Comment 4 for bug 1519733

Just add this to the ISO root dir: http://pinguyos.com/files/ISO_Boot&EFI.zip

Then edit grub.cfg file with your info. This will allow the iso to boot on 32-bit systems.
The main thing that achieves this is the /EFI/BOOT/bootia32.efi file.

As for the packages in the pool for offline install you will need to edit your builder script to include the packages shown here: http://pastebin.com/jBLtUV0U

You will need different packages for 64-bit and 32-bit ISO's. That snippet of code will automate it the process.

As mentioned in earlier posts on G+, if you want to use a startup.nsh file so EFI only bios (as seen in tablets) work you need to create a file ‘startup.nsh’ in /boot/efi and place the following string in:

64-Bit
Code:
fs0:\EFI\ubuntu\grubx64.efi

32-Bit
Code:
\EFI\custom\grubia32.efi

Its up to you how you want to do that but I do it by making a script that edits /usr/share/ubiquity/apt-setup

I use something like this: http://pastebin.com/AZ0MXe9G

This should be all the info you need to get 32-bit UEFI systems to boot and install. As long as you include these packages in the 32-bit iso (efibootmgr grub-common grub-efi grub-efi-ia32 grub-efi-ia32-bin grub-pc-bin grub-pc grub2-common grub-gfxpayload-lists libefivar0 mokutil secureboot-db). Offline install will work.