How to restore EFI in MacBook Pro Retina 13"?

I've stopped an update of OS X in the middle! Now all I have when I boot the system is the normal beep sound of POST for hardware check.

I've found a link that's been mentioned Apple has released a flash version of firmware update but for mid-2015 macbook 15 inches.

Now I'm stuck I don't have access to anything! I have access to an iMac in case needed.

Could someone lead me to a right direction? How should I restore the firmware?

Solution 1:

Based on the chat we had, where I was able to get more details like:

• You wiped out all partitions on the HDD
• You were getting the -2002F error during Internet Recovery

(Both of these are key pieces of info to put into the original question, by the way. )

Your only option is to reinstall OS X from boot media. You can either take it into an Apple Store and have them reinstall or have someone you know has a Mac download OS X and create a bootable USB for you. See the answer here - different question, but the answer is still the same: reinstall OS X from scratch via boot media.