Serial Checksum Generation for Legacy Lenovo Systems

This tool is designed to help restore the original serial number in BIOS for legacy Lenovo systems that have encountered a corrupted BIOS. When a blank BIOS is flashed to revive the system, the serial number is often removed (for privacy reasons), causing an RFID serialization checksum error. This error can result in issues such as invalid Windows licensing.

If you're seeing the error "0188: Invalid RFID Serialization Information Area" on boot, this indicates a failure in the RFID serialization check due to missing or corrupted serialization data. The system will often allow you to continue booting by pressing Esc, but it will not resolve the underlying issue with the missing serial data.

This tool generates the serial number checksum, allowing users to restore their original serial number and resolve these errors.

1. Dump Your BIOS

The BIOS image can be dumped using either:

• A hardware programmer, or
• Intel’s fpt (Flash Programming Tool), if supported by your system.

2. Open the BIOS in a Hex Editor

Open the dumped BIOS file using any hex editor of your choice.

3. Locate the Serial Tag

Search for the string "SER#" — this is displayed in the red box in the reference image.

4. Reference the Image for All Locations

Here’s an image that shows all relevant locations in the BIOS, with color-coded boxes:

The image highlights the locations of the Serial Number, Machine ID, and Checksum in the BIOS dump.

5. Run the Python Script

• Execute the provided Python script.
• When prompted, enter your Machine ID (shown in the green box) and Serial Number (shown in the yellow box).
• These values are typically printed on a sticker on the underside of your laptop.

6. Generate the Checksum

• The script will generate a Hex value and an ASCII string, which represents the new checksum.
• This checksum is used to restore the correct serial number, preventing the RFID serialization checksum error.

7. Modify the BIOS

Once the checksum is generated, you can use it to modify the existing checksum values. This can be done by:

• Replacing the ASCII value (displayed in the blue box) in your hex editor with the new checksum, using either the hex values or ASCII characters.

8. Flash the Modified BIOS

Flash the modified BIOS back to your system using one of the following methods:

• Intel’s fpt tool, if supported and permitted by your system.
• Hardware programmer, such as CH341A, if fpt is not an option.