This document describes how crdyboot is integrated into ChromeOS Flex. Although crdyboot can be built in isolation for ease of development, its intended use is as part of ChromeOS Flex.
The crdyboot ebuild in chromiumos-overlay is used to build the crdyboot executables (one for 64-bit UEFI, one for 32-bit UEFI). In the chroot, it can be built with:
emerge-<board> crdyboot
The executables will be installed under /boot in the board root, and build_image will copy everything under /boot to the EFI system partition.
When building the reven board, crdyboot can be enabled with:
USE=crdyboot build_packages
Image signing handled by scripts in vboot_reference. The sign_uefi.py script has special handling for crdyboot. Each crdyboot file gets the appropriate vbpubk injected into it, then the file is signed in the usual way with sbsign.