dev-embedded/rpi-eeprom Election for Pi4 or Pi5

jlpoole · Guru Joined: 01 Nov 2005 Posts: 483 Location: Salem, OR

I have a Gentoo image from September, 2013, built on the GenPi64 project. I returned to it and was going to update it when I learned of a recent introduction of making an election between Pi 4 and Pi 5 for the package dev-embedded/rpi-eeprom. If this image were just for a single unit, no problem: I select whatever is appropriate.

But here's the rub. I have a Raspberry Pi 5, and several Pi 4s and Zero Pi 2 Ws. What I am hoping to do is have the Pi5 serve as Funtoo-like server where I compile updates and then stage the compiled binaries which the lesser Pis can access and download to the respective platforms and would not have to compile. I have not set up such a system before, e.g. one server compiles everything and then acts as a binary server for the others, but believe Gentoo has a recipe on how to do such which I am about to learn. In the meantime, this update attempt has flagged the issue of making an election and I wonder how making an election would affect the unit as a binary server for other distinct Pis.

Am I going to be able to select "pi5" for my Pi5 unit and select "pi4" for my others (including the Pi Zero 2 W) and then point the non-Pi5s to the Pi5 and pull binaries from the Pi5?

Raspberry Pi Models Compared

Hu · Moderator Joined: 06 Mar 2007 Posts: 21635

With the caveat that I have only read about the pieces in the documentation, and not attempted this, I think what you want is:

Set FEATURES="binpkg-multi-instance" on the Pi5.
Set package.use accordingly on both Pi4 and Pi5 systems.
On the Pi5, build for Pi4 systems: USE=pi4-settings emerge --buildpkgonly dev-embedded/rpi-eeprom.
On the Pi5, build for itself: emerge dev-embedded/rpi-eeprom.
On the Pi4 systems, use emerge --binpkg-respect-use=y --usepkgonly dev-embedded/rpi-eeprom.

Explanation:

This will preserve both the Pi4 build and Pi5 build in the binpkg directory.
This will cause the systems to prefer their own type by default, if not overridden.
This will build a Pi4-compatible package, despite being on the Pi5. It will not be installed, since you don't want to install a Pi4 build on a Pi5 system.
This installs the default (and thus, per step 2, Pi5-compatible) settings on the Pi5 system.
This fetches from the binpkg server, and --binpkg-respect-use=y forces it to grab the Pi4 build.

All this assumes that a Pi5 system can USE=pi4 emerge --buildpkgonly dev-embedded/rpi-eeprom successfully. If building it requires running operations a Pi5 cannot do, then you are stuck.

gentoo_ram · Posted: Wed Mar 13, 2024 5:17 pm Post subject:

I know one major reason why the rpri-eeprom package is different for Pi5 and Pi4: the 'vcgencmd' utility. This utility is used to set and get low-level information in the RPI including the boot loader configs, clock measurements, mode configuration, etc. Different Pi models support different functionality. So it's not just the instruction set differences, it's that the functionality is different on the different devices because the boot loaders on RPI have evolved over time.

I don't have a good answer for you, but realize those utilities (and associated libraries) are different. And, unfortunately, they are all installed in /usr with the same names so they conflict.

Phoenix591 · Guru Joined: 17 Sep 2007 Posts: 487

Hmm, these could actually be dropped here. I've been using my own ebuild for rpi-eeprom that installs all the files and the script is already smart enough to look in the correct directory based on the running system.

jlpoole · Guru Joined: 01 Nov 2005 Posts: 483 Location: Salem, OR

gentoo_ram · Posted: Wed Mar 13, 2024 10:52 pm Post subject:

Phoenix591 · Guru Joined: 17 Sep 2007 Posts: 487

jlpoole · Guru Joined: 01 Nov 2005 Posts: 483 Location: Salem, OR