How to succeed to compile an older Dev branch kernel

Hello

After spending hours of trying to create an older DEV kernel (5.1.21) here are the following steps in order that it will work.

I will describle here about the 5.1.21 kernel but I think it can work for any kernel.

1. create lib.config file under build/userpatches with the following: KERNELBRANCH='branch:orange-pi-5.1'

2. And this is what create the magic:

download the Armbian files that matches that distribution and replace all the files in the build directory:

for example I have downloaded from here - This link is the build version from the branch of the 5.1.:

https://github.com/FireflyTeam/armbian-build/tree/e79c54c73b04ca1354a189477374bd02113553b5

replace all the files in the build folder and build your kernel for example:

BOARD=bananapim64 BRANCH=dev RELEASE=bionic BUILD_DESKTOP=no KERNEL_ONLY=no KERNEL_CONFIGURE=no (CREATE_PATCHES=yes/no depends on your needs)

And now the compiler finish the build without any issue and create a working image.

It could be that not all the files that I have described in section "2" are needed, but lack of support, answers  and directions I have no idea which are the files that are needed, so replaced them all.

Tested and working.

NOTE: Without downloading the matching build environment the process fail and no working image is created, although it create an image but the image fail to load, also it doesnt create the "dtb"  package.

Good Luck.