If by "blank grub loader" you mean that you get a GRUB display that shows no options, then it sounds like you're missing entries in your grub.conf file in /boot/efi/EFI/redhat (that is, the EFI/redhat directory on your first disk). You might be able to get it to work by editing this file manually. Be aware that on EFI installations, Fedora uses GRUB Legacy, not GRUB 2, so follow the instructions for configuring GRUB Legacy when you edit this file.
Another option might be to install another boot loader. I describe several
here. My personal favorite is the Linux kernel's EFI stub boot loader, which is included in the 3.3.0 and later kernels. Since Fedora 17 ships with a suitable kernel, you should be able to get it to work. The trouble is that it requires extra configuration that's usually a bit tricky. The easiest way to get it running is to use my
rEFInd boot manager (or perhaps
gummiboot). In brief, you would:
- Install rEFInd as per its instructions
- Prepare a refind_linux.conf file to hold your boot options, again as described in the rEFInd documentation
- Do one of three things:
- Convert your /boot partition to ext2fs, ext3fs, or ReiserFS and install the appropriate EFI filesystem driver. You can then place refind_linux.conf on /boot and uncomment the "scan_all_linux_kernels" option in refind.conf. When you reboot, rEFInd should then give you options for booting Linux.
- Copy everything from /boot to your ESP (what's currently /boot/efi) and re-mount the ESP as /boot. This effectively gives you a FAT32 /boot partition that the EFI can read. You'll then have to copy refind_linux.conf to /boot and edit refind.conf as just described. When you're done, rEFInd should give you Linux boot options.
- Copy your kernel and initrd files to the ESP, in a subdirectory of EFI (such as EFI/fedora), renaming the kernel so that it ends in .efi. When you reboot, rEFInd should give you Linux boot options. You'll need to manually copy your kernel and initrd every time you upgrade it, though.
Although it may sound complex to set up rEFInd to boot with the EFI stub loader, it's really not that hard, and it's designed to be easy to maintain, particularly if you use a Linux /boot partition that Linux can read (FAT or, though drivers, ext2fs, ext3fs, or ReiserFS).
One more comment: You've referred to your boot device as /dev/md126. This sounds like you may have your motherboard-based RAID support enabled. Such a configuration, particularly if you've got just one hard disk, is an invitation for pain. I see numerous posts from people who have all sorts of problems with such configurations. It's conceivable that your own problem is related to this configuration, but I can't be positive of that. You may want to look into disabling it, but this may involve adjusting some combination of options in your firmware, in Windows, and/or in Linux. You may also need to figure out where on the hard disk the firmware stores RAID settings and wipe that area clean. At the very least, I recommend you do the research to figure out what you've got.