[ TUTORIAL ] Unlock Bootloader MI4C Tanpa Verifikasi Xiaomi

This evening I had the same problem like many of you and I just did not want to wait 2-3 weeks for the unlock code from Xiaomi. I went through a lot of threads and different forums to create this guide.

Requirements
- ADB up and running (I am an Android developer, so I have this installed already - unsure if you need specific ADB drivers for Xiaomi devices though)
- Xiaomi MI4c
- MiFlash: http://bigota.d.miui.com/tools/MiPhone20151028.exe (via http://en.miui.com/a-234.html) - Install
- Mi4c Image: libra_images_6.1.7_20151221.0000.11_5.1_cn_b09dac7 0a0.tgz - unpack until "images" directory is visible!
- [Optional] Mi4c Fastboot Image: miui_MI4c_6.1.21_d1d054460d_5.1.zip
- [Optional] Latest TWRP: http://forum.xda-developers.com/mi-4...p-3-0-t3315059
- [Optional] Latest build of CM 12.1: http://forum.xda-developers.com/mi-4...evice-t3291631

Step-by-step

Step 1 is optional: I was not sure, if I could use the "fastboot oem edl" command in a higher version of MIUI... feedback required. Thus following is a list of known Xiaomi ROMs which support this procedure:
If you are using one of the following ROM versions, you should be able to unlock the device easily with the provided guide. However, I have messages that the versions don't work with higher MIUI ROM versions.

CONFIRMED WORKING
V8.6.9.15 MIUI Dev ROM
V8.0.16.0 MIUI Dev ROM
V7.5.4.0
V7.5.3.0.LXKCNDE
V7.1.4.0.LXKCNCK
V6.1.21 (Download link above)
V6.3.24
V6.3.17
V6.4.21
V6.4.14
V6.5.26
V6.8.25
V6.9.15 (China Dev)

Not confirmed (?)
None

Not working
None

1. (Optional) Downgrade your Mi4c by flashing any image from the list above via the "Updater" app (use top right icon to select image).
2. Reboot into fastboot mode (Power + Vol Down) until you see the MIUI rabbit and "FASTBOOT"
3. Command: fastboot oem edl (this brings your device in a kind of emergency recovery state) -> the device does only show a black screen. Do the next step.
4. Use MiFlash to flash 6.1.7 image (Browse -> select the "images" directory of the 6.1.7 package and start flashing)
5. When completed, reboot the phone by holding the Power button long (~8s)
6. Wait until 6.1.7 is completely loaded (this may take a while)
7. Reboot into fastboot mode (Power + Vol Down)
8. Command: fastboot oem unlock -> at this point you should have an unlocked bootloader
9. Now optionally install TWRP and subsequently CM 12.1 and enjoy (see respective linkes in the requirements for a howto) - TWRP: fastboot flash recovery <twrp>.img

With this post, I want to say thank you to all the developers who take their time to port Cyanogen to exotic Android devices. You are heroes!

In case you want to donate him something: https://paypal.me/wolkenjaeger