Hi,
I tried to mod by BIOS Acer AN517-52.
I am doing clearME, rebuild for ASUS, and other brand, but I am new in BIOS modding.
I have IDA Pro, and programmer for BIOS, so I am not afraid to brick the BIOS 
I tried to follow this topic Acer VX5-591G Unlock Advanced Tab Bios (Insydeh20 rev. 5.0 bios) - #16 by Lost_N_BIOS
Many thanks to this gut sharing some infos about Insyde BIOS.
So, with IDA I tried to mod the bios following topic above.
In the body region, there is similar structure and different.
Left side is my BIOS, right side is the BIOS in the topic linked.
RED color is similar region, brown is different.
In the right side you can see some blocks colored. These blocks are the ones he indicates to modify for the BIOS of the topic
I tried to follow these step, I did it in my BIOS.
But I have nothing more, nothing less.
I might be wrong by trying to follow the method of this old BIOS.
I attached my BIOS and the picture.
If someone can give me advice to do it ! 
Thanks a lot (and sorry if my English is not so good, I am french)
https://www.mediafire.com/file/vt0ak7y4p86wv5q/BIOS_and_picture.7z/file
You can find this subroutine by locating the lea operand which refers to HII GUIDs of various Form Sets inside BIOS setup.
Many thanks !
I’ll try it, meanwhile it’s seem to be another post can you give me the link ?
Because I can’t see clearly the image
Thanks
I tried to find by understanding your message…
But I don"t see clearly, can you explain me more how to locate it ?
How can you match lea with 'HII GUIDs" ?
Look for last 16 bytes of any form set opcode found inside IFRExtractor output.
Here’s, on the quoted pic, the bytes are in the end, but this is from already modded BIOS. Pick 16 bytes after “0E A7”.
Then search for it in that A01ODM module of BIOS. You should encounter an array, which is called by the target subroutine.
I tried, but I think this is not my level …
Can you please give me the unlocked bios directly if you have a few minutes ?
Thanks in advance
Is this possible for you ?
Currently I’m not open for requests. I just have no opportunity.
Many thanks !
I’ll test it
I’m sorry to say that but I d’ont have more option in the bios 
Download it again. It’s at the link above.
Thhanks, i’ll test
Huge thanks ! Working !!
How did you do this if you want to share
hi, I can only translate very short. I know you have ida. So do as the kitten says. Select 16 bytes after looking for “0E A7” in ida. Skip through the labeled data and it will take you to the critical places.
Hello everybody. I own a goofy Xiaomi Mi Notebook Air 13.3 i5 8250u MX150 1D12. The bios (Insyde) has no advanced options!!! I have read @Sweet_Kitten 's solution to this in a similar topic by replacing a tab by modifying GUID and FormID. But now I found this topic and my Bios editing knowledge is not sufficient to understand this 16bytes mod (@553349149, pls explain lol). Thus I wish for anybody to, please, explain this modification and help me with unlocking advanced tab in my bios.
I am going to attach my backup.
Thank you in advance!!!
Hello.
There is a lock inside BiosRegionLockDxe in Xiaomi Air 13.3. It prevents write acces to bios space.
yes i know i have flockdn and i saw this guide on removing it. i also have a ch341a
Great. Should I also remove flockdn in mod?
If you are able to mod my bios, then I would gladly accept it. Do you, by any chance, know sources from which BIOS/UEFI structure can be studied? I really want to understand how hexidecimal code and variables are stored and structured as well as implemintation of Assembly. (also what registers are and how they are edited). Thank you in advance.