Re: [Libreboot] Bricked my c201

[Albin]

Hi,

Sorry for the late reply.

Den 2015-12-24 kl. 16:22, skrev Paul Kocialkowski:
> Hi,
> 
> Le mercredi 16 décembre 2015 à 01:27 +0100, Albin a écrit :
>> Den 2015-12-14 kl. 19:39, skrev Paul Kocialkowski:
>>> Le jeudi 10 décembre 2015 à 22:42 +0100, Albin a écrit :
>>>> Pressing Ctrl+U results in a *beep*, i.e. the Debian kernel on the SD
>>>> card won't get loaded.
>>>
>>> Make sure you set up the partitions correctly. It has to be an EFI
>>> filesystem and I recall that some special properties for CrOS have to be
>>> set.
>>
>> I tried to follow the Debian guide exactly so I didn't try to do
>> anything else than what's written here:
>> https://wiki.debian.org/InstallingDebianOn/Asus/C201
>>
>> Either there is something wrong with the guide or I made mistakes when
>> when trying to follow it.
> 
> I wouldn't exclude the possibility that the guide is missing or
> overlooking some steps. I don't have the device with me at the moment to
> check what exactly should be done to set up an external boot media, but
> I could try to look into it and write something up about it sometime
> soon.
> 
> Either way, it's hard to find out exactly why it's refusing to boot
> externally, provided that Libreboot still shows the warning about
> external media booting being enabled. Still, it is probably either about
> the kernel you extracted not being in the right format or the partitions
> not being set up correctly.
> 
> Perhaps you could send me the kernel file you extracted (I'm not sure I
> have a backup of mine) and I could prepare a known-to-work disk image
> for you to boot from.

That would be very nice but unfortunately I cannot access the files on
the USB drive where I saved it. When I insert it into my other (X86_64)
computer it shows up as an "unknown" device. Besides, external media
booting has now been switched off as well so I really need to reflash
the firmware.

> If that fails, it might mean that you'll have to relfash the SPI flash
> with an image that allows running unsigned kernels, which will give us
> more flexibility.
> 
> Either way, your device is not lost and I'm confident there will always
> be a way to straighten it out. If you feel like you don't want to pull
> this off yourself, we could see about you sending me the device so that
> I do what's needed to fix it.

Thank you for the encouragement! I do have an SPI programmer and some
experience with flashing externally (T60 and macbook2,1) so I would like
to try to unbrick the c201 myself. Still, I could need some help with
how to connect the wires to the BBB. I'm familiar with most of the
abbreviations but I don't know how to connect HOLD#, CLK and CS#. Maybe
you, or somebody else, could expand the documentation with details about
BBB wiring, like it's in the other guides.

Another thing that would be useful, I think, is a libreboot
configuration for veyron_speedy with some of the security features
switched off. That would give somebody who needs to recover their device
another option than reinstalling the backed up factory image.

> 
>>>> Pressing CTRL+D, i.e. booting from internal
>>>> memory, gives me the screen "Welcome to recovery mode! Please insert an
>>>> external recovery media.".
>>>>
>>>> Previously, even with libreboot, I could boot ChromeOS from internal
>>>> memory with boot_signed_only enabled. Now I can't boot at all!
>>>>
>>>> I never got to the part about installing to the internal memory so I
>>>> don't understand what's happened.
>>>>
>>>> Do you have any idea about could have gone wrong and what I can do to
>>>> recover?
>>>
>>> That's strange. If all you did was extract the kernel and set
>>> "crossystem dev_boot_signed_only=1", there is no reason why it would
>>> refuse booting. That is, assuming that you didn't already replace
>>> ChromeOS with something else.
>>
>> It's possible that I made a mistake that damaged both the ChromeOS
>> install and the SD image that I was trying to create since there were a
>> long series of commands that had to be entered as root.
> 
> Let's go with the assumption that internal boot is broken for now and
> that your best shot is to boot externally now, so we have to figure out
> why it isn't working.
> 
> Cheers,
> 

Best regards,

Albin

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