[CentOS] Centos7 kickstart & pxe

Hello All, 

I'm trying to get kickstart to work through pxe. 
So far I've set up dhcp server, tftp and so on. 
But it seems at some point I always get stuck because the iso file is write-protected. 

I've tried remounting it rw, and I 've dd the iso first, I then get EM not a block device. 

Any help would be appreciated. 

Greetings, J.