How do you build a Linux Kernel for Android from the AOSP?

I've found that AOSP build.sh dist creates:

• XML files:

  ./out/soong/.intermediates/kernel/configs/q/android-4.19/kernel_config_q_4.19/gen/conditional.xml./out/soong/.intermediates/kernel/configs/q/android-4.19/kernel_config_q_4.19/matrix.xml

  from the kernel config files:

  kernel/configs/q/├── android-4.14│├── android-base-conditional.xml│├── android-base.config│├── Android.bp│├── android-recommended-arm64.config│├── android-recommended-arm.config│├── android-recommended.config│└── android-recommended-x86.config├── android-4.19│├── android-base-conditional.xml... ...

• A whole copy of the Linux kernel directory in:

  out/target/product/sdm660_64/obj/kernel/msm-4.14

This newly-created msm-4.14 includes a .config file which looks like normal kernel configuration.

How can I compile this kernel for aarch64?

When I use make it prompts to regenerate an x86_64 config file, as .config correctly contains Aarch64 settings.

Perhaps I'm trying the wrong thing, but mm in kernel/msm-4.14 ignored changes to kernel configs, and build.sh dist took hours.

I want to be able to change kernel configuration and source code, and build new kernels in just a few minutes, as I can for desktop machines.

How should I do this for Android?