The EEPROM on BBBw has board_id flashed. And the BBBw is using this id to identify the variations of hardware and boot into right version. My question is which module (U-BOOT, Kernel) is checking the board_id? Or both are checking the ID.
I assume if U-Boot is checking the id, then I only need to modify the u-boot code to by-pass the id checking, which will lead to Debian (kernel) booting.
Also, I found it is hard to locate the exact version of u-boot source code to download. There are many related sites hosting u-boot source. My current version of u-boot is
U-Boot 2019.04-00002-gb96b20de74 (Jun 25 2019 - 11:39:43 -0500), Build: jenkins-github_Bootloader-Builder-122
Also there are U-Boot overlays. Does the latest source of u-boot include all the overlays, or I have to identify myself what overlays needed and download and flash myself. (it seems to me they are all *.dtbo binary files. I am not clear they are flashed with u-boot or flashed with separate from u-boot.)
Please help me to point the git hub source (web link) for downloading.