Bootgen is a tool that lets you stitch binary files together and generate device boot images. Bootgen defines multiple properties, attributes, and parameters that are input while creating boot images for use in a device.
The secure boot feature for devices uses public and private key cryptographic algorithms. Bootgen provides assignment of specific destination memory addresses and alignment requirements for each partition. It also supports encryption and authentication, described in the Bootgen User Guide (UG1283). More advanced authentication flows and key management options are discussed in the Using HSM Mode section of Bootgen User Guide (UG1283), where Bootgen can output intermediate hash files that can be signed offline using private keys to sign the authentication certificates included in the boot image. The program assembles a boot image by adding header blocks to a list of partitions.
Optionally, each partition can be encrypted and authenticated with Bootgen. The output is a single file that can be directly programmed into the boot flash memory of the system.
Various input files can be generated by the tool to support authentication and encryption as well.
Bootgen comes with both a GUI interface and a command line option. The tool is integrated into the software development toolkit, Integrated Development Environment (IDE), for generating basic boot images using a GUI, but the majority of Bootgen options are command line-driven. Command line options can be scripted. The Bootgen tool is driven by a boot image format (BIF) configuration file, with a file extension of *.bif. Along with SoC, Adaptive SoC, and Bootgen has the ability to encrypt and authenticate partitions for and later FPGAs, as described in FPGA Support. In addition to the supported command and attributes that define the behavior of a Boot Image, there are utilities that help you work with Bootgen. Bootgen code is now available on GitHub.