multiboot usb

grub.cfg

# grub.cfg
# it lets you boot linux from iso directly
# the files tree is at the end of file
# last modified: 2016-03-07

set timeout=30
set defaut=0
set fallback=1 # what's it?
set pager=1 # what's it?

# setting up the video
if loadfont /boot/grub/font.pf2 ; then
	set gfxmode=auto
	insmod efi_gop
	insmod efi_uga
	insmod gfxterm
	insmod videotest
	insmod videoinfo
	terminal_output gfxterm
fi

# sysrescuecd release: 2016-01-18 
submenu 'System Rescue CD 4.7.1' {
    submenu '64bit' {
        # NOTE
        # It's either me stupid or grub doesn't keep environment 
        # variables when entering menu items. Thus, we need to set 
        # it up for the each item separately instead of globally 
        # setting directories, filenames, architecture, etc. 
        # Sad but truth
        # P.S. please tell me if i'm missing something
        menuentry 'SystemRescueCd (64bit, default boot options)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (64bit, cache all files in memory)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch docache isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (64bit, alternative kernel with default options)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/altker$arch isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (64bit, disable Kernel-Mode-Settings)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch nomodeset isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (64bit, directly start the graphical environment)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch dostartx isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'Boot existing Linux OS installed on the disk (64bit kernel)' {
            set gfxpayload=keep
            set arch=64
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch root=auto isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
    }
    submenu '32bit' {
        menuentry 'SystemRescueCd (32bit, default boot options)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (32bit, cache all files in memory)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch docache isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (32bit, alternative kernel with default options)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/altker$arch isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (32bit, disable Kernel-Mode-Settings)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch nomodeset isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'SystemRescueCd (32bit, directly start the graphical environment)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch dostartx isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
        menuentry 'Boot existing Linux OS installed on the disk (32bit kernel)' {
            set gfxpayload=keep
            set arch=32
            set isodir='/iso/'
            set isofile=$isodir'systemrescuecd-x86-4.7.1.iso'
            loopback loop $isofile
            linux	(loop)/isolinux/rescue$arch root=auto isoloop=$isofile
            initrd	(loop)/isolinux/initram.igz
        }
    }
}

# archlinux release: 2016-03-01
submenu 'Archlinux Installation Live' {
    menuentry 'x86_64 archlinux-2016.03.01-dual.iso' {
        set gfxpayload=keep
        probe -s root_uuid -u $root
        set arch=x86_64
        set isodir='/iso/'
        set isofile=$isodir'archlinux-2016.03.01-dual.iso'
        loopback loop $isofile
        linux  (loop)/arch/boot/$arch/vmlinuz img_dev=/dev/disk/by-uuid/$root_uuid img_loop=$isofile earlymodules=loop
        initrd (loop)/arch/boot/$arch/archiso.img
    }
    menuentry 'i686   archlinux-2016.03.01-dual.iso' {
        set gfxpayload=keep
        probe -s root_uuid -u $root
        set arch=i686
        set isodir='/iso/'
        set isofile=$isodir'archlinux-2016.03.01-dual.iso'
        loopback loop $isofile
        linux  (loop)/arch/boot/$arch/vmlinuz img_dev=/dev/disk/by-uuid/$root_uuid img_loop=$isofile earlymodules=loop
        initrd (loop)/arch/boot/$arch/archiso.img
    }
}

# memtest86+ release: 05-08-2015
menuentry 'memtest86+' {
    set isodir='/iso/'
    linux16 $isodir'memtest86+-5.01.bin'
}

# $ tree
# .
# ├── boot
# │   └── grub
# │       ├── fonts
# │       │   └── unicode.pf2
# │       ├── grub.cfg
# │       ├── grubenv
# │       ├── i386-pc
# │       │   ├── 915resolution.mod
# │       │   ├── acpi.mod
# │       │   ... blah blah blah ...
# │       │   ├── zfsinfo.mod
# │       │   └── zfs.mod
# │       ├── locale
# │       └── themes
# │           └── starfield
# │               ├── blob_w.png
# │               ├── boot_menu_c.png
# │               ├── ...blah blah blah...
# │               ├── terminal_box_w.png
# │               └── theme.txt
# ├── iso
# │   ├── archlinux-2016.03.01-dual.iso
# │   ├── memtest86+-5.01.bin
# │   ├── systemrescuecd-x86-4.7.1.iso
# 
# 9 directories, 310 files