On 28/07/16 17:35, Gunnar Wolf wrote:
I'm far from an absolute expert in this area... But I am fairly certain of what I say — That is, I have a RPi 1 and 2B, and they cannot boot from the same images.
That depends what is in the image.The current raspberry pi firmware works on all pi models (older firmware will only work with older pi models).
The Pi1 needs a specific kernel. The Pi2 and the Pi3 can run the same 32-bit kernel (at least with foundation kernels, I dunno what the situation is with upstream kernels)
The firmware by default selects a suitable kernel (kernel.img or kernel7.img) and device tree (each Pi model has a different one though IIRC they are pretty similar) based on the detected hardware.
There is some experimental 64-bit kernel/bootloader stuff out there for the raspberry pi 3 https://www.raspberrypi.org/forums/viewtopic.php?f=72&t=137963&hilit=aarch64 https://www.raspberrypi.org/forums/viewtopic.php?f=72&t=143765
Userland obviously has to be compatible with the hardware and kernel. Raspbian or Debian armel userlands should be usable on any Pi model. Debian armhf userland should be usable on a pi2 or pi3 but clearly not a pi1. Debian arm64 will obviously require a 64-bit kernel and a pi3.