Friday, October 18, 2013

C720 News

According to Jay Lee (Author of the Chrubuntu Script), "Ron Minnich has confirmed all the post-Pixel x86 Chrome devices should do SeaBIOS CTRL+L legacy boot."  Reference

Makes one wonder why the pre-Pixel 3rd generation Intel devices haven't been given this ability.  I realize that upgrading the firmware isn't something most people would want to do, but the slot in the C710 firmware was left full of zeros anyway, so ... why not?

15 comments:

  1. I have a first gen Samsung chromebook that can only use linux through crouton so I just want to understand -- does inclusion of Seabios mean that the C720 will boot vanilla Linux usb images without additional hacks? Most of the information I see pertains to getting coreboot on the C710.

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    1. I must apologize. I responded to your question within a couple of hours, but somehow it must've been lost.

      Well, we'll have to wait and see when people actually get their hands on one to be sure, but yes, it should mean exactly that. You'll still have to be in Developer mode, running Dev firmware & press [Ctrl-L] at the scary boot screen, but SeaBIOS should enable you to boot a live USB and install directly to the HDD or rather SSD. Exactly how this will work in the context of Chrome OS's strict GPT partitioning scheme, I don't know.

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  2. What if you were to just wipe chromeos and install linux only? Would that be easier?

    Also, do the newer Chromebooks use hardware that makes it back into the main kernels or do you usually have to hack in support?

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  3. You probably won't have much choice with a 16 GB SSD if you want to run something other than CrOS. But, I don't think it's possible yet to default to Legacy boot, so you'd be stuck with keystroke voodoo to get the device to boot at all.

    I'm not sure what you mean by "newer" but, Linus has been very supportive of Chromebooks, so kernel modules for them have been present since kernel 3.9, but few distros actually support them OOTB. Ubuntu 13.10 still does not, for example. Of course, I can only speak about the C710 here.

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  4. Well I wouldn't mind about the space because with crouton I have about 7 gigs free after install.

    By keystrokes do you mean like pushing ctrl+d or ctrl+l on boot or something more involved? I usually just use sleep mode anyway. I would probably first try Fedora if Ubuntu was not supported, unless all that means is editing a few text files after install.

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  5. Well, Crouton is pretty small compared to most full-blown distros.

    Correct on keystrokes - Ctrl-L would be required for Legacy boot.

    At some point in my trials, the touchpad did in fact work OOTB in Fedora 19-1, but later stopped, I think. But most distros, even with 3.9+ kernels, still require loading the appropriate modules. At least, that's the case with John Lewis's SeaBIOS firmware and I expect Google's build to be very similar.

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  6. So the trackpad is usable but not until the module is loaded? Or there is no module at all?

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  7. In Ubuntu, for example, whatever version, you must update to a 3.9+ kernel that includes the modules. Apparently not all kernels are built with the modules included. Then, you must add the following lines to /etc/modules:

    i2c-i801
    i2c-dev
    chromeos-laptop
    cyapa

    And reboot. Although the details may differ, you'll have to do something similar with most distros. Oh, and in my experience, sleep kills the trackpad. I have to unload chromeos-laptop and re-load it to get the trackpad back.

    In short, I'd have to say that Chromebook hardware is not as ideal for running Linux as we might have hoped. You can get it to work well with a little geek-fu, but if you expect to install Ubuntu and have everything "just work," you're going to be disappointed.

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  8. You think there could be a way to use the chromeos CMT driver for the touchpad? I tried getting it to work in crouton but I got an ABI incompatibilitiy error according to the xorg log. I'm not sure why it wouldn't work when crouton is using the same kernel and I copied over all the libraries. The CMT module seems to have many options the synaptics driver does not.

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  9. I'm not that familiar with Crouton, so I'd suggest asking the developer.

    However, based on the fact that it's a chroot inheriting the Chrome OS kernel, all hardware supported by CrOS should "just work" in Crouton already. So, I'm confused. What's the CrOS CMT module?

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  10. Well I believe this is it, outside of chroot: /usr/lib/xorg/modules/input/cmt_drv.so

    And then the relevant conf files:
    http://pastebin.com/fiXAqT8Z
    http://pastebin.com/47r5Xvw9

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  11. Well I got an Acer c720 and put Fedora 20 beta on it. Everything seems to be working well except for the trackpad like you said. I've been trying to load those modules but it doesn't look like I have the chromeos-laptop module.

    Searching google it seems it's made by this guy? http://vger.kernel.org/~davem/chromebook_pixel_linux.txt

    I tried compiling the module but got some errors.

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    1. That's odd because the trackpad worked on Fedora 19-1 OOTB, even live I think. But, AFAIK you can't simply add the modules, they have to be compiled into the kernel or something like that. And apparently although 3.9+ kernels can support them, few distros are including them in their kernel builds, for some reason. At least that's my understanding of the situation.

      For more info than you'll ever need or want about coreboot with SeaBIOS, consult John Lewis's blog. He probably knows as much as anyone does at this point.

      I assumed from contextual clues that CMT stands for Cyapa Multi-Touch?

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    2. Oh, if you meant that you can manually load all modules except for chromeos-laptop which is "not found", then there's a simple solution that I can't recall ATM. Search the comments under "Pre-built coreboot ... " at John Lewis's blog.

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