Arch Linux

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

On my system, with 3.17-rc5 and without a kernel parameter related to audio:

~: cat /proc/asound/cards
 0 [HDMI           ]: HDA-Intel - HDA Intel HDMI
                      HDA Intel HDMI at 0xe0510000 irq 45
 1 [PCH            ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xe0514000 irq 44

With the kernel parameter "snd_hda_intel.index=1"

~: cat /proc/asound/cards
 0 [PCH            ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xe0514000 irq 44
 1 [HDMI           ]: HDA-Intel - HDA Intel HDMI
                      HDA Intel HDMI at 0xe0510000 irq 45

In this case, the kernel parameter moved the "HDA Intel PCH" device to sound card 0, which enables sound on the laptop speakers. dhead and SolarBoyMatt, does this match what you are seeing?

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

I tried to understand where the following error message during boot coming from

kernel: usb 1-4: string descriptor 0 malformed (err = -61), defaulting to 0x0409

It seems to me it's related to the bluetooth adapter

# lsusb -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/8p, 480M
    |__ Port 3: Dev 2, If 0, Class=Video, Driver=uvcvideo, 480M
    |__ Port 3: Dev 2, If 1, Class=Video, Driver=uvcvideo, 480M
    |__ Port 4: Dev 3, If 0, Class=Wireless, Driver=btusb, 12M
    |__ Port 4: Dev 3, If 1, Class=Wireless, Driver=btusb, 12M
    |__ Port 5: Dev 4, If 0, Class=Human Interface Device, Driver=usbhid, 12M
    |__ Port 5: Dev 4, If 1, Class=Human Interface Device, Driver=usbhid, 12M
    |__ Port 5: Dev 4, If 2, Class=Human Interface Device, Driver=usbhid, 12M

I disabled and enabled the device but didn't received the error message again

# echo '1-4' > /sys/bus/usb/drivers/usb/unbind
# echo '1-4' > /sys/bus/usb/drivers/usb/bind

Looking in bluetooth.service log I see the following errors.

bluetoothd[9539]: Sap driver initialization failed.
bluetoothd[9539]: sap-server: Operation not permitted (1)
bluetoothd[9539]: Failed to set mode: Blocked through rfkill (0x12)
bluetoothd[9539]: Failed to set mode: Blocked through rfkill (0x12)

The last two disappeared when I manually disabled pm (which enabled on my system by kernel parameter) by running

# modprobe ath9k btcoex_enable=1 ps_enable=0 bt_ant_diversity=1"

It didn't help with connecting to devices, I can pair device but can't connect to them.
When trying to connect to device I seeing such messages

Access denied: Rejecting service auth (0000110d-0000-1000-8000-00805f9b34fb) for /org/bluez/hci0/dev_38_E7_D8_C8_A2_33: not HID
Discover: Connection timed out (110)
connect error: Connection refused (111)

Anyway, I didn't really cared about bluetooth, I was just interested in understand where the error message coming from.
I'm guessing if I'll blacklist bluetooth and btusb modules I won't see the error message.

Anyone else know if this a well known bug with the bluetooth adapter (part of the Atheros chip ?) or maybe specific to the Chromebook ?

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

@scot14

The cardlist output exactly the same for me on C720 with 3.17-rc5.
The only difference is that I don't need for PCH to become device 0 in order to get analog output from builtin speakers and headphone jack.

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

The cardlist output exactly the same for me on C720 with 3.17-rc5.
The only difference is that I don't need for PCH to become device 0 in order to get analog output from builtin speakers and headphone jack.

Are you using PulseAudio? If not, will you post your kernel .config?

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

Yes, I'm using PulseAudio (I'm running Gnome).

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

Yes, I'm using PulseAudio (I'm running Gnome).

So the "snd_hda_intel.index=1" kernel parameter or module setting is only necessary with ALSA? Is anyone seeing otherwise?

Latrina

Member

From: Italy - Mexico

Registered: 2014-07-02

Posts: 44

Re: Acer C720/C720P Chromebook

Folks, I have recently updated virtualbox and since then virtualbox-host-dmks is unable to find the headers when they are correctly installed and have used virtualbox with the same linux-mainline-chromebook 3.16-1 kernel and headerds before.

[root@chromebookC720 latrina]# dkms autoinstall
Error! echo
Your kernel headers for kernel 3.16.0-1-mainline-chromebook cannot be found at
/usr/lib/modules/3.16.0-1-mainline-chromebook/build or /usr/lib/modules/3.16.0-1-mainline-chromebook/source.

[latrina@chromebookC720 Downloads]$ sudo pacman -Q |grep virtualbox
virtualbox 4.3.16-1
virtualbox-host-dkms 4.3.16-1

[latrina@chromebookC720 Downloads]$ sudo pacman -Q |grep linux
archlinux-keyring 20140908-1
lib32-util-linux 2.25-1
libutil-linux 2.25.1-1
linux-api-headers 3.16.2-1
linux-chromebook-docs 3.16.1-1
linux-chromebook-headers 3.16.1-1
linux-firmware 20140828.13eb208-1
linux-mainline-chromebook 3.16-1
util-linux 2.25.1-1

[latrina@chromebookC720 Downloads]$ sudo systemctl status dkms.service
● dkms.service - Dynamic Kernel Modules System
   Loaded: loaded (/usr/lib/systemd/system/dkms.service; enabled)
   Active: active (exited) since Sun 2014-09-21 01:16:21 CEST; 2min 25s ago
  Process: 274 ExecStart=/usr/lib/systemd/scripts/dkms start (code=exited, status=0/SUCCESS)
 Main PID: 274 (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/dkms.service

Sep 21 01:16:21 chromebookC720 dkms[274]: Error! echo
Sep 21 01:16:21 chromebookC720 dkms[274]: Your kernel headers for kernel 3.16.0-1-mainline-chromebook cannot be found at
Sep 21 01:16:21 chromebookC720 dkms[274]: /usr/lib/modules/3.16.0-1-mainline-chromebook/build or /usr/lib/modules/3.16.0-1-mainline-chrome.../source.
Sep 21 01:16:21 chromebookC720 systemd[1]: Started Dynamic Kernel Modules System.
Hint: Some lines were ellipsized, use -l to show in full.

Like I said this is weird since I used to have Vbox up and running before and on the same kernel. Can this be a issue with virtualbox or something related to this custom kernel?

Thanks

EDIT

Nevermind a guy on IRC helped me out to find the issue and apparently virtualbox-host-dkms for some reason was looking at a wrong path for the headers..

Solved .. Sorry for breaking in the middle of a important discussion.

Last edited by Latrina (2014-09-21 00:03:11)

---

Sun Netra T1 DC200  (x6 cluster) OpenBSD 5.4; Sun Ultra 5 OpenBSD 5.4; Futro S500 FreeBSD 10.0; Chromebook c720 ArchLinux; etc

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

After doing some reading I believe that there's no limitation in transitioning the Chromebook wiki page into a generic Chromebook installation guide, of course with flashing a custom firmware on models that didn't shipped with SeaBIOS.
I've created a topic on the Talk page which discussed this in detail, if you like to help please read it.

https://wiki.archlinux.org/index.php/Ta … tion_guide

Last edited by dhead (2014-09-21 10:26:06)

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

I added to the Chromebook wiki page a Custom Firmware topic with general information about flashing custom firmware and also basic explanation of the unbricking process.

I believe this is the limit of the relevance of such information to the ArchWiki anything more detailed should only fit in the wikis of Coreboot, Flashrom or John Lewis' and in user posts at the forum and blogs.

IndexUser listSearchProfileLogout
Logged in as dhead Last visit: Today 01:28:47 Topics: Posted | New | Active | Unanswered
Index» Laptop Issues» Acer C720/C720P Chromebook» Edit post
Edit post
Edit:
Let me know if you have any remarks and corrections on the Custom Firmware subject and on the unbricking process.

Edit 2:
p.s.
If anyone want to have a kick with converting the Installing Arch Linux in addition to Chrome OS to manually partition the drive instead of the suggested script (the removal of the cgpt command topic is part of it) then he's more then welcome to do it, I don't believe I'll get to it anytime soon.

Some of the details in the "Understanding the installation process" topic might fit in the "Chromebook Models" topic, if anyone have a better idea than the current situation on how to restructure these two topics then don't be shy, just do it.

The "Touchpad and Touchscreen kernel modules" might be the only Haswell specific step (don't forget the Pixel also comes with SeaBIOS and need suspend fix) so maybe put it in a Haswell fixes sub-topic.

Except the above and grammar I'm pretty happy with the result.

Last edited by dhead (2014-09-21 23:36:15)

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

Except the above and grammar I'm pretty happy with the result.

It looks so much better!

A couple minor possible changes:
- Change "Haswell Chromebooks (Celeron 2955U based models)" to "Chromebooks with SeaBIOS" or something similar?
- Change "If you do not remove the write-protect screw" to "If you do not set the GBB flags"?

I removed the write-protect screw, set the GBB flags, and then re-inserted the screw. After draining the battery a number of times there was no corruption, so maybe the important change is the setting of the flags as opposed to the removing of the screw?

SolarBoyMatt

Member

Registered: 2012-01-07

Posts: 263

Re: Acer C720/C720P Chromebook

After searching the forums I found this topic about the Asus C200 Chromebook, which appears to not include SeaBIOS in it's coreboot, despite being released in June 2014. I think it might not be completely safe to assume that ALL Haswell and newer Chromebooks will always have the SeaBIOS payload. I moved it's info to the non-SeaBIOS table and included a link to that post.

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

Thanks Scot for the input,

- Change "Haswell Chromebooks (Celeron 2955U based models)" to "Chromebooks with SeaBIOS" or something similar?

Done

- Change "If you do not remove the write-protect screw" to "If you do not set the GBB flags"?

I removed the write-protect screw, set the GBB flags, and then re-inserted the screw. After draining the battery a number of times there was no corruption, so maybe the important change is the setting of the flags as opposed to the removing of the screw?

Sounds right, my guess is that the important flags are

GBB_FLAG_FORCE_DEV_SWITCH_ON 0x00000008
GBB_FLAG_FORCE_DEV_BOOT_LEGACY 0x00000080

meaning we should set 0x88

Edit: Maybe even add "run # flashrom wp-disable" before setting the flags ?

After searching the forums I found this topic about the Asus C200 Chromebook, which appears to not include SeaBIOS in it's coreboot, despite being released in June 2014. I think it might not be completely safe to assume that ALL Haswell and newer Chromebooks will always have the SeaBIOS payload. I moved it's info to the non-SeaBIOS table and included a link to that post.

I think it would be best to merge back the two tables but add a SeaBIOS column and then the Bay-Trail models value should be unknown, I already added the column.

Last edited by dhead (2014-09-22 15:25:16)

SolarBoyMatt

Member

Registered: 2012-01-07

Posts: 263

Re: Acer C720/C720P Chromebook

I think it would be best to merge back the two tables but add a SeaBIOS column and then the Bay-Trail models value should be unknown, I already added the column.

Done.

I also think that the  "2.6 Video Driver", "2.7 Touchpad and Touchscreen kernel modules", "2.8 Fixing suspend", and "2.9 Fixing Audio" sections make more sense being in "Post Installation Configuration" than "Installation", since none of those issues directly affect the installation procedure. Any objections?

However, at this point I think we might want to move all of this wiki page talk to the wiki page's discussion section so we don't clutter up the actual C720 discussions...

Last edited by SolarBoyMatt (2014-09-22 16:55:28)

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

@SolarBoyMatt

Agree for both.

Let me know what you think about merging back the Arm based models into the main table, see https://wiki.archlinux.org/index.php/Ta … main_table

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

Sounds right, my guess is that the important flags are

GBB_FLAG_FORCE_DEV_SWITCH_ON 0x00000008
GBB_FLAG_FORCE_DEV_BOOT_LEGACY 0x00000080

meaning we should set 0x88

I've always seen 0x0489 recommended:

GBB_FLAG_DEV_SCREEN_SHORT_DELAY 0×00000001 --> 2 second delay on boot instead of 30 second
GBB_FLAG_FORCE_DEV_SWITCH_ON 0×00000008 --> enable firmware changes?
GBB_FLAG_FORCE_DEV_BOOT_LEGACY 0×00000080 --> allow unsigned kernels?
GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY 0×00000400 --> boot SeaBIOS instead of deptcharge?

Edit: Maybe even add "run # flashrom wp-disable" before setting the flags ?

Seems like a good idea, but I haven't tested.

Last edited by scot14 (2014-09-22 21:16:30)

mshan

Member

Registered: 2013-05-05

Posts: 105

Re: Acer C720/C720P Chromebook

I am running Arch on Acer 720 chromebook.
I completely remove chrome os and set seabios default.
I also removed write-protect screw since before installing Arch.
Everything ok.

but one thing scary and annoying is white Developer Mode screen saying "OS Verfication Off, Press space to re-enable it" at every boot time.
So, what if I press "space"  at that time?

I know I can install custom firmware but it is more scary because if I brick my device I don't have tools to unbrick it and I am sure it's very hard to find those tools.
Is there any workaround to remove that annoying white developer mode screen?
if not, is it safe to accidentally press "space" at that white developer mode screen?

---

Amazing !

SolarBoyMatt

Member

Registered: 2012-01-07

Posts: 263

Re: Acer C720/C720P Chromebook

No it's not safe to, and it's something that you'll have to be careful about, since if you do then you'll be forced to restore Chrome OS. The only real way around it is installing a custom ROM. As long as you follow instructions, there should not be much risk of bricking the device anyways.

Last edited by SolarBoyMatt (2014-09-23 13:09:45)

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

I couldn't resist and upgraded Gnome from the gnome-unstable repo.

My solution to remap the F1-F10 keys by patching xkeyboard-config seems like it's working in Wayland but it looks like Gnome in Wayland doesn't recognize the volume and backlight keysyms (the other keys working)..

Last edited by dhead (2014-09-23 22:09:30)

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

p.s.
this bug solved recently, while the patch is for IVB I did saw in my log regarding IVB so it might also help us users with 2955U, I would hate moving from Chromium, especially with the recent Android apps support.
I don't believe the patch is in rc6 as I seems like it was sent on Sep 20 so only in rc7 (though stable might be released next).

This is the IVB error I saw when I succeeded crashing Wayland by running xmodmap in a Wayland session while both Wayland and X running.

[drm:ivybridge_set_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
[drm:ivb_err_int_handler] *ERROR* Pipe A FIFO underrun

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

is it safe to accidentally press "space" at that white developer mode screen?

More info: https://johnlewis.ie/how-to-make-seabio … acer-c720/

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

I couldn't resist and upgraded Gnome from the gnome-unstable repo.

My solution to remap the F1-F10 keys by patching xkeyboard-config seems like it's working in Wayland but it looks like Gnome in Wayland doesn't recognize the volume and backlight keysyms (the other keys working)..

I was wrong, if you start gnome-shell Wayland session from gdm all the keys are working perfectly

Edit: "gnome-session --session=gnome-wayland" also works.

And it looks like xbindkeys also works in Wayland but it still not a good solution for Gnome as it doesn't work in GTK3 apps like Nautilus and Gedit, only patching xkeyboard-config (AUR xkeyboard-config-chromebook) works perfect in Gnome.

Last edited by dhead (2014-09-24 00:13:50)

mshan

Member

Registered: 2013-05-05

Posts: 105

Re: Acer C720/C720P Chromebook

I flashed custom rom.
I get this message at last.

flashrom v0.9.4  : 14ce0cf : Oct 09 2013 22:16:28 UTC on Linux 3.16.3-1-ARCH (x86_64), built with libpci 3.1.10, GCC 4.7.x-google 20130114 (prerelease), little endian
-------------------------------------------------------------------------------

*** Assuming you didn't get any errors you may reboot. Otherwise, do not reboot under ANY circumstances, and seek help on the G+ community! ***

what does it mean? It seems I didn't get any error and just reboot machine?

Editing: Ok..... I did it. I reboot my machine. Custom firmware is working and it didn't brick my Acer C720. Thank you all

Last edited by mshan (2014-09-24 03:44:28)

---

Amazing !

dhead

Member

Registered: 2012-09-26

Posts: 190

Re: Acer C720/C720P Chromebook

Does anyone with other Chromebook model than the 4GB C720 and stock firmware can check on Arch Linux what is the wp range that flashrom recognize ? for some reason it shows me that the range is

WP: write protect range: start=0x00000000, len=0x00000000

which is absurd.

You'll need to use Chromium OS's flashrom version and to install lib32-glibc from the Mutlilib repo.

wget --no-check-certificate https://johnlewis.ie/flashrom
chmod +x flashrom
sudo ./flashrom --wp-status

Last edited by dhead (2014-09-24 12:06:47)

SolarBoyMatt

Member

Registered: 2012-01-07

Posts: 263

Re: Acer C720/C720P Chromebook

This is the IVB error I saw when I succeeded crashing Wayland by running xmodmap in a Wayland session while both Wayland and X running.

[drm:ivybridge_set_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
[drm:ivb_err_int_handler] *ERROR* Pipe A FIFO underrun

I actually see this error when I exit my i3 session to a tty, so you're not alone in seeing it. I don't recall seeing it before 3.17 though, so I will check 3.16 when I get the chance. I can't seem to find much about this error except for this discussion, http://patchwork.freedesktop.org/patch/25875/. So far I haven't noticed any adverse graphics issues though.

scot14

Member

Registered: 2014-06-02

Posts: 123

Re: Acer C720/C720P Chromebook

This is the IVB error I saw when I succeeded crashing Wayland by running xmodmap in a Wayland session while both Wayland and X running.

[drm:ivybridge_set_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
[drm:ivb_err_int_handler] *ERROR* Pipe A FIFO underrun

I actually see this error when I exit my i3 session to a tty, so you're not alone in seeing it. I don't recall seeing it before 3.17 though, so I will check 3.16 when I get the chance. I can't seem to find much about this error except for this discussion, http://patchwork.freedesktop.org/patch/25875/. So far I haven't noticed any adverse graphics issues though.

Maybe you guys should file a bug report on freedesktop? I don't think you have IvyBridge either, even though that's what the log says.