✨ Prusa Buddy / Buddy XL boards

[thinkyhead]

As requested in #28439

Initial support for Prusa Buddy and Prusa Buddy XL boards.

[Copilot]

Pull request overview

Adds initial Marlin board definitions and PlatformIO environments for Prusa’s STM32F407-based Buddy family boards (Buddy Board Mini / xBuddy), integrating them into Marlin’s board/pins selection system.

Changes:

• Added new STM32F4 pins headers for PRUSA_BUDDY and PRUSA_BUDDY_XL, sharing a common pin definition file.
• Registered new board IDs in boards.h and hooked the new boards into pins.h selection.
• Added new PlatformIO environments for building Buddy firmware targets in ini/stm32f4.ini.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Marlin/src/pins/stm32f4/pins_PRUSA_BUDDY.h	Defines Buddy Mini board info and includes shared pin map.
Marlin/src/pins/stm32f4/pins_PRUSA_BUDDY_XL.h	Defines xBuddy board info and includes shared pin map (with override placeholder).
Marlin/src/pins/stm32f4/pins_PRUSA_BUDDY_common.h	Provides the shared pin map for both Buddy variants.
Marlin/src/pins/pins.h	Adds board-to-pins-header include routing for the new boards.
Marlin/src/core/boards.h	Registers new board numeric IDs for Buddy variants.
ini/stm32f4.ini	Adds PlatformIO build environments for Buddy (and Buddy USB media-share variant).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Patronics]

I haven't tested this on either of my relevant printers (a Prusa Mini and a Prusa Core One) yet (I'm a bit hesitant to do so for an AI-generated (or AI-researched, at least, based on your comment on #28439) commit until someone else tries them and confirms it's functional or at least harmless), but a potential issue I see based on the comments of the xBuddy board, it doesn't seem to have the right STM chip assigned for it? The comments (such as https://github.com/MarlinFirmware/Marlin/pull/28443/changes#diff-ec5185ebdac928ccc8ca33f58dafc737a2ab0230f6875bca5d23a04c3e0dbe2eR28 ) suggest it's using the same F407 series chip as the mini, while that seems inaccurate based on the schematic, which indicates the STM32F427ZIT6. I'm also curious why the file's name is Prusa Buddy XL rather than xBuddy as Prusa calls it and as is used on the Prusa Mk4 and Core One (L). And based on Prusa's Open source page the Buddy XL uses a different XLBuddy board, which apparently doesn't yet have an open source schematic? Did you somehow get enough information to accidentally implement the XLBuddy board rather than the xBuddy board?

[ellensp]

This is a first draft... its got things like ETH_PHY_TYPE LAN8742A, which stock Marlin does not know anything about.

[thinkyhead]

I expected a bit of a mess with this first attempt. I didn't clean up the collected research and used a pretty reliable model, but not the most premium by a long stretch. Of course, nothing goes into Marlin without thorough Human correction and review! Let's show this dumb AI how it's done.

[thinkyhead]

Ok, we have successful build now. I put a smarter model (Sonnet 4.6) on this task and told it to iterate until the build succeeded. Sonnet being a smarter model, it should have most things sorted out correctly, but no guarantees! The step of adding supporting files to the buildroot/PlatformIO folder was a new step that will now be formalized in the workflow and associated skills.

I also put this to the test with the AnyCubic Kobra Max and the Duet 2 Maestro. These trials with a lot of different boards should help to further refine and document the complete process of integrating new boards into Marlin. This will all become useful as a reference document for developers that will be posted on the new marlinfw dot org site.