The iPhone 4 (GSM / 2012) comes with a firmware identifier iPhone3,2. It has a Board Configuration of n90bap and a Board Platform of s5l8930x. The CPID and BDID are 35120 and 4 respectively.
IPSWDL.COM is a website that provides download links for IPSW files, which are used to install or restore firmware on Apple devices. These files are sourced directly from Apple's servers.