Microsoft is preparing to significantly increase the number of smartphones supported by its upcoming Windows 10 operating system.
In February, Microsoft kicked off a preview of Windows 10 for smartphones, a major guidepost in the company's journey toward a single OS that encompasses multiple device classes. The downside was that it supported just six Lumia smartphones (Lumia 630, 635, 636, 638, 730 and 830).
Microsoft is now getting ready to massively expand on that list.
A total of 36 Lumia smartphones, including dual-SIM versions, will be supported by the next build, said Microsoft's Gabe Aul, the Data and Fundamentals lead for the company's Operating Systems Group, in a March 27 announcement. The full list, which includes the new budget-minded Lumia 640, is available in this related blog post.
Aul also revealed that Microsoft was working on releasing Windows 10 Preview builds with the same frequency it does for the PC. But first, the software maker needed to widen hardware support with a new feature called "partition stitching."
The technology allows for in-pace OS updates by adjusting the OS partition dynamically, leaving enough room for the installation process to complete successfully. Prior to partition stitching, Microsoft could only target a limited number of devices known to have OS partitions big enough to accommodate the update process. Today, the feature is nearly ready for release.
"The partition stitching feature code came into our main code branch late last week," revealed Aul.
The Storage and Filesystems Team had been working on this in their branch and it passed all of their quality evaluations."
Aul and his team also spent a week testing Windows 10 on individual devices, including his own Lumia 1020, a smartphone aimed at shutterbugs. "This testing will allow us to support A LOT more phones for the next flight," he said. "I get a ton of questions every day on Twitter about when your favorite phones will be usable, and I'm happy to report that the vast majority will be supported with the next flight."
Windows Insiders won't have to wait long to test the OS on their Lumia smartphones. Aul said his team is confident about the partition stitching code and current builds, "but we likely still have at least one more week of engineering to do to ensure we get a great build for the expanded list of devices." Windows Insiders in China without China Mobile Operator support will also soon be able to upgrade to the latest build.
As with any pre-release software, things don't always go according to plan, he cautioned.
"If, during our testing, we find a device specific bug it MAY be pulled from the list," said Aul. As the list evolves over time, other seemingly forgotten models may be added. "If a phone isn't listed here it is likely because we have found such a bug, but it MAY get fixed before the next flight," he added.