I have a Windows 8 Sony Vaio. If I disable Secure Boot and install Linux on a partition, the Bios doesn't work. Period. I've seen that a number of people got it to work for a while by modifying the grub loader and other hackery but then try updating Linux. Why? Buggy UEFI that is not "standards" compliant.
If I try to use UEFI with a Linux distro that supports UEFI, I get a message saying something like "Can't find Windows."
I also have a Sony Vaio and I got UEFI working. The trick is, it is hardcoded to load the bootloader from /EFI/Boot/bootx64.efi - it does not respect the EFI boot menu.
Linux is installing its UEFI bootloader to someplace like /EFI/debian/grubx64.efi. Move that file to /EFI/Boot/bootx64.efi and it will boot GRUB. You can chainload the Windows bootloader from GRUB.
I had a tough time installing Ubuntu on my Vaio Pro 13, but got there in the end. I had to do a lot of messing around to get the shitty UEFI implementation to read Grub. Didn't have to disable SecureBoot or do anything much to Grub, besides a particular boot flat necessary for the SSD.
It took about a day to get it up and running, but I've had no issues at all since.
I have a Sony Vaio for work, and was completely unable to get it to run Linux even with a live USB or CD. My research turned up the issue you've identified--their UEFI software doesn't work right.
I have a Windows 8 Sony Vaio. If I disable Secure Boot and install Linux on a partition, the Bios doesn't work. Period. I've seen that a number of people got it to work for a while by modifying the grub loader and other hackery but then try updating Linux. Why? Buggy UEFI that is not "standards" compliant.
If I try to use UEFI with a Linux distro that supports UEFI, I get a message saying something like "Can't find Windows."