[Libreboot] Booting from usb/cd without grub graphics

[Bruno Dantas]

> I have two more questions:
> 1) since grub doesn't show up - how can I boot from usb / cd?

Marcel,

Details greatly depend on the distro. Assuming you already have a distro 
installed on your machine, I think this could be your general strategy:

1. On a machine where you can see the grub menu, tinker with a custom entry in 
/boot/grub/grub.cfg until you can successfully boot your usb

2. On your libreboot machine, put that working custom entry in 
/boot/grub/grub.cfg and make it grub's default (either by making it the first 
menuentry or by editing /etc/default/grub as appropriate)

3. Reboot your libreboot machine and it should boot your usb

4. After you are done in the usb and before rebooting, mount the partition 
containing your installed distro and edit /boot/grub/grub.cfg so that your 
installed distro is once again the default

This worked for me for debian 8.5:

menuentry 'Debian usb' {
  linux (usb0)/live/vmlinuz boot=live
  initrd (usb0)/live/initrd.img
}

Configuration for booting some other distros from usb can be found here:
https://wiki.archlinux.org/index.php/Multiboot_USB_drive

-----------------------------

By the way, you don't even have to put the distro on a usb. Just having the iso 
on your hard drive is good enough. This works for me:

menuentry 'Debian iso' {
  set isofile='/home/bruno/Downloads/debian-live-8.3.0-amd64-mate-desktop.iso'
  loopback loop $isofile
  linux (loop)/live/vmlinuz boot=live config fromiso=/dev/sda4/$isofile
  initrd (loop)/live/initrd.img
}

Configurations for booting some other distros from iso can be found here:
http://www.howtogeek.com/196933/how-to-boot-linux-iso-images-directly-from-your-hard-drive/
http://git.marmotte.net/git/glim/tree/grub2