Post

Using Grub2 and LUA installed on USB booting ISO images

Posted
By Petr Ruzicka
views 6 min read

https://linux-old.xvx.cz/2010/03/using-grub2-and-lua-installed-on-usb-booting-iso-images-2/

I got 16 GB USB flash from my brother, because he can’t see me still using my old 64 MB. He decided to buy Imation Nano Flash Drive.

Because of many of my friends and colleagues are using Win, I use NTFS on it. Old FAT is not “usable” in these days, because it can’t handle bigger files.

From the first time I use USB disks I always want to have bootable disk/flash with live CDs - so here are few notes how to create USB flash drive able to boot stored live CDs:

First you need to compile grub2 yourself, because default grub2 installations in distributions do not have LUA support:

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aptitude install autogen automake bison flex gettext gcc autoconf ruby bzr libfreetype6-dev

Debian way compilation and installation:

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aptitude install dpkg-dev fakeroot
apt-get source grub2
apt-get build-dep grub2
dpkg-source -x grub2_1.98-1.dsc

bzr branch http://bzr.savannah.gnu.org/r/grub-extras/lua ./grub2-1.98/debian/grub-extras/lua

cd grub2-1.98
dpkg-buildpackage -rfakeroot -b

cd ..
dpkg -r grub-pc grub-common
dpkg -i ./grub-common_1.98-1_amd64.deb ./grub-pc_1.98-1_amd64.deb

Compilation and installation from source code (not necessary if you follow “Debian steps” above):

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bzr branch http://bzr.savannah.gnu.org/r/grub/trunk/grub
mkdir ./grub/grub-extras
bzr branch http://bzr.savannah.gnu.org/r/grub-extras/lua ./grub/grub-extras/lua
#bzr branch http://bzr.savannah.gnu.org/r/grub-extras/gpxe ./grub/grub-extras/gpxe

cd grub
export GRUB_CONTRIB=./grub-extras/
./autogen.sh
./configure --prefix=/tmp/grub
make
make install

Mount USB to some directory (in my case /mnt/sdb1) and install grub with Lua support on it:

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mount /dev/sdb1 /mnt/sdb1
grub-install --root-directory=/mnt/sdb1 /dev/sdb

To make grub nicer, I add wallpaper and fonts to it:

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wget --directory-prefix=/tmp/ http://unifoundry.com/unifont-5.1.20080820.pcf.gz
grub-mkfont --output=/mnt/sdb1/boot/grub/unifont.pf2 --range=0x0000-0x0241,0x2190-0x21FF,0x2500-0x259f /tmp/unifont-5.1.20080820.pcf.gz -v -b
wget http://ubuntulife.files.wordpress.com/2007/05/linux.jpg /mnt/sdb1/boot/grub/

Last step is creating right configuration and downloading live iso images of various Linux distributions:

Let’s download the ISOs first. It’s better to use most actual ones. These are working fine for me:

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mkdir -v /mnt/sdb1/isos
wget -c --directory-prefix=/mnt/sdb1/isos \
http://ftp.heanet.ie/pub/linuxmint.com/testing/LinuxMint-8-x64-RC1.iso \
http://gd.tuwien.ac.at/opsys/linux/grml/grml64_2009.10.iso \
http://ftp.cc.uoc.gr/mirrors/linux/slax/SLAX-6.x/slax-6.1.2.iso \
http://downloads.sourceforge.net/project/systemrescuecd/sysresccd-x86/1.5.0/systemrescuecd-x86-1.5.0.iso \
http://releases.ubuntu.com/karmic/ubuntu-9.10-desktop-amd64.iso \
http://xpud.googlecode.com/files/xpud-0.9.2.iso

The following code is taken from Ubuntu Forums where I added more live CDs. I also changed the main grub.cfg a little bit and use 64 live CDs amd64.

Save following text as 3 files:

  • /mnt/sdb1/boot/grub/grub.cfg:

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    insmod vbeinfo
insmod font

if loadfont /boot/grub/unifont.pf2 ; then
  set gfxmode="1024x768x32,800x600x32,640x480x32,1024x768,800x600,640x480"
#  set gfxpayload=keep
  insmod gfxterm
#  insmod vbe
  if terminal_output gfxterm; then true ; else
     terminal gfxterm
  fi
fi

insmod jpeg
if background_image /boot/grub/linux.jpg ; then
  set menu_color_normal=black/black
  set color_highlight=red/blue
else
  set menu_color_normal=cyan/blue
  set menu_color_highlight=white/blue
fi

set default=0
set timeout=10

# Uncomment for a different ISO files search path
#set isofolder="/boot/isos"
#export isofolder

# Uncomment for a different live system language
#set isolangcode="us"
#export isolangcode

source /boot/grub/listisos.lua

  • /mnt/sdb1/boot/grub/bootiso.lua:

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    #!lua

-- Detects the live system type and boots it
function boot_iso (isofile, langcode)
  -- grml
  if (dir_exist ("(loop)/boot/grml64")) then
    boot_linux (
      "(loop)/boot/grml64/linux26",
      "(loop)/boot/grml64/initrd.gz",
      "findiso=" .. isofile .. " apm=power-off quiet boot=live nomce"
    )
  -- Parted Magic
  elseif (dir_exist ("(loop)/pmagic")) then
    boot_linux (
      "(loop)/pmagic/bzImage",
      "(loop)/pmagic/initramfs",
      "iso_filename=" .. isofile ..
        " edd=off noapic load_ramdisk=1 prompt_ramdisk=0 rw" ..
        " sleep=10 loglevel=0 keymap=" .. langcode
    )
  -- Sidux
  elseif (dir_exist ("(loop)/sidux")) then
    boot_linux (
      find_file ("(loop)/boot", "vmlinuz%-.*%-sidux%-.*"),
      find_file ("(loop)/boot", "initrd%.img%-.*%-sidux%-.*"),
      "fromiso=" .. isofile .. " boot=fll quiet"
    )
  -- Slax
  elseif (dir_exist ("(loop)/slax")) then
    boot_linux (
      "(loop)/boot/vmlinuz",
      "(loop)/boot/initrd.gz",
      "from=" .. isofile .. " ramdisk_size=6666 root=/dev/ram0 rw"
    )
  -- SystemRescueCd
  elseif (grub.file_exist ("(loop)/isolinux/rescue64")) then
    boot_linux (
      "(loop)/isolinux/rescue64",
      "(loop)/isolinux/initram.igz",
      "isoloop=" .. isofile .. " docache rootpass=xxxx setkmap=" .. langcode
    )
  -- Tinycore
  elseif (grub.file_exist ("(loop)/boot/tinycore.gz")) then
    boot_linux (
      "(loop)/boot/bzImage",
      "(loop)/boot/tinycore.gz"
    )
  -- Ubuntu and Casper based Distros
  elseif (dir_exist ("(loop)/casper")) then
    boot_linux (
      "(loop)/casper/vmlinuz",
      find_file ("(loop)/casper", "initrd%..z"),
      "boot=casper iso-scan/filename=" .. isofile ..
        " quiet splash noprompt" ..
        " keyb=" .. langcode ..
        " debian-installer/language=" .. langcode ..
        " console-setup/layoutcode?=" .. langcode ..
        " --"
    )
  -- Xpud
  elseif (grub.file_exist ("(loop)/boot/xpud")) then
    boot_linux (
      "(loop)/boot/xpud",
      "(loop)/opt/media"
    )
  else
    print_error ("Unsupported ISO type")
  end
end

-- Help function to show an error
function print_error (msg)
  print ("Error: " .. msg)
  grub.run ("read")
end

-- Help function to search for a file
function find_file (folder, match)
  local filename

  local function enum_file (name)
    if (filename == nil) then
      filename = string.match (name, match)
    end
  end

  grub.enum_file (enum_file, folder)

  if (filename) then
    return folder .. "/" .. filename
  else
    return nil
  end
end

-- Help function to check if a directory exist
function dir_exist (dir)
  return (grub.run("test -d '" .. dir .. "'") == 0)
end

-- Boots a Linux live system
function boot_linux (linux, initrd, params)
  if (linux and grub.file_exist (linux)) then
    if (initrd and grub.file_exist (initrd)) then
      if (params) then
        grub.run ("linux " .. linux .. " " .. params)
      else
        grub.run ("linux " .. linux)
      end
      grub.run ("initrd " .. initrd)
    else
      print_error ("Booting Linux failed: cannot find initrd file '" .. initrd .. "'")
    end
  else
    print_error ("Booting Linux failed: cannot find linux file '" .. initrd .. "'")
  end
end

-- Mounts the iso file
function mount_iso (isofile)
  local result = false

  if (isofile == nil) then
    print_error ("variable 'isofile' is undefined")
  elseif (not grub.file_exist (isofile)) then
    print_error ("Cannot find isofile '" .. isofile .. "'")
  else
    local err_no, err_msg = grub.run ("loopback loop " .. isofile)
    if (err_no ~= 0) then
      print_error ("Cannot load ISO: " .. err_msg)
    else
      result = true
    end
  end

  return result
end

-- Getting the environment parameters
isofile = grub.getenv ("isofile")
langcode = grub.getenv ("isolangcode")
if (langcode == nil) then
  langcode = "us"
end

-- Mounting and booting the live system
if (mount_iso (isofile)) then
  boot_iso (isofile, langcode)
end

  • /mnt/sdb1/boot/grub/listisos.lua:

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    #!lua

isofolder = grub.getenv ("isofolder")
if (isofolder == nil) then
  isofolder = "/isos"
end

function enum_file (name)
  local title = string.match (name, "(.*)%.[iI][sS][oO]")

  if (title) then
    local source = "set isofile=" .. isofolder .. "/" .. name ..
      "\nsource /boot/grub/bootiso.lua"

    grub.add_menu (source, title)
  end
end

grub.enum_file (enum_file, isofolder)

UPDATE: In the new grub versions I had to modify following lines (from source -> lua and one module name vbeinfo -> vbe) otherwise it was not running correctly. Please look at these lines and change it in the scripts above:

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insmod vbe

lua /boot/grub/listisos.lua

      "\nlua /boot/grub/bootiso.lua"

After unmounting your USB flash should be bootable and you should get menu similar to this one:

GRUB2 USB Boot Menu

Enjoy :-)

Linux, Debian
GRUB Lua USB PXE live-CD
This post is licensed under CC BY 4.0 by the author.