dev-mode on chell device (HP Chromebook 13 G1)

[Robert Foss]

Hi,

I'm having some issues entering into dev-mode on a Chell unit. I've followed the generic intructions on [1] as they are linked for Chell units in [2].

Rebooting into revcovery (esc+refresh+power) works, but while in recovery enabling dev mode using (ctrl+d) does nothing.

Developer debug info: https://allg.one/4JkM

Are these the right instructions for entering dev mode for the Chell?


[1] https://www.chromium.org/a/chromium.org/dev/chromium-os/developer-information-for-chrome-os-devices/generic

[2] https://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices


Rob.

[Vincent Palatin]

On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss <rober...@collabora.com> wrote:

Hi,

I'm having some issues entering into dev-mode on a Chell unit. I've followed the generic intructions on [1] as they are linked for Chell units in [2].

Rebooting into revcovery (esc+refresh+power) works, but while in recovery enabling dev mode using (ctrl+d) does nothing.

Developer debug info: https://allg.one/4JkM

Are these the right instructions for entering dev mode for the Chell?

Yes they are.

(and actually works on my Chell)

the first Ctrl+D should just slightly modify the wording displayed on the screen and tells you to press 'Enter' to confirm.

On your machine, nothing happens on this Ctrl+D (no beep, no change on the screen ?)

[Robert Foss]

On 2017-01-16 03:20 AM, Vincent Palatin wrote:
>
>
> On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss <rober...@collabora.com
> <mailto:rober...@collabora.com>> wrote:
>
> Hi,
>
> I'm having some issues entering into dev-mode on a Chell unit. I've
> followed the generic intructions on [1] as they are linked for Chell
> units in [2].
>
> Rebooting into revcovery (esc+refresh+power) works, but while in
> recovery enabling dev mode using (ctrl+d) does nothing.
>
> Developer debug info: https://allg.one/4JkM
>
> Are these the right instructions for entering dev mode for the Chell?
>
>
> Yes they are.
> (and actually works on my Chell)
>
> the first Ctrl+D should just slightly modify the wording displayed on
> the screen and tells you to press 'Enter' to confirm.
> On your machine, nothing happens on this Ctrl+D (no beep, no change on
> the screen ?)

No there's no change.

I tried building and flashing a custom ec.bin, but the current version
in trunk of the repo does not seem to work properly as flashing it
results in the chromebook rebooting every 5 seconds or so.

Which version of the ec are you running? Could you give me the revision
number you're running?


Rob.

>
>
>
>
>
> [1]
> https://www.chromium.org/a/chromium.org/dev/chromium-os/developer-information-for-chrome-os-devices/generic

> <https://www.chromium.org/a/chromium.org/dev/chromium-os/developer-information-for-chrome-os-devices/generic>
>
>
> [2]
> https://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices

> <https://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices>
>
>
>

[Vincent Palatin]

On Mon, Jan 16, 2017 at 10:45 PM, Robert Foss <rober...@collabora.com> wrote:

On 2017-01-16 03:20 AM, Vincent Palatin wrote:

On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss <rober...@collabora.com
<mailto:robert.foss@collabora.com>> wrote:

    Hi,

    I'm having some issues entering into dev-mode on a Chell unit. I've
    followed the generic intructions on [1] as they are linked for Chell
    units in [2].

    Rebooting into revcovery (esc+refresh+power) works, but while in
    recovery enabling dev mode using (ctrl+d) does nothing.

    Developer debug info: https://allg.one/4JkM

    Are these the right instructions for entering dev mode for the Chell?


Yes they are.
(and actually works on my Chell)

the first Ctrl+D should just slightly modify the wording displayed on
the screen and tells you to press 'Enter' to confirm.
On your machine, nothing happens on this Ctrl+D (no beep, no change on
the screen ?)

No there's no change.

I tried building and flashing a custom ec.bin, but the current version in trunk of the repo does not seem to work properly as flashing it results in the chromebook rebooting every 5 seconds or so.

ah, you are not trying on an unmodified machine with write-protection. Then that's likely a different set of issues and solutions.

Overall, if you are flashing it through the servo debug interface, it's probably easier to read the serial traces than second guessing from the firmware screens.

Did you disable the EC software-sync before flashing it ?

else the BIOS will overwrite the RW portion and you will run your RO (from master) with the official RW (from the firmware branch) it's unlikely to work properly.

 

Which version of the ec are you running? Could you give me the revision number you're running?

The released one, so 'chell_v1.9.305-51cc5e1' (which means commit with sha1 51cc5e177d3fb6de49b70b435ab30adc6c8bf6cb on branch firmware-glados-7820.B)

which is also the EC binary inside the firmware build Google_Chell.7820.215.0.

To do your own firmware, you want to build it from the skylake firmware branch: firmware-glados-7820.B

The version above is the one which went through extensive QA but Tip of branch should be fine.

--

Vincent

[Robert Foss]

On 2017-01-17 04:13 AM, Vincent Palatin wrote:
>
>
> On Mon, Jan 16, 2017 at 10:45 PM, Robert Foss

> <rober...@collabora.com <mailto:rober...@collabora.com>>

> wrote:
>
>
>
> On 2017-01-16 03:20 AM, Vincent Palatin wrote:
>
>
>
> On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss

> <rober...@collabora.com <mailto:rober...@collabora.com>
> <mailto:rober...@collabora.com

I had a look at flashing the firmware-glados-7820.B but am seeing the
same boot loop as before. Am I missing any part?

$ cros_sdk
$ export BOARD=chell
$ emerge-${BOARD} chromeos-ec
$ ~/trunk/src/platform/ec/util/flash_ec --board=$BOARD


Rob.

[Vincent Palatin]

On Thu, Jan 19, 2017 at 7:02 PM, Robert Foss <rober...@collabora.com> wrote:

On 2017-01-17 04:13 AM, Vincent Palatin wrote:

On Mon, Jan 16, 2017 at 10:45 PM, Robert Foss

<rober...@collabora.com <mailto:robert.foss@collabora.com>>

wrote:



On 2017-01-16 03:20 AM, Vincent Palatin wrote:



On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss

<rober...@collabora.com <mailto:robert.foss@collabora.com>
<mailto:robert.foss@collabora.com

my comment about EC software-sync is still half-valid.

If you haven't disabled it (in the GBB flags on the machine), once you have flashed the new EC (RO+RW), the BIOS will start, detect the wrong RW EC (not matching the signature in the RW BIOS), re-flash the RW EC and boot again. Should not do a boot loop but you won't test your EC either.

Can you record the serial traces ? they might give a clue about what is on-going.

[Robert Foss]

On 2017-01-20 03:11 AM, Vincent Palatin wrote:
>
>
> On Thu, Jan 19, 2017 at 7:02 PM, Robert Foss <rober...@collabora.com
> <mailto:rober...@collabora.com>> wrote:
>
>
>
> On 2017-01-17 04:13 AM, Vincent Palatin wrote:
>
>
>
> On Mon, Jan 16, 2017 at 10:45 PM, Robert Foss

> <rober...@collabora.com <mailto:rober...@collabora.com>
> <mailto:rober...@collabora.com
> <mailto:rober...@collabora.com>>>

> wrote:
>
>
>
> On 2017-01-16 03:20 AM, Vincent Palatin wrote:
>
>
>
> On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss

> <rober...@collabora.com <mailto:rober...@collabora.com>
> <mailto:rober...@collabora.com
> <mailto:rober...@collabora.com>>
> <mailto:rober...@collabora.com <mailto:rober...@collabora.com>
>
> <mailto:rober...@collabora.com

Traces attached.

I had a look at setting the gbb flags |= 0x30, and grepping for a way to
set the flags lead me to make_dev_firmware.sh

$ make_dev_firmware.sh
Disabling system software write protection status...
ERROR: Write protection is still enabled. Please verify that hardware
write protection is disabled.

Which is somewhat alarming, I've attached a pic of the wp-screw being
removed (I think it is the right one).
Granted, I grabbed a tool at almost random and expected it to work with
this device.
But I did find some prior art using this tool:

https://groups.google.com/a/chromium.org/forum/#!topic/chromium-os-dev/I_iyJaLEv1E

$ /usr/share/vboot/bin/make_dev_firmware.sh
$ /usr/share/vboot/bin/set_gbb_flags.sh 0x200

[Vincent Palatin]

On Mon, Jan 23, 2017 at 8:37 PM, Robert Foss <rober...@collabora.com> wrote:

On 2017-01-20 03:11 AM, Vincent Palatin wrote:

On Thu, Jan 19, 2017 at 7:02 PM, Robert Foss <rober...@collabora.com

<mailto:robert.foss@collabora.com>> wrote:



    On 2017-01-17 04:13 AM, Vincent Palatin wrote:



        On Mon, Jan 16, 2017 at 10:45 PM, Robert Foss

        <rober...@collabora.com <mailto:robert.foss@collabora.com>

        <mailto:robert.foss@collabora.com
        <mailto:robert.foss@collabora.com>>>

        wrote:



        On 2017-01-16 03:20 AM, Vincent Palatin wrote:



        On Fri, Jan 13, 2017 at 10:28 PM, Robert Foss

        <rober...@collabora.com <mailto:robert.foss@collabora.com>
        <mailto:robert.foss@collabora.com
        <mailto:robert.foss@collabora.com>>
        <mailto:robert.foss@collabora.com <mailto:robert.foss@collabora.com>

        <mailto:robert.foss@collabora.com

If the HW write-protection is removed (ie no WP screw), you might still need to disable the software one:

flashrom -p ec --wp-disable

(you can check the status before/after:  flashrom -p ec --wp-status)

but given you have flashed the EC through servo before, it shouldn't be the case though.

I'm not sure make_dev_firmware.sh will do anything useful in this case.

Yes set_gbb_flags would be a good start, I would do:

/usr/share/vboot/bin/set_gbb_flags.sh 0xa239