It is hard to do something truly different in the smartphone industry. Companies, especially smaller companies, are all working from the same parts bin with the same manufacturing partners. You take your Qualcomm SoC, your Samsung display, and your Sony camera sensor—and you take a flight to China and visit Foxconn, which, in addition to manufacturing, will even do engineering for you if you want. Smartphones are so samey because they have an established, for-hire supply chain that has a certain way of doing things, and it’s much cheaper, faster, and easier if you just “go with the flow” and do what everyone else is doing.
Big companies like Samsung and Apple have enough money, control, and connections to move the supply chain in whatever direction they want. In terms of smaller companies though, there is a single one trying to blaze its own path: Purism, the maker of open source Linux laptops, is building the Librem 5 smartphone. Not only is the OS open source and based on GNU/Linux—not Android—the hardware is open source, too. The core components have open source firmware, and there are even public hardware schematics. This is as close as you’re going to get to a totally open source smartphone.
If you haven’t noticed, open source smartphone hardware is not a thing that existed before now. There have been phones that run open source builds of Android, or other Linux phones like the PinePhone, but those are full of closed-source firmware from non-open components. The usual hardware companies cautiously guard their hardware designs and drivers, and Purism’s hardline stance on open source has ruled out almost the entire established smartphone supply chain. As the company writes in a blog post, “When we first approached hardware manufacturers almost two years ago with this project most of them instantly said ‘No, sorry, impossible, we can not help you’.” Others warned us, that it could never work, that it was too complicated, ‘the industry does not do that,’ and so forth.”
What followed was a long and winding road, but after two years of work, Purism is finally shipping the Librem 5 smartphones to customers. We were able to spend a few days with a device, and it’s definitely one of the most unusual smartphones in recent memory.
The thing to keep in mind here is that Purism has taken on an absolutely gargantuan task. It somehow scraped together a new supply chain of mostly open source components, it came up with a smartphone design from scratch, and it is building its own smartphone distribution of Linux. Two years is not enough time to do this. The OS and app package is not nearly finished, and it lacks basic smartphone functionality. The hardware is nearly finished, but you’ll have a hard time taking advantage of it right now since the power management isn’t really implemented, and support for things like the cameras are non-existent. If you really want open source smartphones to be a thing, though, this is where you need to start. The Librem 5 is a proof of concept.
The hardware: open source at any cost
“Open source at any cost” really feels like the mantra the Librem 5 was made with. That cost is going to be significant, since 1) the need to go out and build its own supply chain means Purism is doing this with zero economies of scale, and 2) the company needs funding to build the OS. Get ready for some sticker shock: the Librem 5 is currently $750. That’s up from the $700 early-bird price it had in 2019, and when the “Evergreen” 1.0 version launches, the price will go up again to $800. This is high-end smartphone money—and remember, you’re not really buying a finished product. The Librem 5 is only for true believers in the idea of an open source smartphone.
About that “Evergreen” name. Purism has been pumping out the Librem 5 in iterative batches that continually try to improve the manufacturing process, but even the earliest units go up for sale. There has already been “Aspen” and “Birch” batches, and we spent most of our time with a “Chestnut” model, which is version 3 in the iterative manufacturing process. After this, there will be a batch called “Dogwood,” and then the most important version, “Evergreen,” which is a mass-production-ready “version 1.0” model. Purism even has a “Fir” version planned with a second-gen CPU planned some time later.
With none of the normal component vendors willing to participate in an open source smartphone, the spec sheet looks very strange. The SoC is an NXP i.MX 8M Quad at 1.5GHz. No one would call this a fast or modern smartphone SoC. It’s a four-core Cortex A53-based chip built on a 28nm process, which is about equal to a high-end smartphone from 2013 or 2014. Purism couldn’t find an open source provider for the cellular modem or Wi-Fi/Bluetooth cards, so those components each sit on socketed M.2 slots, making the inside of the phone look something like a laptop, with removable cards.
The SoC isn’t really a smartphone part ether: the i.MX 8M Quad is originally meant for “Automotive” and “Industrial” uses, and it has a much larger form factor than a typical smartphone chip. The package size is 17 x 17mm, about twice the size of a Snapdragon chip, which is usually around 8.5 x 8.5mm. In addition, smartphone chips usually have the flash memory stacked on top of the SoC—the Librem 5 needs more board space for this, too. All these non-smartphone parts mean the Librem 5 is extra thick: 16mm, or about the size of two high-end smartphones stacked on top of each other.
Other specs include a low-end 5.7-inch 1440 × 720 IPS LCD, 4GB of RAM, 32GB of storage, and, for now, a 2,000mAh battery. Purism says that, when Evergreen launches, the battery will be upgraded to 3,500mAh. The hardware is consumer-friendly, with an easily removable battery, a headphone jack, and a MicroSD card.
Besides the two connectivity cards, the only other non-open source component is a firmware blob that is part of the i.MX 8’s RAM initialization process. RAM is kind of important, so the best Purism could do is quarantine this code and run it on a secondary M4 processor that is part of the i.MX 8. This allows the main A53 cores to only run open source code. A lot of effort was put into this idea of quarantining proprietary code on the Librem 5. The whole reason the Wi-Fi and cellular cards live on M.2 slots is so they can be locked behind two of the three hardware kill switches, which can turn off these two cards along with the Microphone/Camera.
From a distance, this Chestnut model isn’t terrible. It’s a solid-feeling, plastic-backed smartphone with an old-school smartphone design thanks probably to the peel-off plastic back and the absolute brick of a body. Look closer and you’ll see that the Librem 5 does not have the usual fit and finish from a seasoned Chinese smartphone builder, though, and there’s no shortage of nits to pick. There are uneven glue blobs that have squished out from around the display. The earpiece speaker has some of the display glue on it. The front camera is off-center, and there is uneven, visible glue around that, too. One section of the removable back doesn’t connect to the case correctly, so the seam is uneven.
The most frustrating part of the Librem 5 right now is easily the power management, which isn’t nearly complete. The phone is dead nearly all the time, because so many basic charging features we normally take for granted don’t work. First, the phone doesn’t seem like it has any kind of idle power mode. It is hot from the minute you power on until the battery dies, even with the screen off. You can’t leave the phone on the charger overnight to charge it—you’ll wake up to a dead phone. I think what is happening is that there’s no trickle charge, so the phone charges to full, then stops charging, then the battery dies.
It is hard to diagnose anything that is going on because the charging indicator does not work. The battery percentage doesn’t change, the phone will say it’s charging when it’s unplugged, or it will say it’s not charging when it’s plugged in. The battery state seems to get queried at boot-up and then never again. Another diagnosis problem is that, even when the phone is charged, it doesn’t reliably turn on. Lots of times, the power button does nothing, and it takes one or two battery pulls to get the phone to turn on. So every time I want to use it, I need to play the game of “is the battery dead, or is the power on process being erratic?” To top off all these issues, you can’t run the phone off the charger when it’s at zero percent. You have to plug the phone in and give it a half-hour or so of charging before it will turn on.
All of these basic power problems make the Librem 5 a hassle to use. The battery is constantly dead and the phone is never ready for me when I want to use it. It requires babysitting just to charge and keep charged. My solution so far has been to either plan when I want to use the phone and plug it in an hour beforehand or, at some random point in the day, plug it in, set a timer for an hour or so, and then unplug the phone and pull the battery, just so it doesn’t drain to zero.
The good news is that Purism knows the power management isn’t done, and there’s plenty of room for improvement. The company is working on it.
Listing image by Ron Amadeo