It's never a comforting scenario when you go to boot up your system and you get the following screen:
- In this article I’ll show you how to restore your bootloader, your grub loader that allows you to switch between Windows and Ubuntu – now the bootloader or the grub loader can disappear for a number of reasons. If you have Ubuntu running on your computer but you decide to install Windows after you install Ubuntu, the Bootloader will be.
- All you need is your original Debian install CD, DVD or USB pendrive. Boot your PC from the installer medium, and select Advanced Options by navigating to it with the arrow keys, then press Enter. From the advanced menu, you will need to start the installer in 'rescuse mode'.
- When you’ve done this, you type the command /sbin/grub-install followed by the location in which you want to install the GRUB stage 1 boot loader. For example, to install GRUB in the MBR of the master IDE drive, you type this command. root@gurkulindia1 /# /sbin/grub-install/dev/hda. The next time you boot the system, the GRUB boot loader.
- We will be using the grub-install.exe that ships with the grub-for-windows zip file. Upon completion of these bootloader instructions, your USB flash drive should be Grub2 bootable from UEFI or BIOS on all computer systems.
'Where's the OS?' one might demand. But don't fret, this may not be the end. There are a number of reasons you could be getting this prompt, but it usually all boils down to the fact that GRUB is unable to see any information on how it should load your kernel and operating system.
Installing Grub2 on USB from Windows. Note: Grub2 for BIOS (i386-pc) can be installed on a exFAT, NTFS, or Fat/Fat32 partition.While Grub2 UEFI (i386-efi/x8664-efi) will only install on a Fat/Fat32 formatted partition. Though you can still chainload and run files from NTFS, exFAT partitions.
What is booting?
In computing, booting (also known as a boot-up) is the initial set of operations that a computer system performs after being turned on. When the machine finishes it's Power-On Self-Test (POST), it will look for instructions on how to actually load your Operating System. In the case of a hard disk (which is most common), it will load the code found in the Master Boot Record (MBR), which will generally locate and load the operating system's 'Boot Loader' into memory. In the case here, the boot loader is GRUB. The boot loader is then responsible for preping and starting the Operating System.
How does it work?
The GRand Unified Bootloader (GRUB) was initially developed as a boot loader for the GNU/Hurd project. There are two versions of GRUB in common use, though GRUB version 2 is now used by most distributions (and will be the focus here). GRUB will check it's configs for the location of the requested kernel and attempt to load (or strap) that image into memory. Once loaded, GRUB will pass parameters (if any) and transfer control to the kernel. The kernel will then load both the default configuration file and any other modules needed.
So how do we fix it when things go wrong?
Manually booting your operating system from GRUB is actually pretty easy once you know what you need to do. Before trying to actually do anything with GRUB, you should examine what GRUB can actually see in your system. For starters, if you can see the GRUB prompt you know that the MBR is intact, and that GRUB has been properly loaded into memory. Great! Now let's poke around and see which disks may be visible to GRUB. You can start by using the ls command:grub> ls
(hd0) (hd0,msdos2) (hd0,msdos1)
All of our partitions are showing up here (yours may look slightly different, depending on how things are partitioned). Since it can see our boot volume, let's actually tell it to use that:grub> root=(hd0,msdos1)
Now we can tell it to load or kernel image. (Just note that you must put in the full filename of the image. You can use TAB completion here to help you, especially if you don't remember the name of the file.)grub> linux /vmlinuz root=/dev/sda2
Next, we need to tell the kernel where it can find it's initialization RAM disk (initrd). Remember to use TAB completion to help you:grub> initrd /initrd.img
Finally, you can go ahead and boot your system!grub> boot
For the most part, you should be done. That wasn't so bad, right? LVM gets a little trickier though, as you will need to activate volume groups and specify logical volumes for root partitions (I may cover this in an update to this article).
Grub Bootloader Usb
This tutorial will show you how to add Clover Bootloader to Grub2 and Grub4dos, simply add a menu to chainload Clover from Grub2 and Grub4dos.Install
On this site, I showed you how to install Clover Bootloader as well as how to install Grub2. In UEFI mode, when you install both of these bootloaders, only one bootloader is booted as default. The /EFI/BOOT/BOOTX64.EFI file will determine that, just keep this file, or back up and copy it back to let the system boot into the bootloader you want. Clover Bootloader currently no longer supports UEFI 32-bit.
Install Grub Bootloader On Usb
AIO Boot supports all of these bootloaders, including Enoch Chameleon, Syslinux and rEFInd. In Legacy mode, just run AIOCreator.exe, then click on Bootloaders to install them.
Add Clover to Grub2
Open the Grub2 configuration file (grub.cfg) and add the following code:
The Grub2 configuration file on Ubuntu, Linux and other Linux distributions is /boot/grub/grub.cfg, see how to add Grub2 menu.
Add Clover to Grub4dos
Install Grub Bootloader Kali
Grub4dos only supports Legacy. Open the Grub4dos configuration file (menu.lst) and add the following code:
Syslinux:
In Legacy mode, Grub2 and Grub4dos will boot Clover using the boot0ss file, you can use boot0af or boot0md, see more about these files here.
You can also boot into Grub2 and rEFInd from Clover Bootloader using UEFI Shell or add an entry to config.plist, see how to add Grub2 and boot Ubuntu and Linux Mint from Clover. Good luck!