isodetect.cfg

## grub2
# REQUIRES GRUB2 >= 1.99 TO RUN!!!
#
# grub-script port of isodetect.lua from Super Grub2 Disk[1]
# by Ximin Luo; I release this into the public domain.
#
# isodetect.lua (Jordan Uggla) is based on listisos.lua, bootiso.lua (JustRon[2])
# All of these are released into the public domain.
#
# [1] http://www.supergrubdisk.org/
# [2] http://ubuntuforums.org/showthread.php?t=1288604
#
# This file can be used in the following ways.
#
# - as a child screen (easier to use)
#   - call `configfile $this_file` with IB_AUTOSCAN=true inside a menuentry.
#   When it is activated, detected isos will be listed in a child screen.
#   The user may press ESC to return to the parent screen.
# - as library functionality (more flexible)
#   - call `configfile $this_file` with IB_AUTOSCAN=false, which will return
#     immediately without creating any menu entries in the child screen.
#   - call `ib_init` immediately, before using anything else from this file
#   - do any customisations such as overriding variables
#   - call `iso_scanall` to perform the autoscan in the parent
#   Detected isos will be listed in the parent, and will appear after other
#   entries that already exist in the parent.

function ib_env_defaults
{
# If this is not set, IB_* variables will be reset to their default values.
# For example, if you override any varibles in the GRUB environment block, you
# should also set this variable in it too, or else the overrides will be reset.
IB_VAR_OVERRIDE=set

# Directory containing ISO images
IB_IMG_DIR=img
# Directory containing linux overrides for an image.
# The override for x.iso should be named x.(something), e.g. x.vmlinuz
IB_OVERRIDE_DIR_LINUX=linux
# Directory containing initrd overrides for an image.
# The override for x.iso should be named x.(something), e.g. x.initrd.gz
IB_OVERRIDE_DIR_INITRD=initrd

# Whether to detect non-standard boot layouts (slower). If not, only detects
# the loopback.cfg standard http://www.supergrubdisk.org/wiki/loopback.cfg
IB_DETECT_NONSTANDARD=yes

# Kernel boot options.
# This is currently an implementation detail and subject to change; see source
# code below for how these are used. Sorry!
IB_KERN_LANG=us
IB_LINUX_SPLASH=""
IB_LINUX_INSTALLER_DEB="keyb=$IB_KERN_LANG debian-installer/language=$IB_KERN_LANG console-setup/layoutcode?=$IB_KERN_LANG"
IB_LINUX_INSTALLER="noeject noprompt nopersistent"
}

###############################################################################

# GRUB script is not that sophistiated; we adopt a few conventions to work
# around the lack of local variables or the ability to capture command output.
#
# lower_underscore = public variable
#   set by a function as its result, intended to be consumed by the caller.
# _UPPER_UNDERSCORE = private constant
#   data private to a function, not meant to be accessed inappropriately.
# _lower_underscore = private variable
#   emulates a local variable for a non-reentrant function by making the name
#   obscure enough that it's unlikely to be clobbered by child functions.

insmod regexp # enable wildcard expansion

# note: loopdev variables are devices *without* the enclosing brackets
# this is because the "loopback" command requires it

function pause # ()
{
	echo "Press any key to return to the main menu..."
	read
}

# find a file by regexp
# output: ib_result_find
function find_file_regexp # (abspath, regexp)
{
	ib_result_find=""
	for f in "$1"/*; do
		if ! [ -f "$f" ]; then continue; fi
		if ! regexp "$2" "$f"; then continue; fi
		ib_result_find="$f"; return 0
	done
	return 1
}

# find a file by wildcard glob
# output: ib_result_find
function find_file_glob # (abspath, glob)
{
	ib_result_find=""
	for f in "$1"/$2; do
		if ! [ -f "$f" ]; then continue; fi
		ib_result_find="$f"; return 0
	done
	return 1
}

function ib_init #
{
	#_IB_ALLOWED_PATTERN='^[a-zA-Z0-9_\-\.]*$'  # bug: doesn't work in grub 1.99
	_IB_ALLOWED_PATTERN='^[a-zA-Z0-9_.-]+$'
	_IB_RGX_MAINNAME='^(.+)\.[^.]*$|^([^.]*)$'
	_IB_RGX_BASENAME='^\([^)]+\)/([^/]+/+)+([^/]+)/*$'
	_IB_RGX_PATHNAME='^(\([^)]+\))(.*)$'

	if [ -z "$IB_VAR_OVERRIDE" ]; then
		ib_env_defaults
		save_env IB_VAR_OVERRIDE
		save_env IB_IMG_DIR IB_OVERRIDE_DIR_INITRD IB_OVERRIDE_DIR_LINUX
		save_env IB_DETECT_NONSTANDARD
		save_env IB_KERN_LANG IB_LINUX_SPLASH IB_LINUX_INSTALLER IB_LINUX_INSTALLER_DEB
	fi
}
load_env
ib_init

# output: ib_result_path
function mainname { regexp -s 1:_1 -s 2:_2 "$_IB_RGX_MAINNAME" "$1"; ib_result_path="$_1$_2"; unset _1; unset _2; }
# output: ib_result_path
function basename { regexp -s 2:ib_result_path "$_IB_RGX_BASENAME" "$1"; }
# output: ib_result_path
function pathname { regexp -s 2:ib_result_path "$_IB_RGX_PATHNAME" "$1"; }
# output: ib_result_path
function devname { regexp -s 1:ib_result_path "$_IB_RGX_PATHNAME" "$1"; }
# Check that filename contains only allowed characters
function allowed_name { regexp "$_IB_ALLOWED_PATTERN" "$1"; }

# Show an error
function error_entry # (abspath, loopdev, message)
{
	menuentry "Unsupported: $1" "$1" "$2" "$3" { shift # needed in grub 1.99
		echo "Error: $3"
		echo ""
		echo -n "The iso file $1 is not supported "
		echo -n "by Super GRUB2 disk. The most likely reason is that the iso is not loop "
		echo -n "bootable. An iso must be specifically designed to read its root "
		echo -n "filesystem from an iso file rather than looking for it in your CDROM "
		echo -n "drive. It is impossible to boot an iso file not specifically designed "
		echo -n "this way with GRUB or any other bootloader."
		echo ""
		echo ""
		echo -n "If you believe that this iso file is loop-bootable it is mounted as "
		echo -n "($2) so you can view its contents in the "
		echo -n "grub shell and try to boot it yourself. If there are any distributions "
		echo -n "that you know are loop bootable but are not currently supported by this "
		echo -n "script please check that you are using the latest version of Super GRUB2 "
		echo -n "Disk then send the commands required to boot the iso to "
		echo -n "supergrub-english@lists.berlios.de so support can be added. Or even " ..
		echo -n "better, convince them to ship a loopback.cfg on their isos:"
		echo ""
		echo ""
		echo "http://www.supergrubdisk.org/wiki/loopback.cfg for more info"
		echo ""
		pause
	}
}

# Add a menu entry for a GNU/Linux live system
function linux_entry # (abspath, loopdev, title, linux, initrd, loopkey, params)
{
	# $linux, $initrd should be paths relative to $loopdev
	# we also check for user overrides for the linux and initrd images
	# $ib_cur_scandir is set by iso_scandir

	_linux_entry__linux=""
	if find_file_glob "$ib_cur_scandir$IB_OVERRIDE_DIR_LINUX" "$2"'.*'; then
		_linux_entry__linux="$ib_result_find"
	elif find_file_glob "($2)" "$4"; then
		_linux_entry__linux="$ib_result_find"
	fi

	_linux_entry__initrd=""
	if find_file_glob "$ib_cur_scandir$IB_OVERRIDE_DIR_INITRD" "$2"'.*'; then
		_linux_entry__initrd="$ib_result_find"
	elif find_file_glob "($2)" "$5"; then
		_linux_entry__initrd="$ib_result_find"
	fi

	if [ -z "$_linux_entry__linux" ]; then
		error_entry "$1" "$2" "cannot find linux image ($2)/$4 or $ib_cur_scandir$IB_OVERRIDE_DIR_LINUX/$2.*"
		return 1
	fi

	if [ -z "$_linux_entry__initrd" ]; then
		error_entry "$1" "$2" "cannot find initrd image ($2)/$5 or $ib_cur_scandir$IB_OVERRIDE_DIR_INITRD/$2.*"
		return 1
	fi

	pathname "$1"
	menuentry "$3" "$ib_result_path" "$_linux_entry__linux" "$_linux_entry__initrd" "$6" "$7" { shift # needed in grub 1.99
		# isoloop=.iso needs to be the last entry, or some stuff (e.g. sysrcd) won't boot
		linux "$2" $5 "$4=$1"
		initrd "$3"
	}
	return 0
}

# Mount the iso file as a loopback device
function mount_iso # (abspath, loopdev)
{
	if ! allowed_name "$2"; then
		menuentry "Error: $1 has unallowed characters" "$2" { shift # needed in grub 1.99
			echo -n "Only alphanumeric characters, periods, underscores, and dashes "
			echo -n "are allowed as part of the filename, for compatibility reasons. "
			echo ""
			echo "The exact regex pattern is: $_IB_ALLOWED_PATTERN"
			echo "The failing string is: $1"
			echo ""
			pause
		}
	elif [ -z "$1" ]; then
		error_entry "$1" "$2" "\$abspath is undefined"
	elif ! [ -f "$1" ]; then
		error_entry "$1" "$2" "Cannot find image file $1"
	else
		if loopback "$2" "$1"; then return 0; fi
		# TODO once it's possible to capture command output, use that instead
		# of generic error message
		error_entry "$1" "$2" "Cannot load ISO: loopback init error"
	fi
	return 1
}

# Detect the live system type and boots it
# Must not be called recursively # TODO (put in a guard for this)
function iso_detect # (abspath)
{
	# Pick a device name that's the same name as the iso
	basename "$1"; mainname "$ib_result_path"; _iso_detect__loopdev="$ib_result_path"
	# Linux shouldn't be passed the grub device name, just the relative path
	pathname "$1"; _iso_detect__relpath="$ib_result_path"
	devname "$1"; _iso_detect__devname="$ib_result_path"

	if ! mount_iso "$1" "$_iso_detect__loopdev"; then return 1; fi

	# Any distro providing a loopback.cfg
	_iso_detect__loopcfg=""
	for path in "/boot/grub/loopback.cfg" "/grub/loopback.cfg"; do
		if [ -f "($_iso_detect__loopdev)$path" ]; then
			_iso_detect__loopcfg="$path"
			break
		fi
	done

	iso_detect_inner "$1" "$_iso_detect__loopdev" "$_iso_detect__relpath" "$_iso_detect__loopcfg" "$_iso_detect__devname"
}

function iso_detect_inner # (abspath, loopdev, relpath, loopcfg, devname)
{
	if [ -n "$4" ]; then
		menuentry "Load: $1" "$2" "$3" "$4" { shift # needed in grub 1.99
			set root="($1)"
			set iso_path="$2"
			export iso_path
			configfile "$3"
		}
		return 0

	elif [ "$IB_DETECT_NONSTANDARD" == "no" ]; then
		error_entry "$1" "$2" "Unsupported ISO type"
		return 1

	# auto-detect section. entries marked #? have not yet been tested

	elif [ -d "($2)/casper" ]; then
		# casper distros, e.g. ubuntu, backtrack
		linux_entry "$1" "$2" "Boot casper: $1" 'casper/vmlinuz' 'casper/initrd*.*z' "iso-scan/filename" "boot=casper $IB_LINUX_INSTALLER $IB_LINUX_SPLASH $IB_LINUX_INSTALLER_DEB"
		return 0

	elif [ -d "($2)/live" ]; then
		# debian-live distros, e.g. TAILS, kali. we want to do this before debian-install because some ISOs have both
		_kern_opts="$IB_LINUX_INSTALLER"
		if [ -f "($2)/live/Tails.module" ]; then
			_kern_opts="config noswap live-media=removable nopersistent noprompt timezone=Etc/UTC block.events_dfl_poll_msecs=1000 nox11autologin"
		elif [ -d "($2)/dists/kali" ]; then
			_kern_opts="username=root noconfig=sudo hostname=kali"
		fi
		linux_entry "$1" "$2" "Boot live-boot: $1" 'live/vmlinuz' 'live/initrd.*' "findiso" "boot=live $_kern_opts $IB_LINUX_SPLASH $IB_LINUX_INSTALLER_DEB"
		return 0

	elif [ -d "($2)/dists" -a -d "($2)/pool" ]; then
		# debian install discs
		# as of this writing, you need to download the "hd-media" initrd override as well as whatever .iso image you're using
		# go to https://www.debian.org/devel/debian-installer/ then "other images" then "hd-media" then "initrd.gz"
		# e.g. (no https) http://ftp.nl.debian.org/debian/dists/testing/main/installer-amd64/current/images/hd-media/initrd.gz
		# e.g. https://mirrors.kernel.org/debian/dists/testing/main/installer-amd64/20170407/images/hd-media/initrd.gz
		# put this in $IB_OVERRIDE_DIR_INITRD/$ISO_NAME.initrd.gz then the below should work automatically
		linux_entry "$1" "$2" "Boot debian: $1" 'install*/vmlinuz*' 'install*/initrd.*' "findiso" "$IB_LINUX_INSTALLER $IB_LINUX_SPLASH $IB_LINUX_INSTALLER_DEB"
		return 0

	elif [ -f "($2)/boot/grub/grubsrcd.cfg" ]; then
		# system rescue cd, version 8+
		probe --set img_dev --fs-uuid "$5"
		set img_dev=/dev/disk/by-uuid/$img_dev
		linux_entry "$1" "$2" "Boot sysrcd: $1" 'sysresccd/boot/x86_64/vmlinuz' 'sysresccd/boot/x86_64/sysresccd.img' "img_loop" "img_dev=$img_dev archisobasedir=sysresccd copytoram"
		return 0

	elif [ -f "($2)/sysrcd.dat" ]; then
		# system rescue cd, older versions
		linux_entry "$1" "$2" "Boot sysrcd: $1" 'isolinux/rescue*' 'isolinux/initram.igz' "isoloop" "root=/dev/ram"
		return 0

	elif [ -d "($2)/KNOPPIX" ]; then
		# KNOPPIX
		linux_entry "$1" "$2" "Boot KNOPPIX: $1" 'boot/isolinux/linux' 'boot/isolinux/minirt.gz' "bootfrom" "BOOT_IMAGE=knoppix"
		return 0

	elif [ -d "($2)/aptosid" ]; then
		# aptosid (was sidux)
		linux_entry "$1" "$2" "Boot aptosid: $1" 'boot/vmlinuz*.*' 'boot/initrd*.*' "fromiso" "boot=fll"
		return 0

	elif [ -d "($2)/slax/boot" ]; then
		# slax 7.0+
		linux_entry "$1" "$2" "Boot slax: $1" 'slax/boot/vmlinuz' 'slax/boot/initrfs.img' "from" "load_ramdisk=1 prompt_ramdisk=0 rw printk.time=0 slax.flags=perch,xmode"
		return 0

	elif [ -d "($2)/slax" ]; then
		# slax
		linux_entry "$1" "$2" "Boot slax: $1" 'boot/vmlinuz' 'boot/initrd.gz' "from" "ramdisk_size=6666 root=/dev/ram0 rw"
		return 0

	elif [ -d "($2)/pmagic" ]; then
		#? pmagic
		linux_entry "$1" "$2" "Boot pmagic: $1" 'pmagic/bzImage' 'pmagic/initramfs' "iso_filename" "edd=off noapic load_ramdisk=1 prompt_ramdisk=0 rw sleep=10 loglevel=0 keymap=$IB_KERN_LANG"
		return 0

	elif [ -f "($2)/boot/tinycore.gz" ]; then
		#? tinycore. isoloop isn't actually used but we need that param to be non-empty
		linux_entry "$1" "$2" "Boot tinycore: $1" 'boot/bzImage' 'boot/tinycore.gz' "isoloop" ""
		return 0

	elif [ -f "($2)/boot/gnumach" ]; then
		#? arch hurd, don't think I ever tested this
		menuentry "Boot Arch Hurd: $1" "$2" { shift # needed in grub 1.99
			set root="($1)"
			multiboot /boot/gnumach root=device:"$1"
			module /hurd/iso9660fs.static --multiboot-command-line='${kernel-command-line}' --host-priv-port='${host-port}' --device-master-port='${device-port}' --exec-server-task='${exec-task}' -T typed '${root}' '$(task-create)' '$(task-resume)'
			module /lib/ld-2.11.90.so /hurd/exec '$(exec-task=task-create)'
		}
		return 0

	elif [ -f "($2)/boot/grub/grub.cfg" ]; then
		if ! find_file_glob "($2)/boot/grub" '*supergrub*'; then continue; fi
		# super grub2 disk
		menuentry "Load SG2D: $1" "$2" { shift # needed in grub 1.99
			set root="($1)"
			configfile "/boot/grub/grub.cfg"
		}
		return 0
	fi

	error_entry "$1" "$2" "Unsupported ISO type"
	return 1
}

function verify_checksum # (iso_dir, sum_file, sum_cmd)
{
	if ! [ -f "$1/$2" ]; then return; fi

	menuentry --class="checksum" "Verify $2 in $1" "$1" "$2" "$3" { shift # needed in grub 1.99
		cat "$1/$2"
		echo "Verifying $1/$2..."
		$3 -k -c "$1/$2" -p "$1"
		pause
	}
}

# output ib_cur_scandir, ib_scan_found_iso
function iso_scandir # (boot_dir/)
{
	ib_cur_scandir="$1"
	for _iso_scandir__iso in "$1$IB_IMG_DIR"/*.iso; do
		if ! [ -e "$_iso_scandir__iso" ]; then continue; fi
		if ! iso_detect "$_iso_scandir__iso"; then continue; fi
		ib_scan_found_iso=true
	done
	verify_checksum "$1$IB_IMG_DIR" MD5SUMS md5sum
	verify_checksum "$1$IB_IMG_DIR" SHA1SUMS sha1sum
	verify_checksum "$1$IB_IMG_DIR" SHA256SUMS sha256sum
	verify_checksum "$1$IB_IMG_DIR" SHA512SUMS sha512sum
}

# Scan all devices
function iso_scanall
{
	echo "Scanning for bootable ISOs in all devices. This may take a while..."
	ib_scan_found_iso=false

	for _iso_scanall__device in (*); do
		for _iso_scanall__path in "$_iso_scanall__device/" "$_iso_scanall__device/boot/"; do
			if ! [ -d "$_iso_scanall__path$IB_IMG_DIR" ]; then continue; fi
			iso_scandir "$_iso_scanall__path"
		done
	done

	if $ib_scan_found_iso; then return 0; fi

	echo -n "Error: No iso files were found in the /$IB_IMG_DIR or /boot/$IB_IMG_DIR directories of "
	echo -n "any device. To search inside different directories, set IB_IMG_DIR. "
	echo ""
	pause
	return 1
}

if [ "$IB_AUTOSCAN" = "true" ]; then
	iso_scanall
fi