Purism's Librem 5 To Rely On Secondary Processor For Binary Blobs

With not being able to deliver a 100% fully free software / libre system, the Librem 5 smartphone will rely upon a secondary processor for dealing with the necessary binary blobs for hardware initialization to keep them out of touch from the U-Boot boot-loader and Linux kernel.

The first road-block in their effort to make the Librem 5 smartphone as open as possible is the DDR PHY with firmware blobs needed for the DDR4 memory training process at boot time. With it not being realistic for them to rewrite the firmware blob to do the DDR4 PHY training, they are planning to punt the binary-only blobs out to a secondary processor. In doing so, they can also apply for an exclusion with the Free Software Foundation for still having a device that "Respects Your Freedom" while still having necessary binary blobs at play.

The i.MX8 SoC has Cortex-A53 CPU cores but also an M4 ARM core. While the A53 cores will be busy with Linux/U-Boot, they are planning to use the M4 core to handle the memory training. This approach should keep the A53 processor cores "clean" to the Free Software Foundation standards.

It will be interesting to see how they handle the modem support as well among other components with the Librem 5 smartphone, but for now they are just working on the DDR PHY training. They shared the latest details today on the Purism blog.