Help Booting Kernel-3.8.1 in EFI mode.
 

When bzImage-3.8.1.efi is used as an efistub or with gummiboot it just panics. I think it is not finding a rootfs because
something has changed in the kernel-3.8.1 source. If anyone boots kernel-3.8.1 as a EFISTUB or with GUMMIBOOT, I'd like
to know how you did it (???).

For some unkown reason bzImage-3.8.1.efi fails to read boot options passed to it by the gummiboot-3.8.1.conf, the
efibootmgr with the -u option, typed in a uefi shell or even its own builtin command line.

Here are the results I got when testing kernel-3.8.1 (bzImage-3.8.1.efi) & other EFI configured kernels
with different EFI loaders:
grub2-efi ...Boots: bzImage-3.6.1.efi, bzimage-3.7.1.efi & bzImage-3.8.1.efi
elilo ...Boots: bzImage-3.6.1.efi, bzimage-3.7.1.efi & bzImage-3.8.1.efi
gummiboot ...Boots: bzImage-3.6.1.efi, bzimage-3.7.1.efi
efistub ...Boots: bzImage-3.6.1.efi, bzimage-3.7.1.efi

Here is my efistub cmdline typed in uefi shell:
bzImage-3.8.1.efi root=/dev/sda2 resume=/dev/sda3 ro raid=noautodetect init=/bin/systemd rootfstype=ext4 plymouth.enable=0 init 5

Here is my gummiboot-3.8.1.conf "options" for bzImage-3.8.1.efi:
root=/dev/sdb2 ro resume=/dev/sdb3 vga=791 raid=noautodetect rootfstype=ext4 plymouth.enable=0 init 5

Here is some other info:
distribution ...Fedora-17
init ...systemd
selinux ...permissive mode
initrd ...none
kernel ...bzImage-3.8.1 (Built From Source)
Config_EFI_Partition <y>
Config_FB_EFI <Y>
Config_FrameBuffer_console <Y>
Config_EFI_VARS <Y>
Config_EFI_STUB <Y>
Config_EFI <Y>
Config_CMDLINE_BOOT <Y>
Config_CMDLINE <Y>

This is a very messy area. As someone who had a go and retired in defeat with my samsung & windows 8, go back to the distro kernel if you possibly can.