Last time we've talked about how to Manually UEFI Boot Linux and Windows 10 USB from Grub, today we'd like to talk about creating a multi-boot usb stick with grub 2.https://ameblo.jp/choibiconsu1973/entry-12632887035.html.

• Grub2 linux iso usb multi boot floppy image. Ag100 2014-03-17. GRUB2 multiboot ISO GRUB2 multiboot ISO 2018 update USB: /boot/grub /boot/iso /boot/image /boot/tc4.
• Currently, it is these 4 lines of commands that one can use as a generic pattern in the GRUB 2's mini-shell, i.e., the loopback-linux-initrd-boot sequence plus some argument(s) passed to the given kernel, for example, to bootstrap as many popular Linux ISO images as possible (in this case is with 3 kernel commandline arguments for System Rescue.

Sometimes we need to create multiple linux distribution installation media or bootable usb stick. However, it is always so annoying to re-flush the usb stick again and again.

However, grub actually enables us to boot most of the linux distributions through loop format or iso image files. The iso image format is known for its original design for CD disks or DVD disks so that the distributions are bootable through your CD-ROM drivers. If the distribution is bootable through the CD-ROM drivers and the CD or DVD media is not writable, which it effectively means that we can actually boot from the non-writable iso image file as well.

The next time you boot your computer, you’ll see the ISO boot entry and you can choose it to boot the ISO file. You may have to hold Shift while booting to see the GRUB menu. If you see an error message or a black screen when you attempt to boot the ISO file, you misconfigured the boot entry somehow.

Since we need to boot multiple ISO image files directly from USB, we do really need a large USB stick. Secondly, we need to use a UEFI compatible system to avoid issues and maximize flexibility. Finally, we need to have a working linux distribution to work on which currently I'm using Ubuntu 18.04.2 demoing this tutorial.

We have created an ext4 filesystem partition named OS-Images for ISO image files because fat32 has a maximum file size limit of 4GB.

We now should create separate directories to mount these two partitions and copy over the ISO image files into OS-Images partition which should look very similar to the following layout.

We need to create a bootx64.efi to make sure the USB is bootable on a UEFI platform. Use the following command to generate a working grub bootloader.

We need to further move the bootx64.efi to ESP/EFI/BOOT directory, backup it in the ESP/backup directory, and create a grub configuration file named grub.cfg.

Afterwards, the ESP partition should look like as following.

In grub.cfg, we can specify multiple menu entries to boot different ISO media files. Taking ubuntu 18.04.2 as an example:

Ubuntu

Redhat

CentOS

SUSE Linux Enterprise

Fedora

Archlinux

Grub Boot Iso Image Downloads

After installing an OS, it is possible that the bootloader is corrupted after some hacking.

Ubuntu Grub Boot Iso Image

We can boot to a live CD using our USB stick and then follow the commands listed below to fix the grub bootloader.