booting from optical disk - put grub. Therefore, you may run those commands directly to install GRUB, without using grub-install. efi grubx64. The first problem that you write in UNIX style. Reinstalling grub2 on UEFI-based machines: 1. It's different from that in grub version 1. cfg file with the new entry to launch the EFI shell. Trouble booting up. You can use this command to create a disk image, and/or to fix the drives guessed by GRUB when GRUB fails to determine them correctly, like this: grub> device (fd0) /floppy-image grub> device (hd0) /dev/sd0. If you too are unable to boot into Grub and rebooting Windows 10 repeatedly, I am going to present you the simple solution that worked for me. GRUB then loads the signed grub. Run E2B and select the Windows 7 64-bit. These blocks always start with the menuentry keyword followed by a title, list of options, and an opening curly bracket, and end with a closing curly bracket. Support guides. GRUB-x86_64-efi does not install data into the disk MBR, as was the case for legacy GRUB-i386-pc. efi (coppied as: /boot/efi/shellx64. For complete information on GRUB type info grub in a shell window. But Windows should be able to mount the EFI partition and access it using normal Windows commands. It is well structured (very modular), not very large, and 99. In grub2, (hd0,4) means the first harddrive and the 4th partition. UEFI - GRUB Corrupted. cfg is written in GRUB’s built-in scripting language, which has a syntax quite similar to that of GNU Bash and other Bourne shell derivatives. Therefore, you may run those commands directly to install GRUB, without using grub-install. But, there is (inevitably) a way to fix it. Especially I can use the efi shell (one efi binary) to run grub (another efi binary). cfg to activate the changes. 04 and later may designate the 64-bit kernel as vmlinuz. I think some device has nor memory, So user can do programming on this nor memory to do something in firmware level. From what I see in the bios. The GRUB shell is simple by Linux standards, but it's adequate for many emergency maintenance tasks. The process I went through to install grub was first mounting the EFI file, then running this # grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=arch_grub command. efi; To use it in practice: Make a efi\grub directory and put grub. The interactive GRUB shell has its own prompt ("grub>") and its own built-in commands, some with the same names as BASH shell commands. UEFI on the Pi. For CentOS legacy GRUB SuperGRUB works well. Information on Grub from RHEL's Installation Guide. UEFI should be able to boot whatever disk hasn’t failed, and grub-install will write to the RAID mounted at /boot/efi. It has a very peculiar hardware architecture, consisting of a Broadcom VideoCore 4 GPU, which is the primary core on the SoC, combined with one or more ARM CPUs. Among various code snippets and directives, the grub. From here we need to add our GRUB entry to the NVRAM. In Fedora, it is generally safe to edit /boot/grub2/grub. The goal of this note is to fix the UEFI Boot Manager (located in the NVRAM) for a Debian installation, by using a Debian Live image to mount a broken system via chroot and then reinstall grub-efi. efi "Arch_Grub". Secure boot verifies this binary during boot. This does a lot of work, in order to produce a new version of the /x/boot/grub/grub. The Grub config file in the EFI partition grub. Information on Grub from RHEL's Installation Guide. what is the magic in those programs. grub2-install shouldn't be used on EFI systems. @Lost_N_BIO I needed the tool to find the variable offset in the bios file. UUID=0123-ABCD /boot/efi vfat defaults 0 1; Install GRUB2 on the external drive’s EFI System Partition. This will create a GRUB2 boot which refers to sda. For some reason, instead of loading GRUB to boot Arch it gets me to the EFI Shell where I have to run GRUB manually. The GRUB is used to manage and boot up linux operating systems on computers that use the BIOS system. nsh in the root directory of the EFI file system. Without the GRUB boot loader, the installed system will not boot. In Wheezy (Debian 7. Upon exiting this message, another message displayed saying that the installer had crashed. 'bcd' is the menu file for bootmgr similar to grub. As the tool matured and grew in utility, Intel released it as open source, available on Github. The GRUB EFI file always expects its config file to be at ${prefix}/grub. If you want to make extra sure, you can mount the aforementioned EFI partition, and verify that the path to bootmgfw. "GRUB Installation Failed. The syntax is documented on ipxe website. In such cases grub-install will print source_dir does not exist. I was hired by someone to install Arch on their older computer. efi] In other situation where loopback is available (not in ubuntu case here !!! ) simply run in grub grub>loopback loop efi. efi, I found that Shell. cfg, on Linux you can use the sudo blkid command to get this information, then replace it. I am using the Boot Menu firmware of the Thinkpad (accessed by hitting F12 at boot) as my Boot Manager. This works partially, I can now boot but there is directly the EFI/Grub shell> prompt. In order to boot Manjaro, a Linux-capable boot loader such as GRUB, rEFInd or Syslinux needs to be installed to the Master Boot Record (MBR) or the GUID Partition Table (GPT) of the media containing the Operating System. Then, the EFI boot loader will boot it automatically after 5s. Without --target or --directory option, grub-install cannot determine for which firmware to install. So, here's the guide to rescue broken GRUB on UEFI based systems, more precisely if you prefer to boot the operating system in UEFI mode. 44d0133a-f938-4ccd-ad06-26ba3d2bf870 is the UUID of the partition containing the file /boot/grub/grub. Fortunately I had a windows laptop from which I could try and create bootable media. cfg on the ESP in /EFI/fedora/ whereas the grub2-install command creates a custom grubx64. The problem that I've been struggling with is on each system update on Ubuntu, Grub needs to update its kernel variables on its config file, so, it must rewrite everything back to place. Re: Grub2 UEFI boot and serial console output, Matwey V. If the rescue shell had a cat command, you could list the contents of /boot/grub/device. This may be an issue in which case you can also pass the --removable flag which will ignore your --bootloader-id flag and create /BOOT/BOOTX86. com - switch to out of source / subdir build * Wed Jan 30 2013 [email protected] Does your Android grub. which \efi\microsoft\boot\efisys_noprompt. This means Grub 2 has failed to find the grub folder, the grub. efi looks for BOOTX64. The EFI shell can't run after an OS has booted. I made a. efi from redhat 7, and created a menu entry for each OS that I need to install on a UEFI enabled server. The grub2-mkconfig command creates a new grub. efi) source code. UEFI's Advantages UEFI Shell A shell environment for efi applications (i. 下载 Universal-IFR-Extractor. EFI on a Windows system, but on Red Hat Enterprise Linux it’s EFI\REDHAT\SHIM. img had been created with no partitioning ,no need for this "ESP boot pseudo partition") The content of hd0 is as /efi/boot/[bootx64. This library is run first to ensure that the device has enough power to fully boot. I’ve updated the EFI GRUB tarball that I created for my how to install Linux on an Apple Xserve EFI only machine instructions. I need help to make it automatically load GRUB. When everything is unplugged, turn the PC back on and log into Linux. efi, deletes the original installed one, and looks for grub. Edit the GRUB Configuration File. I need next step as. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. (done) GRUB needs to run as an EFI boot loader. Fortunately I had a windows laptop from which I could try and create bootable media. After Uninstalled using os-uninstaller, only Ubuntu os is removed but not the GRUB. The grub2-efi package installs a prebaked grubx64. Windows 7 Forums is the largest help and support community, providing friendly help and advice for Microsoft Windows 7 Computers such as Dell, HP, Acer, Asus or a custom build. conf is not present or has been moved, GRUB cannot display a menu. In addition to bhyveload and grub-bhyve, the bhyve hypervisor can also boot virtual machines using the UEFI userspace firmware. Launching the Recovery Environment from an EFI shell. Grub replaces the windows boot loader with its own file - but you have a choice to make: Either you load Grub in MBR mode and reinstall Windows in that mode, OR you load Grub in a UEFI-aware version of Linux. Pre-boot environment. This tutorial focuses on GRUB legacy. For boot up up in UEFI mode grub has to be installed in the only UEFI boot partition in its own directory, It is your choice to boot up the live system the right way (the same as windows is installed) to get the installer in the right direction. Actual results: Drops to an empty grub menu. Intel released the EFI and UEFI BIOS to the industry as a standard. In Wheezy (Debian 7. 使用 Universal-IFR-Extractor 把setup菜单 转换成 文本. In the following screenshot you can see the boot options: USB-Stick, DVD Drive, UEFI: USB-Stick, UEFI: DVD Drive and UEFI-Shell. No matter what I do, it acts as if the bootloader isn't even there and just boots straight to windows 10. You will also be shown how to boot into Ubuntu. @Lost_N_BIO I needed the tool to find the variable offset in the bios file. abvasili I'm just a volunteer. The EFI specification was made into a general standard known as UEFI. Separate from the above, I can add a boot menu entry with efibootmgr -c -l '\EFI\centos\shimx64. efi' is analogous to grub. I have an Acer Predator 17 that's running a proprietary UEFI BIOS implementation that really doesn't like the grub bootloader. It seems GNU/Linux will never be treated with dignity under UEFI. Shell> grubaa64. What sorts of things might one use Clover's UEFI Shell for? I just opened it up, and it seems very different than bash. We will use the "device" function of the grub-shell to ensure that Grub uses the correct map between the bios drives and linux devices, and also to ensure that Grub uses the hard drive numbers. Is it also possible to use grub to run for example an efi shell? (In theory this should be no problem, but I did not find the correct command to start such a binary. To install the GRUB boot loader in UEFI machines on the first hard-disk and also detect Arch Linux and configure the GRUB boot loader file, run the following commands as illustrated in the following screenshots. If you run the file, and the. This works partially, I can now boot but there is directly the EFI/Grub shell> prompt. shows the content of drive hd0 (efi. I want to know if I can use the. Note: UEFI fast boot may be too fast to give time to press any key. When you boot up your system and it stops at the grub> prompt, that is the full GRUB 2 command shell. Install grub-efi-amd64. Reinstalling GRUB 2 Red Hat Enterprise Linux 7 | Red Hat Customer Portal. To recover GRUB2 on RHEL7 /CentOS 7 with UEFI, you must have the latest DVD or ISO image to boot the system in rescue mode. Launching the Recovery Environment from an EFI shell. I actually tried to run sudo update-grub first before re-installing GRUB, through "detect EFI bootloaders" with live media (perhaps that caused GRUB menu's disappearance?). Legacy boot mode does not support hard drives that provides more than 2TB disk space, and mostly you would like to use UEFI mode for better Windows 10 support. I was hired by someone to install Arch on their older computer. Cisco recommends that you have knowledge of these topics: Using EFI shell on Cisco UCS Server ; Using StorCli tool and it's command syntax, please refer to the command reference guide below. Hi Bjorn, it looks like that F16 has some problem to update NVRAM records in UEFI and doesn't generate the grub configuration file. UEFI will control the system after it is powered on and the operating system is fully loaded. cfg file on the Linux partition. I have the file in the efi partition, but I don't know how to run it. Intel released the EFI and UEFI BIOS to the industry as a standard. Currently I'm in the grub command shell (not rescue) and don't know how to proceed. This article will show you how, when presented with this situation, to manually load your kernel and find out what went awry. However, this is not necessary when changing the configuration with YaST, because YaST will automatically run this command. Note: The above command will permanently hijack the fallback boot loader, which might be undesirable in dual-boot setups. grub efi shell for setup_var. But the UEFI uses DOS style. Grubby in Fedora patches the configuration when a kernel update is performed and will try to not make any other changes than what is necessary. GRUB rescue on UEFI systems. Always run grub2-install before you create the configuration file with grub2-mkconfig. I need to put the option --force to permit to install it. efi image in the ESP, you should be able to use the quit command from the GRUB2 shell or via a stanza in grub. From the EFI shell, I am invoking Grub. The BIOS was trying to boot grub, which was only displaying “GRUB” and then after a few minutes go into broken rescue shell. It's an HP Pavillion which stopped booting; system recovery didn't work. Other Ways to Tweak Grub. if you run into trouble. You cannot have one OS running legacy mode and the other in UEFI mode. In spite of my strict instructions to the installer to install Grub2 in Parsix, Parsix can only be booted by using the Ubuntu 9. ) With UEFI press (perhaps several times) the Escape key to get grub menu. If you run the file, and the. If you just run QEMU with this setup, you will eventually get to the EFI Shell , which is the default behavior of the EDK2 UEFI image when it can't boot anything. Booting from grub shell Posted: 2008-08-13 debian grub When you install grub to debian and forget to run update-grub the first time before you reboot then there is no menu. 2) Boot to it: insert this CD/DVD/USB to Macbook Pro, hold Option key while booting, choose "EFI boot" (that is your bootable installation media), press "e" key to edit the GRUB options of the Arch Linux archiso x86_64 UEFI CD menu entry while it is selected at the main screen, add nomodeset to the end of this line and press Enter. No I do not reach grub. I am able to run Windows with EFI Shell. 使用 uefitool 提取 Setup 菜单. When the EFI based VM or Server is not booting in hard drive, you will get below message or it will be stuck in GRUB. efi file in the same directory as the grub. 可以使用grub efi shell 设置bios隐藏选项. UEFI (Unified Extensible Firmware Interface) is a new industry standard that specifies the different interfaces that a system must provide in a pre-boot environment. This library allows the user to charge their device while the device is in the boot environment (or is perceived as being turned off). After this launch the UEFI Shell from the UEFI setup/menu (in ASUS UEFI BIOS, switch to advanced mode, press Exit in the top right corner and choose "Launch EFI shell from filesystem device"). 32-bit x86 PC (i386) support for UEFI. After several failed attempts to dual-boot Ubuntu 15. I want to do this programmatically inside my application (app. mod module (and other modules which are located in /boot/grub/[arch]/), but it didn’t find your grub. In this tutorial, I'm goging to simulating a UEFI boot in virtualbox and install Arch Linux. Reinstalling grub2 on UEFI-based machines: 1. 0 Shell>"!). [email protected]:~$ sudo fdisk /dev/sdb Welcome to fdisk (util-linux 2. BootOrder: 0000,0003,0004 Boot0000* void_grub Boot0003* CD/DVD Drive Boot0004 EFI Internal Shell See the man page for efibootmgr for more information on the capabilities and use of this program. efi on FAT32 partition). grub2-install shouldn't be used on EFI systems. Run install-grub: this will generate the appropriate core image (using grub-mkimage), put it in the appropriate place on your EFI partition, and add a "debian" entry to the EFI boot manager menu, pointing to that GRUB code image (using efibootmgr). Hopefully someone has an idea of what I should do as I really don't want to run win10. Although you can scan and boot into most of the operating systems installed on computers such as Windows, Linux, FreeBSD and macOS from the AIO Boot's Grub2 menu. cfg for grub2. efi is the the from the --bootloader-id from the grub-install command above. conf is not present or has been moved, GRUB cannot display a menu. If you see the option "void_grub" and it is listed first in BootOrder, then the variables have been successfully updated, and you can try to reboot. The 2 lines below in multiple Linux grub. rpm is not installed : How to resolve ?? Configure proxy server using netsh in windows : How to?? Skip FSCK while boot / fastboot in linux : Quick View PowerPath Powermt Commands - EMC How to increase semaphore value in linux? How to reset HBA and How to find WWNN & WWPN. Open a terminal, then do the following:. It has been sugested elsewhere that this is due a grub error, or a grubx64. efi from EFI Shell (let me know, if you need a help with that). Now you have to run the initrd command to make the initrd image know to the GRUB bootloader. The versions in my test environment are: XEN 4. In this case it will display the GRUB interactive shell, similar to what you get by typing grub at a Linux command line. For CentOS legacy GRUB SuperGRUB works well. rEFInd is a fork of the rEFIt boot manager. 04 LTS Server on a server with a Supermicro X9SCM-F MotherboardWhen updating the BIOS of a Supermicro X9SCM-F motherboard (from BIOS Version 1. If you have a problem when running grub-install with sysfs or procfs and it says you must run modprobe efivars, try Unified Extensible Firmware Interface#Mount efivarfs. I'm familiar with the classic GRUB, but the GPartEd version of GRUB (EFI GRUB, even) is quite different, it seems. In the simplest case, the EFI boot manager selects grub. lst file in /boot/grub so you boot to the grub shell. A 64 bit hardware system can run 32 bit OS and UEFI can be set to look exactly like a BIOS from the time you turn on the machine. After I burned the DVD ISO, I inserted into the Disk drive and rebooted. Afterwards you can use efibootmgr to setup a menu entry (see above). You will need to boot iPXE to grub. The 'grub-efi-amd64-signed' package failed to install into /target/. cfg is written in GRUB’s built-in scripting language, which has a syntax quite similar to that of GNU Bash and other Bourne shell derivatives. Using the GRUB 2 shell. New Windows PCs come with UEFI firmware and Secure Boot enabled. EFI files are boot loader executables, exist on UEFI (Unified Extensible Firmware Interface) based computer systems, and contain data on how the boot process should proceed. After this launch the UEFI Shell from the UEFI setup/menu (in ASUS UEFI BIOS, switch to advanced mode, press Exit in the top right corner and choose "Launch EFI shell from filesystem device"). Super Grub Disk has a variety of open source boot recovery tools. /grub-mkimage -d. efi for looking up in current directory - grub2-cdpath. cfg Os Prober and Grub will re-scan your PC and look for operating systems like before. It has been sugested elsewhere that this is due a grub error, or a grubx64. exe or run the 'QEMU_MENU_TEST (run as admin). Upon booting to the EFI shell, the embedded OS always looks for a file named startup.