Return to index

This guide assumes that you are using the GRUB bootloader directly. If you’re using SeaBIOS, it’s quite intuitive and works similarly to other BIOS software; refer to the documentation on https://seabios.org/SeaBIOS.

This guide explains how to prepare a bootable USB for libreboot systems that can be used to install several Linux distributions. For this guide, you will only need a USB flash drive and the dd utility (it’s installed into all Linux distributions, by default).

These instructions are intended to be generic, applicable to just about any Linux distribution.

If you downloaded your ISO while on an existing Linux system, here is how to create the bootable Linux USB drive:

Connect the USB drive. Check lsblk, to confirm its device name (e.g., /dev/sdX):

lsblk

For this example, let’s assume that our drive’s name is sdb. Make sure that it’s not mounted:

sudo umount /dev/sdb

Overwrite the drive, writing your distro ISO to it with dd. For example, if we are installing Foobarbaz Linux, and it’s located in our Downloads folder, this is the command we would run:

sudo dd if=~/Downloads/foobarbaz.iso of=/dev/sdb bs=8M; sync

That’s it! You should now be able to boot the installer from your USB drive (the instructions for doing so will be given later).

This page on the NetBSD website shows how to create a NetBSD bootable USB drive, from within NetBSD itself. You should the dd method documented there. This will work with any Linux ISO image.

This page on the FreeBSD website shows how to create a bootable USB drive for installing FreeBSD. Use the dd method documented. This will work with any Linux ISO image.

If you downloaded your ISO on a LibertyBSD or OpenBSD system, here is how to create the bootable Linux USB drive:

Connect the USB drive. Run lsblk to determine which drive it is:

lsblk

To confirm that you have the correct drive, use disklabel. For example, if you thought the correct drive were sd3, run this command:

disklabel sd3

Make sure that the device isn’t mounted, with doas; if it is, this command will unmount it:

doas umount /dev/sd3i

The lsblk command told you what device it is. Overwrite the drive, writing the OpenBSD installer to it with dd. Here’s an example:

doas dd if=linux.iso of=/dev/rsdXc bs=1M; sync

That’s it! You should now be able to boot the installer from your USB drive (the instructions for doing so will be given later).

Pick the menu option: Search for GRUB2 configuration on external media

If the distro installer image has a grub.cfg file inside, this menuentry is scripted to find it. This works well for many distros.

Download the Debian or Devuan net installer. You can download the Debian ISO from the Debian homepage, or the Devuan ISO from the Devuan homepage.

Secondly, create a bootable USB drive using the commands in #prepare-the-usb-drive-in-linux.

You can select the option, in the Libreboot GRUB menu, to load GRUB config from external media, and that should work just fine. Alternatively, pick one of the ISOLINUX-related menu options.

Boot it in GRUB using the Parse ISOLINUX config (USB) option. A new menu should appear in GRUB, showing the boot options for that distro; this is a GRUB menu, converted from the usual ISOLINUX menu provided by that distro.

These are generic instructions. They may or may not be correct for your distribution. You must adapt them appropriately, for whatever Linux distribution it is that you are trying to install.

If the ISOLINUX parser or Search for GRUB configuration options won’t work, then press C in GRUB to access the command line, then run the ls command:

ls

Get the device name from the above output (e.g., usb0). Here’s an example:

cat (usb0)/isolinux/isolinux.cfg

Either the output of this command will be the ISOLINUX menuentries for that ISO, or link to other .cfg files (e.g, /isolinux/foo.cfg). For example, if the file found were foo.cfg, you would use this command:

cat (usb0)/isolinux/foo.cg`

And so on, until you find the correct menuentries for ISOLINUX.

For Debian-based distros (e.g., Ubuntu, Devuan), there are typically menuentries listed in /isolinux/txt.cfg or /isolinux/gtk.cfg. For dual-architecture ISO images (i686 and x86_64), there may be separate files directories for each architecture. Just keep searching through the image, until you find the correct ISOLINUX configuration file.

NOTE: Debian 8.6 ISO only lists 32-bit boot options in txt.cfg. This is important, if you want 64-bit booting on your system. Devuan versions based on Debian 8.x may also have the same issue.

Now, look at the ISOLINUX menuentry; it’ll look like this:

kernel /path/to/kernel append PARAMETERS initrd=/path/to/initrd ...

GRUB works similarly; here are some example GRUB commands:

set root='usb0'
linux /path/to/kernel PARAMETERS MAYBE_MORE_PARAMETERS
initrd /path/to/initrd
boot

Note: usb0 may be incorrect. Check the output of the ls command (in GRUB), to see a list of USB devices/partitions. Of course, this will vary from distro to distro. If you did all of that correctly, then it should now be booting your USB drive in the way that you specified.

Most of these issues occur when using libreboot with coreboot’s text-mode with libgfxinit for video initialization. This mode is useful for text mode payloads, like MemTest86+, which expect text-mode, but for Linux distributions it can be problematic when they are trying to switch to a framebuffer, because no mode switching support is present (Linux/BSD kernels do Kernel Mode Setting, so they are able to initialize a frame buffer in bare metal regardless of whatever coreboot is doing).

When using the ROM images that use Coreboot’s text mode, instead of the coreboot framebuffer, while using libgfxinit, booting the Debian or Devuan net installer results in graphical corruption, because it is trying to switch to a framebuffer while no mode switching support is present. Use this kernel parameter on the linux line, when booting it:

fb=false

This forces debian-installer to start in text-mode, instead of trying to switch to a framebuffer.

If selecting text-mode from a GRUB menu created using the ISOLINUX parser, you can press E on the menu entry to add this. Or, if you are booting manually (from GRUB terminal), then just add the parameters.

Markdown file for this page: https://libreboot.org/docs/linux/grub_boot_installer.md

Subscribe to RSS for this site

Site map

This HTML page was generated by the Untitled Static Site Generator.