Does the Librem 14 Support M.2 B Key?

Hardware
1

Basically title.

The reason I ask this is because I am attempting to interface a USB 3.0 device directly to M.2 B+M key adapter. In other words, I want to attach a USB 3.0 compatible device into the M.2 port on my Librem 14. This as I understand should be possible because the M.2 B key specification electrically supports a single USB 3.0 connection.

I purchased an adapter from a company that sells an adapter for this purpose. The adapter name is “NU63A-E11”. This is a link to the adapter I purchased: https://www.cm-tech.com.tw/zh-tw/product-642747/USB3-2-Gen1-Type-A-to-M-2-B-plus-M-Gold-Finger-Adapter-NU63A.html

Physically the adapter has no damage. I’ve measured each point with a multimeter & all testable traces are working. Both LEDs light up when power is applied. The USB devices I’ve connect to it to test also work & power on.

Thus I’m lead to believe that the Librem 14 might not support the M.2 B key.

Maybe there’s a firmware component? @MrChromebox

@nicole.faerber

2

Keep in mind that the current version of the Librem 14 comes with a larger 4-cell battery - making it impossible to add a second internal drive.

But the options for a single internal drive include both SATA and NVMe, so it’s likely it would work with your M.2 B+M key.

3

The intention is to remove the main M.2 drive & replace it with the adapter so I can use a diskAshur Pro2 SSD from my old laptop setup.

1 Like
4

While the M.2 specification might say that a B+M keyed socket supports USB, it doesn’t mean those lines are wired on the mainboard itself. From what I recall of the schematics, they are not. Only the M.2-2230 socket (Wifi/BT) has USB wired and enabled.

Why not use one of the existing USB3 ports on the L14?

5

A couple reasons.

  1. It would take up one of the few USB type A ports. I’d prefer to keep them free.

  2. In order to boot off the SSD, the USB port would have to powered even when the laptop is disconnected from wall power. This is not the case. As a result I wouldn’t be able to effectively use the laptop + the iStorage diskAshur while away from a power outlet.

    Whereas, with the SSD connected internally to the M.2 port, I can siphon the (IIRC) 8 or 9v from the battery circuit, solder a wire to an LM7805 voltage regulator that outputs 5v, then connect the 5v output to the M.2 adapter’s 5v input. This would provide constant 5v power from the battery & allow the SSD to be powered even when the laptop is completely shut off & disconnected from wall power.

Do you have any pointers to connecting a USB 3.0 device to the M.2 ports? Anything would be helpful.

As far as I’m aware, end users aren’t able to get access the the stock AMI & EC firmware, so I can’t take the approach I was going to take & add custom support for a M.2 PCI-e USB 3.0 adapter.