I'm trying to run u-boot on a Pi Zero W, but after powering up, the Pi shows only the rainbow screen.
I used these instruction, but with a different config file,
I also tried the different methods, but had the same result, the rainbow screen.
May be someone knows the right configuration of U-Boot for the Pi Zero W? Or maybe the Pi Zero W isn't supported by U-Boot?
The software version is: buildroot 2017.05 which contains U-boot 2017.03.
I has found out u-boot doesn't support Pi Zero W and u-boot team doesn't have any plans about adding this support. So I decided to fix it and publish u-boot patch to comunity as well.
U-boot supports Pi A+. So if I understand key differences between Pi Zero and Pi A+ (like connection between BCM2835 and SD card, BCM2835 and HDMI and etc.), I will able to do it with less problems.
So right now I have only 2 question:
Is there full schematic of RPi A+ and RPi Zero W?
Or what is the key difference between RPi A+ and RPi Zero W?
I've made a path to support the RPi Zero W. It passed the review, but it was not accepted into master branch. To use it, download and apply:
git apply U-Boot-v2-1-1-add-support-for-Raspberry-Pi-Zero-W.patch
and after type to configure:
I fixed the build problem, you can download a new patch from link above or this one