Comment 10 for bug 1341944

"The current Linux kernel in Ubuntu 14.04 does support booting the 64-bit signed kernel from a 32-bit Grub EFI bootloader. I can confirm this on at least two 32-bit UEFI devices, the ASUS Transformer T100TA and the Acer Aspire Switch 10. Unfortunately, the lack of official 32-bit EFI bootloader support in Ubuntu makes accomplishing this far from trivial and beyond the capacity of many users new to Linux as an alternative to Microsoft Windows."

Are you certain? Collin Watson remarked the other day at a UDS discussion about this issue that it is not possible to boot a 64 bit kernel on a 32 bit uefi since it would not be able to make calls into the 32 bit uefi firmware. Can you provide a syslog of such a boot?