[arch-general] USB flash installation medium in BIOS machines

[Óscar García Amor]

El lun., 2 nov. 2020 a las 10:57, Juergen Werner via arch-general
(<arch-general at archlinux.org>) escribió:

> I tried 2 different USB drives and different USB ports. Am I missing something?

Hi jotz. I tell you a method to have a Live USB that boots directly
from ISO and that can have several ISOs.

Let's assume that your USB is /dev/sdX

1. Partition It:
sudo fdisk /dev/sdX
One DOS partition, press o to new table, n to new partition a enter to
end to pick full disk. Set the partition type with t command to c (W95
FAT32 (LBA)) and use a to activate partition.

2. Format as FAT:
sudo mkfs.fat -F32 -n MULTIBOOT /dev/sdX1

3. Mount it in /usb (or in any site that you like, in my sample I'm using /usb).
sudo mkdir /usb
sudo mount /dev/sdX1 /usb

4. Make a boot dir in USB
sudo mkdir /usb/boot

5. Install GRUB for BIOS and UEFI (First line is for BIOS and second
one for UEFI)
sudo grub-install --target=i386-pc --recheck --boot-directory=/usb/boot /dev/sdX
sudo grub-install --target x86_64-efi --removable
--boot-directory=/usb/boot --efi-directory=/usb

6. Edit grub menu file (/usb/boot/grub/grub.cfg) writ this into it:
insmod all_video
set gfxpayload=keep

submenu "Arch Linux   --->" {
  set isover="2020.11.01"
  set isoarch="x86_64"
  set isofile="/iso/archlinux-${isover}-${isoarch}.iso"
  loopback loop ${isofile}
  menuentry "Arch Linux ${isover} ${isoarch}" {
    echo "Using ${isofile}..."
    probe -u ${root} --set=rootuuid
    linux  (loop)/arch/boot/${isoarch}/vmlinuz-linux
img_dev=/dev/disk/by-uuid/${rootuuid} img_loop=${isofile}
    initrd (loop)/arch/boot/intel-ucode.img
(loop)/arch/boot/amd-ucode.img
(loop)/arch/boot/${isoarch}/initramfs-linux.img
  }
  menuentry "Run Memtest86+ (RAM test)" {
    echo "Using ${isofile}..."
    linux16 (loop)/arch/boot/memtest
  }
}

7. Create a /usb/iso directory and copy archlinux-2020.11.01-x86_64.iso into it.

8. Sync and umount
sync
umount /usb

Reboot and enjoy. If you want more entries for the grub menu or have
other ISOs in your USB you can see my article about it[1] (it's in
Spanish but Google translate makes miracles).

Greetings.

[1]: https://blog.ogarcia.me/crear-un-usb-multiboot/
-- 
Óscar García Amor | ogarcia at moire.org | http://ogarcia.me