Public bug reported: Several Lenovo Yoga laptops do not allow the user to install any current Linux distributions due to being BIOS-locked to a RAID mode and Linux does not support this. You can boot a Linux live environment, but when you go to install, it will not see the Solid State Drive and it does not appear as a PCI device.
The affected models are the Yoga 900 ISK2, 900S, 710S, and 900 ISK for Business, and probably the new Yoga Book and Yoga 910 as well. Lenovo has stated that removing the AHCI option from the BIOS is a feature and that they don't plan to fix this. There have been some blog postings and news articles about this issue lately. Here is the Lenovo Forums topic: https://forums.lenovo.com/t5/Linux-Discussion/Yoga-900-13ISK2-BIOS- update-for-setting-RAID-mode-for-missing/td-p/3339206/highlight/false (Note that this says it is solved, but it is not. Lenovo replied that they won't fix it and that Linux is not supported on these laptops.) Matthew Garrett's blog post is here: https://mjg59.dreamwidth.org/44694.html I approached him with the idea that perhaps the Linux kernel could be modified to reset the hardware and put it into AHCI mode after GRUB loads the kernel (according to him, GRUB doesn't need to be modified because it uses the uEFI firmware's disk access), and then Linux could proceed to boot. Here's what he said: "If you wanted to try that, the best place to do it would be the UEFI setup code in the kernel under arch/x86/boot/compressed/eboot.c - that way you can do it independent of bootloader. Grub's able to read files anyway since it's using the firmware calls to do that. The power management thing isn't about the SSD itself, it's about ensuring that the controller is programmed correctly so that the entire CPU package can enter deep sleep states. Modern systems should idle at around 4W at most, so small amounts make abig difference here." [...] "If the firmware hasn't locked the control bit and if the hardware is ok with suddenly being reconfigured, sure, that ought to work. Doing it in eboot.c means you're doing it before any PCI enumeration has occurred, which makes it more likely that things will work out well." [...] "I'll take a quick look at the 10-series chipset docs to see if it's documented, and if so I'll throw a quick patch together - but I'm probably not going to try pushing it upstream, I'm afraid. If it does work, I'm fine with anybody else doing so." I heaven't heard anything back lately, so I am putting this in a bug report so that the Ubuntu maintainers are aware of the issue. It seems like a few lines of kernel code are all that is really required to fix this and restore the ability of Linux distributions to be installed on half a dozen laptops (probably more to come, since Lenovo says that the industry is moving to this!). ** Affects: linux (Ubuntu) Importance: Undecided Status: Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1627905 Title: Ubuntu can't be installed to certain Lenovo Yoga laptops because the fakeraid storage mode is not supported. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1627905/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
