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[Guide] Lenovo G50-70 and Z50-70 Bios whitelist removal

Joined
Nov 16, 2015
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Lenovo G50-70-Clover
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Lenovo G50-70 , Z40-70 and Z50-70
Bios whitelist removal howto


Disclaimer


This is a DANGEROUS procedure and it may damage your laptop if you make mistakes. It worked for me and some friends so I decided to share it.
Use the informations contained in this document at your own risk, I take no responsibility for any damage.


Prerequisites


If you have a newer bios installed you can downgrade it: in bios setup enable the Bios Back Flash option and flash the required version (9ACN26WW or 9BCN26WW).
Once you have the proper version installed, load the default settings before proceeding. You can adjust some options but DO NOT CHANGE the Graphic Device related options.
From now on I will refer to the G50-70 bios name, if you have a Z50-70 be aware the filename differs.


Backup Bios

Execute Universal Bios Backup as administrator and backup your actual bios. You will get a file called LENOVO-9ACN26WW.rom , it’s your bios image.
Put it in an empty folder we will use as workspace.


Decompile and Modify Bios

Launch PhoenixTool.exe and open your bios image with it.

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Your image is now being extracted, be patient and press OK to the two info popup.
When the extraction process finishes, in the Manufacturer dropdown list choose Lenovo and once done press the Advanced button. In the Options window check the options marked with red in the image

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Press Done. You’ll go back to the previous window where you have now to press Go. Wait until it finishes working and shows you this message:

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DO NOT PRESS OK YET!!!!
Open the workspace folder where LENOVO-9ACN26WW.rom was and you should find the DUMP directory, navigate into it and look for a file named 11D378C2-B472-412F-AD87-1BE4CD8B33A6_xxxx.ROM .
There will be more than one file with the same name except for the _xxxx part,
open the bigger one (7k) with the hex editor.
Disable the autobackup feature in HxD or you'll eventually repack the bios with the .bak file inside, resulting in a wrong (and maybe dangerous) bios to flash.

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We are now going to modify the bios, be sure to edit the proper bytes.
At the offsets 2F9, 322 and 366 you will find the value 74, it represents a conditional jump instruction in assembly, change it to EB which is an unconditional jump instruction. When executed it won’t perform the WWAN and WLAN whitelist checks. The next two images will show you the file before and after the edit:

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if you found the very same values and modified the file as instructed, save the file and close the hex editor.
You can now press OK on the PhoenixTool popup. It will repack your bios and after a while you will find LENOVO-9ACN26WW_SLIC.rom besides the backup one in the workspace folder. This is your whitelist free bios image.


Flash Modified Bios

Rename LENOVO-9ACN26WW_SLIC.rom to bios.bin and copy it in the same folder where fptw64.exe is.
Use the sleep bug to disable bios write protection (optional but sometimes required): close the lid, wait for the laptop sleep, reopen the lid.
Open a CLI window as administrator, navigate to the folder where ftpw64.exe and bios.bin are and type:
Code:
fptw64.exe -f bios.bin -bios
Press Enter and wait until it ends.
Cross your fingers and reboot.
If you did everything properly your Lenovo G50-70 is now whitelist free.
Remember to enable wifi in the bios setup ;)

Now you are ready to install macOS: have a look at this excellent guide by @the-braveknight


Bios Upgrade

Whitelist removal is not permanent. If you upgrade the bios you'll loose the modification.
You can remove the whitelist from newer bios versions using the guide, please be sure to find the very same values at the very same offsets.
Steps to upgrade:
  1. Install desired version (let's say v30)
  2. back it up
  3. mod the backup
  4. install original v26
  5. flash modded v30
You have to be on v26 to flash a modded bios with fptw


Credits

I wish to thank donovan6000 for his excellent guide. Although there are many differences in the bios code it puts me in the right direction.
 
Last edited:
Joined
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[GUIDE] Lenovo G50-70 Bios whitelist removal

Hello,

Thank you for you guide on modifying the bios for the Lenovo g50-70. I am currently running the same bios as the one in the guide.

Could i ask a huge favour from you? Would you mind sending me a copy of the modified bios for me to flash?

Cheers
 
Joined
Nov 16, 2015
Messages
119
Motherboard
Lenovo G50-70-Clover
CPU
i5-4210U
Graphics
HD 4400 1920x1080
Mac
MacBook Air, MacBook Pro
Mobile Phone
Android
[GUIDE] Lenovo G50-70 Bios whitelist removal

You have to modify your own bios backup image.
If you flash someone else's bios you'll clone his laptop because it contains laptop UUID ans SN.
There's no easy way to modify and repack the factory image downloaded from Lenovo because of signature.
Follow the guide and you'll be done. If you have any doubt post here or pm me.
 

RehabMan

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Joined
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Running W10 in Parallels. Cant seem to get Universal Bios Backup Toolkit to work, asks me to run as admin, even when i am running as admin.

Any ideas?
 

RehabMan

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Running W10 in Parallels. Cant seem to get Universal Bios Backup Toolkit to work, asks me to run as admin, even when i am running as admin.

Any ideas?
You cannot backup BIOS in a VM.
 
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Thanks RehabMan, I did a fresh w10 install and created my whitelist bios.

Having trouble in CMD though, I get error 201 when I run

fptw64.exe -f bios.bin -bios

Any ideas?
 
Joined
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Hi daigosx,

Thanks for your guide, I followed it to the letter.

When I open a CLI window as admin I get error 201.

any ideas?
 

RehabMan

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Joined
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Motherboard
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Core i7-2600K
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Hi daigosx,

Thanks for your guide, I followed it to the letter.

When I open a CLI window as admin I get error 201.

any ideas?
Did you run CMD.EXE with elevated privs? Right click on the Windows menu.
 
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