Hi Harish,
No problem at all.
Shawn does a great job of discussing a 2.6 build here that might be helpful for you. We already ship the 104, so instead of BOARDDIR, you’d just need BOARDS=ZCU104. We’d encourage you to switch to 2.7 if possible, but I remember you saying before that you had a dependency on 2.6.
Hope this helps a bit.
All the best,
Shane