I'm in the process of unofficial device bringup, and I'm stuck unable to progress due to Android Verified Boot. As per specification Android Verified Boot can be disabled with the --disable-verity and --disable-verification flags. The device I'm working with does not conform to specification and hence is unable to disable Android Verified Boot. One of the solutions is to build a vbmeta image myself which will then be used to verify my custom generated boot image. The question at hand is how to properly generate such an image. The documentation on the topic is exceedingly scarce and looking up similar community made files with a hex editor yields little in terms of information for me. As mentioned here, I should be able to generate one with the avbtool, which I did, very likely wrongly, as it still refuses to even flash it via fastboot. The only way I've found of allowing such a thing is to flash a blank vbmeta image, which in term fails to verify the kernel and fails.