Windows 10: Add UEFI entries to boot menu

I was wondering if there is any way to add a UEFI option to the bootmgr menu. I am trying to add GRUB to the boot menu; however, since Windows doesn't load anything but Windows in secure boot mode, I can't just load the GRUB file, hence the need to add the UEFI entry. My system is a Lenovo IdeaPad Flex 6 laptop, Windows 10 Home.


Thanks in advance.

:)

 

UEFI boot -- get rid of loads of OS'es (about 7) on boot menu

Well, Every entry on the multiple boot menu, by deleting an entry from BCD or rebuild the BCD should remove the orphan entries and UEFI firmware should reflect what's in the BCD. If for some reason it doesn't then next step is to download Easy UEFI:
Manage EFI/UEFI boot options & Manage EFI System Partitions & Fix EFI/UEFI boot issues the easy way!

Run and delete all the entries except Windows Boot Manager. This will update the NVRAM.

 

Can't disable UEFI boot on HP 250 G3

I got it, I was not accustomed to UEFI (because on HP 4540s I disabled it) and I automatically thought that if I boot from the first menu it will boot in UEFI mode, but I have to go to second menu "Boot From EFI File" to get a list of EFI boot options:



I installed Ubuntu Mate and Windows 8.1 from the first menu (the picture) and they both installed in BIOS mode. Quite simple really.

 

UEFI Boot Menu

If it finds UEFI partition BIOS should show it as Windows UEFI..... otherwise will just show disk as what it's firmware describes it.