Yocto is often seen as fairly complex, and at Bootlin we believe one reason for this perception is the unnecessary complexity of the BSP layers provided by silicon or board vendors, each of which often includes highly custom logic that isn’t needed. That’s why, back in 2023, we released meta-kiss, an example layer demonstrating how simple it can be to support various hardware platforms with Yocto, without relying on any vendor-provided BSP layer.

Since then, we’ve kept this layer up-to-date and added several new features. In this blog post, we’d like to highlight recent significant updates: an upgrade to Yocto Scarthgap, support for the i.MX93 FRDM platform, and the ability to build OP-TEE for the previously supported STM32MP1 platform.

Update to support Yocto Scarthgap

While the initial release of meta-kiss was designed to be used with Yocto Kirkstone, this LTS release will reach its end of life in April next year. So it was about time to switch to the current Yocto LTS: Scarthgap, supported until April 2028.

The Linux kernel and U-Boot were not forgotten in the process, and both were updated to their latest available releases: Linux to v6.16, and U-Boot to 2025.07.

A new board: NXP i.MX93 FRDM

The biggest news is most certainly the addition of a new board Yocto machine: the freiheit93. This machine adds support for the NXP FRDM i.MX93 Development Board, featuring the SoC of the same name, dual gigabit Ethernet, USB, and much more.

As usual, our meta-kiss implements this support in the simplest possible way: no dependency on vendor layers, just core layers, meta-arm and voilà!

In terms of features, here’s what we already have today:

• Booting from either the SD card, internal eMMC, or USB serial download. The latter can be used with either uuu or Snagboot.
• Support for both Ethernet and USB.
• All security firmwares included: TF-A, OP-TEE, and i.MX EdgeLock Secure Enclave (ELE) firmware.
• All of the Linux kernel, U-Boot, TF-A and OP-TEE use upstream projects with minor patches for changes being upstreamed.

OP-TEE support on STM32MP1

The Stompduck machine, implementing support for the STM32MP157A Discovery Kit, also got some updates, as Bootlin engineer Köry added OP-TEE support. This extends the possibilities of the Stompduck board with new security features.

Conclusion

Whatever the board, the feature or the Yocto version, the main point of meta-kiss remains the same: keep it simple!. It aims at providing a realistic example of a Yocto setup without unnecessary complications. Give it a try!, and if you want to learn more about Yocto, check out our Yocto training course!