I recently got my pi 3B+. I am trying to run centos7 on it. I downloaded http://mirror.centos.org/altarch/7/isos/armhfp/CentOS-Userland-7-armv7hl-Minimal-1708-RaspberryPi3.img.xz (I know its not for Pi 3B+, but its the closest available), extracted and copied the image to an SD card and tried to boot, but was stuck at the rainbow colored display screen. Some reading online made me realize that the start.elf might not be compatible. So i copied all the files, except the kernel.img, from the /boot partition of my Raspbian Stretch Lite (downloaded from https://downloads.raspberrypi.org/raspbian_lite_latest) and replaced the corresponding file versions in my Centos 7 image. Now i am able to boot and it een gives me the login prompt, but my keyboard doesnt seem to work. I am using a standard USB keyboard. Anyone else had any better luck running centos 7 on a pi 3B+ ?
Mine works or ...normal setup copy to sd card .bootberry.img used bootberry to install from SD to microSD ...the booted fine to setup .am using KDE version too ..fast and a little buggy.. but on the most works fine!