Some known information about encryption
Used encryption is not very advanced, not DES or AES :-)
Based on statistical analysis I found that it uses dynamic 256 byte key and XOR operations.
Encrypted part starts at 0x100.
All firmware files also have second part, also encrypted (for GX20 firmware it is located at 0x800000).
Decryption of this part is similar to first part, and is already successfully performed by decryptor.
Encrypted file (GX20 firmware v1.01):
Decrypted firmware file :
Goto Download section to download command-line decryption program.