[personal profile] mjg59
Update: Patches to fix this have been posted

There's a story going round that Lenovo have signed an agreement with Microsoft that prevents installing free operating systems. This is sensationalist, untrue and distracts from a genuine problem.

The background is straightforward. Intel platforms allow the storage to be configured in two different ways - "standard" (normal AHCI on SATA systems, normal NVMe on NVMe systems) or "RAID". "RAID" mode is typically just changing the PCI IDs so that the normal drivers won't bind, ensuring that drivers that support the software RAID mode are used. Intel have not submitted any patches to Linux to support the "RAID" mode.

In this specific case, Lenovo's firmware defaults to "RAID" mode and doesn't allow you to change that. Since Linux has no support for the hardware when configured this way, you can't install Linux (distribution installers will boot, but won't find any storage device to install the OS to).

Why would Lenovo do this? I don't know for sure, but it's potentially related to something I've written about before - recent Intel hardware needs special setup for good power management. The storage driver that Microsoft ship doesn't do that setup. The Intel-provided driver does. "RAID" mode prevents the Microsoft driver from binding and forces the user to use the Intel driver, which means they get the correct power management configuration, battery life is better and the machine doesn't melt.

(Why not offer the option to disable it? A user who does would end up with a machine that doesn't boot, and if they managed to figure that out they'd have worse power management. That increases support costs. For a consumer device, why would you want to? The number of people buying these laptops to run anything other than Windows is miniscule)

Things are somewhat obfuscated due to a statement from a Lenovo rep:This system has a Signature Edition of Windows 10 Home installed. It is locked per our agreement with Microsoft. It's unclear what this is meant to mean. Microsoft could be insisting that Signature Edition systems ship in "RAID" mode in order to ensure that users get a good power management experience. Or it could be a misunderstanding regarding UEFI Secure Boot - Microsoft do require that Secure Boot be enabled on all Windows 10 systems, but (a) the user must be able to manage the key database and (b) there are several free operating systems that support UEFI Secure Boot and have appropriate signatures. Neither interpretation indicates that there's a deliberate attempt to prevent users from installing their choice of operating system.

The real problem here is that Intel do very little to ensure that free operating systems work well on their consumer hardware - we still have no information from Intel on how to configure systems to ensure good power management, we have no support for storage devices in "RAID" mode and we have no indication that this is going to get better in future. If Intel had provided that support, this issue would never have occurred. Rather than be angry at Lenovo, let's put pressure on Intel to provide support for their hardware.

Re: Liar.

Date: 2016-09-21 08:03 pm (UTC)
From: [identity profile] snuxoll.id.fedoraproject.org
Yeah, sure. The guy who was employed by Red Hat and worked (and continues to discuss) on getting UEFI secure boot and is fully aware of the ways vendors can "lock out" free operating systems is a shill.

Lenovo made sane (although disagreeable as far as the Linux community is concerned) decisions with regards to supporting a consumer device, Intel has drivers for the RAID mode in their storage controller on Windows and that's what Lenovo ships and supports on the device. Manufacturers not giving a damn about Linux support and using hardware and configurations that isn't supported under anything but Windows at launch is hardly new (remember when Dell launched the updated XPS13 that moved a bunch of stuff to an I2C bus that wasn't supported by the Linux kernel for some time?)

This isn't the first time a "RAID" controller hasn't been supported under Linux, it's been less frequent because most of the time these were in workstation or server gear where there was incentive to provide support for something other than Windows. This is a consumer device, the vast majority of consumers just use Windows on their systems and OEM's have no reason to support anything else 99% of the time. Go yell at Intel and get them to either provide drivers or specifications so someone who wants to can do it.

Re: Liar.

Date: 2016-09-21 10:58 pm (UTC)
From: (Anonymous)
It wasn't even an oversight though, Lenovo had to intentionally modify the BIOS themselves to lock themselves out of the option that allows Intel's hardware to be supported by Linux (as it stands, Intel's RAID controller _does_ support Linux out of the box, BEFORE Lenovo mucked with it and locked everybody out).


Matthew Garrett

About Matthew

Power management, mobile and firmware developer on Linux. Security developer at Google. Ex-biologist. @mjg59 on Twitter. Content here should not be interpreted as the opinion of my employer.

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