Re: [Libreboot] flashing the c201

[Rendov Norra]

Tried various configurations of powering /WP and /HOLD, but it still
doesn't want to talk. Can't find an option to set the clock speed.

On Thursday, August 18, 2016, Rendov Norra <address@hidden> wrote:

> Yes, that's exactly what I meant. I power all three because it's suggested
> various places, and the datasheet from the manufacturer states "The /WP pin
> is active low" implying write protection is active when the pin is
> unpowered, and "When /HOLD is brought high, device operation can resume"
> implying that the hold pin needs power in order for the chip to be active.
>
> But I'm not exactly an expert in this sort of thing, so I could be wrong.
> That said, I have tried not powering those pins, but I'll probably try
> again this evening (EST) just to make sure.
>
> On Thursday, August 18, 2016, Marcel Maci <address@hidden> wrote:
>
>> Hello Paulk and Rendov
>> I've never flashed a c201 but what surprises me a lot are these lines:
>>
>> The power, hold, and wp pins are all bridged and receiving power from
>>
>> {pin1,pin17} of the rpi, which is documented to provide 3.3v.
>>
>>
>> Does "bridged" mean that you put 3.3V to all three pins? Personally I
>> only power the VCC pin and I'm using pin 1 (not 17) of the Raspberry Pi.
>> Hope this helps,
>> Marcel
>>
>> El 17 ago 2016, a las 3:35, Rendov Norra <address@hidden> escribió:
>>
>> This is a continuation of an email I sent paulk, since he suggested I post
>> here as well.
>>
>> I checked all of his suggestions except maybe if all the required pins are
>> getting 3.3v. I'm not entirely clear on how to measure that. I get ~2v
>> when
>> measuring from the power source to the pin, and the ground connected.
>> Measuring straight from the power to ground gives me 3.3v.
>>
>> The power, hold, and wp pins are all bridged and receiving power from
>> {pin1,pin17} of the rpi, which is documented to provide 3.3v.
>>
>> I'm wiring it according to the following documents (pdf warning):
>>
>> https://www.winbond.com/resource-files/w25q32bv_revi_100413_
>> wo_automotive.pdf
>>
>> https://github.com/bibanon/Coreboot-ThinkPads/wiki/Hardware-
>> Flashing-with-Raspberry-Pi
>>
>>
>> ---------- Forwarded message ----------
>> From: *Paul Kocialkowski* <address@hidden>
>> Date: Monday, August 8, 2016
>> Subject: On flashing the c201
>> To: Rendov Norra <address@hidden>
>>
>>
>> Hi,
>>
>> Le dimanche 07 août 2016 à 19:45 -0400, Rendov Norra a écrit :
>>
>> This is a bit of a longshot, but I'm pretty desperate.
>>
>>
>> I managed to make chromeos boot on the c201, and external device boot is
>>
>> off,
>>
>> and the chromebook recovery images fail after ~5 minutes, so as far as I
>>
>> can
>>
>> tell, using internal spi to flash is out of the question. I've resorted to
>>
>> hardware flashing, but I can't get it (RasPi 3) talking to the chip. And
>>
>> it
>>
>> boots into the firmware (and into recovery), so I know I haven't managed
>>
>> to
>>
>> fry it.. At least I hope.
>>
>>
>> I've set the pins according to multiple sources, and re-checked them God
>>
>> knows
>>
>> how many times. I've tried different configurations of powering the hold
>>
>> and
>>
>> write protect pins. I've checked continuity between the RPi and the legs
>>
>> of
>>
>> the chip too many times. The write protect screw is out. I've even tried
>>
>> having it sit in the developer/recovery screens and use the power
>>
>> supplied by
>>
>> the board. I've tried using upstream Flashrom, and I've tried using
>>
>> google's
>>
>> Flashrom. No matter what I do, it returns "Unknown SPI chip".
>>
>>
>> I figured if anyone knew anything about this, it'd be you. Thanks for your
>>
>> time.
>>
>>
>> Please consider posting this to the Libreboot mailing list as well. This
>> way,
>> more people can help you and answer your inquiry while others can benefit
>> from
>> the question and its answers as well.
>>
>> Some notes and suggestion that may help you:
>> * Make sure you've followed https://libreboot.org/docs/install/c201.html
>>  and especially "Installing Libreboot externally, with a SPI flash
>> programmer"
>> * Check that the VDD, #WP and #HOLD of the chip are +3.3V during activity
>> * Make sure that you're not using 1.8V logic, the chip seems to accept
>> 3.3V
>> only
>> * Make sure you've disconnected the device's battery
>> * Make sure you've disconnected any source of power
>> * Maybe try with the battery connected, just in case
>>
>> Note that I'll be providing a recovery SPI flash image and rootfs with
>> Debian
>> that should allow recovering from these kinds of situations. Of course,
>> your
>> device is not irremediably bricked.
>>
>> Cheers,
>>
>> --
>> Paul Kocialkowski, developer of low-level free software for embedded
>> devices
>>
>> Website: https://www.paulk.fr/
>> Coding blog: https://code.paulk.fr/
>> Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/
>>
>>
>